Merge pull request #18215 from smowton/smowton/ke2/basic-generics

KE2: Upgrade to Kotlin 2.1.0; restore basic type parameter and type argument extraction
Rename classId
2026-05-16 04:09:27 +02:00 · 2024-12-13 15:39:54 +00:00 · 2024-12-11 15:58:44 +00:00 · 2024-12-11 15:57:09 +00:00 · 2024-12-11 15:46:03 +00:00 · 2024-12-11 15:32:44 +00:00
2320 changed files with 64730 additions and 48388 deletions
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -1,5 +1,4 @@
 {
-  "image": "mcr.microsoft.com/devcontainers/base:ubuntu-24.04",
  "extensions": [
    "rust-lang.rust-analyzer",
    "bungcip.better-toml",
--- a/.gitattributes
+++ b/.gitattributes
@@ -50,6 +50,7 @@
 *.dll -text
 *.pdb -text

+/maven_install.json linguist-generated=true
 /java/ql/test/stubs/**/*.java linguist-generated=true
 /java/ql/test/experimental/stubs/**/*.java linguist-generated=true
 /java/kotlin-extractor/deps/*.jar filter=lfs diff=lfs merge=lfs -text
--- a/.github/labeler.yml
+++ b/.github/labeler.yml
@@ -11,7 +11,7 @@ Go:
  - change-notes/**/*go.*

 Java:
-  - any: [ 'java/**/*', '!java/kotlin-extractor/**/*', '!java/ql/test/kotlin/**/*' ]
+  - any: [ 'java/**/*', '!java/kotlin-extractor/**/*', '!java/kotlin-extractor2/**/*', '!java/ql/test-kotlin*/**/*' ]
  - change-notes/**/*java.*

 JS:
@@ -20,6 +20,7 @@ JS:

 Kotlin:
  - java/kotlin-extractor/**/*
+  - java/kotlin-extractor2/**/*
  - java/ql/test-kotlin*/**/*

 Python:
--- a/.github/workflows/compile-queries.yml
+++ b/.github/workflows/compile-queries.yml
@@ -7,11 +7,6 @@ on:
      - "rc/*"
      - "codeql-cli-*"
  pull_request:
-    paths:
-      - '**.ql'
-      - '**.qll'
-      - '**/qlpack.yml'
-      - '**.dbscheme'

 permissions:
  contents: read
@@ -38,9 +33,9 @@ jobs:
        # 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 }}" --compilation-cache-size=500 --ram=56000
+        run: codeql query compile -q -j0 */ql/{src,examples} --keep-going --warnings=error --check-only --compilation-cache "${{ steps.query-cache.outputs.cache-dir }}" --compilation-cache-size=500
      - 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 }}" --compilation-cache-size=500 --ram=56000
+        run: codeql query compile -q -j0 */ql/{src,examples} --keep-going --warnings=error --compilation-cache "${{ steps.query-cache.outputs.cache-dir }}" --compilation-cache-size=500
--- a/.github/workflows/cpp-swift-analysis.yml
+++ b/.github/workflows/cpp-swift-analysis.yml
@@ -48,7 +48,7 @@ jobs:
    - name: "Build Swift extractor using Bazel"
      run: |
        bazel clean --expunge
-        bazel run //swift:install --nouse_action_cache --noremote_accept_cached --noremote_upload_local_results --spawn_strategy=local
+        bazel run //swift:create-extractor-pack --nouse_action_cache --noremote_accept_cached --noremote_upload_local_results --spawn_strategy=local
        bazel shutdown

    - name: Perform CodeQL Analysis
--- a/.github/workflows/csharp-qltest.yml
+++ b/.github/workflows/csharp-qltest.yml
@@ -5,10 +5,8 @@ on:
    paths:
      - "csharp/**"
      - "shared/**"
-      - "misc/bazel/**"
      - .github/actions/fetch-codeql/action.yml
      - codeql-workspace.yml
-      - "MODULE.bazel"
    branches:
      - main
      - "rc/*"
@@ -16,11 +14,9 @@ on:
    paths:
      - "csharp/**"
      - "shared/**"
-      - "misc/bazel/**"
      - .github/workflows/csharp-qltest.yml
      - .github/actions/fetch-codeql/action.yml
      - codeql-workspace.yml
-      - "MODULE.bazel"
    branches:
      - main
      - "rc/*"
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -72,7 +72,7 @@ repos:

      - id: rust-codegen
        name: Run Rust checked in code generation
-        files: ^misc/codegen/|^rust/(prefix\.dbscheme|schema/|codegen/|.*/generated/|ql/lib/(rust\.dbscheme$|codeql/rust/elements)|\.generated.list)
+        files: ^misc/codegen/|^rust/(schema.py$|codegen/|.*/generated/|ql/lib/(rust\.dbscheme$|codeql/rust/elements)|\.generated.list)
        language: system
        entry: bazel run //rust/codegen -- --quiet
        pass_filenames: false
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -38,93 +38,6 @@
                "command": "${config:python.pythonPath}",
            },
            "problemMatcher": []
-        },
-        {
-            "label": "Create query change note",
-            "type": "process",
-            "command": "python3",
-            "args": [
-                "misc/scripts/create-change-note.py",
-                "${input:language}",
-                "src",
-                "${input:name}",
-                "${input:categoryQuery}"
-            ],
-            "presentation": {
-                "reveal": "never",
-                "close": true
-            },
-            "problemMatcher": []
-        },
-                {
-            "label": "Create library change note",
-            "type": "process",
-            "command": "python3",
-            "args": [
-                "misc/scripts/create-change-note.py",
-                "${input:language}",
-                "lib",
-                "${input:name}",
-                "${input:categoryLibrary}"
-            ],
-            "presentation": {
-                "reveal": "never",
-                "close": true
-            },
-            "problemMatcher": []
-        }
-    ],
-    "inputs": [
-        {
-            "type": "pickString",
-            "id": "language",
-            "description": "Language",
-            "options":
-            [
-                "go",
-                "java",
-                "javascript",
-                "cpp",
-                "csharp",
-                "python",
-                "ruby",
-                "rust",
-                "swift",
-            ]
-        },
-        {
-            "type": "promptString",
-            "id": "name",
-            "description": "Short name (kebab-case)"
-        },
-        {
-            "type": "pickString",
-            "id": "categoryQuery",
-            "description": "Category (query change)",
-            "options":
-            [
-                "breaking",
-                "deprecated",
-                "newQuery",
-                "queryMetadata",
-                "majorAnalysis",
-                "minorAnalysis",
-                "fix",
-            ]
-        },
-                {
-            "type": "pickString",
-            "id": "categoryLibrary",
-            "description": "Category (library change)",
-            "options":
-            [
-                "breaking",
-                "deprecated",
-                "feature",
-                "majorAnalysis",
-                "minorAnalysis",
-                "fix",
-            ]
        }
    ]
 }
--- a/2024-11-25-ts57.md
+++ b/2024-11-25-ts57.md
@@ -1,4 +0,0 @@
---
-category: majorAnalysis
---
-* Added support for TypeScript 5.7.
--- a/4
+++ b/4
@@ -10,6 +10,7 @@
 /swift/ @github/codeql-swift
 /misc/codegen/ @github/codeql-swift
 /java/kotlin-extractor/ @github/codeql-kotlin
+/java/kotlin-extractor2/ @github/codeql-kotlin
 /java/ql/test-kotlin1/ @github/codeql-kotlin
 /java/ql/test-kotlin2/ @github/codeql-kotlin

@@ -42,6 +43,3 @@ MODULE.bazel @github/codeql-ci-reviewers
 # Misc
 /misc/scripts/accept-expected-changes-from-ci.py @RasmusWL
 /misc/scripts/generate-code-scanning-query-list.py @RasmusWL
-
-# .devcontainer
-/.devcontainer/ @github/codeql-ci-reviewers
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -381,10 +381,8 @@ version = "0.1.0"
 dependencies = [
 "anyhow",
 "argfile",
- "chrono",
 "clap",
 "codeql-extractor",
- "dunce",
 "figment",
 "glob",
 "itertools 0.13.0",
@@ -406,7 +404,6 @@ dependencies = [
 "ra_ap_vfs",
 "rust-extractor-macros",
 "serde",
- "serde_json",
 "serde_with",
 "stderrlog",
 "triomphe",
@@ -543,12 +540,6 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9bda8e21c04aca2ae33ffc2fd8c23134f3cac46db123ba97bd9d3f3b8a4a85e1"

-[[package]]
-name = "dunce"
-version = "1.0.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "92773504d58c093f6de2459af4af33faa518c13451eb8f2b5698ed3d36e7c813"
-
 [[package]]
 name = "either"
 version = "1.13.0"
@@ -2043,9 +2034,9 @@ dependencies = [

 [[package]]
 name = "serde_json"
-version = "1.0.133"
+version = "1.0.132"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7fceb2473b9166b2294ef05efcb65a3db80803f0b03ef86a5fc88a2b85ee377"
+checksum = "d726bfaff4b320266d395898905d0eba0345aae23b54aee3a737e260fd46db03"
 dependencies = [
 "itoa",
 "memchr",
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -28,6 +28,7 @@ bazel_dep(name = "gazelle", version = "0.38.0")
 bazel_dep(name = "rules_dotnet", version = "0.17.4")
 bazel_dep(name = "googletest", version = "1.14.0.bcr.1")
 bazel_dep(name = "rules_rust", version = "0.52.2")
+bazel_dep(name = "rules_jvm_external", version = "6.2")

 bazel_dep(name = "buildifier_prebuilt", version = "6.4.0", dev_dependency = True)

@@ -68,7 +69,7 @@ use_repo(py_deps, "vendor__anyhow-1.0.44", "vendor__cc-1.0.70", "vendor__clap-2.
 # deps for ruby+rust
 # keep in sync by running `misc/bazel/3rdparty/update_cargo_deps.sh`
 tree_sitter_extractors_deps = use_extension("//misc/bazel/3rdparty:tree_sitter_extractors_extension.bzl", "r")
-use_repo(tree_sitter_extractors_deps, "vendor__anyhow-1.0.93", "vendor__argfile-0.2.1", "vendor__chrono-0.4.38", "vendor__clap-4.5.20", "vendor__dunce-1.0.5", "vendor__encoding-0.2.33", "vendor__figment-0.10.19", "vendor__flate2-1.0.34", "vendor__glob-0.3.1", "vendor__globset-0.4.15", "vendor__itertools-0.10.5", "vendor__itertools-0.13.0", "vendor__lazy_static-1.5.0", "vendor__log-0.4.22", "vendor__num-traits-0.2.19", "vendor__num_cpus-1.16.0", "vendor__proc-macro2-1.0.89", "vendor__quote-1.0.37", "vendor__ra_ap_base_db-0.0.232", "vendor__ra_ap_cfg-0.0.232", "vendor__ra_ap_hir-0.0.232", "vendor__ra_ap_hir_def-0.0.232", "vendor__ra_ap_hir_expand-0.0.232", "vendor__ra_ap_ide_db-0.0.232", "vendor__ra_ap_intern-0.0.232", "vendor__ra_ap_load-cargo-0.0.232", "vendor__ra_ap_parser-0.0.232", "vendor__ra_ap_paths-0.0.232", "vendor__ra_ap_project_model-0.0.232", "vendor__ra_ap_span-0.0.232", "vendor__ra_ap_syntax-0.0.232", "vendor__ra_ap_vfs-0.0.232", "vendor__rand-0.8.5", "vendor__rayon-1.10.0", "vendor__regex-1.11.1", "vendor__serde-1.0.214", "vendor__serde_json-1.0.133", "vendor__serde_with-3.11.0", "vendor__stderrlog-0.6.0", "vendor__syn-2.0.87", "vendor__tracing-0.1.40", "vendor__tracing-subscriber-0.3.18", "vendor__tree-sitter-0.24.4", "vendor__tree-sitter-embedded-template-0.23.2", "vendor__tree-sitter-json-0.24.8", "vendor__tree-sitter-ql-0.23.1", "vendor__tree-sitter-ruby-0.23.1", "vendor__triomphe-0.1.14", "vendor__ungrammar-1.16.1")
+use_repo(tree_sitter_extractors_deps, "vendor__anyhow-1.0.93", "vendor__argfile-0.2.1", "vendor__chrono-0.4.38", "vendor__clap-4.5.20", "vendor__encoding-0.2.33", "vendor__figment-0.10.19", "vendor__flate2-1.0.34", "vendor__glob-0.3.1", "vendor__globset-0.4.15", "vendor__itertools-0.10.5", "vendor__itertools-0.13.0", "vendor__lazy_static-1.5.0", "vendor__log-0.4.22", "vendor__num-traits-0.2.19", "vendor__num_cpus-1.16.0", "vendor__proc-macro2-1.0.89", "vendor__quote-1.0.37", "vendor__ra_ap_base_db-0.0.232", "vendor__ra_ap_cfg-0.0.232", "vendor__ra_ap_hir-0.0.232", "vendor__ra_ap_hir_def-0.0.232", "vendor__ra_ap_hir_expand-0.0.232", "vendor__ra_ap_ide_db-0.0.232", "vendor__ra_ap_intern-0.0.232", "vendor__ra_ap_load-cargo-0.0.232", "vendor__ra_ap_parser-0.0.232", "vendor__ra_ap_paths-0.0.232", "vendor__ra_ap_project_model-0.0.232", "vendor__ra_ap_span-0.0.232", "vendor__ra_ap_syntax-0.0.232", "vendor__ra_ap_vfs-0.0.232", "vendor__rand-0.8.5", "vendor__rayon-1.10.0", "vendor__regex-1.11.1", "vendor__serde-1.0.214", "vendor__serde_json-1.0.132", "vendor__serde_with-3.11.0", "vendor__stderrlog-0.6.0", "vendor__syn-2.0.87", "vendor__tracing-0.1.40", "vendor__tracing-subscriber-0.3.18", "vendor__tree-sitter-0.24.4", "vendor__tree-sitter-embedded-template-0.23.2", "vendor__tree-sitter-json-0.24.8", "vendor__tree-sitter-ql-0.23.1", "vendor__tree-sitter-ruby-0.23.1", "vendor__triomphe-0.1.14", "vendor__ungrammar-1.16.1")

 dotnet = use_extension("@rules_dotnet//dotnet:extensions.bzl", "dotnet")
 dotnet.toolchain(dotnet_version = "9.0.100")
@@ -162,6 +163,35 @@ use_repo(
    "kotlin-stdlib-2.1.0-Beta1",
 )

+maven = use_extension("@rules_jvm_external//:extensions.bzl", "maven")
+
+# run
+#   REPIN=1 bazel run @maven_deps//:pin
+# from this directory after modifying the following to update maven_install.json
+maven.install(
+    name = "maven_deps",
+    # The Caffeine version needs to match https://github.com/JetBrains/kotlin/blob/master/gradle/libs.versions.toml
+    # See also https://youtrack.jetbrains.com/issue/KT-73751/Analysis-API-Caffeine-dependency which seeks a better
+    # way of including the needed dependency.
+    artifacts = [
+        "org.jetbrains.kotlin:%s:2.1.0" % kotlin_lib
+        for kotlin_lib in ("kotlin-annotation-processing", "kotlin-compiler")
+    ] + [ "com.github.ben-manes.caffeine:caffeine:2.9.3" ]  ,
+    lock_file = "//:maven_install.json",
+    repositories = [
+        "https://repo1.maven.org/maven2",
+        # some of these URLs might be needed at some point
+        #        "https://maven.pkg.jetbrains.space/kotlin/p/kotlin/bootstrap",
+        #        "https://maven.pkg.jetbrains.space/kotlin/p/kotlin/kotlin-ide-plugin-dependencies",
+        #        "https://www.jetbrains.com/intellij-repository/releases",
+        #        "https://cache-redirector.jetbrains.com/intellij-third-party-dependencies",
+    ],
+)
+use_repo(
+    maven,
+    "maven_deps",
+)
+
 go_sdk = use_extension("@rules_go//go:extensions.bzl", "go_sdk")
 go_sdk.download(version = "1.23.1")

--- a/actions/BUILD.bazel
+++ b/actions/BUILD.bazel
@@ -2,8 +2,19 @@ load("//misc/bazel:pkg.bzl", "codeql_pack")

 package(default_visibility = ["//visibility:public"])

-codeql_pack(
-    name = "actions",
-    srcs = ["//actions/extractor"],
-    experimental = True,
-)
+[
+    codeql_pack(
+        name = "-".join(parts),
+        srcs = [
+            "//actions/extractor",
+        ],
+        pack_prefix = "/".join(parts),
+    )
+    for parts in (
+        [
+            "experimental",
+            "actions",
+        ],
+        ["actions"],
+    )
+]
--- a/config/identical-files.json
+++ b/config/identical-files.json
@@ -1,4 +1,58 @@
 {
+  "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",
+    "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/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",
+    "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",
+    "go/ql/lib/semmle/go/dataflow/internal/DataFlowImpl1.qll",
+    "go/ql/lib/semmle/go/dataflow/internal/DataFlowImpl2.qll",
+    "python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl1.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",
+    "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImpl1.qll",
+    "ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImpl2.qll",
+    "swift/ql/lib/codeql/swift/dataflow/internal/DataFlowImpl1.qll"
+  ],
+  "TaintTracking Legacy 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",
+    "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",
+    "csharp/ql/lib/semmle/code/csharp/dataflow/internal/tainttracking4/TaintTrackingImpl.qll",
+    "csharp/ql/lib/semmle/code/csharp/dataflow/internal/tainttracking5/TaintTrackingImpl.qll",
+    "go/ql/lib/semmle/go/dataflow/internal/tainttracking1/TaintTrackingImpl.qll",
+    "go/ql/lib/semmle/go/dataflow/internal/tainttracking2/TaintTrackingImpl.qll",
+    "java/ql/lib/semmle/code/java/dataflow/internal/tainttracking1/TaintTrackingImpl.qll",
+    "java/ql/lib/semmle/code/java/dataflow/internal/tainttracking2/TaintTrackingImpl.qll",
+    "java/ql/lib/semmle/code/java/dataflow/internal/tainttracking3/TaintTrackingImpl.qll",
+    "python/ql/lib/semmle/python/dataflow/new/internal/tainttracking1/TaintTrackingImpl.qll",
+    "python/ql/lib/semmle/python/dataflow/new/internal/tainttracking2/TaintTrackingImpl.qll",
+    "python/ql/lib/semmle/python/dataflow/new/internal/tainttracking3/TaintTrackingImpl.qll",
+    "python/ql/lib/semmle/python/dataflow/new/internal/tainttracking4/TaintTrackingImpl.qll",
+    "ruby/ql/lib/codeql/ruby/dataflow/internal/tainttracking1/TaintTrackingImpl.qll",
+    "swift/ql/lib/codeql/swift/dataflow/internal/tainttracking1/TaintTrackingImpl.qll"
+  ],
  "SsaReadPosition Java/C#": [
    "java/ql/lib/semmle/code/java/dataflow/internal/rangeanalysis/SsaReadPositionCommon.qll",
    "csharp/ql/lib/semmle/code/csharp/dataflow/internal/rangeanalysis/SsaReadPositionCommon.qll"
--- a/cpp/downgrades/f0156f5f88ab5967c79162012c20f30600ca5ebf/old.dbscheme
+++ b/cpp/downgrades/f0156f5f88ab5967c79162012c20f30600ca5ebf/old.dbscheme
--- a/cpp/downgrades/f0156f5f88ab5967c79162012c20f30600ca5ebf/semmlecode.cpp.dbscheme
+++ b/cpp/downgrades/f0156f5f88ab5967c79162012c20f30600ca5ebf/semmlecode.cpp.dbscheme
--- a/cpp/downgrades/f0156f5f88ab5967c79162012c20f30600ca5ebf/upgrade.properties
+++ b/cpp/downgrades/f0156f5f88ab5967c79162012c20f30600ca5ebf/upgrade.properties
@@ -1,3 +0,0 @@
-description: Implement compilation_build_mode/2
-compatibility: full
-compilation_build_mode.rel: delete
--- a/cpp/ql/lib/CHANGELOG.md
+++ b/cpp/ql/lib/CHANGELOG.md
@@ -1,17 +1,3 @@
-## 3.0.0
-
-### Breaking Changes
-
-* Deleted the old deprecated data flow API that was based on extending a configuration class. See https://github.blog/changelog/2023-08-14-new-dataflow-api-for-writing-custom-codeql-queries for instructions on migrating your queries to use the new API.
-
-### Deprecated APIs
-
-* The `NonThrowing` class (`semmle.code.cpp.models.interfaces.NonThrowing`) has been deprecated. Please use the `NonCppThrowingFunction` class instead.
-
-## 2.1.1
-
-No user-facing changes.
-
 ## 2.1.0

 ### New Features
--- a/cpp/ql/lib/change-notes/2024-11-18-guard-conditions.md
+++ b/cpp/ql/lib/change-notes/2024-11-18-guard-conditions.md
@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* The `Guards` library (`semmle.code.cpp.controlflow.Guards`) has been improved to recognize more guard conditions. Additionally, the guards library no longer considers guards in static local initializers or global initializers as `GuardCondition`s.
--- a/cpp/ql/lib/change-notes/released/2.1.1.md
+++ b/cpp/ql/lib/change-notes/released/2.1.1.md
@@ -1,3 +0,0 @@
-## 2.1.1
-
-No user-facing changes.
--- a/cpp/ql/lib/change-notes/released/3.0.0.md
+++ b/cpp/ql/lib/change-notes/released/3.0.0.md
@@ -1,9 +0,0 @@
-## 3.0.0
-
-### Breaking Changes
-
-* Deleted the old deprecated data flow API that was based on extending a configuration class. See https://github.blog/changelog/2023-08-14-new-dataflow-api-for-writing-custom-codeql-queries for instructions on migrating your queries to use the new API.
-
-### Deprecated APIs
-
-* The `NonThrowing` class (`semmle.code.cpp.models.interfaces.NonThrowing`) has been deprecated. Please use the `NonCppThrowingFunction` class instead.
--- a/cpp/ql/lib/codeql-pack.release.yml
+++ b/cpp/ql/lib/codeql-pack.release.yml
@@ -1,2 +1,2 @@
 ---
-lastReleaseVersion: 3.0.0
+lastReleaseVersion: 2.1.0
--- a/cpp/ql/lib/qlpack.yml
+++ b/cpp/ql/lib/qlpack.yml
@@ -1,5 +1,5 @@
 name: codeql/cpp-all
-version: 3.0.0
+version: 2.1.1-dev
 groups: cpp
 dbscheme: semmlecode.cpp.dbscheme
 extractor: cpp
--- a/cpp/ql/lib/semmle/code/cpp/Compilation.qll
+++ b/cpp/ql/lib/semmle/code/cpp/Compilation.qll
@@ -112,7 +112,4 @@ class Compilation extends @compilation {
   * termination, but crashing due to something like a segfault is not.
   */
  predicate normalTermination() { compilation_finished(this, _, _) }
-
-  /** Holds if this compilation was compiled using the "none" build mode. */
-  predicate buildModeNone() { compilation_build_mode(this, 0) }
 }
--- a/cpp/ql/lib/semmle/code/cpp/controlflow/IRGuards.qll
+++ b/cpp/ql/lib/semmle/code/cpp/controlflow/IRGuards.qll
@@ -5,6 +5,7 @@

 import cpp
 import semmle.code.cpp.ir.IR
+private import semmle.code.cpp.ir.ValueNumbering
 private import semmle.code.cpp.ir.implementation.raw.internal.TranslatedExpr
 private import semmle.code.cpp.ir.implementation.raw.internal.InstructionTag

@@ -59,7 +60,91 @@ class MatchValue extends AbstractValue, TMatchValue {
 }

 /**
- * A Boolean condition in the AST that guards one or more basic blocks.
+ * A value number such that at least one of the instructions is
+ * a `CompareInstruction`.
+ */
+private class CompareValueNumber extends ValueNumber {
+  CompareInstruction cmp;
+
+  CompareValueNumber() { cmp = this.getAnInstruction() }
+
+  /** Gets a `CompareInstruction` belonging to this value number. */
+  CompareInstruction getCompareInstruction() { result = cmp }
+
+  /**
+   * Gets the left and right operands of a `CompareInstruction` that
+   * belong to this value number.
+   */
+  predicate hasOperands(Operand left, Operand right) {
+    left = cmp.getLeftOperand() and
+    right = cmp.getRightOperand()
+  }
+}
+
+private class CompareEQValueNumber extends CompareValueNumber {
+  override CompareEQInstruction cmp;
+}
+
+private class CompareNEValueNumber extends CompareValueNumber {
+  override CompareNEInstruction cmp;
+}
+
+private class CompareLTValueNumber extends CompareValueNumber {
+  override CompareLTInstruction cmp;
+}
+
+private class CompareGTValueNumber extends CompareValueNumber {
+  override CompareGTInstruction cmp;
+}
+
+private class CompareLEValueNumber extends CompareValueNumber {
+  override CompareLEInstruction cmp;
+}
+
+private class CompareGEValueNumber extends CompareValueNumber {
+  override CompareGEInstruction cmp;
+}
+
+/**
+ * A value number such that at least one of the instructions provides
+ * the integer value controlling a  `SwitchInstruction`.
+ */
+private class SwitchConditionValueNumber extends ValueNumber {
+  SwitchInstruction switch;
+
+  pragma[nomagic]
+  SwitchConditionValueNumber() { this.getAnInstruction() = switch.getExpression() }
+
+  /** Gets an expression that belongs to this value number. */
+  Operand getExpressionOperand() { result = switch.getExpressionOperand() }
+
+  Instruction getSuccessor(CaseEdge kind) { result = switch.getSuccessor(kind) }
+}
+
+private class BuiltinExpectCallValueNumber extends ValueNumber {
+  BuiltinExpectCallInstruction instr;
+
+  BuiltinExpectCallValueNumber() { this.getAnInstruction() = instr }
+
+  ValueNumber getCondition() { result.getAnInstruction() = instr.getCondition() }
+
+  Operand getAUse() { result = instr.getAUse() }
+}
+
+private class LogicalNotValueNumber extends ValueNumber {
+  LogicalNotInstruction instr;
+
+  LogicalNotValueNumber() { this.getAnInstruction() = instr }
+
+  ValueNumber getUnary() { result.getAnInstruction() = instr.getUnary() }
+}
+
+/**
+ * A Boolean condition in the AST that guards one or more basic blocks. This includes
+ * operands of logical operators but not switch statements.
+ *
+ * For performance reasons conditions inside static local initializers or
+ * global initializers are not considered `GuardCondition`s.
 */
 cached
 class GuardCondition extends Expr {
@@ -369,6 +454,9 @@ private predicate nonExcludedIRAndBasicBlock(IRBlock irb, BasicBlock controlled)
 *
 * Note that `&&` and `||` don't have an explicit representation in the IR,
 * and therefore will not appear as IRGuardConditions.
+ *
+ * For performance reasons conditions inside static local initializers or
+ * global initializers are not considered `IRGuardCondition`s.
 */
 cached
 class IRGuardCondition extends Instruction {
@@ -517,7 +605,7 @@ class IRGuardCondition extends Instruction {
  cached
  predicate comparesLt(Operand left, Operand right, int k, boolean isLessThan, boolean testIsTrue) {
    exists(BooleanValue value |
-      compares_lt(this, left, right, k, isLessThan, value) and
+      compares_lt(valueNumber(this), left, right, k, isLessThan, value) and
      value.getValue() = testIsTrue
    )
  }
@@ -528,7 +616,7 @@ class IRGuardCondition extends Instruction {
   */
  cached
  predicate comparesLt(Operand op, int k, boolean isLessThan, AbstractValue value) {
-    compares_lt(this, op, k, isLessThan, value)
+    compares_lt(valueNumber(this), op, k, isLessThan, value)
  }

  /**
@@ -538,7 +626,8 @@ class IRGuardCondition extends Instruction {
  cached
  predicate ensuresLt(Operand left, Operand right, int k, IRBlock block, boolean isLessThan) {
    exists(AbstractValue value |
-      compares_lt(this, left, right, k, isLessThan, value) and this.valueControls(block, value)
+      compares_lt(valueNumber(this), left, right, k, isLessThan, value) and
+      this.valueControls(block, value)
    )
  }

@@ -549,7 +638,8 @@ class IRGuardCondition extends Instruction {
  cached
  predicate ensuresLt(Operand op, int k, IRBlock block, boolean isLessThan) {
    exists(AbstractValue value |
-      compares_lt(this, op, k, isLessThan, value) and this.valueControls(block, value)
+      compares_lt(valueNumber(this), op, k, isLessThan, value) and
+      this.valueControls(block, value)
    )
  }

@@ -562,7 +652,7 @@ class IRGuardCondition extends Instruction {
    Operand left, Operand right, int k, IRBlock pred, IRBlock succ, boolean isLessThan
  ) {
    exists(AbstractValue value |
-      compares_lt(this, left, right, k, isLessThan, value) and
+      compares_lt(valueNumber(this), left, right, k, isLessThan, value) and
      this.valueControlsEdge(pred, succ, value)
    )
  }
@@ -574,7 +664,7 @@ class IRGuardCondition extends Instruction {
  cached
  predicate ensuresLtEdge(Operand left, int k, IRBlock pred, IRBlock succ, boolean isLessThan) {
    exists(AbstractValue value |
-      compares_lt(this, left, k, isLessThan, value) and
+      compares_lt(valueNumber(this), left, k, isLessThan, value) and
      this.valueControlsEdge(pred, succ, value)
    )
  }
@@ -583,7 +673,7 @@ class IRGuardCondition extends Instruction {
  cached
  predicate comparesEq(Operand left, Operand right, int k, boolean areEqual, boolean testIsTrue) {
    exists(BooleanValue value |
-      compares_eq(this, left, right, k, areEqual, value) and
+      compares_eq(valueNumber(this), left, right, k, areEqual, value) and
      value.getValue() = testIsTrue
    )
  }
@@ -591,7 +681,7 @@ class IRGuardCondition extends Instruction {
  /** Holds if (determined by this guard) `op == k` evaluates to `areEqual` if this expression evaluates to `value`. */
  cached
  predicate comparesEq(Operand op, int k, boolean areEqual, AbstractValue value) {
-    unary_compares_eq(this, op, k, areEqual, false, value)
+    unary_compares_eq(valueNumber(this), op, k, areEqual, false, value)
  }

  /**
@@ -601,7 +691,8 @@ class IRGuardCondition extends Instruction {
  cached
  predicate ensuresEq(Operand left, Operand right, int k, IRBlock block, boolean areEqual) {
    exists(AbstractValue value |
-      compares_eq(this, left, right, k, areEqual, value) and this.valueControls(block, value)
+      compares_eq(valueNumber(this), left, right, k, areEqual, value) and
+      this.valueControls(block, value)
    )
  }

@@ -612,7 +703,8 @@ class IRGuardCondition extends Instruction {
  cached
  predicate ensuresEq(Operand op, int k, IRBlock block, boolean areEqual) {
    exists(AbstractValue value |
-      unary_compares_eq(this, op, k, areEqual, false, value) and this.valueControls(block, value)
+      unary_compares_eq(valueNumber(this), op, k, areEqual, false, value) and
+      this.valueControls(block, value)
    )
  }

@@ -625,7 +717,7 @@ class IRGuardCondition extends Instruction {
    Operand left, Operand right, int k, IRBlock pred, IRBlock succ, boolean areEqual
  ) {
    exists(AbstractValue value |
-      compares_eq(this, left, right, k, areEqual, value) and
+      compares_eq(valueNumber(this), left, right, k, areEqual, value) and
      this.valueControlsEdge(pred, succ, value)
    )
  }
@@ -637,7 +729,7 @@ class IRGuardCondition extends Instruction {
  cached
  predicate ensuresEqEdge(Operand op, int k, IRBlock pred, IRBlock succ, boolean areEqual) {
    exists(AbstractValue value |
-      unary_compares_eq(this, op, k, areEqual, false, value) and
+      unary_compares_eq(valueNumber(this), op, k, areEqual, false, value) and
      this.valueControlsEdge(pred, succ, value)
    )
  }
@@ -725,13 +817,20 @@ class IRGuardCondition extends Instruction {
 }

 private Instruction getBranchForCondition(Instruction guard) {
-  result.(ConditionalBranchInstruction).getCondition() = guard
+  // There are a lot of guards inside global or static local initializers,
+  // and on certain databases this can make the `ensures*` predicates
+  // blow up.
+  // These guards are likely not super important anyway.
+  guard.getEnclosingFunction() instanceof Function and
+  (
+    result.(ConditionalBranchInstruction).getCondition() = guard
+    or
+    result.(SwitchInstruction).getExpression() = guard
+  )
  or
  exists(LogicalNotInstruction cond |
    result = getBranchForCondition(cond) and cond.getUnary() = guard
  )
-  or
-  result.(SwitchInstruction).getExpression() = guard
 }

 /**
@@ -740,7 +839,7 @@ private Instruction getBranchForCondition(Instruction guard) {
 * Beware making mistaken logical implications here relating `areEqual` and `testIsTrue`.
 */
 private predicate compares_eq(
-  Instruction test, Operand left, Operand right, int k, boolean areEqual, AbstractValue value
+  ValueNumber test, Operand left, Operand right, int k, boolean areEqual, AbstractValue value
 ) {
  /* The simple case where the test *is* the comparison so areEqual = testIsTrue xor eq. */
  exists(AbstractValue v | simple_comparison_eq(test, left, right, k, v) |
@@ -759,10 +858,10 @@ private predicate compares_eq(
  or
  /* (x is true => (left == right + k)) => (!x is false => (left == right + k)) */
  exists(AbstractValue dual | value = dual.getDualValue() |
-    compares_eq(test.(LogicalNotInstruction).getUnary(), left, right, k, areEqual, dual)
+    compares_eq(test.(LogicalNotValueNumber).getUnary(), left, right, k, areEqual, dual)
  )
  or
-  compares_eq(test.(BuiltinExpectCallInstruction).getCondition(), left, right, k, areEqual, value)
+  compares_eq(test.(BuiltinExpectCallValueNumber).getCondition(), left, right, k, areEqual, value)
 }

 /**
@@ -801,12 +900,10 @@ private predicate compares_eq(
 * latter.
 */
 private predicate unary_compares_eq(
-  Instruction test, Operand op, int k, boolean areEqual, boolean inNonZeroCase, AbstractValue value
+  ValueNumber test, Operand op, int k, boolean areEqual, boolean inNonZeroCase, AbstractValue value
 ) {
  /* The simple case where the test *is* the comparison so areEqual = testIsTrue xor eq. */
-  exists(AbstractValue v |
-    unary_simple_comparison_eq(test, k, inNonZeroCase, v) and op.getDef() = test
-  |
+  exists(AbstractValue v | unary_simple_comparison_eq(test, op, k, inNonZeroCase, v) |
    areEqual = true and value = v
    or
    areEqual = false and value = v.getDualValue()
@@ -817,7 +914,7 @@ private predicate unary_compares_eq(
  /* (x is true => (op == k)) => (!x is false => (op == k)) */
  exists(AbstractValue dual, boolean inNonZeroCase0 |
    value = dual.getDualValue() and
-    unary_compares_eq(test.(LogicalNotInstruction).getUnary(), op, k, inNonZeroCase0, areEqual, dual)
+    unary_compares_eq(test.(LogicalNotValueNumber).getUnary(), op, k, inNonZeroCase0, areEqual, dual)
  |
    k = 0 and inNonZeroCase = inNonZeroCase0
    or
@@ -827,82 +924,95 @@ private predicate unary_compares_eq(
  // ((test is `areEqual` => op == const + k2) and const == `k1`) =>
  // test is `areEqual` => op == k1 + k2
  inNonZeroCase = false and
-  exists(int k1, int k2, ConstantInstruction const |
+  exists(int k1, int k2, Instruction const |
    compares_eq(test, op, const.getAUse(), k2, areEqual, value) and
    int_value(const) = k1 and
    k = k1 + k2
  )
  or
-  unary_compares_eq(test.(BuiltinExpectCallInstruction).getCondition(), op, k, areEqual,
+  unary_compares_eq(test.(BuiltinExpectCallValueNumber).getCondition(), op, k, areEqual,
    inNonZeroCase, value)
 }

 /** Rearrange various simple comparisons into `left == right + k` form. */
 private predicate simple_comparison_eq(
-  CompareInstruction cmp, Operand left, Operand right, int k, AbstractValue value
+  CompareValueNumber cmp, Operand left, Operand right, int k, AbstractValue value
 ) {
-  left = cmp.getLeftOperand() and
-  cmp instanceof CompareEQInstruction and
-  right = cmp.getRightOperand() and
+  cmp instanceof CompareEQValueNumber and
+  cmp.hasOperands(left, right) and
  k = 0 and
  value.(BooleanValue).getValue() = true
  or
-  left = cmp.getLeftOperand() and
-  cmp instanceof CompareNEInstruction and
-  right = cmp.getRightOperand() and
+  cmp instanceof CompareNEValueNumber and
+  cmp.hasOperands(left, right) and
  k = 0 and
  value.(BooleanValue).getValue() = false
 }

 /**
- * Rearrange various simple comparisons into `op == k` form.
+ * Holds if `op` is an operand that is eventually used in a unary comparison
+ * with a constant.
 */
+private predicate isRelevantUnaryComparisonOperand(Operand op) {
+  // Base case: `op` is an operand of a `CompareEQInstruction` or `CompareNEInstruction`,
+  // and the other operand is a constant.
+  exists(CompareInstruction eq, Instruction instr |
+    eq.hasOperands(op, instr.getAUse()) and
+    exists(int_value(instr))
+  |
+    eq instanceof CompareEQInstruction
+    or
+    eq instanceof CompareNEInstruction
+  )
+  or
+  // C doesn't have int-to-bool conversions, so `if(x)` will just generate:
+  // r2_1(glval<int>) = VariableAddress[x]
+  // r2_2(int)        = Load[x]                : &:r2_1, m1_6
+  // v2_3(void)       = ConditionalBranch      : r2_2
+  exists(ConditionalBranchInstruction branch | branch.getConditionOperand() = op)
+  or
+  // If `!x` is a relevant unary comparison then so is `x`.
+  exists(LogicalNotInstruction logicalNot |
+    isRelevantUnaryComparisonOperand(unique( | | logicalNot.getAUse())) and
+    logicalNot.getUnaryOperand() = op
+  )
+  or
+  // If `y` is a relevant unary comparison and `y = x` then so is `x`.
+  not op.isDefinitionInexact() and
+  exists(CopyInstruction copy |
+    isRelevantUnaryComparisonOperand(unique( | | copy.getAUse())) and
+    op = copy.getSourceValueOperand()
+  )
+  or
+  // If phi(x1, x2) is a relevant unary comparison then so are `x1` and `x2`.
+  not op.isDefinitionInexact() and
+  exists(PhiInstruction phi |
+    isRelevantUnaryComparisonOperand(unique( | | phi.getAUse())) and
+    op = phi.getAnInputOperand()
+  )
+  or
+  // If `__builtin_expect(x)` is a relevant unary comparison then so is `x`.
+  exists(BuiltinExpectCallInstruction call |
+    isRelevantUnaryComparisonOperand(unique( | | call.getAUse())) and
+    op = call.getConditionOperand()
+  )
+}
+
+/** Rearrange various simple comparisons into `op == k` form. */
 private predicate unary_simple_comparison_eq(
-  Instruction test, int k, boolean inNonZeroCase, AbstractValue value
+  ValueNumber test, Operand op, int k, boolean inNonZeroCase, AbstractValue value
 ) {
-  exists(SwitchInstruction switch, CaseEdge case |
-    test = switch.getExpression() and
+  exists(CaseEdge case, SwitchConditionValueNumber condition |
+    condition = test and
+    op = condition.getExpressionOperand() and
    case = value.(MatchValue).getCase() and
-    exists(switch.getSuccessor(case)) and
+    exists(condition.getSuccessor(case)) and
    case.getValue().toInt() = k and
    inNonZeroCase = false
  )
  or
-  // Any instruction with an integral type could potentially be part of a
-  // check for nullness when used in a guard. So we include all integral
-  // typed instructions here. However, since some of these instructions are
-  // already included as guards in other cases, we exclude those here.
-  // These are instructions that compute a binary equality or inequality
-  // relation. For example, the following:
-  // ```cpp
-  // if(a == b + 42) { ... }
-  // ```
-  // generates the following IR:
-  // ```
-  // r1(glval<int>) = VariableAddress[a]     :
-  // r2(int)        = Load[a]                : &:r1, m1
-  // r3(glval<int>) = VariableAddress[b]     :
-  // r4(int)        = Load[b]                : &:r3, m2
-  // r5(int)        = Constant[42]           :
-  // r6(int)        = Add                    : r4, r5
-  // r7(bool)       = CompareEQ              : r2, r6
-  // v1(void)       = ConditionalBranch      : r7
-  // ```
-  // and since `r7` is an integral typed instruction this predicate could
-  // include a case for when `r7` evaluates to true (in which case we would
-  // infer that `r6` was non-zero, and a case for when `r7` evaluates to false
-  // (in which case we would infer that `r6` was zero).
-  // However, since `a == b + 42` is already supported when reasoning about
-  // binary equalities we exclude those cases here.
-  not test.isGLValue() and
-  not simple_comparison_eq(test, _, _, _, _) and
-  not simple_comparison_lt(test, _, _, _) and
-  not test = any(SwitchInstruction switch).getExpression() and
-  (
-    test.getResultIRType() instanceof IRAddressType or
-    test.getResultIRType() instanceof IRIntegerType or
-    test.getResultIRType() instanceof IRBooleanType
-  ) and
+  isRelevantUnaryComparisonOperand(op) and
+  op.getDef() = test.getAnInstruction() and
  (
    k = 1 and
    value.(BooleanValue).getValue() = true and
@@ -919,10 +1029,12 @@ private class BuiltinExpectCallInstruction extends CallInstruction {
  BuiltinExpectCallInstruction() { this.getStaticCallTarget().hasName("__builtin_expect") }

  /** Gets the condition of this call. */
-  Instruction getCondition() {
+  Instruction getCondition() { result = this.getConditionOperand().getDef() }
+
+  Operand getConditionOperand() {
    // The first parameter of `__builtin_expect` has type `long`. So we skip
    // the conversion when inferring guards.
-    result = this.getArgument(0).(ConvertInstruction).getUnary()
+    result = this.getArgument(0).(ConvertInstruction).getUnaryOperand()
  }
 }

@@ -932,23 +1044,23 @@ private class BuiltinExpectCallInstruction extends CallInstruction {
 * `__builtin_expect(left == right + k, _)` to `0`.
 */
 private predicate builtin_expect_eq(
-  CompareInstruction cmp, Operand left, Operand right, int k, boolean areEqual, AbstractValue value
+  CompareValueNumber cmp, Operand left, Operand right, int k, boolean areEqual, AbstractValue value
 ) {
-  exists(BuiltinExpectCallInstruction call, Instruction const, AbstractValue innerValue |
+  exists(BuiltinExpectCallValueNumber call, Instruction const, AbstractValue innerValue |
    int_value(const) = 0 and
    cmp.hasOperands(call.getAUse(), const.getAUse()) and
    compares_eq(call.getCondition(), left, right, k, areEqual, innerValue)
  |
-    cmp instanceof CompareNEInstruction and
+    cmp instanceof CompareNEValueNumber and
    value = innerValue
    or
-    cmp instanceof CompareEQInstruction and
+    cmp instanceof CompareEQValueNumber and
    value.getDualValue() = innerValue
  )
 }

 private predicate complex_eq(
-  CompareInstruction cmp, Operand left, Operand right, int k, boolean areEqual, AbstractValue value
+  ValueNumber cmp, Operand left, Operand right, int k, boolean areEqual, AbstractValue value
 ) {
  sub_eq(cmp, left, right, k, areEqual, value)
  or
@@ -962,24 +1074,24 @@ private predicate complex_eq(
 * an instruction that compares the value of `__builtin_expect(op == k, _)` to `0`.
 */
 private predicate unary_builtin_expect_eq(
-  CompareInstruction cmp, Operand op, int k, boolean areEqual, boolean inNonZeroCase,
+  CompareValueNumber cmp, Operand op, int k, boolean areEqual, boolean inNonZeroCase,
  AbstractValue value
 ) {
-  exists(BuiltinExpectCallInstruction call, Instruction const, AbstractValue innerValue |
+  exists(BuiltinExpectCallValueNumber call, Instruction const, AbstractValue innerValue |
    int_value(const) = 0 and
    cmp.hasOperands(call.getAUse(), const.getAUse()) and
    unary_compares_eq(call.getCondition(), op, k, areEqual, inNonZeroCase, innerValue)
  |
-    cmp instanceof CompareNEInstruction and
+    cmp instanceof CompareNEValueNumber and
    value = innerValue
    or
-    cmp instanceof CompareEQInstruction and
+    cmp instanceof CompareEQValueNumber and
    value.getDualValue() = innerValue
  )
 }

 private predicate unary_complex_eq(
-  Instruction test, Operand op, int k, boolean areEqual, boolean inNonZeroCase, AbstractValue value
+  ValueNumber test, Operand op, int k, boolean areEqual, boolean inNonZeroCase, AbstractValue value
 ) {
  unary_sub_eq(test, op, k, areEqual, inNonZeroCase, value)
  or
@@ -995,7 +1107,7 @@ private predicate unary_complex_eq(

 /** Holds if `left < right + k` evaluates to `isLt` given that test is `testIsTrue`. */
 private predicate compares_lt(
-  Instruction test, Operand left, Operand right, int k, boolean isLt, AbstractValue value
+  ValueNumber test, Operand left, Operand right, int k, boolean isLt, AbstractValue value
 ) {
  /* In the simple case, the test is the comparison, so isLt = testIsTrue */
  simple_comparison_lt(test, left, right, k) and
@@ -1008,23 +1120,22 @@ private predicate compares_lt(
  or
  /* (x is true => (left < right + k)) => (!x is false => (left < right + k)) */
  exists(AbstractValue dual | value = dual.getDualValue() |
-    compares_lt(test.(LogicalNotInstruction).getUnary(), left, right, k, isLt, dual)
+    compares_lt(test.(LogicalNotValueNumber).getUnary(), left, right, k, isLt, dual)
  )
 }

 /** Holds if `op < k` evaluates to `isLt` given that `test` evaluates to `value`. */
-private predicate compares_lt(Instruction test, Operand op, int k, boolean isLt, AbstractValue value) {
-  unary_simple_comparison_lt(test, k, isLt, value) and
-  op.getDef() = test
+private predicate compares_lt(ValueNumber test, Operand op, int k, boolean isLt, AbstractValue value) {
+  unary_simple_comparison_lt(test, op, k, isLt, value)
  or
  complex_lt(test, op, k, isLt, value)
  or
  /* (x is true => (op < k)) => (!x is false => (op < k)) */
  exists(AbstractValue dual | value = dual.getDualValue() |
-    compares_lt(test.(LogicalNotInstruction).getUnary(), op, k, isLt, dual)
+    compares_lt(test.(LogicalNotValueNumber).getUnary(), op, k, isLt, dual)
  )
  or
-  exists(int k1, int k2, ConstantInstruction const |
+  exists(int k1, int k2, Instruction const |
    compares_lt(test, op, const.getAUse(), k2, isLt, value) and
    int_value(const) = k1 and
    k = k1 + k2
@@ -1033,42 +1144,38 @@ private predicate compares_lt(Instruction test, Operand op, int k, boolean isLt,

 /** `(a < b + k) => (b > a - k) => (b >= a + (1-k))` */
 private predicate compares_ge(
-  Instruction test, Operand left, Operand right, int k, boolean isGe, AbstractValue value
+  ValueNumber test, Operand left, Operand right, int k, boolean isGe, AbstractValue value
 ) {
  exists(int onemk | k = 1 - onemk | compares_lt(test, right, left, onemk, isGe, value))
 }

 /** Rearrange various simple comparisons into `left < right + k` form. */
-private predicate simple_comparison_lt(CompareInstruction cmp, Operand left, Operand right, int k) {
-  left = cmp.getLeftOperand() and
-  cmp instanceof CompareLTInstruction and
-  right = cmp.getRightOperand() and
+private predicate simple_comparison_lt(CompareValueNumber cmp, Operand left, Operand right, int k) {
+  cmp.hasOperands(left, right) and
+  cmp instanceof CompareLTValueNumber and
  k = 0
  or
-  left = cmp.getLeftOperand() and
-  cmp instanceof CompareLEInstruction and
-  right = cmp.getRightOperand() and
+  cmp.hasOperands(left, right) and
+  cmp instanceof CompareLEValueNumber and
  k = 1
  or
-  right = cmp.getLeftOperand() and
-  cmp instanceof CompareGTInstruction and
-  left = cmp.getRightOperand() and
+  cmp.hasOperands(right, left) and
+  cmp instanceof CompareGTValueNumber and
  k = 0
  or
-  right = cmp.getLeftOperand() and
-  cmp instanceof CompareGEInstruction and
-  left = cmp.getRightOperand() and
+  cmp.hasOperands(right, left) and
+  cmp instanceof CompareGEValueNumber and
  k = 1
 }

 /** Rearrange various simple comparisons into `op < k` form. */
 private predicate unary_simple_comparison_lt(
-  Instruction test, int k, boolean isLt, AbstractValue value
+  SwitchConditionValueNumber test, Operand op, int k, boolean isLt, AbstractValue value
 ) {
-  exists(SwitchInstruction switch, CaseEdge case |
-    test = switch.getExpression() and
+  exists(CaseEdge case |
+    test.getExpressionOperand() = op and
    case = value.(MatchValue).getCase() and
-    exists(switch.getSuccessor(case)) and
+    exists(test.getSuccessor(case)) and
    case.getMaxValue() > case.getMinValue()
  |
    // op <= k => op < k - 1
@@ -1081,7 +1188,7 @@ private predicate unary_simple_comparison_lt(
 }

 private predicate complex_lt(
-  CompareInstruction cmp, Operand left, Operand right, int k, boolean isLt, AbstractValue value
+  ValueNumber cmp, Operand left, Operand right, int k, boolean isLt, AbstractValue value
 ) {
  sub_lt(cmp, left, right, k, isLt, value)
  or
@@ -1089,7 +1196,7 @@ private predicate complex_lt(
 }

 private predicate complex_lt(
-  Instruction test, Operand left, int k, boolean isLt, AbstractValue value
+  ValueNumber test, Operand left, int k, boolean isLt, AbstractValue value
 ) {
  sub_lt(test, left, k, isLt, value)
  or
@@ -1099,7 +1206,7 @@ private predicate complex_lt(
 // left - x < right + c => left < right + (c+x)
 // left < (right - x) + c => left < right + (c-x)
 private predicate sub_lt(
-  CompareInstruction cmp, Operand left, Operand right, int k, boolean isLt, AbstractValue value
+  ValueNumber cmp, Operand left, Operand right, int k, boolean isLt, AbstractValue value
 ) {
  exists(SubInstruction lhs, int c, int x |
    compares_lt(cmp, lhs.getAUse(), right, c, isLt, value) and
@@ -1130,7 +1237,7 @@ private predicate sub_lt(
  )
 }

-private predicate sub_lt(Instruction test, Operand left, int k, boolean isLt, AbstractValue value) {
+private predicate sub_lt(ValueNumber test, Operand left, int k, boolean isLt, AbstractValue value) {
  exists(SubInstruction lhs, int c, int x |
    compares_lt(test, lhs.getAUse(), c, isLt, value) and
    left = lhs.getLeftOperand() and
@@ -1149,7 +1256,7 @@ private predicate sub_lt(Instruction test, Operand left, int k, boolean isLt, Ab
 // left + x < right + c => left < right + (c-x)
 // left < (right + x) + c => left < right + (c+x)
 private predicate add_lt(
-  CompareInstruction cmp, Operand left, Operand right, int k, boolean isLt, AbstractValue value
+  ValueNumber cmp, Operand left, Operand right, int k, boolean isLt, AbstractValue value
 ) {
  exists(AddInstruction lhs, int c, int x |
    compares_lt(cmp, lhs.getAUse(), right, c, isLt, value) and
@@ -1192,7 +1299,7 @@ private predicate add_lt(
  )
 }

-private predicate add_lt(Instruction test, Operand left, int k, boolean isLt, AbstractValue value) {
+private predicate add_lt(ValueNumber test, Operand left, int k, boolean isLt, AbstractValue value) {
  exists(AddInstruction lhs, int c, int x |
    compares_lt(test, lhs.getAUse(), c, isLt, value) and
    (
@@ -1217,7 +1324,7 @@ private predicate add_lt(Instruction test, Operand left, int k, boolean isLt, Ab
 // left - x == right + c => left == right + (c+x)
 // left == (right - x) + c => left == right + (c-x)
 private predicate sub_eq(
-  CompareInstruction cmp, Operand left, Operand right, int k, boolean areEqual, AbstractValue value
+  ValueNumber cmp, Operand left, Operand right, int k, boolean areEqual, AbstractValue value
 ) {
  exists(SubInstruction lhs, int c, int x |
    compares_eq(cmp, lhs.getAUse(), right, c, areEqual, value) and
@@ -1250,7 +1357,7 @@ private predicate sub_eq(

 // op - x == c => op == (c+x)
 private predicate unary_sub_eq(
-  Instruction test, Operand op, int k, boolean areEqual, boolean inNonZeroCase, AbstractValue value
+  ValueNumber test, Operand op, int k, boolean areEqual, boolean inNonZeroCase, AbstractValue value
 ) {
  inNonZeroCase = false and
  exists(SubInstruction sub, int c, int x |
@@ -1272,7 +1379,7 @@ private predicate unary_sub_eq(
 // left + x == right + c => left == right + (c-x)
 // left == (right + x) + c => left == right + (c+x)
 private predicate add_eq(
-  CompareInstruction cmp, Operand left, Operand right, int k, boolean areEqual, AbstractValue value
+  ValueNumber cmp, Operand left, Operand right, int k, boolean areEqual, AbstractValue value
 ) {
  exists(AddInstruction lhs, int c, int x |
    compares_eq(cmp, lhs.getAUse(), right, c, areEqual, value) and
@@ -1317,7 +1424,7 @@ private predicate add_eq(

 // left + x == right + c => left == right + (c-x)
 private predicate unary_add_eq(
-  Instruction test, Operand left, int k, boolean areEqual, boolean inNonZeroCase,
+  ValueNumber test, Operand left, int k, boolean areEqual, boolean inNonZeroCase,
  AbstractValue value
 ) {
  inNonZeroCase = false and
@@ -1351,6 +1458,4 @@ private class IntegerOrPointerConstantInstruction extends ConstantInstruction {
 }

 /** The int value of integer constant expression. */
-private int int_value(Instruction i) {
-  result = i.(IntegerOrPointerConstantInstruction).getValue().toInt()
-}
+private int int_value(IntegerOrPointerConstantInstruction i) { result = i.getValue().toInt() }
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow.qll
@@ -29,5 +29,5 @@ deprecated module DataFlow {
  private import semmle.code.cpp.dataflow.internal.DataFlowImplSpecific
  private import codeql.dataflow.DataFlow
  import DataFlowMake<Location, CppOldDataFlow>
-  import Public
+  import semmle.code.cpp.dataflow.internal.DataFlowImpl1
 }
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow2.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow2.qll
@@ -0,0 +1,22 @@
+/**
+ * Provides a `DataFlow2` module, which is a copy of the `DataFlow` module. Use
+ * this class when data-flow configurations must depend on each other. Two
+ * classes extending `DataFlow::Configuration` should never depend on each
+ * other, but one of them should instead depend on a
+ * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
+ * `DataFlow4::Configuration`.
+ *
+ * See `semmle.code.cpp.dataflow.DataFlow` for the full documentation.
+ */
+
+import cpp
+
+/**
+ * DEPRECATED: Use `semmle.code.cpp.dataflow.new.DataFlow2` instead.
+ *
+ * Provides classes for performing local (intra-procedural) and
+ * global (inter-procedural) data flow analyses.
+ */
+deprecated module DataFlow2 {
+  import semmle.code.cpp.dataflow.internal.DataFlowImpl2
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow3.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow3.qll
@@ -0,0 +1,22 @@
+/**
+ * Provides a `DataFlow3` module, which is a copy of the `DataFlow` module. Use
+ * this class when data-flow configurations must depend on each other. Two
+ * classes extending `DataFlow::Configuration` should never depend on each
+ * other, but one of them should instead depend on a
+ * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
+ * `DataFlow4::Configuration`.
+ *
+ * See `semmle.code.cpp.dataflow.DataFlow` for the full documentation.
+ */
+
+import cpp
+
+/**
+ * DEPRECATED: Use `semmle.code.cpp.dataflow.new.DataFlow3` instead.
+ *
+ * Provides classes for performing local (intra-procedural) and
+ * global (inter-procedural) data flow analyses.
+ */
+deprecated module DataFlow3 {
+  import semmle.code.cpp.dataflow.internal.DataFlowImpl3
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow4.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/DataFlow4.qll
@@ -0,0 +1,22 @@
+/**
+ * Provides a `DataFlow4` module, which is a copy of the `DataFlow` module. Use
+ * this class when data-flow configurations must depend on each other. Two
+ * classes extending `DataFlow::Configuration` should never depend on each
+ * other, but one of them should instead depend on a
+ * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
+ * `DataFlow4::Configuration`.
+ *
+ * See `semmle.code.cpp.dataflow.DataFlow` for the full documentation.
+ */
+
+import cpp
+
+/**
+ * DEPRECATED: Use `semmle.code.cpp.dataflow.new.DataFlow4` instead.
+ *
+ * Provides classes for performing local (intra-procedural) and
+ * global (inter-procedural) data flow analyses.
+ */
+deprecated module DataFlow4 {
+  import semmle.code.cpp.dataflow.internal.DataFlowImpl4
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/ExternalFlow.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/ExternalFlow.qll
@@ -793,27 +793,28 @@ private Element interpretElement0(
 ) {
  (
    // Non-member functions
-    funcHasQualifiedName(result, namespace, name) and
+    elementSpec(namespace, type, subtypes, name, signature, _) and
    subtypes = false and
    type = "" and
    (
      elementSpecMatchesSignature(result, namespace, type, subtypes, name, signature)
      or
      signature = "" and
-      elementSpec(namespace, type, subtypes, name, signature, _)
+      elementSpec(namespace, type, subtypes, name, "", _) and
+      funcHasQualifiedName(result, namespace, name)
    )
    or
    // Member functions
    exists(Class namedClass, Class classWithMethod |
-      hasClassAndName(classWithMethod, result, name) and
-      classHasQualifiedName(namedClass, namespace, type)
-    |
      (
-        elementSpecMatchesSignature(result, namespace, type, subtypes, name, signature)
+        elementSpecMatchesSignature(result, namespace, type, subtypes, name, signature) and
+        hasClassAndName(classWithMethod, result, name)
        or
        signature = "" and
-        elementSpec(namespace, type, subtypes, name, "", _)
+        elementSpec(namespace, type, subtypes, name, "", _) and
+        hasClassAndName(classWithMethod, result, name)
      ) and
+      classHasQualifiedName(namedClass, namespace, type) and
      (
        // member declared in the named type or a subtype of it
        subtypes = true and
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/RecursionPrevention.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/RecursionPrevention.qll
@@ -0,0 +1,39 @@
+/**
+ * DEPRECATED: Recursion through `DataFlow::Configuration` is impossible in
+ * any supported tooling. There is no need for this module because it's
+ * impossible to accidentally depend on recursion through
+ * `DataFlow::Configuration` in current releases.
+ *
+ * When this module is imported, recursive use of `DataFlow::Configuration` is
+ * disallowed. Importing this module will guarantee the absence of such
+ * recursion, which is unsupported and will be unconditionally disallowed in a
+ * future release.
+ *
+ * Recursive use of `DataFlow{2..4}::Configuration` is always disallowed, so no
+ * import is needed for those.
+ */
+
+import cpp
+private import semmle.code.cpp.dataflow.DataFlow
+
+/**
+ * This class exists to prevent mutual recursion between the user-overridden
+ * member predicates of `Configuration` and the rest of the data-flow library.
+ * Good performance cannot be guaranteed in the presence of such recursion, so
+ * it should be replaced by using more than one copy of the data flow library.
+ * Four copies are available: `DataFlow` through `DataFlow4`.
+ */
+abstract private class ConfigurationRecursionPrevention extends DataFlow::Configuration {
+  bindingset[this]
+  ConfigurationRecursionPrevention() { any() }
+
+  override predicate hasFlow(DataFlow::Node source, DataFlow::Node sink) {
+    strictcount(DataFlow::Node n | this.isSource(n)) < 0
+    or
+    strictcount(DataFlow::Node n | this.isSink(n)) < 0
+    or
+    strictcount(DataFlow::Node n1, DataFlow::Node n2 | this.isAdditionalFlowStep(n1, n2)) < 0
+    or
+    super.hasFlow(source, sink)
+  }
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/TaintTracking.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/TaintTracking.qll
@@ -16,6 +16,7 @@
 */

 import semmle.code.cpp.dataflow.DataFlow
+import semmle.code.cpp.dataflow.DataFlow2

 /**
 * DEPRECATED: Use `semmle.code.cpp.dataflow.new.TaintTracking` instead.
@@ -24,9 +25,10 @@ import semmle.code.cpp.dataflow.DataFlow
 * global (inter-procedural) taint-tracking analyses.
 */
 deprecated module TaintTracking {
-  import semmle.code.cpp.dataflow.internal.TaintTrackingUtil
+  import semmle.code.cpp.dataflow.internal.tainttracking1.TaintTrackingParameter::Public
  private import semmle.code.cpp.dataflow.internal.DataFlowImplSpecific
  private import semmle.code.cpp.dataflow.internal.TaintTrackingImplSpecific
  private import codeql.dataflow.TaintTracking
  import TaintFlowMake<Location, CppOldDataFlow, CppOldTaintTracking>
+  import semmle.code.cpp.dataflow.internal.tainttracking1.TaintTrackingImpl
 }
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/TaintTracking2.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/TaintTracking2.qll
@@ -0,0 +1,22 @@
+/**
+ * Provides a `TaintTracking2` module, which is a copy of the `TaintTracking`
+ * module. Use this class when data-flow configurations or taint-tracking
+ * configurations must depend on each other. Two classes extending
+ * `DataFlow::Configuration` should never depend on each other, but one of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`. The
+ * `TaintTracking::Configuration` class extends `DataFlow::Configuration`, and
+ * `TaintTracking2::Configuration` extends `DataFlow2::Configuration`.
+ *
+ * See `semmle.code.cpp.dataflow.TaintTracking` for the full documentation.
+ */
+
+/**
+ * DEPRECATED: Use `semmle.code.cpp.dataflow.new.TaintTracking2` instead.
+ *
+ * Provides classes for performing local (intra-procedural) and
+ * global (inter-procedural) taint-tracking analyses.
+ */
+deprecated module TaintTracking2 {
+  import semmle.code.cpp.dataflow.internal.tainttracking2.TaintTrackingImpl
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl1.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl1.qll
@@ -0,0 +1,361 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * Provides a `Configuration` class backwards-compatible interface to the data
+ * flow library.
+ */
+
+private import DataFlowImplCommon
+private import DataFlowImplSpecific::Private
+import DataFlowImplSpecific::Public
+private import DataFlowImpl
+import DataFlowImplCommonPublic
+deprecated import FlowStateString
+private import codeql.util.Unit
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * A configuration of interprocedural data flow analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the global data flow library must define its own unique extension
+ * of this abstract class. 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 DataFlow::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isBarrier`.
+ *   // Optionally override `isAdditionalFlowStep`.
+ * }
+ * ```
+ * Conceptually, this defines a graph where the nodes are `DataFlow::Node`s and
+ * the edges are those data-flow steps that preserve the value of the node
+ * along with any additional edges defined by `isAdditionalFlowStep`.
+ * Specifying nodes in `isBarrier` will remove those nodes from the graph, and
+ * specifying nodes in `isBarrierIn` and/or `isBarrierOut` will remove in-going
+ * and/or out-going edges from those nodes, respectively.
+ *
+ * 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 two classes extending
+ * `DataFlow::Configuration` should never depend on each other. One of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`.
+ */
+abstract deprecated class Configuration extends string {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant data flow source.
+   */
+  predicate isSource(Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant data flow source with the given initial
+   * `state`.
+   */
+  predicate isSource(Node source, FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink.
+   */
+  predicate isSink(Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink accepting `state`.
+   */
+  predicate isSink(Node sink, FlowState state) { none() }
+
+  /**
+   * Holds if data flow through `node` is prohibited. This completely removes
+   * `node` from the data flow graph.
+   */
+  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) { none() }
+
+  /** Holds if data flow into `node` is prohibited. */
+  predicate isBarrierIn(Node node) { none() }
+
+  /** Holds if data flow out of `node` is prohibited. */
+  predicate isBarrierOut(Node node) { none() }
+
+  /**
+   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
+   */
+  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) {
+    none()
+  }
+
+  /**
+   * Holds if an arbitrary number of implicit read steps of content `c` may be
+   * taken at `node`.
+   */
+  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.
+   */
+  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.
+   */
+  FlowFeature getAFeature() { none() }
+
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   */
+  predicate hasFlow(Node source, Node sink) { hasFlow(source, sink, this) }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   *
+   * The corresponding paths are generated from the end-points and the graph
+   * included in the module `PathGraph`.
+   */
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowTo(Node sink) { hasFlowTo(sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowToExpr(DataFlowExpr sink) { this.hasFlowTo(exprNode(sink)) }
+
+  /**
+   * 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 (for example in a `path-problem` query).
+   */
+  predicate includeHiddenNodes() { none() }
+}
+
+/**
+ * This class exists to prevent mutual recursion between the user-overridden
+ * member predicates of `Configuration` and the rest of the data-flow library.
+ * Good performance cannot be guaranteed in the presence of such recursion, so
+ * it should be replaced by using more than one copy of the data flow library.
+ */
+abstract deprecated private class ConfigurationRecursionPrevention extends Configuration {
+  bindingset[this]
+  ConfigurationRecursionPrevention() { any() }
+
+  override predicate hasFlow(Node source, Node sink) {
+    strictcount(Node n | this.isSource(n)) < 0
+    or
+    strictcount(Node n | this.isSource(n, _)) < 0
+    or
+    strictcount(Node n | this.isSink(n)) < 0
+    or
+    strictcount(Node n | this.isSink(n, _)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, n2)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, _, n2, _)) < 0
+    or
+    super.hasFlow(source, sink)
+  }
+}
+
+deprecated private FlowState relevantState(Configuration config) {
+  config.isSource(_, result) or
+  config.isSink(_, result) or
+  config.isBarrier(_, result) or
+  config.isAdditionalFlowStep(_, result, _, _) or
+  config.isAdditionalFlowStep(_, _, _, result)
+}
+
+private newtype TConfigState =
+  deprecated TMkConfigState(Configuration config, FlowState state) {
+    state = relevantState(config) or state instanceof FlowStateEmpty
+  }
+
+deprecated private Configuration getConfig(TConfigState state) { state = TMkConfigState(result, _) }
+
+deprecated private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
+
+deprecated private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
+deprecated private module Config implements FullStateConfigSig {
+  class FlowState = TConfigState;
+
+  predicate isSource(Node source, FlowState state) {
+    getConfig(state).isSource(source, getState(state))
+    or
+    getConfig(state).isSource(source) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isSink(Node sink) { none() }
+
+  predicate isSink(Node sink, FlowState state) {
+    getConfig(state).isSink(sink, getState(state))
+    or
+    getConfig(state).isSink(sink) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isBarrier(Node node) { none() }
+
+  predicate isBarrier(Node node, FlowState state) {
+    getConfig(state).isBarrier(node, getState(state)) or
+    getConfig(state).isBarrier(node)
+  }
+
+  predicate isBarrierIn(Node node) { any(Configuration config).isBarrierIn(node) }
+
+  predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
+
+  predicate isBarrierIn(Node node, FlowState state) { none() }
+
+  predicate isBarrierOut(Node node, FlowState state) { none() }
+
+  predicate isAdditionalFlowStep(Node node1, Node node2, string model) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2) and
+    model = ""
+  }
+
+  predicate isAdditionalFlowStep(
+    Node node1, FlowState state1, Node node2, FlowState state2, string model
+  ) {
+    getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
+    getConfig(state2) = getConfig(state1) and
+    model = ""
+    or
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1 and
+    model = ""
+  }
+
+  predicate allowImplicitRead(Node node, ContentSet c) {
+    any(Configuration config).allowImplicitRead(node, c)
+  }
+
+  predicate neverSkip(Node node) { none() }
+
+  int fieldFlowBranchLimit() { result = min(any(Configuration config).fieldFlowBranchLimit()) }
+
+  int accessPathLimit() { result = 5 }
+
+  FlowFeature getAFeature() { result = any(Configuration config).getAFeature() }
+
+  predicate includeHiddenNodes() { any(Configuration config).includeHiddenNodes() }
+
+  predicate observeDiffInformedIncrementalMode() { none() }
+}
+
+deprecated private import Impl<Config> as I
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+deprecated class PathNode instanceof I::PathNode {
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { result = super.getNode() }
+
+  /** Gets the `FlowState` of this node. */
+  deprecated final FlowState getState() { result = getState(super.getState()) }
+
+  /** Gets the associated configuration. */
+  deprecated final Configuration getConfiguration() { result = getConfig(super.getState()) }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getASuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { super.isSourceGroup(group) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { super.isSinkGroup(group) }
+}
+
+deprecated module PathGraph = I::PathGraph;
+
+deprecated private predicate hasFlow(Node source, Node sink, Configuration config) {
+  exists(PathNode source0, PathNode sink0 |
+    hasFlowPath(source0, sink0, config) and
+    source0.getNode() = source and
+    sink0.getNode() = sink
+  )
+}
+
+deprecated private predicate hasFlowPath(PathNode source, PathNode sink, Configuration config) {
+  I::flowPath(source, sink) and source.getConfiguration() = config
+}
+
+deprecated private predicate hasFlowTo(Node sink, Configuration config) { hasFlow(_, sink, config) }
+
+deprecated predicate flowsTo = hasFlow/3;
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll
@@ -0,0 +1,361 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * Provides a `Configuration` class backwards-compatible interface to the data
+ * flow library.
+ */
+
+private import DataFlowImplCommon
+private import DataFlowImplSpecific::Private
+import DataFlowImplSpecific::Public
+private import DataFlowImpl
+import DataFlowImplCommonPublic
+deprecated import FlowStateString
+private import codeql.util.Unit
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * A configuration of interprocedural data flow analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the global data flow library must define its own unique extension
+ * of this abstract class. 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 DataFlow::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isBarrier`.
+ *   // Optionally override `isAdditionalFlowStep`.
+ * }
+ * ```
+ * Conceptually, this defines a graph where the nodes are `DataFlow::Node`s and
+ * the edges are those data-flow steps that preserve the value of the node
+ * along with any additional edges defined by `isAdditionalFlowStep`.
+ * Specifying nodes in `isBarrier` will remove those nodes from the graph, and
+ * specifying nodes in `isBarrierIn` and/or `isBarrierOut` will remove in-going
+ * and/or out-going edges from those nodes, respectively.
+ *
+ * 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 two classes extending
+ * `DataFlow::Configuration` should never depend on each other. One of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`.
+ */
+abstract deprecated class Configuration extends string {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant data flow source.
+   */
+  predicate isSource(Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant data flow source with the given initial
+   * `state`.
+   */
+  predicate isSource(Node source, FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink.
+   */
+  predicate isSink(Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink accepting `state`.
+   */
+  predicate isSink(Node sink, FlowState state) { none() }
+
+  /**
+   * Holds if data flow through `node` is prohibited. This completely removes
+   * `node` from the data flow graph.
+   */
+  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) { none() }
+
+  /** Holds if data flow into `node` is prohibited. */
+  predicate isBarrierIn(Node node) { none() }
+
+  /** Holds if data flow out of `node` is prohibited. */
+  predicate isBarrierOut(Node node) { none() }
+
+  /**
+   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
+   */
+  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) {
+    none()
+  }
+
+  /**
+   * Holds if an arbitrary number of implicit read steps of content `c` may be
+   * taken at `node`.
+   */
+  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.
+   */
+  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.
+   */
+  FlowFeature getAFeature() { none() }
+
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   */
+  predicate hasFlow(Node source, Node sink) { hasFlow(source, sink, this) }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   *
+   * The corresponding paths are generated from the end-points and the graph
+   * included in the module `PathGraph`.
+   */
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowTo(Node sink) { hasFlowTo(sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowToExpr(DataFlowExpr sink) { this.hasFlowTo(exprNode(sink)) }
+
+  /**
+   * 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 (for example in a `path-problem` query).
+   */
+  predicate includeHiddenNodes() { none() }
+}
+
+/**
+ * This class exists to prevent mutual recursion between the user-overridden
+ * member predicates of `Configuration` and the rest of the data-flow library.
+ * Good performance cannot be guaranteed in the presence of such recursion, so
+ * it should be replaced by using more than one copy of the data flow library.
+ */
+abstract deprecated private class ConfigurationRecursionPrevention extends Configuration {
+  bindingset[this]
+  ConfigurationRecursionPrevention() { any() }
+
+  override predicate hasFlow(Node source, Node sink) {
+    strictcount(Node n | this.isSource(n)) < 0
+    or
+    strictcount(Node n | this.isSource(n, _)) < 0
+    or
+    strictcount(Node n | this.isSink(n)) < 0
+    or
+    strictcount(Node n | this.isSink(n, _)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, n2)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, _, n2, _)) < 0
+    or
+    super.hasFlow(source, sink)
+  }
+}
+
+deprecated private FlowState relevantState(Configuration config) {
+  config.isSource(_, result) or
+  config.isSink(_, result) or
+  config.isBarrier(_, result) or
+  config.isAdditionalFlowStep(_, result, _, _) or
+  config.isAdditionalFlowStep(_, _, _, result)
+}
+
+private newtype TConfigState =
+  deprecated TMkConfigState(Configuration config, FlowState state) {
+    state = relevantState(config) or state instanceof FlowStateEmpty
+  }
+
+deprecated private Configuration getConfig(TConfigState state) { state = TMkConfigState(result, _) }
+
+deprecated private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
+
+deprecated private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
+deprecated private module Config implements FullStateConfigSig {
+  class FlowState = TConfigState;
+
+  predicate isSource(Node source, FlowState state) {
+    getConfig(state).isSource(source, getState(state))
+    or
+    getConfig(state).isSource(source) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isSink(Node sink) { none() }
+
+  predicate isSink(Node sink, FlowState state) {
+    getConfig(state).isSink(sink, getState(state))
+    or
+    getConfig(state).isSink(sink) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isBarrier(Node node) { none() }
+
+  predicate isBarrier(Node node, FlowState state) {
+    getConfig(state).isBarrier(node, getState(state)) or
+    getConfig(state).isBarrier(node)
+  }
+
+  predicate isBarrierIn(Node node) { any(Configuration config).isBarrierIn(node) }
+
+  predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
+
+  predicate isBarrierIn(Node node, FlowState state) { none() }
+
+  predicate isBarrierOut(Node node, FlowState state) { none() }
+
+  predicate isAdditionalFlowStep(Node node1, Node node2, string model) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2) and
+    model = ""
+  }
+
+  predicate isAdditionalFlowStep(
+    Node node1, FlowState state1, Node node2, FlowState state2, string model
+  ) {
+    getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
+    getConfig(state2) = getConfig(state1) and
+    model = ""
+    or
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1 and
+    model = ""
+  }
+
+  predicate allowImplicitRead(Node node, ContentSet c) {
+    any(Configuration config).allowImplicitRead(node, c)
+  }
+
+  predicate neverSkip(Node node) { none() }
+
+  int fieldFlowBranchLimit() { result = min(any(Configuration config).fieldFlowBranchLimit()) }
+
+  int accessPathLimit() { result = 5 }
+
+  FlowFeature getAFeature() { result = any(Configuration config).getAFeature() }
+
+  predicate includeHiddenNodes() { any(Configuration config).includeHiddenNodes() }
+
+  predicate observeDiffInformedIncrementalMode() { none() }
+}
+
+deprecated private import Impl<Config> as I
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+deprecated class PathNode instanceof I::PathNode {
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { result = super.getNode() }
+
+  /** Gets the `FlowState` of this node. */
+  deprecated final FlowState getState() { result = getState(super.getState()) }
+
+  /** Gets the associated configuration. */
+  deprecated final Configuration getConfiguration() { result = getConfig(super.getState()) }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getASuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { super.isSourceGroup(group) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { super.isSinkGroup(group) }
+}
+
+deprecated module PathGraph = I::PathGraph;
+
+deprecated private predicate hasFlow(Node source, Node sink, Configuration config) {
+  exists(PathNode source0, PathNode sink0 |
+    hasFlowPath(source0, sink0, config) and
+    source0.getNode() = source and
+    sink0.getNode() = sink
+  )
+}
+
+deprecated private predicate hasFlowPath(PathNode source, PathNode sink, Configuration config) {
+  I::flowPath(source, sink) and source.getConfiguration() = config
+}
+
+deprecated private predicate hasFlowTo(Node sink, Configuration config) { hasFlow(_, sink, config) }
+
+deprecated predicate flowsTo = hasFlow/3;
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll
@@ -0,0 +1,361 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * Provides a `Configuration` class backwards-compatible interface to the data
+ * flow library.
+ */
+
+private import DataFlowImplCommon
+private import DataFlowImplSpecific::Private
+import DataFlowImplSpecific::Public
+private import DataFlowImpl
+import DataFlowImplCommonPublic
+deprecated import FlowStateString
+private import codeql.util.Unit
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * A configuration of interprocedural data flow analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the global data flow library must define its own unique extension
+ * of this abstract class. 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 DataFlow::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isBarrier`.
+ *   // Optionally override `isAdditionalFlowStep`.
+ * }
+ * ```
+ * Conceptually, this defines a graph where the nodes are `DataFlow::Node`s and
+ * the edges are those data-flow steps that preserve the value of the node
+ * along with any additional edges defined by `isAdditionalFlowStep`.
+ * Specifying nodes in `isBarrier` will remove those nodes from the graph, and
+ * specifying nodes in `isBarrierIn` and/or `isBarrierOut` will remove in-going
+ * and/or out-going edges from those nodes, respectively.
+ *
+ * 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 two classes extending
+ * `DataFlow::Configuration` should never depend on each other. One of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`.
+ */
+abstract deprecated class Configuration extends string {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant data flow source.
+   */
+  predicate isSource(Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant data flow source with the given initial
+   * `state`.
+   */
+  predicate isSource(Node source, FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink.
+   */
+  predicate isSink(Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink accepting `state`.
+   */
+  predicate isSink(Node sink, FlowState state) { none() }
+
+  /**
+   * Holds if data flow through `node` is prohibited. This completely removes
+   * `node` from the data flow graph.
+   */
+  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) { none() }
+
+  /** Holds if data flow into `node` is prohibited. */
+  predicate isBarrierIn(Node node) { none() }
+
+  /** Holds if data flow out of `node` is prohibited. */
+  predicate isBarrierOut(Node node) { none() }
+
+  /**
+   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
+   */
+  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) {
+    none()
+  }
+
+  /**
+   * Holds if an arbitrary number of implicit read steps of content `c` may be
+   * taken at `node`.
+   */
+  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.
+   */
+  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.
+   */
+  FlowFeature getAFeature() { none() }
+
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   */
+  predicate hasFlow(Node source, Node sink) { hasFlow(source, sink, this) }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   *
+   * The corresponding paths are generated from the end-points and the graph
+   * included in the module `PathGraph`.
+   */
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowTo(Node sink) { hasFlowTo(sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowToExpr(DataFlowExpr sink) { this.hasFlowTo(exprNode(sink)) }
+
+  /**
+   * 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 (for example in a `path-problem` query).
+   */
+  predicate includeHiddenNodes() { none() }
+}
+
+/**
+ * This class exists to prevent mutual recursion between the user-overridden
+ * member predicates of `Configuration` and the rest of the data-flow library.
+ * Good performance cannot be guaranteed in the presence of such recursion, so
+ * it should be replaced by using more than one copy of the data flow library.
+ */
+abstract deprecated private class ConfigurationRecursionPrevention extends Configuration {
+  bindingset[this]
+  ConfigurationRecursionPrevention() { any() }
+
+  override predicate hasFlow(Node source, Node sink) {
+    strictcount(Node n | this.isSource(n)) < 0
+    or
+    strictcount(Node n | this.isSource(n, _)) < 0
+    or
+    strictcount(Node n | this.isSink(n)) < 0
+    or
+    strictcount(Node n | this.isSink(n, _)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, n2)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, _, n2, _)) < 0
+    or
+    super.hasFlow(source, sink)
+  }
+}
+
+deprecated private FlowState relevantState(Configuration config) {
+  config.isSource(_, result) or
+  config.isSink(_, result) or
+  config.isBarrier(_, result) or
+  config.isAdditionalFlowStep(_, result, _, _) or
+  config.isAdditionalFlowStep(_, _, _, result)
+}
+
+private newtype TConfigState =
+  deprecated TMkConfigState(Configuration config, FlowState state) {
+    state = relevantState(config) or state instanceof FlowStateEmpty
+  }
+
+deprecated private Configuration getConfig(TConfigState state) { state = TMkConfigState(result, _) }
+
+deprecated private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
+
+deprecated private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
+deprecated private module Config implements FullStateConfigSig {
+  class FlowState = TConfigState;
+
+  predicate isSource(Node source, FlowState state) {
+    getConfig(state).isSource(source, getState(state))
+    or
+    getConfig(state).isSource(source) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isSink(Node sink) { none() }
+
+  predicate isSink(Node sink, FlowState state) {
+    getConfig(state).isSink(sink, getState(state))
+    or
+    getConfig(state).isSink(sink) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isBarrier(Node node) { none() }
+
+  predicate isBarrier(Node node, FlowState state) {
+    getConfig(state).isBarrier(node, getState(state)) or
+    getConfig(state).isBarrier(node)
+  }
+
+  predicate isBarrierIn(Node node) { any(Configuration config).isBarrierIn(node) }
+
+  predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
+
+  predicate isBarrierIn(Node node, FlowState state) { none() }
+
+  predicate isBarrierOut(Node node, FlowState state) { none() }
+
+  predicate isAdditionalFlowStep(Node node1, Node node2, string model) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2) and
+    model = ""
+  }
+
+  predicate isAdditionalFlowStep(
+    Node node1, FlowState state1, Node node2, FlowState state2, string model
+  ) {
+    getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
+    getConfig(state2) = getConfig(state1) and
+    model = ""
+    or
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1 and
+    model = ""
+  }
+
+  predicate allowImplicitRead(Node node, ContentSet c) {
+    any(Configuration config).allowImplicitRead(node, c)
+  }
+
+  predicate neverSkip(Node node) { none() }
+
+  int fieldFlowBranchLimit() { result = min(any(Configuration config).fieldFlowBranchLimit()) }
+
+  int accessPathLimit() { result = 5 }
+
+  FlowFeature getAFeature() { result = any(Configuration config).getAFeature() }
+
+  predicate includeHiddenNodes() { any(Configuration config).includeHiddenNodes() }
+
+  predicate observeDiffInformedIncrementalMode() { none() }
+}
+
+deprecated private import Impl<Config> as I
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+deprecated class PathNode instanceof I::PathNode {
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { result = super.getNode() }
+
+  /** Gets the `FlowState` of this node. */
+  deprecated final FlowState getState() { result = getState(super.getState()) }
+
+  /** Gets the associated configuration. */
+  deprecated final Configuration getConfiguration() { result = getConfig(super.getState()) }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getASuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { super.isSourceGroup(group) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { super.isSinkGroup(group) }
+}
+
+deprecated module PathGraph = I::PathGraph;
+
+deprecated private predicate hasFlow(Node source, Node sink, Configuration config) {
+  exists(PathNode source0, PathNode sink0 |
+    hasFlowPath(source0, sink0, config) and
+    source0.getNode() = source and
+    sink0.getNode() = sink
+  )
+}
+
+deprecated private predicate hasFlowPath(PathNode source, PathNode sink, Configuration config) {
+  I::flowPath(source, sink) and source.getConfiguration() = config
+}
+
+deprecated private predicate hasFlowTo(Node sink, Configuration config) { hasFlow(_, sink, config) }
+
+deprecated predicate flowsTo = hasFlow/3;
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll
@@ -0,0 +1,361 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * Provides a `Configuration` class backwards-compatible interface to the data
+ * flow library.
+ */
+
+private import DataFlowImplCommon
+private import DataFlowImplSpecific::Private
+import DataFlowImplSpecific::Public
+private import DataFlowImpl
+import DataFlowImplCommonPublic
+deprecated import FlowStateString
+private import codeql.util.Unit
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * A configuration of interprocedural data flow analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the global data flow library must define its own unique extension
+ * of this abstract class. 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 DataFlow::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isBarrier`.
+ *   // Optionally override `isAdditionalFlowStep`.
+ * }
+ * ```
+ * Conceptually, this defines a graph where the nodes are `DataFlow::Node`s and
+ * the edges are those data-flow steps that preserve the value of the node
+ * along with any additional edges defined by `isAdditionalFlowStep`.
+ * Specifying nodes in `isBarrier` will remove those nodes from the graph, and
+ * specifying nodes in `isBarrierIn` and/or `isBarrierOut` will remove in-going
+ * and/or out-going edges from those nodes, respectively.
+ *
+ * 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 two classes extending
+ * `DataFlow::Configuration` should never depend on each other. One of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`.
+ */
+abstract deprecated class Configuration extends string {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant data flow source.
+   */
+  predicate isSource(Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant data flow source with the given initial
+   * `state`.
+   */
+  predicate isSource(Node source, FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink.
+   */
+  predicate isSink(Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink accepting `state`.
+   */
+  predicate isSink(Node sink, FlowState state) { none() }
+
+  /**
+   * Holds if data flow through `node` is prohibited. This completely removes
+   * `node` from the data flow graph.
+   */
+  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) { none() }
+
+  /** Holds if data flow into `node` is prohibited. */
+  predicate isBarrierIn(Node node) { none() }
+
+  /** Holds if data flow out of `node` is prohibited. */
+  predicate isBarrierOut(Node node) { none() }
+
+  /**
+   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
+   */
+  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) {
+    none()
+  }
+
+  /**
+   * Holds if an arbitrary number of implicit read steps of content `c` may be
+   * taken at `node`.
+   */
+  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.
+   */
+  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.
+   */
+  FlowFeature getAFeature() { none() }
+
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   */
+  predicate hasFlow(Node source, Node sink) { hasFlow(source, sink, this) }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   *
+   * The corresponding paths are generated from the end-points and the graph
+   * included in the module `PathGraph`.
+   */
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowTo(Node sink) { hasFlowTo(sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowToExpr(DataFlowExpr sink) { this.hasFlowTo(exprNode(sink)) }
+
+  /**
+   * 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 (for example in a `path-problem` query).
+   */
+  predicate includeHiddenNodes() { none() }
+}
+
+/**
+ * This class exists to prevent mutual recursion between the user-overridden
+ * member predicates of `Configuration` and the rest of the data-flow library.
+ * Good performance cannot be guaranteed in the presence of such recursion, so
+ * it should be replaced by using more than one copy of the data flow library.
+ */
+abstract deprecated private class ConfigurationRecursionPrevention extends Configuration {
+  bindingset[this]
+  ConfigurationRecursionPrevention() { any() }
+
+  override predicate hasFlow(Node source, Node sink) {
+    strictcount(Node n | this.isSource(n)) < 0
+    or
+    strictcount(Node n | this.isSource(n, _)) < 0
+    or
+    strictcount(Node n | this.isSink(n)) < 0
+    or
+    strictcount(Node n | this.isSink(n, _)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, n2)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, _, n2, _)) < 0
+    or
+    super.hasFlow(source, sink)
+  }
+}
+
+deprecated private FlowState relevantState(Configuration config) {
+  config.isSource(_, result) or
+  config.isSink(_, result) or
+  config.isBarrier(_, result) or
+  config.isAdditionalFlowStep(_, result, _, _) or
+  config.isAdditionalFlowStep(_, _, _, result)
+}
+
+private newtype TConfigState =
+  deprecated TMkConfigState(Configuration config, FlowState state) {
+    state = relevantState(config) or state instanceof FlowStateEmpty
+  }
+
+deprecated private Configuration getConfig(TConfigState state) { state = TMkConfigState(result, _) }
+
+deprecated private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
+
+deprecated private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
+deprecated private module Config implements FullStateConfigSig {
+  class FlowState = TConfigState;
+
+  predicate isSource(Node source, FlowState state) {
+    getConfig(state).isSource(source, getState(state))
+    or
+    getConfig(state).isSource(source) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isSink(Node sink) { none() }
+
+  predicate isSink(Node sink, FlowState state) {
+    getConfig(state).isSink(sink, getState(state))
+    or
+    getConfig(state).isSink(sink) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isBarrier(Node node) { none() }
+
+  predicate isBarrier(Node node, FlowState state) {
+    getConfig(state).isBarrier(node, getState(state)) or
+    getConfig(state).isBarrier(node)
+  }
+
+  predicate isBarrierIn(Node node) { any(Configuration config).isBarrierIn(node) }
+
+  predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
+
+  predicate isBarrierIn(Node node, FlowState state) { none() }
+
+  predicate isBarrierOut(Node node, FlowState state) { none() }
+
+  predicate isAdditionalFlowStep(Node node1, Node node2, string model) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2) and
+    model = ""
+  }
+
+  predicate isAdditionalFlowStep(
+    Node node1, FlowState state1, Node node2, FlowState state2, string model
+  ) {
+    getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
+    getConfig(state2) = getConfig(state1) and
+    model = ""
+    or
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1 and
+    model = ""
+  }
+
+  predicate allowImplicitRead(Node node, ContentSet c) {
+    any(Configuration config).allowImplicitRead(node, c)
+  }
+
+  predicate neverSkip(Node node) { none() }
+
+  int fieldFlowBranchLimit() { result = min(any(Configuration config).fieldFlowBranchLimit()) }
+
+  int accessPathLimit() { result = 5 }
+
+  FlowFeature getAFeature() { result = any(Configuration config).getAFeature() }
+
+  predicate includeHiddenNodes() { any(Configuration config).includeHiddenNodes() }
+
+  predicate observeDiffInformedIncrementalMode() { none() }
+}
+
+deprecated private import Impl<Config> as I
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+deprecated class PathNode instanceof I::PathNode {
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { result = super.getNode() }
+
+  /** Gets the `FlowState` of this node. */
+  deprecated final FlowState getState() { result = getState(super.getState()) }
+
+  /** Gets the associated configuration. */
+  deprecated final Configuration getConfiguration() { result = getConfig(super.getState()) }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getASuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { super.isSourceGroup(group) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { super.isSinkGroup(group) }
+}
+
+deprecated module PathGraph = I::PathGraph;
+
+deprecated private predicate hasFlow(Node source, Node sink, Configuration config) {
+  exists(PathNode source0, PathNode sink0 |
+    hasFlowPath(source0, sink0, config) and
+    source0.getNode() = source and
+    sink0.getNode() = sink
+  )
+}
+
+deprecated private predicate hasFlowPath(PathNode source, PathNode sink, Configuration config) {
+  I::flowPath(source, sink) and source.getConfiguration() = config
+}
+
+deprecated private predicate hasFlowTo(Node sink, Configuration config) { hasFlow(_, sink, config) }
+
+deprecated predicate flowsTo = hasFlow/3;
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplLocal.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplLocal.qll
@@ -0,0 +1,361 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * Provides a `Configuration` class backwards-compatible interface to the data
+ * flow library.
+ */
+
+private import DataFlowImplCommon
+private import DataFlowImplSpecific::Private
+import DataFlowImplSpecific::Public
+private import DataFlowImpl
+import DataFlowImplCommonPublic
+deprecated import FlowStateString
+private import codeql.util.Unit
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * A configuration of interprocedural data flow analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the global data flow library must define its own unique extension
+ * of this abstract class. 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 DataFlow::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isBarrier`.
+ *   // Optionally override `isAdditionalFlowStep`.
+ * }
+ * ```
+ * Conceptually, this defines a graph where the nodes are `DataFlow::Node`s and
+ * the edges are those data-flow steps that preserve the value of the node
+ * along with any additional edges defined by `isAdditionalFlowStep`.
+ * Specifying nodes in `isBarrier` will remove those nodes from the graph, and
+ * specifying nodes in `isBarrierIn` and/or `isBarrierOut` will remove in-going
+ * and/or out-going edges from those nodes, respectively.
+ *
+ * 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 two classes extending
+ * `DataFlow::Configuration` should never depend on each other. One of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`.
+ */
+abstract deprecated class Configuration extends string {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant data flow source.
+   */
+  predicate isSource(Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant data flow source with the given initial
+   * `state`.
+   */
+  predicate isSource(Node source, FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink.
+   */
+  predicate isSink(Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink accepting `state`.
+   */
+  predicate isSink(Node sink, FlowState state) { none() }
+
+  /**
+   * Holds if data flow through `node` is prohibited. This completely removes
+   * `node` from the data flow graph.
+   */
+  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) { none() }
+
+  /** Holds if data flow into `node` is prohibited. */
+  predicate isBarrierIn(Node node) { none() }
+
+  /** Holds if data flow out of `node` is prohibited. */
+  predicate isBarrierOut(Node node) { none() }
+
+  /**
+   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
+   */
+  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) {
+    none()
+  }
+
+  /**
+   * Holds if an arbitrary number of implicit read steps of content `c` may be
+   * taken at `node`.
+   */
+  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.
+   */
+  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.
+   */
+  FlowFeature getAFeature() { none() }
+
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   */
+  predicate hasFlow(Node source, Node sink) { hasFlow(source, sink, this) }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   *
+   * The corresponding paths are generated from the end-points and the graph
+   * included in the module `PathGraph`.
+   */
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowTo(Node sink) { hasFlowTo(sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowToExpr(DataFlowExpr sink) { this.hasFlowTo(exprNode(sink)) }
+
+  /**
+   * 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 (for example in a `path-problem` query).
+   */
+  predicate includeHiddenNodes() { none() }
+}
+
+/**
+ * This class exists to prevent mutual recursion between the user-overridden
+ * member predicates of `Configuration` and the rest of the data-flow library.
+ * Good performance cannot be guaranteed in the presence of such recursion, so
+ * it should be replaced by using more than one copy of the data flow library.
+ */
+abstract deprecated private class ConfigurationRecursionPrevention extends Configuration {
+  bindingset[this]
+  ConfigurationRecursionPrevention() { any() }
+
+  override predicate hasFlow(Node source, Node sink) {
+    strictcount(Node n | this.isSource(n)) < 0
+    or
+    strictcount(Node n | this.isSource(n, _)) < 0
+    or
+    strictcount(Node n | this.isSink(n)) < 0
+    or
+    strictcount(Node n | this.isSink(n, _)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, n2)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, _, n2, _)) < 0
+    or
+    super.hasFlow(source, sink)
+  }
+}
+
+deprecated private FlowState relevantState(Configuration config) {
+  config.isSource(_, result) or
+  config.isSink(_, result) or
+  config.isBarrier(_, result) or
+  config.isAdditionalFlowStep(_, result, _, _) or
+  config.isAdditionalFlowStep(_, _, _, result)
+}
+
+private newtype TConfigState =
+  deprecated TMkConfigState(Configuration config, FlowState state) {
+    state = relevantState(config) or state instanceof FlowStateEmpty
+  }
+
+deprecated private Configuration getConfig(TConfigState state) { state = TMkConfigState(result, _) }
+
+deprecated private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
+
+deprecated private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
+deprecated private module Config implements FullStateConfigSig {
+  class FlowState = TConfigState;
+
+  predicate isSource(Node source, FlowState state) {
+    getConfig(state).isSource(source, getState(state))
+    or
+    getConfig(state).isSource(source) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isSink(Node sink) { none() }
+
+  predicate isSink(Node sink, FlowState state) {
+    getConfig(state).isSink(sink, getState(state))
+    or
+    getConfig(state).isSink(sink) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isBarrier(Node node) { none() }
+
+  predicate isBarrier(Node node, FlowState state) {
+    getConfig(state).isBarrier(node, getState(state)) or
+    getConfig(state).isBarrier(node)
+  }
+
+  predicate isBarrierIn(Node node) { any(Configuration config).isBarrierIn(node) }
+
+  predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
+
+  predicate isBarrierIn(Node node, FlowState state) { none() }
+
+  predicate isBarrierOut(Node node, FlowState state) { none() }
+
+  predicate isAdditionalFlowStep(Node node1, Node node2, string model) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2) and
+    model = ""
+  }
+
+  predicate isAdditionalFlowStep(
+    Node node1, FlowState state1, Node node2, FlowState state2, string model
+  ) {
+    getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
+    getConfig(state2) = getConfig(state1) and
+    model = ""
+    or
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1 and
+    model = ""
+  }
+
+  predicate allowImplicitRead(Node node, ContentSet c) {
+    any(Configuration config).allowImplicitRead(node, c)
+  }
+
+  predicate neverSkip(Node node) { none() }
+
+  int fieldFlowBranchLimit() { result = min(any(Configuration config).fieldFlowBranchLimit()) }
+
+  int accessPathLimit() { result = 5 }
+
+  FlowFeature getAFeature() { result = any(Configuration config).getAFeature() }
+
+  predicate includeHiddenNodes() { any(Configuration config).includeHiddenNodes() }
+
+  predicate observeDiffInformedIncrementalMode() { none() }
+}
+
+deprecated private import Impl<Config> as I
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+deprecated class PathNode instanceof I::PathNode {
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { result = super.getNode() }
+
+  /** Gets the `FlowState` of this node. */
+  deprecated final FlowState getState() { result = getState(super.getState()) }
+
+  /** Gets the associated configuration. */
+  deprecated final Configuration getConfiguration() { result = getConfig(super.getState()) }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getASuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { super.isSourceGroup(group) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { super.isSinkGroup(group) }
+}
+
+deprecated module PathGraph = I::PathGraph;
+
+deprecated private predicate hasFlow(Node source, Node sink, Configuration config) {
+  exists(PathNode source0, PathNode sink0 |
+    hasFlowPath(source0, sink0, config) and
+    source0.getNode() = source and
+    sink0.getNode() = sink
+  )
+}
+
+deprecated private predicate hasFlowPath(PathNode source, PathNode sink, Configuration config) {
+  I::flowPath(source, sink) and source.getConfiguration() = config
+}
+
+deprecated private predicate hasFlowTo(Node sink, Configuration config) { hasFlow(_, sink, config) }
+
+deprecated predicate flowsTo = hasFlow/3;
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowUtil.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowUtil.qll
@@ -729,39 +729,41 @@ private predicate exprToDefinitionByReferenceStep(Expr exprIn, Expr argOut) {

 private module FieldFlow {
  private import DataFlowImplCommon
+  private import DataFlowImplLocal
  private import DataFlowPrivate
-  private import semmle.code.cpp.dataflow.DataFlow

  /**
-   * A configuration for finding local-only flow through fields.
+   * A configuration for finding local-only flow through fields. This uses the
+   * `Configuration` class in the dedicated `DataFlowImplLocal` copy of the
+   * shared library that's not user-exposed directly.
   *
   * To keep the flow local to a single function, we put barriers on parameters
   * and return statements. Sources and sinks are the values that go into and
   * out of fields, respectively.
   */
-  private module FieldConfig implements DataFlow::ConfigSig {
-    predicate isSource(Node source) {
+  private class FieldConfiguration extends Configuration {
+    FieldConfiguration() { this = "FieldConfiguration" }
+
+    override predicate isSource(Node source) {
      storeStep(source, _, _)
      or
      // Also mark `foo(a.b);` as a source when `a.b` may be overwritten by `foo`.
      readStep(_, _, any(Node node | node.asExpr() = source.asDefiningArgument()))
    }

-    predicate isSink(Node sink) { readStep(_, _, sink) }
+    override predicate isSink(Node sink) { readStep(_, _, sink) }

-    predicate isBarrier(Node node) { node instanceof ParameterNode }
+    override predicate isBarrier(Node node) { node instanceof ParameterNode }

-    predicate isBarrierOut(Node node) {
+    override predicate isBarrierOut(Node node) {
      node.asExpr().getParent() instanceof ReturnStmt
      or
      node.asExpr().getParent() instanceof ThrowExpr
    }
  }

-  private module Flow = DataFlow::Global<FieldConfig>;
-
  predicate fieldFlow(Node node1, Node node2) {
-    Flow::flow(node1, node2) and
+    exists(FieldConfiguration cfg | cfg.hasFlow(node1, node2)) and
    // This configuration should not be able to cross function boundaries, but
    // we double-check here just to be sure.
    getNodeEnclosingCallable(node1) = getNodeEnclosingCallable(node2)
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking1/TaintTrackingImpl.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking1/TaintTrackingImpl.qll
@@ -0,0 +1,168 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * 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
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * 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 deprecated 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) }
+
+  /**
+   * 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)
+  }
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking1/TaintTrackingParameter.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking1/TaintTrackingParameter.qll
@@ -0,0 +1,10 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ */
+
+import semmle.code.cpp.dataflow.internal.TaintTrackingUtil as Public
+
+module Private {
+  import semmle.code.cpp.dataflow.DataFlow::DataFlow as DataFlow
+  import semmle.code.cpp.dataflow.internal.DataFlowImpl as DataFlowInternal
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking2/TaintTrackingImpl.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking2/TaintTrackingImpl.qll
@@ -0,0 +1,168 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * 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
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * 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 deprecated 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) }
+
+  /**
+   * 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)
+  }
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking2/TaintTrackingParameter.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/internal/tainttracking2/TaintTrackingParameter.qll
@@ -0,0 +1,9 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ */
+
+import semmle.code.cpp.dataflow.internal.TaintTrackingUtil as Public
+
+module Private {
+  import semmle.code.cpp.dataflow.DataFlow2::DataFlow2 as DataFlow
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/new/DataFlow.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/new/DataFlow.qll
@@ -29,5 +29,5 @@ module DataFlow {
  private import semmle.code.cpp.ir.dataflow.internal.DataFlowImplSpecific
  private import codeql.dataflow.DataFlow
  import DataFlowMake<Location, CppDataFlow>
-  import Public
+  import semmle.code.cpp.ir.dataflow.internal.DataFlowImpl1
 }
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/new/DataFlow2.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/new/DataFlow2.qll
@@ -0,0 +1,20 @@
+/**
+ * Provides a `DataFlow2` module, which is a copy of the `DataFlow` module. Use
+ * this class when data-flow configurations must depend on each other. Two
+ * classes extending `DataFlow::Configuration` should never depend on each
+ * other, but one of them should instead depend on a
+ * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
+ * `DataFlow4::Configuration`.
+ *
+ * See `semmle.code.cpp.dataflow.new.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
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/new/DataFlow3.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/new/DataFlow3.qll
@@ -0,0 +1,20 @@
+/**
+ * Provides a `DataFlow3` module, which is a copy of the `DataFlow` module. Use
+ * this class when data-flow configurations must depend on each other. Two
+ * classes extending `DataFlow::Configuration` should never depend on each
+ * other, but one of them should instead depend on a
+ * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
+ * `DataFlow4::Configuration`.
+ *
+ * See `semmle.code.cpp.dataflow.new.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
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/new/DataFlow4.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/new/DataFlow4.qll
@@ -0,0 +1,20 @@
+/**
+ * Provides a `DataFlow4` module, which is a copy of the `DataFlow` module. Use
+ * this class when data-flow configurations must depend on each other. Two
+ * classes extending `DataFlow::Configuration` should never depend on each
+ * other, but one of them should instead depend on a
+ * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
+ * `DataFlow4::Configuration`.
+ *
+ * See `semmle.code.cpp.dataflow.new.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
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/new/TaintTracking.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/new/TaintTracking.qll
@@ -16,16 +16,18 @@
 */

 import semmle.code.cpp.dataflow.new.DataFlow
+import semmle.code.cpp.dataflow.new.DataFlow2

 /**
 * Provides classes for performing local (intra-procedural) and
 * global (inter-procedural) taint-tracking analyses.
 */
 module TaintTracking {
-  import semmle.code.cpp.ir.dataflow.internal.TaintTrackingUtil
+  import semmle.code.cpp.ir.dataflow.internal.tainttracking1.TaintTrackingParameter::Public
  private import semmle.code.cpp.ir.dataflow.internal.DataFlowImplSpecific
  private import semmle.code.cpp.ir.dataflow.internal.TaintTrackingImplSpecific
  private import codeql.dataflow.TaintTracking
  private import semmle.code.cpp.Location
  import TaintFlowMake<Location, CppDataFlow, CppTaintTracking>
+  import semmle.code.cpp.ir.dataflow.internal.tainttracking1.TaintTrackingImpl
 }
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/new/TaintTracking2.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/new/TaintTracking2.qll
@@ -0,0 +1,20 @@
+/**
+ * Provides a `TaintTracking2` module, which is a copy of the `TaintTracking`
+ * module. Use this class when data-flow configurations or taint-tracking
+ * configurations must depend on each other. Two classes extending
+ * `DataFlow::Configuration` should never depend on each other, but one of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`. The
+ * `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.
+ */
+module TaintTracking2 {
+  import semmle.code.cpp.ir.dataflow.internal.tainttracking2.TaintTrackingImpl
+}
--- a/cpp/ql/lib/semmle/code/cpp/dataflow/new/TaintTracking3.qll
+++ b/cpp/ql/lib/semmle/code/cpp/dataflow/new/TaintTracking3.qll
@@ -0,0 +1,20 @@
+/**
+ * Provides a `TaintTracking3` module, which is a copy of the `TaintTracking`
+ * module. Use this class when data-flow configurations or taint-tracking
+ * configurations must depend on each other. Two classes extending
+ * `DataFlow::Configuration` should never depend on each other, but one of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`. The
+ * `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.
+ */
+module TaintTracking3 {
+  import semmle.code.cpp.ir.dataflow.internal.tainttracking3.TaintTrackingImpl
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/DataFlow.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/DataFlow.qll
@@ -25,5 +25,5 @@ module DataFlow {
  private import semmle.code.cpp.ir.dataflow.internal.DataFlowImplSpecific
  private import codeql.dataflow.DataFlow
  import DataFlowMake<Location, CppDataFlow>
-  import Public
+  import semmle.code.cpp.ir.dataflow.internal.DataFlowImpl1
 }
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/DataFlow2.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/DataFlow2.qll
@@ -0,0 +1,16 @@
+/**
+ * Provides a `DataFlow2` module, which is a copy of the `DataFlow` module. Use
+ * this class when data-flow configurations must depend on each other. Two
+ * classes extending `DataFlow::Configuration` should never depend on each
+ * other, but one of them should instead depend on a
+ * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
+ * `DataFlow4::Configuration`.
+ *
+ * See `semmle.code.cpp.ir.dataflow.DataFlow` for the full documentation.
+ */
+
+import cpp
+
+module DataFlow2 {
+  import semmle.code.cpp.ir.dataflow.internal.DataFlowImpl2
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/DataFlow3.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/DataFlow3.qll
@@ -0,0 +1,16 @@
+/**
+ * Provides a `DataFlow3` module, which is a copy of the `DataFlow` module. Use
+ * this class when data-flow configurations must depend on each other. Two
+ * classes extending `DataFlow::Configuration` should never depend on each
+ * other, but one of them should instead depend on a
+ * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
+ * `DataFlow4::Configuration`.
+ *
+ * See `semmle.code.cpp.ir.dataflow.DataFlow` for the full documentation.
+ */
+
+import cpp
+
+module DataFlow3 {
+  import semmle.code.cpp.ir.dataflow.internal.DataFlowImpl3
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/DataFlow4.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/DataFlow4.qll
@@ -0,0 +1,16 @@
+/**
+ * Provides a `DataFlow4` module, which is a copy of the `DataFlow` module. Use
+ * this class when data-flow configurations must depend on each other. Two
+ * classes extending `DataFlow::Configuration` should never depend on each
+ * other, but one of them should instead depend on a
+ * `DataFlow2::Configuration`, a `DataFlow3::Configuration`, or a
+ * `DataFlow4::Configuration`.
+ *
+ * See `semmle.code.cpp.ir.dataflow.DataFlow` for the full documentation.
+ */
+
+import cpp
+
+module DataFlow4 {
+  import semmle.code.cpp.ir.dataflow.internal.DataFlowImpl4
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/TaintTracking.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/TaintTracking.qll
@@ -16,11 +16,13 @@
 */

 import semmle.code.cpp.ir.dataflow.DataFlow
+import semmle.code.cpp.ir.dataflow.DataFlow2

 module TaintTracking {
-  import semmle.code.cpp.ir.dataflow.internal.TaintTrackingUtil
+  import semmle.code.cpp.ir.dataflow.internal.tainttracking1.TaintTrackingParameter::Public
  private import semmle.code.cpp.ir.dataflow.internal.DataFlowImplSpecific
  private import semmle.code.cpp.ir.dataflow.internal.TaintTrackingImplSpecific
  private import codeql.dataflow.TaintTracking
  import TaintFlowMake<Location, CppDataFlow, CppTaintTracking>
+  import semmle.code.cpp.ir.dataflow.internal.tainttracking1.TaintTrackingImpl
 }
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/TaintTracking2.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/TaintTracking2.qll
@@ -0,0 +1,15 @@
+/**
+ * Provides a `TaintTracking2` module, which is a copy of the `TaintTracking`
+ * module. Use this class when data-flow configurations or taint-tracking
+ * configurations must depend on each other. Two classes extending
+ * `DataFlow::Configuration` should never depend on each other, but one of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`. The
+ * `TaintTracking::Configuration` class extends `DataFlow::Configuration`, and
+ * `TaintTracking2::Configuration` extends `DataFlow2::Configuration`.
+ *
+ * See `semmle.code.cpp.ir.dataflow.TaintTracking` for the full documentation.
+ */
+module TaintTracking2 {
+  import semmle.code.cpp.ir.dataflow.internal.tainttracking2.TaintTrackingImpl
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/TaintTracking3.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/TaintTracking3.qll
@@ -0,0 +1,15 @@
+/**
+ * Provides a `TaintTracking3` module, which is a copy of the `TaintTracking`
+ * module. Use this class when data-flow configurations or taint-tracking
+ * configurations must depend on each other. Two classes extending
+ * `DataFlow::Configuration` should never depend on each other, but one of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`. The
+ * `TaintTracking::Configuration` class extends `DataFlow::Configuration`, and
+ * `TaintTracking2::Configuration` extends `DataFlow2::Configuration`.
+ *
+ * See `semmle.code.cpp.ir.dataflow.TaintTracking` for the full documentation.
+ */
+module TaintTracking3 {
+  import semmle.code.cpp.ir.dataflow.internal.tainttracking3.TaintTrackingImpl
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl1.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl1.qll
@@ -0,0 +1,361 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * Provides a `Configuration` class backwards-compatible interface to the data
+ * flow library.
+ */
+
+private import DataFlowImplCommon
+private import DataFlowImplSpecific::Private
+import DataFlowImplSpecific::Public
+private import DataFlowImpl
+import DataFlowImplCommonPublic
+deprecated import FlowStateString
+private import codeql.util.Unit
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * A configuration of interprocedural data flow analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the global data flow library must define its own unique extension
+ * of this abstract class. 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 DataFlow::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isBarrier`.
+ *   // Optionally override `isAdditionalFlowStep`.
+ * }
+ * ```
+ * Conceptually, this defines a graph where the nodes are `DataFlow::Node`s and
+ * the edges are those data-flow steps that preserve the value of the node
+ * along with any additional edges defined by `isAdditionalFlowStep`.
+ * Specifying nodes in `isBarrier` will remove those nodes from the graph, and
+ * specifying nodes in `isBarrierIn` and/or `isBarrierOut` will remove in-going
+ * and/or out-going edges from those nodes, respectively.
+ *
+ * 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 two classes extending
+ * `DataFlow::Configuration` should never depend on each other. One of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`.
+ */
+abstract deprecated class Configuration extends string {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant data flow source.
+   */
+  predicate isSource(Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant data flow source with the given initial
+   * `state`.
+   */
+  predicate isSource(Node source, FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink.
+   */
+  predicate isSink(Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink accepting `state`.
+   */
+  predicate isSink(Node sink, FlowState state) { none() }
+
+  /**
+   * Holds if data flow through `node` is prohibited. This completely removes
+   * `node` from the data flow graph.
+   */
+  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) { none() }
+
+  /** Holds if data flow into `node` is prohibited. */
+  predicate isBarrierIn(Node node) { none() }
+
+  /** Holds if data flow out of `node` is prohibited. */
+  predicate isBarrierOut(Node node) { none() }
+
+  /**
+   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
+   */
+  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) {
+    none()
+  }
+
+  /**
+   * Holds if an arbitrary number of implicit read steps of content `c` may be
+   * taken at `node`.
+   */
+  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.
+   */
+  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.
+   */
+  FlowFeature getAFeature() { none() }
+
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   */
+  predicate hasFlow(Node source, Node sink) { hasFlow(source, sink, this) }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   *
+   * The corresponding paths are generated from the end-points and the graph
+   * included in the module `PathGraph`.
+   */
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowTo(Node sink) { hasFlowTo(sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowToExpr(DataFlowExpr sink) { this.hasFlowTo(exprNode(sink)) }
+
+  /**
+   * 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 (for example in a `path-problem` query).
+   */
+  predicate includeHiddenNodes() { none() }
+}
+
+/**
+ * This class exists to prevent mutual recursion between the user-overridden
+ * member predicates of `Configuration` and the rest of the data-flow library.
+ * Good performance cannot be guaranteed in the presence of such recursion, so
+ * it should be replaced by using more than one copy of the data flow library.
+ */
+abstract deprecated private class ConfigurationRecursionPrevention extends Configuration {
+  bindingset[this]
+  ConfigurationRecursionPrevention() { any() }
+
+  override predicate hasFlow(Node source, Node sink) {
+    strictcount(Node n | this.isSource(n)) < 0
+    or
+    strictcount(Node n | this.isSource(n, _)) < 0
+    or
+    strictcount(Node n | this.isSink(n)) < 0
+    or
+    strictcount(Node n | this.isSink(n, _)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, n2)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, _, n2, _)) < 0
+    or
+    super.hasFlow(source, sink)
+  }
+}
+
+deprecated private FlowState relevantState(Configuration config) {
+  config.isSource(_, result) or
+  config.isSink(_, result) or
+  config.isBarrier(_, result) or
+  config.isAdditionalFlowStep(_, result, _, _) or
+  config.isAdditionalFlowStep(_, _, _, result)
+}
+
+private newtype TConfigState =
+  deprecated TMkConfigState(Configuration config, FlowState state) {
+    state = relevantState(config) or state instanceof FlowStateEmpty
+  }
+
+deprecated private Configuration getConfig(TConfigState state) { state = TMkConfigState(result, _) }
+
+deprecated private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
+
+deprecated private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
+deprecated private module Config implements FullStateConfigSig {
+  class FlowState = TConfigState;
+
+  predicate isSource(Node source, FlowState state) {
+    getConfig(state).isSource(source, getState(state))
+    or
+    getConfig(state).isSource(source) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isSink(Node sink) { none() }
+
+  predicate isSink(Node sink, FlowState state) {
+    getConfig(state).isSink(sink, getState(state))
+    or
+    getConfig(state).isSink(sink) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isBarrier(Node node) { none() }
+
+  predicate isBarrier(Node node, FlowState state) {
+    getConfig(state).isBarrier(node, getState(state)) or
+    getConfig(state).isBarrier(node)
+  }
+
+  predicate isBarrierIn(Node node) { any(Configuration config).isBarrierIn(node) }
+
+  predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
+
+  predicate isBarrierIn(Node node, FlowState state) { none() }
+
+  predicate isBarrierOut(Node node, FlowState state) { none() }
+
+  predicate isAdditionalFlowStep(Node node1, Node node2, string model) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2) and
+    model = ""
+  }
+
+  predicate isAdditionalFlowStep(
+    Node node1, FlowState state1, Node node2, FlowState state2, string model
+  ) {
+    getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
+    getConfig(state2) = getConfig(state1) and
+    model = ""
+    or
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1 and
+    model = ""
+  }
+
+  predicate allowImplicitRead(Node node, ContentSet c) {
+    any(Configuration config).allowImplicitRead(node, c)
+  }
+
+  predicate neverSkip(Node node) { none() }
+
+  int fieldFlowBranchLimit() { result = min(any(Configuration config).fieldFlowBranchLimit()) }
+
+  int accessPathLimit() { result = 5 }
+
+  FlowFeature getAFeature() { result = any(Configuration config).getAFeature() }
+
+  predicate includeHiddenNodes() { any(Configuration config).includeHiddenNodes() }
+
+  predicate observeDiffInformedIncrementalMode() { none() }
+}
+
+deprecated private import Impl<Config> as I
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+deprecated class PathNode instanceof I::PathNode {
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { result = super.getNode() }
+
+  /** Gets the `FlowState` of this node. */
+  deprecated final FlowState getState() { result = getState(super.getState()) }
+
+  /** Gets the associated configuration. */
+  deprecated final Configuration getConfiguration() { result = getConfig(super.getState()) }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getASuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { super.isSourceGroup(group) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { super.isSinkGroup(group) }
+}
+
+deprecated module PathGraph = I::PathGraph;
+
+deprecated private predicate hasFlow(Node source, Node sink, Configuration config) {
+  exists(PathNode source0, PathNode sink0 |
+    hasFlowPath(source0, sink0, config) and
+    source0.getNode() = source and
+    sink0.getNode() = sink
+  )
+}
+
+deprecated private predicate hasFlowPath(PathNode source, PathNode sink, Configuration config) {
+  I::flowPath(source, sink) and source.getConfiguration() = config
+}
+
+deprecated private predicate hasFlowTo(Node sink, Configuration config) { hasFlow(_, sink, config) }
+
+deprecated predicate flowsTo = hasFlow/3;
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll
@@ -0,0 +1,361 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * Provides a `Configuration` class backwards-compatible interface to the data
+ * flow library.
+ */
+
+private import DataFlowImplCommon
+private import DataFlowImplSpecific::Private
+import DataFlowImplSpecific::Public
+private import DataFlowImpl
+import DataFlowImplCommonPublic
+deprecated import FlowStateString
+private import codeql.util.Unit
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * A configuration of interprocedural data flow analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the global data flow library must define its own unique extension
+ * of this abstract class. 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 DataFlow::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isBarrier`.
+ *   // Optionally override `isAdditionalFlowStep`.
+ * }
+ * ```
+ * Conceptually, this defines a graph where the nodes are `DataFlow::Node`s and
+ * the edges are those data-flow steps that preserve the value of the node
+ * along with any additional edges defined by `isAdditionalFlowStep`.
+ * Specifying nodes in `isBarrier` will remove those nodes from the graph, and
+ * specifying nodes in `isBarrierIn` and/or `isBarrierOut` will remove in-going
+ * and/or out-going edges from those nodes, respectively.
+ *
+ * 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 two classes extending
+ * `DataFlow::Configuration` should never depend on each other. One of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`.
+ */
+abstract deprecated class Configuration extends string {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant data flow source.
+   */
+  predicate isSource(Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant data flow source with the given initial
+   * `state`.
+   */
+  predicate isSource(Node source, FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink.
+   */
+  predicate isSink(Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink accepting `state`.
+   */
+  predicate isSink(Node sink, FlowState state) { none() }
+
+  /**
+   * Holds if data flow through `node` is prohibited. This completely removes
+   * `node` from the data flow graph.
+   */
+  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) { none() }
+
+  /** Holds if data flow into `node` is prohibited. */
+  predicate isBarrierIn(Node node) { none() }
+
+  /** Holds if data flow out of `node` is prohibited. */
+  predicate isBarrierOut(Node node) { none() }
+
+  /**
+   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
+   */
+  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) {
+    none()
+  }
+
+  /**
+   * Holds if an arbitrary number of implicit read steps of content `c` may be
+   * taken at `node`.
+   */
+  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.
+   */
+  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.
+   */
+  FlowFeature getAFeature() { none() }
+
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   */
+  predicate hasFlow(Node source, Node sink) { hasFlow(source, sink, this) }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   *
+   * The corresponding paths are generated from the end-points and the graph
+   * included in the module `PathGraph`.
+   */
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowTo(Node sink) { hasFlowTo(sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowToExpr(DataFlowExpr sink) { this.hasFlowTo(exprNode(sink)) }
+
+  /**
+   * 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 (for example in a `path-problem` query).
+   */
+  predicate includeHiddenNodes() { none() }
+}
+
+/**
+ * This class exists to prevent mutual recursion between the user-overridden
+ * member predicates of `Configuration` and the rest of the data-flow library.
+ * Good performance cannot be guaranteed in the presence of such recursion, so
+ * it should be replaced by using more than one copy of the data flow library.
+ */
+abstract deprecated private class ConfigurationRecursionPrevention extends Configuration {
+  bindingset[this]
+  ConfigurationRecursionPrevention() { any() }
+
+  override predicate hasFlow(Node source, Node sink) {
+    strictcount(Node n | this.isSource(n)) < 0
+    or
+    strictcount(Node n | this.isSource(n, _)) < 0
+    or
+    strictcount(Node n | this.isSink(n)) < 0
+    or
+    strictcount(Node n | this.isSink(n, _)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, n2)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, _, n2, _)) < 0
+    or
+    super.hasFlow(source, sink)
+  }
+}
+
+deprecated private FlowState relevantState(Configuration config) {
+  config.isSource(_, result) or
+  config.isSink(_, result) or
+  config.isBarrier(_, result) or
+  config.isAdditionalFlowStep(_, result, _, _) or
+  config.isAdditionalFlowStep(_, _, _, result)
+}
+
+private newtype TConfigState =
+  deprecated TMkConfigState(Configuration config, FlowState state) {
+    state = relevantState(config) or state instanceof FlowStateEmpty
+  }
+
+deprecated private Configuration getConfig(TConfigState state) { state = TMkConfigState(result, _) }
+
+deprecated private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
+
+deprecated private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
+deprecated private module Config implements FullStateConfigSig {
+  class FlowState = TConfigState;
+
+  predicate isSource(Node source, FlowState state) {
+    getConfig(state).isSource(source, getState(state))
+    or
+    getConfig(state).isSource(source) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isSink(Node sink) { none() }
+
+  predicate isSink(Node sink, FlowState state) {
+    getConfig(state).isSink(sink, getState(state))
+    or
+    getConfig(state).isSink(sink) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isBarrier(Node node) { none() }
+
+  predicate isBarrier(Node node, FlowState state) {
+    getConfig(state).isBarrier(node, getState(state)) or
+    getConfig(state).isBarrier(node)
+  }
+
+  predicate isBarrierIn(Node node) { any(Configuration config).isBarrierIn(node) }
+
+  predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
+
+  predicate isBarrierIn(Node node, FlowState state) { none() }
+
+  predicate isBarrierOut(Node node, FlowState state) { none() }
+
+  predicate isAdditionalFlowStep(Node node1, Node node2, string model) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2) and
+    model = ""
+  }
+
+  predicate isAdditionalFlowStep(
+    Node node1, FlowState state1, Node node2, FlowState state2, string model
+  ) {
+    getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
+    getConfig(state2) = getConfig(state1) and
+    model = ""
+    or
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1 and
+    model = ""
+  }
+
+  predicate allowImplicitRead(Node node, ContentSet c) {
+    any(Configuration config).allowImplicitRead(node, c)
+  }
+
+  predicate neverSkip(Node node) { none() }
+
+  int fieldFlowBranchLimit() { result = min(any(Configuration config).fieldFlowBranchLimit()) }
+
+  int accessPathLimit() { result = 5 }
+
+  FlowFeature getAFeature() { result = any(Configuration config).getAFeature() }
+
+  predicate includeHiddenNodes() { any(Configuration config).includeHiddenNodes() }
+
+  predicate observeDiffInformedIncrementalMode() { none() }
+}
+
+deprecated private import Impl<Config> as I
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+deprecated class PathNode instanceof I::PathNode {
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { result = super.getNode() }
+
+  /** Gets the `FlowState` of this node. */
+  deprecated final FlowState getState() { result = getState(super.getState()) }
+
+  /** Gets the associated configuration. */
+  deprecated final Configuration getConfiguration() { result = getConfig(super.getState()) }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getASuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { super.isSourceGroup(group) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { super.isSinkGroup(group) }
+}
+
+deprecated module PathGraph = I::PathGraph;
+
+deprecated private predicate hasFlow(Node source, Node sink, Configuration config) {
+  exists(PathNode source0, PathNode sink0 |
+    hasFlowPath(source0, sink0, config) and
+    source0.getNode() = source and
+    sink0.getNode() = sink
+  )
+}
+
+deprecated private predicate hasFlowPath(PathNode source, PathNode sink, Configuration config) {
+  I::flowPath(source, sink) and source.getConfiguration() = config
+}
+
+deprecated private predicate hasFlowTo(Node sink, Configuration config) { hasFlow(_, sink, config) }
+
+deprecated predicate flowsTo = hasFlow/3;
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll
@@ -0,0 +1,361 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * Provides a `Configuration` class backwards-compatible interface to the data
+ * flow library.
+ */
+
+private import DataFlowImplCommon
+private import DataFlowImplSpecific::Private
+import DataFlowImplSpecific::Public
+private import DataFlowImpl
+import DataFlowImplCommonPublic
+deprecated import FlowStateString
+private import codeql.util.Unit
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * A configuration of interprocedural data flow analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the global data flow library must define its own unique extension
+ * of this abstract class. 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 DataFlow::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isBarrier`.
+ *   // Optionally override `isAdditionalFlowStep`.
+ * }
+ * ```
+ * Conceptually, this defines a graph where the nodes are `DataFlow::Node`s and
+ * the edges are those data-flow steps that preserve the value of the node
+ * along with any additional edges defined by `isAdditionalFlowStep`.
+ * Specifying nodes in `isBarrier` will remove those nodes from the graph, and
+ * specifying nodes in `isBarrierIn` and/or `isBarrierOut` will remove in-going
+ * and/or out-going edges from those nodes, respectively.
+ *
+ * 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 two classes extending
+ * `DataFlow::Configuration` should never depend on each other. One of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`.
+ */
+abstract deprecated class Configuration extends string {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant data flow source.
+   */
+  predicate isSource(Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant data flow source with the given initial
+   * `state`.
+   */
+  predicate isSource(Node source, FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink.
+   */
+  predicate isSink(Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink accepting `state`.
+   */
+  predicate isSink(Node sink, FlowState state) { none() }
+
+  /**
+   * Holds if data flow through `node` is prohibited. This completely removes
+   * `node` from the data flow graph.
+   */
+  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) { none() }
+
+  /** Holds if data flow into `node` is prohibited. */
+  predicate isBarrierIn(Node node) { none() }
+
+  /** Holds if data flow out of `node` is prohibited. */
+  predicate isBarrierOut(Node node) { none() }
+
+  /**
+   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
+   */
+  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) {
+    none()
+  }
+
+  /**
+   * Holds if an arbitrary number of implicit read steps of content `c` may be
+   * taken at `node`.
+   */
+  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.
+   */
+  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.
+   */
+  FlowFeature getAFeature() { none() }
+
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   */
+  predicate hasFlow(Node source, Node sink) { hasFlow(source, sink, this) }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   *
+   * The corresponding paths are generated from the end-points and the graph
+   * included in the module `PathGraph`.
+   */
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowTo(Node sink) { hasFlowTo(sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowToExpr(DataFlowExpr sink) { this.hasFlowTo(exprNode(sink)) }
+
+  /**
+   * 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 (for example in a `path-problem` query).
+   */
+  predicate includeHiddenNodes() { none() }
+}
+
+/**
+ * This class exists to prevent mutual recursion between the user-overridden
+ * member predicates of `Configuration` and the rest of the data-flow library.
+ * Good performance cannot be guaranteed in the presence of such recursion, so
+ * it should be replaced by using more than one copy of the data flow library.
+ */
+abstract deprecated private class ConfigurationRecursionPrevention extends Configuration {
+  bindingset[this]
+  ConfigurationRecursionPrevention() { any() }
+
+  override predicate hasFlow(Node source, Node sink) {
+    strictcount(Node n | this.isSource(n)) < 0
+    or
+    strictcount(Node n | this.isSource(n, _)) < 0
+    or
+    strictcount(Node n | this.isSink(n)) < 0
+    or
+    strictcount(Node n | this.isSink(n, _)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, n2)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, _, n2, _)) < 0
+    or
+    super.hasFlow(source, sink)
+  }
+}
+
+deprecated private FlowState relevantState(Configuration config) {
+  config.isSource(_, result) or
+  config.isSink(_, result) or
+  config.isBarrier(_, result) or
+  config.isAdditionalFlowStep(_, result, _, _) or
+  config.isAdditionalFlowStep(_, _, _, result)
+}
+
+private newtype TConfigState =
+  deprecated TMkConfigState(Configuration config, FlowState state) {
+    state = relevantState(config) or state instanceof FlowStateEmpty
+  }
+
+deprecated private Configuration getConfig(TConfigState state) { state = TMkConfigState(result, _) }
+
+deprecated private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
+
+deprecated private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
+deprecated private module Config implements FullStateConfigSig {
+  class FlowState = TConfigState;
+
+  predicate isSource(Node source, FlowState state) {
+    getConfig(state).isSource(source, getState(state))
+    or
+    getConfig(state).isSource(source) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isSink(Node sink) { none() }
+
+  predicate isSink(Node sink, FlowState state) {
+    getConfig(state).isSink(sink, getState(state))
+    or
+    getConfig(state).isSink(sink) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isBarrier(Node node) { none() }
+
+  predicate isBarrier(Node node, FlowState state) {
+    getConfig(state).isBarrier(node, getState(state)) or
+    getConfig(state).isBarrier(node)
+  }
+
+  predicate isBarrierIn(Node node) { any(Configuration config).isBarrierIn(node) }
+
+  predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
+
+  predicate isBarrierIn(Node node, FlowState state) { none() }
+
+  predicate isBarrierOut(Node node, FlowState state) { none() }
+
+  predicate isAdditionalFlowStep(Node node1, Node node2, string model) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2) and
+    model = ""
+  }
+
+  predicate isAdditionalFlowStep(
+    Node node1, FlowState state1, Node node2, FlowState state2, string model
+  ) {
+    getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
+    getConfig(state2) = getConfig(state1) and
+    model = ""
+    or
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1 and
+    model = ""
+  }
+
+  predicate allowImplicitRead(Node node, ContentSet c) {
+    any(Configuration config).allowImplicitRead(node, c)
+  }
+
+  predicate neverSkip(Node node) { none() }
+
+  int fieldFlowBranchLimit() { result = min(any(Configuration config).fieldFlowBranchLimit()) }
+
+  int accessPathLimit() { result = 5 }
+
+  FlowFeature getAFeature() { result = any(Configuration config).getAFeature() }
+
+  predicate includeHiddenNodes() { any(Configuration config).includeHiddenNodes() }
+
+  predicate observeDiffInformedIncrementalMode() { none() }
+}
+
+deprecated private import Impl<Config> as I
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+deprecated class PathNode instanceof I::PathNode {
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { result = super.getNode() }
+
+  /** Gets the `FlowState` of this node. */
+  deprecated final FlowState getState() { result = getState(super.getState()) }
+
+  /** Gets the associated configuration. */
+  deprecated final Configuration getConfiguration() { result = getConfig(super.getState()) }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getASuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { super.isSourceGroup(group) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { super.isSinkGroup(group) }
+}
+
+deprecated module PathGraph = I::PathGraph;
+
+deprecated private predicate hasFlow(Node source, Node sink, Configuration config) {
+  exists(PathNode source0, PathNode sink0 |
+    hasFlowPath(source0, sink0, config) and
+    source0.getNode() = source and
+    sink0.getNode() = sink
+  )
+}
+
+deprecated private predicate hasFlowPath(PathNode source, PathNode sink, Configuration config) {
+  I::flowPath(source, sink) and source.getConfiguration() = config
+}
+
+deprecated private predicate hasFlowTo(Node sink, Configuration config) { hasFlow(_, sink, config) }
+
+deprecated predicate flowsTo = hasFlow/3;
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll
@@ -0,0 +1,361 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * Provides a `Configuration` class backwards-compatible interface to the data
+ * flow library.
+ */
+
+private import DataFlowImplCommon
+private import DataFlowImplSpecific::Private
+import DataFlowImplSpecific::Public
+private import DataFlowImpl
+import DataFlowImplCommonPublic
+deprecated import FlowStateString
+private import codeql.util.Unit
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * A configuration of interprocedural data flow analysis. This defines
+ * sources, sinks, and any other configurable aspect of the analysis. Each
+ * use of the global data flow library must define its own unique extension
+ * of this abstract class. 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 DataFlow::Configuration {
+ *   MyAnalysisConfiguration() { this = "MyAnalysisConfiguration" }
+ *   // Override `isSource` and `isSink`.
+ *   // Optionally override `isBarrier`.
+ *   // Optionally override `isAdditionalFlowStep`.
+ * }
+ * ```
+ * Conceptually, this defines a graph where the nodes are `DataFlow::Node`s and
+ * the edges are those data-flow steps that preserve the value of the node
+ * along with any additional edges defined by `isAdditionalFlowStep`.
+ * Specifying nodes in `isBarrier` will remove those nodes from the graph, and
+ * specifying nodes in `isBarrierIn` and/or `isBarrierOut` will remove in-going
+ * and/or out-going edges from those nodes, respectively.
+ *
+ * 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 two classes extending
+ * `DataFlow::Configuration` should never depend on each other. One of them
+ * should instead depend on a `DataFlow2::Configuration`, a
+ * `DataFlow3::Configuration`, or a `DataFlow4::Configuration`.
+ */
+abstract deprecated class Configuration extends string {
+  bindingset[this]
+  Configuration() { any() }
+
+  /**
+   * Holds if `source` is a relevant data flow source.
+   */
+  predicate isSource(Node source) { none() }
+
+  /**
+   * Holds if `source` is a relevant data flow source with the given initial
+   * `state`.
+   */
+  predicate isSource(Node source, FlowState state) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink.
+   */
+  predicate isSink(Node sink) { none() }
+
+  /**
+   * Holds if `sink` is a relevant data flow sink accepting `state`.
+   */
+  predicate isSink(Node sink, FlowState state) { none() }
+
+  /**
+   * Holds if data flow through `node` is prohibited. This completely removes
+   * `node` from the data flow graph.
+   */
+  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) { none() }
+
+  /** Holds if data flow into `node` is prohibited. */
+  predicate isBarrierIn(Node node) { none() }
+
+  /** Holds if data flow out of `node` is prohibited. */
+  predicate isBarrierOut(Node node) { none() }
+
+  /**
+   * Holds if data may flow from `node1` to `node2` in addition to the normal data-flow steps.
+   */
+  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) {
+    none()
+  }
+
+  /**
+   * Holds if an arbitrary number of implicit read steps of content `c` may be
+   * taken at `node`.
+   */
+  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.
+   */
+  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.
+   */
+  FlowFeature getAFeature() { none() }
+
+  /** Holds if sources should be grouped in the result of `hasFlowPath`. */
+  predicate sourceGrouping(Node source, string sourceGroup) { none() }
+
+  /** Holds if sinks should be grouped in the result of `hasFlowPath`. */
+  predicate sinkGrouping(Node sink, string sinkGroup) { none() }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   */
+  predicate hasFlow(Node source, Node sink) { hasFlow(source, sink, this) }
+
+  /**
+   * Holds if data may flow from `source` to `sink` for this configuration.
+   *
+   * The corresponding paths are generated from the end-points and the graph
+   * included in the module `PathGraph`.
+   */
+  predicate hasFlowPath(PathNode source, PathNode sink) { hasFlowPath(source, sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowTo(Node sink) { hasFlowTo(sink, this) }
+
+  /**
+   * Holds if data may flow from some source to `sink` for this configuration.
+   */
+  predicate hasFlowToExpr(DataFlowExpr sink) { this.hasFlowTo(exprNode(sink)) }
+
+  /**
+   * 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 (for example in a `path-problem` query).
+   */
+  predicate includeHiddenNodes() { none() }
+}
+
+/**
+ * This class exists to prevent mutual recursion between the user-overridden
+ * member predicates of `Configuration` and the rest of the data-flow library.
+ * Good performance cannot be guaranteed in the presence of such recursion, so
+ * it should be replaced by using more than one copy of the data flow library.
+ */
+abstract deprecated private class ConfigurationRecursionPrevention extends Configuration {
+  bindingset[this]
+  ConfigurationRecursionPrevention() { any() }
+
+  override predicate hasFlow(Node source, Node sink) {
+    strictcount(Node n | this.isSource(n)) < 0
+    or
+    strictcount(Node n | this.isSource(n, _)) < 0
+    or
+    strictcount(Node n | this.isSink(n)) < 0
+    or
+    strictcount(Node n | this.isSink(n, _)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, n2)) < 0
+    or
+    strictcount(Node n1, Node n2 | this.isAdditionalFlowStep(n1, _, n2, _)) < 0
+    or
+    super.hasFlow(source, sink)
+  }
+}
+
+deprecated private FlowState relevantState(Configuration config) {
+  config.isSource(_, result) or
+  config.isSink(_, result) or
+  config.isBarrier(_, result) or
+  config.isAdditionalFlowStep(_, result, _, _) or
+  config.isAdditionalFlowStep(_, _, _, result)
+}
+
+private newtype TConfigState =
+  deprecated TMkConfigState(Configuration config, FlowState state) {
+    state = relevantState(config) or state instanceof FlowStateEmpty
+  }
+
+deprecated private Configuration getConfig(TConfigState state) { state = TMkConfigState(result, _) }
+
+deprecated private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
+
+deprecated private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
+deprecated private module Config implements FullStateConfigSig {
+  class FlowState = TConfigState;
+
+  predicate isSource(Node source, FlowState state) {
+    getConfig(state).isSource(source, getState(state))
+    or
+    getConfig(state).isSource(source) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isSink(Node sink) { none() }
+
+  predicate isSink(Node sink, FlowState state) {
+    getConfig(state).isSink(sink, getState(state))
+    or
+    getConfig(state).isSink(sink) and getState(state) instanceof FlowStateEmpty
+  }
+
+  predicate isBarrier(Node node) { none() }
+
+  predicate isBarrier(Node node, FlowState state) {
+    getConfig(state).isBarrier(node, getState(state)) or
+    getConfig(state).isBarrier(node)
+  }
+
+  predicate isBarrierIn(Node node) { any(Configuration config).isBarrierIn(node) }
+
+  predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
+
+  predicate isBarrierIn(Node node, FlowState state) { none() }
+
+  predicate isBarrierOut(Node node, FlowState state) { none() }
+
+  predicate isAdditionalFlowStep(Node node1, Node node2, string model) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2) and
+    model = ""
+  }
+
+  predicate isAdditionalFlowStep(
+    Node node1, FlowState state1, Node node2, FlowState state2, string model
+  ) {
+    getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
+    getConfig(state2) = getConfig(state1) and
+    model = ""
+    or
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1 and
+    model = ""
+  }
+
+  predicate allowImplicitRead(Node node, ContentSet c) {
+    any(Configuration config).allowImplicitRead(node, c)
+  }
+
+  predicate neverSkip(Node node) { none() }
+
+  int fieldFlowBranchLimit() { result = min(any(Configuration config).fieldFlowBranchLimit()) }
+
+  int accessPathLimit() { result = 5 }
+
+  FlowFeature getAFeature() { result = any(Configuration config).getAFeature() }
+
+  predicate includeHiddenNodes() { any(Configuration config).includeHiddenNodes() }
+
+  predicate observeDiffInformedIncrementalMode() { none() }
+}
+
+deprecated private import Impl<Config> as I
+
+/**
+ * A `Node` augmented with a call context (except for sinks), an access path, and a configuration.
+ * Only those `PathNode`s that are reachable from a source, and which can reach a sink, are generated.
+ */
+deprecated class PathNode instanceof I::PathNode {
+  /** Gets a textual representation of this element. */
+  final string toString() { result = super.toString() }
+
+  /**
+   * Gets a textual representation of this element, including a textual
+   * representation of the call context.
+   */
+  final string toStringWithContext() { result = super.toStringWithContext() }
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startcolumn` of line `startline` to
+   * column `endcolumn` of line `endline` in file `filepath`.
+   * For more information, see
+   * [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  final predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    super.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+
+  /** Gets the underlying `Node`. */
+  final Node getNode() { result = super.getNode() }
+
+  /** Gets the `FlowState` of this node. */
+  deprecated final FlowState getState() { result = getState(super.getState()) }
+
+  /** Gets the associated configuration. */
+  deprecated final Configuration getConfiguration() { result = getConfig(super.getState()) }
+
+  /** Gets a successor of this node, if any. */
+  final PathNode getASuccessor() { result = super.getASuccessor() }
+
+  /** Holds if this node is a source. */
+  final predicate isSource() { super.isSource() }
+
+  /** Holds if this node is a grouping of source nodes. */
+  final predicate isSourceGroup(string group) { super.isSourceGroup(group) }
+
+  /** Holds if this node is a grouping of sink nodes. */
+  final predicate isSinkGroup(string group) { super.isSinkGroup(group) }
+}
+
+deprecated module PathGraph = I::PathGraph;
+
+deprecated private predicate hasFlow(Node source, Node sink, Configuration config) {
+  exists(PathNode source0, PathNode sink0 |
+    hasFlowPath(source0, sink0, config) and
+    source0.getNode() = source and
+    sink0.getNode() = sink
+  )
+}
+
+deprecated private predicate hasFlowPath(PathNode source, PathNode sink, Configuration config) {
+  I::flowPath(source, sink) and source.getConfiguration() = config
+}
+
+deprecated private predicate hasFlowTo(Node sink, Configuration config) { hasFlow(_, sink, config) }
+
+deprecated predicate flowsTo = hasFlow/3;
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/ProductFlow.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/ProductFlow.qll
@@ -545,7 +545,7 @@ module ProductFlow {
    private predicate outImpl1(Flow1::PathNode pred1, Flow1::PathNode succ1, DataFlowCall call) {
      Flow1::PathGraph::edges(pred1, succ1, _, _) and
      exists(ReturnKindExt returnKind |
-        succ1.getNode() = getAnOutNodeExt(call, returnKind) and
+        succ1.getNode() = returnKind.getAnOutNode(call) and
        returnKind = getParamReturnPosition(_, pred1.asParameterReturnNode()).getKind()
      )
    }
@@ -573,7 +573,7 @@ module ProductFlow {
    private predicate outImpl2(Flow2::PathNode pred2, Flow2::PathNode succ2, DataFlowCall call) {
      Flow2::PathGraph::edges(pred2, succ2, _, _) and
      exists(ReturnKindExt returnKind |
-        succ2.getNode() = getAnOutNodeExt(call, returnKind) and
+        succ2.getNode() = returnKind.getAnOutNode(call) and
        returnKind = getParamReturnPosition(_, pred2.asParameterReturnNode()).getKind()
      )
    }
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking1/TaintTrackingImpl.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking1/TaintTrackingImpl.qll
@@ -0,0 +1,168 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * 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
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * 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 deprecated 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) }
+
+  /**
+   * 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)
+  }
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking1/TaintTrackingParameter.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking1/TaintTrackingParameter.qll
@@ -0,0 +1,6 @@
+import semmle.code.cpp.ir.dataflow.internal.TaintTrackingUtil as Public
+
+module Private {
+  import semmle.code.cpp.ir.dataflow.DataFlow::DataFlow as DataFlow
+  import semmle.code.cpp.ir.dataflow.internal.DataFlowImpl as DataFlowInternal
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking2/TaintTrackingImpl.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking2/TaintTrackingImpl.qll
@@ -0,0 +1,168 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * 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
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * 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 deprecated 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) }
+
+  /**
+   * 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)
+  }
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking2/TaintTrackingParameter.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking2/TaintTrackingParameter.qll
@@ -0,0 +1,5 @@
+import semmle.code.cpp.ir.dataflow.internal.TaintTrackingUtil as Public
+
+module Private {
+  import semmle.code.cpp.ir.dataflow.DataFlow2::DataFlow2 as DataFlow
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking3/TaintTrackingImpl.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking3/TaintTrackingImpl.qll
@@ -0,0 +1,168 @@
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * 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
+
+/**
+ * DEPRECATED: Use `Global` and `GlobalWithState` instead.
+ *
+ * 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 deprecated 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) }
+
+  /**
+   * 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)
+  }
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking3/TaintTrackingParameter.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/tainttracking3/TaintTrackingParameter.qll
@@ -0,0 +1,5 @@
+import semmle.code.cpp.ir.dataflow.internal.TaintTrackingUtil as Public
+
+module Private {
+  import semmle.code.cpp.ir.dataflow.DataFlow3::DataFlow3 as DataFlow
+}
--- a/cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedCall.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedCall.qll
@@ -364,14 +364,10 @@ class TranslatedFunctionCall extends TranslatedCallExpr, TranslatedDirectCall {

  final override predicate mayThrowException() {
    expr.getTarget().(ThrowingFunction).mayThrowException(_)
-    or
-    expr.getTarget() instanceof AlwaysSehThrowingFunction
  }

  final override predicate mustThrowException() {
    expr.getTarget().(ThrowingFunction).mayThrowException(true)
-    or
-    expr.getTarget() instanceof AlwaysSehThrowingFunction
  }
 }

--- a/cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedElement.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedElement.qll
@@ -196,8 +196,6 @@ private predicate isInvalidFunction(Function func) {
    expr.getEnclosingFunction() = func and
    not exists(expr.getType())
  )
-  or
-  count(func.getEntryPoint().getLocation()) > 1
 }

 /**
--- a/cpp/ql/lib/semmle/code/cpp/models/Models.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/Models.qll
@@ -49,4 +49,3 @@ private import implementations.PostgreSql
 private import implementations.System
 private import implementations.StructuredExceptionHandling
 private import implementations.ZMQ
-private import implementations.Win32CommandExecution
--- a/cpp/ql/lib/semmle/code/cpp/models/implementations/Memcpy.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/implementations/Memcpy.qll
@@ -16,7 +16,7 @@ import semmle.code.cpp.models.interfaces.NonThrowing
 * `__builtin___memcpy_chk`.
 */
 private class MemcpyFunction extends ArrayFunction, DataFlowFunction, SideEffectFunction,
-  AliasFunction, NonCppThrowingFunction
+  AliasFunction, NonThrowingFunction
 {
  MemcpyFunction() {
    // memcpy(dest, src, num)
--- a/cpp/ql/lib/semmle/code/cpp/models/implementations/Memset.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/implementations/Memset.qll
@@ -11,7 +11,7 @@ import semmle.code.cpp.models.interfaces.SideEffect
 import semmle.code.cpp.models.interfaces.NonThrowing

 private class MemsetFunctionModel extends ArrayFunction, DataFlowFunction, AliasFunction,
-  SideEffectFunction, NonCppThrowingFunction
+  SideEffectFunction, NonThrowingFunction
 {
  MemsetFunctionModel() {
    this.hasGlobalOrStdOrBslName("memset")
--- a/cpp/ql/lib/semmle/code/cpp/models/implementations/NoexceptFunction.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/implementations/NoexceptFunction.qll
@@ -6,6 +6,6 @@ import semmle.code.cpp.models.interfaces.NonThrowing
 *
 * Note: The `throw` specifier was deprecated in C++11 and removed in C++17.
 */
-class NoexceptFunction extends NonCppThrowingFunction {
+class NoexceptFunction extends NonThrowingFunction {
  NoexceptFunction() { this.isNoExcept() or this.isNoThrow() }
 }
--- a/cpp/ql/lib/semmle/code/cpp/models/implementations/Printf.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/implementations/Printf.qll
@@ -13,7 +13,7 @@ import semmle.code.cpp.models.interfaces.NonThrowing
 /**
 * The standard functions `printf`, `wprintf` and their glib variants.
 */
-private class Printf extends FormattingFunction, AliasFunction, NonCppThrowingFunction {
+private class Printf extends FormattingFunction, AliasFunction, NonThrowingFunction {
  Printf() {
    this instanceof TopLevelFunction and
    (
@@ -37,7 +37,7 @@ private class Printf extends FormattingFunction, AliasFunction, NonCppThrowingFu
 /**
 * The standard functions `fprintf`, `fwprintf` and their glib variants.
 */
-private class Fprintf extends FormattingFunction, NonCppThrowingFunction {
+private class Fprintf extends FormattingFunction, NonThrowingFunction {
  Fprintf() {
    this instanceof TopLevelFunction and
    (
@@ -55,7 +55,7 @@ private class Fprintf extends FormattingFunction, NonCppThrowingFunction {
 /**
 * The standard function `sprintf` and its Microsoft and glib variants.
 */
-private class Sprintf extends FormattingFunction, NonCppThrowingFunction {
+private class Sprintf extends FormattingFunction, NonThrowingFunction {
  Sprintf() {
    this instanceof TopLevelFunction and
    (
@@ -98,9 +98,7 @@ private class Sprintf extends FormattingFunction, NonCppThrowingFunction {
 /**
 * Implements `Snprintf`.
 */
-private class SnprintfImpl extends Snprintf, AliasFunction, SideEffectFunction,
-  NonCppThrowingFunction
-{
+private class SnprintfImpl extends Snprintf, AliasFunction, SideEffectFunction, NonThrowingFunction {
  SnprintfImpl() {
    this instanceof TopLevelFunction and
    (
@@ -207,7 +205,7 @@ private class StringCchPrintf extends FormattingFunction {
 /**
 * The standard function `syslog`.
 */
-private class Syslog extends FormattingFunction, NonCppThrowingFunction {
+private class Syslog extends FormattingFunction, NonThrowingFunction {
  Syslog() {
    this instanceof TopLevelFunction and
    this.hasGlobalName("syslog") and
--- a/cpp/ql/lib/semmle/code/cpp/models/implementations/Strcat.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/implementations/Strcat.qll
@@ -15,7 +15,7 @@ import semmle.code.cpp.models.interfaces.NonThrowing
 * Does not include `strlcat`, which is covered by `StrlcatFunction`
 */
 class StrcatFunction extends TaintFunction, DataFlowFunction, ArrayFunction, SideEffectFunction,
-  NonCppThrowingFunction
+  NonThrowingFunction
 {
  StrcatFunction() {
    this.hasGlobalOrStdOrBslName([
--- a/cpp/ql/lib/semmle/code/cpp/models/implementations/Strcpy.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/implementations/Strcpy.qll
@@ -13,7 +13,7 @@ import semmle.code.cpp.models.interfaces.NonThrowing
 * The standard function `strcpy` and its wide, sized, and Microsoft variants.
 */
 class StrcpyFunction extends ArrayFunction, DataFlowFunction, TaintFunction, SideEffectFunction,
-  NonCppThrowingFunction
+  NonThrowingFunction
 {
  StrcpyFunction() {
    this.hasGlobalOrStdOrBslName([
--- a/cpp/ql/lib/semmle/code/cpp/models/implementations/StructuredExceptionHandling.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/implementations/StructuredExceptionHandling.qll
@@ -1,7 +1,9 @@
 import semmle.code.cpp.models.interfaces.Throwing

-class WindowsDriverExceptionAnnotation extends AlwaysSehThrowingFunction {
-  WindowsDriverExceptionAnnotation() {
+class WindowsDriverFunction extends ThrowingFunction {
+  WindowsDriverFunction() {
    this.hasGlobalName(["RaiseException", "ExRaiseAccessViolation", "ExRaiseDatatypeMisalignment"])
  }
+
+  final override predicate mayThrowException(boolean unconditional) { unconditional = true }
 }
--- a/cpp/ql/lib/semmle/code/cpp/models/implementations/Win32CommandExecution.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/implementations/Win32CommandExecution.qll
@@ -1,56 +0,0 @@
-private import semmle.code.cpp.models.interfaces.CommandExecution
-
-/** The `ShellExecute` family of functions from Win32. */
-class ShellExecute extends Function {
-  ShellExecute() { this.hasGlobalName("ShellExecute" + ["", "A", "W"]) }
-}
-
-private class ShellExecuteModel extends ShellExecute, CommandExecutionFunction {
-  override predicate hasCommandArgument(FunctionInput input) { input.isParameterDeref(2) }
-}
-
-/** The `WinExec` function from Win32. */
-class WinExec extends Function {
-  WinExec() { this.hasGlobalName("WinExec") }
-}
-
-private class WinExecModel extends WinExec, CommandExecutionFunction {
-  override predicate hasCommandArgument(FunctionInput input) { input.isParameterDeref(0) }
-}
-
-/** The `CreateProcess` family of functions from Win32. */
-class CreateProcess extends Function {
-  CreateProcess() { this.hasGlobalName("CreateProcess" + ["", "A", "W"]) }
-}
-
-private class CreateProcessModel extends CreateProcess, CommandExecutionFunction {
-  override predicate hasCommandArgument(FunctionInput input) { input.isParameterDeref(0) }
-}
-
-/** The `CreateProcessAsUser` family of functions from Win32. */
-class CreateProcessAsUser extends Function {
-  CreateProcessAsUser() { this.hasGlobalName("CreateProcessAsUser" + ["", "A", "W"]) }
-}
-
-private class CreateProcessAsUserModel extends CreateProcessAsUser, CommandExecutionFunction {
-  override predicate hasCommandArgument(FunctionInput input) { input.isParameterDeref(1) }
-}
-
-/** The `CreateProcessWithLogonW` function from Win32. */
-class CreateProcessWithLogonW extends Function {
-  CreateProcessWithLogonW() { this.hasGlobalName("CreateProcessWithLogonW") }
-}
-
-private class CreateProcessWithLogonModel extends CreateProcessWithLogonW, CommandExecutionFunction {
-  override predicate hasCommandArgument(FunctionInput input) { input.isParameterDeref(4) }
-}
-
-/** The `CreateProcessWithTokenW` function from Win32. */
-class CreateProcessWithTokenW extends Function {
-  CreateProcessWithTokenW() { this.hasGlobalName("CreateProcessWithTokenW") }
-}
-
-private class CreateProcessWithTokenWModel extends CreateProcessWithTokenW, CommandExecutionFunction
-{
-  override predicate hasCommandArgument(FunctionInput input) { input.isParameterDeref(2) }
-}
--- a/cpp/ql/lib/semmle/code/cpp/models/interfaces/NonThrowing.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/interfaces/NonThrowing.qll
@@ -5,16 +5,7 @@
 import semmle.code.cpp.Function
 import semmle.code.cpp.models.Models

-/**
- * A function that is guaranteed to never throw a C++ exception
- *
- * The function may still raise a structured exception handling (SEH) exception.
- */
-abstract class NonCppThrowingFunction extends Function { }
-
 /**
 * A function that is guaranteed to never throw.
- *
- * DEPRECATED: use `NonCppThrowingFunction` instead.
 */
-deprecated class NonThrowingFunction = NonCppThrowingFunction;
+abstract class NonThrowingFunction extends Function { }
--- a/cpp/ql/lib/semmle/code/cpp/models/interfaces/Throwing.qll
+++ b/cpp/ql/lib/semmle/code/cpp/models/interfaces/Throwing.qll
@@ -11,7 +11,7 @@ import semmle.code.cpp.models.Models
 import semmle.code.cpp.models.interfaces.FunctionInputsAndOutputs

 /**
- * A function that is known to raise an exception.
+ * A class that models the exceptional behavior of a function.
 */
 abstract class ThrowingFunction extends Function {
  /**
@@ -20,8 +20,3 @@ abstract class ThrowingFunction extends Function {
   */
  abstract predicate mayThrowException(boolean unconditional);
 }
-
-/**
- * A function that unconditionally raises a structured exception handling (SEH) exception.
- */
-abstract class AlwaysSehThrowingFunction extends Function { }
--- a/cpp/ql/lib/semmlecode.cpp.dbscheme
+++ b/cpp/ql/lib/semmlecode.cpp.dbscheme
@@ -46,22 +46,6 @@ compilation_args(
    string arg : string ref
 );

-/**
- * Optionally, record the build mode for each compilation.
- */
-compilation_build_mode(
-    unique int id : @compilation ref,
-    int mode : int ref
-);
-
-/*
-case @compilation_build_mode.mode of
-  0 = @build_mode_none
-| 1 = @build_mode_manual
-| 2 = @build_mode_auto
-;
-*/
-
 /**
 * The source files that are compiled by a compiler invocation.
 * If `id` is for the compiler invocation
--- a/cpp/ql/lib/semmlecode.cpp.dbscheme.stats
+++ b/cpp/ql/lib/semmlecode.cpp.dbscheme.stats
--- a/cpp/ql/lib/upgrades/e51fad7a2436caefab0c6bd52f05e28e7cce4d92/old.dbscheme
+++ b/cpp/ql/lib/upgrades/e51fad7a2436caefab0c6bd52f05e28e7cce4d92/old.dbscheme
--- a/cpp/ql/lib/upgrades/e51fad7a2436caefab0c6bd52f05e28e7cce4d92/semmlecode.cpp.dbscheme
+++ b/cpp/ql/lib/upgrades/e51fad7a2436caefab0c6bd52f05e28e7cce4d92/semmlecode.cpp.dbscheme
--- a/cpp/ql/lib/upgrades/e51fad7a2436caefab0c6bd52f05e28e7cce4d92/upgrade.properties
+++ b/cpp/ql/lib/upgrades/e51fad7a2436caefab0c6bd52f05e28e7cce4d92/upgrade.properties
@@ -1,2 +0,0 @@
-description: Implement compilation_build_mode/2
-compatibility: backwards
--- a/Practices/GuardedFree.ql
+++ b/Practices/GuardedFree.ql
@@ -1,47 +0,0 @@
-/**
- * @name Guarded Free
- * @description NULL-condition guards before function calls to the memory-deallocation
- *              function free(3) are unnecessary, because passing NULL to free(3) is a no-op.
- * @kind problem
- * @problem.severity recommendation
- * @precision very-high
- * @id cpp/guarded-free
- * @tags maintainability
- *       readability
- */
-
-import cpp
-import semmle.code.cpp.controlflow.Guards
-
-class FreeCall extends FunctionCall {
-  FreeCall() { this.getTarget().hasGlobalName("free") }
-}
-
-predicate blockContainsPreprocessorBranches(BasicBlock bb) {
-  exists(PreprocessorBranch ppb, Location bbLoc, Location ppbLoc |
-    bbLoc = bb.(Stmt).getLocation() and ppbLoc = ppb.getLocation()
-  |
-    bbLoc.getFile() = ppb.getFile() and
-    bbLoc.getStartLine() < ppbLoc.getStartLine() and
-    ppbLoc.getEndLine() < bbLoc.getEndLine()
-  )
-}
-
-from GuardCondition gc, FreeCall fc, Variable v, BasicBlock bb
-where
-  gc.ensuresEq(v.getAnAccess(), 0, bb, false) and
-  fc.getArgument(0) = v.getAnAccess() and
-  bb = fc.getBasicBlock() and
-  (
-    // No block statement: if (x) free(x);
-    bb = fc.getEnclosingStmt()
-    or
-    // Block statement with a single nested statement: if (x) { free(x); }
-    strictcount(bb.(BlockStmt).getAStmt()) = 1
-  ) and
-  strictcount(BasicBlock bb2 | gc.ensuresEq(_, 0, bb2, _) | bb2) = 1 and
-  not fc.isInMacroExpansion() and
-  not blockContainsPreprocessorBranches(bb) and
-  not (gc instanceof BinaryOperation and not gc instanceof ComparisonOperation) and
-  not exists(CommaExpr c | c.getAChild*() = fc)
-select gc, "unnecessary NULL check before call to $@", fc, "free"
--- a/cpp/ql/src/CHANGELOG.md
+++ b/cpp/ql/src/CHANGELOG.md
@@ -1,17 +1,3 @@
-## 1.3.0
-
-### New Queries
-
-* Added a new high-precision quality query, `cpp/guarded-free`, which detects useless NULL pointer checks before calls to `free`. A variation of this query was originally contributed as an [experimental query by @mario-campos](https://github.com/github/codeql/pull/16331).
-
-### Minor Analysis Improvements
-
-* The "Call to function with fewer arguments than declared parameters" query (`cpp/too-few-arguments`) query no longer produces results if the function has been implicitly declared.
-
-## 1.2.7
-
-No user-facing changes.
-
 ## 1.2.6

 ### Minor Analysis Improvements
--- a/cpp/ql/src/Critical/UseAfterFree.qhelp
+++ b/cpp/ql/src/Critical/UseAfterFree.qhelp
@@ -8,7 +8,7 @@
 <p>
 This rule finds accesses through a pointer of a memory location that has already been freed (i.e. through a dangling pointer). 
 Such memory blocks have already been released to the dynamic memory manager, and modifying them can lead to anything 
-from a segfault to memory corruption that would cause subsequent calls to the dynamic memory manager to behave 
+from a segfault to memory corruption that would cause subsequent calls to the dynamic memory manger to behave 
 erratically, to a possible security vulnerability.
 </p>

--- a/Functions/TooFewArguments.qll
+++ b/Functions/TooFewArguments.qll
@@ -51,7 +51,5 @@ predicate tooFewArguments(FunctionCall fc, Function f) {
    hasDefiniteNumberOfParameters(fde)
  |
    fde.getNumberOfParameters() > fc.getNumberOfArguments()
-  ) and
-  // Don't report on implicit function declarations, as these are likely extraction errors.
-  not f.getADeclarationEntry().isImplicit()
+  )
 }
--- a/cpp/ql/src/Security/CWE/CWE-078/ExecTainted.ql
+++ b/cpp/ql/src/Security/CWE/CWE-078/ExecTainted.ql
@@ -19,6 +19,7 @@ import semmle.code.cpp.security.Security
 import semmle.code.cpp.valuenumbering.GlobalValueNumbering
 import semmle.code.cpp.ir.IR
 import semmle.code.cpp.ir.dataflow.TaintTracking
+import semmle.code.cpp.ir.dataflow.TaintTracking2
 import semmle.code.cpp.security.FlowSources
 import semmle.code.cpp.models.implementations.Strcat
 import ExecTaint::PathGraph
--- a/cpp/ql/src/Security/CWE/CWE-570/IncorrectAllocationErrorHandling.ql
+++ b/cpp/ql/src/Security/CWE/CWE-570/IncorrectAllocationErrorHandling.ql
@@ -45,7 +45,7 @@ predicate deleteMayThrow(DeleteOrDeleteArrayExpr deleteExpr) {
 * like it might throw an exception, and the function does not have a `noexcept` or `throw()` specifier.
 */
 predicate functionMayThrow(Function f) {
-  not f instanceof NonCppThrowingFunction and
+  not f instanceof NonThrowingFunction and
  (not exists(f.getBlock()) or stmtMayThrow(f.getBlock()))
 }

--- a/cpp/ql/src/change-notes/released/1.2.7.md
+++ b/cpp/ql/src/change-notes/released/1.2.7.md
@@ -1,3 +0,0 @@
-## 1.2.7
-
-No user-facing changes.
--- a/cpp/ql/src/change-notes/released/1.3.0.md
+++ b/cpp/ql/src/change-notes/released/1.3.0.md
@@ -1,9 +0,0 @@
-## 1.3.0
-
-### New Queries
-
-* Added a new high-precision quality query, `cpp/guarded-free`, which detects useless NULL pointer checks before calls to `free`. A variation of this query was originally contributed as an [experimental query by @mario-campos](https://github.com/github/codeql/pull/16331).
-
-### Minor Analysis Improvements
-
-* The "Call to function with fewer arguments than declared parameters" query (`cpp/too-few-arguments`) query no longer produces results if the function has been implicitly declared.
--- a/cpp/ql/src/codeql-pack.release.yml
+++ b/cpp/ql/src/codeql-pack.release.yml
@@ -1,2 +1,2 @@
 ---
-lastReleaseVersion: 1.3.0
+lastReleaseVersion: 1.2.6
--- a/cpp/ql/src/experimental/Best
+++ b/cpp/ql/src/experimental/Best
--- a/cpp/ql/src/experimental/Best
+++ b/cpp/ql/src/experimental/Best
@@ -1,28 +1,18 @@
-<!DOCTYPE qhelp PUBLIC
-  "-//Semmle//qhelp//EN"
-  "qhelp.dtd">
+<!DOCTYPE qhelp SYSTEM "qhelp.dtd">
 <qhelp>
-
 <overview>
-<p>The <code>free</code> function, which deallocates heap memory, may accept a NULL pointer and take no action. Therefore, it is unnecessary to check the argument for the value of NULL before a function call to <code>free</code>. As such, these guards may hinder performance and readability.</p>
+<p>The <code>free</code> function, which deallocates heap memory, may accept a NULL pointer and take no action. Therefore, it is unnecessary to check its argument for the value of NULL before a function call to <code>free</code>. As such, these guards may hinder performance and readability.</p>
 </overview>
-
 <recommendation>
-<p>A function call to <code>free</code> should not depend upon the value of its argument. Delete the condition preceding a function call to <code>free</code> when its only purpose is to check the value of the pointer to be freed.</p>
+<p>A function call to <code>free</code> should not depend upon the value of its argument. Delete the <code>if</code> condition preceeding a function call to <code>free</code> when its only purpose is to check the value of the pointer to be freed.</p>
 </recommendation>
-
 <example>
 <sample src = "GuardedFree.cpp" />
-
-<p>In this example, the condition checking the value of <code>foo</code> can be deleted.</p>
-
 </example>
-
 <references>
 <li>
    The Open Group Base Specifications Issue 7, 2018 Edition:
-    <a href="https://pubs.opengroup.org/onlinepubs/9699919799/functions/free.html">free - free allocated memory</a>.
+    <a href="https://pubs.opengroup.org/onlinepubs/9699919799/functions/free.html">free - free allocated memory</a>
 </li>
 </references>
-
-</qhelp>
+</qhelp>
--- a/cpp/ql/src/experimental/Best
+++ b/cpp/ql/src/experimental/Best
@@ -0,0 +1,26 @@
+/**
+ * @name Guarded Free
+ * @description NULL-condition guards before function calls to the memory-deallocation
+ *              function free(3) are unnecessary, because passing NULL to free(3) is a no-op.
+ * @kind problem
+ * @problem.severity recommendation
+ * @precision very-high
+ * @id cpp/guarded-free
+ * @tags maintainability
+ *       readability
+ *       experimental
+ */
+
+import cpp
+import semmle.code.cpp.controlflow.Guards
+
+class FreeCall extends FunctionCall {
+  FreeCall() { this.getTarget().hasGlobalName("free") }
+}
+
+from GuardCondition gc, FreeCall fc, Variable v, BasicBlock bb
+where
+  gc.ensuresEq(v.getAnAccess(), 0, bb, false) and
+  fc.getArgument(0) = v.getAnAccess() and
+  bb = fc.getEnclosingStmt()
+select gc, "unnecessary NULL check before call to $@", fc, "free"
--- a/cpp/ql/src/qlpack.yml
+++ b/cpp/ql/src/qlpack.yml
@@ -1,5 +1,5 @@
 name: codeql/cpp-queries
-version: 1.3.0
+version: 1.2.7-dev
 groups:
  - cpp
  - queries
--- a/cpp/ql/test/experimental/library-tests/rangeanalysis/rangeanalysis/RangeAnalysis.expected
+++ b/cpp/ql/test/experimental/library-tests/rangeanalysis/rangeanalysis/RangeAnalysis.expected
@@ -17,6 +17,7 @@
 | test.cpp:49:12:49:12 | Load: x | test.cpp:46:22:46:22 | ValueNumberBound | -1 | true | CompareLT: ... < ... | test.cpp:48:9:48:13 | test.cpp:48:9:48:13 |
 | test.cpp:49:12:49:12 | Load: x | test.cpp:46:29:46:29 | ValueNumberBound | -2 | true | CompareLT: ... < ... | test.cpp:48:9:48:13 | test.cpp:48:9:48:13 |
 | test.cpp:54:12:54:12 | Load: x | test.cpp:46:22:46:22 | ValueNumberBound | -1 | true | CompareLT: ... < ... | test.cpp:52:7:52:11 | test.cpp:52:7:52:11 |
+| test.cpp:54:12:54:12 | Load: x | test.cpp:46:29:46:29 | ValueNumberBound | -2 | true | CompareLT: ... < ... | test.cpp:52:7:52:11 | test.cpp:52:7:52:11 |
 | test.cpp:62:10:62:13 | Load: iter | test.cpp:60:17:60:17 | ValueNumberBound | 0 | false | NoReason | file://:0:0:0:0 | file://:0:0:0:0 |
 | test.cpp:62:10:62:13 | Load: iter | test.cpp:60:17:60:17 | ValueNumberBound | 3 | true | CompareLT: ... < ... | test.cpp:61:32:61:51 | test.cpp:61:32:61:51 |
 | test.cpp:62:10:62:13 | Load: iter | test.cpp:61:39:61:51 | ValueNumberBound | -1 | true | CompareLT: ... < ... | test.cpp:61:32:61:51 | test.cpp:61:32:61:51 |
--- a/Show More
+++ b/Show More