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 file sets the basic flags for the C++ language in CMake.
6# It also loads the available platform file for the system-compiler
7# if it exists.
8# It also loads a system - compiler - processor (or target hardware)
9# specific file, which is mainly useful for crosscompiling and embedded systems.
10
11include(CMakeLanguageInformation)
12
13# some compilers use different extensions (e.g. sdcc uses .rel)
14# so set the extension here first so it can be overridden by the compiler specific file
15if(UNIX)
16  set(CMAKE_CXX_OUTPUT_EXTENSION .o)
17else()
18  set(CMAKE_CXX_OUTPUT_EXTENSION .obj)
19endif()
20
21set(_INCLUDED_FILE 0)
22
23# Load compiler-specific information.
24if(CMAKE_CXX_COMPILER_ID)
25  include(Compiler/${CMAKE_CXX_COMPILER_ID}-CXX OPTIONAL)
26endif()
27
28set(CMAKE_BASE_NAME)
29get_filename_component(CMAKE_BASE_NAME "${CMAKE_CXX_COMPILER}" NAME_WE)
30# since the gnu compiler has several names force g++
31if(CMAKE_COMPILER_IS_GNUCXX)
32  set(CMAKE_BASE_NAME g++)
33endif()
34
35
36# load a hardware specific file, mostly useful for embedded compilers
37if(CMAKE_SYSTEM_PROCESSOR)
38  if(CMAKE_CXX_COMPILER_ID)
39    include(Platform/${CMAKE_EFFECTIVE_SYSTEM_NAME}-${CMAKE_CXX_COMPILER_ID}-CXX-${CMAKE_SYSTEM_PROCESSOR} OPTIONAL RESULT_VARIABLE _INCLUDED_FILE)
40  endif()
41  if (NOT _INCLUDED_FILE)
42    include(Platform/${CMAKE_EFFECTIVE_SYSTEM_NAME}-${CMAKE_BASE_NAME}-${CMAKE_SYSTEM_PROCESSOR} OPTIONAL)
43  endif ()
44endif()
45
46# load the system- and compiler specific files
47if(CMAKE_CXX_COMPILER_ID)
48  include(Platform/${CMAKE_EFFECTIVE_SYSTEM_NAME}-${CMAKE_CXX_COMPILER_ID}-CXX OPTIONAL RESULT_VARIABLE _INCLUDED_FILE)
49endif()
50if (NOT _INCLUDED_FILE)
51  include(Platform/${CMAKE_EFFECTIVE_SYSTEM_NAME}-${CMAKE_BASE_NAME} OPTIONAL
52          RESULT_VARIABLE _INCLUDED_FILE)
53endif ()
54
55# load any compiler-wrapper specific information
56if (CMAKE_CXX_COMPILER_WRAPPER)
57  __cmake_include_compiler_wrapper(CXX)
58endif ()
59
60# We specify the compiler information in the system file for some
61# platforms, but this language may not have been enabled when the file
62# was first included.  Include it again to get the language info.
63# Remove this when all compiler info is removed from system files.
64if (NOT _INCLUDED_FILE)
65  include(Platform/${CMAKE_SYSTEM_NAME} OPTIONAL)
66endif ()
67
68if(CMAKE_CXX_SIZEOF_DATA_PTR)
69  foreach(f ${CMAKE_CXX_ABI_FILES})
70    include(${f})
71  endforeach()
72  unset(CMAKE_CXX_ABI_FILES)
73endif()
74
75# This should be included before the _INIT variables are
76# used to initialize the cache.  Since the rule variables
77# have if blocks on them, users can still define them here.
78# But, it should still be after the platform file so changes can
79# be made to those values.
80
81if(CMAKE_USER_MAKE_RULES_OVERRIDE)
82  # Save the full path of the file so try_compile can use it.
83  include(${CMAKE_USER_MAKE_RULES_OVERRIDE} RESULT_VARIABLE _override)
84  set(CMAKE_USER_MAKE_RULES_OVERRIDE "${_override}")
85endif()
86
87if(CMAKE_USER_MAKE_RULES_OVERRIDE_CXX)
88  # Save the full path of the file so try_compile can use it.
89  include(${CMAKE_USER_MAKE_RULES_OVERRIDE_CXX} RESULT_VARIABLE _override)
90  set(CMAKE_USER_MAKE_RULES_OVERRIDE_CXX "${_override}")
91endif()
92
93
94# Create a set of shared library variable specific to C++
95# For 90% of the systems, these are the same flags as the C versions
96# so if these are not set just copy the flags from the c version
97if(NOT CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS)
98  set(CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS ${CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS})
99endif()
100
101if(NOT CMAKE_CXX_COMPILE_OPTIONS_PIC)
102  set(CMAKE_CXX_COMPILE_OPTIONS_PIC ${CMAKE_C_COMPILE_OPTIONS_PIC})
103endif()
104
105if(NOT CMAKE_CXX_COMPILE_OPTIONS_PIE)
106  set(CMAKE_CXX_COMPILE_OPTIONS_PIE ${CMAKE_C_COMPILE_OPTIONS_PIE})
107endif()
108if(NOT CMAKE_CXX_LINK_OPTIONS_PIE)
109  set(CMAKE_CXX_LINK_OPTIONS_PIE ${CMAKE_C_LINK_OPTIONS_PIE})
110endif()
111if(NOT CMAKE_CXX_LINK_OPTIONS_NO_PIE)
112  set(CMAKE_CXX_LINK_OPTIONS_NO_PIE ${CMAKE_C_LINK_OPTIONS_NO_PIE})
113endif()
114
115if(NOT CMAKE_CXX_COMPILE_OPTIONS_DLL)
116  set(CMAKE_CXX_COMPILE_OPTIONS_DLL ${CMAKE_C_COMPILE_OPTIONS_DLL})
117endif()
118
119if(NOT CMAKE_SHARED_LIBRARY_CXX_FLAGS)
120  set(CMAKE_SHARED_LIBRARY_CXX_FLAGS ${CMAKE_SHARED_LIBRARY_C_FLAGS})
121endif()
122
123if(NOT DEFINED CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS)
124  set(CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS ${CMAKE_SHARED_LIBRARY_LINK_C_FLAGS})
125endif()
126
127if(NOT CMAKE_SHARED_LIBRARY_RUNTIME_CXX_FLAG)
128  set(CMAKE_SHARED_LIBRARY_RUNTIME_CXX_FLAG ${CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG})
129endif()
130
131if(NOT CMAKE_SHARED_LIBRARY_RUNTIME_CXX_FLAG_SEP)
132  set(CMAKE_SHARED_LIBRARY_RUNTIME_CXX_FLAG_SEP ${CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG_SEP})
133endif()
134
135if(NOT CMAKE_SHARED_LIBRARY_RPATH_LINK_CXX_FLAG)
136  set(CMAKE_SHARED_LIBRARY_RPATH_LINK_CXX_FLAG ${CMAKE_SHARED_LIBRARY_RPATH_LINK_C_FLAG})
137endif()
138
139if(NOT DEFINED CMAKE_EXE_EXPORTS_CXX_FLAG)
140  set(CMAKE_EXE_EXPORTS_CXX_FLAG ${CMAKE_EXE_EXPORTS_C_FLAG})
141endif()
142
143if(NOT DEFINED CMAKE_SHARED_LIBRARY_SONAME_CXX_FLAG)
144  set(CMAKE_SHARED_LIBRARY_SONAME_CXX_FLAG ${CMAKE_SHARED_LIBRARY_SONAME_C_FLAG})
145endif()
146
147if(NOT CMAKE_EXECUTABLE_RUNTIME_CXX_FLAG)
148  set(CMAKE_EXECUTABLE_RUNTIME_CXX_FLAG ${CMAKE_SHARED_LIBRARY_RUNTIME_CXX_FLAG})
149endif()
150
151if(NOT CMAKE_EXECUTABLE_RUNTIME_CXX_FLAG_SEP)
152  set(CMAKE_EXECUTABLE_RUNTIME_CXX_FLAG_SEP ${CMAKE_SHARED_LIBRARY_RUNTIME_CXX_FLAG_SEP})
153endif()
154
155if(NOT CMAKE_EXECUTABLE_RPATH_LINK_CXX_FLAG)
156  set(CMAKE_EXECUTABLE_RPATH_LINK_CXX_FLAG ${CMAKE_SHARED_LIBRARY_RPATH_LINK_CXX_FLAG})
157endif()
158
159if(NOT DEFINED CMAKE_SHARED_LIBRARY_LINK_CXX_WITH_RUNTIME_PATH)
160  set(CMAKE_SHARED_LIBRARY_LINK_CXX_WITH_RUNTIME_PATH ${CMAKE_SHARED_LIBRARY_LINK_C_WITH_RUNTIME_PATH})
161endif()
162
163if(NOT CMAKE_INCLUDE_FLAG_CXX)
164  set(CMAKE_INCLUDE_FLAG_CXX ${CMAKE_INCLUDE_FLAG_C})
165endif()
166
167# for most systems a module is the same as a shared library
168# so unless the variable CMAKE_MODULE_EXISTS is set just
169# copy the values from the LIBRARY variables
170if(NOT CMAKE_MODULE_EXISTS)
171  set(CMAKE_SHARED_MODULE_CXX_FLAGS ${CMAKE_SHARED_LIBRARY_CXX_FLAGS})
172  set(CMAKE_SHARED_MODULE_CREATE_CXX_FLAGS ${CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS})
173endif()
174
175# repeat for modules
176if(NOT CMAKE_SHARED_MODULE_CREATE_CXX_FLAGS)
177  set(CMAKE_SHARED_MODULE_CREATE_CXX_FLAGS ${CMAKE_SHARED_MODULE_CREATE_C_FLAGS})
178endif()
179
180if(NOT CMAKE_SHARED_MODULE_CXX_FLAGS)
181  set(CMAKE_SHARED_MODULE_CXX_FLAGS ${CMAKE_SHARED_MODULE_C_FLAGS})
182endif()
183
184# Initialize CXX link type selection flags from C versions.
185foreach(type SHARED_LIBRARY SHARED_MODULE EXE)
186  if(NOT CMAKE_${type}_LINK_STATIC_CXX_FLAGS)
187    set(CMAKE_${type}_LINK_STATIC_CXX_FLAGS
188      ${CMAKE_${type}_LINK_STATIC_C_FLAGS})
189  endif()
190  if(NOT CMAKE_${type}_LINK_DYNAMIC_CXX_FLAGS)
191    set(CMAKE_${type}_LINK_DYNAMIC_CXX_FLAGS
192      ${CMAKE_${type}_LINK_DYNAMIC_C_FLAGS})
193  endif()
194endforeach()
195
196if(CMAKE_EXECUTABLE_FORMAT STREQUAL "ELF")
197  if(NOT DEFINED CMAKE_CXX_LINK_WHAT_YOU_USE_FLAG)
198    set(CMAKE_CXX_LINK_WHAT_YOU_USE_FLAG "LINKER:--no-as-needed")
199  endif()
200  if(NOT DEFINED CMAKE_LINK_WHAT_YOU_USE_CHECK)
201    set(CMAKE_LINK_WHAT_YOU_USE_CHECK ldd -u -r)
202  endif()
203endif()
204
205# add the flags to the cache based
206# on the initial values computed in the platform/*.cmake files
207# use _INIT variables so that this only happens the first time
208# and you can set these flags in the cmake cache
209set(CMAKE_CXX_FLAGS_INIT "$ENV{CXXFLAGS} ${CMAKE_CXX_FLAGS_INIT}")
210
211cmake_initialize_per_config_variable(CMAKE_CXX_FLAGS "Flags used by the CXX compiler")
212
213if(CMAKE_CXX_STANDARD_LIBRARIES_INIT)
214  set(CMAKE_CXX_STANDARD_LIBRARIES "${CMAKE_CXX_STANDARD_LIBRARIES_INIT}"
215    CACHE STRING "Libraries linked by default with all C++ applications.")
216  mark_as_advanced(CMAKE_CXX_STANDARD_LIBRARIES)
217endif()
218
219if(NOT CMAKE_CXX_COMPILER_LAUNCHER AND DEFINED ENV{CMAKE_CXX_COMPILER_LAUNCHER})
220  set(CMAKE_CXX_COMPILER_LAUNCHER "$ENV{CMAKE_CXX_COMPILER_LAUNCHER}"
221    CACHE STRING "Compiler launcher for CXX.")
222endif()
223
224if(NOT CMAKE_CXX_LINKER_LAUNCHER AND DEFINED ENV{CMAKE_CXX_LINKER_LAUNCHER})
225  set(CMAKE_CXX_LINKER_LAUNCHER "$ENV{CMAKE_CXX_LINKER_LAUNCHER}"
226    CACHE STRING "Linker launcher for CXX.")
227endif()
228
229include(CMakeCommonLanguageInclude)
230
231# now define the following rules:
232# CMAKE_CXX_CREATE_SHARED_LIBRARY
233# CMAKE_CXX_CREATE_SHARED_MODULE
234# CMAKE_CXX_COMPILE_OBJECT
235# CMAKE_CXX_LINK_EXECUTABLE
236
237# variables supplied by the generator at use time
238# <TARGET>
239# <TARGET_BASE> the target without the suffix
240# <OBJECTS>
241# <OBJECT>
242# <LINK_LIBRARIES>
243# <FLAGS>
244# <LINK_FLAGS>
245
246# CXX compiler information
247# <CMAKE_CXX_COMPILER>
248# <CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS>
249# <CMAKE_CXX_SHARED_MODULE_CREATE_FLAGS>
250# <CMAKE_CXX_LINK_FLAGS>
251
252# Static library tools
253# <CMAKE_AR>
254# <CMAKE_RANLIB>
255
256
257# create a shared C++ library
258if(NOT CMAKE_CXX_CREATE_SHARED_LIBRARY)
259  set(CMAKE_CXX_CREATE_SHARED_LIBRARY
260      "<CMAKE_CXX_COMPILER> <CMAKE_SHARED_LIBRARY_CXX_FLAGS> <LANGUAGE_COMPILE_FLAGS> <LINK_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS> <SONAME_FLAG><TARGET_SONAME> -o <TARGET> <OBJECTS> <LINK_LIBRARIES>")
261endif()
262
263# create a c++ shared module copy the shared library rule by default
264if(NOT CMAKE_CXX_CREATE_SHARED_MODULE)
265  set(CMAKE_CXX_CREATE_SHARED_MODULE ${CMAKE_CXX_CREATE_SHARED_LIBRARY})
266endif()
267
268
269# Create a static archive incrementally for large object file counts.
270# If CMAKE_CXX_CREATE_STATIC_LIBRARY is set it will override these.
271if(NOT DEFINED CMAKE_CXX_ARCHIVE_CREATE)
272  set(CMAKE_CXX_ARCHIVE_CREATE "<CMAKE_AR> qc <TARGET> <LINK_FLAGS> <OBJECTS>")
273endif()
274if(NOT DEFINED CMAKE_CXX_ARCHIVE_APPEND)
275  set(CMAKE_CXX_ARCHIVE_APPEND "<CMAKE_AR> q <TARGET> <LINK_FLAGS> <OBJECTS>")
276endif()
277if(NOT DEFINED CMAKE_CXX_ARCHIVE_FINISH)
278  set(CMAKE_CXX_ARCHIVE_FINISH "<CMAKE_RANLIB> <TARGET>")
279endif()
280
281# compile a C++ file into an object file
282if(NOT CMAKE_CXX_COMPILE_OBJECT)
283  set(CMAKE_CXX_COMPILE_OBJECT
284    "<CMAKE_CXX_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT> -c <SOURCE>")
285endif()
286
287if(NOT CMAKE_CXX_LINK_EXECUTABLE)
288  set(CMAKE_CXX_LINK_EXECUTABLE
289    "<CMAKE_CXX_COMPILER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
290endif()
291
292mark_as_advanced(
293CMAKE_VERBOSE_MAKEFILE
294)
295
296set(CMAKE_CXX_INFORMATION_LOADED 1)
297