[PATCH v2 00/11] CMake build system for git

This is an attempt to build Git using CMake. CMake is cross-platform build generator which works well on a variety of platforms(primarily Linux and Windows). Using CMake we can check whether certain headers exist, certain functions exist, the required libraries are present and configure the build accordingly. Using CMake we can also build and test Git out of source, resulting in a clean source tree.

Tested platforms

Ubuntu 18.04 GCC 7.4 Clang 8.0.1

Windows MinGW GCC 9.2 Clang 9 Visual Studio 2015,2017,2019

Changes:

1) The CMake script has been relocated to contrib/buildsystems 2) The CMake
script parses the Makefile for the sources. 3) Philip suggested to change
the error message if sh/bash was not found on windows. 4) CMake now tests
for ICONV_OMITS_BOM, NO_ST_BLOCKS_IN_STRUCT_STAT

Sibi Siddharthan (11):
  Introduce CMake support for configuring Git on Linux
  cmake: generate the shell/perl/python scripts and templates,
    translations
  cmake: installation support for git
  cmake: support for testing git with ctest
  cmake: support for testing git when building out of the source tree
  cmake: support for building git on windows with mingw
  cmake: support for building git on windows with msvc and clang.
  cmake: added checks for struct stat and libiconv
  cmake: relocated script file contrib/buildsystems
  cmake: parse the makefile for the sources.
  ci: modification of main.yml to use cmake for vs-build job

 .github/workflows/main.yml          |  46 +-
 contrib/buildsystems/CMakeLists.txt | 945 ++++++++++++++++++++++++++++
 2 files changed, 971 insertions(+), 20 deletions(-)
 create mode 100644 contrib/buildsystems/CMakeLists.txt

base-commit: 744177e7f7fd407c26e9e4aa3b19696859010c48
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-614%2FSibiSiddharthan%2Fgit-og-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-614/SibiSiddharthan/git-og-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/614

Range-diff vs v1:

  1:  70ab1f03dd5 =  1:  70ab1f03dd5 Introduce CMake support for configuring Git on Linux
  2:  ca242cf5bda =  2:  ca242cf5bda cmake: generate the shell/perl/python scripts and templates, translations
  3:  10390063a39 !  3:  b2974432d77 cmake: installation support for git
     @@ Commit message
      
          Then run `make install`
      
     +    Changes:
     +    Removed a comment regarding the installation of gitk.
     +
          Signed-off-by: Sibi Siddharthan <sibisiddharthan.github@gmail.com>
      
       ## CMakeLists.txt ##
     @@ CMakeLists.txt: if(MSGFMT_EXE)
      +#install
      +install(TARGETS git git-shell
      +	RUNTIME DESTINATION bin)
     -+install(PROGRAMS ${CMAKE_BINARY_DIR}/git-cvsserver  #${CMAKE_SOURCE_DIR}/gitk-git/gitk check
     ++install(PROGRAMS ${CMAKE_BINARY_DIR}/git-cvsserver
      +	DESTINATION bin)
      +
      +list(REMOVE_ITEM PROGRAMS_BUILT git git-shell)
  4:  35a3554df3e !  4:  2bd8870fb96 cmake: support for testing git with ctest
     @@ Commit message
      
          NOTE: Testing only works when building in source for now.
      
     +    Changes:
     +    Renamed the variable test_helper_sources to test-tool_SOURCES
     +    to be consistent with the naming of source variables.
     +
          Signed-off-by: Sibi Siddharthan <sibisiddharthan.github@gmail.com>
      
       ## CMakeLists.txt ##
     @@ CMakeLists.txt: install(DIRECTORY ${CMAKE_BINARY_DIR}/templates/blt/ DESTINATION
      +add_executable(test-svn-fe t/helper/test-svn-fe.c)
      +target_link_libraries(test-svn-fe common-main vcs-svn)
      +
     -+set(test_helper_sources
     ++set(test-tool_SOURCES
      +	t/helper/test-tool.c t/helper/test-advise.c t/helper/test-bloom.c t/helper/test-chmtime.c
      +	t/helper/test-config.c t/helper/test-ctype.c t/helper/test-date.c t/helper/test-delta.c
      +	t/helper/test-dir-iterator.c t/helper/test-drop-caches.c t/helper/test-dump-cache-tree.c
     @@ CMakeLists.txt: install(DIRECTORY ${CMAKE_BINARY_DIR}/templates/blt/ DESTINATION
      +	t/helper/test-trace2.c t/helper/test-urlmatch-normalization.c t/helper/test-xml-encode.c
      +	t/helper/test-wildmatch.c t/helper/test-windows-named-pipe.c t/helper/test-write-cache.c)
      +
     -+add_executable(test-tool ${test_helper_sources})
     ++add_executable(test-tool ${test-tool_SOURCES})
      +target_link_libraries(test-tool common-main)
      +
      +set_target_properties(test-fake-ssh test-line-buffer test-svn-fe test-tool
  5:  166b78f7175 =  5:  096f6311ad5 cmake: support for testing git when building out of the source tree
  6:  d6c630028bf !  6:  00cae10bbb7 cmake: support for building git on windows with mingw
     @@ Commit message
          To use CMake on Windows with MinGW do this:
          cmake `relative-path-to-srcdir` -G "MinGW Makefiles"
      
     +    Changes:
     +    Changed the error message when sh.exe is not found on Windows as
     +    suggested by Philip Oakley <philipoakley@iee.email>
     +
          Signed-off-by: Sibi Siddharthan <sibisiddharthan.github@gmail.com>
      
       ## CMakeLists.txt ##
     @@ CMakeLists.txt: if(Intl_FOUND)
       
       find_program(SH_EXE sh)
      +if(NOT SH_EXE)
     -+	message(FATAL_ERROR "sh interpreter was not found in your path, please install one. On Windows you can get it from here https://gitforwindows.org/")
     ++	message(FATAL_ERROR "sh: shell interpreter was not found in your path, please install one."
     ++			"On Windows, you can get it as part of 'Git for Windows' install at https://gitforwindows.org/")
      +endif()
      +
      +if(WIN32)
  7:  0577d7bf0a8 !  7:  af6c606881d cmake: support for building git on windows with msvc and clang.
     @@ CMakeLists.txt: find_package(ZLIB REQUIRED)
       if(NOT Intl_FOUND)
       	add_compile_definitions(NO_GETTEXT)
      @@ CMakeLists.txt: if(NOT SH_EXE)
     - 	message(FATAL_ERROR "sh interpreter was not found in your path, please install one. On Windows you can get it from here https://gitforwindows.org/")
     + 			"On Windows, you can get it as part of 'Git for Windows' install at https://gitforwindows.org/")
       endif()
       
      -if(WIN32)
  -:  ----------- >  8:  f496cd7d8aa cmake: added checks for struct stat and libiconv
  -:  ----------- >  9:  9c674372fb5 cmake: relocated script file contrib/buildsystems
  -:  ----------- > 10:  b0a321a714a cmake: parse the makefile for the sources.
  8:  f0294be3f11 ! 11:  fa1b8032906 ci: modification of main.yml to use cmake for vs-build job
     @@ Commit message
          FindCURL module. An extra definition (-DCURL_NO_CURL_CMAKE=ON) has been
          added to revert to the old behaviour.
      
     +    Edit(Explanation for the reordering of build steps):
     +    In the configuration phase CMake looks for the required libraries for
     +    building git (eg zlib,libiconv). So we extract the libraries before we
     +    configure.
     +
     +    Changes:
     +    The CMake script has been relocated to contib/buildsystems, so point
     +    to the CMakeLists.txt in the invocation commands.
     +
     +    The generation command now uses the absolute paths for the generation
     +    step.
     +
     +    To check for ICONV_OMITS_BOM libiconv.dll needs to be in the working
     +    directory of script or path. So we copy the dlls before we configure.
     +
          Signed-off-by: Sibi Siddharthan <sibisiddharthan.github@gmail.com>
      
       ## .github/workflows/main.yml ##
     @@ .github/workflows/main.yml: jobs:
               Remove-Item compat.zip
           - name: add msbuild to PATH
             uses: microsoft/setup-msbuild@v1.0.0
     -+    - name: generate Visual Studio solution
     ++    - name: copy dlls to root
      +      shell: powershell
      +      run: |
     -+        & .\git-sdk-64-minimal\usr\bin\bash.exe -lc @"
     -+          cmake . -DCMAKE_PREFIX_PATH=./compat/vcbuild/vcpkg/installed/x64-windows -DMSGFMT_EXE=./git-sdk-64-minimal/mingw64/bin/msgfmt.exe -DPERL_TESTS=OFF -DPYTHON_TESTS=OFF -DCURL_NO_CURL_CMAKE=ON
     -+        "@
     ++        & compat\vcbuild\vcpkg_copy_dlls.bat release
      +        if (!$?) { exit(1) }
     ++    - name: generate Visual Studio solution
     ++      shell: bash
     ++      run: cmake `pwd`/contrib/buildsystems/ -DCMAKE_PREFIX_PATH=`pwd`/compat/vcbuild/vcpkg/installed/x64-windows -DMSGFMT_EXE=`pwd`/git-sdk-64-minimal/mingw64/bin/msgfmt.exe -DPERL_TESTS=OFF -DPYTHON_TESTS=OFF -DCURL_NO_CURL_CMAKE=ON
           - name: MSBuild
             run: msbuild git.sln -property:Configuration=Release -property:Platform=x64 -maxCpuCount:4 -property:PlatformToolset=v142
           - name: bundle artifact tar
     +@@ .github/workflows/main.yml: jobs:
     +         MSVC: 1
     +         VCPKG_ROOT: ${{github.workspace}}\compat\vcbuild\vcpkg
     +       run: |
     +-        & compat\vcbuild\vcpkg_copy_dlls.bat release
     +-        if (!$?) { exit(1) }
     +         & git-sdk-64-minimal\usr\bin\bash.exe -lc @"
     +           mkdir -p artifacts &&
     +           eval \"`$(make -n artifacts-tar INCLUDE_DLLS_IN_ARTIFACTS=YesPlease ARTIFACTS_DIRECTORY=artifacts 2>&1 | grep ^tar)\"
      @@ .github/workflows/main.yml: jobs:
               nr: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
           steps: