On Tue, Aug 23 2022, Johannes Schindelin via GitGitGadget wrote:
> From: Johannes Schindelin <johannes.schindelin@xxxxxx>
>
> In 7f5397a07c6c (cmake: support for testing git when building out of the
> source tree, 2020-06-26), we implemented support for running Git's test
> scripts even after building Git in a different directory than the source
> directory.
>
> The way we did this was to edit the file `t/test-lib.sh` to override
> `GIT_BUILD_DIR` to point somewhere else than the parent of the `t/`
> directory.
>
> This is unideal because it always leaves a tracked file marked as
> modified, and it is all too easy to commit that change by mistake.
>
> Let's change the strategy by teaching `t/test-lib.sh` to detect the
> presence of a file called `GIT-BUILD-DIR` in the source directory. If it
> exists, the contents are interpreted as the location to the _actual_
> build directory. We then write this file as part of the CTest
> definition.
>
> To support building Git via a regular `make` invocation after building
> it using CMake, we ensure that the `GIT-BUILD-DIR` file is deleted (for
> convenience, this is done as part of the Makefile rule that is already
> run with every `make` invocation to ensure that `GIT-BUILD-OPTIONS` is
> up to date).
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
> ---
> .gitignore | 1 +
> Makefile | 1 +
> contrib/buildsystems/CMakeLists.txt | 7 +------
> t/test-lib.sh | 11 ++++++++++-
> 4 files changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/.gitignore b/.gitignore
> index a4522157641..b72ddf09346 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -2,6 +2,7 @@
> /fuzz_corpora
> /fuzz-pack-headers
> /fuzz-pack-idx
> +/GIT-BUILD-DIR
> /GIT-BUILD-OPTIONS
> /GIT-CFLAGS
> /GIT-LDFLAGS
> diff --git a/Makefile b/Makefile
> index 04d0fd1fe60..9347ed90da7 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -3028,6 +3028,7 @@ else
> @echo RUNTIME_PREFIX=\'false\' >>$@+
> endif
> @if cmp $@+ $@ >/dev/null 2>&1; then $(RM) $@+; else mv $@+ $@; fi
> + @if test -f GIT-BUILD-DIR; then rm GIT-BUILD-DIR; fi
>
> ### Detect Python interpreter path changes
> ifndef NO_PYTHON
> diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
> index fe606c179f7..29d7e236ae1 100644
> --- a/contrib/buildsystems/CMakeLists.txt
> +++ b/contrib/buildsystems/CMakeLists.txt
> @@ -1067,14 +1067,9 @@ endif()
> #Make the tests work when building out of the source tree
> get_filename_component(CACHE_PATH ${CMAKE_CURRENT_LIST_DIR}/../../CMakeCache.txt ABSOLUTE)
> if(NOT ${CMAKE_BINARY_DIR}/CMakeCache.txt STREQUAL ${CACHE_PATH})
> - file(RELATIVE_PATH BUILD_DIR_RELATIVE ${CMAKE_SOURCE_DIR} ${CMAKE_BINARY_DIR}/CMakeCache.txt)
> - string(REPLACE "/CMakeCache.txt" "" BUILD_DIR_RELATIVE ${BUILD_DIR_RELATIVE})
> #Setting the build directory in test-lib.sh before running tests
> file(WRITE ${CMAKE_BINARY_DIR}/CTestCustom.cmake
> - "file(STRINGS ${CMAKE_SOURCE_DIR}/t/test-lib.sh GIT_BUILD_DIR_REPL REGEX \"GIT_BUILD_DIR=(.*)\")\n"
> - "file(STRINGS ${CMAKE_SOURCE_DIR}/t/test-lib.sh content NEWLINE_CONSUME)\n"
> - "string(REPLACE \"\${GIT_BUILD_DIR_REPL}\" \"GIT_BUILD_DIR=\\\"$TEST_DIRECTORY/../${BUILD_DIR_RELATIVE}\\\"\" content \"\${content}\")\n"
> - "file(WRITE ${CMAKE_SOURCE_DIR}/t/test-lib.sh \${content})")
> + "file(WRITE ${CMAKE_SOURCE_DIR}/GIT-BUILD-DIR \"${CMAKE_BINARY_DIR}\")")
> #misc copies
> file(COPY ${CMAKE_SOURCE_DIR}/t/chainlint.sed DESTINATION ${CMAKE_BINARY_DIR}/t/)
> file(COPY ${CMAKE_SOURCE_DIR}/po/is.po DESTINATION ${CMAKE_BINARY_DIR}/po/)
> diff --git a/t/test-lib.sh b/t/test-lib.sh
> index 55857af601b..4468ac51f25 100644
> --- a/t/test-lib.sh
> +++ b/t/test-lib.sh
> @@ -42,7 +42,16 @@ then
> TEST_OUTPUT_DIRECTORY=$TEST_DIRECTORY
> fi
> GIT_BUILD_DIR="${TEST_DIRECTORY%/t}"
> -if test "$TEST_DIRECTORY" = "$GIT_BUILD_DIR"
> +if test -f "$GIT_BUILD_DIR/GIT-BUILD-DIR"
> +then
> + GIT_BUILD_DIR="$(cat "$GIT_BUILD_DIR/GIT-BUILD-DIR")" || exit 1
> + # On Windows, we must convert Windows paths lest they contain a colon
> + case "$(uname -s)" in
> + *MINGW*)
> + GIT_BUILD_DIR="$(cygpath -au "$GIT_BUILD_DIR")"
> + ;;
> + esac
> +elif test "$TEST_DIRECTORY" = "$GIT_BUILD_DIR"
> then
> echo "PANIC: Running in a $TEST_DIRECTORY that doesn't end in '/t'?" >&2
> exit 1
As pointed out in the v1 this breaks the cmake<->make interaction in
some scenarios, but from some brief testing there seemed to be an easy
workaround which didn't suffer from that problem:
https://lore.kernel.org/git/220811.86sfm3ov5z.gmgdl@xxxxxxxxxxxxxxxxxxx/
