1# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
2# file Copyright.txt or https://cmake.org/licensing for details.
3
4
5# This module is shared by multiple languages; use include blocker.
6if(__COMPILER_GNU)
7  return()
8endif()
9set(__COMPILER_GNU 1)
10
11include(Compiler/CMakeCommonCompilerMacros)
12
13set(__pch_header_C "c-header")
14set(__pch_header_CXX "c++-header")
15set(__pch_header_OBJC "objective-c-header")
16set(__pch_header_OBJCXX "objective-c++-header")
17
18macro(__compiler_gnu lang)
19  # Feature flags.
20  set(CMAKE_${lang}_VERBOSE_FLAG "-v")
21  set(CMAKE_${lang}_COMPILE_OPTIONS_PIC "-fPIC")
22  set (_CMAKE_${lang}_PIE_MAY_BE_SUPPORTED_BY_LINKER NO)
23  if(NOT CMAKE_${lang}_COMPILER_VERSION VERSION_LESS 3.4)
24    set(CMAKE_${lang}_COMPILE_OPTIONS_PIE "-fPIE")
25    # Support of PIE at link stage depends on various elements : platform, compiler, linker
26    # so to activate it, module CheckPIESupported must be used.
27    set (_CMAKE_${lang}_PIE_MAY_BE_SUPPORTED_BY_LINKER YES)
28    set(CMAKE_${lang}_LINK_OPTIONS_PIE ${CMAKE_${lang}_COMPILE_OPTIONS_PIE} "-pie")
29    set(CMAKE_${lang}_LINK_OPTIONS_NO_PIE "-no-pie")
30  endif()
31  if(NOT CMAKE_${lang}_COMPILER_VERSION VERSION_LESS 4.0)
32    set(CMAKE_${lang}_COMPILE_OPTIONS_VISIBILITY "-fvisibility=")
33  endif()
34  set(CMAKE_SHARED_LIBRARY_${lang}_FLAGS "-fPIC")
35  set(CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS "-shared")
36  set(CMAKE_${lang}_COMPILE_OPTIONS_SYSROOT "--sysroot=")
37
38  set(CMAKE_${lang}_LINKER_WRAPPER_FLAG "-Wl,")
39  set(CMAKE_${lang}_LINKER_WRAPPER_FLAG_SEP ",")
40
41  # Older versions of gcc (< 4.5) contain a bug causing them to report a missing
42  # header file as a warning if depfiles are enabled, causing check_header_file
43  # tests to always succeed.  Work around this by disabling dependency tracking
44  # in try_compile mode.
45  get_property(_IN_TC GLOBAL PROPERTY IN_TRY_COMPILE)
46  if(CMAKE_${lang}_COMPILER_ID STREQUAL "GNU" AND _IN_TC AND NOT CMAKE_FORCE_DEPFILES)
47  else()
48    # distcc does not transform -o to -MT when invoking the preprocessor
49    # internally, as it ought to.  Work around this bug by setting -MT here
50    # even though it isn't strictly necessary.
51    set(CMAKE_DEPFILE_FLAGS_${lang} "-MD -MT <DEP_TARGET> -MF <DEP_FILE>")
52  endif()
53
54  # Initial configuration flags.
55  string(APPEND CMAKE_${lang}_FLAGS_INIT " ")
56  string(APPEND CMAKE_${lang}_FLAGS_DEBUG_INIT " -g")
57  string(APPEND CMAKE_${lang}_FLAGS_MINSIZEREL_INIT " -Os -DNDEBUG")
58  string(APPEND CMAKE_${lang}_FLAGS_RELEASE_INIT " -O3 -DNDEBUG")
59  string(APPEND CMAKE_${lang}_FLAGS_RELWITHDEBINFO_INIT " -O2 -g -DNDEBUG")
60  set(CMAKE_${lang}_CREATE_PREPROCESSED_SOURCE "<CMAKE_${lang}_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -E <SOURCE> > <PREPROCESSED_SOURCE>")
61  set(CMAKE_${lang}_CREATE_ASSEMBLY_SOURCE "<CMAKE_${lang}_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -S <SOURCE> -o <ASSEMBLY_SOURCE>")
62  if(NOT APPLE OR NOT CMAKE_${lang}_COMPILER_VERSION VERSION_LESS 4) # work around #4462
63    set(CMAKE_INCLUDE_SYSTEM_FLAG_${lang} "-isystem ")
64  endif()
65
66  set(_CMAKE_${lang}_IPO_SUPPORTED_BY_CMAKE YES)
67  set(_CMAKE_${lang}_IPO_MAY_BE_SUPPORTED_BY_COMPILER NO)
68
69  # '-flto' introduced since GCC 4.5:
70  # * https://gcc.gnu.org/onlinedocs/gcc-4.4.7/gcc/Option-Summary.html (no)
71  # * https://gcc.gnu.org/onlinedocs/gcc-4.5.4/gcc/Option-Summary.html (yes)
72  if(NOT CMAKE_${lang}_COMPILER_VERSION VERSION_LESS 4.5)
73    set(_CMAKE_${lang}_IPO_MAY_BE_SUPPORTED_BY_COMPILER YES)
74    set(__lto_flags -flto)
75
76    if(NOT CMAKE_${lang}_COMPILER_VERSION VERSION_LESS 4.7)
77      # '-ffat-lto-objects' introduced since GCC 4.7:
78      # * https://gcc.gnu.org/onlinedocs/gcc-4.6.4/gcc/Option-Summary.html (no)
79      # * https://gcc.gnu.org/onlinedocs/gcc-4.7.4/gcc/Option-Summary.html (yes)
80      list(APPEND __lto_flags -fno-fat-lto-objects)
81    endif()
82
83    set(CMAKE_${lang}_COMPILE_OPTIONS_IPO ${__lto_flags})
84
85    # Need to use version of 'ar'/'ranlib' with plugin support.
86    # Quote from [documentation][1]:
87    #
88    #   To create static libraries suitable for LTO,
89    #   use gcc-ar and gcc-ranlib instead of ar and ranlib
90    #
91    # [1]: https://gcc.gnu.org/onlinedocs/gcc-4.9.4/gcc/Optimize-Options.html
92    set(CMAKE_${lang}_ARCHIVE_CREATE_IPO
93      "\"${CMAKE_${lang}_COMPILER_AR}\" cr <TARGET> <LINK_FLAGS> <OBJECTS>"
94    )
95
96    set(CMAKE_${lang}_ARCHIVE_APPEND_IPO
97      "\"${CMAKE_${lang}_COMPILER_AR}\" r <TARGET> <LINK_FLAGS> <OBJECTS>"
98    )
99
100    set(CMAKE_${lang}_ARCHIVE_FINISH_IPO
101      "\"${CMAKE_${lang}_COMPILER_RANLIB}\" <TARGET>"
102    )
103  endif()
104
105  set(CMAKE_${lang}_COMPILER_PREDEFINES_COMMAND "${CMAKE_${lang}_COMPILER}")
106  if(CMAKE_${lang}_COMPILER_ARG1)
107    separate_arguments(_COMPILER_ARGS NATIVE_COMMAND "${CMAKE_${lang}_COMPILER_ARG1}")
108    list(APPEND CMAKE_${lang}_COMPILER_PREDEFINES_COMMAND ${_COMPILER_ARGS})
109    unset(_COMPILER_ARGS)
110  endif()
111  list(APPEND CMAKE_${lang}_COMPILER_PREDEFINES_COMMAND "-dM" "-E" "-c" "${CMAKE_ROOT}/Modules/CMakeCXXCompilerABI.cpp")
112
113  if(NOT "x${lang}" STREQUAL "xFortran")
114    set(CMAKE_PCH_EXTENSION .gch)
115    if (NOT CMAKE_GENERATOR MATCHES "Xcode")
116      set(CMAKE_PCH_PROLOGUE "#pragma GCC system_header")
117    endif()
118    set(CMAKE_${lang}_COMPILE_OPTIONS_INVALID_PCH -Winvalid-pch)
119    set(CMAKE_${lang}_COMPILE_OPTIONS_USE_PCH -include <PCH_HEADER>)
120    set(CMAKE_${lang}_COMPILE_OPTIONS_CREATE_PCH -x ${__pch_header_${lang}} -include <PCH_HEADER>)
121  endif()
122endmacro()
123