[PATCH v3 4/5] cmake: avoid editing t/test-lib.sh

From: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Date: Oct 18, 2022, 10:59 UTC
Message-ID: <5b0c2a150e9fce1ca0284d65628b42ed5a7aad9a.1666090745.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.1320.v3.git.1666090745.gitgitgadget@gmail.com>

From: Johannes Schindelin <johannes.schindelin@gmx.de>

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@gmx.de>
---
 .gitignore                          |  1 +
 Makefile                            |  1 +
 contrib/buildsystems/CMakeLists.txt |  7 +------
 t/test-lib.sh                       | 10 ++++++++++
 4 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/.gitignore b/.gitignore
index 73df7295795..89ad7e68b4b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 /fuzz_corpora
+/GIT-BUILD-DIR
 /GIT-BUILD-OPTIONS
 /GIT-CFLAGS
 /GIT-LDFLAGS
diff --git a/Makefile b/Makefile
index 88178c5b466..886614340c7 100644
--- a/Makefile
+++ b/Makefile
@@ -3029,6 +3029,7 @@ 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 0c741e7d878..1d8cebb4cfe 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 120f11812c3..dfc0144ed3b 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -47,6 +47,16 @@ then
 	echo "PANIC: Running in a $TEST_DIRECTORY that doesn't end in '/t'?" >&2
 	exit 1
 fi
+if test -f "$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
+fi
 
 # Prepend a string to a VAR using an arbitrary ":" delimiter, not
 # adding the delimiter if VAR or VALUE is empty. I.e. a generalized:

-- 
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