Merge branch 'main' into python-clean-up-import-resolution

.github/ISSUE_TEMPLATE/lgtm-com---false-positive.md

@@ -1,24 +0,0 @@
----
-name: LGTM.com - false positive
-about: Tell us about an alert that shouldn't be reported
-title: LGTM.com - false positive
-labels: false-positive
-assignees: ''
-
----
-
-**Description of the false positive**
-
-<!-- Please explain briefly why you think it shouldn't be included. -->
-
-**URL to the alert on the project page on LGTM.com**
-
-<!--
-1. Open the project on LGTM.com.
-For example, https://lgtm.com/projects/g/pallets/click/.
-2. Switch to the `Alerts` tab. For example, https://lgtm.com/projects/g/pallets/click/alerts/.
-3. Scroll to the alert that you would like to report.
-4. Click on the right most icon `View this alert within the complete file`.
-5. A new browser tab opens. Copy and paste the page URL here.
-For example, https://lgtm.com/projects/g/pallets/click/snapshot/719fb7d8322b0767cdd1e5903ba3eb3233ba8dd5/files/click/_winconsole.py#xa08d213ab3289f87:1.
--->

.github/ISSUE_TEMPLATE/ql--false-positive.md

@@ -0,0 +1,36 @@
+---
+name: CodeQL False positive
+about: Report CodeQL alerts that you think should not have been detected (not applicable, not exploitable, etc.)
+title: False positive
+labels: false-positive
+assignees: ''
+
+---
+
+**Description of the false positive**
+
+<!-- Please explain briefly why you think it shouldn't be included. -->
+
+**Code samples or links to source code**
+
+<!--
+For open source code: file links with line numbers on GitHub, for example:
+https://github.com/github/codeql/blob/dc440aaee6695deb0d9676b87e06ea984e1b4ae5/javascript/ql/test/query-tests/Security/CWE-078/CommandInjection/exec-sh2.js#L10
+
+For closed source code: (redacted) code samples that illustrate the problem, for example:
+
+```
+function execSh(command, options) {
+    return cp.spawn(getShell(), ["-c", command], options) // <- command line injection
+};
+```
+-->
+
+**URL to the alert on GitHub code scanning (optional)**
+
+<!--
+1. Open the project on GitHub.com.
+2. Switch to the `Security` tab.
+3. Browse to the alert that you would like to report.
+4. Copy and paste the page URL here.
+-->

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

@@ -1,14 +1,22 @@
 name: Fetch CodeQL
 description: Fetches the latest version of CodeQL
+
+inputs:
+  channel:
+    description: 'The CodeQL channel to use'
+    required: false
+    default: 'nightly'
+
 runs:
   using: composite
   steps:
     - name: Fetch CodeQL
       shell: bash
-      run: |
-        gh extension install github/gh-codeql
-        gh codeql set-channel nightly
-        gh codeql version
-        gh codeql version --format=json | jq -r .unpackedLocation >> "${GITHUB_PATH}"
       env:
         GITHUB_TOKEN: ${{ github.token }}
+        CHANNEL: ${{ inputs.channel }}
+      run: |
+        gh extension install github/gh-codeql
+        gh codeql set-channel "$CHANNEL"
+        gh codeql version
+        gh codeql version --format=json | jq -r .unpackedLocation >> "${GITHUB_PATH}"

.github/labeler.yml

@@ -43,3 +43,14 @@ documentation:
 "QL-for-QL":
   - ql/**/*
   - .github/workflows/ql-for-ql*
+
+# Since these are all shared files that need to be synced, just pick _one_ copy of each.
+"DataFlow Library":
+  - "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl.qll"
+  - "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImplCommon.qll"
+  - "java/ql/lib/semmle/code/java/dataflow/internal/tainttracking1/TaintTrackingImpl.qll"
+  - "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImplConsistency.qll"
+  - "java/ql/lib/semmle/code/java/dataflow/internal/FlowSummaryImpl.qll"
+
+"ATM":
+  - javascript/ql/experimental/adaptivethreatmodeling/**/*

.github/workflows/atm-check-query-suite.yml

@@ -0,0 +1,93 @@
+name: "ATM - Check query suite"
+
+env:
+  QUERY_PACK: javascript/ql/experimental/adaptivethreatmodeling/src
+  QUERY_SUITE: codeql-suites/javascript-atm-code-scanning.qls
+
+on:
+  pull_request:
+    paths:
+      - ".github/workflows/atm-check-query-suite.yml"
+      - "javascript/ql/experimental/adaptivethreatmodeling/**"
+  workflow_dispatch:
+
+jobs:
+  atm-check-query-suite:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Setup CodeQL
+        uses: ./.github/actions/fetch-codeql
+        with:
+          channel: release
+
+      - name: Install ATM model
+        run: |
+          set -exu
+
+          # Install dependencies of ATM query pack, i.e. the ATM model
+          codeql pack install "${QUERY_PACK}"
+
+          # Retrieve model checksum
+          model_checksum=$(codeql resolve extensions "${QUERY_PACK}/${QUERY_SUITE}" | jq -r '.models[0].checksum')
+
+          # Trust the model so that we can use it in the ATM boosted queries
+          mkdir -p "$HOME/.config/codeql"
+          echo "--insecurely-execute-ml-model-checksums ${model_checksum}" >> "$HOME/.config/codeql/config"
+
+      - name: Create test DB
+        run: |
+          DB_PATH="${RUNNER_TEMP}/db"
+          echo "DB_PATH=${DB_PATH}" >> "${GITHUB_ENV}"
+
+          codeql database create "${DB_PATH}" --source-root config/atm --language javascript 
+
+      - name: Run ATM query suite
+        run: |
+          SARIF_PATH="${RUNNER_TEMP}/sarif.json"
+          echo "SARIF_PATH=${SARIF_PATH}" >> "${GITHUB_ENV}"
+
+          codeql database analyze \
+            --format sarif-latest \
+            --output "${SARIF_PATH}" \
+            --sarif-group-rules-by-pack \
+            -vv \
+            -- \
+            "${DB_PATH}" \
+            "${QUERY_PACK}/${QUERY_SUITE}"
+
+      - name: Upload SARIF
+        uses: actions/upload-artifact@v3
+        with:
+          name: javascript-ml-powered-queries.sarif
+          path: "${{ env.SARIF_PATH }}"
+          retention-days: 5
+
+      - name: Check results
+        run: |
+          # We should run at least the ML-powered queries in `expected_rules`.
+          expected_rules="js/ml-powered/nosql-injection js/ml-powered/path-injection js/ml-powered/sql-injection js/ml-powered/xss"
+
+          for rule in ${expected_rules}; do
+            found_rule=$(jq --arg rule "${rule}" '[.runs[0].tool.extensions[].rules | select(. != null) |
+              flatten | .[].id] | any(. == $rule)' "${SARIF_PATH}")
+            if [[ "${found_rule}" != "true" ]]; then
+              echo "Expected SARIF output to contain rule '${rule}', but found no such rule."
+              exit 1
+            else
+              echo "Found rule '${rule}'."
+            fi
+          done
+
+          # We should have at least one alert from an ML-powered query.
+          num_alerts=$(jq '[.runs[0].results[] |
+            select(.properties.score != null and (.rule.id | startswith("js/ml-powered/")))] | length' \
+            "${SARIF_PATH}")
+          if [[ "${num_alerts}" -eq 0 ]]; then
+            echo "Expected to find at least one alert from an ML-powered query but found ${num_alerts}."
+            exit 1
+          else
+            echo "Found ${num_alerts} alerts from ML-powered queries.";
+          fi

.github/workflows/atm-model-integration-tests.yml

@@ -0,0 +1,12 @@
+name: ATM Model Integration Tests
+
+on:
+  workflow_dispatch:
+
+jobs:
+  hello-world:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: foo
+        run: echo "Hello world"

.github/workflows/compile-queries.yml

@@ -0,0 +1,71 @@
+name: "Compile all queries using the latest stable CodeQL CLI"
+
+on:
+  push:
+    branches:  # makes sure the cache gets populated - running on the branches people tend to merge into.
+      - main
+      - "rc/*"
+      - "codeql-cli-*"
+  pull_request:
+
+jobs:
+  compile-queries:
+    runs-on: ubuntu-latest-xl
+
+    steps:
+      - uses: actions/checkout@v3
+      # calculate the merge-base with main, in a way that works both on PRs and pushes to main. 
+      - name: Calculate merge-base
+        if: ${{ github.event_name == 'pull_request' }}
+        env:
+          BASE_BRANCH: ${{ github.base_ref }}
+        run: |
+          MERGE_BASE=$(git cat-file commit $GITHUB_SHA | grep '^parent ' | head -1 | cut -f 2 -d " ")
+          echo "merge-base=$MERGE_BASE" >> $GITHUB_ENV
+      - name: Read CodeQL query compilation - PR
+        if: ${{ github.event_name == 'pull_request' }}
+        uses: actions/cache@v3
+        with:
+          path: '*/ql/src/.cache'
+          key: codeql-compile-pr-${{ github.sha }} # deliberately not using the `compile-compile-main` keys here.
+          restore-keys: |
+            codeql-compile-${{ github.base_ref }}-${{ env.merge-base }}
+            codeql-compile-${{ github.base_ref }}-
+            codeql-compile-main-
+      - name: Fill CodeQL query compilation cache - main
+        if: ${{ github.event_name != 'pull_request' }}
+        uses: actions/cache@v3
+        with:
+          path: '*/ql/src/.cache'
+          key: codeql-compile-${{ github.ref_name }}-${{ github.sha }} # just fill on main
+          restore-keys: | # restore from another random commit, to speed up compilation.
+            codeql-compile-${{ github.ref_name }}- 
+            codeql-compile-main-
+      - name: Setup CodeQL
+        uses: ./.github/actions/fetch-codeql
+        with:
+          channel: 'release'
+      - name: check formatting
+        run: find */ql -type f \( -name "*.qll" -o -name "*.ql" \) -print0 | xargs -0 codeql query format --check-only
+      - name: compile queries - check-only
+        # run with --check-only if running in a PR (github.sha != main)
+        if : ${{ github.event_name == 'pull_request' }}
+        shell: bash
+        run: codeql query compile -j0 */ql/src --keep-going --warnings=error --check-only
+      - name: compile queries - full
+        # do full compile if running on main - this populates the cache
+        if : ${{ github.event_name != 'pull_request' }}
+        shell: bash
+        run: |
+          # Move all the existing cache into another folder, so we only preserve the cache for the current queries.
+          mkdir -p ${COMBINED_CACHE_DIR}
+          rm */ql/src/.cache/{lock,size}
+          # copy the contents of the .cache folders into the combined cache folder.
+          cp -r */ql/src/.cache/* ${COMBINED_CACHE_DIR}/
+          # clean up the .cache folders
+          rm -rf */ql/src/.cache/*
+
+          # compile the queries
+          codeql query compile -j0 */ql/src --keep-going --warnings=error --compilation-cache ${COMBINED_CACHE_DIR}
+        env: 
+          COMBINED_CACHE_DIR: ${{ github.workspace }}/compilation-dir

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

@@ -23,19 +23,6 @@ defaults:
     working-directory: javascript/ql/experimental/adaptivethreatmodeling
 
 jobs:
-  qlformat:
-    name: Check QL formatting
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-
-      - 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

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

@@ -24,13 +24,13 @@ jobs:
       - uses: actions/checkout@v3
       - name: Find codeql
         id: find-codeql
-        uses: github/codeql-action/init@71a8b35ff4c80fcfcd05bc1cd932fe3c08f943ca
+        uses: github/codeql-action/init@77a8d2d10c0b403a8b4aadbd223dc489ecd22683
         with:
           languages: javascript # does not matter
       - name: Get CodeQL version
         id: get-codeql-version
         run: |
-          echo "::set-output name=version::$("${CODEQL}" --version | head -n 1 | rev | cut -d " " -f 1 | rev)"
+          echo "version=$("${CODEQL}" --version | head -n 1 | rev | cut -d " " -f 1 | rev)" >> $GITHUB_OUTPUT
         shell: bash
         env:
           CODEQL: ${{ steps.find-codeql.outputs.codeql-path }}
@@ -133,7 +133,7 @@ jobs:
         env:
           CONF: ./ql-for-ql-config.yml
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@71a8b35ff4c80fcfcd05bc1cd932fe3c08f943ca
+        uses: github/codeql-action/init@77a8d2d10c0b403a8b4aadbd223dc489ecd22683
         with:
           languages: ql
           db-location: ${{ runner.temp }}/db
@@ -145,7 +145,7 @@ jobs:
           PACK: ${{ runner.temp }}/pack
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@71a8b35ff4c80fcfcd05bc1cd932fe3c08f943ca
+        uses: github/codeql-action/analyze@77a8d2d10c0b403a8b4aadbd223dc489ecd22683
         with:
           category: "ql-for-ql"
       - name: Copy sarif file to CWD

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

@@ -25,7 +25,7 @@ jobs:
 
       - name: Find codeql
         id: find-codeql
-        uses: github/codeql-action/init@71a8b35ff4c80fcfcd05bc1cd932fe3c08f943ca
+        uses: github/codeql-action/init@77a8d2d10c0b403a8b4aadbd223dc489ecd22683
         with:
           languages: javascript # does not matter
       - uses: actions/cache@v3

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

@@ -22,7 +22,7 @@ jobs:
       - uses: actions/checkout@v3
       - name: Find codeql
         id: find-codeql
-        uses: github/codeql-action/init@71a8b35ff4c80fcfcd05bc1cd932fe3c08f943ca
+        uses: github/codeql-action/init@77a8d2d10c0b403a8b4aadbd223dc489ecd22683
         with:
           languages: javascript # does not matter
       - uses: actions/cache@v3

.github/workflows/ruby-build.yml

@@ -96,8 +96,8 @@ jobs:
       - name: Build Query Pack
         run: |
           codeql pack create ../shared/ssa --output target/packs
+          codeql pack create ../misc/suite-helpers --output target/packs
           codeql pack create ql/lib --output target/packs
-          codeql pack install ql/src
           codeql pack create ql/src --output target/packs
           PACK_FOLDER=$(readlink -f target/packs/codeql/ruby-queries/*)
           codeql generate query-help --format=sarifv2.1.0 --output="${PACK_FOLDER}/rules.sarif" ql/src
@@ -202,7 +202,7 @@ jobs:
           echo 'name: sample-tests
           version: 0.0.0
           dependencies:
-            codeql/ruby-all: 0.0.1
+            codeql/ruby-all: "*"
           extractor: ruby
           tests: .
           ' > qlpack.yml

.github/workflows/ruby-qltest.yml

@@ -28,13 +28,6 @@ defaults:
     working-directory: ruby
 
 jobs:
-  qlformat:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - 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:

.github/workflows/swift-codegen.yml

@@ -1,39 +0,0 @@
-name: "Swift: Check code generation"
-
-on:
-  pull_request:
-    paths:
-      - "swift/**"
-      - "misc/bazel/**"
-      - "*.bazel*"
-      - .github/workflows/swift-codegen.yml
-      - .github/actions/fetch-codeql/action.yml
-    branches:
-      - main
-
-jobs:
-  codegen:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - uses: ./.github/actions/fetch-codeql
-      - uses: bazelbuild/setup-bazelisk@v2
-      - uses: actions/setup-python@v3
-      - uses: pre-commit/action@v3.0.0
-        name: Check that python code is properly formatted
-        with:
-          extra_args: autopep8 --all-files
-      - name: Run unit tests
-        run: |
-          bazel test //swift/codegen/test --test_output=errors
-      - uses: pre-commit/action@v3.0.0
-        name: Check that QL generated code was checked in
-        with:
-          extra_args: swift-codegen --all-files
-      - name: Generate C++ files
-        run: |
-          bazel run //swift/codegen:codegen -- --generate=trap,cpp --cpp-output=$PWD/swift-generated-cpp-files
-      - uses: actions/upload-artifact@v3
-        with:
-          name: swift-generated-cpp-files
-          path: swift-generated-cpp-files/**

.github/workflows/swift-integration-tests.yml

@@ -1,45 +0,0 @@
-name: "Swift: Run Integration Tests"
-
-on:
-  pull_request:
-    paths:
-      - "swift/**"
-      - "misc/bazel/**"
-      - "*.bazel*"
-      - .github/workflows/swift-integration-tests.yml
-      - .github/actions/fetch-codeql/action.yml
-      - codeql-workspace.yml
-    branches:
-      - main
-defaults:
-  run:
-    working-directory: swift
-
-jobs:
-  integration-tests:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      fail-fast: false
-      matrix:
-        os:
-          - ubuntu-20.04
-#          - macos-latest  TODO
-    steps:
-      - uses: actions/checkout@v3
-      - uses: ./.github/actions/fetch-codeql
-      - uses: bazelbuild/setup-bazelisk@v2
-      - uses: actions/setup-python@v3
-      - name: Build Swift extractor
-        run: |
-          bazel run //swift:create-extractor-pack
-      - name: Get Swift version
-        id: get_swift_version
-        run: |
-          VERSION=$(bazel run //swift/extractor -- --version | sed -ne 's/.*version \(\S*\).*/\1/p')
-          echo "::set-output name=version::$VERSION"
-      - uses: swift-actions/setup-swift@v1
-        with:
-          swift-version: "${{steps.get_swift_version.outputs.version}}"
-      - name: Run integration tests
-        run: |
-          python integration-tests/runner.py

.github/workflows/swift-qltest.yml

@@ -1,43 +0,0 @@
-name: "Swift: Run QL Tests"
-
-on:
-  pull_request:
-    paths:
-      - "swift/**"
-      - "misc/bazel/**"
-      - "*.bazel*"
-      - .github/workflows/swift-qltest.yml
-      - .github/actions/fetch-codeql/action.yml
-      - codeql-workspace.yml
-    branches:
-      - main
-defaults:
-  run:
-    working-directory: swift
-
-jobs:
-  qlformat:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - 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
-  qltest:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      fail-fast: false
-      matrix:
-        os : [ubuntu-20.04, macos-latest]
-    steps:
-      - uses: actions/checkout@v3
-      - uses: ./.github/actions/fetch-codeql
-      - uses: bazelbuild/setup-bazelisk@v2
-      - name: Build Swift extractor
-        run: |
-          bazel run //swift:create-extractor-pack
-      - name: Run QL tests
-        run: |
-          codeql test run --threads=0 --ram 5000 --search-path "${{ github.workspace }}/swift/extractor-pack" --check-databases --check-unused-labels --check-repeated-labels --check-redefined-labels --check-use-before-definition ql/test
-        env:
-          GITHUB_TOKEN: ${{ github.token }}

.github/workflows/swift.yml

@@ -0,0 +1,120 @@
+name: "Swift"
+
+on:
+  pull_request:
+    paths:
+      - "swift/**"
+      - "misc/bazel/**"
+      - "*.bazel*"
+      - .github/workflows/swift.yml
+      - .github/actions/fetch-codeql/action.yml
+      - codeql-workspace.yml
+      - .pre-commit-config.yaml
+      - "!**/*.md"
+      - "!**/*.qhelp"
+    branches:
+      - main
+
+jobs:
+  changes:
+    runs-on: ubuntu-latest
+    outputs:
+      codegen: ${{ steps.filter.outputs.codegen }}
+      ql: ${{ steps.filter.outputs.ql }}
+    steps:
+      - uses: dorny/paths-filter@4512585405083f25c027a35db413c2b3b9006d50
+        id: filter
+        with:
+          filters: |
+            codegen:
+              - '.github/workflows/swift.yml'
+              - "misc/bazel/**"
+              - "*.bazel*"
+              - 'swift/actions/setup-env/**'
+              - '.pre-commit-config.yaml'
+              - 'swift/codegen/**'
+              - 'swift/schema.py'
+              - 'swift/**/*.dbscheme'
+              - 'swift/ql/lib/codeql/swift/elements.qll'
+              - 'swift/ql/lib/codeql/swift/elements/**'
+              - 'swift/ql/lib/codeql/swift/generated/**'
+              - 'swift/ql/test/extractor-tests/generated/**'
+            ql:
+              - 'github/workflows/swift.yml'
+              - 'swift/**/*.ql'
+              - 'swift/**/*.qll'
+  # not using a matrix as you cannot depend on a specific job in a matrix, and we want to start linux checks
+  # without waiting for the macOS build
+  build-and-test-macos:
+    runs-on: macos-12-xl
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ./swift/actions/create-extractor-pack
+      - uses: ./swift/actions/run-quick-tests
+      - uses: ./swift/actions/print-unextracted
+  build-and-test-linux:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ./swift/actions/create-extractor-pack
+      - uses: ./swift/actions/run-quick-tests
+      - uses: ./swift/actions/print-unextracted
+  qltests-linux:
+    needs: build-and-test-linux
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ./swift/actions/run-ql-tests
+  qltests-macos:
+    needs: build-and-test-macos
+    runs-on: macos-12-xl
+    strategy:
+      fail-fast: false
+      matrix:
+        slice: ["1/2", "2/2"]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ./swift/actions/run-ql-tests
+        with:
+          flags: --slice ${{ matrix.slice }}
+  integration-tests-linux:
+    needs: build-and-test-linux
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ./swift/actions/run-integration-tests
+  integration-tests-macos:
+    needs: build-and-test-macos
+    runs-on: macos-12-xl
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ./swift/actions/run-integration-tests
+  codegen:
+    runs-on: ubuntu-latest
+    needs: changes
+    if: ${{ needs.changes.outputs.codegen == 'true' }}
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ./swift/actions/setup-env
+      - uses: pre-commit/action@v3.0.0
+        name: Check that python code is properly formatted
+        with:
+          extra_args: autopep8 --all-files
+      - uses: ./.github/actions/fetch-codeql
+      - uses: pre-commit/action@v3.0.0
+        name: Check that QL generated code was checked in
+        with:
+          extra_args: swift-codegen --all-files
+      - name: Generate C++ files
+        run: |
+          bazel run //swift/codegen:codegen -- --generate=trap,cpp --cpp-output=$PWD/generated-cpp-files
+      - uses: actions/upload-artifact@v3
+        with:
+          name: swift-generated-cpp-files
+          path: generated-cpp-files/**
+  database-upgrade-scripts:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ./.github/actions/fetch-codeql
+      - uses: ./swift/actions/database-upgrade-scripts

.pre-commit-config.yaml

@@ -19,7 +19,7 @@ repos:
     rev: v1.6.0
     hooks:
       - id: autopep8
-        files: ^swift/codegen/.*\.py
+        files: ^swift/.*\.py
 
   - repo: local
     hooks:
@@ -31,7 +31,7 @@ repos:
 
       - id: sync-files
         name: Fix files required to be identical
-        files: \.(qll?|qhelp|swift)$
+        files: \.(qll?|qhelp|swift)$|^config/identical-files\.json$
         language: system
         entry: python3 config/sync-files.py --latest
         pass_filenames: false
@@ -44,7 +44,7 @@ repos:
 
       - id: swift-codegen
         name: Run Swift checked in code generation
-        files: ^swift/(codegen/|.*/generated/|ql/lib/(swift\.dbscheme$|codeql/swift/elements))
+        files: ^swift/(schema.py$|codegen/|.*/generated/|ql/lib/(swift\.dbscheme$|codeql/swift/elements))
         language: system
         entry: bazel run //swift/codegen -- --quiet
         pass_filenames: false

CODEOWNERS

@@ -20,9 +20,9 @@
 /java/ql/src/semmle/code/java/dataflow/internal/tainttracking2/TaintTrackingImpl.qll @github/codeql-java @github/codeql-go
 
 # CodeQL tools and associated docs
-/docs/codeql-cli/ @github/codeql-cli-reviewers
+/docs/codeql/codeql-cli/ @github/codeql-cli-reviewers
-/docs/codeql-for-visual-studio-code/ @github/codeql-vscode-reviewers
+/docs/codeql/codeql-for-visual-studio-code/ @github/codeql-vscode-reviewers
-/docs/ql-language-reference/ @github/codeql-frontend-reviewers
+/docs/codeql/ql-language-reference/ @github/codeql-frontend-reviewers
 /docs/query-*-style-guide.md @github/codeql-analysis-reviewers
 
 # QL for QL reviewers
@@ -40,8 +40,9 @@ WORKSPACE.bazel @github/codeql-ci-reviewers
 
 # Workflows
 /.github/workflows/ @github/codeql-ci-reviewers
+/.github/workflows/atm-* @github/codeql-ml-powered-queries-reviewers
 /.github/workflows/go-* @github/codeql-go
 /.github/workflows/js-ml-tests.yml @github/codeql-ml-powered-queries-reviewers
 /.github/workflows/ql-for-ql-* @github/codeql-ql-for-ql-reviewers
 /.github/workflows/ruby-* @github/codeql-ruby
-/.github/workflows/swift-* @github/codeql-c
+/.github/workflows/swift.yml @github/codeql-c

change-notes/1.20/analysis-javascript.md

@@ -52,7 +52,7 @@
 | Unneeded defensive code | More true positive and fewer false positive results | This query now recognizes additional defensive code patterns. |
 | Unsafe dynamic method access              | Fewer false positive results | This query no longer flags concatenated strings as unsafe method names. |
 | Unused parameter                           | Fewer false positive results | This query no longer flags parameters with leading underscore. |
-| Unused variable, import, function or class | Fewer false positive results | This query now flags fewer variables that are implictly used by JSX elements. It no longer flags variables with a leading underscore and variables in dead code. |
+| Unused variable, import, function or class | Fewer false positive results | This query now flags fewer variables that are implicitly used by JSX elements. It no longer flags variables with a leading underscore and variables in dead code. |
 | Unvalidated dynamic method call           | More true positive results | This query now flags concatenated strings as unvalidated method names in more cases. |
 | Useless assignment to property. | Fewer false positive results | This query now treats assignments with complex right-hand sides correctly. |
 | Useless conditional | Fewer results | Additional defensive coding patterns are now ignored. |

change-notes/1.23/analysis-cpp.md

@@ -19,7 +19,7 @@ The following changes in version 1.23 affect C/C++ analysis in all applications.
 | Hard-coded Japanese era start date in call (`cpp/japanese-era/constructor-or-method-with-exact-era-date`) | Deprecated | This query has been deprecated.  Use the new combined query Hard-coded Japanese era start date (`cpp/japanese-era/exact-era-date`) instead. |
 | Hard-coded Japanese era start date in struct (`cpp/japanese-era/struct-with-exact-era-date`) | Deprecated | This query has been deprecated.  Use the new combined query Hard-coded Japanese era start date (`cpp/japanese-era/exact-era-date`) instead. |
 | Hard-coded Japanese era start date (`cpp/japanese-era/exact-era-date`) | More correct results | This query now checks for the beginning date of the Reiwa era (1st May 2019). |
-| Non-constant format string (`cpp/non-constant-format`) | Fewer false positive results | Fixed false positive results triggrered by mismatching declarations of a formatting function. |
+| Non-constant format string (`cpp/non-constant-format`) | Fewer false positive results | Fixed false positive results triggered by mismatching declarations of a formatting function. |
 | Sign check of bitwise operation (`cpp/bitwise-sign-check`) | Fewer false positive results | Results involving `>=` or `<=` are no longer reported. |
 | Too few arguments to formatting function (`cpp/wrong-number-format-arguments`) | Fewer false positive results | Fixed false positive results triggered by mismatching declarations of a formatting function. |
 | Too many arguments to formatting function (`cpp/too-many-format-arguments`) | Fewer false positive results | Fixed false positive results triggered by mismatching declarations of a formatting function. |

change-notes/1.24/analysis-javascript.md

@@ -91,7 +91,7 @@
 
 ## Changes to libraries
 
-* The predicates `RegExpTerm.getSuccessor` and `RegExpTerm.getPredecessor` have been changed to reflect textual, not operational, matching order. This only makes a difference in lookbehind assertions, which are operationally matched backwards. Previously, `getSuccessor` would mimick this, so in an assertion `(?<=ab)` the term `b` would be considered the predecessor, not the successor, of `a`. Textually, however, `a` is still matched before `b`, and this is the order we now follow.
+* The predicates `RegExpTerm.getSuccessor` and `RegExpTerm.getPredecessor` have been changed to reflect textual, not operational, matching order. This only makes a difference in lookbehind assertions, which are operationally matched backwards. Previously, `getSuccessor` would mimic this, so in an assertion `(?<=ab)` the term `b` would be considered the predecessor, not the successor, of `a`. Textually, however, `a` is still matched before `b`, and this is the order we now follow.
 * An extensible model of the `EventEmitter` pattern has been implemented.
 * Taint-tracking configurations now interact differently with the `data` flow label, which may affect queries
   that combine taint-tracking and flow labels.

codeql-workspace.yml

@@ -17,6 +17,7 @@ provide:
   # - "javascript/ql/experimental/adaptivethreatmodeling/model/qlpack.yml"
   - "javascript/ql/experimental/adaptivethreatmodeling/modelbuilding/qlpack.yml"
   - "javascript/ql/experimental/adaptivethreatmodeling/src/qlpack.yml"
+  - "javascript/ql/experimental/adaptivethreatmodeling/test/qlpack.yml"
   - "csharp/ql/campaigns/Solorigate/lib/qlpack.yml"
   - "csharp/ql/campaigns/Solorigate/src/qlpack.yml"
   - "csharp/ql/campaigns/Solorigate/test/qlpack.yml"

config/atm/ml-powered-queries-repo/add-note.js

@@ -0,0 +1,21 @@
+const mongoose = require('mongoose');
+
+Logger = require('./logger').Logger;
+Note = require('./models/note').Note;
+
+(async () => {
+  if (process.argv.length != 5) {
+    Logger.log("Creates a private note.  Usage: node add-note.js <token> <title> <body>")
+    return;
+  }
+
+  // Open the default mongoose connection
+  await mongoose.connect('mongodb://localhost:27017/notes', { useFindAndModify: false });
+
+  const [userToken, title, body] = process.argv.slice(2);
+  await Note.create({ title, body, userToken });
+
+  Logger.log(`Created private note with title ${title} and body ${body} belonging to user with token ${userToken}.`);
+
+  await mongoose.connection.close();
+})();

config/atm/ml-powered-queries-repo/app.js

@@ -0,0 +1,68 @@
+const bodyParser = require('body-parser');
+const express = require('express');
+const mongoose = require('mongoose');
+
+const notesApi = require('./notes-api');
+const usersApi = require('./users-api');
+
+const addSampleData = module.exports.addSampleData = async () => {
+  const [userA, userB] = await User.create([
+    {
+      name: "A",
+      token: "tokenA"
+    },
+    {
+      name: "B",
+      token: "tokenB"
+    }
+  ]);
+
+  await Note.create([
+    {
+      title: "Public note belonging to A",
+      body: "This is a public note belonging to A",
+      isPublic: true,
+      ownerToken: userA.token
+    },
+    {
+      title: "Public note belonging to B",
+      body: "This is a public note belonging to B",
+      isPublic: true,
+      ownerToken: userB.token
+    },
+    {
+      title: "Private note belonging to A",
+      body: "This is a private note belonging to A",
+      ownerToken: userA.token
+    },
+    {
+      title: "Private note belonging to B",
+      body: "This is a private note belonging to B",
+      ownerToken: userB.token
+    }
+  ]);
+}
+
+module.exports.startApp = async () => {
+  // Open the default mongoose connection
+  await mongoose.connect('mongodb://mongo:27017/notes', { useFindAndModify: false });
+  // Drop contents of DB
+  mongoose.connection.dropDatabase();
+  // Add some sample data
+  await addSampleData();
+
+  const app = express();
+
+  app.use(bodyParser.json());
+  app.use(bodyParser.urlencoded());
+
+  app.get('/', async (_req, res) => {
+    res.send('Hello World');
+  });
+
+  app.use('/api/notes', notesApi.router);
+  app.use('/api/users', usersApi.router);
+
+  app.listen(3000);
+  Logger.log('Express started on port 3000');
+};

config/atm/ml-powered-queries-repo/index.js

@@ -0,0 +1,7 @@
+const startApp = require('./app').startApp;
+
+Logger = require('./logger').Logger;
+Note = require('./models/note').Note;
+User = require('./models/user').User;
+
+startApp();

config/atm/ml-powered-queries-repo/logger.js

@@ -0,0 +1,5 @@
+module.exports.Logger = class {
+  log(message, ...objs) {
+    console.log(message, objs);
+  }
+};

config/atm/ml-powered-queries-repo/models/note.js

@@ -0,0 +1,8 @@
+const mongoose = require('mongoose');
+
+module.exports.Note = mongoose.model('Note', new mongoose.Schema({
+  title: String,
+  body: String,
+  ownerToken: String,
+  isPublic: Boolean
+}));

config/atm/ml-powered-queries-repo/models/user.js

@@ -0,0 +1,6 @@
+const mongoose = require('mongoose');
+
+module.exports.User = mongoose.model('User', new mongoose.Schema({
+  name: String,
+  token: String
+}));

config/atm/ml-powered-queries-repo/notes-api.js

@@ -0,0 +1,44 @@
+const express = require('express')
+
+const router = module.exports.router = express.Router();
+
+function serializeNote(note) {
+  return {
+    title: note.title,
+    body: note.body
+  };
+}
+
+router.post('/find', async (req, res) => {
+  const notes = await Note.find({
+    ownerToken: req.body.token
+  }).exec();
+  res.json({
+    notes: notes.map(serializeNote)
+  });
+});
+
+router.get('/findPublic', async (_req, res) => {
+  const notes = await Note.find({
+    isPublic: true
+  }).exec();
+  res.json({
+    notes: notes.map(serializeNote)
+  });
+});
+
+router.post('/findVisible', async (req, res) => {
+  const notes = await Note.find({
+    $or: [
+      {
+        isPublic: true
+      },
+      {
+        ownerToken: req.body.token
+      }
+    ]
+  }).exec();
+  res.json({
+    notes: notes.map(serializeNote)
+  });
+});

config/atm/ml-powered-queries-repo/read-notes.js

@@ -0,0 +1,37 @@
+const mongoose = require('mongoose');
+
+Logger = require('./logger').Logger;
+Note = require('./models/note').Note;
+User = require('./models/user').User;
+
+(async () => {
+  if (process.argv.length != 3) {
+    Logger.log("Outputs all notes visible to a user.  Usage: node read-notes.js <token>")
+    return;
+  }
+
+  // Open the default mongoose connection
+  await mongoose.connect('mongodb://localhost:27017/notes', { useFindAndModify: false });
+
+  const ownerToken = process.argv[2];
+
+  const user = await User.findOne({
+    token: ownerToken
+  }).exec();
+
+  const notes = await Note.find({
+    $or: [
+      { isPublic: true },
+      { ownerToken }
+    ]
+  }).exec();
+
+  notes.map(note => {
+    Logger.log("Title:" + note.title);
+    Logger.log("By:" + user.name);
+    Logger.log("Body:" + note.body);
+    Logger.log();
+  });
+
+  await mongoose.connection.close();
+})();

config/atm/ml-powered-queries-repo/users-api.js

@@ -0,0 +1,25 @@
+const express = require('express')
+
+Logger = require('./logger').Logger;
+const router = module.exports.router = express.Router();
+
+router.post('/updateName', async (req, res) => {
+  Logger.log("/updateName called with new name", req.body.name);
+  await User.findOneAndUpdate({
+    token: req.body.token
+  }, {
+    name: req.body.name
+  }).exec();
+  res.json({
+    name: req.body.name
+  });
+});
+
+router.post('/getName', async (req, res) => {
+  const user = await User.findOne({
+    token: req.body.token
+  }).exec();
+  res.json({
+    name: user.name
+  });
+});

config/identical-files.json

@@ -94,8 +94,8 @@
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/rangeanalysis/SsaReadPositionCommon.qll"
   ],
   "Model as Data Generation Java/C# - CaptureModels": [
-    "java/ql/src/utils/model-generator/internal/CaptureModels.qll",
+    "java/ql/src/utils/modelgenerator/internal/CaptureModels.qll",
-    "csharp/ql/src/utils/model-generator/internal/CaptureModels.qll"
+    "csharp/ql/src/utils/modelgenerator/internal/CaptureModels.qll"
   ],
   "Sign Java/C#": [
     "java/ql/lib/semmle/code/java/dataflow/internal/rangeanalysis/Sign.qll",
@@ -486,40 +486,6 @@
     "python/ql/lib/semmle/python/security/internal/SensitiveDataHeuristics.qll",
     "ruby/ql/lib/codeql/ruby/security/internal/SensitiveDataHeuristics.qll"
   ],
-  "ReDoS Util Python/JS/Ruby/Java": [
-    "javascript/ql/lib/semmle/javascript/security/regexp/NfaUtils.qll",
-    "python/ql/lib/semmle/python/security/regexp/NfaUtils.qll",
-    "ruby/ql/lib/codeql/ruby/security/regexp/NfaUtils.qll",
-    "java/ql/lib/semmle/code/java/security/regexp/NfaUtils.qll"
-  ],
-  "ReDoS Exponential Python/JS/Ruby/Java": [
-    "javascript/ql/lib/semmle/javascript/security/regexp/ExponentialBackTracking.qll",
-    "python/ql/lib/semmle/python/security/regexp/ExponentialBackTracking.qll",
-    "ruby/ql/lib/codeql/ruby/security/regexp/ExponentialBackTracking.qll",
-    "java/ql/lib/semmle/code/java/security/regexp/ExponentialBackTracking.qll"
-  ],
-  "ReDoS Polynomial Python/JS/Ruby/Java": [
-    "javascript/ql/lib/semmle/javascript/security/regexp/SuperlinearBackTracking.qll",
-    "python/ql/lib/semmle/python/security/regexp/SuperlinearBackTracking.qll",
-    "ruby/ql/lib/codeql/ruby/security/regexp/SuperlinearBackTracking.qll",
-    "java/ql/lib/semmle/code/java/security/regexp/SuperlinearBackTracking.qll"
-  ],
-  "RegexpMatching Python/JS/Ruby": [
-    "javascript/ql/lib/semmle/javascript/security/regexp/RegexpMatching.qll",
-    "python/ql/lib/semmle/python/security/regexp/RegexpMatching.qll",
-    "ruby/ql/lib/codeql/ruby/security/regexp/RegexpMatching.qll"
-  ],
-  "BadTagFilterQuery Python/JS/Ruby": [
-    "javascript/ql/lib/semmle/javascript/security/BadTagFilterQuery.qll",
-    "python/ql/lib/semmle/python/security/BadTagFilterQuery.qll",
-    "ruby/ql/lib/codeql/ruby/security/BadTagFilterQuery.qll"
-  ],
-  "OverlyLargeRange Python/JS/Ruby/Java": [
-    "javascript/ql/lib/semmle/javascript/security/OverlyLargeRangeQuery.qll",
-    "python/ql/lib/semmle/python/security/OverlyLargeRangeQuery.qll",
-    "ruby/ql/lib/codeql/ruby/security/OverlyLargeRangeQuery.qll",
-    "java/ql/lib/semmle/code/java/security/OverlyLargeRangeQuery.qll"
-  ],
   "CFG": [
     "csharp/ql/lib/semmle/code/csharp/controlflow/internal/ControlFlowGraphImplShared.qll",
     "ruby/ql/lib/codeql/ruby/controlflow/internal/ControlFlowGraphImplShared.qll",
@@ -600,8 +566,12 @@
     "swift/ql/test/extractor-tests/patterns/patterns.swift",
     "swift/ql/test/library-tests/ast/patterns.swift"
   ],
+  "Swift control flow test file": [
+    "swift/ql/test/library-tests/controlflow/graph/cfg.swift",
+    "swift/ql/test/library-tests/ast/cfg.swift"
+  ],
   "IncompleteMultiCharacterSanitization JS/Ruby": [
     "javascript/ql/lib/semmle/javascript/security/IncompleteMultiCharacterSanitizationQuery.qll",
     "ruby/ql/lib/codeql/ruby/security/IncompleteMultiCharacterSanitizationQuery.qll"
   ]
-}
+}

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

@@ -11,11 +11,12 @@
   <ItemGroup>
     <PackageReference Include="System.IO.FileSystem" Version="4.3.0" />
     <PackageReference Include="System.IO.FileSystem.Primitives" Version="4.3.0" />
-    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="xunit" Version="2.4.2" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1">
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.0" />
   </ItemGroup>
 
   <ItemGroup>

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

@@ -17,7 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Build" Version="16.11.0" />
+    <PackageReference Include="Microsoft.Build" Version="17.3.2" />
   </ItemGroup>
 
   <ItemGroup>

cpp/ql/examples/qlpack.yml

@@ -3,4 +3,4 @@ groups:
   - cpp
   - examples
 dependencies:
-  codeql/cpp-all: "*"
+  codeql/cpp-all: ${workspace}

cpp/ql/lib/CHANGELOG.md

@@ -1,3 +1,13 @@
+## 0.4.3
+
+### Minor Analysis Improvements
+
+* Fixed bugs in the `FormatLiteral` class that were causing `getMaxConvertedLength` and related predicates to return no results when the format literal was `%e`, `%f` or `%g` and an explicit precision was specified.
+
+## 0.4.2
+
+No user-facing changes.
+
 ## 0.4.1
 
 No user-facing changes.

cpp/ql/lib/change-notes/released/0.4.2.md

@@ -0,0 +1,3 @@
+## 0.4.2
+
+No user-facing changes.

cpp/ql/lib/change-notes/released/0.4.3.md

@@ -0,0 +1,5 @@
+## 0.4.3
+
+### Minor Analysis Improvements
+
+* Fixed bugs in the `FormatLiteral` class that were causing `getMaxConvertedLength` and related predicates to return no results when the format literal was `%e`, `%f` or `%g` and an explicit precision was specified.

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

@@ -1,2 +1,2 @@
 ---
-lastReleaseVersion: 0.4.1
+lastReleaseVersion: 0.4.3

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -136,6 +136,18 @@ module Consistency {
     msg = "Local flow step does not preserve enclosing callable."
   }
 
+  query predicate readStepIsLocal(Node n1, Node n2, string msg) {
+    readStep(n1, _, n2) and
+    nodeGetEnclosingCallable(n1) != nodeGetEnclosingCallable(n2) and
+    msg = "Read step does not preserve enclosing callable."
+  }
+
+  query predicate storeStepIsLocal(Node n1, Node n2, string msg) {
+    storeStep(n1, _, n2) and
+    nodeGetEnclosingCallable(n1) != nodeGetEnclosingCallable(n2) and
+    msg = "Store step does not preserve enclosing callable."
+  }
+
   private DataFlowType typeRepr() { result = getNodeType(_) }
 
   query predicate compatibleTypesReflexive(DataFlowType t, string msg) {

cpp/ql/lib/experimental/semmle/code/cpp/semantic/analysis/ModulusAnalysis.qll

@@ -4,6 +4,12 @@
  * variable), and `v` is an integer in the range `[0 .. m-1]`.
  */
 
+/*
+ * The main recursion has base cases in both `ssaModulus` (for guarded reads) and `semExprModulus`
+ * (for constant values). The most interesting recursive case is `phiModulusRankStep`, which
+ * handles phi inputs.
+ */
+
 private import ModulusAnalysisSpecific::Private
 private import experimental.semmle.code.cpp.semantic.Semantic
 private import ConstantAnalysis
@@ -162,6 +168,11 @@ private predicate phiModulusInit(SemSsaPhiNode phi, SemBound b, int val, int mod
  */
 pragma[nomagic]
 private predicate phiModulusRankStep(SemSsaPhiNode phi, SemBound b, int val, int mod, int rix) {
+  /*
+   * base case. If any phi input is equal to `b + val` modulo `mod`, that's a potential congruence
+   * class for the phi node.
+   */
+
   rix = 0 and
   phiModulusInit(phi, b, val, mod)
   or
@@ -169,6 +180,12 @@ private predicate phiModulusRankStep(SemSsaPhiNode phi, SemBound b, int val, int
     mod != 1 and
     val = remainder(v1, mod)
   |
+    /*
+     * Recursive case. If `inp` = `b + v2` mod `m2`, we combine that with the preceding potential
+     * congruence class `b + v1` mod `m1`. The result will be the congruence class of `v1` modulo
+     * the greatest common denominator of `m1`, `m2`, and `v1 - v2`.
+     */
+
     exists(int v2, int m2 |
       rankedPhiInput(pragma[only_bind_out](phi), inp, edge, rix) and
       phiModulusRankStep(phi, b, v1, m1, rix - 1) and
@@ -176,6 +193,12 @@ private predicate phiModulusRankStep(SemSsaPhiNode phi, SemBound b, int val, int
       mod = m1.gcd(m2).gcd(v1 - v2)
     )
     or
+    /*
+     * Recursive case. If `inp` = `phi` mod `m2`, we combine that with the preceding potential
+     * congruence class `b + v1` mod `m1`. The result will be a congruence class modulo the greatest
+     * common denominator of `m1` and `m2`.
+     */
+
     exists(int m2 |
       rankedPhiInput(phi, inp, edge, rix) and
       phiModulusRankStep(phi, b, v1, m1, rix - 1) and

cpp/ql/lib/qlpack.yml

@@ -1,9 +1,9 @@
 name: codeql/cpp-all
-version: 0.4.2-dev
+version: 0.4.4-dev
 groups: cpp
 dbscheme: semmlecode.cpp.dbscheme
 extractor: cpp
 library: true
 upgrades: upgrades
 dependencies:
-  codeql/ssa: 0.0.1
+  codeql/ssa: ${workspace}

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

@@ -1125,12 +1125,12 @@ class FormatLiteral extends Literal {
         exists(int dot, int afterdot |
           (if this.getPrecision(n) = 0 then dot = 0 else dot = 1) and
           (
-            (
+            if this.hasExplicitPrecision(n)
-              if this.hasExplicitPrecision(n)
+            then afterdot = this.getPrecision(n)
-              then afterdot = this.getPrecision(n)
+            else (
-              else not this.hasImplicitPrecision(n)
+              not this.hasImplicitPrecision(n) and
-            ) and
+              afterdot = 6
-            afterdot = 6
+            )
           ) and
           len = 1 + 309 + dot + afterdot
         ) and
@@ -1140,12 +1140,12 @@ class FormatLiteral extends Literal {
         exists(int dot, int afterdot |
           (if this.getPrecision(n) = 0 then dot = 0 else dot = 1) and
           (
-            (
+            if this.hasExplicitPrecision(n)
-              if this.hasExplicitPrecision(n)
+            then afterdot = this.getPrecision(n)
-              then afterdot = this.getPrecision(n)
+            else (
-              else not this.hasImplicitPrecision(n)
+              not this.hasImplicitPrecision(n) and
-            ) and
+              afterdot = 6
-            afterdot = 6
+            )
           ) and
           len = 1 + 1 + dot + afterdot + 1 + 1 + 3
         ) and
@@ -1155,12 +1155,12 @@ class FormatLiteral extends Literal {
         exists(int dot, int afterdot |
           (if this.getPrecision(n) = 0 then dot = 0 else dot = 1) and
           (
-            (
+            if this.hasExplicitPrecision(n)
-              if this.hasExplicitPrecision(n)
+            then afterdot = this.getPrecision(n)
-              then afterdot = this.getPrecision(n)
+            else (
-              else not this.hasImplicitPrecision(n)
+              not this.hasImplicitPrecision(n) and
-            ) and
+              afterdot = 6
-            afterdot = 6
+            )
           ) and
           // note: this could be displayed in the style %e or %f;
           //       however %f is only used when 'P > X >= -4'

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -136,6 +136,18 @@ module Consistency {
     msg = "Local flow step does not preserve enclosing callable."
   }
 
+  query predicate readStepIsLocal(Node n1, Node n2, string msg) {
+    readStep(n1, _, n2) and
+    nodeGetEnclosingCallable(n1) != nodeGetEnclosingCallable(n2) and
+    msg = "Read step does not preserve enclosing callable."
+  }
+
+  query predicate storeStepIsLocal(Node n1, Node n2, string msg) {
+    storeStep(n1, _, n2) and
+    nodeGetEnclosingCallable(n1) != nodeGetEnclosingCallable(n2) and
+    msg = "Store step does not preserve enclosing callable."
+  }
+
   private DataFlowType typeRepr() { result = getNodeType(_) }
 
   query predicate compatibleTypesReflexive(DataFlowType t, string msg) {

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -147,6 +147,12 @@ abstract class Configuration extends string {
    */
   FlowFeature getAFeature() { none() }
 
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
   /**
    * Holds if data may flow from `source` to `sink` for this configuration.
    */
@@ -158,7 +164,7 @@ abstract class Configuration extends string {
    * The corresponding paths are generated from the end-points and the graph
    * included in the module `PathGraph`.
    */
-  predicate hasFlowPath(PathNode source, PathNode sink) { flowsTo(source, sink, _, _, this) }
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
 
   /**
    * Holds if data may flow from some source to `sink` for this configuration.
@@ -2629,6 +2635,7 @@ private predicate evalUnfold(AccessPathApprox apa, boolean unfold, Configuration
 /**
  * Gets the number of `AccessPath`s that correspond to `apa`.
  */
+pragma[assume_small_delta]
 private int countAps(AccessPathApprox apa, Configuration config) {
   evalUnfold(apa, false, config) and
   result = 1 and
@@ -2647,6 +2654,7 @@ private int countAps(AccessPathApprox apa, Configuration config) {
  * that it is expanded to a precise head-tail representation.
  */
 language[monotonicAggregates]
+pragma[assume_small_delta]
 private int countPotentialAps(AccessPathApprox apa, Configuration config) {
   apa instanceof AccessPathApproxNil and result = 1
   or
@@ -2681,6 +2689,7 @@ private newtype TAccessPath =
   }
 
 private newtype TPathNode =
+  pragma[assume_small_delta]
   TPathNodeMid(
     NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap, Configuration config
   ) {
@@ -2709,6 +2718,18 @@ private newtype TPathNode =
       state = sink.getState() and
       config = sink.getConfiguration()
     )
+  } or
+  TPathNodeSourceGroup(string sourceGroup, Configuration config) {
+    exists(PathNodeImpl source |
+      sourceGroup = source.getSourceGroup() and
+      config = source.getConfiguration()
+    )
+  } or
+  TPathNodeSinkGroup(string sinkGroup, Configuration config) {
+    exists(PathNodeSink sink |
+      sinkGroup = sink.getSinkGroup() and
+      config = sink.getConfiguration()
+    )
   }
 
 /**
@@ -2778,6 +2799,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
 
   override AccessPathFrontHead getFront() { result = TFrontHead(head) }
 
+  pragma[assume_small_delta]
   override AccessPathApproxCons getApprox() {
     result = TConsNil(head, tail.(AccessPathNil).getType())
     or
@@ -2786,6 +2808,7 @@ private class AccessPathCons extends AccessPath, TAccessPathCons {
     result = TCons1(head, this.length())
   }
 
+  pragma[assume_small_delta]
   override int length() { result = 1 + tail.length() }
 
   private string toStringImpl(boolean needsSuffix) {
@@ -2874,54 +2897,16 @@ private class AccessPathCons1 extends AccessPath, TAccessPathCons1 {
   }
 }
 
-/**
+abstract private class PathNodeImpl extends TPathNode {
- * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
- * Only those `PathNode`s that are reachable from a source are generated.
- */
-class PathNode extends TPathNode {
-  /** Gets a textual representation of this element. */
-  string toString() { none() }
-
-  /**
-   * Gets a textual representation of this element, including a textual
-   * representation of the call context.
-   */
-  string toStringWithContext() { none() }
-
-  /**
-   * Holds if this element is at the specified location.
-   * The location spans column `startcolumn` of line `startline` to
-   * column `endcolumn` of line `endline` in file `filepath`.
-   * For more information, see
-   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
-   */
-  predicate hasLocationInfo(
-    string filepath, int startline, int startcolumn, int endline, int endcolumn
-  ) {
-    none()
-  }
-
-  /** Gets the underlying `Node`. */
-  final Node getNode() { this.(PathNodeImpl).getNodeEx().projectToNode() = result }
-
   /** Gets the `FlowState` of this node. */
-  FlowState getState() { none() }
+  abstract FlowState getState();
 
   /** Gets the associated configuration. */
-  Configuration getConfiguration() { none() }
+  abstract Configuration getConfiguration();
-
-  /** Gets a successor of this node, if any. */
-  final PathNode getASuccessor() {
-    result = this.(PathNodeImpl).getANonHiddenSuccessor() and
-    reach(this) and
-    reach(result)
-  }
 
   /** Holds if this node is a source. */
-  predicate isSource() { none() }
+  abstract predicate isSource();
-}
 
-abstract private class PathNodeImpl extends PathNode {
   abstract PathNodeImpl getASuccessorImpl();
 
   private PathNodeImpl getASuccessorIfHidden() {
@@ -2953,6 +2938,22 @@ abstract private class PathNodeImpl extends PathNode {
     )
   }
 
+  string getSourceGroup() {
+    this.isSource() and
+    this.getConfiguration().sourceGrouping(this.getNodeEx().asNode(), result)
+  }
+
+  predicate isFlowSource() {
+    this.isSource() and not exists(this.getSourceGroup())
+    or
+    this instanceof PathNodeSourceGroup
+  }
+
+  predicate isFlowSink() {
+    this = any(PathNodeSink sink | not exists(sink.getSinkGroup())) or
+    this instanceof PathNodeSinkGroup
+  }
+
   private string ppAp() {
     this instanceof PathNodeSink and result = ""
     or
@@ -2967,13 +2968,23 @@ abstract private class PathNodeImpl extends PathNode {
     result = " <" + this.(PathNodeMid).getCallContext().toString() + ">"
   }
 
-  override string toString() { result = this.getNodeEx().toString() + this.ppAp() }
+  /** Gets a textual representation of this element. */
+  string toString() { result = this.getNodeEx().toString() + this.ppAp() }
 
-  override string toStringWithContext() {
+  /**
-    result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx()
+   * Gets a textual representation of this element, including a textual
-  }
+   * representation of the call context.
+   */
+  string toStringWithContext() { result = this.getNodeEx().toString() + this.ppAp() + this.ppCtx() }
 
-  override predicate hasLocationInfo(
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
     string filepath, int startline, int startcolumn, int endline, int endcolumn
   ) {
     this.getNodeEx().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
@@ -2982,18 +2993,71 @@ abstract private class PathNodeImpl extends PathNode {
 
 /** Holds if `n` can reach a sink. */
 private predicate directReach(PathNodeImpl n) {
-  n instanceof PathNodeSink or directReach(n.getANonHiddenSuccessor())
+  n instanceof PathNodeSink or
+  n instanceof PathNodeSinkGroup or
+  directReach(n.getANonHiddenSuccessor())
 }
 
 /** Holds if `n` can reach a sink or is used in a subpath that can reach a sink. */
-private predicate reach(PathNode n) { directReach(n) or Subpaths::retReach(n) }
+private predicate reach(PathNodeImpl n) { directReach(n) or Subpaths::retReach(n) }
 
 /** Holds if `n1.getASuccessor() = n2` and `n2` can reach a sink. */
-private predicate pathSucc(PathNodeImpl n1, PathNode n2) {
+private predicate pathSucc(PathNodeImpl n1, PathNodeImpl n2) {
   n1.getANonHiddenSuccessor() = n2 and directReach(n2)
 }
 
-private predicate pathSuccPlus(PathNode n1, PathNode n2) = fastTC(pathSucc/2)(n1, n2)
+private predicate pathSuccPlus(PathNodeImpl n1, PathNodeImpl n2) = fastTC(pathSucc/2)(n1, n2)
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+class PathNode instanceof PathNodeImpl {
+  PathNode() { reach(this) }
+
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { super.getNodeEx().projectToNode() = result }
+
+  /** Gets the `FlowState` of this node. */
+  final FlowState getState() { result = super.getState() }
+
+  /** Gets the associated configuration. */
+  final Configuration getConfiguration() { result = super.getConfiguration() }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getANonHiddenSuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { this = TPathNodeSourceGroup(group, _) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { this = TPathNodeSinkGroup(group, _) }
+}
 
 /**
  * Provides the query predicates needed to include a graph in a path-problem query.
@@ -3004,7 +3068,7 @@ module PathGraph {
 
   /** Holds if `n` is a node in the graph of data flow path explanations. */
   query predicate nodes(PathNode n, string key, string val) {
-    reach(n) and key = "semmle.label" and val = n.toString()
+    key = "semmle.label" and val = n.toString()
   }
 
   /**
@@ -3013,11 +3077,7 @@ module PathGraph {
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
   query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-    Subpaths::subpaths(arg, par, ret, out) and
+    Subpaths::subpaths(arg, par, ret, out)
-    reach(arg) and
-    reach(par) and
-    reach(ret) and
-    reach(out)
   }
 }
 
@@ -3118,9 +3178,66 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
 
   override Configuration getConfiguration() { result = config }
 
-  override PathNodeImpl getASuccessorImpl() { none() }
+  override PathNodeImpl getASuccessorImpl() {
+    result = TPathNodeSinkGroup(this.getSinkGroup(), config)
+  }
 
   override predicate isSource() { sourceNode(node, state, config) }
+
+  string getSinkGroup() { config.sinkGrouping(node.asNode(), result) }
+}
+
+private class PathNodeSourceGroup extends PathNodeImpl, TPathNodeSourceGroup {
+  string sourceGroup;
+  Configuration config;
+
+  PathNodeSourceGroup() { this = TPathNodeSourceGroup(sourceGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() {
+    result.getSourceGroup() = sourceGroup and
+    result.getConfiguration() = config
+  }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sourceGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
+}
+
+private class PathNodeSinkGroup extends PathNodeImpl, TPathNodeSinkGroup {
+  string sinkGroup;
+  Configuration config;
+
+  PathNodeSinkGroup() { this = TPathNodeSinkGroup(sinkGroup, config) }
+
+  override NodeEx getNodeEx() { none() }
+
+  override FlowState getState() { none() }
+
+  override Configuration getConfiguration() { result = config }
+
+  override PathNodeImpl getASuccessorImpl() { none() }
+
+  override predicate isSource() { none() }
+
+  override string toString() { result = sinkGroup }
+
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
+  }
 }
 
 private predicate pathNode(
@@ -3142,6 +3259,7 @@ private predicate pathNode(
  * Holds if data may flow from `mid` to `node`. The last step in or out of
  * a callable is recorded by `cc`.
  */
+pragma[assume_small_delta]
 pragma[nomagic]
 private predicate pathStep(
   PathNodeMid mid, NodeEx node, FlowState state, CallContext cc, SummaryCtx sc, AccessPath ap
@@ -3399,7 +3517,7 @@ private module Subpaths {
    */
   pragma[nomagic]
   private predicate subpaths02(
-    PathNode arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
+    PathNodeImpl arg, ParamNodeEx par, SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind,
     NodeEx out, FlowState sout, AccessPath apout
   ) {
     subpaths01(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3407,14 +3525,14 @@ private module Subpaths {
   }
 
   pragma[nomagic]
-  private Configuration getPathNodeConf(PathNode n) { result = n.getConfiguration() }
+  private Configuration getPathNodeConf(PathNodeImpl n) { result = n.getConfiguration() }
 
   /**
    * Holds if `(arg, par, ret, out)` forms a subpath-tuple.
    */
   pragma[nomagic]
   private predicate subpaths03(
-    PathNode arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
+    PathNodeImpl arg, ParamNodeEx par, PathNodeMid ret, NodeEx out, FlowState sout, AccessPath apout
   ) {
     exists(SummaryCtxSome sc, CallContext innercc, ReturnKindExt kind, RetNodeEx retnode |
       subpaths02(arg, par, sc, innercc, kind, out, sout, apout) and
@@ -3444,7 +3562,7 @@ private module Subpaths {
    * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
    * `ret -> out` is summarized as the edge `arg -> out`.
    */
-  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNode out) {
+  predicate subpaths(PathNodeImpl arg, PathNodeImpl par, PathNodeImpl ret, PathNodeImpl out) {
     exists(ParamNodeEx p, NodeEx o, FlowState sout, AccessPath apout, PathNodeMid out0 |
       pragma[only_bind_into](arg).getANonHiddenSuccessor() = pragma[only_bind_into](out0) and
       subpaths03(pragma[only_bind_into](arg), p, localStepToHidden*(ret), o, sout, apout) and
@@ -3460,7 +3578,7 @@ private module Subpaths {
    * Holds if `n` can reach a return node in a summarized subpath that can reach a sink.
    */
   predicate retReach(PathNodeImpl n) {
-    exists(PathNode out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
+    exists(PathNodeImpl out | subpaths(_, _, n, out) | directReach(out) or retReach(out))
     or
     exists(PathNodeImpl mid |
       retReach(mid) and
@@ -3476,12 +3594,22 @@ private module Subpaths {
  * Will only have results if `configuration` has non-empty sources and
  * sinks.
  */
+private predicate hasFlowPath(
+  PathNodeImpl flowsource, PathNodeImpl flowsink, Configuration configuration
+) {
+  flowsource.isFlowSource() and
+  flowsource.getConfiguration() = configuration and
+  (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
+  flowsink.isFlowSink()
+}
+
 private predicate flowsTo(
-  PathNode flowsource, PathNodeSink flowsink, Node source, Node sink, Configuration configuration
+  PathNodeImpl flowsource, PathNodeSink flowsink, Node source, Node sink,
+  Configuration configuration
 ) {
   flowsource.isSource() and
   flowsource.getConfiguration() = configuration and
-  flowsource.(PathNodeImpl).getNodeEx().asNode() = source and
+  flowsource.getNodeEx().asNode() = source and
   (flowsource = flowsink or pathSuccPlus(flowsource, flowsink)) and
   flowsink.getNodeEx().asNode() = sink
 }
@@ -3504,14 +3632,14 @@ private predicate finalStats(
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0)) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap)) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state)) and
-  tuples = count(PathNode pn)
+  tuples = count(PathNodeImpl pn)
   or
   fwd = false and
   nodes = count(NodeEx n0 | exists(PathNodeImpl pn | pn.getNodeEx() = n0 and reach(pn))) and
   fields = count(TypedContent f0 | exists(PathNodeMid pn | pn.getAp().getHead() = f0 and reach(pn))) and
   conscand = count(AccessPath ap | exists(PathNodeMid pn | pn.getAp() = ap and reach(pn))) and
   states = count(FlowState state | exists(PathNodeMid pn | pn.getState() = state and reach(pn))) and
-  tuples = count(PathNode pn | reach(pn))
+  tuples = count(PathNode pn)
 }
 
 /**

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

@@ -136,6 +136,18 @@ module Consistency {
     msg = "Local flow step does not preserve enclosing callable."
   }
 
+  query predicate readStepIsLocal(Node n1, Node n2, string msg) {
+    readStep(n1, _, n2) and
+    nodeGetEnclosingCallable(n1) != nodeGetEnclosingCallable(n2) and
+    msg = "Read step does not preserve enclosing callable."
+  }
+
+  query predicate storeStepIsLocal(Node n1, Node n2, string msg) {
+    storeStep(n1, _, n2) and
+    nodeGetEnclosingCallable(n1) != nodeGetEnclosingCallable(n2) and
+    msg = "Store step does not preserve enclosing callable."
+  }
+
   private DataFlowType typeRepr() { result = getNodeType(_) }
 
   query predicate compatibleTypesReflexive(DataFlowType t, string msg) {

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

@@ -98,16 +98,16 @@ class ParameterPosition = Position;
 /** An argument position represented by an integer. */
 class ArgumentPosition = Position;
 
-class Position extends TPosition {
+abstract class Position extends TPosition {
   abstract string toString();
 }
 
-class DirectPosition extends TDirectPosition {
+class DirectPosition extends Position, TDirectPosition {
   int index;
 
   DirectPosition() { this = TDirectPosition(index) }
 
-  string toString() {
+  override string toString() {
     index = -1 and
     result = "this"
     or
@@ -118,12 +118,12 @@ class DirectPosition extends TDirectPosition {
   int getIndex() { result = index }
 }
 
-class IndirectionPosition extends TIndirectionPosition {
+class IndirectionPosition extends Position, TIndirectionPosition {
   int index;
 
   IndirectionPosition() { this = TIndirectionPosition(index) }
 
-  string toString() {
+  override string toString() {
     index = -1 and
     result = "this"
     or

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

@@ -16,21 +16,23 @@ private class StdBasicString extends ClassTemplateInstantiation {
 }
 
 /**
- * Additional model for `std::string` constructors that reference the character
+ * The `std::basic_string::iterator` declaration.
- * type of the container, or an iterator.  For example construction from
- * iterators:
- * ```
- * std::string b(a.begin(), a.end());
- * ```
  */
-private class StdStringConstructor extends Constructor, TaintFunction {
+private class StdBasicStringIterator extends Iterator, Type {
-  StdStringConstructor() { this.getDeclaringType() instanceof StdBasicString }
+  StdBasicStringIterator() {
+    this.getEnclosingElement() instanceof StdBasicString and this.hasName("iterator")
+  }
+}
 
+/**
+ * A `std::string` function for which taint should be propagated.
+ */
+abstract private class StdStringTaintFunction extends TaintFunction {
   /**
    * Gets the index of a parameter to this function that is a string (or
    * character).
    */
-  int getAStringParameterIndex() {
+  final int getAStringParameterIndex() {
     exists(Type paramType | paramType = this.getParameter(result).getUnspecifiedType() |
       // e.g. `std::basic_string::CharT *`
       paramType instanceof PointerType
@@ -41,15 +43,28 @@ private class StdStringConstructor extends Constructor, TaintFunction {
         this.getDeclaringType().getTemplateArgument(2).(Type).getUnspecifiedType()
       or
       // i.e. `std::basic_string::CharT`
-      this.getParameter(result).getUnspecifiedType() =
+      paramType = this.getDeclaringType().getTemplateArgument(0).(Type).getUnspecifiedType()
-        this.getDeclaringType().getTemplateArgument(0).(Type).getUnspecifiedType()
     )
   }
 
   /**
    * Gets the index of a parameter to this function that is an iterator.
    */
-  int getAnIteratorParameterIndex() { this.getParameter(result).getType() instanceof Iterator }
+  final int getAnIteratorParameterIndex() {
+    this.getParameter(result).getType() instanceof Iterator
+  }
+}
+
+/**
+ * Additional model for `std::string` constructors that reference the character
+ * type of the container, or an iterator.  For example construction from
+ * iterators:
+ * ```
+ * std::string b(a.begin(), a.end());
+ * ```
+ */
+private class StdStringConstructor extends Constructor, StdStringTaintFunction {
+  StdStringConstructor() { this.getDeclaringType() instanceof StdBasicString }
 
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
     // taint flow from any parameter of the value type to the returned object
@@ -68,7 +83,7 @@ private class StdStringConstructor extends Constructor, TaintFunction {
 /**
  * The `std::string` function `c_str`.
  */
-private class StdStringCStr extends TaintFunction {
+private class StdStringCStr extends StdStringTaintFunction {
   StdStringCStr() { this.getClassAndName("c_str") instanceof StdBasicString }
 
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
@@ -81,7 +96,7 @@ private class StdStringCStr extends TaintFunction {
 /**
  * The `std::string` function `data`.
  */
-private class StdStringData extends TaintFunction {
+private class StdStringData extends StdStringTaintFunction {
   StdStringData() { this.getClassAndName("data") instanceof StdBasicString }
 
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
@@ -99,7 +114,7 @@ private class StdStringData extends TaintFunction {
 /**
  * The `std::string` function `push_back`.
  */
-private class StdStringPush extends TaintFunction {
+private class StdStringPush extends StdStringTaintFunction {
   StdStringPush() { this.getClassAndName("push_back") instanceof StdBasicString }
 
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
@@ -112,7 +127,7 @@ private class StdStringPush extends TaintFunction {
 /**
  * The `std::string` functions `front` and `back`.
  */
-private class StdStringFrontBack extends TaintFunction {
+private class StdStringFrontBack extends StdStringTaintFunction {
   StdStringFrontBack() { this.getClassAndName(["front", "back"]) instanceof StdBasicString }
 
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
@@ -125,7 +140,7 @@ private class StdStringFrontBack extends TaintFunction {
 /**
  * The (non-member) `std::string` function `operator+`.
  */
-private class StdStringPlus extends TaintFunction {
+private class StdStringPlus extends StdStringTaintFunction {
   StdStringPlus() {
     this.hasQualifiedName(["std", "bsl"], "operator+") and
     this.getUnspecifiedType() instanceof StdBasicString
@@ -142,31 +157,15 @@ private class StdStringPlus extends TaintFunction {
 }
 
 /**
- * The `std::string` functions `operator+=`, `append`, `insert` and
+ * The `std::string` functions `operator+=`, `append` and `replace`.
- * `replace`. All of these functions combine the existing string
+ * All of these functions combine the existing string with a new
- * with a new string (or character) from one of the arguments.
+ * string (or character) from one of the arguments.
  */
-private class StdStringAppend extends TaintFunction {
+private class StdStringAppend extends StdStringTaintFunction {
   StdStringAppend() {
-    this.getClassAndName(["operator+=", "append", "insert", "replace"]) instanceof StdBasicString
+    this.getClassAndName(["operator+=", "append", "replace"]) instanceof StdBasicString
   }
 
-  /**
-   * Gets the index of a parameter to this function that is a string (or
-   * character).
-   */
-  int getAStringParameterIndex() {
-    this.getParameter(result).getType() instanceof PointerType or // e.g. `std::basic_string::CharT *`
-    this.getParameter(result).getType() instanceof ReferenceType or // e.g. `std::basic_string &`
-    this.getParameter(result).getUnspecifiedType() =
-      this.getDeclaringType().getTemplateArgument(0).(Type).getUnspecifiedType() // i.e. `std::basic_string::CharT`
-  }
-
-  /**
-   * Gets the index of a parameter to this function that is an iterator.
-   */
-  int getAnIteratorParameterIndex() { this.getParameter(result).getType() instanceof Iterator }
-
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
     // flow from string and parameter to string (qualifier) and return value
     (
@@ -186,28 +185,44 @@ private class StdStringAppend extends TaintFunction {
   }
 }
 
+/**
+ * The `std::string` function `insert`.
+ */
+private class StdStringInsert extends StdStringTaintFunction {
+  StdStringInsert() { this.getClassAndName("insert") instanceof StdBasicString }
+
+  /**
+   * Holds if the return type is an iterator.
+   */
+  predicate hasIteratorReturnValue() { this.getType() instanceof Iterator }
+
+  override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+    // flow from string and parameter to string (qualifier) and return value
+    (
+      input.isQualifierObject() or
+      input.isParameterDeref(this.getAStringParameterIndex()) or
+      input.isParameter(this.getAnIteratorParameterIndex())
+    ) and
+    (
+      output.isQualifierObject()
+      or
+      if this.hasIteratorReturnValue() then output.isReturnValue() else output.isReturnValueDeref()
+    )
+    or
+    // reverse flow from returned reference to the qualifier (for writes to
+    // the result)
+    not this.hasIteratorReturnValue() and
+    input.isReturnValueDeref() and
+    output.isQualifierObject()
+  }
+}
+
 /**
  * The standard function `std::string.assign`.
  */
-private class StdStringAssign extends TaintFunction {
+private class StdStringAssign extends StdStringTaintFunction {
   StdStringAssign() { this.getClassAndName("assign") instanceof StdBasicString }
 
-  /**
-   * Gets the index of a parameter to this function that is a string (or
-   * character).
-   */
-  int getAStringParameterIndex() {
-    this.getParameter(result).getType() instanceof PointerType or // e.g. `std::basic_string::CharT *`
-    this.getParameter(result).getType() instanceof ReferenceType or // e.g. `std::basic_string &`
-    this.getParameter(result).getUnspecifiedType() =
-      this.getDeclaringType().getTemplateArgument(0).(Type).getUnspecifiedType() // i.e. `std::basic_string::CharT`
-  }
-
-  /**
-   * Gets the index of a parameter to this function that is an iterator.
-   */
-  int getAnIteratorParameterIndex() { this.getParameter(result).getType() instanceof Iterator }
-
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
     // flow from parameter to string itself (qualifier) and return value
     (
@@ -229,7 +244,7 @@ private class StdStringAssign extends TaintFunction {
 /**
  * The standard function `std::string.copy`.
  */
-private class StdStringCopy extends TaintFunction {
+private class StdStringCopy extends StdStringTaintFunction {
   StdStringCopy() { this.getClassAndName("copy") instanceof StdBasicString }
 
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
@@ -242,7 +257,7 @@ private class StdStringCopy extends TaintFunction {
 /**
  * The standard function `std::string.substr`.
  */
-private class StdStringSubstr extends TaintFunction {
+private class StdStringSubstr extends StdStringTaintFunction {
   StdStringSubstr() { this.getClassAndName("substr") instanceof StdBasicString }
 
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
@@ -255,7 +270,7 @@ private class StdStringSubstr extends TaintFunction {
 /**
  * The `std::string` functions `at` and `operator[]`.
  */
-private class StdStringAt extends TaintFunction {
+private class StdStringAt extends StdStringTaintFunction {
   StdStringAt() { this.getClassAndName(["at", "operator[]"]) instanceof StdBasicString }
 
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {

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

@@ -50,19 +50,18 @@ class StrcatFunction extends TaintFunction, DataFlowFunction, ArrayFunction, Sid
   }
 
   override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
-    this.getName() = ["strncat", "wcsncat", "_mbsncat", "_mbsncat_l"] and
+    (
-    input.isParameter(2) and
+      this.getName() = ["strncat", "wcsncat", "_mbsncat", "_mbsncat_l"] and
-    output.isParameterDeref(0)
+      input.isParameter(2)
-    or
+      or
-    this.getName() = ["_mbsncat_l", "_mbsnbcat_l"] and
+      this.getName() = ["_mbsncat_l", "_mbsnbcat_l"] and
-    input.isParameter(3) and
+      input.isParameter(3)
-    output.isParameterDeref(0)
+      or
-    or
+      input.isParameterDeref(0)
-    input.isParameterDeref(0) and
+      or
-    output.isParameterDeref(0)
+      input.isParameterDeref(1)
-    or
+    ) and
-    input.isParameterDeref(1) and
+    (output.isParameterDeref(0) or output.isReturnValueDeref())
-    output.isParameterDeref(0)
   }
 
   override predicate hasArrayInput(int param) {

cpp/ql/src/Best Practices/Likely Errors/CommaBeforeMisleadingIndentation.ql

@@ -16,15 +16,36 @@
 import cpp
 import semmle.code.cpp.commons.Exclusions
 
-/** Gets the sub-expression of 'e' with the earliest-starting Location */
+/**
+ * Gets a child of `e`, including conversions but excluding call arguments.
+ */
+pragma[inline]
+Expr getAChildWithConversions(Expr e) {
+  result.getParentWithConversions() = e and
+  not result = any(Call c).getAnArgument()
+}
+
+/**
+ * Gets the left-most column position of any transitive child of `e` (including
+ * conversions but excluding call arguments).
+ */
+int getCandidateColumn(Expr e) {
+  result = e.getLocation().getStartColumn() or
+  result = getCandidateColumn(getAChildWithConversions(e))
+}
+
+/**
+ * Gets the transitive child of `e` (including conversions but excluding call
+ * arguments) at the left-most column position, preferring less deeply nested
+ * expressions if there is a choice.
+ */
 Expr normalizeExpr(Expr e) {
-  result =
+  e.getLocation().getStartColumn() = min(getCandidateColumn(e)) and
-    min(Expr child |
+  result = e
-      child.getParentWithConversions*() = e.getFullyConverted() and
+  or
-      not child.getParentWithConversions*() = any(Call c).getAnArgument()
+  not e.getLocation().getStartColumn() = min(getCandidateColumn(e)) and
-    |
+  result = normalizeExpr(getAChildWithConversions(e)) and
-      child order by child.getLocation().getStartColumn(), count(child.getParentWithConversions*())
+  result.getLocation().getStartColumn() = min(getCandidateColumn(e))
-    )
 }
 
 predicate isParenthesized(CommaExpr ce) {
@@ -43,8 +64,8 @@ from CommaExpr ce, Expr left, Expr right, Location leftLoc, Location rightLoc
 where
   ce.fromSource() and
   not isFromMacroDefinition(ce) and
-  left = normalizeExpr(ce.getLeftOperand()) and
+  left = normalizeExpr(ce.getLeftOperand().getFullyConverted()) and
-  right = normalizeExpr(ce.getRightOperand()) and
+  right = normalizeExpr(ce.getRightOperand().getFullyConverted()) and
   leftLoc = left.getLocation() and
   rightLoc = right.getLocation() and
   not isParenthesized(ce) and

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

@@ -13,16 +13,32 @@
 
 import cpp
 
+pragma[noinline]
+predicate possiblyIncompleteFile(File f) {
+  exists(Diagnostic d | d.getFile() = f and d.getSeverity() >= 3)
+}
+
 predicate immediatelyReachableFunction(Function f) {
-  not f.isStatic() or
+  not f.isStatic()
-  exists(BlockExpr be | be.getFunction() = f) or
+  or
-  f instanceof MemberFunction or
+  exists(BlockExpr be | be.getFunction() = f)
-  f instanceof TemplateFunction or
+  or
-  f.getFile() instanceof HeaderFile or
+  f instanceof MemberFunction
-  f.getAnAttribute().hasName("constructor") or
+  or
-  f.getAnAttribute().hasName("destructor") or
+  f instanceof TemplateFunction
-  f.getAnAttribute().hasName("used") or
+  or
+  f.getFile() instanceof HeaderFile
+  or
+  f.getAnAttribute().hasName("constructor")
+  or
+  f.getAnAttribute().hasName("destructor")
+  or
+  f.getAnAttribute().hasName("used")
+  or
   f.getAnAttribute().hasName("unused")
+  or
+  // a compiler error in the same file suggests we may be missing data
+  possiblyIncompleteFile(f.getFile())
 }
 
 predicate immediatelyReachableVariable(Variable v) {

cpp/ql/src/CHANGELOG.md

@@ -1,3 +1,20 @@
+## 0.4.3
+
+### Minor Analysis Improvements
+
+* Fixed a bug in `cpp/jsf/av-rule-76` that caused the query to miss results when an implicitly-defined copy constructor or copy assignment operator was generated.
+
+## 0.4.2
+
+### New Queries
+
+* Added a new medium-precision query, `cpp/comma-before-misleading-indentation`, which detects instances of whitespace that have readability issues.
+
+### Minor Analysis Improvements
+
+* The "Unterminated variadic call" (`cpp/unterminated-variadic-call`) query has been tuned to produce fewer false positive results.
+* Fixed false positives from the "Unused static function" (`cpp/unused-static-function`) query in files that had errors during compilation.
+
 ## 0.4.1
 
 ### Minor Analysis Improvements

cpp/ql/src/Likely Bugs/Format/TooManyFormatArguments.ql

@@ -13,11 +13,18 @@
 
 import cpp
 
-from FormatLiteral fl, FormattingFunctionCall ffc, int expected, int given
+from FormatLiteral fl, FormattingFunctionCall ffc, int expected, int given, string ffcName
 where
   ffc = fl.getUse() and
   expected = fl.getNumArgNeeded() and
   given = ffc.getNumFormatArgument() and
   expected < given and
-  fl.specsAreKnown()
+  fl.specsAreKnown() and
-select ffc, "Format expects " + expected.toString() + " arguments but given " + given.toString()
+  (
+    if ffc.isInMacroExpansion()
+    then ffcName = ffc.getTarget().getName() + " (in a macro expansion)"
+    else ffcName = ffc.getTarget().getName()
+  )
+select ffc,
+  "Format for " + ffcName + " expects " + expected.toString() + " arguments but given " +
+    given.toString()

cpp/ql/src/Likely Bugs/Format/WrongNumberOfFormatArguments.ql

@@ -16,11 +16,18 @@
 
 import cpp
 
-from FormatLiteral fl, FormattingFunctionCall ffc, int expected, int given
+from FormatLiteral fl, FormattingFunctionCall ffc, int expected, int given, string ffcName
 where
   ffc = fl.getUse() and
   expected = fl.getNumArgNeeded() and
   given = ffc.getNumFormatArgument() and
   expected > given and
-  fl.specsAreKnown()
+  fl.specsAreKnown() and
-select ffc, "Format expects " + expected.toString() + " arguments but given " + given.toString()
+  (
+    if ffc.isInMacroExpansion()
+    then ffcName = ffc.getTarget().getName() + " (in a macro expansion)"
+    else ffcName = ffc.getTarget().getName()
+  )
+select ffc,
+  "Format for " + ffcName + " expects " + expected.toString() + " arguments but given " +
+    given.toString()

cpp/ql/src/change-notes/2022-09-30-comma-before-missing-indentation.md

@@ -1,4 +0,0 @@
----
-category: newQuery
----
-* Added a new medium-precision query, `cpp/comma-before-misleading-indentation`, which detects instances of whitespace that have readability issues.

cpp/ql/src/change-notes/2022-10-06-unterminated-variadic-call.md

@@ -1,4 +0,0 @@
----
-category: minorAnalysis
----
-* The "Unterminated variadic call" (`cpp/unterminated-variadic-call`) query has been tuned to produce fewer false positive results.

cpp/ql/src/change-notes/released/0.4.2.md

@@ -0,0 +1,10 @@
+## 0.4.2
+
+### New Queries
+
+* Added a new medium-precision query, `cpp/comma-before-misleading-indentation`, which detects instances of whitespace that have readability issues.
+
+### Minor Analysis Improvements
+
+* The "Unterminated variadic call" (`cpp/unterminated-variadic-call`) query has been tuned to produce fewer false positive results.
+* Fixed false positives from the "Unused static function" (`cpp/unused-static-function`) query in files that had errors during compilation.

cpp/ql/src/change-notes/released/0.4.3.md

@@ -0,0 +1,5 @@
+## 0.4.3
+
+### Minor Analysis Improvements
+
+* Fixed a bug in `cpp/jsf/av-rule-76` that caused the query to miss results when an implicitly-defined copy constructor or copy assignment operator was generated.

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

@@ -1,2 +1,2 @@
 ---
-lastReleaseVersion: 0.4.1
+lastReleaseVersion: 0.4.3

cpp/ql/src/jsf/4.10 Classes/AV Rule 76.ql

@@ -38,9 +38,9 @@ predicate hasNontrivialDestructor(Class c) {
 from Class c
 where
   (hasPointerMember(c) or hasNontrivialDestructor(c)) and
-  not (
+  (
-    c.getAMemberFunction() instanceof CopyConstructor and
+    c.hasImplicitCopyAssignmentOperator() or
-    c.getAMemberFunction() instanceof CopyAssignmentOperator
+    c.hasImplicitCopyConstructor()
   ) and
   not c instanceof Struct
 select c,

cpp/ql/src/qlpack.yml

@@ -1,11 +1,11 @@
 name: codeql/cpp-queries
-version: 0.4.2-dev
+version: 0.4.4-dev
 groups: 
   - cpp
   - queries
 dependencies:
-    codeql/cpp-all: "*"
+    codeql/cpp-all: ${workspace}
-    codeql/suite-helpers: "*"
+    codeql/suite-helpers: ${workspace}
 suites: codeql-suites
 extractor: cpp
 defaultSuiteFile: codeql-suites/cpp-code-scanning.qls

cpp/ql/test/TestUtilities/InlineExpectationsTest.qll

@@ -137,6 +137,7 @@ abstract class InlineExpectationsTest extends string {
   final predicate hasFailureMessage(FailureLocatable element, string message) {
     exists(ActualResult actualResult |
       actualResult.getTest() = this and
+      actualResult.getTag() = this.getARelevantTag() and
       element = actualResult and
       (
         exists(FalseNegativeExpectation falseNegative |
@@ -150,9 +151,18 @@ abstract class InlineExpectationsTest extends string {
       )
     )
     or
+    exists(ActualResult actualResult |
+      actualResult.getTest() = this and
+      not actualResult.getTag() = this.getARelevantTag() and
+      element = actualResult and
+      message =
+        "Tag mismatch: Actual result with tag '" + actualResult.getTag() +
+          "' that is not part of getARelevantTag()"
+    )
+    or
     exists(ValidExpectation expectation |
       not exists(ActualResult actualResult | expectation.matchesActualResult(actualResult)) and
-      expectation.getTag() = getARelevantTag() and
+      expectation.getTag() = this.getARelevantTag() and
       element = expectation and
       (
         expectation instanceof GoodExpectation and

cpp/ql/test/experimental/query-tests/Security/CWE/CWE-193/pointer-deref/InvalidPointerDeref.expected

@@ -2,43 +2,21 @@ edges
 | test.cpp:4:15:4:20 | call to malloc | test.cpp:5:15:5:15 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:5:15:5:22 | ... + ... |
 | test.cpp:5:15:5:15 | Load | test.cpp:5:15:5:22 | ... + ... |
-| test.cpp:5:15:5:15 | Load | test.cpp:5:15:5:22 | ... + ... |
-| test.cpp:5:15:5:15 | Load | test.cpp:5:15:5:22 | ... + ... |
-| test.cpp:5:15:5:15 | Load | test.cpp:5:15:5:22 | Store |
-| test.cpp:5:15:5:15 | Load | test.cpp:5:15:5:22 | Store |
 | test.cpp:5:15:5:15 | Load | test.cpp:5:15:5:22 | Store |
 | test.cpp:5:15:5:15 | Load | test.cpp:5:15:5:22 | Store |
 | test.cpp:5:15:5:15 | Load | test.cpp:6:15:6:15 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:6:15:6:15 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:6:15:6:15 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:6:15:6:15 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:7:16:7:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:7:16:7:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:7:16:7:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:7:16:7:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:8:16:8:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:8:16:8:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:8:16:8:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:8:16:8:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:8:16:8:20 | ... + ... |
-| test.cpp:5:15:5:15 | Load | test.cpp:8:16:8:20 | ... + ... |
-| test.cpp:5:15:5:15 | Load | test.cpp:8:16:8:20 | ... + ... |
-| test.cpp:5:15:5:15 | Load | test.cpp:8:16:8:20 | ... + ... |
-| test.cpp:5:15:5:15 | Load | test.cpp:9:16:9:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:9:16:9:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:9:16:9:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:9:16:9:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:10:16:10:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:10:16:10:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:10:16:10:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:10:16:10:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:11:16:11:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:11:16:11:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:11:16:11:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:11:16:11:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:12:16:12:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:12:16:12:16 | Load |
-| test.cpp:5:15:5:15 | Load | test.cpp:12:16:12:16 | Load |
 | test.cpp:5:15:5:15 | Load | test.cpp:12:16:12:16 | Load |
 | test.cpp:5:15:5:22 | ... + ... | test.cpp:5:15:5:22 | Store |
 | test.cpp:5:15:5:22 | ... + ... | test.cpp:5:15:5:22 | Store |
@@ -116,7 +94,6 @@ edges
 | test.cpp:8:16:8:16 | Load | test.cpp:11:16:11:16 | Load |
 | test.cpp:8:16:8:16 | Load | test.cpp:12:16:12:16 | Load |
 | test.cpp:8:16:8:20 | ... + ... | test.cpp:8:14:8:21 | Load: * ... |
-| test.cpp:8:16:8:20 | ... + ... | test.cpp:8:14:8:21 | Load: * ... |
 | test.cpp:9:16:9:16 | Load | test.cpp:6:14:6:15 | Load: * ... |
 | test.cpp:9:16:9:16 | Load | test.cpp:6:14:6:15 | Load: * ... |
 | test.cpp:9:16:9:16 | Load | test.cpp:8:14:8:21 | Load: * ... |
@@ -139,62 +116,30 @@ edges
 | test.cpp:11:16:11:16 | Load | test.cpp:8:14:8:21 | Load: * ... |
 | test.cpp:11:16:11:16 | Load | test.cpp:12:16:12:16 | Load |
 | test.cpp:12:16:12:16 | Load | test.cpp:6:14:6:15 | Load: * ... |
-| test.cpp:12:16:12:16 | Load | test.cpp:6:14:6:15 | Load: * ... |
-| test.cpp:12:16:12:16 | Load | test.cpp:8:14:8:21 | Load: * ... |
 | test.cpp:12:16:12:16 | Load | test.cpp:8:14:8:21 | Load: * ... |
 | test.cpp:16:15:16:20 | call to malloc | test.cpp:17:15:17:15 | Load |
 | test.cpp:17:15:17:15 | Load | test.cpp:17:15:17:22 | ... + ... |
-| test.cpp:17:15:17:15 | Load | test.cpp:17:15:17:22 | ... + ... |
-| test.cpp:17:15:17:15 | Load | test.cpp:17:15:17:22 | ... + ... |
-| test.cpp:17:15:17:15 | Load | test.cpp:17:15:17:22 | ... + ... |
-| test.cpp:17:15:17:15 | Load | test.cpp:20:16:20:20 | ... + ... |
-| test.cpp:17:15:17:15 | Load | test.cpp:20:16:20:20 | ... + ... |
-| test.cpp:17:15:17:15 | Load | test.cpp:20:16:20:20 | ... + ... |
 | test.cpp:17:15:17:15 | Load | test.cpp:20:16:20:20 | ... + ... |
 | test.cpp:17:15:17:22 | ... + ... | test.cpp:20:14:20:21 | Load: * ... |
-| test.cpp:17:15:17:22 | ... + ... | test.cpp:20:14:20:21 | Load: * ... |
-| test.cpp:20:16:20:20 | ... + ... | test.cpp:20:14:20:21 | Load: * ... |
 | test.cpp:20:16:20:20 | ... + ... | test.cpp:20:14:20:21 | Load: * ... |
 | test.cpp:28:15:28:20 | call to malloc | test.cpp:29:15:29:15 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:29:15:29:28 | ... + ... |
 | test.cpp:29:15:29:15 | Load | test.cpp:29:15:29:28 | ... + ... |
-| test.cpp:29:15:29:15 | Load | test.cpp:29:15:29:28 | ... + ... |
-| test.cpp:29:15:29:15 | Load | test.cpp:29:15:29:28 | ... + ... |
-| test.cpp:29:15:29:15 | Load | test.cpp:29:15:29:28 | Store |
-| test.cpp:29:15:29:15 | Load | test.cpp:29:15:29:28 | Store |
 | test.cpp:29:15:29:15 | Load | test.cpp:29:15:29:28 | Store |
 | test.cpp:29:15:29:15 | Load | test.cpp:29:15:29:28 | Store |
 | test.cpp:29:15:29:15 | Load | test.cpp:30:15:30:15 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:30:15:30:15 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:30:15:30:15 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:30:15:30:15 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:31:16:31:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:31:16:31:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:31:16:31:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:31:16:31:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:32:16:32:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:32:16:32:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:32:16:32:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:32:16:32:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:32:16:32:20 | ... + ... |
-| test.cpp:29:15:29:15 | Load | test.cpp:32:16:32:20 | ... + ... |
-| test.cpp:29:15:29:15 | Load | test.cpp:32:16:32:20 | ... + ... |
-| test.cpp:29:15:29:15 | Load | test.cpp:32:16:32:20 | ... + ... |
-| test.cpp:29:15:29:15 | Load | test.cpp:33:16:33:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:33:16:33:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:33:16:33:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:33:16:33:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:34:16:34:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:34:16:34:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:34:16:34:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:34:16:34:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:35:16:35:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:35:16:35:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:35:16:35:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:35:16:35:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:36:16:36:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:36:16:36:16 | Load |
-| test.cpp:29:15:29:15 | Load | test.cpp:36:16:36:16 | Load |
 | test.cpp:29:15:29:15 | Load | test.cpp:36:16:36:16 | Load |
 | test.cpp:29:15:29:28 | ... + ... | test.cpp:29:15:29:28 | Store |
 | test.cpp:29:15:29:28 | ... + ... | test.cpp:29:15:29:28 | Store |
@@ -272,7 +217,6 @@ edges
 | test.cpp:32:16:32:16 | Load | test.cpp:35:16:35:16 | Load |
 | test.cpp:32:16:32:16 | Load | test.cpp:36:16:36:16 | Load |
 | test.cpp:32:16:32:20 | ... + ... | test.cpp:32:14:32:21 | Load: * ... |
-| test.cpp:32:16:32:20 | ... + ... | test.cpp:32:14:32:21 | Load: * ... |
 | test.cpp:33:16:33:16 | Load | test.cpp:30:14:30:15 | Load: * ... |
 | test.cpp:33:16:33:16 | Load | test.cpp:30:14:30:15 | Load: * ... |
 | test.cpp:33:16:33:16 | Load | test.cpp:32:14:32:21 | Load: * ... |
@@ -295,49 +239,25 @@ edges
 | test.cpp:35:16:35:16 | Load | test.cpp:32:14:32:21 | Load: * ... |
 | test.cpp:35:16:35:16 | Load | test.cpp:36:16:36:16 | Load |
 | test.cpp:36:16:36:16 | Load | test.cpp:30:14:30:15 | Load: * ... |
-| test.cpp:36:16:36:16 | Load | test.cpp:30:14:30:15 | Load: * ... |
-| test.cpp:36:16:36:16 | Load | test.cpp:32:14:32:21 | Load: * ... |
 | test.cpp:36:16:36:16 | Load | test.cpp:32:14:32:21 | Load: * ... |
 | test.cpp:40:15:40:20 | call to malloc | test.cpp:41:15:41:15 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:41:15:41:28 | ... + ... |
 | test.cpp:41:15:41:15 | Load | test.cpp:41:15:41:28 | ... + ... |
-| test.cpp:41:15:41:15 | Load | test.cpp:41:15:41:28 | ... + ... |
-| test.cpp:41:15:41:15 | Load | test.cpp:41:15:41:28 | ... + ... |
-| test.cpp:41:15:41:15 | Load | test.cpp:41:15:41:28 | Store |
-| test.cpp:41:15:41:15 | Load | test.cpp:41:15:41:28 | Store |
 | test.cpp:41:15:41:15 | Load | test.cpp:41:15:41:28 | Store |
 | test.cpp:41:15:41:15 | Load | test.cpp:41:15:41:28 | Store |
 | test.cpp:41:15:41:15 | Load | test.cpp:42:15:42:15 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:42:15:42:15 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:42:15:42:15 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:42:15:42:15 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:43:16:43:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:43:16:43:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:43:16:43:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:43:16:43:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:44:16:44:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:44:16:44:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:44:16:44:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:44:16:44:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:44:16:44:20 | ... + ... |
-| test.cpp:41:15:41:15 | Load | test.cpp:44:16:44:20 | ... + ... |
-| test.cpp:41:15:41:15 | Load | test.cpp:44:16:44:20 | ... + ... |
-| test.cpp:41:15:41:15 | Load | test.cpp:44:16:44:20 | ... + ... |
-| test.cpp:41:15:41:15 | Load | test.cpp:45:16:45:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:45:16:45:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:45:16:45:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:45:16:45:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:46:16:46:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:46:16:46:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:46:16:46:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:46:16:46:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:47:16:47:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:47:16:47:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:47:16:47:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:47:16:47:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:48:16:48:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:48:16:48:16 | Load |
-| test.cpp:41:15:41:15 | Load | test.cpp:48:16:48:16 | Load |
 | test.cpp:41:15:41:15 | Load | test.cpp:48:16:48:16 | Load |
 | test.cpp:41:15:41:28 | ... + ... | test.cpp:41:15:41:28 | Store |
 | test.cpp:41:15:41:28 | ... + ... | test.cpp:41:15:41:28 | Store |
@@ -415,7 +335,6 @@ edges
 | test.cpp:44:16:44:16 | Load | test.cpp:47:16:47:16 | Load |
 | test.cpp:44:16:44:16 | Load | test.cpp:48:16:48:16 | Load |
 | test.cpp:44:16:44:20 | ... + ... | test.cpp:44:14:44:21 | Load: * ... |
-| test.cpp:44:16:44:20 | ... + ... | test.cpp:44:14:44:21 | Load: * ... |
 | test.cpp:45:16:45:16 | Load | test.cpp:42:14:42:15 | Load: * ... |
 | test.cpp:45:16:45:16 | Load | test.cpp:42:14:42:15 | Load: * ... |
 | test.cpp:45:16:45:16 | Load | test.cpp:44:14:44:21 | Load: * ... |
@@ -438,8 +357,6 @@ edges
 | test.cpp:47:16:47:16 | Load | test.cpp:44:14:44:21 | Load: * ... |
 | test.cpp:47:16:47:16 | Load | test.cpp:48:16:48:16 | Load |
 | test.cpp:48:16:48:16 | Load | test.cpp:42:14:42:15 | Load: * ... |
-| test.cpp:48:16:48:16 | Load | test.cpp:42:14:42:15 | Load: * ... |
-| test.cpp:48:16:48:16 | Load | test.cpp:44:14:44:21 | Load: * ... |
 | test.cpp:48:16:48:16 | Load | test.cpp:44:14:44:21 | Load: * ... |
 | test.cpp:51:7:51:14 | VariableAddress indirection | test.cpp:62:39:62:39 | Load |
 | test.cpp:51:7:51:14 | VariableAddress indirection | test.cpp:66:39:66:39 | Load |
@@ -449,18 +366,13 @@ edges
 | test.cpp:52:19:52:24 | call to malloc | test.cpp:53:12:53:16 | Load |
 | test.cpp:53:5:53:23 | Store | test.cpp:51:33:51:35 | Load indirection |
 | test.cpp:53:12:53:16 | Load | test.cpp:53:5:53:23 | Store |
-| test.cpp:53:12:53:16 | Load | test.cpp:53:5:53:23 | Store |
-| test.cpp:53:12:53:16 | Load | test.cpp:53:12:53:23 | ... + ... |
 | test.cpp:53:12:53:16 | Load | test.cpp:53:12:53:23 | ... + ... |
 | test.cpp:53:12:53:23 | ... + ... | test.cpp:51:33:51:35 | Load indirection |
 | test.cpp:60:34:60:37 | mk_array output argument | test.cpp:62:32:62:34 | Load |
 | test.cpp:60:34:60:37 | mk_array output argument | test.cpp:66:32:66:34 | Load |
 | test.cpp:60:34:60:37 | mk_array output argument | test.cpp:70:31:70:33 | Load |
 | test.cpp:62:32:62:34 | Load | test.cpp:67:9:67:14 | Store: ... = ... |
-| test.cpp:62:32:62:34 | Load | test.cpp:67:9:67:14 | Store: ... = ... |
 | test.cpp:66:32:66:34 | Load | test.cpp:67:9:67:14 | Store: ... = ... |
-| test.cpp:66:32:66:34 | Load | test.cpp:67:9:67:14 | Store: ... = ... |
-| test.cpp:70:31:70:33 | Load | test.cpp:67:9:67:14 | Store: ... = ... |
 | test.cpp:70:31:70:33 | Load | test.cpp:67:9:67:14 | Store: ... = ... |
 | test.cpp:80:9:80:16 | VariableAddress indirection [begin] | test.cpp:91:20:91:22 | arr indirection [begin] |
 | test.cpp:80:9:80:16 | VariableAddress indirection [begin] | test.cpp:95:20:95:22 | arr indirection [begin] |
@@ -479,8 +391,6 @@ edges
 | test.cpp:83:15:83:17 | arr indirection [begin] | test.cpp:83:19:83:23 | begin |
 | test.cpp:83:15:83:30 | ... + ... | test.cpp:83:5:83:30 | Store |
 | test.cpp:83:19:83:23 | Load | test.cpp:83:5:83:30 | Store |
-| test.cpp:83:19:83:23 | Load | test.cpp:83:5:83:30 | Store |
-| test.cpp:83:19:83:23 | Load | test.cpp:83:15:83:30 | ... + ... |
 | test.cpp:83:19:83:23 | Load | test.cpp:83:15:83:30 | ... + ... |
 | test.cpp:83:19:83:23 | begin | test.cpp:83:19:83:23 | Load |
 | test.cpp:91:20:91:22 | arr indirection [begin] | test.cpp:91:24:91:28 | begin |
@@ -488,21 +398,18 @@ edges
 | test.cpp:91:24:91:28 | begin | test.cpp:91:47:91:47 | Load |
 | test.cpp:91:36:91:38 | arr indirection [end] | test.cpp:91:40:91:42 | end |
 | test.cpp:91:40:91:42 | Load | test.cpp:96:9:96:14 | Store: ... = ... |
-| test.cpp:91:40:91:42 | Load | test.cpp:96:9:96:14 | Store: ... = ... |
 | test.cpp:91:40:91:42 | end | test.cpp:91:40:91:42 | Load |
 | test.cpp:95:20:95:22 | arr indirection [begin] | test.cpp:95:24:95:28 | begin |
 | test.cpp:95:20:95:22 | arr indirection [begin] | test.cpp:95:47:95:47 | Load |
 | test.cpp:95:24:95:28 | begin | test.cpp:95:47:95:47 | Load |
 | test.cpp:95:36:95:38 | arr indirection [end] | test.cpp:95:40:95:42 | end |
 | test.cpp:95:40:95:42 | Load | test.cpp:96:9:96:14 | Store: ... = ... |
-| test.cpp:95:40:95:42 | Load | test.cpp:96:9:96:14 | Store: ... = ... |
 | test.cpp:95:40:95:42 | end | test.cpp:95:40:95:42 | Load |
 | test.cpp:99:20:99:22 | arr indirection [begin] | test.cpp:99:24:99:28 | begin |
 | test.cpp:99:20:99:22 | arr indirection [begin] | test.cpp:99:46:99:46 | Load |
 | test.cpp:99:24:99:28 | begin | test.cpp:99:46:99:46 | Load |
 | test.cpp:99:35:99:37 | arr indirection [end] | test.cpp:99:39:99:41 | end |
 | test.cpp:99:39:99:41 | Load | test.cpp:96:9:96:14 | Store: ... = ... |
-| test.cpp:99:39:99:41 | Load | test.cpp:96:9:96:14 | Store: ... = ... |
 | test.cpp:99:39:99:41 | end | test.cpp:99:39:99:41 | Load |
 | test.cpp:104:27:104:29 | arr [begin] | test.cpp:105:20:105:22 | arr indirection [begin] |
 | test.cpp:104:27:104:29 | arr [begin] | test.cpp:109:20:109:22 | arr indirection [begin] |
@@ -515,21 +422,18 @@ edges
 | test.cpp:105:24:105:28 | begin | test.cpp:105:47:105:47 | Load |
 | test.cpp:105:36:105:38 | arr indirection [end] | test.cpp:105:40:105:42 | end |
 | test.cpp:105:40:105:42 | Load | test.cpp:110:9:110:14 | Store: ... = ... |
-| test.cpp:105:40:105:42 | Load | test.cpp:110:9:110:14 | Store: ... = ... |
 | test.cpp:105:40:105:42 | end | test.cpp:105:40:105:42 | Load |
 | test.cpp:109:20:109:22 | arr indirection [begin] | test.cpp:109:24:109:28 | begin |
 | test.cpp:109:20:109:22 | arr indirection [begin] | test.cpp:109:47:109:47 | Load |
 | test.cpp:109:24:109:28 | begin | test.cpp:109:47:109:47 | Load |
 | test.cpp:109:36:109:38 | arr indirection [end] | test.cpp:109:40:109:42 | end |
 | test.cpp:109:40:109:42 | Load | test.cpp:110:9:110:14 | Store: ... = ... |
-| test.cpp:109:40:109:42 | Load | test.cpp:110:9:110:14 | Store: ... = ... |
 | test.cpp:109:40:109:42 | end | test.cpp:109:40:109:42 | Load |
 | test.cpp:113:20:113:22 | arr indirection [begin] | test.cpp:113:24:113:28 | begin |
 | test.cpp:113:20:113:22 | arr indirection [begin] | test.cpp:113:46:113:46 | Load |
 | test.cpp:113:24:113:28 | begin | test.cpp:113:46:113:46 | Load |
 | test.cpp:113:35:113:37 | arr indirection [end] | test.cpp:113:39:113:41 | end |
 | test.cpp:113:39:113:41 | Load | test.cpp:110:9:110:14 | Store: ... = ... |
-| test.cpp:113:39:113:41 | Load | test.cpp:110:9:110:14 | Store: ... = ... |
 | test.cpp:113:39:113:41 | end | test.cpp:113:39:113:41 | Load |
 | test.cpp:119:18:119:25 | call to mk_array [begin] | test.cpp:104:27:104:29 | arr [begin] |
 | test.cpp:119:18:119:25 | call to mk_array [end] | test.cpp:104:27:104:29 | arr [end] |
@@ -558,8 +462,6 @@ edges
 | test.cpp:144:16:144:18 | Load indirection [begin] | test.cpp:144:21:144:25 | begin |
 | test.cpp:144:16:144:32 | ... + ... | test.cpp:144:5:144:32 | Store |
 | test.cpp:144:21:144:25 | Load | test.cpp:144:5:144:32 | Store |
-| test.cpp:144:21:144:25 | Load | test.cpp:144:5:144:32 | Store |
-| test.cpp:144:21:144:25 | Load | test.cpp:144:16:144:32 | ... + ... |
 | test.cpp:144:21:144:25 | Load | test.cpp:144:16:144:32 | ... + ... |
 | test.cpp:144:21:144:25 | begin | test.cpp:144:21:144:25 | Load |
 | test.cpp:150:20:150:29 | Call indirection [begin] | test.cpp:152:20:152:22 | Load indirection [begin] |
@@ -574,7 +476,6 @@ edges
 | test.cpp:156:25:156:29 | begin | test.cpp:156:49:156:49 | Load |
 | test.cpp:156:37:156:39 | Load indirection [end] | test.cpp:156:42:156:44 | end |
 | test.cpp:156:42:156:44 | Load | test.cpp:157:9:157:14 | Store: ... = ... |
-| test.cpp:156:42:156:44 | Load | test.cpp:157:9:157:14 | Store: ... = ... |
 | test.cpp:156:42:156:44 | end | test.cpp:156:42:156:44 | Load |
 | test.cpp:160:20:160:22 | Load indirection [begin] | test.cpp:160:25:160:29 | begin |
 | test.cpp:160:20:160:22 | Load indirection [begin] | test.cpp:160:48:160:48 | Load |
@@ -590,21 +491,18 @@ edges
 | test.cpp:166:25:166:29 | begin | test.cpp:166:49:166:49 | Load |
 | test.cpp:166:37:166:39 | Load indirection [end] | test.cpp:166:42:166:44 | end |
 | test.cpp:166:42:166:44 | Load | test.cpp:171:9:171:14 | Store: ... = ... |
-| test.cpp:166:42:166:44 | Load | test.cpp:171:9:171:14 | Store: ... = ... |
 | test.cpp:166:42:166:44 | end | test.cpp:166:42:166:44 | Load |
 | test.cpp:170:20:170:22 | Load indirection [begin] | test.cpp:170:25:170:29 | begin |
 | test.cpp:170:20:170:22 | Load indirection [begin] | test.cpp:170:49:170:49 | Load |
 | test.cpp:170:25:170:29 | begin | test.cpp:170:49:170:49 | Load |
 | test.cpp:170:37:170:39 | Load indirection [end] | test.cpp:170:42:170:44 | end |
 | test.cpp:170:42:170:44 | Load | test.cpp:171:9:171:14 | Store: ... = ... |
-| test.cpp:170:42:170:44 | Load | test.cpp:171:9:171:14 | Store: ... = ... |
 | test.cpp:170:42:170:44 | end | test.cpp:170:42:170:44 | Load |
 | test.cpp:174:20:174:22 | Load indirection [begin] | test.cpp:174:25:174:29 | begin |
 | test.cpp:174:20:174:22 | Load indirection [begin] | test.cpp:174:48:174:48 | Load |
 | test.cpp:174:25:174:29 | begin | test.cpp:174:48:174:48 | Load |
 | test.cpp:174:36:174:38 | Load indirection [end] | test.cpp:174:41:174:43 | end |
 | test.cpp:174:41:174:43 | Load | test.cpp:171:9:171:14 | Store: ... = ... |
-| test.cpp:174:41:174:43 | Load | test.cpp:171:9:171:14 | Store: ... = ... |
 | test.cpp:174:41:174:43 | end | test.cpp:174:41:174:43 | Load |
 | test.cpp:180:19:180:28 | call to mk_array_p indirection [begin] | test.cpp:165:29:165:31 | arr indirection [begin] |
 | test.cpp:180:19:180:28 | call to mk_array_p indirection [end] | test.cpp:165:29:165:31 | arr indirection [end] |
@@ -614,19 +512,9 @@ edges
 | test.cpp:194:23:194:28 | call to malloc | test.cpp:201:5:201:5 | Load |
 | test.cpp:195:17:195:17 | Load | test.cpp:195:17:195:23 | ... + ... |
 | test.cpp:195:17:195:17 | Load | test.cpp:195:17:195:23 | ... + ... |
-| test.cpp:195:17:195:17 | Load | test.cpp:195:17:195:23 | ... + ... |
-| test.cpp:195:17:195:17 | Load | test.cpp:195:17:195:23 | ... + ... |
-| test.cpp:195:17:195:17 | Load | test.cpp:195:17:195:23 | Store |
-| test.cpp:195:17:195:17 | Load | test.cpp:195:17:195:23 | Store |
 | test.cpp:195:17:195:17 | Load | test.cpp:195:17:195:23 | Store |
 | test.cpp:195:17:195:17 | Load | test.cpp:195:17:195:23 | Store |
 | test.cpp:195:17:195:17 | Load | test.cpp:197:20:197:22 | Load |
-| test.cpp:195:17:195:17 | Load | test.cpp:197:20:197:22 | Load |
-| test.cpp:195:17:195:17 | Load | test.cpp:197:20:197:22 | Load |
-| test.cpp:195:17:195:17 | Load | test.cpp:197:20:197:22 | Load |
-| test.cpp:195:17:195:17 | Load | test.cpp:201:5:201:12 | access to array |
-| test.cpp:195:17:195:17 | Load | test.cpp:201:5:201:12 | access to array |
-| test.cpp:195:17:195:17 | Load | test.cpp:201:5:201:12 | access to array |
 | test.cpp:195:17:195:17 | Load | test.cpp:201:5:201:12 | access to array |
 | test.cpp:195:17:195:23 | ... + ... | test.cpp:195:17:195:23 | Store |
 | test.cpp:195:17:195:23 | ... + ... | test.cpp:195:17:195:23 | Store |
@@ -637,29 +525,15 @@ edges
 | test.cpp:195:17:195:23 | Store | test.cpp:201:5:201:19 | Store: ... = ... |
 | test.cpp:195:17:195:23 | Store | test.cpp:201:5:201:19 | Store: ... = ... |
 | test.cpp:197:20:197:22 | Load | test.cpp:201:5:201:19 | Store: ... = ... |
-| test.cpp:197:20:197:22 | Load | test.cpp:201:5:201:19 | Store: ... = ... |
-| test.cpp:201:5:201:12 | access to array | test.cpp:201:5:201:19 | Store: ... = ... |
 | test.cpp:201:5:201:12 | access to array | test.cpp:201:5:201:19 | Store: ... = ... |
 | test.cpp:205:23:205:28 | call to malloc | test.cpp:206:17:206:17 | Load |
 | test.cpp:205:23:205:28 | call to malloc | test.cpp:208:15:208:15 | Load |
 | test.cpp:206:17:206:17 | Load | test.cpp:206:17:206:23 | ... + ... |
 | test.cpp:206:17:206:17 | Load | test.cpp:206:17:206:23 | ... + ... |
-| test.cpp:206:17:206:17 | Load | test.cpp:206:17:206:23 | ... + ... |
-| test.cpp:206:17:206:17 | Load | test.cpp:206:17:206:23 | ... + ... |
-| test.cpp:206:17:206:17 | Load | test.cpp:206:17:206:23 | Store |
-| test.cpp:206:17:206:17 | Load | test.cpp:206:17:206:23 | Store |
 | test.cpp:206:17:206:17 | Load | test.cpp:206:17:206:23 | Store |
 | test.cpp:206:17:206:17 | Load | test.cpp:206:17:206:23 | Store |
 | test.cpp:206:17:206:17 | Load | test.cpp:209:12:209:14 | Load |
-| test.cpp:206:17:206:17 | Load | test.cpp:209:12:209:14 | Load |
-| test.cpp:206:17:206:17 | Load | test.cpp:209:12:209:14 | Load |
-| test.cpp:206:17:206:17 | Load | test.cpp:209:12:209:14 | Load |
 | test.cpp:206:17:206:17 | Load | test.cpp:213:5:213:6 | * ... |
-| test.cpp:206:17:206:17 | Load | test.cpp:213:5:213:6 | * ... |
-| test.cpp:206:17:206:17 | Load | test.cpp:213:5:213:6 | * ... |
-| test.cpp:206:17:206:17 | Load | test.cpp:213:5:213:6 | * ... |
-| test.cpp:206:17:206:17 | Load | test.cpp:213:6:213:6 | Load |
-| test.cpp:206:17:206:17 | Load | test.cpp:213:6:213:6 | Load |
 | test.cpp:206:17:206:17 | Load | test.cpp:213:6:213:6 | Load |
 | test.cpp:206:17:206:17 | Load | test.cpp:213:6:213:6 | Load |
 | test.cpp:206:17:206:23 | ... + ... | test.cpp:206:17:206:23 | Store |
@@ -671,8 +545,6 @@ edges
 | test.cpp:206:17:206:23 | Store | test.cpp:213:5:213:13 | Store: ... = ... |
 | test.cpp:206:17:206:23 | Store | test.cpp:213:5:213:13 | Store: ... = ... |
 | test.cpp:209:12:209:14 | Load | test.cpp:213:5:213:13 | Store: ... = ... |
-| test.cpp:209:12:209:14 | Load | test.cpp:213:5:213:13 | Store: ... = ... |
-| test.cpp:213:5:213:6 | * ... | test.cpp:213:5:213:13 | Store: ... = ... |
 | test.cpp:213:5:213:6 | * ... | test.cpp:213:5:213:13 | Store: ... = ... |
 | test.cpp:213:6:213:6 | Load | test.cpp:213:5:213:6 | * ... |
 | test.cpp:213:6:213:6 | Load | test.cpp:213:5:213:13 | Store: ... = ... |

cpp/ql/test/library-tests/dataflow/dataflow-tests/dataflow-consistency.expected

@@ -6,6 +6,8 @@ uniqueNodeToString
 missingToString
 parameterCallable
 localFlowIsLocal
+readStepIsLocal
+storeStepIsLocal
 compatibleTypesReflexive
 unreachableNodeCCtx
 localCallNodes
@@ -87,4 +89,7 @@ postWithInFlow
 | test.cpp:465:3:465:4 | * ... [post update] | PostUpdateNode should not be the target of local flow. |
 | test.cpp:465:4:465:4 | p [inner post update] | PostUpdateNode should not be the target of local flow. |
 | test.cpp:470:22:470:22 | x [inner post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:499:3:499:4 | * ... [post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:499:4:499:4 | p [inner post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:505:35:505:35 | x [inner post update] | PostUpdateNode should not be the target of local flow. |
 viableImplInCallContextTooLarge

cpp/ql/test/library-tests/dataflow/dataflow-tests/dataflow-ir-consistency.expected

@@ -21,6 +21,8 @@ uniqueNodeToString
 missingToString
 parameterCallable
 localFlowIsLocal
+readStepIsLocal
+storeStepIsLocal
 compatibleTypesReflexive
 unreachableNodeCCtx
 localCallNodes
@@ -582,6 +584,13 @@ postWithInFlow
 | test.cpp:489:7:489:7 | VariableAddress [post update] | PostUpdateNode should not be the target of local flow. |
 | test.cpp:491:5:491:5 | x [post update] | PostUpdateNode should not be the target of local flow. |
 | test.cpp:494:5:494:5 | x [post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:499:3:499:4 | * ... [post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:499:4:499:4 | VariableAddress [post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:499:4:499:4 | p [post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:504:7:504:7 | VariableAddress [post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:505:34:505:35 | & ... [post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:505:34:505:35 | & ... [post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:505:35:505:35 | x [post update] | PostUpdateNode should not be the target of local flow. |
 | true_upon_entry.cpp:9:7:9:7 | VariableAddress [post update] | PostUpdateNode should not be the target of local flow. |
 | true_upon_entry.cpp:10:12:10:12 | VariableAddress [post update] | PostUpdateNode should not be the target of local flow. |
 | true_upon_entry.cpp:10:27:10:27 | VariableAddress [post update] | PostUpdateNode should not be the target of local flow. |

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

@@ -87,7 +87,7 @@ Top *identity(Top *top) {
 
 void callIdentityFunctions(Top *top, Bottom *bottom) {
   identity(bottom)->isSink(source()); // $ MISSING: ast,ir
-  identity(top)->isSink(source()); // now flow
+  identity(top)->isSink(source()); // no flow
 }
 
 using SinkFunctionType = void (*)(int);

cpp/ql/test/library-tests/dataflow/dataflow-tests/test.cpp

@@ -329,21 +329,21 @@ namespace NestedTests {
 namespace FlowThroughGlobals {
   int globalVar;
 
-  int taintGlobal() {
+  void taintGlobal() {
     globalVar = source();
   }
 
-  int f() {
+  void f() {
     sink(globalVar); // $ ir=333:17 ir=347:17 // tainted or clean? Not sure.
     taintGlobal();
     sink(globalVar); // $ ir=333:17 ir=347:17 MISSING: ast
   }
 
-  int calledAfterTaint() {
+  void calledAfterTaint() {
     sink(globalVar); // $ ir=333:17 ir=347:17 MISSING: ast
   }
 
-  int taintAndCall() {
+  void taintAndCall() {
     globalVar = source();
     calledAfterTaint();
     sink(globalVar); // $ ast ir=333:17 ir=347:17
@@ -494,3 +494,14 @@ void regression_with_phi_flow(int clean1) {
     x = source();
   }
 }
+
+int intOutparamSourceMissingReturn(int *p) {
+  *p = source();
+  // return deliberately omitted to test IR dataflow behavior
+}
+
+void viaOutparamMissingReturn() {
+  int x = 0;
+  intOutparamSourceMissingReturn(&x);
+  sink(x); // $ ast,ir
+}

cpp/ql/test/library-tests/dataflow/dataflow-tests/test.ql

@@ -77,27 +77,9 @@ module IRTest {
       )
     }
 
-    override predicate isAdditionalFlowStep(DataFlow::Node n1, DataFlow::Node n2) {
-      exists(GlobalOrNamespaceVariable var | var.getName().matches("flowTestGlobal%") |
-        writesVariable(n1.asInstruction(), var) and
-        var = n2.asVariable()
-        or
-        readsVariable(n2.asInstruction(), var) and
-        var = n1.asVariable()
-      )
-    }
-
     override predicate isBarrier(DataFlow::Node barrier) {
       barrier.asExpr().(VariableAccess).getTarget().hasName("barrier") or
       barrier = DataFlow::InstructionBarrierGuard<testBarrierGuard/3>::getABarrierNode()
     }
   }
-
-  private predicate readsVariable(LoadInstruction load, Variable var) {
-    load.getSourceAddress().(VariableAddressInstruction).getAstVariable() = var
-  }
-
-  private predicate writesVariable(StoreInstruction store, Variable var) {
-    store.getDestinationAddress().(VariableAddressInstruction).getAstVariable() = var
-  }
 }

cpp/ql/test/library-tests/dataflow/dataflow-tests/true_upon_entry.cpp

@@ -5,7 +5,7 @@ int source();
 void sink(...);
 bool random();
 
-int test1() {
+void test1() {
   int x = source();
   for (int i = 0; i < 10; i++) {
     x = 0;
@@ -13,7 +13,7 @@ int test1() {
   sink(x); // $ SPURIOUS: ir
 }
 
-int test2(int iterations) {
+void test2(int iterations) {
   int x = source();
   for (int i = 0; i < iterations; i++) {
     x = 0;
@@ -21,7 +21,7 @@ int test2(int iterations) {
   sink(x); // $ ast,ir
 }
 
-int test3() {
+void test3() {
   int x = 0;
   for (int i = 0; i < 10; i++) {
     x = source();
@@ -29,7 +29,7 @@ int test3() {
   sink(x); // $ ast,ir
 }
 
-int test4() {
+void test4() {
   int x = source();
   for (int i = 0; i < 10; i++) {
     if (random())
@@ -39,7 +39,7 @@ int test4() {
   sink(x); // $ ast,ir
 }
 
-int test5() {
+void test5() {
   int x = source();
   for (int i = 0; i < 10; i++) {
     if (random())
@@ -49,7 +49,7 @@ int test5() {
   sink(x); // $ ast,ir
 }
 
-int test6() {
+void test6() {
   int y;
   int x = source();
   for (int i = 0; i < 10 && (y = 1); i++) {
@@ -57,7 +57,7 @@ int test6() {
   sink(x); // $ ast,ir
 }
 
-int test7() {
+void test7() {
   int y;
   int x = source();
   for (int i = 0; i < 10 && (y = 1); i++) {
@@ -66,7 +66,7 @@ int test7() {
   sink(x); // $ SPURIOUS: ir
 }
 
-int test8() {
+void test8() {
   int x = source();
   // It appears to the analysis that the condition can exit after `i < 10`
   // without having assigned to `x`. That is an effect of how the
@@ -78,7 +78,7 @@ int test8() {
   sink(x); // $ SPURIOUS: ast,ir
 }
 
-int test9() {
+void test9() {
   int y;
   int x = source();
   for (int i = 0; (y = 1) && i < 10; i++) {
@@ -86,21 +86,21 @@ int test9() {
   sink(x); // $ ast,ir
 }
 
-int test10() {
+void test10() {
   int x = source();
   for (int i = 0; (x = 1) && i < 10; i++) {
   }
   sink(x); // no flow
 }
 
-int test10(int b, int d) {
+void test10(int b, int d) {
   int i = 0;
   int x = source();
   if (b)
     goto L;
   for (; i < 10; i += d) {
     x = 0;
-    L:
+    L: ;
   }
   sink(x); // $ ir MISSING: ast
 }

cpp/ql/test/library-tests/dataflow/fields/dataflow-consistency.expected

@@ -12,6 +12,8 @@ uniqueNodeToString
 missingToString
 parameterCallable
 localFlowIsLocal
+readStepIsLocal
+storeStepIsLocal
 compatibleTypesReflexive
 unreachableNodeCCtx
 localCallNodes

cpp/ql/test/library-tests/dataflow/fields/dataflow-ir-consistency.expected

@@ -15,6 +15,8 @@ uniqueNodeToString
 missingToString
 parameterCallable
 localFlowIsLocal
+readStepIsLocal
+storeStepIsLocal
 compatibleTypesReflexive
 unreachableNodeCCtx
 localCallNodes

cpp/ql/test/library-tests/dataflow/taint-tests/bsd.cpp

@@ -9,7 +9,7 @@ struct sockaddr {
 	char* sa_data;
 };
 
-int accept(int, const sockaddr*, int*);
+int accept(int, sockaddr*, int*);
 
 void sink(sockaddr);
 
@@ -20,5 +20,5 @@ void test_accept() {
   int a = accept(s, &addr, &size);
 
   sink(a); // $ ast=17:11 ir SPURIOUS: ast=18:12
-  sink(addr); // $ ast,ir
+  sink(addr); // $ ast=17:11 ir SPURIOUS: ast=18:12
 }

cpp/ql/test/library-tests/dataflow/taint-tests/localTaint.expected

@@ -142,9 +142,14 @@
 | bsd.cpp:19:14:19:29 | sizeof(sockaddr) | bsd.cpp:20:29:20:32 | size |  |
 | bsd.cpp:20:11:20:16 | call to accept | bsd.cpp:22:8:22:8 | a |  |
 | bsd.cpp:20:18:20:18 | s | bsd.cpp:20:11:20:16 | call to accept | TAINT |
+| bsd.cpp:20:18:20:18 | s | bsd.cpp:20:21:20:25 | ref arg & ... | TAINT |
 | bsd.cpp:20:21:20:25 | & ... | bsd.cpp:20:11:20:16 | call to accept | TAINT |
+| bsd.cpp:20:21:20:25 | & ... | bsd.cpp:20:21:20:25 | ref arg & ... | TAINT |
+| bsd.cpp:20:21:20:25 | ref arg & ... | bsd.cpp:20:22:20:25 | addr [inner post update] |  |
+| bsd.cpp:20:21:20:25 | ref arg & ... | bsd.cpp:23:8:23:11 | addr |  |
 | bsd.cpp:20:22:20:25 | addr | bsd.cpp:20:11:20:16 | call to accept | TAINT |
 | bsd.cpp:20:22:20:25 | addr | bsd.cpp:20:21:20:25 | & ... |  |
+| bsd.cpp:20:22:20:25 | addr | bsd.cpp:20:21:20:25 | ref arg & ... | TAINT |
 | bsd.cpp:20:28:20:32 | ref arg & ... | bsd.cpp:20:29:20:32 | size [inner post update] |  |
 | bsd.cpp:20:29:20:32 | size | bsd.cpp:20:28:20:32 | & ... |  |
 | constructor_delegation.cpp:8:2:8:8 | this | constructor_delegation.cpp:8:20:8:24 | constructor init of field x [pre-this] |  |
@@ -5964,6 +5969,7 @@
 | taint.cpp:172:10:172:15 | buffer | taint.cpp:172:3:172:8 | call to strcat |  |
 | taint.cpp:172:10:172:15 | buffer | taint.cpp:172:10:172:15 | ref arg buffer | TAINT |
 | taint.cpp:172:10:172:15 | ref arg buffer | taint.cpp:173:8:173:13 | buffer |  |
+| taint.cpp:172:18:172:24 | tainted | taint.cpp:172:3:172:8 | call to strcat | TAINT |
 | taint.cpp:172:18:172:24 | tainted | taint.cpp:172:10:172:15 | ref arg buffer | TAINT |
 | taint.cpp:180:19:180:19 | p | taint.cpp:180:19:180:19 | p |  |
 | taint.cpp:180:19:180:19 | p | taint.cpp:181:9:181:9 | p |  |
@@ -6373,12 +6379,14 @@
 | taint.cpp:561:9:561:13 | dest1 | taint.cpp:561:9:561:13 | ref arg dest1 | TAINT |
 | taint.cpp:561:9:561:13 | ref arg dest1 | taint.cpp:560:24:560:28 | dest1 |  |
 | taint.cpp:561:9:561:13 | ref arg dest1 | taint.cpp:562:7:562:11 | dest1 |  |
+| taint.cpp:561:16:561:21 | source | taint.cpp:561:2:561:7 | call to strcat | TAINT |
 | taint.cpp:561:16:561:21 | source | taint.cpp:561:9:561:13 | ref arg dest1 | TAINT |
 | taint.cpp:562:7:562:11 | ref arg dest1 | taint.cpp:560:24:560:28 | dest1 |  |
 | taint.cpp:564:9:564:13 | dest2 | taint.cpp:564:2:564:7 | call to strcat |  |
 | taint.cpp:564:9:564:13 | dest2 | taint.cpp:564:9:564:13 | ref arg dest2 | TAINT |
 | taint.cpp:564:9:564:13 | ref arg dest2 | taint.cpp:560:37:560:41 | dest2 |  |
 | taint.cpp:564:9:564:13 | ref arg dest2 | taint.cpp:565:7:565:11 | dest2 |  |
+| taint.cpp:564:16:564:20 | clean | taint.cpp:564:2:564:7 | call to strcat | TAINT |
 | taint.cpp:564:16:564:20 | clean | taint.cpp:564:9:564:13 | ref arg dest2 | TAINT |
 | taint.cpp:565:7:565:11 | ref arg dest2 | taint.cpp:560:37:560:41 | dest2 |  |
 | taint.cpp:572:37:572:41 | dest1 | taint.cpp:572:37:572:41 | dest1 |  |
@@ -6405,9 +6413,12 @@
 | taint.cpp:574:36:574:40 | ref arg dest1 | taint.cpp:572:37:572:41 | dest1 |  |
 | taint.cpp:574:36:574:40 | ref arg dest1 | taint.cpp:575:7:575:11 | dest1 |  |
 | taint.cpp:574:36:574:40 | ref arg dest1 | taint.cpp:576:8:576:12 | dest1 |  |
+| taint.cpp:574:43:574:45 | ptr | taint.cpp:574:25:574:34 | call to _mbsncat_l | TAINT |
 | taint.cpp:574:43:574:45 | ptr | taint.cpp:574:36:574:40 | ref arg dest1 | TAINT |
+| taint.cpp:574:48:574:48 | n | taint.cpp:574:25:574:34 | call to _mbsncat_l | TAINT |
 | taint.cpp:574:48:574:48 | n | taint.cpp:574:36:574:40 | ref arg dest1 | TAINT |
 | taint.cpp:574:51:574:56 | ref arg source | taint.cpp:573:49:573:54 | source |  |
+| taint.cpp:574:51:574:56 | source | taint.cpp:574:25:574:34 | call to _mbsncat_l | TAINT |
 | taint.cpp:574:51:574:56 | source | taint.cpp:574:36:574:40 | ref arg dest1 | TAINT |
 | taint.cpp:575:7:575:11 | ref arg dest1 | taint.cpp:572:37:572:41 | dest1 |  |
 | taint.cpp:575:7:575:11 | ref arg dest1 | taint.cpp:576:8:576:12 | dest1 |  |
@@ -6421,8 +6432,11 @@
 | taint.cpp:580:36:580:40 | ref arg dest3 | taint.cpp:572:85:572:89 | dest3 |  |
 | taint.cpp:580:36:580:40 | ref arg dest3 | taint.cpp:581:7:581:11 | dest3 |  |
 | taint.cpp:580:36:580:40 | ref arg dest3 | taint.cpp:582:8:582:12 | dest3 |  |
+| taint.cpp:580:43:580:45 | ptr | taint.cpp:580:25:580:34 | call to _mbsncat_l | TAINT |
 | taint.cpp:580:43:580:45 | ptr | taint.cpp:580:36:580:40 | ref arg dest3 | TAINT |
+| taint.cpp:580:48:580:48 | n | taint.cpp:580:25:580:34 | call to _mbsncat_l | TAINT |
 | taint.cpp:580:48:580:48 | n | taint.cpp:580:36:580:40 | ref arg dest3 | TAINT |
+| taint.cpp:580:51:580:55 | clean | taint.cpp:580:25:580:34 | call to _mbsncat_l | TAINT |
 | taint.cpp:580:51:580:55 | clean | taint.cpp:580:36:580:40 | ref arg dest3 | TAINT |
 | taint.cpp:580:51:580:55 | ref arg clean | taint.cpp:573:32:573:36 | clean |  |
 | taint.cpp:581:7:581:11 | ref arg dest3 | taint.cpp:572:85:572:89 | dest3 |  |

cpp/ql/test/library-tests/dataflow/taint-tests/taint.cpp

@@ -574,8 +574,8 @@ void test__mbsncat_l(unsigned char* dest1, unsigned const char* ptr, unsigned ch
 	unsigned char* dest2 = _mbsncat_l(dest1, ptr, n, source);
 	sink(dest1); // $ SPURIOUS: ast,ir
 	sink(*dest1); // $ ast,ir
-	sink(dest2); // $ SPURIOUS: ir
+	sink(dest2); // $ SPURIOUS: ast,ir
-	sink(*dest2); // $ ir
+	sink(*dest2); // $ ast,ir
 
 	unsigned char* dest4 = _mbsncat_l(dest3, ptr, n, clean);
 	sink(dest3);

cpp/ql/test/library-tests/dataflow/taint-tests/taint.ql

@@ -95,16 +95,7 @@ module IRTest {
     override predicate isSink(DataFlow::Node sink) {
       exists(FunctionCall call |
         call.getTarget().getName() = "sink" and
-        sink.asConvertedExpr() = call.getAnArgument()
+        sink.asExpr() = call.getAnArgument()
-        or
-        call.getTarget().getName() = "sink" and
-        sink.asExpr() = call.getAnArgument() and
-        sink.asConvertedExpr() instanceof ReferenceDereferenceExpr
-      )
-      or
-      exists(ReadSideEffectInstruction read |
-        read.getSideEffectOperand() = sink.asOperand() and
-        read.getPrimaryInstruction().(CallInstruction).getStaticCallTarget().hasName("sink")
       )
     }
 

cpp/ql/test/library-tests/printf/formatAttribute/AttributeFormattingFunction.cpp

@@ -0,0 +1,6 @@
+
+typedef void *va_list;
+
+int myPrintf(const char *format, ...) __attribute__((format(printf, 1, 2)));
+int mySprintf(char *buffer, const char *format, ...) __attribute__((format(__printf__, 2, 3)));
+int myVprintf(const char *format, va_list arg) __attribute__((format(printf, 1, 0)));

cpp/ql/test/library-tests/printf/formatAttribute/AttributeFormattingFunction.expected

@@ -0,0 +1,2 @@
+| AttributeFormattingFunction.cpp:4:5:4:12 | myPrintf | 0 | char | wchar_t | wchar_t |
+| AttributeFormattingFunction.cpp:5:5:5:13 | mySprintf | 1 | char | wchar_t | wchar_t |

cpp/ql/test/library-tests/printf/formatAttribute/AttributeFormattingFunction.ql

@@ -0,0 +1,5 @@
+import cpp
+
+from AttributeFormattingFunction f
+select f, f.getFormatParameterIndex(), concat(f.getDefaultCharType().toString(), ", "),
+  concat(f.getWideCharType().toString(), ", "), concat(f.getNonDefaultCharType().toString(), ", ")

cpp/ql/test/library-tests/printf/formatAttribute/FormatAttribute.expected

@@ -0,0 +1,3 @@
+| AttributeFormattingFunction.cpp:4:54:4:59 | format | printf | 0 | 1 |
+| AttributeFormattingFunction.cpp:5:69:5:74 | format | __printf__ | 1 | 2 |
+| AttributeFormattingFunction.cpp:6:63:6:68 | format | printf | 0 |  |

cpp/ql/test/library-tests/printf/formatAttribute/FormatAttribute.ql

@@ -0,0 +1,5 @@
+import cpp
+
+from FormatAttribute fa
+select fa, fa.getArchetype(), concat(fa.getFormatIndex().toString(), ", "),
+  concat(fa.getFirstFormatArgIndex().toString(), ", ")

cpp/ql/test/library-tests/printf/formatLiteral/formatLiteral.expected

@@ -0,0 +1,53 @@
+| test.c:14:9:14:10 |  | 1 |
+| test.c:15:9:15:14 |   | 2 |
+| test.c:16:9:16:12 | \t | 2 |
+| test.c:17:9:17:12 | %% | 2 |
+| test.c:20:9:20:12 | %c | 2 |
+| test.c:21:9:21:16 | %c%c%c | 4 |
+| test.c:24:9:24:23 | Hello, world! | 14 |
+| test.c:25:9:25:12 | %s | 14 |
+| test.c:26:9:26:14 | %.4s | 5 |
+| test.c:27:9:27:16 | %s, %s | 14 |
+| test.c:30:9:30:12 | %i | 12 |
+| test.c:31:9:31:14 | %lli | 12 |
+| test.c:32:9:32:12 | %i | 12 |
+| test.c:33:9:33:14 | %lli | 21 |
+| test.c:34:9:34:12 | %d | 12 |
+| test.c:35:9:35:12 | %u | 11 |
+| test.c:36:9:36:12 | %x | 9 |
+| test.c:37:9:37:12 | %X | 9 |
+| test.c:38:9:38:13 | %#x | 11 |
+| test.c:39:9:39:12 | %o | 12 |
+| test.c:40:9:40:13 | %#o | 13 |
+| test.c:43:9:43:12 | %f | 318 |
+| test.c:44:9:44:14 | %.2f | 314 |
+| test.c:45:9:45:12 | %e | 15 |
+| test.c:59:10:59:14 | %Ii | 12 |
+| test.c:66:10:66:14 | %zu | 21 |
+| test.c:67:10:67:14 | %Zu | 21 |
+| test.c:74:10:74:14 | %lc | 2 |
+| test.c:78:9:78:20 | %2$i, %1$i | 5 |
+| test.c:79:9:79:20 | %2$i, %1$i | 25 |
+| test.c:81:9:81:24 | %2$02i %1$4.2f |  |
+| test.c:85:10:85:18 | %2$*1$d |  |
+| test.c:86:10:86:19 | %2$0*1$d |  |
+| test.c:92:10:92:19 | %2$.*1$f |  |
+| test.c:99:10:99:12 | # | 2 |
+| test.c:100:10:100:13 | %% | 2 |
+| test.c:101:10:101:15 | %%%% | 3 |
+| test.c:102:10:102:15 | %%%f | 319 |
+| test.c:103:10:103:17 | %%%%%f | 320 |
+| test.c:104:10:104:18 | %4.2f%% | 315 |
+| test.c:105:10:105:17 | %%%f%% | 320 |
+| test.c:112:10:112:13 | %f | 318 |
+| test.c:113:10:113:15 | %.1f | 313 |
+| test.c:114:10:114:14 | %1f | 318 |
+| test.c:115:10:115:16 | %1.1f | 313 |
+| test.c:116:10:116:13 | %e | 15 |
+| test.c:117:10:117:15 | %.2e | 11 |
+| test.c:118:10:118:14 | %3e | 15 |
+| test.c:119:10:119:16 | %3.2e | 11 |
+| test.c:120:10:120:13 | %g | 15 |
+| test.c:121:10:121:15 | %.1g | 10 |
+| test.c:122:10:122:14 | %4g | 15 |
+| test.c:123:10:123:16 | %4.1g | 10 |

cpp/ql/test/library-tests/printf/formatLiteral/formatLiteral.ql

@@ -0,0 +1,4 @@
+import semmle.code.cpp.commons.Printf
+
+from FormatLiteral fl
+select fl, concat(fl.getMaxConvertedLength().toString(), ", ")

cpp/ql/test/library-tests/printf/formatLiteral/formatType.expected

@@ -0,0 +1,51 @@
+| test.c:20:9:20:12 | %c | 0 |  | c |  | file://:0:0:0:0 | char |
+| test.c:21:9:21:16 | %c%c%c | 0 |  | c |  | file://:0:0:0:0 | char |
+| test.c:21:9:21:16 | %c%c%c | 1 |  | c |  | file://:0:0:0:0 | char |
+| test.c:21:9:21:16 | %c%c%c | 2 |  | c |  | file://:0:0:0:0 | char |
+| test.c:25:9:25:12 | %s | 0 |  | s |  | file://:0:0:0:0 | char * |
+| test.c:26:9:26:14 | %.4s | 0 |  | s |  | file://:0:0:0:0 | char * |
+| test.c:27:9:27:16 | %s, %s | 0 |  | s |  | file://:0:0:0:0 | char * |
+| test.c:27:9:27:16 | %s, %s | 1 |  | s |  | file://:0:0:0:0 | char * |
+| test.c:30:9:30:12 | %i | 0 |  | i |  | file://:0:0:0:0 | int |
+| test.c:31:9:31:14 | %lli | 0 |  | i | ll | file://:0:0:0:0 | long long |
+| test.c:32:9:32:12 | %i | 0 |  | i |  | file://:0:0:0:0 | int |
+| test.c:33:9:33:14 | %lli | 0 |  | i | ll | file://:0:0:0:0 | long long |
+| test.c:34:9:34:12 | %d | 0 |  | d |  | file://:0:0:0:0 | int |
+| test.c:35:9:35:12 | %u | 0 |  | u |  | file://:0:0:0:0 | unsigned int |
+| test.c:36:9:36:12 | %x | 0 |  | x |  | file://:0:0:0:0 | unsigned int |
+| test.c:37:9:37:12 | %X | 0 |  | X |  | file://:0:0:0:0 | unsigned int |
+| test.c:38:9:38:13 | %#x | 0 |  | x |  | file://:0:0:0:0 | unsigned int |
+| test.c:39:9:39:12 | %o | 0 |  | o |  | file://:0:0:0:0 | unsigned int |
+| test.c:40:9:40:13 | %#o | 0 |  | o |  | file://:0:0:0:0 | unsigned int |
+| test.c:43:9:43:12 | %f | 0 |  | f |  | file://:0:0:0:0 | double |
+| test.c:44:9:44:14 | %.2f | 0 |  | f |  | file://:0:0:0:0 | double |
+| test.c:45:9:45:12 | %e | 0 |  | e |  | file://:0:0:0:0 | double |
+| test.c:59:10:59:14 | %Ii | 0 |  | i |  | file://:0:0:0:0 | int |
+| test.c:66:10:66:14 | %zu | 0 |  | u | z | test.c:50:27:50:32 | size_t |
+| test.c:67:10:67:14 | %Zu | 0 |  | u | Z | test.c:50:27:50:32 | size_t |
+| test.c:74:10:74:14 | %lc | 0 |  | c | l | file://:0:0:0:0 | wchar_t |
+| test.c:78:9:78:20 | %2$i, %1$i | 0 | 2$ | i |  | file://:0:0:0:0 | int |
+| test.c:78:9:78:20 | %2$i, %1$i | 1 | 1$ | i |  | file://:0:0:0:0 | int |
+| test.c:79:9:79:20 | %2$i, %1$i | 0 | 2$ | i |  | file://:0:0:0:0 | int |
+| test.c:79:9:79:20 | %2$i, %1$i | 1 | 1$ | i |  | file://:0:0:0:0 | int |
+| test.c:81:9:81:24 | %2$02i %1$4.2f | 0 | 2$ | i |  | file://:0:0:0:0 | int |
+| test.c:81:9:81:24 | %2$02i %1$4.2f | 1 | 1$ | f |  | file://:0:0:0:0 | double |
+| test.c:85:10:85:18 | %2$*1$d | 0 | 2$ | d |  | file://:0:0:0:0 | int |
+| test.c:86:10:86:19 | %2$0*1$d | 0 | 2$ | d |  | file://:0:0:0:0 | int |
+| test.c:92:10:92:19 | %2$.*1$f | 0 | 2$ | f |  | file://:0:0:0:0 | double |
+| test.c:102:10:102:15 | %%%f | 0 |  | f |  | file://:0:0:0:0 | double |
+| test.c:103:10:103:17 | %%%%%f | 0 |  | f |  | file://:0:0:0:0 | double |
+| test.c:104:10:104:18 | %4.2f%% | 0 |  | f |  | file://:0:0:0:0 | double |
+| test.c:105:10:105:17 | %%%f%% | 0 |  | f |  | file://:0:0:0:0 | double |
+| test.c:112:10:112:13 | %f | 0 |  | f |  | file://:0:0:0:0 | double |
+| test.c:113:10:113:15 | %.1f | 0 |  | f |  | file://:0:0:0:0 | double |
+| test.c:114:10:114:14 | %1f | 0 |  | f |  | file://:0:0:0:0 | double |
+| test.c:115:10:115:16 | %1.1f | 0 |  | f |  | file://:0:0:0:0 | double |
+| test.c:116:10:116:13 | %e | 0 |  | e |  | file://:0:0:0:0 | double |
+| test.c:117:10:117:15 | %.2e | 0 |  | e |  | file://:0:0:0:0 | double |
+| test.c:118:10:118:14 | %3e | 0 |  | e |  | file://:0:0:0:0 | double |
+| test.c:119:10:119:16 | %3.2e | 0 |  | e |  | file://:0:0:0:0 | double |
+| test.c:120:10:120:13 | %g | 0 |  | g |  | file://:0:0:0:0 | double |
+| test.c:121:10:121:15 | %.1g | 0 |  | g |  | file://:0:0:0:0 | double |
+| test.c:122:10:122:14 | %4g | 0 |  | g |  | file://:0:0:0:0 | double |
+| test.c:123:10:123:16 | %4.1g | 0 |  | g |  | file://:0:0:0:0 | double |

cpp/ql/test/library-tests/printf/formatLiteral/formatType.ql

@@ -0,0 +1,6 @@
+import semmle.code.cpp.commons.Printf
+
+from FormatLiteral fl, int i
+select fl, i, concat(fl.getParameterField(i).toString(), ", "), fl.getConversionChar(i),
+  fl.getLength(i), concat(fl.getConversionType(i).getLocation().toString(), ", "),
+  concat(fl.getConversionType(i).toString(), ", ")

cpp/ql/test/library-tests/printf/formatLiteral/test.c

@@ -0,0 +1,125 @@
+/** standard printf functions */
+
+int printf(const char *format, ...);
+
+/** test program */
+
+int main(int argc, char *argv[])
+{
+	long long int lli;
+	double d;
+	int i;
+
+	// constant expressions
+	printf("");
+	printf("\x20");
+	printf("\t");
+	printf("%%");
+
+	// characters
+	printf("%c", 'a');
+	printf("%c%c%c", 'a', 'b', 'c');
+
+	// strings
+	printf("Hello, world!");
+	printf("%s", "Hello, world!");
+	printf("%.4s", "Hello, world!");
+	printf("%s, %s", "Hello", "world!");
+
+	// integers
+	printf("%i", i);
+	printf("%lli", i);
+	printf("%i", lli);
+	printf("%lli", lli);
+	printf("%d", i);
+	printf("%u", i);
+	printf("%x", i);
+	printf("%X", i);
+	printf("%#x", i);
+	printf("%o", i);
+	printf("%#o", i);
+
+	// doubles
+	printf("%f", d);
+	printf("%.2f", d);
+	printf("%e", d);
+
+	return 0;
+}
+
+typedef long unsigned int size_t;
+typedef unsigned int wint_t;
+
+void more_cases(int a, int b)
+{
+	// integers
+	{
+		int i;
+
+		printf("%Ii", i); // glibc 2.2 'I' prefix
+	}
+
+	// size_t
+	{
+		size_t st;
+
+		printf("%zu", st); // size_t
+		printf("%Zu", st); // non-standard synonym for 'z'
+	}
+
+	// wint_t
+	{
+		wint_t wt;
+
+		printf("%lc", wt); // wide character
+	}
+
+	// posix indexed format arguments
+	printf("%2$i, %1$i", 1, 2); // '2, 1'
+	printf("%2$i, %1$i", a, b);
+	
+	printf("%2$02i %1$4.2f", 3.3333f, 6); // 06, 3.33
+	{
+		int width, num;
+
+		printf("%2$*1$d", width, num);
+		printf("%2$0*1$d", width, num);
+	}
+	{
+		int precision;
+		float num;
+
+		printf("%2$.*1$f", precision, num);
+	}
+
+	// %%
+	{
+		float num;
+
+		printf("#");
+		printf("%%");
+		printf("%%%%");
+		printf("%%%f", num);
+		printf("%%%%%f", num);
+		printf("%4.2f%%", num);
+		printf("%%%f%%", num);
+	}
+
+	// more tests of width and precision
+	{
+		float num;
+
+		printf("%f", num);
+		printf("%.1f", num);
+		printf("%1f", num);
+		printf("%1.1f", num);
+		printf("%e", num);
+		printf("%.2e", num);
+		printf("%3e", num);
+		printf("%3.2e", num);
+		printf("%g", num);
+		printf("%.1g", num);
+		printf("%4g", num);
+		printf("%4.1g", num);
+	}
+}

cpp/ql/test/library-tests/syntax-zoo/dataflow-consistency.expected

@@ -52,6 +52,8 @@ uniqueNodeToString
 missingToString
 parameterCallable
 localFlowIsLocal
+readStepIsLocal
+storeStepIsLocal
 compatibleTypesReflexive
 unreachableNodeCCtx
 localCallNodes

cpp/ql/test/library-tests/syntax-zoo/dataflow-ir-consistency.expected

@@ -1463,6 +1463,8 @@ uniqueNodeToString
 missingToString
 parameterCallable
 localFlowIsLocal
+readStepIsLocal
+storeStepIsLocal
 compatibleTypesReflexive
 unreachableNodeCCtx
 localCallNodes