Add codex-generated sinks for most DBs in the Java nightly source suite, using MaD columns and code context in the prompt

.git-blame-ignore-revs

@@ -1,21 +0,0 @@
-# .git-blame-ignore-revs
-# Auto-formatted Java
-730eae952139209fe9fdf598541d608f4c0c0c84
-# Auto-formatted C#
-5ad7ed49dd3de03ec6dcfcb6848758a6a987e11c
-# Auto-formatted C/C++
-ef97e539ec1971494d4bba5cafe82e00bc8217ac
-# Auto-formatted Python
-21d5fa836b3a7d020ba45e8b8168b145a9772131
-# Auto-formatted JavaScript
-8d97fe9ed327a9546ff2eaf515cf0f5214deddd9
-# Auto-formatted Ruby
-a5d229903d2f12d45f2c2c38822f1d0e7504ae7f
-# Auto-formatted Go
-08c658e66bf867090033ea096e244a93d46c0aa7
-# Auto-formatted Swift
-711d7057f79fb7d72fc3b35e010bd018f9009169
-# Auto-formatted shared ql packs
-3640b6d3a8ce9edf8e1d3ed106fe8526cf255bc0
-# Auto-formatted taint tracking files
-159d8e978c51959b380838c080d891b66e763b19

.github/actions/cache-query-compilation/action.yml

@@ -9,7 +9,7 @@ inputs:
 outputs:
   cache-dir:
     description: "The directory where the cache was stored"
-    value: ${{ steps.output-compilation-dir.outputs.compdir }}
+    value: ${{ steps.fill-compilation-dir.outputs.compdir }}
 
 runs:
   using: composite
@@ -27,9 +27,7 @@ runs:
       if: ${{ github.event_name == 'pull_request' }}
       uses: actions/cache/restore@v3
       with:
-        path: |
-          **/.cache
-          ~/.codeql/compile-cache
+        path: '**/.cache'
         key: codeql-compile-${{ inputs.key }}-pr-${{ github.sha }}
         restore-keys: |
           codeql-compile-${{ inputs.key }}-${{ github.base_ref }}-${{ env.merge_base }}
@@ -39,111 +37,18 @@ runs:
       if: ${{ github.event_name != 'pull_request' }}
       uses: actions/cache@v3
       with:
-        path: |
-          **/.cache
-          ~/.codeql/compile-cache
+        path: '**/.cache'
         key: codeql-compile-${{ inputs.key }}-${{ github.ref_name }}-${{ github.sha }} # just fill on main
         restore-keys: | # restore the latest cache if the exact cache is unavailable, to speed up compilation.
           codeql-compile-${{ inputs.key }}-${{ github.ref_name }}-
           codeql-compile-${{ inputs.key }}-main-
-    - name: Output-compilationdir
-      id: output-compilation-dir
+    - name: Fill compilation cache directory
+      id: fill-compilation-dir
       shell: bash
       run: |
+        # Move all the existing cache into another folder, so we only preserve the cache for the current queries.
+        node $GITHUB_WORKSPACE/.github/actions/cache-query-compilation/move-caches.js ${COMBINED_CACHE_DIR}
+
         echo "compdir=${COMBINED_CACHE_DIR}" >> $GITHUB_OUTPUT
       env:
         COMBINED_CACHE_DIR: ${{ runner.temp }}/compilation-dir
-    - name: Fill compilation cache directory
-      id: fill-compilation-dir
-      uses: actions/github-script@v6
-      env: 
-        COMBINED_CACHE_DIR: ${{ runner.temp }}/compilation-dir
-      with:
-        script: |
-          // # Move all the existing cache into another folder, so we only preserve the cache for the current queries.
-          // mkdir -p ${COMBINED_CACHE_DIR}
-          // rm -f **/.cache/{lock,size} # -f to avoid errors if the cache is empty.
-          // # copy the contents of the .cache folders into the combined cache folder.
-          // cp -r **/.cache/* ${COMBINED_CACHE_DIR}/ || : # ignore missing files
-          // # clean up the .cache folders
-          // rm -rf **/.cache/*
-
-          const fs = require("fs");
-          const path = require("path");
-          const os = require("os");
-
-          // the first argv is the cache folder to create.
-          const COMBINED_CACHE_DIR = process.env.COMBINED_CACHE_DIR;
-
-          function* walkCaches(dir) {
-            const files = fs.readdirSync(dir, { withFileTypes: true });
-            for (const file of files) {
-              if (file.isDirectory()) {
-                const filePath = path.join(dir, file.name);
-                yield* walkCaches(filePath);
-                if (file.name === ".cache") {
-                  yield filePath;
-                }
-              }
-            }
-          }
-
-          async function copyDir(src, dest) {
-            for await (const file of await fs.promises.readdir(src, { withFileTypes: true })) {
-              const srcPath = path.join(src, file.name);
-              const destPath = path.join(dest, file.name);
-              if (file.isDirectory()) {
-                if (!fs.existsSync(destPath)) {
-                  fs.mkdirSync(destPath);
-                }
-                await copyDir(srcPath, destPath);
-              } else {
-                await fs.promises.copyFile(srcPath, destPath);
-              }
-            }
-          }
-
-          async function main() {
-            const cacheDirs = [...walkCaches(".")];
-
-            for (const dir of cacheDirs) {
-              console.log(`Found .cache dir at ${dir}`);
-            }
-
-            const globalCacheDir = path.join(os.homedir(), ".codeql", "compile-cache");
-            if (fs.existsSync(globalCacheDir)) {
-              console.log("Found global home dir: " + globalCacheDir);
-              cacheDirs.push(globalCacheDir);
-            }
-
-            if (cacheDirs.length === 0) {
-              console.log("No cache dirs found");
-              return;
-            }
-
-            // mkdir -p ${COMBINED_CACHE_DIR}
-            fs.mkdirSync(COMBINED_CACHE_DIR, { recursive: true });
-
-            // rm -f **/.cache/{lock,size} # -f to avoid errors if the cache is empty.
-            await Promise.all(
-              cacheDirs.map((cacheDir) =>
-                (async function () {
-                  await fs.promises.rm(path.join(cacheDir, "lock"), { force: true });
-                  await fs.promises.rm(path.join(cacheDir, "size"), { force: true });
-                })()
-              )
-            );
-
-            // # copy the contents of the .cache folders into the combined cache folder.
-            // cp -r **/.cache/* ${COMBINED_CACHE_DIR}/ || : # ignore missing files
-            await Promise.all(
-              cacheDirs.map((cacheDir) => copyDir(cacheDir, COMBINED_CACHE_DIR))
-            );
-
-            // # clean up the .cache folders
-            // rm -rf **/.cache/*
-            await Promise.all(
-              cacheDirs.map((cacheDir) => fs.promises.rm(cacheDir, { recursive: true }))
-            );
-          }
-          main();

.github/actions/cache-query-compilation/move-caches.js

@@ -0,0 +1,75 @@
+// # Move all the existing cache into another folder, so we only preserve the cache for the current queries.
+// mkdir -p ${COMBINED_CACHE_DIR}
+// rm -f **/.cache/{lock,size} # -f to avoid errors if the cache is empty.
+// # copy the contents of the .cache folders into the combined cache folder.
+// cp -r **/.cache/* ${COMBINED_CACHE_DIR}/ || : # ignore missing files
+// # clean up the .cache folders
+// rm -rf **/.cache/*
+
+const fs = require("fs");
+const path = require("path");
+
+// the first argv is the cache folder to create.
+const COMBINED_CACHE_DIR = process.argv[2];
+
+function* walkCaches(dir) {
+  const files = fs.readdirSync(dir, { withFileTypes: true });
+  for (const file of files) {
+    if (file.isDirectory()) {
+      const filePath = path.join(dir, file.name);
+      yield* walkCaches(filePath);
+      if (file.name === ".cache") {
+        yield filePath;
+      }
+    }
+  }
+}
+
+async function copyDir(src, dest) {
+  for await (const file of await fs.promises.readdir(src, { withFileTypes: true })) {
+    const srcPath = path.join(src, file.name);
+    const destPath = path.join(dest, file.name);
+    if (file.isDirectory()) {
+      if (!fs.existsSync(destPath)) {
+        fs.mkdirSync(destPath);
+      }
+      await copyDir(srcPath, destPath);
+    } else {
+      await fs.promises.copyFile(srcPath, destPath);
+    }
+  }
+}
+
+async function main() {
+  const cacheDirs = [...walkCaches(".")];
+
+  for (const dir of cacheDirs) {
+    console.log(`Found .cache dir at ${dir}`);
+  }
+
+  // mkdir -p ${COMBINED_CACHE_DIR}
+  fs.mkdirSync(COMBINED_CACHE_DIR, { recursive: true });
+
+  // rm -f **/.cache/{lock,size} # -f to avoid errors if the cache is empty.
+  await Promise.all(
+    cacheDirs.map((cacheDir) =>
+      (async function () {
+        await fs.promises.rm(path.join(cacheDir, "lock"), { force: true });
+        await fs.promises.rm(path.join(cacheDir, "size"), { force: true });
+      })()
+    )
+  );
+
+  // # copy the contents of the .cache folders into the combined cache folder.
+  // cp -r **/.cache/* ${COMBINED_CACHE_DIR}/ || : # ignore missing files
+  await Promise.all(
+    cacheDirs.map((cacheDir) => copyDir(cacheDir, COMBINED_CACHE_DIR))
+  );
+
+  // # clean up the .cache folders
+  // rm -rf **/.cache/*
+  await Promise.all(
+    cacheDirs.map((cacheDir) => fs.promises.rm(cacheDir, { recursive: true }))
+  );
+}
+main();

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

@@ -19,6 +19,4 @@ runs:
         gh extension install github/gh-codeql
         gh codeql set-channel "$CHANNEL"
         gh codeql version
-        printf "CODEQL_FETCHED_CODEQL_PATH=" >> "${GITHUB_ENV}"
-        gh codeql version --format=json | jq -r .unpackedLocation >> "${GITHUB_ENV}"
         gh codeql version --format=json | jq -r .unpackedLocation >> "${GITHUB_PATH}"

.github/actions/find-latest-bundle/action.yml

@@ -0,0 +1,26 @@
+name: Find Latest CodeQL Bundle
+description: Finds the URL of the latest released version of the CodeQL bundle.
+outputs:
+  url:
+    description: The download URL of the latest CodeQL bundle release
+    value: ${{ steps.find-latest.outputs.url }}
+runs:
+  using: composite
+  steps:
+    - name: Find Latest Release
+      id: find-latest
+      shell: pwsh
+      run: |
+        $Latest = gh release list --repo github/codeql-action --exclude-drafts --limit 1000 |
+          ForEach-Object { $C = $_ -split "`t"; return @{ type = $C[1]; tag = $C[2]; } } |
+          Where-Object { $_.type -eq 'Latest' }
+
+        $Tag = $Latest.tag
+        if ($Tag -eq '') {
+          throw 'Failed to find latest bundle release.'
+        }
+
+        Write-Output "Latest bundle tag is '${Tag}'."
+        "url=https://github.com/github/codeql-action/releases/download/${Tag}/codeql-bundle-linux64.tar.gz" >> $env:GITHUB_OUTPUT
+      env:
+        GITHUB_TOKEN: ${{ github.token }}

.github/dependabot.yml

@@ -1,12 +1,19 @@
 version: 2
 updates:
   - package-ecosystem: "cargo"
-    directory: "ruby"
+    directory: "ruby/node-types"
     schedule:
       interval: "daily"
-
   - package-ecosystem: "cargo"
-    directory: "ql"
+    directory: "ruby/generator"
+    schedule:
+      interval: "daily"
+  - package-ecosystem: "cargo"
+    directory: "ruby/extractor"
+    schedule:
+      interval: "daily"
+  - package-ecosystem: "cargo"
+    directory: "ruby/autobuilder"
     schedule:
       interval: "daily"
 

.github/workflows/check-qldoc.yml

@@ -26,8 +26,9 @@ jobs:
         shell: bash
         run: |
           EXIT_CODE=0
+          # TODO: remove the swift exception from the regex when we fix generated QLdoc
           # TODO: remove the shared exception from the regex when coverage of qlpacks without dbschemes is supported
-          changed_lib_packs="$(git diff --name-only --diff-filter=ACMRT HEAD^ HEAD | { grep -Po '^(?!(shared))[a-z]*/ql/lib' || true; } | sort -u)"
+          changed_lib_packs="$(git diff --name-only --diff-filter=ACMRT HEAD^ HEAD | { grep -Po '^(?!(swift|shared))[a-z]*/ql/lib' || true; } | sort -u)"
           for pack_dir in ${changed_lib_packs}; do
             lang="${pack_dir%/ql/lib}"
             codeql generate library-doc-coverage --output="${RUNNER_TEMP}/${lang}-current.txt" --dir="${pack_dir}"

.github/workflows/codeql-analysis.yml

@@ -28,9 +28,9 @@ jobs:
 
     steps:
     - name: Setup dotnet
-      uses: actions/setup-dotnet@v3
+      uses: actions/setup-dotnet@v2
       with:
-        dotnet-version: 7.0.102
+        dotnet-version: 6.0.202
 
     - name: Checkout repository
       uses: actions/checkout@v3

.github/workflows/compile-queries.yml

@@ -24,14 +24,14 @@ jobs:
         with: 
           key: all-queries
       - name: check formatting
-        run: find */ql -type f \( -name "*.qll" -o -name "*.ql" \) -print0 | xargs -0 -n 3000 -P 10 codeql query format -q --check-only
+        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 : ${{ github.event_name == 'pull_request' }}
         shell: bash
-        run: codeql query compile -q -j0 */ql/{src,examples} --keep-going --warnings=error --check-only --compilation-cache "${{ steps.query-cache.outputs.cache-dir }}"
+        run: codeql query compile -j0 */ql/{src,examples} --keep-going --warnings=error --check-only --compilation-cache "${{ steps.query-cache.outputs.cache-dir }}"
       - name: compile queries - full
         # do full compile if running on main - this populates the cache
         if : ${{ github.event_name != 'pull_request' }}
         shell: bash
-        run: codeql query compile -q -j0 */ql/{src,examples} --keep-going --warnings=error --compilation-cache "${{ steps.query-cache.outputs.cache-dir }}"
+        run: codeql query compile -j0 */ql/{src,examples} --keep-going --warnings=error --compilation-cache "${{ steps.query-cache.outputs.cache-dir }}"

.github/workflows/csharp-qltest.yml

@@ -77,10 +77,10 @@ jobs:
       - name: Setup dotnet
         uses: actions/setup-dotnet@v3
         with:
-          dotnet-version: 7.0.102
+          dotnet-version: 6.0.202
       - name: Extractor unit tests
         run: |
-          dotnet test -p:RuntimeFrameworkVersion=7.0.2 "${{ github.workspace }}/csharp/extractor/Semmle.Util.Tests"
-          dotnet test -p:RuntimeFrameworkVersion=7.0.2 "${{ github.workspace }}/csharp/extractor/Semmle.Extraction.Tests"
-          dotnet test -p:RuntimeFrameworkVersion=7.0.2 "${{ github.workspace }}/csharp/autobuilder/Semmle.Autobuild.CSharp.Tests"
-          dotnet test -p:RuntimeFrameworkVersion=7.0.2 "${{ github.workspace }}/cpp/autobuilder/Semmle.Autobuild.Cpp.Tests"
+          dotnet test -p:RuntimeFrameworkVersion=6.0.4 "${{ github.workspace }}/csharp/extractor/Semmle.Util.Tests"
+          dotnet test -p:RuntimeFrameworkVersion=6.0.4 "${{ github.workspace }}/csharp/extractor/Semmle.Extraction.Tests"
+          dotnet test -p:RuntimeFrameworkVersion=6.0.4 "${{ github.workspace }}/csharp/autobuilder/Semmle.Autobuild.CSharp.Tests"
+          dotnet test -p:RuntimeFrameworkVersion=6.0.4 "${{ github.workspace }}/cpp/autobuilder/Semmle.Autobuild.Cpp.Tests"

.github/workflows/go-tests-other-os.yml

@@ -12,10 +12,10 @@ jobs:
     name: Test MacOS
     runs-on: macos-latest
     steps:
-      - name: Set up Go 1.20
-        uses: actions/setup-go@v4
+      - name: Set up Go 1.19
+        uses: actions/setup-go@v3
         with:
-          go-version: 1.20.0
+          go-version: 1.19
         id: go
 
       - name: Check out code
@@ -47,10 +47,10 @@ jobs:
     name: Test Windows
     runs-on: windows-latest-xl
     steps:
-      - name: Set up Go 1.20
-        uses: actions/setup-go@v4
+      - name: Set up Go 1.19
+        uses: actions/setup-go@v3
         with:
-          go-version: 1.20.0
+          go-version: 1.19
         id: go
 
       - name: Check out code

.github/workflows/go-tests.yml

@@ -20,10 +20,10 @@ jobs:
     name: Test Linux (Ubuntu)
     runs-on: ubuntu-latest-xl
     steps:
-      - name: Set up Go 1.20
-        uses: actions/setup-go@v4
+      - name: Set up Go 1.19
+        uses: actions/setup-go@v3
         with:
-          go-version: 1.20.0
+          go-version: 1.19
         id: go
 
       - name: Check out code

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

@@ -5,6 +5,13 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+    paths:
+      - "ql/**"
+      - "**.qll"
+      - "**.ql"
+      - "**.dbscheme"
+      - "**/qlpack.yml"
+      - ".github/workflows/ql-for-ql-build.yml"
 
 env:
   CARGO_TERM_COLOR: always
@@ -15,26 +22,66 @@ jobs:
     steps:
       ### Build the queries ###
       - uses: actions/checkout@v3
-        with:
-          fetch-depth: 0
+      - name: Find latest bundle
+        id: find-latest-bundle
+        uses: ./.github/actions/find-latest-bundle
       - name: Find codeql
         id: find-codeql
-        uses: github/codeql-action/init@v2
+        uses: github/codeql-action/init@45955cb1830b640e2c1603ad72ad542a49d47b96
         with:
           languages: javascript # does not matter
+          tools: ${{ steps.find-latest-bundle.outputs.url }}
+      - name: Get CodeQL version
+        id: get-codeql-version
+        run: |
+          echo "version=$("${CODEQL}" --version | head -n 1 | rev | cut -d " " -f 1 | rev)" >> $GITHUB_OUTPUT
+        shell: bash
+        env:
+          CODEQL: ${{ steps.find-codeql.outputs.codeql-path }}
       - uses: ./.github/actions/os-version
         id: os_version
+      - name: Cache entire pack
+        id: cache-pack
+        uses: actions/cache@v3
+        with:
+          path: ${{ runner.temp }}/pack
+          key: ${{ runner.os }}-${{ steps.os_version.outputs.version }}-pack-${{ hashFiles('ql/**/Cargo.lock') }}-${{ hashFiles('ql/**/*.rs') }}-${{ hashFiles('ql/**/*.ql*') }}-${{ hashFiles('ql/**/qlpack.yml') }}-${{ hashFiles('ql/ql/src/ql.dbscheme*') }}-${{ steps.get-codeql-version.outputs.version }}--${{ hashFiles('.github/workflows/ql-for-ql-build.yml') }}
+      - name: Cache queries
+        if: steps.cache-pack.outputs.cache-hit != 'true'
+        id: cache-queries
+        uses: actions/cache@v3
+        with:
+          path: ${{ runner.temp }}/queries
+          key: queries-${{ hashFiles('ql/**/*.ql*') }}-${{ hashFiles('ql/**/qlpack.yml') }}-${{ hashFiles('ql/ql/src/ql.dbscheme*') }}-${{ steps.get-codeql-version.outputs.version }}--${{ hashFiles('.github/workflows/ql-for-ql-build.yml') }}
+      - name: Build query pack
+        if: steps.cache-queries.outputs.cache-hit != 'true' && steps.cache-pack.outputs.cache-hit != 'true'
+        run: |
+          cd ql/ql/src
+          "${CODEQL}" pack create -j 16
+          mv .codeql/pack/codeql/ql/0.0.0 ${{ runner.temp }}/queries
+        env:
+          CODEQL: ${{ steps.find-codeql.outputs.codeql-path }}
+      - name: Move cache queries to pack
+        if: steps.cache-pack.outputs.cache-hit != 'true'
+        run: |
+          cp -r ${{ runner.temp }}/queries ${{ runner.temp }}/pack
+        env:
+          CODEQL: ${{ steps.find-codeql.outputs.codeql-path }}
+
       ### Build the extractor ###
       - name: Cache entire extractor
+        if: steps.cache-pack.outputs.cache-hit != 'true'
         id: cache-extractor
         uses: actions/cache@v3
         with:
           path: |
-            ql/extractor-pack/
-            ql/target/release/buramu
+            ql/target/release/ql-autobuilder
+            ql/target/release/ql-autobuilder.exe
+            ql/target/release/ql-extractor
+            ql/target/release/ql-extractor.exe
           key: ${{ runner.os }}-${{ steps.os_version.outputs.version }}-extractor-${{ hashFiles('ql/**/Cargo.lock') }}-${{ hashFiles('ql/**/*.rs') }}
       - name: Cache cargo
-        if: steps.cache-extractor.outputs.cache-hit != 'true'
+        if: steps.cache-extractor.outputs.cache-hit != 'true' && steps.cache-pack.outputs.cache-hit != 'true'
         uses: actions/cache@v3
         with:
           path: |
@@ -42,33 +89,77 @@ jobs:
             ~/.cargo/git
             ql/target
           key: ${{ runner.os }}-${{ steps.os_version.outputs.version }}-rust-cargo-${{ hashFiles('ql/**/Cargo.lock') }}
+      - name: Check formatting
+        if: steps.cache-extractor.outputs.cache-hit != 'true' && steps.cache-pack.outputs.cache-hit != 'true'
+        run: cd ql; cargo fmt --all -- --check
+      - name: Build
+        if: steps.cache-extractor.outputs.cache-hit != 'true' && steps.cache-pack.outputs.cache-hit != 'true'
+        run: cd ql; cargo build --verbose
+      - name: Run tests
+        if: steps.cache-extractor.outputs.cache-hit != 'true' && steps.cache-pack.outputs.cache-hit != 'true'
+        run: cd ql; cargo test --verbose
       - name: Release build
-        if: steps.cache-extractor.outputs.cache-hit != 'true'
-        run: cd ql; ./scripts/create-extractor-pack.sh       
-        env:
-          GH_TOKEN: ${{ github.token }}   
-      - name: Cache compilation cache
-        id: query-cache
-        uses: ./.github/actions/cache-query-compilation
-        with: 
-          key: run-ql-for-ql
-      - name: Make database and analyze
+        if: steps.cache-extractor.outputs.cache-hit != 'true' && steps.cache-pack.outputs.cache-hit != 'true'
+        run: cd ql; cargo build --release
+      - name: Generate dbscheme
+        if: steps.cache-extractor.outputs.cache-hit != 'true' && steps.cache-pack.outputs.cache-hit != 'true'
+        run: ql/target/release/ql-generator --dbscheme ql/ql/src/ql.dbscheme --library ql/ql/src/codeql_ql/ast/internal/TreeSitter.qll
+
+      ### Package the queries and extractor ###
+      - name: Package pack
+        if: steps.cache-pack.outputs.cache-hit != 'true'
         run: |
-          ./ql/target/release/buramu | tee deprecated.blame # Add a blame file for the extractor to parse.
-          ${CODEQL} database create -l=ql --search-path ql/extractor-pack ${DB}
-          ${CODEQL} database analyze -j0 --format=sarif-latest --output=ql-for-ql.sarif ${DB} ql/ql/src/codeql-suites/ql-code-scanning.qls  --compilation-cache "${{ steps.query-cache.outputs.cache-dir }}"
-        env: 
-          CODEQL: ${{ steps.find-codeql.outputs.codeql-path }}
-          DB: ${{ runner.temp }}/DB
-          LGTM_INDEX_FILTERS: |
-            exclude:ql/ql/test
-            exclude:*/ql/lib/upgrades/
-            exclude:java/ql/integration-tests
-      - name: Upload sarif to code-scanning
-        uses: github/codeql-action/upload-sarif@v2
+          cp -r ql/codeql-extractor.yml ql/tools ql/ql/src/ql.dbscheme.stats ${PACK}/
+          mkdir -p ${PACK}/tools/linux64
+          cp ql/target/release/ql-autobuilder  ${PACK}/tools/linux64/autobuilder
+          cp ql/target/release/ql-extractor ${PACK}/tools/linux64/extractor
+          chmod +x ${PACK}/tools/linux64/autobuilder
+          chmod +x ${PACK}/tools/linux64/extractor
+        env:
+          PACK: ${{ runner.temp }}/pack
+
+      ### Run the analysis ###
+      - name: Hack codeql-action options
+        run: |
+          JSON=$(jq -nc --arg pack "${PACK}" '.database."run-queries"=["--search-path", $pack] | .resolve.queries=["--search-path", $pack] | .resolve.extractor=["--search-path", $pack] | .resolve.languages=["--search-path", $pack] | .database.init=["--search-path", $pack]')
+          echo "CODEQL_ACTION_EXTRA_OPTIONS=${JSON}" >> ${GITHUB_ENV}
+        env:
+          PACK: ${{ runner.temp }}/pack
+
+      - name: Create CodeQL config file
+        run: |
+          echo "paths-ignore:" >> ${CONF}
+          echo "  - ql/ql/test" >> ${CONF}
+          echo "  - \"*/ql/lib/upgrades/\"" >> ${CONF}
+          echo "disable-default-queries: true" >> ${CONF}
+          echo "queries:" >> ${CONF}
+          echo "  - uses: ./ql/ql/src/codeql-suites/ql-code-scanning.qls" >> ${CONF}
+          echo "Config file: "
+          cat ${CONF}
+        env:
+          CONF: ./ql-for-ql-config.yml
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@45955cb1830b640e2c1603ad72ad542a49d47b96
         with:
-          sarif_file: ql-for-ql.sarif
-          category: ql-for-ql
+          languages: ql
+          db-location: ${{ runner.temp }}/db
+          config-file: ./ql-for-ql-config.yml
+          tools: ${{ steps.find-latest-bundle.outputs.url }}
+      - name: Move pack queries
+        run: |
+          cp -r ${PACK}/queries ql/ql/src
+        env:
+          PACK: ${{ runner.temp }}/pack
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@45955cb1830b640e2c1603ad72ad542a49d47b96
+        with:
+          category: "ql-for-ql"
+      - name: Copy sarif file to CWD
+        run: cp ../results/ql.sarif ./ql-for-ql.sarif
+      - name: Fixup the $scema in sarif  # Until https://github.com/microsoft/sarif-vscode-extension/pull/436/ is part in a stable release
+        run: |
+          sed -i 's/\$schema.*/\$schema": "https:\/\/raw.githubusercontent.com\/oasis-tcs\/sarif-spec\/master\/Schemata\/sarif-schema-2.1.0",/' ql-for-ql.sarif
       - name: Sarif as artifact
         uses: actions/upload-artifact@v3
         with:

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

@@ -25,7 +25,7 @@ jobs:
 
       - name: Find codeql
         id: find-codeql
-        uses: github/codeql-action/init@v2
+        uses: github/codeql-action/init@45955cb1830b640e2c1603ad72ad542a49d47b96
         with:
           languages: javascript # does not matter
       - uses: ./.github/actions/os-version

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

@@ -6,13 +6,11 @@ on:
     paths:
       - "ql/**"
       - codeql-workspace.yml
-      - .github/workflows/ql-for-ql-tests.yml
   pull_request:
     branches: [main]
     paths:
       - "ql/**"
       - codeql-workspace.yml
-      - .github/workflows/ql-for-ql-tests.yml
 
 env:
   CARGO_TERM_COLOR: always
@@ -24,7 +22,7 @@ jobs:
       - uses: actions/checkout@v3
       - name: Find codeql
         id: find-codeql
-        uses: github/codeql-action/init@v2
+        uses: github/codeql-action/init@45955cb1830b640e2c1603ad72ad542a49d47b96
         with:
           languages: javascript # does not matter
       - uses: ./.github/actions/os-version
@@ -36,8 +34,6 @@ jobs:
             ~/.cargo/git
             ql/target
           key: ${{ runner.os }}-${{ steps.os_version.outputs.version }}-qltest-cargo-${{ hashFiles('ql/rust-toolchain.toml', 'ql/**/Cargo.lock') }}
-      - name: Check formatting
-        run: cd ql; cargo fmt --all -- --check
       - name: Build extractor
         run: |
           cd ql;
@@ -69,7 +65,7 @@ jobs:
           echo "/usr/local/opt/gnu-tar/libexec/gnubin" >> $GITHUB_PATH
       - name: Find codeql
         id: find-codeql
-        uses: github/codeql-action/init@v2
+        uses: github/codeql-action/init@77a8d2d10c0b403a8b4aadbd223dc489ecd22683
         with:
           languages: javascript # does not matter
       - uses: ./.github/actions/os-version

.github/workflows/ruby-build.yml

@@ -55,12 +55,12 @@ jobs:
         id: cache-extractor
         with:
           path: |
-            ruby/extractor/target/release/autobuilder
-            ruby/extractor/target/release/autobuilder.exe
-            ruby/extractor/target/release/extractor
-            ruby/extractor/target/release/extractor.exe
-            ruby/extractor/ql/lib/codeql/ruby/ast/internal/TreeSitter.qll
-          key: ${{ runner.os }}-${{ steps.os_version.outputs.version }}-ruby-extractor-${{ hashFiles('ruby/extractor/rust-toolchain.toml', 'ruby/extractor/Cargo.lock') }}--${{ hashFiles('ruby/extractor/**/*.rs') }}
+            ruby/target/release/ruby-autobuilder
+            ruby/target/release/ruby-autobuilder.exe
+            ruby/target/release/ruby-extractor
+            ruby/target/release/ruby-extractor.exe
+            ruby/ql/lib/codeql/ruby/ast/internal/TreeSitter.qll
+          key: ${{ runner.os }}-${{ steps.os_version.outputs.version }}-ruby-extractor-${{ hashFiles('ruby/rust-toolchain.toml', 'ruby/**/Cargo.lock') }}--${{ hashFiles('ruby/**/*.rs') }}
       - uses: actions/cache@v3
         if: steps.cache-extractor.outputs.cache-hit != 'true'
         with:
@@ -68,22 +68,22 @@ jobs:
             ~/.cargo/registry
             ~/.cargo/git
             ruby/target
-          key: ${{ runner.os }}-${{ steps.os_version.outputs.version }}-ruby-rust-cargo-${{ hashFiles('ruby/extractor/rust-toolchain.toml', 'ruby/extractor/**/Cargo.lock') }}
+          key: ${{ runner.os }}-${{ steps.os_version.outputs.version }}-ruby-rust-cargo-${{ hashFiles('ruby/rust-toolchain.toml', 'ruby/**/Cargo.lock') }}
       - name: Check formatting
         if: steps.cache-extractor.outputs.cache-hit != 'true'
-        run: cd extractor && cargo fmt --all -- --check
+        run: cargo fmt --all -- --check
       - name: Build
         if: steps.cache-extractor.outputs.cache-hit != 'true'
-        run: cd extractor && cargo build --verbose
+        run: cargo build --verbose
       - name: Run tests
         if: steps.cache-extractor.outputs.cache-hit != 'true'
-        run: cd extractor && cargo test --verbose
+        run: cargo test --verbose
       - name: Release build
         if: steps.cache-extractor.outputs.cache-hit != 'true'
-        run: cd extractor && cargo build --release
+        run: cargo build --release
       - name: Generate dbscheme
         if: ${{ matrix.os == 'ubuntu-latest' && steps.cache-extractor.outputs.cache-hit != 'true'}}
-        run: extractor/target/release/generator --dbscheme ql/lib/ruby.dbscheme --library ql/lib/codeql/ruby/ast/internal/TreeSitter.qll
+        run: target/release/ruby-generator --dbscheme ql/lib/ruby.dbscheme --library ql/lib/codeql/ruby/ast/internal/TreeSitter.qll
       - uses: actions/upload-artifact@v3
         if: ${{ matrix.os == 'ubuntu-latest' }}
         with:
@@ -98,10 +98,10 @@ jobs:
         with:
           name: extractor-${{ matrix.os }}
           path: |
-            ruby/extractor/target/release/autobuilder
-            ruby/extractor/target/release/autobuilder.exe
-            ruby/extractor/target/release/extractor
-            ruby/extractor/target/release/extractor.exe
+            ruby/target/release/ruby-autobuilder
+            ruby/target/release/ruby-autobuilder.exe
+            ruby/target/release/ruby-extractor
+            ruby/target/release/ruby-extractor.exe
           retention-days: 1
   compile-queries:
     runs-on: ubuntu-latest-xl
@@ -116,22 +116,21 @@ jobs:
           key: ruby-build
       - name: Build Query Pack
         run: |
-          PACKS=${{ runner.temp }}/query-packs
-          rm -rf $PACKS
-          codeql pack create ../misc/suite-helpers --output "$PACKS"
-          codeql pack create ../shared/regex --output "$PACKS"
-          codeql pack create ../shared/ssa --output "$PACKS"
-          codeql pack create ../shared/tutorial --output "$PACKS"
-          codeql pack create ql/lib --output "$PACKS"
-          codeql pack create -j0 ql/src --output "$PACKS" --compilation-cache "${{ steps.query-cache.outputs.cache-dir }}"
-          PACK_FOLDER=$(readlink -f "$PACKS"/codeql/ruby-queries/*)
+          rm -rf target/packs
+          codeql pack create ../misc/suite-helpers --output target/packs
+          codeql pack create ../shared/regex --output target/packs
+          codeql pack create ../shared/ssa --output target/packs
+          codeql pack create ../shared/tutorial --output target/packs
+          codeql pack create ql/lib --output target/packs
+          codeql pack create -j0 ql/src --output target/packs --compilation-cache "${{ steps.query-cache.outputs.cache-dir }}"
+          PACK_FOLDER=$(readlink -f target/packs/codeql/ruby-queries/*)
           codeql generate query-help --format=sarifv2.1.0 --output="${PACK_FOLDER}/rules.sarif" ql/src
           (cd ql/src; find queries \( -name '*.qhelp' -o -name '*.rb' -o -name '*.erb' \) -exec bash -c 'mkdir -p "'"${PACK_FOLDER}"'/$(dirname "{}")"' \; -exec cp "{}" "${PACK_FOLDER}/{}" \;)
       - uses: actions/upload-artifact@v3
         with:
           name: codeql-ruby-queries
           path: |
-            ${{ runner.temp }}/query-packs/*
+            ruby/target/packs/*
           retention-days: 1
 
   package:
@@ -159,12 +158,12 @@ jobs:
           mkdir -p ruby
           cp -r codeql-extractor.yml tools ql/lib/ruby.dbscheme.stats ruby/
           mkdir -p ruby/tools/{linux64,osx64,win64}
-          cp linux64/autobuilder ruby/tools/linux64/autobuilder
-          cp osx64/autobuilder ruby/tools/osx64/autobuilder
-          cp win64/autobuilder.exe ruby/tools/win64/autobuilder.exe
-          cp linux64/extractor ruby/tools/linux64/extractor
-          cp osx64/extractor ruby/tools/osx64/extractor
-          cp win64/extractor.exe ruby/tools/win64/extractor.exe
+          cp linux64/ruby-autobuilder ruby/tools/linux64/autobuilder
+          cp osx64/ruby-autobuilder ruby/tools/osx64/autobuilder
+          cp win64/ruby-autobuilder.exe ruby/tools/win64/autobuilder.exe
+          cp linux64/ruby-extractor ruby/tools/linux64/extractor
+          cp osx64/ruby-extractor ruby/tools/osx64/extractor
+          cp win64/ruby-extractor.exe ruby/tools/win64/extractor.exe
           chmod +x ruby/tools/{linux64,osx64}/{autobuilder,extractor}
           zip -rq codeql-ruby.zip ruby
       - uses: actions/upload-artifact@v3

.github/workflows/swift.yml

@@ -5,7 +5,6 @@ on:
     paths:
       - "swift/**"
       - "misc/bazel/**"
-      - "misc/codegen/**"
       - "*.bazel*"
       - .github/workflows/swift.yml
       - .github/actions/**
@@ -20,7 +19,6 @@ on:
     paths:
       - "swift/**"
       - "misc/bazel/**"
-      - "misc/codegen/**"
       - "*.bazel*"
       - .github/workflows/swift.yml
       - .github/actions/**

.pre-commit-config.yaml

@@ -53,5 +53,5 @@ repos:
         name: Run Swift code generation unit tests
         files: ^swift/codegen/.*\.py$
         language: system
-        entry: bazel test //misc/codegen/test
+        entry: bazel test //swift/codegen/test
         pass_filenames: false

CODEOWNERS

@@ -6,7 +6,6 @@
 /python/ @github/codeql-python
 /ruby/ @github/codeql-ruby
 /swift/ @github/codeql-swift
-/misc/codegen/ @github/codeql-swift
 /java/kotlin-extractor/ @github/codeql-kotlin
 /java/kotlin-explorer/ @github/codeql-kotlin
 

README.md

@@ -10,8 +10,6 @@ There is [extensive documentation](https://codeql.github.com/docs/) on getting s
 
 We welcome contributions to our standard library and standard checks. Do you have an idea for a new check, or how to improve an existing query? Then please go ahead and open a pull request! Before you do, though, please take the time to read our [contributing guidelines](CONTRIBUTING.md). You can also consult our [style guides](https://github.com/github/codeql/tree/main/docs) to learn how to format your code for consistency and clarity, how to write query metadata, and how to write query help documentation for your query.
 
-For information on contributing to CodeQL documentation, see the "[contributing guide](docs/codeql/CONTRIBUTING.md)" for docs.
-
 ## License
 
 The code in this repository is licensed under the [MIT License](LICENSE) by [GitHub](https://github.com).

config/identical-files.json

@@ -1,86 +1,65 @@
 {
   "DataFlow Java/C++/C#/Go/Python/Ruby/Swift": [
-    "java/ql/lib/semmle/code/java/dataflow/internal/DataFlow.qll",
-    "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlow.qll",
-    "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlow.qll",
-    "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlow.qll",
-    "go/ql/lib/semmle/go/dataflow/internal/DataFlow.qll",
-    "python/ql/lib/semmle/python/dataflow/new/internal/DataFlow.qll",
-    "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlow.qll",
-    "swift/ql/lib/codeql/swift/dataflow/internal/DataFlow.qll"
-  ],
-  "DataFlowImpl Java/C++/C#/Go/Python/Ruby/Swift": [
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl.qll",
-    "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll",
-    "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll",
-    "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll",
-    "go/ql/lib/semmle/go/dataflow/internal/DataFlowImpl.qll",
-    "python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl.qll",
-    "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImpl.qll",
-    "swift/ql/lib/codeql/swift/dataflow/internal/DataFlowImpl.qll"
-  ],
-  "DataFlow Java/C++/C#/Go/Python/Ruby/Swift Legacy Configuration": [
-    "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl1.qll",
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl2.qll",
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl3.qll",
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl4.qll",
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl5.qll",
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl6.qll",
-    "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl1.qll",
+    "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImplForSerializability.qll",
+    "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImplForOnActivityResult.qll",
+    "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll",
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll",
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll",
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll",
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplLocal.qll",
-    "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl1.qll",
+    "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll",
     "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll",
     "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll",
     "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll",
-    "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl1.qll",
+    "cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll",
+    "cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll",
+    "cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll",
+    "cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll",
+    "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll",
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl2.qll",
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl3.qll",
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl4.qll",
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl5.qll",
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImplForContentDataFlow.qll",
-    "go/ql/lib/semmle/go/dataflow/internal/DataFlowImpl1.qll",
+    "go/ql/lib/semmle/go/dataflow/internal/DataFlowImpl.qll",
     "go/ql/lib/semmle/go/dataflow/internal/DataFlowImpl2.qll",
-    "go/ql/lib/semmle/go/dataflow/internal/DataFlowImplForStringsNewReplacer.qll",
-    "python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl1.qll",
+    "python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl.qll",
     "python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl2.qll",
     "python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl3.qll",
     "python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl4.qll",
-    "python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImplForRegExp.qll",
-    "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImpl1.qll",
+    "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImpl.qll",
     "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImpl2.qll",
+    "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImplForRegExp.qll",
     "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImplForHttpClientLibraries.qll",
     "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImplForPathname.qll",
-    "swift/ql/lib/codeql/swift/dataflow/internal/DataFlowImpl1.qll"
+    "swift/ql/lib/codeql/swift/dataflow/internal/DataFlowImpl.qll"
   ],
   "DataFlow Java/C++/C#/Go/Python/Ruby/Swift Common": [
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImplCommon.qll",
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplCommon.qll",
     "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll",
+    "cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll",
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImplCommon.qll",
     "go/ql/lib/semmle/go/dataflow/internal/DataFlowImplCommon.qll",
     "python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImplCommon.qll",
     "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImplCommon.qll",
     "swift/ql/lib/codeql/swift/dataflow/internal/DataFlowImplCommon.qll"
   ],
-  "TaintTracking Java/C++/C#/Go/Python/Ruby/Swift": [
-    "cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking1/TaintTracking.qll",
-    "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking1/TaintTracking.qll",
-    "csharp/ql/lib/semmle/code/csharp/dataflow/internal/tainttracking1/TaintTracking.qll",
-    "go/ql/lib/semmle/go/dataflow/internal/tainttracking1/TaintTracking.qll",
-    "java/ql/lib/semmle/code/java/dataflow/internal/tainttracking1/TaintTracking.qll",
-    "python/ql/lib/semmle/python/dataflow/new/internal/tainttracking1/TaintTracking.qll",
-    "ruby/ql/lib/codeql/ruby/dataflow/internal/tainttracking1/TaintTracking.qll",
-    "swift/ql/lib/codeql/swift/dataflow/internal/tainttracking1/TaintTracking.qll"
-  ],
-  "TaintTracking Legacy Configuration Java/C++/C#/Go/Python/Ruby/Swift": [
+  "TaintTracking::Configuration Java/C++/C#/Go/Python/Ruby/Swift": [
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking1/TaintTrackingImpl.qll",
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking2/TaintTrackingImpl.qll",
     "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking1/TaintTrackingImpl.qll",
     "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking2/TaintTrackingImpl.qll",
     "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking3/TaintTrackingImpl.qll",
+    "cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/tainttracking1/TaintTrackingImpl.qll",
+    "cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/tainttracking2/TaintTrackingImpl.qll",
+    "cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/tainttracking3/TaintTrackingImpl.qll",
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/tainttracking1/TaintTrackingImpl.qll",
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/tainttracking2/TaintTrackingImpl.qll",
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/tainttracking3/TaintTrackingImpl.qll",
@@ -102,6 +81,7 @@
     "java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImplConsistency.qll",
     "cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplConsistency.qll",
     "cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImplConsistency.qll",
+    "cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/DataFlowImplConsistency.qll",
     "csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImplConsistency.qll",
     "python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImplConsistency.qll",
     "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImplConsistency.qll",

cpp/autobuilder/Semmle.Autobuild.Cpp.Tests/BuildScripts.cs

@@ -1,6 +1,5 @@
 using Xunit;
 using Semmle.Autobuild.Shared;
-using Semmle.Util;
 using System.Collections.Generic;
 using System;
 using System.Linq;
@@ -76,15 +75,6 @@ namespace Semmle.Autobuild.Cpp.Tests
             throw new ArgumentException("Missing RunProcess " + pattern);
         }
 
-        int IBuildActions.RunProcess(string cmd, string args, string? workingDirectory, IDictionary<string, string>? env, BuildOutputHandler onOutput, BuildOutputHandler onError)
-        {
-            var ret = (this as IBuildActions).RunProcess(cmd, args, workingDirectory, env, out var stdout);
-
-            stdout.ForEach(line => onOutput(line));
-
-            return ret;
-        }
-
         public IList<string> DirectoryDeleteIn = new List<string>();
 
         void IBuildActions.DirectoryDelete(string dir, bool recursive)
@@ -141,14 +131,6 @@ namespace Semmle.Autobuild.Cpp.Tests
 
         bool IBuildActions.IsWindows() => IsWindows;
 
-        public bool IsMacOs { get; set; }
-
-        bool IBuildActions.IsMacOs() => IsMacOs;
-
-        public bool IsArm { get; set; }
-
-        bool IBuildActions.IsArm() => IsArm;
-
         string IBuildActions.PathCombine(params string[] parts)
         {
             return string.Join(IsWindows ? '\\' : '/', parts.Where(p => !string.IsNullOrWhiteSpace(p)));
@@ -194,15 +176,6 @@ namespace Semmle.Autobuild.Cpp.Tests
             if (!DownloadFiles.Contains((address, fileName)))
                 throw new ArgumentException($"Missing DownloadFile, {address}, {fileName}");
         }
-
-        public IDiagnosticsWriter CreateDiagnosticsWriter(string filename) => new TestDiagnosticWriter();
-    }
-
-    internal class TestDiagnosticWriter : IDiagnosticsWriter
-    {
-        public IList<DiagnosticMessage> Diagnostics { get; } = new List<DiagnosticMessage>();
-
-        public void AddEntry(DiagnosticMessage message) => this.Diagnostics.Add(message);
     }
 
     /// <summary>
@@ -262,7 +235,6 @@ namespace Semmle.Autobuild.Cpp.Tests
             Actions.GetEnvironmentVariable[$"CODEQL_EXTRACTOR_{codeqlUpperLanguage}_TRAP_DIR"] = "";
             Actions.GetEnvironmentVariable[$"CODEQL_EXTRACTOR_{codeqlUpperLanguage}_SOURCE_ARCHIVE_DIR"] = "";
             Actions.GetEnvironmentVariable[$"CODEQL_EXTRACTOR_{codeqlUpperLanguage}_ROOT"] = $@"C:\codeql\{codeqlUpperLanguage.ToLowerInvariant()}";
-            Actions.GetEnvironmentVariable[$"CODEQL_EXTRACTOR_{codeqlUpperLanguage}_DIAGNOSTIC_DIR"] = "";
             Actions.GetEnvironmentVariable["CODEQL_JAVA_HOME"] = @"C:\codeql\tools\java";
             Actions.GetEnvironmentVariable["CODEQL_PLATFORM"] = "win64";
             Actions.GetEnvironmentVariable["SEMMLE_DIST"] = @"C:\odasa";

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

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <RuntimeIdentifiers>win-x64;linux-x64;osx-x64</RuntimeIdentifiers>
     <Nullable>enable</Nullable>

cpp/autobuilder/Semmle.Autobuild.Cpp/CppAutobuilder.cs

@@ -1,5 +1,4 @@
 using Semmle.Autobuild.Shared;
-using Semmle.Util;
 
 namespace Semmle.Autobuild.Cpp
 {
@@ -22,7 +21,7 @@ namespace Semmle.Autobuild.Cpp
 
     public class CppAutobuilder : Autobuilder<CppAutobuildOptions>
     {
-        public CppAutobuilder(IBuildActions actions, CppAutobuildOptions options) : base(actions, options, new DiagnosticClassifier()) { }
+        public CppAutobuilder(IBuildActions actions, CppAutobuildOptions options) : base(actions, options) { }
 
         public override BuildScript GetBuildScript()
         {

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

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <AssemblyName>Semmle.Autobuild.Cpp</AssemblyName>
     <RootNamespace>Semmle.Autobuild.Cpp</RootNamespace>
     <ApplicationIcon />

cpp/ql/lib/CHANGELOG.md

@@ -1,19 +1,3 @@
-## 0.5.4
-
-No user-facing changes.
-
-## 0.5.3
-
-No user-facing changes.
-
-## 0.5.2
-
-No user-facing changes.
-
-## 0.5.1
-
-No user-facing changes.
-
 ## 0.5.0
 
 ### Breaking Changes

cpp/ql/lib/change-notes/2023-02-10-buffer-and-nill-termination-dataflow.md

@@ -1,4 +0,0 @@
----
-category: breaking
----
-* The `semmle.code.cpp.commons.Buffer` and `semmle.code.cpp.commons.NullTermination` libraries no longer expose `semmle.code.cpp.dataflow.DataFlow`. Please import `semmle.code.cpp.dataflow.DataFlow` directly.

cpp/ql/lib/change-notes/2023-03-02-dataflow-conf-module.md

@@ -1,9 +0,0 @@
----
-category: majorAnalysis
----
-* The main data flow and taint tracking APIs have been changed. The old APIs
-  remain in place for now and translate to the new through a
-  backwards-compatible wrapper. If multiple configurations are in scope
-  simultaneously, then this may affect results slightly. The new API is quite
-  similar to the old, but makes use of a configuration module instead of a
-  configuration class.

cpp/ql/lib/change-notes/2023-03-03-delete-deps.md

@@ -1,12 +0,0 @@
----
-category: minorAnalysis
----
-* Deleted the deprecated `hasGeneratedCopyConstructor` and `hasGeneratedCopyAssignmentOperator` predicates from the `Folder` class.
-* Deleted the deprecated `getPath` and `getFolder` predicates from the `XmlFile` class.
-* Deleted the deprecated `getMustlockFunction`, `getTrylockFunction`, `getLockFunction`, and `getUnlockFunction` predicates from the `MutexType` class.
-* Deleted the deprecated `getPosInBasicBlock` predicate from the `SubBasicBlock` class.
-* Deleted the deprecated `getExpr` predicate from the `PointerDereferenceExpr` class.
-* Deleted the deprecated `getUseInstruction` and `getDefinitionInstruction` predicates from the `Operand` class.
-* Deleted the deprecated `isInParameter`, `isInParameterPointer`, and `isInQualifier` predicates from the `FunctionInput` class.
-* Deleted the deprecated `isOutParameterPointer`, `isOutQualifier`, `isOutReturnValue`, and `isOutReturnPointer` predicate from the `FunctionOutput` class.
-* Deleted the deprecated 3-argument `isGuardPhi` predicate from the `RangeSsaDefinition` class.

cpp/ql/lib/change-notes/2023-03-08-deprecated-dataflow-configurations.md

@@ -1,4 +0,0 @@
----
-category: deprecated
----
-* The `WriteConfig` taint tracking configuration has been deprecated. Please use `WriteFlow`.

cpp/ql/lib/change-notes/2023-03-13-mergepathgraph.md

@@ -1,4 +0,0 @@
----
-category: feature
----
-* Added support for merging two `PathGraph`s via disjoint union to allow results from multiple data flow computations in a single `path-problem` query.

cpp/ql/lib/change-notes/2023-03-16-use-use-flow.md

@@ -1,11 +0,0 @@
----
-category: majorAnalysis
----
-* A new C/C++ dataflow library (`semmle.code.cpp.dataflow.new.DataFlow`) has been added.
-  The new library behaves much more like the dataflow library of other CodeQL supported
-  languages by following use-use dataflow paths instead of def-use dataflow paths.
-  The new library also better supports dataflow through indirections, and new predicates
-  such as `Node::asIndirectExpr` have been added to facilitate working with indirections.
-
-  The `semmle.code.cpp.ir.dataflow.DataFlow` library is now identical to the new
-  `semmle.code.cpp.dataflow.new.DataFlow` library.

cpp/ql/lib/change-notes/released/0.5.1.md

@@ -1,3 +0,0 @@
-## 0.5.1
-
-No user-facing changes.

cpp/ql/lib/change-notes/released/0.5.2.md

@@ -1,3 +0,0 @@
-## 0.5.2
-
-No user-facing changes.

cpp/ql/lib/change-notes/released/0.5.3.md

@@ -1,3 +0,0 @@
-## 0.5.3
-
-No user-facing changes.

cpp/ql/lib/change-notes/released/0.5.4.md

@@ -1,3 +0,0 @@
-## 0.5.4
-
-No user-facing changes.

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

@@ -1,2 +1,2 @@
 ---
-lastReleaseVersion: 0.5.4
+lastReleaseVersion: 0.5.0

cpp/ql/lib/experimental/semmle/code/cpp/dataflow/ProductFlow.qll

@@ -1,5 +1,5 @@
-import semmle.code.cpp.ir.dataflow.DataFlow
-import semmle.code.cpp.ir.dataflow.DataFlow2
+import experimental.semmle.code.cpp.ir.dataflow.DataFlow
+import experimental.semmle.code.cpp.ir.dataflow.DataFlow2
 
 module ProductFlow {
   abstract class Configuration extends string {

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/DataFlow.qll

@@ -8,8 +8,8 @@
  * results than the AST-based library in most scenarios.
  *
  * Unless configured otherwise, _flow_ means that the exact value of
- * the source may reach the sink. To track flow where the exact value
- * may not be preserved, import `semmle.code.cpp.dataflow.new.TaintTracking`.
+ * the source may reach the sink. We do not track flow across pointer
+ * dereferences or array indexing.
  *
  * To use global (interprocedural) data flow, extend the class
  * `DataFlow::Configuration` as documented on that class. To use local
@@ -21,11 +21,6 @@
 
 import cpp
 
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) data flow analyses.
- */
 module DataFlow {
-  import semmle.code.cpp.ir.dataflow.internal.DataFlow
-  import semmle.code.cpp.ir.dataflow.internal.DataFlowImpl1
+  import experimental.semmle.code.cpp.ir.dataflow.internal.DataFlowImpl
 }

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/DataFlow2.qll

@@ -6,15 +6,11 @@
  * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
  * `DataFlow4::Configuration`.
  *
- * See `semmle.code.cpp.dataflow.new.DataFlow` for the full documentation.
+ * See `semmle.code.cpp.ir.dataflow.DataFlow` for the full documentation.
  */
 
 import cpp
 
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) data flow analyses.
- */
 module DataFlow2 {
-  import semmle.code.cpp.ir.dataflow.internal.DataFlowImpl2
+  import experimental.semmle.code.cpp.ir.dataflow.internal.DataFlowImpl2
 }

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/DataFlow3.qll

@@ -6,15 +6,11 @@
  * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
  * `DataFlow4::Configuration`.
  *
- * See `semmle.code.cpp.dataflow.new.DataFlow` for the full documentation.
+ * See `semmle.code.cpp.ir.dataflow.DataFlow` for the full documentation.
  */
 
 import cpp
 
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) data flow analyses.
- */
 module DataFlow3 {
-  import semmle.code.cpp.ir.dataflow.internal.DataFlowImpl3
+  import experimental.semmle.code.cpp.ir.dataflow.internal.DataFlowImpl3
 }

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/DataFlow4.qll

@@ -6,15 +6,11 @@
  * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
  * `DataFlow4::Configuration`.
  *
- * See `semmle.code.cpp.dataflow.new.DataFlow` for the full documentation.
+ * See `semmle.code.cpp.ir.dataflow.DataFlow` for the full documentation.
  */
 
 import cpp
 
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) data flow analyses.
- */
 module DataFlow4 {
-  import semmle.code.cpp.ir.dataflow.internal.DataFlowImpl4
+  import experimental.semmle.code.cpp.ir.dataflow.internal.DataFlowImpl4
 }

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/ResolveCall.qll

@@ -0,0 +1,23 @@
+/**
+ * Provides a predicate for non-contextual virtual dispatch and function
+ * pointer resolution.
+ */
+
+import cpp
+private import semmle.code.cpp.ir.ValueNumbering
+private import internal.DataFlowDispatch
+private import semmle.code.cpp.ir.IR
+
+/**
+ * Resolve potential target function(s) for `call`.
+ *
+ * If `call` is a call through a function pointer (`ExprCall`) or its target is
+ * a virtual member function, simple data flow analysis is performed in order
+ * to identify the possible target(s).
+ */
+Function resolveCall(Call call) {
+  exists(CallInstruction callInstruction |
+    callInstruction.getAst() = call and
+    result = viableCallable(callInstruction)
+  )
+}

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/TaintTracking.qll

@@ -15,14 +15,9 @@
  * `TaintTracking::localTaintStep` with arguments of type `DataFlow::Node`.
  */
 
-import semmle.code.cpp.dataflow.new.DataFlow
-import semmle.code.cpp.dataflow.new.DataFlow2
+import semmle.code.cpp.ir.dataflow.DataFlow
+import semmle.code.cpp.ir.dataflow.DataFlow2
 
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) taint-tracking analyses.
- */
 module TaintTracking {
-  import semmle.code.cpp.ir.dataflow.internal.tainttracking1.TaintTracking
-  import semmle.code.cpp.ir.dataflow.internal.tainttracking1.TaintTrackingImpl
+  import experimental.semmle.code.cpp.ir.dataflow.internal.tainttracking1.TaintTrackingImpl
 }

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/TaintTracking2.qll

@@ -8,13 +8,8 @@
  * `TaintTracking::Configuration` class extends `DataFlow::Configuration`, and
  * `TaintTracking2::Configuration` extends `DataFlow2::Configuration`.
  *
- * See `semmle.code.cpp.dataflow.new.TaintTracking` for the full documentation.
- */
-
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) taint-tracking analyses.
+ * See `semmle.code.cpp.ir.dataflow.TaintTracking` for the full documentation.
  */
 module TaintTracking2 {
-  import semmle.code.cpp.ir.dataflow.internal.tainttracking2.TaintTrackingImpl
+  import experimental.semmle.code.cpp.ir.dataflow.internal.tainttracking2.TaintTrackingImpl
 }

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/TaintTracking3.qll

@@ -8,13 +8,8 @@
  * `TaintTracking::Configuration` class extends `DataFlow::Configuration`, and
  * `TaintTracking2::Configuration` extends `DataFlow2::Configuration`.
  *
- * See `semmle.code.cpp.dataflow.new.TaintTracking` for the full documentation.
- */
-
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) taint-tracking analyses.
+ * See `semmle.code.cpp.ir.dataflow.TaintTracking` for the full documentation.
  */
 module TaintTracking3 {
-  import semmle.code.cpp.ir.dataflow.internal.tainttracking3.TaintTrackingImpl
+  import experimental.semmle.code.cpp.ir.dataflow.internal.tainttracking3.TaintTrackingImpl
 }

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

@@ -0,0 +1,273 @@
+private import cpp
+private import semmle.code.cpp.ir.IR
+private import experimental.semmle.code.cpp.ir.dataflow.DataFlow
+private import experimental.semmle.code.cpp.ir.dataflow.internal.DataFlowPrivate
+private import experimental.semmle.code.cpp.ir.dataflow.internal.DataFlowUtil
+private import DataFlowImplCommon as DataFlowImplCommon
+
+/**
+ * Gets a function that might be called by `call`.
+ */
+cached
+Function viableCallable(CallInstruction call) {
+  DataFlowImplCommon::forceCachingInSameStage() and
+  result = call.getStaticCallTarget()
+  or
+  // If the target of the call does not have a body in the snapshot, it might
+  // be because the target is just a header declaration, and the real target
+  // will be determined at run time when the caller and callee are linked
+  // together by the operating system's dynamic linker. In case a _unique_
+  // function with the right signature is present in the database, we return
+  // that as a potential callee.
+  exists(string qualifiedName, int nparams |
+    callSignatureWithoutBody(qualifiedName, nparams, call) and
+    functionSignatureWithBody(qualifiedName, nparams, result) and
+    strictcount(Function other | functionSignatureWithBody(qualifiedName, nparams, other)) = 1
+  )
+  or
+  // Virtual dispatch
+  result = call.(VirtualDispatch::DataSensitiveCall).resolve()
+}
+
+/**
+ * Provides virtual dispatch support compatible with the original
+ * implementation of `semmle.code.cpp.security.TaintTracking`.
+ */
+private module VirtualDispatch {
+  /** A call that may dispatch differently depending on the qualifier value. */
+  abstract class DataSensitiveCall extends DataFlowCall {
+    /**
+     * Gets the node whose value determines the target of this call. This node
+     * could be the qualifier of a virtual dispatch or the function-pointer
+     * expression in a call to a function pointer. What they have in common is
+     * that we need to find out which data flows there, and then it's up to the
+     * `resolve` predicate to stitch that information together and resolve the
+     * call.
+     */
+    abstract DataFlow::Node getDispatchValue();
+
+    /** Gets a candidate target for this call. */
+    abstract Function resolve();
+
+    /**
+     * Whether `src` can flow to this call.
+     *
+     * Searches backwards from `getDispatchValue()` to `src`. The `allowFromArg`
+     * parameter is true when the search is allowed to continue backwards into
+     * a parameter; non-recursive callers should pass `_` for `allowFromArg`.
+     */
+    predicate flowsFrom(DataFlow::Node src, boolean allowFromArg) {
+      src = this.getDispatchValue() and allowFromArg = true
+      or
+      exists(DataFlow::Node other, boolean allowOtherFromArg |
+        this.flowsFrom(other, allowOtherFromArg)
+      |
+        // Call argument
+        exists(DataFlowCall call, Position i |
+          other
+              .(DataFlow::ParameterNode)
+              .isParameterOf(pragma[only_bind_into](call).getStaticCallTarget(), i) and
+          src.(ArgumentNode).argumentOf(call, pragma[only_bind_into](pragma[only_bind_out](i)))
+        ) and
+        allowOtherFromArg = true and
+        allowFromArg = true
+        or
+        // Call return
+        exists(DataFlowCall call, ReturnKind returnKind |
+          other = getAnOutNode(call, returnKind) and
+          returnNodeWithKindAndEnclosingCallable(src, returnKind, call.getStaticCallTarget())
+        ) and
+        allowFromArg = false
+        or
+        // Local flow
+        DataFlow::localFlowStep(src, other) and
+        allowFromArg = allowOtherFromArg
+        or
+        // Flow from global variable to load.
+        exists(LoadInstruction load, GlobalOrNamespaceVariable var |
+          var = src.asVariable() and
+          other.asInstruction() = load and
+          addressOfGlobal(load.getSourceAddress(), var) and
+          // The `allowFromArg` concept doesn't play a role when `src` is a
+          // global variable, so we just set it to a single arbitrary value for
+          // performance.
+          allowFromArg = true
+        )
+        or
+        // Flow from store to global variable.
+        exists(StoreInstruction store, GlobalOrNamespaceVariable var |
+          var = other.asVariable() and
+          store = src.asInstruction() and
+          storeIntoGlobal(store, var) and
+          // Setting `allowFromArg` to `true` like in the base case means we
+          // treat a store to a global variable like the dispatch itself: flow
+          // may come from anywhere.
+          allowFromArg = true
+        )
+      )
+    }
+  }
+
+  pragma[noinline]
+  private predicate storeIntoGlobal(StoreInstruction store, GlobalOrNamespaceVariable var) {
+    addressOfGlobal(store.getDestinationAddress(), var)
+  }
+
+  /** Holds if `addressInstr` is an instruction that produces the address of `var`. */
+  private predicate addressOfGlobal(Instruction addressInstr, GlobalOrNamespaceVariable var) {
+    // Access directly to the global variable
+    addressInstr.(VariableAddressInstruction).getAstVariable() = var
+    or
+    // Access to a field on a global union
+    exists(FieldAddressInstruction fa |
+      fa = addressInstr and
+      fa.getObjectAddress().(VariableAddressInstruction).getAstVariable() = var and
+      fa.getField().getDeclaringType() instanceof Union
+    )
+  }
+
+  /**
+   * A ReturnNode with its ReturnKind and its enclosing callable.
+   *
+   * Used to fix a join ordering issue in flowsFrom.
+   */
+  pragma[noinline]
+  private predicate returnNodeWithKindAndEnclosingCallable(
+    ReturnNode node, ReturnKind kind, DataFlowCallable callable
+  ) {
+    node.getKind() = kind and
+    node.getEnclosingCallable() = callable
+  }
+
+  /** Call through a function pointer. */
+  private class DataSensitiveExprCall extends DataSensitiveCall {
+    DataSensitiveExprCall() { not exists(this.getStaticCallTarget()) }
+
+    override DataFlow::Node getDispatchValue() { result.asInstruction() = this.getCallTarget() }
+
+    override Function resolve() {
+      exists(FunctionInstruction fi |
+        this.flowsFrom(DataFlow::instructionNode(fi), _) and
+        result = fi.getFunctionSymbol()
+      ) and
+      (
+        this.getNumberOfArguments() <= result.getEffectiveNumberOfParameters() and
+        this.getNumberOfArguments() >= result.getEffectiveNumberOfParameters()
+        or
+        result.isVarargs()
+      )
+    }
+  }
+
+  /** Call to a virtual function. */
+  private class DataSensitiveOverriddenFunctionCall extends DataSensitiveCall {
+    DataSensitiveOverriddenFunctionCall() {
+      exists(this.getStaticCallTarget().(VirtualFunction).getAnOverridingFunction())
+    }
+
+    override DataFlow::Node getDispatchValue() { result.asInstruction() = this.getThisArgument() }
+
+    override MemberFunction resolve() {
+      exists(Class overridingClass |
+        this.overrideMayAffectCall(overridingClass, result) and
+        this.hasFlowFromCastFrom(overridingClass)
+      )
+    }
+
+    /**
+     * Holds if `this` is a virtual function call whose static target is
+     * overridden by `overridingFunction` in `overridingClass`.
+     */
+    pragma[noinline]
+    private predicate overrideMayAffectCall(Class overridingClass, MemberFunction overridingFunction) {
+      overridingFunction.getAnOverriddenFunction+() = this.getStaticCallTarget().(VirtualFunction) and
+      overridingFunction.getDeclaringType() = overridingClass
+    }
+
+    /**
+     * Holds if the qualifier of `this` has flow from an upcast from
+     * `derivedClass`.
+     */
+    pragma[noinline]
+    private predicate hasFlowFromCastFrom(Class derivedClass) {
+      exists(ConvertToBaseInstruction toBase |
+        this.flowsFrom(DataFlow::instructionNode(toBase), _) and
+        derivedClass = toBase.getDerivedClass()
+      )
+    }
+  }
+}
+
+/**
+ * Holds if `f` is a function with a body that has name `qualifiedName` and
+ * `nparams` parameter count. See `functionSignature`.
+ */
+private predicate functionSignatureWithBody(string qualifiedName, int nparams, Function f) {
+  functionSignature(f, qualifiedName, nparams) and
+  exists(f.getBlock())
+}
+
+/**
+ * Holds if the target of `call` is a function _with no definition_ that has
+ * name `qualifiedName` and `nparams` parameter count. See `functionSignature`.
+ */
+pragma[noinline]
+private predicate callSignatureWithoutBody(string qualifiedName, int nparams, CallInstruction call) {
+  exists(Function target |
+    target = call.getStaticCallTarget() and
+    not exists(target.getBlock()) and
+    functionSignature(target, qualifiedName, nparams)
+  )
+}
+
+/**
+ * Holds if `f` has name `qualifiedName` and `nparams` parameter count. This is
+ * an approximation of its signature for the purpose of matching functions that
+ * might be the same across link targets.
+ */
+private predicate functionSignature(Function f, string qualifiedName, int nparams) {
+  qualifiedName = f.getQualifiedName() and
+  nparams = f.getNumberOfParameters() and
+  not f.isStatic()
+}
+
+/**
+ * Holds if the set of viable implementations that can be called by `call`
+ * might be improved by knowing the call context.
+ */
+predicate mayBenefitFromCallContext(CallInstruction call, Function f) {
+  mayBenefitFromCallContext(call, f, _)
+}
+
+/**
+ * Holds if `call` is a call through a function pointer, and the pointer
+ * value is given as the `arg`'th argument to `f`.
+ */
+private predicate mayBenefitFromCallContext(
+  VirtualDispatch::DataSensitiveCall call, Function f, int arg
+) {
+  f = pragma[only_bind_out](call).getEnclosingCallable() and
+  exists(InitializeParameterInstruction init |
+    not exists(call.getStaticCallTarget()) and
+    init.getEnclosingFunction() = f and
+    call.flowsFrom(DataFlow::instructionNode(init), _) and
+    init.getParameter().getIndex() = arg
+  )
+}
+
+/**
+ * Gets a viable dispatch target of `call` in the context `ctx`. This is
+ * restricted to those `call`s for which a context might make a difference.
+ */
+Function viableImplInCallContext(CallInstruction call, CallInstruction ctx) {
+  result = viableCallable(call) and
+  exists(int i, Function f |
+    mayBenefitFromCallContext(pragma[only_bind_into](call), f, i) and
+    f = ctx.getStaticCallTarget() and
+    result = ctx.getArgument(i).getUnconvertedResultExpression().(FunctionAccess).getTarget()
+  )
+}
+
+/** Holds if arguments at position `apos` match parameters at position `ppos`. */
+pragma[inline]
+predicate parameterMatch(ParameterPosition ppos, ArgumentPosition apos) { ppos = apos }

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

@@ -0,0 +1,266 @@
+/**
+ * Provides consistency queries for checking invariants in the language-specific
+ * data-flow classes and predicates.
+ */
+
+private import DataFlowImplSpecific::Private
+private import DataFlowImplSpecific::Public
+private import tainttracking1.TaintTrackingParameter::Private
+private import tainttracking1.TaintTrackingParameter::Public
+
+module Consistency {
+  private newtype TConsistencyConfiguration = MkConsistencyConfiguration()
+
+  /** A class for configuring the consistency queries. */
+  class ConsistencyConfiguration extends TConsistencyConfiguration {
+    string toString() { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `uniqueEnclosingCallable`. */
+    predicate uniqueEnclosingCallableExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `uniqueNodeLocation`. */
+    predicate uniqueNodeLocationExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `missingLocation`. */
+    predicate missingLocationExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `postWithInFlow`. */
+    predicate postWithInFlowExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `argHasPostUpdate`. */
+    predicate argHasPostUpdateExclude(ArgumentNode n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `reverseRead`. */
+    predicate reverseReadExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `postHasUniquePre`. */
+    predicate postHasUniquePreExclude(PostUpdateNode n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `uniquePostUpdate`. */
+    predicate uniquePostUpdateExclude(Node n) { none() }
+
+    /** Holds if `(call, ctx)` should be excluded from the consistency test `viableImplInCallContextTooLargeExclude`. */
+    predicate viableImplInCallContextTooLargeExclude(
+      DataFlowCall call, DataFlowCall ctx, DataFlowCallable callable
+    ) {
+      none()
+    }
+  }
+
+  private class RelevantNode extends Node {
+    RelevantNode() {
+      this instanceof ArgumentNode or
+      this instanceof ParameterNode or
+      this instanceof ReturnNode or
+      this = getAnOutNode(_, _) or
+      simpleLocalFlowStep(this, _) or
+      simpleLocalFlowStep(_, this) or
+      jumpStep(this, _) or
+      jumpStep(_, this) or
+      storeStep(this, _, _) or
+      storeStep(_, _, this) or
+      readStep(this, _, _) or
+      readStep(_, _, this) or
+      defaultAdditionalTaintStep(this, _) or
+      defaultAdditionalTaintStep(_, this)
+    }
+  }
+
+  query predicate uniqueEnclosingCallable(Node n, string msg) {
+    exists(int c |
+      n instanceof RelevantNode and
+      c = count(nodeGetEnclosingCallable(n)) and
+      c != 1 and
+      not any(ConsistencyConfiguration conf).uniqueEnclosingCallableExclude(n) and
+      msg = "Node should have one enclosing callable but has " + c + "."
+    )
+  }
+
+  query predicate uniqueType(Node n, string msg) {
+    exists(int c |
+      n instanceof RelevantNode and
+      c = count(getNodeType(n)) and
+      c != 1 and
+      msg = "Node should have one type but has " + c + "."
+    )
+  }
+
+  query predicate uniqueNodeLocation(Node n, string msg) {
+    exists(int c |
+      c =
+        count(string filepath, int startline, int startcolumn, int endline, int endcolumn |
+          n.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+        ) and
+      c != 1 and
+      not any(ConsistencyConfiguration conf).uniqueNodeLocationExclude(n) and
+      msg = "Node should have one location but has " + c + "."
+    )
+  }
+
+  query predicate missingLocation(string msg) {
+    exists(int c |
+      c =
+        strictcount(Node n |
+          not n.hasLocationInfo(_, _, _, _, _) and
+          not any(ConsistencyConfiguration conf).missingLocationExclude(n)
+        ) and
+      msg = "Nodes without location: " + c
+    )
+  }
+
+  query predicate uniqueNodeToString(Node n, string msg) {
+    exists(int c |
+      c = count(n.toString()) and
+      c != 1 and
+      msg = "Node should have one toString but has " + c + "."
+    )
+  }
+
+  query predicate missingToString(string msg) {
+    exists(int c |
+      c = strictcount(Node n | not exists(n.toString())) and
+      msg = "Nodes without toString: " + c
+    )
+  }
+
+  query predicate parameterCallable(ParameterNode p, string msg) {
+    exists(DataFlowCallable c | isParameterNode(p, c, _) and c != nodeGetEnclosingCallable(p)) and
+    msg = "Callable mismatch for parameter."
+  }
+
+  query predicate localFlowIsLocal(Node n1, Node n2, string msg) {
+    simpleLocalFlowStep(n1, n2) and
+    nodeGetEnclosingCallable(n1) != nodeGetEnclosingCallable(n2) and
+    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) {
+    t = typeRepr() and
+    not compatibleTypes(t, t) and
+    msg = "Type compatibility predicate is not reflexive."
+  }
+
+  query predicate unreachableNodeCCtx(Node n, DataFlowCall call, string msg) {
+    isUnreachableInCall(n, call) and
+    exists(DataFlowCallable c |
+      c = nodeGetEnclosingCallable(n) and
+      not viableCallable(call) = c
+    ) and
+    msg = "Call context for isUnreachableInCall is inconsistent with call graph."
+  }
+
+  query predicate localCallNodes(DataFlowCall call, Node n, string msg) {
+    (
+      n = getAnOutNode(call, _) and
+      msg = "OutNode and call does not share enclosing callable."
+      or
+      n.(ArgumentNode).argumentOf(call, _) and
+      msg = "ArgumentNode and call does not share enclosing callable."
+    ) and
+    nodeGetEnclosingCallable(n) != call.getEnclosingCallable()
+  }
+
+  // This predicate helps the compiler forget that in some languages
+  // it is impossible for a result of `getPreUpdateNode` to be an
+  // instance of `PostUpdateNode`.
+  private Node getPre(PostUpdateNode n) {
+    result = n.getPreUpdateNode()
+    or
+    none()
+  }
+
+  query predicate postIsNotPre(PostUpdateNode n, string msg) {
+    getPre(n) = n and
+    msg = "PostUpdateNode should not equal its pre-update node."
+  }
+
+  query predicate postHasUniquePre(PostUpdateNode n, string msg) {
+    not any(ConsistencyConfiguration conf).postHasUniquePreExclude(n) and
+    exists(int c |
+      c = count(n.getPreUpdateNode()) and
+      c != 1 and
+      msg = "PostUpdateNode should have one pre-update node but has " + c + "."
+    )
+  }
+
+  query predicate uniquePostUpdate(Node n, string msg) {
+    not any(ConsistencyConfiguration conf).uniquePostUpdateExclude(n) and
+    1 < strictcount(PostUpdateNode post | post.getPreUpdateNode() = n) and
+    msg = "Node has multiple PostUpdateNodes."
+  }
+
+  query predicate postIsInSameCallable(PostUpdateNode n, string msg) {
+    nodeGetEnclosingCallable(n) != nodeGetEnclosingCallable(n.getPreUpdateNode()) and
+    msg = "PostUpdateNode does not share callable with its pre-update node."
+  }
+
+  private predicate hasPost(Node n) { exists(PostUpdateNode post | post.getPreUpdateNode() = n) }
+
+  query predicate reverseRead(Node n, string msg) {
+    exists(Node n2 | readStep(n, _, n2) and hasPost(n2) and not hasPost(n)) and
+    not any(ConsistencyConfiguration conf).reverseReadExclude(n) and
+    msg = "Origin of readStep is missing a PostUpdateNode."
+  }
+
+  query predicate argHasPostUpdate(ArgumentNode n, string msg) {
+    not hasPost(n) and
+    not any(ConsistencyConfiguration c).argHasPostUpdateExclude(n) and
+    msg = "ArgumentNode is missing PostUpdateNode."
+  }
+
+  // This predicate helps the compiler forget that in some languages
+  // it is impossible for a `PostUpdateNode` to be the target of
+  // `simpleLocalFlowStep`.
+  private predicate isPostUpdateNode(Node n) { n instanceof PostUpdateNode or none() }
+
+  query predicate postWithInFlow(Node n, string msg) {
+    isPostUpdateNode(n) and
+    not clearsContent(n, _) and
+    simpleLocalFlowStep(_, n) and
+    not any(ConsistencyConfiguration c).postWithInFlowExclude(n) and
+    msg = "PostUpdateNode should not be the target of local flow."
+  }
+
+  query predicate viableImplInCallContextTooLarge(
+    DataFlowCall call, DataFlowCall ctx, DataFlowCallable callable
+  ) {
+    callable = viableImplInCallContext(call, ctx) and
+    not callable = viableCallable(call) and
+    not any(ConsistencyConfiguration c).viableImplInCallContextTooLargeExclude(call, ctx, callable)
+  }
+
+  query predicate uniqueParameterNodeAtPosition(
+    DataFlowCallable c, ParameterPosition pos, Node p, string msg
+  ) {
+    isParameterNode(p, c, pos) and
+    not exists(unique(Node p0 | isParameterNode(p0, c, pos))) and
+    msg = "Parameters with overlapping positions."
+  }
+
+  query predicate uniqueParameterNodePosition(
+    DataFlowCallable c, ParameterPosition pos, Node p, string msg
+  ) {
+    isParameterNode(p, c, pos) and
+    not exists(unique(ParameterPosition pos0 | isParameterNode(p, c, pos0))) and
+    msg = "Parameter node with multiple positions."
+  }
+
+  query predicate uniqueContentApprox(Content c, string msg) {
+    not exists(unique(ContentApprox approx | approx = getContentApprox(c))) and
+    msg = "Non-unique content approximation."
+  }
+}

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

@@ -0,0 +1,11 @@
+/**
+ * Provides IR-specific definitions for use in the data flow library.
+ */
+module Private {
+  import DataFlowPrivate
+  import DataFlowDispatch
+}
+
+module Public {
+  import DataFlowUtil
+}

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

@@ -0,0 +1,567 @@
+private import cpp as Cpp
+private import DataFlowUtil
+private import semmle.code.cpp.ir.IR
+private import DataFlowDispatch
+private import DataFlowImplConsistency
+private import semmle.code.cpp.ir.internal.IRCppLanguage
+private import SsaInternals as Ssa
+
+/** Gets the callable in which this node occurs. */
+DataFlowCallable nodeGetEnclosingCallable(Node n) { result = n.getEnclosingCallable() }
+
+/** Holds if `p` is a `ParameterNode` of `c` with position `pos`. */
+predicate isParameterNode(ParameterNode p, DataFlowCallable c, ParameterPosition pos) {
+  p.isParameterOf(c, pos)
+}
+
+/** Holds if `arg` is an `ArgumentNode` of `c` with position `pos`. */
+predicate isArgumentNode(ArgumentNode arg, DataFlowCall c, ArgumentPosition pos) {
+  arg.argumentOf(c, pos)
+}
+
+/**
+ * A data flow node that occurs as the argument of a call and is passed as-is
+ * to the callable. Instance arguments (`this` pointer) and read side effects
+ * on parameters are also included.
+ */
+abstract class ArgumentNode extends Node {
+  /**
+   * Holds if this argument occurs at the given position in the given call.
+   * The instance argument is considered to have index `-1`.
+   */
+  abstract predicate argumentOf(DataFlowCall call, ArgumentPosition pos);
+
+  /** Gets the call in which this node is an argument. */
+  DataFlowCall getCall() { this.argumentOf(result, _) }
+}
+
+/**
+ * A data flow node that occurs as the argument to a call, or an
+ * implicit `this` pointer argument.
+ */
+private class PrimaryArgumentNode extends ArgumentNode, OperandNode {
+  override ArgumentOperand op;
+
+  PrimaryArgumentNode() { exists(CallInstruction call | op = call.getAnArgumentOperand()) }
+
+  override predicate argumentOf(DataFlowCall call, ArgumentPosition pos) {
+    op = call.getArgumentOperand(pos.(DirectPosition).getIndex())
+  }
+
+  override string toStringImpl() { result = argumentOperandToString(op) }
+}
+
+private string argumentOperandToString(ArgumentOperand op) {
+  exists(Expr unconverted |
+    unconverted = op.getDef().getUnconvertedResultExpression() and
+    result = unconverted.toString()
+  )
+  or
+  // Certain instructions don't map to an unconverted result expression. For these cases
+  // we fall back to a simpler naming scheme. This can happen in IR-generated constructors.
+  not exists(op.getDef().getUnconvertedResultExpression()) and
+  (
+    result = "Argument " + op.(PositionalArgumentOperand).getIndex()
+    or
+    op instanceof ThisArgumentOperand and result = "Argument this"
+  )
+}
+
+private class SideEffectArgumentNode extends ArgumentNode, SideEffectOperandNode {
+  override predicate argumentOf(DataFlowCall dfCall, ArgumentPosition pos) {
+    this.getCallInstruction() = dfCall and
+    pos.(IndirectionPosition).getArgumentIndex() = this.getArgumentIndex() and
+    pos.(IndirectionPosition).getIndirectionIndex() = super.getIndirectionIndex()
+  }
+
+  override string toStringImpl() {
+    result = argumentOperandToString(this.getAddressOperand()) + " indirection"
+  }
+}
+
+/** A parameter position represented by an integer. */
+class ParameterPosition = Position;
+
+/** An argument position represented by an integer. */
+class ArgumentPosition = Position;
+
+class Position extends TPosition {
+  abstract string toString();
+}
+
+class DirectPosition extends Position, TDirectPosition {
+  int index;
+
+  DirectPosition() { this = TDirectPosition(index) }
+
+  override string toString() { if index = -1 then result = "this" else result = index.toString() }
+
+  int getIndex() { result = index }
+}
+
+class IndirectionPosition extends Position, TIndirectionPosition {
+  int argumentIndex;
+  int indirectionIndex;
+
+  IndirectionPosition() { this = TIndirectionPosition(argumentIndex, indirectionIndex) }
+
+  override string toString() {
+    if argumentIndex = -1
+    then if indirectionIndex > 0 then result = "this indirection" else result = "this"
+    else
+      if indirectionIndex > 0
+      then result = argumentIndex.toString() + " indirection"
+      else result = argumentIndex.toString()
+  }
+
+  int getArgumentIndex() { result = argumentIndex }
+
+  int getIndirectionIndex() { result = indirectionIndex }
+}
+
+newtype TPosition =
+  TDirectPosition(int index) { exists(any(CallInstruction c).getArgument(index)) } or
+  TIndirectionPosition(int argumentIndex, int indirectionIndex) {
+    hasOperandAndIndex(_, any(CallInstruction call).getArgumentOperand(argumentIndex),
+      indirectionIndex)
+  }
+
+private newtype TReturnKind =
+  TNormalReturnKind(int index) {
+    exists(IndirectReturnNode return |
+      return.getAddressOperand() = any(ReturnValueInstruction r).getReturnAddressOperand() and
+      index = return.getIndirectionIndex() - 1 // We subtract one because the return loads the value.
+    )
+  } or
+  TIndirectReturnKind(int argumentIndex, int indirectionIndex) {
+    exists(IndirectReturnNode return, ReturnIndirectionInstruction returnInd |
+      returnInd.hasIndex(argumentIndex) and
+      return.getAddressOperand() = returnInd.getSourceAddressOperand() and
+      indirectionIndex = return.getIndirectionIndex()
+    )
+  }
+
+/**
+ * A return kind. A return kind describes how a value can be returned
+ * from a callable. For C++, this is simply a function return.
+ */
+class ReturnKind extends TReturnKind {
+  /** Gets a textual representation of this return kind. */
+  abstract string toString();
+}
+
+private class NormalReturnKind extends ReturnKind, TNormalReturnKind {
+  int index;
+
+  NormalReturnKind() { this = TNormalReturnKind(index) }
+
+  override string toString() { result = "indirect return" }
+}
+
+private class IndirectReturnKind extends ReturnKind, TIndirectReturnKind {
+  int argumentIndex;
+  int indirectionIndex;
+
+  IndirectReturnKind() { this = TIndirectReturnKind(argumentIndex, indirectionIndex) }
+
+  override string toString() { result = "indirect outparam[" + argumentIndex.toString() + "]" }
+}
+
+/** A data flow node that occurs as the result of a `ReturnStmt`. */
+class ReturnNode extends Node instanceof IndirectReturnNode {
+  /** Gets the kind of this returned value. */
+  abstract ReturnKind getKind();
+}
+
+/**
+ * This predicate represents an annoying hack that we have to do. We use the
+ * `ReturnIndirectionInstruction` to determine which variables need flow back
+ * out of a function. However, the IR will unconditionally create those for a
+ * variable passed to a function even though the variable was never updated by
+ * the function. And if a function has too many `ReturnNode`s the dataflow
+ * library lowers its precision for that function by disabling field flow.
+ *
+ * So we those eliminate `ReturnNode`s that would have otherwise been created
+ * by this unconditional `ReturnIndirectionInstruction` by requiring that there
+ * must exist an SSA definition of the IR variable in the function.
+ */
+private predicate hasNonInitializeParameterDef(IRVariable v) {
+  exists(Ssa::Def def |
+    not def.getDefiningInstruction() instanceof InitializeParameterInstruction and
+    v = def.getSourceVariable().getBaseVariable().(Ssa::BaseIRVariable).getIRVariable()
+  )
+}
+
+class ReturnIndirectionNode extends IndirectReturnNode, ReturnNode {
+  override ReturnKind getKind() {
+    exists(int argumentIndex, ReturnIndirectionInstruction returnInd |
+      returnInd.hasIndex(argumentIndex) and
+      this.getAddressOperand() = returnInd.getSourceAddressOperand() and
+      result = TIndirectReturnKind(argumentIndex, this.getIndirectionIndex()) and
+      hasNonInitializeParameterDef(returnInd.getIRVariable())
+    )
+    or
+    this.getAddressOperand() = any(ReturnValueInstruction r).getReturnAddressOperand() and
+    result = TNormalReturnKind(this.getIndirectionIndex() - 1)
+  }
+}
+
+private Operand fullyConvertedCallStep(Operand op) {
+  not exists(getANonConversionUse(op)) and
+  exists(Instruction instr |
+    conversionFlow(op, instr, _) and
+    result = getAUse(instr)
+  )
+}
+
+/**
+ * Gets the instruction that uses this operand, if the instruction is not
+ * ignored for dataflow purposes.
+ */
+private Instruction getUse(Operand op) {
+  result = op.getUse() and
+  not Ssa::ignoreOperand(op)
+}
+
+/** Gets a use of the instruction `instr` that is not ignored for dataflow purposes. */
+Operand getAUse(Instruction instr) {
+  result = instr.getAUse() and
+  not Ssa::ignoreOperand(result)
+}
+
+/**
+ * Gets a use of `operand` that is:
+ * - not ignored for dataflow purposes, and
+ * - not a conversion-like instruction.
+ */
+private Instruction getANonConversionUse(Operand operand) {
+  result = getUse(operand) and
+  not conversionFlow(_, result, _)
+}
+
+/**
+ * Gets the operand that represents the first use of the value of `call` following
+ * a sequence of conversion-like instructions.
+ */
+predicate operandForfullyConvertedCall(Operand operand, CallInstruction call) {
+  exists(getANonConversionUse(operand)) and
+  (
+    operand = getAUse(call)
+    or
+    operand = fullyConvertedCallStep*(getAUse(call))
+  )
+}
+
+/**
+ * Gets the instruction that represents the first use of the value of `call` following
+ * a sequence of conversion-like instructions.
+ *
+ * This predicate only holds if there is no suitable operand (i.e., no operand of a non-
+ * conversion instruction) to use to represent the value of `call` after conversions.
+ */
+predicate instructionForfullyConvertedCall(Instruction instr, CallInstruction call) {
+  not operandForfullyConvertedCall(_, call) and
+  (
+    // If there is no use of the call then we pick the call instruction
+    not exists(getAUse(call)) and
+    instr = call
+    or
+    // Otherwise, flow to the first non-conversion use.
+    exists(Operand operand | operand = fullyConvertedCallStep*(getAUse(call)) |
+      instr = getANonConversionUse(operand)
+    )
+  )
+}
+
+/** Holds if `node` represents the output node for `call`. */
+private predicate simpleOutNode(Node node, CallInstruction call) {
+  operandForfullyConvertedCall(node.asOperand(), call)
+  or
+  instructionForfullyConvertedCall(node.asInstruction(), call)
+}
+
+/** A data flow node that represents the output of a call. */
+class OutNode extends Node {
+  OutNode() {
+    // Return values not hidden behind indirections
+    simpleOutNode(this, _)
+    or
+    // Return values hidden behind indirections
+    this instanceof IndirectReturnOutNode
+    or
+    // Modified arguments hidden behind indirections
+    this instanceof IndirectArgumentOutNode
+  }
+
+  /** Gets the underlying call. */
+  abstract DataFlowCall getCall();
+
+  abstract ReturnKind getReturnKind();
+}
+
+private class DirectCallOutNode extends OutNode {
+  CallInstruction call;
+
+  DirectCallOutNode() { simpleOutNode(this, call) }
+
+  override DataFlowCall getCall() { result = call }
+
+  override ReturnKind getReturnKind() { result = TNormalReturnKind(0) }
+}
+
+private class IndirectCallOutNode extends OutNode, IndirectReturnOutNode {
+  override DataFlowCall getCall() { result = this.getCallInstruction() }
+
+  override ReturnKind getReturnKind() { result = TNormalReturnKind(this.getIndirectionIndex()) }
+}
+
+private class SideEffectOutNode extends OutNode, IndirectArgumentOutNode {
+  override DataFlowCall getCall() { result = this.getCallInstruction() }
+
+  override ReturnKind getReturnKind() {
+    result = TIndirectReturnKind(this.getArgumentIndex(), this.getIndirectionIndex())
+  }
+}
+
+/**
+ * Gets a node that can read the value returned from `call` with return kind
+ * `kind`.
+ */
+OutNode getAnOutNode(DataFlowCall call, ReturnKind kind) {
+  result.getCall() = call and
+  result.getReturnKind() = kind
+}
+
+/**
+ * Holds if data can flow from `node1` to `node2` in a way that loses the
+ * calling context. For example, this would happen with flow through a
+ * global or static variable.
+ */
+predicate jumpStep(Node n1, Node n2) {
+  exists(Cpp::GlobalOrNamespaceVariable v |
+    v =
+      n1.asInstruction()
+          .(StoreInstruction)
+          .getResultAddress()
+          .(VariableAddressInstruction)
+          .getAstVariable() and
+    v = n2.asVariable()
+    or
+    v =
+      n2.asInstruction()
+          .(LoadInstruction)
+          .getSourceAddress()
+          .(VariableAddressInstruction)
+          .getAstVariable() and
+    v = n1.asVariable()
+  )
+}
+
+/**
+ * Holds if data can flow from `node1` to `node2` via an assignment to `f`.
+ * Thus, `node2` references an object with a field `f` that contains the
+ * value of `node1`.
+ */
+predicate storeStep(Node node1, Content c, PostFieldUpdateNode node2) {
+  exists(int indirectionIndex1, int numberOfLoads, StoreInstruction store |
+    nodeHasInstruction(node1, store, pragma[only_bind_into](indirectionIndex1)) and
+    node2.getIndirectionIndex() = 1 and
+    numberOfLoadsFromOperand(node2.getFieldAddress(), store.getDestinationAddressOperand(),
+      numberOfLoads)
+  |
+    exists(FieldContent fc | fc = c |
+      fc.getField() = node2.getUpdatedField() and
+      fc.getIndirectionIndex() = 1 + indirectionIndex1 + numberOfLoads
+    )
+    or
+    exists(UnionContent uc | uc = c |
+      uc.getAField() = node2.getUpdatedField() and
+      uc.getIndirectionIndex() = 1 + indirectionIndex1 + numberOfLoads
+    )
+  )
+}
+
+/**
+ * Holds if `operandFrom` flows to `operandTo` using a sequence of conversion-like
+ * operations and exactly `n` `LoadInstruction` operations.
+ */
+private predicate numberOfLoadsFromOperandRec(Operand operandFrom, Operand operandTo, int ind) {
+  exists(LoadInstruction load | load.getSourceAddressOperand() = operandFrom |
+    operandTo = operandFrom and ind = 0
+    or
+    numberOfLoadsFromOperand(load.getAUse(), operandTo, ind - 1)
+  )
+  or
+  exists(Operand op, Instruction instr |
+    instr = op.getDef() and
+    conversionFlow(operandFrom, instr, _) and
+    numberOfLoadsFromOperand(op, operandTo, ind)
+  )
+}
+
+/**
+ * Holds if `operandFrom` flows to `operandTo` using a sequence of conversion-like
+ * operations and exactly `n` `LoadInstruction` operations.
+ */
+private predicate numberOfLoadsFromOperand(Operand operandFrom, Operand operandTo, int n) {
+  numberOfLoadsFromOperandRec(operandFrom, operandTo, n)
+  or
+  not any(LoadInstruction load).getSourceAddressOperand() = operandFrom and
+  not conversionFlow(operandFrom, _, _) and
+  operandFrom = operandTo and
+  n = 0
+}
+
+// Needed to join on both an operand and an index at the same time.
+pragma[noinline]
+predicate nodeHasOperand(Node node, Operand operand, int indirectionIndex) {
+  node.asOperand() = operand and indirectionIndex = 0
+  or
+  hasOperandAndIndex(node, operand, indirectionIndex)
+}
+
+// Needed to join on both an instruction and an index at the same time.
+pragma[noinline]
+predicate nodeHasInstruction(Node node, Instruction instr, int indirectionIndex) {
+  node.asInstruction() = instr and indirectionIndex = 0
+  or
+  hasInstructionAndIndex(node, instr, indirectionIndex)
+}
+
+/**
+ * Holds if data can flow from `node1` to `node2` via a read of `f`.
+ * Thus, `node1` references an object with a field `f` whose value ends up in
+ * `node2`.
+ */
+predicate readStep(Node node1, Content c, Node node2) {
+  exists(FieldAddress fa1, Operand operand, int numberOfLoads, int indirectionIndex2 |
+    nodeHasOperand(node2, operand, indirectionIndex2) and
+    nodeHasOperand(node1, fa1.getObjectAddressOperand(), _) and
+    numberOfLoadsFromOperand(fa1, operand, numberOfLoads)
+  |
+    exists(FieldContent fc | fc = c |
+      fc.getField() = fa1.getField() and
+      fc.getIndirectionIndex() = indirectionIndex2 + numberOfLoads
+    )
+    or
+    exists(UnionContent uc | uc = c |
+      uc.getAField() = fa1.getField() and
+      uc.getIndirectionIndex() = indirectionIndex2 + numberOfLoads
+    )
+  )
+}
+
+/**
+ * Holds if values stored inside content `c` are cleared at node `n`.
+ */
+predicate clearsContent(Node n, Content c) {
+  none() // stub implementation
+}
+
+/**
+ * Holds if the value that is being tracked is expected to be stored inside content `c`
+ * at node `n`.
+ */
+predicate expectsContent(Node n, ContentSet c) { none() }
+
+/** Gets the type of `n` used for type pruning. */
+DataFlowType getNodeType(Node n) {
+  suppressUnusedNode(n) and
+  result instanceof VoidType // stub implementation
+}
+
+/** Gets a string representation of a type returned by `getNodeType`. */
+string ppReprType(DataFlowType t) { none() } // stub implementation
+
+/**
+ * Holds if `t1` and `t2` are compatible, that is, whether data can flow from
+ * a node of type `t1` to a node of type `t2`.
+ */
+pragma[inline]
+predicate compatibleTypes(DataFlowType t1, DataFlowType t2) {
+  any() // stub implementation
+}
+
+private predicate suppressUnusedNode(Node n) { any() }
+
+//////////////////////////////////////////////////////////////////////////////
+// Java QL library compatibility wrappers
+//////////////////////////////////////////////////////////////////////////////
+/** A node that performs a type cast. */
+class CastNode extends Node {
+  CastNode() { none() } // stub implementation
+}
+
+/**
+ * A function that may contain code or a variable that may contain itself. When
+ * flow crosses from one _enclosing callable_ to another, the interprocedural
+ * data-flow library discards call contexts and inserts a node in the big-step
+ * relation used for human-readable path explanations.
+ */
+class DataFlowCallable = Cpp::Declaration;
+
+class DataFlowExpr = Expr;
+
+class DataFlowType = Type;
+
+/** A function call relevant for data flow. */
+class DataFlowCall extends CallInstruction {
+  Function getEnclosingCallable() { result = this.getEnclosingFunction() }
+}
+
+predicate isUnreachableInCall(Node n, DataFlowCall call) { none() } // stub implementation
+
+int accessPathLimit() { result = 5 }
+
+/**
+ * Holds if access paths with `c` at their head always should be tracked at high
+ * precision. This disables adaptive access path precision for such access paths.
+ */
+predicate forceHighPrecision(Content c) { none() }
+
+/** The unit type. */
+private newtype TUnit = TMkUnit()
+
+/** The trivial type with a single element. */
+class Unit extends TUnit {
+  /** Gets a textual representation of this element. */
+  string toString() { result = "unit" }
+}
+
+/** Holds if `n` should be hidden from path explanations. */
+predicate nodeIsHidden(Node n) { n instanceof OperandNode and not n instanceof ArgumentNode }
+
+class LambdaCallKind = Unit;
+
+/** Holds if `creation` is an expression that creates a lambda of kind `kind` for `c`. */
+predicate lambdaCreation(Node creation, LambdaCallKind kind, DataFlowCallable c) { none() }
+
+/** Holds if `call` is a lambda call of kind `kind` where `receiver` is the lambda expression. */
+predicate lambdaCall(DataFlowCall call, LambdaCallKind kind, Node receiver) { none() }
+
+/** Extra data-flow steps needed for lambda flow analysis. */
+predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preservesValue) { none() }
+
+/**
+ * Holds if flow is allowed to pass from parameter `p` and back to itself as a
+ * side-effect, resulting in a summary from `p` to itself.
+ *
+ * One example would be to allow flow like `p.foo = p.bar;`, which is disallowed
+ * by default as a heuristic.
+ */
+predicate allowParameterReturnInSelf(ParameterNode p) { none() }
+
+/** An approximated `Content`. */
+class ContentApprox = Unit;
+
+/** Gets an approximated value for content `c`. */
+pragma[inline]
+ContentApprox getContentApprox(Content c) { any() }
+
+private class MyConsistencyConfiguration extends Consistency::ConsistencyConfiguration {
+  override predicate argHasPostUpdateExclude(ArgumentNode n) {
+    // The rules for whether an IR argument gets a post-update node are too
+    // complex to model here.
+    any()
+  }
+}

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

@@ -0,0 +1,93 @@
+/**
+ * Provides predicates for mapping the `FunctionInput` and `FunctionOutput`
+ * classes used in function models to the corresponding instructions.
+ */
+
+private import semmle.code.cpp.ir.IR
+private import experimental.semmle.code.cpp.ir.dataflow.DataFlow
+private import experimental.semmle.code.cpp.ir.dataflow.internal.DataFlowUtil
+private import SsaInternals as Ssa
+
+/**
+ * Gets the instruction that goes into `input` for `call`.
+ */
+DataFlow::Node callInput(CallInstruction call, FunctionInput input) {
+  // An argument or qualifier
+  exists(int index |
+    result.asOperand() = call.getArgumentOperand(index) and
+    input.isParameterOrQualifierAddress(index)
+  )
+  or
+  // A value pointed to by an argument or qualifier
+  exists(int index, int indirectionIndex |
+    hasOperandAndIndex(result, call.getArgumentOperand(index), indirectionIndex) and
+    input.isParameterDerefOrQualifierObject(index, indirectionIndex)
+  )
+  or
+  exists(int ind |
+    result = getIndirectReturnOutNode(call, ind) and
+    input.isReturnValueDeref(ind)
+  )
+}
+
+/**
+ * Gets the instruction that holds the `output` for `call`.
+ */
+Node callOutput(CallInstruction call, FunctionOutput output) {
+  // The return value
+  result.asInstruction() = call and
+  output.isReturnValue()
+  or
+  // The side effect of a call on the value pointed to by an argument or qualifier
+  exists(int index, int indirectionIndex |
+    result.(IndirectArgumentOutNode).getArgumentIndex() = index and
+    result.(IndirectArgumentOutNode).getIndirectionIndex() = indirectionIndex and
+    result.(IndirectArgumentOutNode).getCallInstruction() = call and
+    output.isParameterDerefOrQualifierObject(index, indirectionIndex)
+  )
+  or
+  exists(int ind |
+    result = getIndirectReturnOutNode(call, ind) and
+    output.isReturnValueDeref(ind)
+  )
+}
+
+DataFlow::Node callInput(CallInstruction call, FunctionInput input, int d) {
+  exists(DataFlow::Node n | n = callInput(call, input) and d > 0 |
+    // An argument or qualifier
+    hasOperandAndIndex(result, n.asOperand(), d)
+    or
+    exists(Operand operand, int indirectionIndex |
+      // A value pointed to by an argument or qualifier
+      hasOperandAndIndex(n, operand, indirectionIndex) and
+      hasOperandAndIndex(result, operand, indirectionIndex + d)
+    )
+  )
+}
+
+private IndirectReturnOutNode getIndirectReturnOutNode(CallInstruction call, int d) {
+  result.getCallInstruction() = call and
+  result.getIndirectionIndex() = d
+}
+
+/**
+ * Gets the instruction that holds the `output` for `call`.
+ */
+bindingset[d]
+Node callOutput(CallInstruction call, FunctionOutput output, int d) {
+  exists(DataFlow::Node n | n = callOutput(call, output) and d > 0 |
+    // The return value
+    result = getIndirectReturnOutNode(n.asInstruction(), d)
+    or
+    // If there isn't an indirect out node for the call with indirection `d` then
+    // we conflate this with the underlying `CallInstruction`.
+    not exists(getIndirectReturnOutNode(call, d)) and
+    n.asInstruction() = result.asInstruction()
+    or
+    // The side effect of a call on the value pointed to by an argument or qualifier
+    exists(Operand operand, int indirectionIndex |
+      Ssa::outNodeHasAddressAndIndex(n, operand, indirectionIndex) and
+      Ssa::outNodeHasAddressAndIndex(result, operand, indirectionIndex + d)
+    )
+  )
+}

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

@@ -0,0 +1,136 @@
+private import cpp
+// The `ValueNumbering` library has to be imported right after `cpp` to ensure
+// that the cached IR gets the same checksum here as it does in queries that use
+// `ValueNumbering` without `DataFlow`.
+private import semmle.code.cpp.ir.ValueNumbering
+private import semmle.code.cpp.ir.IR
+private import semmle.code.cpp.ir.dataflow.DataFlow
+private import semmle.code.cpp.ir.dataflow.internal.DataFlowUtil
+private import PrintIRUtilities
+
+/**
+ * Gets the local dataflow from other nodes in the same function to this node.
+ */
+private string getFromFlow(DataFlow::Node useNode, int order1, int order2) {
+  exists(DataFlow::Node defNode, string prefix |
+    (
+      simpleLocalFlowStep(defNode, useNode) and prefix = ""
+      or
+      any(DataFlow::Configuration cfg).isAdditionalFlowStep(defNode, useNode) and
+      defNode.getEnclosingCallable() = useNode.getEnclosingCallable() and
+      prefix = "+"
+    ) and
+    if defNode.asInstruction() = useNode.asOperand().getAnyDef()
+    then
+      // Shorthand for flow from the def of this operand.
+      result = prefix + "def" and
+      order1 = -1 and
+      order2 = 0
+    else
+      if defNode.asOperand().getUse() = useNode.asInstruction()
+      then
+        // Shorthand for flow from an operand of this instruction
+        result = prefix + defNode.asOperand().getDumpId() and
+        order1 = -1 and
+        order2 = defNode.asOperand().getDumpSortOrder()
+      else result = prefix + nodeId(defNode, order1, order2)
+  )
+}
+
+/**
+ * Gets the local dataflow from this node to other nodes in the same function.
+ */
+private string getToFlow(DataFlow::Node defNode, int order1, int order2) {
+  exists(DataFlow::Node useNode, string prefix |
+    (
+      simpleLocalFlowStep(defNode, useNode) and prefix = ""
+      or
+      any(DataFlow::Configuration cfg).isAdditionalFlowStep(defNode, useNode) and
+      defNode.getEnclosingCallable() = useNode.getEnclosingCallable() and
+      prefix = "+"
+    ) and
+    if useNode.asInstruction() = defNode.asOperand().getUse()
+    then
+      // Shorthand for flow to this operand's instruction.
+      result = prefix + "result" and
+      order1 = -1 and
+      order2 = 0
+    else result = prefix + nodeId(useNode, order1, order2)
+  )
+}
+
+/**
+ * Gets the properties of the dataflow node `node`.
+ */
+private string getNodeProperty(DataFlow::Node node, string key) {
+  // List dataflow into and out of this node. Flow into this node is printed as `src->@`, and flow
+  // out of this node is printed as `@->dest`.
+  key = "flow" and
+  result =
+    strictconcat(string flow, boolean to, int order1, int order2 |
+      flow = getFromFlow(node, order1, order2) + "->@" and to = false
+      or
+      flow = "@->" + getToFlow(node, order1, order2) and to = true
+    |
+      flow, ", " order by to, order1, order2, flow
+    )
+  or
+  // Is this node a dataflow sink?
+  key = "sink" and
+  any(DataFlow::Configuration cfg).isSink(node) and
+  result = "true"
+  or
+  // Is this node a dataflow source?
+  key = "source" and
+  any(DataFlow::Configuration cfg).isSource(node) and
+  result = "true"
+  or
+  // Is this node a dataflow barrier, and if so, what kind?
+  key = "barrier" and
+  result =
+    strictconcat(string kind |
+      any(DataFlow::Configuration cfg).isBarrier(node) and kind = "full"
+      or
+      any(DataFlow::Configuration cfg).isBarrierIn(node) and kind = "in"
+      or
+      any(DataFlow::Configuration cfg).isBarrierOut(node) and kind = "out"
+    |
+      kind, ", "
+    )
+  or
+  // Is there partial flow from a source to this node?
+  // This property will only be emitted if partial flow is enabled by overriding
+  // `DataFlow::Configuration::explorationLimit()`.
+  key = "pflow" and
+  result =
+    strictconcat(DataFlow::PartialPathNode sourceNode, DataFlow::PartialPathNode destNode, int dist,
+      int order1, int order2 |
+      any(DataFlow::Configuration cfg).hasPartialFlow(sourceNode, destNode, dist) and
+      destNode.getNode() = node and
+      // Only print flow from a source in the same function.
+      sourceNode.getNode().getEnclosingCallable() = node.getEnclosingCallable()
+    |
+      nodeId(sourceNode.getNode(), order1, order2) + "+" + dist.toString(), ", "
+      order by
+        order1, order2, dist desc
+    )
+}
+
+/**
+ * Property provider for local IR dataflow.
+ */
+class LocalFlowPropertyProvider extends IRPropertyProvider {
+  override string getOperandProperty(Operand operand, string key) {
+    exists(DataFlow::Node node |
+      operand = node.asOperand() and
+      result = getNodeProperty(node, key)
+    )
+  }
+
+  override string getInstructionProperty(Instruction instruction, string key) {
+    exists(DataFlow::Node node |
+      instruction = node.asInstruction() and
+      result = getNodeProperty(node, key)
+    )
+  }
+}

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

@@ -0,0 +1,33 @@
+/**
+ * Print the dataflow local store steps in IR dumps.
+ */
+
+private import cpp
+// The `ValueNumbering` library has to be imported right after `cpp` to ensure
+// that the cached IR gets the same checksum here as it does in queries that use
+// `ValueNumbering` without `DataFlow`.
+private import semmle.code.cpp.ir.ValueNumbering
+private import semmle.code.cpp.ir.IR
+private import semmle.code.cpp.ir.dataflow.DataFlow
+private import semmle.code.cpp.ir.dataflow.internal.DataFlowUtil
+private import semmle.code.cpp.ir.dataflow.internal.DataFlowPrivate
+private import PrintIRUtilities
+
+/**
+ * Property provider for local IR dataflow store steps.
+ */
+class LocalFlowPropertyProvider extends IRPropertyProvider {
+  override string getInstructionProperty(Instruction instruction, string key) {
+    exists(DataFlow::Node objectNode, Content content |
+      key = "content[" + content.toString() + "]" and
+      instruction = objectNode.asInstruction() and
+      result =
+        strictconcat(string element, DataFlow::Node fieldNode |
+          storeStep(fieldNode, content, objectNode) and
+          element = nodeId(fieldNode, _, _)
+        |
+          element, ", "
+        )
+    )
+  }
+}

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

@@ -0,0 +1,39 @@
+/**
+ * Shared utilities used when printing dataflow annotations in IR dumps.
+ */
+
+private import cpp
+// The `ValueNumbering` library has to be imported right after `cpp` to ensure
+// that the cached IR gets the same checksum here as it does in queries that use
+// `ValueNumbering` without `DataFlow`.
+private import semmle.code.cpp.ir.ValueNumbering
+private import semmle.code.cpp.ir.IR
+private import semmle.code.cpp.ir.dataflow.DataFlow
+
+/**
+ * Gets a short ID for an IR dataflow node.
+ * - For `Instruction`s, this is just the result ID of the instruction (e.g. `m128`).
+ * - For `Operand`s, this is the label of the operand, prefixed with the result ID of the
+ *   instruction and a dot (e.g. `m128.left`).
+ * - For `Variable`s, this is the qualified name of the variable.
+ */
+string nodeId(DataFlow::Node node, int order1, int order2) {
+  exists(Instruction instruction | instruction = node.asInstruction() |
+    result = instruction.getResultId() and
+    order1 = instruction.getBlock().getDisplayIndex() and
+    order2 = instruction.getDisplayIndexInBlock()
+  )
+  or
+  exists(Operand operand, Instruction instruction |
+    operand = node.asOperand() and
+    instruction = operand.getUse()
+  |
+    result = instruction.getResultId() + "." + operand.getDumpId() and
+    order1 = instruction.getBlock().getDisplayIndex() and
+    order2 = instruction.getDisplayIndexInBlock()
+  )
+  or
+  result = "var(" + node.asVariable().getQualifiedName() + ")" and
+  order1 = 1000000 and
+  order2 = 0
+}

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

@@ -0,0 +1,552 @@
+private import codeql.ssa.Ssa as SsaImplCommon
+private import semmle.code.cpp.ir.IR
+private import DataFlowUtil
+private import DataFlowImplCommon as DataFlowImplCommon
+private import semmle.code.cpp.models.interfaces.Allocation as Alloc
+private import semmle.code.cpp.models.interfaces.DataFlow as DataFlow
+private import semmle.code.cpp.ir.internal.IRCppLanguage
+private import DataFlowPrivate
+private import ssa0.SsaInternals as SsaInternals0
+import SsaInternalsCommon
+
+private module SourceVariables {
+  int getMaxIndirectionForIRVariable(IRVariable var) {
+    exists(Type type, boolean isGLValue |
+      var.getLanguageType().hasType(type, isGLValue) and
+      if isGLValue = true
+      then result = 1 + getMaxIndirectionsForType(type)
+      else result = getMaxIndirectionsForType(type)
+    )
+  }
+
+  class BaseSourceVariable = SsaInternals0::BaseSourceVariable;
+
+  class BaseIRVariable = SsaInternals0::BaseIRVariable;
+
+  class BaseCallVariable = SsaInternals0::BaseCallVariable;
+
+  cached
+  private newtype TSourceVariable =
+    TSourceIRVariable(BaseIRVariable baseVar, int ind) {
+      ind = [0 .. getMaxIndirectionForIRVariable(baseVar.getIRVariable())]
+    } or
+    TCallVariable(AllocationInstruction call, int ind) {
+      ind = [0 .. countIndirectionsForCppType(getResultLanguageType(call))]
+    }
+
+  abstract class SourceVariable extends TSourceVariable {
+    int ind;
+
+    bindingset[ind]
+    SourceVariable() { any() }
+
+    abstract string toString();
+
+    int getIndirection() { result = ind }
+
+    abstract BaseSourceVariable getBaseVariable();
+  }
+
+  class SourceIRVariable extends SourceVariable, TSourceIRVariable {
+    BaseIRVariable var;
+
+    SourceIRVariable() { this = TSourceIRVariable(var, ind) }
+
+    IRVariable getIRVariable() { result = var.getIRVariable() }
+
+    override BaseIRVariable getBaseVariable() { result.getIRVariable() = this.getIRVariable() }
+
+    override string toString() {
+      ind = 0 and
+      result = this.getIRVariable().toString()
+      or
+      ind > 0 and
+      result = this.getIRVariable().toString() + " indirection"
+    }
+  }
+
+  class CallVariable extends SourceVariable, TCallVariable {
+    AllocationInstruction call;
+
+    CallVariable() { this = TCallVariable(call, ind) }
+
+    AllocationInstruction getCall() { result = call }
+
+    override BaseCallVariable getBaseVariable() { result.getCallInstruction() = call }
+
+    override string toString() {
+      ind = 0 and
+      result = "Call"
+      or
+      ind > 0 and
+      result = "Call indirection"
+    }
+  }
+}
+
+import SourceVariables
+
+predicate hasIndirectOperand(Operand op, int indirectionIndex) {
+  exists(CppType type, int m |
+    not ignoreOperand(op) and
+    type = getLanguageType(op) and
+    m = countIndirectionsForCppType(type) and
+    indirectionIndex = [1 .. m]
+  )
+}
+
+predicate hasIndirectInstruction(Instruction instr, int indirectionIndex) {
+  exists(CppType type, int m |
+    not ignoreInstruction(instr) and
+    type = getResultLanguageType(instr) and
+    m = countIndirectionsForCppType(type) and
+    indirectionIndex = [1 .. m]
+  )
+}
+
+cached
+private newtype TDefOrUseImpl =
+  TDefImpl(Operand address, int indirectionIndex) {
+    isDef(_, _, address, _, _, indirectionIndex) and
+    // We only include the definition if the SSA pruning stage
+    // concluded that the definition is live after the write.
+    any(SsaInternals0::Def def).getAddressOperand() = address
+  } or
+  TUseImpl(Operand operand, int indirectionIndex) {
+    isUse(_, operand, _, _, indirectionIndex) and
+    not isDef(_, _, operand, _, _, _)
+  }
+
+abstract private class DefOrUseImpl extends TDefOrUseImpl {
+  /** Gets a textual representation of this element. */
+  abstract string toString();
+
+  /** Gets the block of this definition or use. */
+  abstract IRBlock getBlock();
+
+  /** Holds if this definition or use has index `index` in block `block`. */
+  abstract predicate hasIndexInBlock(IRBlock block, int index);
+
+  final predicate hasIndexInBlock(IRBlock block, int index, SourceVariable sv) {
+    this.hasIndexInBlock(block, index) and
+    sv = this.getSourceVariable()
+  }
+
+  /** Gets the location of this element. */
+  abstract Cpp::Location getLocation();
+
+  /**
+   * Gets the index (i.e., the number of loads required) of this
+   * definition or use.
+   *
+   * Note that this is _not_ the definition's (or use's) index in
+   * the enclosing basic block. To obtain this index, use
+   * `DefOrUseImpl::hasIndexInBlock/2` or `DefOrUseImpl::hasIndexInBlock/3`.
+   */
+  abstract int getIndirectionIndex();
+
+  /**
+   * Gets the instruction that computes the base of this definition or use.
+   * This is always a `VariableAddressInstruction` or an `AllocationInstruction`.
+   */
+  abstract Instruction getBase();
+
+  final BaseSourceVariable getBaseSourceVariable() {
+    exists(IRVariable var |
+      result.(BaseIRVariable).getIRVariable() = var and
+      instructionHasIRVariable(this.getBase(), var)
+    )
+    or
+    result.(BaseCallVariable).getCallInstruction() = this.getBase()
+  }
+
+  /** Gets the variable that is defined or used. */
+  final SourceVariable getSourceVariable() {
+    exists(BaseSourceVariable v, int ind |
+      sourceVariableHasBaseAndIndex(result, v, ind) and
+      defOrUseHasSourceVariable(this, v, ind)
+    )
+  }
+}
+
+pragma[noinline]
+private predicate instructionHasIRVariable(VariableAddressInstruction vai, IRVariable var) {
+  vai.getIRVariable() = var
+}
+
+private predicate defOrUseHasSourceVariable(DefOrUseImpl defOrUse, BaseSourceVariable bv, int ind) {
+  defHasSourceVariable(defOrUse, bv, ind)
+  or
+  useHasSourceVariable(defOrUse, bv, ind)
+}
+
+pragma[noinline]
+private predicate defHasSourceVariable(DefImpl def, BaseSourceVariable bv, int ind) {
+  bv = def.getBaseSourceVariable() and
+  ind = def.getIndirection()
+}
+
+pragma[noinline]
+private predicate useHasSourceVariable(UseImpl use, BaseSourceVariable bv, int ind) {
+  bv = use.getBaseSourceVariable() and
+  ind = use.getIndirection()
+}
+
+pragma[noinline]
+private predicate sourceVariableHasBaseAndIndex(SourceVariable v, BaseSourceVariable bv, int ind) {
+  v.getBaseVariable() = bv and
+  v.getIndirection() = ind
+}
+
+class DefImpl extends DefOrUseImpl, TDefImpl {
+  Operand address;
+  int ind;
+
+  DefImpl() { this = TDefImpl(address, ind) }
+
+  override Instruction getBase() { isDef(_, _, address, result, _, _) }
+
+  Operand getAddressOperand() { result = address }
+
+  int getIndirection() { isDef(_, _, address, _, result, ind) }
+
+  override int getIndirectionIndex() { result = ind }
+
+  Instruction getDefiningInstruction() { isDef(_, result, address, _, _, _) }
+
+  override string toString() { result = "DefImpl" }
+
+  override IRBlock getBlock() { result = this.getDefiningInstruction().getBlock() }
+
+  override Cpp::Location getLocation() { result = this.getDefiningInstruction().getLocation() }
+
+  final override predicate hasIndexInBlock(IRBlock block, int index) {
+    this.getDefiningInstruction() = block.getInstruction(index)
+  }
+
+  predicate isCertain() { isDef(true, _, address, _, _, ind) }
+}
+
+class UseImpl extends DefOrUseImpl, TUseImpl {
+  Operand operand;
+  int ind;
+
+  UseImpl() { this = TUseImpl(operand, ind) }
+
+  Operand getOperand() { result = operand }
+
+  override string toString() { result = "UseImpl" }
+
+  final override predicate hasIndexInBlock(IRBlock block, int index) {
+    operand.getUse() = block.getInstruction(index)
+  }
+
+  final override IRBlock getBlock() { result = operand.getUse().getBlock() }
+
+  final override Cpp::Location getLocation() { result = operand.getLocation() }
+
+  final int getIndirection() { isUse(_, operand, _, result, ind) }
+
+  override int getIndirectionIndex() { result = ind }
+
+  override Instruction getBase() { isUse(_, operand, result, _, ind) }
+
+  predicate isCertain() { isUse(true, operand, _, _, ind) }
+}
+
+/**
+ * Holds if `defOrUse1` is a definition which is first read by `use`,
+ * or if `defOrUse1` is a use and `use` is a next subsequent use.
+ *
+ * In both cases, `use` can either be an explicit use written in the
+ * source file, or it can be a phi node as computed by the SSA library.
+ */
+predicate adjacentDefRead(DefOrUse defOrUse1, UseOrPhi use) {
+  exists(IRBlock bb1, int i1, SourceVariable v |
+    defOrUse1.asDefOrUse().hasIndexInBlock(bb1, i1, v)
+  |
+    exists(IRBlock bb2, int i2 |
+      adjacentDefRead(_, pragma[only_bind_into](bb1), pragma[only_bind_into](i1),
+        pragma[only_bind_into](bb2), pragma[only_bind_into](i2))
+    |
+      use.asDefOrUse().(UseImpl).hasIndexInBlock(bb2, i2, v)
+    )
+    or
+    exists(PhiNode phi |
+      lastRefRedef(_, bb1, i1, phi) and
+      use.asPhi() = phi and
+      phi.getSourceVariable() = pragma[only_bind_into](v)
+    )
+  )
+}
+
+private predicate useToNode(UseOrPhi use, Node nodeTo) {
+  exists(UseImpl useImpl |
+    useImpl = use.asDefOrUse() and
+    nodeHasOperand(nodeTo, useImpl.getOperand(), useImpl.getIndirectionIndex())
+  )
+  or
+  nodeTo.(SsaPhiNode).getPhiNode() = use.asPhi()
+}
+
+pragma[noinline]
+predicate outNodeHasAddressAndIndex(
+  IndirectArgumentOutNode out, Operand address, int indirectionIndex
+) {
+  out.getAddressOperand() = address and
+  out.getIndirectionIndex() = indirectionIndex
+}
+
+private predicate defToNode(Node nodeFrom, Def def) {
+  nodeHasInstruction(nodeFrom, def.getDefiningInstruction(), def.getIndirectionIndex())
+}
+
+/**
+ * INTERNAL: Do not use.
+ *
+ * Holds if `nodeFrom` is the node that correspond to the definition or use `defOrUse`.
+ */
+predicate nodeToDefOrUse(Node nodeFrom, SsaDefOrUse defOrUse) {
+  // Node -> Def
+  defToNode(nodeFrom, defOrUse)
+  or
+  // Node -> Use
+  useToNode(defOrUse, nodeFrom)
+}
+
+/**
+ * Perform a single conversion-like step from `nFrom` to `nTo`. This relation
+ * only holds when there is no use-use relation out of `nTo`.
+ */
+private predicate indirectConversionFlowStep(Node nFrom, Node nTo) {
+  not exists(UseOrPhi defOrUse |
+    nodeToDefOrUse(nTo, defOrUse) and
+    adjacentDefRead(defOrUse, _)
+  ) and
+  exists(Operand op1, Operand op2, int indirectionIndex, Instruction instr |
+    hasOperandAndIndex(nFrom, op1, pragma[only_bind_into](indirectionIndex)) and
+    hasOperandAndIndex(nTo, op2, pragma[only_bind_into](indirectionIndex)) and
+    instr = op2.getDef() and
+    conversionFlow(op1, instr, _)
+  )
+}
+
+/**
+ * The reason for this predicate is a bit annoying:
+ * We cannot mark a `PointerArithmeticInstruction` that computes an offset based on some SSA
+ * variable `x` as a use of `x` since this creates taint-flow in the following example:
+ * ```c
+ * int x = array[source]
+ * sink(*array)
+ * ```
+ * This is because `source` would flow from the operand of `PointerArithmeticInstruction` to the
+ * result of the instruction, and into the `IndirectOperand` that represents the value of `*array`.
+ * Then, via use-use flow, flow will arrive at `*array` in `sink(*array)`.
+ *
+ * So this predicate recurses back along conversions and `PointerArithmeticInstruction`s to find the
+ * first use that has provides use-use flow, and uses that target as the target of the `nodeFrom`.
+ */
+private predicate adjustForPointerArith(Node nodeFrom, UseOrPhi use) {
+  nodeFrom = any(PostUpdateNode pun).getPreUpdateNode() and
+  exists(DefOrUse defOrUse, Node adjusted |
+    indirectConversionFlowStep*(adjusted, nodeFrom) and
+    nodeToDefOrUse(adjusted, defOrUse) and
+    adjacentDefRead(defOrUse, use)
+  )
+}
+
+/** Holds if there is def-use or use-use flow from `nodeFrom` to `nodeTo`. */
+predicate ssaFlow(Node nodeFrom, Node nodeTo) {
+  // `nodeFrom = any(PostUpdateNode pun).getPreUpdateNode()` is implied by adjustedForPointerArith.
+  exists(UseOrPhi use |
+    adjustForPointerArith(nodeFrom, use) and
+    useToNode(use, nodeTo)
+  )
+  or
+  not nodeFrom = any(PostUpdateNode pun).getPreUpdateNode() and
+  exists(DefOrUse defOrUse1, UseOrPhi use |
+    nodeToDefOrUse(nodeFrom, defOrUse1) and
+    adjacentDefRead(defOrUse1, use) and
+    useToNode(use, nodeTo)
+  )
+}
+
+/** Holds if `nodeTo` receives flow from the phi node `nodeFrom`. */
+predicate fromPhiNode(SsaPhiNode nodeFrom, Node nodeTo) {
+  exists(PhiNode phi, SourceVariable sv, IRBlock bb1, int i1, UseOrPhi use |
+    phi = nodeFrom.getPhiNode() and
+    phi.definesAt(sv, bb1, i1) and
+    useToNode(use, nodeTo)
+  |
+    exists(IRBlock bb2, int i2 |
+      use.asDefOrUse().hasIndexInBlock(bb2, i2, sv) and
+      adjacentDefRead(phi, bb1, i1, bb2, i2)
+    )
+    or
+    exists(PhiNode phiTo |
+      lastRefRedef(phi, _, _, phiTo) and
+      nodeTo.(SsaPhiNode).getPhiNode() = phiTo
+    )
+  )
+}
+
+private SsaInternals0::SourceVariable getOldSourceVariable(SourceVariable v) {
+  v.getBaseVariable().(BaseIRVariable).getIRVariable() =
+    result.getBaseVariable().(SsaInternals0::BaseIRVariable).getIRVariable()
+  or
+  v.getBaseVariable().(BaseCallVariable).getCallInstruction() =
+    result.getBaseVariable().(SsaInternals0::BaseCallVariable).getCallInstruction()
+}
+
+/**
+ * Holds if there is a write at index `i` in basic block `bb` to variable `v` that's
+ * subsequently read (as determined by the SSA pruning stage).
+ */
+private predicate variableWriteCand(IRBlock bb, int i, SourceVariable v) {
+  exists(SsaInternals0::Def def, SsaInternals0::SourceVariable v0 |
+    def.asDefOrUse().hasIndexInBlock(bb, i, v0) and
+    v0 = getOldSourceVariable(v)
+  )
+}
+
+private module SsaInput implements SsaImplCommon::InputSig {
+  import InputSigCommon
+  import SourceVariables
+
+  /**
+   * Holds if the `i`'th write in block `bb` writes to the variable `v`.
+   * `certain` is `true` if the write is guaranteed to overwrite the entire variable.
+   */
+  predicate variableWrite(IRBlock bb, int i, SourceVariable v, boolean certain) {
+    DataFlowImplCommon::forceCachingInSameStage() and
+    variableWriteCand(bb, i, v) and
+    exists(DefImpl def | def.hasIndexInBlock(bb, i, v) |
+      if def.isCertain() then certain = true else certain = false
+    )
+  }
+
+  /**
+   * Holds if the `i`'th read in block `bb` reads to the variable `v`.
+   * `certain` is `true` if the read is guaranteed. For C++, this is always the case.
+   */
+  predicate variableRead(IRBlock bb, int i, SourceVariable v, boolean certain) {
+    exists(UseImpl use | use.hasIndexInBlock(bb, i, v) |
+      if use.isCertain() then certain = true else certain = false
+    )
+  }
+}
+
+/**
+ * The final SSA predicates used for dataflow purposes.
+ */
+cached
+module SsaCached {
+  /**
+   * Holds if `def` is accessed at index `i1` in basic block `bb1` (either a read
+   * or a write), `def` is read at index `i2` in basic block `bb2`, and there is a
+   * path between them without any read of `def`.
+   */
+  cached
+  predicate adjacentDefRead(Definition def, IRBlock bb1, int i1, IRBlock bb2, int i2) {
+    SsaImpl::adjacentDefRead(def, bb1, i1, bb2, i2)
+  }
+
+  /**
+   * Holds if the node at index `i` in `bb` is a last reference to SSA definition
+   * `def`. The reference is last because it can reach another write `next`,
+   * without passing through another read or write.
+   */
+  cached
+  predicate lastRefRedef(Definition def, IRBlock bb, int i, Definition next) {
+    SsaImpl::lastRefRedef(def, bb, i, next)
+  }
+}
+
+cached
+private newtype TSsaDefOrUse =
+  TDefOrUse(DefOrUseImpl defOrUse) {
+    defOrUse instanceof UseImpl
+    or
+    // Like in the pruning stage, we only include definition that's live after the
+    // write as the final definitions computed by SSA.
+    exists(Definition def, SourceVariable sv, IRBlock bb, int i |
+      def.definesAt(sv, bb, i) and
+      defOrUse.(DefImpl).hasIndexInBlock(bb, i, sv)
+    )
+  } or
+  TPhi(PhiNode phi)
+
+abstract private class SsaDefOrUse extends TSsaDefOrUse {
+  string toString() { none() }
+
+  DefOrUseImpl asDefOrUse() { none() }
+
+  PhiNode asPhi() { none() }
+
+  abstract Location getLocation();
+}
+
+class DefOrUse extends TDefOrUse, SsaDefOrUse {
+  DefOrUseImpl defOrUse;
+
+  DefOrUse() { this = TDefOrUse(defOrUse) }
+
+  final override DefOrUseImpl asDefOrUse() { result = defOrUse }
+
+  final override Location getLocation() { result = defOrUse.getLocation() }
+
+  final SourceVariable getSourceVariable() { result = defOrUse.getSourceVariable() }
+
+  override string toString() { result = defOrUse.toString() }
+}
+
+class Phi extends TPhi, SsaDefOrUse {
+  PhiNode phi;
+
+  Phi() { this = TPhi(phi) }
+
+  final override PhiNode asPhi() { result = phi }
+
+  final override Location getLocation() { result = phi.getBasicBlock().getLocation() }
+
+  override string toString() { result = "Phi" }
+}
+
+class UseOrPhi extends SsaDefOrUse {
+  UseOrPhi() {
+    this.asDefOrUse() instanceof UseImpl
+    or
+    this instanceof Phi
+  }
+
+  final override Location getLocation() {
+    result = this.asDefOrUse().getLocation() or result = this.(Phi).getLocation()
+  }
+}
+
+class Def extends DefOrUse {
+  override DefImpl defOrUse;
+
+  Operand getAddressOperand() { result = defOrUse.getAddressOperand() }
+
+  Instruction getAddress() { result = this.getAddressOperand().getDef() }
+
+  /**
+   * This predicate ensures that joins go from `defOrUse` to the result
+   * instead of the other way around.
+   */
+  pragma[inline]
+  int getIndirectionIndex() {
+    pragma[only_bind_into](result) = pragma[only_bind_out](defOrUse).getIndirectionIndex()
+  }
+
+  Instruction getDefiningInstruction() { result = defOrUse.getDefiningInstruction() }
+}
+
+private module SsaImpl = SsaImplCommon::Make<SsaInput>;
+
+class PhiNode = SsaImpl::PhiNode;
+
+class Definition = SsaImpl::Definition;
+
+import SsaCached

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

@@ -0,0 +1,270 @@
+import cpp as Cpp
+import semmle.code.cpp.ir.IR
+import semmle.code.cpp.ir.internal.IRCppLanguage
+private import semmle.code.cpp.ir.implementation.raw.internal.SideEffects as SideEffects
+private import DataFlowImplCommon as DataFlowImplCommon
+private import DataFlowUtil
+
+/**
+ * Holds if `operand` is an operand that is not used by the dataflow library.
+ * Ignored operands are not recognizd as uses by SSA, and they don't have a
+ * corresponding `(Indirect)OperandNode`.
+ */
+predicate ignoreOperand(Operand operand) {
+  operand = any(Instruction instr | ignoreInstruction(instr)).getAnOperand() or
+  operand = any(Instruction instr | ignoreInstruction(instr)).getAUse() or
+  operand instanceof MemoryOperand
+}
+
+/**
+ * Holds if `instr` is an instruction that is not used by the dataflow library.
+ * Ignored instructions are not recognized as reads/writes by SSA, and they
+ * don't have a corresponding `(Indirect)InstructionNode`.
+ */
+predicate ignoreInstruction(Instruction instr) {
+  DataFlowImplCommon::forceCachingInSameStage() and
+  (
+    instr instanceof WriteSideEffectInstruction or
+    instr instanceof PhiInstruction or
+    instr instanceof ReadSideEffectInstruction or
+    instr instanceof ChiInstruction or
+    instr instanceof InitializeIndirectionInstruction
+  )
+}
+
+/**
+ * Gets the C++ type of `this` in the member function `f`.
+ * The result is a glvalue if `isGLValue` is true, and
+ * a prvalue if `isGLValue` is false.
+ */
+bindingset[isGLValue]
+private CppType getThisType(Cpp::MemberFunction f, boolean isGLValue) {
+  result.hasType(f.getTypeOfThis(), isGLValue)
+}
+
+/**
+ * Gets the C++ type of the instruction `i`.
+ *
+ * This is equivalent to `i.getResultLanguageType()` with the exception
+ * of instructions that directly references a `this` IRVariable. In this
+ * case, `i.getResultLanguageType()` gives an unknown type, whereas the
+ * predicate gives the expected type (i.e., a potentially cv-qualified
+ * type `A*` where `A` is the declaring type of the member function that
+ * contains `i`).
+ */
+cached
+CppType getResultLanguageType(Instruction i) {
+  if i.(VariableAddressInstruction).getIRVariable() instanceof IRThisVariable
+  then
+    if i.isGLValue()
+    then result = getThisType(i.getEnclosingFunction(), true)
+    else result = getThisType(i.getEnclosingFunction(), false)
+  else result = i.getResultLanguageType()
+}
+
+/**
+ * Gets the C++ type of the operand `operand`.
+ * This is equivalent to the type of the operand's defining instruction.
+ *
+ * See `getResultLanguageType` for a description of this behavior.
+ */
+CppType getLanguageType(Operand operand) { result = getResultLanguageType(operand.getDef()) }
+
+/**
+ * Gets the maximum number of indirections a glvalue of type `type` can have.
+ * For example:
+ * - If `type = int`, the result is 1
+ * - If `type = MyStruct`, the result is 1
+ * - If `type = char*`, the result is 2
+ */
+int getMaxIndirectionsForType(Type type) {
+  result = countIndirectionsForCppType(getTypeForGLValue(type))
+}
+
+/**
+ * Gets the maximum number of indirections a value of type `type` can have.
+ *
+ * Note that this predicate is intended to be called on unspecified types
+ * (i.e., `countIndirections(e.getUnspecifiedType())`).
+ */
+private int countIndirections(Type t) {
+  result =
+    1 +
+      countIndirections([t.(Cpp::PointerType).getBaseType(), t.(Cpp::ReferenceType).getBaseType()])
+  or
+  not t instanceof Cpp::PointerType and
+  not t instanceof Cpp::ReferenceType and
+  result = 0
+}
+
+/**
+ * Gets the maximum number of indirections a value of C++
+ * type `langType` can have.
+ */
+int countIndirectionsForCppType(LanguageType langType) {
+  exists(Type type | langType.hasType(type, true) |
+    result = 1 + countIndirections(type.getUnspecifiedType())
+  )
+  or
+  exists(Type type | langType.hasType(type, false) |
+    result = countIndirections(type.getUnspecifiedType())
+  )
+}
+
+/**
+ * A `CallInstruction` that calls an allocation function such
+ * as `malloc` or `operator new`.
+ */
+class AllocationInstruction extends CallInstruction {
+  AllocationInstruction() { this.getStaticCallTarget() instanceof Cpp::AllocationFunction }
+}
+
+/**
+ * Holds if `i` is a base instruction that starts a sequence of uses
+ * of some variable that SSA can handle.
+ *
+ * This is either when `i` is a `VariableAddressInstruction` or when
+ * `i` is a fresh allocation produced by an `AllocationInstruction`.
+ */
+private predicate isSourceVariableBase(Instruction i) {
+  i instanceof VariableAddressInstruction or i instanceof AllocationInstruction
+}
+
+/**
+ * Holds if the value pointed to by `operand` can potentially be
+ * modified be the caller.
+ */
+predicate isModifiableByCall(ArgumentOperand operand) {
+  exists(CallInstruction call, int index, CppType type |
+    type = getLanguageType(operand) and
+    call.getArgumentOperand(index) = operand and
+    if index = -1
+    then not call.getStaticCallTarget() instanceof Cpp::ConstMemberFunction
+    else not SideEffects::isConstPointerLike(any(Type t | type.hasType(t, _)))
+  )
+}
+
+cached
+private module Cached {
+  /**
+   * Holds if `op` is a use of an SSA variable rooted at `base` with `ind` number
+   * of indirections.
+   *
+   * `certain` is `true` if the operand is guaranteed to read the variable, and
+   * `indirectionIndex` specifies the number of loads required to read the variable.
+   */
+  cached
+  predicate isUse(boolean certain, Operand op, Instruction base, int ind, int indirectionIndex) {
+    not ignoreOperand(op) and
+    certain = true and
+    exists(LanguageType type, int m, int ind0 |
+      type = getLanguageType(op) and
+      m = countIndirectionsForCppType(type) and
+      isUseImpl(op, base, ind0) and
+      ind = ind0 + [0 .. m] and
+      indirectionIndex = ind - ind0
+    )
+  }
+
+  /**
+   * Holds if `operand` is a use of an SSA variable rooted at `base`, and the
+   * path from `base` to `operand` passes through `ind` load-like instructions.
+   */
+  private predicate isUseImpl(Operand operand, Instruction base, int ind) {
+    DataFlowImplCommon::forceCachingInSameStage() and
+    ind = 0 and
+    operand.getDef() = base and
+    isSourceVariableBase(base)
+    or
+    exists(Operand mid, Instruction instr |
+      isUseImpl(mid, base, ind) and
+      instr = operand.getDef() and
+      conversionFlow(mid, instr, false)
+    )
+    or
+    exists(int ind0 |
+      isUseImpl(operand.getDef().(LoadInstruction).getSourceAddressOperand(), base, ind0)
+      or
+      isUseImpl(operand.getDef().(InitializeParameterInstruction).getAnOperand(), base, ind0)
+    |
+      ind0 = ind - 1
+    )
+  }
+
+  /**
+   * Holds if `address` is an address of an SSA variable rooted at `base`,
+   * and `instr` is a definition of the SSA variable with `ind` number of indirections.
+   *
+   * `certain` is `true` if `instr` is guaranteed to write to the variable, and
+   * `indirectionIndex` specifies the number of loads required to read the variable
+   * after the write operation.
+   */
+  cached
+  predicate isDef(
+    boolean certain, Instruction instr, Operand address, Instruction base, int ind,
+    int indirectionIndex
+  ) {
+    certain = true and
+    exists(int ind0, CppType type, int m |
+      address =
+        [
+          instr.(StoreInstruction).getDestinationAddressOperand(),
+          instr.(InitializeParameterInstruction).getAnOperand(),
+          instr.(InitializeDynamicAllocationInstruction).getAllocationAddressOperand(),
+          instr.(UninitializedInstruction).getAnOperand()
+        ]
+    |
+      isDefImpl(address, base, ind0) and
+      type = getLanguageType(address) and
+      m = countIndirectionsForCppType(type) and
+      ind = ind0 + [1 .. m] and
+      indirectionIndex = ind - (ind0 + 1)
+    )
+  }
+
+  /**
+   * Holds if `address` is a use of an SSA variable rooted at `base`, and the
+   * path from `base` to `address` passes through `ind` load-like instructions.
+   *
+   * Note: Unlike `isUseImpl`, this predicate recurses through pointer-arithmetic
+   * instructions.
+   */
+  private predicate isDefImpl(Operand address, Instruction base, int ind) {
+    DataFlowImplCommon::forceCachingInSameStage() and
+    ind = 0 and
+    address.getDef() = base and
+    isSourceVariableBase(base)
+    or
+    exists(Operand mid, Instruction instr |
+      isDefImpl(mid, base, ind) and
+      instr = address.getDef() and
+      conversionFlow(mid, instr, _)
+    )
+    or
+    exists(int ind0 |
+      isDefImpl(address.getDef().(LoadInstruction).getSourceAddressOperand(), base, ind0)
+      or
+      isDefImpl(address.getDef().(InitializeParameterInstruction).getAnOperand(), base, ind0)
+    |
+      ind0 = ind - 1
+    )
+  }
+}
+
+import Cached
+
+/**
+ * Inputs to the shared SSA library's parameterized module that is shared
+ * between the SSA pruning stage, and the final SSA stage.
+ */
+module InputSigCommon {
+  class BasicBlock = IRBlock;
+
+  BasicBlock getImmediateBasicBlockDominator(BasicBlock bb) { result.immediatelyDominates(bb) }
+
+  BasicBlock getABasicBlockSuccessor(BasicBlock bb) { result = bb.getASuccessor() }
+
+  class ExitBasicBlock extends IRBlock {
+    ExitBasicBlock() { this.getLastInstruction() instanceof ExitFunctionInstruction }
+  }
+}

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

@@ -0,0 +1,208 @@
+private import semmle.code.cpp.ir.IR
+private import experimental.semmle.code.cpp.ir.dataflow.DataFlow
+private import ModelUtil
+private import semmle.code.cpp.models.interfaces.DataFlow
+private import semmle.code.cpp.models.interfaces.SideEffect
+private import DataFlowUtil
+private import DataFlowPrivate
+private import semmle.code.cpp.models.Models
+
+/**
+ * Holds if taint propagates from `nodeFrom` to `nodeTo` in exactly one local
+ * (intra-procedural) step.
+ */
+predicate localTaintStep(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
+  DataFlow::localFlowStep(nodeFrom, nodeTo)
+  or
+  localAdditionalTaintStep(nodeFrom, nodeTo)
+}
+
+/**
+ * Holds if taint can flow in one local step from `nodeFrom` to `nodeTo` excluding
+ * local data flow steps. That is, `nodeFrom` and `nodeTo` are likely to represent
+ * different objects.
+ */
+cached
+predicate localAdditionalTaintStep(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
+  operandToInstructionTaintStep(nodeFrom.asOperand(), nodeTo.asInstruction())
+  or
+  modeledTaintStep(nodeFrom, nodeTo)
+  or
+  // Flow from `op` to `*op`.
+  exists(Operand operand, int indirectionIndex |
+    nodeHasOperand(nodeFrom, operand, indirectionIndex) and
+    nodeHasOperand(nodeTo, operand, indirectionIndex - 1)
+  )
+  or
+  // Flow from `instr` to `*instr`.
+  exists(Instruction instr, int indirectionIndex |
+    nodeHasInstruction(nodeFrom, instr, indirectionIndex) and
+    nodeHasInstruction(nodeTo, instr, indirectionIndex - 1)
+  )
+  or
+  // Flow from (the indirection of) an operand of a pointer arithmetic instruction to the
+  // indirection of the pointer arithmetic instruction. This provides flow from `source`
+  // in `x[source]` to the result of the associated load instruction.
+  exists(PointerArithmeticInstruction pai, int indirectionIndex |
+    nodeHasOperand(nodeFrom, pai.getAnOperand(), pragma[only_bind_into](indirectionIndex)) and
+    hasInstructionAndIndex(nodeTo, pai, indirectionIndex + 1)
+  )
+}
+
+/**
+ * Holds if taint propagates from `nodeFrom` to `nodeTo` in exactly one local
+ * (intra-procedural) step.
+ */
+private predicate operandToInstructionTaintStep(Operand opFrom, Instruction instrTo) {
+  // Taint can flow through expressions that alter the value but preserve
+  // more than one bit of it _or_ expressions that follow data through
+  // pointer indirections.
+  instrTo.getAnOperand() = opFrom and
+  (
+    instrTo instanceof ArithmeticInstruction
+    or
+    instrTo instanceof BitwiseInstruction
+    or
+    instrTo instanceof PointerArithmeticInstruction
+  )
+  or
+  // The `CopyInstruction` case is also present in non-taint data flow, but
+  // that uses `getDef` rather than `getAnyDef`. For taint, we want flow
+  // from a definition of `myStruct` to a `myStruct.myField` expression.
+  instrTo.(LoadInstruction).getSourceAddressOperand() = opFrom
+  or
+  // Unary instructions tend to preserve enough information in practice that we
+  // want taint to flow through.
+  // The exception is `FieldAddressInstruction`. Together with the rules below for
+  // `LoadInstruction`s and `ChiInstruction`s, flow through `FieldAddressInstruction`
+  // could cause flow into one field to come out an unrelated field.
+  // This would happen across function boundaries, where the IR would not be able to
+  // match loads to stores.
+  instrTo.(UnaryInstruction).getUnaryOperand() = opFrom and
+  (
+    not instrTo instanceof FieldAddressInstruction
+    or
+    instrTo.(FieldAddressInstruction).getField().getDeclaringType() instanceof Union
+  )
+}
+
+/**
+ * Holds if taint may propagate from `source` to `sink` in zero or more local
+ * (intra-procedural) steps.
+ */
+pragma[inline]
+predicate localTaint(DataFlow::Node source, DataFlow::Node sink) { localTaintStep*(source, sink) }
+
+/**
+ * Holds if taint can flow from `i1` to `i2` in zero or more
+ * local (intra-procedural) steps.
+ */
+pragma[inline]
+predicate localInstructionTaint(Instruction i1, Instruction i2) {
+  localTaint(DataFlow::instructionNode(i1), DataFlow::instructionNode(i2))
+}
+
+/**
+ * Holds if taint can flow from `e1` to `e2` in zero or more
+ * local (intra-procedural) steps.
+ */
+pragma[inline]
+predicate localExprTaint(Expr e1, Expr e2) {
+  localTaint(DataFlow::exprNode(e1), DataFlow::exprNode(e2))
+}
+
+/**
+ * Holds if the additional step from `src` to `sink` should be included in all
+ * global taint flow configurations.
+ */
+predicate defaultAdditionalTaintStep(DataFlow::Node src, DataFlow::Node sink) {
+  localAdditionalTaintStep(src, sink)
+}
+
+/**
+ * Holds if default `TaintTracking::Configuration`s should allow implicit reads
+ * of `c` at sinks and inputs to additional taint steps.
+ */
+bindingset[node]
+predicate defaultImplicitTaintRead(DataFlow::Node node, DataFlow::Content c) { none() }
+
+/**
+ * Holds if `node` should be a sanitizer in all global taint flow configurations
+ * but not in local taint.
+ */
+predicate defaultTaintSanitizer(DataFlow::Node node) { none() }
+
+/**
+ * Holds if taint can flow from `instrIn` to `instrOut` through a call to a
+ * modeled function.
+ */
+predicate modeledTaintStep(DataFlow::Node nodeIn, DataFlow::Node nodeOut) {
+  // Normal taint steps
+  exists(CallInstruction call, TaintFunction func, FunctionInput modelIn, FunctionOutput modelOut |
+    call.getStaticCallTarget() = func and
+    func.hasTaintFlow(modelIn, modelOut)
+  |
+    (
+      nodeIn = callInput(call, modelIn)
+      or
+      exists(int n |
+        modelIn.isParameterDerefOrQualifierObject(n) and
+        if n = -1
+        then nodeIn = callInput(call, any(InQualifierAddress inQualifier))
+        else nodeIn = callInput(call, any(InParameter inParam | inParam.getIndex() = n))
+      )
+    ) and
+    nodeOut = callOutput(call, modelOut)
+    or
+    exists(int d |
+      nodeIn = callInput(call, modelIn, d)
+      or
+      exists(int n |
+        d = 1 and
+        modelIn.isParameterDerefOrQualifierObject(n) and
+        if n = -1
+        then nodeIn = callInput(call, any(InQualifierAddress inQualifier))
+        else nodeIn = callInput(call, any(InParameter inParam | inParam.getIndex() = n))
+      )
+    |
+      call.getStaticCallTarget() = func and
+      func.hasTaintFlow(modelIn, modelOut) and
+      nodeOut = callOutput(call, modelOut, d)
+    )
+  )
+  or
+  // Taint flow from one argument to another and data flow from an argument to a
+  // return value. This happens in functions like `strcat` and `memcpy`. We
+  // could model this flow in two separate steps, but that would add reverse
+  // flow from the write side-effect to the call instruction, which may not be
+  // desirable.
+  exists(
+    CallInstruction call, Function func, FunctionInput modelIn, OutParameterDeref modelMidOut,
+    int indexMid, InParameter modelMidIn, OutReturnValue modelOut
+  |
+    nodeIn = callInput(call, modelIn) and
+    nodeOut = callOutput(call, modelOut) and
+    call.getStaticCallTarget() = func and
+    func.(TaintFunction).hasTaintFlow(modelIn, modelMidOut) and
+    func.(DataFlowFunction).hasDataFlow(modelMidIn, modelOut) and
+    modelMidOut.isParameterDeref(indexMid) and
+    modelMidIn.isParameter(indexMid)
+  )
+  or
+  // Taint flow from a pointer argument to an output, when the model specifies flow from the deref
+  // to that output, but the deref is not modeled in the IR for the caller.
+  exists(
+    CallInstruction call, DataFlow::SideEffectOperandNode indirectArgument, Function func,
+    FunctionInput modelIn, FunctionOutput modelOut
+  |
+    indirectArgument = callInput(call, modelIn) and
+    indirectArgument.getAddressOperand() = nodeIn.asOperand() and
+    call.getStaticCallTarget() = func and
+    (
+      func.(DataFlowFunction).hasDataFlow(modelIn, modelOut)
+      or
+      func.(TaintFunction).hasTaintFlow(modelIn, modelOut)
+    ) and
+    nodeOut = callOutput(call, modelOut)
+  )
+}

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/ssa0/SsaInternals.qll

@@ -0,0 +1,314 @@
+/**
+ * This module defines an initial SSA pruning stage that doesn't take
+ * indirections into account.
+ */
+
+private import codeql.ssa.Ssa as SsaImplCommon
+private import semmle.code.cpp.ir.IR
+private import experimental.semmle.code.cpp.ir.dataflow.internal.DataFlowImplCommon as DataFlowImplCommon
+private import semmle.code.cpp.models.interfaces.Allocation as Alloc
+private import semmle.code.cpp.models.interfaces.DataFlow as DataFlow
+private import semmle.code.cpp.ir.implementation.raw.internal.SideEffects as SideEffects
+private import semmle.code.cpp.ir.internal.IRCppLanguage
+private import experimental.semmle.code.cpp.ir.dataflow.internal.DataFlowPrivate
+private import experimental.semmle.code.cpp.ir.dataflow.internal.DataFlowUtil
+private import experimental.semmle.code.cpp.ir.dataflow.internal.SsaInternalsCommon
+
+private module SourceVariables {
+  newtype TBaseSourceVariable =
+    // Each IR variable gets its own source variable
+    TBaseIRVariable(IRVariable var) or
+    // Each allocation gets its own source variable
+    TBaseCallVariable(AllocationInstruction call)
+
+  abstract class BaseSourceVariable extends TBaseSourceVariable {
+    abstract string toString();
+
+    abstract DataFlowType getType();
+  }
+
+  class BaseIRVariable extends BaseSourceVariable, TBaseIRVariable {
+    IRVariable var;
+
+    IRVariable getIRVariable() { result = var }
+
+    BaseIRVariable() { this = TBaseIRVariable(var) }
+
+    override string toString() { result = var.toString() }
+
+    override DataFlowType getType() { result = var.getType() }
+  }
+
+  class BaseCallVariable extends BaseSourceVariable, TBaseCallVariable {
+    AllocationInstruction call;
+
+    BaseCallVariable() { this = TBaseCallVariable(call) }
+
+    AllocationInstruction getCallInstruction() { result = call }
+
+    override string toString() { result = call.toString() }
+
+    override DataFlowType getType() { result = call.getResultType() }
+  }
+
+  private newtype TSourceVariable =
+    TSourceIRVariable(BaseIRVariable baseVar) or
+    TCallVariable(AllocationInstruction call)
+
+  abstract class SourceVariable extends TSourceVariable {
+    abstract string toString();
+
+    abstract BaseSourceVariable getBaseVariable();
+  }
+
+  class SourceIRVariable extends SourceVariable, TSourceIRVariable {
+    BaseIRVariable var;
+
+    SourceIRVariable() { this = TSourceIRVariable(var) }
+
+    IRVariable getIRVariable() { result = var.getIRVariable() }
+
+    override BaseIRVariable getBaseVariable() { result.getIRVariable() = this.getIRVariable() }
+
+    override string toString() { result = this.getIRVariable().toString() }
+  }
+
+  class CallVariable extends SourceVariable, TCallVariable {
+    AllocationInstruction call;
+
+    CallVariable() { this = TCallVariable(call) }
+
+    AllocationInstruction getCall() { result = call }
+
+    override BaseCallVariable getBaseVariable() { result.getCallInstruction() = call }
+
+    override string toString() { result = "Call" }
+  }
+}
+
+import SourceVariables
+
+private newtype TDefOrUseImpl =
+  TDefImpl(Operand address) { isDef(_, _, address, _, _, _) } or
+  TUseImpl(Operand operand) {
+    isUse(_, operand, _, _, _) and
+    not isDef(_, _, operand, _, _, _)
+  }
+
+abstract private class DefOrUseImpl extends TDefOrUseImpl {
+  /** Gets a textual representation of this element. */
+  abstract string toString();
+
+  /** Gets the block of this definition or use. */
+  abstract IRBlock getBlock();
+
+  /** Holds if this definition or use has index `index` in block `block`. */
+  abstract predicate hasIndexInBlock(IRBlock block, int index);
+
+  final predicate hasIndexInBlock(IRBlock block, int index, SourceVariable sv) {
+    this.hasIndexInBlock(block, index) and
+    sv = this.getSourceVariable()
+  }
+
+  /** Gets the location of this element. */
+  abstract Cpp::Location getLocation();
+
+  abstract Instruction getBase();
+
+  final BaseSourceVariable getBaseSourceVariable() {
+    exists(IRVariable var |
+      result.(BaseIRVariable).getIRVariable() = var and
+      instructionHasIRVariable(this.getBase(), var)
+    )
+    or
+    result.(BaseCallVariable).getCallInstruction() = this.getBase()
+  }
+
+  /** Gets the variable that is defined or used. */
+  final SourceVariable getSourceVariable() {
+    exists(BaseSourceVariable v |
+      sourceVariableHasBaseAndIndex(result, v) and
+      defOrUseHasSourceVariable(this, v)
+    )
+  }
+}
+
+pragma[noinline]
+private predicate instructionHasIRVariable(VariableAddressInstruction vai, IRVariable var) {
+  vai.getIRVariable() = var
+}
+
+private predicate defOrUseHasSourceVariable(DefOrUseImpl defOrUse, BaseSourceVariable bv) {
+  defHasSourceVariable(defOrUse, bv)
+  or
+  useHasSourceVariable(defOrUse, bv)
+}
+
+pragma[noinline]
+private predicate defHasSourceVariable(DefImpl def, BaseSourceVariable bv) {
+  bv = def.getBaseSourceVariable()
+}
+
+pragma[noinline]
+private predicate useHasSourceVariable(UseImpl use, BaseSourceVariable bv) {
+  bv = use.getBaseSourceVariable()
+}
+
+pragma[noinline]
+private predicate sourceVariableHasBaseAndIndex(SourceVariable v, BaseSourceVariable bv) {
+  v.getBaseVariable() = bv
+}
+
+class DefImpl extends DefOrUseImpl, TDefImpl {
+  Operand address;
+
+  DefImpl() { this = TDefImpl(address) }
+
+  override Instruction getBase() { isDef(_, _, address, result, _, _) }
+
+  Operand getAddressOperand() { result = address }
+
+  Instruction getDefiningInstruction() { isDef(_, result, address, _, _, _) }
+
+  override string toString() { result = address.toString() }
+
+  override IRBlock getBlock() { result = this.getDefiningInstruction().getBlock() }
+
+  override Cpp::Location getLocation() { result = this.getDefiningInstruction().getLocation() }
+
+  final override predicate hasIndexInBlock(IRBlock block, int index) {
+    this.getDefiningInstruction() = block.getInstruction(index)
+  }
+
+  predicate isCertain() { isDef(true, _, address, _, _, _) }
+}
+
+class UseImpl extends DefOrUseImpl, TUseImpl {
+  Operand operand;
+
+  UseImpl() { this = TUseImpl(operand) }
+
+  Operand getOperand() { result = operand }
+
+  override string toString() { result = operand.toString() }
+
+  final override predicate hasIndexInBlock(IRBlock block, int index) {
+    operand.getUse() = block.getInstruction(index)
+  }
+
+  final override IRBlock getBlock() { result = operand.getUse().getBlock() }
+
+  final override Cpp::Location getLocation() { result = operand.getLocation() }
+
+  override Instruction getBase() { isUse(_, operand, result, _, _) }
+
+  predicate isCertain() { isUse(true, operand, _, _, _) }
+}
+
+private module SsaInput implements SsaImplCommon::InputSig {
+  import InputSigCommon
+  import SourceVariables
+
+  /**
+   * Holds if the `i`'th write in block `bb` writes to the variable `v`.
+   * `certain` is `true` if the write is guaranteed to overwrite the entire variable.
+   */
+  predicate variableWrite(IRBlock bb, int i, SourceVariable v, boolean certain) {
+    DataFlowImplCommon::forceCachingInSameStage() and
+    exists(DefImpl def | def.hasIndexInBlock(bb, i, v) |
+      if def.isCertain() then certain = true else certain = false
+    )
+  }
+
+  /**
+   * Holds if the `i`'th read in block `bb` reads to the variable `v`.
+   * `certain` is `true` if the read is guaranteed.
+   */
+  predicate variableRead(IRBlock bb, int i, SourceVariable v, boolean certain) {
+    exists(UseImpl use | use.hasIndexInBlock(bb, i, v) |
+      if use.isCertain() then certain = true else certain = false
+    )
+  }
+}
+
+private newtype TSsaDefOrUse =
+  TDefOrUse(DefOrUseImpl defOrUse) {
+    defOrUse instanceof UseImpl
+    or
+    // If `defOrUse` is a definition we only include it if the
+    // SSA library concludes that it's live after the write.
+    exists(Definition def, SourceVariable sv, IRBlock bb, int i |
+      def.definesAt(sv, bb, i) and
+      defOrUse.(DefImpl).hasIndexInBlock(bb, i, sv)
+    )
+  } or
+  TPhi(PhiNode phi)
+
+abstract private class SsaDefOrUse extends TSsaDefOrUse {
+  string toString() { result = "SsaDefOrUse" }
+
+  DefOrUseImpl asDefOrUse() { none() }
+
+  PhiNode asPhi() { none() }
+
+  abstract Location getLocation();
+}
+
+class DefOrUse extends TDefOrUse, SsaDefOrUse {
+  DefOrUseImpl defOrUse;
+
+  DefOrUse() { this = TDefOrUse(defOrUse) }
+
+  final override DefOrUseImpl asDefOrUse() { result = defOrUse }
+
+  final override Location getLocation() { result = defOrUse.getLocation() }
+
+  final SourceVariable getSourceVariable() { result = defOrUse.getSourceVariable() }
+}
+
+class Phi extends TPhi, SsaDefOrUse {
+  PhiNode phi;
+
+  Phi() { this = TPhi(phi) }
+
+  final override PhiNode asPhi() { result = phi }
+
+  final override Location getLocation() { result = phi.getBasicBlock().getLocation() }
+}
+
+class UseOrPhi extends SsaDefOrUse {
+  UseOrPhi() {
+    this.asDefOrUse() instanceof UseImpl
+    or
+    this instanceof Phi
+  }
+
+  final override Location getLocation() {
+    result = this.asDefOrUse().getLocation() or result = this.(Phi).getLocation()
+  }
+
+  override string toString() {
+    result = this.asDefOrUse().toString()
+    or
+    this instanceof Phi and
+    result = "Phi"
+  }
+}
+
+class Def extends DefOrUse {
+  override DefImpl defOrUse;
+
+  Operand getAddressOperand() { result = defOrUse.getAddressOperand() }
+
+  Instruction getAddress() { result = this.getAddressOperand().getDef() }
+
+  Instruction getDefiningInstruction() { result = defOrUse.getDefiningInstruction() }
+
+  override string toString() { result = this.asDefOrUse().toString() + " (def)" }
+}
+
+private module SsaImpl = SsaImplCommon::Make<SsaInput>;
+
+class PhiNode = SsaImpl::PhiNode;
+
+class Definition = SsaImpl::Definition;

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

@@ -0,0 +1,191 @@
+/**
+ * Provides an implementation of global (interprocedural) taint tracking.
+ * This file re-exports the local (intraprocedural) taint-tracking analysis
+ * from `TaintTrackingParameter::Public` and adds a global analysis, mainly
+ * exposed through the `Configuration` class. For some languages, this file
+ * exists in several identical copies, allowing queries to use multiple
+ * `Configuration` classes that depend on each other without introducing
+ * mutual recursion among those configurations.
+ */
+
+import TaintTrackingParameter::Public
+private import TaintTrackingParameter::Private
+
+/**
+ * A configuration of interprocedural taint tracking analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the taint tracking library must define its own unique extension of
+ * this abstract class.
+ *
+ * A taint-tracking configuration is a special data flow configuration
+ * (`DataFlow::Configuration`) that allows for flow through nodes that do not
+ * necessarily preserve values but are still relevant from a taint tracking
+ * perspective. (For example, string concatenation, where one of the operands
+ * is tainted.)
+ *
+ * To create a configuration, extend this class with a subclass whose
+ * characteristic predicate is a unique singleton string. For example, write
+ *
+ * ```ql
+ * class MyAnalysisConfiguration extends TaintTracking::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isSanitizer`.
+ *   // Optionally override `isSanitizerIn`.
+ *   // Optionally override `isSanitizerOut`.
+ *   // Optionally override `isSanitizerGuard`.
+ *   // Optionally override `isAdditionalTaintStep`.
+ * }
+ * ```
+ *
+ * Then, to query whether there is flow between some `source` and `sink`,
+ * write
+ *
+ * ```ql
+ * exists(MyAnalysisConfiguration cfg | cfg.hasFlow(source, sink))
+ * ```
+ *
+ * Multiple configurations can coexist, but it is unsupported to depend on
+ * another `TaintTracking::Configuration` or a `DataFlow::Configuration` in the
+ * overridden predicates that define sources, sinks, or additional steps.
+ * Instead, the dependency should go to a `TaintTracking2::Configuration` or a
+ * `DataFlow2::Configuration`, `DataFlow3::Configuration`, etc.
+ */
+abstract class Configuration extends DataFlow::Configuration {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant taint source.
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSource(DataFlow::Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant taint source with the given initial
+   * `state`.
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSource(DataFlow::Node source, DataFlow::FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant taint sink
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSink(DataFlow::Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant taint sink accepting `state`.
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSink(DataFlow::Node sink, DataFlow::FlowState state) { none() }
+
+  /** Holds if the node `node` is a taint sanitizer. */
+  predicate isSanitizer(DataFlow::Node node) { none() }
+
+  final override predicate isBarrier(DataFlow::Node node) {
+    this.isSanitizer(node) or
+    defaultTaintSanitizer(node)
+  }
+
+  /**
+   * Holds if the node `node` is a taint sanitizer when the flow state is
+   * `state`.
+   */
+  predicate isSanitizer(DataFlow::Node node, DataFlow::FlowState state) { none() }
+
+  final override predicate isBarrier(DataFlow::Node node, DataFlow::FlowState state) {
+    this.isSanitizer(node, state)
+  }
+
+  /** Holds if taint propagation into `node` is prohibited. */
+  predicate isSanitizerIn(DataFlow::Node node) { none() }
+
+  final override predicate isBarrierIn(DataFlow::Node node) { this.isSanitizerIn(node) }
+
+  /** Holds if taint propagation out of `node` is prohibited. */
+  predicate isSanitizerOut(DataFlow::Node node) { none() }
+
+  final override predicate isBarrierOut(DataFlow::Node node) { this.isSanitizerOut(node) }
+
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
+
+  deprecated final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
+    this.isSanitizerGuard(guard)
+  }
+
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited
+   * when the flow state is `state`.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+    none()
+  }
+
+  deprecated final override predicate isBarrierGuard(
+    DataFlow::BarrierGuard guard, DataFlow::FlowState state
+  ) {
+    this.isSanitizerGuard(guard, state)
+  }
+
+  /**
+   * Holds if taint may propagate from `node1` to `node2` in addition to the normal data-flow and taint steps.
+   */
+  predicate isAdditionalTaintStep(DataFlow::Node node1, DataFlow::Node node2) { none() }
+
+  final override predicate isAdditionalFlowStep(DataFlow::Node node1, DataFlow::Node node2) {
+    this.isAdditionalTaintStep(node1, node2) or
+    defaultAdditionalTaintStep(node1, node2)
+  }
+
+  /**
+   * Holds if taint may propagate from `node1` to `node2` in addition to the normal data-flow and taint steps.
+   * This step is only applicable in `state1` and updates the flow state to `state2`.
+   */
+  predicate isAdditionalTaintStep(
+    DataFlow::Node node1, DataFlow::FlowState state1, DataFlow::Node node2,
+    DataFlow::FlowState state2
+  ) {
+    none()
+  }
+
+  final override predicate isAdditionalFlowStep(
+    DataFlow::Node node1, DataFlow::FlowState state1, DataFlow::Node node2,
+    DataFlow::FlowState state2
+  ) {
+    this.isAdditionalTaintStep(node1, state1, node2, state2)
+  }
+
+  override predicate allowImplicitRead(DataFlow::Node node, DataFlow::ContentSet c) {
+    (
+      this.isSink(node) or
+      this.isSink(node, _) or
+      this.isAdditionalTaintStep(node, _) or
+      this.isAdditionalTaintStep(node, _, _, _)
+    ) and
+    defaultImplicitTaintRead(node, c)
+  }
+
+  /**
+   * Holds if taint may flow from `source` to `sink` for this configuration.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate hasFlow(DataFlow::Node source, DataFlow::Node sink) {
+    super.hasFlow(source, sink)
+  }
+}

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

@@ -0,0 +1,5 @@
+import experimental.semmle.code.cpp.ir.dataflow.internal.TaintTrackingUtil as Public
+
+module Private {
+  import experimental.semmle.code.cpp.ir.dataflow.DataFlow::DataFlow as DataFlow
+}

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

@@ -0,0 +1,191 @@
+/**
+ * Provides an implementation of global (interprocedural) taint tracking.
+ * This file re-exports the local (intraprocedural) taint-tracking analysis
+ * from `TaintTrackingParameter::Public` and adds a global analysis, mainly
+ * exposed through the `Configuration` class. For some languages, this file
+ * exists in several identical copies, allowing queries to use multiple
+ * `Configuration` classes that depend on each other without introducing
+ * mutual recursion among those configurations.
+ */
+
+import TaintTrackingParameter::Public
+private import TaintTrackingParameter::Private
+
+/**
+ * A configuration of interprocedural taint tracking analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the taint tracking library must define its own unique extension of
+ * this abstract class.
+ *
+ * A taint-tracking configuration is a special data flow configuration
+ * (`DataFlow::Configuration`) that allows for flow through nodes that do not
+ * necessarily preserve values but are still relevant from a taint tracking
+ * perspective. (For example, string concatenation, where one of the operands
+ * is tainted.)
+ *
+ * To create a configuration, extend this class with a subclass whose
+ * characteristic predicate is a unique singleton string. For example, write
+ *
+ * ```ql
+ * class MyAnalysisConfiguration extends TaintTracking::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isSanitizer`.
+ *   // Optionally override `isSanitizerIn`.
+ *   // Optionally override `isSanitizerOut`.
+ *   // Optionally override `isSanitizerGuard`.
+ *   // Optionally override `isAdditionalTaintStep`.
+ * }
+ * ```
+ *
+ * Then, to query whether there is flow between some `source` and `sink`,
+ * write
+ *
+ * ```ql
+ * exists(MyAnalysisConfiguration cfg | cfg.hasFlow(source, sink))
+ * ```
+ *
+ * Multiple configurations can coexist, but it is unsupported to depend on
+ * another `TaintTracking::Configuration` or a `DataFlow::Configuration` in the
+ * overridden predicates that define sources, sinks, or additional steps.
+ * Instead, the dependency should go to a `TaintTracking2::Configuration` or a
+ * `DataFlow2::Configuration`, `DataFlow3::Configuration`, etc.
+ */
+abstract class Configuration extends DataFlow::Configuration {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant taint source.
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSource(DataFlow::Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant taint source with the given initial
+   * `state`.
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSource(DataFlow::Node source, DataFlow::FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant taint sink
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSink(DataFlow::Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant taint sink accepting `state`.
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSink(DataFlow::Node sink, DataFlow::FlowState state) { none() }
+
+  /** Holds if the node `node` is a taint sanitizer. */
+  predicate isSanitizer(DataFlow::Node node) { none() }
+
+  final override predicate isBarrier(DataFlow::Node node) {
+    this.isSanitizer(node) or
+    defaultTaintSanitizer(node)
+  }
+
+  /**
+   * Holds if the node `node` is a taint sanitizer when the flow state is
+   * `state`.
+   */
+  predicate isSanitizer(DataFlow::Node node, DataFlow::FlowState state) { none() }
+
+  final override predicate isBarrier(DataFlow::Node node, DataFlow::FlowState state) {
+    this.isSanitizer(node, state)
+  }
+
+  /** Holds if taint propagation into `node` is prohibited. */
+  predicate isSanitizerIn(DataFlow::Node node) { none() }
+
+  final override predicate isBarrierIn(DataFlow::Node node) { this.isSanitizerIn(node) }
+
+  /** Holds if taint propagation out of `node` is prohibited. */
+  predicate isSanitizerOut(DataFlow::Node node) { none() }
+
+  final override predicate isBarrierOut(DataFlow::Node node) { this.isSanitizerOut(node) }
+
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
+
+  deprecated final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
+    this.isSanitizerGuard(guard)
+  }
+
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited
+   * when the flow state is `state`.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+    none()
+  }
+
+  deprecated final override predicate isBarrierGuard(
+    DataFlow::BarrierGuard guard, DataFlow::FlowState state
+  ) {
+    this.isSanitizerGuard(guard, state)
+  }
+
+  /**
+   * Holds if taint may propagate from `node1` to `node2` in addition to the normal data-flow and taint steps.
+   */
+  predicate isAdditionalTaintStep(DataFlow::Node node1, DataFlow::Node node2) { none() }
+
+  final override predicate isAdditionalFlowStep(DataFlow::Node node1, DataFlow::Node node2) {
+    this.isAdditionalTaintStep(node1, node2) or
+    defaultAdditionalTaintStep(node1, node2)
+  }
+
+  /**
+   * Holds if taint may propagate from `node1` to `node2` in addition to the normal data-flow and taint steps.
+   * This step is only applicable in `state1` and updates the flow state to `state2`.
+   */
+  predicate isAdditionalTaintStep(
+    DataFlow::Node node1, DataFlow::FlowState state1, DataFlow::Node node2,
+    DataFlow::FlowState state2
+  ) {
+    none()
+  }
+
+  final override predicate isAdditionalFlowStep(
+    DataFlow::Node node1, DataFlow::FlowState state1, DataFlow::Node node2,
+    DataFlow::FlowState state2
+  ) {
+    this.isAdditionalTaintStep(node1, state1, node2, state2)
+  }
+
+  override predicate allowImplicitRead(DataFlow::Node node, DataFlow::ContentSet c) {
+    (
+      this.isSink(node) or
+      this.isSink(node, _) or
+      this.isAdditionalTaintStep(node, _) or
+      this.isAdditionalTaintStep(node, _, _, _)
+    ) and
+    defaultImplicitTaintRead(node, c)
+  }
+
+  /**
+   * Holds if taint may flow from `source` to `sink` for this configuration.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate hasFlow(DataFlow::Node source, DataFlow::Node sink) {
+    super.hasFlow(source, sink)
+  }
+}

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

@@ -0,0 +1,5 @@
+import experimental.semmle.code.cpp.ir.dataflow.internal.TaintTrackingUtil as Public
+
+module Private {
+  import experimental.semmle.code.cpp.ir.dataflow.DataFlow2::DataFlow2 as DataFlow
+}

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

@@ -0,0 +1,191 @@
+/**
+ * Provides an implementation of global (interprocedural) taint tracking.
+ * This file re-exports the local (intraprocedural) taint-tracking analysis
+ * from `TaintTrackingParameter::Public` and adds a global analysis, mainly
+ * exposed through the `Configuration` class. For some languages, this file
+ * exists in several identical copies, allowing queries to use multiple
+ * `Configuration` classes that depend on each other without introducing
+ * mutual recursion among those configurations.
+ */
+
+import TaintTrackingParameter::Public
+private import TaintTrackingParameter::Private
+
+/**
+ * A configuration of interprocedural taint tracking analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the taint tracking library must define its own unique extension of
+ * this abstract class.
+ *
+ * A taint-tracking configuration is a special data flow configuration
+ * (`DataFlow::Configuration`) that allows for flow through nodes that do not
+ * necessarily preserve values but are still relevant from a taint tracking
+ * perspective. (For example, string concatenation, where one of the operands
+ * is tainted.)
+ *
+ * To create a configuration, extend this class with a subclass whose
+ * characteristic predicate is a unique singleton string. For example, write
+ *
+ * ```ql
+ * class MyAnalysisConfiguration extends TaintTracking::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isSanitizer`.
+ *   // Optionally override `isSanitizerIn`.
+ *   // Optionally override `isSanitizerOut`.
+ *   // Optionally override `isSanitizerGuard`.
+ *   // Optionally override `isAdditionalTaintStep`.
+ * }
+ * ```
+ *
+ * Then, to query whether there is flow between some `source` and `sink`,
+ * write
+ *
+ * ```ql
+ * exists(MyAnalysisConfiguration cfg | cfg.hasFlow(source, sink))
+ * ```
+ *
+ * Multiple configurations can coexist, but it is unsupported to depend on
+ * another `TaintTracking::Configuration` or a `DataFlow::Configuration` in the
+ * overridden predicates that define sources, sinks, or additional steps.
+ * Instead, the dependency should go to a `TaintTracking2::Configuration` or a
+ * `DataFlow2::Configuration`, `DataFlow3::Configuration`, etc.
+ */
+abstract class Configuration extends DataFlow::Configuration {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant taint source.
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSource(DataFlow::Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant taint source with the given initial
+   * `state`.
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSource(DataFlow::Node source, DataFlow::FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant taint sink
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSink(DataFlow::Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant taint sink accepting `state`.
+   *
+   * The smaller this predicate is, the faster `hasFlow()` will converge.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate isSink(DataFlow::Node sink, DataFlow::FlowState state) { none() }
+
+  /** Holds if the node `node` is a taint sanitizer. */
+  predicate isSanitizer(DataFlow::Node node) { none() }
+
+  final override predicate isBarrier(DataFlow::Node node) {
+    this.isSanitizer(node) or
+    defaultTaintSanitizer(node)
+  }
+
+  /**
+   * Holds if the node `node` is a taint sanitizer when the flow state is
+   * `state`.
+   */
+  predicate isSanitizer(DataFlow::Node node, DataFlow::FlowState state) { none() }
+
+  final override predicate isBarrier(DataFlow::Node node, DataFlow::FlowState state) {
+    this.isSanitizer(node, state)
+  }
+
+  /** Holds if taint propagation into `node` is prohibited. */
+  predicate isSanitizerIn(DataFlow::Node node) { none() }
+
+  final override predicate isBarrierIn(DataFlow::Node node) { this.isSanitizerIn(node) }
+
+  /** Holds if taint propagation out of `node` is prohibited. */
+  predicate isSanitizerOut(DataFlow::Node node) { none() }
+
+  final override predicate isBarrierOut(DataFlow::Node node) { this.isSanitizerOut(node) }
+
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard) { none() }
+
+  deprecated final override predicate isBarrierGuard(DataFlow::BarrierGuard guard) {
+    this.isSanitizerGuard(guard)
+  }
+
+  /**
+   * DEPRECATED: Use `isSanitizer` and `BarrierGuard` module instead.
+   *
+   * Holds if taint propagation through nodes guarded by `guard` is prohibited
+   * when the flow state is `state`.
+   */
+  deprecated predicate isSanitizerGuard(DataFlow::BarrierGuard guard, DataFlow::FlowState state) {
+    none()
+  }
+
+  deprecated final override predicate isBarrierGuard(
+    DataFlow::BarrierGuard guard, DataFlow::FlowState state
+  ) {
+    this.isSanitizerGuard(guard, state)
+  }
+
+  /**
+   * Holds if taint may propagate from `node1` to `node2` in addition to the normal data-flow and taint steps.
+   */
+  predicate isAdditionalTaintStep(DataFlow::Node node1, DataFlow::Node node2) { none() }
+
+  final override predicate isAdditionalFlowStep(DataFlow::Node node1, DataFlow::Node node2) {
+    this.isAdditionalTaintStep(node1, node2) or
+    defaultAdditionalTaintStep(node1, node2)
+  }
+
+  /**
+   * Holds if taint may propagate from `node1` to `node2` in addition to the normal data-flow and taint steps.
+   * This step is only applicable in `state1` and updates the flow state to `state2`.
+   */
+  predicate isAdditionalTaintStep(
+    DataFlow::Node node1, DataFlow::FlowState state1, DataFlow::Node node2,
+    DataFlow::FlowState state2
+  ) {
+    none()
+  }
+
+  final override predicate isAdditionalFlowStep(
+    DataFlow::Node node1, DataFlow::FlowState state1, DataFlow::Node node2,
+    DataFlow::FlowState state2
+  ) {
+    this.isAdditionalTaintStep(node1, state1, node2, state2)
+  }
+
+  override predicate allowImplicitRead(DataFlow::Node node, DataFlow::ContentSet c) {
+    (
+      this.isSink(node) or
+      this.isSink(node, _) or
+      this.isAdditionalTaintStep(node, _) or
+      this.isAdditionalTaintStep(node, _, _, _)
+    ) and
+    defaultImplicitTaintRead(node, c)
+  }
+
+  /**
+   * Holds if taint may flow from `source` to `sink` for this configuration.
+   */
+  // overridden to provide taint-tracking specific qldoc
+  override predicate hasFlow(DataFlow::Node source, DataFlow::Node sink) {
+    super.hasFlow(source, sink)
+  }
+}

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

@@ -0,0 +1,5 @@
+import experimental.semmle.code.cpp.ir.dataflow.internal.TaintTrackingUtil as Public
+
+module Private {
+  import experimental.semmle.code.cpp.ir.dataflow.DataFlow3::DataFlow3 as DataFlow
+}

cpp/ql/lib/experimental/semmle/code/cpp/rangeanalysis/extensions/ConstantShiftExprRange.qll

@@ -1,263 +0,0 @@
-private import cpp
-private import experimental.semmle.code.cpp.models.interfaces.SimpleRangeAnalysisExpr
-private import semmle.code.cpp.rangeanalysis.RangeAnalysisUtils
-
-float evaluateConstantExpr(Expr e) {
-  result = e.getValue().toFloat()
-  or
-  // This handles when a constant value is put into a variable
-  // and the variable is used later
-  exists(SsaDefinition defn, StackVariable sv |
-    defn.getAUse(sv) = e and
-    result = defn.getDefiningValue(sv).getValue().toFloat()
-  )
-}
-
-// If the constant right operand is negative or is greater than or equal to the number of
-// bits in the left operands type, then the result is undefined (except on the IA-32
-// architecture where the shift value is masked with 0b00011111, but we can't
-// assume the architecture).
-bindingset[val]
-private predicate isValidShiftExprShift(float val, Expr l) {
-  val >= 0 and
-  // We use getFullyConverted because the spec says to use the *promoted* left operand
-  val < (l.getFullyConverted().getUnderlyingType().getSize() * 8)
-}
-
-bindingset[val, shift, max_val]
-private predicate canLShiftOverflow(int val, int shift, int max_val) {
-  // val << shift = val * 2^shift > max_val => val > max_val/2^shift = max_val >> b
-  val > max_val.bitShiftRight(shift)
-}
-
-/**
- * A range analysis expression consisting of the `>>` or `>>=` operator when at least
- * one operand is a constant (and if the right operand is a constant, it must be "valid"
- * (see `isValidShiftExprShift`)). When handling any undefined behavior, it leaves the
- * values unconstrained. From the C++ standard: "The behavior is undefined if the right
- * operand is negative, or greater than or equal to the length in bits of the promoted
- * left operand. The value of E1 >> E2 is E1 right-shifted E2 bit positions. If E1 has an
- * unsigned type or if E1 has a signed type and a non-negative value, the value of the
- * result is the integral part of the quotient of E1/2^E2. If E1 has a signed type and a
- * negative value, the resulting value is implementation-defined."
- */
-class ConstantRShiftExprRange extends SimpleRangeAnalysisExpr {
-  /**
-   * Holds for `a >> b` or `a >>= b` in one of the following two cases:
-   * 1. `a` is a constant and `b` is not
-   * 2. `b` is constant
-   *
-   * We don't handle the case where `a` and `b` are both non-constant values.
-   */
-  ConstantRShiftExprRange() {
-    getUnspecifiedType() instanceof IntegralType and
-    exists(Expr l, Expr r |
-      l = this.(RShiftExpr).getLeftOperand() and
-      r = this.(RShiftExpr).getRightOperand()
-      or
-      l = this.(AssignRShiftExpr).getLValue() and
-      r = this.(AssignRShiftExpr).getRValue()
-    |
-      l.getUnspecifiedType() instanceof IntegralType and
-      r.getUnspecifiedType() instanceof IntegralType and
-      (
-        // If the left operand is a constant, verify that the right operand is not a constant
-        exists(evaluateConstantExpr(l)) and not exists(evaluateConstantExpr(r))
-        or
-        // If the right operand is a constant, check if it is a valid shift expression
-        exists(float constROp |
-          constROp = evaluateConstantExpr(r) and isValidShiftExprShift(constROp, l)
-        )
-      )
-    )
-  }
-
-  Expr getLeftOperand() {
-    result = this.(RShiftExpr).getLeftOperand() or
-    result = this.(AssignRShiftExpr).getLValue()
-  }
-
-  Expr getRightOperand() {
-    result = this.(RShiftExpr).getRightOperand() or
-    result = this.(AssignRShiftExpr).getRValue()
-  }
-
-  override float getLowerBounds() {
-    exists(int lLower, int lUpper, int rLower, int rUpper |
-      lLower = getFullyConvertedLowerBounds(getLeftOperand()) and
-      lUpper = getFullyConvertedUpperBounds(getLeftOperand()) and
-      rLower = getFullyConvertedLowerBounds(getRightOperand()) and
-      rUpper = getFullyConvertedUpperBounds(getRightOperand()) and
-      lLower <= lUpper and
-      rLower <= rUpper
-    |
-      if
-        lLower < 0
-        or
-        not (
-          isValidShiftExprShift(rLower, getLeftOperand()) and
-          isValidShiftExprShift(rUpper, getLeftOperand())
-        )
-      then
-        // We don't want to deal with shifting negative numbers at the moment,
-        // and a negative shift is implementation defined, so we set the result
-        // to the minimum value
-        result = exprMinVal(this)
-      else
-        // We can get the smallest value by shifting the smallest bound by the largest bound
-        result = lLower.bitShiftRight(rUpper)
-    )
-  }
-
-  override float getUpperBounds() {
-    exists(int lLower, int lUpper, int rLower, int rUpper |
-      lLower = getFullyConvertedLowerBounds(getLeftOperand()) and
-      lUpper = getFullyConvertedUpperBounds(getLeftOperand()) and
-      rLower = getFullyConvertedLowerBounds(getRightOperand()) and
-      rUpper = getFullyConvertedUpperBounds(getRightOperand()) and
-      lLower <= lUpper and
-      rLower <= rUpper
-    |
-      if
-        lLower < 0
-        or
-        not (
-          isValidShiftExprShift(rLower, getLeftOperand()) and
-          isValidShiftExprShift(rUpper, getLeftOperand())
-        )
-      then
-        // We don't want to deal with shifting negative numbers at the moment,
-        // and a negative shift is implementation defined, so we set the result
-        // to the maximum value
-        result = exprMaxVal(this)
-      else
-        // We can get the largest value by shifting the largest bound by the smallest bound
-        result = lUpper.bitShiftRight(rLower)
-    )
-  }
-
-  override predicate dependsOnChild(Expr child) {
-    child = getLeftOperand() or child = getRightOperand()
-  }
-}
-
-/**
- * A range analysis expression consisting of the `<<` or `<<=` operator when at least
- * one operand is a constant (and if the right operand is a constant, it must be "valid"
- * (see `isValidShiftExprShift`)). When handling any undefined behavior, it leaves the
- * values unconstrained. From the C++ standard: "The behavior is undefined if the right
- * operand is negative, or greater than or equal to the length in bits of the promoted left operand.
- * The value of E1 << E2 is E1 left-shifted E2 bit positions; vacated bits are zero-filled. If E1
- * has an unsigned type, the value of the result is E1 x 2 E2, reduced modulo one more than the
- * maximum value representable in the result type. Otherwise, if E1 has a signed type and
- * non-negative value, and E1 x 2 E2 is representable in the corresponding unsigned type of the
- * result type, then that value, converted to the result type, is the resulting value; otherwise,
- * the behavior is undefined."
- */
-class ConstantLShiftExprRange extends SimpleRangeAnalysisExpr {
-  /**
-   * Holds for `a << b` or `a <<= b` in one of the following two cases:
-   * 1. `a` is a constant and `b` is not
-   * 2. `b` is constant
-   *
-   * We don't handle the case where `a` and `b` are both non-constant values.
-   */
-  ConstantLShiftExprRange() {
-    getUnspecifiedType() instanceof IntegralType and
-    exists(Expr l, Expr r |
-      l = this.(LShiftExpr).getLeftOperand() and
-      r = this.(LShiftExpr).getRightOperand()
-      or
-      l = this.(AssignLShiftExpr).getLValue() and
-      r = this.(AssignLShiftExpr).getRValue()
-    |
-      l.getUnspecifiedType() instanceof IntegralType and
-      r.getUnspecifiedType() instanceof IntegralType and
-      (
-        // If the left operand is a constant, verify that the right operand is not a constant
-        exists(evaluateConstantExpr(l)) and not exists(evaluateConstantExpr(r))
-        or
-        // If the right operand is a constant, check if it is a valid shift expression
-        exists(float constROp |
-          constROp = evaluateConstantExpr(r) and isValidShiftExprShift(constROp, l)
-        )
-      )
-    )
-  }
-
-  Expr getLeftOperand() {
-    result = this.(LShiftExpr).getLeftOperand() or
-    result = this.(AssignLShiftExpr).getLValue()
-  }
-
-  Expr getRightOperand() {
-    result = this.(LShiftExpr).getRightOperand() or
-    result = this.(AssignLShiftExpr).getRValue()
-  }
-
-  override float getLowerBounds() {
-    exists(int lLower, int lUpper, int rLower, int rUpper |
-      lLower = getFullyConvertedLowerBounds(getLeftOperand()) and
-      lUpper = getFullyConvertedUpperBounds(getLeftOperand()) and
-      rLower = getFullyConvertedLowerBounds(getRightOperand()) and
-      rUpper = getFullyConvertedUpperBounds(getRightOperand()) and
-      lLower <= lUpper and
-      rLower <= rUpper
-    |
-      if
-        lLower < 0
-        or
-        not (
-          isValidShiftExprShift(rLower, getLeftOperand()) and
-          isValidShiftExprShift(rUpper, getLeftOperand())
-        )
-      then
-        // We don't want to deal with shifting negative numbers at the moment,
-        // and a negative shift is undefined, so we set to the minimum value
-        result = exprMinVal(this)
-      else
-        // If we have `0b01010000 << [0, 2]`, the max value for 8 bits is 0b10100000
-        // (a shift of 1) but doing a shift by the upper bound would give 0b01000000.
-        // So if the left shift operation causes an overflow, we just assume the max value
-        // If necessary, we may be able to improve this bound in the future
-        if canLShiftOverflow(lUpper, rUpper, exprMaxVal(this))
-        then result = exprMinVal(this)
-        else result = lLower.bitShiftLeft(rLower)
-    )
-  }
-
-  override float getUpperBounds() {
-    exists(int lLower, int lUpper, int rLower, int rUpper |
-      lLower = getFullyConvertedLowerBounds(getLeftOperand()) and
-      lUpper = getFullyConvertedUpperBounds(getLeftOperand()) and
-      rLower = getFullyConvertedLowerBounds(getRightOperand()) and
-      rUpper = getFullyConvertedUpperBounds(getRightOperand()) and
-      lLower <= lUpper and
-      rLower <= rUpper
-    |
-      if
-        lLower < 0
-        or
-        not (
-          isValidShiftExprShift(rLower, getLeftOperand()) and
-          isValidShiftExprShift(rUpper, getLeftOperand())
-        )
-      then
-        // We don't want to deal with shifting negative numbers at the moment,
-        // and a negative shift is undefined, so we set it to the maximum value
-        result = exprMaxVal(this)
-      else
-        // If we have `0b01010000 << [0, 2]`, the max value for 8 bits is 0b10100000
-        // (a shift of 1) but doing a shift by the upper bound would give 0b01000000.
-        // So if the left shift operation causes an overflow, we just assume the max value
-        // If necessary, we may be able to improve this bound in the future
-        if canLShiftOverflow(lUpper, rUpper, exprMaxVal(this))
-        then result = exprMaxVal(this)
-        else result = lUpper.bitShiftLeft(rUpper)
-    )
-  }
-
-  override predicate dependsOnChild(Expr child) {
-    child = getLeftOperand() or child = getRightOperand()
-  }
-}

cpp/ql/lib/experimental/semmle/code/cpp/security/PrivateCleartextWrite.qll

@@ -3,7 +3,7 @@
  */
 
 import cpp
-import semmle.code.cpp.ir.dataflow.TaintTracking
+import semmle.code.cpp.dataflow.TaintTracking
 import semmle.code.cpp.security.PrivateData
 import semmle.code.cpp.security.FileWrite
 import semmle.code.cpp.security.BufferWrite
@@ -36,7 +36,7 @@ module PrivateCleartextWrite {
     }
   }
 
-  deprecated class WriteConfig extends TaintTracking::Configuration {
+  class WriteConfig extends TaintTracking::Configuration {
     WriteConfig() { this = "Write configuration" }
 
     override predicate isSource(DataFlow::Node source) { source instanceof Source }
@@ -46,16 +46,6 @@ module PrivateCleartextWrite {
     override predicate isSanitizer(DataFlow::Node node) { node instanceof Sanitizer }
   }
 
-  private module WriteConfig implements DataFlow::ConfigSig {
-    predicate isSource(DataFlow::Node source) { source instanceof Source }
-
-    predicate isSink(DataFlow::Node sink) { sink instanceof Sink }
-
-    predicate isBarrier(DataFlow::Node node) { node instanceof Sanitizer }
-  }
-
-  module WriteFlow = TaintTracking::Make<WriteConfig>;
-
   class PrivateDataSource extends Source {
     PrivateDataSource() { this.getExpr() instanceof PrivateDataExpr }
   }

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

@@ -1,29 +0,0 @@
-private import RangeAnalysisStage
-
-module FloatDelta implements DeltaSig {
-  class Delta = float;
-
-  bindingset[d]
-  bindingset[result]
-  float toFloat(Delta d) { result = d }
-
-  bindingset[d]
-  bindingset[result]
-  int toInt(Delta d) { result = d }
-
-  bindingset[n]
-  bindingset[result]
-  Delta fromInt(int n) { result = n }
-
-  bindingset[f]
-  Delta fromFloat(float f) {
-    result =
-      min(float diff, float res |
-        diff = (res - f) and res = f.ceil()
-        or
-        diff = (f - res) and res = f.floor()
-      |
-        res order by diff
-      )
-  }
-}

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

@@ -14,328 +14,321 @@ private import ModulusAnalysisSpecific::Private
 private import experimental.semmle.code.cpp.semantic.Semantic
 private import ConstantAnalysis
 private import RangeUtils
-private import RangeAnalysisStage
 
-module ModulusAnalysis<DeltaSig D, BoundSig<D> Bounds, UtilSig<D> U> {
-  /**
-   * Holds if `e + delta` equals `v` at `pos`.
-   */
-  private predicate valueFlowStepSsa(SemSsaVariable v, SemSsaReadPosition pos, SemExpr e, int delta) {
-    U::semSsaUpdateStep(v, e, D::fromInt(delta)) and pos.hasReadOfVar(v)
-    or
-    exists(SemGuard guard, boolean testIsTrue |
-      pos.hasReadOfVar(v) and
-      guard = U::semEqFlowCond(v, e, D::fromInt(delta), true, testIsTrue) and
-      semGuardDirectlyControlsSsaRead(guard, pos, testIsTrue)
-    )
-  }
+/**
+ * Holds if `e + delta` equals `v` at `pos`.
+ */
+private predicate valueFlowStepSsa(SemSsaVariable v, SemSsaReadPosition pos, SemExpr e, int delta) {
+  semSsaUpdateStep(v, e, delta) and pos.hasReadOfVar(v)
+  or
+  exists(SemGuard guard, boolean testIsTrue |
+    pos.hasReadOfVar(v) and
+    guard = semEqFlowCond(v, e, delta, true, testIsTrue) and
+    semGuardDirectlyControlsSsaRead(guard, pos, testIsTrue)
+  )
+}
 
-  /**
-   * Holds if `add` is the addition of `larg` and `rarg`, neither of which are
-   * `ConstantIntegerExpr`s.
-   */
-  private predicate nonConstAddition(SemExpr add, SemExpr larg, SemExpr rarg) {
-    exists(SemAddExpr a | a = add |
-      larg = a.getLeftOperand() and
-      rarg = a.getRightOperand()
-    ) and
-    not larg instanceof SemConstantIntegerExpr and
-    not rarg instanceof SemConstantIntegerExpr
-  }
+/**
+ * Holds if `add` is the addition of `larg` and `rarg`, neither of which are
+ * `ConstantIntegerExpr`s.
+ */
+private predicate nonConstAddition(SemExpr add, SemExpr larg, SemExpr rarg) {
+  exists(SemAddExpr a | a = add |
+    larg = a.getLeftOperand() and
+    rarg = a.getRightOperand()
+  ) and
+  not larg instanceof SemConstantIntegerExpr and
+  not rarg instanceof SemConstantIntegerExpr
+}
 
-  /**
-   * Holds if `sub` is the subtraction of `larg` and `rarg`, where `rarg` is not
-   * a `ConstantIntegerExpr`.
-   */
-  private predicate nonConstSubtraction(SemExpr sub, SemExpr larg, SemExpr rarg) {
-    exists(SemSubExpr s | s = sub |
-      larg = s.getLeftOperand() and
-      rarg = s.getRightOperand()
-    ) and
-    not rarg instanceof SemConstantIntegerExpr
-  }
+/**
+ * Holds if `sub` is the subtraction of `larg` and `rarg`, where `rarg` is not
+ * a `ConstantIntegerExpr`.
+ */
+private predicate nonConstSubtraction(SemExpr sub, SemExpr larg, SemExpr rarg) {
+  exists(SemSubExpr s | s = sub |
+    larg = s.getLeftOperand() and
+    rarg = s.getRightOperand()
+  ) and
+  not rarg instanceof SemConstantIntegerExpr
+}
 
-  /** Gets an expression that is the remainder modulo `mod` of `arg`. */
-  private SemExpr modExpr(SemExpr arg, int mod) {
-    exists(SemRemExpr rem |
-      result = rem and
-      arg = rem.getLeftOperand() and
-      rem.getRightOperand().(SemConstantIntegerExpr).getIntValue() = mod and
-      mod >= 2
-    )
-    or
-    exists(SemConstantIntegerExpr c |
-      mod = 2.pow([1 .. 30]) and
-      c.getIntValue() = mod - 1 and
-      result.(SemBitAndExpr).hasOperands(arg, c)
-    )
-  }
+/** Gets an expression that is the remainder modulo `mod` of `arg`. */
+private SemExpr modExpr(SemExpr arg, int mod) {
+  exists(SemRemExpr rem |
+    result = rem and
+    arg = rem.getLeftOperand() and
+    rem.getRightOperand().(SemConstantIntegerExpr).getIntValue() = mod and
+    mod >= 2
+  )
+  or
+  exists(SemConstantIntegerExpr c |
+    mod = 2.pow([1 .. 30]) and
+    c.getIntValue() = mod - 1 and
+    result.(SemBitAndExpr).hasOperands(arg, c)
+  )
+}
 
-  /**
-   * Gets a guard that tests whether `v` is congruent with `val` modulo `mod` on
-   * its `testIsTrue` branch.
-   */
-  private SemGuard moduloCheck(SemSsaVariable v, int val, int mod, boolean testIsTrue) {
-    exists(SemExpr rem, SemConstantIntegerExpr c, int r, boolean polarity |
-      result.isEquality(rem, c, polarity) and
-      c.getIntValue() = r and
-      rem = modExpr(v.getAUse(), mod) and
-      (
-        testIsTrue = polarity and val = r
-        or
-        testIsTrue = polarity.booleanNot() and
-        mod = 2 and
-        val = 1 - r and
-        (r = 0 or r = 1)
-      )
-    )
-  }
-
-  /**
-   * Holds if a guard ensures that `v` at `pos` is congruent with `val` modulo `mod`.
-   */
-  private predicate moduloGuardedRead(SemSsaVariable v, SemSsaReadPosition pos, int val, int mod) {
-    exists(SemGuard guard, boolean testIsTrue |
-      pos.hasReadOfVar(v) and
-      guard = moduloCheck(v, val, mod, testIsTrue) and
-      semGuardControlsSsaRead(guard, pos, testIsTrue)
-    )
-  }
-
-  /** Holds if `factor` is a power of 2 that divides `mask`. */
-  bindingset[mask]
-  private predicate andmaskFactor(int mask, int factor) {
-    mask % factor = 0 and
-    factor = 2.pow([1 .. 30])
-  }
-
-  /** Holds if `e` is evenly divisible by `factor`. */
-  private predicate evenlyDivisibleExpr(SemExpr e, int factor) {
-    exists(SemConstantIntegerExpr c, int k | k = c.getIntValue() |
-      e.(SemMulExpr).getAnOperand() = c and factor = k.abs() and factor >= 2
+/**
+ * Gets a guard that tests whether `v` is congruent with `val` modulo `mod` on
+ * its `testIsTrue` branch.
+ */
+private SemGuard moduloCheck(SemSsaVariable v, int val, int mod, boolean testIsTrue) {
+  exists(SemExpr rem, SemConstantIntegerExpr c, int r, boolean polarity |
+    result.isEquality(rem, c, polarity) and
+    c.getIntValue() = r and
+    rem = modExpr(v.getAUse(), mod) and
+    (
+      testIsTrue = polarity and val = r
       or
-      e.(SemShiftLeftExpr).getRightOperand() = c and factor = 2.pow(k) and k > 0
-      or
-      e.(SemBitAndExpr).getAnOperand() = c and factor = max(int f | andmaskFactor(k, f))
+      testIsTrue = polarity.booleanNot() and
+      mod = 2 and
+      val = 1 - r and
+      (r = 0 or r = 1)
     )
-  }
+  )
+}
 
-  /**
-   * Holds if `rix` is the number of input edges to `phi`.
-   */
-  private predicate maxPhiInputRank(SemSsaPhiNode phi, int rix) {
-    rix = max(int r | rankedPhiInput(phi, _, _, r))
-  }
+/**
+ * Holds if a guard ensures that `v` at `pos` is congruent with `val` modulo `mod`.
+ */
+private predicate moduloGuardedRead(SemSsaVariable v, SemSsaReadPosition pos, int val, int mod) {
+  exists(SemGuard guard, boolean testIsTrue |
+    pos.hasReadOfVar(v) and
+    guard = moduloCheck(v, val, mod, testIsTrue) and
+    semGuardControlsSsaRead(guard, pos, testIsTrue)
+  )
+}
 
-  /**
-   * Gets the remainder of `val` modulo `mod`.
-   *
-   * For `mod = 0` the result equals `val` and for `mod > 1` the result is within
-   * the range `[0 .. mod-1]`.
-   */
-  bindingset[val, mod]
-  private int remainder(int val, int mod) {
-    mod = 0 and result = val
+/** Holds if `factor` is a power of 2 that divides `mask`. */
+bindingset[mask]
+private predicate andmaskFactor(int mask, int factor) {
+  mask % factor = 0 and
+  factor = 2.pow([1 .. 30])
+}
+
+/** Holds if `e` is evenly divisible by `factor`. */
+private predicate evenlyDivisibleExpr(SemExpr e, int factor) {
+  exists(SemConstantIntegerExpr c, int k | k = c.getIntValue() |
+    e.(SemMulExpr).getAnOperand() = c and factor = k.abs() and factor >= 2
     or
-    mod > 1 and result = ((val % mod) + mod) % mod
-  }
+    e.(SemShiftLeftExpr).getRightOperand() = c and factor = 2.pow(k) and k > 0
+    or
+    e.(SemBitAndExpr).getAnOperand() = c and factor = max(int f | andmaskFactor(k, f))
+  )
+}
 
-  /**
-   * Holds if `inp` is an input to `phi` and equals `phi` modulo `mod` along `edge`.
-   */
-  private predicate phiSelfModulus(
-    SemSsaPhiNode phi, SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge, int mod
-  ) {
-    exists(Bounds::SemSsaBound phibound, int v, int m |
-      edge.phiInput(phi, inp) and
-      phibound.getAVariable() = phi and
-      ssaModulus(inp, edge, phibound, v, m) and
-      mod = m.gcd(v) and
-      mod != 1
-    )
-  }
+/**
+ * Holds if `rix` is the number of input edges to `phi`.
+ */
+private predicate maxPhiInputRank(SemSsaPhiNode phi, int rix) {
+  rix = max(int r | rankedPhiInput(phi, _, _, r))
+}
 
-  /**
-   * Holds if `b + val` modulo `mod` is a candidate congruence class for `phi`.
-   */
-  private predicate phiModulusInit(SemSsaPhiNode phi, Bounds::SemBound b, int val, int mod) {
-    exists(SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge |
-      edge.phiInput(phi, inp) and
-      ssaModulus(inp, edge, b, val, mod)
-    )
-  }
+/**
+ * Gets the remainder of `val` modulo `mod`.
+ *
+ * For `mod = 0` the result equals `val` and for `mod > 1` the result is within
+ * the range `[0 .. mod-1]`.
+ */
+bindingset[val, mod]
+private int remainder(int val, int mod) {
+  mod = 0 and result = val
+  or
+  mod > 1 and result = ((val % mod) + mod) % mod
+}
 
-  /**
-   * Holds if all inputs to `phi` numbered `1` to `rix` are equal to `b + val` modulo `mod`.
+/**
+ * Holds if `inp` is an input to `phi` and equals `phi` modulo `mod` along `edge`.
+ */
+private predicate phiSelfModulus(
+  SemSsaPhiNode phi, SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge, int mod
+) {
+  exists(SemSsaBound phibound, int v, int m |
+    edge.phiInput(phi, inp) and
+    phibound.getAVariable() = phi and
+    ssaModulus(inp, edge, phibound, v, m) and
+    mod = m.gcd(v) and
+    mod != 1
+  )
+}
+
+/**
+ * Holds if `b + val` modulo `mod` is a candidate congruence class for `phi`.
+ */
+private predicate phiModulusInit(SemSsaPhiNode phi, SemBound b, int val, int mod) {
+  exists(SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge |
+    edge.phiInput(phi, inp) and
+    ssaModulus(inp, edge, b, val, mod)
+  )
+}
+
+/**
+ * Holds if all inputs to `phi` numbered `1` to `rix` are equal to `b + val` modulo `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.
    */
-  pragma[nomagic]
-  private predicate phiModulusRankStep(
-    SemSsaPhiNode phi, Bounds::SemBound b, int val, int mod, int rix
-  ) {
+
+  rix = 0 and
+  phiModulusInit(phi, b, val, mod)
+  or
+  exists(SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge, int v1, int m1 |
+    mod != 1 and
+    val = remainder(v1, mod)
+  |
     /*
-     * base case. If any phi input is equal to `b + val` modulo `mod`, that's a potential congruence
-     * class for the phi node.
+     * 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`.
      */
 
-    rix = 0 and
-    phiModulusInit(phi, b, val, mod)
-    or
-    exists(SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge, int v1, int m1 |
-      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
-        ssaModulus(inp, edge, b, v2, m2) and
-        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
-        phiSelfModulus(phi, inp, edge, m2) and
-        mod = m1.gcd(m2)
-      )
+    exists(int v2, int m2 |
+      rankedPhiInput(pragma[only_bind_out](phi), inp, edge, rix) and
+      phiModulusRankStep(phi, b, v1, m1, rix - 1) and
+      ssaModulus(inp, edge, b, v2, m2) and
+      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`.
+     */
 
-  /**
-   * Holds if `phi` is equal to `b + val` modulo `mod`.
-   */
-  private predicate phiModulus(SemSsaPhiNode phi, Bounds::SemBound b, int val, int mod) {
-    exists(int r |
-      maxPhiInputRank(phi, r) and
-      phiModulusRankStep(phi, b, val, mod, r)
+    exists(int m2 |
+      rankedPhiInput(phi, inp, edge, rix) and
+      phiModulusRankStep(phi, b, v1, m1, rix - 1) and
+      phiSelfModulus(phi, inp, edge, m2) and
+      mod = m1.gcd(m2)
     )
-  }
+  )
+}
 
-  /**
-   * Holds if `v` at `pos` is equal to `b + val` modulo `mod`.
-   */
-  private predicate ssaModulus(
-    SemSsaVariable v, SemSsaReadPosition pos, Bounds::SemBound b, int val, int mod
-  ) {
-    phiModulus(v, b, val, mod) and pos.hasReadOfVar(v)
+/**
+ * Holds if `phi` is equal to `b + val` modulo `mod`.
+ */
+private predicate phiModulus(SemSsaPhiNode phi, SemBound b, int val, int mod) {
+  exists(int r |
+    maxPhiInputRank(phi, r) and
+    phiModulusRankStep(phi, b, val, mod, r)
+  )
+}
+
+/**
+ * Holds if `v` at `pos` is equal to `b + val` modulo `mod`.
+ */
+private predicate ssaModulus(SemSsaVariable v, SemSsaReadPosition pos, SemBound b, int val, int mod) {
+  phiModulus(v, b, val, mod) and pos.hasReadOfVar(v)
+  or
+  b.(SemSsaBound).getAVariable() = v and pos.hasReadOfVar(v) and val = 0 and mod = 0
+  or
+  exists(SemExpr e, int val0, int delta |
+    semExprModulus(e, b, val0, mod) and
+    valueFlowStepSsa(v, pos, e, delta) and
+    val = remainder(val0 + delta, mod)
+  )
+  or
+  moduloGuardedRead(v, pos, val, mod) and b instanceof SemZeroBound
+}
+
+/**
+ * Holds if `e` is equal to `b + val` modulo `mod`.
+ *
+ * There are two cases for the modulus:
+ * - `mod = 0`: The equality `e = b + val` is an ordinary equality.
+ * - `mod > 1`: `val` lies within the range `[0 .. mod-1]`.
+ */
+cached
+predicate semExprModulus(SemExpr e, SemBound b, int val, int mod) {
+  not ignoreExprModulus(e) and
+  (
+    e = b.getExpr(val) and mod = 0
     or
-    b.(Bounds::SemSsaBound).getAVariable() = v and pos.hasReadOfVar(v) and val = 0 and mod = 0
+    evenlyDivisibleExpr(e, mod) and
+    val = 0 and
+    b instanceof SemZeroBound
     or
-    exists(SemExpr e, int val0, int delta |
-      semExprModulus(e, b, val0, mod) and
-      valueFlowStepSsa(v, pos, e, delta) and
+    exists(SemSsaVariable v, SemSsaReadPositionBlock bb |
+      ssaModulus(v, bb, b, val, mod) and
+      e = v.getAUse() and
+      bb.getAnExpr() = e
+    )
+    or
+    exists(SemExpr mid, int val0, int delta |
+      semExprModulus(mid, b, val0, mod) and
+      semValueFlowStep(e, mid, delta) and
       val = remainder(val0 + delta, mod)
     )
     or
-    moduloGuardedRead(v, pos, val, mod) and b instanceof Bounds::SemZeroBound
-  }
-
-  /**
-   * Holds if `e` is equal to `b + val` modulo `mod`.
-   *
-   * There are two cases for the modulus:
-   * - `mod = 0`: The equality `e = b + val` is an ordinary equality.
-   * - `mod > 1`: `val` lies within the range `[0 .. mod-1]`.
-   */
-  cached
-  predicate semExprModulus(SemExpr e, Bounds::SemBound b, int val, int mod) {
-    not ignoreExprModulus(e) and
-    (
-      e = b.getExpr(D::fromInt(val)) and mod = 0
-      or
-      evenlyDivisibleExpr(e, mod) and
-      val = 0 and
-      b instanceof Bounds::SemZeroBound
-      or
-      exists(SemSsaVariable v, SemSsaReadPositionBlock bb |
-        ssaModulus(v, bb, b, val, mod) and
-        e = v.getAUse() and
-        bb.getAnExpr() = e
-      )
-      or
-      exists(SemExpr mid, int val0, int delta |
-        semExprModulus(mid, b, val0, mod) and
-        U::semValueFlowStep(e, mid, D::fromInt(delta)) and
-        val = remainder(val0 + delta, mod)
-      )
-      or
-      exists(SemConditionalExpr cond, int v1, int v2, int m1, int m2 |
-        cond = e and
-        condExprBranchModulus(cond, true, b, v1, m1) and
-        condExprBranchModulus(cond, false, b, v2, m2) and
-        mod = m1.gcd(m2).gcd(v1 - v2) and
-        mod != 1 and
-        val = remainder(v1, mod)
-      )
-      or
-      exists(Bounds::SemBound b1, Bounds::SemBound b2, int v1, int v2, int m1, int m2 |
-        addModulus(e, true, b1, v1, m1) and
-        addModulus(e, false, b2, v2, m2) and
-        mod = m1.gcd(m2) and
-        mod != 1 and
-        val = remainder(v1 + v2, mod)
-      |
-        b = b1 and b2 instanceof Bounds::SemZeroBound
-        or
-        b = b2 and b1 instanceof Bounds::SemZeroBound
-      )
-      or
-      exists(int v1, int v2, int m1, int m2 |
-        subModulus(e, true, b, v1, m1) and
-        subModulus(e, false, any(Bounds::SemZeroBound zb), v2, m2) and
-        mod = m1.gcd(m2) and
-        mod != 1 and
-        val = remainder(v1 - v2, mod)
-      )
+    exists(SemConditionalExpr cond, int v1, int v2, int m1, int m2 |
+      cond = e and
+      condExprBranchModulus(cond, true, b, v1, m1) and
+      condExprBranchModulus(cond, false, b, v2, m2) and
+      mod = m1.gcd(m2).gcd(v1 - v2) and
+      mod != 1 and
+      val = remainder(v1, mod)
     )
-  }
-
-  private predicate condExprBranchModulus(
-    SemConditionalExpr cond, boolean branch, Bounds::SemBound b, int val, int mod
-  ) {
-    semExprModulus(cond.getBranchExpr(branch), b, val, mod)
-  }
-
-  private predicate addModulus(SemExpr add, boolean isLeft, Bounds::SemBound b, int val, int mod) {
-    exists(SemExpr larg, SemExpr rarg | nonConstAddition(add, larg, rarg) |
-      semExprModulus(larg, b, val, mod) and isLeft = true
+    or
+    exists(SemBound b1, SemBound b2, int v1, int v2, int m1, int m2 |
+      addModulus(e, true, b1, v1, m1) and
+      addModulus(e, false, b2, v2, m2) and
+      mod = m1.gcd(m2) and
+      mod != 1 and
+      val = remainder(v1 + v2, mod)
+    |
+      b = b1 and b2 instanceof SemZeroBound
       or
-      semExprModulus(rarg, b, val, mod) and isLeft = false
+      b = b2 and b1 instanceof SemZeroBound
     )
-  }
-
-  private predicate subModulus(SemExpr sub, boolean isLeft, Bounds::SemBound b, int val, int mod) {
-    exists(SemExpr larg, SemExpr rarg | nonConstSubtraction(sub, larg, rarg) |
-      semExprModulus(larg, b, val, mod) and isLeft = true
-      or
-      semExprModulus(rarg, b, val, mod) and isLeft = false
+    or
+    exists(int v1, int v2, int m1, int m2 |
+      subModulus(e, true, b, v1, m1) and
+      subModulus(e, false, any(SemZeroBound zb), v2, m2) and
+      mod = m1.gcd(m2) and
+      mod != 1 and
+      val = remainder(v1 - v2, mod)
+    )
+  )
+}
+
+private predicate condExprBranchModulus(
+  SemConditionalExpr cond, boolean branch, SemBound b, int val, int mod
+) {
+  semExprModulus(cond.getBranchExpr(branch), b, val, mod)
+}
+
+private predicate addModulus(SemExpr add, boolean isLeft, SemBound b, int val, int mod) {
+  exists(SemExpr larg, SemExpr rarg | nonConstAddition(add, larg, rarg) |
+    semExprModulus(larg, b, val, mod) and isLeft = true
+    or
+    semExprModulus(rarg, b, val, mod) and isLeft = false
+  )
+}
+
+private predicate subModulus(SemExpr sub, boolean isLeft, SemBound b, int val, int mod) {
+  exists(SemExpr larg, SemExpr rarg | nonConstSubtraction(sub, larg, rarg) |
+    semExprModulus(larg, b, val, mod) and isLeft = true
+    or
+    semExprModulus(rarg, b, val, mod) and isLeft = false
+  )
+}
+
+/**
+ * Holds if `inp` is an input to `phi` along `edge` and this input has index `r`
+ * in an arbitrary 1-based numbering of the input edges to `phi`.
+ */
+private predicate rankedPhiInput(
+  SemSsaPhiNode phi, SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge, int r
+) {
+  edge.phiInput(phi, inp) and
+  edge =
+    rank[r](SemSsaReadPositionPhiInputEdge e |
+      e.phiInput(phi, _)
+    |
+      e order by e.getOrigBlock().getUniqueId()
     )
-  }
-
-  /**
-   * Holds if `inp` is an input to `phi` along `edge` and this input has index `r`
-   * in an arbitrary 1-based numbering of the input edges to `phi`.
-   */
-  private predicate rankedPhiInput(
-    SemSsaPhiNode phi, SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge, int r
-  ) {
-    edge.phiInput(phi, inp) and
-    edge =
-      rank[r](SemSsaReadPositionPhiInputEdge e |
-        e.phiInput(phi, _)
-      |
-        e order by e.getOrigBlock().getUniqueId()
-      )
-  }
 }

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

@@ -1,24 +1,830 @@
-private import RangeAnalysisStage
-private import RangeAnalysisSpecific
-private import experimental.semmle.code.cpp.semantic.analysis.FloatDelta
+/**
+ * Provides classes and predicates for range analysis.
+ *
+ * An inferred bound can either be a specific integer, the abstract value of an
+ * SSA variable, or the abstract value of an interesting expression. The latter
+ * category includes array lengths that are not SSA variables.
+ *
+ * If an inferred bound relies directly on a condition, then this condition is
+ * reported as the reason for the bound.
+ */
+
+/*
+ * This library tackles range analysis as a flow problem. Consider e.g.:
+ * ```
+ *   len = arr.length;
+ *   if (x < len) { ... y = x-1; ... y ... }
+ * ```
+ * In this case we would like to infer `y <= arr.length - 2`, and this is
+ * accomplished by tracking the bound through a sequence of steps:
+ * ```
+ *   arr.length --> len = .. --> x < len --> x-1 --> y = .. --> y
+ * ```
+ *
+ * In its simplest form the step relation `E1 --> E2` relates two expressions
+ * such that `E1 <= B` implies `E2 <= B` for any `B` (with a second separate
+ * step relation handling lower bounds). Examples of such steps include
+ * assignments `E2 = E1` and conditions `x <= E1` where `E2` is a use of `x`
+ * guarded by the condition.
+ *
+ * In order to handle subtractions and additions with constants, and strict
+ * comparisons, the step relation is augmented with an integer delta. With this
+ * generalization `E1 --(delta)--> E2` relates two expressions and an integer
+ * such that `E1 <= B` implies `E2 <= B + delta` for any `B`. This corresponds
+ * to the predicate `boundFlowStep`.
+ *
+ * The complete range analysis is then implemented as the transitive closure of
+ * the step relation summing the deltas along the way. If `E1` transitively
+ * steps to `E2`, `delta` is the sum of deltas along the path, and `B` is an
+ * interesting bound equal to the value of `E1` then `E2 <= B + delta`. This
+ * corresponds to the predicate `bounded`.
+ *
+ * Phi nodes need a little bit of extra handling. Consider `x0 = phi(x1, x2)`.
+ * There are essentially two cases:
+ * - If `x1 <= B + d1` and `x2 <= B + d2` then `x0 <= B + max(d1,d2)`.
+ * - If `x1 <= B + d1` and `x2 <= x0 + d2` with `d2 <= 0` then `x0 <= B + d1`.
+ * The first case is for whenever a bound can be proven without taking looping
+ * into account. The second case is relevant when `x2` comes from a back-edge
+ * where we can prove that the variable has been non-increasing through the
+ * loop-iteration as this means that any upper bound that holds prior to the
+ * loop also holds for the variable during the loop.
+ * This generalizes to a phi node with `n` inputs, so if
+ * `x0 = phi(x1, ..., xn)` and `xi <= B + delta` for one of the inputs, then we
+ * also have `x0 <= B + delta` if we can prove either:
+ * - `xj <= B + d` with `d <= delta` or
+ * - `xj <= x0 + d` with `d <= 0`
+ * for each input `xj`.
+ *
+ * As all inferred bounds can be related directly to a path in the source code
+ * the only source of non-termination is if successive redundant (and thereby
+ * increasingly worse) bounds are calculated along a loop in the source code.
+ * We prevent this by weakening the bound to a small finite set of bounds when
+ * a path follows a second back-edge (we postpone weakening till the second
+ * back-edge as a precise bound might require traversing a loop once).
+ */
+
+private import RangeAnalysisSpecific as Specific
 private import RangeUtils
-private import experimental.semmle.code.cpp.semantic.SemanticBound as SemanticBound
+private import SignAnalysisCommon
+private import ModulusAnalysis
+private import experimental.semmle.code.cpp.semantic.Semantic
+private import ConstantAnalysis
 
-module Bounds implements BoundSig<FloatDelta> {
-  class SemBound instanceof SemanticBound::SemBound {
-    string toString() { result = super.toString() }
-
-    SemExpr getExpr(float delta) { result = super.getExpr(delta) }
+cached
+private module RangeAnalysisCache {
+  cached
+  module RangeAnalysisPublic {
+    /**
+     * Holds if `b + delta` is a valid bound for `e`.
+     * - `upper = true`  : `e <= b + delta`
+     * - `upper = false` : `e >= b + delta`
+     *
+     * The reason for the bound is given by `reason` and may be either a condition
+     * or `NoReason` if the bound was proven directly without the use of a bounding
+     * condition.
+     */
+    cached
+    predicate semBounded(SemExpr e, SemBound b, int delta, boolean upper, SemReason reason) {
+      bounded(e, b, delta, upper, _, _, reason) and
+      bestBound(e, b, delta, upper)
+    }
   }
 
-  class SemZeroBound extends SemBound instanceof SemanticBound::SemZeroBound { }
-
-  class SemSsaBound extends SemBound instanceof SemanticBound::SemSsaBound {
-    SemSsaVariable getAVariable() { result = this.(SemanticBound::SemSsaBound).getAVariable() }
+  /**
+   * Holds if `guard = boundFlowCond(_, _, _, _, _) or guard = eqFlowCond(_, _, _, _, _)`.
+   */
+  cached
+  predicate possibleReason(SemGuard guard) {
+    guard = boundFlowCond(_, _, _, _, _) or guard = semEqFlowCond(_, _, _, _, _)
   }
 }
 
-private module CppRangeAnalysis =
-  RangeStage<FloatDelta, Bounds, CppLangImpl, RangeUtil<FloatDelta, CppLangImpl>>;
+private import RangeAnalysisCache
+import RangeAnalysisPublic
 
-import CppRangeAnalysis
+/**
+ * Holds if `b + delta` is a valid bound for `e` and this is the best such delta.
+ * - `upper = true`  : `e <= b + delta`
+ * - `upper = false` : `e >= b + delta`
+ */
+private predicate bestBound(SemExpr e, SemBound b, int delta, boolean upper) {
+  delta = min(int d | bounded(e, b, d, upper, _, _, _)) and upper = true
+  or
+  delta = max(int d | bounded(e, b, d, upper, _, _, _)) and upper = false
+}
+
+/**
+ * Holds if `comp` corresponds to:
+ * - `upper = true`  : `v <= e + delta` or `v < e + delta`
+ * - `upper = false` : `v >= e + delta` or `v > e + delta`
+ */
+private predicate boundCondition(
+  SemRelationalExpr comp, SemSsaVariable v, SemExpr e, int delta, boolean upper
+) {
+  comp.getLesserOperand() = semSsaRead(v, delta) and e = comp.getGreaterOperand() and upper = true
+  or
+  comp.getGreaterOperand() = semSsaRead(v, delta) and e = comp.getLesserOperand() and upper = false
+  or
+  exists(SemSubExpr sub, SemConstantIntegerExpr c, int d |
+    // (v - d) - e < c
+    comp.getLesserOperand() = sub and
+    comp.getGreaterOperand() = c and
+    sub.getLeftOperand() = semSsaRead(v, d) and
+    sub.getRightOperand() = e and
+    upper = true and
+    delta = d + c.getIntValue()
+    or
+    // (v - d) - e > c
+    comp.getGreaterOperand() = sub and
+    comp.getLesserOperand() = c and
+    sub.getLeftOperand() = semSsaRead(v, d) and
+    sub.getRightOperand() = e and
+    upper = false and
+    delta = d + c.getIntValue()
+    or
+    // e - (v - d) < c
+    comp.getLesserOperand() = sub and
+    comp.getGreaterOperand() = c and
+    sub.getLeftOperand() = e and
+    sub.getRightOperand() = semSsaRead(v, d) and
+    upper = false and
+    delta = d - c.getIntValue()
+    or
+    // e - (v - d) > c
+    comp.getGreaterOperand() = sub and
+    comp.getLesserOperand() = c and
+    sub.getLeftOperand() = e and
+    sub.getRightOperand() = semSsaRead(v, d) and
+    upper = true and
+    delta = d - c.getIntValue()
+  )
+}
+
+/**
+ * Holds if `comp` is a comparison between `x` and `y` for which `y - x` has a
+ * fixed value modulo some `mod > 1`, such that the comparison can be
+ * strengthened by `strengthen` when evaluating to `testIsTrue`.
+ */
+private predicate modulusComparison(SemRelationalExpr comp, boolean testIsTrue, int strengthen) {
+  exists(
+    SemBound b, int v1, int v2, int mod1, int mod2, int mod, boolean resultIsStrict, int d, int k
+  |
+    // If `x <= y` and `x =(mod) b + v1` and `y =(mod) b + v2` then
+    // `0 <= y - x =(mod) v2 - v1`. By choosing `k =(mod) v2 - v1` with
+    // `0 <= k < mod` we get `k <= y - x`. If the resulting comparison is
+    // strict then the strengthening amount is instead `k - 1` modulo `mod`:
+    // `x < y` means `0 <= y - x - 1 =(mod) k - 1` so `k - 1 <= y - x - 1` and
+    // thus `k - 1 < y - x` with `0 <= k - 1 < mod`.
+    semExprModulus(comp.getLesserOperand(), b, v1, mod1) and
+    semExprModulus(comp.getGreaterOperand(), b, v2, mod2) and
+    mod = mod1.gcd(mod2) and
+    mod != 1 and
+    (testIsTrue = true or testIsTrue = false) and
+    (
+      if comp.isStrict()
+      then resultIsStrict = testIsTrue
+      else resultIsStrict = testIsTrue.booleanNot()
+    ) and
+    (
+      resultIsStrict = true and d = 1
+      or
+      resultIsStrict = false and d = 0
+    ) and
+    (
+      testIsTrue = true and k = v2 - v1
+      or
+      testIsTrue = false and k = v1 - v2
+    ) and
+    strengthen = (((k - d) % mod) + mod) % mod
+  )
+}
+
+/**
+ * Gets a condition that tests whether `v` is bounded by `e + delta`.
+ *
+ * If the condition evaluates to `testIsTrue`:
+ * - `upper = true`  : `v <= e + delta`
+ * - `upper = false` : `v >= e + delta`
+ */
+private SemGuard boundFlowCond(
+  SemSsaVariable v, SemExpr e, int delta, boolean upper, boolean testIsTrue
+) {
+  exists(
+    SemRelationalExpr comp, int d1, int d2, int d3, int strengthen, boolean compIsUpper,
+    boolean resultIsStrict
+  |
+    comp = result.asExpr() and
+    boundCondition(comp, v, e, d1, compIsUpper) and
+    (testIsTrue = true or testIsTrue = false) and
+    upper = compIsUpper.booleanXor(testIsTrue.booleanNot()) and
+    (
+      if comp.isStrict()
+      then resultIsStrict = testIsTrue
+      else resultIsStrict = testIsTrue.booleanNot()
+    ) and
+    (
+      if
+        getTrackedTypeForSsaVariable(v) instanceof SemIntegerType or
+        getTrackedTypeForSsaVariable(v) instanceof SemAddressType
+      then
+        upper = true and strengthen = -1
+        or
+        upper = false and strengthen = 1
+      else strengthen = 0
+    ) and
+    (
+      exists(int k | modulusComparison(comp, testIsTrue, k) and d2 = strengthen * k)
+      or
+      not modulusComparison(comp, testIsTrue, _) and d2 = 0
+    ) and
+    // A strict inequality `x < y` can be strengthened to `x <= y - 1`.
+    (
+      resultIsStrict = true and d3 = strengthen
+      or
+      resultIsStrict = false and d3 = 0
+    ) and
+    delta = d1 + d2 + d3
+  )
+  or
+  exists(boolean testIsTrue0 |
+    semImplies_v2(result, testIsTrue, boundFlowCond(v, e, delta, upper, testIsTrue0), testIsTrue0)
+  )
+  or
+  result = semEqFlowCond(v, e, delta, true, testIsTrue) and
+  (upper = true or upper = false)
+  or
+  // guard that tests whether `v2` is bounded by `e + delta + d1 - d2` and
+  // exists a guard `guardEq` such that `v = v2 - d1 + d2`.
+  exists(SemSsaVariable v2, SemGuard guardEq, boolean eqIsTrue, int d1, int d2 |
+    guardEq = semEqFlowCond(v, semSsaRead(v2, d1), d2, true, eqIsTrue) and
+    result = boundFlowCond(v2, e, delta + d1 - d2, upper, testIsTrue) and
+    // guardEq needs to control guard
+    guardEq.directlyControls(result.getBasicBlock(), eqIsTrue)
+  )
+}
+
+private newtype TSemReason =
+  TSemNoReason() or
+  TSemCondReason(SemGuard guard) { possibleReason(guard) }
+
+/**
+ * A reason for an inferred bound. This can either be `CondReason` if the bound
+ * is due to a specific condition, or `NoReason` if the bound is inferred
+ * without going through a bounding condition.
+ */
+abstract class SemReason extends TSemReason {
+  /** Gets a textual representation of this reason. */
+  abstract string toString();
+}
+
+/**
+ * A reason for an inferred bound that indicates that the bound is inferred
+ * without going through a bounding condition.
+ */
+class SemNoReason extends SemReason, TSemNoReason {
+  override string toString() { result = "NoReason" }
+}
+
+/** A reason for an inferred bound pointing to a condition. */
+class SemCondReason extends SemReason, TSemCondReason {
+  /** Gets the condition that is the reason for the bound. */
+  SemGuard getCond() { this = TSemCondReason(result) }
+
+  override string toString() { result = getCond().toString() }
+}
+
+/**
+ * Holds if `e + delta` is a valid bound for `v` at `pos`.
+ * - `upper = true`  : `v <= e + delta`
+ * - `upper = false` : `v >= e + delta`
+ */
+private predicate boundFlowStepSsa(
+  SemSsaVariable v, SemSsaReadPosition pos, SemExpr e, int delta, boolean upper, SemReason reason
+) {
+  semSsaUpdateStep(v, e, delta) and
+  pos.hasReadOfVar(v) and
+  (upper = true or upper = false) and
+  reason = TSemNoReason()
+  or
+  exists(SemGuard guard, boolean testIsTrue |
+    pos.hasReadOfVar(v) and
+    guard = boundFlowCond(v, e, delta, upper, testIsTrue) and
+    semGuardDirectlyControlsSsaRead(guard, pos, testIsTrue) and
+    reason = TSemCondReason(guard)
+  )
+}
+
+/** Holds if `v != e + delta` at `pos` and `v` is of integral type. */
+private predicate unequalFlowStepIntegralSsa(
+  SemSsaVariable v, SemSsaReadPosition pos, SemExpr e, int delta, SemReason reason
+) {
+  getTrackedTypeForSsaVariable(v) instanceof SemIntegerType and
+  exists(SemGuard guard, boolean testIsTrue |
+    pos.hasReadOfVar(v) and
+    guard = semEqFlowCond(v, e, delta, false, testIsTrue) and
+    semGuardDirectlyControlsSsaRead(guard, pos, testIsTrue) and
+    reason = TSemCondReason(guard)
+  )
+}
+
+/**
+ * An expression that does conversion, boxing, or unboxing
+ */
+private class ConvertOrBoxExpr extends SemUnaryExpr {
+  ConvertOrBoxExpr() {
+    this instanceof SemConvertExpr
+    or
+    this instanceof SemBoxExpr
+    or
+    this instanceof SemUnboxExpr
+  }
+}
+
+/**
+ * A cast that can be ignored for the purpose of range analysis.
+ */
+private class SafeCastExpr extends ConvertOrBoxExpr {
+  SafeCastExpr() {
+    conversionCannotOverflow(getTrackedType(pragma[only_bind_into](getOperand())),
+      getTrackedType(this))
+  }
+}
+
+/**
+ * Holds if `typ` is a small integral type with the given lower and upper bounds.
+ */
+private predicate typeBound(SemIntegerType typ, int lowerbound, int upperbound) {
+  exists(int bitSize | bitSize = typ.getByteSize() * 8 |
+    bitSize < 32 and
+    (
+      if typ.isSigned()
+      then (
+        upperbound = 1.bitShiftLeft(bitSize - 1) - 1 and
+        lowerbound = -upperbound - 1
+      ) else (
+        lowerbound = 0 and
+        upperbound = 1.bitShiftLeft(bitSize) - 1
+      )
+    )
+  )
+}
+
+/**
+ * A cast to a small integral type that may overflow or underflow.
+ */
+private class NarrowingCastExpr extends ConvertOrBoxExpr {
+  NarrowingCastExpr() {
+    not this instanceof SafeCastExpr and
+    typeBound(getTrackedType(this), _, _)
+  }
+
+  /** Gets the lower bound of the resulting type. */
+  int getLowerBound() { typeBound(getTrackedType(this), result, _) }
+
+  /** Gets the upper bound of the resulting type. */
+  int getUpperBound() { typeBound(getTrackedType(this), _, result) }
+}
+
+/** Holds if `e >= 1` as determined by sign analysis. */
+private predicate strictlyPositiveIntegralExpr(SemExpr e) {
+  semStrictlyPositive(e) and getTrackedType(e) instanceof SemIntegerType
+}
+
+/** Holds if `e <= -1` as determined by sign analysis. */
+private predicate strictlyNegativeIntegralExpr(SemExpr e) {
+  semStrictlyNegative(e) and getTrackedType(e) instanceof SemIntegerType
+}
+
+/**
+ * Holds if `e1 + delta` is a valid bound for `e2`.
+ * - `upper = true`  : `e2 <= e1 + delta`
+ * - `upper = false` : `e2 >= e1 + delta`
+ */
+private predicate boundFlowStep(SemExpr e2, SemExpr e1, int delta, boolean upper) {
+  semValueFlowStep(e2, e1, delta) and
+  (upper = true or upper = false)
+  or
+  e2.(SafeCastExpr).getOperand() = e1 and
+  delta = 0 and
+  (upper = true or upper = false)
+  or
+  exists(SemExpr x | e2.(SemAddExpr).hasOperands(e1, x) |
+    // `x instanceof ConstantIntegerExpr` is covered by valueFlowStep
+    not x instanceof SemConstantIntegerExpr and
+    not e1 instanceof SemConstantIntegerExpr and
+    if strictlyPositiveIntegralExpr(x)
+    then upper = false and delta = 1
+    else
+      if semPositive(x)
+      then upper = false and delta = 0
+      else
+        if strictlyNegativeIntegralExpr(x)
+        then upper = true and delta = -1
+        else
+          if semNegative(x)
+          then upper = true and delta = 0
+          else none()
+  )
+  or
+  exists(SemExpr x, SemSubExpr sub |
+    e2 = sub and
+    sub.getLeftOperand() = e1 and
+    sub.getRightOperand() = x
+  |
+    // `x instanceof ConstantIntegerExpr` is covered by valueFlowStep
+    not x instanceof SemConstantIntegerExpr and
+    if strictlyPositiveIntegralExpr(x)
+    then upper = true and delta = -1
+    else
+      if semPositive(x)
+      then upper = true and delta = 0
+      else
+        if strictlyNegativeIntegralExpr(x)
+        then upper = false and delta = 1
+        else
+          if semNegative(x)
+          then upper = false and delta = 0
+          else none()
+  )
+  or
+  e2.(SemRemExpr).getRightOperand() = e1 and
+  semPositive(e1) and
+  delta = -1 and
+  upper = true
+  or
+  e2.(SemRemExpr).getLeftOperand() = e1 and semPositive(e1) and delta = 0 and upper = true
+  or
+  e2.(SemBitAndExpr).getAnOperand() = e1 and
+  semPositive(e1) and
+  delta = 0 and
+  upper = true
+  or
+  e2.(SemBitOrExpr).getAnOperand() = e1 and
+  semPositive(e2) and
+  delta = 0 and
+  upper = false
+  or
+  Specific::hasBound(e2, e1, delta, upper)
+}
+
+/** Holds if `e2 = e1 * factor` and `factor > 0`. */
+private predicate boundFlowStepMul(SemExpr e2, SemExpr e1, int factor) {
+  exists(SemConstantIntegerExpr c, int k | k = c.getIntValue() and k > 0 |
+    e2.(SemMulExpr).hasOperands(e1, c) and factor = k
+    or
+    exists(SemShiftLeftExpr e |
+      e = e2 and e.getLeftOperand() = e1 and e.getRightOperand() = c and factor = 2.pow(k)
+    )
+  )
+}
+
+/**
+ * Holds if `e2 = e1 / factor` and `factor > 0`.
+ *
+ * This conflates division, right shift, and unsigned right shift and is
+ * therefore only valid for non-negative numbers.
+ */
+private predicate boundFlowStepDiv(SemExpr e2, SemExpr e1, int factor) {
+  exists(SemConstantIntegerExpr c, int k | k = c.getIntValue() and k > 0 |
+    exists(SemDivExpr e |
+      e = e2 and e.getLeftOperand() = e1 and e.getRightOperand() = c and factor = k
+    )
+    or
+    exists(SemShiftRightExpr e |
+      e = e2 and e.getLeftOperand() = e1 and e.getRightOperand() = c and factor = 2.pow(k)
+    )
+    or
+    exists(SemShiftRightUnsignedExpr e |
+      e = e2 and e.getLeftOperand() = e1 and e.getRightOperand() = c and factor = 2.pow(k)
+    )
+  )
+}
+
+/**
+ * Holds if `b + delta` is a valid bound for `v` at `pos`.
+ * - `upper = true`  : `v <= b + delta`
+ * - `upper = false` : `v >= b + delta`
+ */
+private predicate boundedSsa(
+  SemSsaVariable v, SemSsaReadPosition pos, SemBound b, int delta, boolean upper,
+  boolean fromBackEdge, int origdelta, SemReason reason
+) {
+  exists(SemExpr mid, int d1, int d2, SemReason r1, SemReason r2 |
+    boundFlowStepSsa(v, pos, mid, d1, upper, r1) and
+    bounded(mid, b, d2, upper, fromBackEdge, origdelta, r2) and
+    // upper = true:  v <= mid + d1 <= b + d1 + d2 = b + delta
+    // upper = false: v >= mid + d1 >= b + d1 + d2 = b + delta
+    delta = d1 + d2 and
+    (if r1 instanceof SemNoReason then reason = r2 else reason = r1)
+  )
+  or
+  exists(int d, SemReason r1, SemReason r2 |
+    boundedSsa(v, pos, b, d, upper, fromBackEdge, origdelta, r2) or
+    boundedPhi(v, b, d, upper, fromBackEdge, origdelta, r2)
+  |
+    unequalIntegralSsa(v, pos, b, d, r1) and
+    (
+      upper = true and delta = d - 1
+      or
+      upper = false and delta = d + 1
+    ) and
+    (
+      reason = r1
+      or
+      reason = r2 and not r2 instanceof SemNoReason
+    )
+  )
+}
+
+/**
+ * Holds if `v != b + delta` at `pos` and `v` is of integral type.
+ */
+private predicate unequalIntegralSsa(
+  SemSsaVariable v, SemSsaReadPosition pos, SemBound b, int delta, SemReason reason
+) {
+  exists(SemExpr e, int d1, int d2 |
+    unequalFlowStepIntegralSsa(v, pos, e, d1, reason) and
+    boundedUpper(e, b, d1) and
+    boundedLower(e, b, d2) and
+    delta = d2 + d1
+  )
+}
+
+/**
+ * Holds if `b + delta` is an upper bound for `e`.
+ *
+ * This predicate only exists to prevent a bad standard order in `unequalIntegralSsa`.
+ */
+pragma[nomagic]
+private predicate boundedUpper(SemExpr e, SemBound b, int delta) {
+  bounded(e, b, delta, true, _, _, _)
+}
+
+/**
+ * Holds if `b + delta` is a lower bound for `e`.
+ *
+ * This predicate only exists to prevent a bad standard order in `unequalIntegralSsa`.
+ */
+pragma[nomagic]
+private predicate boundedLower(SemExpr e, SemBound b, int delta) {
+  bounded(e, b, delta, false, _, _, _)
+}
+
+/** Weakens a delta to lie in the range `[-1..1]`. */
+bindingset[delta, upper]
+private int weakenDelta(boolean upper, int delta) {
+  delta in [-1 .. 1] and result = delta
+  or
+  upper = true and result = -1 and delta < -1
+  or
+  upper = false and result = 1 and delta > 1
+}
+
+/**
+ * Holds if `b + delta` is a valid bound for `inp` when used as an input to
+ * `phi` along `edge`.
+ * - `upper = true`  : `inp <= b + delta`
+ * - `upper = false` : `inp >= b + delta`
+ */
+private predicate boundedPhiInp(
+  SemSsaPhiNode phi, SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge, SemBound b, int delta,
+  boolean upper, boolean fromBackEdge, int origdelta, SemReason reason
+) {
+  edge.phiInput(phi, inp) and
+  exists(int d, boolean fromBackEdge0 |
+    boundedSsa(inp, edge, b, d, upper, fromBackEdge0, origdelta, reason)
+    or
+    boundedPhi(inp, b, d, upper, fromBackEdge0, origdelta, reason)
+    or
+    b.(SemSsaBound).getAVariable() = inp and
+    d = 0 and
+    (upper = true or upper = false) and
+    fromBackEdge0 = false and
+    origdelta = 0 and
+    reason = TSemNoReason()
+  |
+    if semBackEdge(phi, inp, edge)
+    then
+      fromBackEdge = true and
+      (
+        fromBackEdge0 = true and delta = weakenDelta(upper, d - origdelta) + origdelta
+        or
+        fromBackEdge0 = false and delta = d
+      )
+    else (
+      delta = d and fromBackEdge = fromBackEdge0
+    )
+  )
+}
+
+/**
+ * Holds if `b + delta` is a valid bound for `inp` when used as an input to
+ * `phi` along `edge`.
+ * - `upper = true`  : `inp <= b + delta`
+ * - `upper = false` : `inp >= b + delta`
+ *
+ * Equivalent to `boundedPhiInp(phi, inp, edge, b, delta, upper, _, _, _)`.
+ */
+pragma[noinline]
+private predicate boundedPhiInp1(
+  SemSsaPhiNode phi, SemBound b, boolean upper, SemSsaVariable inp,
+  SemSsaReadPositionPhiInputEdge edge, int delta
+) {
+  boundedPhiInp(phi, inp, edge, b, delta, upper, _, _, _)
+}
+
+/**
+ * Holds if `phi` is a valid bound for `inp` when used as an input to `phi`
+ * along `edge`.
+ * - `upper = true`  : `inp <= phi`
+ * - `upper = false` : `inp >= phi`
+ */
+private predicate selfBoundedPhiInp(
+  SemSsaPhiNode phi, SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge, boolean upper
+) {
+  exists(int d, SemSsaBound phibound |
+    phibound.getAVariable() = phi and
+    boundedPhiInp(phi, inp, edge, phibound, d, upper, _, _, _) and
+    (
+      upper = true and d <= 0
+      or
+      upper = false and d >= 0
+    )
+  )
+}
+
+/**
+ * Holds if `b + delta` is a valid bound for some input, `inp`, to `phi`, and
+ * thus a candidate bound for `phi`.
+ * - `upper = true`  : `inp <= b + delta`
+ * - `upper = false` : `inp >= b + delta`
+ */
+pragma[noinline]
+private predicate boundedPhiCand(
+  SemSsaPhiNode phi, boolean upper, SemBound b, int delta, boolean fromBackEdge, int origdelta,
+  SemReason reason
+) {
+  boundedPhiInp(phi, _, _, b, delta, upper, fromBackEdge, origdelta, reason)
+}
+
+/**
+ * Holds if the candidate bound `b + delta` for `phi` is valid for the phi input
+ * `inp` along `edge`.
+ */
+private predicate boundedPhiCandValidForEdge(
+  SemSsaPhiNode phi, SemBound b, int delta, boolean upper, boolean fromBackEdge, int origdelta,
+  SemReason reason, SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge
+) {
+  boundedPhiCand(phi, upper, b, delta, fromBackEdge, origdelta, reason) and
+  (
+    exists(int d | boundedPhiInp1(phi, b, upper, inp, edge, d) | upper = true and d <= delta)
+    or
+    exists(int d | boundedPhiInp1(phi, b, upper, inp, edge, d) | upper = false and d >= delta)
+    or
+    selfBoundedPhiInp(phi, inp, edge, upper)
+  )
+}
+
+/**
+ * Holds if `b + delta` is a valid bound for `phi`.
+ * - `upper = true`  : `phi <= b + delta`
+ * - `upper = false` : `phi >= b + delta`
+ */
+private predicate boundedPhi(
+  SemSsaPhiNode phi, SemBound b, int delta, boolean upper, boolean fromBackEdge, int origdelta,
+  SemReason reason
+) {
+  forex(SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge | edge.phiInput(phi, inp) |
+    boundedPhiCandValidForEdge(phi, b, delta, upper, fromBackEdge, origdelta, reason, inp, edge)
+  )
+}
+
+/**
+ * Holds if `e` has an upper (for `upper = true`) or lower
+ * (for `upper = false`) bound of `b`.
+ */
+private predicate baseBound(SemExpr e, int b, boolean upper) {
+  Specific::hasConstantBound(e, b, upper)
+  or
+  upper = false and
+  b = 0 and
+  semPositive(e.(SemBitAndExpr).getAnOperand()) and
+  // REVIEW: We let the language opt out here to preserve original results.
+  not Specific::ignoreZeroLowerBound(e)
+}
+
+/**
+ * Holds if the value being cast has an upper (for `upper = true`) or lower
+ * (for `upper = false`) bound within the bounds of the resulting type.
+ * For `upper = true` this means that the cast will not overflow and for
+ * `upper = false` this means that the cast will not underflow.
+ */
+private predicate safeNarrowingCast(NarrowingCastExpr cast, boolean upper) {
+  exists(int bound | bounded(cast.getOperand(), any(SemZeroBound zb), bound, upper, _, _, _) |
+    upper = true and bound <= cast.getUpperBound()
+    or
+    upper = false and bound >= cast.getLowerBound()
+  )
+}
+
+pragma[noinline]
+private predicate boundedCastExpr(
+  NarrowingCastExpr cast, SemBound b, int delta, boolean upper, boolean fromBackEdge, int origdelta,
+  SemReason reason
+) {
+  bounded(cast.getOperand(), b, delta, upper, fromBackEdge, origdelta, reason)
+}
+
+/**
+ * Holds if `b + delta` is a valid bound for `e`.
+ * - `upper = true`  : `e <= b + delta`
+ * - `upper = false` : `e >= b + delta`
+ */
+private predicate bounded(
+  SemExpr e, SemBound b, int delta, boolean upper, boolean fromBackEdge, int origdelta,
+  SemReason reason
+) {
+  not Specific::ignoreExprBound(e) and
+  (
+    e = b.getExpr(delta) and
+    (upper = true or upper = false) and
+    fromBackEdge = false and
+    origdelta = delta and
+    reason = TSemNoReason()
+    or
+    baseBound(e, delta, upper) and
+    b instanceof SemZeroBound and
+    fromBackEdge = false and
+    origdelta = delta and
+    reason = TSemNoReason()
+    or
+    exists(SemSsaVariable v, SemSsaReadPositionBlock bb |
+      boundedSsa(v, bb, b, delta, upper, fromBackEdge, origdelta, reason) and
+      e = v.getAUse() and
+      bb.getBlock() = e.getBasicBlock()
+    )
+    or
+    exists(SemExpr mid, int d1, int d2 |
+      boundFlowStep(e, mid, d1, upper) and
+      // Constants have easy, base-case bounds, so let's not infer any recursive bounds.
+      not e instanceof SemConstantIntegerExpr and
+      bounded(mid, b, d2, upper, fromBackEdge, origdelta, reason) and
+      // upper = true:  e <= mid + d1 <= b + d1 + d2 = b + delta
+      // upper = false: e >= mid + d1 >= b + d1 + d2 = b + delta
+      delta = d1 + d2
+    )
+    or
+    exists(SemSsaPhiNode phi |
+      boundedPhi(phi, b, delta, upper, fromBackEdge, origdelta, reason) and
+      e = phi.getAUse()
+    )
+    or
+    exists(SemExpr mid, int factor, int d |
+      boundFlowStepMul(e, mid, factor) and
+      not e instanceof SemConstantIntegerExpr and
+      bounded(mid, b, d, upper, fromBackEdge, origdelta, reason) and
+      b instanceof SemZeroBound and
+      delta = d * factor
+    )
+    or
+    exists(SemExpr mid, int factor, int d |
+      boundFlowStepDiv(e, mid, factor) and
+      not e instanceof SemConstantIntegerExpr and
+      bounded(mid, b, d, upper, fromBackEdge, origdelta, reason) and
+      b instanceof SemZeroBound and
+      d >= 0 and
+      delta = d / factor
+    )
+    or
+    exists(NarrowingCastExpr cast |
+      cast = e and
+      safeNarrowingCast(cast, upper.booleanNot()) and
+      boundedCastExpr(cast, b, delta, upper, fromBackEdge, origdelta, reason)
+    )
+    or
+    exists(
+      SemConditionalExpr cond, int d1, int d2, boolean fbe1, boolean fbe2, int od1, int od2,
+      SemReason r1, SemReason r2
+    |
+      cond = e and
+      boundedConditionalExpr(cond, b, upper, true, d1, fbe1, od1, r1) and
+      boundedConditionalExpr(cond, b, upper, false, d2, fbe2, od2, r2) and
+      (
+        delta = d1 and fromBackEdge = fbe1 and origdelta = od1 and reason = r1
+        or
+        delta = d2 and fromBackEdge = fbe2 and origdelta = od2 and reason = r2
+      )
+    |
+      upper = true and delta = d1.maximum(d2)
+      or
+      upper = false and delta = d1.minimum(d2)
+    )
+  )
+}
+
+private predicate boundedConditionalExpr(
+  SemConditionalExpr cond, SemBound b, boolean upper, boolean branch, int delta,
+  boolean fromBackEdge, int origdelta, SemReason reason
+) {
+  bounded(cond.getBranchExpr(branch), b, delta, upper, fromBackEdge, origdelta, reason)
+}

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

@@ -3,90 +3,86 @@
  */
 
 private import experimental.semmle.code.cpp.semantic.Semantic
-private import RangeAnalysisStage
-private import experimental.semmle.code.cpp.semantic.analysis.FloatDelta
 
-module CppLangImpl implements LangSig<FloatDelta> {
-  /**
-   * Holds if the specified expression should be excluded from the result of `ssaRead()`.
-   *
-   * This predicate is to keep the results identical to the original Java implementation. It should be
-   * removed once we have the new implementation matching the old results exactly.
-   */
-  predicate ignoreSsaReadCopy(SemExpr e) { none() }
+/**
+ * Holds if the specified expression should be excluded from the result of `ssaRead()`.
+ *
+ * This predicate is to keep the results identical to the original Java implementation. It should be
+ * removed once we have the new implementation matching the old results exactly.
+ */
+predicate ignoreSsaReadCopy(SemExpr e) { none() }
 
-  /**
-   * Ignore the bound on this expression.
-   *
-   * This predicate is to keep the results identical to the original Java implementation. It should be
-   * removed once we have the new implementation matching the old results exactly.
-   */
-  predicate ignoreExprBound(SemExpr e) { none() }
+/**
+ * Ignore the bound on this expression.
+ *
+ * This predicate is to keep the results identical to the original Java implementation. It should be
+ * removed once we have the new implementation matching the old results exactly.
+ */
+predicate ignoreExprBound(SemExpr e) { none() }
 
-  /**
-   * Ignore any inferred zero lower bound on this expression.
-   *
-   * This predicate is to keep the results identical to the original Java implementation. It should be
-   * removed once we have the new implementation matching the old results exactly.
-   */
-  predicate ignoreZeroLowerBound(SemExpr e) { none() }
+/**
+ * Ignore any inferred zero lower bound on this expression.
+ *
+ * This predicate is to keep the results identical to the original Java implementation. It should be
+ * removed once we have the new implementation matching the old results exactly.
+ */
+predicate ignoreZeroLowerBound(SemExpr e) { none() }
 
-  /**
-   * Holds if the specified expression should be excluded from the result of `ssaRead()`.
-   *
-   * This predicate is to keep the results identical to the original Java implementation. It should be
-   * removed once we have the new implementation matching the old results exactly.
-   */
-  predicate ignoreSsaReadArithmeticExpr(SemExpr e) { none() }
+/**
+ * Holds if the specified expression should be excluded from the result of `ssaRead()`.
+ *
+ * This predicate is to keep the results identical to the original Java implementation. It should be
+ * removed once we have the new implementation matching the old results exactly.
+ */
+predicate ignoreSsaReadArithmeticExpr(SemExpr e) { none() }
 
-  /**
-   * Holds if the specified variable should be excluded from the result of `ssaRead()`.
-   *
-   * This predicate is to keep the results identical to the original Java implementation. It should be
-   * removed once we have the new implementation matching the old results exactly.
-   */
-  predicate ignoreSsaReadAssignment(SemSsaVariable v) { none() }
+/**
+ * Holds if the specified variable should be excluded from the result of `ssaRead()`.
+ *
+ * This predicate is to keep the results identical to the original Java implementation. It should be
+ * removed once we have the new implementation matching the old results exactly.
+ */
+predicate ignoreSsaReadAssignment(SemSsaVariable v) { none() }
 
-  /**
-   * Adds additional results to `ssaRead()` that are specific to Java.
-   *
-   * This predicate handles propagation of offsets for post-increment and post-decrement expressions
-   * in exactly the same way as the old Java implementation. Once the new implementation matches the
-   * old one, we should remove this predicate and propagate deltas for all similar patterns, whether
-   * or not they come from a post-increment/decrement expression.
-   */
-  SemExpr specificSsaRead(SemSsaVariable v, float delta) { none() }
+/**
+ * Adds additional results to `ssaRead()` that are specific to Java.
+ *
+ * This predicate handles propagation of offsets for post-increment and post-decrement expressions
+ * in exactly the same way as the old Java implementation. Once the new implementation matches the
+ * old one, we should remove this predicate and propagate deltas for all similar patterns, whether
+ * or not they come from a post-increment/decrement expression.
+ */
+SemExpr specificSsaRead(SemSsaVariable v, int delta) { none() }
 
-  /**
-   * Holds if `e >= bound` (if `upper = false`) or `e <= bound` (if `upper = true`).
-   */
-  predicate hasConstantBound(SemExpr e, float bound, boolean upper) { none() }
+/**
+ * Holds if `e >= bound` (if `upper = false`) or `e <= bound` (if `upper = true`).
+ */
+predicate hasConstantBound(SemExpr e, int bound, boolean upper) { none() }
 
-  /**
-   * Holds if `e >= bound + delta` (if `upper = false`) or `e <= bound + delta` (if `upper = true`).
-   */
-  predicate hasBound(SemExpr e, SemExpr bound, float delta, boolean upper) { none() }
+/**
+ * Holds if `e >= bound + delta` (if `upper = false`) or `e <= bound + delta` (if `upper = true`).
+ */
+predicate hasBound(SemExpr e, SemExpr bound, int delta, boolean upper) { none() }
 
-  /**
-   * Holds if the value of `dest` is known to be `src + delta`.
-   */
-  predicate additionalValueFlowStep(SemExpr dest, SemExpr src, float delta) { none() }
+/**
+ * Holds if the value of `dest` is known to be `src + delta`.
+ */
+predicate additionalValueFlowStep(SemExpr dest, SemExpr src, int delta) { none() }
 
-  /**
-   * Gets the type that range analysis should use to track the result of the specified expression,
-   * if a type other than the original type of the expression is to be used.
-   *
-   * This predicate is commonly used in languages that support immutable "boxed" types that are
-   * actually references but whose values can be tracked as the type contained in the box.
-   */
-  SemType getAlternateType(SemExpr e) { none() }
+/**
+ * Gets the type that range analysis should use to track the result of the specified expression,
+ * if a type other than the original type of the expression is to be used.
+ *
+ * This predicate is commonly used in languages that support immutable "boxed" types that are
+ * actually references but whose values can be tracked as the type contained in the box.
+ */
+SemType getAlternateType(SemExpr e) { none() }
 
-  /**
-   * Gets the type that range analysis should use to track the result of the specified source
-   * variable, if a type other than the original type of the expression is to be used.
-   *
-   * This predicate is commonly used in languages that support immutable "boxed" types that are
-   * actually references but whose values can be tracked as the type contained in the box.
-   */
-  SemType getAlternateTypeForSsaVariable(SemSsaVariable var) { none() }
-}
+/**
+ * Gets the type that range analysis should use to track the result of the specified source
+ * variable, if a type other than the original type of the expression is to be used.
+ *
+ * This predicate is commonly used in languages that support immutable "boxed" types that are
+ * actually references but whose values can be tracked as the type contained in the box.
+ */
+SemType getAlternateTypeForSsaVariable(SemSsaVariable var) { none() }

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

@@ -3,138 +3,133 @@
  */
 
 private import experimental.semmle.code.cpp.semantic.Semantic
-private import RangeAnalysisSpecific
-private import RangeAnalysisStage as Range
+private import RangeAnalysisSpecific as Specific
 private import ConstantAnalysis
 
-module RangeUtil<Range::DeltaSig D, Range::LangSig<D> Lang> implements Range::UtilSig<D> {
-  /**
-   * Gets an expression that equals `v - d`.
-   */
-  SemExpr semSsaRead(SemSsaVariable v, D::Delta delta) {
-    // There are various language-specific extension points that can be removed once we no longer
-    // expect to match the original Java implementation's results exactly.
-    result = v.getAUse() and delta = D::fromInt(0)
-    or
-    exists(D::Delta d1, SemConstantIntegerExpr c |
-      result.(SemAddExpr).hasOperands(semSsaRead(v, d1), c) and
-      delta = D::fromFloat(D::toFloat(d1) - c.getIntValue()) and
-      not Lang::ignoreSsaReadArithmeticExpr(result)
-    )
-    or
-    exists(SemSubExpr sub, D::Delta d1, SemConstantIntegerExpr c |
-      result = sub and
-      sub.getLeftOperand() = semSsaRead(v, d1) and
-      sub.getRightOperand() = c and
-      delta = D::fromFloat(D::toFloat(d1) + c.getIntValue()) and
-      not Lang::ignoreSsaReadArithmeticExpr(result)
-    )
-    or
-    result = v.(SemSsaExplicitUpdate).getSourceExpr() and
-    delta = D::fromFloat(0) and
-    not Lang::ignoreSsaReadAssignment(v)
-    or
-    result = Lang::specificSsaRead(v, delta)
-    or
-    result.(SemCopyValueExpr).getOperand() = semSsaRead(v, delta) and
-    not Lang::ignoreSsaReadCopy(result)
-    or
-    result.(SemStoreExpr).getOperand() = semSsaRead(v, delta)
-  }
-
-  /**
-   * Gets a condition that tests whether `v` equals `e + delta`.
-   *
-   * If the condition evaluates to `testIsTrue`:
-   * - `isEq = true`  : `v == e + delta`
-   * - `isEq = false` : `v != e + delta`
-   */
-  SemGuard semEqFlowCond(
-    SemSsaVariable v, SemExpr e, D::Delta delta, boolean isEq, boolean testIsTrue
-  ) {
-    exists(boolean eqpolarity |
-      result.isEquality(semSsaRead(v, delta), e, eqpolarity) and
-      (testIsTrue = true or testIsTrue = false) and
-      eqpolarity.booleanXor(testIsTrue).booleanNot() = isEq
-    )
-    or
-    exists(boolean testIsTrue0 |
-      semImplies_v2(result, testIsTrue, semEqFlowCond(v, e, delta, isEq, testIsTrue0), testIsTrue0)
-    )
-  }
-
-  /**
-   * Holds if `v` is an `SsaExplicitUpdate` that equals `e + delta`.
-   */
-  predicate semSsaUpdateStep(SemSsaExplicitUpdate v, SemExpr e, D::Delta delta) {
-    exists(SemExpr defExpr | defExpr = v.getSourceExpr() |
-      defExpr.(SemCopyValueExpr).getOperand() = e and delta = D::fromFloat(0)
-      or
-      defExpr.(SemStoreExpr).getOperand() = e and delta = D::fromFloat(0)
-      or
-      defExpr.(SemAddOneExpr).getOperand() = e and delta = D::fromFloat(1)
-      or
-      defExpr.(SemSubOneExpr).getOperand() = e and delta = D::fromFloat(-1)
-      or
-      e = defExpr and
-      not (
-        defExpr instanceof SemCopyValueExpr or
-        defExpr instanceof SemStoreExpr or
-        defExpr instanceof SemAddOneExpr or
-        defExpr instanceof SemSubOneExpr
-      ) and
-      delta = D::fromFloat(0)
-    )
-  }
-
-  /**
-   * Holds if `e1 + delta` equals `e2`.
-   */
-  predicate semValueFlowStep(SemExpr e2, SemExpr e1, D::Delta delta) {
-    e2.(SemCopyValueExpr).getOperand() = e1 and delta = D::fromFloat(0)
-    or
-    e2.(SemStoreExpr).getOperand() = e1 and delta = D::fromFloat(0)
-    or
-    e2.(SemAddOneExpr).getOperand() = e1 and delta = D::fromFloat(1)
-    or
-    e2.(SemSubOneExpr).getOperand() = e1 and delta = D::fromFloat(-1)
-    or
-    Lang::additionalValueFlowStep(e2, e1, delta)
-    or
-    exists(SemExpr x | e2.(SemAddExpr).hasOperands(e1, x) |
-      D::fromInt(x.(SemConstantIntegerExpr).getIntValue()) = delta
-    )
-    or
-    exists(SemExpr x, SemSubExpr sub |
-      e2 = sub and
-      sub.getLeftOperand() = e1 and
-      sub.getRightOperand() = x
-    |
-      D::fromInt(-x.(SemConstantIntegerExpr).getIntValue()) = delta
-    )
-  }
-
-  /**
-   * Gets the type used to track the specified expression's range information.
-   *
-   * Usually, this just `e.getSemType()`, but the language can override this to track immutable boxed
-   * primitive types as the underlying primitive type.
-   */
-  SemType getTrackedType(SemExpr e) {
-    result = Lang::getAlternateType(e)
-    or
-    not exists(Lang::getAlternateType(e)) and result = e.getSemType()
-  }
-
-  /**
-   * Gets the type used to track the specified source variable's range information.
-   *
-   * Usually, this just `e.getType()`, but the language can override this to track immutable boxed
-   * primitive types as the underlying primitive type.
-   */
-  SemType getTrackedTypeForSsaVariable(SemSsaVariable var) {
-    result = Lang::getAlternateTypeForSsaVariable(var)
-    or
-    not exists(Lang::getAlternateTypeForSsaVariable(var)) and result = var.getType()
-  }
+/**
+ * Gets an expression that equals `v - d`.
+ */
+SemExpr semSsaRead(SemSsaVariable v, int delta) {
+  // There are various language-specific extension points that can be removed once we no longer
+  // expect to match the original Java implementation's results exactly.
+  result = v.getAUse() and delta = 0
+  or
+  exists(int d1, SemConstantIntegerExpr c |
+    result.(SemAddExpr).hasOperands(semSsaRead(v, d1), c) and
+    delta = d1 - c.getIntValue() and
+    not Specific::ignoreSsaReadArithmeticExpr(result)
+  )
+  or
+  exists(SemSubExpr sub, int d1, SemConstantIntegerExpr c |
+    result = sub and
+    sub.getLeftOperand() = semSsaRead(v, d1) and
+    sub.getRightOperand() = c and
+    delta = d1 + c.getIntValue() and
+    not Specific::ignoreSsaReadArithmeticExpr(result)
+  )
+  or
+  result = v.(SemSsaExplicitUpdate).getSourceExpr() and
+  delta = 0 and
+  not Specific::ignoreSsaReadAssignment(v)
+  or
+  result = Specific::specificSsaRead(v, delta)
+  or
+  result.(SemCopyValueExpr).getOperand() = semSsaRead(v, delta) and
+  not Specific::ignoreSsaReadCopy(result)
+  or
+  result.(SemStoreExpr).getOperand() = semSsaRead(v, delta)
+}
+
+/**
+ * Gets a condition that tests whether `v` equals `e + delta`.
+ *
+ * If the condition evaluates to `testIsTrue`:
+ * - `isEq = true`  : `v == e + delta`
+ * - `isEq = false` : `v != e + delta`
+ */
+SemGuard semEqFlowCond(SemSsaVariable v, SemExpr e, int delta, boolean isEq, boolean testIsTrue) {
+  exists(boolean eqpolarity |
+    result.isEquality(semSsaRead(v, delta), e, eqpolarity) and
+    (testIsTrue = true or testIsTrue = false) and
+    eqpolarity.booleanXor(testIsTrue).booleanNot() = isEq
+  )
+  or
+  exists(boolean testIsTrue0 |
+    semImplies_v2(result, testIsTrue, semEqFlowCond(v, e, delta, isEq, testIsTrue0), testIsTrue0)
+  )
+}
+
+/**
+ * Holds if `v` is an `SsaExplicitUpdate` that equals `e + delta`.
+ */
+predicate semSsaUpdateStep(SemSsaExplicitUpdate v, SemExpr e, int delta) {
+  exists(SemExpr defExpr | defExpr = v.getSourceExpr() |
+    defExpr.(SemCopyValueExpr).getOperand() = e and delta = 0
+    or
+    defExpr.(SemStoreExpr).getOperand() = e and delta = 0
+    or
+    defExpr.(SemAddOneExpr).getOperand() = e and delta = 1
+    or
+    defExpr.(SemSubOneExpr).getOperand() = e and delta = -1
+    or
+    e = defExpr and
+    not (
+      defExpr instanceof SemCopyValueExpr or
+      defExpr instanceof SemStoreExpr or
+      defExpr instanceof SemAddOneExpr or
+      defExpr instanceof SemSubOneExpr
+    ) and
+    delta = 0
+  )
+}
+
+/**
+ * Holds if `e1 + delta` equals `e2`.
+ */
+predicate semValueFlowStep(SemExpr e2, SemExpr e1, int delta) {
+  e2.(SemCopyValueExpr).getOperand() = e1 and delta = 0
+  or
+  e2.(SemStoreExpr).getOperand() = e1 and delta = 0
+  or
+  e2.(SemAddOneExpr).getOperand() = e1 and delta = 1
+  or
+  e2.(SemSubOneExpr).getOperand() = e1 and delta = -1
+  or
+  Specific::additionalValueFlowStep(e2, e1, delta)
+  or
+  exists(SemExpr x | e2.(SemAddExpr).hasOperands(e1, x) |
+    x.(SemConstantIntegerExpr).getIntValue() = delta
+  )
+  or
+  exists(SemExpr x, SemSubExpr sub |
+    e2 = sub and
+    sub.getLeftOperand() = e1 and
+    sub.getRightOperand() = x
+  |
+    x.(SemConstantIntegerExpr).getIntValue() = -delta
+  )
+}
+
+/**
+ * Gets the type used to track the specified expression's range information.
+ *
+ * Usually, this just `e.getSemType()`, but the language can override this to track immutable boxed
+ * primitive types as the underlying primitive type.
+ */
+SemType getTrackedType(SemExpr e) {
+  result = Specific::getAlternateType(e)
+  or
+  not exists(Specific::getAlternateType(e)) and result = e.getSemType()
+}
+
+/**
+ * Gets the type used to track the specified source variable's range information.
+ *
+ * Usually, this just `e.getType()`, but the language can override this to track immutable boxed
+ * primitive types as the underlying primitive type.
+ */
+SemType getTrackedTypeForSsaVariable(SemSsaVariable var) {
+  result = Specific::getAlternateTypeForSsaVariable(var)
+  or
+  not exists(Specific::getAlternateTypeForSsaVariable(var)) and result = var.getType()
 }

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

@@ -6,494 +6,488 @@
  * three-valued domain `{negative, zero, positive}`.
  */
 
-private import RangeAnalysisStage
 private import SignAnalysisSpecific as Specific
 private import experimental.semmle.code.cpp.semantic.Semantic
 private import ConstantAnalysis
 private import RangeUtils
 private import Sign
 
-module SignAnalysis<DeltaSig D, UtilSig<D> Utils> {
-  /**
-   * An SSA definition for which the analysis can compute the sign.
-   *
-   * The actual computation of the sign is done in an override of the `getSign()` predicate. The
-   * charpred of any subclass must _not_ invoke `getSign()`, directly or indirectly. This ensures
-   * that the charpred does not introduce negative recursion. The `getSign()` predicate may be
-   * recursive.
-   */
-  abstract private class SignDef instanceof SemSsaVariable {
-    final string toString() { result = super.toString() }
+/**
+ * An SSA definition for which the analysis can compute the sign.
+ *
+ * The actual computation of the sign is done in an override of the `getSign()` predicate. The
+ * charpred of any subclass must _not_ invoke `getSign()`, directly or indirectly. This ensures
+ * that the charpred does not introduce negative recursion. The `getSign()` predicate may be
+ * recursive.
+ */
+abstract private class SignDef instanceof SemSsaVariable {
+  final string toString() { result = super.toString() }
 
-    /** Gets the possible signs of this SSA definition. */
-    abstract Sign getSign();
-  }
+  /** Gets the possible signs of this SSA definition. */
+  abstract Sign getSign();
+}
 
-  /** An SSA definition whose sign is computed based on standard flow. */
-  abstract private class FlowSignDef extends SignDef {
-    abstract override Sign getSign();
-  }
+/** An SSA definition whose sign is computed based on standard flow. */
+abstract private class FlowSignDef extends SignDef {
+  abstract override Sign getSign();
+}
 
-  /** An SSA definition whose sign is determined by the sign of that definitions source expression. */
-  private class ExplicitSignDef extends FlowSignDef instanceof SemSsaExplicitUpdate {
-    final override Sign getSign() { result = semExprSign(super.getSourceExpr()) }
-  }
+/** An SSA definition whose sign is determined by the sign of that definitions source expression. */
+private class ExplicitSignDef extends FlowSignDef instanceof SemSsaExplicitUpdate {
+  final override Sign getSign() { result = semExprSign(super.getSourceExpr()) }
+}
 
-  /** An SSA Phi definition, whose sign is the union of the signs of its inputs. */
-  private class PhiSignDef extends FlowSignDef instanceof SemSsaPhiNode {
-    final override Sign getSign() {
-      exists(SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge |
-        edge.phiInput(this, inp) and
-        result = semSsaSign(inp, edge)
-      )
-    }
-  }
-
-  /** An SSA definition whose sign is computed by a language-specific implementation. */
-  abstract class CustomSignDef extends SignDef {
-    abstract override Sign getSign();
-  }
-
-  /**
-   * An expression for which the analysis can compute the sign.
-   *
-   * The actual computation of the sign is done in an override of the `getSign()` predicate. The
-   * charpred of any subclass must _not_ invoke `getSign()`, directly or indirectly. This ensures
-   * that the charpred does not introduce negative recursion. The `getSign()` predicate may be
-   * recursive.
-   *
-   * Concrete implementations extend one of the following subclasses:
-   * - `ConstantSignExpr`, for expressions with a compile-time constant value.
-   * - `FlowSignExpr`, for expressions whose sign can be computed from the signs of their operands.
-   * - `CustomsignExpr`, for expressions whose sign can be computed by a language-specific
-   *   implementation.
-   *
-   * If the same expression matches more than one of the above subclasses, the sign is computed as
-   * follows:
-   * - The sign of a `ConstantSignExpr` is computed solely from `ConstantSignExpr.getSign()`,
-   *   regardless of any other subclasses.
-   * - If a non-`ConstantSignExpr` expression matches exactly one of `FlowSignExpr` or
-   *   `CustomSignExpr`, the sign is computed by that class' `getSign()` predicate.
-   * - If a non-`ConstantSignExpr` expression matches both `FlowSignExpr` and `CustomSignExpr`, the
-   *   sign is the _intersection_ of the signs of those two classes' `getSign()` predicates. Thus,
-   *   both classes have the opportunity to _restrict_ the set of possible signs, not to generate new
-   *   possible signs.
-   * - If an expression does not match any of the three subclasses, then it can have any sign.
-   *
-   * Note that the `getSign()` predicate is introduced only in subclasses of `SignExpr`.
-   */
-  abstract class SignExpr instanceof SemExpr {
-    SignExpr() { not Specific::ignoreExprSign(this) }
-
-    final string toString() { result = super.toString() }
-
-    abstract Sign getSign();
-  }
-
-  /** An expression whose sign is determined by its constant numeric value. */
-  private class ConstantSignExpr extends SignExpr {
-    ConstantSignExpr() {
-      this instanceof SemConstantIntegerExpr or
-      exists(this.(SemNumericLiteralExpr).getApproximateFloatValue())
-    }
-
-    final override Sign getSign() {
-      exists(int i | this.(SemConstantIntegerExpr).getIntValue() = i |
-        i < 0 and result = TNeg()
-        or
-        i = 0 and result = TZero()
-        or
-        i > 0 and result = TPos()
-      )
-      or
-      not exists(this.(SemConstantIntegerExpr).getIntValue()) and
-      exists(float f | f = this.(SemNumericLiteralExpr).getApproximateFloatValue() |
-        f < 0 and result = TNeg()
-        or
-        f = 0 and result = TZero()
-        or
-        f > 0 and result = TPos()
-      )
-    }
-  }
-
-  abstract private class NonConstantSignExpr extends SignExpr {
-    NonConstantSignExpr() { not this instanceof ConstantSignExpr }
-
-    final override Sign getSign() {
-      // The result is the _intersection_ of the signs computed from flow and by the language.
-      (result = this.(FlowSignExpr).getSignRestriction() or not this instanceof FlowSignExpr) and
-      (result = this.(CustomSignExpr).getSignRestriction() or not this instanceof CustomSignExpr)
-    }
-  }
-
-  /** An expression whose sign is computed from the signs of its operands. */
-  abstract private class FlowSignExpr extends NonConstantSignExpr {
-    abstract Sign getSignRestriction();
-  }
-
-  /** An expression whose sign is computed by a language-specific implementation. */
-  abstract class CustomSignExpr extends NonConstantSignExpr {
-    abstract Sign getSignRestriction();
-  }
-
-  /** An expression whose sign is unknown. */
-  private class UnknownSignExpr extends SignExpr {
-    UnknownSignExpr() {
-      not this instanceof FlowSignExpr and
-      not this instanceof CustomSignExpr and
-      not this instanceof ConstantSignExpr and
-      (
-        // Only track numeric types.
-        Utils::getTrackedType(this) instanceof SemNumericType
-        or
-        // Unless the language says to track this expression anyway.
-        Specific::trackUnknownNonNumericExpr(this)
-      )
-    }
-
-    final override Sign getSign() { semAnySign(result) }
-  }
-
-  /**
-   * A `Load` expression whose sign is computed from the sign of its SSA definition, restricted by
-   * inference from any intervening guards.
-   */
-  class UseSignExpr extends FlowSignExpr {
-    SemSsaVariable v;
-
-    UseSignExpr() { v.getAUse() = this }
-
-    override Sign getSignRestriction() {
-      // Propagate via SSA
-      // Propagate the sign from the def of `v`, incorporating any inference from guards.
-      result = semSsaSign(v, any(SemSsaReadPositionBlock bb | bb.getAnExpr() = this))
-      or
-      // No block for this read. Just use the sign of the def.
-      // REVIEW: How can this happen?
-      not exists(SemSsaReadPositionBlock bb | bb.getAnExpr() = this) and
-      result = semSsaDefSign(v)
-    }
-  }
-
-  /** A binary expression whose sign is computed from the signs of its operands. */
-  private class BinarySignExpr extends FlowSignExpr {
-    SemBinaryExpr binary;
-
-    BinarySignExpr() { binary = this }
-
-    override Sign getSignRestriction() {
-      exists(SemExpr left, SemExpr right |
-        binaryExprOperands(binary, left, right) and
-        result =
-          semExprSign(pragma[only_bind_out](left))
-              .applyBinaryOp(semExprSign(pragma[only_bind_out](right)), binary.getOpcode())
-      )
-      or
-      exists(SemDivExpr div | div = binary |
-        result = semExprSign(div.getLeftOperand()) and
-        result != TZero() and
-        div.getRightOperand().(SemFloatingPointLiteralExpr).getFloatValue() = 0
-      )
-    }
-  }
-
-  pragma[nomagic]
-  private predicate binaryExprOperands(SemBinaryExpr binary, SemExpr left, SemExpr right) {
-    binary.getLeftOperand() = left and binary.getRightOperand() = right
-  }
-
-  /**
-   * A `Convert`, `Box`, or `Unbox` expression.
-   */
-  private class SemCastExpr instanceof SemUnaryExpr {
-    string toString() { result = super.toString() }
-
-    SemCastExpr() {
-      this instanceof SemConvertExpr
-      or
-      this instanceof SemBoxExpr
-      or
-      this instanceof SemUnboxExpr
-    }
-  }
-
-  /** A unary expression whose sign is computed from the sign of its operand. */
-  private class UnarySignExpr extends FlowSignExpr {
-    SemUnaryExpr unary;
-
-    UnarySignExpr() { unary = this and not this instanceof SemCastExpr }
-
-    override Sign getSignRestriction() {
-      result =
-        semExprSign(pragma[only_bind_out](unary.getOperand())).applyUnaryOp(unary.getOpcode())
-    }
-  }
-
-  /**
-   * A `Convert`, `Box`, or `Unbox` expression, whose sign is computed based on
-   * the sign of its operand and the source and destination types.
-   */
-  abstract private class CastSignExpr extends FlowSignExpr {
-    SemUnaryExpr cast;
-
-    CastSignExpr() { cast = this and cast instanceof SemCastExpr }
-
-    override Sign getSignRestriction() { result = semExprSign(cast.getOperand()) }
-  }
-
-  /**
-   * A `Convert` expression.
-   */
-  private class ConvertSignExpr extends CastSignExpr {
-    override SemConvertExpr cast;
-  }
-
-  /**
-   * A `Box` expression.
-   */
-  private class BoxSignExpr extends CastSignExpr {
-    override SemBoxExpr cast;
-  }
-
-  /**
-   * An `Unbox` expression.
-   */
-  private class UnboxSignExpr extends CastSignExpr {
-    override SemUnboxExpr cast;
-
-    UnboxSignExpr() {
-      exists(SemType fromType | fromType = Utils::getTrackedType(cast.getOperand()) |
-        // Only numeric source types are handled here.
-        fromType instanceof SemNumericType
-      )
-    }
-  }
-
-  private predicate unknownSign(SemExpr e) { e instanceof UnknownSignExpr }
-
-  /**
-   * Holds if `lowerbound` is a lower bound for `v` at `pos`. This is restricted
-   * to only include bounds for which we might determine a sign.
-   */
-  private predicate lowerBound(
-    SemExpr lowerbound, SemSsaVariable v, SemSsaReadPosition pos, boolean isStrict
-  ) {
-    exists(boolean testIsTrue, SemRelationalExpr comp |
-      pos.hasReadOfVar(v) and
-      semGuardControlsSsaRead(semGetComparisonGuard(comp), pos, testIsTrue) and
-      not unknownSign(lowerbound)
-    |
-      testIsTrue = true and
-      comp.getLesserOperand() = lowerbound and
-      comp.getGreaterOperand() = Utils::semSsaRead(v, D::fromInt(0)) and
-      (if comp.isStrict() then isStrict = true else isStrict = false)
-      or
-      testIsTrue = false and
-      comp.getGreaterOperand() = lowerbound and
-      comp.getLesserOperand() = Utils::semSsaRead(v, D::fromInt(0)) and
-      (if comp.isStrict() then isStrict = false else isStrict = true)
+/** An SSA Phi definition, whose sign is the union of the signs of its inputs. */
+private class PhiSignDef extends FlowSignDef instanceof SemSsaPhiNode {
+  final override Sign getSign() {
+    exists(SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge |
+      edge.phiInput(this, inp) and
+      result = semSsaSign(inp, edge)
     )
   }
-
-  /**
-   * Holds if `upperbound` is an upper bound for `v` at `pos`. This is restricted
-   * to only include bounds for which we might determine a sign.
-   */
-  private predicate upperBound(
-    SemExpr upperbound, SemSsaVariable v, SemSsaReadPosition pos, boolean isStrict
-  ) {
-    exists(boolean testIsTrue, SemRelationalExpr comp |
-      pos.hasReadOfVar(v) and
-      semGuardControlsSsaRead(semGetComparisonGuard(comp), pos, testIsTrue) and
-      not unknownSign(upperbound)
-    |
-      testIsTrue = true and
-      comp.getGreaterOperand() = upperbound and
-      comp.getLesserOperand() = Utils::semSsaRead(v, D::fromInt(0)) and
-      (if comp.isStrict() then isStrict = true else isStrict = false)
-      or
-      testIsTrue = false and
-      comp.getLesserOperand() = upperbound and
-      comp.getGreaterOperand() = Utils::semSsaRead(v, D::fromInt(0)) and
-      (if comp.isStrict() then isStrict = false else isStrict = true)
-    )
-  }
-
-  /**
-   * Holds if `eqbound` is an equality/inequality for `v` at `pos`. This is
-   * restricted to only include bounds for which we might determine a sign. The
-   * boolean `isEq` gives the polarity:
-   *  - `isEq = true` : `v = eqbound`
-   *  - `isEq = false` : `v != eqbound`
-   */
-  private predicate eqBound(SemExpr eqbound, SemSsaVariable v, SemSsaReadPosition pos, boolean isEq) {
-    exists(SemGuard guard, boolean testIsTrue, boolean polarity |
-      pos.hasReadOfVar(v) and
-      semGuardControlsSsaRead(guard, pos, testIsTrue) and
-      guard.isEquality(eqbound, Utils::semSsaRead(v, D::fromInt(0)), polarity) and
-      isEq = polarity.booleanXor(testIsTrue).booleanNot() and
-      not unknownSign(eqbound)
-    )
-  }
-
-  /**
-   * Holds if `bound` is a bound for `v` at `pos` that needs to be positive in
-   * order for `v` to be positive.
-   */
-  private predicate posBound(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
-    upperBound(bound, v, pos, _) or
-    eqBound(bound, v, pos, true)
-  }
-
-  /**
-   * Holds if `bound` is a bound for `v` at `pos` that needs to be negative in
-   * order for `v` to be negative.
-   */
-  private predicate negBound(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
-    lowerBound(bound, v, pos, _) or
-    eqBound(bound, v, pos, true)
-  }
-
-  /**
-   * Holds if `bound` is a bound for `v` at `pos` that can restrict whether `v`
-   * can be zero.
-   */
-  private predicate zeroBound(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
-    lowerBound(bound, v, pos, _) or
-    upperBound(bound, v, pos, _) or
-    eqBound(bound, v, pos, _)
-  }
-
-  /** Holds if `bound` allows `v` to be positive at `pos`. */
-  private predicate posBoundOk(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
-    posBound(bound, v, pos) and TPos() = semExprSign(bound)
-  }
-
-  /** Holds if `bound` allows `v` to be negative at `pos`. */
-  private predicate negBoundOk(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
-    negBound(bound, v, pos) and TNeg() = semExprSign(bound)
-  }
-
-  /** Holds if `bound` allows `v` to be zero at `pos`. */
-  private predicate zeroBoundOk(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
-    lowerBound(bound, v, pos, _) and TNeg() = semExprSign(bound)
-    or
-    lowerBound(bound, v, pos, false) and TZero() = semExprSign(bound)
-    or
-    upperBound(bound, v, pos, _) and TPos() = semExprSign(bound)
-    or
-    upperBound(bound, v, pos, false) and TZero() = semExprSign(bound)
-    or
-    eqBound(bound, v, pos, true) and TZero() = semExprSign(bound)
-    or
-    eqBound(bound, v, pos, false) and TZero() != semExprSign(bound)
-  }
-
-  /**
-   * Holds if there is a bound that might restrict whether `v` has the sign `s`
-   * at `pos`.
-   */
-  private predicate hasGuard(SemSsaVariable v, SemSsaReadPosition pos, Sign s) {
-    s = TPos() and posBound(_, v, pos)
-    or
-    s = TNeg() and negBound(_, v, pos)
-    or
-    s = TZero() and zeroBound(_, v, pos)
-  }
-
-  /**
-   * Gets a possible sign of `v` at `pos` based on its definition, where the sign
-   * might be ruled out by a guard.
-   */
-  pragma[noinline]
-  private Sign guardedSsaSign(SemSsaVariable v, SemSsaReadPosition pos) {
-    result = semSsaDefSign(v) and
-    pos.hasReadOfVar(v) and
-    hasGuard(v, pos, result)
-  }
-
-  /**
-   * Gets a possible sign of `v` at `pos` based on its definition, where no guard
-   * can rule it out.
-   */
-  pragma[noinline]
-  private Sign unguardedSsaSign(SemSsaVariable v, SemSsaReadPosition pos) {
-    result = semSsaDefSign(v) and
-    pos.hasReadOfVar(v) and
-    not hasGuard(v, pos, result)
-  }
-
-  /**
-   * Gets a possible sign of `v` at read position `pos`, where a guard could have
-   * ruled out the sign but does not.
-   * This does not check that the definition of `v` also allows the sign.
-   */
-  private Sign guardedSsaSignOk(SemSsaVariable v, SemSsaReadPosition pos) {
-    result = TPos() and
-    forex(SemExpr bound | posBound(bound, v, pos) | posBoundOk(bound, v, pos))
-    or
-    result = TNeg() and
-    forex(SemExpr bound | negBound(bound, v, pos) | negBoundOk(bound, v, pos))
-    or
-    result = TZero() and
-    forex(SemExpr bound | zeroBound(bound, v, pos) | zeroBoundOk(bound, v, pos))
-  }
-
-  /** Gets a possible sign for `v` at `pos`. */
-  private Sign semSsaSign(SemSsaVariable v, SemSsaReadPosition pos) {
-    result = unguardedSsaSign(v, pos)
-    or
-    result = guardedSsaSign(v, pos) and
-    result = guardedSsaSignOk(v, pos)
-  }
-
-  /** Gets a possible sign for `v`. */
-  pragma[nomagic]
-  Sign semSsaDefSign(SemSsaVariable v) { result = v.(SignDef).getSign() }
-
-  /** Gets a possible sign for `e`. */
-  cached
-  Sign semExprSign(SemExpr e) {
-    exists(Sign s | s = e.(SignExpr).getSign() |
-      if
-        Utils::getTrackedType(e) instanceof SemUnsignedIntegerType and
-        s = TNeg() and
-        not Specific::ignoreTypeRestrictions(e)
-      then result = TPos()
-      else result = s
-    )
-  }
-
-  /**
-   * Dummy predicate that holds for any sign. This is added to improve readability
-   * of cases where the sign is unrestricted.
-   */
-  predicate semAnySign(Sign s) { any() }
-
-  /** Holds if `e` can be positive and cannot be negative. */
-  predicate semPositive(SemExpr e) {
-    semExprSign(e) = TPos() and
-    not semExprSign(e) = TNeg()
-  }
-
-  /** Holds if `e` can be negative and cannot be positive. */
-  predicate semNegative(SemExpr e) {
-    semExprSign(e) = TNeg() and
-    not semExprSign(e) = TPos()
-  }
-
-  /** Holds if `e` is strictly positive. */
-  predicate semStrictlyPositive(SemExpr e) {
-    semExprSign(e) = TPos() and
-    not semExprSign(e) = TNeg() and
-    not semExprSign(e) = TZero()
-  }
-
-  /** Holds if `e` is strictly negative. */
-  predicate semStrictlyNegative(SemExpr e) {
-    semExprSign(e) = TNeg() and
-    not semExprSign(e) = TPos() and
-    not semExprSign(e) = TZero()
-  }
+}
+
+/** An SSA definition whose sign is computed by a language-specific implementation. */
+abstract class CustomSignDef extends SignDef {
+  abstract override Sign getSign();
+}
+
+/**
+ * An expression for which the analysis can compute the sign.
+ *
+ * The actual computation of the sign is done in an override of the `getSign()` predicate. The
+ * charpred of any subclass must _not_ invoke `getSign()`, directly or indirectly. This ensures
+ * that the charpred does not introduce negative recursion. The `getSign()` predicate may be
+ * recursive.
+ *
+ * Concrete implementations extend one of the following subclasses:
+ * - `ConstantSignExpr`, for expressions with a compile-time constant value.
+ * - `FlowSignExpr`, for expressions whose sign can be computed from the signs of their operands.
+ * - `CustomsignExpr`, for expressions whose sign can be computed by a language-specific
+ *   implementation.
+ *
+ * If the same expression matches more than one of the above subclasses, the sign is computed as
+ * follows:
+ * - The sign of a `ConstantSignExpr` is computed solely from `ConstantSignExpr.getSign()`,
+ *   regardless of any other subclasses.
+ * - If a non-`ConstantSignExpr` expression matches exactly one of `FlowSignExpr` or
+ *   `CustomSignExpr`, the sign is computed by that class' `getSign()` predicate.
+ * - If a non-`ConstantSignExpr` expression matches both `FlowSignExpr` and `CustomSignExpr`, the
+ *   sign is the _intersection_ of the signs of those two classes' `getSign()` predicates. Thus,
+ *   both classes have the opportunity to _restrict_ the set of possible signs, not to generate new
+ *   possible signs.
+ * - If an expression does not match any of the three subclasses, then it can have any sign.
+ *
+ * Note that the `getSign()` predicate is introduced only in subclasses of `SignExpr`.
+ */
+abstract class SignExpr instanceof SemExpr {
+  SignExpr() { not Specific::ignoreExprSign(this) }
+
+  final string toString() { result = super.toString() }
+
+  abstract Sign getSign();
+}
+
+/** An expression whose sign is determined by its constant numeric value. */
+private class ConstantSignExpr extends SignExpr {
+  ConstantSignExpr() {
+    this instanceof SemConstantIntegerExpr or
+    exists(this.(SemNumericLiteralExpr).getApproximateFloatValue())
+  }
+
+  final override Sign getSign() {
+    exists(int i | this.(SemConstantIntegerExpr).getIntValue() = i |
+      i < 0 and result = TNeg()
+      or
+      i = 0 and result = TZero()
+      or
+      i > 0 and result = TPos()
+    )
+    or
+    not exists(this.(SemConstantIntegerExpr).getIntValue()) and
+    exists(float f | f = this.(SemNumericLiteralExpr).getApproximateFloatValue() |
+      f < 0 and result = TNeg()
+      or
+      f = 0 and result = TZero()
+      or
+      f > 0 and result = TPos()
+    )
+  }
+}
+
+abstract private class NonConstantSignExpr extends SignExpr {
+  NonConstantSignExpr() { not this instanceof ConstantSignExpr }
+
+  final override Sign getSign() {
+    // The result is the _intersection_ of the signs computed from flow and by the language.
+    (result = this.(FlowSignExpr).getSignRestriction() or not this instanceof FlowSignExpr) and
+    (result = this.(CustomSignExpr).getSignRestriction() or not this instanceof CustomSignExpr)
+  }
+}
+
+/** An expression whose sign is computed from the signs of its operands. */
+abstract private class FlowSignExpr extends NonConstantSignExpr {
+  abstract Sign getSignRestriction();
+}
+
+/** An expression whose sign is computed by a language-specific implementation. */
+abstract class CustomSignExpr extends NonConstantSignExpr {
+  abstract Sign getSignRestriction();
+}
+
+/** An expression whose sign is unknown. */
+private class UnknownSignExpr extends SignExpr {
+  UnknownSignExpr() {
+    not this instanceof FlowSignExpr and
+    not this instanceof CustomSignExpr and
+    not this instanceof ConstantSignExpr and
+    (
+      // Only track numeric types.
+      getTrackedType(this) instanceof SemNumericType
+      or
+      // Unless the language says to track this expression anyway.
+      Specific::trackUnknownNonNumericExpr(this)
+    )
+  }
+
+  final override Sign getSign() { semAnySign(result) }
+}
+
+/**
+ * A `Load` expression whose sign is computed from the sign of its SSA definition, restricted by
+ * inference from any intervening guards.
+ */
+class UseSignExpr extends FlowSignExpr {
+  SemSsaVariable v;
+
+  UseSignExpr() { v.getAUse() = this }
+
+  override Sign getSignRestriction() {
+    // Propagate via SSA
+    // Propagate the sign from the def of `v`, incorporating any inference from guards.
+    result = semSsaSign(v, any(SemSsaReadPositionBlock bb | bb.getAnExpr() = this))
+    or
+    // No block for this read. Just use the sign of the def.
+    // REVIEW: How can this happen?
+    not exists(SemSsaReadPositionBlock bb | bb.getAnExpr() = this) and
+    result = semSsaDefSign(v)
+  }
+}
+
+/** A binary expression whose sign is computed from the signs of its operands. */
+private class BinarySignExpr extends FlowSignExpr {
+  SemBinaryExpr binary;
+
+  BinarySignExpr() { binary = this }
+
+  override Sign getSignRestriction() {
+    exists(SemExpr left, SemExpr right |
+      binaryExprOperands(binary, left, right) and
+      result =
+        semExprSign(pragma[only_bind_out](left))
+            .applyBinaryOp(semExprSign(pragma[only_bind_out](right)), binary.getOpcode())
+    )
+    or
+    exists(SemDivExpr div | div = binary |
+      result = semExprSign(div.getLeftOperand()) and
+      result != TZero() and
+      div.getRightOperand().(SemFloatingPointLiteralExpr).getFloatValue() = 0
+    )
+  }
+}
+
+pragma[nomagic]
+private predicate binaryExprOperands(SemBinaryExpr binary, SemExpr left, SemExpr right) {
+  binary.getLeftOperand() = left and binary.getRightOperand() = right
+}
+
+/**
+ * A `Convert`, `Box`, or `Unbox` expression.
+ */
+private class SemCastExpr extends SemUnaryExpr {
+  SemCastExpr() {
+    this instanceof SemConvertExpr
+    or
+    this instanceof SemBoxExpr
+    or
+    this instanceof SemUnboxExpr
+  }
+}
+
+/** A unary expression whose sign is computed from the sign of its operand. */
+private class UnarySignExpr extends FlowSignExpr {
+  SemUnaryExpr unary;
+
+  UnarySignExpr() { unary = this and not this instanceof SemCastExpr }
+
+  override Sign getSignRestriction() {
+    result = semExprSign(pragma[only_bind_out](unary.getOperand())).applyUnaryOp(unary.getOpcode())
+  }
+}
+
+/**
+ * A `Convert`, `Box`, or `Unbox` expression, whose sign is computed based on
+ * the sign of its operand and the source and destination types.
+ */
+abstract private class CastSignExpr extends FlowSignExpr {
+  SemUnaryExpr cast;
+
+  CastSignExpr() { cast = this and cast instanceof SemCastExpr }
+
+  override Sign getSignRestriction() { result = semExprSign(cast.getOperand()) }
+}
+
+/**
+ * A `Convert` expression.
+ */
+private class ConvertSignExpr extends CastSignExpr {
+  override SemConvertExpr cast;
+}
+
+/**
+ * A `Box` expression.
+ */
+private class BoxSignExpr extends CastSignExpr {
+  override SemBoxExpr cast;
+}
+
+/**
+ * An `Unbox` expression.
+ */
+private class UnboxSignExpr extends CastSignExpr {
+  override SemUnboxExpr cast;
+
+  UnboxSignExpr() {
+    exists(SemType fromType | fromType = getTrackedType(cast.getOperand()) |
+      // Only numeric source types are handled here.
+      fromType instanceof SemNumericType
+    )
+  }
+}
+
+private predicate unknownSign(SemExpr e) { e instanceof UnknownSignExpr }
+
+/**
+ * Holds if `lowerbound` is a lower bound for `v` at `pos`. This is restricted
+ * to only include bounds for which we might determine a sign.
+ */
+private predicate lowerBound(
+  SemExpr lowerbound, SemSsaVariable v, SemSsaReadPosition pos, boolean isStrict
+) {
+  exists(boolean testIsTrue, SemRelationalExpr comp |
+    pos.hasReadOfVar(v) and
+    semGuardControlsSsaRead(semGetComparisonGuard(comp), pos, testIsTrue) and
+    not unknownSign(lowerbound)
+  |
+    testIsTrue = true and
+    comp.getLesserOperand() = lowerbound and
+    comp.getGreaterOperand() = semSsaRead(v, 0) and
+    (if comp.isStrict() then isStrict = true else isStrict = false)
+    or
+    testIsTrue = false and
+    comp.getGreaterOperand() = lowerbound and
+    comp.getLesserOperand() = semSsaRead(v, 0) and
+    (if comp.isStrict() then isStrict = false else isStrict = true)
+  )
+}
+
+/**
+ * Holds if `upperbound` is an upper bound for `v` at `pos`. This is restricted
+ * to only include bounds for which we might determine a sign.
+ */
+private predicate upperBound(
+  SemExpr upperbound, SemSsaVariable v, SemSsaReadPosition pos, boolean isStrict
+) {
+  exists(boolean testIsTrue, SemRelationalExpr comp |
+    pos.hasReadOfVar(v) and
+    semGuardControlsSsaRead(semGetComparisonGuard(comp), pos, testIsTrue) and
+    not unknownSign(upperbound)
+  |
+    testIsTrue = true and
+    comp.getGreaterOperand() = upperbound and
+    comp.getLesserOperand() = semSsaRead(v, 0) and
+    (if comp.isStrict() then isStrict = true else isStrict = false)
+    or
+    testIsTrue = false and
+    comp.getLesserOperand() = upperbound and
+    comp.getGreaterOperand() = semSsaRead(v, 0) and
+    (if comp.isStrict() then isStrict = false else isStrict = true)
+  )
+}
+
+/**
+ * Holds if `eqbound` is an equality/inequality for `v` at `pos`. This is
+ * restricted to only include bounds for which we might determine a sign. The
+ * boolean `isEq` gives the polarity:
+ *  - `isEq = true` : `v = eqbound`
+ *  - `isEq = false` : `v != eqbound`
+ */
+private predicate eqBound(SemExpr eqbound, SemSsaVariable v, SemSsaReadPosition pos, boolean isEq) {
+  exists(SemGuard guard, boolean testIsTrue, boolean polarity |
+    pos.hasReadOfVar(v) and
+    semGuardControlsSsaRead(guard, pos, testIsTrue) and
+    guard.isEquality(eqbound, semSsaRead(v, 0), polarity) and
+    isEq = polarity.booleanXor(testIsTrue).booleanNot() and
+    not unknownSign(eqbound)
+  )
+}
+
+/**
+ * Holds if `bound` is a bound for `v` at `pos` that needs to be positive in
+ * order for `v` to be positive.
+ */
+private predicate posBound(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  upperBound(bound, v, pos, _) or
+  eqBound(bound, v, pos, true)
+}
+
+/**
+ * Holds if `bound` is a bound for `v` at `pos` that needs to be negative in
+ * order for `v` to be negative.
+ */
+private predicate negBound(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  lowerBound(bound, v, pos, _) or
+  eqBound(bound, v, pos, true)
+}
+
+/**
+ * Holds if `bound` is a bound for `v` at `pos` that can restrict whether `v`
+ * can be zero.
+ */
+private predicate zeroBound(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  lowerBound(bound, v, pos, _) or
+  upperBound(bound, v, pos, _) or
+  eqBound(bound, v, pos, _)
+}
+
+/** Holds if `bound` allows `v` to be positive at `pos`. */
+private predicate posBoundOk(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  posBound(bound, v, pos) and TPos() = semExprSign(bound)
+}
+
+/** Holds if `bound` allows `v` to be negative at `pos`. */
+private predicate negBoundOk(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  negBound(bound, v, pos) and TNeg() = semExprSign(bound)
+}
+
+/** Holds if `bound` allows `v` to be zero at `pos`. */
+private predicate zeroBoundOk(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  lowerBound(bound, v, pos, _) and TNeg() = semExprSign(bound)
+  or
+  lowerBound(bound, v, pos, false) and TZero() = semExprSign(bound)
+  or
+  upperBound(bound, v, pos, _) and TPos() = semExprSign(bound)
+  or
+  upperBound(bound, v, pos, false) and TZero() = semExprSign(bound)
+  or
+  eqBound(bound, v, pos, true) and TZero() = semExprSign(bound)
+  or
+  eqBound(bound, v, pos, false) and TZero() != semExprSign(bound)
+}
+
+/**
+ * Holds if there is a bound that might restrict whether `v` has the sign `s`
+ * at `pos`.
+ */
+private predicate hasGuard(SemSsaVariable v, SemSsaReadPosition pos, Sign s) {
+  s = TPos() and posBound(_, v, pos)
+  or
+  s = TNeg() and negBound(_, v, pos)
+  or
+  s = TZero() and zeroBound(_, v, pos)
+}
+
+/**
+ * Gets a possible sign of `v` at `pos` based on its definition, where the sign
+ * might be ruled out by a guard.
+ */
+pragma[noinline]
+private Sign guardedSsaSign(SemSsaVariable v, SemSsaReadPosition pos) {
+  result = semSsaDefSign(v) and
+  pos.hasReadOfVar(v) and
+  hasGuard(v, pos, result)
+}
+
+/**
+ * Gets a possible sign of `v` at `pos` based on its definition, where no guard
+ * can rule it out.
+ */
+pragma[noinline]
+private Sign unguardedSsaSign(SemSsaVariable v, SemSsaReadPosition pos) {
+  result = semSsaDefSign(v) and
+  pos.hasReadOfVar(v) and
+  not hasGuard(v, pos, result)
+}
+
+/**
+ * Gets a possible sign of `v` at read position `pos`, where a guard could have
+ * ruled out the sign but does not.
+ * This does not check that the definition of `v` also allows the sign.
+ */
+private Sign guardedSsaSignOk(SemSsaVariable v, SemSsaReadPosition pos) {
+  result = TPos() and
+  forex(SemExpr bound | posBound(bound, v, pos) | posBoundOk(bound, v, pos))
+  or
+  result = TNeg() and
+  forex(SemExpr bound | negBound(bound, v, pos) | negBoundOk(bound, v, pos))
+  or
+  result = TZero() and
+  forex(SemExpr bound | zeroBound(bound, v, pos) | zeroBoundOk(bound, v, pos))
+}
+
+/** Gets a possible sign for `v` at `pos`. */
+private Sign semSsaSign(SemSsaVariable v, SemSsaReadPosition pos) {
+  result = unguardedSsaSign(v, pos)
+  or
+  result = guardedSsaSign(v, pos) and
+  result = guardedSsaSignOk(v, pos)
+}
+
+/** Gets a possible sign for `v`. */
+pragma[nomagic]
+Sign semSsaDefSign(SemSsaVariable v) { result = v.(SignDef).getSign() }
+
+/** Gets a possible sign for `e`. */
+cached
+Sign semExprSign(SemExpr e) {
+  exists(Sign s | s = e.(SignExpr).getSign() |
+    if
+      getTrackedType(e) instanceof SemUnsignedIntegerType and
+      s = TNeg() and
+      not Specific::ignoreTypeRestrictions(e)
+    then result = TPos()
+    else result = s
+  )
+}
+
+/**
+ * Dummy predicate that holds for any sign. This is added to improve readability
+ * of cases where the sign is unrestricted.
+ */
+predicate semAnySign(Sign s) { any() }
+
+/** Holds if `e` can be positive and cannot be negative. */
+predicate semPositive(SemExpr e) {
+  semExprSign(e) = TPos() and
+  not semExprSign(e) = TNeg()
+}
+
+/** Holds if `e` can be negative and cannot be positive. */
+predicate semNegative(SemExpr e) {
+  semExprSign(e) = TNeg() and
+  not semExprSign(e) = TPos()
+}
+
+/** Holds if `e` is strictly positive. */
+predicate semStrictlyPositive(SemExpr e) {
+  semExprSign(e) = TPos() and
+  not semExprSign(e) = TNeg() and
+  not semExprSign(e) = TZero()
+}
+
+/** Holds if `e` is strictly negative. */
+predicate semStrictlyNegative(SemExpr e) {
+  semExprSign(e) = TNeg() and
+  not semExprSign(e) = TPos() and
+  not semExprSign(e) = TZero()
 }

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

@@ -1,132 +0,0 @@
-/**
- * Wrapper for the semantic range analysis library that mimics the
- * interface of the simple range analysis library.
- */
-
-private import cpp
-private import semmle.code.cpp.ir.IR
-private import experimental.semmle.code.cpp.semantic.SemanticBound
-private import experimental.semmle.code.cpp.semantic.SemanticExprSpecific
-private import RangeAnalysis
-
-/**
- * Gets the lower bound of the expression.
- *
- * Note: expressions in C/C++ are often implicitly or explicitly cast to a
- * different result type. Such casts can cause the value of the expression
- * to overflow or to be truncated. This predicate computes the lower bound
- * of the expression without including the effect of the casts. To compute
- * the lower bound of the expression after all the casts have been applied,
- * call `lowerBound` like this:
- *
- *    `lowerBound(expr.getFullyConverted())`
- */
-float lowerBound(Expr expr) {
-  exists(Instruction i, SemBound b | i.getAst() = expr and b instanceof SemZeroBound |
-    semBounded(getSemanticExpr(i), b, result, false, _)
-  )
-}
-
-/**
- * Gets the upper bound of the expression.
- *
- * Note: expressions in C/C++ are often implicitly or explicitly cast to a
- * different result type. Such casts can cause the value of the expression
- * to overflow or to be truncated. This predicate computes the upper bound
- * of the expression without including the effect of the casts. To compute
- * the upper bound of the expression after all the casts have been applied,
- * call `upperBound` like this:
- *
- *    `upperBound(expr.getFullyConverted())`
- */
-float upperBound(Expr expr) {
-  exists(Instruction i, SemBound b | i.getAst() = expr and b instanceof SemZeroBound |
-    semBounded(getSemanticExpr(i), b, result, true, _)
-  )
-}
-
-/**
- * Holds if the upper bound of `expr` may have been widened. This means the
- * upper bound is in practice likely to be overly wide.
- */
-predicate upperBoundMayBeWidened(Expr e) { none() }
-
-/**
- * Holds if `expr` has a provably empty range. For example:
- *
- *   10 < expr and expr < 5
- *
- * The range of an expression can only be empty if it can never be
- * executed. For example:
- *
- * ```cpp
- * if (10 < x) {
- *   if (x < 5) {
- *     // Unreachable code
- *     return x; // x has an empty range: 10 < x && x < 5
- *   }
- * }
- * ```
- */
-predicate exprWithEmptyRange(Expr expr) { lowerBound(expr) > upperBound(expr) }
-
-/** Holds if the definition might overflow negatively. */
-predicate defMightOverflowNegatively(RangeSsaDefinition def, StackVariable v) { none() }
-
-/** Holds if the definition might overflow positively. */
-predicate defMightOverflowPositively(RangeSsaDefinition def, StackVariable v) { none() }
-
-/**
- * Holds if the definition might overflow (either positively or
- * negatively).
- */
-predicate defMightOverflow(RangeSsaDefinition def, StackVariable v) {
-  defMightOverflowNegatively(def, v) or
-  defMightOverflowPositively(def, v)
-}
-
-/**
- * Holds if the expression might overflow negatively. This predicate
- * does not consider the possibility that the expression might overflow
- * due to a conversion.
- */
-predicate exprMightOverflowNegatively(Expr expr) { none() }
-
-/**
- * Holds if the expression might overflow negatively. Conversions
- * are also taken into account. For example the expression
- * `(int16)(x+y)` might overflow due to the `(int16)` cast, rather than
- * due to the addition.
- */
-predicate convertedExprMightOverflowNegatively(Expr expr) {
-  exprMightOverflowNegatively(expr) or
-  convertedExprMightOverflowNegatively(expr.getConversion())
-}
-
-/**
- * Holds if the expression might overflow positively. This predicate
- * does not consider the possibility that the expression might overflow
- * due to a conversion.
- */
-predicate exprMightOverflowPositively(Expr expr) { none() }
-
-/**
- * Holds if the expression might overflow positively. Conversions
- * are also taken into account. For example the expression
- * `(int16)(x+y)` might overflow due to the `(int16)` cast, rather than
- * due to the addition.
- */
-predicate convertedExprMightOverflowPositively(Expr expr) {
-  exprMightOverflowPositively(expr) or
-  convertedExprMightOverflowPositively(expr.getConversion())
-}
-
-/**
- * Holds if the expression might overflow (either positively or
- * negatively). The possibility that the expression might overflow
- * due to an implicit or explicit cast is also considered.
- */
-predicate convertedExprMightOverflow(Expr expr) {
-  convertedExprMightOverflowNegatively(expr) or
-  convertedExprMightOverflowPositively(expr)
-}

cpp/ql/lib/qlpack.yml

@@ -1,5 +1,5 @@
 name: codeql/cpp-all
-version: 0.5.5-dev
+version: 0.5.1-dev
 groups: cpp
 dbscheme: semmlecode.cpp.dbscheme
 extractor: cpp

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

@@ -227,6 +227,18 @@ class Class extends UserType {
     result = this.accessOfBaseMember(member.getDeclaringType(), member.getASpecifier())
   }
 
+  /**
+   * DEPRECATED: name changed to `hasImplicitCopyConstructor` to reflect that
+   * `= default` members are no longer included.
+   */
+  deprecated predicate hasGeneratedCopyConstructor() { this.hasImplicitCopyConstructor() }
+
+  /**
+   * DEPRECATED: name changed to `hasImplicitCopyAssignmentOperator` to
+   * reflect that `= default` members are no longer included.
+   */
+  deprecated predicate hasGeneratedCopyAssignmentOperator() { this.hasImplicitCopyConstructor() }
+
   /**
    * Holds if this class, struct or union has an implicitly-declared copy
    * constructor that is not _deleted_. This predicate is more accurate than

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

@@ -68,9 +68,7 @@ class Declaration extends Locatable, @declaration {
    * Holds if this declaration has the fully-qualified name `qualifiedName`.
    * See `getQualifiedName`.
    */
-  deprecated predicate hasQualifiedName(string qualifiedName) {
-    this.getQualifiedName() = qualifiedName
-  }
+  predicate hasQualifiedName(string qualifiedName) { this.getQualifiedName() = qualifiedName }
 
   /**
    * Holds if this declaration has a fully-qualified name with a name-space
@@ -186,7 +184,7 @@ class Declaration extends Locatable, @declaration {
   predicate hasDefinition() { exists(this.getDefinition()) }
 
   /** DEPRECATED: Use `hasDefinition` instead. */
-  deprecated predicate isDefined() { this.hasDefinition() }
+  predicate isDefined() { this.hasDefinition() }
 
   /** Gets the preferred location of this declaration, if any. */
   override Location getLocation() { none() }
@@ -619,10 +617,11 @@ private class DirectAccessHolder extends Element {
   /**
    * Like `couldAccessMember` but only contains derivations in which either
    * (5.2), (5.3) or (5.4) must be invoked. In other words, the `this`
-   * parameter is not ignored. We check for 11.4 as part of (5.3), since
-   * this further limits the number of tuples produced by this predicate.
+   * parameter is not ignored. This restriction makes it feasible to fully
+   * enumerate this predicate even on large code bases. We check for 11.4 as
+   * part of (5.3), since this further limits the number of tuples produced by
+   * this predicate.
    */
-  pragma[inline]
   predicate thisCouldAccessMember(Class memberClass, AccessSpecifier memberAccess, Class derived) {
     // Only (5.4) is recursive, and chains of invocations of (5.4) can always
     // be collapsed to one invocation by the transitivity of 11.2/4.
@@ -664,9 +663,7 @@ private class DirectAccessHolder extends Element {
     //    bypasses `p`. Then that path must be public, or we are in case 2.
     exists(AccessSpecifier public | public.hasName("public") |
       exists(Class between, Class p |
-        between
-            .accessOfBaseMember(pragma[only_bind_into](memberClass), memberAccess)
-            .hasName("protected") and
+        between.accessOfBaseMember(memberClass, memberAccess).hasName("protected") and
         this.isFriendOfOrEqualTo(p) and
         (
           // This is case 1 from above. If `p` derives privately from `between`

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

@@ -41,7 +41,7 @@ class Function extends Declaration, ControlFlowNode, AccessHolder, @function {
    * `min<int>(int, int) -> int`, and the full signature of the uninstantiated
    * template on the first line would be `min<T>(T, T) -> T`.
    */
-  deprecated string getFullSignature() {
+  string getFullSignature() {
     exists(string name, string templateArgs, string args |
       result = name + templateArgs + args + " -> " + this.getType().toString() and
       name = this.getQualifiedName() and

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

@@ -159,8 +159,7 @@ class NameQualifyingElement extends Element, @namequalifyingelement {
  * A special name-qualifying element. For example: `__super`.
  */
 library class SpecialNameQualifyingElement extends NameQualifyingElement,
-  @specialnamequalifyingelement
-{
+  @specialnamequalifyingelement {
   /** Gets the name of this special qualifying element. */
   override string getName() { specialnamequalifyingelements(underlyingElement(this), result) }
 

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

@@ -108,6 +108,20 @@ class XmlFile extends XmlParent, File {
   /** Gets the name of this XML file. */
   override string getName() { result = File.super.getAbsolutePath() }
 
+  /**
+   * DEPRECATED: Use `getAbsolutePath()` instead.
+   *
+   * Gets the path of this XML file.
+   */
+  deprecated string getPath() { result = this.getAbsolutePath() }
+
+  /**
+   * DEPRECATED: Use `getParentContainer().getAbsolutePath()` instead.
+   *
+   * Gets the path of the folder that contains this XML file.
+   */
+  deprecated string getFolder() { result = this.getParentContainer().getAbsolutePath() }
+
   /** Gets the encoding of this XML file. */
   string getEncoding() { xmlEncoding(this, result) }
 

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

@@ -12,9 +12,7 @@ predicate freeFunction(Function f, int argNum) { argNum = f.(DeallocationFunctio
  *
  * DEPRECATED: Use `DeallocationExpr` instead (this also includes `delete` expressions).
  */
-deprecated predicate freeCall(FunctionCall fc, Expr arg) {
-  arg = fc.(DeallocationExpr).getFreedExpr()
-}
+predicate freeCall(FunctionCall fc, Expr arg) { arg = fc.(DeallocationExpr).getFreedExpr() }
 
 /**
  * Is e some kind of allocation or deallocation (`new`, `alloc`, `realloc`, `delete`, `free` etc)?

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

@@ -1,5 +1,5 @@
 import cpp
-private import semmle.code.cpp.ir.dataflow.DataFlow
+import semmle.code.cpp.dataflow.DataFlow
 
 /**
  * Holds if `v` is a member variable of `c` that looks like it might be variable sized
@@ -25,12 +25,10 @@ predicate memberMayBeVarSize(Class c, MemberVariable v) {
 }
 
 /**
- * Holds if `bufferExpr` is an allocation-like expression.
- *
- * This includes both actual allocations, as well as various operations that return a pointer to
- * stack-allocated objects.
+ * Get the size in bytes of the buffer pointed to by an expression (if this can be determined).
  */
-private int isSource(Expr bufferExpr, Element why) {
+language[monotonicAggregates]
+int getBufferSize(Expr bufferExpr, Element why) {
   exists(Variable bufferVar | bufferVar = bufferExpr.(VariableAccess).getTarget() |
     // buffer is a fixed size array
     result = bufferVar.getUnspecifiedType().(ArrayType).getSize() and
@@ -48,12 +46,42 @@ private int isSource(Expr bufferExpr, Element why) {
     ) and
     result = why.(Expr).getType().(ArrayType).getSize() and
     not exists(bufferVar.getUnspecifiedType().(ArrayType).getSize())
+    or
+    exists(Class parentClass, VariableAccess parentPtr, int bufferSize |
+      // buffer is the parentPtr->bufferVar of a 'variable size struct'
+      memberMayBeVarSize(parentClass, bufferVar) and
+      why = bufferVar and
+      parentPtr = bufferExpr.(VariableAccess).getQualifier() and
+      parentPtr.getTarget().getUnspecifiedType().(PointerType).getBaseType() = parentClass and
+      (
+        if exists(bufferVar.getType().getSize())
+        then bufferSize = bufferVar.getType().getSize()
+        else bufferSize = 0
+      ) and
+      result = getBufferSize(parentPtr, _) + bufferSize - parentClass.getSize()
+    )
   )
   or
   // buffer is a fixed size dynamic allocation
   result = bufferExpr.(AllocationExpr).getSizeBytes() and
   why = bufferExpr
   or
+  exists(DataFlow::ExprNode bufferExprNode |
+    // dataflow (all sources must be the same size)
+    bufferExprNode = DataFlow::exprNode(bufferExpr) and
+    result =
+      unique(Expr def |
+        DataFlow::localFlowStep(DataFlow::exprNode(def), bufferExprNode)
+      |
+        getBufferSize(def, _)
+      ) and
+    // find reason
+    exists(Expr def | DataFlow::localFlowStep(DataFlow::exprNode(def), bufferExprNode) |
+      why = def or
+      exists(getBufferSize(def, why))
+    )
+  )
+  or
   exists(Type bufferType |
     // buffer is the address of a variable
     why = bufferExpr.(AddressOfExpr).getAddressable() and
@@ -72,30 +100,3 @@ private int isSource(Expr bufferExpr, Element why) {
     result = bufferType.getSize()
   )
 }
-
-/**
- * Get the size in bytes of the buffer pointed to by an expression (if this can be determined).
- */
-language[monotonicAggregates]
-int getBufferSize(Expr bufferExpr, Element why) {
-  result = isSource(bufferExpr, why)
-  or
-  exists(Class parentClass, VariableAccess parentPtr, int bufferSize, Variable bufferVar |
-    bufferVar = bufferExpr.(VariableAccess).getTarget() and
-    // buffer is the parentPtr->bufferVar of a 'variable size struct'
-    memberMayBeVarSize(parentClass, bufferVar) and
-    why = bufferVar and
-    parentPtr = bufferExpr.(VariableAccess).getQualifier() and
-    parentPtr.getTarget().getUnspecifiedType().(PointerType).getBaseType() = parentClass and
-    result = getBufferSize(parentPtr, _) + bufferSize - parentClass.getSize()
-  |
-    if exists(bufferVar.getType().getSize())
-    then bufferSize = bufferVar.getType().getSize()
-    else bufferSize = 0
-  )
-  or
-  // dataflow (all sources must be the same size)
-  result = unique(Expr def | DataFlow::localExprFlowStep(def, bufferExpr) | getBufferSize(def, _)) and
-  // find reason
-  exists(Expr def | DataFlow::localExprFlowStep(def, bufferExpr) | exists(getBufferSize(def, why)))
-}

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

@@ -1,7 +1,7 @@
 import cpp
 private import semmle.code.cpp.models.interfaces.ArrayFunction
 private import semmle.code.cpp.models.implementations.Strcat
-private import semmle.code.cpp.ir.dataflow.DataFlow
+import semmle.code.cpp.dataflow.DataFlow
 
 /**
  * Holds if the expression `e` assigns something including `va` to a

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

@@ -59,6 +59,26 @@ abstract class MutexType extends Type {
    * Gets a call that unlocks any mutex of this type.
    */
   FunctionCall getUnlockAccess() { this.unlockAccess(result, _) }
+
+  /**
+   * DEPRECATED: use mustlockAccess(fc, arg) instead.
+   */
+  deprecated Function getMustlockFunction() { result = this.getMustlockAccess().getTarget() }
+
+  /**
+   * DEPRECATED: use trylockAccess(fc, arg) instead.
+   */
+  deprecated Function getTrylockFunction() { result = this.getTrylockAccess().getTarget() }
+
+  /**
+   * DEPRECATED: use lockAccess(fc, arg) instead.
+   */
+  deprecated Function getLockFunction() { result = this.getLockAccess().getTarget() }
+
+  /**
+   * DEPRECATED: use unlockAccess(fc, arg) instead.
+   */
+  deprecated Function getUnlockFunction() { result = this.getUnlockAccess().getTarget() }
 }
 
 /**

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

@@ -75,6 +75,13 @@ class SubBasicBlock extends ControlFlowNodeBase {
     )
   }
 
+  /**
+   * DEPRECATED: use `getRankInBasicBlock` instead. Note that this predicate
+   * returns a 0-based position, while `getRankInBasicBlock` returns a 1-based
+   * position.
+   */
+  deprecated int getPosInBasicBlock(BasicBlock bb) { result = this.getRankInBasicBlock(bb) - 1 }
+
   pragma[noinline]
   private int getIndexInBasicBlock(BasicBlock bb) { this = bb.getNode(result) }
 

cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow.qll

@@ -19,11 +19,6 @@
 
 import cpp
 
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) data flow analyses.
- */
 module DataFlow {
-  import semmle.code.cpp.dataflow.internal.DataFlow
-  import semmle.code.cpp.dataflow.internal.DataFlowImpl1
+  import semmle.code.cpp.dataflow.internal.DataFlowImpl
 }

cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow2.qll

@@ -11,10 +11,6 @@
 
 import cpp
 
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) data flow analyses.
- */
 module DataFlow2 {
   import semmle.code.cpp.dataflow.internal.DataFlowImpl2
 }

cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow3.qll

@@ -11,10 +11,6 @@
 
 import cpp
 
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) data flow analyses.
- */
 module DataFlow3 {
   import semmle.code.cpp.dataflow.internal.DataFlowImpl3
 }

cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow4.qll

@@ -11,10 +11,6 @@
 
 import cpp
 
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) data flow analyses.
- */
 module DataFlow4 {
   import semmle.code.cpp.dataflow.internal.DataFlowImpl4
 }

cpp/ql/lib/semmle/code/cpp/dataflow/StackAddress.qll

@@ -95,11 +95,6 @@ predicate stackPointerFlowsToUse(Expr use, Type useType, Expr source, boolean is
 cached
 private PointerType getExprPtrType(Expr use) { result = use.getUnspecifiedType() }
 
-/**
- * Holds if `use` has type `useType` and `source` is an access to a stack variable
- * that flows to `use`. `isLocal` is `true` if `use` is accessed via a parameter, and
- * `false` otherwise.
- */
 predicate stackReferenceFlowsToUse(Expr use, Type useType, Expr source, boolean isLocal) {
   // Stack variables
   exists(StackVariable var |

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

@@ -18,11 +18,6 @@
 import semmle.code.cpp.dataflow.DataFlow
 import semmle.code.cpp.dataflow.DataFlow2
 
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) taint-tracking analyses.
- */
 module TaintTracking {
-  import semmle.code.cpp.dataflow.internal.tainttracking1.TaintTracking
   import semmle.code.cpp.dataflow.internal.tainttracking1.TaintTrackingImpl
 }

cpp/ql/lib/semmle/code/cpp/dataflow/TaintTracking2.qll

@@ -10,11 +10,6 @@
  *
  * See `semmle.code.cpp.dataflow.TaintTracking` for the full documentation.
  */
-
-/**
- * Provides classes for performing local (intra-procedural) and
- * global (inter-procedural) taint-tracking analyses.
- */
 module TaintTracking2 {
   import semmle.code.cpp.dataflow.internal.tainttracking2.TaintTrackingImpl
 }

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

@@ -1,353 +0,0 @@
-/**
- * Provides an implementation of global (interprocedural) data flow. This file
- * re-exports the local (intraprocedural) data flow analysis from
- * `DataFlowImplSpecific::Public` and adds a global analysis, mainly exposed
- * through the `Make` and `MakeWithState` modules.
- */
-
-private import DataFlowImplCommon
-private import DataFlowImplSpecific::Private
-import DataFlowImplSpecific::Public
-import DataFlowImplCommonPublic
-private import DataFlowImpl
-
-/** An input configuration for data flow. */
-signature module ConfigSig {
-  /**
-   * Holds if `source` is a relevant data flow source.
-   */
-  predicate isSource(Node source);
-
-  /**
-   * Holds if `sink` is a relevant data flow sink.
-   */
-  predicate isSink(Node sink);
-
-  /**
-   * Holds if data flow through `node` is prohibited. This completely removes
-   * `node` from the data flow graph.
-   */
-  default predicate isBarrier(Node node) { none() }
-
-  /** Holds if data flow into `node` is prohibited. */
-  default predicate isBarrierIn(Node node) { none() }
-
-  /** Holds if data flow out of `node` is prohibited. */
-  default predicate isBarrierOut(Node node) { none() }
-
-  /**
-   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
-   */
-  default predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
-
-  /**
-   * Holds if an arbitrary number of implicit read steps of content `c` may be
-   * taken at `node`.
-   */
-  default predicate allowImplicitRead(Node node, ContentSet c) { none() }
-
-  /**
-   * Gets the virtual dispatch branching limit when calculating field flow.
-   * This can be overridden to a smaller value to improve performance (a
-   * value of 0 disables field flow), or a larger value to get more results.
-   */
-  default int fieldFlowBranchLimit() { result = 2 }
-
-  /**
-   * Gets a data flow configuration feature to add restrictions to the set of
-   * valid flow paths.
-   *
-   * - `FeatureHasSourceCallContext`:
-   *    Assume that sources have some existing call context to disallow
-   *    conflicting return-flow directly following the source.
-   * - `FeatureHasSinkCallContext`:
-   *    Assume that sinks have some existing call context to disallow
-   *    conflicting argument-to-parameter flow directly preceding the sink.
-   * - `FeatureEqualSourceSinkCallContext`:
-   *    Implies both of the above and additionally ensures that the entire flow
-   *    path preserves the call context.
-   *
-   * These features are generally not relevant for typical end-to-end data flow
-   * queries, but should only be used for constructing paths that need to
-   * somehow be pluggable in another path context.
-   */
-  default FlowFeature getAFeature() { none() }
-
-  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
-  default predicate sourceGrouping(Node source, string sourceGroup) { none() }
-
-  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
-  default predicate sinkGrouping(Node sink, string sinkGroup) { none() }
-
-  /**
-   * Holds if hidden nodes should be included in the data flow graph.
-   *
-   * This feature should only be used for debugging or when the data flow graph
-   * is not visualized (as it is in a `path-problem` query).
-   */
-  default predicate includeHiddenNodes() { none() }
-}
-
-/** An input configuration for data flow using flow state. */
-signature module StateConfigSig {
-  bindingset[this]
-  class FlowState;
-
-  /**
-   * Holds if `source` is a relevant data flow source with the given initial
-   * `state`.
-   */
-  predicate isSource(Node source, FlowState state);
-
-  /**
-   * Holds if `sink` is a relevant data flow sink accepting `state`.
-   */
-  predicate isSink(Node sink, FlowState state);
-
-  /**
-   * Holds if data flow through `node` is prohibited. This completely removes
-   * `node` from the data flow graph.
-   */
-  default predicate isBarrier(Node node) { none() }
-
-  /**
-   * Holds if data flow through `node` is prohibited when the flow state is
-   * `state`.
-   */
-  predicate isBarrier(Node node, FlowState state);
-
-  /** Holds if data flow into `node` is prohibited. */
-  default predicate isBarrierIn(Node node) { none() }
-
-  /** Holds if data flow out of `node` is prohibited. */
-  default predicate isBarrierOut(Node node) { none() }
-
-  /**
-   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
-   */
-  default predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
-
-  /**
-   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
-   * This step is only applicable in `state1` and updates the flow state to `state2`.
-   */
-  predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2);
-
-  /**
-   * Holds if an arbitrary number of implicit read steps of content `c` may be
-   * taken at `node`.
-   */
-  default predicate allowImplicitRead(Node node, ContentSet c) { none() }
-
-  /**
-   * Gets the virtual dispatch branching limit when calculating field flow.
-   * This can be overridden to a smaller value to improve performance (a
-   * value of 0 disables field flow), or a larger value to get more results.
-   */
-  default int fieldFlowBranchLimit() { result = 2 }
-
-  /**
-   * Gets a data flow configuration feature to add restrictions to the set of
-   * valid flow paths.
-   *
-   * - `FeatureHasSourceCallContext`:
-   *    Assume that sources have some existing call context to disallow
-   *    conflicting return-flow directly following the source.
-   * - `FeatureHasSinkCallContext`:
-   *    Assume that sinks have some existing call context to disallow
-   *    conflicting argument-to-parameter flow directly preceding the sink.
-   * - `FeatureEqualSourceSinkCallContext`:
-   *    Implies both of the above and additionally ensures that the entire flow
-   *    path preserves the call context.
-   *
-   * These features are generally not relevant for typical end-to-end data flow
-   * queries, but should only be used for constructing paths that need to
-   * somehow be pluggable in another path context.
-   */
-  default FlowFeature getAFeature() { none() }
-
-  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
-  default predicate sourceGrouping(Node source, string sourceGroup) { none() }
-
-  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
-  default predicate sinkGrouping(Node sink, string sinkGroup) { none() }
-
-  /**
-   * Holds if hidden nodes should be included in the data flow graph.
-   *
-   * This feature should only be used for debugging or when the data flow graph
-   * is not visualized (as it is in a `path-problem` query).
-   */
-  default predicate includeHiddenNodes() { none() }
-}
-
-/**
- * Gets the exploration limit for `hasPartialFlow` and `hasPartialFlowRev`
- * measured in approximate number of interprocedural steps.
- */
-signature int explorationLimitSig();
-
-/**
- * The output of a data flow computation.
- */
-signature module DataFlowSig {
-  /**
-   * A `Node` augmented with a call context (except for sinks) and an access path.
-   * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
-   */
-  class PathNode;
-
-  /**
-   * Holds if data can flow from `source` to `sink`.
-   *
-   * The corresponding paths are generated from the end-points and the graph
-   * included in the module `PathGraph`.
-   */
-  predicate hasFlowPath(PathNode source, PathNode sink);
-
-  /**
-   * Holds if data can flow from `source` to `sink`.
-   */
-  predicate hasFlow(Node source, Node sink);
-
-  /**
-   * Holds if data can flow from some source to `sink`.
-   */
-  predicate hasFlowTo(Node sink);
-
-  /**
-   * Holds if data can flow from some source to `sink`.
-   */
-  predicate hasFlowToExpr(DataFlowExpr sink);
-}
-
-/**
- * Constructs a standard data flow computation.
- */
-module Make<ConfigSig Config> implements DataFlowSig {
-  private module C implements FullStateConfigSig {
-    import DefaultState<Config>
-    import Config
-  }
-
-  import Impl<C>
-}
-
-/**
- * Constructs a data flow computation using flow state.
- */
-module MakeWithState<StateConfigSig Config> implements DataFlowSig {
-  private module C implements FullStateConfigSig {
-    import Config
-  }
-
-  import Impl<C>
-}
-
-signature class PathNodeSig {
-  /** Gets a textual representation of this element. */
-  string toString();
-
-  /**
-   * 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
-  );
-
-  /** Gets the underlying `Node`. */
-  Node getNode();
-}
-
-signature module PathGraphSig<PathNodeSig PathNode> {
-  /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-  predicate edges(PathNode a, PathNode b);
-
-  /** Holds if `n` is a node in the graph of data flow path explanations. */
-  predicate nodes(PathNode n, string key, string val);
-
-  /**
-   * Holds if `(arg, par, ret, out)` forms a subpath-tuple, that is, flow through
-   * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
-   * `ret -> out` is summarized as the edge `arg -> out`.
-   */
-  predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out);
-}
-
-/**
- * Constructs a `PathGraph` from two `PathGraph`s by disjoint union.
- */
-module MergePathGraph<
-  PathNodeSig PathNode1, PathNodeSig PathNode2, PathGraphSig<PathNode1> Graph1,
-  PathGraphSig<PathNode2> Graph2>
-{
-  private newtype TPathNode =
-    TPathNode1(PathNode1 p) or
-    TPathNode2(PathNode2 p)
-
-  /** A node in a graph of path explanations that is formed by disjoint union of the two given graphs. */
-  class PathNode extends TPathNode {
-    /** Gets this as a projection on the first given `PathGraph`. */
-    PathNode1 asPathNode1() { this = TPathNode1(result) }
-
-    /** Gets this as a projection on the second given `PathGraph`. */
-    PathNode2 asPathNode2() { this = TPathNode2(result) }
-
-    /** Gets a textual representation of this element. */
-    string toString() {
-      result = this.asPathNode1().toString() or
-      result = this.asPathNode2().toString()
-    }
-
-    /**
-     * 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.asPathNode1().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn) or
-      this.asPathNode2().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
-    }
-
-    /** Gets the underlying `Node`. */
-    Node getNode() {
-      result = this.asPathNode1().getNode() or
-      result = this.asPathNode2().getNode()
-    }
-  }
-
-  /**
-   * Provides the query predicates needed to include a graph in a path-problem query.
-   */
-  module PathGraph implements PathGraphSig<PathNode> {
-    /** Holds if `(a,b)` is an edge in the graph of data flow path explanations. */
-    query predicate edges(PathNode a, PathNode b) {
-      Graph1::edges(a.asPathNode1(), b.asPathNode1()) or
-      Graph2::edges(a.asPathNode2(), b.asPathNode2())
-    }
-
-    /** Holds if `n` is a node in the graph of data flow path explanations. */
-    query predicate nodes(PathNode n, string key, string val) {
-      Graph1::nodes(n.asPathNode1(), key, val) or
-      Graph2::nodes(n.asPathNode2(), key, val)
-    }
-
-    /**
-     * Holds if `(arg, par, ret, out)` forms a subpath-tuple, that is, flow through
-     * a subpath between `par` and `ret` with the connecting edges `arg -> par` and
-     * `ret -> out` is summarized as the edge `arg -> out`.
-     */
-    query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-      Graph1::subpaths(arg.asPathNode1(), par.asPathNode1(), ret.asPathNode1(), out.asPathNode1()) or
-      Graph2::subpaths(arg.asPathNode2(), par.asPathNode2(), ret.asPathNode2(), out.asPathNode2())
-    }
-  }
-}

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

@@ -1,6 +1,6 @@
 private import cpp
-private import DataFlowPrivate
-private import DataFlowUtil
+private import semmle.code.cpp.dataflow.internal.DataFlowPrivate
+private import semmle.code.cpp.dataflow.internal.DataFlowUtil
 
 /**
  * Gets a function that might be called by `call`.