summaryrefslogtreecommitdiff
path: root/Modules/CMakeDetermineCXXCompiler.cmake
blob: 59da3e60d78282eb5ed9770a66aeaeae3ba073c0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172

#=============================================================================
# Copyright 2002-2009 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
#  License text for the above reference.)

# determine the compiler to use for C++ programs
# NOTE, a generator may set CMAKE_CXX_COMPILER before
# loading this file to force a compiler.
# use environment variable CXX first if defined by user, next use
# the cmake variable CMAKE_GENERATOR_CXX which can be defined by a generator
# as a default compiler
# If the internal cmake variable _CMAKE_TOOLCHAIN_PREFIX is set, this is used
# as prefix for the tools (e.g. arm-elf-g++, arm-elf-ar etc.)
#
# Sets the following variables:
#   CMAKE_CXX_COMPILER
#   CMAKE_COMPILER_IS_GNUCXX
#   CMAKE_AR
#   CMAKE_RANLIB
#
# If not already set before, it also sets
#   _CMAKE_TOOLCHAIN_PREFIX

include(${CMAKE_ROOT}/Modules/CMakeDetermineCompiler.cmake)

# Load system-specific compiler preferences for this language.
include(Platform/${CMAKE_SYSTEM_NAME}-CXX OPTIONAL)
if(NOT CMAKE_CXX_COMPILER_NAMES)
  set(CMAKE_CXX_COMPILER_NAMES CC)
endif()

if(${CMAKE_GENERATOR} MATCHES "Visual Studio")
elseif("${CMAKE_GENERATOR}" MATCHES "Xcode")
  set(CMAKE_CXX_COMPILER_XCODE_TYPE sourcecode.cpp.cpp)
else()
  if(NOT CMAKE_CXX_COMPILER)
    set(CMAKE_CXX_COMPILER_INIT NOTFOUND)

    # prefer the environment variable CXX
    if($ENV{CXX} MATCHES ".+")
      get_filename_component(CMAKE_CXX_COMPILER_INIT $ENV{CXX} PROGRAM PROGRAM_ARGS CMAKE_CXX_FLAGS_ENV_INIT)
      if(CMAKE_CXX_FLAGS_ENV_INIT)
        set(CMAKE_CXX_COMPILER_ARG1 "${CMAKE_CXX_FLAGS_ENV_INIT}" CACHE STRING "First argument to CXX compiler")
      endif()
      if(NOT EXISTS ${CMAKE_CXX_COMPILER_INIT})
        message(FATAL_ERROR "Could not find compiler set in environment variable CXX:\n$ENV{CXX}.\n${CMAKE_CXX_COMPILER_INIT}")
      endif()
    endif()

    # next prefer the generator specified compiler
    if(CMAKE_GENERATOR_CXX)
      if(NOT CMAKE_CXX_COMPILER_INIT)
        set(CMAKE_CXX_COMPILER_INIT ${CMAKE_GENERATOR_CXX})
      endif()
    endif()

    # finally list compilers to try
    if(NOT CMAKE_CXX_COMPILER_INIT)
      set(CMAKE_CXX_COMPILER_LIST CC ${_CMAKE_TOOLCHAIN_PREFIX}c++ ${_CMAKE_TOOLCHAIN_PREFIX}g++ aCC cl bcc xlC clang++)
    endif()

    _cmake_find_compiler(CXX)
  else()

    # we only get here if CMAKE_CXX_COMPILER was specified using -D or a pre-made CMakeCache.txt
    # (e.g. via ctest) or set in CMAKE_TOOLCHAIN_FILE
    #
    # if CMAKE_CXX_COMPILER is a list of length 2, use the first item as
    # CMAKE_CXX_COMPILER and the 2nd one as CMAKE_CXX_COMPILER_ARG1

    list(LENGTH CMAKE_CXX_COMPILER _CMAKE_CXX_COMPILER_LIST_LENGTH)
    if("${_CMAKE_CXX_COMPILER_LIST_LENGTH}" EQUAL 2)
      list(GET CMAKE_CXX_COMPILER 1 CMAKE_CXX_COMPILER_ARG1)
      list(GET CMAKE_CXX_COMPILER 0 CMAKE_CXX_COMPILER)
    endif()

    # if a compiler was specified by the user but without path,
    # now try to find it with the full path
    # if it is found, force it into the cache,
    # if not, don't overwrite the setting (which was given by the user) with "NOTFOUND"
    # if the CXX compiler already had a path, reuse it for searching the C compiler
    get_filename_component(_CMAKE_USER_CXX_COMPILER_PATH "${CMAKE_CXX_COMPILER}" PATH)
    if(NOT _CMAKE_USER_CXX_COMPILER_PATH)
      find_program(CMAKE_CXX_COMPILER_WITH_PATH NAMES ${CMAKE_CXX_COMPILER})
      mark_as_advanced(CMAKE_CXX_COMPILER_WITH_PATH)
      if(CMAKE_CXX_COMPILER_WITH_PATH)
        set(CMAKE_CXX_COMPILER ${CMAKE_CXX_COMPILER_WITH_PATH} CACHE STRING "CXX compiler" FORCE)
      endif()
    endif()
  endif()
  mark_as_advanced(CMAKE_CXX_COMPILER)

  # Each entry in this list is a set of extra flags to try
  # adding to the compile line to see if it helps produce
  # a valid identification file.
  set(CMAKE_CXX_COMPILER_ID_TEST_FLAGS
    # Try compiling to an object file only.
    "-c"
    )
endif()

# Build a small source file to identify the compiler.
if(NOT CMAKE_CXX_COMPILER_ID_RUN)
  set(CMAKE_CXX_COMPILER_ID_RUN 1)

  # Try to identify the compiler.
  set(CMAKE_CXX_COMPILER_ID)
  file(READ ${CMAKE_ROOT}/Modules/CMakePlatformId.h.in
    CMAKE_CXX_COMPILER_ID_PLATFORM_CONTENT)
  include(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerId.cmake)
  CMAKE_DETERMINE_COMPILER_ID(CXX CXXFLAGS CMakeCXXCompilerId.cpp)

  # Set old compiler and platform id variables.
  if("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU")
    set(CMAKE_COMPILER_IS_GNUCXX 1)
  endif()
  if("${CMAKE_CXX_PLATFORM_ID}" MATCHES "MinGW")
    set(CMAKE_COMPILER_IS_MINGW 1)
  elseif("${CMAKE_CXX_PLATFORM_ID}" MATCHES "Cygwin")
    set(CMAKE_COMPILER_IS_CYGWIN 1)
  endif()
endif()

if (NOT _CMAKE_TOOLCHAIN_LOCATION)
  get_filename_component(_CMAKE_TOOLCHAIN_LOCATION "${CMAKE_CXX_COMPILER}" PATH)
endif ()

# if we have a g++ cross compiler, they have usually some prefix, like
# e.g. powerpc-linux-g++, arm-elf-g++ or i586-mingw32msvc-g++ , optionally
# with a 3-component version number at the end (e.g. arm-eabi-gcc-4.5.2).
# The other tools of the toolchain usually have the same prefix
# NAME_WE cannot be used since then this test will fail for names lile
# "arm-unknown-nto-qnx6.3.0-gcc.exe", where BASENAME would be
# "arm-unknown-nto-qnx6" instead of the correct "arm-unknown-nto-qnx6.3.0-"
if (CMAKE_CROSSCOMPILING
    AND "${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU"
    AND NOT _CMAKE_TOOLCHAIN_PREFIX)
  get_filename_component(COMPILER_BASENAME "${CMAKE_CXX_COMPILER}" NAME)
  if (COMPILER_BASENAME MATCHES "^(.+-)[gc]\\+\\+(-[0-9]+\\.[0-9]+\\.[0-9]+)?(\\.exe)?$")
    set(_CMAKE_TOOLCHAIN_PREFIX ${CMAKE_MATCH_1})
  endif ()

  # if "llvm-" is part of the prefix, remove it, since llvm doesn't have its own binutils
  # but uses the regular ar, objcopy, etc. (instead of llvm-objcopy etc.)
  if ("${_CMAKE_TOOLCHAIN_PREFIX}" MATCHES "(.+-)?llvm-$")
    set(_CMAKE_TOOLCHAIN_PREFIX ${CMAKE_MATCH_1})
  endif ()

endif ()

include(${CMAKE_ROOT}/Modules/CMakeClDeps.cmake)
include(CMakeFindBinUtils)
if(MSVC_CXX_ARCHITECTURE_ID)
  set(SET_MSVC_CXX_ARCHITECTURE_ID
    "set(MSVC_CXX_ARCHITECTURE_ID ${MSVC_CXX_ARCHITECTURE_ID})")
endif()
# configure all variables set in this file
configure_file(${CMAKE_ROOT}/Modules/CMakeCXXCompiler.cmake.in
  ${CMAKE_PLATFORM_INFO_DIR}/CMakeCXXCompiler.cmake
  @ONLY IMMEDIATE # IMMEDIATE must be here for compatibility mode <= 2.0
  )

set(CMAKE_CXX_COMPILER_ENV_VAR "CXX")