Re: [PATCH 5/8] cmake: support for testing git when building out of the source tree

From: Danh Doan <congdanhqx@gmail.com>
To: Sibi Siddharthan via GitGitGadget <gitgitgadget@gmail.com>
Cc: git@vger.kernel.org, Sibi Siddharthan <sibisiddharthan.github@gmail.com>
Subject: Re: [PATCH 5/8] cmake: support for testing git when building out of the source tree
Date: Sat, 25 Apr 2020 00:34:33 +0700	[thread overview]
Message-ID: <20200424173433.GL1949@danh.dev> (raw)
In-Reply-To: <166b78f71755bb3f9967b32bfe282210c2bb240d.1587700897.git.gitgitgadget@gmail.com>

On 2020-04-24 04:01:34+0000, Sibi Siddharthan via GitGitGadget <gitgitgadget@gmail.com> wrote:
> From: Sibi Siddharthan <sibisiddharthan.github@gmail.com>
> 
> This patch allows git to be tested when performin out of source builds.
> 
> This involves changing GIT_BUILD_DIR in t/test-lib.sh to point to the
> build directory. Also some miscellaneous copies from the source directory
> to the build directory.
> The copies are:
> t/chainlint.sed needed by a bunch of test scripts
> po/is.po needed by t0204-gettext-rencode-sanity
> mergetools/tkdiff needed by t7800-difftool
> contrib/completion/git-prompt.sh needed by t9903-bash-prompt
> contrib/completion/git-completion.bash needed by t9902-completion
> contrib/svn-fe/svnrdump_sim.py needed by t9020-remote-svn
> 
> NOTE: t/test-lib.sh is only modified when tests are run not during
> the build or configure.
> The trash directory is still srcdir/t
> 
> Signed-off-by: Sibi Siddharthan <sibisiddharthan.github@gmail.com>
> ---
>  CMakeLists.txt | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/CMakeLists.txt b/CMakeLists.txt
> index 141ccefa559..29a23eb11f7 100644
> --- a/CMakeLists.txt
> +++ b/CMakeLists.txt
> @@ -812,6 +812,25 @@ file(APPEND ${CMAKE_BINARY_DIR}/GIT-BUILD-OPTIONS "NO_GETTEXT='${NO_GETTEXT}'\n"
>  file(APPEND ${CMAKE_BINARY_DIR}/GIT-BUILD-OPTIONS "RUNTIME_PREFIX='${RUNTIME_PREFIX}'\n")
>  file(APPEND ${CMAKE_BINARY_DIR}/GIT-BUILD-OPTIONS "NO_PYTHON='${NO_PYTHON}'\n")
>  
> +#Make the tests work when building out of the source tree
> +if(NOT ${CMAKE_BINARY_DIR} STREQUAL ${CMAKE_SOURCE_DIR})

IIRC, CMake recommends _NOT_ expand variable inside if()
This very inconsistent recommendation of CMake (when should I use
${var} and when should I use var?) is one of reason I hate CMake

> +	file(RELATIVE_PATH BUILD_DIR_RELATIVE ${CMAKE_SOURCE_DIR} ${CMAKE_BINARY_DIR}/CMakeCache.txt)
> +	string(REPLACE "/CMakeCache.txt" "" BUILD_DIR_RELATIVE ${BUILD_DIR_RELATIVE})

I don't know what is going on here!

> +	#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})")
> +	#misc copies
> +	file(COPY ${CMAKE_SOURCE_DIR}/t/chainlint.sed DESTINATION ${CMAKE_BINARY_DIR}/t/)

So, some sed will be used in Windows without POSIX-like system,
interesting!

> +	file(COPY ${CMAKE_SOURCE_DIR}/po/is.po DESTINATION ${CMAKE_BINARY_DIR}/po/)
> +	file(COPY ${CMAKE_SOURCE_DIR}/mergetools/tkdiff DESTINATION ${CMAKE_BINARY_DIR}/mergetools/)
> +	file(COPY ${CMAKE_SOURCE_DIR}/contrib/completion/git-prompt.sh DESTINATION ${CMAKE_BINARY_DIR}/contrib/completion/)
> +	file(COPY ${CMAKE_SOURCE_DIR}/contrib/completion/git-completion.bash DESTINATION ${CMAKE_BINARY_DIR}/contrib/completion/)
> +	file(COPY ${CMAKE_SOURCE_DIR}/contrib/svn-fe/svnrdump_sim.py DESTINATION ${CMAKE_BINARY_DIR}/contrib/svn-fe/)
> +endif()
> +
>  file(GLOB test_scipts "${CMAKE_SOURCE_DIR}/t/t[0-9]*.sh")

Remember cmake won't be re-run if nothing was changed in CMakeList.txt
If I only change some code, and I decided the change I make should be
tested by a-new-and-independent-test-script.
I need to re-run cmake manually! I don't like it, at all.

-- 
Danh