Merge pull request git-for-windows#3327 from dennisameling/fix-host-cpu

cmake(): allow setting HOST_CPU for cross-compilation

Author: dscho

.github/workflows/main.yml

@@ -198,7 +198,7 @@ jobs:
       shell: bash
       run: |
         cmake `pwd`/contrib/buildsystems/ -DCMAKE_PREFIX_PATH=`pwd`/lib/compat/vcbuild/vcpkg/installed/${{ matrix.arch }}-windows \
-        -DNO_GETTEXT=YesPlease -DPERL_TESTS=OFF -DPYTHON_TESTS=OFF -DCURL_NO_CURL_CMAKE=ON -DCMAKE_GENERATOR_PLATFORM=${{ matrix.arch }} -DVCPKG_ARCH=${{ matrix.arch }}-windows
+        -DNO_GETTEXT=YesPlease -DPERL_TESTS=OFF -DPYTHON_TESTS=OFF -DCURL_NO_CURL_CMAKE=ON -DCMAKE_GENERATOR_PLATFORM=${{ matrix.arch }} -DVCPKG_ARCH=${{ matrix.arch }}-windows -DHOST_CPU=${{ matrix.arch }}
     - name: MSBuild
       run: |
         $sln = if (Test-Path git.slnx) { 'git.slnx' } else { 'git.sln' }

contrib/buildsystems/CMakeLists.txt

@@ -213,7 +213,14 @@ endif()
 #default behaviour
 include_directories(${CMAKE_SOURCE_DIR})
 include_directories(${CMAKE_SOURCE_DIR}/lib)
-add_compile_definitions(GIT_HOST_CPU="${CMAKE_SYSTEM_PROCESSOR}")
+
+# When cross-compiling, define HOST_CPU as the canonical name of the CPU on
+# which the built Git will run (for instance "x86_64").
+if(NOT HOST_CPU)
+	add_compile_definitions(GIT_HOST_CPU="${CMAKE_SYSTEM_PROCESSOR}")
+else()
+	add_compile_definitions(GIT_HOST_CPU="${HOST_CPU}")
+endif()
 add_compile_definitions(SHA256_BLK INTERNAL_QSORT RUNTIME_PREFIX)
 add_compile_definitions(NO_OPENSSL SHA1_DC SHA1DC_NO_STANDARD_INCLUDES
 			SHA1DC_INIT_SAFE_HASH_DEFAULT=0