Reinstate LLVMCheckCompilerLinkerFlag, to correctly encapsulate link …

…flag check

This partially reverts commit 1515c2c.

Co-Authored-By: Ryan Prichard <[email protected]>

cmake/Modules/LLVMCheckCompilerLinkerFlag.cmake

@@ -0,0 +1,23 @@
+include(CMakePushCheckState)
+
+include(CheckCompilerFlag OPTIONAL)
+
+if(NOT COMMAND check_compiler_flag)
+  include(CheckCCompilerFlag)
+  include(CheckCXXCompilerFlag)
+endif()
+
+function(llvm_check_compiler_linker_flag lang flag out_var)
+  # If testing a flag with check_c_compiler_flag, it gets added to the compile
+  # command only, but not to the linker command in that test. If the flag
+  # is vital for linking to succeed, the test would fail even if it would
+  # have succeeded if it was included on both commands.
+  #
+  # Therefore, try adding the flag to CMAKE_REQUIRED_FLAGS, which gets
+  # added to both compiling and linking commands in the tests.
+
+  cmake_push_check_state()
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${flag}")
+  check_compiler_flag("${lang}" "" ${out_var})
+  cmake_pop_check_state()
+endfunction()

compiler-rt/cmake/config-ix.cmake

@@ -1,10 +1,10 @@
 include(CMakePushCheckState)
 include(AddLLVM)
-include(CheckCompilerFlag)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 include(CheckIncludeFiles)
 include(CheckLibraryExists)
+include(LLVMCheckCompilerLinkerFlag)
 include(CheckSymbolExists)
 include(TestBigEndian)
 
@@ -15,7 +15,7 @@ include(TestBigEndian)
 # libunwind (and the compiler implicit -lunwind wouldn't succeed as the newly
 # built libunwind isn't installed yet). For those cases, it'd be good to
 # link with --unwindlib=none. Check if that option works.
-check_compiler_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_NONE_FLAG)
+llvm_check_compiler_linker_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_NONE_FLAG)
 
 check_library_exists(c fopen "" COMPILER_RT_HAS_LIBC)
 if (COMPILER_RT_USE_BUILTINS_LIBRARY)
@@ -190,12 +190,12 @@ check_library_exists(c++ __cxa_throw "" COMPILER_RT_HAS_LIBCXX)
 check_library_exists(stdc++ __cxa_throw "" COMPILER_RT_HAS_LIBSTDCXX)
 
 # Linker flags.
-check_compiler_flag(C "-Wl,-z,text" COMPILER_RT_HAS_Z_TEXT)
-check_compiler_flag(C "-fuse-ld=lld" COMPILER_RT_HAS_FUSE_LD_LLD_FLAG)
+llvm_check_compiler_linker_flag(C "-Wl,-z,text" COMPILER_RT_HAS_Z_TEXT)
+llvm_check_compiler_linker_flag(C "-fuse-ld=lld" COMPILER_RT_HAS_FUSE_LD_LLD_FLAG)
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "SunOS" AND LLVM_LINKER_IS_SOLARISLD)
   set(VERS_COMPAT_OPTION "-Wl,-z,gnu-version-script-compat")
-  check_compiler_flag(C "${VERS_COMPAT_OPTION}" COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
+  llvm_check_compiler_linker_flag(C "${VERS_COMPAT_OPTION}" COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
 endif()
 
 set(DUMMY_VERS ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/dummy.vers)
@@ -206,10 +206,10 @@ if(COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
   # -z gnu-version-script-compat.
   string(APPEND VERS_OPTION " ${VERS_COMPAT_OPTION}")
 endif()
-check_compiler_flag(C "${VERS_OPTION}" COMPILER_RT_HAS_VERSION_SCRIPT)
+llvm_check_compiler_linker_flag(C "${VERS_OPTION}" COMPILER_RT_HAS_VERSION_SCRIPT)
 
 if(ANDROID)
-  check_compiler_flag(C "-Wl,-z,global" COMPILER_RT_HAS_Z_GLOBAL)
+  llvm_check_compiler_linker_flag(C "-Wl,-z,global" COMPILER_RT_HAS_Z_GLOBAL)
   check_library_exists(log __android_log_write "" COMPILER_RT_HAS_LIBLOG)
 endif()
 
@@ -494,7 +494,7 @@ if(APPLE)
     -lc++
     -lc++abi)
 
-  check_compiler_flag(C "-fapplication-extension" COMPILER_RT_HAS_APP_EXTENSION)
+  llvm_check_compiler_linker_flag(C "-fapplication-extension" COMPILER_RT_HAS_APP_EXTENSION)
   if(COMPILER_RT_HAS_APP_EXTENSION)
     list(APPEND DARWIN_COMMON_LINK_FLAGS "-fapplication-extension")
   endif()

libcxx/cmake/config-ix.cmake

@@ -1,7 +1,7 @@
 include(CMakePushCheckState)
 include(CheckLibraryExists)
 include(CheckSymbolExists)
-include(CheckCompilerFlag)
+include(LLVMCheckCompilerLinkerFlag)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 include(CheckCSourceCompiles)
@@ -13,7 +13,7 @@ include(CheckCSourceCompiles)
 # libunwind (and the compiler implicit -lunwind wouldn't succeed as the newly
 # built libunwind isn't installed yet). For those cases, it'd be good to
 # link with --unwindlib=none. Check if that option works.
-check_compiler_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
+llvm_check_compiler_linker_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
 
 if (NOT LIBCXX_USE_COMPILER_RT)
   if(WIN32 AND NOT MINGW)

libunwind/cmake/config-ix.cmake

@@ -2,14 +2,14 @@ include(CMakePushCheckState)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 include(CheckLibraryExists)
-include(CheckCompilerFlag)
+include(LLVMCheckCompilerLinkerFlag)
 include(CheckSymbolExists)
 include(CheckCSourceCompiles)
 
 # The compiler driver may be implicitly trying to link against libunwind, which
 # might not work if libunwind doesn't exist yet. Try to check if
 # --unwindlib=none is supported, and use that if possible.
-check_compiler_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
+llvm_check_compiler_linker_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
 
 if (HAIKU)
   check_library_exists(root fopen "" LIBUNWIND_HAS_ROOT_LIB)
@@ -35,11 +35,11 @@ endif()
 # required for the link to go through. We remove sanitizers from the
 # configuration checks to avoid spurious link errors.
 
-check_compiler_flag(CXX "-nostdlib++" CXX_SUPPORTS_NOSTDLIBXX_FLAG)
+llvm_check_compiler_linker_flag(CXX "-nostdlib++" CXX_SUPPORTS_NOSTDLIBXX_FLAG)
 if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
 else()
-  check_compiler_flag(C "-nodefaultlibs" C_SUPPORTS_NODEFAULTLIBS_FLAG)
+  llvm_check_compiler_linker_flag(C "-nodefaultlibs" C_SUPPORTS_NODEFAULTLIBS_FLAG)
   if (C_SUPPORTS_NODEFAULTLIBS_FLAG)
     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs")
   endif()

offload/CMakeLists.txt

@@ -294,9 +294,9 @@ endmacro()
 
 if(OPENMP_STANDALONE_BUILD OR TARGET omp)
   # Check LIBOMP_HAVE_VERSION_SCRIPT_FLAG
-  include(CheckCompilerFlag)
+  include(LLVMCheckCompilerLinkerFlag)
   if(NOT APPLE)
-    check_compiler_flag(C "-Wl,--version-script=${CMAKE_CURRENT_LIST_DIR}/../openmp/runtime/src/exports_test_so.txt" LIBOMP_HAVE_VERSION_SCRIPT_FLAG)
+    llvm_check_compiler_linker_flag(C "-Wl,--version-script=${CMAKE_CURRENT_LIST_DIR}/../openmp/runtime/src/exports_test_so.txt" LIBOMP_HAVE_VERSION_SCRIPT_FLAG)
   endif()
 endif()
 

openmp/runtime/cmake/config-ix.cmake

@@ -8,7 +8,6 @@
 #//===----------------------------------------------------------------------===//
 #
 
-include(CheckCompilerFlag)
 include(CheckCCompilerFlag)
 include(CheckCSourceCompiles)
 include(CheckCXXSourceCompiles)
@@ -18,6 +17,7 @@ include(CheckLibraryExists)
 include(CheckIncludeFiles)
 include(CheckSymbolExists)
 include(LibompCheckFortranFlag)
+include(LLVMCheckCompilerLinkerFlag)
 
 # Check for versioned symbols
 function(libomp_check_version_symbols retval)
@@ -128,13 +128,13 @@ check_symbol_exists(_aligned_malloc "malloc.h" LIBOMP_HAVE__ALIGNED_MALLOC)
 
 # Check linker flags
 if(WIN32)
-  check_compiler_flag(C /SAFESEH LIBOMP_HAVE_SAFESEH_FLAG)
+  llvm_check_compiler_linker_flag(C /SAFESEH LIBOMP_HAVE_SAFESEH_FLAG)
 elseif(NOT APPLE)
-  check_compiler_flag(C -Wl,-x LIBOMP_HAVE_X_FLAG)
-  check_compiler_flag(C -Wl,--as-needed LIBOMP_HAVE_AS_NEEDED_FLAG)
-  check_compiler_flag(C "-Wl,--version-script=${LIBOMP_SRC_DIR}/exports_test_so.txt" LIBOMP_HAVE_VERSION_SCRIPT_FLAG)
-  check_compiler_flag(C -static-libgcc LIBOMP_HAVE_STATIC_LIBGCC_FLAG)
-  check_compiler_flag(C -Wl,-z,noexecstack LIBOMP_HAVE_Z_NOEXECSTACK_FLAG)
+  llvm_check_compiler_linker_flag(C -Wl,-x LIBOMP_HAVE_X_FLAG)
+  llvm_check_compiler_linker_flag(C -Wl,--as-needed LIBOMP_HAVE_AS_NEEDED_FLAG)
+  llvm_check_compiler_linker_flag(C "-Wl,--version-script=${LIBOMP_SRC_DIR}/exports_test_so.txt" LIBOMP_HAVE_VERSION_SCRIPT_FLAG)
+  llvm_check_compiler_linker_flag(C -static-libgcc LIBOMP_HAVE_STATIC_LIBGCC_FLAG)
+  llvm_check_compiler_linker_flag(C -Wl,-z,noexecstack LIBOMP_HAVE_Z_NOEXECSTACK_FLAG)
 endif()
 
 # Check Intel(R) C Compiler specific flags
@@ -145,8 +145,8 @@ if(CMAKE_C_COMPILER_ID STREQUAL "Intel" OR CMAKE_C_COMPILER_ID STREQUAL "IntelLL
   check_cxx_compiler_flag(-Qoption,cpp,--extended_float_types LIBOMP_HAVE_EXTENDED_FLOAT_TYPES_FLAG)
   check_cxx_compiler_flag(-falign-stack=maintain-16-byte LIBOMP_HAVE_FALIGN_STACK_FLAG)
   check_cxx_compiler_flag("-opt-streaming-stores never" LIBOMP_HAVE_OPT_STREAMING_STORES_FLAG)
-  check_compiler_flag(C -static-intel LIBOMP_HAVE_STATIC_INTEL_FLAG)
-  check_compiler_flag(C -no-intel-extensions LIBOMP_HAVE_NO_INTEL_EXTENSIONS_FLAG)
+  llvm_check_compiler_linker_flag(C -static-intel LIBOMP_HAVE_STATIC_INTEL_FLAG)
+  llvm_check_compiler_linker_flag(C -no-intel-extensions LIBOMP_HAVE_NO_INTEL_EXTENSIONS_FLAG)
   check_library_exists(irc_pic _intel_fast_memcpy "" LIBOMP_HAVE_IRC_PIC_LIBRARY)
 endif()
 

runtimes/CMakeLists.txt

@@ -79,7 +79,7 @@ set(LLVM_CMAKE_DIR ${LLVM_MAIN_SRC_DIR}/cmake/modules)
 set(LLVM_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../llvm)
 
 include(CheckLibraryExists)
-include(CheckCompilerFlag)
+include(LLVMCheckCompilerLinkerFlag)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 
@@ -114,7 +114,7 @@ filter_prefixed("${CMAKE_ASM_IMPLICIT_INCLUDE_DIRECTORIES}" ${LLVM_BINARY_DIR} C
 # Currently, we counteract this issue by adding -fno-sanitize=all flag in
 # the project specific code within */cmake/config-ix.cmake files but that's
 # brittle. We should ideally move this to runtimes/CMakeLists.txt.
-check_compiler_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
+llvm_check_compiler_linker_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
 if (CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
   set(ORIG_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} --unwindlib=none")
@@ -143,7 +143,7 @@ endif()
 # Check for -nostdlib++ first; if there's no C++ standard library yet,
 # all check_cxx_compiler_flag commands will fail until we add -nostdlib++
 # (or -nodefaultlibs).
-check_compiler_flag(CXX "-nostdlib++" CXX_SUPPORTS_NOSTDLIBXX_FLAG)
+llvm_check_compiler_linker_flag(CXX "-nostdlib++" CXX_SUPPORTS_NOSTDLIBXX_FLAG)
 if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
 endif()