Revert "JS: Recognize DomSanitizer from @angular/core"

This reverts commit ff1d0cc4c7.

.codeqlmanifest.json

@@ -6,7 +6,6 @@
         "*/ql/examples/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/modelbuilding/qlpack.yml",
         "javascript/ql/experimental/adaptivethreatmodeling/src/qlpack.yml",
         "csharp/ql/campaigns/Solorigate/lib/qlpack.yml",
         "csharp/ql/campaigns/Solorigate/src/qlpack.yml",

.gitattributes

@@ -50,9 +50,4 @@
 *.pdb -text
 
 java/ql/test/stubs/**/*.java linguist-generated=true
-java/ql/test/experimental/stubs/**/*.java linguist-generated=true
-
-# Generated test files - these are synced from the standard JavaScript libraries using
-# `javascript/ql/experimental/adaptivethreatmodeling/test/update_endpoint_test_files.py`.
-javascript/ql/experimental/adaptivethreatmodeling/test/endpoint_large_scale/autogenerated/**/*.js linguist-generated=true -merge
-javascript/ql/experimental/adaptivethreatmodeling/test/endpoint_large_scale/autogenerated/**/*.ts linguist-generated=true -merge
+java/ql/test/experimental/stubs/**/*.java linguist-generated=true

.github/workflows/codeql-analysis.yml

@@ -27,11 +27,6 @@ jobs:
       pull-requests: read
 
     steps:
-    - name: Setup dotnet
-      uses: actions/setup-dotnet@v1
-      with:
-        dotnet-version: 6.0.101
-
     - name: Checkout repository
       uses: actions/checkout@v2
 
@@ -56,7 +51,7 @@ jobs:
     #    uses a compiled language
 
     - run: |
-       dotnet build csharp /p:UseSharedCompilation=false
+       dotnet build csharp
 
     - name: Perform CodeQL Analysis
       uses: github/codeql-action/analyze@main

.github/workflows/js-ml-tests.yml

@@ -1,67 +0,0 @@
-name: JS ML-powered queries tests
-
-on:
-  push:
-    paths:
-      - "javascript/ql/experimental/adaptivethreatmodeling/**"
-      - .github/workflows/js-ml-tests.yml
-    branches:
-      - main
-      - "rc/*"
-  pull_request:
-    paths:
-      - "javascript/ql/experimental/adaptivethreatmodeling/**"
-      - .github/workflows/js-ml-tests.yml
-
-defaults:
-  run:
-    working-directory: javascript/ql/experimental/adaptivethreatmodeling
-
-jobs:
-  qlformat:
-    name: Check QL formatting
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-
-      - uses: ./.github/actions/fetch-codeql
-
-      - name: Check QL formatting
-        run: |
-          find . "(" -name "*.ql" -or -name "*.qll" ")" -print0 | \
-            xargs -0 codeql query format --check-only
-
-  qlcompile:
-    name: Check QL compilation
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-
-      - uses: ./.github/actions/fetch-codeql
-
-      - name: Check QL compilation
-        run: |
-          codeql query compile \
-            --check-only \
-            --ram 5120 \
-            --additional-packs "${{ github.workspace }}" \
-            --threads=0 \
-            -- \
-            lib modelbuilding src
-
-  qltest:
-    name: Run QL tests
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-
-      - uses: ./.github/actions/fetch-codeql
-
-      - name: Run QL tests
-        run: |
-          codeql test run \
-            --threads=0 \
-            --ram 5120 \
-            --additional-packs "${{ github.workspace }}" \
-            -- \
-            test

.github/workflows/mad_modelDiff.yml

@@ -1,103 +0,0 @@
-name: Models as Data - Diff
-
-on:
-  workflow_dispatch:
-    inputs:
-      projects:
-        description: "The projects to generate models for"
-        required: true
-        default: '["netty/netty"]'
-  pull_request:
-    branches:
-      - main
-    paths:
-      - "java/ql/src/utils/model-generator/**/*.*"
-      - ".github/workflows/mad_modelDiff.yml"
-
-permissions:
-  contents: read
-
-jobs:
-  model-diff:
-    name: Model Difference
-    runs-on: ubuntu-latest
-    if: github.repository == 'github/codeql'
-    strategy:
-      matrix:
-        slug: ${{fromJson(github.event.inputs.projects || '["apache/commons-codec", "apache/commons-io", "apache/commons-beanutils", "apache/commons-logging", "apache/commons-fileupload", "apache/commons-lang", "apache/commons-validator", "apache/commons-csv", "apache/dubbo"]' )}}
-    steps:
-      - name: Clone github/codeql from PR
-        uses: actions/checkout@v2
-        if: github.event.pull_request
-        with:
-          path: codeql-pr
-      - name: Clone github/codeql from main
-        uses: actions/checkout@v2
-        with:
-          path: codeql-main
-          ref: main
-      - uses: ./codeql-main/.github/actions/fetch-codeql
-      - name: Download database
-        env:
-          SLUG: ${{ matrix.slug }}
-        run: |
-          set -x
-          mkdir lib-dbs
-          SHORTNAME=${SLUG//[^a-zA-Z0-9_]/}
-          projectId=`curl -s https://lgtm.com/api/v1.0/projects/g/${SLUG} | jq .id`
-          curl -L "https://lgtm.com/api/v1.0/snapshots/$projectId/java" -o "$SHORTNAME.zip"
-          unzip -q -d "${SHORTNAME}-db" "${SHORTNAME}.zip"
-          mkdir "lib-dbs/$SHORTNAME/"
-          mv "${SHORTNAME}-db/"$(ls -1 "${SHORTNAME}"-db)/* "lib-dbs/${SHORTNAME}/"
-      - name: Generate Models (PR and main)
-        run: |
-          set -x
-          mkdir tmp-models
-          MODELS=`pwd`/tmp-models
-          DATABASES=`pwd`/lib-dbs
-
-          analyzeDatabaseWithCheckout() {
-            QL_VARIANT=$1
-            DATABASE=$2
-            cd codeql-$QL_VARIANT
-            SHORTNAME=`basename $DATABASE`
-            python java/ql/src/utils/model-generator/GenerateFlowModel.py $DATABASE $MODELS/${SHORTNAME}.qll
-            mv $MODELS/${SHORTNAME}.qll $MODELS/${SHORTNAME}Generated_${QL_VARIANT}.qll
-            cd ..
-          }
-
-          for d in $DATABASES/*/ ; do
-            ls -1 "$d"
-
-            analyzeDatabaseWithCheckout "main" $d
-            if [[ "$GITHUB_EVENT_NAME" == "pull_request" ]]
-            then
-              analyzeDatabaseWithCheckout "pr" $d
-            fi
-          done
-      - name: Install diff2html
-        if: github.event.pull_request
-        run: |
-          npm install -g diff2html-cli
-      - name: Generate Model Diff
-        if: github.event.pull_request
-        run: |
-          set -x
-          MODELS=`pwd`/tmp-models
-          ls -1 tmp-models/
-          for m in $MODELS/*_main.qll ; do
-            t="${m/main/"pr"}"
-            basename=`basename $m`
-            name="diff_${basename/_main.qll/""}"
-            (diff -w -u $m $t | diff2html -i stdin -F $MODELS/$name.html) || true
-          done
-      - uses: actions/upload-artifact@v2
-        with:
-          name: models
-          path: tmp-models/*.qll
-          retention-days: 20
-      - uses: actions/upload-artifact@v2
-        with:
-          name: diffs
-          path: tmp-models/*.html
-          retention-days: 20

.github/workflows/mad_regenerate-models.yml

@@ -1,62 +0,0 @@
-name: Regenerate framework models
-
-on:
-  workflow_dispatch:
-  schedule:
-    - cron: "30 2 * * *"
-  pull_request:
-    branches:
-      - main
-    paths:
-      - ".github/workflows/mad_regenerate-models.yml"
-
-jobs:
-  regenerate-models:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        # placeholder required for each axis, excluded below, replaced by the actual combinations (see include)
-        slug: ["placeholder"]
-        ref: ["placeholder"]
-        include:
-          - slug: "apache/commons-io"
-            ref: "8985de8fe74f6622a419b37a6eed0dbc484dc128"
-        exclude:
-          - slug: "placeholder"
-            ref: "placeholder"
-    steps:
-      - name: Clone self (github/codeql)
-        uses: actions/checkout@v2
-      - name: Setup CodeQL binaries
-        uses: ./.github/actions/fetch-codeql
-      - name: Clone repositories
-        uses: actions/checkout@v2
-        with:
-          path: repos/${{ matrix.ref }}
-          ref: ${{ matrix.ref }}
-          repository: ${{ matrix.slug }}
-      - name: Build database
-        env:
-          SLUG: ${{ matrix.slug }}
-          REF: ${{ matrix.ref }}
-        run: |
-          mkdir dbs
-          cd repos/${REF}
-          SHORTNAME=${SLUG//[^a-zA-Z0-9_]/}
-          codeql database create --language=java ../../dbs/${SHORTNAME}
-      - name: Regenerate models in-place
-        env:
-          SLUG: ${{ matrix.slug }}
-        run: |
-          SHORTNAME=${SLUG//[^a-zA-Z0-9_]/}
-          java/ql/src/utils/model-generator/RegenerateModels.py "${SLUG}" dbs/${SHORTNAME}
-      - name: Stage changes
-        run: |
-          find java -name "*.qll" -print0 | xargs -0 git add
-          git status
-          git diff --cached > models.patch
-      - uses: actions/upload-artifact@v2
-        with:
-          name: patch
-          path: models.patch
-          retention-days: 7

.github/workflows/ql-for-ql-build.yml

@@ -189,11 +189,4 @@ jobs:
         uses: github/codeql-action/analyze@erik-krogh/ql
         with: 
           category: "ql-for-ql-${{ matrix.folder }}"
-      - name: Copy sarif file to CWD
-        run: cp ../results/ql.sarif ./${{ matrix.folder }}.sarif
-      - name: Sarif as artifact
-        uses: actions/upload-artifact@v2
-        with:
-          name: ${{ matrix.folder }}.sarif
-          path: ${{ matrix.folder }}.sarif
 

.github/workflows/ql-for-ql-dataset_measure.yml

@@ -17,7 +17,7 @@ jobs:
       CODEQL_THREADS: 4 # TODO: remove this once it's set by the CLI
     strategy:
       matrix:
-        repo:
+        repo: 
           - github/codeql
           - github/codeql-go
     runs-on: ubuntu-latest
@@ -35,7 +35,7 @@ jobs:
             ~/.cargo/registry
             ~/.cargo/git
             ql/target
-          key: ${{ runner.os }}-qltest-cargo-${{ hashFiles('ql/**/Cargo.lock') }}
+          key: ${{ runner.os }}-qltest-cargo-${{ hashFiles('**/Cargo.lock') }}
       - name: Build Extractor
         run: cd ql; env "PATH=$PATH:`dirname ${CODEQL}`" ./create-extractor-pack.sh
         env:

.github/workflows/ql-for-ql-tests.yml

@@ -29,24 +29,24 @@ jobs:
             ~/.cargo/registry
             ~/.cargo/git
             ql/target
-          key: ${{ runner.os }}-qltest-cargo-${{ hashFiles('ql/**/Cargo.lock') }}
+          key: ${{ runner.os }}-qltest-cargo-${{ hashFiles('**/Cargo.lock') }}
       - name: Build extractor
         run: |
           cd ql;
           codeqlpath=$(dirname ${{ steps.find-codeql.outputs.codeql-path }});
           env "PATH=$PATH:$codeqlpath" ./create-extractor-pack.sh
       - name: Run QL tests
-        run: |
+        run: | 
           "${CODEQL}" test run --check-databases --check-unused-labels --check-repeated-labels --check-redefined-labels --check-use-before-definition --search-path "${{ github.workspace }}/ql/extractor-pack" --consistency-queries ql/ql/consistency-queries ql/ql/test
         env:
           CODEQL: ${{ steps.find-codeql.outputs.codeql-path }}
       - name: Check QL formatting
-        run: |
+        run: | 
           find ql/ql "(" -name "*.ql" -or -name "*.qll" ")" -print0 | xargs -0 "${CODEQL}" query format --check-only
         env:
           CODEQL: ${{ steps.find-codeql.outputs.codeql-path }}
       - name: Check QL compilation
-        run: |
+        run: | 
           "${CODEQL}" query compile --check-only --threads=4 --warnings=error --search-path "${{ github.workspace }}/ql/extractor-pack" "ql/ql/src" "ql/ql/examples"
         env:
           CODEQL: ${{ steps.find-codeql.outputs.codeql-path }}

.github/workflows/ruby-build.yml

@@ -50,7 +50,7 @@ jobs:
             ~/.cargo/registry
             ~/.cargo/git
             ruby/target
-          key: ${{ runner.os }}-ruby-rust-cargo-${{ hashFiles('ruby/rust-toolchain.toml', 'ruby/**/Cargo.lock') }}
+          key: ${{ runner.os }}-rust-cargo-${{ hashFiles('**/Cargo.lock') }}
       - name: Check formatting
         run: cargo fmt --all -- --check
       - name: Build

.github/workflows/ruby-qltest.yml

@@ -24,45 +24,27 @@ defaults:
     working-directory: ruby
 
 jobs:
-  qlformat:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: ./.github/actions/fetch-codeql
-      - name: Check QL formatting
-        run: find ql "(" -name "*.ql" -or -name "*.qll" ")" -print0 | xargs -0 codeql query format --check-only
-  qlcompile:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: ./.github/actions/fetch-codeql
-      - name: Check QL compilation
-        run: |
-          codeql query compile --check-only --threads=0 --ram 5000 --warnings=error "ql/src" "ql/examples"
-        env:
-          GITHUB_TOKEN: ${{ github.token }}
-  qlupgrade:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: ./.github/actions/fetch-codeql
-      - name: Check DB upgrade scripts
-        run: |
-          echo >empty.trap
-          codeql dataset import -S ql/lib/upgrades/initial/ruby.dbscheme testdb empty.trap
-          codeql dataset upgrade testdb --additional-packs ql/lib
-          diff -q testdb/ruby.dbscheme ql/lib/ruby.dbscheme
   qltest:
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        slice: ["1/2", "2/2"]
     steps:
       - uses: actions/checkout@v2
       - uses: ./.github/actions/fetch-codeql
       - uses: ./ruby/actions/create-extractor-pack
       - name: Run QL tests
         run: |
-          codeql test run --threads=0 --ram 5000 --slice ${{ matrix.slice }} --search-path "${{ 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
+          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 "ql/src" "ql/examples"
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+      - name: Check DB upgrade scripts
+        run: |
+          echo >empty.trap
+          codeql dataset import -S ql/lib/upgrades/initial/ruby.dbscheme testdb empty.trap
+          codeql dataset upgrade testdb --additional-packs ql/lib
+          diff -q testdb/ruby.dbscheme ql/lib/ruby.dbscheme

CODEOWNERS

@@ -27,4 +27,4 @@
 /docs/query-*-style-guide.md @github/codeql-analysis-reviewers
 
 # QL for QL reviewers
-/ql/ @github/codeql-ql-for-ql-reviewers
+/ql/ @erik-krogh @tausbn

CONTRIBUTING.md

@@ -4,9 +4,6 @@ We welcome contributions to our CodeQL libraries and queries. Got an idea for a
 
 There is lots of useful documentation to help you write queries, ranging from information about query file structure to tutorials for specific target languages. For more information on the documentation available, see [CodeQL queries](https://help.semmle.com/QL/learn-ql/writing-queries/writing-queries.html) on [help.semmle.com](https://help.semmle.com).
 
-## Change notes
-
-Any nontrivial user-visible change to a query pack or library pack should have a change note. For details on how to add a change note for your change, see [this guide](docs/change-notes.md).
 
 ## Submitting a new experimental query
 

config/identical-files.json

@@ -7,7 +7,6 @@
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl5.qll",
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl6.qll",
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImplForSerializability.qll",
-    "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImplForOnActivityResult.qll",
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll",
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll",
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll",

cpp/autobuilder/Semmle.Autobuild.Cpp.Tests/Semmle.Autobuild.Cpp.Tests.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <RuntimeIdentifiers>win-x64;linux-x64;osx-x64</RuntimeIdentifiers>
     <Nullable>enable</Nullable>

cpp/autobuilder/Semmle.Autobuild.Cpp/Semmle.Autobuild.Cpp.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
     <AssemblyName>Semmle.Autobuild.Cpp</AssemblyName>
     <RootNamespace>Semmle.Autobuild.Cpp</RootNamespace>
     <ApplicationIcon />

cpp/config/suites/security/cwe-120

@@ -5,11 +5,9 @@
   @name Badly bounded write (CWE-120)
 + semmlecode-cpp-queries/Security/CWE/CWE-120/OverrunWrite.ql: /CWE/CWE-120
   @name Potentially overrunning write (CWE-120)
-+ semmlecode-cpp-queries/Security/CWE/CWE-120/VeryLikelyOverrunWrite.ql: /CWE/CWE-120
-  @name Likely overrunning write
 + semmlecode-cpp-queries/Security/CWE/CWE-120/OverrunWriteFloat.ql: /CWE/CWE-120
   @name Potentially overrunning write with float to string conversion (CWE-120)
 + semmlecode-cpp-queries/Best Practices/Likely Errors/OffsetUseBeforeRangeCheck.ql: /CWE/CWE-120
   @name Array offset used before range check (CWE-120)
 + semmlecode-cpp-queries/Likely Bugs/Memory Management/UnsafeUseOfStrcat.ql: /CWE/CWE-120
-  @name Potentially unsafe use of strcat (CWE-120)
+    @name Potentially unsafe use of strcat (CWE-120)

cpp/ql/examples/qlpack.yml

@@ -1,6 +1,4 @@
 name: codeql/cpp-examples
-groups: 
-  - cpp
-  - examples
+version: 0.0.2
 dependencies:
   codeql/cpp-all: "*"

cpp/ql/lib/CHANGELOG.md

@@ -1,7 +1,3 @@
-## 0.0.7
-
-## 0.0.6
-
 ## 0.0.5
 
 ## 0.0.4

cpp/ql/lib/change-notes/2022-01-11-remove-upgrades-packs.md

@@ -1,4 +0,0 @@
----
-category: deprecated
----
-* The `codeql/cpp-upgrades` CodeQL pack has been removed. All upgrades scripts have been merged into the `codeql/cpp-all` CodeQL pack.

cpp/ql/lib/change-notes/2022-01-14-hex-format-range-analysis.md

@@ -1,5 +0,0 @@
----
-category: minorAnalysis
----
-* `FormatLiteral::getMaxConvertedLength` now uses range analysis to provide a
-  more accurate length for integers formatted with `%x`

cpp/ql/lib/change-notes/released/0.0.6.md

@@ -1 +0,0 @@
-## 0.0.6

cpp/ql/lib/change-notes/released/0.0.7.md

@@ -1 +0,0 @@
-## 0.0.7

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

@@ -1,2 +1,2 @@
 ---
-lastReleaseVersion: 0.0.7
+lastReleaseVersion: 0.0.5

cpp/ql/lib/qlpack.yml

@@ -1,5 +1,5 @@
 name: codeql/cpp-all
-version: 0.0.8-dev
+version: 0.0.6-dev
 groups: cpp
 dbscheme: semmlecode.cpp.dbscheme
 extractor: cpp

cpp/ql/lib/semmle/code/cpp/Class.qll

@@ -206,7 +206,9 @@ class Class extends UserType {
    * it is callable by a particular caller. For C++11, there's also a question
    * of whether to include members that are defaulted or deleted.
    */
-  deprecated predicate hasCopyConstructor() { this.getAMemberFunction() instanceof CopyConstructor }
+  deprecated predicate hasCopyConstructor() {
+    exists(CopyConstructor cc | cc = this.getAMemberFunction())
+  }
 
   /**
    * Holds if this class has a copy assignment operator that is either
@@ -222,7 +224,7 @@ class Class extends UserType {
    * or deleted.
    */
   deprecated predicate hasCopyAssignmentOperator() {
-    this.getAMemberFunction() instanceof CopyAssignmentOperator
+    exists(CopyAssignmentOperator coa | coa = this.getAMemberFunction())
   }
 
   /**
@@ -885,7 +887,7 @@ class NestedClass extends Class {
  * pure virtual function.
  */
 class AbstractClass extends Class {
-  AbstractClass() { this.getAMemberFunction() instanceof PureVirtualFunction }
+  AbstractClass() { exists(PureVirtualFunction f | this.getAMemberFunction() = f) }
 
   override string getAPrimaryQlClass() { result = "AbstractClass" }
 }

cpp/ql/lib/semmle/code/cpp/Specifier.qll

@@ -286,13 +286,13 @@ class AttributeArgument extends Element, @attribute_arg {
   override Location getLocation() { attribute_args(underlyingElement(this), _, _, _, result) }
 
   override string toString() {
-    if underlyingElement(this) instanceof @attribute_arg_empty
+    if exists(@attribute_arg_empty self | self = underlyingElement(this))
     then result = "empty argument"
     else
       exists(string prefix, string tail |
         (if exists(this.getName()) then prefix = this.getName() + "=" else prefix = "") and
         (
-          if underlyingElement(this) instanceof @attribute_arg_type
+          if exists(@attribute_arg_type self | self = underlyingElement(this))
           then tail = this.getValueType().getName()
           else tail = this.getValueText()
         ) and

cpp/ql/lib/semmle/code/cpp/XML.qll

@@ -233,7 +233,7 @@ class XMLElement extends @xmlelement, XMLParent, XMLLocatable {
   XMLAttribute getAttribute(string name) { result.getElement() = this and result.getName() = name }
 
   /** Holds if this XML element has an attribute with the specified `name`. */
-  predicate hasAttribute(string name) { exists(this.getAttribute(name)) }
+  predicate hasAttribute(string name) { exists(XMLAttribute a | a = this.getAttribute(name)) }
 
   /** Gets the value of the attribute with the specified `name`, if any. */
   string getAttributeValue(string name) { result = this.getAttribute(name).getValue() }

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

@@ -101,21 +101,6 @@ predicate functionArgumentMustBeNullTerminated(Function f, int i) {
   f instanceof StrcatFunction and i = 0
 }
 
-/**
- * Holds if `arg` is a string format argument to a formatting function call
- * `ffc`.
- */
-predicate formatArgumentMustBeNullTerminated(FormattingFunctionCall ffc, Expr arg) {
-  // String argument to a formatting function (such as `printf`)
-  exists(int n, FormatLiteral fl |
-    ffc.getConversionArgument(n) = arg and
-    fl = ffc.getFormat() and
-    fl.getConversionType(n) instanceof PointerType and // `%s`, `%ws` etc
-    not fl.getConversionType(n) instanceof VoidPointerType and // exclude: `%p`
-    not fl.hasPrecision(n) // exclude: `%.*s`
-  )
-}
-
 /**
  * Holds if `va` is a variable access where the contents must be null terminated.
  */
@@ -128,7 +113,13 @@ predicate variableMustBeNullTerminated(VariableAccess va) {
     )
     or
     // String argument to a formatting function (such as `printf`)
-    formatArgumentMustBeNullTerminated(fc, va)
+    exists(int n, FormatLiteral fl |
+      fc.(FormattingFunctionCall).getConversionArgument(n) = va and
+      fl = fc.(FormattingFunctionCall).getFormat() and
+      fl.getConversionType(n) instanceof PointerType and // `%s`, `%ws` etc
+      not fl.getConversionType(n) instanceof VoidPointerType and // exclude: `%p`
+      not fl.hasPrecision(n) // exclude: `%.*s`
+    )
     or
     // Call to a wrapper function that requires null termination
     // (not itself adding a null terminator)

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

@@ -10,22 +10,10 @@ private import semmle.code.cpp.rangeanalysis.SimpleRangeAnalysis
 private import semmle.code.cpp.rangeanalysis.RangeAnalysisUtils
 
 private newtype TBufferWriteEstimationReason =
-  TUnspecifiedEstimateReason() or
+  TNoSpecifiedEstimateReason() or
   TTypeBoundsAnalysis() or
-  TWidenedValueFlowAnalysis() or
   TValueFlowAnalysis()
 
-private predicate gradeToReason(int grade, TBufferWriteEstimationReason reason) {
-  // when combining reasons, lower grade takes precedence
-  grade = 0 and reason = TUnspecifiedEstimateReason()
-  or
-  grade = 1 and reason = TTypeBoundsAnalysis()
-  or
-  grade = 2 and reason = TWidenedValueFlowAnalysis()
-  or
-  grade = 3 and reason = TValueFlowAnalysis()
-}
-
 /**
  * A reason for a specific buffer write size estimate.
  */
@@ -44,13 +32,7 @@ abstract class BufferWriteEstimationReason extends TBufferWriteEstimationReason
    * Combine estimate reasons. Used to give a reason for the size of a format string
    * conversion given reasons coming from its individual specifiers.
    */
-  BufferWriteEstimationReason combineWith(BufferWriteEstimationReason other) {
-    exists(int grade, int otherGrade |
-      gradeToReason(grade, this) and gradeToReason(otherGrade, other)
-    |
-      if otherGrade < grade then result = other else result = this
-    )
-  }
+  abstract BufferWriteEstimationReason combineWith(BufferWriteEstimationReason other);
 }
 
 /**
@@ -58,10 +40,16 @@ abstract class BufferWriteEstimationReason extends TBufferWriteEstimationReason
  * classes derived from BufferWrite and overriding `getMaxData/0` still work with the
  * queries as intended.
  */
-class UnspecifiedEstimateReason extends BufferWriteEstimationReason, TUnspecifiedEstimateReason {
-  override string toString() { result = "UnspecifiedEstimateReason" }
+class NoSpecifiedEstimateReason extends BufferWriteEstimationReason, TNoSpecifiedEstimateReason {
+  override string toString() { result = "NoSpecifiedEstimateReason" }
 
   override string getDescription() { result = "no reason specified" }
+
+  override BufferWriteEstimationReason combineWith(BufferWriteEstimationReason other) {
+    // this reason should not be used in format specifiers, so it should not be combined
+    // with other reasons
+    none()
+  }
 }
 
 /**
@@ -72,24 +60,9 @@ class TypeBoundsAnalysis extends BufferWriteEstimationReason, TTypeBoundsAnalysi
   override string toString() { result = "TypeBoundsAnalysis" }
 
   override string getDescription() { result = "based on type bounds" }
-}
 
-/**
- * The estimation comes from non trivial bounds found via actual flow analysis,
- * but a widening aproximation might have been used for variables in loops.
- * For example
- * ```
- * for (int i = 0; i < 10; ++i) {
- *    int j = i + i;
- *    //...  <- estimation done here based on j
- * }
- * ```
- */
-class WidenedValueFlowAnalysis extends BufferWriteEstimationReason, TWidenedValueFlowAnalysis {
-  override string toString() { result = "WidenedValueFlowAnalysis" }
-
-  override string getDescription() {
-    result = "based on flow analysis of value bounds with a widening approximation"
+  override BufferWriteEstimationReason combineWith(BufferWriteEstimationReason other) {
+    other != TNoSpecifiedEstimateReason() and result = TTypeBoundsAnalysis()
   }
 }
 
@@ -107,6 +80,10 @@ class ValueFlowAnalysis extends BufferWriteEstimationReason, TValueFlowAnalysis
   override string toString() { result = "ValueFlowAnalysis" }
 
   override string getDescription() { result = "based on flow analysis of value bounds" }
+
+  override BufferWriteEstimationReason combineWith(BufferWriteEstimationReason other) {
+    other != TNoSpecifiedEstimateReason() and result = other
+  }
 }
 
 class PrintfFormatAttribute extends FormatAttribute {
@@ -382,38 +359,6 @@ private int lengthInBase10(float f) {
   result = f.log10().floor() + 1
 }
 
-pragma[nomagic]
-private predicate isPointerTypeWithBase(Type base, PointerType pt) { base = pt.getBaseType() }
-
-bindingset[expr]
-private BufferWriteEstimationReason getEstimationReasonForIntegralExpression(Expr expr) {
-  // we consider the range analysis non trivial if it
-  // * constrained non-trivially both sides of a signed value, or
-  // * constrained non-trivially the positive side of an unsigned value
-  // expr should already be given as getFullyConverted
-  if
-    upperBound(expr) < exprMaxVal(expr) and
-    (exprMinVal(expr) >= 0 or lowerBound(expr) > exprMinVal(expr))
-  then
-    // next we check whether the estimate may have been widened
-    if upperBoundMayBeWidened(expr)
-    then result = TWidenedValueFlowAnalysis()
-    else result = TValueFlowAnalysis()
-  else result = TTypeBoundsAnalysis()
-}
-
-/**
- * Gets the number of hex digits required to represent the integer represented by `f`.
- *
- * `f` is assumed to be nonnegative.
- */
-bindingset[f]
-private int lengthInBase16(float f) {
-  f = 0 and result = 1
-  or
-  result = (f.log2() / 4.0).floor() + 1
-}
-
 /**
  * A class to represent format strings that occur as arguments to invocations of formatting functions.
  */
@@ -965,19 +910,19 @@ class FormatLiteral extends Literal {
       (
         conv = ["s", "S"] and
         len = "h" and
-        isPointerTypeWithBase(any(PlainCharType plainCharType), result)
+        result.(PointerType).getBaseType() instanceof PlainCharType
         or
         conv = ["s", "S"] and
         len = ["l", "w"] and
-        isPointerTypeWithBase(this.getWideCharType(), result)
+        result.(PointerType).getBaseType() = this.getWideCharType()
         or
         conv = "s" and
         (len != "l" and len != "w" and len != "h") and
-        isPointerTypeWithBase(this.getDefaultCharType(), result)
+        result.(PointerType).getBaseType() = this.getDefaultCharType()
         or
         conv = "S" and
         (len != "l" and len != "w" and len != "h") and
-        isPointerTypeWithBase(this.getNonDefaultCharType(), result)
+        result.(PointerType).getBaseType() = this.getNonDefaultCharType()
       )
     )
   }
@@ -1122,7 +1067,7 @@ class FormatLiteral extends Literal {
    * conversion specifier of this format string; has no result if this cannot
    * be determined.
    */
-  int getMaxConvertedLength(int n) { result = max(this.getMaxConvertedLength(n, _)) }
+  int getMaxConvertedLength(int n) { result = max(getMaxConvertedLength(n, _)) }
 
   /**
    * Gets the maximum length of the string that can be produced by the nth
@@ -1212,10 +1157,12 @@ class FormatLiteral extends Literal {
             1 + lengthInBase10(2.pow(this.getIntegralDisplayType(n).getSize() * 8 - 1)) and
           // 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 |
+          exists(Expr arg, float lower, float upper, float typeLower, float typeUpper |
             arg = this.getUse().getConversionArgument(n) and
             lower = lowerBound(arg.getFullyConverted()) and
-            upper = upperBound(arg.getFullyConverted())
+            upper = upperBound(arg.getFullyConverted()) and
+            typeLower = exprMinVal(arg.getFullyConverted()) and
+            typeUpper = exprMaxVal(arg.getFullyConverted())
           |
             valueBasedBound =
               max(int cand |
@@ -1232,9 +1179,11 @@ class FormatLiteral extends Literal {
                   else cand = lengthInBase10(upper)
                 )
               ) and
-            // we don't want to call this on `arg.getFullyConverted()` as we want
-            // to detect non-trivial range analysis without taking into account up-casting
-            reason = getEstimationReasonForIntegralExpression(arg)
+            (
+              if lower > typeLower or upper < typeUpper
+              then reason = TValueFlowAnalysis()
+              else reason = TTypeBoundsAnalysis()
+            )
           ) and
           len = valueBasedBound.minimum(typeBasedBound)
         )
@@ -1246,40 +1195,6 @@ class FormatLiteral extends Literal {
           typeBasedBound = lengthInBase10(2.pow(this.getIntegralDisplayType(n).getSize() * 8) - 1) and
           // 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, float upper |
-            arg = this.getUse().getConversionArgument(n) and
-            lower = lowerBound(arg.getFullyConverted()) and
-            upper = upperBound(arg.getFullyConverted())
-          |
-            valueBasedBound =
-              lengthInBase10(max(float cand |
-                  // If lower can be negative we use `(unsigned)-1` as the candidate value.
-                  lower < 0 and
-                  cand = 2.pow(any(IntType t | t.isUnsigned()).getSize() * 8)
-                  or
-                  cand = upper
-                )) and
-            // we don't want to call this on `arg.getFullyConverted()` as we want
-            // to detect non-trivial range analysis without taking into account up-casting
-            reason = getEstimationReasonForIntegralExpression(arg)
-          ) and
-          len = valueBasedBound.minimum(typeBasedBound)
-        )
-        or
-        this.getConversionChar(n).toLowerCase() = "x" and
-        // e.g. "12345678"
-        exists(int baseLen, int typeBasedBound, int valueBasedBound |
-          typeBasedBound =
-            min(int digits |
-              digits = 2 * this.getIntegralDisplayType(n).getSize()
-              or
-              exists(IntegralType t |
-                t = this.getUse().getConversionArgument(n).getType().getUnderlyingType()
-              |
-                t.isUnsigned() and
-                digits = 2 * t.getSize()
-              )
-            ) and
           exists(Expr arg, float lower, float upper, float typeLower, float typeUpper |
             arg = this.getUse().getConversionArgument(n) and
             lower = lowerBound(arg.getFullyConverted()) and
@@ -1288,7 +1203,7 @@ class FormatLiteral extends Literal {
             typeUpper = exprMaxVal(arg.getFullyConverted())
           |
             valueBasedBound =
-              lengthInBase16(max(float cand |
+              lengthInBase10(max(float cand |
                   // If lower can be negative we use `(unsigned)-1` as the candidate value.
                   lower < 0 and
                   cand = 2.pow(any(IntType t | t.isUnsigned()).getSize() * 8)
@@ -1301,10 +1216,29 @@ class FormatLiteral extends Literal {
               else reason = TTypeBoundsAnalysis()
             )
           ) and
-          baseLen = valueBasedBound.minimum(typeBasedBound) and
-          if this.hasAlternateFlag(n) then len = 2 + baseLen else len = baseLen // "0x"
+          len = valueBasedBound.minimum(typeBasedBound)
         )
         or
+        this.getConversionChar(n).toLowerCase() = "x" and
+        // e.g. "12345678"
+        exists(int sizeBytes, int baseLen |
+          sizeBytes =
+            min(int bytes |
+              bytes = this.getIntegralDisplayType(n).getSize()
+              or
+              exists(IntegralType t |
+                t = this.getUse().getConversionArgument(n).getType().getUnderlyingType()
+              |
+                t.isUnsigned() and bytes = t.getSize()
+              )
+            ) and
+          baseLen = sizeBytes * 2 and
+          (
+            if this.hasAlternateFlag(n) then len = 2 + baseLen else len = baseLen // "0x"
+          )
+        ) and
+        reason = TTypeBoundsAnalysis()
+        or
         this.getConversionChar(n).toLowerCase() = "p" and
         exists(PointerType ptrType, int baseLen |
           ptrType = this.getFullyConverted().getType() and
@@ -1353,7 +1287,7 @@ class FormatLiteral extends Literal {
    * determining whether a buffer overflow is caused by long float to string
    * conversions.
    */
-  int getMaxConvertedLengthLimited(int n) { result = max(this.getMaxConvertedLengthLimited(n, _)) }
+  int getMaxConvertedLengthLimited(int n) { result = max(getMaxConvertedLengthLimited(n, _)) }
 
   /**
    * Gets the maximum length of the string that can be produced by the nth

cpp/ql/lib/semmle/code/cpp/controlflow/IRGuards.qll

@@ -29,7 +29,7 @@ class GuardCondition extends Expr {
     exists(IRGuardCondition ir | this = ir.getUnconvertedResultExpression())
     or
     // no binary operators in the IR
-    this.(BinaryLogicalOperation).getAnOperand() instanceof GuardCondition
+    exists(GuardCondition gc | this.(BinaryLogicalOperation).getAnOperand() = gc)
     or
     // the IR short-circuits if(!x)
     // don't produce a guard condition for `y = !x` and other non-short-circuited cases
@@ -98,7 +98,7 @@ class GuardCondition extends Expr {
  */
 private class GuardConditionFromBinaryLogicalOperator extends GuardCondition {
   GuardConditionFromBinaryLogicalOperator() {
-    this.(BinaryLogicalOperation).getAnOperand() instanceof GuardCondition
+    exists(GuardCondition gc | this.(BinaryLogicalOperation).getAnOperand() = gc)
   }
 
   override predicate controls(BasicBlock controlled, boolean testIsTrue) {

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

@@ -3,17 +3,6 @@ private import DataFlowImplSpecific::Public
 import Cached
 
 module DataFlowImplCommonPublic {
-  /** A state value to track during data flow. */
-  class FlowState = string;
-
-  /**
-   * The default state, which is used when the state is unspecified for a source
-   * or a sink.
-   */
-  class FlowStateEmpty extends FlowState {
-    FlowStateEmpty() { this = "" }
-  }
-
   private newtype TFlowFeature =
     TFeatureHasSourceCallContext() or
     TFeatureHasSinkCallContext() or
@@ -1290,7 +1279,7 @@ class DataFlowCallOption extends TDataFlowCallOption {
   }
 }
 
-/** A `Content` tagged with the type of a containing object. */
+/** Content tagged with the type of a containing object. */
 class TypedContent extends MkTypedContent {
   private Content c;
   private DataFlowType t;

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

@@ -48,7 +48,7 @@ private class Argument extends Expr {
  */
 class ArgumentNode extends Node {
   ArgumentNode() {
-    this.asExpr() instanceof Argument or
+    exists(Argument arg | this.asExpr() = arg) or
     this = getInstanceArgument(_)
   }
 

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

@@ -592,14 +592,12 @@ predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
  * Holds if data flows from `source` to `sink` in zero or more local
  * (intra-procedural) steps.
  */
-pragma[inline]
 predicate localFlow(Node source, Node sink) { localFlowStep*(source, sink) }
 
 /**
  * Holds if data can flow from `e1` to `e2` in zero or more
  * local (intra-procedural) steps.
  */
-pragma[inline]
 predicate localExprFlow(Expr e1, Expr e2) { localFlow(exprNode(e1), exprNode(e2)) }
 
 /**

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

@@ -435,7 +435,7 @@ module FlowVar_internal {
       parameterIsNonConstReference(p) and
       p = v and
       // This definition reaches the exit node of the function CFG
-      getAReachedBlockVarSBB(this).getEnd() = p.getFunction()
+      getAReachedBlockVarSBB(this).getANode() = p.getFunction()
     }
 
     override predicate definedByInitialValue(StackVariable lsv) {

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

@@ -47,12 +47,6 @@ predicate defaultImplicitTaintRead(DataFlow::Node node, DataFlow::Content c) { n
  */
 predicate defaultTaintSanitizer(DataFlow::Node node) { none() }
 
-/**
- * Holds if `guard` should be a sanitizer guard in all global taint flow configurations
- * but not in local taint.
- */
-predicate defaultTaintSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
-
 /**
  * Holds if taint can flow in one local step from `nodeFrom` to `nodeTo` excluding
  * local data flow steps. That is, `nodeFrom` and `nodeTo` are likely to represent
@@ -124,14 +118,12 @@ predicate localAdditionalTaintStep(DataFlow::Node nodeFrom, DataFlow::Node nodeT
  * Holds if taint may propagate from `source` to `sink` in zero or more local
  * (intra-procedural) steps.
  */
-pragma[inline]
 predicate localTaint(DataFlow::Node source, DataFlow::Node sink) { localTaintStep*(source, sink) }
 
 /**
  * Holds if taint can flow from `e1` to `e2` in zero or more
  * local (intra-procedural) steps.
  */
-pragma[inline]
 predicate localExprTaint(Expr e1, Expr e2) {
   localTaint(DataFlow::exprNode(e1), DataFlow::exprNode(e2))
 }

cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking1/TaintTrackingImpl.qll

@@ -61,7 +61,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  override predicate isSource(DataFlow::Node source) { none() }
+  abstract override predicate isSource(DataFlow::Node source);
 
   /**
    * Holds if `sink` is a relevant taint sink.
@@ -69,7 +69,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  override predicate isSink(DataFlow::Node sink) { none() }
+  abstract override predicate isSink(DataFlow::Node sink);
 
   /** Holds if the node `node` is a taint sanitizer. */
   predicate isSanitizer(DataFlow::Node node) { none() }
@@ -93,7 +93,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+    this.isSanitizerGuard(guard)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking2/TaintTrackingImpl.qll

@@ -61,7 +61,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  override predicate isSource(DataFlow::Node source) { none() }
+  abstract override predicate isSource(DataFlow::Node source);
 
   /**
    * Holds if `sink` is a relevant taint sink.
@@ -69,7 +69,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  override predicate isSink(DataFlow::Node sink) { none() }
+  abstract override predicate isSink(DataFlow::Node sink);
 
   /** Holds if the node `node` is a taint sanitizer. */
   predicate isSanitizer(DataFlow::Node node) { none() }
@@ -93,7 +93,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+    this.isSanitizerGuard(guard)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/exprs/Access.qll

@@ -84,8 +84,8 @@ class VariableAccess extends Access, @varaccess {
     exists(Assignment a | a.getLValue() = this) or
     exists(CrementOperation c | c.getOperand() = this) or
     exists(AddressOfExpr addof | addof.getOperand() = this) or
-    this.getConversion() instanceof ReferenceToExpr or
-    this.getConversion() instanceof ArrayToPointerConversion
+    exists(ReferenceToExpr rte | this.getConversion() = rte) or
+    exists(ArrayToPointerConversion atpc | this.getConversion() = atpc)
   }
 
   /**
@@ -104,8 +104,8 @@ class VariableAccess extends Access, @varaccess {
   predicate isRValue() {
     not exists(AssignExpr ae | ae.getLValue() = this) and
     not exists(AddressOfExpr addof | addof.getOperand() = this) and
-    not this.getConversion() instanceof ReferenceToExpr and
-    not this.getConversion() instanceof ArrayToPointerConversion
+    not exists(ReferenceToExpr rte | this.getConversion() = rte) and
+    not exists(ArrayToPointerConversion atpc | this.getConversion() = atpc)
   }
 
   /**
@@ -218,7 +218,9 @@ class PointerFieldAccess extends FieldAccess {
 class DotFieldAccess extends FieldAccess {
   override string getAPrimaryQlClass() { result = "DotFieldAccess" }
 
-  DotFieldAccess() { this.getQualifier().getFullyConverted().getUnspecifiedType() instanceof Class }
+  DotFieldAccess() {
+    exists(Class c | c = this.getQualifier().getFullyConverted().getUnspecifiedType())
+  }
 }
 
 /**

cpp/ql/lib/semmle/code/cpp/exprs/Call.qll

@@ -35,7 +35,7 @@ class Call extends Expr, NameQualifiableElement, TCall {
    *
    * For example, `ptr->f()` has a qualifier, whereas plain `f()` does not.
    */
-  predicate hasQualifier() { exists(this.getChild(-1)) }
+  predicate hasQualifier() { exists(Expr e | this.getChild(-1) = e) }
 
   /**
    * Gets the expression to the left of the function name or function pointer variable name.

cpp/ql/lib/semmle/code/cpp/exprs/Cast.qll

@@ -724,7 +724,7 @@ class SizeofOperator extends Expr, @runtime_sizeof {
  * ```
  */
 class SizeofExprOperator extends SizeofOperator {
-  SizeofExprOperator() { exists(this.getChild(0)) }
+  SizeofExprOperator() { exists(Expr e | this.getChild(0) = e) }
 
   override string getAPrimaryQlClass() { result = "SizeofExprOperator" }
 
@@ -787,7 +787,7 @@ class AlignofOperator extends Expr, @runtime_alignof {
  * ```
  */
 class AlignofExprOperator extends AlignofOperator {
-  AlignofExprOperator() { exists(this.getChild(0)) }
+  AlignofExprOperator() { exists(Expr e | this.getChild(0) = e) }
 
   /**
    * Gets the contained expression.

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

@@ -1,8 +1,3 @@
-/**
- * An IR taint tracking library that uses an IR DataFlow configuration to track
- * taint from user inputs as defined by `semmle.code.cpp.security.Security`.
- */
-
 import cpp
 import semmle.code.cpp.security.Security
 private import semmle.code.cpp.ir.dataflow.DataFlow

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

@@ -3,17 +3,6 @@ private import DataFlowImplSpecific::Public
 import Cached
 
 module DataFlowImplCommonPublic {
-  /** A state value to track during data flow. */
-  class FlowState = string;
-
-  /**
-   * The default state, which is used when the state is unspecified for a source
-   * or a sink.
-   */
-  class FlowStateEmpty extends FlowState {
-    FlowStateEmpty() { this = "" }
-  }
-
   private newtype TFlowFeature =
     TFeatureHasSourceCallContext() or
     TFeatureHasSinkCallContext() or
@@ -1290,7 +1279,7 @@ class DataFlowCallOption extends TDataFlowCallOption {
   }
 }
 
-/** A `Content` tagged with the type of a containing object. */
+/** Content tagged with the type of a containing object. */
 class TypedContent extends MkTypedContent {
   private Content c;
   private DataFlowType t;

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

@@ -1032,14 +1032,12 @@ SideEffectInstruction getSideEffectFor(CallInstruction call, int argument) {
  * Holds if data flows from `source` to `sink` in zero or more local
  * (intra-procedural) steps.
  */
-pragma[inline]
 predicate localFlow(Node source, Node sink) { localFlowStep*(source, sink) }
 
 /**
  * Holds if data can flow from `i1` to `i2` in zero or more
  * local (intra-procedural) steps.
  */
-pragma[inline]
 predicate localInstructionFlow(Instruction e1, Instruction e2) {
   localFlow(instructionNode(e1), instructionNode(e2))
 }
@@ -1048,7 +1046,6 @@ predicate localInstructionFlow(Instruction e1, Instruction e2) {
  * Holds if data can flow from `e1` to `e2` in zero or more
  * local (intra-procedural) steps.
  */
-pragma[inline]
 predicate localExprFlow(Expr e1, Expr e2) { localFlow(exprNode(e1), exprNode(e2)) }
 
 private newtype TContent =

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

@@ -170,16 +170,10 @@ private class ReturnParameterIndirection extends Use, TReturnParamIndirection {
 }
 
 private predicate isExplicitUse(Operand op) {
-  exists(VariableAddressInstruction vai | vai = op.getDef() |
-    // Don't include this operand as a use if it only exists to initialize the
-    // indirection of a parameter.
-    not exists(LoadInstruction load |
-      load.getSourceAddressOperand() = op and
-      load.getAUse().getUse() instanceof InitializeIndirectionInstruction
-    ) and
-    // Don't include this operand as a use if the only use of the address is for a write
-    // that definitely overrides a variable.
-    not (explicitWrite(true, _, vai) and exists(unique( | | vai.getAUse())))
+  op.getDef() instanceof VariableAddressInstruction and
+  not exists(LoadInstruction load |
+    load.getSourceAddressOperand() = op and
+    load.getAUse().getUse() instanceof InitializeIndirectionInstruction
   )
 }
 

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

@@ -121,14 +121,12 @@ private predicate operandToInstructionTaintStep(Operand opFrom, Instruction inst
  * Holds if taint may propagate from `source` to `sink` in zero or more local
  * (intra-procedural) steps.
  */
-pragma[inline]
 predicate localTaint(DataFlow::Node source, DataFlow::Node sink) { localTaintStep*(source, sink) }
 
 /**
  * Holds if taint can flow from `i1` to `i2` in zero or more
  * local (intra-procedural) steps.
  */
-pragma[inline]
 predicate localInstructionTaint(Instruction i1, Instruction i2) {
   localTaint(DataFlow::instructionNode(i1), DataFlow::instructionNode(i2))
 }
@@ -137,7 +135,6 @@ predicate localInstructionTaint(Instruction i1, Instruction i2) {
  * Holds if taint can flow from `e1` to `e2` in zero or more
  * local (intra-procedural) steps.
  */
-pragma[inline]
 predicate localExprTaint(Expr e1, Expr e2) {
   localTaint(DataFlow::exprNode(e1), DataFlow::exprNode(e2))
 }
@@ -163,12 +160,6 @@ predicate defaultImplicitTaintRead(DataFlow::Node node, DataFlow::Content c) { n
  */
 predicate defaultTaintSanitizer(DataFlow::Node node) { none() }
 
-/**
- * Holds if `guard` should be a sanitizer guard in all global taint flow configurations
- * but not in local taint.
- */
-predicate defaultTaintSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
-
 /**
  * Holds if taint can flow from `instrIn` to `instrOut` through a call to a
  * modeled function.

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking1/TaintTrackingImpl.qll

@@ -61,7 +61,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  override predicate isSource(DataFlow::Node source) { none() }
+  abstract override predicate isSource(DataFlow::Node source);
 
   /**
    * Holds if `sink` is a relevant taint sink.
@@ -69,7 +69,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  override predicate isSink(DataFlow::Node sink) { none() }
+  abstract override predicate isSink(DataFlow::Node sink);
 
   /** Holds if the node `node` is a taint sanitizer. */
   predicate isSanitizer(DataFlow::Node node) { none() }
@@ -93,7 +93,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+    this.isSanitizerGuard(guard)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking2/TaintTrackingImpl.qll

@@ -61,7 +61,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  override predicate isSource(DataFlow::Node source) { none() }
+  abstract override predicate isSource(DataFlow::Node source);
 
   /**
    * Holds if `sink` is a relevant taint sink.
@@ -69,7 +69,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  override predicate isSink(DataFlow::Node sink) { none() }
+  abstract override predicate isSink(DataFlow::Node sink);
 
   /** Holds if the node `node` is a taint sanitizer. */
   predicate isSanitizer(DataFlow::Node node) { none() }
@@ -93,7 +93,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+    this.isSanitizerGuard(guard)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking3/TaintTrackingImpl.qll

@@ -61,7 +61,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  override predicate isSource(DataFlow::Node source) { none() }
+  abstract override predicate isSource(DataFlow::Node source);
 
   /**
    * Holds if `sink` is a relevant taint sink.
@@ -69,7 +69,7 @@ abstract class Configuration extends DataFlow::Configuration {
    * The smaller this predicate is, the faster `hasFlow()` will converge.
    */
   // overridden to provide taint-tracking specific qldoc
-  override predicate isSink(DataFlow::Node sink) { none() }
+  abstract override predicate isSink(DataFlow::Node sink);
 
   /** Holds if the node `node` is a taint sanitizer. */
   predicate isSanitizer(DataFlow::Node node) { none() }
@@ -93,7 +93,7 @@ abstract class Configuration extends DataFlow::Configuration {
   predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
 
   final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
-    this.isSanitizerGuard(guard) or defaultTaintSanitizerGuard(guard)
+    this.isSanitizerGuard(guard)
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/SideEffects.qll

@@ -111,45 +111,6 @@ private predicate hasDefaultSideEffect(Call call, ParameterIndex i, boolean buff
   )
 }
 
-/**
- * A `Call` or `NewOrNewArrayExpr`.
- *
- * Both kinds of expression invoke a function as part of their evaluation. This class provides a
- * way to treat both kinds of function similarly, and to get the invoked `Function`.
- */
-class CallOrAllocationExpr extends Expr {
-  CallOrAllocationExpr() {
-    this instanceof Call
-    or
-    this instanceof NewOrNewArrayExpr
-  }
-
-  /** Gets the `Function` invoked by this expression, if known. */
-  final Function getTarget() {
-    result = this.(Call).getTarget()
-    or
-    result = this.(NewOrNewArrayExpr).getAllocator()
-  }
-}
-
-/**
- * Returns the side effect opcode, if any, that represents any side effects not specifically modeled
- * by an argument side effect.
- */
-Opcode getCallSideEffectOpcode(CallOrAllocationExpr expr) {
-  not exists(expr.getTarget().(SideEffectFunction)) and result instanceof Opcode::CallSideEffect
-  or
-  exists(SideEffectFunction sideEffectFunction |
-    sideEffectFunction = expr.getTarget() and
-    if not sideEffectFunction.hasOnlySpecificWriteSideEffects()
-    then result instanceof Opcode::CallSideEffect
-    else (
-      not sideEffectFunction.hasOnlySpecificReadSideEffects() and
-      result instanceof Opcode::CallReadSideEffect
-    )
-  )
-}
-
 /**
  * Returns a side effect opcode for parameter index `i` of the specified call.
  *

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedCall.qll

@@ -49,6 +49,19 @@ abstract class TranslatedCall extends TranslatedExpr {
     tag = CallTag() and
     opcode instanceof Opcode::Call and
     resultType = getTypeForPRValue(getCallResultType())
+    or
+    hasSideEffect() and
+    tag = CallSideEffectTag() and
+    (
+      if hasWriteSideEffect()
+      then (
+        opcode instanceof Opcode::CallSideEffect and
+        resultType = getUnknownType()
+      ) else (
+        opcode instanceof Opcode::CallReadSideEffect and
+        resultType = getVoidType()
+      )
+    )
   }
 
   override Instruction getChildSuccessor(TranslatedElement child) {
@@ -71,8 +84,25 @@ abstract class TranslatedCall extends TranslatedExpr {
 
   override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) {
     kind instanceof GotoEdge and
-    tag = CallTag() and
-    result = getSideEffects().getFirstInstruction()
+    (
+      (
+        tag = CallTag() and
+        if hasSideEffect()
+        then result = getInstruction(CallSideEffectTag())
+        else
+          if hasPreciseSideEffect()
+          then result = getSideEffects().getFirstInstruction()
+          else result = getParent().getChildSuccessor(this)
+      )
+      or
+      (
+        hasSideEffect() and
+        tag = CallSideEffectTag() and
+        if hasPreciseSideEffect()
+        then result = getSideEffects().getFirstInstruction()
+        else result = getParent().getChildSuccessor(this)
+      )
+    )
   }
 
   override Instruction getInstructionRegisterOperand(InstructionTag tag, OperandTag operandTag) {
@@ -91,6 +121,15 @@ abstract class TranslatedCall extends TranslatedExpr {
     )
   }
 
+  final override CppType getInstructionMemoryOperandType(
+    InstructionTag tag, TypedOperandTag operandTag
+  ) {
+    tag = CallSideEffectTag() and
+    hasSideEffect() and
+    operandTag instanceof SideEffectOperandTag and
+    result = getUnknownType()
+  }
+
   final override Instruction getResult() { result = getInstruction(CallTag()) }
 
   /**
@@ -161,31 +200,40 @@ abstract class TranslatedCall extends TranslatedExpr {
    */
   abstract predicate hasArguments();
 
+  predicate hasReadSideEffect() { any() }
+
+  predicate hasWriteSideEffect() { any() }
+
+  private predicate hasSideEffect() { hasReadSideEffect() or hasWriteSideEffect() }
+
+  override Instruction getPrimaryInstructionForSideEffect(InstructionTag tag) {
+    hasSideEffect() and
+    tag = CallSideEffectTag() and
+    result = getResult()
+  }
+
+  predicate hasPreciseSideEffect() { exists(getSideEffects()) }
+
   final TranslatedSideEffects getSideEffects() { result.getExpr() = expr }
 }
 
-/**
- * The IR translation of the side effects of the parent `TranslatedElement`.
- *
- * This object does not itself generate the side effect instructions. Instead, its children provide
- * the actual side effects, with this object acting as a placeholder so the parent only needs to
- * insert this one element at the point where all the side effects are supposed to occur.
- */
 abstract class TranslatedSideEffects extends TranslatedElement {
-  /** Gets the expression whose side effects are being modeled. */
   abstract Expr getExpr();
 
   final override Locatable getAST() { result = getExpr() }
 
   final override Function getFunction() { result = getExpr().getEnclosingFunction() }
 
-  final override TranslatedElement getChild(int i) {
+  override TranslatedElement getChild(int i) {
     result =
-      rank[i + 1](TranslatedSideEffect tse, int group, int indexInGroup |
-        tse.getPrimaryExpr() = getExpr() and
-        tse.sortOrder(group, indexInGroup)
+      rank[i + 1](TranslatedSideEffect tse, int isWrite, int index |
+        (
+          tse.getCall() = getExpr() and
+          tse.getArgumentIndex() = index and
+          if tse.isWrite() then isWrite = 1 else isWrite = 0
+        )
       |
-        tse order by group, indexInGroup
+        tse order by isWrite, index
       )
   }
 
@@ -198,21 +246,12 @@ abstract class TranslatedSideEffects extends TranslatedElement {
     )
   }
 
-  final override predicate hasInstruction(Opcode opcode, InstructionTag tag, CppType type) {
-    none()
+  /**
+   * Gets the `TranslatedFunction` containing this expression.
+   */
+  final TranslatedFunction getEnclosingFunction() {
+    result = getTranslatedFunction(getExpr().getEnclosingFunction())
   }
-
-  final override Instruction getFirstInstruction() {
-    result = getChild(0).getFirstInstruction()
-    or
-    // Some functions, like `std::move()`, have no side effects whatsoever.
-    not exists(getChild(0)) and result = getParent().getChildSuccessor(this)
-  }
-
-  final override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) { none() }
-
-  /** Gets the primary instruction to be associated with each side effect instruction. */
-  abstract Instruction getPrimaryInstruction();
 }
 
 /**
@@ -286,6 +325,14 @@ class TranslatedFunctionCall extends TranslatedCallExpr, TranslatedDirectCall {
     tag = CallTargetTag() and result = expr.getTarget()
   }
 
+  override predicate hasReadSideEffect() {
+    not expr.getTarget().(SideEffectFunction).hasOnlySpecificReadSideEffects()
+  }
+
+  override predicate hasWriteSideEffect() {
+    not expr.getTarget().(SideEffectFunction).hasOnlySpecificWriteSideEffects()
+  }
+
   override Instruction getQualifierResult() {
     hasQualifier() and
     result = getQualifier().getResult()
@@ -316,116 +363,209 @@ class TranslatedStructorCall extends TranslatedFunctionCall {
   override predicate hasQualifier() { any() }
 }
 
-/**
- * The IR translation of the side effects of a function call, including the implicit allocator
- * call in a `new` or `new[]` expression.
- */
+class TranslatedAllocationSideEffects extends TranslatedSideEffects,
+  TTranslatedAllocationSideEffects {
+  AllocationExpr expr;
+
+  TranslatedAllocationSideEffects() { this = TTranslatedAllocationSideEffects(expr) }
+
+  final override AllocationExpr getExpr() { result = expr }
+
+  override string toString() { result = "(allocation side effects for " + expr.toString() + ")" }
+
+  override Instruction getFirstInstruction() { result = getInstruction(OnlyInstructionTag()) }
+
+  override predicate hasInstruction(Opcode opcode, InstructionTag tag, CppType type) {
+    opcode instanceof Opcode::InitializeDynamicAllocation and
+    tag = OnlyInstructionTag() and
+    type = getUnknownType()
+  }
+
+  override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) {
+    tag = OnlyInstructionTag() and
+    kind = EdgeKind::gotoEdge() and
+    if exists(getChild(0))
+    then result = getChild(0).getFirstInstruction()
+    else result = getParent().getChildSuccessor(this)
+  }
+
+  override Instruction getInstructionRegisterOperand(InstructionTag tag, OperandTag operandTag) {
+    tag = OnlyInstructionTag() and
+    operandTag = addressOperand() and
+    result = getPrimaryInstructionForSideEffect(OnlyInstructionTag())
+  }
+
+  override Instruction getPrimaryInstructionForSideEffect(InstructionTag tag) {
+    tag = OnlyInstructionTag() and
+    if expr instanceof NewOrNewArrayExpr
+    then result = getTranslatedAllocatorCall(expr).getInstruction(CallTag())
+    else result = getTranslatedCallInstruction(expr)
+  }
+}
+
 class TranslatedCallSideEffects extends TranslatedSideEffects, TTranslatedCallSideEffects {
-  Expr expr;
+  Call expr;
 
   TranslatedCallSideEffects() { this = TTranslatedCallSideEffects(expr) }
 
-  final override string toString() { result = "(side effects  for " + expr.toString() + ")" }
+  override string toString() { result = "(side effects  for " + expr.toString() + ")" }
 
-  final override Expr getExpr() { result = expr }
+  override Call getExpr() { result = expr }
 
-  final override Instruction getPrimaryInstruction() {
-    expr instanceof Call and result = getTranslatedCallInstruction(expr)
-    or
-    expr instanceof NewOrNewArrayExpr and
-    result = getTranslatedAllocatorCall(expr).getInstruction(CallTag())
-  }
-}
+  override predicate hasInstruction(Opcode opcode, InstructionTag tag, CppType type) { none() }
 
-/** Returns the sort group index for argument read side effects. */
-private int argumentReadGroup() { result = 1 }
+  override Instruction getFirstInstruction() { result = getChild(0).getFirstInstruction() }
 
-/** Returns the sort group index for conservative call side effects. */
-private int callSideEffectGroup() {
-  result = 0 // Make this group first for now to preserve the existing ordering
-}
+  override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) { none() }
 
-/** Returns the sort group index for argument write side effects. */
-private int argumentWriteGroup() { result = 2 }
-
-/** Returns the sort group index for dynamic allocation side effects. */
-private int initializeAllocationGroup() { result = 3 }
-
-/**
- * The IR translation of a single side effect of a call.
- */
-abstract class TranslatedSideEffect extends TranslatedElement {
-  final override TranslatedElement getChild(int n) { none() }
-
-  final override Instruction getChildSuccessor(TranslatedElement child) { none() }
-
-  final override Instruction getFirstInstruction() { result = getInstruction(OnlyInstructionTag()) }
-
-  final override predicate hasInstruction(Opcode opcode, InstructionTag tag, CppType type) {
+  override Instruction getPrimaryInstructionForSideEffect(InstructionTag tag) {
     tag = OnlyInstructionTag() and
-    sideEffectInstruction(opcode, type)
+    result = getTranslatedCallInstruction(expr)
+  }
+}
+
+class TranslatedStructorCallSideEffects extends TranslatedCallSideEffects {
+  TranslatedStructorCallSideEffects() {
+    getParent().(TranslatedStructorCall).hasQualifier() and
+    getASideEffectOpcode(expr, -1) instanceof WriteSideEffectOpcode
   }
 
-  final override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) {
+  override predicate hasInstruction(Opcode opcode, InstructionTag tag, CppType t) {
+    tag instanceof OnlyInstructionTag and
+    t = getTypeForPRValue(expr.getTarget().getDeclaringType()) and
+    opcode = getASideEffectOpcode(expr, -1).(WriteSideEffectOpcode)
+  }
+
+  override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) {
+    (
+      if exists(getChild(0))
+      then result = getChild(0).getFirstInstruction()
+      else result = getParent().getChildSuccessor(this)
+    ) and
+    tag = OnlyInstructionTag() and
+    kind instanceof GotoEdge
+  }
+
+  override Instruction getFirstInstruction() { result = getInstruction(OnlyInstructionTag()) }
+
+  override Instruction getInstructionRegisterOperand(InstructionTag tag, OperandTag operandTag) {
+    tag instanceof OnlyInstructionTag and
+    operandTag instanceof AddressOperandTag and
+    result = getParent().(TranslatedStructorCall).getQualifierResult()
+  }
+
+  final override int getInstructionIndex(InstructionTag tag) {
+    tag = OnlyInstructionTag() and
+    result = -1
+  }
+}
+
+class TranslatedSideEffect extends TranslatedElement, TTranslatedArgumentSideEffect {
+  Call call;
+  Expr arg;
+  int index;
+  SideEffectOpcode sideEffectOpcode;
+
+  TranslatedSideEffect() {
+    this = TTranslatedArgumentSideEffect(call, arg, index, sideEffectOpcode)
+  }
+
+  override Locatable getAST() { result = arg }
+
+  Expr getExpr() { result = arg }
+
+  Call getCall() { result = call }
+
+  int getArgumentIndex() { result = index }
+
+  predicate isWrite() { sideEffectOpcode instanceof WriteSideEffectOpcode }
+
+  override string toString() {
+    isWrite() and
+    result = "(write side effect for " + arg.toString() + ")"
+    or
+    not isWrite() and
+    result = "(read side effect for " + arg.toString() + ")"
+  }
+
+  override TranslatedElement getChild(int n) { none() }
+
+  override Instruction getChildSuccessor(TranslatedElement child) { none() }
+
+  override Instruction getFirstInstruction() { result = getInstruction(OnlyInstructionTag()) }
+
+  override predicate hasInstruction(Opcode opcode, InstructionTag tag, CppType type) {
+    tag = OnlyInstructionTag() and
+    opcode = sideEffectOpcode and
+    (
+      isWrite() and
+      (
+        opcode instanceof BufferAccessOpcode and
+        type = getUnknownType()
+        or
+        not opcode instanceof BufferAccessOpcode and
+        exists(Type baseType | baseType = arg.getUnspecifiedType().(DerivedType).getBaseType() |
+          if baseType instanceof VoidType
+          then type = getUnknownType()
+          else type = getTypeForPRValueOrUnknown(baseType)
+        )
+        or
+        index = -1 and
+        not arg.getUnspecifiedType() instanceof DerivedType and
+        type = getTypeForPRValueOrUnknown(arg.getUnspecifiedType())
+      )
+      or
+      not isWrite() and
+      type = getVoidType()
+    )
+  }
+
+  override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) {
     result = getParent().getChildSuccessor(this) and
     tag = OnlyInstructionTag() and
     kind instanceof GotoEdge
   }
 
-  final override Function getFunction() { result = getParent().getFunction() }
-
-  final override Instruction getPrimaryInstructionForSideEffect(InstructionTag tag) {
-    tag = OnlyInstructionTag() and
-    result = getParent().(TranslatedSideEffects).getPrimaryInstruction()
-  }
-
-  /**
-   * Gets the expression that caused this side effect.
-   *
-   * All side effects with the same `getPrimaryExpr()` will appear in the same contiguous sequence
-   * in the IR.
-   */
-  abstract Expr getPrimaryExpr();
-
-  /**
-   * Gets the order in which this side effect should be sorted with respect to other side effects
-   * for the same expression.
-   *
-   * Side effects are sorted first by `group`, and then by `indexInGroup`.
-   */
-  abstract predicate sortOrder(int group, int indexInGroup);
-
-  /**
-   * Gets the opcode and result type for the side effect instruction.
-   */
-  abstract predicate sideEffectInstruction(Opcode opcode, CppType type);
-}
-
-/**
- * The IR translation of a single argument side effect for a call.
- */
-abstract class TranslatedArgumentSideEffect extends TranslatedSideEffect {
-  Call call;
-  int index;
-  SideEffectOpcode sideEffectOpcode;
-
-  // All subclass charpreds must bind the `index` field.
-  bindingset[index]
-  TranslatedArgumentSideEffect() { any() }
-
-  override string toString() {
-    isWrite() and
-    result = "(write side effect for " + getArgString() + ")"
+  override Instruction getInstructionRegisterOperand(InstructionTag tag, OperandTag operandTag) {
+    tag instanceof OnlyInstructionTag and
+    operandTag instanceof AddressOperandTag and
+    result = getTranslatedExpr(arg).getResult()
     or
-    not isWrite() and
-    result = "(read side effect for " + getArgString() + ")"
+    tag instanceof OnlyInstructionTag and
+    operandTag instanceof BufferSizeOperandTag and
+    result =
+      getTranslatedExpr(call.getArgument(call.getTarget()
+              .(SideEffectFunction)
+              .getParameterSizeIndex(index)).getFullyConverted()).getResult()
   }
 
-  override Call getPrimaryExpr() { result = call }
+  override CppType getInstructionMemoryOperandType(InstructionTag tag, TypedOperandTag operandTag) {
+    not isWrite() and
+    if sideEffectOpcode instanceof BufferAccessOpcode
+    then
+      result = getUnknownType() and
+      tag instanceof OnlyInstructionTag and
+      operandTag instanceof SideEffectOperandTag
+    else
+      exists(Type operandType |
+        tag instanceof OnlyInstructionTag and
+        operandType = arg.getType().getUnspecifiedType().(DerivedType).getBaseType() and
+        operandTag instanceof SideEffectOperandTag
+        or
+        tag instanceof OnlyInstructionTag and
+        operandType = arg.getType().getUnspecifiedType() and
+        not operandType instanceof DerivedType and
+        operandTag instanceof SideEffectOperandTag
+      |
+        // If the type we select is an incomplete type (e.g. a forward-declared `struct`), there will
+        // not be a `CppType` that represents that type. In that case, fall back to `UnknownCppType`.
+        result = getTypeForPRValueOrUnknown(operandType)
+      )
+  }
 
-  override predicate sortOrder(int group, int indexInGroup) {
-    indexInGroup = index and
-    if isWrite() then group = argumentWriteGroup() else group = argumentReadGroup()
+  override Instruction getPrimaryInstructionForSideEffect(InstructionTag tag) {
+    tag = OnlyInstructionTag() and
+    result = getTranslatedCallInstruction(call)
   }
 
   final override int getInstructionIndex(InstructionTag tag) {
@@ -437,199 +577,11 @@ abstract class TranslatedArgumentSideEffect extends TranslatedSideEffect {
    * Gets the `TranslatedFunction` containing this expression.
    */
   final TranslatedFunction getEnclosingFunction() {
-    result = getTranslatedFunction(call.getEnclosingFunction())
+    result = getTranslatedFunction(arg.getEnclosingFunction())
   }
 
-  final override predicate sideEffectInstruction(Opcode opcode, CppType type) {
-    opcode = sideEffectOpcode and
-    (
-      isWrite() and
-      (
-        opcode instanceof BufferAccessOpcode and
-        type = getUnknownType()
-        or
-        not opcode instanceof BufferAccessOpcode and
-        exists(Type indirectionType | indirectionType = getIndirectionType() |
-          if indirectionType instanceof VoidType
-          then type = getUnknownType()
-          else type = getTypeForPRValueOrUnknown(indirectionType)
-        )
-      )
-      or
-      not isWrite() and
-      type = getVoidType()
-    )
-  }
-
-  final override CppType getInstructionMemoryOperandType(
-    InstructionTag tag, TypedOperandTag operandTag
-  ) {
-    not isWrite() and
-    if sideEffectOpcode instanceof BufferAccessOpcode
-    then
-      result = getUnknownType() and
-      tag instanceof OnlyInstructionTag and
-      operandTag instanceof SideEffectOperandTag
-    else
-      exists(Type operandType |
-        tag instanceof OnlyInstructionTag and
-        operandType = getIndirectionType() and
-        operandTag instanceof SideEffectOperandTag
-      |
-        // If the type we select is an incomplete type (e.g. a forward-declared `struct`), there will
-        // not be a `CppType` that represents that type. In that case, fall back to `UnknownCppType`.
-        result = getTypeForPRValueOrUnknown(operandType)
-      )
-  }
-
-  final override Instruction getInstructionRegisterOperand(InstructionTag tag, OperandTag operandTag) {
-    tag instanceof OnlyInstructionTag and
-    operandTag instanceof AddressOperandTag and
-    result = getArgInstruction()
-    or
-    tag instanceof OnlyInstructionTag and
-    operandTag instanceof BufferSizeOperandTag and
-    result =
-      getTranslatedExpr(call.getArgument(call.getTarget()
-              .(SideEffectFunction)
-              .getParameterSizeIndex(index)).getFullyConverted()).getResult()
-  }
-
-  /** Holds if this side effect is a write side effect, rather than a read side effect. */
-  final predicate isWrite() { sideEffectOpcode instanceof WriteSideEffectOpcode }
-
-  /** Gets a text representation of the argument. */
-  abstract string getArgString();
-
-  /** Gets the `Instruction` whose result is the value of the argument. */
-  abstract Instruction getArgInstruction();
-
-  /** Gets the type pointed to by the argument. */
-  abstract Type getIndirectionType();
-}
-
-/**
- * The IR translation of an argument side effect where the argument has an `Expr` object in the AST.
- *
- * This generally applies to all positional arguments, as well as qualifier (`this`) arguments for
- * calls other than constructor calls.
- */
-class TranslatedArgumentExprSideEffect extends TranslatedArgumentSideEffect,
-  TTranslatedArgumentExprSideEffect {
-  Expr arg;
-
-  TranslatedArgumentExprSideEffect() {
-    this = TTranslatedArgumentExprSideEffect(call, arg, index, sideEffectOpcode)
-  }
-
-  final override Locatable getAST() { result = arg }
-
-  final override Type getIndirectionType() {
-    result = arg.getUnspecifiedType().(DerivedType).getBaseType()
-    or
-    // Sometimes the qualifier type gets the type of the class itself, rather than a pointer to the
-    // class.
-    index = -1 and
-    not arg.getUnspecifiedType() instanceof DerivedType and
-    result = arg.getUnspecifiedType()
-  }
-
-  final override string getArgString() { result = arg.toString() }
-
-  final override Instruction getArgInstruction() { result = getTranslatedExpr(arg).getResult() }
-}
-
-/**
- * The IR translation of an argument side effect for `*this` on a call, where there is no `Expr`
- * object that represents the `this` argument.
- *
- * The applies only to constructor calls, as the AST has explioit qualifier `Expr`s for all other
- * calls to non-static member functions.
- */
-class TranslatedStructorQualifierSideEffect extends TranslatedArgumentSideEffect,
-  TTranslatedStructorQualifierSideEffect {
-  TranslatedStructorQualifierSideEffect() {
-    this = TTranslatedStructorQualifierSideEffect(call, sideEffectOpcode) and
-    index = -1
-  }
-
-  final override Locatable getAST() { result = call }
-
-  final override Type getIndirectionType() { result = call.getTarget().getDeclaringType() }
-
-  final override string getArgString() { result = "this" }
-
-  final override Instruction getArgInstruction() {
-    exists(TranslatedStructorCall structorCall |
-      structorCall.getExpr() = call and
-      result = structorCall.getQualifierResult()
-    )
-  }
-}
-
-/** The IR translation of the non-argument-specific side effect of a call. */
-class TranslatedCallSideEffect extends TranslatedSideEffect, TTranslatedCallSideEffect {
-  Expr expr;
-  SideEffectOpcode sideEffectOpcode;
-
-  TranslatedCallSideEffect() { this = TTranslatedCallSideEffect(expr, sideEffectOpcode) }
-
-  override Locatable getAST() { result = expr }
-
-  override Expr getPrimaryExpr() { result = expr }
-
-  override predicate sortOrder(int group, int indexInGroup) {
-    group = callSideEffectGroup() and indexInGroup = 0
-  }
-
-  override string toString() { result = "(call side effect for '" + expr.toString() + "')" }
-
-  override predicate sideEffectInstruction(Opcode opcode, CppType type) {
-    opcode = sideEffectOpcode and
-    (
-      opcode instanceof Opcode::CallSideEffect and
-      type = getUnknownType()
-      or
-      opcode instanceof Opcode::CallReadSideEffect and
-      type = getVoidType()
-    )
-  }
-
-  override CppType getInstructionMemoryOperandType(InstructionTag tag, TypedOperandTag operandTag) {
-    tag instanceof OnlyInstructionTag and
-    operandTag instanceof SideEffectOperandTag and
-    result = getUnknownType()
-  }
-}
-
-/**
- * The IR translation of the allocation side effect of a call to a memory allocation function.
- *
- * This side effect provides a definition for the newly-allocated memory.
- */
-class TranslatedAllocationSideEffect extends TranslatedSideEffect, TTranslatedAllocationSideEffect {
-  AllocationExpr expr;
-
-  TranslatedAllocationSideEffect() { this = TTranslatedAllocationSideEffect(expr) }
-
-  override Locatable getAST() { result = expr }
-
-  override Expr getPrimaryExpr() { result = expr }
-
-  override predicate sortOrder(int group, int indexInGroup) {
-    group = initializeAllocationGroup() and indexInGroup = 0
-  }
-
-  override string toString() { result = "(allocation side effect for '" + expr.toString() + "')" }
-
-  override Instruction getInstructionRegisterOperand(InstructionTag tag, OperandTag operandTag) {
-    tag = OnlyInstructionTag() and
-    operandTag = addressOperand() and
-    result = getPrimaryInstructionForSideEffect(OnlyInstructionTag())
-  }
-
-  override predicate sideEffectInstruction(Opcode opcode, CppType type) {
-    opcode instanceof Opcode::InitializeDynamicAllocation and
-    type = getUnknownType()
-  }
+  /**
+   * Gets the `Function` containing this expression.
+   */
+  override Function getFunction() { result = arg.getEnclosingFunction() }
 }

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedElement.qll

@@ -135,20 +135,6 @@ private predicate ignoreExpr(Expr expr) {
   ignoreExprAndDescendants(expr)
 }
 
-/**
- * Holds if the side effects of `expr` should be ignoredf for the purposes of IR generation.
- *
- * In cases involving `constexpr`, a call can wind up as a constant expression. `ignoreExpr()` will
- * not hold for such a call, since we do need to translate the call (as a constant), but we need to
- * ignore all of the side effects of that call, since we will not actually be generating a `Call`
- * instruction.
- */
-private predicate ignoreSideEffects(Expr expr) {
-  ignoreExpr(expr)
-  or
-  isIRConstant(expr)
-}
-
 /**
  * Holds if `func` contains an AST that cannot be translated into IR. This is mostly used to work
  * around extractor bugs. Once the relevant extractor bugs are fixed, this predicate can be removed.
@@ -567,13 +553,6 @@ newtype TTranslatedElement =
   } or
   // The initialization of a base class from within a constructor.
   TTranslatedConstructorBaseInit(ConstructorBaseInit init) { not ignoreExpr(init) } or
-  // Workaround for a case where no base constructor is generated but a targetless base
-  // constructor call is present.
-  TTranslatedConstructorBareInit(ConstructorInit init) {
-    not ignoreExpr(init) and
-    not init instanceof ConstructorBaseInit and
-    not init instanceof ConstructorFieldInit
-  } or
   // The destruction of a base class from within a destructor.
   TTranslatedDestructorBaseDestruction(DestructorBaseDestruction destruction) {
     not ignoreExpr(destruction)
@@ -642,34 +621,32 @@ newtype TTranslatedElement =
   // The declaration/initialization part of a `ConditionDeclExpr`
   TTranslatedConditionDecl(ConditionDeclExpr expr) { not ignoreExpr(expr) } or
   // The side effects of a `Call`
-  TTranslatedCallSideEffects(CallOrAllocationExpr expr) { not ignoreSideEffects(expr) } or
-  // The non-argument-specific side effect of a `Call`
-  TTranslatedCallSideEffect(Expr expr, SideEffectOpcode opcode) {
-    not ignoreSideEffects(expr) and
-    opcode = getCallSideEffectOpcode(expr)
+  TTranslatedCallSideEffects(Call expr) {
+    // Exclude allocations such as `malloc` (which happen to also be function calls).
+    // Both `TranslatedCallSideEffects` and `TranslatedAllocationSideEffects` generate
+    // the same side effects for its children as they both extend the `TranslatedSideEffects`
+    // class.
+    // Note: We can separate allocation side effects and call side effects into two
+    // translated elements as no call can be both a `ConstructorCall` and an `AllocationExpr`.
+    not expr instanceof AllocationExpr and
+    (
+      exists(TTranslatedArgumentSideEffect(expr, _, _, _)) or
+      expr instanceof ConstructorCall
+    )
   } or
+  // The side effects of an allocation, i.e. `new`, `new[]` or `malloc`
+  TTranslatedAllocationSideEffects(AllocationExpr expr) { not ignoreExpr(expr) } or
   // A precise side effect of an argument to a `Call`
-  TTranslatedArgumentExprSideEffect(Call call, Expr expr, int n, SideEffectOpcode opcode) {
+  TTranslatedArgumentSideEffect(Call call, Expr expr, int n, SideEffectOpcode opcode) {
     not ignoreExpr(expr) and
-    not ignoreSideEffects(call) and
+    not ignoreExpr(call) and
     (
       n >= 0 and expr = call.getArgument(n).getFullyConverted()
       or
       n = -1 and expr = call.getQualifier().getFullyConverted()
     ) and
     opcode = getASideEffectOpcode(call, n)
-  } or
-  // Constructor calls lack a qualifier (`this`) expression, so we need to handle the side effects
-  // on `*this` without an `Expr`.
-  TTranslatedStructorQualifierSideEffect(Call call, SideEffectOpcode opcode) {
-    not ignoreSideEffects(call) and
-    // Don't bother with destructor calls for now, since we won't see very many of them in the IR
-    // until we start injecting implicit destructor calls.
-    call instanceof ConstructorCall and
-    opcode = getASideEffectOpcode(call, -1)
-  } or
-  // The side effect that initializes newly-allocated memory.
-  TTranslatedAllocationSideEffect(AllocationExpr expr) { not ignoreSideEffects(expr) }
+  }
 
 /**
  * Gets the index of the first explicitly initialized element in `initList`

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedFunction.qll

@@ -573,11 +573,6 @@ class TranslatedConstructorInitList extends TranslatedElement, InitializationCon
       baseInit = func.(Constructor).getInitializer(id) and
       result = getTranslatedConstructorBaseInit(baseInit)
     )
-    or
-    exists(ConstructorInit bareInit |
-      bareInit = func.(Constructor).getInitializer(id) and
-      result = getTranslatedConstructorBareInit(bareInit)
-    )
   }
 
   override Instruction getFirstInstruction() {

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedInitialization.qll

@@ -917,36 +917,3 @@ class TranslatedDestructorBaseDestruction extends TranslatedBaseStructorCall,
 
   final override string toString() { result = "destroy base: " + call.toString() }
 }
-
-/**
- * A constructor base init call where no base constructor has been generated.
- *
- * Workaround for an extractor issue.
- */
-class TranslatedConstructorBareInit extends TranslatedElement, TTranslatedConstructorBareInit {
-  ConstructorInit init;
-
-  TranslatedConstructorBareInit() { this = TTranslatedConstructorBareInit(init) }
-
-  override Locatable getAST() { result = init }
-
-  final override string toString() { result = "construct base (no constructor)" }
-
-  override Instruction getFirstInstruction() { result = getParent().getChildSuccessor(this) }
-
-  override predicate hasInstruction(Opcode opcode, InstructionTag tag, CppType resultType) {
-    none()
-  }
-
-  override TranslatedElement getChild(int id) { none() }
-
-  override Function getFunction() { result = getParent().getFunction() }
-
-  override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) { none() }
-
-  override Instruction getChildSuccessor(TranslatedElement child) { none() }
-}
-
-TranslatedConstructorBareInit getTranslatedConstructorBareInit(ConstructorInit init) {
-  result.getAST() = init
-}

cpp/ql/lib/semmle/code/cpp/metrics/MetricClass.qll

@@ -308,45 +308,45 @@ class MetricClass extends Class {
   }
 
   private string getAUsedHalsteadN1Operator() {
-    this.getAnEnclosedExpression() instanceof CommaExpr and result = "comma"
+    exists(CommaExpr e | e = this.getAnEnclosedExpression()) and result = "comma"
     or
-    this.getAnEnclosedExpression() instanceof ReferenceToExpr and result = "refTo"
+    exists(ReferenceToExpr e | e = this.getAnEnclosedExpression()) and result = "refTo"
     or
-    this.getAnEnclosedExpression() instanceof PointerDereferenceExpr and result = "dereference"
+    exists(PointerDereferenceExpr e | e = this.getAnEnclosedExpression()) and result = "dereference"
     or
-    this.getAnEnclosedExpression() instanceof CStyleCast and result = "cCast"
+    exists(CStyleCast e | e = this.getAnEnclosedExpression()) and result = "cCast"
     or
-    this.getAnEnclosedExpression() instanceof StaticCast and result = "staticCast"
+    exists(StaticCast e | e = this.getAnEnclosedExpression()) and result = "staticCast"
     or
-    this.getAnEnclosedExpression() instanceof ConstCast and result = "constCast"
+    exists(ConstCast e | e = this.getAnEnclosedExpression()) and result = "constCast"
     or
-    this.getAnEnclosedExpression() instanceof ReinterpretCast and result = "reinterpretCast"
+    exists(ReinterpretCast e | e = this.getAnEnclosedExpression()) and result = "reinterpretCast"
     or
-    this.getAnEnclosedExpression() instanceof DynamicCast and result = "dynamicCast"
+    exists(DynamicCast e | e = this.getAnEnclosedExpression()) and result = "dynamicCast"
     or
-    this.getAnEnclosedExpression() instanceof SizeofExprOperator and result = "sizeofExpr"
+    exists(SizeofExprOperator e | e = this.getAnEnclosedExpression()) and result = "sizeofExpr"
     or
-    this.getAnEnclosedExpression() instanceof SizeofTypeOperator and result = "sizeofType"
+    exists(SizeofTypeOperator e | e = this.getAnEnclosedExpression()) and result = "sizeofType"
     or
-    this.getAnEnclosedStmt() instanceof IfStmt and result = "ifVal"
+    exists(IfStmt e | e = this.getAnEnclosedStmt()) and result = "ifVal"
     or
-    this.getAnEnclosedStmt() instanceof SwitchStmt and result = "switchVal"
+    exists(SwitchStmt e | e = this.getAnEnclosedStmt()) and result = "switchVal"
     or
-    this.getAnEnclosedStmt() instanceof ForStmt and result = "forVal"
+    exists(ForStmt e | e = this.getAnEnclosedStmt()) and result = "forVal"
     or
-    this.getAnEnclosedStmt() instanceof DoStmt and result = "doVal"
+    exists(DoStmt e | e = this.getAnEnclosedStmt()) and result = "doVal"
     or
-    this.getAnEnclosedStmt() instanceof WhileStmt and result = "whileVal"
+    exists(WhileStmt e | e = this.getAnEnclosedStmt()) and result = "whileVal"
     or
-    this.getAnEnclosedStmt() instanceof GotoStmt and result = "gotoVal"
+    exists(GotoStmt e | e = this.getAnEnclosedStmt()) and result = "gotoVal"
     or
-    this.getAnEnclosedStmt() instanceof ContinueStmt and result = "continueVal"
+    exists(ContinueStmt e | e = this.getAnEnclosedStmt()) and result = "continueVal"
     or
-    this.getAnEnclosedStmt() instanceof BreakStmt and result = "breakVal"
+    exists(BreakStmt e | e = this.getAnEnclosedStmt()) and result = "breakVal"
     or
-    this.getAnEnclosedStmt() instanceof ReturnStmt and result = "returnVal"
+    exists(ReturnStmt e | e = this.getAnEnclosedStmt()) and result = "returnVal"
     or
-    this.getAnEnclosedStmt() instanceof SwitchCase and result = "caseVal"
+    exists(SwitchCase e | e = this.getAnEnclosedStmt()) and result = "caseVal"
     or
     exists(IfStmt s | s = this.getAnEnclosedStmt() and s.hasElse()) and
     result = "elseVal"

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

@@ -11,14 +11,15 @@ import semmle.code.cpp.models.interfaces.SideEffect
 import semmle.code.cpp.models.interfaces.FlowSource
 
 /**
- * The standard functions `fgets` and `fgetws`.
+ * The standard functions `gets` and `fgets`.
  */
-private class FgetsFunction extends DataFlowFunction, TaintFunction, ArrayFunction, AliasFunction,
+private class GetsFunction extends DataFlowFunction, TaintFunction, ArrayFunction, AliasFunction,
   SideEffectFunction, RemoteFlowSourceFunction {
-  FgetsFunction() {
+  GetsFunction() {
+    // gets(str)
     // fgets(str, num, stream)
     // fgetws(wstr, num, stream)
-    this.hasGlobalOrStdOrBslName(["fgets", "fgetws"])
+    this.hasGlobalOrStdOrBslName(["gets", "fgets", "fgetws"])
   }
 
   override predicate hasDataFlow(FunctionInput input, FunctionOutput output) {
@@ -50,61 +51,18 @@ private class FgetsFunction extends DataFlowFunction, TaintFunction, ArrayFuncti
   override predicate hasRemoteFlowSource(FunctionOutput output, string description) {
     output.isParameterDeref(0) and
     description = "String read by " + this.getName()
-    or
-    output.isReturnValue() and
-    description = "String read by " + this.getName()
   }
 
   override predicate hasArrayWithVariableSize(int bufParam, int countParam) {
+    not this.hasName("gets") and
     bufParam = 0 and
     countParam = 1
   }
 
-  override predicate hasArrayOutput(int bufParam) { bufParam = 0 }
-
-  override predicate hasSocketInput(FunctionInput input) { input.isParameterDeref(2) }
-}
-
-/**
- * The standard functions `gets`.
- */
-private class GetsFunction extends DataFlowFunction, ArrayFunction, AliasFunction,
-  SideEffectFunction, LocalFlowSourceFunction {
-  GetsFunction() {
-    // gets(str)
-    this.hasGlobalOrStdOrBslName("gets")
+  override predicate hasArrayWithUnknownSize(int bufParam) {
+    this.hasName("gets") and
+    bufParam = 0
   }
 
-  override predicate hasDataFlow(FunctionInput input, FunctionOutput output) {
-    input.isParameter(0) and
-    output.isReturnValue()
-  }
-
-  override predicate parameterNeverEscapes(int index) { none() }
-
-  override predicate parameterEscapesOnlyViaReturn(int index) { index = 0 }
-
-  override predicate parameterIsAlwaysReturned(int index) { index = 0 }
-
-  override predicate hasOnlySpecificReadSideEffects() { any() }
-
-  override predicate hasOnlySpecificWriteSideEffects() { any() }
-
-  override predicate hasSpecificWriteSideEffect(ParameterIndex i, boolean buffer, boolean mustWrite) {
-    i = 0 and
-    buffer = true and
-    mustWrite = true
-  }
-
-  override predicate hasLocalFlowSource(FunctionOutput output, string description) {
-    output.isParameterDeref(0) and
-    description = "String read by " + this.getName()
-    or
-    output.isReturnValue() and
-    description = "String read by " + this.getName()
-  }
-
-  override predicate hasArrayWithUnknownSize(int bufParam) { bufParam = 0 }
-
   override predicate hasArrayOutput(int bufParam) { bufParam = 0 }
 }

cpp/ql/lib/semmle/code/cpp/models/interfaces/FlowSource.qll

@@ -20,9 +20,8 @@ abstract class RemoteFlowSourceFunction extends Function {
   abstract predicate hasRemoteFlowSource(FunctionOutput output, string description);
 
   /**
-   * Holds if remote data from this source comes from a socket or stream
-   * described by `input`. There is no result if none is specified by a
-   * parameter.
+   * Holds if remote data from this source comes from a socket described by
+   * `input`. There is no result if a socket is not specified.
    */
   predicate hasSocketInput(FunctionInput input) { none() }
 }
@@ -60,9 +59,8 @@ abstract class RemoteFlowSinkFunction extends Function {
   abstract predicate hasRemoteFlowSink(FunctionInput input, string description);
 
   /**
-   * Holds if data put into this sink is transmitted through a socket or stream
-   * described by `input`. There is no result if none is specified by a
-   * parameter.
+   * Holds if data put into this sink is transmitted through a socket described
+   * by `input`. There is no result if a socket is not specified.
    */
   predicate hasSocketInput(FunctionInput input) { none() }
 }

cpp/ql/lib/semmle/code/cpp/padding/Padding.qll

@@ -397,7 +397,7 @@ class PaddedType extends Class {
     // Support only single inheritance for now. If multiple inheritance is
     // supported, be sure to fix up the calls to getABaseClass*() to correctly
     // handle the presence of multiple base class subojects with the same type.
-    not exists(this.getDerivation(1))
+    not exists(ClassDerivation cd | cd = this.getDerivation(1))
   }
 
   /**

cpp/ql/lib/semmle/code/cpp/pointsto/PointsTo.qll

@@ -72,7 +72,7 @@ predicate lvalue(Element e) {
   or
   exists(Cast c | lvalue(c) and e.(Expr).getConversion() = c)
   or
-  e.(Expr).getConversion() instanceof ReferenceToExpr
+  exists(ReferenceToExpr toref | e.(Expr).getConversion() = toref)
   or
   // If f is a function-pointer, then the following two
   // calls are equivalent:  f()  and  (*f)()

cpp/ql/lib/semmle/code/cpp/security/BufferWrite.qll

@@ -76,7 +76,7 @@ abstract class BufferWrite extends Expr {
    * can be found), specifying the reason for the estimation.
    */
   int getMaxData(BufferWriteEstimationReason reason) {
-    reason instanceof UnspecifiedEstimateReason and result = this.getMaxData()
+    reason instanceof NoSpecifiedEstimateReason and result = getMaxData()
   }
 
   /**
@@ -85,7 +85,7 @@ abstract class BufferWrite extends Expr {
    * much smaller (8 bytes) than their true maximum length.  This can be
    * helpful in determining the cause of a buffer overflow issue.
    */
-  int getMaxDataLimited() { result = this.getMaxData() }
+  int getMaxDataLimited() { result = getMaxData() }
 
   /**
    * Gets an upper bound to the amount of data that's being written (if one
@@ -94,7 +94,7 @@ abstract class BufferWrite extends Expr {
    * than their true maximum length.  This can be helpful in determining the
    * cause of a buffer overflow issue.
    */
-  int getMaxDataLimited(BufferWriteEstimationReason reason) { result = this.getMaxData(reason) }
+  int getMaxDataLimited(BufferWriteEstimationReason reason) { result = getMaxData(reason) }
 
   /**
    * Gets the size of a single character of the type this
@@ -159,11 +159,9 @@ class StrCopyBW extends BufferWriteCall {
       this.getArgument(this.getParamSrc()).(AnalysedString).getMaxLength() * this.getCharSize()
   }
 
-  override int getMaxData(BufferWriteEstimationReason reason) {
-    result = this.getMaxDataImpl(reason)
-  }
+  override int getMaxData(BufferWriteEstimationReason reason) { result = getMaxDataImpl(reason) }
 
-  override int getMaxData() { result = max(this.getMaxDataImpl(_)) }
+  override int getMaxData() { result = max(getMaxDataImpl(_)) }
 }
 
 /**
@@ -205,11 +203,9 @@ class StrCatBW extends BufferWriteCall {
       this.getArgument(this.getParamSrc()).(AnalysedString).getMaxLength() * this.getCharSize()
   }
 
-  override int getMaxData(BufferWriteEstimationReason reason) {
-    result = this.getMaxDataImpl(reason)
-  }
+  override int getMaxData(BufferWriteEstimationReason reason) { result = getMaxDataImpl(reason) }
 
-  override int getMaxData() { result = max(this.getMaxDataImpl(_)) }
+  override int getMaxData() { result = max(getMaxDataImpl(_)) }
 }
 
 /**
@@ -273,11 +269,9 @@ class SprintfBW extends BufferWriteCall {
     )
   }
 
-  override int getMaxData(BufferWriteEstimationReason reason) {
-    result = this.getMaxDataImpl(reason)
-  }
+  override int getMaxData(BufferWriteEstimationReason reason) { result = getMaxDataImpl(reason) }
 
-  override int getMaxData() { result = max(this.getMaxDataImpl(_)) }
+  override int getMaxData() { result = max(getMaxDataImpl(_)) }
 
   private int getMaxDataLimitedImpl(BufferWriteEstimationReason reason) {
     exists(FormatLiteral fl |
@@ -287,10 +281,10 @@ class SprintfBW extends BufferWriteCall {
   }
 
   override int getMaxDataLimited(BufferWriteEstimationReason reason) {
-    result = this.getMaxDataLimitedImpl(reason)
+    result = getMaxDataLimitedImpl(reason)
   }
 
-  override int getMaxDataLimited() { result = max(this.getMaxDataLimitedImpl(_)) }
+  override int getMaxDataLimited() { result = max(getMaxDataLimitedImpl(_)) }
 }
 
 /**
@@ -388,11 +382,9 @@ class SnprintfBW extends BufferWriteCall {
     )
   }
 
-  override int getMaxData(BufferWriteEstimationReason reason) {
-    result = this.getMaxDataImpl(reason)
-  }
+  override int getMaxData(BufferWriteEstimationReason reason) { result = getMaxDataImpl(reason) }
 
-  override int getMaxData() { result = max(this.getMaxDataImpl(_)) }
+  override int getMaxData() { result = max(getMaxDataImpl(_)) }
 
   private int getMaxDataLimitedImpl(BufferWriteEstimationReason reason) {
     exists(FormatLiteral fl |
@@ -402,10 +394,10 @@ class SnprintfBW extends BufferWriteCall {
   }
 
   override int getMaxDataLimited(BufferWriteEstimationReason reason) {
-    result = this.getMaxDataLimitedImpl(reason)
+    result = getMaxDataLimitedImpl(reason)
   }
 
-  override int getMaxDataLimited() { result = max(this.getMaxDataLimitedImpl(_)) }
+  override int getMaxDataLimited() { result = max(getMaxDataLimitedImpl(_)) }
 }
 
 /**
@@ -503,11 +495,9 @@ class ScanfBW extends BufferWrite {
     )
   }
 
-  override int getMaxData(BufferWriteEstimationReason reason) {
-    result = this.getMaxDataImpl(reason)
-  }
+  override int getMaxData(BufferWriteEstimationReason reason) { result = getMaxDataImpl(reason) }
 
-  override int getMaxData() { result = max(this.getMaxDataImpl(_)) }
+  override int getMaxData() { result = max(getMaxDataImpl(_)) }
 
   override string getBWDesc() {
     exists(FunctionCall fc |
@@ -546,9 +536,7 @@ class RealpathBW extends BufferWriteCall {
     this = this // Suppress a compiler warning
   }
 
-  override int getMaxData(BufferWriteEstimationReason reason) {
-    result = this.getMaxDataImpl(reason)
-  }
+  override int getMaxData(BufferWriteEstimationReason reason) { result = getMaxDataImpl(reason) }
 
-  override int getMaxData() { result = max(this.getMaxDataImpl(_)) }
+  override int getMaxData() { result = max(getMaxDataImpl(_)) }
 }

cpp/ql/lib/semmle/code/cpp/security/TaintTracking.qll

@@ -1,10 +1,7 @@
 /*
- * Support for tracking tainted data through the program. This is an alias for
- * `semmle.code.cpp.ir.dataflow.DefaultTaintTracking` provided for backwards
- * compatibility.
+ * Support for tracking tainted data through the program.
  *
- * Prefer to use `semmle.code.cpp.dataflow.TaintTracking` or
- * `semmle.code.cpp.ir.dataflow.TaintTracking` when designing new queries.
+ * Prefer to use `semmle.code.cpp.dataflow.TaintTracking` when designing new queries.
  */
 
 import semmle.code.cpp.ir.dataflow.DefaultTaintTracking

cpp/ql/lib/semmle/code/cpp/security/TaintTrackingImpl.qll

@@ -258,7 +258,7 @@ private predicate insideFunctionValueMoveTo(Element src, Element dest) {
           format.getConversionChar(sourceArg - ffc.getTarget().getNumberOfParameters()) = ["s", "S"]
         )
         or
-        not c.(FormattingFunctionCall).getFormat() instanceof FormatLiteral
+        not exists(FormatLiteral fl | fl = c.(FormattingFunctionCall).getFormat())
         or
         not c instanceof FormattingFunctionCall
       ) and

cpp/ql/lib/semmle/code/cpp/stmts/Stmt.qll

@@ -271,7 +271,7 @@ class IfStmt extends ConditionalStmt, @stmt_if {
    * if (b) { x = 1; }
    * ```
    */
-  predicate hasElse() { exists(this.getElse()) }
+  predicate hasElse() { exists(Stmt s | this.getElse() = s) }
 
   override string toString() { result = "if (...) ... " }
 
@@ -357,7 +357,7 @@ class ConstexprIfStmt extends ConditionalStmt, @stmt_constexpr_if {
    * if constexpr (b) { x = 1; }
    * ```
    */
-  predicate hasElse() { exists(this.getElse()) }
+  predicate hasElse() { exists(Stmt s | this.getElse() = s) }
 
   override string toString() { result = "if constexpr (...) ... " }
 

cpp/ql/lib/tutorial.qll

@@ -6,22 +6,122 @@
  */
 class Person extends string {
   Person() {
-    this =
-      [
-        "Ronil", "Dina", "Ravi", "Bruce", "Jo", "Aida", "Esme", "Charlie", "Fred", "Meera", "Maya",
-        "Chad", "Tiana", "Laura", "George", "Will", "Mary", "Almira", "Susannah", "Rhoda",
-        "Cynthia", "Eunice", "Olive", "Virginia", "Angeline", "Helen", "Cornelia", "Harriet",
-        "Mahala", "Abby", "Margaret", "Deb", "Minerva", "Severus", "Lavina", "Adeline", "Cath",
-        "Elisa", "Lucretia", "Anne", "Eleanor", "Joanna", "Adam", "Agnes", "Rosanna", "Clara",
-        "Melissa", "Amy", "Isabel", "Jemima", "Cordelia", "Melinda", "Delila", "Jeremiah", "Elijah",
-        "Hester", "Walter", "Oliver", "Hugh", "Aaron", "Reuben", "Eli", "Amos", "Augustus",
-        "Theodore", "Ira", "Timothy", "Cyrus", "Horace", "Simon", "Asa", "Frank", "Nelson",
-        "Leonard", "Harrison", "Anthony", "Louis", "Milton", "Noah", "Cornelius", "Abdul", "Warren",
-        "Harvey", "Dennis", "Wesley", "Sylvester", "Gilbert", "Sullivan", "Edmund", "Wilson",
-        "Perry", "Matthew", "Simba", "Nala", "Rafiki", "Shenzi", "Ernest", "Gertrude", "Oscar",
-        "Lilian", "Raymond", "Elgar", "Elmer", "Herbert", "Maude", "Mae", "Otto", "Edwin",
-        "Ophelia", "Parsley", "Sage", "Rosemary", "Thyme", "Garfunkel", "King Basil", "Stephen"
-      ]
+    this = "Ronil" or
+    this = "Dina" or
+    this = "Ravi" or
+    this = "Bruce" or
+    this = "Jo" or
+    this = "Aida" or
+    this = "Esme" or
+    this = "Charlie" or
+    this = "Fred" or
+    this = "Meera" or
+    this = "Maya" or
+    this = "Chad" or
+    this = "Tiana" or
+    this = "Laura" or
+    this = "George" or
+    this = "Will" or
+    this = "Mary" or
+    this = "Almira" or
+    this = "Susannah" or
+    this = "Rhoda" or
+    this = "Cynthia" or
+    this = "Eunice" or
+    this = "Olive" or
+    this = "Virginia" or
+    this = "Angeline" or
+    this = "Helen" or
+    this = "Cornelia" or
+    this = "Harriet" or
+    this = "Mahala" or
+    this = "Abby" or
+    this = "Margaret" or
+    this = "Deb" or
+    this = "Minerva" or
+    this = "Severus" or
+    this = "Lavina" or
+    this = "Adeline" or
+    this = "Cath" or
+    this = "Elisa" or
+    this = "Lucretia" or
+    this = "Anne" or
+    this = "Eleanor" or
+    this = "Joanna" or
+    this = "Adam" or
+    this = "Agnes" or
+    this = "Rosanna" or
+    this = "Clara" or
+    this = "Melissa" or
+    this = "Amy" or
+    this = "Isabel" or
+    this = "Jemima" or
+    this = "Cordelia" or
+    this = "Melinda" or
+    this = "Delila" or
+    this = "Jeremiah" or
+    this = "Elijah" or
+    this = "Hester" or
+    this = "Walter" or
+    this = "Oliver" or
+    this = "Hugh" or
+    this = "Aaron" or
+    this = "Reuben" or
+    this = "Eli" or
+    this = "Amos" or
+    this = "Augustus" or
+    this = "Theodore" or
+    this = "Ira" or
+    this = "Timothy" or
+    this = "Cyrus" or
+    this = "Horace" or
+    this = "Simon" or
+    this = "Asa" or
+    this = "Frank" or
+    this = "Nelson" or
+    this = "Leonard" or
+    this = "Harrison" or
+    this = "Anthony" or
+    this = "Louis" or
+    this = "Milton" or
+    this = "Noah" or
+    this = "Cornelius" or
+    this = "Abdul" or
+    this = "Warren" or
+    this = "Harvey" or
+    this = "Dennis" or
+    this = "Wesley" or
+    this = "Sylvester" or
+    this = "Gilbert" or
+    this = "Sullivan" or
+    this = "Edmund" or
+    this = "Wilson" or
+    this = "Perry" or
+    this = "Matthew" or
+    this = "Simba" or
+    this = "Nala" or
+    this = "Rafiki" or
+    this = "Shenzi" or
+    this = "Ernest" or
+    this = "Gertrude" or
+    this = "Oscar" or
+    this = "Lilian" or
+    this = "Raymond" or
+    this = "Elgar" or
+    this = "Elmer" or
+    this = "Herbert" or
+    this = "Maude" or
+    this = "Mae" or
+    this = "Otto" or
+    this = "Edwin" or
+    this = "Ophelia" or
+    this = "Parsley" or
+    this = "Sage" or
+    this = "Rosemary" or
+    this = "Thyme" or
+    this = "Garfunkel" or
+    this = "King Basil" or
+    this = "Stephen"
   }
 
   /** Gets the hair color of the person. If the person is bald, there is no result. */
@@ -836,12 +936,25 @@ class Person extends string {
 
   /** Holds if the person is deceased. */
   predicate isDeceased() {
-    this =
-      [
-        "Ernest", "Gertrude", "Oscar", "Lilian", "Edwin", "Raymond", "Elgar", "Elmer", "Herbert",
-        "Maude", "Mae", "Otto", "Ophelia", "Parsley", "Sage", "Rosemary", "Thyme", "Garfunkel",
-        "King Basil"
-      ]
+    this = "Ernest" or
+    this = "Gertrude" or
+    this = "Oscar" or
+    this = "Lilian" or
+    this = "Edwin" or
+    this = "Raymond" or
+    this = "Elgar" or
+    this = "Elmer" or
+    this = "Herbert" or
+    this = "Maude" or
+    this = "Mae" or
+    this = "Otto" or
+    this = "Ophelia" or
+    this = "Parsley" or
+    this = "Sage" or
+    this = "Rosemary" or
+    this = "Thyme" or
+    this = "Garfunkel" or
+    this = "King Basil"
   }
 
   /** Gets a parent of the person (alive or deceased). */
@@ -1082,7 +1195,12 @@ class Person extends string {
   }
 
   /** Holds if the person is allowed in the region. Initially, all villagers are allowed in every region. */
-  predicate isAllowedIn(string region) { region = ["north", "south", "east", "west"] }
+  predicate isAllowedIn(string region) {
+    region = "north" or
+    region = "south" or
+    region = "east" or
+    region = "west"
+  }
 }
 
 /** Returns a parent of the person. */

cpp/ql/src/Best Practices/Hiding/DeclarationHidesVariable.ql

@@ -18,7 +18,6 @@ where
   not lv1.isCompilerGenerated() and
   not lv2.isCompilerGenerated() and
   not lv1.getParentScope().(BlockStmt).isInMacroExpansion() and
-  not lv2.getParentScope().(BlockStmt).isInMacroExpansion() and
-  not lv1.getName() = "(unnamed local variable)"
+  not lv2.getParentScope().(BlockStmt).isInMacroExpansion()
 select lv1, "Variable " + lv1.getName() + " hides another variable of the same name (on $@).", lv2,
   "line " + lv2.getLocation().getStartLine().toString()

cpp/ql/src/CHANGELOG.md

@@ -1,7 +1,3 @@
-## 0.0.7
-
-## 0.0.6
-
 ## 0.0.5
 
 ### New Queries

cpp/ql/src/Critical/DeadCodeGoto.ql

@@ -30,8 +30,8 @@ where
   // the next statement isn't breaking out of a switch
   not s.(BreakStmt).getBreakable() instanceof SwitchStmt and
   // the next statement isn't a loop that can be jumped into
-  not s.(Loop).getStmt().getAChild*() instanceof LabelStmt and
-  not s.(Loop).getStmt().getAChild*() instanceof SwitchCase and
+  not exists(LabelStmt ls | s.(Loop).getStmt().getAChild*() = ls) and
+  not exists(SwitchCase sc | s.(Loop).getStmt().getAChild*() = sc) and
   // no preprocessor logic applies
   not functionContainsPreprocCode(js.getEnclosingFunction())
 select js, "This statement makes $@ unreachable.", s, s.toString()

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

@@ -55,7 +55,7 @@ abstract class LeapYearFieldAccess extends YearFieldAccess {
       op.getAnOperand() = this and
       (
         op instanceof AssignArithmeticOperation or
-        op.getAnOperand() instanceof BinaryArithmeticOperation or
+        exists(BinaryArithmeticOperation bao | bao = op.getAnOperand()) or
         op instanceof CrementOperation
       )
     )
@@ -212,7 +212,9 @@ class ChecksForLeapYearFunctionCall extends FunctionCall {
 class LeapYearCheckConfiguration extends DataFlow::Configuration {
   LeapYearCheckConfiguration() { this = "LeapYearCheckConfiguration" }
 
-  override predicate isSource(DataFlow::Node source) { source.asExpr() instanceof VariableAccess }
+  override predicate isSource(DataFlow::Node source) {
+    exists(VariableAccess va | va = source.asExpr())
+  }
 
   override predicate isSink(DataFlow::Node sink) {
     exists(ChecksForLeapYearFunctionCall fc | sink.asExpr() = fc.getAnArgument())

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

@@ -23,10 +23,6 @@ DeclStmt declWithNoInit(LocalVariable v) {
   not exists(v.getInitializer())
 }
 
-/**
- * Control flow reachability from a buffer that is not not null terminated to a
- * sink that requires null termination.
- */
 class ImproperNullTerminationReachability extends StackVariableReachabilityWithReassignment {
   ImproperNullTerminationReachability() { this = "ImproperNullTerminationReachability" }
 
@@ -56,44 +52,12 @@ class ImproperNullTerminationReachability extends StackVariableReachabilityWithR
 
   override predicate isBarrier(ControlFlowNode node, StackVariable v) {
     exprDefinition(v, node, _) or
+    mayAddNullTerminator(node, v.getAnAccess()) or
+    node.(AddressOfExpr).getOperand() = v.getAnAccess() or // address taken
     isSinkActual(node, v) // only report first use
   }
 }
 
-/**
- * Flow from a place where null termination is added, to a sink of
- * `ImproperNullTerminationReachability`. This was previously implemented as a
- * simple barrier in `ImproperNullTerminationReachability`, but there were
- * false positive results involving multiple paths from source to sink.  We'd
- * prefer to report only the results we are sure of.
- */
-class NullTerminationReachability extends StackVariableReachabilityWithReassignment {
-  NullTerminationReachability() { this = "NullTerminationReachability" }
-
-  override predicate isSourceActual(ControlFlowNode node, StackVariable v) {
-    mayAddNullTerminator(node, v.getAnAccess()) or // null termination
-    node.(AddressOfExpr).getOperand() = v.getAnAccess() // address taken (possible null termination)
-  }
-
-  override predicate isSinkActual(ControlFlowNode node, StackVariable v) {
-    // have the same sinks as `ImproperNullTerminationReachability`.
-    exists(ImproperNullTerminationReachability r | r.isSinkActual(node, v))
-  }
-
-  override predicate isBarrier(ControlFlowNode node, StackVariable v) {
-    // don't look further back than the source, or further forward than the sink
-    exists(ImproperNullTerminationReachability r | r.isSourceActual(node, v)) or
-    exists(ImproperNullTerminationReachability r | r.isSinkActual(node, v))
-  }
-}
-
-from
-  ImproperNullTerminationReachability reaches, NullTerminationReachability nullTermReaches,
-  ControlFlowNode source, LocalVariable v, VariableAccess sink
-where
-  reaches.reaches(source, v, sink) and
-  not exists(ControlFlowNode termination |
-    nullTermReaches.reaches(termination, _, sink) and
-    termination != source
-  )
-select sink, "Variable $@ may not be null terminated.", v, v.getName()
+from ImproperNullTerminationReachability r, LocalVariable v, VariableAccess va
+where r.reaches(_, v, va)
+select va, "Variable $@ may not be null terminated.", v, v.getName()

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

@@ -4,4 +4,4 @@ Record* fixRecord(Record* r) {
 
 	myRecord.fix();
 	return &myRecord; //returns reference to myRecord, which is a stack-allocated object
-}
+}

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

@@ -3,172 +3,68 @@
  * @description A function returns a pointer to a stack-allocated region of
  *              memory. This memory is deallocated at the end of the function,
  *              which may lead the caller to dereference a dangling pointer.
- * @kind path-problem
+ * @kind problem
  * @id cpp/return-stack-allocated-memory
  * @problem.severity warning
- * @security-severity 9.3
  * @precision high
  * @tags reliability
- *       security
  *       external/cwe/cwe-825
  */
 
 import cpp
-// We don't actually use the global value numbering library in this query, but without it we end up
-// recomputing the IR.
-private import semmle.code.cpp.valuenumbering.GlobalValueNumbering
-import semmle.code.cpp.ir.IR
-import semmle.code.cpp.ir.dataflow.DataFlow::DataFlow
+import semmle.code.cpp.dataflow.EscapesTree
+import semmle.code.cpp.models.interfaces.PointerWrapper
+import semmle.code.cpp.dataflow.DataFlow
 
-/** Holds if `f` has a name that we intrepret as evidence of intentionally returning the value of the stack pointer. */
-predicate intentionallyReturnsStackPointer(Function f) {
-  f.getName().toLowerCase().matches(["%stack%", "%sp%"])
+/**
+ * Holds if `n1` may flow to `n2`, ignoring flow through fields because these
+ * are currently modeled as an overapproximation that assumes all objects may
+ * alias.
+ */
+predicate conservativeDataFlowStep(DataFlow::Node n1, DataFlow::Node n2) {
+  DataFlow::localFlowStep(n1, n2) and
+  not n2.asExpr() instanceof FieldAccess and
+  not hasNontrivialConversion(n2.asExpr())
 }
 
 /**
- * Holds if `source` is a node that represents the use of a stack variable
+ * Holds if `e` has a conversion that changes it from lvalue to pointer or
+ * back. As the data-flow library does not support conversions, we cannot track
+ * data flow through such expressions.
  */
-predicate isSource(Node source) {
-  exists(VariableAddressInstruction var, Function func |
-    var = source.asInstruction() and
-    func = var.getEnclosingFunction() and
-    var.getASTVariable() instanceof StackVariable and
-    // Pointer-to-member types aren't properly handled in the dbscheme.
-    not var.getResultType() instanceof PointerToMemberType and
-    // Rule out FPs caused by extraction errors.
-    not any(ErrorExpr e).getEnclosingFunction() = func and
-    not intentionallyReturnsStackPointer(func)
-  )
-}
-
-/**
- * Holds if `sink` is a node that represents the `StoreInstruction` that is subsequently used in
- * a `ReturnValueInstruction`. We use the `StoreInstruction` instead of the instruction that defines the
- * `ReturnValueInstruction`'s source value oprand because the former has better location information.
- */
-predicate isSink(Node sink) {
-  exists(StoreInstruction store |
-    store.getDestinationAddress().(VariableAddressInstruction).getIRVariable() instanceof
-      IRReturnVariable and
-    sink.asOperand() = store.getSourceValueOperand()
-  )
-}
-
-/** Holds if `node1` _must_ flow to `node2`. */
-predicate step(Node node1, Node node2) {
-  instructionToOperandStep(node1.asInstruction(), node2.asOperand())
-  or
-  operandToInstructionStep(node1.asOperand(), node2.asInstruction())
-}
-
-predicate instructionToOperandStep(Instruction instr, Operand operand) { operand.getDef() = instr }
-
-/**
- * Holds if `operand` flows to the result of `instr`.
- *
- * This predicate ignores flow through `PhiInstruction`s to create a 'must flow' relation. It also
- * intentionally conflates addresses of fields and their object, and pointer offsets with their
- * base pointer as this allows us to detect cases where an object's address flows to a return statement
- * via a field. For example:
- *
- * ```cpp
- * struct S { int x, y };
- * int* test() {
- *   S s;
- *   return &s.x; // BAD: &s.x is an address of a variable on the stack.
- * }
- * ```
- */
-predicate operandToInstructionStep(Operand operand, Instruction instr) {
-  instr.(CopyInstruction).getSourceValueOperand() = operand
-  or
-  instr.(ConvertInstruction).getUnaryOperand() = operand
-  or
-  instr.(CheckedConvertOrNullInstruction).getUnaryOperand() = operand
-  or
-  instr.(InheritanceConversionInstruction).getUnaryOperand() = operand
-  or
-  instr.(FieldAddressInstruction).getObjectAddressOperand() = operand
-  or
-  instr.(PointerOffsetInstruction).getLeftOperand() = operand
-}
-
-/** Holds if a source node flows to `n`. */
-predicate branchlessLocalFlow0(Node n) {
-  isSource(n)
-  or
-  exists(Node mid |
-    branchlessLocalFlow0(mid) and
-    step(mid, n)
-  )
-}
-
-/** Holds if `n` is reachable through some source node, and `n` also eventually reaches a sink. */
-predicate branchlessLocalFlow1(Node n) {
-  branchlessLocalFlow0(n) and
-  (
-    isSink(n)
+predicate hasNontrivialConversion(Expr e) {
+  e instanceof Conversion and
+  not (
+    e instanceof Cast
     or
-    exists(Node mid |
-      branchlessLocalFlow1(mid) and
-      step(n, mid)
+    e instanceof ParenthesisExpr
+  )
+  or
+  // A smart pointer can be stack-allocated while the data it points to is heap-allocated.
+  // So we exclude such "conversions" from this predicate.
+  e = any(PointerWrapper wrapper).getAnUnwrapperFunction().getACallToThisFunction()
+  or
+  hasNontrivialConversion(e.getConversion())
+}
+
+from StackVariable var, VariableAccess va, ReturnStmt r
+where
+  not var.getUnspecifiedType() instanceof ReferenceType and
+  not r.isFromUninstantiatedTemplate(_) and
+  va = var.getAnAccess() and
+  (
+    // To check if the address escapes directly from `e` in `return e`, we need
+    // to check the fully-converted `e` in case there are implicit
+    // array-to-pointer conversions or reference conversions.
+    variableAddressEscapesTree(va, r.getExpr().getFullyConverted())
+    or
+    // The data flow library doesn't support conversions, so here we check that
+    // the address escapes into some expression `pointerToLocal`, which flows
+    // in one or more steps to a returned expression.
+    exists(Expr pointerToLocal |
+      variableAddressEscapesTree(va, pointerToLocal.getFullyConverted()) and
+      not hasNontrivialConversion(pointerToLocal) and
+      conservativeDataFlowStep+(DataFlow::exprNode(pointerToLocal), DataFlow::exprNode(r.getExpr()))
     )
   )
-}
-
-newtype TLocalPathNode =
-  TLocalPathNodeMid(Node n) {
-    branchlessLocalFlow1(n) and
-    (
-      isSource(n) or
-      exists(LocalPathNodeMid mid | step(mid.getNode(), n))
-    )
-  }
-
-abstract class LocalPathNode extends TLocalPathNode {
-  Node n;
-
-  /** Gets the underlying node. */
-  Node getNode() { result = n }
-
-  /** Gets a textual representation of this node. */
-  string toString() { result = n.toString() }
-
-  /** Gets the location of this element. */
-  Location getLocation() { result = n.getLocation() }
-
-  /** Gets a successor `LocalPathNode`, if any. */
-  LocalPathNode getASuccessor() { step(this.getNode(), result.getNode()) }
-}
-
-class LocalPathNodeMid extends LocalPathNode, TLocalPathNodeMid {
-  LocalPathNodeMid() { this = TLocalPathNodeMid(n) }
-}
-
-class LocalPathNodeSink extends LocalPathNodeMid {
-  LocalPathNodeSink() { isSink(this.getNode()) }
-}
-
-/**
- * Holds if `source` is a source node, `sink` is a sink node, and there's flow
- * from `source` to `sink` using `step` relation.
- */
-predicate hasFlow(LocalPathNode source, LocalPathNodeSink sink) {
-  isSource(source.getNode()) and
-  source.getASuccessor+() = sink
-}
-
-predicate reach(LocalPathNode n) { n instanceof LocalPathNodeSink or reach(n.getASuccessor()) }
-
-query predicate edges(LocalPathNode a, LocalPathNode b) { a.getASuccessor() = b and reach(b) }
-
-query predicate nodes(LocalPathNode n, string key, string val) {
-  reach(n) and key = "semmle.label" and val = n.toString()
-}
-
-from LocalPathNode source, LocalPathNodeSink sink, VariableAddressInstruction var
-where
-  hasFlow(source, sink) and
-  source.getNode().asInstruction() = var
-select sink.getNode(), source, sink, "May return stack-allocated memory from $@.", var.getAST(),
-  var.getAST().toString()
+select r, "May return stack-allocated memory from $@.", va, va.toString()

cpp/ql/src/Security/CWE/CWE-120/BadlyBoundedWrite.qhelp

@@ -18,5 +18,8 @@
 <p>To fix the problem, either the second argument to <code>snprintf</code> should be changed to 80, or the buffer extended to 256 characters.  A further improvement is to use a preprocessor define so that the size is only specified in one place, potentially preventing future recurrence of this issue.</p>
 
 </example>
-<include src="OverrunWriteReferences.inc.qhelp" />
+<references>
+
+
+</references>
 </qhelp>

cpp/ql/src/Security/CWE/CWE-120/OverrunWrite.c

@@ -1,9 +1,9 @@
-void sayHello(uint32_t userId)
+void sayHello()
 {
-	char buffer[18];
+	char buffer[10];
 
-	// BAD: this message overflows the buffer if userId >= 10000
-	sprintf(buffer, "Hello, user %d!", userId);
+	// BAD: this message overflows the buffer
+	strcpy(buffer, "Hello, world!");
 
 	MessageBox(hWnd, buffer, "New Message", MB_OK);
 }

cpp/ql/src/Security/CWE/CWE-120/OverrunWrite.qhelp

@@ -6,20 +6,30 @@
 <p>The program performs a buffer copy or write operation with no upper limit on the size of the copy, and it appears that certain inputs will cause a buffer overflow to occur in this case.  In addition to causing program instability, techniques exist which may allow an attacker to use this vulnerability to execute arbitrary code.</p>
 
 </overview>
-<include src="OverrunWriteRecommendation.inc.qhelp" />
+<recommendation>
+<p>Always control the length of buffer copy and buffer write operations.  <code>strncpy</code> should be used over <code>strcpy</code>, <code>snprintf</code> over <code>sprintf</code>, and in other cases 'n-variant' functions should be preferred.</p>
+
+</recommendation>
 <example>
 <sample src="OverrunWrite.c" />
 
-<p>In this example, the call to <code>sprintf</code> writes a message of 14 characters (including the terminating null) plus the length of the string conversion of `userId` into a buffer with space for just 18 characters.  As such, if `userId` is greater or equal to `10000`, the last characters overflow the buffer resulting in undefined behavior.</p>
+<p>In this example, the call to <code>strcpy</code> copies a message of 14 characters (including the terminating null) into a buffer with space for just 10 characters.  As such, the last four characters overflow the buffer resulting in undefined behavior.</p>
 
-<p>To fix this issue these changes should be made:</p>
+<p>To fix this issue three changes should be made:</p>
 <ul>
-  <li>Control the size of the buffer by declaring it with a compile time constant.</li>
-  <li>Preferably, replace the call to <code>sprintf</code> with <code>snprintf</code>, using the defined constant size of the buffer or `sizeof(buffer)` as maximum length to write. This will prevent the buffer overflow.</li>
-  <li>Optionally, if `userId` is expected to be less than `10000`, then return or throw an error if `userId` is out of bounds.</li>
-  <li>Otherwise, consider increasing the buffer size to at least 25 characters, so that the message is displayed correctly regardless of the value of `userId`.</li>
+  <li>Control the size of the buffer using a preprocessor define.</li>
+  <li>Replace the call to <code>strcpy</code> with <code>strncpy</code>, specifying the define as the maximum length to copy.  This will prevent the buffer overflow.</li>
+  <li>Consider increasing the buffer size, say to 20 characters, so that the message is displayed correctly.</li>
 </ul>
 
 </example>
-<include src="OverrunWriteReferences.inc.qhelp" />
+<references>
+
+<li>CERT C Coding Standard: <a href="https://www.securecoding.cert.org/confluence/display/c/STR31-C.+Guarantee+that+storage+for+strings+has+sufficient+space+for+character+data+and+the+null+terminator">STR31-C. Guarantee that storage for strings has sufficient space for character data and the null terminator</a>.</li>
+
+
+<!--  LocalWords:  preprocessor CWE STR
+ -->
+
+</references>
 </qhelp>

cpp/ql/src/Security/CWE/CWE-120/OverrunWrite.ql

@@ -21,14 +21,12 @@ import semmle.code.cpp.commons.Alloc
  * See CWE-120/UnboundedWrite.ql for a summary of CWE-120 alert cases.
  */
 
-from BufferWrite bw, Expr dest, int destSize, int estimated, BufferWriteEstimationReason reason
+from BufferWrite bw, Expr dest, int destSize, int estimated
 where
   not bw.hasExplicitLimit() and // has no explicit size limit
   dest = bw.getDest() and
   destSize = getBufferSize(dest, _) and
-  estimated = bw.getMaxDataLimited(reason) and
-  // we exclude ValueFlowAnalysis as it is reported in cpp/very-likely-overruning-write
-  not reason instanceof ValueFlowAnalysis and
+  estimated = bw.getMaxDataLimited(_) and
   // we can deduce that too much data may be copied (even without
   // long '%f' conversions)
   estimated > destSize

cpp/ql/src/Security/CWE/CWE-120/OverrunWriteFloat.qhelp

@@ -6,19 +6,30 @@
 <p>The program performs a buffer copy or write operation that includes one or more float to string conversions (i.e. the %f format specifier), which may overflow the destination buffer if extreme inputs are given.  In addition to causing program instability, techniques exist which may allow an attacker to use this vulnerability to execute arbitrary code.</p>
 
 </overview>
-<include src="OverrunWriteRecommendation.inc.qhelp" />
+<recommendation>
+<p>Always control the length of buffer copy and buffer write operations.  <code>strncpy</code> should be used over <code>strcpy</code>, <code>snprintf</code> over <code>sprintf</code>, and in other cases 'n-variant' functions should be preferred.</p>
+
+</recommendation>
 <example>
 <sample src="OverrunWriteFloat.c" />
 
-<p>In this example, the call to <code>sprintf</code> contains a <code>%f</code> format specifier.  Though a 256 character buffer has been allowed, it is not sufficient for the most extreme floating point inputs.  For example the representation of double value 1e304 (that is 1 with 304 zeroes after it) will overflow a buffer of this length.</p>
+<p>In this example, the call to <code>sprintf</code> contains a %f format specifier.  Though a 256 character buffer has been allowed, it is not sufficient for the most extreme floating point inputs.  For example the representation of double value 1e304 (that is 1 with 304 zeroes after it) will overflow a buffer of this length.</p>
 
 <p>To fix this issue three changes should be made:</p>
 <ul>
   <li>Control the size of the buffer using a preprocessor define.</li>
   <li>Replace the call to <code>sprintf</code> with <code>snprintf</code>, specifying the define as the maximum length to copy.  This will prevent the buffer overflow.</li>
-  <li>Consider using the <code>%g</code> format specifier instead of <code>%f</code>.</li>
+  <li>Consider using the %g format specifier instead of %f.</li>
 </ul>
 
 </example>
-<include src="OverrunWriteReferences.inc.qhelp" />
+<references>
+
+<li>CERT C Coding
+Standard: <a href="https://www.securecoding.cert.org/confluence/display/c/STR31-C.+Guarantee+that+storage+for+strings+has+sufficient+space+for+character+data+and+the+null+terminator">STR31-C. Guarantee
+that storage for strings has sufficient space for character data and
+the null terminator</a>.</li>
+
+
+</references>
 </qhelp>

cpp/ql/src/Security/CWE/CWE-120/OverrunWriteRecommendation.inc.qhelp

@@ -1,8 +0,0 @@
-<!DOCTYPE qhelp PUBLIC
-  "-//Semmle//qhelp//EN"
-  "qhelp.dtd">
-<qhelp>
-<recommendation>
-<p>Always control the length of buffer copy and buffer write operations. <code>strncpy</code> should be used over <code>strcpy</code>, <code>snprintf</code> over <code>sprintf</code>, and in other cases 'n-variant' functions should be preferred.</p>
-</recommendation>
-</qhelp>

cpp/ql/src/Security/CWE/CWE-120/OverrunWriteReferences.inc.qhelp

@@ -1,14 +0,0 @@
-<!DOCTYPE qhelp PUBLIC
-  "-//Semmle//qhelp//EN"
-  "qhelp.dtd">
-<qhelp>
-<references>
-
-<li>CERT C Coding Standard: <a href="https://www.securecoding.cert.org/confluence/display/c/STR31-C.+Guarantee+that+storage+for+strings+has+sufficient+space+for+character+data+and+the+null+terminator">STR31-C. Guarantee that storage for strings has sufficient space for character data and the null terminator</a>.</li>
-<li>CERT C++ Coding Standard: <a href="https://www.securecoding.cert.org/confluence/display/cplusplus/STR50-CPP.+Guarantee+that+storage+for+strings+has+sufficient+space+for+character+data+and+the+null+terminator">STR50-CPP. Guarantee that storage for strings has sufficient space for character data and the null terminator</a>.</li>
-
-<!--  LocalWords:  preprocessor CWE STR
- -->
-
-</references>
-</qhelp>

cpp/ql/src/Security/CWE/CWE-120/UnboundedWrite.qhelp

@@ -6,7 +6,10 @@
 <p>The program performs a buffer copy or write operation with no upper limit on the size of the copy.  An unexpectedly long input that reaches this code will cause the buffer to overflow.  In addition to causing program instability, techniques exist which may allow an attacker to use this vulnerability to execute arbitrary code.</p>
 
 </overview>
-<include src="OverrunWriteRecommendation.inc.qhelp" />
+<recommendation>
+<p>Always control the length of buffer copy and buffer write operations.  <code>strncpy</code> should be used over <code>strcpy</code>, <code>snprintf</code> over <code>sprintf</code> etc.  In general 'n-variant' functions should be preferred.</p>
+
+</recommendation>
 <example>
 <sample src="UnboundedWrite.c" />
 
@@ -15,5 +18,13 @@
 <p>To fix the problem the call to <code>sprintf</code> should be replaced with <code>snprintf</code>, specifying a maximum length of 80 characters.</p>
 
 </example>
-<include src="OverrunWriteReferences.inc.qhelp" />
+<references>
+
+<li>CERT C++ Coding Standard: <a href="https://www.securecoding.cert.org/confluence/display/cplusplus/STR50-CPP.+Guarantee+that+storage+for+strings+has+sufficient+space+for+character+data+and+the+null+terminator">STR50-CPP. Guarantee that storage for strings has sufficient space for character data and the null terminator</a>.</li>
+
+
+<!--  LocalWords:  CWE STR
+ -->
+
+</references>
 </qhelp>

cpp/ql/src/Security/CWE/CWE-120/UnboundedWrite.ql

@@ -33,7 +33,7 @@ import TaintedWithPath
  *    hasExplicitLimit()    exists(getMaxData())  exists(getBufferSize(bw.getDest(), _))) handled by
  *    NO                    NO                    either                                  UnboundedWrite.ql isUnboundedWrite()
  *    NO                    YES                   NO                                      UnboundedWrite.ql isMaybeUnboundedWrite()
- *    NO                    YES                   YES                                     VeryLikelyOverrunWrite.ql, OverrunWrite.ql, OverrunWriteFloat.ql
+ *    NO                    YES                   YES                                     OverrunWrite.ql, OverrunWriteFloat.ql
  *    YES                   either                YES                                     BadlyBoundedWrite.ql
  *    YES                   either                NO                                      (assumed OK)
  */

cpp/ql/src/Security/CWE/CWE-120/VeryLikelyOverrunWrite.c

@@ -1,14 +0,0 @@
-int sayHello(uint32_t userId)
-{
-	char buffer[17];
-
-	if (userId > 9999) return USER_ID_OUT_OF_BOUNDS;
-
-	// BAD: this message overflows the buffer if userId >= 1000,
-	// as no space for the null terminator was accounted for
-	sprintf(buffer, "Hello, user %d!", userId);
-
-	MessageBox(hWnd, buffer, "New Message", MB_OK);
-	
-	return SUCCESS;
-}

cpp/ql/src/Security/CWE/CWE-120/VeryLikelyOverrunWrite.qhelp

@@ -1,24 +0,0 @@
-<!DOCTYPE qhelp PUBLIC
-  "-//Semmle//qhelp//EN"
-  "qhelp.dtd">
-<qhelp>
-<overview>
-<p>The program performs a buffer copy or write operation with no upper limit on the size of the copy. By analyzing the bounds of the expressions involved, it appears that certain inputs will cause a buffer overflow to occur in this case.  In addition to causing program instability, techniques exist which may allow an attacker to use this vulnerability to execute arbitrary code.</p>
-
-</overview>
-<include src="OverrunWriteRecommendation.inc.qhelp" />
-<example>
-<sample src="VeryLikelyOverrunWrite.c" />
-
-<p>In this example, the call to <code>sprintf</code> writes a message of 14 characters (including the terminating null) plus the length of the string conversion of `userId` into a buffer with space for just 17 characters. While `userId` is checked to occupy no more than 4 characters when converted, there is no space in the buffer for the terminating null character if `userId >= 1000`. In this case, the null character overflows the buffer resulting in undefined behavior.</p>
-
-<p>To fix this issue these changes should be made:</p>
-<ul>
-  <li>Control the size of the buffer by declaring it with a compile time constant.</li>
-  <li>Preferably, replace the call to <code>sprintf</code> with <code>snprintf</code>, using the defined constant size of the buffer or `sizeof(buffer)` as maximum length to write. This will prevent the buffer overflow.</li>
-  <li>Increasing the buffer size to account for the full range of `userId` and the terminating null character.</li>
-</ul>
-
-</example>
-<include src="OverrunWriteReferences.inc.qhelp" />
-</qhelp>

cpp/ql/src/Security/CWE/CWE-120/VeryLikelyOverrunWrite.ql

@@ -1,34 +0,0 @@
-/**
- * @name Likely overrunning write
- * @description Buffer write operations that do not control the length
- *              of data written may overflow
- * @kind problem
- * @problem.severity error
- * @security-severity 9.3
- * @precision high
- * @id cpp/very-likely-overrunning-write
- * @tags reliability
- *       security
- *       external/cwe/cwe-120
- *       external/cwe/cwe-787
- *       external/cwe/cwe-805
- */
-
-import semmle.code.cpp.security.BufferWrite
-import semmle.code.cpp.commons.Alloc
-
-/*
- * See CWE-120/UnboundedWrite.ql for a summary of CWE-120 alert cases.
- */
-
-from BufferWrite bw, Expr dest, int destSize, int estimated, ValueFlowAnalysis reason
-where
-  not bw.hasExplicitLimit() and // has no explicit size limit
-  dest = bw.getDest() and
-  destSize = getBufferSize(dest, _) and
-  estimated = bw.getMaxDataLimited(reason) and
-  // we can deduce from non-trivial range analysis that too much data may be copied
-  estimated > destSize
-select bw,
-  "This '" + bw.getBWDesc() + "' operation requires " + estimated +
-    " bytes but the destination is only " + destSize + " bytes."

cpp/ql/src/Security/CWE/CWE-131/NoSpaceForZeroTerminator.ql

@@ -19,7 +19,6 @@ import cpp
 import semmle.code.cpp.dataflow.DataFlow
 import semmle.code.cpp.models.interfaces.ArrayFunction
 import semmle.code.cpp.models.interfaces.Allocation
-import semmle.code.cpp.commons.NullTermination
 
 predicate terminationProblem(AllocationExpr malloc, string msg) {
   // malloc(strlen(...))
@@ -36,7 +35,13 @@ predicate terminationProblem(AllocationExpr malloc, string msg) {
       af.hasArrayWithUnknownSize(arg)
       or
       // flows into string argument to a formatting function (such as `printf`)
-      formatArgumentMustBeNullTerminated(fc, fc.getArgument(arg))
+      exists(int n, FormatLiteral fl |
+        fc.getArgument(arg) = fc.(FormattingFunctionCall).getConversionArgument(n) and
+        fl = fc.(FormattingFunctionCall).getFormat() and
+        fl.getConversionType(n) instanceof PointerType and // `%s`, `%ws` etc
+        not fl.getConversionType(n) instanceof VoidPointerType and // exclude: `%p`
+        not fl.hasPrecision(n) // exclude: `%.*s`
+      )
     )
   ) and
   msg = "This allocation does not include space to null-terminate the string."

cpp/ql/src/Security/CWE/CWE-191/UnsignedDifferenceExpressionComparedZero.ql

@@ -22,13 +22,11 @@ import semmle.code.cpp.dataflow.DataFlow
  *  Holds if `sub` is guarded by a condition which ensures that
  * `left >= right`.
  */
-pragma[nomagic]
+pragma[noinline]
 predicate isGuarded(SubExpr sub, Expr left, Expr right) {
-  exprIsSubLeftOrLess(pragma[only_bind_into](sub), _) and // Manual magic
-  exists(GuardCondition guard, int k, BasicBlock bb |
-    pragma[only_bind_into](bb) = sub.getBasicBlock() and
-    guard.controls(pragma[only_bind_into](bb), _) and
-    guard.ensuresLt(left, right, k, bb, false) and
+  exists(GuardCondition guard, int k |
+    guard.controls(sub.getBasicBlock(), _) and
+    guard.ensuresLt(left, right, k, sub.getBasicBlock(), false) and
     k >= 0
   )
 }
@@ -38,56 +36,47 @@ predicate isGuarded(SubExpr sub, Expr left, Expr right) {
  * `sub.getLeftOperand()`.
  */
 predicate exprIsSubLeftOrLess(SubExpr sub, DataFlow::Node n) {
-  interestingSubExpr(sub, _) and // Manual magic
-  (
-    n.asExpr() = sub.getLeftOperand()
-    or
-    exists(DataFlow::Node other |
-      // dataflow
-      exprIsSubLeftOrLess(sub, other) and
-      (
-        DataFlow::localFlowStep(n, other) or
-        DataFlow::localFlowStep(other, n)
-      )
-    )
-    or
-    exists(DataFlow::Node other |
-      // guard constraining `sub`
-      exprIsSubLeftOrLess(sub, other) and
-      isGuarded(sub, other.asExpr(), n.asExpr()) // other >= n
-    )
-    or
-    exists(DataFlow::Node other, float p, float q |
-      // linear access of `other`
-      exprIsSubLeftOrLess(sub, other) and
-      linearAccess(n.asExpr(), other.asExpr(), p, q) and // n = p * other + q
-      p <= 1 and
-      q <= 0
-    )
-    or
-    exists(DataFlow::Node other, float p, float q |
-      // linear access of `n`
-      exprIsSubLeftOrLess(sub, other) and
-      linearAccess(other.asExpr(), n.asExpr(), p, q) and // other = p * n + q
-      p >= 1 and
-      q >= 0
+  n.asExpr() = sub.getLeftOperand()
+  or
+  exists(DataFlow::Node other |
+    // dataflow
+    exprIsSubLeftOrLess(sub, other) and
+    (
+      DataFlow::localFlowStep(n, other) or
+      DataFlow::localFlowStep(other, n)
     )
   )
-}
-
-predicate interestingSubExpr(SubExpr sub, RelationalOperation ro) {
-  not isFromMacroDefinition(sub) and
-  ro.getLesserOperand().getValue().toInt() = 0 and
-  ro.getGreaterOperand() = sub and
-  sub.getFullyConverted().getUnspecifiedType().(IntegralType).isUnsigned() and
-  // generally catches false positives involving constants
-  exprMightOverflowNegatively(sub.getFullyConverted())
+  or
+  exists(DataFlow::Node other |
+    // guard constraining `sub`
+    exprIsSubLeftOrLess(sub, other) and
+    isGuarded(sub, other.asExpr(), n.asExpr()) // other >= n
+  )
+  or
+  exists(DataFlow::Node other, float p, float q |
+    // linear access of `other`
+    exprIsSubLeftOrLess(sub, other) and
+    linearAccess(n.asExpr(), other.asExpr(), p, q) and // n = p * other + q
+    p <= 1 and
+    q <= 0
+  )
+  or
+  exists(DataFlow::Node other, float p, float q |
+    // linear access of `n`
+    exprIsSubLeftOrLess(sub, other) and
+    linearAccess(other.asExpr(), n.asExpr(), p, q) and // other = p * n + q
+    p >= 1 and
+    q >= 0
+  )
 }
 
 from RelationalOperation ro, SubExpr sub
 where
-  interestingSubExpr(sub, ro) and
   not isFromMacroDefinition(ro) and
-  // generally catches false positives where there's a relation between the left and right operands
-  not exprIsSubLeftOrLess(sub, DataFlow::exprNode(sub.getRightOperand()))
+  not isFromMacroDefinition(sub) and
+  ro.getLesserOperand().getValue().toInt() = 0 and
+  ro.getGreaterOperand() = sub and
+  sub.getFullyConverted().getUnspecifiedType().(IntegralType).isUnsigned() and
+  exprMightOverflowNegatively(sub.getFullyConverted()) and // generally catches false positives involving constants
+  not exprIsSubLeftOrLess(sub, DataFlow::exprNode(sub.getRightOperand())) // generally catches false positives where there's a relation between the left and right operands
 select ro, "Unsigned subtraction can never be negative."

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

@@ -12,33 +12,23 @@
  */
 
 import cpp
-import semmle.code.cpp.security.BufferWrite as BufferWrite
+import semmle.code.cpp.security.BufferWrite
+import semmle.code.cpp.security.TaintTracking
 import semmle.code.cpp.security.SensitiveExprs
-import semmle.code.cpp.security.FlowSources
-import semmle.code.cpp.ir.dataflow.TaintTracking
-import DataFlow::PathGraph
+import TaintedWithPath
 
-/**
- * Taint flow from user input to a buffer write.
- */
-class ToBufferConfiguration extends TaintTracking::Configuration {
-  ToBufferConfiguration() { this = "ToBufferConfiguration" }
-
-  override predicate isSource(DataFlow::Node source) { source instanceof FlowSource }
-
-  override predicate isSink(DataFlow::Node sink) {
-    exists(BufferWrite::BufferWrite w | w.getASource() = sink.asExpr())
-  }
+class Configuration extends TaintTrackingConfiguration {
+  override predicate isSink(Element tainted) { exists(BufferWrite w | w.getASource() = tainted) }
 }
 
 from
-  ToBufferConfiguration config, BufferWrite::BufferWrite w, DataFlow::PathNode sourceNode,
-  DataFlow::PathNode sinkNode, FlowSource source, SensitiveExpr dest
+  BufferWrite w, Expr taintedArg, Expr taintSource, PathNode sourceNode, PathNode sinkNode,
+  string taintCause, SensitiveExpr dest
 where
-  config.hasFlowPath(sourceNode, sinkNode) and
-  sourceNode.getNode() = source and
-  w.getASource() = sinkNode.getNode().asExpr() and
+  taintedWithPath(taintSource, taintedArg, sourceNode, sinkNode) and
+  isUserInput(taintSource, taintCause) and
+  w.getASource() = taintedArg and
   dest = w.getDest()
 select w, sourceNode, sinkNode,
-  "This write into buffer '" + dest.toString() + "' may contain unencrypted data from $@", source,
-  "user input (" + source.getSourceType() + ")"
+  "This write into buffer '" + dest.toString() + "' may contain unencrypted data from $@",
+  taintSource, "user input (" + taintCause + ")"

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

@@ -2,7 +2,7 @@
  * @name Cleartext storage of sensitive information in file
  * @description Storing sensitive information in cleartext can expose it
  *              to an attacker.
- * @kind path-problem
+ * @kind problem
  * @problem.severity warning
  * @security-severity 7.5
  * @precision high
@@ -17,19 +17,6 @@ import semmle.code.cpp.security.SensitiveExprs
 import semmle.code.cpp.security.FileWrite
 import semmle.code.cpp.dataflow.DataFlow
 import semmle.code.cpp.valuenumbering.GlobalValueNumbering
-import semmle.code.cpp.dataflow.TaintTracking
-import DataFlow::PathGraph
-
-/**
- * Taint flow from a sensitive expression to a `FileWrite` sink.
- */
-class FromSensitiveConfiguration extends TaintTracking::Configuration {
-  FromSensitiveConfiguration() { this = "FromSensitiveConfiguration" }
-
-  override predicate isSource(DataFlow::Node source) { source.asExpr() instanceof SensitiveExpr }
-
-  override predicate isSink(DataFlow::Node sink) { any(FileWrite w).getASource() = sink.asExpr() }
-}
 
 /**
  * An operation on a filename.
@@ -56,18 +43,12 @@ predicate isFileName(GVN gvn) {
   )
 }
 
-from
-  FromSensitiveConfiguration config, SensitiveExpr source, DataFlow::PathNode sourceNode, Expr mid,
-  DataFlow::PathNode midNode, FileWrite w, Expr dest
+from FileWrite w, SensitiveExpr source, Expr mid, Expr dest
 where
-  config.hasFlowPath(sourceNode, midNode) and
-  sourceNode.getNode().asExpr() = source and
-  midNode.getNode().asExpr() = mid and
+  DataFlow::localFlow(DataFlow::exprNode(source), DataFlow::exprNode(mid)) and
   mid = w.getASource() and
   dest = w.getDest() and
-  not dest.(VariableAccess).getTarget().getName() = ["stdin", "stdout", "stderr"] and // exclude calls with standard streams
   not isFileName(globalValueNumber(source)) and // file names are not passwords
   not exists(string convChar | convChar = w.getSourceConvChar(mid) | not convChar = ["s", "S"]) // ignore things written with other conversion characters
-select w, sourceNode, midNode,
-  "This write into file '" + dest.toString() + "' may contain unencrypted data from $@", source,
-  "this source."
+select w, "This write into file '" + dest.toString() + "' may contain unencrypted data from $@",
+  source, "this source."

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

@@ -5,7 +5,7 @@
  * @kind path-problem
  * @problem.severity warning
  * @security-severity 7.5
- * @precision high
+ * @precision medium
  * @id cpp/cleartext-transmission
  * @tags security
  *       external/cwe/cwe-319
@@ -14,8 +14,8 @@
 import cpp
 import semmle.code.cpp.security.SensitiveExprs
 import semmle.code.cpp.dataflow.TaintTracking
+import semmle.code.cpp.valuenumbering.GlobalValueNumbering
 import semmle.code.cpp.models.interfaces.FlowSource
-import semmle.code.cpp.commons.File
 import DataFlow::PathGraph
 
 /**
@@ -27,7 +27,6 @@ class SensitiveNode extends DataFlow::Node {
     this.asExpr() = any(SensitiveVariable sv).getInitializer().getExpr() or
     this.asExpr().(VariableAccess).getTarget() =
       any(SensitiveVariable sv).(GlobalOrNamespaceVariable) or
-    this.asExpr().(VariableAccess).getTarget() = any(SensitiveVariable v | v instanceof Field) or
     this.asUninitialized() instanceof SensitiveVariable or
     this.asParameter() instanceof SensitiveVariable or
     this.asExpr().(FunctionCall).getTarget() instanceof SensitiveFunction
@@ -59,10 +58,7 @@ class Send extends SendRecv instanceof RemoteFlowSinkFunction {
     call.getTarget() = this and
     exists(FunctionInput input, int arg |
       super.hasSocketInput(input) and
-      (
-        input.isParameter(arg) or
-        input.isParameterDeref(arg)
-      ) and
+      input.isParameter(arg) and
       result = call.getArgument(arg)
     )
   }
@@ -85,10 +81,7 @@ class Recv extends SendRecv instanceof RemoteFlowSourceFunction {
     call.getTarget() = this and
     exists(FunctionInput input, int arg |
       super.hasSocketInput(input) and
-      (
-        input.isParameter(arg) or
-        input.isParameterDeref(arg)
-      ) and
+      input.isParameter(arg) and
       result = call.getArgument(arg)
     )
   }
@@ -112,8 +105,8 @@ class Recv extends SendRecv instanceof RemoteFlowSourceFunction {
  * practice it usually isn't very important which query reports a result as
  * long as its reported exactly once.
  *
- * We do exclude function calls that specify an apparently constant socket,
- * which is likely to mean standard input, standard output or a similar channel.
+ * We do exclude function calls that specify a constant socket, which is
+ * likely to mean standard input, standard output or a similar channel.
  */
 abstract class NetworkSendRecv extends FunctionCall {
   SendRecv target;
@@ -121,32 +114,17 @@ abstract class NetworkSendRecv extends FunctionCall {
   NetworkSendRecv() {
     this.getTarget() = target and
     // exclude calls based on the socket...
-    not exists(DataFlow::Node src, DataFlow::Node dest |
-      DataFlow::localFlow(src, dest) and
-      dest.asExpr() = target.getSocketExpr(this) and
+    not exists(GVN g |
+      g = globalValueNumber(target.getSocketExpr(this)) and
       (
         // literal constant
-        src.asExpr() instanceof Literal
+        globalValueNumber(any(Literal l)) = g
         or
         // variable (such as a global) initialized to a literal constant
         exists(Variable v |
           v.getInitializer().getExpr() instanceof Literal and
-          src.asExpr() = v.getAnAccess()
+          g = globalValueNumber(v.getAnAccess())
         )
-        or
-        // result of a function call with literal inputs (likely constant)
-        forex(Expr arg | arg = src.asExpr().(FunctionCall).getAnArgument() | arg instanceof Literal)
-        or
-        // variable called `stdin`, `stdout` or `stderr`
-        src.asExpr().(VariableAccess).getTarget().getName() = ["stdin", "stdout", "stderr"]
-        or
-        // open of `"/dev/tty"`
-        exists(FunctionCall fc |
-          fopenCall(fc) and
-          fc.getAnArgument().getValue() = "/dev/tty" and
-          src.asExpr() = fc
-        )
-        // (this is not exhaustive)
       )
     )
   }
@@ -169,28 +147,18 @@ class NetworkRecv extends NetworkSendRecv {
 }
 
 /**
- * An expression that is an argument or return value from an encryption /
- * decryption call. This is quite inclusive to minimize false positives, for
- * example `SecureZeroMemory` is not an encryption routine but a clue that
- * encryption may be present.
+ * An expression that is an argument or return value from an encryption or
+ * decryption call.
  */
 class Encrypted extends Expr {
   Encrypted() {
     exists(FunctionCall fc |
-      fc.getTarget()
-          .getName()
-          .toLowerCase()
-          .regexpMatch(".*(crypt|encode|decode|hash|securezero).*") and
+      fc.getTarget().getName().toLowerCase().regexpMatch(".*(crypt|encode|decode).*") and
       (
         this = fc or
         this = fc.getAnArgument()
       )
     )
-    or
-    exists(Type t |
-      this.getType().refersTo(t) and
-      t.getName().toLowerCase().regexpMatch(".*(crypt|encode|decode|hash|securezero).*")
-    )
   }
 }
 

cpp/ql/src/Security/CWE/CWE-732/UnsafeDaclSecurityDescriptor.ql

@@ -34,7 +34,9 @@ class SetSecurityDescriptorDaclFunctionCall extends FunctionCall {
 class NullDaclConfig extends DataFlow::Configuration {
   NullDaclConfig() { this = "NullDaclConfig" }
 
-  override predicate isSource(DataFlow::Node source) { source.asExpr() instanceof NullValue }
+  override predicate isSource(DataFlow::Node source) {
+    exists(NullValue nullExpr | source.asExpr() = nullExpr)
+  }
 
   override predicate isSink(DataFlow::Node sink) {
     exists(SetSecurityDescriptorDaclFunctionCall call, VariableAccess val | val = sink.asExpr() |

cpp/ql/src/change-notes/2021-12-14-overruning-write-split.md

@@ -1,4 +0,0 @@
----
-category: newQuery
----
-* A new `cpp/very-likely-overruning-write` query has been added to the default query suite for C/C++. The query reports some results that were formerly flagged by `cpp/overruning-write`.

cpp/ql/src/change-notes/2022-01-18-improper-null-termination.md

@@ -1,4 +0,0 @@
----
-category: minorAnalysis
----
-* The "Potential improper null termination" (`cpp/improper-null-termination`) query now produces fewer false positive results around control flow branches and loops.