[libunwind][CMake] Add cached compile and link flags to libunwind

[mgrzywac]

Summary

Add flags allowing to use compile flags and libraries provided in cache with libunwind.
Similar flags are already present in libc++ and libc++abi CMakeLists files.

[ldionne]

libunwind/CMakeLists.txt

159–160

Could you instead do target_compile_options(${target} PUBLIC "${LIBUNWIND_ADDITIONAL_COMPILE_FLAGS}") in libunwind/src for unwind_static and unwind_shared? And target_link_libraries(${target} PUBLIC "${LIBUNWIND_ADDITIONAL_LIBRARIES}") for the libraries part.

We're trying to move away from global functions like add_compile_flags and add_library_flags.

[mgrzywac]

Moved flag and libs addition to libunwind/src

libunwind/CMakeLists.txt

159–160

Sure, I moved flag and libs addition.

[phosek]

LGTM

[mgrzywac]

I don't have commit access, can you please land this for me? Please use Maciej Grzywacz [e-mail] for the commit :)

[mgrzywac]

Hi @phosek, could You land this change for me? This is my first change and I don't have commit access yet :)

libunwind/CMakeLists.txt

 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
 
 set(LIBUNWIND_C_FLAGS "")
 set(LIBUNWIND_CXX_FLAGS "")
 set(LIBUNWIND_COMPILE_FLAGS "")
 set(LIBUNWIND_LINK_FLAGS "")
+set(LIBUNWIND_ADDITIONAL_COMPILE_FLAGS "" CACHE STRING
+    "Additional Compile only flags which can be provided in cache")
+set(LIBUNWIND_ADDITIONAL_LIBRARIES "" CACHE STRING
+    "Additional libraries libunwind is linked to which can be provided in cache")
 
 # Include macros for adding and removing libunwind flags.
 include(HandleLibunwindFlags)
 
 #===============================================================================
 # Setup Compiler Flags
 #===============================================================================
 
 # Configure compiler.
 include(config-ix)
 
 if (LIBUNWIND_USE_COMPILER_RT AND NOT LIBUNWIND_HAS_NODEFAULTLIBS_FLAG)
   list(APPEND LIBUNWIND_LINK_FLAGS "-rtlib=compiler-rt")
 endif()
 
 add_compile_flags_if_supported(-Werror=return-type)
 
 if (LIBUNWIND_ENABLE_CET)
   add_compile_flags_if_supported(-fcf-protection=full)

libunwind/src/CMakeLists.txt

 add_library(unwind_shared_objects OBJECT EXCLUDE_FROM_ALL ${LIBUNWIND_SOURCES} ${LIBUNWIND_HEADERS})
 cxx_add_warning_flags(unwind_shared_objects ${LIBUNWIND_ENABLE_WERROR} ${LIBUNWIND_ENABLE_PEDANTIC})
 if(CMAKE_C_COMPILER_ID STREQUAL MSVC)
   target_compile_options(unwind_shared_objects PRIVATE /GR-)
 else()
   target_compile_options(unwind_shared_objects PRIVATE -fno-rtti)
 endif()
 target_link_libraries(unwind_shared_objects PRIVATE unwind-headers ${LIBUNWIND_LIBRARIES})
+target_compile_options(unwind_shared_objects PUBLIC "${LIBUNWIND_ADDITIONAL_COMPILE_FLAGS}")
+target_link_libraries(unwind_shared_objects PUBLIC "${LIBUNWIND_ADDITIONAL_LIBRARIES}")
 set_target_properties(unwind_shared_objects
   PROPERTIES
     CXX_EXTENSIONS OFF
     CXX_STANDARD 11
     CXX_STANDARD_REQUIRED ON
     COMPILE_FLAGS "${LIBUNWIND_COMPILE_FLAGS}"
 )
 if (CMAKE_POSITION_INDEPENDENT_CODE OR NOT DEFINED CMAKE_POSITION_INDEPENDENT_CODE)

 add_library(unwind_static_objects OBJECT EXCLUDE_FROM_ALL ${LIBUNWIND_SOURCES} ${LIBUNWIND_HEADERS})
 cxx_add_warning_flags(unwind_static_objects ${LIBUNWIND_ENABLE_WERROR} ${LIBUNWIND_ENABLE_PEDANTIC})
 if(CMAKE_C_COMPILER_ID STREQUAL MSVC)
   target_compile_options(unwind_static_objects PRIVATE /GR-)
 else()
   target_compile_options(unwind_static_objects PRIVATE -fno-rtti)
 endif()
 target_link_libraries(unwind_static_objects PRIVATE unwind-headers ${LIBUNWIND_LIBRARIES})
+target_compile_options(unwind_static_objects PUBLIC "${LIBUNWIND_ADDITIONAL_COMPILE_FLAGS}")
+target_link_libraries(unwind_static_objects PUBLIC "${LIBUNWIND_ADDITIONAL_LIBRARIES}")
 set_target_properties(unwind_static_objects
   PROPERTIES
     CXX_EXTENSIONS OFF
     CXX_STANDARD 11
     CXX_STANDARD_REQUIRED ON
     COMPILE_FLAGS "${LIBUNWIND_COMPILE_FLAGS}"
 )