[llvm] 10e5c51 - Revert "[cmake] Duplicate `{llvm,compiler_rt}_check_linker_flag` for runtime libs and llvm"

Petr Hosek via llvm-commits llvm-commits at lists.llvm.org
Fri Jan 21 09:53:59 PST 2022


Author: Petr Hosek
Date: 2022-01-21T09:53:14-08:00
New Revision: 10e5c513b59bff0a049cc2a24bb7d41cd874ad7a

URL: https://github.com/llvm/llvm-project/commit/10e5c513b59bff0a049cc2a24bb7d41cd874ad7a
DIFF: https://github.com/llvm/llvm-project/commit/10e5c513b59bff0a049cc2a24bb7d41cd874ad7a.diff

LOG: Revert "[cmake] Duplicate `{llvm,compiler_rt}_check_linker_flag` for runtime libs and llvm"

This reverts commit 4af11272f57a4a6fed2932e9e0857b2c1a707c51.

Added: 
    cmake/Modules/CheckLinkerFlag.cmake

Modified: 
    compiler-rt/cmake/config-ix.cmake
    libcxx/cmake/config-ix.cmake
    libunwind/cmake/config-ix.cmake
    llvm/cmake/modules/LLVMCheckLinkerFlag.cmake
    runtimes/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/cmake/Modules/CheckLinkerFlag.cmake b/cmake/Modules/CheckLinkerFlag.cmake
new file mode 100644
index 0000000000000..722fe5b1b8ead
--- /dev/null
+++ b/cmake/Modules/CheckLinkerFlag.cmake
@@ -0,0 +1,17 @@
+include(CMakePushCheckState)
+include(CheckCCompilerFlag)
+
+function(llvm_check_linker_flag flag dest)
+  # 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_c_compiler_flag("" ${dest})
+  cmake_pop_check_state()
+endfunction()

diff  --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
index 596f61e8c82ec..33693ce60321d 100644
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -1,5 +1,4 @@
 include(CMakePushCheckState)
-include(LLVMCheckLinkerFlag) # Compat until CMake 3.18
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 include(CheckIncludeFiles)
@@ -7,6 +6,13 @@ include(CheckLibraryExists)
 include(CheckSymbolExists)
 include(TestBigEndian)
 
+function(compiler_rt_check_linker_flag flag out_var)
+  cmake_push_check_state()
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${flag}")
+  check_cxx_compiler_flag("" ${out_var})
+  cmake_pop_check_state()
+endfunction()
+
 check_library_exists(c fopen "" COMPILER_RT_HAS_LIBC)
 if (COMPILER_RT_USE_BUILTINS_LIBRARY)
   include(HandleCompilerRT)
@@ -165,12 +171,12 @@ check_library_exists(c++ __cxa_throw "" COMPILER_RT_HAS_LIBCXX)
 check_library_exists(stdc++ __cxa_throw "" COMPILER_RT_HAS_LIBSTDCXX)
 
 # Linker flags.
-llvm_check_linker_flag(CXX "-Wl,-z,text" COMPILER_RT_HAS_Z_TEXT)
-llvm_check_linker_flag(CXX "-fuse-ld=lld" COMPILER_RT_HAS_FUSE_LD_LLD_FLAG)
+compiler_rt_check_linker_flag("-Wl,-z,text" COMPILER_RT_HAS_Z_TEXT)
+compiler_rt_check_linker_flag("-fuse-ld=lld" COMPILER_RT_HAS_FUSE_LD_LLD_FLAG)
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "SunOS")
   set(VERS_COMPAT_OPTION "-Wl,-z,gnu-version-script-compat")
-  llvm_check_linker_flag(CXX "${VERS_COMPAT_OPTION}" COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
+  compiler_rt_check_linker_flag("${VERS_COMPAT_OPTION}" COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
 endif()
 
 set(DUMMY_VERS ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/dummy.vers)
@@ -181,10 +187,10 @@ if(COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
   # -z gnu-version-script-compat.
   string(APPEND VERS_OPTION " ${VERS_COMPAT_OPTION}")
 endif()
-llvm_check_linker_flag(CXX "${VERS_OPTION}" COMPILER_RT_HAS_VERSION_SCRIPT)
+compiler_rt_check_linker_flag("${VERS_OPTION}" COMPILER_RT_HAS_VERSION_SCRIPT)
 
 if(ANDROID)
-  llvm_check_linker_flag(CXX "-Wl,-z,global" COMPILER_RT_HAS_Z_GLOBAL)
+  compiler_rt_check_linker_flag("-Wl,-z,global" COMPILER_RT_HAS_Z_GLOBAL)
   check_library_exists(log __android_log_write "" COMPILER_RT_HAS_LIBLOG)
 endif()
 
@@ -430,7 +436,7 @@ if(APPLE)
     -lc++
     -lc++abi)
 
-  llvm_check_linker_flag(CXX "-fapplication-extension" COMPILER_RT_HAS_APP_EXTENSION)
+  compiler_rt_check_linker_flag("-fapplication-extension" COMPILER_RT_HAS_APP_EXTENSION)
   if(COMPILER_RT_HAS_APP_EXTENSION)
     list(APPEND DARWIN_COMMON_LINK_FLAGS "-fapplication-extension")
   endif()

diff  --git a/libcxx/cmake/config-ix.cmake b/libcxx/cmake/config-ix.cmake
index e114337f081a3..689a9d09c0179 100644
--- a/libcxx/cmake/config-ix.cmake
+++ b/libcxx/cmake/config-ix.cmake
@@ -1,6 +1,6 @@
 include(CMakePushCheckState)
 include(CheckLibraryExists)
-include(LLVMCheckLinkerFlag) # Compat until CMake 3.18
+include(CheckLinkerFlag)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 include(CheckCSourceCompiles)
@@ -12,7 +12,7 @@ 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 --uwnindlib=none. Check if that option works.
-llvm_check_linker_flag(C "--unwindlib=none" LIBCXX_SUPPORTS_UNWINDLIB_NONE_FLAG)
+llvm_check_linker_flag("--unwindlib=none" LIBCXX_SUPPORTS_UNWINDLIB_NONE_FLAG)
 if (LIBCXX_SUPPORTS_UNWINDLIB_NONE_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} --unwindlib=none")
 endif()

diff  --git a/libunwind/cmake/config-ix.cmake b/libunwind/cmake/config-ix.cmake
index c1e1b4631abfe..c814611d43785 100644
--- a/libunwind/cmake/config-ix.cmake
+++ b/libunwind/cmake/config-ix.cmake
@@ -2,14 +2,14 @@ include(CMakePushCheckState)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 include(CheckLibraryExists)
-include(LLVMCheckLinkerFlag) # Compat until CMake 3.18
+include(CheckLinkerFlag)
 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.
-llvm_check_linker_flag(C "--unwindlib=none" LIBUNWIND_SUPPORTS_UNWINDLIB_NONE_FLAG)
+llvm_check_linker_flag("--unwindlib=none" LIBUNWIND_SUPPORTS_UNWINDLIB_NONE_FLAG)
 if (LIBUNWIND_SUPPORTS_UNWINDLIB_NONE_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} --unwindlib=none")
 endif()
@@ -34,11 +34,11 @@ endif()
 # required for the link to go through. We remove sanitizers from the
 # configuration checks to avoid spurious link errors.
 
-llvm_check_linker_flag(C "-nostdlib++" LIBUNWIND_SUPPORTS_NOSTDLIBXX_FLAG)
+llvm_check_linker_flag(-nostdlib++ LIBUNWIND_SUPPORTS_NOSTDLIBXX_FLAG)
 if (LIBUNWIND_SUPPORTS_NOSTDLIBXX_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
 else()
-  llvm_check_linker_flag(C "-nodefaultlibs" LIBUNWIND_SUPPORTS_NODEFAULTLIBS_FLAG)
+  llvm_check_linker_flag(-nodefaultlibs LIBUNWIND_SUPPORTS_NODEFAULTLIBS_FLAG)
   if (LIBUNWIND_SUPPORTS_NODEFAULTLIBS_FLAG)
     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs")
   endif()

diff  --git a/llvm/cmake/modules/LLVMCheckLinkerFlag.cmake b/llvm/cmake/modules/LLVMCheckLinkerFlag.cmake
index 79c4e2cb4c2cd..253dd768654a2 100644
--- a/llvm/cmake/modules/LLVMCheckLinkerFlag.cmake
+++ b/llvm/cmake/modules/LLVMCheckLinkerFlag.cmake
@@ -5,22 +5,14 @@ if (COMMAND check_linker_flag)
     check_linker_flag(${ARGN})
   endmacro()
 else()
-  # Until the minimum CMAKE version is 3.18
-
   include(CheckCXXCompilerFlag)
   include(CMakePushCheckState)
 
-  # cmake builtin compatible, except we assume lang is C or CXX
+  # cmake builtin compatible, except we assume lang is CXX
   function(llvm_check_linker_flag lang flag out_var)
     cmake_push_check_state()
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${flag}")
-    if("${lang}" STREQUAL "C")
-      check_c_compiler_flag("" ${out_var})
-    elseif("${lang}" STREQUAL "CXX")
-      check_cxx_compiler_flag("" ${out_var})
-    else()
-      message(FATAL_ERROR "\"${lang}\" is not C or CXX")
-    endif()
+    check_cxx_compiler_flag("" ${out_var})
     cmake_pop_check_state()
   endfunction()
 endif()

diff  --git a/runtimes/CMakeLists.txt b/runtimes/CMakeLists.txt
index 1a50d9e8c98b3..cedce7b3541e5 100644
--- a/runtimes/CMakeLists.txt
+++ b/runtimes/CMakeLists.txt
@@ -88,7 +88,7 @@ set(LLVM_CMAKE_DIR ${LLVM_MAIN_SRC_DIR}/cmake/modules)
 set(LLVM_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../llvm)
 
 include(CheckLibraryExists)
-include(LLVMCheckLinkerFlag) # Compat until CMake 3.18
+include(CheckLinkerFlag)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 
@@ -100,7 +100,7 @@ if (NOT LLVM_RUNTIMES_LINKING_WORKS)
   # --unwindlib=none is supported, and use that if possible.
   # Don't add this if not necessary to fix linking, as it can break using
   # e.g. ASAN/TSAN.
-  llvm_check_linker_flag(C "--unwindlib=none" LLVM_RUNTIMES_SUPPORT_UNWINDLIB_NONE_FLAG)
+  llvm_check_linker_flag("--unwindlib=none" LLVM_RUNTIMES_SUPPORT_UNWINDLIB_NONE_FLAG)
   if (LLVM_RUNTIMES_SUPPORT_UNWINDLIB_NONE_FLAG)
     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} --unwindlib=none")
   endif()
@@ -110,7 +110,7 @@ endif()
 # Check for -nostdlib++ first; if there's no C++ standard library yet,
 # all check_cxx_compiler_flag commands will fail until we add -nostdlib++
 # (or -nodefaultlibs).
-llvm_check_linker_flag(C "-nostdlib++" LLVM_RUNTIMES_SUPPORT_NOSTDLIBXX_FLAG)
+llvm_check_linker_flag(-nostdlib++ LLVM_RUNTIMES_SUPPORT_NOSTDLIBXX_FLAG)
 if (LLVM_RUNTIMES_SUPPORT_NOSTDLIBXX_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
 endif()


        


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