Add FLATBUFFERS_STRICT_MODE (#7408)

2026-06-02 04:04:19 +00:00 · 2022-08-06 21:06:14 -07:00
parent 950444a343
commit 9a5ff89003
4 changed files with 45 additions and 35 deletions
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -19,7 +19,7 @@ jobs:
    steps:
    - uses: actions/checkout@v2
    - name: cmake
-      run: CXX=${{ matrix.cxx }} cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release .
+      run: CXX=${{ matrix.cxx }} cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON .
    - name: build
      run: make -j
    - name: test
@@ -42,7 +42,7 @@ jobs:
    - name: Add msbuild to PATH
      uses: microsoft/setup-msbuild@v1.1
    - name: cmake
-      run: cmake -G "Visual Studio 16 2019" -A x64 -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_BUILD_CPP17=ON .
+      run: cmake -G "Visual Studio 16 2019" -A x64 -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_BUILD_CPP17=ON -DFLATBUFFERS_STRICT_MODE=ON .
    - name: build
      run: msbuild.exe FlatBuffers.sln /p:Configuration=Release /p:Platform=x64
    - name: test
@@ -61,7 +61,7 @@ jobs:
    - name: Add msbuild to PATH
      uses: microsoft/setup-msbuild@v1.1
    - name: cmake
-      run: cmake -G "Visual Studio 16 2019" -A x64 -DCMAKE_BUILD_TYPE=Release .
+      run: cmake -G "Visual Studio 16 2019" -A x64 -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON .
    - name: build tool version 15 (VS 2017)
      run: msbuild.exe FlatBuffers.sln /p:Configuration=Release /p:Platform=x64 /p:VisualStudioVersion=15.0
    - name: test
@@ -75,7 +75,7 @@ jobs:
    - name: Add msbuild to PATH
      uses: microsoft/setup-msbuild@v1.1
    - name: cmake
-      run: cmake -G "Visual Studio 14 2015" -A x64 -DCMAKE_BUILD_TYPE=Release .
+      run: cmake -G "Visual Studio 14 2015" -A x64 -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON .
    - name: build tool version 14 (VS 2015)
      run: msbuild.exe FlatBuffers.sln /p:Configuration=Release /p:Platform=x64 /p:VisualStudioVersion=14.0
    - name: test
@@ -115,7 +115,7 @@ jobs:
    steps:
    - uses: actions/checkout@v2
    - name: cmake
-      run: cmake -G "Xcode" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_FLATC_EXECUTABLE=_build/Release/flatc .
+      run: cmake -G "Xcode" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_FLATC_EXECUTABLE=_build/Release/flatc -DFLATBUFFERS_STRICT_MODE=ON .
    - name: build
      # NOTE: we need this _build dir to not have xcodebuild's default ./build dir clash with the BUILD file.
      run: xcodebuild -toolchain clang -configuration Release -target flattests SYMROOT=$(PWD)/_build
@@ -142,7 +142,7 @@ jobs:
    steps:
    - uses: actions/checkout@v2
    - name: cmake
-      run: cmake -G "Xcode" -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_FLATC_EXECUTABLE=_build/Release/flatc .
+      run: cmake -G "Xcode" -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_FLATC_EXECUTABLE=_build/Release/flatc -DFLATBUFFERS_STRICT_MODE=ON .
    - name: build
      # NOTE: we need this _build dir to not have xcodebuild's default ./build dir clash with the BUILD file.
      run: xcodebuild -toolchain clang -configuration Release -target flattests SYMROOT=$(PWD)/_build
@@ -176,7 +176,7 @@ jobs:
       java-version: 1.8
   - name: set up flatc
     run: |
-       cmake -DFLATBUFFERS_BUILD_TESTS=OFF -DFLATBUFFERS_BUILD_FLATLIB=OFF -DFLATBUFFERS_BUILD_FLATHASH=OFF .
+       cmake -DFLATBUFFERS_BUILD_TESTS=OFF -DFLATBUFFERS_BUILD_FLATLIB=OFF -DFLATBUFFERS_BUILD_FLATHASH=OFF -DFLATBUFFERS_STRICT_MODE=ON .
       make -j
       echo "${PWD}" >> $GITHUB_PATH
   - name: build
@@ -192,7 +192,7 @@ jobs:
    steps:
    - uses: actions/checkout@v2
    - name: cmake
-      run: CXX=${{ matrix.cxx }} cmake -G "Unix Makefiles" -DFLATBUFFERS_BUILD_TESTS=OFF -DCMAKE_BUILD_TYPE=Release . && make -j
+      run: CXX=${{ matrix.cxx }} cmake -G "Unix Makefiles" -DFLATBUFFERS_BUILD_TESTS=OFF -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON . && make -j
    - name: Generate
      run: scripts/check_generate_code.py
    - name: Generate gRPC
@@ -207,7 +207,7 @@ jobs:
    steps:
    - uses: actions/checkout@v2
    - name: cmake
-      run: CXX=${{ matrix.cxx }} cmake -G "Unix Makefiles" -DFLATBUFFERS_CXX_FLAGS="-Wno-unused-parameter -fno-aligned-new" -DFLATBUFFERS_BUILD_BENCHMARKS=ON -DCMAKE_BUILD_TYPE=Release . && make -j
+      run: CXX=${{ matrix.cxx }} cmake -G "Unix Makefiles" -DFLATBUFFERS_CXX_FLAGS="-Wno-unused-parameter -fno-aligned-new" -DFLATBUFFERS_BUILD_BENCHMARKS=ON -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON . && make -j
    - name: Run benchmarks
      run: ./flatbenchmark --benchmark_repetitions=5 --benchmark_display_aggregates_only=true --benchmark_out_format=console --benchmark_out=benchmarks/results_${{matrix.cxx}}
    - name: Upload benchmarks results
@@ -283,7 +283,7 @@ jobs:
    - uses: actions/checkout@v2
    - 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
+      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
    - name: test
      working-directory: tests
      run: bash GoTest.sh
@@ -331,7 +331,7 @@ jobs:
          sdk: stable
      - 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
+        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
      - name: test
        working-directory: tests
        run: bash DartTest.sh
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -64,7 +64,7 @@ jobs:
    #    uses a compiled language

    - run: |
-       cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release .
+       cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_STRICT_MODE=ON .
       make -j       

    - name: Perform CodeQL Analysis
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -74,6 +74,9 @@ option(FLATBUFFERS_ENABLE_PCH
 option(FLATBUFFERS_SKIP_MONSTER_EXTRA 
      "Skip generating monster_extra.fbs that contains non-supported numerical\"
      types." OFF)
+option(FLATBUFFERS_STRICT_MODE 
+      "Build flatbuffers with all warnings as errors (-Werror or /WX)."
+      OFF)

 set(MSVC_LIKE OFF)
 if(MSVC OR CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC")
@@ -344,7 +347,9 @@ if(MSVC_LIKE)
  target_compile_options(ProjectConfig
    INTERFACE 
      /W4
-      /WX
+      $<$<BOOL:${FLATBUFFERS_STRICT_MODE}>:
+        /WX       # Treat all compiler warnings as errors
+      >
      /wd4512   # C4512: assignment operator could not be generated
      /wd4316   # C4316: object allocated on the heap may not be aligned
      /wd4456   # C4456: hides previous local declaration
@@ -356,9 +361,10 @@ else()
  target_compile_options(ProjectConfig
    INTERFACE
      -Wall
-      -Werror
+      $<$<BOOL:${FLATBUFFERS_STRICT_MODE}>:
+        -Werror   # Treat all compiler warnings as errors
+      >
      -pedantic 
-      -Werror 
      -Wextra 
      -Wno-unused-parameter
      -Wold-style-cast
@@ -370,20 +376,26 @@ else()
        $<$<VERSION_GREATER:$<CXX_COMPILER_VERSION>,3.8>:
          -Wimplicit-fallthrough
          -Wextra-semi
-          -Werror=unused-private-field
+          $<$<BOOL:${FLATBUFFERS_STRICT_MODE}>:            
+            -Werror=unused-private-field
+          >
        >
      >

      $<$<CXX_COMPILER_ID:GNU>:
        $<$<VERSION_GREATER:$<CXX_COMPILER_VERSION>,4.4>:
-          -Wunused-result 
-          -Werror=unused-result 
+          -Wunused-result
          -Wunused-parameter 
-          -Werror=unused-parameter
+          $<$<BOOL:${FLATBUFFERS_STRICT_MODE}>:
+            -Werror=unused-result           
+            -Werror=unused-parameter
+          >
        >
        $<$<VERSION_GREATER:$<CXX_COMPILER_VERSION>,7.0>:
          -faligned-new 
-          -Werror=implicit-fallthrough=2
+          $<$<BOOL:${FLATBUFFERS_STRICT_MODE}>:
+            -Werror=implicit-fallthrough=2
+          >
        >
        $<$<VERSION_GREATER:$<CXX_COMPILER_VERSION>,8.0>:
          -Wextra-semi
--- a/docs/source/Building.md
+++ b/docs/source/Building.md
@@ -31,24 +31,22 @@ run 'flattests' or `flatsampletext`, or it will fail to load its files.*

 ### Make all warnings into errors

-By default all Flatbuffers `cmake` targets are build with `-Werror` flag.
-With this flag (or `/WX` for MSVC) C++ compiler will treat all warnings as errors.
-Additionally `-Wall -pedantic -Wextra` (or `/W4` form MSVC) flags are set.
-These flags minimize the number of possible defects in code and keep code highly portable.
-Using these flags is considered good practice but sometimes it can break dependent projects 
-if a compiler is upgraded or a toolset is changed.
-Usually, newer compiler versions add new compile-time diagnostics that were unavailable before.
-These new diagnostic warnings could stop the build process if `-Werror` flag is set.
+By default all Flatbuffers `cmake` targets are **not** built with the `-Werror` 
+(or `/WX` for MSVC) flag that treats any warning as an error. This allows more 
+flexibility for users of Flatbuffers to use newer compilers and toolsets that
+may add new warnings that would cause a build failure.

-It is possible to cancel `warnings as errors` flag at `cmake` configuration stage using 
-`FLATBUFFERS_CXX_FLAGS` option. Compilation flags declared in `FLATBUFFERS_CXX_FLAGS` will be 
-appended to the project-level `CMAKE_CXX_FLAGS` variable.
-Examples:
+To enable a stricter build that does treat warnings as errors, set the
+`FLATBUFFERS_STRICT_MODE` `cmake` compliation flag to `ON`. 

- GCC and Clang: `cmake . -D FLATBUFFERS_CXX_FLAGS="-Wno-error"`
- MSVC: `cmake . -D FLATBUFFERS_CXX_FLAGS="/WX-"`
- MSVC: `cmake . -D FLATBUFFERS_CXX_FLAGS="/Wv <compiler.version>"`
+```
+cmake . -DFLATBUFFERS_STRICT_MODE=ON
+```

+Our CI builds run with strict mode on, ensuring the code that is committed to 
+the project is as portable and warning free as possible. Thus developers
+contributing to the project should enable strict mode locally before making a 
+PR.

 ## Building with VCPKG