[WIP] Enable building Git for Windows with LLVM/Clang

.github/workflows/git-artifacts.yml

@@ -23,6 +23,9 @@ env:
   BUILD_ONLY: "${{github.event.inputs.build_only}}"
   REPOSITORY: "${{github.event.inputs.repository}}"
   REF: "${{github.event.inputs.ref}}"
+  LLVM_VERSION: 20211002
+  LLVM_TYPE: msvcrt
+  VCPKG_VERSION_FOR_CACHE: 1
 
 jobs:
   bundle-artifacts:
@@ -200,9 +203,9 @@ jobs:
           printf '#!/bin/sh\n\nexec /mingw64/bin/git.exe "$@"\n' >/usr/bin/git &&
 
           # Restrict `PATH` to MSYS2 and to Visual Studio (to let `cv2pdb` find the relevant DLLs)
-          PATH="/mingw64/bin:/usr/bin:/C/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin${{matrix.arch.bin}}:/C/Windows/system32"
+          PATH="/mingw64/bin:/usr/bin:/C/Windows/system32"
 
-          type -p mspdb140.dll || exit 1
+          # type -p mspdb140.dll || exit 1
           sh -x /usr/src/build-extra/please.sh build-mingw-w64-git --only-${{matrix.arch.bitness}}-bit --build-src-pkg -o artifacts HEAD &&
           cp bundle-artifacts/ver artifacts/ &&
           if test -n "$GPGKEY"
@@ -268,43 +271,85 @@ jobs:
           git remote add -f origin https://github.com/git-for-windows/git &&
           git fetch --tags bundle-artifacts/git.bundle $(cat bundle-artifacts/next_version) &&
           git reset --hard $(cat bundle-artifacts/next_version)
-      - name: initialize vcpkg
+      - name: Set LLVM path
         if: env.SKIP != 'true'
-        uses: actions/checkout@v2
+        shell: bash
+        run: echo "LLVM_PATH=`pwd`/llvm-build/llvm-mingw-${{ env.LLVM_VERSION }}-${{ env.LLVM_TYPE }}-x86_64" >> $GITHUB_ENV
+      - name: Cache LLVM
+        if: env.SKIP != 'true'
+        id: cache-llvm
+        uses: actions/cache@v2
         with:
-          repository: 'microsoft/vcpkg'
-          path: 'compat/vcbuild/vcpkg'
-      - name: download vcpkg artifacts
+          path: llvm-build
+          key: llvm-build-${{ env.LLVM_VERSION }}-${{ env.LLVM_TYPE }}
+      - shell: pwsh
+        if: steps.cache-llvm.outputs.cache-hit != 'true' && env.SKIP != 'true'
+        run: |
+          Invoke-WebRequest -Uri "https://github.com/mstorsjo/llvm-mingw/releases/download/${{ 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: Setup MSYS2
         if: env.SKIP != 'true'
-        uses: git-for-windows/get-azure-pipelines-artifact@v0
+        uses: msys2/setup-msys2@v2
         with:
-          repository: git/git
-          definitionId: 9
-      - name: add msbuild to PATH
+          msystem: MSYS
+      - name: Add clangarm64 server
         if: env.SKIP != 'true'
-        uses: microsoft/setup-msbuild@v1
-      - name: copy dlls to root
+        shell: msys2 {0}
+        run: |
+          cat <<EOF >> /etc/pacman.conf
+          [clangarm64]
+          Server = https://mirror.msys2.org/mingw/clangarm64/
+          EOF
+      - name: Update package database with arm64 entries
         if: env.SKIP != 'true'
-        shell: powershell
+        shell: msys2 {0}
+        run: pacman -Sy
+      - name: Install packages
+        if: env.SKIP != 'true'
+        shell: msys2 {0}
         run: |
-          & compat\vcbuild\vcpkg_copy_dlls.bat release arm64-windows
-          if (!$?) { exit(1) }
-      - name: generate Visual Studio solution
+          pacman -S --noconfirm mingw-w64-clang-aarch64-openssl mingw-w64-clang-aarch64-zlib \
+          mingw-w64-clang-aarch64-curl mingw-w64-clang-aarch64-expat \
+          mingw-w64-clang-aarch64-libiconv mingw-w64-clang-aarch64-toolchain
+      - name: Set MSYS2 root as env variable
         if: env.SKIP != 'true'
-        shell: bash
+        shell: msys2 {0}
+        run: echo "MSYS_ROOT=$(cygpath -m /)" >> $GITHUB_ENV
+      - shell: bash
+        if: env.SKIP != 'true'
+        # We need to remove mingw32-make.exe (which is arm64-native) as it clashes with cmake
         run: |
-          cmake `pwd`/contrib/buildsystems/ -DCMAKE_PREFIX_PATH=`pwd`/compat/vcbuild/vcpkg/installed/arm64-windows \
-          -DNO_GETTEXT=YesPlease -DPERL_TESTS=OFF -DPYTHON_TESTS=OFF -DCURL_NO_CURL_CMAKE=ON -DCMAKE_GENERATOR_PLATFORM=arm64 -DVCPKG_ARCH=arm64-windows \
-          -DCMAKE_INSTALL_PREFIX="`pwd`/git-arm64" -DSKIP_DASHED_BUILT_INS=ON -DHOST_CPU=arm64
-      - name: MSBuild
+          rm ${{ env.MSYS_ROOT }}clangarm64/bin/mingw32-make.exe
+          mkdir `pwd`/git-arm64
+          cmake `pwd`/contrib/buildsystems/ -DCMAKE_PREFIX_PATH=${{ env.MSYS_ROOT }}clangarm64 -DNO_GETTEXT=YesPlease \
+          -DPERL_TESTS=OFF -DPYTHON_TESTS=OFF -DCURL_NO_CURL_CMAKE=ON \
+          -DCMAKE_C_COMPILER=${{ env.LLVM_PATH }}/bin/aarch64-w64-mingw32-clang.exe \
+          -DCMAKE_CXX_COMPILER=${{ env.LLVM_PATH }}/bin/aarch64-w64-mingw32-clang++.exe \
+          -DCMAKE_RC_COMPILER=${{ env.LLVM_PATH }}/bin/aarch64-w64-mingw32-windres.exe \
+          -DCMAKE_INSTALL_PREFIX=`pwd`/git-arm64 -DSKIP_DASHED_BUILT_INS=ON -DHOST_CPU=arm64 -DUSE_VCPKG=OFF -G "MinGW Makefiles"
+      - shell: pwsh
         if: env.SKIP != 'true'
-        run: msbuild git.sln -property:Configuration=Release
-      - name: Link the Git executables
+        run: make -j2
+      - shell: pwsh
         if: env.SKIP != 'true'
-        run: msbuild INSTALL.vcxproj -property:Configuration=Release
+        run: make install
+      # Workaround to get the DLLs into the installation directory
+      - name: Copy DLLs
+        if: env.SKIP != 'true'
+        shell: msys2 {0}
+        run: |
+          DLLS="libbrotlicommon.dll libbrotlidec.dll libcrypto-1_1.dll libcurl-4.dll libexpat-1.dll \
+          libiconv-2.dll libidn2-0.dll libintl-8.dll libnghttp2-14.dll libpsl-5.dll libssh2-1.dll \
+          libssl-1_1.dll libunistring-2.dll libwinpthread-1.dll libzstd.dll zlib1.dll"
+
+          for ITEM in ${DLLS}
+          do
+            cp /clangarm64/bin/${ITEM} `pwd`/git-arm64/bin
+            cp /clangarm64/bin/${ITEM} `pwd`/git-arm64/libexec/git-core
+          done
       - name: upload build artifacts
         if: env.SKIP != 'true'
-        uses: actions/upload-artifact@v1
+        uses: actions/upload-artifact@v2
         with:
           name: arm64-artifacts
           path: ./git-arm64
@@ -433,7 +478,7 @@ jobs:
           fi &&
           openssl dgst -sha256 artifacts/${{matrix.artifact.fileprefix}}-*.${{matrix.artifact.fileextension}} | sed "s/.* //" >artifacts/sha-256.txt
       - name: Copy package-versions and pdbs
-        if: env.SKIP != 'true' && matrix.artifact.name == 'installer'
+        if: env.SKIP != 'true' && matrix.artifact.name == 'installer' && 'skipThisForNow' == 'dummy'
         shell: bash
         run: |
           cp /usr/src/build-extra/installer/package-versions.txt artifacts/ &&

.github/workflows/llvm-build.yml

@@ -0,0 +1,100 @@
+name: LLVM build
+
+on:
+  pull_request:
+
+env:
+  LLVM_VERSION: 20211002
+  LLVM_TYPE: msvcrt
+  DEVELOPER: 1
+
+jobs:
+  llvm-build:
+    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
+            msysArch: clang64
+          - arch: arm64
+            compilerArch: aarch64
+            msysArch: clangarm64
+    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: Setup MSYS2
+      uses: msys2/setup-msys2@v2
+      with:
+        msystem: MSYS
+    - name: Add clangarm64 server
+      if: matrix.msysArch == 'clangarm64'
+      shell: msys2 {0}
+      run: |
+        cat <<EOF >> /etc/pacman.conf
+        [clangarm64]
+        Server = https://mirror.msys2.org/mingw/clangarm64/
+        EOF
+    - name: Update package database with arm64 entries
+      if: matrix.msysArch == 'clangarm64'
+      shell: msys2 {0}
+      run: pacman -Sy
+    - name: Install packages
+      shell: msys2 {0}
+      run: |
+        pacman -S --noconfirm mingw-w64-clang-${{ matrix.compilerArch }}-openssl mingw-w64-clang-${{ matrix.compilerArch }}-zlib \
+        mingw-w64-clang-${{ matrix.compilerArch }}-curl mingw-w64-clang-${{ matrix.compilerArch }}-expat \
+        mingw-w64-clang-${{ matrix.compilerArch }}-libiconv mingw-w64-clang-${{ matrix.compilerArch }}-toolchain
+    - name: Set MSYS2 root as env variable
+      shell: msys2 {0}
+      run: echo "MSYS_ROOT=$(cygpath -m /)" >> $GITHUB_ENV
+    - shell: bash
+      # We need to remove mingw32-make.exe (which is arm64-native) as it clashes with cmake
+      run: |
+        rm ${{ env.MSYS_ROOT }}${{ matrix.msysArch }}/bin/mingw32-make.exe
+        mkdir `pwd`/artifacts
+        cmake `pwd`/contrib/buildsystems/ -DCMAKE_PREFIX_PATH=${{ env.MSYS_ROOT }}${{ matrix.msysArch }} -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_RC_COMPILER=${{ env.LLVM_PATH }}/bin/${{ matrix.compilerArch }}-w64-mingw32-windres.exe \
+        -DCMAKE_INSTALL_PREFIX=`pwd`/artifacts -DSKIP_DASHED_BUILT_INS=ON -DHOST_CPU=${{ matrix.arch }} -DUSE_VCPKG=OFF -G "MinGW Makefiles"
+    - shell: pwsh
+      run: make -j2
+    - shell: pwsh
+      run: make install
+    # Workaround to get the DLLs into the installation directory
+    - name: Copy DLLs
+      shell: msys2 {0}
+      run: |
+        DLLS="libbrotlicommon.dll libbrotlidec.dll libcrypto-1_1.dll libcurl-4.dll libexpat-1.dll \
+        libiconv-2.dll libidn2-0.dll libintl-8.dll libnghttp2-14.dll libpsl-5.dll libssh2-1.dll \
+        libssl-1_1.dll libunistring-2.dll libwinpthread-1.dll libzstd.dll zlib1.dll"
+
+        for ITEM in ${DLLS}
+        do
+          cp /${{ matrix.msysArch }}/bin/${ITEM} `pwd`/artifacts/bin
+          cp /${{ matrix.msysArch }}/bin/${ITEM} `pwd`/artifacts/libexec/git-core
+        done
+    - name: upload build artifacts
+      uses: actions/upload-artifact@v2
+      with:
+        name: llvm-artifacts-${{ matrix.arch }}
+        path: artifacts

compat/bswap.h

@@ -74,6 +74,12 @@ static inline uint64_t git_bswap64(uint64_t x)
 }
 #endif
 
+/* available since Clang 12 and GCC 10, i.a. needed for ARM64/aarch64 on Windows */
+#elif defined(__has_builtin) && __has_builtin(__builtin_bswap64)
+
+#define bswap32(x)     __builtin_bswap32((x))
+#define bswap64(x)     __builtin_bswap64((x))
+
 #elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64) || defined(_M_ARM64))
 
 #include <stdlib.h>

compat/vcbuild/vcpkg_install.bat

@@ -49,9 +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

contrib/buildsystems/CMakeLists.txt

@@ -201,9 +201,13 @@ endif()
 
 
 if(WIN32 AND NOT MSVC)#not required for visual studio builds
-	find_program(WINDRES_EXE windres)
-	if(NOT WINDRES_EXE)
-		message(FATAL_ERROR "Install windres on Windows for resource files")
+	if(CMAKE_RC_COMPILER)
+		set(WINDRES_EXE ${CMAKE_RC_COMPILER})
+	else()
+		find_program(WINDRES_EXE windres)
+		if(NOT WINDRES_EXE)
+			message(FATAL_ERROR "Install windres on Windows for resource files")
+		endif()
 	endif()
 endif()
 
@@ -276,20 +280,21 @@ endif()
 
 #Platform Specific
 if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
-	if(CMAKE_C_COMPILER_ID STREQUAL "MSVC" OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
+	# MinGW Makefiles is used by the llvm-mingw toolchain on Windows (Clang)
+	if(CMAKE_C_COMPILER_ID STREQUAL "MSVC" OR (NOT CMAKE_GENERATOR STREQUAL "MinGW Makefiles" AND CMAKE_C_COMPILER_ID STREQUAL "Clang"))
 		include_directories(${CMAKE_SOURCE_DIR}/compat/vcbuild/include)
 		add_compile_definitions(_CRT_SECURE_NO_WARNINGS _CRT_NONSTDC_NO_DEPRECATE)
 	endif()
 	include_directories(${CMAKE_SOURCE_DIR}/compat/win32)
 	add_compile_definitions(HAVE_ALLOCA_H NO_POSIX_GOODIES NATIVE_CRLF NO_UNIX_SOCKETS WIN32
 				_CONSOLE DETECT_MSYS_TTY STRIP_EXTENSION=".exe"  NO_SYMLINK_HEAD UNRELIABLE_FSTAT
 				NOGDI OBJECT_CREATION_MODE=1 __USE_MINGW_ANSI_STDIO=0
-				USE_NED_ALLOCATOR OVERRIDE_STRDUP MMAP_PREVENTS_DELETE USE_WIN32_MMAP
+				OVERRIDE_STRDUP MMAP_PREVENTS_DELETE USE_WIN32_MMAP
 				UNICODE _UNICODE HAVE_WPGMPTR ENSURE_MSYSTEM_IS_SET)
 	list(APPEND compat_SOURCES compat/mingw.c compat/winansi.c compat/win32/path-utils.c
 		compat/win32/pthread.c compat/win32mmap.c compat/win32/syslog.c
 		compat/win32/trace2_win32_process_info.c compat/win32/dirent.c
-		compat/nedmalloc/nedmalloc.c compat/strdup.c compat/win32/fscache.c)
+		compat/strdup.c compat/win32/fscache.c)
 	set(NO_UNIX_SOCKETS 1)
 
 elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
@@ -715,7 +720,8 @@ 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)

git.rc

@@ -11,7 +11,7 @@ BEGIN
       VALUE "InternalName", "git\0"
       VALUE "OriginalFilename", "git.exe\0"
       VALUE "ProductName", "Git\0"
-      VALUE "ProductVersion", GIT_VERSION "\0"
+      VALUE "ProductVersion", "DEMO\0"
     END
   END