[CMake][runtimes] Add file level dependency to merge_archives commands
Both libc++ and libc++abi have options of merging with another archive. In the case of libc++abi, libunwind can be merged into it and in the case of libc++, libc++abi can be merged into it.
This is realized using add_custom_command with POST_BUILD and the usage of the CMake generator expression TARGET_LINKER_FILE in the arguments. For such generator expressions CMake doc states: "This target-level dependency does NOT add a file-level dependency that would cause the custom command to re-run whenever the executable is recompiled" [1]
This patch adds a DEPENDS argument to both add_custom_command invocations so that the archives also have a file-level dependency on the target they are merging with. That way, changes in say, libunwind source code, will be updated in the libc++abi and/or libc++ static libraries as well.
[1] https://cmake.org/cmake/help/v3.20/command/add_custom_command.html
Differential Revision: https://reviews.llvm.org/D98129
GitOrigin-RevId: 6359049c35042adb34ffe6ba77008613c1436ee1
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 50afdf6..ea8c545 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -302,6 +302,7 @@
"$<TARGET_LINKER_FILE:cxxabi_static>"
"$<TARGET_LINKER_FILE:unwind_static>"
WORKING_DIRECTORY ${LIBCXXABI_BUILD_DIR}
+ DEPENDS unwind_static
)
endif()
endif()
