[PATCH v9 05/17] cmake: optionally build `scalar`, too

From: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Date: Nov 30, 2021, 11:54 UTC
Message-ID: <a39b9c812146f6721353a066670d248159161615.1638273289.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.1005.v9.git.1638273289.gitgitgadget@gmail.com>

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

The CMake configuration unfortunately does not let us easily encapsulate Scalar's build definition in the `contrib/scalar/` subdirectory: The `scalar` executable needs to link in `libgit.a` and `common-main.o`, for example.

Also, `scalar.c` includes Git's header files, which means that `scalar.c` needs to be compiled with the very same flags as `libgit.a` lest `scalar.o` and `libgit.a` have different ideas of, say, `platform_SHA_CTX`, which would naturally lead to memory corruption.

To alleviate that somewhat, we guard the inclusion of Scalar via the `INCLUDE_SCALAR` environment variable.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 contrib/buildsystems/CMakeLists.txt | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index fd1399c440f..dd7496b0322 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -729,6 +729,13 @@ if(CURL_FOUND)
 	endif()
 endif()
 
+if(DEFINED ENV{INCLUDE_SCALAR} AND NOT ENV{INCLUDE_SCALAR} STREQUAL "")
+	add_executable(scalar ${CMAKE_SOURCE_DIR}/contrib/scalar/scalar.c)
+	target_link_libraries(scalar common-main)
+	set_target_properties(scalar PROPERTIES RUNTIME_OUTPUT_DIRECTORY_DEBUG ${CMAKE_BINARY_DIR}/contrib/scalar)
+	set_target_properties(scalar PROPERTIES RUNTIME_OUTPUT_DIRECTORY_RELEASE ${CMAKE_BINARY_DIR}/contrib/scalar)
+endif()
+
 parse_makefile_for_executables(git_builtin_extra "BUILT_INS")
 
 option(SKIP_DASHED_BUILT_INS "Skip hardlinking the dashed versions of the built-ins")
@@ -953,6 +960,13 @@ string(REPLACE "@@BUILD_DIR@@" "${CMAKE_BINARY_DIR}" content "${content}")
 string(REPLACE "@@PROG@@" "git-cvsserver" content "${content}")
 file(WRITE ${CMAKE_BINARY_DIR}/bin-wrappers/git-cvsserver ${content})
 
+if(DEFINED ENV{INCLUDE_SCALAR} AND NOT ENV{INCLUDE_SCALAR} STREQUAL "")
+	file(STRINGS ${CMAKE_SOURCE_DIR}/wrap-for-bin.sh content NEWLINE_CONSUME)
+	string(REPLACE "@@BUILD_DIR@@" "${CMAKE_BINARY_DIR}" content "${content}")
+	string(REPLACE "@@PROG@@" "contrib/scalar/scalar${EXE_EXTENSION}" content "${content}")
+	file(WRITE ${CMAKE_BINARY_DIR}/bin-wrappers/scalar ${content})
+endif()
+
 #options for configuring test options
 option(PERL_TESTS "Perform tests that use perl" ON)
 option(PYTHON_TESTS "Perform tests that use python" ON)

-- 
gitgitgadget