Removing _LIBCPP_DISABLE_UNUSED_STRUCT_WARNINGS from libc++ enables

`[[gnu::__warn_unused__]]` on standard library types (such as `std::string` and `std::set`), surfacing `-Wunused-variable` warnings in `//third_party/flatbuffers`. See [upstream LLVM commit](https://github.com/llvm/llvm-project/commit/ab8b037ef7b398aa864959a69f328fa69b567f74) for reference. Remove unreferenced variable declarations across the code generators and binary annotator whose initializers have no observable side effects. PiperOrigin-RevId: 999136370
Pin swift-crypto for the Swift CI matrix (#9412 )
2026-11-08 05:09:09 +00:00 · 2026-10-26 16:02:57 -07:00 · 2026-10-26 10:11:08 -07:00 · 2026-10-26 09:06:45 -07:00 · 2026-10-21 13:37:51 -07:00 · 2026-10-21 13:25:17 -07:00
19 changed files with 154 additions and 81 deletions
@@ -30,7 +30,7 @@ jobs:
        cxx: [g++-13, clang++-18]
      fail-fast: false
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: cmake
      run: CXX=${{ matrix.cxx }} cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON -DFLATBUFFERS_STATIC_FLATC=ON .
    - name: build
@@ -68,7 +68,7 @@ jobs:
    name: Build Linux with -DFLATBUFFERS_NO_FILE_TESTS
    runs-on: ubuntu-24.04
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: cmake
      run: CXX=clang++-18 cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON -DFLATBUFFERS_CXX_FLAGS="-DFLATBUFFERS_NO_FILE_TESTS" .
    - name: build
@@ -80,7 +80,7 @@ jobs:
    name: Build Linux with out-of-source build location
    runs-on: ubuntu-24.04
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: make build directory
      run: mkdir build
    - name: cmake
@@ -112,7 +112,7 @@ jobs:
            std: 23

    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: cmake
      run: >
        CXX=${{ matrix.cxx }} cmake -G "Unix Makefiles"
@@ -135,7 +135,7 @@ jobs:
        std: [11, 14, 17, 20, 23]
      fail-fast: false
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: Add msbuild to PATH
      uses: microsoft/setup-msbuild@v2
    - name: cmake
@@ -160,7 +160,7 @@ jobs:
    name: Build Windows 2022
    runs-on: windows-2022
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: Add msbuild to PATH
      uses: microsoft/setup-msbuild@v2
    - name: cmake
@@ -200,7 +200,7 @@ jobs:
          '-p:EnableSpanT=true,UnsafeByteBuffer=true'
          ]
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: Setup .NET Core SDK
      uses: actions/setup-dotnet@v5
      with:
@@ -229,7 +229,7 @@ jobs:
    name: Build Mac (for Intel)
    runs-on: macos-15-intel
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: cmake
      run: cmake -G "Xcode" -DCMAKE_OSX_ARCHITECTURES="x86_64" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON .
    - name: build
@@ -272,7 +272,7 @@ jobs:
    name: Build Mac (universal build)
    runs-on: macos-latest
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: cmake
      run: cmake -G "Xcode" -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON .
    - name: build
@@ -312,7 +312,7 @@ jobs:
   if: false #disabled due to continual failure
   runs-on: ubuntu-24.04
   steps:
-   - uses: actions/checkout@v7
+   - uses: actions/checkout@v6
   - name: set up Java
     uses: actions/setup-java@v5
     with:
@@ -336,7 +336,7 @@ jobs:
      matrix:
        cxx: [g++-13, clang++-18]
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: cmake
      run: CXX=${{ matrix.cxx }} cmake -G "Unix Makefiles" -DFLATBUFFERS_BUILD_TESTS=OFF -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON . && make -j
    - name: Generate
@@ -348,7 +348,7 @@ jobs:
    name: Check Generated Code on Windows
    runs-on: windows-2022
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: Add msbuild to PATH
      uses: microsoft/setup-msbuild@v2
    - name: cmake
@@ -367,7 +367,7 @@ jobs:
      matrix:
        cxx: [g++-13]
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: cmake
      run: CXX=${{ matrix.cxx }} cmake -G "Unix Makefiles" -DFLATBUFFERS_CXX_FLAGS="-Wno-unused-parameter -fno-aligned-new" -DFLATBUFFERS_BUILD_BENCHMARKS=ON -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON . && make -j
    - name: Run benchmarks
@@ -382,7 +382,7 @@ jobs:
    name: Build Java
    runs-on: ubuntu-24.04
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: test
      working-directory: java
      run: mvn test
@@ -392,7 +392,7 @@ jobs:
    runs-on: macos-15
    steps:
    - name: Checkout
-      uses: actions/checkout@v7
+      uses: actions/checkout@v6
    - name: set up Java
      uses: actions/setup-java@v5
      with:
@@ -415,7 +415,7 @@ jobs:
    runs-on: ubuntu-24.04
    steps:
    - name: Checkout
-      uses: actions/checkout@v7
+      uses: actions/checkout@v6
    - name: set up Java
      uses: actions/setup-java@v5
      with:
@@ -439,7 +439,7 @@ jobs:
    name: Build Rust Linux
    runs-on: ubuntu-24.04
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: test
      working-directory: tests
      run: bash RustTest.sh
@@ -448,7 +448,7 @@ jobs:
    name: Build Rust Windows
    runs-on: windows-2022
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: test
      working-directory: tests
      run: ./RustTest.bat
@@ -457,7 +457,7 @@ jobs:
    name: Build Python
    runs-on: ubuntu-24.04
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: flatc
      # FIXME: make test script not rely on flatc
      run: cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_BUILD_TESTS=OFF -DFLATBUFFERS_INSTALL=OFF -DFLATBUFFERS_BUILD_FLATLIB=OFF -DFLATBUFFERS_BUILD_FLATHASH=OFF -DFLATBUFFERS_STRICT_MODE=ON . && make -j
@@ -469,7 +469,7 @@ jobs:
    name: Build Go
    runs-on: ubuntu-24.04
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: flatc
      # FIXME: make test script not rely on flatc
      run: cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_BUILD_TESTS=OFF -DFLATBUFFERS_INSTALL=OFF -DFLATBUFFERS_BUILD_FLATLIB=OFF -DFLATBUFFERS_BUILD_FLATHASH=OFF -DFLATBUFFERS_STRICT_MODE=ON . && make -j
@@ -481,7 +481,7 @@ jobs:
   name: Build PHP
   runs-on: ubuntu-24.04
   steps:
-   - uses: actions/checkout@v7
+   - uses: actions/checkout@v6
   - name: flatc
     # FIXME: make test script not rely on flatc
     run: cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_BUILD_TESTS=OFF -DFLATBUFFERS_INSTALL=OFF -DFLATBUFFERS_BUILD_FLATLIB=OFF -DFLATBUFFERS_BUILD_FLATHASH=OFF -DFLATBUFFERS_STRICT_MODE=ON . && make -j
@@ -498,7 +498,7 @@ jobs:
        swift: ["6.0", "6.1", "6.2"]
    runs-on: ubuntu-24.04
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - uses: swift-actions/setup-swift@v2
      with:
        swift-version: ${{ matrix.swift }}
@@ -511,7 +511,7 @@ jobs:
    name: Test swift windows
    runs-on: windows-latest
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v6
      - uses: SwiftyLab/setup-swift@latest
        with:
          swift-version: '6.1'
@@ -522,7 +522,7 @@ jobs:
    name: Test Swift Wasm
    runs-on: ubuntu-24.04
    steps:
-       - uses: actions/checkout@v7
+       - uses: actions/checkout@v6
       - uses: swift-actions/setup-swift@v2
         with:
           swift-version: 6.2.1
@@ -540,7 +540,7 @@ jobs:
    name: Build TS
    runs-on: ubuntu-24.04
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: flatc
      # FIXME: make test script not rely on flatc
      run: cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_BUILD_TESTS=OFF -DFLATBUFFERS_INSTALL=OFF -DFLATBUFFERS_BUILD_FLATLIB=OFF -DFLATBUFFERS_BUILD_FLATHASH=OFF . && make -j
@@ -559,7 +559,7 @@ jobs:
    name: Build Dart
    runs-on: ubuntu-24.04
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v6
      - uses: dart-lang/setup-dart@v1
        with:
          sdk: stable
@@ -574,7 +574,7 @@ jobs:
    name: Build Nim
    runs-on: ubuntu-24.04
    steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v6
    - name: flatc
      # FIXME: make test script not rely on flatc
      run: cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_BUILD_TESTS=OFF -DFLATBUFFERS_INSTALL=OFF -DFLATBUFFERS_BUILD_FLATLIB=OFF -DFLATBUFFERS_BUILD_FLATHASH=OFF . && make -j
@@ -590,7 +590,7 @@ jobs:
    name: Bazel
    runs-on: ubuntu-24.04
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v6
      # Explicitly use 8.5.1 until we can update or https://github.com/actions/runner-images/issues/13564 is fixed.
      - name: Set env
        run: >
@@ -16,7 +16,7 @@ jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v6
      - name: Configure Git Credentials
        run: |
          git config user.name github-actions[bot]
@@ -12,7 +12,7 @@ jobs:
    name: Publish NPM
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v6
      - uses: actions/setup-node@v6
        with:
          node-version: '20.x'
@@ -29,7 +29,7 @@ jobs:
      run:
        working-directory: ./python
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v6
      - uses: actions/setup-python@v6
        with:
          python-version: '3.10'
@@ -57,7 +57,7 @@ jobs:
      run:
        working-directory: ./net/flatbuffers
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v6
      - uses: actions/setup-dotnet@v5
        with:
          dotnet-version: '8.0.x'
@@ -80,7 +80,7 @@ jobs:
      run:
        working-directory: ./java
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v6

      - name: Set up Maven Central Repository
        uses: actions/setup-java@v5
@@ -108,7 +108,7 @@ jobs:
      run:
        working-directory: ./kotlin
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v6
      - name: Set up Maven Central Repository
        uses: actions/setup-java@v5
        with:
@@ -133,7 +133,7 @@ jobs:
    name: Publish crates.io
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v6
      - uses: actions-rs/toolchain@v1
        with:
          toolchain: stable
@@ -75,6 +75,17 @@ extension Array where Element == Package.Dependency {
      .package(
        url: "https://github.com/grpc/grpc-swift-nio-transport.git",
        from: "2.0.0"),
+      // swift-crypto arrives through grpc-swift-nio-transport -> swift-nio-ssl
+      // and is otherwise resolved afresh on every build, because this package
+      // ships no Package.resolved. 5.x asks for swift-tools-version 6.2, so only
+      // the 6.2 CI job selects it - and then fails to compile it, because 5.x
+      // uses `@nonexhaustive`, which the 6.2.x toolchains do not accept yet.
+      // Stay on the last 4.x release that still builds with every toolchain in
+      // the Swift CI matrix (4.3.0 declares swift-tools-version 6.0; 4.4+ asks
+      // for 6.1 and would drop the 6.0 job).
+      .package(
+        url: "https://github.com/apple/swift-crypto.git",
+        "4.0.0" ..< "4.4.0"),
    ]
    #endif
  }
@@ -504,7 +504,6 @@ grpc::string GenerateInterface(grpc_generator::File* file,
                               const grpc::string& filename) {
  grpc::string output;

-  std::set<grpc::string> generated_functions;
  std::map<grpc::string, grpc::string> vars;

  vars["PATH"] = file->package();
@@ -271,7 +271,7 @@ namespace flatbuffers {
  #if (defined(_MSC_VER) && _MSC_VER >= 1800) || \
      (defined(__ANDROID__) && defined(__ANDROID_API__) && __ANDROID_API__>= 26) || \
      (defined(_XOPEN_VERSION) && (_XOPEN_VERSION >= 700)) && \
-      !defined(__Fuchsia__)
+      !defined(__Fuchsia__) && (!defined(__linux__) || defined(__GLIBC__))
    #define FLATBUFFERS_LOCALE_INDEPENDENT 1
  #else
    #define FLATBUFFERS_LOCALE_INDEPENDENT 0
@@ -24,15 +24,14 @@ class handle:
 struct offset:
    o:int

-enum sizeof:
-    sz_8 = 1
-    sz_16 = 2
-    sz_32 = 4
-    sz_64 = 8
-    sz_voffset = 2
-    sz_uoffset = 4
-    sz_soffset = 4
-    sz_metadata_fields = 2
+let sz_8 = 1
+let sz_16 = 2
+let sz_32 = 4
+let sz_64 = 8
+let sz_voffset = 2
+let sz_uoffset = 4
+let sz_soffset = 4
+let sz_metadata_fields = 2

 class builder:
    buf = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
@@ -722,8 +722,6 @@ void BinaryAnnotator::BuildTable(const uint64_t table_offset,
    BinaryRegionComment offset_field_comment;
    offset_field_comment.type = BinaryRegionCommentType::TableOffsetField;
    offset_field_comment.name = field->name()->c_str();
-    const std::string offset_prefix =
-        "offset to field `" + std::string(field->name()->c_str()) + "`";

    // Validate any field that isn't inline (i.e., non-structs).
    if (!IsInlineField(field)) {
@@ -404,7 +404,7 @@ class CppGenerator : public BaseGenerator {
      code_ += "struct {{STRUCT_NAME}}BinarySchema {";
      code_ += "  static const uint8_t *data() {";
      code_ += "    // Buffer containing the binary schema.";
-      code_ += "    static const uint8_t bfbsData[" +
+      code_ += "    alignas(uint64_t) static const uint8_t bfbsData[" +
               NumToString(parser_.builder_.GetSize()) + "] = {";
      code_ += binary_schema_hex_text;
      code_ += "    };";
@@ -2737,7 +2737,6 @@ class CppGenerator : public BaseGenerator {
    if (!field.IsScalarOptional()) {
      const bool is_scalar = IsScalar(type.base_type);
      std::string accessor;
-      std::string offset_size = "";
      if (is_scalar) {
        accessor = "GetField<";
      } else if (IsStruct(type)) {
@@ -2815,7 +2814,6 @@ class CppGenerator : public BaseGenerator {

  void GenTableFieldType(const FieldDef& field) {
    const auto& type = field.value.type;
-    const auto offset_str = GenFieldOffsetName(field);
    if (!field.IsScalarOptional()) {
      std::string afterptr = " *" + NullableExtension();
      code_.SetValue("FIELD_TYPE",
@@ -1149,8 +1149,6 @@ static bool GenerateDart(const Parser& parser, const std::string& path,

 static std::string DartMakeRule(const Parser& parser, const std::string& path,
                                const std::string& file_name) {
-  auto filebase =
-      flatbuffers::StripPath(flatbuffers::StripExtension(file_name));
  dart::DartGenerator generator(parser, path, file_name);
  auto make_rule = generator.Filename("") + ": ";

@@ -966,8 +966,6 @@ class KotlinGenerator : public BaseGenerator {
      auto bbgetter = ByteBufferGetter(field.value.type, "bb");
      auto ucast = CastToUsigned(field);
      auto offset_val = NumToString(field.value.offset);
-      auto offset_prefix =
-          "val o = __offset(" + offset_val + "); return o != 0 ? ";
      auto value_base_type = field.value.type.base_type;
      // Most field accessors need to retrieve and test the field offset
      // first, this is the offset value for that:
@@ -146,7 +146,6 @@ class KotlinKMPGenerator : public BaseGenerator {

    std::string code =
        "// " + std::string(FlatBuffersGeneratedWarning()) + "\n\n";
-    auto qualified = ns.GetFullyQualifiedName("");
    std::string namespace_name = namer_.Namespace(ns);
    if (!namespace_name.empty()) {
      code += "package " + namespace_name;
@@ -341,7 +340,6 @@ class KotlinKMPGenerator : public BaseGenerator {
  std::string GenDefaultBufferValue(const FieldDef& field) const {
    auto& value = field.value;
    auto base_type = value.type.base_type;
-    auto field_name = field.name;
    std::string suffix = IsScalar(base_type) ? LiteralSuffix(value.type) : "";
    if (field.IsScalarOptional()) {
      return "null";
@@ -373,7 +371,6 @@ class KotlinKMPGenerator : public BaseGenerator {
  std::string GenDefaultValue(const FieldDef& field) const {
    auto& value = field.value;
    auto base_type = value.type.base_type;
-    auto field_name = field.name;
    std::string suffix = LiteralSuffix(value.type);
    if (field.IsScalarOptional()) {
      return "null";
@@ -1082,8 +1079,6 @@ class KotlinKMPGenerator : public BaseGenerator {
      auto return_type = GetterReturnType(field);
      auto bbgetter = ByteBufferGetter(field.value.type, "bb");
      auto offset_val = NumToString(field.value.offset);
-      auto offset_prefix =
-          "val o = offset(" + offset_val + "); return o != 0 ? ";
      auto value_base_type = field.value.type.base_type;
      // Most field accessors need to retrieve and test the field offset
      // first, this is the offset value for that:
@@ -2010,8 +2010,6 @@ class PythonGenerator : public BaseGenerator {
  void InitializeFromPackedBuf(const StructDef& struct_def,
                               std::string* code_ptr) const {
    auto& code = *code_ptr;
-    const auto struct_var = namer_.Variable(struct_def);
-    const auto struct_type = namer_.Type(struct_def);

    code += GenIndents(1) + "@classmethod";
    code += GenIndents(1) + "def InitFromPackedBuf(cls, buf, pos=0):";
@@ -787,7 +787,6 @@ class SwiftGenerator : public BaseGenerator {
  }

  void GenTableReaderFields(const FieldDef& field) {
-    const auto offset = NumToString(field.value.offset);
    const auto field_field = namer_.Field(field);
    const auto type = GenType(field.value.type);
    code_.SetValue("FIELDVAR", namer_.Variable(field));
@@ -1382,7 +1381,6 @@ class SwiftGenerator : public BaseGenerator {
      const auto& field = **it;
      if (field.deprecated) continue;

-      const auto type = GenType(field.value.type);
      code_.SetValue("FIELDVAR", namer_.Variable(field));
      if (IsArray(field.value.type)) {
        code_.SetValue(
@@ -196,7 +196,6 @@ class TsGenerator : public BaseGenerator {
                                SkipDir::OutputPathAndTrailingPathSeparator);
      symbolic_name = definition.defined_namespace->components.back();
    } else {
-      auto def_mod_name = namer_.File(definition, SkipFile::SuffixAndExtension);
      symbolic_name = file_name_;
      filepath = path_ + symbolic_name + ".ts";
    }
@@ -286,12 +285,10 @@ class TsGenerator : public BaseGenerator {
        auto base_name =
            namer_.Directories(it.second.ns->components, SkipDir::OutputPath) +
            base_file_name;
-        auto ts_file_path = base_name + ".ts";
        auto base_name_rel = std::string("./");
        base_name_rel +=
            namer_.Directories(rel_components, SkipDir::OutputPath);
        base_name_rel += base_file_name;
-        auto ts_file_path_rel = base_name_rel + ".ts";
        auto type_name = def.first;
        auto fully_qualified_type_name =
            it.second.ns->GetFullyQualifiedName(type_name);
@@ -311,7 +308,6 @@ class TsGenerator : public BaseGenerator {
      const auto child_ns_level = it.second.ns->components.size() + 1;
      for (const auto& it2 : ns_defs_) {
        if (it2.second.ns->components.size() != child_ns_level) continue;
-        auto ts_file_path = it2.second.path + ".ts";
        code += "export * as " + it2.second.symbolic_name + " from './";
        int count = it2.second.ns->components.size() > 1 ? 2 : 1;
        std::vector<std::string> rel_path;
@@ -1176,7 +1172,6 @@ class TsGenerator : public BaseGenerator {
    if (union_type.enum_def) {
      const auto& enum_def = *union_type.enum_def;
      const auto enum_type = AddImport(imports, dependent, enum_def).name;
-      const std::string union_accessor = "this." + field_name;

      const auto union_has_string = UnionHasStringType(enum_def);
      const auto field_binded_method = "this." + field_name + ".bind(this)";
@@ -16,6 +16,30 @@

 import Foundation

+@inline(__always)
+private func verifySizePrefix(
+  byteBuffer: inout ByteBuffer,
+  requireExactSize: Bool,
+  options: VerifierOptions) throws
+{
+  let verifier = try Verifier(buffer: &byteBuffer, options: options)
+  let prefixPosition = byteBuffer.reader
+  let prefix: UOffset = try verifier.getValue(at: prefixPosition)
+  let availableSize = byteBuffer.size &- UOffset(MemoryLayout<UOffset>.size)
+
+  if requireExactSize {
+    guard prefix == availableSize else {
+      throw FlatbuffersErrors.prefixedSizeNotEqualToBufferSize
+    }
+  } else if prefix > availableSize {
+    throw FlatbuffersErrors.outOfBounds(
+      position: UInt(prefixPosition)
+        &+ UInt(MemoryLayout<UOffset>.size)
+        &+ UInt(prefix),
+      end: byteBuffer.capacity)
+  }
+}
+
 /// Takes in a prefixed sized buffer, where the prefixed size would be skipped.
 /// And would verify that the buffer passed is a valid `Flatbuffers` Object.
 /// - Parameters:
@@ -31,6 +55,10 @@ public func getPrefixedSizeCheckedRoot<T: FlatBufferTable & Verifiable>(
  fileId: String? = nil,
  options: VerifierOptions = .init()) throws -> T
 {
+  try verifySizePrefix(
+    byteBuffer: &byteBuffer,
+    requireExactSize: false,
+    options: options)
  byteBuffer.skipPrefix()
  return try getCheckedRoot(
    byteBuffer: &byteBuffer,
@@ -53,10 +81,11 @@ public func getCheckedPrefixedSizeRoot<T: FlatBufferTable & Verifiable>(
  fileId: String? = nil,
  options: VerifierOptions = .init()) throws -> T
 {
-  let prefix = byteBuffer.skipPrefix()
-  if prefix != byteBuffer.size {
-    throw FlatbuffersErrors.prefixedSizeNotEqualToBufferSize
-  }
+  try verifySizePrefix(
+    byteBuffer: &byteBuffer,
+    requireExactSize: true,
+    options: options)
+  byteBuffer.skipPrefix()
  return try getCheckedRoot(
    byteBuffer: &byteBuffer,
    fileId: fileId,
@@ -95,14 +124,15 @@ public func getCheckedRoot<T: FlatBufferTable & Verifiable>(
  options: VerifierOptions = .init()) throws -> T
 {
  var verifier = try Verifier(buffer: &byteBuffer, options: options)
+  let rootPosition = byteBuffer.reader
  if let fileId = fileId {
-    try verifier.verify(id: fileId)
+    try verifier.verify(id: fileId, at: rootPosition)
  }
-  try ForwardOffset<T>.verify(&verifier, at: 0, of: T.self)
+  try ForwardOffset<T>.verify(&verifier, at: rootPosition, of: T.self)
  return T.init(
    byteBuffer,
-    o: Int32(byteBuffer.read(def: UOffset.self, position: byteBuffer.reader))
-      &+ Int32(byteBuffer.reader))
+    o: Int32(byteBuffer.read(def: UOffset.self, position: rootPosition))
+      &+ Int32(rootPosition))
 }

 /// Returns a `NON-Checked` flatbuffers object
@@ -215,12 +215,16 @@ public struct Verifier {
  }

  @inline(__always)
-  func verify(id: String) throws {
+  func verify(id: String, at position: Int) throws {
    let size = MemoryLayout<Int32>.size
-    guard storage.capacity >= (size &* 2) else {
+    guard
+      position >= 0,
+      position <= storage.capacity,
+      storage.capacity - position >= size &* 2
+    else {
      throw FlatbuffersErrors.bufferDoesntContainID
    }
-    let str = _buffer.readString(at: size, count: size)
+    let str = _buffer.readString(at: position &+ size, count: size)
    if id == str {
      return
    }
@@ -12,7 +12,7 @@ namespace Example {
 struct MonsterBinarySchema {
  static const uint8_t *data() {
    // Buffer containing the binary schema.
-    static const uint8_t bfbsData[14520] = {
+    alignas(uint64_t) static const uint8_t bfbsData[14520] = {
      0x20,0x00,0x00,0x00,0x42,0x46,0x42,0x53,0x00,0x00,0x00,0x00,0x14,0x00,0x20,0x00,0x04,0x00,0x08,0x00,
      0x0C,0x00,0x10,0x00,0x14,0x00,0x18,0x00,0x00,0x00,0x1C,0x00,0x14,0x00,0x00,0x00,0x58,0x00,0x00,0x00,
      0x34,0x00,0x00,0x00,0x24,0x00,0x00,0x00,0x18,0x00,0x00,0x00,0x70,0x0D,0x00,0x00,0x08,0x00,0x00,0x00,
@@ -373,6 +373,58 @@ final class FlatbuffersVerifierTests {
    }
  }

+  @Test
+  func testSizePrefixedVerifierUsesPostPrefixRoot() throws {
+    // The size prefix points to a valid empty decoy table at byte 44. The real
+    // root at byte 4 points to a truncated UInt64 vector that must be rejected.
+    let bytes: [UInt8] = [
+      44, 0, 0, 0,
+      16, 0, 0, 0,
+      6, 0, 8, 0, 4, 0,
+      0, 0, 0, 0, 0, 0,
+      12, 0, 0, 0,
+      8, 0, 0, 0, 0, 0, 0, 0,
+      2, 0, 0, 0, 65, 66,
+      0, 0,
+      4, 0, 4, 0,
+      4, 0, 0, 0,
+    ]
+
+    var strictBuffer = ByteBuffer(bytes: bytes)
+    #expect(throws: FlatbuffersErrors.self) {
+      try getCheckedPrefixedSizeRoot(
+        byteBuffer: &strictBuffer) as Swift_Tests_Vectors
+    }
+
+    var prefixedBuffer = ByteBuffer(bytes: bytes)
+    #expect(throws: FlatbuffersErrors.self) {
+      try getPrefixedSizeCheckedRoot(
+        byteBuffer: &prefixedBuffer) as Swift_Tests_Vectors
+    }
+
+    var builder = FlatBufferBuilder()
+    let movie = Movie.createMovie(&builder)
+    Movie.finish(&builder, end: movie, prefix: true)
+    var validBuffer = builder.sizedBuffer
+    let _: Movie = try getCheckedPrefixedSizeRoot(
+      byteBuffer: &validBuffer,
+      fileId: Movie.id)
+
+    var shortBuffer = ByteBuffer(bytes: [0, 0, 0, 0])
+    #expect(throws: FlatbuffersErrors.bufferDoesntContainID) {
+      try getCheckedRoot(
+        byteBuffer: &shortBuffer,
+        fileId: Movie.id) as Movie
+    }
+
+    var oversizedPrefix = ByteBuffer(bytes: [5, 0, 0, 0, 0, 0, 0, 0])
+    #expect(throws: FlatbuffersErrors.outOfBounds(position: 9, end: 8)) {
+      try getPrefixedSizeCheckedRoot(
+        byteBuffer: &oversizedPrefix) as Movie
+    }
+    #expect(oversizedPrefix.reader == 0)
+  }
+
  @Test
  func testFullVerifier() throws {
    _ =
Author	SHA1	Message	Date
Anshul Nigham	e38e7aa00c	Removing `_LIBCPP_DISABLE_UNUSED_STRUCT_WARNINGS` from libc++ enables `[[gnu::__warn_unused__]]` on standard library types (such as `std::string` and `std::set`), surfacing `-Wunused-variable` warnings in `//third_party/flatbuffers`. See [upstream LLVM commit](https://github.com/llvm/llvm-project/commit/ab8b037ef7b398aa864959a69f328fa69b567f74) for reference. Remove unreferenced variable declarations across the code generators and binary annotator whose initializers have no observable side effects. PiperOrigin-RevId: 999136370	2026-10-26 16:02:57 -07:00
Omar AbdelsalamandDerek Bailey	f58d5768f1	Pin swift-crypto for the Swift CI matrix (#9412 ) The Swift test job pulls in grpc-swift-2 -> grpc-swift-nio-transport -> swift-nio-ssl -> swift-crypto, and this package ships no Package.resolved, so that whole graph is resolved afresh on every run. On 2026-10-15 it resolved swift-crypto 5.0.1 (released three days earlier) and "Test Swift Linux (6.2)" turned red before a single line of FlatBuffers' Swift code was compiled: Sources/Crypto/HPKE/Ciphersuite/HPKE-AEAD.swift:27:6: error: unknown attribute 'nonexhaustive' 5.x declares swift-tools-version 6.2, which is why only the 6.2 job selects it; the 6.0 and 6.1 jobs prune it and keep building. The 6.2.x toolchains then reject the `@nonexhaustive` that 5.x uses, a combination swift-crypto does not exercise because it builds on nightly. Restrict the test-only graph to 4.0.0 ..< 4.4.0, which resolves to 4.3.0: the last 4.x release that declares swift-tools-version 6.0 and so builds with every toolchain in the matrix. 4.4+ asks for 6.1 and would break the 6.0 job, and the whole 4.x line is free of `@nonexhaustive`. Co-authored-by: Derek Bailey <derekbailey@google.com>	2026-10-26 10:11:08 -07:00
Derek Bailey	7af1efe4b2	Regenerate monster_test_bfbs_generated.h with alignas(uint64_t) (#9434 ) Commit `6dda43bb` (#9425) added `alignas(uint64_t)` to embedded binary schemas generated by `flatc --bfbs-gen-embed`. Regenerate `tests/monster_test_bfbs_generated.h` via `scripts/generate_code.py` to keep checked-in test artifacts in sync and unblock CI Check Generated Code. GitOrigin-RevId: 3786479bebd33365edc91aa13388cdf95d7313d9	2026-10-26 09:06:45 -07:00
Derek Bailey	6dda43bbaa	Ensure embedded FlatBuffers binary schemas are 8-byte aligned (#9425 ) In `src/idl_gen_cpp.cpp`, code generated by `flatc --bfbs-gen-embed` emits `static const uint8_t bfbsData[...] = { ... };`. Because `uint8_t` has 1-byte alignment, the array may be placed at an unaligned address in `.rodata`, triggering alignment traps under Clang UBSan on Arm when accessed via FlatBuffers root accessors. Add `alignas(uint64_t)` to the generated `bfbsData` array declaration in `GenerateBinarySchema` so embedded binary schemas are 8-byte aligned across all architectures. PiperOrigin-RevId: 1003962636	2026-10-21 13:37:51 -07:00
Derek Bailey	9a8a511b52	Enable locale-independent strtod_l/strtof_l on Linux glibc (#9424 ) Restrict the `__linux__` check for `FLATBUFFERS_LOCALE_INDEPENDENT` in `include/flatbuffers/base.h` to `(!defined(__linux__) \|\| defined(__GLIBC__))` so Linux with glibc enables `strtod_l`/`strtof_l`. PiperOrigin-RevId: 1002266254	2026-10-21 13:25:17 -07:00
Wouter van Oortmerssen	b8431fbcd7	Lobster: change builder size constants (enum -> let) This is because newer versions of the Lobster compiler reject enums with the same values, and older compilers are fine with the let versions also.	2026-09-14 11:02:13 -07:00
carrerasdarren-cellandDarren Carreras	5761d6e67a	[Swift] Verify size-prefixed roots from reader position (#9196 ) * [Swift] Verify size-prefixed roots from reader position Validate the size prefix before advancing ByteBuffer.reader, then use the active reader position consistently for root, file identifier, and returned-object verification. Cover malformed decoy roots, oversized prefixes, short identifiers, and valid prefixed identifiers. * Use wrapping arithmetic in Swift verifier --------- Co-authored-by: Darren Carreras <283775510+carrerasdarren-cell@users.noreply.github.com>	2026-08-11 21:49:44 +02:00