Switch to Ninja generator for windows cmake builds.

These will still use MSVC as the compiler, but will no longer generate Visual Studio projects for the builds.  Visual Studio is particularly bad at parallelizing builds, and is hostile to ccache.

This change also tweaks the ccache setup to prevent unbounded the growth observed in our github caches.  Windows builds have had debug symbols stripped to reduce ccache size by a factor of 2x, and ccache maximum have been tweaked so that we persist fewer older builds.

Before this change, each CMake build took 12 minutes on every run (plus some constant overhead from staleness/gcloud), even with caching or on large multi-core runners.  No amount of caching or parallelization made any noticeable difference above noise.  With this change, we see the following improvements:
- 12 minutes to build from scratch on normal runners (unchanged)
- 4 minutes on 32-core runners from scratch
- 1 minute with optimal caches available on normal runners.
- 30 seconds on 32-core runners with optimal caches

PiperOrigin-RevId: 508799909

.github/actions/ccache/action.yml

@@ -12,6 +12,18 @@ inputs:
 runs:
   using: 'composite'
   steps:
+    - name: Configure ccache environment variables
+      shell: bash
+      run: |
+        echo "CCACHE_BASEDIR=${{ github.workspace }}" >> $GITHUB_ENV
+        echo "CCACHE_DIR=${{ github.workspace }}/.ccache" >> $GITHUB_ENV
+        echo "CCACHE_COMPRESS=true" >> $GITHUB_ENV
+        echo "CCACHE_COMPRESSLEVEL=5" >> $GITHUB_ENV
+        echo "CCACHE_MAXSIZE=100M" >> $GITHUB_ENV
+        echo "CCACHE_SLOPPINESS=clang_index_store,include_file_ctime,include_file_mtime,file_macro,time_macros" >> $GITHUB_ENV
+        echo "CCACHE_DIRECT=true" >> $GITHUB_ENV
+        echo "CCACHE_CMAKE_FLAGS=-Dprotobuf_ALLOW_CCACHE=ON -DCMAKE_C_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_COMPILER_LAUNCHER=ccache" >> $GITHUB_ENV
+
     - name: Setup ccache on Windows
       if: ${{ runner.os == 'Windows' }}
       uses: ./.github/actions/internal/ccache-setup-windows
@@ -23,7 +35,10 @@ runs:
     - name: Setup fixed path ccache caching
       uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
       with:
-        path: .ccache
+        path: |
+          .ccache/**
+          !.ccache/lock
+          !.ccache/tmp
         # Always push to a cache key unique to this commit.
         key: ${{ format('ccache-{0}-{1}-{2}', inputs.cache-prefix, github.ref_name, github.sha) }}
         # Select a cache to restore from with the follow order of preference:
@@ -35,18 +50,6 @@ runs:
           ${{ format('ccache-{0}-{1}', inputs.cache-prefix, github.ref_name) }}
           ${{ format('ccache-{0}-{1}', inputs.cache-prefix, github.base_ref) }}
 
-    - name: Configure ccache environment variables
-      shell: bash
-      run: |
-        echo "CCACHE_BASEDIR=${{ github.workspace }}" >> $GITHUB_ENV
-        echo "CCACHE_DIR=${{ github.workspace }}/.ccache" >> $GITHUB_ENV
-        echo "CCACHE_COMPRESS=true" >> $GITHUB_ENV
-        echo "CCACHE_COMPRESSLEVEL=6" >> $GITHUB_ENV
-        echo "CCACHE_MAXSIZE=600M" >> $GITHUB_ENV
-        echo "CCACHE_SLOPPINESS=clang_index_store,include_file_ctime,include_file_mtime,file_macro,time_macros" >> $GITHUB_ENV
-        echo "CCACHE_DIRECT=true" >> $GITHUB_ENV
-        echo "CCACHE_CMAKE_FLAGS=-Dprotobuf_ALLOW_CCACHE=ON -DCMAKE_C_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_COMPILER_LAUNCHER=ccache $CCACHE_CMAKE_FLAGS" >> $GITHUB_ENV
-
     - name: Enable module support
       if: ${{ inputs.support-modules }}
       shell: bash
@@ -55,11 +58,6 @@ runs:
         echo "CCACHE_DEPEND=true" >> $GITHUB_ENV
 
     - name: Zero out ccache
-      if: ${{ runner.os == 'macOS' }}
+      if: ${{ runner.os != 'Linux' }}
       shell: bash
       run: ccache -z
-
-    - name: Zero out ccache
-      if: ${{ runner.os == 'Windows' }}
-      shell: pwsh
-      run: ${{ github.workspace }}\ccache.exe -z

.github/actions/internal/ccache-setup-windows/action.yml

@@ -10,6 +10,16 @@ inputs:
 runs:
   using: 'composite'
   steps:
+    - name: Setup MSVC
+      uses: ilammy/msvc-dev-cmd@cec98b9d092141f74527d0afa6feb2af698cfe89 # v1.12.1
+      with:
+        arch: x64
+        vsversion: '2019'
+
+    - name: Install ccache
+      shell: bash
+      run: choco install ccache --version=4.7.4
+
     - name: Configure ccache environment variables
       shell: pwsh
       run: |
@@ -18,19 +28,9 @@ runs:
         echo "CCACHE_COMPILER=$cllocation" | Out-File -FilePath $Env:GITHUB_ENV -Encoding utf8 -Append
         echo "CCACHE_COMPILERTYPE=msvc" | Out-File -FilePath $Env:GITHUB_ENV -Encoding utf8 -Append
 
-    - name: Download ccache
+    - name: Configure Windows-specific ccache environment variables
       shell: bash
+      # Windows caches are about 2x larger than other platforms.
       run: |
-        curl -kLSs "https://github.com/ccache/ccache/releases/download/v${{ inputs.ccache-version }}/ccache-${{ inputs.ccache-version }}-windows-x86_64.zip" -o ccache.zip
-        unzip ccache.zip
-        cp ccache-${{ inputs.ccache-version }}-windows-x86_64/ccache.exe ccache.exe
-        cp ccache.exe cl.exe
-        rm ccache.zip
-
-    - name: Configure msbuild flags
-      shell: bash
-      run: echo "CCACHE_MSBUILD_FLAGS=/p:CLToolExe=cl.exe /p:CLToolPath=${{ github.workspace}}" >> $GITHUB_ENV
-
-    - name: Configure cmake flags
-      shell: bash
-      run: echo "CCACHE_CMAKE_FLAGS=-Dprotobuf_ALLOW_CCACHE=ON" >> $GITHUB_ENV
+        echo "CCACHE_COMPRESSLEVEL=10" >> $GITHUB_ENV
+        echo "CCACHE_MAXSIZE=200M" >> $GITHUB_ENV

.github/workflows/test_cpp.yml

@@ -179,9 +179,34 @@ jobs:
           bazel: test ${{ matrix.bazel }}
           bazel-cache: cpp_${{ matrix.os }}
 
-  macos-cmake:
-    name: MacOS CMake
-    runs-on: macos-12
+  non-linux-cmake:
+    strategy:
+      fail-fast: false   # Don't cancel all jobs if one fails.
+      matrix:
+        include:
+          - name: MacOS CMake
+            os: macos-12
+            flags: -DCMAKE_CXX_STANDARD=14
+          - name: Windows CMake
+            os: windows-2019
+            flags: >-
+              -G Ninja -Dprotobuf_WITH_ZLIB=OFF -Dprotobuf_BUILD_CONFORMANCE=OFF
+              -Dprotobuf_BUILD_SHARED_LIBS=OFF
+              -Dprotobuf_BUILD_EXAMPLES=ON
+          - name: Windows CMake Shared
+            os: windows-2019
+            flags: >-
+              -G Ninja -Dprotobuf_WITH_ZLIB=OFF -Dprotobuf_BUILD_CONFORMANCE=OFF
+              -Dprotobuf_BUILD_SHARED_LIBS=ON
+          - name: Windows CMake Install
+            os: windows-2019
+            install-flags: -G Ninja -Dprotobuf_WITH_ZLIB=OFF -Dprotobuf_BUILD_CONFORMANCE=OFF -Dprotobuf_BUILD_TESTS=OFF
+            flags: >-
+              -G Ninja -Dprotobuf_WITH_ZLIB=OFF -Dprotobuf_BUILD_CONFORMANCE=OFF
+              -Dprotobuf_REMOVE_INSTALLED_HEADERS=ON
+              -Dprotobuf_BUILD_PROTOBUF_BINARIES=OFF
+    name: ${{ matrix.name }}
+    runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout pending changes
         uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
@@ -192,139 +217,46 @@ jobs:
       - name: Setup ccache
         uses: ./.github/actions/ccache
         with:
-          cache-prefix: macos-cmake
+          cache-prefix: ${{ matrix.name }}
+
+      # Install phase.
+      - name: Configure CMake for install
+        if: matrix.install-flags
+        uses: ./.github/actions/bash
+        with:
+          credentials: ${{ secrets.GAR_SERVICE_ACCOUNT }}
+          command: cmake . ${{ matrix.install-flags }} ${{ env.CCACHE_CMAKE_FLAGS }}
+      - name: Build for install
+        if: matrix.install-flags
+        shell: bash
+        run: VERBOSE=1 cmake --build . --parallel 20
+      - name: Install
+        if: matrix.install-flags
+        shell: bash
+        run: cmake --build . --target install
+      - name: Report and clear ccache stats
+        if: matrix.install-flags
+        shell: bash
+        run: ccache -s -v && ccache -z
+      - name: Clear CMake cache
+        if: matrix.install-flags
+        shell: bash
+        run: cmake --build . --target clean && rm CMakeCache.txt
 
       - name: Configure CMake
         uses: ./.github/actions/bash
         with:
           credentials: ${{ secrets.GAR_SERVICE_ACCOUNT }}
-          command: cmake . -DCMAKE_CXX_STANDARD=14 ${{ env.CCACHE_CMAKE_FLAGS }}
+          command: cmake . ${{ matrix.flags }} ${{ env.CCACHE_CMAKE_FLAGS }}
+
       - name: Build
-        run: cmake --build . --parallel 8
+        shell: bash
+        run: VERBOSE=1 cmake --build . --parallel 20
+
       - name: Test
+        shell: bash
         run: ctest --verbose --parallel 20 -C Debug
 
       - name: Report ccache stats
         shell: bash
         run: ccache -s -v
-
-  windows-cmake:
-    strategy:
-      fail-fast: false   # Don't cancel all jobs if one fails.
-      matrix:
-        include:
-          - name: Visual Studio
-            flags: >-
-              -Dprotobuf_BUILD_SHARED_LIBS=OFF
-              -Dprotobuf_BUILD_EXAMPLES=ON
-          - name: Shared
-            flags: -Dprotobuf_BUILD_SHARED_LIBS=ON
-
-    name: Windows CMake ${{ matrix.name}}
-    runs-on: windows-2019
-    steps:
-      - name: Checkout pending changes
-        uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-        with:
-          submodules: recursive
-          ref: ${{ inputs.safe-checkout }}
-
-      - name: Setup MSVC
-        uses: ilammy/msvc-dev-cmd@cec98b9d092141f74527d0afa6feb2af698cfe89 # v1.12.1
-        with:
-          arch: x64
-          vsversion: '2019'
-
-      - name: Setup ccache
-        uses: ./.github/actions/ccache
-        with:
-          cache-prefix: windows-cmake-${{ matrix.name }}
-
-      - name: Configure CMake
-        uses: ./.github/actions/bash
-        with:
-          credentials: ${{ secrets.GAR_SERVICE_ACCOUNT }}
-          command: |
-            cmake . -G "Visual Studio 16 2019" -A x64 \
-              ${{ env.CCACHE_CMAKE_FLAGS }} \
-              -Dprotobuf_BUILD_CONFORMANCE=OFF \
-              -Dprotobuf_WITH_ZLIB=OFF \
-              ${{ matrix.flags }}
-
-      - name: Build for Windows 15 2017
-        run: >-
-          msbuild.exe protobuf.sln /p:MultiProcessorCompilation=true /p:CL_MPCount=8 /maxcpucount:8 /p:BuildInParallel=true
-          /p:Configuration=Debug /p:Platform=x64 /p:VisualStudioVersion=15.0
-          ${{ env.CCACHE_MSBUILD_FLAGS }}
-
-      - name: Run Tests
-        run: ctest --verbose --parallel 20 -C Debug
-
-      - name: Report ccache stats
-        run: ${{ github.workspace }}\ccache.exe -s -v
-
-  windows-cmake-install:
-    name: Windows CMake Install
-    runs-on: windows-2019
-    steps:
-      - name: Checkout pending changes
-        uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-        with:
-          submodules: recursive
-          ref: ${{ inputs.safe-checkout }}
-
-      - name: Setup MSVC
-        uses: ilammy/msvc-dev-cmd@cec98b9d092141f74527d0afa6feb2af698cfe89 # v1.12.1
-        with:
-          arch: x64
-          vsversion: '2019'
-
-      - name: Setup ccache
-        uses: ./.github/actions/ccache
-        with:
-          cache-prefix: windows-cmake
-
-      - name: Configure CMake for Install
-        uses: ./.github/actions/bash
-        with:
-          credentials: ${{ secrets.GAR_SERVICE_ACCOUNT }}
-          command: |
-            mkdir build
-            pushd build
-            cmake .. -G "Visual Studio 16 2019" -A x64 \
-              ${{ env.CCACHE_CMAKE_FLAGS }} \
-              -Dprotobuf_BUILD_CONFORMANCE=OFF \
-              -Dprotobuf_WITH_ZLIB=OFF
-            popd
-
-      - name: Build and Install Protobuf for Windows 15 2017
-        run: |
-          pushd build
-          msbuild.exe INSTALL.vcxproj /p:Platform=x64 /p:VisualStudioVersion=15.0 /p:MultiProcessorCompilation=true /p:CL_MPCount=8 /maxcpucount:8 /p:BuildInParallel=true ${{ env.CCACHE_MSBUILD_FLAGS }}
-          popd
-
-      - name: Clear CMake cache
-        shell: bash
-        run: rm -rf build/*
-
-      - name: Configure CMake
-        shell: bash
-        run: |
-          cmake . -G "Visual Studio 16 2019" -A x64 \
-            ${{ env.CCACHE_CMAKE_FLAGS }} \
-            -Dprotobuf_REMOVE_INSTALLED_HEADERS=ON \
-            -Dprotobuf_BUILD_PROTOBUF_BINARIES=OFF \
-            -Dprotobuf_BUILD_CONFORMANCE=OFF \
-            -Dprotobuf_WITH_ZLIB=OFF
-
-      - name: Build for Windows 15 2017
-        run: >-
-          msbuild.exe protobuf.sln /p:MultiProcessorCompilation=true /p:CL_MPCount=8 /maxcpucount:8 /p:BuildInParallel=true
-          /p:Configuration=Debug /p:Platform=x64 /p:VisualStudioVersion=15.0
-          ${{ env.CCACHE_MSBUILD_FLAGS }}
-
-      - name: Run Tests
-        run: ctest --verbose --parallel 20 -C Debug
-
-      - name: Report ccache stats
-        run: ${{ github.workspace }}\ccache.exe -s -v

CMakeLists.txt

@@ -292,13 +292,17 @@ if (MSVC)
   string(REPLACE "." ","  protobuf_RC_FILEVERSION "${protobuf_VERSION}")
 
   if (protobuf_ALLOW_CCACHE)
-    # In order to support ccache, we replace the /Zi option with /Z7.  This
+    # In order to support ccache, we need to remove the /Zi option because it
+    # puts debug symbols into separate pdb files (which in incompatible with
+    # ccache).  This can be replaced with /Z7 to preserve debug symbols, which
     # embeds debug symbols into the object files instead of creating a separate
-    # pdb file, which isn't currently supported by ccache.
-    string(REPLACE "/Zi" "/Z7" CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG}")
-    string(REPLACE "/Zi" "/Z7" CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}")
-    string(REPLACE "/Zi" "/Z7" CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO}")
-    string(REPLACE "/Zi" "/Z7" CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
+    # pdb file, which isn't currently supported by ccache.  However, this bloats
+    # the ccache size by about a factor of 2x, making it very expensive in CI.
+    # Instead, we strip debug symbols to reduce this overhead.
+    string(REPLACE "/Zi" "/DEBUG:NONE" CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG}")
+    string(REPLACE "/Zi" "/DEBUG:NONE" CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}")
+    string(REPLACE "/Zi" "/DEBUG:NONE" CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO}")
+    string(REPLACE "/Zi" "/DEBUG:NONE" CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
   endif()
 
   # Suppress linker warnings about files with no symbols defined.