summaryrefslogtreecommitdiffstats
path: root/Modules/CMakeDetermineCXXCompiler.cmake
blob: 41b5e475da6edb6ce350e4340053ec7e4bee1a0e (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

# 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.)
# It also tries to detect a MS crosscompiler and find out its 
# suffix (clarm.exe), which will be stored in _CMAKE_TOOLCHAIN_SUFFIX and
# reused for the C compiler.
#
# 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
#   _CMAKE_TOOLCHAIN_SUFFIX

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(CMAKE_CXX_FLAGS_ENV_INIT)
    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(NOT EXISTS ${CMAKE_CXX_COMPILER_INIT})
  ENDIF($ENV{CXX} MATCHES ".+")

  # 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(NOT CMAKE_CXX_COMPILER_INIT)
  ENDIF(CMAKE_GENERATOR_CXX)

  # finally list compilers to try
  IF(CMAKE_CXX_COMPILER_INIT)
    SET(CMAKE_CXX_COMPILER_LIST ${CMAKE_CXX_COMPILER_INIT})
  ELSE(CMAKE_CXX_COMPILER_INIT)
    SET(CMAKE_CXX_COMPILER_LIST ${_CMAKE_TOOLCHAIN_PREFIX}c++ ${_CMAKE_TOOLCHAIN_PREFIX}g++ CC aCC cl${_CMAKE_TOOLCHAIN_SUFFIX} bcc xlC)
  ENDIF(CMAKE_CXX_COMPILER_INIT)

  # Find the compiler.
  IF (_CMAKE_USER_C_COMPILER_PATH)
    FIND_PROGRAM(CMAKE_CXX_COMPILER NAMES ${CMAKE_CXX_COMPILER_LIST} PATHS ${_CMAKE_USER_C_COMPILER_PATH} DOC "C++ compiler" NO_DEFAULT_PATH)
  ENDIF (_CMAKE_USER_C_COMPILER_PATH)
  FIND_PROGRAM(CMAKE_CXX_COMPILER NAMES ${CMAKE_CXX_COMPILER_LIST} DOC "C++ compiler")
  
  IF(CMAKE_CXX_COMPILER_INIT AND NOT CMAKE_CXX_COMPILER)
    SET(CMAKE_CXX_COMPILER "${CMAKE_CXX_COMPILER_INIT}" CACHE FILEPATH "C++ compiler" FORCE)
  ENDIF(CMAKE_CXX_COMPILER_INIT AND NOT CMAKE_CXX_COMPILER)
ELSE(NOT CMAKE_CXX_COMPILER)

# if a compiler was specified by the user but without path, 
# now try to find it with the full path and force it into the cache
  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)
    SET(CMAKE_CXX_COMPILER ${CMAKE_CXX_COMPILER_WITH_PATH} CACHE FILEPATH "CXX compiler" FORCE)
  ENDIF(NOT _CMAKE_USER_CXX_COMPILER_PATH)
ENDIF(NOT CMAKE_CXX_COMPILER)
MARK_AS_ADVANCED(CMAKE_CXX_COMPILER)

IF (NOT _CMAKE_TOOLCHAIN_LOCATION)
  GET_FILENAME_COMPONENT(_CMAKE_TOOLCHAIN_LOCATION "${CMAKE_CXX_COMPILER}" PATH)
ENDIF (NOT _CMAKE_TOOLCHAIN_LOCATION)

# 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++
# the other tools of the toolchain usually have the same prefix
IF (NOT _CMAKE_TOOLCHAIN_PREFIX)
  GET_FILENAME_COMPONENT(COMPILER_BASENAME "${CMAKE_CXX_COMPILER}" NAME_WE)
  IF (COMPILER_BASENAME MATCHES "^(.+-)[gc]\\+\\+")
    STRING(REGEX REPLACE "^(.+-)[gc]\\+\\+"  "\\1" _CMAKE_TOOLCHAIN_PREFIX "${COMPILER_BASENAME}")
  ENDIF (COMPILER_BASENAME MATCHES "^(.+-)[gc]\\+\\+")
ENDIF (NOT _CMAKE_TOOLCHAIN_PREFIX)

# if we have a MS cross compiler, it usually has a suffix, like 
# e.g. clarm.exe or clmips.exe. Use this suffix for the CXX compiler too.
IF (NOT _CMAKE_TOOLCHAIN_SUFFIX)
  GET_FILENAME_COMPONENT(COMPILER_BASENAME "${CMAKE_CXX_COMPILER}" NAME)
  IF (COMPILER_BASENAME MATCHES "^cl(.+)\\.exe$")
    STRING(REGEX REPLACE "^cl(.+)\\.exe$"  "\\1" _CMAKE_TOOLCHAIN_SUFFIX "${COMPILER_BASENAME}")
  ENDIF (COMPILER_BASENAME MATCHES "^cl(.+)\\.exe$")
ENDIF (NOT _CMAKE_TOOLCHAIN_SUFFIX)


# some exotic compilers have different extensions (e.g. sdcc uses .rel)
# so don't overwrite it if it has been already defined by the user
IF(NOT CMAKE_CXX_OUTPUT_EXTENSION)
  IF(UNIX)
    SET(CMAKE_CXX_OUTPUT_EXTENSION .o)
  ELSE(UNIX)
    SET(CMAKE_CXX_OUTPUT_EXTENSION .obj)
  ENDIF(UNIX)
ENDIF(NOT CMAKE_CXX_OUTPUT_EXTENSION)


# This block was used before the compiler was identified by building a
# source file.  Unless g++ crashes when building a small C++
# executable this should no longer be needed.
#
# The g++ that comes with BeOS 5 segfaults if you run "g++ -E"
#  ("gcc -E" is fine), which throws up a system dialog box that hangs cmake
#  until the user clicks "OK"...so for now, we just assume it's g++.
# IF(BEOS)
#   SET(CMAKE_COMPILER_IS_GNUCXX 1)
#   SET(CMAKE_COMPILER_IS_GNUCXX_RUN 1)
# ENDIF(BEOS)

# Build a small source file to identify the compiler.
IF(${CMAKE_GENERATOR} MATCHES "Visual Studio")
  SET(CMAKE_CXX_COMPILER_ID_RUN 1)
  SET(CMAKE_CXX_PLATFORM_ID "Windows")

  # TODO: Set the compiler id.  It is probably MSVC but
  # the user may be using an integrated Intel compiler.
  # SET(CMAKE_CXX_COMPILER_ID "MSVC")
ENDIF(${CMAKE_GENERATOR} MATCHES "Visual Studio")
IF(NOT CMAKE_CXX_COMPILER_ID_RUN)
  SET(CMAKE_CXX_COMPILER_ID_RUN 1)

  # Try to identify the compiler.
  SET(CMAKE_CXX_COMPILER_ID)
  INCLUDE(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerId.cmake)
  CMAKE_DETERMINE_COMPILER_ID(CXX CXXFLAGS ${CMAKE_ROOT}/Modules/CMakeCXXCompilerId.cpp)

  # Set old compiler and platform id variables.
  IF("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU")
    SET(CMAKE_COMPILER_IS_GNUCXX 1)
  ENDIF("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU")
  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("${CMAKE_CXX_PLATFORM_ID}" MATCHES "MinGW")
ENDIF(NOT CMAKE_CXX_COMPILER_ID_RUN)

INCLUDE(CMakeFindBinUtils)

# configure all variables set in this file
CONFIGURE_FILE(${CMAKE_ROOT}/Modules/CMakeCXXCompiler.cmake.in 
               ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeCXXCompiler.cmake IMMEDIATE)

SET(CMAKE_CXX_COMPILER_ENV_VAR "CXX")