Release preparation for version 2.7.5

Post-release preparation 2.7.3

.codeqlmanifest.json

@@ -1,11 +1,23 @@
-{ "provide": [ "ruby/.codeqlmanifest.json",
-                "*/ql/src/qlpack.yml",
-               "*/ql/lib/qlpack.yml",
-               "*/ql/test/qlpack.yml",
-               "cpp/ql/test/query-tests/Security/CWE/CWE-190/semmle/tainted/qlpack.yml",
-               "*/ql/examples/qlpack.yml",
-               "*/upgrades/qlpack.yml",
-               "javascript/ql/experimental/adaptivethreatmodeling/lib/qlpack.yml",
-               "javascript/ql/experimental/adaptivethreatmodeling/src/qlpack.yml",
-               "misc/legacy-support/*/qlpack.yml",
-               "misc/suite-helpers/qlpack.yml" ] }
+{
+    "provide": [
+        "*/ql/src/qlpack.yml",
+        "*/ql/lib/qlpack.yml",
+        "*/ql/test/qlpack.yml",
+        "*/ql/examples/qlpack.yml",
+        "*/upgrades/qlpack.yml",
+        "cpp/ql/test/query-tests/Security/CWE/CWE-190/semmle/tainted/qlpack.yml",
+        "javascript/ql/experimental/adaptivethreatmodeling/lib/qlpack.yml",
+        "javascript/ql/experimental/adaptivethreatmodeling/src/qlpack.yml",
+        "misc/legacy-support/*/qlpack.yml",
+        "misc/suite-helpers/qlpack.yml",
+        "ruby/extractor-pack/codeql-extractor.yml",
+        "ruby/ql/consistency-queries/qlpack.yml"
+    ],
+    "versionPolicies": {
+      "default": {
+        "requireChangeNotes": true,
+        "committedPrereleaseSuffix": "dev",
+        "committedVersion": "nextPatchRelease"
+      }
+    }
+}

.github/actions/fetch-codeql/action.yml

@@ -1,29 +1,14 @@
 name: Fetch CodeQL
 description: Fetches the latest version of CodeQL
-inputs:
-  use-bundle:
-    description: Set to `true` to download the CodeQL CLI bundle that also includes compiled queries.
-    default: 'false'
-    required: false
-
 runs:
   using: composite
   steps:
     - name: Fetch CodeQL
       shell: bash
       run: |
-        LATEST=$(gh release list --repo $REPO | cut -f 3 | grep -v beta | sort --version-sort | tail -1)
-        gh release download --repo $REPO --pattern "$PATTERN" "$LATEST"
-
-        if [ "$USE_BUNDLE" == 'true' ]; then
-          tar -xzf "$PATTERN" -C "${RUNNER_TEMP}"
-        else
-          unzip -q -d "${RUNNER_TEMP}" "$PATTERN"
-        fi
+        LATEST=$(gh release list --repo https://github.com/github/codeql-cli-binaries | cut -f 1 | grep -v beta | sort --version-sort | tail -1)
+        gh release download --repo https://github.com/github/codeql-cli-binaries --pattern codeql-linux64.zip "$LATEST"
+        unzip -q -d "${RUNNER_TEMP}" codeql-linux64.zip
         echo "${RUNNER_TEMP}/codeql" >> "${GITHUB_PATH}"
       env:
         GITHUB_TOKEN: ${{ github.token }}
-        USE_BUNDLE: '${{ inputs.use-bundle == ''true'' }}'
-        REPO: '${{ inputs.use-bundle == ''true'' && ''https://github.com/dsp-testing/codeql-cli-nightlies'' || ''https://github.com/github/codeql-cli-binaries''}}'
-        # REPO: '${{ inputs.use-bundle == ''true'' && ''https://github.com/github/codeql-action'' || ''https://github.com/github/codeql-cli-binaries''}}'
-        PATTERN: '${{ inputs.use-bundle == ''true'' && ''codeql-bundle-linux64.tar.gz'' || ''codeql-linux64.zip''}}'

.github/workflows/pack-publisher.yml

@@ -1,88 +0,0 @@
-# Publishes the core libraries to the CodeQL package registry.
-name: Publish CodeQL core libraries
-on:
-  pull_request:
-    paths:
-      - '.github/workflows/pack-publisher.yml' # for testing changes to this workflow
-
-  workflow_dispatch:
-    # the cli to use, or blank to build it again
-    # the pre-built packs, or blank to build again
-    inputs:
-      packages-build-number:
-        description: |
-          A CodeQL CLI workflow run number to download the packages artifacts from.
-          Leave blank to build packages from this repository.
-        default: ''
-        required: false
-
-permissions:
-  contents: write
-
-jobs:
-  codeql-package-publish:
-    name: CodeQL Package - Publish
-    runs-on: ubuntu-20.04
-    env:
-      GITHUB_TOKEN: ${{ github.token }}
-
-    steps:
-      - name: Dump environment
-        run: env
-      - name: Dump GitHub event context
-        env:
-          GITHUB_CONTEXT: '${{ toJson(github.event) }}'
-        run: echo "$GITHUB_CONTEXT"
-
-      - name: Checkout repository
-        uses: actions/checkout@v2
-
-      # TODO add a way to specify different versions of the CLI
-      - name: Download CLI
-        uses: ./.github/actions/fetch-codeql
-        with:
-          use-bundle: 'true'
-
-      - name: Publish packs
-        run: |
-          # do not publish go or suite-helpers
-          # `ls` all directories in the bundle remove suite-helpers and go
-          PACK_FOLDERS_TO_PUBLISH="$(ls -d $RUNNER_TEMP/codeql/qlpacks/codeql/*/* | grep -v suite | grep -v "\-go")"
-          ARCHIVES="$RUNNER_TEMP/archives"
-
-          mkdir -p "$ARCHIVES"
-
-          echo "Running on: $PACK_FOLDERS_TO_PUBLISH"
-
-          # tgz each folder
-          # then run pack publish on it
-          for folder in $PACK_FOLDERS_TO_PUBLISH
-          do
-            echo "Archiving $folder for publishing"
-            tar cfz "$ARCHIVES/archive.tgz" -C "$folder" .
-            echo "Publishing $ARCHIVES/archive.tgz"
-            echo "Would have run: 'codeql pack publish --file "$ARCHIVES/archive.tgz"'"
-          done
-
-      - name: Bump versions
-        run: |
-          echo "Would have run 'codeql pack release'"
-
-      - name: Update git config
-        run: |
-          git config --global user.email "github-actions@github.com"
-          git config --global user.name "github-actions[bot]"
-
-      - name: Create PR
-        run: |
-          set -exu
-          git add .
-          git commit -m "Post-release preparation"
-          NEW_BRANCH="post-release-prep-$(git show -s --format=%h)"
-          git checkout -b $NEW_BRANCH
-          git push origin "$NEW_BRANCH"
-          gh pr create \
-            --head "$NEW_BRANCH" \
-            --base "$GITHUB_BASE_REF" \
-            --fill \
-            --draft

.github/workflows/ruby-build.yml

@@ -102,16 +102,6 @@ jobs:
           PACK_FOLDER=$(readlink -f target/packs/codeql/ruby-queries/*)
           codeql/codeql generate query-help --format=sarifv2.1.0 --output="${PACK_FOLDER}/rules.sarif" ql/src
           (cd ql/src; find queries \( -name '*.qhelp' -o -name '*.rb' -o -name '*.erb' \) -exec bash -c 'mkdir -p "'"${PACK_FOLDER}"'/$(dirname "{}")"' \; -exec cp "{}" "${PACK_FOLDER}/{}" \;)
-      - name: Compile with previous CodeQL versions
-        run: |
-          for version in  $(gh release list --repo https://github.com/github/codeql-cli-binaries | cut -f 1 | sort --version-sort | tail -3 | head -2); do
-            rm -f codeql-linux64.zip
-            gh release download --repo https://github.com/github/codeql-cli-binaries --pattern codeql-linux64.zip "$version"
-            rm -rf codeql; unzip -q codeql-linux64.zip
-            codeql/codeql query compile target/packs/*
-          done
-        env:
-          GITHUB_TOKEN: ${{ github.token }}
       - uses: actions/upload-artifact@v2
         with:
           name: codeql-ruby-queries

.github/workflows/ruby-dataset-measure.yml

@@ -24,7 +24,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        repo: [rails/rails, discourse/discourse, spree/spree]
+        repo: [rails/rails, discourse/discourse, spree/spree, ruby/ruby]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -41,7 +41,7 @@ jobs:
       - name: Create database
         run: |
           codeql database create \
-            --search-path "${{ github.workspace }}/ruby" \
+            --search-path "${{ github.workspace }}/ruby/extractor-pack" \
             --threads 4 \
             --language ruby --source-root "${{ github.workspace }}/repo" \
             "${{ runner.temp }}/database"

.github/workflows/ruby-qltest.yml

@@ -32,14 +32,14 @@ jobs:
       - uses: ./ruby/actions/create-extractor-pack
       - name: Run QL tests
         run: |
-          codeql test run --check-databases --check-unused-labels --check-repeated-labels --check-redefined-labels --check-use-before-definition --search-path "${{ github.workspace }}/ruby" --additional-packs "${{ github.workspace }}"  --consistency-queries ql/consistency-queries ql/test
+          codeql test run --search-path "${{ github.workspace }}/ruby/extractor-pack" --check-databases --check-unused-labels --check-repeated-labels --check-redefined-labels --check-use-before-definition --consistency-queries ql/consistency-queries ql/test
         env:
           GITHUB_TOKEN: ${{ github.token }}
       - name: Check QL formatting
         run: find ql "(" -name "*.ql" -or -name "*.qll" ")" -print0 | xargs -0 codeql query format --check-only
       - name: Check QL compilation
         run: |
-          codeql query compile --check-only --threads=4 --warnings=error --search-path "${{ github.workspace }}/ruby" --additional-packs "${{ github.workspace }}" "ql/src" "ql/examples"
+          codeql query compile --check-only --threads=4 --warnings=error "ql/src" "ql/examples"
         env:
           GITHUB_TOKEN: ${{ github.token }}
       - name: Check DB upgrade scripts

.gitignore

@@ -27,3 +27,6 @@ csharp/extractor/Semmle.Extraction.CSharp.Driver/Properties/launchSettings.json
 
 # Avoid committing cached package components
 .codeql
+
+# Compiled class file
+*.class

config/identical-files.json

@@ -460,9 +460,10 @@
     "javascript/ql/lib/semmle/javascript/security/internal/SensitiveDataHeuristics.qll",
     "python/ql/lib/semmle/python/security/internal/SensitiveDataHeuristics.qll"
   ],
-  "ReDoS Util Python/JS": [
+  "ReDoS Util Python/JS/Ruby": [
     "javascript/ql/lib/semmle/javascript/security/performance/ReDoSUtil.qll",
-    "python/ql/lib/semmle/python/security/performance/ReDoSUtil.qll"
+    "python/ql/lib/semmle/python/security/performance/ReDoSUtil.qll",
+    "ruby/ql/lib/codeql/ruby/security/performance/ReDoSUtil.qll"
   ],
   "ReDoS Exponential Python/JS": [
     "javascript/ql/lib/semmle/javascript/security/performance/ExponentialBackTracking.qll",
@@ -471,7 +472,12 @@
   "ReDoS Polynomial Python/JS": [
     "javascript/ql/lib/semmle/javascript/security/performance/SuperlinearBackTracking.qll",
     "python/ql/lib/semmle/python/security/performance/SuperlinearBackTracking.qll",
-    "ruby/ql/lib/codeql/ruby/regexp/SuperlinearBackTracking.qll"
+    "ruby/ql/lib/codeql/ruby/security/performance/SuperlinearBackTracking.qll"
+  ],
+  "BadTagFilterQuery Python/JS/Ruby": [
+    "javascript/ql/lib/semmle/javascript/security/BadTagFilterQuery.qll",
+    "python/ql/lib/semmle/python/security/BadTagFilterQuery.qll",
+    "ruby/ql/lib/codeql/ruby/security/BadTagFilterQuery.qll"
   ],
   "CFG": [
     "csharp/ql/lib/semmle/code/csharp/controlflow/internal/ControlFlowGraphImplShared.qll",

cpp/change-notes/2021-11-09-use-of-http.md

@@ -0,0 +1,2 @@
+lgtm,codescanning
+* A new query `cpp/non-https-url` has been added for C/C++. The query flags uses of `http` URLs that might be better replaced with `https`.

cpp/change-notes/2021-11-25-certificate-not-checked.md

@@ -0,0 +1,2 @@
+lgtm,codescanning
+* A new query `cpp/certificate-not-checked` has been added for C/C++. The query flags unsafe use of OpenSSL and similar libraries.

cpp/change-notes/2021-11-25-certificate-result-conflation.md

@@ -0,0 +1,2 @@
+lgtm,codescanning
+* A new query `cpp/certificate-result-conflation` has been added for C/C++. The query flags unsafe use of OpenSSL and similar libraries.

cpp/ql/lib/CHANGELOG.md

@@ -0,0 +1,9 @@
+## 0.0.5
+
+## 0.0.4
+
+### New Features
+
+* The QL library `semmle.code.cpp.commons.Exclusions` now contains a predicate
+  `isFromSystemMacroDefinition` for identifying code that originates from a
+  macro outside the project being analyzed.

cpp/ql/lib/change-notes/released/0.0.4.md

@@ -0,0 +1,7 @@
+## 0.0.4
+
+### New Features
+
+* The QL library `semmle.code.cpp.commons.Exclusions` now contains a predicate
+  `isFromSystemMacroDefinition` for identifying code that originates from a
+  macro outside the project being analyzed.

cpp/ql/lib/change-notes/released/0.0.5.md

@@ -0,0 +1 @@
+## 0.0.5

cpp/ql/lib/codeql-pack.release.yml

@@ -0,0 +1,2 @@
+---
+lastReleaseVersion: 0.0.5

cpp/ql/lib/qlpack.yml

@@ -1,7 +1,8 @@
 name: codeql/cpp-all
-version: 0.0.2
+version: 0.0.5
+groups: cpp
 dbscheme: semmlecode.cpp.dbscheme
 extractor: cpp
 library: true
 dependencies:
-  codeql/cpp-upgrades: 0.0.2
+  codeql/cpp-upgrades: 0.0.3

cpp/ql/lib/semmle/code/cpp/commons/Printf.qll

@@ -6,6 +6,8 @@ import semmle.code.cpp.Type
 import semmle.code.cpp.commons.CommonType
 import semmle.code.cpp.commons.StringAnalysis
 import semmle.code.cpp.models.interfaces.FormattingFunction
+private import semmle.code.cpp.rangeanalysis.SimpleRangeAnalysis
+private import semmle.code.cpp.rangeanalysis.RangeAnalysisUtils
 
 class PrintfFormatAttribute extends FormatAttribute {
   PrintfFormatAttribute() { this.getArchetype() = ["printf", "__printf__"] }
@@ -268,6 +270,18 @@ class FormattingFunctionCall extends Expr {
   }
 }
 
+/**
+ * Gets the number of digits required to represent the integer represented by `f`.
+ *
+ * `f` is assumed to be nonnegative.
+ */
+bindingset[f]
+private int lengthInBase10(float f) {
+  f = 0 and result = 1
+  or
+  result = f.log10().floor() + 1
+}
+
 /**
  * A class to represent format strings that occur as arguments to invocations of formatting functions.
  */
@@ -1046,39 +1060,63 @@ class FormatLiteral extends Literal {
         or
         this.getConversionChar(n).toLowerCase() = ["d", "i"] and
         // e.g. -2^31 = "-2147483648"
-        exists(int sizeBits |
-          sizeBits =
-            min(int bits |
-              bits = this.getIntegralDisplayType(n).getSize() * 8
-              or
-              exists(IntegralType t |
-                t = this.getUse().getConversionArgument(n).getType().getUnderlyingType()
-              |
-                t.isSigned() and bits = t.getSize() * 8
-              )
-            ) and
-          len = 1 + ((sizeBits - 1) / 10.0.log2()).ceil()
-          // this calculation is as %u (below) only we take out the sign bit (- 1) and allow a whole
-          // character for it to be expressed as '-'.
-        )
+        len =
+          min(float cand |
+            // The first case handles length sub-specifiers
+            // Subtract one in the exponent because one bit is for the sign.
+            // Add 1 to account for the possible sign in the output.
+            cand = 1 + lengthInBase10(2.pow(this.getIntegralDisplayType(n).getSize() * 8 - 1))
+            or
+            // The second case uses range analysis to deduce a length that's shorter than the length
+            // of the number -2^31.
+            exists(Expr arg, float lower, float upper |
+              arg = this.getUse().getConversionArgument(n) and
+              lower = lowerBound(arg.getFullyConverted()) and
+              upper = upperBound(arg.getFullyConverted())
+            |
+              cand =
+                max(int cand0 |
+                  // Include the sign bit in the length if it can be negative
+                  (
+                    if lower < 0
+                    then cand0 = 1 + lengthInBase10(lower.abs())
+                    else cand0 = lengthInBase10(lower)
+                  )
+                  or
+                  (
+                    if upper < 0
+                    then cand0 = 1 + lengthInBase10(upper.abs())
+                    else cand0 = lengthInBase10(upper)
+                  )
+                )
+            )
+          )
         or
         this.getConversionChar(n).toLowerCase() = "u" and
         // e.g. 2^32 - 1 = "4294967295"
-        exists(int sizeBits |
-          sizeBits =
-            min(int bits |
-              bits = this.getIntegralDisplayType(n).getSize() * 8
-              or
-              exists(IntegralType t |
-                t = this.getUse().getConversionArgument(n).getType().getUnderlyingType()
-              |
-                t.isUnsigned() and bits = t.getSize() * 8
-              )
-            ) and
-          len = (sizeBits / 10.0.log2()).ceil()
-          // convert the size from bits to decimal characters, and round up as you can't have
-          // fractional characters (10.0.log2() is the number of bits expressed per decimal character)
-        )
+        len =
+          min(float cand |
+            // The first case handles length sub-specifiers
+            cand = 2.pow(this.getIntegralDisplayType(n).getSize() * 8)
+            or
+            // The second case uses range analysis to deduce a length that's shorter than
+            // the length of the number 2^31 - 1.
+            exists(Expr arg, float lower |
+              arg = this.getUse().getConversionArgument(n) and
+              lower = lowerBound(arg.getFullyConverted())
+            |
+              cand =
+                max(float cand0 |
+                  // If lower can be negative we use `(unsigned)-1` as the candidate value.
+                  lower < 0 and
+                  cand0 = 2.pow(any(IntType t | t.isUnsigned()).getSize() * 8)
+                  or
+                  cand0 = upperBound(arg.getFullyConverted())
+                )
+            )
+          |
+            lengthInBase10(cand)
+          )
         or
         this.getConversionChar(n).toLowerCase() = "x" and
         // e.g. "12345678"

cpp/ql/lib/semmle/code/cpp/controlflow/internal/ConstantExprs.qll

@@ -626,9 +626,9 @@ library class ExprEvaluator extends int {
       // All assignments must have the same int value
       result =
         unique(Expr value |
-          value = v.getAnAssignedValue() and not ignoreVariableAssignment(e, v, value)
+          value = v.getAnAssignedValue() and not this.ignoreVariableAssignment(e, v, value)
         |
-          getValueInternalNonSubExpr(value)
+          this.getValueInternalNonSubExpr(value)
         )
     )
   }

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowDispatch.qll

@@ -1,4 +1,6 @@
 private import cpp
+private import semmle.code.cpp.dataflow.internal.DataFlowPrivate
+private import semmle.code.cpp.dataflow.internal.DataFlowUtil
 
 /**
  * Gets a function that might be called by `call`.
@@ -63,3 +65,17 @@ predicate mayBenefitFromCallContext(Call call, Function f) { none() }
  * restricted to those `call`s for which a context might make a difference.
  */
 Function viableImplInCallContext(Call call, Call ctx) { none() }
+
+/** A parameter position represented by an integer. */
+class ParameterPosition extends int {
+  ParameterPosition() { any(ParameterNode p).isParameterOf(_, this) }
+}
+
+/** An argument position represented by an integer. */
+class ArgumentPosition extends int {
+  ArgumentPosition() { any(ArgumentNode a).argumentOf(_, this) }
+}
+
+/** Holds if arguments at position `apos` match parameters at position `ppos`. */
+pragma[inline]
+predicate parameterMatch(ParameterPosition ppos, ArgumentPosition apos) { ppos = apos }

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll

@@ -256,11 +256,11 @@ private class ArgNodeEx extends NodeEx {
 private class ParamNodeEx extends NodeEx {
   ParamNodeEx() { this.asNode() instanceof ParamNode }
 
-  predicate isParameterOf(DataFlowCallable c, int i) {
-    this.asNode().(ParamNode).isParameterOf(c, i)
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
+    this.asNode().(ParamNode).isParameterOf(c, pos)
   }
 
-  int getPosition() { this.isParameterOf(_, result) }
+  ParameterPosition getPosition() { this.isParameterOf(_, result) }
 
   predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1427,7 +1447,7 @@ private module Stage2 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2122,7 +2142,7 @@ private module Stage3 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2888,7 +2908,7 @@ private module Stage4 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2972,7 +2992,7 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
 
-  int getParameterPos() { p.isParameterOf(_, result) }
+  ParameterPosition getParameterPos() { p.isParameterOf(_, result) }
 
   ParamNodeEx getParamNode() { result = p }
 
@@ -3619,39 +3639,40 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
-  Configuration config
+  PathNodeMid mid, ParameterPosition ppos, CallContext cc, DataFlowCall call, AccessPath ap,
+  AccessPathApprox apa, Configuration config
 ) {
-  exists(ArgNode arg |
+  exists(ArgNode arg, ArgumentPosition apos |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
-    arg.argumentOf(call, i) and
+    arg.argumentOf(call, apos) and
     ap = mid.getAp() and
     apa = ap.getApprox() and
-    config = mid.getConfiguration()
+    config = mid.getConfiguration() and
+    parameterMatch(ppos, apos)
   )
 }
 
 pragma[nomagic]
 private predicate parameterCand(
-  DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
+  DataFlowCallable callable, ParameterPosition pos, AccessPathApprox apa, Configuration config
 ) {
   exists(ParamNodeEx p |
     Stage4::revFlow(p, _, _, apa, config) and
-    p.isParameterOf(callable, i)
+    p.isParameterOf(callable, pos)
   )
 }
 
 pragma[nomagic]
 private predicate pathIntoCallable0(
-  PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap, Configuration config
+  PathNodeMid mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
+  DataFlowCall call, AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+    pathIntoArg(mid, pragma[only_bind_into](pos), outercc, call, ap, pragma[only_bind_into](apa),
       pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+    parameterCand(callable, pragma[only_bind_into](pos), pragma[only_bind_into](apa),
       pragma[only_bind_into](config))
   )
 }
@@ -3666,9 +3687,9 @@ private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call, Configuration config
 ) {
-  exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-    p.isParameterOf(callable, i) and
+  exists(ParameterPosition pos, DataFlowCallable callable, AccessPath ap |
+    pathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+    p.isParameterOf(callable, pos) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
@@ -3692,7 +3713,7 @@ private predicate paramFlowsThrough(
   ReturnKindExt kind, CallContextCall cc, SummaryCtxSome sc, AccessPath ap, AccessPathApprox apa,
   Configuration config
 ) {
-  exists(PathNodeMid mid, RetNodeEx ret, int pos |
+  exists(PathNodeMid mid, RetNodeEx ret, ParameterPosition pos |
     mid.getNodeEx() = ret and
     kind = ret.getKind() and
     cc = mid.getCallContext() and
@@ -3740,13 +3761,14 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
     exists(Configuration config |
       pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
       pathIntoCallable(arg, par, _, innercc, sc, _, config) and
-      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config))
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
     )
   }
 
@@ -3780,8 +3802,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3790,11 +3821,12 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
       pragma[only_bind_into](arg).getASuccessor() = par and
       pragma[only_bind_into](arg).getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
@@ -4410,24 +4442,25 @@ private module FlowExploration {
 
   pragma[noinline]
   private predicate partialPathIntoArg(
-    PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
-    Configuration config
+    PartialPathNodeFwd mid, ParameterPosition ppos, CallContext cc, DataFlowCall call,
+    PartialAccessPath ap, Configuration config
   ) {
-    exists(ArgNode arg |
+    exists(ArgNode arg, ArgumentPosition apos |
       arg = mid.getNodeEx().asNode() and
       cc = mid.getCallContext() and
-      arg.argumentOf(call, i) and
+      arg.argumentOf(call, apos) and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate partialPathIntoCallable0(
-    PartialPathNodeFwd mid, DataFlowCallable callable, int i, CallContext outercc,
+    PartialPathNodeFwd mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
     DataFlowCall call, PartialAccessPath ap, Configuration config
   ) {
-    partialPathIntoArg(mid, i, outercc, call, ap, config) and
+    partialPathIntoArg(mid, pos, outercc, call, ap, config) and
     callable = resolveCall(call, outercc)
   }
 
@@ -4436,9 +4469,9 @@ private module FlowExploration {
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(int i, DataFlowCallable callable |
-      partialPathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-      p.isParameterOf(callable, i) and
+    exists(ParameterPosition pos, DataFlowCallable callable |
+      partialPathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+      p.isParameterOf(callable, pos) and
       sc1 = TSummaryCtx1Param(p) and
       sc2 = TSummaryCtx2Some(ap)
     |
@@ -4602,22 +4635,23 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathFlowsThrough(
-    int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
-    Configuration config
+    ArgumentPosition apos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2,
+    RevPartialAccessPath ap, Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParamNodeEx p |
+    exists(PartialPathNodeRev mid, ParamNodeEx p, ParameterPosition ppos |
       mid.getNodeEx() = p and
-      p.getPosition() = pos and
+      p.getPosition() = ppos and
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable0(
-    DataFlowCall call, PartialPathNodeRev mid, int pos, RevPartialAccessPath ap,
+    DataFlowCall call, PartialPathNodeRev mid, ArgumentPosition pos, RevPartialAccessPath ap,
     Configuration config
   ) {
     exists(TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2 |
@@ -4630,7 +4664,7 @@ private module FlowExploration {
   private predicate revPartialPathThroughCallable(
     PartialPathNodeRev mid, ArgNodeEx node, RevPartialAccessPath ap, Configuration config
   ) {
-    exists(DataFlowCall call, int pos |
+    exists(DataFlowCall call, ArgumentPosition pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and
       node.asNode().(ArgNode).argumentOf(call, pos)
     )

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll

@@ -256,11 +256,11 @@ private class ArgNodeEx extends NodeEx {
 private class ParamNodeEx extends NodeEx {
   ParamNodeEx() { this.asNode() instanceof ParamNode }
 
-  predicate isParameterOf(DataFlowCallable c, int i) {
-    this.asNode().(ParamNode).isParameterOf(c, i)
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
+    this.asNode().(ParamNode).isParameterOf(c, pos)
   }
 
-  int getPosition() { this.isParameterOf(_, result) }
+  ParameterPosition getPosition() { this.isParameterOf(_, result) }
 
   predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1427,7 +1447,7 @@ private module Stage2 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2122,7 +2142,7 @@ private module Stage3 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2888,7 +2908,7 @@ private module Stage4 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2972,7 +2992,7 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
 
-  int getParameterPos() { p.isParameterOf(_, result) }
+  ParameterPosition getParameterPos() { p.isParameterOf(_, result) }
 
   ParamNodeEx getParamNode() { result = p }
 
@@ -3619,39 +3639,40 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
-  Configuration config
+  PathNodeMid mid, ParameterPosition ppos, CallContext cc, DataFlowCall call, AccessPath ap,
+  AccessPathApprox apa, Configuration config
 ) {
-  exists(ArgNode arg |
+  exists(ArgNode arg, ArgumentPosition apos |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
-    arg.argumentOf(call, i) and
+    arg.argumentOf(call, apos) and
     ap = mid.getAp() and
     apa = ap.getApprox() and
-    config = mid.getConfiguration()
+    config = mid.getConfiguration() and
+    parameterMatch(ppos, apos)
   )
 }
 
 pragma[nomagic]
 private predicate parameterCand(
-  DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
+  DataFlowCallable callable, ParameterPosition pos, AccessPathApprox apa, Configuration config
 ) {
   exists(ParamNodeEx p |
     Stage4::revFlow(p, _, _, apa, config) and
-    p.isParameterOf(callable, i)
+    p.isParameterOf(callable, pos)
   )
 }
 
 pragma[nomagic]
 private predicate pathIntoCallable0(
-  PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap, Configuration config
+  PathNodeMid mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
+  DataFlowCall call, AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+    pathIntoArg(mid, pragma[only_bind_into](pos), outercc, call, ap, pragma[only_bind_into](apa),
       pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+    parameterCand(callable, pragma[only_bind_into](pos), pragma[only_bind_into](apa),
       pragma[only_bind_into](config))
   )
 }
@@ -3666,9 +3687,9 @@ private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call, Configuration config
 ) {
-  exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-    p.isParameterOf(callable, i) and
+  exists(ParameterPosition pos, DataFlowCallable callable, AccessPath ap |
+    pathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+    p.isParameterOf(callable, pos) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
@@ -3692,7 +3713,7 @@ private predicate paramFlowsThrough(
   ReturnKindExt kind, CallContextCall cc, SummaryCtxSome sc, AccessPath ap, AccessPathApprox apa,
   Configuration config
 ) {
-  exists(PathNodeMid mid, RetNodeEx ret, int pos |
+  exists(PathNodeMid mid, RetNodeEx ret, ParameterPosition pos |
     mid.getNodeEx() = ret and
     kind = ret.getKind() and
     cc = mid.getCallContext() and
@@ -3740,13 +3761,14 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
     exists(Configuration config |
       pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
       pathIntoCallable(arg, par, _, innercc, sc, _, config) and
-      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config))
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
     )
   }
 
@@ -3780,8 +3802,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3790,11 +3821,12 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
       pragma[only_bind_into](arg).getASuccessor() = par and
       pragma[only_bind_into](arg).getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
@@ -4410,24 +4442,25 @@ private module FlowExploration {
 
   pragma[noinline]
   private predicate partialPathIntoArg(
-    PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
-    Configuration config
+    PartialPathNodeFwd mid, ParameterPosition ppos, CallContext cc, DataFlowCall call,
+    PartialAccessPath ap, Configuration config
   ) {
-    exists(ArgNode arg |
+    exists(ArgNode arg, ArgumentPosition apos |
       arg = mid.getNodeEx().asNode() and
       cc = mid.getCallContext() and
-      arg.argumentOf(call, i) and
+      arg.argumentOf(call, apos) and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate partialPathIntoCallable0(
-    PartialPathNodeFwd mid, DataFlowCallable callable, int i, CallContext outercc,
+    PartialPathNodeFwd mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
     DataFlowCall call, PartialAccessPath ap, Configuration config
   ) {
-    partialPathIntoArg(mid, i, outercc, call, ap, config) and
+    partialPathIntoArg(mid, pos, outercc, call, ap, config) and
     callable = resolveCall(call, outercc)
   }
 
@@ -4436,9 +4469,9 @@ private module FlowExploration {
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(int i, DataFlowCallable callable |
-      partialPathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-      p.isParameterOf(callable, i) and
+    exists(ParameterPosition pos, DataFlowCallable callable |
+      partialPathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+      p.isParameterOf(callable, pos) and
       sc1 = TSummaryCtx1Param(p) and
       sc2 = TSummaryCtx2Some(ap)
     |
@@ -4602,22 +4635,23 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathFlowsThrough(
-    int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
-    Configuration config
+    ArgumentPosition apos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2,
+    RevPartialAccessPath ap, Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParamNodeEx p |
+    exists(PartialPathNodeRev mid, ParamNodeEx p, ParameterPosition ppos |
       mid.getNodeEx() = p and
-      p.getPosition() = pos and
+      p.getPosition() = ppos and
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable0(
-    DataFlowCall call, PartialPathNodeRev mid, int pos, RevPartialAccessPath ap,
+    DataFlowCall call, PartialPathNodeRev mid, ArgumentPosition pos, RevPartialAccessPath ap,
     Configuration config
   ) {
     exists(TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2 |
@@ -4630,7 +4664,7 @@ private module FlowExploration {
   private predicate revPartialPathThroughCallable(
     PartialPathNodeRev mid, ArgNodeEx node, RevPartialAccessPath ap, Configuration config
   ) {
-    exists(DataFlowCall call, int pos |
+    exists(DataFlowCall call, ArgumentPosition pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and
       node.asNode().(ArgNode).argumentOf(call, pos)
     )

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll

@@ -256,11 +256,11 @@ private class ArgNodeEx extends NodeEx {
 private class ParamNodeEx extends NodeEx {
   ParamNodeEx() { this.asNode() instanceof ParamNode }
 
-  predicate isParameterOf(DataFlowCallable c, int i) {
-    this.asNode().(ParamNode).isParameterOf(c, i)
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
+    this.asNode().(ParamNode).isParameterOf(c, pos)
   }
 
-  int getPosition() { this.isParameterOf(_, result) }
+  ParameterPosition getPosition() { this.isParameterOf(_, result) }
 
   predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1427,7 +1447,7 @@ private module Stage2 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2122,7 +2142,7 @@ private module Stage3 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2888,7 +2908,7 @@ private module Stage4 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2972,7 +2992,7 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
 
-  int getParameterPos() { p.isParameterOf(_, result) }
+  ParameterPosition getParameterPos() { p.isParameterOf(_, result) }
 
   ParamNodeEx getParamNode() { result = p }
 
@@ -3619,39 +3639,40 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
-  Configuration config
+  PathNodeMid mid, ParameterPosition ppos, CallContext cc, DataFlowCall call, AccessPath ap,
+  AccessPathApprox apa, Configuration config
 ) {
-  exists(ArgNode arg |
+  exists(ArgNode arg, ArgumentPosition apos |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
-    arg.argumentOf(call, i) and
+    arg.argumentOf(call, apos) and
     ap = mid.getAp() and
     apa = ap.getApprox() and
-    config = mid.getConfiguration()
+    config = mid.getConfiguration() and
+    parameterMatch(ppos, apos)
   )
 }
 
 pragma[nomagic]
 private predicate parameterCand(
-  DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
+  DataFlowCallable callable, ParameterPosition pos, AccessPathApprox apa, Configuration config
 ) {
   exists(ParamNodeEx p |
     Stage4::revFlow(p, _, _, apa, config) and
-    p.isParameterOf(callable, i)
+    p.isParameterOf(callable, pos)
   )
 }
 
 pragma[nomagic]
 private predicate pathIntoCallable0(
-  PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap, Configuration config
+  PathNodeMid mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
+  DataFlowCall call, AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+    pathIntoArg(mid, pragma[only_bind_into](pos), outercc, call, ap, pragma[only_bind_into](apa),
       pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+    parameterCand(callable, pragma[only_bind_into](pos), pragma[only_bind_into](apa),
       pragma[only_bind_into](config))
   )
 }
@@ -3666,9 +3687,9 @@ private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call, Configuration config
 ) {
-  exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-    p.isParameterOf(callable, i) and
+  exists(ParameterPosition pos, DataFlowCallable callable, AccessPath ap |
+    pathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+    p.isParameterOf(callable, pos) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
@@ -3692,7 +3713,7 @@ private predicate paramFlowsThrough(
   ReturnKindExt kind, CallContextCall cc, SummaryCtxSome sc, AccessPath ap, AccessPathApprox apa,
   Configuration config
 ) {
-  exists(PathNodeMid mid, RetNodeEx ret, int pos |
+  exists(PathNodeMid mid, RetNodeEx ret, ParameterPosition pos |
     mid.getNodeEx() = ret and
     kind = ret.getKind() and
     cc = mid.getCallContext() and
@@ -3740,13 +3761,14 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
     exists(Configuration config |
       pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
       pathIntoCallable(arg, par, _, innercc, sc, _, config) and
-      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config))
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
     )
   }
 
@@ -3780,8 +3802,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3790,11 +3821,12 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
       pragma[only_bind_into](arg).getASuccessor() = par and
       pragma[only_bind_into](arg).getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
@@ -4410,24 +4442,25 @@ private module FlowExploration {
 
   pragma[noinline]
   private predicate partialPathIntoArg(
-    PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
-    Configuration config
+    PartialPathNodeFwd mid, ParameterPosition ppos, CallContext cc, DataFlowCall call,
+    PartialAccessPath ap, Configuration config
   ) {
-    exists(ArgNode arg |
+    exists(ArgNode arg, ArgumentPosition apos |
       arg = mid.getNodeEx().asNode() and
       cc = mid.getCallContext() and
-      arg.argumentOf(call, i) and
+      arg.argumentOf(call, apos) and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate partialPathIntoCallable0(
-    PartialPathNodeFwd mid, DataFlowCallable callable, int i, CallContext outercc,
+    PartialPathNodeFwd mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
     DataFlowCall call, PartialAccessPath ap, Configuration config
   ) {
-    partialPathIntoArg(mid, i, outercc, call, ap, config) and
+    partialPathIntoArg(mid, pos, outercc, call, ap, config) and
     callable = resolveCall(call, outercc)
   }
 
@@ -4436,9 +4469,9 @@ private module FlowExploration {
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(int i, DataFlowCallable callable |
-      partialPathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-      p.isParameterOf(callable, i) and
+    exists(ParameterPosition pos, DataFlowCallable callable |
+      partialPathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+      p.isParameterOf(callable, pos) and
       sc1 = TSummaryCtx1Param(p) and
       sc2 = TSummaryCtx2Some(ap)
     |
@@ -4602,22 +4635,23 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathFlowsThrough(
-    int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
-    Configuration config
+    ArgumentPosition apos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2,
+    RevPartialAccessPath ap, Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParamNodeEx p |
+    exists(PartialPathNodeRev mid, ParamNodeEx p, ParameterPosition ppos |
       mid.getNodeEx() = p and
-      p.getPosition() = pos and
+      p.getPosition() = ppos and
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable0(
-    DataFlowCall call, PartialPathNodeRev mid, int pos, RevPartialAccessPath ap,
+    DataFlowCall call, PartialPathNodeRev mid, ArgumentPosition pos, RevPartialAccessPath ap,
     Configuration config
   ) {
     exists(TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2 |
@@ -4630,7 +4664,7 @@ private module FlowExploration {
   private predicate revPartialPathThroughCallable(
     PartialPathNodeRev mid, ArgNodeEx node, RevPartialAccessPath ap, Configuration config
   ) {
-    exists(DataFlowCall call, int pos |
+    exists(DataFlowCall call, ArgumentPosition pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and
       node.asNode().(ArgNode).argumentOf(call, pos)
     )

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll

@@ -256,11 +256,11 @@ private class ArgNodeEx extends NodeEx {
 private class ParamNodeEx extends NodeEx {
   ParamNodeEx() { this.asNode() instanceof ParamNode }
 
-  predicate isParameterOf(DataFlowCallable c, int i) {
-    this.asNode().(ParamNode).isParameterOf(c, i)
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
+    this.asNode().(ParamNode).isParameterOf(c, pos)
   }
 
-  int getPosition() { this.isParameterOf(_, result) }
+  ParameterPosition getPosition() { this.isParameterOf(_, result) }
 
   predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1427,7 +1447,7 @@ private module Stage2 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2122,7 +2142,7 @@ private module Stage3 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2888,7 +2908,7 @@ private module Stage4 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2972,7 +2992,7 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
 
-  int getParameterPos() { p.isParameterOf(_, result) }
+  ParameterPosition getParameterPos() { p.isParameterOf(_, result) }
 
   ParamNodeEx getParamNode() { result = p }
 
@@ -3619,39 +3639,40 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
-  Configuration config
+  PathNodeMid mid, ParameterPosition ppos, CallContext cc, DataFlowCall call, AccessPath ap,
+  AccessPathApprox apa, Configuration config
 ) {
-  exists(ArgNode arg |
+  exists(ArgNode arg, ArgumentPosition apos |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
-    arg.argumentOf(call, i) and
+    arg.argumentOf(call, apos) and
     ap = mid.getAp() and
     apa = ap.getApprox() and
-    config = mid.getConfiguration()
+    config = mid.getConfiguration() and
+    parameterMatch(ppos, apos)
   )
 }
 
 pragma[nomagic]
 private predicate parameterCand(
-  DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
+  DataFlowCallable callable, ParameterPosition pos, AccessPathApprox apa, Configuration config
 ) {
   exists(ParamNodeEx p |
     Stage4::revFlow(p, _, _, apa, config) and
-    p.isParameterOf(callable, i)
+    p.isParameterOf(callable, pos)
   )
 }
 
 pragma[nomagic]
 private predicate pathIntoCallable0(
-  PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap, Configuration config
+  PathNodeMid mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
+  DataFlowCall call, AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+    pathIntoArg(mid, pragma[only_bind_into](pos), outercc, call, ap, pragma[only_bind_into](apa),
       pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+    parameterCand(callable, pragma[only_bind_into](pos), pragma[only_bind_into](apa),
       pragma[only_bind_into](config))
   )
 }
@@ -3666,9 +3687,9 @@ private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call, Configuration config
 ) {
-  exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-    p.isParameterOf(callable, i) and
+  exists(ParameterPosition pos, DataFlowCallable callable, AccessPath ap |
+    pathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+    p.isParameterOf(callable, pos) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
@@ -3692,7 +3713,7 @@ private predicate paramFlowsThrough(
   ReturnKindExt kind, CallContextCall cc, SummaryCtxSome sc, AccessPath ap, AccessPathApprox apa,
   Configuration config
 ) {
-  exists(PathNodeMid mid, RetNodeEx ret, int pos |
+  exists(PathNodeMid mid, RetNodeEx ret, ParameterPosition pos |
     mid.getNodeEx() = ret and
     kind = ret.getKind() and
     cc = mid.getCallContext() and
@@ -3740,13 +3761,14 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
     exists(Configuration config |
       pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
       pathIntoCallable(arg, par, _, innercc, sc, _, config) and
-      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config))
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
     )
   }
 
@@ -3780,8 +3802,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3790,11 +3821,12 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
       pragma[only_bind_into](arg).getASuccessor() = par and
       pragma[only_bind_into](arg).getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
@@ -4410,24 +4442,25 @@ private module FlowExploration {
 
   pragma[noinline]
   private predicate partialPathIntoArg(
-    PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
-    Configuration config
+    PartialPathNodeFwd mid, ParameterPosition ppos, CallContext cc, DataFlowCall call,
+    PartialAccessPath ap, Configuration config
   ) {
-    exists(ArgNode arg |
+    exists(ArgNode arg, ArgumentPosition apos |
       arg = mid.getNodeEx().asNode() and
       cc = mid.getCallContext() and
-      arg.argumentOf(call, i) and
+      arg.argumentOf(call, apos) and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate partialPathIntoCallable0(
-    PartialPathNodeFwd mid, DataFlowCallable callable, int i, CallContext outercc,
+    PartialPathNodeFwd mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
     DataFlowCall call, PartialAccessPath ap, Configuration config
   ) {
-    partialPathIntoArg(mid, i, outercc, call, ap, config) and
+    partialPathIntoArg(mid, pos, outercc, call, ap, config) and
     callable = resolveCall(call, outercc)
   }
 
@@ -4436,9 +4469,9 @@ private module FlowExploration {
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(int i, DataFlowCallable callable |
-      partialPathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-      p.isParameterOf(callable, i) and
+    exists(ParameterPosition pos, DataFlowCallable callable |
+      partialPathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+      p.isParameterOf(callable, pos) and
       sc1 = TSummaryCtx1Param(p) and
       sc2 = TSummaryCtx2Some(ap)
     |
@@ -4602,22 +4635,23 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathFlowsThrough(
-    int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
-    Configuration config
+    ArgumentPosition apos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2,
+    RevPartialAccessPath ap, Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParamNodeEx p |
+    exists(PartialPathNodeRev mid, ParamNodeEx p, ParameterPosition ppos |
       mid.getNodeEx() = p and
-      p.getPosition() = pos and
+      p.getPosition() = ppos and
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable0(
-    DataFlowCall call, PartialPathNodeRev mid, int pos, RevPartialAccessPath ap,
+    DataFlowCall call, PartialPathNodeRev mid, ArgumentPosition pos, RevPartialAccessPath ap,
     Configuration config
   ) {
     exists(TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2 |
@@ -4630,7 +4664,7 @@ private module FlowExploration {
   private predicate revPartialPathThroughCallable(
     PartialPathNodeRev mid, ArgNodeEx node, RevPartialAccessPath ap, Configuration config
   ) {
-    exists(DataFlowCall call, int pos |
+    exists(DataFlowCall call, ArgumentPosition pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and
       node.asNode().(ArgNode).argumentOf(call, pos)
     )

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplCommon.qll

@@ -62,6 +62,18 @@ predicate accessPathCostLimits(int apLimit, int tupleLimit) {
   tupleLimit = 1000
 }
 
+/**
+ * Holds if `arg` is an argument of `call` with an argument position that matches
+ * parameter position `ppos`.
+ */
+pragma[noinline]
+predicate argumentPositionMatch(DataFlowCall call, ArgNode arg, ParameterPosition ppos) {
+  exists(ArgumentPosition apos |
+    arg.argumentOf(call, apos) and
+    parameterMatch(ppos, apos)
+  )
+}
+
 /**
  * Provides a simple data-flow analysis for resolving lambda calls. The analysis
  * currently excludes read-steps, store-steps, and flow-through.
@@ -71,25 +83,27 @@ predicate accessPathCostLimits(int apLimit, int tupleLimit) {
  * calls. For this reason, we cannot reuse the code from `DataFlowImpl.qll` directly.
  */
 private module LambdaFlow {
-  private predicate viableParamNonLambda(DataFlowCall call, int i, ParamNode p) {
-    p.isParameterOf(viableCallable(call), i)
+  pragma[noinline]
+  private predicate viableParamNonLambda(DataFlowCall call, ParameterPosition ppos, ParamNode p) {
+    p.isParameterOf(viableCallable(call), ppos)
   }
 
-  private predicate viableParamLambda(DataFlowCall call, int i, ParamNode p) {
-    p.isParameterOf(viableCallableLambda(call, _), i)
+  pragma[noinline]
+  private predicate viableParamLambda(DataFlowCall call, ParameterPosition ppos, ParamNode p) {
+    p.isParameterOf(viableCallableLambda(call, _), ppos)
   }
 
   private predicate viableParamArgNonLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
-    exists(int i |
-      viableParamNonLambda(call, i, p) and
-      arg.argumentOf(call, i)
+    exists(ParameterPosition ppos |
+      viableParamNonLambda(call, ppos, p) and
+      argumentPositionMatch(call, arg, ppos)
     )
   }
 
   private predicate viableParamArgLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
-    exists(int i |
-      viableParamLambda(call, i, p) and
-      arg.argumentOf(call, i)
+    exists(ParameterPosition ppos |
+      viableParamLambda(call, ppos, p) and
+      argumentPositionMatch(call, arg, ppos)
     )
   }
 
@@ -322,7 +336,7 @@ private module Cached {
     or
     exists(ArgNode arg |
       result.(PostUpdateNode).getPreUpdateNode() = arg and
-      arg.argumentOf(call, k.(ParamUpdateReturnKind).getPosition())
+      arg.argumentOf(call, k.(ParamUpdateReturnKind).getAMatchingArgumentPosition())
     )
   }
 
@@ -330,7 +344,7 @@ private module Cached {
   predicate returnNodeExt(Node n, ReturnKindExt k) {
     k = TValueReturn(n.(ReturnNode).getKind())
     or
-    exists(ParamNode p, int pos |
+    exists(ParamNode p, ParameterPosition pos |
       parameterValueFlowsToPreUpdate(p, n) and
       p.isParameterOf(_, pos) and
       k = TParamUpdate(pos)
@@ -352,11 +366,13 @@ private module Cached {
   }
 
   cached
-  predicate parameterNode(Node p, DataFlowCallable c, int pos) { isParameterNode(p, c, pos) }
+  predicate parameterNode(Node p, DataFlowCallable c, ParameterPosition pos) {
+    isParameterNode(p, c, pos)
+  }
 
   cached
-  predicate argumentNode(Node n, DataFlowCall call, int pos) {
-    n.(ArgumentNode).argumentOf(call, pos)
+  predicate argumentNode(Node n, DataFlowCall call, ArgumentPosition pos) {
+    isArgumentNode(n, call, pos)
   }
 
   /**
@@ -374,12 +390,12 @@ private module Cached {
   }
 
   /**
-   * Holds if `p` is the `i`th parameter of a viable dispatch target of `call`.
-   * The instance parameter is considered to have index `-1`.
+   * Holds if `p` is the parameter of a viable dispatch target of `call`,
+   * and `p` has position `ppos`.
    */
   pragma[nomagic]
-  private predicate viableParam(DataFlowCall call, int i, ParamNode p) {
-    p.isParameterOf(viableCallableExt(call), i)
+  private predicate viableParam(DataFlowCall call, ParameterPosition ppos, ParamNode p) {
+    p.isParameterOf(viableCallableExt(call), ppos)
   }
 
   /**
@@ -388,9 +404,9 @@ private module Cached {
    */
   cached
   predicate viableParamArg(DataFlowCall call, ParamNode p, ArgNode arg) {
-    exists(int i |
-      viableParam(call, i, p) and
-      arg.argumentOf(call, i) and
+    exists(ParameterPosition ppos |
+      viableParam(call, ppos, p) and
+      argumentPositionMatch(call, arg, ppos) and
       compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(p))
     )
   }
@@ -862,7 +878,7 @@ private module Cached {
   cached
   newtype TReturnKindExt =
     TValueReturn(ReturnKind kind) or
-    TParamUpdate(int pos) { exists(ParamNode p | p.isParameterOf(_, pos)) }
+    TParamUpdate(ParameterPosition pos) { exists(ParamNode p | p.isParameterOf(_, pos)) }
 
   cached
   newtype TBooleanOption =
@@ -1054,9 +1070,9 @@ class ParamNode extends Node {
 
   /**
    * Holds if this node is the parameter of callable `c` at the specified
-   * (zero-based) position.
+   * position.
    */
-  predicate isParameterOf(DataFlowCallable c, int i) { parameterNode(this, c, i) }
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) { parameterNode(this, c, pos) }
 }
 
 /** A data-flow node that represents a call argument. */
@@ -1064,7 +1080,9 @@ class ArgNode extends Node {
   ArgNode() { argumentNode(this, _, _) }
 
   /** Holds if this argument occurs at the given position in the given call. */
-  final predicate argumentOf(DataFlowCall call, int pos) { argumentNode(this, call, pos) }
+  final predicate argumentOf(DataFlowCall call, ArgumentPosition pos) {
+    argumentNode(this, call, pos)
+  }
 }
 
 /**
@@ -1110,11 +1128,14 @@ class ValueReturnKind extends ReturnKindExt, TValueReturn {
 }
 
 class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
-  private int pos;
+  private ParameterPosition pos;
 
   ParamUpdateReturnKind() { this = TParamUpdate(pos) }
 
-  int getPosition() { result = pos }
+  ParameterPosition getPosition() { result = pos }
+
+  pragma[nomagic]
+  ArgumentPosition getAMatchingArgumentPosition() { parameterMatch(pos, result) }
 
   override string toString() { result = "param update " + pos }
 }

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplConsistency.qll

@@ -9,6 +9,19 @@ private import tainttracking1.TaintTrackingParameter::Private
 private import tainttracking1.TaintTrackingParameter::Public
 
 module Consistency {
+  private newtype TConsistencyConfiguration = MkConsistencyConfiguration()
+
+  /** A class for configuring the consistency queries. */
+  class ConsistencyConfiguration extends TConsistencyConfiguration {
+    string toString() { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `postWithInFlow`. */
+    predicate postWithInFlowExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `argHasPostUpdate`. */
+    predicate argHasPostUpdateExclude(ArgumentNode n) { none() }
+  }
+
   private class RelevantNode extends Node {
     RelevantNode() {
       this instanceof ArgumentNode or
@@ -164,7 +177,7 @@ module Consistency {
 
   query predicate argHasPostUpdate(ArgumentNode n, string msg) {
     not hasPost(n) and
-    not isImmutableOrUnobservable(n) and
+    not any(ConsistencyConfiguration c).argHasPostUpdateExclude(n) and
     msg = "ArgumentNode is missing PostUpdateNode."
   }
 
@@ -177,6 +190,7 @@ module Consistency {
     isPostUpdateNode(n) and
     not clearsContent(n, _) and
     simpleLocalFlowStep(_, n) and
+    not any(ConsistencyConfiguration c).postWithInFlowExclude(n) and
     msg = "PostUpdateNode should not be the target of local flow."
   }
 }

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplLocal.qll

@@ -256,11 +256,11 @@ private class ArgNodeEx extends NodeEx {
 private class ParamNodeEx extends NodeEx {
   ParamNodeEx() { this.asNode() instanceof ParamNode }
 
-  predicate isParameterOf(DataFlowCallable c, int i) {
-    this.asNode().(ParamNode).isParameterOf(c, i)
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
+    this.asNode().(ParamNode).isParameterOf(c, pos)
   }
 
-  int getPosition() { this.isParameterOf(_, result) }
+  ParameterPosition getPosition() { this.isParameterOf(_, result) }
 
   predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1427,7 +1447,7 @@ private module Stage2 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2122,7 +2142,7 @@ private module Stage3 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2888,7 +2908,7 @@ private module Stage4 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2972,7 +2992,7 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
 
-  int getParameterPos() { p.isParameterOf(_, result) }
+  ParameterPosition getParameterPos() { p.isParameterOf(_, result) }
 
   ParamNodeEx getParamNode() { result = p }
 
@@ -3619,39 +3639,40 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
-  Configuration config
+  PathNodeMid mid, ParameterPosition ppos, CallContext cc, DataFlowCall call, AccessPath ap,
+  AccessPathApprox apa, Configuration config
 ) {
-  exists(ArgNode arg |
+  exists(ArgNode arg, ArgumentPosition apos |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
-    arg.argumentOf(call, i) and
+    arg.argumentOf(call, apos) and
     ap = mid.getAp() and
     apa = ap.getApprox() and
-    config = mid.getConfiguration()
+    config = mid.getConfiguration() and
+    parameterMatch(ppos, apos)
   )
 }
 
 pragma[nomagic]
 private predicate parameterCand(
-  DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
+  DataFlowCallable callable, ParameterPosition pos, AccessPathApprox apa, Configuration config
 ) {
   exists(ParamNodeEx p |
     Stage4::revFlow(p, _, _, apa, config) and
-    p.isParameterOf(callable, i)
+    p.isParameterOf(callable, pos)
   )
 }
 
 pragma[nomagic]
 private predicate pathIntoCallable0(
-  PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap, Configuration config
+  PathNodeMid mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
+  DataFlowCall call, AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+    pathIntoArg(mid, pragma[only_bind_into](pos), outercc, call, ap, pragma[only_bind_into](apa),
       pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+    parameterCand(callable, pragma[only_bind_into](pos), pragma[only_bind_into](apa),
       pragma[only_bind_into](config))
   )
 }
@@ -3666,9 +3687,9 @@ private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call, Configuration config
 ) {
-  exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-    p.isParameterOf(callable, i) and
+  exists(ParameterPosition pos, DataFlowCallable callable, AccessPath ap |
+    pathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+    p.isParameterOf(callable, pos) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
@@ -3692,7 +3713,7 @@ private predicate paramFlowsThrough(
   ReturnKindExt kind, CallContextCall cc, SummaryCtxSome sc, AccessPath ap, AccessPathApprox apa,
   Configuration config
 ) {
-  exists(PathNodeMid mid, RetNodeEx ret, int pos |
+  exists(PathNodeMid mid, RetNodeEx ret, ParameterPosition pos |
     mid.getNodeEx() = ret and
     kind = ret.getKind() and
     cc = mid.getCallContext() and
@@ -3740,13 +3761,14 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
     exists(Configuration config |
       pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
       pathIntoCallable(arg, par, _, innercc, sc, _, config) and
-      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config))
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
     )
   }
 
@@ -3780,8 +3802,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3790,11 +3821,12 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
       pragma[only_bind_into](arg).getASuccessor() = par and
       pragma[only_bind_into](arg).getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
@@ -4410,24 +4442,25 @@ private module FlowExploration {
 
   pragma[noinline]
   private predicate partialPathIntoArg(
-    PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
-    Configuration config
+    PartialPathNodeFwd mid, ParameterPosition ppos, CallContext cc, DataFlowCall call,
+    PartialAccessPath ap, Configuration config
   ) {
-    exists(ArgNode arg |
+    exists(ArgNode arg, ArgumentPosition apos |
       arg = mid.getNodeEx().asNode() and
       cc = mid.getCallContext() and
-      arg.argumentOf(call, i) and
+      arg.argumentOf(call, apos) and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate partialPathIntoCallable0(
-    PartialPathNodeFwd mid, DataFlowCallable callable, int i, CallContext outercc,
+    PartialPathNodeFwd mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
     DataFlowCall call, PartialAccessPath ap, Configuration config
   ) {
-    partialPathIntoArg(mid, i, outercc, call, ap, config) and
+    partialPathIntoArg(mid, pos, outercc, call, ap, config) and
     callable = resolveCall(call, outercc)
   }
 
@@ -4436,9 +4469,9 @@ private module FlowExploration {
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(int i, DataFlowCallable callable |
-      partialPathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-      p.isParameterOf(callable, i) and
+    exists(ParameterPosition pos, DataFlowCallable callable |
+      partialPathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+      p.isParameterOf(callable, pos) and
       sc1 = TSummaryCtx1Param(p) and
       sc2 = TSummaryCtx2Some(ap)
     |
@@ -4602,22 +4635,23 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathFlowsThrough(
-    int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
-    Configuration config
+    ArgumentPosition apos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2,
+    RevPartialAccessPath ap, Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParamNodeEx p |
+    exists(PartialPathNodeRev mid, ParamNodeEx p, ParameterPosition ppos |
       mid.getNodeEx() = p and
-      p.getPosition() = pos and
+      p.getPosition() = ppos and
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable0(
-    DataFlowCall call, PartialPathNodeRev mid, int pos, RevPartialAccessPath ap,
+    DataFlowCall call, PartialPathNodeRev mid, ArgumentPosition pos, RevPartialAccessPath ap,
     Configuration config
   ) {
     exists(TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2 |
@@ -4630,7 +4664,7 @@ private module FlowExploration {
   private predicate revPartialPathThroughCallable(
     PartialPathNodeRev mid, ArgNodeEx node, RevPartialAccessPath ap, Configuration config
   ) {
-    exists(DataFlowCall call, int pos |
+    exists(DataFlowCall call, ArgumentPosition pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and
       node.asNode().(ArgNode).argumentOf(call, pos)
     )

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowPrivate.qll

@@ -2,12 +2,20 @@ private import cpp
 private import DataFlowUtil
 private import DataFlowDispatch
 private import FlowVar
+private import DataFlowImplConsistency
 
 /** Gets the callable in which this node occurs. */
 DataFlowCallable nodeGetEnclosingCallable(Node n) { result = n.getEnclosingCallable() }
 
 /** Holds if `p` is a `ParameterNode` of `c` with position `pos`. */
-predicate isParameterNode(ParameterNode p, DataFlowCallable c, int pos) { p.isParameterOf(c, pos) }
+predicate isParameterNode(ParameterNode p, DataFlowCallable c, ParameterPosition pos) {
+  p.isParameterOf(c, pos)
+}
+
+/** Holds if `arg` is an `ArgumentNode` of `c` with position `pos`. */
+predicate isArgumentNode(ArgumentNode arg, DataFlowCall c, ArgumentPosition pos) {
+  arg.argumentOf(c, pos)
+}
 
 /** Gets the instance argument of a non-static call. */
 private Node getInstanceArgument(Call call) {
@@ -259,27 +267,6 @@ class Unit extends TUnit {
   string toString() { result = "unit" }
 }
 
-/**
- * Holds if `n` does not require a `PostUpdateNode` as it either cannot be
- * modified or its modification cannot be observed, for example if it is a
- * freshly created object that is not saved in a variable.
- *
- * This predicate is only used for consistency checks.
- */
-predicate isImmutableOrUnobservable(Node n) {
-  // Is the null pointer (or something that's not really a pointer)
-  exists(n.asExpr().getValue())
-  or
-  // Isn't a pointer or is a pointer to const
-  forall(DerivedType dt | dt = n.asExpr().getActualType() |
-    dt.getBaseType().isConst()
-    or
-    dt.getBaseType() instanceof RoutineType
-  )
-  // The above list of cases isn't exhaustive, but it narrows down the
-  // consistency alerts enough that most of them are interesting.
-}
-
 /** Holds if `n` should be hidden from path explanations. */
 predicate nodeIsHidden(Node n) { none() }
 
@@ -302,3 +289,19 @@ predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preserves
  * by default as a heuristic.
  */
 predicate allowParameterReturnInSelf(ParameterNode p) { none() }
+
+private class MyConsistencyConfiguration extends Consistency::ConsistencyConfiguration {
+  override predicate argHasPostUpdateExclude(ArgumentNode n) {
+    // Is the null pointer (or something that's not really a pointer)
+    exists(n.asExpr().getValue())
+    or
+    // Isn't a pointer or is a pointer to const
+    forall(DerivedType dt | dt = n.asExpr().getActualType() |
+      dt.getBaseType().isConst()
+      or
+      dt.getBaseType() instanceof RoutineType
+    )
+    // The above list of cases isn't exhaustive, but it narrows down the
+    // consistency alerts enough that most of them are interesting.
+  }
+}

cpp/ql/lib/semmle/code/cpp/ir/dataflow/DefaultTaintTracking.qll

@@ -484,8 +484,9 @@ module TaintedWithPath {
     /** Gets the element that `pathNode` wraps, if any. */
     Element getElementFromPathNode(PathNode pathNode) {
       exists(DataFlow::Node node | node = pathNode.(WrapPathNode).inner().getNode() |
-        result = node.asExpr() or
-        result = node.asParameter()
+        result = node.asInstruction().getAST()
+        or
+        result = node.asOperand().getDef().getAST()
       )
       or
       result = pathNode.(EndpointPathNode).inner()

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowDispatch.qll

@@ -2,6 +2,7 @@ private import cpp
 private import semmle.code.cpp.ir.IR
 private import semmle.code.cpp.ir.dataflow.DataFlow
 private import semmle.code.cpp.ir.dataflow.internal.DataFlowPrivate
+private import semmle.code.cpp.ir.dataflow.internal.DataFlowUtil
 private import DataFlowImplCommon as DataFlowImplCommon
 
 /**
@@ -266,3 +267,17 @@ Function viableImplInCallContext(CallInstruction call, CallInstruction ctx) {
     result = ctx.getArgument(i).getUnconvertedResultExpression().(FunctionAccess).getTarget()
   )
 }
+
+/** A parameter position represented by an integer. */
+class ParameterPosition extends int {
+  ParameterPosition() { any(ParameterNode p).isParameterOf(_, this) }
+}
+
+/** An argument position represented by an integer. */
+class ArgumentPosition extends int {
+  ArgumentPosition() { any(ArgumentNode a).argumentOf(_, this) }
+}
+
+/** Holds if arguments at position `apos` match parameters at position `ppos`. */
+pragma[inline]
+predicate parameterMatch(ParameterPosition ppos, ArgumentPosition apos) { ppos = apos }

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll

@@ -256,11 +256,11 @@ private class ArgNodeEx extends NodeEx {
 private class ParamNodeEx extends NodeEx {
   ParamNodeEx() { this.asNode() instanceof ParamNode }
 
-  predicate isParameterOf(DataFlowCallable c, int i) {
-    this.asNode().(ParamNode).isParameterOf(c, i)
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
+    this.asNode().(ParamNode).isParameterOf(c, pos)
   }
 
-  int getPosition() { this.isParameterOf(_, result) }
+  ParameterPosition getPosition() { this.isParameterOf(_, result) }
 
   predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1427,7 +1447,7 @@ private module Stage2 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2122,7 +2142,7 @@ private module Stage3 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2888,7 +2908,7 @@ private module Stage4 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2972,7 +2992,7 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
 
-  int getParameterPos() { p.isParameterOf(_, result) }
+  ParameterPosition getParameterPos() { p.isParameterOf(_, result) }
 
   ParamNodeEx getParamNode() { result = p }
 
@@ -3619,39 +3639,40 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
-  Configuration config
+  PathNodeMid mid, ParameterPosition ppos, CallContext cc, DataFlowCall call, AccessPath ap,
+  AccessPathApprox apa, Configuration config
 ) {
-  exists(ArgNode arg |
+  exists(ArgNode arg, ArgumentPosition apos |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
-    arg.argumentOf(call, i) and
+    arg.argumentOf(call, apos) and
     ap = mid.getAp() and
     apa = ap.getApprox() and
-    config = mid.getConfiguration()
+    config = mid.getConfiguration() and
+    parameterMatch(ppos, apos)
   )
 }
 
 pragma[nomagic]
 private predicate parameterCand(
-  DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
+  DataFlowCallable callable, ParameterPosition pos, AccessPathApprox apa, Configuration config
 ) {
   exists(ParamNodeEx p |
     Stage4::revFlow(p, _, _, apa, config) and
-    p.isParameterOf(callable, i)
+    p.isParameterOf(callable, pos)
   )
 }
 
 pragma[nomagic]
 private predicate pathIntoCallable0(
-  PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap, Configuration config
+  PathNodeMid mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
+  DataFlowCall call, AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+    pathIntoArg(mid, pragma[only_bind_into](pos), outercc, call, ap, pragma[only_bind_into](apa),
       pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+    parameterCand(callable, pragma[only_bind_into](pos), pragma[only_bind_into](apa),
       pragma[only_bind_into](config))
   )
 }
@@ -3666,9 +3687,9 @@ private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call, Configuration config
 ) {
-  exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-    p.isParameterOf(callable, i) and
+  exists(ParameterPosition pos, DataFlowCallable callable, AccessPath ap |
+    pathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+    p.isParameterOf(callable, pos) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
@@ -3692,7 +3713,7 @@ private predicate paramFlowsThrough(
   ReturnKindExt kind, CallContextCall cc, SummaryCtxSome sc, AccessPath ap, AccessPathApprox apa,
   Configuration config
 ) {
-  exists(PathNodeMid mid, RetNodeEx ret, int pos |
+  exists(PathNodeMid mid, RetNodeEx ret, ParameterPosition pos |
     mid.getNodeEx() = ret and
     kind = ret.getKind() and
     cc = mid.getCallContext() and
@@ -3740,13 +3761,14 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
     exists(Configuration config |
       pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
       pathIntoCallable(arg, par, _, innercc, sc, _, config) and
-      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config))
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
     )
   }
 
@@ -3780,8 +3802,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3790,11 +3821,12 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
       pragma[only_bind_into](arg).getASuccessor() = par and
       pragma[only_bind_into](arg).getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
@@ -4410,24 +4442,25 @@ private module FlowExploration {
 
   pragma[noinline]
   private predicate partialPathIntoArg(
-    PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
-    Configuration config
+    PartialPathNodeFwd mid, ParameterPosition ppos, CallContext cc, DataFlowCall call,
+    PartialAccessPath ap, Configuration config
   ) {
-    exists(ArgNode arg |
+    exists(ArgNode arg, ArgumentPosition apos |
       arg = mid.getNodeEx().asNode() and
       cc = mid.getCallContext() and
-      arg.argumentOf(call, i) and
+      arg.argumentOf(call, apos) and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate partialPathIntoCallable0(
-    PartialPathNodeFwd mid, DataFlowCallable callable, int i, CallContext outercc,
+    PartialPathNodeFwd mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
     DataFlowCall call, PartialAccessPath ap, Configuration config
   ) {
-    partialPathIntoArg(mid, i, outercc, call, ap, config) and
+    partialPathIntoArg(mid, pos, outercc, call, ap, config) and
     callable = resolveCall(call, outercc)
   }
 
@@ -4436,9 +4469,9 @@ private module FlowExploration {
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(int i, DataFlowCallable callable |
-      partialPathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-      p.isParameterOf(callable, i) and
+    exists(ParameterPosition pos, DataFlowCallable callable |
+      partialPathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+      p.isParameterOf(callable, pos) and
       sc1 = TSummaryCtx1Param(p) and
       sc2 = TSummaryCtx2Some(ap)
     |
@@ -4602,22 +4635,23 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathFlowsThrough(
-    int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
-    Configuration config
+    ArgumentPosition apos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2,
+    RevPartialAccessPath ap, Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParamNodeEx p |
+    exists(PartialPathNodeRev mid, ParamNodeEx p, ParameterPosition ppos |
       mid.getNodeEx() = p and
-      p.getPosition() = pos and
+      p.getPosition() = ppos and
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable0(
-    DataFlowCall call, PartialPathNodeRev mid, int pos, RevPartialAccessPath ap,
+    DataFlowCall call, PartialPathNodeRev mid, ArgumentPosition pos, RevPartialAccessPath ap,
     Configuration config
   ) {
     exists(TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2 |
@@ -4630,7 +4664,7 @@ private module FlowExploration {
   private predicate revPartialPathThroughCallable(
     PartialPathNodeRev mid, ArgNodeEx node, RevPartialAccessPath ap, Configuration config
   ) {
-    exists(DataFlowCall call, int pos |
+    exists(DataFlowCall call, ArgumentPosition pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and
       node.asNode().(ArgNode).argumentOf(call, pos)
     )

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll

@@ -256,11 +256,11 @@ private class ArgNodeEx extends NodeEx {
 private class ParamNodeEx extends NodeEx {
   ParamNodeEx() { this.asNode() instanceof ParamNode }
 
-  predicate isParameterOf(DataFlowCallable c, int i) {
-    this.asNode().(ParamNode).isParameterOf(c, i)
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
+    this.asNode().(ParamNode).isParameterOf(c, pos)
   }
 
-  int getPosition() { this.isParameterOf(_, result) }
+  ParameterPosition getPosition() { this.isParameterOf(_, result) }
 
   predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1427,7 +1447,7 @@ private module Stage2 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2122,7 +2142,7 @@ private module Stage3 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2888,7 +2908,7 @@ private module Stage4 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2972,7 +2992,7 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
 
-  int getParameterPos() { p.isParameterOf(_, result) }
+  ParameterPosition getParameterPos() { p.isParameterOf(_, result) }
 
   ParamNodeEx getParamNode() { result = p }
 
@@ -3619,39 +3639,40 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
-  Configuration config
+  PathNodeMid mid, ParameterPosition ppos, CallContext cc, DataFlowCall call, AccessPath ap,
+  AccessPathApprox apa, Configuration config
 ) {
-  exists(ArgNode arg |
+  exists(ArgNode arg, ArgumentPosition apos |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
-    arg.argumentOf(call, i) and
+    arg.argumentOf(call, apos) and
     ap = mid.getAp() and
     apa = ap.getApprox() and
-    config = mid.getConfiguration()
+    config = mid.getConfiguration() and
+    parameterMatch(ppos, apos)
   )
 }
 
 pragma[nomagic]
 private predicate parameterCand(
-  DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
+  DataFlowCallable callable, ParameterPosition pos, AccessPathApprox apa, Configuration config
 ) {
   exists(ParamNodeEx p |
     Stage4::revFlow(p, _, _, apa, config) and
-    p.isParameterOf(callable, i)
+    p.isParameterOf(callable, pos)
   )
 }
 
 pragma[nomagic]
 private predicate pathIntoCallable0(
-  PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap, Configuration config
+  PathNodeMid mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
+  DataFlowCall call, AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+    pathIntoArg(mid, pragma[only_bind_into](pos), outercc, call, ap, pragma[only_bind_into](apa),
       pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+    parameterCand(callable, pragma[only_bind_into](pos), pragma[only_bind_into](apa),
       pragma[only_bind_into](config))
   )
 }
@@ -3666,9 +3687,9 @@ private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call, Configuration config
 ) {
-  exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-    p.isParameterOf(callable, i) and
+  exists(ParameterPosition pos, DataFlowCallable callable, AccessPath ap |
+    pathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+    p.isParameterOf(callable, pos) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
@@ -3692,7 +3713,7 @@ private predicate paramFlowsThrough(
   ReturnKindExt kind, CallContextCall cc, SummaryCtxSome sc, AccessPath ap, AccessPathApprox apa,
   Configuration config
 ) {
-  exists(PathNodeMid mid, RetNodeEx ret, int pos |
+  exists(PathNodeMid mid, RetNodeEx ret, ParameterPosition pos |
     mid.getNodeEx() = ret and
     kind = ret.getKind() and
     cc = mid.getCallContext() and
@@ -3740,13 +3761,14 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
     exists(Configuration config |
       pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
       pathIntoCallable(arg, par, _, innercc, sc, _, config) and
-      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config))
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
     )
   }
 
@@ -3780,8 +3802,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3790,11 +3821,12 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
       pragma[only_bind_into](arg).getASuccessor() = par and
       pragma[only_bind_into](arg).getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
@@ -4410,24 +4442,25 @@ private module FlowExploration {
 
   pragma[noinline]
   private predicate partialPathIntoArg(
-    PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
-    Configuration config
+    PartialPathNodeFwd mid, ParameterPosition ppos, CallContext cc, DataFlowCall call,
+    PartialAccessPath ap, Configuration config
   ) {
-    exists(ArgNode arg |
+    exists(ArgNode arg, ArgumentPosition apos |
       arg = mid.getNodeEx().asNode() and
       cc = mid.getCallContext() and
-      arg.argumentOf(call, i) and
+      arg.argumentOf(call, apos) and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate partialPathIntoCallable0(
-    PartialPathNodeFwd mid, DataFlowCallable callable, int i, CallContext outercc,
+    PartialPathNodeFwd mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
     DataFlowCall call, PartialAccessPath ap, Configuration config
   ) {
-    partialPathIntoArg(mid, i, outercc, call, ap, config) and
+    partialPathIntoArg(mid, pos, outercc, call, ap, config) and
     callable = resolveCall(call, outercc)
   }
 
@@ -4436,9 +4469,9 @@ private module FlowExploration {
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(int i, DataFlowCallable callable |
-      partialPathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-      p.isParameterOf(callable, i) and
+    exists(ParameterPosition pos, DataFlowCallable callable |
+      partialPathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+      p.isParameterOf(callable, pos) and
       sc1 = TSummaryCtx1Param(p) and
       sc2 = TSummaryCtx2Some(ap)
     |
@@ -4602,22 +4635,23 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathFlowsThrough(
-    int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
-    Configuration config
+    ArgumentPosition apos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2,
+    RevPartialAccessPath ap, Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParamNodeEx p |
+    exists(PartialPathNodeRev mid, ParamNodeEx p, ParameterPosition ppos |
       mid.getNodeEx() = p and
-      p.getPosition() = pos and
+      p.getPosition() = ppos and
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable0(
-    DataFlowCall call, PartialPathNodeRev mid, int pos, RevPartialAccessPath ap,
+    DataFlowCall call, PartialPathNodeRev mid, ArgumentPosition pos, RevPartialAccessPath ap,
     Configuration config
   ) {
     exists(TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2 |
@@ -4630,7 +4664,7 @@ private module FlowExploration {
   private predicate revPartialPathThroughCallable(
     PartialPathNodeRev mid, ArgNodeEx node, RevPartialAccessPath ap, Configuration config
   ) {
-    exists(DataFlowCall call, int pos |
+    exists(DataFlowCall call, ArgumentPosition pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and
       node.asNode().(ArgNode).argumentOf(call, pos)
     )

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll

@@ -256,11 +256,11 @@ private class ArgNodeEx extends NodeEx {
 private class ParamNodeEx extends NodeEx {
   ParamNodeEx() { this.asNode() instanceof ParamNode }
 
-  predicate isParameterOf(DataFlowCallable c, int i) {
-    this.asNode().(ParamNode).isParameterOf(c, i)
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
+    this.asNode().(ParamNode).isParameterOf(c, pos)
   }
 
-  int getPosition() { this.isParameterOf(_, result) }
+  ParameterPosition getPosition() { this.isParameterOf(_, result) }
 
   predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1427,7 +1447,7 @@ private module Stage2 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2122,7 +2142,7 @@ private module Stage3 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2888,7 +2908,7 @@ private module Stage4 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2972,7 +2992,7 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
 
-  int getParameterPos() { p.isParameterOf(_, result) }
+  ParameterPosition getParameterPos() { p.isParameterOf(_, result) }
 
   ParamNodeEx getParamNode() { result = p }
 
@@ -3619,39 +3639,40 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
-  Configuration config
+  PathNodeMid mid, ParameterPosition ppos, CallContext cc, DataFlowCall call, AccessPath ap,
+  AccessPathApprox apa, Configuration config
 ) {
-  exists(ArgNode arg |
+  exists(ArgNode arg, ArgumentPosition apos |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
-    arg.argumentOf(call, i) and
+    arg.argumentOf(call, apos) and
     ap = mid.getAp() and
     apa = ap.getApprox() and
-    config = mid.getConfiguration()
+    config = mid.getConfiguration() and
+    parameterMatch(ppos, apos)
   )
 }
 
 pragma[nomagic]
 private predicate parameterCand(
-  DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
+  DataFlowCallable callable, ParameterPosition pos, AccessPathApprox apa, Configuration config
 ) {
   exists(ParamNodeEx p |
     Stage4::revFlow(p, _, _, apa, config) and
-    p.isParameterOf(callable, i)
+    p.isParameterOf(callable, pos)
   )
 }
 
 pragma[nomagic]
 private predicate pathIntoCallable0(
-  PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap, Configuration config
+  PathNodeMid mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
+  DataFlowCall call, AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+    pathIntoArg(mid, pragma[only_bind_into](pos), outercc, call, ap, pragma[only_bind_into](apa),
       pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+    parameterCand(callable, pragma[only_bind_into](pos), pragma[only_bind_into](apa),
       pragma[only_bind_into](config))
   )
 }
@@ -3666,9 +3687,9 @@ private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call, Configuration config
 ) {
-  exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-    p.isParameterOf(callable, i) and
+  exists(ParameterPosition pos, DataFlowCallable callable, AccessPath ap |
+    pathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+    p.isParameterOf(callable, pos) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
@@ -3692,7 +3713,7 @@ private predicate paramFlowsThrough(
   ReturnKindExt kind, CallContextCall cc, SummaryCtxSome sc, AccessPath ap, AccessPathApprox apa,
   Configuration config
 ) {
-  exists(PathNodeMid mid, RetNodeEx ret, int pos |
+  exists(PathNodeMid mid, RetNodeEx ret, ParameterPosition pos |
     mid.getNodeEx() = ret and
     kind = ret.getKind() and
     cc = mid.getCallContext() and
@@ -3740,13 +3761,14 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
     exists(Configuration config |
       pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
       pathIntoCallable(arg, par, _, innercc, sc, _, config) and
-      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config))
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
     )
   }
 
@@ -3780,8 +3802,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3790,11 +3821,12 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
       pragma[only_bind_into](arg).getASuccessor() = par and
       pragma[only_bind_into](arg).getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
@@ -4410,24 +4442,25 @@ private module FlowExploration {
 
   pragma[noinline]
   private predicate partialPathIntoArg(
-    PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
-    Configuration config
+    PartialPathNodeFwd mid, ParameterPosition ppos, CallContext cc, DataFlowCall call,
+    PartialAccessPath ap, Configuration config
   ) {
-    exists(ArgNode arg |
+    exists(ArgNode arg, ArgumentPosition apos |
       arg = mid.getNodeEx().asNode() and
       cc = mid.getCallContext() and
-      arg.argumentOf(call, i) and
+      arg.argumentOf(call, apos) and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate partialPathIntoCallable0(
-    PartialPathNodeFwd mid, DataFlowCallable callable, int i, CallContext outercc,
+    PartialPathNodeFwd mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
     DataFlowCall call, PartialAccessPath ap, Configuration config
   ) {
-    partialPathIntoArg(mid, i, outercc, call, ap, config) and
+    partialPathIntoArg(mid, pos, outercc, call, ap, config) and
     callable = resolveCall(call, outercc)
   }
 
@@ -4436,9 +4469,9 @@ private module FlowExploration {
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(int i, DataFlowCallable callable |
-      partialPathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-      p.isParameterOf(callable, i) and
+    exists(ParameterPosition pos, DataFlowCallable callable |
+      partialPathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+      p.isParameterOf(callable, pos) and
       sc1 = TSummaryCtx1Param(p) and
       sc2 = TSummaryCtx2Some(ap)
     |
@@ -4602,22 +4635,23 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathFlowsThrough(
-    int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
-    Configuration config
+    ArgumentPosition apos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2,
+    RevPartialAccessPath ap, Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParamNodeEx p |
+    exists(PartialPathNodeRev mid, ParamNodeEx p, ParameterPosition ppos |
       mid.getNodeEx() = p and
-      p.getPosition() = pos and
+      p.getPosition() = ppos and
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable0(
-    DataFlowCall call, PartialPathNodeRev mid, int pos, RevPartialAccessPath ap,
+    DataFlowCall call, PartialPathNodeRev mid, ArgumentPosition pos, RevPartialAccessPath ap,
     Configuration config
   ) {
     exists(TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2 |
@@ -4630,7 +4664,7 @@ private module FlowExploration {
   private predicate revPartialPathThroughCallable(
     PartialPathNodeRev mid, ArgNodeEx node, RevPartialAccessPath ap, Configuration config
   ) {
-    exists(DataFlowCall call, int pos |
+    exists(DataFlowCall call, ArgumentPosition pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and
       node.asNode().(ArgNode).argumentOf(call, pos)
     )

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll

@@ -256,11 +256,11 @@ private class ArgNodeEx extends NodeEx {
 private class ParamNodeEx extends NodeEx {
   ParamNodeEx() { this.asNode() instanceof ParamNode }
 
-  predicate isParameterOf(DataFlowCallable c, int i) {
-    this.asNode().(ParamNode).isParameterOf(c, i)
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
+    this.asNode().(ParamNode).isParameterOf(c, pos)
   }
 
-  int getPosition() { this.isParameterOf(_, result) }
+  ParameterPosition getPosition() { this.isParameterOf(_, result) }
 
   predicate allowParameterReturnInSelf() { allowParameterReturnInSelfCached(this.asNode()) }
 }
@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1427,7 +1447,7 @@ private module Stage2 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2122,7 +2142,7 @@ private module Stage3 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2888,7 +2908,7 @@ private module Stage4 {
   }
 
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
-    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, int pos |
+    exists(RetNodeEx ret, Ap ap0, ReturnKindExt kind, ParameterPosition pos |
       parameterFlow(p, ap, ap0, c, config) and
       c = ret.getEnclosingCallable() and
       revFlow(pragma[only_bind_into](ret), true, apSome(_), pragma[only_bind_into](ap0),
@@ -2972,7 +2992,7 @@ private class SummaryCtxSome extends SummaryCtx, TSummaryCtxSome {
 
   SummaryCtxSome() { this = TSummaryCtxSome(p, ap) }
 
-  int getParameterPos() { p.isParameterOf(_, result) }
+  ParameterPosition getParameterPos() { p.isParameterOf(_, result) }
 
   ParamNodeEx getParamNode() { result = p }
 
@@ -3619,39 +3639,40 @@ private predicate pathOutOfCallable(PathNodeMid mid, NodeEx out, CallContext cc)
  */
 pragma[noinline]
 private predicate pathIntoArg(
-  PathNodeMid mid, int i, CallContext cc, DataFlowCall call, AccessPath ap, AccessPathApprox apa,
-  Configuration config
+  PathNodeMid mid, ParameterPosition ppos, CallContext cc, DataFlowCall call, AccessPath ap,
+  AccessPathApprox apa, Configuration config
 ) {
-  exists(ArgNode arg |
+  exists(ArgNode arg, ArgumentPosition apos |
     arg = mid.getNodeEx().asNode() and
     cc = mid.getCallContext() and
-    arg.argumentOf(call, i) and
+    arg.argumentOf(call, apos) and
     ap = mid.getAp() and
     apa = ap.getApprox() and
-    config = mid.getConfiguration()
+    config = mid.getConfiguration() and
+    parameterMatch(ppos, apos)
   )
 }
 
 pragma[nomagic]
 private predicate parameterCand(
-  DataFlowCallable callable, int i, AccessPathApprox apa, Configuration config
+  DataFlowCallable callable, ParameterPosition pos, AccessPathApprox apa, Configuration config
 ) {
   exists(ParamNodeEx p |
     Stage4::revFlow(p, _, _, apa, config) and
-    p.isParameterOf(callable, i)
+    p.isParameterOf(callable, pos)
   )
 }
 
 pragma[nomagic]
 private predicate pathIntoCallable0(
-  PathNodeMid mid, DataFlowCallable callable, int i, CallContext outercc, DataFlowCall call,
-  AccessPath ap, Configuration config
+  PathNodeMid mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
+  DataFlowCall call, AccessPath ap, Configuration config
 ) {
   exists(AccessPathApprox apa |
-    pathIntoArg(mid, pragma[only_bind_into](i), outercc, call, ap, pragma[only_bind_into](apa),
+    pathIntoArg(mid, pragma[only_bind_into](pos), outercc, call, ap, pragma[only_bind_into](apa),
       pragma[only_bind_into](config)) and
     callable = resolveCall(call, outercc) and
-    parameterCand(callable, pragma[only_bind_into](i), pragma[only_bind_into](apa),
+    parameterCand(callable, pragma[only_bind_into](pos), pragma[only_bind_into](apa),
       pragma[only_bind_into](config))
   )
 }
@@ -3666,9 +3687,9 @@ private predicate pathIntoCallable(
   PathNodeMid mid, ParamNodeEx p, CallContext outercc, CallContextCall innercc, SummaryCtx sc,
   DataFlowCall call, Configuration config
 ) {
-  exists(int i, DataFlowCallable callable, AccessPath ap |
-    pathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-    p.isParameterOf(callable, i) and
+  exists(ParameterPosition pos, DataFlowCallable callable, AccessPath ap |
+    pathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+    p.isParameterOf(callable, pos) and
     (
       sc = TSummaryCtxSome(p, ap)
       or
@@ -3692,7 +3713,7 @@ private predicate paramFlowsThrough(
   ReturnKindExt kind, CallContextCall cc, SummaryCtxSome sc, AccessPath ap, AccessPathApprox apa,
   Configuration config
 ) {
-  exists(PathNodeMid mid, RetNodeEx ret, int pos |
+  exists(PathNodeMid mid, RetNodeEx ret, ParameterPosition pos |
     mid.getNodeEx() = ret and
     kind = ret.getKind() and
     cc = mid.getCallContext() and
@@ -3740,13 +3761,14 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths01(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, AccessPath apout
   ) {
     exists(Configuration config |
       pathThroughCallable(arg, out, _, pragma[only_bind_into](apout)) and
       pathIntoCallable(arg, par, _, innercc, sc, _, config) and
-      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config))
+      paramFlowsThrough(kind, innercc, sc, pragma[only_bind_into](apout), _, unbindConf(config)) and
+      not arg.isHidden()
     )
   }
 
@@ -3780,8 +3802,17 @@ private module Subpaths {
       innercc = ret.getCallContext() and
       sc = ret.getSummaryCtx() and
       ret.getConfiguration() = unbindConf(getPathNodeConf(arg)) and
-      apout = ret.getAp() and
-      not ret.isHidden()
+      apout = ret.getAp()
+    )
+  }
+
+  private PathNodeImpl localStepToHidden(PathNodeImpl n) {
+    n.getASuccessorImpl() = result and
+    result.isHidden() and
+    exists(NodeEx n1, NodeEx n2 | n1 = n.getNodeEx() and n2 = result.getNodeEx() |
+      localFlowBigStep(n1, n2, _, _, _, _) or
+      store(n1, _, n2, _, _) or
+      read(n1, _, n2, _)
     )
   }
 
@@ -3790,11 +3821,12 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeMid ret, PathNodeMid out) {
+  predicate subpaths(PathNode arg, PathNodeImpl par, PathNodeImpl ret, PathNodeMid out) {
     exists(ParamNodeEx p, NodeEx o, AccessPath apout |
       pragma[only_bind_into](arg).getASuccessor() = par and
       pragma[only_bind_into](arg).getASuccessor() = out and
-      subpaths03(arg, p, ret, o, apout) and
+      subpaths03(arg, p, localStepToHidden*(ret), o, apout) and
+      not ret.isHidden() and
       par.getNodeEx() = p and
       out.getNodeEx() = o and
       out.getAp() = apout
@@ -4410,24 +4442,25 @@ private module FlowExploration {
 
   pragma[noinline]
   private predicate partialPathIntoArg(
-    PartialPathNodeFwd mid, int i, CallContext cc, DataFlowCall call, PartialAccessPath ap,
-    Configuration config
+    PartialPathNodeFwd mid, ParameterPosition ppos, CallContext cc, DataFlowCall call,
+    PartialAccessPath ap, Configuration config
   ) {
-    exists(ArgNode arg |
+    exists(ArgNode arg, ArgumentPosition apos |
       arg = mid.getNodeEx().asNode() and
       cc = mid.getCallContext() and
-      arg.argumentOf(call, i) and
+      arg.argumentOf(call, apos) and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate partialPathIntoCallable0(
-    PartialPathNodeFwd mid, DataFlowCallable callable, int i, CallContext outercc,
+    PartialPathNodeFwd mid, DataFlowCallable callable, ParameterPosition pos, CallContext outercc,
     DataFlowCall call, PartialAccessPath ap, Configuration config
   ) {
-    partialPathIntoArg(mid, i, outercc, call, ap, config) and
+    partialPathIntoArg(mid, pos, outercc, call, ap, config) and
     callable = resolveCall(call, outercc)
   }
 
@@ -4436,9 +4469,9 @@ private module FlowExploration {
     TSummaryCtx1 sc1, TSummaryCtx2 sc2, DataFlowCall call, PartialAccessPath ap,
     Configuration config
   ) {
-    exists(int i, DataFlowCallable callable |
-      partialPathIntoCallable0(mid, callable, i, outercc, call, ap, config) and
-      p.isParameterOf(callable, i) and
+    exists(ParameterPosition pos, DataFlowCallable callable |
+      partialPathIntoCallable0(mid, callable, pos, outercc, call, ap, config) and
+      p.isParameterOf(callable, pos) and
       sc1 = TSummaryCtx1Param(p) and
       sc2 = TSummaryCtx2Some(ap)
     |
@@ -4602,22 +4635,23 @@ private module FlowExploration {
 
   pragma[nomagic]
   private predicate revPartialPathFlowsThrough(
-    int pos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2, RevPartialAccessPath ap,
-    Configuration config
+    ArgumentPosition apos, TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2,
+    RevPartialAccessPath ap, Configuration config
   ) {
-    exists(PartialPathNodeRev mid, ParamNodeEx p |
+    exists(PartialPathNodeRev mid, ParamNodeEx p, ParameterPosition ppos |
       mid.getNodeEx() = p and
-      p.getPosition() = pos and
+      p.getPosition() = ppos and
       sc1 = mid.getSummaryCtx1() and
       sc2 = mid.getSummaryCtx2() and
       ap = mid.getAp() and
-      config = mid.getConfiguration()
+      config = mid.getConfiguration() and
+      parameterMatch(ppos, apos)
     )
   }
 
   pragma[nomagic]
   private predicate revPartialPathThroughCallable0(
-    DataFlowCall call, PartialPathNodeRev mid, int pos, RevPartialAccessPath ap,
+    DataFlowCall call, PartialPathNodeRev mid, ArgumentPosition pos, RevPartialAccessPath ap,
     Configuration config
   ) {
     exists(TRevSummaryCtx1Some sc1, TRevSummaryCtx2Some sc2 |
@@ -4630,7 +4664,7 @@ private module FlowExploration {
   private predicate revPartialPathThroughCallable(
     PartialPathNodeRev mid, ArgNodeEx node, RevPartialAccessPath ap, Configuration config
   ) {
-    exists(DataFlowCall call, int pos |
+    exists(DataFlowCall call, ArgumentPosition pos |
       revPartialPathThroughCallable0(call, mid, pos, ap, config) and
       node.asNode().(ArgNode).argumentOf(call, pos)
     )

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll

@@ -62,6 +62,18 @@ predicate accessPathCostLimits(int apLimit, int tupleLimit) {
   tupleLimit = 1000
 }
 
+/**
+ * Holds if `arg` is an argument of `call` with an argument position that matches
+ * parameter position `ppos`.
+ */
+pragma[noinline]
+predicate argumentPositionMatch(DataFlowCall call, ArgNode arg, ParameterPosition ppos) {
+  exists(ArgumentPosition apos |
+    arg.argumentOf(call, apos) and
+    parameterMatch(ppos, apos)
+  )
+}
+
 /**
  * Provides a simple data-flow analysis for resolving lambda calls. The analysis
  * currently excludes read-steps, store-steps, and flow-through.
@@ -71,25 +83,27 @@ predicate accessPathCostLimits(int apLimit, int tupleLimit) {
  * calls. For this reason, we cannot reuse the code from `DataFlowImpl.qll` directly.
  */
 private module LambdaFlow {
-  private predicate viableParamNonLambda(DataFlowCall call, int i, ParamNode p) {
-    p.isParameterOf(viableCallable(call), i)
+  pragma[noinline]
+  private predicate viableParamNonLambda(DataFlowCall call, ParameterPosition ppos, ParamNode p) {
+    p.isParameterOf(viableCallable(call), ppos)
   }
 
-  private predicate viableParamLambda(DataFlowCall call, int i, ParamNode p) {
-    p.isParameterOf(viableCallableLambda(call, _), i)
+  pragma[noinline]
+  private predicate viableParamLambda(DataFlowCall call, ParameterPosition ppos, ParamNode p) {
+    p.isParameterOf(viableCallableLambda(call, _), ppos)
   }
 
   private predicate viableParamArgNonLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
-    exists(int i |
-      viableParamNonLambda(call, i, p) and
-      arg.argumentOf(call, i)
+    exists(ParameterPosition ppos |
+      viableParamNonLambda(call, ppos, p) and
+      argumentPositionMatch(call, arg, ppos)
     )
   }
 
   private predicate viableParamArgLambda(DataFlowCall call, ParamNode p, ArgNode arg) {
-    exists(int i |
-      viableParamLambda(call, i, p) and
-      arg.argumentOf(call, i)
+    exists(ParameterPosition ppos |
+      viableParamLambda(call, ppos, p) and
+      argumentPositionMatch(call, arg, ppos)
     )
   }
 
@@ -322,7 +336,7 @@ private module Cached {
     or
     exists(ArgNode arg |
       result.(PostUpdateNode).getPreUpdateNode() = arg and
-      arg.argumentOf(call, k.(ParamUpdateReturnKind).getPosition())
+      arg.argumentOf(call, k.(ParamUpdateReturnKind).getAMatchingArgumentPosition())
     )
   }
 
@@ -330,7 +344,7 @@ private module Cached {
   predicate returnNodeExt(Node n, ReturnKindExt k) {
     k = TValueReturn(n.(ReturnNode).getKind())
     or
-    exists(ParamNode p, int pos |
+    exists(ParamNode p, ParameterPosition pos |
       parameterValueFlowsToPreUpdate(p, n) and
       p.isParameterOf(_, pos) and
       k = TParamUpdate(pos)
@@ -352,11 +366,13 @@ private module Cached {
   }
 
   cached
-  predicate parameterNode(Node p, DataFlowCallable c, int pos) { isParameterNode(p, c, pos) }
+  predicate parameterNode(Node p, DataFlowCallable c, ParameterPosition pos) {
+    isParameterNode(p, c, pos)
+  }
 
   cached
-  predicate argumentNode(Node n, DataFlowCall call, int pos) {
-    n.(ArgumentNode).argumentOf(call, pos)
+  predicate argumentNode(Node n, DataFlowCall call, ArgumentPosition pos) {
+    isArgumentNode(n, call, pos)
   }
 
   /**
@@ -374,12 +390,12 @@ private module Cached {
   }
 
   /**
-   * Holds if `p` is the `i`th parameter of a viable dispatch target of `call`.
-   * The instance parameter is considered to have index `-1`.
+   * Holds if `p` is the parameter of a viable dispatch target of `call`,
+   * and `p` has position `ppos`.
    */
   pragma[nomagic]
-  private predicate viableParam(DataFlowCall call, int i, ParamNode p) {
-    p.isParameterOf(viableCallableExt(call), i)
+  private predicate viableParam(DataFlowCall call, ParameterPosition ppos, ParamNode p) {
+    p.isParameterOf(viableCallableExt(call), ppos)
   }
 
   /**
@@ -388,9 +404,9 @@ private module Cached {
    */
   cached
   predicate viableParamArg(DataFlowCall call, ParamNode p, ArgNode arg) {
-    exists(int i |
-      viableParam(call, i, p) and
-      arg.argumentOf(call, i) and
+    exists(ParameterPosition ppos |
+      viableParam(call, ppos, p) and
+      argumentPositionMatch(call, arg, ppos) and
       compatibleTypes(getNodeDataFlowType(arg), getNodeDataFlowType(p))
     )
   }
@@ -862,7 +878,7 @@ private module Cached {
   cached
   newtype TReturnKindExt =
     TValueReturn(ReturnKind kind) or
-    TParamUpdate(int pos) { exists(ParamNode p | p.isParameterOf(_, pos)) }
+    TParamUpdate(ParameterPosition pos) { exists(ParamNode p | p.isParameterOf(_, pos)) }
 
   cached
   newtype TBooleanOption =
@@ -1054,9 +1070,9 @@ class ParamNode extends Node {
 
   /**
    * Holds if this node is the parameter of callable `c` at the specified
-   * (zero-based) position.
+   * position.
    */
-  predicate isParameterOf(DataFlowCallable c, int i) { parameterNode(this, c, i) }
+  predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) { parameterNode(this, c, pos) }
 }
 
 /** A data-flow node that represents a call argument. */
@@ -1064,7 +1080,9 @@ class ArgNode extends Node {
   ArgNode() { argumentNode(this, _, _) }
 
   /** Holds if this argument occurs at the given position in the given call. */
-  final predicate argumentOf(DataFlowCall call, int pos) { argumentNode(this, call, pos) }
+  final predicate argumentOf(DataFlowCall call, ArgumentPosition pos) {
+    argumentNode(this, call, pos)
+  }
 }
 
 /**
@@ -1110,11 +1128,14 @@ class ValueReturnKind extends ReturnKindExt, TValueReturn {
 }
 
 class ParamUpdateReturnKind extends ReturnKindExt, TParamUpdate {
-  private int pos;
+  private ParameterPosition pos;
 
   ParamUpdateReturnKind() { this = TParamUpdate(pos) }
 
-  int getPosition() { result = pos }
+  ParameterPosition getPosition() { result = pos }
+
+  pragma[nomagic]
+  ArgumentPosition getAMatchingArgumentPosition() { parameterMatch(pos, result) }
 
   override string toString() { result = "param update " + pos }
 }

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImplConsistency.qll

@@ -9,6 +9,19 @@ private import tainttracking1.TaintTrackingParameter::Private
 private import tainttracking1.TaintTrackingParameter::Public
 
 module Consistency {
+  private newtype TConsistencyConfiguration = MkConsistencyConfiguration()
+
+  /** A class for configuring the consistency queries. */
+  class ConsistencyConfiguration extends TConsistencyConfiguration {
+    string toString() { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `postWithInFlow`. */
+    predicate postWithInFlowExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `argHasPostUpdate`. */
+    predicate argHasPostUpdateExclude(ArgumentNode n) { none() }
+  }
+
   private class RelevantNode extends Node {
     RelevantNode() {
       this instanceof ArgumentNode or
@@ -164,7 +177,7 @@ module Consistency {
 
   query predicate argHasPostUpdate(ArgumentNode n, string msg) {
     not hasPost(n) and
-    not isImmutableOrUnobservable(n) and
+    not any(ConsistencyConfiguration c).argHasPostUpdateExclude(n) and
     msg = "ArgumentNode is missing PostUpdateNode."
   }
 
@@ -177,6 +190,7 @@ module Consistency {
     isPostUpdateNode(n) and
     not clearsContent(n, _) and
     simpleLocalFlowStep(_, n) and
+    not any(ConsistencyConfiguration c).postWithInFlowExclude(n) and
     msg = "PostUpdateNode should not be the target of local flow."
   }
 }

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll

@@ -2,12 +2,20 @@ private import cpp
 private import DataFlowUtil
 private import semmle.code.cpp.ir.IR
 private import DataFlowDispatch
+private import DataFlowImplConsistency
 
 /** Gets the callable in which this node occurs. */
 DataFlowCallable nodeGetEnclosingCallable(Node n) { result = n.getEnclosingCallable() }
 
 /** Holds if `p` is a `ParameterNode` of `c` with position `pos`. */
-predicate isParameterNode(ParameterNode p, DataFlowCallable c, int pos) { p.isParameterOf(c, pos) }
+predicate isParameterNode(ParameterNode p, DataFlowCallable c, ParameterPosition pos) {
+  p.isParameterOf(c, pos)
+}
+
+/** Holds if `arg` is an `ArgumentNode` of `c` with position `pos`. */
+predicate isArgumentNode(ArgumentNode arg, DataFlowCall c, ArgumentPosition pos) {
+  arg.argumentOf(c, pos)
+}
 
 /**
  * A data flow node that occurs as the argument of a call and is passed as-is
@@ -285,21 +293,18 @@ class Unit extends TUnit {
   string toString() { result = "unit" }
 }
 
-/**
- * Holds if `n` does not require a `PostUpdateNode` as it either cannot be
- * modified or its modification cannot be observed, for example if it is a
- * freshly created object that is not saved in a variable.
- *
- * This predicate is only used for consistency checks.
- */
-predicate isImmutableOrUnobservable(Node n) {
-  // The rules for whether an IR argument gets a post-update node are too
-  // complex to model here.
-  any()
-}
-
 /** Holds if `n` should be hidden from path explanations. */
-predicate nodeIsHidden(Node n) { n instanceof OperandNode and not n instanceof ArgumentNode }
+predicate nodeIsHidden(Node n) {
+  n instanceof OperandNode and not n instanceof ArgumentNode
+  or
+  StoreNodeFlow::flowThrough(n, _) and
+  not StoreNodeFlow::flowOutOf(n, _) and
+  not StoreNodeFlow::flowInto(_, n)
+  or
+  ReadNodeFlow::flowThrough(n, _) and
+  not ReadNodeFlow::flowOutOf(n, _) and
+  not ReadNodeFlow::flowInto(_, n)
+}
 
 class LambdaCallKind = Unit;
 
@@ -320,3 +325,11 @@ predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preserves
  * by default as a heuristic.
  */
 predicate allowParameterReturnInSelf(ParameterNode p) { none() }
+
+private class MyConsistencyConfiguration extends Consistency::ConsistencyConfiguration {
+  override predicate argHasPostUpdateExclude(ArgumentNode n) {
+    // The rules for whether an IR argument gets a post-update node are too
+    // complex to model here.
+    any()
+  }
+}

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll

@@ -452,7 +452,7 @@ class SsaPhiNode extends Node, TSsaPhiNode {
 
   /** Holds if this phi node has input from the `rnk`'th write operation in block `block`. */
   final predicate hasInputAtRankInBlock(IRBlock block, int rnk) {
-    hasInputAtRankInBlock(block, rnk, _)
+    this.hasInputAtRankInBlock(block, rnk, _)
   }
 
   /**
@@ -806,7 +806,7 @@ predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
   simpleOperandLocalFlowStep(nodeFrom.asInstruction(), nodeTo.asOperand())
   or
   // Flow into, through, and out of store nodes
-  StoreNodeFlow::flowInto(nodeFrom, nodeTo)
+  StoreNodeFlow::flowInto(nodeFrom.asInstruction(), nodeTo)
   or
   StoreNodeFlow::flowThrough(nodeFrom, nodeTo)
   or
@@ -831,23 +831,19 @@ private predicate adjacentDefUseFlow(Node nodeFrom, Node nodeTo) {
     //Def-use flow
     Ssa::ssaFlow(nodeFrom, nodeTo)
     or
-    exists(Instruction loadAddress | loadAddress = Ssa::getSourceAddressFromNode(nodeFrom) |
-      // Use-use flow through reads
-      exists(Node address |
-        Ssa::addressFlowTC(address.asInstruction(), loadAddress) and
-        Ssa::ssaFlow(address, nodeTo)
-      )
-      or
-      // Use-use flow through stores.
-      exists(Node store |
-        Ssa::explicitWrite(_, store.asInstruction(), loadAddress) and
-        Ssa::ssaFlow(store, nodeTo)
-      )
+    // Use-use flow through stores.
+    exists(Instruction loadAddress, Node store |
+      loadAddress = Ssa::getSourceAddressFromNode(nodeFrom) and
+      Ssa::explicitWrite(_, store.asInstruction(), loadAddress) and
+      Ssa::ssaFlow(store, nodeTo)
     )
   )
 }
 
-private module ReadNodeFlow {
+/**
+ * INTERNAL: Do not use.
+ */
+module ReadNodeFlow {
   /** Holds if the read node `nodeTo` should receive flow from `nodeFrom`. */
   predicate flowInto(Node nodeFrom, ReadNode nodeTo) {
     nodeTo.isInitial() and
@@ -867,7 +863,12 @@ private module ReadNodeFlow {
     )
   }
 
-  /** Holds if the read node `nodeTo` should receive flow from the read node `nodeFrom`. */
+  /**
+   * Holds if the read node `nodeTo` should receive flow from the read node `nodeFrom`.
+   *
+   * This happens when `readFrom` is _not_ the source of a `readStep`, and `nodeTo` is
+   * the `ReadNode` that represents an address that directly depends on `nodeFrom`.
+   */
   predicate flowThrough(ReadNode nodeFrom, ReadNode nodeTo) {
     not readStep(nodeFrom, _, _) and
     nodeFrom.getOuter() = nodeTo
@@ -906,17 +907,25 @@ private module ReadNodeFlow {
   }
 }
 
-private module StoreNodeFlow {
+/**
+ * INTERNAL: Do not use.
+ */
+module StoreNodeFlow {
   /** Holds if the store node `nodeTo` should receive flow from `nodeFrom`. */
-  predicate flowInto(Node nodeFrom, StoreNode nodeTo) {
-    nodeTo.flowInto(Ssa::getDestinationAddress(nodeFrom.asInstruction()))
+  predicate flowInto(Instruction instrFrom, StoreNode nodeTo) {
+    nodeTo.flowInto(Ssa::getDestinationAddress(instrFrom))
   }
 
-  /** Holds if the store node `nodeTo` should receive flow from `nodeFom`. */
-  predicate flowThrough(StoreNode nFrom, StoreNode nodeTo) {
+  /**
+   * Holds if the store node `nodeTo` should receive flow from `nodeFom`.
+   *
+   * This happens when `nodeFrom` is _not_ the source of a `storeStep`, and `nodeFrom` is
+   * the `Storenode` that represents an address that directly depends on `nodeTo`.
+   */
+  predicate flowThrough(StoreNode nodeFrom, StoreNode nodeTo) {
     // Flow through a post update node that doesn't need a store step.
-    not storeStep(nFrom, _, _) and
-    nodeTo.getOuter() = nFrom
+    not storeStep(nodeFrom, _, _) and
+    nodeTo.getOuter() = nodeFrom
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaImplCommon.qll

@@ -634,3 +634,29 @@ class UncertainWriteDefinition extends WriteDefinition {
     )
   }
 }
+
+/** Provides a set of consistency queries. */
+module Consistency {
+  abstract class RelevantDefinition extends Definition {
+    abstract predicate hasLocationInfo(
+      string filepath, int startline, int startcolumn, int endline, int endcolumn
+    );
+  }
+
+  query predicate nonUniqueDef(RelevantDefinition def, SourceVariable v, BasicBlock bb, int i) {
+    ssaDefReachesRead(v, def, bb, i) and
+    not exists(unique(Definition def0 | ssaDefReachesRead(v, def0, bb, i)))
+  }
+
+  query predicate readWithoutDef(SourceVariable v, BasicBlock bb, int i) {
+    variableRead(bb, i, v, _) and
+    not ssaDefReachesRead(v, _, bb, i)
+  }
+
+  query predicate deadDef(RelevantDefinition def, SourceVariable v) {
+    v = def.getSourceVariable() and
+    not ssaDefReachesRead(_, def, _, _) and
+    not phiHasInputFromBlock(_, def, _) and
+    not uncertainWriteDefinitionInput(_, def)
+  }
+}

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaInternals.qll

@@ -244,17 +244,6 @@ Instruction getDestinationAddress(Instruction instr) {
     ]
 }
 
-class ReferenceToInstruction extends CopyValueInstruction {
-  ReferenceToInstruction() {
-    this.getResultType() instanceof Cpp::ReferenceType and
-    not this.getUnary().getResultType() instanceof Cpp::ReferenceType
-  }
-
-  Instruction getSourceAddress() { result = getSourceAddressOperand().getDef() }
-
-  Operand getSourceAddressOperand() { result = this.getUnaryOperand() }
-}
-
 /** Gets the source address of `instr` if it is an instruction that behaves like a `LoadInstruction`. */
 Instruction getSourceAddress(Instruction instr) { result = getSourceAddressOperand(instr).getDef() }
 
@@ -266,11 +255,7 @@ Operand getSourceAddressOperand(Instruction instr) {
   result =
     [
       instr.(LoadInstruction).getSourceAddressOperand(),
-      instr.(ReadSideEffectInstruction).getArgumentOperand(),
-      // `ReferenceToInstruction` is really more of an address-of operation,
-      // but by including it in this list we break out of `flowOutOfAddressStep` at an
-      // instruction that, at the source level, looks like a use of a variable.
-      instr.(ReferenceToInstruction).getSourceAddressOperand()
+      instr.(ReadSideEffectInstruction).getArgumentOperand()
     ]
 }
 
@@ -295,10 +280,6 @@ Operand getSourceValueOperand(Instruction instr) {
   result = instr.(LoadInstruction).getSourceValueOperand()
   or
   result = instr.(ReadSideEffectInstruction).getSideEffectOperand()
-  or
-  // See the comment on the `ReferenceToInstruction` disjunct in `getSourceAddressOperand` for why
-  // this case is included.
-  result = instr.(ReferenceToInstruction).getSourceValueOperand()
 }
 
 /**
@@ -513,6 +494,64 @@ private module Cached {
       explicitWrite(false, storeNode.getStoreInstruction(), def)
     )
     or
+    // The destination of a store operation has undergone lvalue-to-rvalue conversion and is now a
+    // right-hand-side of a store operation.
+    // Find the next use of the variable in that store operation, and recursively find the load of that
+    // pointer. For example, consider this case:
+    //
+    // ```cpp
+    // int x = source();
+    // int* p = &x;
+    // sink(*p);
+    // ```
+    //
+    // if we want to find the load of the address of `x`, we see that the pointer is stored into `p`,
+    // and we then need to recursively look for the load of `p`.
+    exists(
+      Def def, StoreInstruction store, IRBlock block1, int rnk1, Use use, IRBlock block2, int rnk2
+    |
+      store = def.getInstruction() and
+      store.getSourceValueOperand() = operand and
+      def.hasRankInBlock(block1, rnk1) and
+      use.hasRankInBlock(block2, rnk2) and
+      adjacentDefRead(_, block1, rnk1, block2, rnk2)
+    |
+      // The shared SSA library has determined that `use` is the next use of the operand
+      // so we find the next load of that use (but only if there is no `PostUpdateNode`) we
+      // need to flow into first.
+      not StoreNodeFlow::flowInto(store, _) and
+      flowOutOfAddressStep(use.getOperand(), nodeTo)
+      or
+      // It may also be the case that `store` gives rise to another store step. So let's make sure that
+      // we also take those into account.
+      StoreNodeFlow::flowInto(store, nodeTo)
+    )
+    or
+    // As we find the next load of an address, we might come across another use of the same variable.
+    // In that case, we recursively find the next use of _that_ operand, and continue searching for
+    // the next load of that operand. For example, consider this case:
+    //
+    // ```cpp
+    // int x = source();
+    // use(&x);
+    // int* p = &x;
+    // sink(*p);
+    // ```
+    //
+    // The next use of `x` after its definition is `use(&x)`, but there is a later load of the address
+    // of `x` that we want to flow to. So we use the shared SSA library to find the next load.
+    not operand = getSourceAddressOperand(_) and
+    exists(Use use1, Use use2, IRBlock block1, int rnk1, IRBlock block2, int rnk2 |
+      use1.getOperand() = operand and
+      use1.hasRankInBlock(block1, rnk1) and
+      // Don't flow to the next use if this use is part of a store operation that totally
+      // overrides a variable.
+      not explicitWrite(true, _, use1.getOperand().getDef()) and
+      adjacentDefRead(_, block1, rnk1, block2, rnk2) and
+      use2.hasRankInBlock(block2, rnk2) and
+      flowOutOfAddressStep(use2.getOperand(), nodeTo)
+    )
+    or
     operand = getSourceAddressOperand(nodeTo.asInstruction())
     or
     exists(ReturnIndirectionInstruction ret |

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/Operand.qll

@@ -20,6 +20,14 @@ private import internal.OperandInternal
 private class TStageOperand =
   TRegisterOperand or TNonSSAMemoryOperand or TPhiOperand or TChiOperand;
 
+/**
+ * A known location. Testing `loc instanceof KnownLocation` will account for non existing locations, as
+ * opposed to testing `not loc isntanceof UnknownLocation`
+ */
+private class KnownLocation extends Language::Location {
+  KnownLocation() { not this instanceof Language::UnknownLocation }
+}
+
 /**
  * An operand of an `Instruction`. The operand represents a use of the result of one instruction
  * (the defining instruction) in another instruction (the use instruction)
@@ -45,8 +53,10 @@ class Operand extends TStageOperand {
 
   /**
    * Gets the location of the source code for this operand.
+   * By default this is where the operand is used, but some subclasses may override this
+   * using `getAnyDef()` if it makes more sense.
    */
-  final Language::Location getLocation() { result = this.getUse().getLocation() }
+  Language::Location getLocation() { result = this.getUse().getLocation() }
 
   /**
    * Gets the function that contains this operand.
@@ -269,6 +279,10 @@ class RegisterOperand extends NonPhiOperand, TRegisterOperand {
 
   final override string toString() { result = tag.toString() }
 
+  // most `RegisterOperands` have a more meaningful location at the definition
+  // the only exception are specific cases of `ThisArgumentOperand`
+  override Language::Location getLocation() { result = this.getAnyDef().getLocation() }
+
   final override Instruction getAnyDef() { result = defInstr }
 
   final override Overlap getDefinitionOverlap() {
@@ -293,7 +307,7 @@ class NonPhiMemoryOperand extends NonPhiOperand, MemoryOperand, TNonPhiMemoryOpe
   final override string toString() { result = tag.toString() }
 
   final override Instruction getAnyDef() {
-    result = unique(Instruction defInstr | hasDefinition(defInstr, _))
+    result = unique(Instruction defInstr | this.hasDefinition(defInstr, _))
   }
 
   final override Overlap getDefinitionOverlap() { this.hasDefinition(_, result) }
@@ -401,11 +415,19 @@ class ArgumentOperand extends RegisterOperand {
 }
 
 /**
- * An operand representing the implicit 'this' argument to a member function
+ * An operand representing the implicit `this` argument to a member function
  * call.
  */
 class ThisArgumentOperand extends ArgumentOperand {
   override ThisArgumentOperandTag tag;
+
+  // in most cases the def location makes more sense, but in some corner cases it
+  // has an unknown location: in those cases we fall back to the use location
+  override Language::Location getLocation() {
+    if this.getAnyDef().getLocation() instanceof KnownLocation
+    then result = this.getAnyDef().getLocation()
+    else result = this.getUse().getLocation()
+  }
 }
 
 /**

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/Operand.qll

@@ -20,6 +20,14 @@ private import internal.OperandInternal
 private class TStageOperand =
   TRegisterOperand or TNonSSAMemoryOperand or TPhiOperand or TChiOperand;
 
+/**
+ * A known location. Testing `loc instanceof KnownLocation` will account for non existing locations, as
+ * opposed to testing `not loc isntanceof UnknownLocation`
+ */
+private class KnownLocation extends Language::Location {
+  KnownLocation() { not this instanceof Language::UnknownLocation }
+}
+
 /**
  * An operand of an `Instruction`. The operand represents a use of the result of one instruction
  * (the defining instruction) in another instruction (the use instruction)
@@ -45,8 +53,10 @@ class Operand extends TStageOperand {
 
   /**
    * Gets the location of the source code for this operand.
+   * By default this is where the operand is used, but some subclasses may override this
+   * using `getAnyDef()` if it makes more sense.
    */
-  final Language::Location getLocation() { result = this.getUse().getLocation() }
+  Language::Location getLocation() { result = this.getUse().getLocation() }
 
   /**
    * Gets the function that contains this operand.
@@ -269,6 +279,10 @@ class RegisterOperand extends NonPhiOperand, TRegisterOperand {
 
   final override string toString() { result = tag.toString() }
 
+  // most `RegisterOperands` have a more meaningful location at the definition
+  // the only exception are specific cases of `ThisArgumentOperand`
+  override Language::Location getLocation() { result = this.getAnyDef().getLocation() }
+
   final override Instruction getAnyDef() { result = defInstr }
 
   final override Overlap getDefinitionOverlap() {
@@ -293,7 +307,7 @@ class NonPhiMemoryOperand extends NonPhiOperand, MemoryOperand, TNonPhiMemoryOpe
   final override string toString() { result = tag.toString() }
 
   final override Instruction getAnyDef() {
-    result = unique(Instruction defInstr | hasDefinition(defInstr, _))
+    result = unique(Instruction defInstr | this.hasDefinition(defInstr, _))
   }
 
   final override Overlap getDefinitionOverlap() { this.hasDefinition(_, result) }
@@ -401,11 +415,19 @@ class ArgumentOperand extends RegisterOperand {
 }
 
 /**
- * An operand representing the implicit 'this' argument to a member function
+ * An operand representing the implicit `this` argument to a member function
  * call.
  */
 class ThisArgumentOperand extends ArgumentOperand {
   override ThisArgumentOperandTag tag;
+
+  // in most cases the def location makes more sense, but in some corner cases it
+  // has an unknown location: in those cases we fall back to the use location
+  override Language::Location getLocation() {
+    if this.getAnyDef().getLocation() instanceof KnownLocation
+    then result = this.getAnyDef().getLocation()
+    else result = this.getUse().getLocation()
+  }
 }
 
 /**

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/Operand.qll

@@ -20,6 +20,14 @@ private import internal.OperandInternal
 private class TStageOperand =
   TRegisterOperand or TNonSSAMemoryOperand or TPhiOperand or TChiOperand;
 
+/**
+ * A known location. Testing `loc instanceof KnownLocation` will account for non existing locations, as
+ * opposed to testing `not loc isntanceof UnknownLocation`
+ */
+private class KnownLocation extends Language::Location {
+  KnownLocation() { not this instanceof Language::UnknownLocation }
+}
+
 /**
  * An operand of an `Instruction`. The operand represents a use of the result of one instruction
  * (the defining instruction) in another instruction (the use instruction)
@@ -45,8 +53,10 @@ class Operand extends TStageOperand {
 
   /**
    * Gets the location of the source code for this operand.
+   * By default this is where the operand is used, but some subclasses may override this
+   * using `getAnyDef()` if it makes more sense.
    */
-  final Language::Location getLocation() { result = this.getUse().getLocation() }
+  Language::Location getLocation() { result = this.getUse().getLocation() }
 
   /**
    * Gets the function that contains this operand.
@@ -269,6 +279,10 @@ class RegisterOperand extends NonPhiOperand, TRegisterOperand {
 
   final override string toString() { result = tag.toString() }
 
+  // most `RegisterOperands` have a more meaningful location at the definition
+  // the only exception are specific cases of `ThisArgumentOperand`
+  override Language::Location getLocation() { result = this.getAnyDef().getLocation() }
+
   final override Instruction getAnyDef() { result = defInstr }
 
   final override Overlap getDefinitionOverlap() {
@@ -293,7 +307,7 @@ class NonPhiMemoryOperand extends NonPhiOperand, MemoryOperand, TNonPhiMemoryOpe
   final override string toString() { result = tag.toString() }
 
   final override Instruction getAnyDef() {
-    result = unique(Instruction defInstr | hasDefinition(defInstr, _))
+    result = unique(Instruction defInstr | this.hasDefinition(defInstr, _))
   }
 
   final override Overlap getDefinitionOverlap() { this.hasDefinition(_, result) }
@@ -401,11 +415,19 @@ class ArgumentOperand extends RegisterOperand {
 }
 
 /**
- * An operand representing the implicit 'this' argument to a member function
+ * An operand representing the implicit `this` argument to a member function
  * call.
  */
 class ThisArgumentOperand extends ArgumentOperand {
   override ThisArgumentOperandTag tag;
+
+  // in most cases the def location makes more sense, but in some corner cases it
+  // has an unknown location: in those cases we fall back to the use location
+  override Language::Location getLocation() {
+    if this.getAnyDef().getLocation() instanceof KnownLocation
+    then result = this.getAnyDef().getLocation()
+    else result = this.getUse().getLocation()
+  }
 }
 
 /**

cpp/ql/lib/semmle/code/cpp/models/implementations/Iterator.qll

@@ -34,6 +34,16 @@ private class IteratorByTraits extends Iterator {
   IteratorByTraits() { exists(IteratorTraits it | it.getIteratorType() = this) }
 }
 
+/**
+ * The C++ standard includes an `std::iterator_traits` specialization for pointer types. When
+ * this specialization is included in the database, a pointer type `T*` will be an instance
+ * of the `IteratorByTraits` class. However, if the `T*` specialization is not in the database,
+ * we need to explicitly include them with this class.
+ */
+private class IteratorByPointer extends Iterator instanceof PointerType {
+  IteratorByPointer() { not this instanceof IteratorByTraits }
+}
+
 /**
  * A type which has the typedefs expected for an iterator.
  */

cpp/ql/src/AlertSuppression.ql

@@ -18,12 +18,12 @@ class SuppressionComment extends Comment {
     (
       this instanceof CppStyleComment and
       // strip the beginning slashes
-      text = getContents().suffix(2)
+      text = this.getContents().suffix(2)
       or
       this instanceof CStyleComment and
       // strip both the beginning /* and the end */ the comment
       exists(string text0 |
-        text0 = getContents().suffix(2) and
+        text0 = this.getContents().suffix(2) and
         text = text0.prefix(text0.length() - 2)
       ) and
       // The /* */ comment must be a single-line comment

cpp/ql/src/Architecture/Refactoring Opportunities/ClassesWithManyFields.ql

@@ -153,12 +153,12 @@ class ExtClass extends Class {
   }
 
   predicate hasLocationInfo(string path, int startline, int startcol, int endline, int endcol) {
-    if hasOneVariableGroup()
+    if this.hasOneVariableGroup()
     then
       exists(VariableDeclarationGroup vdg | vdg.getClass() = this |
         vdg.hasLocationInfo(path, startline, startcol, endline, endcol)
       )
-    else getLocation().hasLocationInfo(path, startline, startcol, endline, endcol)
+    else this.getLocation().hasLocationInfo(path, startline, startcol, endline, endcol)
   }
 }
 

cpp/ql/src/Best Practices/Unused Entities/UnusedStaticFunctions.ql

@@ -50,6 +50,16 @@ predicate reachableThing(Thing t) {
   exists(Thing mid | reachableThing(mid) and mid.callsOrAccesses() = t)
 }
 
+pragma[nomagic]
+predicate callsOrAccessesPlus(Thing thing1, FunctionToRemove thing2) {
+  thing1.callsOrAccesses() = thing2
+  or
+  exists(Thing mid |
+    thing1.callsOrAccesses() = mid and
+    callsOrAccessesPlus(mid, thing2)
+  )
+}
+
 class Thing extends Locatable {
   Thing() {
     this instanceof Function or
@@ -81,7 +91,7 @@ class FunctionToRemove extends Function {
   }
 
   Thing getOther() {
-    result.callsOrAccesses+() = this and
+    callsOrAccessesPlus(result, this) and
     this != result and
     // We will already be reporting the enclosing function of a
     // local variable, so don't also report the variable

cpp/ql/src/CHANGELOG.md

@@ -0,0 +1,7 @@
+## 0.0.5
+
+## 0.0.4
+
+### New Queries
+
+* A new query `cpp/non-https-url` has been added for C/C++. The query flags uses of `http` URLs that might be better replaced with `https`.

cpp/ql/src/Critical/OverflowStatic.ql

@@ -103,9 +103,9 @@ class CallWithBufferSize extends FunctionCall {
     // `upperBound(e)` defaults to `exprMaxVal(e)` when `e` isn't analyzable. So to get a meaningful
     // result in this case we pick the minimum value obtainable from dataflow and range analysis.
     result =
-      upperBound(statedSizeExpr())
+      upperBound(this.statedSizeExpr())
           .minimum(min(Expr statedSizeSrc |
-              DataFlow::localExprFlow(statedSizeSrc, statedSizeExpr())
+              DataFlow::localExprFlow(statedSizeSrc, this.statedSizeExpr())
             |
               statedSizeSrc.getValue().toInt()
             ))

cpp/ql/src/JPL_C/LOC-2/Rule 09/Semaphores.qll

@@ -22,7 +22,7 @@ abstract class LockOperation extends FunctionCall {
   ControlFlowNode getAReachedNode() {
     result = this
     or
-    exists(ControlFlowNode mid | mid = getAReachedNode() |
+    exists(ControlFlowNode mid | mid = this.getAReachedNode() |
       not mid != this.getMatchingUnlock() and
       result = mid.getASuccessor()
     )

cpp/ql/src/Likely Bugs/Leap Year/LeapYear.qll

@@ -156,8 +156,8 @@ abstract class LeapYearFieldAccess extends YearFieldAccess {
     //
     // https://aa.usno.navy.mil/faq/docs/calendars.php
     this.isUsedInMod4Operation() and
-    additionalModulusCheckForLeapYear(400) and
-    additionalModulusCheckForLeapYear(100)
+    this.additionalModulusCheckForLeapYear(400) and
+    this.additionalModulusCheckForLeapYear(100)
   }
 }
 
@@ -176,17 +176,17 @@ class StructTmLeapYearFieldAccess extends LeapYearFieldAccess {
 
   override predicate isUsedInCorrectLeapYearCheck() {
     this.isUsedInMod4Operation() and
-    additionalModulusCheckForLeapYear(400) and
-    additionalModulusCheckForLeapYear(100) and
+    this.additionalModulusCheckForLeapYear(400) and
+    this.additionalModulusCheckForLeapYear(100) and
     // tm_year represents years since 1900
     (
-      additionalAdditionOrSubstractionCheckForLeapYear(1900)
+      this.additionalAdditionOrSubstractionCheckForLeapYear(1900)
       or
       // some systems may use 2000 for 2-digit year conversions
-      additionalAdditionOrSubstractionCheckForLeapYear(2000)
+      this.additionalAdditionOrSubstractionCheckForLeapYear(2000)
       or
       // converting from/to Unix epoch
-      additionalAdditionOrSubstractionCheckForLeapYear(1970)
+      this.additionalAdditionOrSubstractionCheckForLeapYear(1970)
     )
   }
 }

cpp/ql/src/Likely Bugs/Memory Management/AllocaInLoop.ql

@@ -57,7 +57,7 @@ class LoopWithAlloca extends Stmt {
     or
     // `e == 0`
     exists(EQExpr eq |
-      conditionRequires(eq, truth.booleanNot()) and
+      this.conditionRequires(eq, truth.booleanNot()) and
       eq.getAnOperand().getValue().toInt() = 0 and
       e = eq.getAnOperand() and
       not exists(e.getValue())
@@ -65,7 +65,7 @@ class LoopWithAlloca extends Stmt {
     or
     // `e != 0`
     exists(NEExpr eq |
-      conditionRequires(eq, truth) and
+      this.conditionRequires(eq, truth) and
       eq.getAnOperand().getValue().toInt() = 0 and
       e = eq.getAnOperand() and
       not exists(e.getValue())
@@ -73,7 +73,7 @@ class LoopWithAlloca extends Stmt {
     or
     // `(bool)e == true`
     exists(EQExpr eq |
-      conditionRequires(eq, truth) and
+      this.conditionRequires(eq, truth) and
       eq.getAnOperand().getValue().toInt() = 1 and
       e = eq.getAnOperand() and
       e.getUnspecifiedType() instanceof BoolType and
@@ -82,7 +82,7 @@ class LoopWithAlloca extends Stmt {
     or
     // `(bool)e != true`
     exists(NEExpr eq |
-      conditionRequires(eq, truth.booleanNot()) and
+      this.conditionRequires(eq, truth.booleanNot()) and
       eq.getAnOperand().getValue().toInt() = 1 and
       e = eq.getAnOperand() and
       e.getUnspecifiedType() instanceof BoolType and
@@ -90,7 +90,7 @@ class LoopWithAlloca extends Stmt {
     )
     or
     exists(NotExpr notExpr |
-      conditionRequires(notExpr, truth.booleanNot()) and
+      this.conditionRequires(notExpr, truth.booleanNot()) and
       e = notExpr.getOperand()
     )
     or
@@ -98,7 +98,7 @@ class LoopWithAlloca extends Stmt {
     // requires both of its operand to be true as well.
     exists(LogicalAndExpr andExpr |
       truth = true and
-      conditionRequires(andExpr, truth) and
+      this.conditionRequires(andExpr, truth) and
       e = andExpr.getAnOperand()
     )
     or
@@ -106,7 +106,7 @@ class LoopWithAlloca extends Stmt {
     // it requires both of its operand to be false as well.
     exists(LogicalOrExpr orExpr |
       truth = false and
-      conditionRequires(orExpr, truth) and
+      this.conditionRequires(orExpr, truth) and
       e = orExpr.getAnOperand()
     )
   }
@@ -141,9 +141,9 @@ class LoopWithAlloca extends Stmt {
    * `conditionRequiresInequality`.
    */
   private Variable getAControllingVariable() {
-    conditionRequires(result.getAnAccess(), _)
+    this.conditionRequires(result.getAnAccess(), _)
     or
-    conditionRequiresInequality(result.getAnAccess(), _, _)
+    this.conditionRequiresInequality(result.getAnAccess(), _, _)
   }
 
   /**

cpp/ql/src/Likely Bugs/Memory Management/NtohlArrayNoBound.qll

@@ -61,72 +61,72 @@ class PointerArithmeticAccess extends BufferAccess, Expr {
  * A pair of buffer accesses through a call to memcpy.
  */
 class MemCpy extends BufferAccess, FunctionCall {
-  MemCpy() { getTarget().hasName("memcpy") }
+  MemCpy() { this.getTarget().hasName("memcpy") }
 
   override Expr getPointer() {
-    result = getArgument(0) or
-    result = getArgument(1)
+    result = this.getArgument(0) or
+    result = this.getArgument(1)
   }
 
-  override Expr getAccessedLength() { result = getArgument(2) }
+  override Expr getAccessedLength() { result = this.getArgument(2) }
 }
 
 class StrncpySizeExpr extends BufferAccess, FunctionCall {
-  StrncpySizeExpr() { getTarget().hasName("strncpy") }
+  StrncpySizeExpr() { this.getTarget().hasName("strncpy") }
 
   override Expr getPointer() {
-    result = getArgument(0) or
-    result = getArgument(1)
+    result = this.getArgument(0) or
+    result = this.getArgument(1)
   }
 
-  override Expr getAccessedLength() { result = getArgument(2) }
+  override Expr getAccessedLength() { result = this.getArgument(2) }
 }
 
 class RecvSizeExpr extends BufferAccess, FunctionCall {
-  RecvSizeExpr() { getTarget().hasName("recv") }
+  RecvSizeExpr() { this.getTarget().hasName("recv") }
 
-  override Expr getPointer() { result = getArgument(1) }
+  override Expr getPointer() { result = this.getArgument(1) }
 
-  override Expr getAccessedLength() { result = getArgument(2) }
+  override Expr getAccessedLength() { result = this.getArgument(2) }
 }
 
 class SendSizeExpr extends BufferAccess, FunctionCall {
-  SendSizeExpr() { getTarget().hasName("send") }
+  SendSizeExpr() { this.getTarget().hasName("send") }
 
-  override Expr getPointer() { result = getArgument(1) }
+  override Expr getPointer() { result = this.getArgument(1) }
 
-  override Expr getAccessedLength() { result = getArgument(2) }
+  override Expr getAccessedLength() { result = this.getArgument(2) }
 }
 
 class SnprintfSizeExpr extends BufferAccess, FunctionCall {
-  SnprintfSizeExpr() { getTarget().hasName("snprintf") }
+  SnprintfSizeExpr() { this.getTarget().hasName("snprintf") }
 
-  override Expr getPointer() { result = getArgument(0) }
+  override Expr getPointer() { result = this.getArgument(0) }
 
-  override Expr getAccessedLength() { result = getArgument(1) }
+  override Expr getAccessedLength() { result = this.getArgument(1) }
 }
 
 class MemcmpSizeExpr extends BufferAccess, FunctionCall {
-  MemcmpSizeExpr() { getTarget().hasName("Memcmp") }
+  MemcmpSizeExpr() { this.getTarget().hasName("Memcmp") }
 
   override Expr getPointer() {
-    result = getArgument(0) or
-    result = getArgument(1)
+    result = this.getArgument(0) or
+    result = this.getArgument(1)
   }
 
-  override Expr getAccessedLength() { result = getArgument(2) }
+  override Expr getAccessedLength() { result = this.getArgument(2) }
 }
 
 class MallocSizeExpr extends BufferAccess, FunctionCall {
-  MallocSizeExpr() { getTarget().hasName("malloc") }
+  MallocSizeExpr() { this.getTarget().hasName("malloc") }
 
   override Expr getPointer() { none() }
 
-  override Expr getAccessedLength() { result = getArgument(0) }
+  override Expr getAccessedLength() { result = this.getArgument(0) }
 }
 
 class NetworkFunctionCall extends FunctionCall {
-  NetworkFunctionCall() { getTarget().hasName(["ntohd", "ntohf", "ntohl", "ntohll", "ntohs"]) }
+  NetworkFunctionCall() { this.getTarget().hasName(["ntohd", "ntohf", "ntohl", "ntohll", "ntohs"]) }
 }
 
 class NetworkToBufferSizeConfiguration extends DataFlow::Configuration {

cpp/ql/src/Likely Bugs/Protocols/TlsSettingsMisconfiguration.ql

@@ -3,8 +3,10 @@
  * @description Using the TLS or SSLv23 protocol from the boost::asio library, but not disabling deprecated protocols, or disabling minimum-recommended protocols.
  * @kind problem
  * @problem.severity error
+ * @security-severity 7.5
  * @id cpp/boost/tls-settings-misconfiguration
  * @tags security
+ *       external/cwe/cwe-326
  */
 
 import cpp

cpp/ql/src/Likely Bugs/Protocols/UseOfDeprecatedHardcodedProtocol.ql

@@ -3,8 +3,10 @@
  * @description Using a deprecated hard-coded protocol using the boost::asio library.
  * @kind problem
  * @problem.severity error
+ * @security-severity 7.5
  * @id cpp/boost/use-of-deprecated-hardcoded-security-protocol
  * @tags security
+ *       external/cwe/cwe-327
  */
 
 import cpp

cpp/ql/src/Power of 10/Rule 4/FunctionTooLong.ql

@@ -13,7 +13,7 @@ import cpp
 
 class MacroFunctionCall extends MacroInvocation {
   MacroFunctionCall() {
-    not exists(getParentInvocation()) and
+    not exists(this.getParentInvocation()) and
     this.getMacro().getHead().matches("%(%")
   }
 

cpp/ql/src/Power of 10/Rule 5/AssertionDensity.ql

@@ -13,7 +13,7 @@ import semmle.code.cpp.commons.Assertions
 
 class MacroFunctionCall extends MacroInvocation {
   MacroFunctionCall() {
-    not exists(getParentInvocation()) and
+    not exists(this.getParentInvocation()) and
     this.getMacro().getHead().matches("%(%")
   }
 

cpp/ql/src/Security/CWE/CWE-020/ExternalAPIsSpecific.qll

@@ -38,7 +38,7 @@ class ExternalAPIDataNode extends DataFlow::Node {
   int getIndex() { result = i }
 
   /** Gets the description of the function being called. */
-  string getFunctionDescription() { result = getExternalFunction().toString() }
+  string getFunctionDescription() { result = this.getExternalFunction().toString() }
 }
 
 /** A configuration for tracking flow from `RemoteFlowSource`s to `ExternalAPIDataNode`s. */

cpp/ql/src/Security/CWE/CWE-020/ir/ExternalAPIsSpecific.qll

@@ -38,7 +38,7 @@ class ExternalAPIDataNode extends DataFlow::Node {
   int getIndex() { result = i }
 
   /** Gets the description of the function being called. */
-  string getFunctionDescription() { result = getExternalFunction().toString() }
+  string getFunctionDescription() { result = this.getExternalFunction().toString() }
 }
 
 /** A configuration for tracking flow from `RemoteFlowSource`s to `ExternalAPIDataNode`s. */

cpp/ql/src/Security/CWE/CWE-121/UnterminatedVarargsCall.ql

@@ -42,7 +42,7 @@ class VarargsFunction extends Function {
   }
 
   private int trailingArgValueCount(string value) {
-    result = strictcount(FunctionCall fc | trailingArgValue(fc) = value)
+    result = strictcount(FunctionCall fc | this.trailingArgValue(fc) = value)
   }
 
   string nonTrailingVarArgValue(FunctionCall fc, int index) {
@@ -58,11 +58,11 @@ class VarargsFunction extends Function {
 
   string normalTerminator(int cnt) {
     result = ["0", "-1"] and
-    cnt = trailingArgValueCount(result) and
-    2 * cnt > totalCount() and
+    cnt = this.trailingArgValueCount(result) and
+    2 * cnt > this.totalCount() and
     not exists(FunctionCall fc, int index |
       // terminator value is used in a non-terminating position
-      nonTrailingVarArgValue(fc, index) = result
+      this.nonTrailingVarArgValue(fc, index) = result
     )
   }
 

cpp/ql/src/Security/CWE/CWE-170/ImproperNullTerminationTainted.ql

@@ -42,7 +42,7 @@ class TaintSource extends VariableAccess {
     definitionUsePair(_, this, va)
     or
     exists(VariableAccess mid, Expr def |
-      sourceReaches(mid) and
+      this.sourceReaches(mid) and
       exprDefinition(_, def, mid) and
       definitionUsePair(_, def, va)
     )
@@ -53,11 +53,11 @@ class TaintSource extends VariableAccess {
    * from `va`, possibly using intermediate reassignments.
    */
   private predicate reachesSink(VariableAccess va, VariableAccess sink) {
-    isSink(sink) and
+    this.isSink(sink) and
     va = sink
     or
     exists(VariableAccess mid, Expr def |
-      reachesSink(mid, sink) and
+      this.reachesSink(mid, sink) and
       exprDefinition(_, def, va) and
       definitionUsePair(_, def, mid)
     )
@@ -71,15 +71,15 @@ class TaintSource extends VariableAccess {
    * this source to `sink` found via `tainted(source, sink)`.)
    */
   predicate reaches(VariableAccess sink) {
-    isSink(sink) and
+    this.isSink(sink) and
     not exists(VariableAccess va |
       va != this and
       va != sink and
       mayAddNullTerminator(_, va)
     |
-      sourceReaches(va)
+      this.sourceReaches(va)
       or
-      reachesSink(va, sink)
+      this.reachesSink(va, sink)
     )
   }
 }

cpp/ql/src/Security/CWE/CWE-295/SSLResultConflation.qhelp

@@ -0,0 +1,28 @@
+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+<overview>
+<p>When checking the result of SSL certificate verification, accepting any error code may allow an attacker to impersonate someone who is trusted.</p>
+
+</overview>
+<recommendation>
+
+<p>When checking an SSL certificate with <code>SSL_get_verify_result</code>, only <code>X509_V_OK</code> is a success code. If there is any other result the certificate should not be accepted.</p>
+
+</recommendation>
+<example>
+
+<p>In this example the error code <code>X509_V_ERR_CERT_HAS_EXPIRED</code> is treated the same as an OK result. An expired certificate should not be accepted as it is more likely to be compromised than a valid certificate.</p>
+
+<sample src="SSLResultConflationBad.cpp" />
+
+<p>In the corrected example, only a result of <code>X509_V_OK</code> is accepted.</p>
+
+<sample src="SSLResultConflationGood.cpp" />
+
+</example>
+<references>
+
+</references>
+</qhelp>

cpp/ql/src/Security/CWE/CWE-295/SSLResultConflation.ql

@@ -0,0 +1,50 @@
+/**
+ * @name Certificate result conflation
+ * @description Only accept SSL certificates that pass certificate verification.
+ * @kind problem
+ * @problem.severity error
+ * @security-severity 7.5
+ * @precision medium
+ * @id cpp/certificate-result-conflation
+ * @tags security
+ *       external/cwe/cwe-295
+ */
+
+import cpp
+import semmle.code.cpp.controlflow.Guards
+import semmle.code.cpp.dataflow.DataFlow
+
+/**
+ * A call to `SSL_get_verify_result`.
+ */
+class SSLGetVerifyResultCall extends FunctionCall {
+  SSLGetVerifyResultCall() { getTarget().getName() = "SSL_get_verify_result" }
+}
+
+/**
+ * Data flow from a call to `SSL_get_verify_result` to a guard condition
+ * that references the result.
+ */
+class VerifyResultConfig extends DataFlow::Configuration {
+  VerifyResultConfig() { this = "VerifyResultConfig" }
+
+  override predicate isSource(DataFlow::Node source) {
+    source.asExpr() instanceof SSLGetVerifyResultCall
+  }
+
+  override predicate isSink(DataFlow::Node sink) {
+    exists(GuardCondition guard | guard.getAChild*() = sink.asExpr())
+  }
+}
+
+from
+  VerifyResultConfig config, DataFlow::Node source, DataFlow::Node sink1, DataFlow::Node sink2,
+  GuardCondition guard, Expr c1, Expr c2, boolean testIsTrue
+where
+  config.hasFlow(source, sink1) and
+  config.hasFlow(source, sink2) and
+  guard.comparesEq(sink1.asExpr(), c1, 0, false, testIsTrue) and // (value != c1) => testIsTrue
+  guard.comparesEq(sink2.asExpr(), c2, 0, false, testIsTrue) and // (value != c2) => testIsTrue
+  c1.getValue().toInt() = 0 and
+  c2.getValue().toInt() != 0
+select guard, "This expression conflates OK and non-OK results from $@.", source, source.toString()

cpp/ql/src/Security/CWE/CWE-295/SSLResultConflationBad.cpp

@@ -0,0 +1,13 @@
+// ...
+
+if (cert = SSL_get_peer_certificate(ssl))
+{
+	result = SSL_get_verify_result(ssl);
+
+	if ((result == X509_V_OK) || (result == X509_V_ERR_CERT_HAS_EXPIRED)) // BAD (conflates OK and a non-OK codes)
+	{
+		do_ok();
+	} else {
+		do_error();
+	}
+}

cpp/ql/src/Security/CWE/CWE-295/SSLResultConflationGood.cpp

@@ -0,0 +1,13 @@
+// ...
+
+if (cert = SSL_get_peer_certificate(ssl))
+{
+	result = SSL_get_verify_result(ssl);
+
+	if (result == X509_V_OK) // GOOD
+	{
+		do_ok();
+	} else {
+		do_error();
+	}
+}

cpp/ql/src/Security/CWE/CWE-295/SSLResultNotChecked.qhelp

@@ -0,0 +1,28 @@
+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+<overview>
+<p>After fetching an SSL certificate, always check the result of certificate verification.</p>
+
+</overview>
+<recommendation>
+
+<p>Always check the result of SSL certificate verification. A certificate that has been revoked may indicate that data is coming from an attacker, whereas a certificate that has expired or was self-signed may indicate an increased likelihood that the data is malicious.</p>
+
+</recommendation>
+<example>
+
+<p>In this example, the <code>SSL_get_peer_certificate</code> function is used to get the certificate of a peer. However it is unsafe to use that information without checking if the certificate is valid.</p>
+
+<sample src="SSLResultNotCheckedBad.cpp" />
+
+<p>In the corrected example, we use <code>SSL_get_verify_result</code> to check that certificate verification was successful.</p>
+
+<sample src="SSLResultNotCheckedGood.cpp" />
+
+</example>
+<references>
+
+</references>
+</qhelp>

cpp/ql/src/Security/CWE/CWE-295/SSLResultNotChecked.ql

@@ -0,0 +1,120 @@
+/**
+ * @name Certificate not checked
+ * @description Always check the result of certificate verification after fetching an SSL certificate.
+ * @kind problem
+ * @problem.severity error
+ * @security-severity 7.5
+ * @precision medium
+ * @id cpp/certificate-not-checked
+ * @tags security
+ *       external/cwe/cwe-295
+ */
+
+import cpp
+import semmle.code.cpp.valuenumbering.GlobalValueNumbering
+import semmle.code.cpp.controlflow.IRGuards
+
+/**
+ * A call to `SSL_get_peer_certificate`.
+ */
+class SSLGetPeerCertificateCall extends FunctionCall {
+  SSLGetPeerCertificateCall() {
+    getTarget().getName() = "SSL_get_peer_certificate" // SSL_get_peer_certificate(ssl)
+  }
+
+  Expr getSSLArgument() { result = getArgument(0) }
+}
+
+/**
+ * A call to `SSL_get_verify_result`.
+ */
+class SSLGetVerifyResultCall extends FunctionCall {
+  SSLGetVerifyResultCall() {
+    getTarget().getName() = "SSL_get_verify_result" // SSL_get_peer_certificate(ssl)
+  }
+
+  Expr getSSLArgument() { result = getArgument(0) }
+}
+
+/**
+ * Holds if the SSL object passed into `SSL_get_peer_certificate` is checked with
+ * `SSL_get_verify_result` entering `node`.
+ */
+predicate resultIsChecked(SSLGetPeerCertificateCall getCertCall, ControlFlowNode node) {
+  exists(Expr ssl, SSLGetVerifyResultCall check |
+    ssl = globalValueNumber(getCertCall.getSSLArgument()).getAnExpr() and
+    ssl = check.getSSLArgument() and
+    node = check
+  )
+}
+
+/**
+ * Holds if the certificate returned by `SSL_get_peer_certificate` is found to be
+ * `0` on the edge `node1` to `node2`.
+ */
+predicate certIsZero(
+  SSLGetPeerCertificateCall getCertCall, ControlFlowNode node1, ControlFlowNode node2
+) {
+  exists(Expr cert | cert = globalValueNumber(getCertCall).getAnExpr() |
+    exists(GuardCondition guard, Expr zero |
+      zero.getValue().toInt() = 0 and
+      node1 = guard and
+      (
+        // if (cert == zero) {
+        guard.comparesEq(cert, zero, 0, true, true) and
+        node2 = guard.getATrueSuccessor()
+        or
+        // if (cert != zero) { }
+        guard.comparesEq(cert, zero, 0, false, true) and
+        node2 = guard.getAFalseSuccessor()
+      )
+    )
+    or
+    (
+      // if (cert) { }
+      node1 = cert
+      or
+      // if (!cert) {
+      node1.(NotExpr).getAChild() = cert
+    ) and
+    node2 = node1.getASuccessor() and
+    not cert.(GuardCondition).controls(node2, true) // cert may be false
+  )
+}
+
+/**
+ * Holds if the SSL object passed into `SSL_get_peer_certificate` has not been checked with
+ * `SSL_get_verify_result` at `node`. Note that this is only computed at the call to
+ * `SSL_get_peer_certificate` and at the start and end of `BasicBlock`s.
+ */
+predicate certNotChecked(SSLGetPeerCertificateCall getCertCall, ControlFlowNode node) {
+  // cert is not checked at the call to `SSL_get_peer_certificate`
+  node = getCertCall
+  or
+  exists(BasicBlock bb, int pos |
+    // flow to end of a `BasicBlock`
+    certNotChecked(getCertCall, bb.getNode(pos)) and
+    node = bb.getEnd() and
+    // check for barrier node
+    not exists(int pos2 |
+      pos2 > pos and
+      resultIsChecked(getCertCall, bb.getNode(pos2))
+    )
+  )
+  or
+  exists(BasicBlock pred, BasicBlock bb |
+    // flow from the end of one `BasicBlock` to the beginning of a successor
+    certNotChecked(getCertCall, pred.getEnd()) and
+    bb = pred.getASuccessor() and
+    node = bb.getStart() and
+    // check for barrier bb
+    not certIsZero(getCertCall, pred.getEnd(), bb.getStart())
+  )
+}
+
+from SSLGetPeerCertificateCall getCertCall, ControlFlowNode node
+where
+  certNotChecked(getCertCall, node) and
+  node instanceof Function // (function exit)
+select getCertCall,
+  "This " + getCertCall.toString() + " is not followed by a call to SSL_get_verify_result."

cpp/ql/src/Security/CWE/CWE-295/SSLResultNotCheckedBad.cpp

@@ -0,0 +1,5 @@
+// ...
+
+X509 *cert = SSL_get_peer_certificate(ssl); // BAD (SSL_get_verify_result is never called)
+
+// ...

cpp/ql/src/Security/CWE/CWE-295/SSLResultNotCheckedGood.cpp

@@ -0,0 +1,9 @@
+// ...
+
+X509 *cert = SSL_get_peer_certificate(ssl); // GOOD
+if (cert)
+{
+	result = SSL_get_verify_result(ssl);
+	if (result == X509_V_OK)
+	{
+		// ...

cpp/ql/src/Security/CWE/CWE-311/CleartextFileWrite.ql

@@ -8,6 +8,7 @@
  * @precision high
  * @id cpp/cleartext-storage-file
  * @tags security
+ *       external/cwe/cwe-260
  *       external/cwe/cwe-313
  */
 

cpp/ql/src/Security/CWE/CWE-313/CleartextSqliteDatabase.ql

@@ -29,7 +29,7 @@ class SqliteFunctionCall extends FunctionCall {
 }
 
 predicate sqlite_encryption_used() {
-  any(StringLiteral l).getValue().toLowerCase().regexpMatch("pragma key.*") or
+  any(StringLiteral l).getValue().toLowerCase().matches("pragma key%") or
   any(StringLiteral l).getValue().toLowerCase().matches("%attach%database%key%") or
   any(FunctionCall fc).getTarget().getName().matches("sqlite%\\_key\\_%")
 }

cpp/ql/src/Security/CWE/CWE-319/UseOfHttp.cpp

@@ -0,0 +1,9 @@
+
+void openUrl(char *url)
+{
+	// ...
+}
+
+openUrl("http://example.com"); // BAD
+
+openUrl("https://example.com"); // GOOD: Opening a connection to a URL using HTTPS enforces SSL.

cpp/ql/src/Security/CWE/CWE-319/UseOfHttp.qhelp

@@ -0,0 +1,35 @@
+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+<overview>
+
+<p>Constructing URLs with the HTTP protocol can lead to unsecured connections.</p>
+
+</overview>
+<recommendation>
+
+<p>When you construct a URL, ensure that you use an HTTPS URL rather than an HTTP URL. Then, any connections that are made using that URL are secure SSL connections.</p>
+
+</recommendation>
+<example>
+
+<p>The following example shows two ways of opening a connection using a URL. When the connection is 
+opened using an HTTP URL rather than an HTTPS URL, the connection is unsecured. When the connection is opened using an HTTPS URL, the connection is a secure SSL connection.</p>
+
+<sample src="UseOfHttp.cpp" />
+
+</example>
+<references>
+
+<li>
+OWASP:
+<a href="https://cheatsheetseries.owasp.org/cheatsheets/Transport_Layer_Protection_Cheat_Sheet.html">Transport Layer Protection Cheat Sheet</a>.
+</li>
+<li>
+OWASP Top 10:
+<a href="https://owasp.org/Top10/A08_2021-Software_and_Data_Integrity_Failures/">A08:2021 - Software and Data Integrity Failures</a>.
+</li>
+
+</references>
+</qhelp>

cpp/ql/src/Security/CWE/CWE-319/UseOfHttp.ql

@@ -0,0 +1,90 @@
+/**
+ * @name Failure to use HTTPS URLs
+ * @description Non-HTTPS connections can be intercepted by third parties.
+ * @kind path-problem
+ * @problem.severity warning
+ * @precision medium
+ * @id cpp/non-https-url
+ * @tags security
+ *       external/cwe/cwe-319
+ *       external/cwe/cwe-345
+ */
+
+import cpp
+import semmle.code.cpp.dataflow.TaintTracking
+import DataFlow::PathGraph
+
+/**
+ * A string matching private host names of IPv4 and IPv6, which only matches
+ * the host portion therefore checking for port is not necessary.
+ * Several examples are localhost, reserved IPv4 IP addresses including
+ * 127.0.0.1, 10.x.x.x, 172.16.x,x, 192.168.x,x, and reserved IPv6 addresses
+ * including [0:0:0:0:0:0:0:1] and [::1]
+ */
+class PrivateHostName extends string {
+  bindingset[this]
+  PrivateHostName() {
+    this.regexpMatch("(?i)localhost(?:[:/?#].*)?|127\\.0\\.0\\.1(?:[:/?#].*)?|10(?:\\.[0-9]+){3}(?:[:/?#].*)?|172\\.16(?:\\.[0-9]+){2}(?:[:/?#].*)?|192.168(?:\\.[0-9]+){2}(?:[:/?#].*)?|\\[?0:0:0:0:0:0:0:1\\]?(?:[:/?#].*)?|\\[?::1\\]?(?:[:/?#].*)?")
+  }
+}
+
+/**
+ * A string containing an HTTP URL not in a private domain.
+ */
+class HttpStringLiteral extends StringLiteral {
+  HttpStringLiteral() {
+    exists(string s | this.getValue() = s |
+      s = "http"
+      or
+      exists(string tail |
+        tail = s.regexpCapture("http://(.*)", 1) and not tail instanceof PrivateHostName
+      ) and
+      not TaintTracking::localExprTaint(any(StringLiteral p |
+          p.getValue() instanceof PrivateHostName
+        ), this.getParent*())
+    )
+  }
+}
+
+/**
+ * Taint tracking configuration for HTTP connections.
+ */
+class HttpStringToUrlOpenConfig extends TaintTracking::Configuration {
+  HttpStringToUrlOpenConfig() { this = "HttpStringToUrlOpenConfig" }
+
+  override predicate isSource(DataFlow::Node src) {
+    // Sources are strings containing an HTTP URL not in a private domain.
+    src.asExpr() instanceof HttpStringLiteral
+  }
+
+  override predicate isSink(DataFlow::Node sink) {
+    // Sinks can be anything that demonstrates the string is likely to be
+    // accessed as a URL, for example using it in a network access. Some
+    // URLs are only ever displayed or used for data processing.
+    exists(FunctionCall fc |
+      fc.getTarget()
+          .hasGlobalOrStdName([
+              "system", "gethostbyname", "gethostbyname2", "gethostbyname_r", "getaddrinfo",
+              "X509_load_http", "X509_CRL_load_http"
+            ]) and
+      sink.asExpr() = fc.getArgument(0)
+      or
+      fc.getTarget().hasGlobalOrStdName(["send", "URLDownloadToFile", "URLDownloadToCacheFile"]) and
+      sink.asExpr() = fc.getArgument(1)
+      or
+      fc.getTarget().hasGlobalOrStdName(["curl_easy_setopt", "getnameinfo"]) and
+      sink.asExpr() = fc.getArgument(2)
+      or
+      fc.getTarget().hasGlobalOrStdName(["ShellExecute", "ShellExecuteA", "ShellExecuteW"]) and
+      sink.asExpr() = fc.getArgument(3)
+    )
+  }
+}
+
+from
+  HttpStringToUrlOpenConfig config, DataFlow::PathNode source, DataFlow::PathNode sink,
+  HttpStringLiteral str
+where
+  config.hasFlowPath(source, sink) and
+  str = source.getNode().asExpr()
+select str, source, sink, "A URL may be constructed with the HTTP protocol."

cpp/ql/src/Security/CWE/CWE-457/InitializationFunctions.qll

@@ -84,8 +84,8 @@ class ParameterNullCheck extends ParameterCheck {
     p.getFunction() instanceof InitializationFunction and
     p.getType().getUnspecifiedType() instanceof PointerType and
     exists(VariableAccess va | va = p.getAnAccess() |
-      nullSuccessor = getATrueSuccessor() and
-      notNullSuccessor = getAFalseSuccessor() and
+      nullSuccessor = this.getATrueSuccessor() and
+      notNullSuccessor = this.getAFalseSuccessor() and
       (
         va = this.(NotExpr).getOperand() or
         va = any(EQExpr eq | eq = this and eq.getAnOperand().getValue() = "0").getAnOperand() or
@@ -95,8 +95,8 @@ class ParameterNullCheck extends ParameterCheck {
               .getAnOperand()
       )
       or
-      nullSuccessor = getAFalseSuccessor() and
-      notNullSuccessor = getATrueSuccessor() and
+      nullSuccessor = this.getAFalseSuccessor() and
+      notNullSuccessor = this.getATrueSuccessor() and
       (
         va = this or
         va = any(NEExpr eq | eq = this and eq.getAnOperand().getValue() = "0").getAnOperand() or
@@ -132,7 +132,7 @@ class ValidatedExternalCondInitFunction extends ExternalData {
   ValidatedExternalCondInitFunction() { this.getDataPath().matches("%cond-init%.csv") }
 
   predicate isExternallyVerified(Function f, int param) {
-    functionSignature(f, getField(1), getField(2)) and param = getFieldAsInt(3)
+    functionSignature(f, this.getField(1), this.getField(2)) and param = this.getFieldAsInt(3)
   }
 }
 
@@ -193,7 +193,7 @@ class InitializationFunction extends Function {
             .getAnOverridingFunction+()
             .(InitializationFunction)
             .initializedParameter() or
-      getParameter(i) = any(InitializationFunctionCall c).getAnInitParameter()
+      this.getParameter(i) = any(InitializationFunctionCall c).getAnInitParameter()
     )
     or
     // If we have no definition, we look at SAL annotations
@@ -227,7 +227,7 @@ class InitializationFunction extends Function {
         result = getAnInitializedArgument(any(Call c))
         or
         exists(IfStmt check | result = check.getCondition().getAChild*() |
-          paramReassignmentCondition(check)
+          this.paramReassignmentCondition(check)
         )
       )
       or
@@ -249,15 +249,15 @@ class InitializationFunction extends Function {
 
   /** Holds if `n` can be reached without the parameter at `index` being reassigned. */
   predicate paramNotReassignedAt(ControlFlowNode n, int index, Context c) {
-    c = getAContext(index) and
+    c = this.getAContext(index) and
     (
       not exists(this.getEntryPoint()) and index = i and n = this
       or
       n = this.getEntryPoint() and index = i
       or
-      exists(ControlFlowNode mid | paramNotReassignedAt(mid, index, c) |
+      exists(ControlFlowNode mid | this.paramNotReassignedAt(mid, index, c) |
         n = mid.getASuccessor() and
-        not n = paramReassignment(index) and
+        not n = this.paramReassignment(index) and
         /*
          * Ignore successor edges where the parameter is null, because it is then confirmed to be
          * initialized.
@@ -265,7 +265,7 @@ class InitializationFunction extends Function {
 
         not exists(ParameterNullCheck nullCheck |
           nullCheck = mid and
-          nullCheck = getANullCheck(index) and
+          nullCheck = this.getANullCheck(index) and
           n = nullCheck.getNullSuccessor()
         ) and
         /*
@@ -281,13 +281,13 @@ class InitializationFunction extends Function {
 
   /** Gets a null-check on the parameter at `index`. */
   private ParameterNullCheck getANullCheck(int index) {
-    getParameter(index) = result.getParameter()
+    this.getParameter(index) = result.getParameter()
   }
 
   /** Gets a parameter which is not at the given index. */
   private Parameter getOtherParameter(int index) {
     index = i and
-    result = getAParameter() and
+    result = this.getAParameter() and
     not result.getIndex() = index
   }
 
@@ -306,10 +306,10 @@ class InitializationFunction extends Function {
     if
       strictcount(Parameter p |
         exists(Context c | c = ParamNull(p) or c = ParamNotNull(p)) and
-        p = getOtherParameter(index)
+        p = this.getOtherParameter(index)
       ) = 1
     then
-      exists(Parameter p | p = getOtherParameter(index) |
+      exists(Parameter p | p = this.getOtherParameter(index) |
         result = ParamNull(p) or result = ParamNotNull(p)
       )
     else
@@ -424,8 +424,8 @@ class ConditionalInitializationCall extends FunctionCall {
 
   /** Gets the argument passed for the given parameter to this call. */
   Expr getArgumentForParameter(Parameter p) {
-    p = getTarget().getAParameter() and
-    result = getArgument(p.getIndex())
+    p = this.getTarget().getAParameter() and
+    result = this.getArgument(p.getIndex())
   }
 
   /**
@@ -442,7 +442,7 @@ class ConditionalInitializationCall extends FunctionCall {
         context = ParamNotNull(otherP) or
         context = ParamNull(otherP)
       |
-        otherArg = getArgumentForParameter(otherP) and
+        otherArg = this.getArgumentForParameter(otherP) and
         (otherArg instanceof AddressOfExpr implies context = ParamNotNull(otherP)) and
         (otherArg.getType() instanceof ArrayType implies context = ParamNotNull(otherP)) and
         (otherArg.getValue() = "0" implies context = ParamNull(otherP))
@@ -511,8 +511,8 @@ class ConditionalInitializationCall extends FunctionCall {
         )
     )
     or
-    exists(ControlFlowNode mid | mid = uncheckedReaches(var) |
-      not mid = getStatusVariable().getAnAccess() and
+    exists(ControlFlowNode mid | mid = this.uncheckedReaches(var) |
+      not mid = this.getStatusVariable().getAnAccess() and
       not mid = var.getAnAccess() and
       not exists(VariableAccess write | result = write and write = var.getAnAccess() |
         write = any(AssignExpr a).getLValue() or

cpp/ql/src/Security/CWE/CWE-457/UninitializedVariables.qll

@@ -44,7 +44,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     // Find a call that conditionally initializes this variable
     hasConditionalInitialization(f, call, this, initAccess, e) and
     // Ignore cases where the variable is assigned prior to the call
-    not reaches(getAnAssignedValue(), initAccess) and
+    not reaches(this.getAnAssignedValue(), initAccess) and
     // Ignore cases where the variable is assigned field-wise prior to the call.
     not exists(FieldAccess fa |
       exists(Assignment a |
@@ -56,7 +56,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     ) and
     // Ignore cases where the variable is assigned by a prior call to an initialization function
     not exists(Call c |
-      getAnAccess() = getAnInitializedArgument(c).(AddressOfExpr).getOperand() and
+      this.getAnAccess() = getAnInitializedArgument(c).(AddressOfExpr).getOperand() and
       reaches(c, initAccess)
     ) and
     /*
@@ -64,7 +64,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
      * the CFG, but should always be considered as initialized, so exclude them.
      */
 
-    not exists(getInitializer().getExpr())
+    not exists(this.getInitializer().getExpr())
   }
 
   /**
@@ -90,7 +90,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     // Variable associated with this particular call
     call = initializingCall and
     // Access is a meaningful read access
-    result = getAReadAccess() and
+    result = this.getAReadAccess() and
     // Which occurs after the call
     reaches(call, result) and
     /*
@@ -124,7 +124,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     call = initializingCall and
     initializingFunction = f and
     e = evidence and
-    result = getAReadAccessAfterCall(initializingCall) and
+    result = this.getAReadAccessAfterCall(initializingCall) and
     (
       // Access is risky because status return code ignored completely
       call instanceof ExprInVoidContext
@@ -148,7 +148,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     call = initializingCall and
     initializingFunction = f and
     e = evidence and
-    result = getAReadAccessAfterCall(initializingCall) and
+    result = this.getAReadAccessAfterCall(initializingCall) and
     exists(LocalVariable status, Assignment a |
       a.getRValue() = call and
       call = status.getAnAssignedValue() and
@@ -184,7 +184,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     ConditionalInitializationFunction initializingFunction,
     ConditionalInitializationCall initializingCall, Evidence evidence
   ) {
-    result = getARiskyAccessBeforeStatusCheck(initializingFunction, initializingCall, evidence) or
-    result = getARiskyAccessWithNoStatusCheck(initializingFunction, initializingCall, evidence)
+    result = this.getARiskyAccessBeforeStatusCheck(initializingFunction, initializingCall, evidence) or
+    result = this.getARiskyAccessWithNoStatusCheck(initializingFunction, initializingCall, evidence)
   }
 }

cpp/ql/src/Security/CWE/CWE-497/ExposedSystemData.ql

@@ -31,15 +31,15 @@ abstract class SystemData extends Element {
    */
   Expr getAnExprIndirect() {
     // direct SystemData
-    result = getAnExpr() or
+    result = this.getAnExpr() or
     // flow via global or member variable (conservative approximation)
-    result = getAnAffectedVar().getAnAccess() or
+    result = this.getAnAffectedVar().getAnAccess() or
     // flow via stack variable
-    definitionUsePair(_, getAnExprIndirect(), result) or
-    useUsePair(_, getAnExprIndirect(), result) or
-    useUsePair(_, result, getAnExprIndirect()) or
+    definitionUsePair(_, this.getAnExprIndirect(), result) or
+    useUsePair(_, this.getAnExprIndirect(), result) or
+    useUsePair(_, result, this.getAnExprIndirect()) or
     // flow from assigned value to assignment expression
-    result.(AssignExpr).getRValue() = getAnExprIndirect()
+    result.(AssignExpr).getRValue() = this.getAnExprIndirect()
   }
 
   /**

cpp/ql/src/Security/CWE/CWE-676/DangerousUseOfCin.ql

@@ -67,16 +67,16 @@ class IFStream extends Type {
  */
 class CinVariable extends NamespaceVariable {
   CinVariable() {
-    getName() = ["cin", "wcin"] and
-    getNamespace().getName() = "std"
+    this.getName() = ["cin", "wcin"] and
+    this.getNamespace().getName() = "std"
   }
 }
 
 /** A call to `std::operator>>`. */
 class OperatorRShiftCall extends FunctionCall {
   OperatorRShiftCall() {
-    getTarget().getNamespace().getName() = "std" and
-    getTarget().hasName("operator>>")
+    this.getTarget().getNamespace().getName() = "std" and
+    this.getTarget().hasName("operator>>")
   }
 
   /*
@@ -87,15 +87,15 @@ class OperatorRShiftCall extends FunctionCall {
    */
 
   Expr getSource() {
-    if getTarget() instanceof MemberFunction
-    then result = getQualifier()
-    else result = getArgument(0)
+    if this.getTarget() instanceof MemberFunction
+    then result = this.getQualifier()
+    else result = this.getArgument(0)
   }
 
   Expr getDest() {
-    if getTarget() instanceof MemberFunction
-    then result = getArgument(0)
-    else result = getArgument(1)
+    if this.getTarget() instanceof MemberFunction
+    then result = this.getArgument(0)
+    else result = this.getArgument(1)
   }
 }
 
@@ -119,7 +119,7 @@ abstract class PotentiallyDangerousInput extends Expr {
    * Gets the width restriction that applies to the input stream
    * for this expression, if any.
    */
-  Expr getWidth() { result = getPreviousAccess().getWidthAfter() }
+  Expr getWidth() { result = this.getPreviousAccess().getWidthAfter() }
 
   private Expr getWidthSetHere() {
     exists(FunctionCall widthCall |
@@ -154,11 +154,11 @@ abstract class PotentiallyDangerousInput extends Expr {
    * after this expression, if any.
    */
   Expr getWidthAfter() {
-    result = getWidthSetHere()
+    result = this.getWidthSetHere()
     or
-    not exists(getWidthSetHere()) and
-    not isWidthConsumedHere() and
-    result = getWidth()
+    not exists(this.getWidthSetHere()) and
+    not this.isWidthConsumedHere() and
+    result = this.getWidth()
   }
 }
 

cpp/ql/src/change-notes/released/0.0.4.md

@@ -0,0 +1,5 @@
+## 0.0.4
+
+### New Queries
+
+* A new query `cpp/non-https-url` has been added for C/C++. The query flags uses of `http` URLs that might be better replaced with `https`.

cpp/ql/src/change-notes/released/0.0.5.md

@@ -0,0 +1 @@
+## 0.0.5

cpp/ql/src/codeql-pack.release.yml

@@ -0,0 +1,2 @@
+---
+lastReleaseVersion: 0.0.5

cpp/ql/src/experimental/Security/CWE/CWE-273/PrivilegeDroppingOutoforder.ql

@@ -21,9 +21,9 @@ predicate argumentMayBeRoot(Expr e) {
 
 class SetuidLikeFunctionCall extends FunctionCall {
   SetuidLikeFunctionCall() {
-    (getTarget().hasGlobalName("setuid") or getTarget().hasGlobalName("setresuid")) and
+    (this.getTarget().hasGlobalName("setuid") or this.getTarget().hasGlobalName("setresuid")) and
     // setuid/setresuid with the root user are false positives.
-    not argumentMayBeRoot(getArgument(0))
+    not argumentMayBeRoot(this.getArgument(0))
   }
 }
 
@@ -44,7 +44,7 @@ class SetuidLikeWrapperCall extends FunctionCall {
 
 class CallBeforeSetuidFunctionCall extends FunctionCall {
   CallBeforeSetuidFunctionCall() {
-    getTarget()
+    this.getTarget()
         .hasGlobalName([
             "setgid", "setresgid",
             // Compatibility may require skipping initgroups and setgroups return checks.
@@ -52,7 +52,7 @@ class CallBeforeSetuidFunctionCall extends FunctionCall {
             "initgroups", "setgroups"
           ]) and
     // setgid/setresgid/etc with the root group are false positives.
-    not argumentMayBeRoot(getArgument(0))
+    not argumentMayBeRoot(this.getArgument(0))
   }
 }
 

cpp/ql/src/experimental/Security/CWE/CWE-377/InsecureTemporaryFile.cpp

@@ -0,0 +1,14 @@
+...
+  fp = fopen("/tmp/name.tmp","w"); // BAD
+...
+  char filename = tmpnam(NULL);
+  fp = fopen(filename,"w"); // BAD
+...
+
+  strcat (filename, "/tmp/name.XXXXXX");
+  fd = mkstemp(filename);
+  if ( fd < 0 ) {
+    return error;
+  }
+  fp = fdopen(fd,"w") // GOOD
+...

cpp/ql/src/experimental/Security/CWE/CWE-377/InsecureTemporaryFile.qhelp

@@ -0,0 +1,23 @@
+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+<overview>
+<p>Working with a file, without checking its existence and its rights, as well as working with names that can be predicted, may not be safe. Requires the attention of developers.</p>
+
+</overview>
+
+<example>
+<p>The following example demonstrates erroneous and corrected work with file.</p>
+<sample src="InsecureTemporaryFile.cpp" />
+
+</example>
+<references>
+
+<li>
+  CERT C Coding Standard:
+  <a href="https://wiki.sei.cmu.edu/confluence/display/c/CON33-C.+Avoid+race+conditions+when+using+library+functions">CON33-C. Avoid race conditions when using library functions</a>.
+</li>
+
+</references>
+</qhelp>

cpp/ql/src/experimental/Security/CWE/CWE-377/InsecureTemporaryFile.ql

@@ -0,0 +1,112 @@
+/**
+ * @name Insecure generation of filenames.
+ * @description Using a predictable filename when creating a temporary file can lead to an attacker-controlled input.
+ * @kind problem
+ * @id cpp/insecure-generation-of-filename
+ * @problem.severity warning
+ * @precision medium
+ * @tags correctness
+ *       security
+ *       external/cwe/cwe-377
+ */
+
+import cpp
+import semmle.code.cpp.valuenumbering.GlobalValueNumbering
+
+/** Holds for a function `f` that has an argument at index `apos` used to read the file. */
+predicate numberArgumentRead(Function f, int apos) {
+  f.hasGlobalOrStdName("fgets") and apos = 2
+  or
+  f.hasGlobalOrStdName("fread") and apos = 3
+  or
+  f.hasGlobalOrStdName("read") and apos = 0
+  or
+  f.hasGlobalOrStdName("fscanf") and apos = 0
+}
+
+/** Holds for a function `f` that has an argument at index `apos` used to write to file */
+predicate numberArgumentWrite(Function f, int apos) {
+  f.hasGlobalOrStdName("fprintf") and apos = 0
+  or
+  f.hasGlobalOrStdName("fputs") and apos = 1
+  or
+  f.hasGlobalOrStdName("write") and apos = 0
+  or
+  f.hasGlobalOrStdName("fwrite") and apos = 3
+  or
+  f.hasGlobalOrStdName("fflush") and apos = 0
+}
+
+from FunctionCall fc, string msg
+where
+  // search for functions for generating a name, without a guarantee of the absence of a file during the period of work with it.
+  (
+    fc.getTarget().hasGlobalOrStdName("tmpnam") or
+    fc.getTarget().hasGlobalOrStdName("tmpnam_s") or
+    fc.getTarget().hasGlobalOrStdName("tmpnam_r")
+  ) and
+  not exists(FunctionCall fctmp |
+    (
+      fctmp.getTarget().hasGlobalOrStdName("mktemp") or
+      fctmp.getTarget().hasGlobalOrStdName("mkstemp") or
+      fctmp.getTarget().hasGlobalOrStdName("mkstemps") or
+      fctmp.getTarget().hasGlobalOrStdName("mkdtemp")
+    ) and
+    (
+      fc.getBasicBlock().getASuccessor*() = fctmp.getBasicBlock() or
+      fctmp.getBasicBlock().getASuccessor*() = fc.getBasicBlock()
+    )
+  ) and
+  msg =
+    "Finding the name of a file that does not exist does not mean that it will not be exist at the next operation."
+  or
+  // finding places to work with a file without setting permissions, but with predictable names.
+  (
+    fc.getTarget().hasGlobalOrStdName("fopen") or
+    fc.getTarget().hasGlobalOrStdName("open")
+  ) and
+  fc.getNumberOfArguments() = 2 and
+  exists(FunctionCall fctmp, int i |
+    numberArgumentWrite(fctmp.getTarget(), i) and
+    globalValueNumber(fc) = globalValueNumber(fctmp.getArgument(i))
+  ) and
+  not exists(FunctionCall fctmp, int i |
+    numberArgumentRead(fctmp.getTarget(), i) and
+    globalValueNumber(fc) = globalValueNumber(fctmp.getArgument(i))
+  ) and
+  exists(FunctionCall fctmp |
+    (
+      fctmp.getTarget().hasGlobalOrStdName("strcat") or
+      fctmp.getTarget().hasGlobalOrStdName("strcpy")
+    ) and
+    globalValueNumber(fc.getArgument(0)) = globalValueNumber(fctmp.getAnArgument())
+    or
+    fctmp.getTarget().hasGlobalOrStdName("getenv") and
+    globalValueNumber(fc.getArgument(0)) = globalValueNumber(fctmp)
+    or
+    (
+      fctmp.getTarget().hasGlobalOrStdName("asprintf") or
+      fctmp.getTarget().hasGlobalOrStdName("vasprintf") or
+      fctmp.getTarget().hasGlobalOrStdName("xasprintf") or
+      fctmp.getTarget().hasGlobalOrStdName("xvasprintf ")
+    ) and
+    exists(Variable vrtmp |
+      vrtmp = fc.getArgument(0).(VariableAccess).getTarget() and
+      vrtmp = fctmp.getArgument(0).(AddressOfExpr).getAddressable().(Variable) and
+      not vrtmp instanceof Field
+    )
+  ) and
+  not exists(FunctionCall fctmp |
+    (
+      fctmp.getTarget().hasGlobalOrStdName("umask") or
+      fctmp.getTarget().hasGlobalOrStdName("fchmod") or
+      fctmp.getTarget().hasGlobalOrStdName("chmod")
+    ) and
+    (
+      fc.getBasicBlock().getASuccessor*() = fctmp.getBasicBlock() or
+      fctmp.getBasicBlock().getASuccessor*() = fc.getBasicBlock()
+    )
+  ) and
+  msg =
+    "Creating a file for writing without evaluating its existence and setting permissions can be unsafe."
+select fc, msg

cpp/ql/src/experimental/Security/CWE/CWE-401/MemoryLeakOnFailedCallToRealloc.ql

@@ -24,7 +24,7 @@ class CallMayNotReturn extends FunctionCall {
     not exists(this.(ControlFlowNode).getASuccessor())
     or
     // call to another function that may not return
-    exists(CallMayNotReturn exit | getTarget() = exit.getEnclosingFunction())
+    exists(CallMayNotReturn exit | this.getTarget() = exit.getEnclosingFunction())
   }
 }
 

cpp/ql/src/experimental/Security/CWE/CWE-703/FindIncorrectlyUsedExceptions.ql

@@ -38,13 +38,7 @@ where
     fc.getTargetType().(Class).getABaseClass+().hasGlobalOrStdName("exception") or
     fc.getTargetType().(Class).getABaseClass+().hasGlobalOrStdName("CException")
   ) and
+  fc instanceof ExprInVoidContext and
   not fc.isInMacroExpansion() and
-  not exists(ThrowExpr texp | fc.getEnclosingStmt() = texp.getEnclosingStmt()) and
-  not exists(FunctionCall fctmp | fctmp.getAnArgument() = fc) and
-  not fc instanceof ConstructorDirectInit and
-  not fc.getEnclosingStmt() instanceof DeclStmt and
-  not fc instanceof ConstructorDelegationInit and
-  not fc.getParent() instanceof Initializer and
-  not fc.getParent() instanceof AllocationExpr and
-  msg = "This object does not generate an exception."
+  msg = "Object creation of exception type on stack. Did you forget the throw keyword?"
 select fc, msg

cpp/ql/src/jsf/4.10 Classes/AV Rule 79.ql

@@ -118,7 +118,7 @@ private predicate exprReleases(Expr e, Expr released, string kind) {
 }
 
 class Resource extends MemberVariable {
-  Resource() { not isStatic() }
+  Resource() { not this.isStatic() }
 
   // Check that an expr is somewhere in this class - does not have to be a constructor
   predicate inSameClass(Expr e) {
@@ -129,7 +129,7 @@ class Resource extends MemberVariable {
     f instanceof Destructor and f.getDeclaringType() = this.getDeclaringType()
     or
     exists(Function mid, FunctionCall fc |
-      calledFromDestructor(mid) and
+      this.calledFromDestructor(mid) and
       fc.getEnclosingFunction() = mid and
       fc.getTarget() = f and
       f.getDeclaringType() = this.getDeclaringType()
@@ -137,7 +137,7 @@ class Resource extends MemberVariable {
   }
 
   predicate inDestructor(Expr e) {
-    exists(Function f | f = e.getEnclosingFunction() | calledFromDestructor(f))
+    exists(Function f | f = e.getEnclosingFunction() | this.calledFromDestructor(f))
   }
 
   predicate acquisitionWithRequiredKind(Assignment acquireAssign, string kind) {

cpp/ql/src/qlpack.yml

@@ -1,5 +1,6 @@
 name: codeql/cpp-queries
-version: 0.0.2
+version: 0.0.5
+groups: cpp
 dependencies:
     codeql/cpp-all: "*"
     codeql/suite-helpers: "*"

cpp/ql/test/experimental/library-tests/rangeanalysis/extensibility/extensibility.ql

@@ -29,7 +29,8 @@ class CustomAddFunctionCall extends SimpleRangeAnalysisExpr, FunctionCall {
 
 class SelfSub extends SimpleRangeAnalysisExpr, SubExpr {
   SelfSub() {
-    getLeftOperand().(VariableAccess).getTarget() = getRightOperand().(VariableAccess).getTarget()
+    this.getLeftOperand().(VariableAccess).getTarget() =
+      this.getRightOperand().(VariableAccess).getTarget()
   }
 
   override float getLowerBounds() { result = 0 }

cpp/ql/test/experimental/query-tests/Security/CWE/CWE-377/semmle/tests/InsecureTemporaryFile.expected

@@ -0,0 +1,2 @@
+| test.cpp:16:20:16:25 | call to tmpnam | Finding the name of a file that does not exist does not mean that it will not be exist at the next operation. |
+| test.cpp:42:8:42:12 | call to fopen | Creating a file for writing without evaluating its existence and setting permissions can be unsafe. |

cpp/ql/test/experimental/query-tests/Security/CWE/CWE-377/semmle/tests/InsecureTemporaryFile.qlref

@@ -0,0 +1 @@
+experimental/Security/CWE/CWE-377/InsecureTemporaryFile.ql

cpp/ql/test/experimental/query-tests/Security/CWE/CWE-377/semmle/tests/test.cpp

@@ -0,0 +1,68 @@
+typedef int FILE;
+#define NULL (0)
+FILE *fopen(char *filename, const char *mode);
+FILE *fdopen(int handle, char *mode);
+char * tmpnam(char * name);
+int mkstemp(char * name);
+char * strcat(char *str1, const char *str2);
+int umask(int pmode);
+int chmod(char * filename,int pmode);
+int fprintf(FILE *fp,const char *fmt, ...);
+int fclose(FILE *stream);
+
+int funcTest1()
+{
+  FILE *fp;
+  char *filename = tmpnam(NULL); // BAD
+  fp = fopen(filename,"w");
+  fprintf(fp,"%s\n","data to file");
+  fclose(fp);
+  return 0;
+}
+
+int funcTest2()
+{
+  FILE *fp;
+  int fd;
+  char filename[80];
+  strcat (filename, "/tmp/name.XXXXXX");
+  fd = mkstemp(filename);
+  if ( fd < 0 ) {
+    return 1;
+  }
+  fp = fdopen(fd,"w"); // GOOD
+  return 0;
+}
+
+int funcTest3()
+{
+  FILE *fp;
+  char filename[80];
+  strcat(filename, "/tmp/tmp.name");
+  fp = fopen(filename,"w"); // BAD
+  fprintf(fp,"%s\n","data to file");
+  fclose(fp);
+  return 0;
+}
+
+int funcTest4()
+{
+  FILE *fp;
+  char filename[80];
+  umask(0022);
+  strcat(filename, "/tmp/tmp.name");
+  fp = fopen(filename,"w"); // GOOD
+  chmod(filename,0666);
+  fprintf(fp,"%s\n","data to file");
+  fclose(fp);
+  return 0;
+}
+
+int main(int argc, char *argv[])
+{
+  funcTest1();
+  funcTest2();
+  funcTest3();
+  funcTest4();
+  return 0;
+}

cpp/ql/test/experimental/query-tests/Security/CWE/CWE-703/semmle/tests/FindIncorrectlyUsedExceptions.expected

@@ -1,3 +1,3 @@
-| test.cpp:35:3:35:33 | call to runtime_error | This object does not generate an exception. |
+| test.cpp:35:3:35:33 | call to runtime_error | Object creation of exception type on stack. Did you forget the throw keyword? |
 | test.cpp:41:3:41:11 | call to funcTest1 | There is an exception in the function that requires your attention. |
 | test.cpp:42:3:42:9 | call to DllMain | DllMain contains an exeption not wrapped in a try..catch block. |

cpp/ql/test/library-tests/dataflow/DefaultTaintTracking/annotate_path_to_sink/dispatch.cpp

@@ -4,8 +4,8 @@ using SinkFunction = void (*)(int);
 
 void notSink(int notSinkParam);
 
-void callsSink(int sinkParam) { // $ ir-path=31:28 ir-path=32:31 ir-path=34:22
-  sink(sinkParam); // $ ir-sink=31:28 ir-sink=32:31 ir-sink=34:22 ast=31:28 ast=32:31 ast=34:22 MISSING: ast,ir=28
+void callsSink(int sinkParam) { // $ ir-path=31:23 ir-path=32:26 ir-path=34:17
+  sink(sinkParam); // $ ast=31:28 ast=32:31 ast=34:22 ir-sink
 }
 
 struct {
@@ -25,7 +25,7 @@ void assignGlobals() {
 };
 
 void testStruct() {
-  globalStruct.sinkPtr(atoi(getenv("TAINTED"))); // $ ir MISSING: ast
+  globalStruct.sinkPtr(atoi(getenv("TAINTED"))); // $ MISSING: ir-path,ast
   globalStruct.notSinkPtr(atoi(getenv("TAINTED"))); // clean
 
   globalUnion.sinkPtr(atoi(getenv("TAINTED"))); // $ ast ir-path
@@ -48,8 +48,8 @@ class D2 : public D1 {
 
 class D3 : public D2 {
     public:
-    void f(const char* p) override { // $ ir-path=58:10 ir-path=60:17 ir-path=61:28 ir-path=62:29 ir-path=63:33 ir-path=73:30
-        sink(p); // $ ir-sink=58:10 ir-sink=60:17 ir-sink=61:28 ir-sink=62:29 ir-sink=63:33 ast=58:10 ast=60:17 ast=61:28 ast=62:29 ast=63:33 SPURIOUS: ast=73:30 ir-sink=73:30
+    void f(const char* p) override { // $ ir-path=58:10 ir-path=60:17 ir-path=61:28 ir-path=62:29 ir-path=63:33 SPURIOUS: ir-path=73:30
+        sink(p); // $ ast=58:10 ast=60:17 ast=61:28 ast=62:29 ast=63:33 ir-sink SPURIOUS: ast=73:30
     }
 };
 

cpp/ql/test/library-tests/dataflow/DefaultTaintTracking/annotate_path_to_sink/tainted.ql

@@ -23,11 +23,10 @@ class SourceConfiguration extends TaintedWithPath::TaintTrackingConfiguration {
   override predicate isSink(Element e) { isSinkArgument(e) }
 }
 
-predicate irTaint(Element source, Element sink, string tag) {
-  exists(TaintedWithPath::PathNode sinkNode, TaintedWithPath::PathNode predNode |
+predicate irTaint(Element source, TaintedWithPath::PathNode predNode, string tag) {
+  exists(TaintedWithPath::PathNode sinkNode |
     TaintedWithPath::taintedWithPath(source, _, _, sinkNode) and
     predNode = getAPredecessor*(sinkNode) and
-    sink = getElementFromPathNode(predNode) and
     // Make sure the path is actually reachable from this predecessor.
     // Otherwise, we could pick `predNode` to be b when `source` is
     // `source1` in this dataflow graph:
@@ -35,7 +34,7 @@ predicate irTaint(Element source, Element sink, string tag) {
     //                   ^
     // source2 ---> b --/
     source = getElementFromPathNode(getAPredecessor*(predNode)) and
-    if sinkNode = predNode then tag = "ir-sink" else tag = "ir-path"
+    if predNode = sinkNode then tag = "ir-sink" else tag = "ir-path"
   )
 }
 
@@ -45,21 +44,25 @@ class IRDefaultTaintTrackingTest extends InlineExpectationsTest {
   override string getARelevantTag() { result = ["ir-path", "ir-sink"] }
 
   override predicate hasActualResult(Location location, string element, string tag, string value) {
-    exists(Element source, Element tainted, int n |
-      irTaint(source, tainted, tag) and
-      n = strictcount(Element otherSource | irTaint(otherSource, tainted, _)) and
-      (
-        n = 1 and value = ""
-        or
-        // If there is more than one source for this sink
-        // we specify the source location explicitly.
-        n > 1 and
+    exists(Element source, Element elem, TaintedWithPath::PathNode node, int n |
+      irTaint(source, node, tag) and
+      elem = getElementFromPathNode(node) and
+      n = count(int startline | getAPredecessor(node).hasLocationInfo(_, startline, _, _, _)) and
+      location = elem.getLocation() and
+      element = elem.toString()
+    |
+      // Zero predecessors means it's a source, and 1 predecessor means it has a unique predecessor.
+      // In either of these cases we leave out the location.
+      n = [0, 1] and value = ""
+      or
+      // If there is more than one predecessor for this node
+      // we specify the source location explicitly.
+      n > 1 and
+      exists(TaintedWithPath::PathNode pred | pred = getAPredecessor(node) |
         value =
-          source.getLocation().getStartLine().toString() + ":" +
-            source.getLocation().getStartColumn()
-      ) and
-      location = tainted.getLocation() and
-      element = tainted.toString()
+          getElementFromPathNode(pred).getLocation().getStartLine().toString() + ":" +
+            getElementFromPathNode(pred).getLocation().getStartColumn()
+      )
     )
   }
 }

cpp/ql/test/library-tests/dataflow/DefaultTaintTracking/annotate_path_to_sink/test_diff.cpp

@@ -13,8 +13,8 @@ struct S {
     }
 };
 
-void calls_sink_with_argv(const char* a) { // $ ir-path=96:26 ir-path=98:18
-    sink(a); // $ ast=96:26 ast=98:18 ir-sink=96:26 ir-sink=98:18
+void calls_sink_with_argv(const char* a) { // $ ir-path=96:26 ir-path=102:26
+    sink(a); // $ ast=96:26 ast=98:18 ir-sink
 }
 
 extern int i;
@@ -27,7 +27,7 @@ public:
 class DerivedCallsSink : public BaseWithPureVirtual {
 public:
     void f(const char* p) override { // $ ir-path
-        sink(p); // $ ir-sink ast=108:10 SPURIOUS: ast=111:10
+        sink(p); // $ ast=108:10 ir-sink SPURIOUS: ast=111:10
     }
 };
 
@@ -49,8 +49,8 @@ public:
 };
 
 class DerivesMultiple : public DerivedCallsSinkDiamond1, public DerivedDoesNotCallSinkDiamond2 {
-    void f(const char* p) override { // $ ir-path
-        DerivedCallsSinkDiamond1::f(p);
+    void f(const char* p) override { // $ ir-path=53:37 ir-path=115:11
+        DerivedCallsSinkDiamond1::f(p); // $ ir-path
     }
 };
 
@@ -58,7 +58,7 @@ template<typename T>
 class CRTP {
 public:
     void f(const char* p) { // $ ir-path
-        static_cast<T*>(this)->g(p);
+        static_cast<T*>(this)->g(p); // $ ir-path
     }
 };
 
@@ -79,7 +79,7 @@ class Derived2 : public Derived1 {
 class Derived3 : public Derived2 {
     public:
     void f(const char* p) override { // $ ir-path=124:19 ir-path=126:43 ir-path=128:44
-        sink(p); // $ ast,ir-sink=124:19 ast,ir-sink=126:43 ast,ir-sink=128:44
+        sink(p); // $ ast=124:19 ast=126:43 ast=128:44 ir-sink
     }
 };
 
@@ -97,11 +97,11 @@ int main(int argc, char *argv[]) {
 
     char*** p = &argv; // $ ast,ir-path
 
-    sink(*p[0]); // $ ast,ir-sink
+    sink(*p[0]); // $ ast ir-sink=96:26 ir-sink=98:18
 
-    calls_sink_with_argv(*p[i]); // $ MISSING: ast,ir-path
+    calls_sink_with_argv(*p[i]); // $ ir-path=96:26 ir-path=98:18 MISSING:ast
 
-    sink(*(argv + 1)); // $ ast,ir-path ir-sink
+    sink(*(argv + 1)); // $ ast ir-path ir-sink
 
     BaseWithPureVirtual* b = new DerivedCallsSink;
 

cpp/ql/test/library-tests/dataflow/DefaultTaintTracking/annotate_sinks_only/defaulttainttracking.cpp

@@ -190,9 +190,9 @@ void test_pointers1()
 	sink(ptr1); // $ ast MISSING: ir
 	sink(ptr2); // $ SPURIOUS: ast
 	sink(*ptr2); // $ ast MISSING: ir
-	sink(ptr3); // $ ast MISSING: ir
-	sink(ptr4); // $ SPURIOUS: ast
-	sink(*ptr4); // $ ast MISSING: ir
+	sink(ptr3); // $ ast,ir
+	sink(ptr4); // $ SPURIOUS: ast,ir
+	sink(*ptr4); // $ ast,ir
 }
 
 void test_pointers2()