1# On Windows, CMAKE_*_FLAGS are built for MSVC but we use the GCC clang.exe, 2# which uses completely different flags. Translate some common flag types, and 3# drop the rest. 4function(translate_msvc_cflags out_flags msvc_flags) 5 # Insert an empty string in the list to simplify processing. 6 set(msvc_flags ";${msvc_flags}") 7 8 # Canonicalize /flag to -flag. 9 string(REPLACE ";/" ";-" msvc_flags "${msvc_flags}") 10 11 # Make space separated -D and -U flags into joined flags. 12 string(REGEX REPLACE ";-\([DU]\);" ";-\\1" msvc_flags "${msvc_flags}") 13 14 set(clang_flags "") 15 foreach(flag ${msvc_flags}) 16 if ("${flag}" MATCHES "^-[DU]") 17 # Pass through basic command line macro definitions (-DNDEBUG). 18 list(APPEND clang_flags "${flag}") 19 elseif ("${flag}" MATCHES "^-O[2x]") 20 # Canonicalize normal optimization flags to -O2. 21 list(APPEND clang_flags "-O2") 22 endif() 23 endforeach() 24 set(${out_flags} "${clang_flags}" PARENT_SCOPE) 25endfunction() 26 27# Compile a source into an object file with COMPILER_RT_TEST_COMPILER using 28# a provided compile flags and dependenices. 29# clang_compile(<object> <source> 30# CFLAGS <list of compile flags> 31# DEPS <list of dependencies>) 32macro(clang_compile object_file source) 33 cmake_parse_arguments(SOURCE "" "" "CFLAGS;DEPS" ${ARGN}) 34 get_filename_component(source_rpath ${source} REALPATH) 35 if(NOT COMPILER_RT_STANDALONE_BUILD) 36 list(APPEND SOURCE_DEPS clang compiler-rt-headers) 37 endif() 38 if (TARGET CompilerRTUnitTestCheckCxx) 39 list(APPEND SOURCE_DEPS CompilerRTUnitTestCheckCxx) 40 endif() 41 string(REGEX MATCH "[.](cc|cpp)$" is_cxx ${source_rpath}) 42 if(is_cxx) 43 string(REPLACE " " ";" global_flags "${CMAKE_CXX_FLAGS}") 44 else() 45 string(REPLACE " " ";" global_flags "${CMAKE_C_FLAGS}") 46 endif() 47 48 if (MSVC) 49 translate_msvc_cflags(global_flags "${global_flags}") 50 endif() 51 52 if (APPLE) 53 set(global_flags ${OSX_SYSROOT_FLAG} ${global_flags}) 54 endif() 55 56 # Ignore unknown warnings. CMAKE_CXX_FLAGS may contain GCC-specific options 57 # which are not supported by Clang. 58 list(APPEND global_flags -Wno-unknown-warning-option) 59 set(compile_flags ${global_flags} ${SOURCE_CFLAGS}) 60 add_custom_command( 61 OUTPUT ${object_file} 62 COMMAND ${COMPILER_RT_TEST_COMPILER} ${compile_flags} -c 63 -o "${object_file}" 64 ${source_rpath} 65 MAIN_DEPENDENCY ${source} 66 DEPENDS ${SOURCE_DEPS}) 67endmacro() 68 69# On Darwin, there are no system-wide C++ headers and the just-built clang is 70# therefore not able to compile C++ files unless they are copied/symlinked into 71# ${LLVM_BINARY_DIR}/include/c++ 72# The just-built clang is used to build compiler-rt unit tests. Let's detect 73# this before we try to build the tests and print out a suggestion how to fix 74# it. 75# On other platforms, this is currently not an issue. 76macro(clang_compiler_add_cxx_check) 77 if (APPLE) 78 set(CMD 79 "echo '#include <iostream>' | ${COMPILER_RT_TEST_COMPILER} ${OSX_SYSROOT_FLAG} -E -x c++ - > /dev/null" 80 "if [ $? != 0 ] " 81 " then echo" 82 " echo 'Your just-built clang cannot find C++ headers, which are needed to build and run compiler-rt tests.'" 83 " echo 'You should copy or symlink your system C++ headers into ${LLVM_BINARY_DIR}/include/c++'" 84 " if [ -d $(dirname $(dirname $(xcrun -f clang)))/include/c++ ]" 85 " then echo 'e.g. with:'" 86 " echo ' cp -r' $(dirname $(dirname $(xcrun -f clang)))/include/c++ '${LLVM_BINARY_DIR}/include/'" 87 " elif [ -d $(dirname $(dirname $(xcrun -f clang)))/lib/c++ ]" 88 " then echo 'e.g. with:'" 89 " echo ' cp -r' $(dirname $(dirname $(xcrun -f clang)))/lib/c++ '${LLVM_BINARY_DIR}/include/'" 90 " fi" 91 " echo 'This can also be fixed by checking out the libcxx project from llvm.org and installing the headers'" 92 " echo 'into your build directory:'" 93 " echo ' cd ${LLVM_MAIN_SRC_DIR}/projects && svn co http://llvm.org/svn/llvm-project/libcxx/trunk libcxx'" 94 " echo ' cd ${LLVM_BINARY_DIR} && make -C ${LLVM_MAIN_SRC_DIR}/projects/libcxx installheaders HEADER_DIR=${LLVM_BINARY_DIR}/include'" 95 " echo" 96 " false" 97 "fi" 98 ) 99 add_custom_target(CompilerRTUnitTestCheckCxx 100 COMMAND bash -c "${CMD}" 101 COMMENT "Checking that just-built clang can find C++ headers..." 102 VERBATIM) 103 if (TARGET clang) 104 ADD_DEPENDENCIES(CompilerRTUnitTestCheckCxx clang) 105 endif() 106 endif() 107endmacro() 108