Reland "[CMake][libunwind] Use -nodefaultlibs for CMake checks"
This is a reland of commit r299796.
Turned out that we need gcc_s or compiler-rt on ARM when checking
the support for -funwind-tables which creates a dependency on
__aeabi_unwind_cpp_pr0 symbol that's provided by the compiler
runtime.
Differential Revision: https://reviews.llvm.org/D31858
llvm-svn: 300020
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 57d49236cc0750490ba0be8eeff7fb9b32b753ca
diff --git a/cmake/Modules/HandleCompilerRT.cmake b/cmake/Modules/HandleCompilerRT.cmake
new file mode 100644
index 0000000..5696ec3
--- /dev/null
+++ b/cmake/Modules/HandleCompilerRT.cmake
@@ -0,0 +1,58 @@
+function(find_compiler_rt_library name dest)
+ if (NOT DEFINED LIBUNWIND_COMPILE_FLAGS)
+ message(FATAL_ERROR "LIBUNWIND_COMPILE_FLAGS must be defined when using this function")
+ endif()
+ set(dest "" PARENT_SCOPE)
+ set(CLANG_COMMAND ${CMAKE_CXX_COMPILER} ${TARGET_TRIPLE} ${LIBUNWIND_COMPILE_FLAGS}
+ "--rtlib=compiler-rt" "--print-libgcc-file-name")
+ if (CMAKE_CXX_COMPILER_ID MATCHES Clang AND CMAKE_CXX_COMPILER_TARGET)
+ list(APPEND CLANG_COMMAND "--target=${CMAKE_CXX_COMPILER_TARGET}")
+ endif()
+ execute_process(
+ COMMAND ${CLANG_COMMAND}
+ RESULT_VARIABLE HAD_ERROR
+ OUTPUT_VARIABLE LIBRARY_FILE
+ )
+ string(STRIP "${LIBRARY_FILE}" LIBRARY_FILE)
+ string(REPLACE "builtins" "${name}" LIBRARY_FILE "${LIBRARY_FILE}")
+ if (NOT HAD_ERROR AND EXISTS "${LIBRARY_FILE}")
+ message(STATUS "Found compiler-rt library: ${LIBRARY_FILE}")
+ set(${dest} "${LIBRARY_FILE}" PARENT_SCOPE)
+ else()
+ message(STATUS "Failed to find compiler-rt library")
+ endif()
+endfunction()
+
+function(find_compiler_rt_dir dest)
+ if (NOT DEFINED LIBUNWIND_COMPILE_FLAGS)
+ message(FATAL_ERROR "LIBUNWIND_COMPILE_FLAGS must be defined when using this function")
+ endif()
+ set(dest "" PARENT_SCOPE)
+ if (APPLE)
+ set(CLANG_COMMAND ${CMAKE_CXX_COMPILER} ${LIBUNWIND_COMPILE_FLAGS}
+ "-print-file-name=lib")
+ execute_process(
+ COMMAND ${CLANG_COMMAND}
+ RESULT_VARIABLE HAD_ERROR
+ OUTPUT_VARIABLE LIBRARY_DIR
+ )
+ string(STRIP "${LIBRARY_DIR}" LIBRARY_DIR)
+ set(LIBRARY_DIR "${LIBRARY_DIR}/darwin")
+ else()
+ set(CLANG_COMMAND ${CMAKE_CXX_COMPILER} ${LIBUNWIND_COMPILE_FLAGS}
+ "--rtlib=compiler-rt" "--print-libgcc-file-name")
+ execute_process(
+ COMMAND ${CLANG_COMMAND}
+ RESULT_VARIABLE HAD_ERROR
+ OUTPUT_VARIABLE LIBRARY_FILE
+ )
+ string(STRIP "${LIBRARY_FILE}" LIBRARY_FILE)
+ get_filename_component(LIBRARY_DIR "${LIBRARY_FILE}" DIRECTORY)
+ endif()
+ if (NOT HAD_ERROR AND EXISTS "${LIBRARY_DIR}")
+ message(STATUS "Found compiler-rt directory: ${LIBRARY_DIR}")
+ set(${dest} "${LIBRARY_DIR}" PARENT_SCOPE)
+ else()
+ message(STATUS "Failed to find compiler-rt directory")
+ endif()
+endfunction()