Allow building Git for Windows with LLVM

This is a work in progress. Will provide a proper commit message later. Signed-off-by: Dennis Ameling <dennis@dennisameling.com>
git-for-windows · Oct 23, 2021 · 9ca3275 · 9ca3275
1 parent 3f28c5f
commit 9ca3275
Show file tree

Hide file tree

Showing 3 changed files with 135 additions and 6 deletions.
diff --git a/.github/workflows/llvm-build.yml b/.github/workflows/llvm-build.yml
@@ -0,0 +1,127 @@
+name: LLVM build
+
+on:
+  pull_request:
+
+env:
+  LLVM_VERSION: 20210423
+  LLVM_TYPE: msvcrt
+  VCPKG_VERSION_FOR_CACHE: 1
+  DEVELOPER: 1
+
+jobs:
+  vcpkg:
+    runs-on: windows-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        arch: [arm64, x64]
+    steps:
+    - uses: actions/checkout@v2
+    - shell: cmd
+      run: where windres
+    - name: Set LLVM path
+      shell: bash
+      run: echo "LLVM_PATH=`pwd`/llvm-build/llvm-mingw-${{ env.LLVM_VERSION }}-${{ env.LLVM_TYPE }}-x86_64" >> $GITHUB_ENV
+    - name: Cache LLVM
+      id: cache-llvm
+      uses: actions/cache@v2
+      with:
+        path: llvm-build
+        key: llvm-build-${{ env.LLVM_VERSION }}-${{ env.LLVM_TYPE }}
+    - shell: pwsh
+      if: steps.cache-llvm.outputs.cache-hit != 'true'
+      run: |
+        Invoke-WebRequest -Uri "https://github.com/mstorsjo/llvm-mingw/releases/download/${{ env.LLVM_VERSION }}/llvm-mingw-${{ env.LLVM_VERSION }}-${{ env.LLVM_TYPE }}-x86_64.zip" -OutFile "./llvm.zip"
+        Expand-Archive -LiteralPath './llvm.zip' -DestinationPath ./llvm-build
+    - name: initialize vcpkg
+      uses: actions/checkout@v2
+      with:
+        repository: 'dennisameling/vcpkg'
+        ref: 'llvm-mingw-clang'
+        path: 'compat/vcbuild/vcpkg'
+    - name: Cache vcpkg artifacts
+      id: cache-vcpkg
+      uses: actions/cache@v2
+      with:
+        path: compat/vcbuild/vcpkg/installed
+        key: vcpkg-cache-${{ env.VCPKG_VERSION_FOR_CACHE }}-${{ matrix.arch }}-${{ env.LLVM_VERSION }}-${{ env.LLVM_TYPE }}
+    - name: build packages
+      if: steps.cache-vcpkg.outputs.cache-hit != 'true'
+      shell: pwsh
+      run: .\compat\vcbuild\vcpkg_install.bat ${{ matrix.arch }}-windows-llvm-mingw
+      env:
+        # Temp workaround to get the paths to work
+        LLVM_PATH: D:/a/git/git/llvm-build/llvm-mingw-${{ env.LLVM_VERSION }}-${{ env.LLVM_TYPE }}-x86_64
+        VCPKG_ROOT: D:/a/git/git/compat/vcbuild/vcpkg
+        VCPKG_KEEP_ENV_VARS: "LLVM_PATH;VCPKG_ROOT"
+    - name: upload vcpkg artifacts
+      uses: actions/upload-artifact@v2
+      with:
+        name: vcpkg-artifacts-${{ matrix.arch }}
+        path: compat/vcbuild/vcpkg/installed
+
+  llvm-build:
+    needs: vcpkg
+    runs-on: windows-latest
+    env:
+      NO_PERL: 1
+      GIT_CONFIG_PARAMETERS: "'user.name=CI' 'user.email=ci@git'"
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - arch: x64
+            compilerArch: x86_64
+          - arch: arm64
+            compilerArch: aarch64
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set LLVM path
+      shell: bash
+      run: echo "LLVM_PATH=`pwd`/llvm-build/llvm-mingw-${{ env.LLVM_VERSION }}-${{ env.LLVM_TYPE }}-x86_64" >> $GITHUB_ENV
+    - name: Cache LLVM
+      id: cache-llvm
+      uses: actions/cache@v2
+      with:
+        path: llvm-build
+        key: llvm-build-${{ env.LLVM_VERSION }}-${{ env.LLVM_TYPE }}
+    - shell: pwsh
+      if: steps.cache-llvm.outputs.cache-hit != 'true'
+      run: |
+        Invoke-WebRequest -Uri "https://github.com/mstorsjo/llvm-mingw/releases/download/${{ env.LLVM_VERSION }}/llvm-mingw-${{ env.LLVM_VERSION }}-${{ env.LLVM_TYPE }}-x86_64.zip" -OutFile "./llvm.zip"
+        Expand-Archive -LiteralPath './llvm.zip' -DestinationPath ./llvm-build
+    - name: initialize vcpkg
+      uses: actions/checkout@v2
+      with:
+        repository: 'microsoft/vcpkg'
+        path: 'compat/vcbuild/vcpkg'
+    - name: download vcpkg artifacts
+      uses: actions/download-artifact@v2
+      with:
+        name: vcpkg-artifacts-${{ matrix.arch }}
+        path: compat/vcbuild/vcpkg/installed
+    - name: copy dlls to root
+      shell: cmd
+      run: compat\vcbuild\vcpkg_copy_dlls.bat release ${{ matrix.arch }}-windows-llvm-mingw
+    - shell: bash
+      run: |
+        mkdir `pwd`/artifacts
+        cmake `pwd`/contrib/buildsystems/ -DCMAKE_PREFIX_PATH=`pwd`/compat/vcbuild/vcpkg/installed/${{ matrix.arch }}-windows-llvm-mingw -DVCPKG_ARCH=${{ matrix.arch }}-windows-llvm-mingw \
+        -DNO_GETTEXT=YesPlease -DPERL_TESTS=OFF -DPYTHON_TESTS=OFF -DCURL_NO_CURL_CMAKE=ON -DCMAKE_C_COMPILER=${{ env.LLVM_PATH }}/bin/${{ matrix.compilerArch }}-w64-mingw32-clang.exe \
+        -DCMAKE_CXX_COMPILER=${{ env.LLVM_PATH }}/bin/${{ matrix.compilerArch }}-w64-mingw32-clang++.exe -DCMAKE_INSTALL_PREFIX=`pwd`/artifacts -G "MinGW Makefiles"
+    - shell: pwsh
+      run: make -j2
+    - shell: pwsh
+      run: make install
+    - name: Copy DLLs
+      shell: bash
+      # Workaround to get the DLLs into the installation directory
+      run: |
+        cp `pwd`/compat/vcbuild/vcpkg/installed/${{ matrix.arch }}-windows-llvm-mingw/bin/*.dll `pwd`/artifacts/bin
+        cp `pwd`/compat/vcbuild/vcpkg/installed/${{ matrix.arch }}-windows-llvm-mingw/bin/*.dll `pwd`/artifacts/libexec/git-core
+    - name: upload build artifacts
+      uses: actions/upload-artifact@v2
+      with:
+        name: llvm-artifacts-${{ matrix.arch }}
+        path: artifacts
diff --git a/compat/vcbuild/vcpkg_install.bat b/compat/vcbuild/vcpkg_install.bat
@@ -49,10 +49,11 @@ REM ================================================================
 	echo "***"
 	EXIT /B 1 )
 
-	echo Fetching vcpkg in %cwd%vcpkg
-	git.exe clone https://github.com/Microsoft/vcpkg vcpkg
-	IF ERRORLEVEL 1 ( EXIT /B 1 )
-
+	IF NOT EXIST vcpkg (
+		echo Fetching vcpkg in %cwd%vcpkg
+		git.exe clone https://github.com/Microsoft/vcpkg vcpkg
+		IF ERRORLEVEL 1 ( EXIT /B 1 )
+	)
 	cd vcpkg
 	echo Building vcpkg
 	powershell -exec bypass scripts\bootstrap.ps1

diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
@@ -276,7 +276,7 @@ endif()
 
 #Platform Specific
 if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
-	if(CMAKE_C_COMPILER_ID STREQUAL "MSVC" OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
+	if(CMAKE_C_COMPILER_ID STREQUAL "MSVC" OR (NOT CMAKE_GENERATOR STREQUAL "MinGW Makefiles" AND CMAKE_C_COMPILER_ID STREQUAL "Clang"))
 		include_directories(${CMAKE_SOURCE_DIR}/compat/vcbuild/include)
 		add_compile_definitions(_CRT_SECURE_NO_WARNINGS _CRT_NONSTDC_NO_DEPRECATE)
 	endif()
@@ -715,7 +715,8 @@ endif()
 if(WIN32)
 	target_link_libraries(common-main ws2_32 ntdll ${CMAKE_BINARY_DIR}/git.res)
 	add_dependencies(common-main git-rc)
-	if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
+	# MinGW Makefiles is used by the llvm-mingw toolchain on Windows (Clang)
+	if(CMAKE_C_COMPILER_ID STREQUAL "GNU" OR (CMAKE_GENERATOR STREQUAL "MinGW Makefiles" AND CMAKE_C_COMPILER_ID STREQUAL "Clang"))
 		target_link_options(common-main PUBLIC -municode -Wl,--nxcompat -Wl,--dynamicbase -Wl,--pic-executable,-e,mainCRTStartup)
 	elseif(CMAKE_C_COMPILER_ID STREQUAL "Clang")
 		target_link_options(common-main PUBLIC -municode -Wl,-nxcompat -Wl,-dynamicbase -Wl,-entry:wmainCRTStartup -Wl,invalidcontinue.obj)