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