CMake/Modules/CMakeCInformation.cmake
Brad King 9682de566e Revert "Disable shared library support when compiler links statically" (#15855)
In commit v3.4.0-rc1~18^2 (Disable shared library support when compiler
links statically, 2015-09-30) we tried to detect when the compiler is
not capable of linking shared libraries (possibly due to flags in use).
However, the approach is not robust against flags like `-nostdlib`.
Revert it for now pending another solution to the original problem.
2015-11-23 10:16:32 -05:00

220 lines
7.5 KiB
CMake

#=============================================================================
# Copyright 2004-2011 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.)
# This file sets the basic flags for the C language in CMake.
# It also loads the available platform file for the system-compiler
# if it exists.
# It also loads a system - compiler - processor (or target hardware)
# specific file, which is mainly useful for crosscompiling and embedded systems.
# some compilers use different extensions (e.g. sdcc uses .rel)
# so set the extension here first so it can be overridden by the compiler specific file
if(UNIX)
set(CMAKE_C_OUTPUT_EXTENSION .o)
else()
set(CMAKE_C_OUTPUT_EXTENSION .obj)
endif()
set(_INCLUDED_FILE 0)
# Load compiler-specific information.
if(CMAKE_C_COMPILER_ID)
include(Compiler/${CMAKE_C_COMPILER_ID}-C OPTIONAL)
endif()
set(CMAKE_BASE_NAME)
get_filename_component(CMAKE_BASE_NAME "${CMAKE_C_COMPILER}" NAME_WE)
if(CMAKE_COMPILER_IS_GNUCC)
set(CMAKE_BASE_NAME gcc)
endif()
# load a hardware specific file, mostly useful for embedded compilers
if(CMAKE_SYSTEM_PROCESSOR)
if(CMAKE_C_COMPILER_ID)
include(Platform/${CMAKE_SYSTEM_NAME}-${CMAKE_C_COMPILER_ID}-C-${CMAKE_SYSTEM_PROCESSOR} OPTIONAL RESULT_VARIABLE _INCLUDED_FILE)
endif()
if (NOT _INCLUDED_FILE)
include(Platform/${CMAKE_SYSTEM_NAME}-${CMAKE_BASE_NAME}-${CMAKE_SYSTEM_PROCESSOR} OPTIONAL)
endif ()
endif()
# load the system- and compiler specific files
if(CMAKE_C_COMPILER_ID)
include(Platform/${CMAKE_SYSTEM_NAME}-${CMAKE_C_COMPILER_ID}-C
OPTIONAL RESULT_VARIABLE _INCLUDED_FILE)
endif()
if (NOT _INCLUDED_FILE)
include(Platform/${CMAKE_SYSTEM_NAME}-${CMAKE_BASE_NAME}
OPTIONAL RESULT_VARIABLE _INCLUDED_FILE)
endif ()
# We specify the compiler information in the system file for some
# platforms, but this language may not have been enabled when the file
# was first included. Include it again to get the language info.
# Remove this when all compiler info is removed from system files.
if (NOT _INCLUDED_FILE)
include(Platform/${CMAKE_SYSTEM_NAME} OPTIONAL)
endif ()
if(CMAKE_C_SIZEOF_DATA_PTR)
foreach(f ${CMAKE_C_ABI_FILES})
include(${f})
endforeach()
unset(CMAKE_C_ABI_FILES)
endif()
# This should be included before the _INIT variables are
# used to initialize the cache. Since the rule variables
# have if blocks on them, users can still define them here.
# But, it should still be after the platform file so changes can
# be made to those values.
if(CMAKE_USER_MAKE_RULES_OVERRIDE)
# Save the full path of the file so try_compile can use it.
include(${CMAKE_USER_MAKE_RULES_OVERRIDE} RESULT_VARIABLE _override)
set(CMAKE_USER_MAKE_RULES_OVERRIDE "${_override}")
endif()
if(CMAKE_USER_MAKE_RULES_OVERRIDE_C)
# Save the full path of the file so try_compile can use it.
include(${CMAKE_USER_MAKE_RULES_OVERRIDE_C} RESULT_VARIABLE _override)
set(CMAKE_USER_MAKE_RULES_OVERRIDE_C "${_override}")
endif()
# for most systems a module is the same as a shared library
# so unless the variable CMAKE_MODULE_EXISTS is set just
# copy the values from the LIBRARY variables
if(NOT CMAKE_MODULE_EXISTS)
set(CMAKE_SHARED_MODULE_C_FLAGS ${CMAKE_SHARED_LIBRARY_C_FLAGS})
set(CMAKE_SHARED_MODULE_CREATE_C_FLAGS ${CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS})
endif()
set(CMAKE_C_FLAGS_INIT "$ENV{CFLAGS} ${CMAKE_C_FLAGS_INIT}")
# avoid just having a space as the initial value for the cache
if(CMAKE_C_FLAGS_INIT STREQUAL " ")
set(CMAKE_C_FLAGS_INIT)
endif()
set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS_INIT}" CACHE STRING
"Flags used by the compiler during all build types.")
if(NOT CMAKE_NOT_USING_CONFIG_FLAGS)
# default build type is none
if(NOT CMAKE_NO_BUILD_TYPE)
set (CMAKE_BUILD_TYPE ${CMAKE_BUILD_TYPE_INIT} CACHE STRING
"Choose the type of build, options are: None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used) Debug Release RelWithDebInfo MinSizeRel.")
endif()
set (CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG_INIT}" CACHE STRING
"Flags used by the compiler during debug builds.")
set (CMAKE_C_FLAGS_MINSIZEREL "${CMAKE_C_FLAGS_MINSIZEREL_INIT}" CACHE STRING
"Flags used by the compiler during release builds for minimum size.")
set (CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE_INIT}" CACHE STRING
"Flags used by the compiler during release builds.")
set (CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO_INIT}" CACHE STRING
"Flags used by the compiler during release builds with debug info.")
endif()
if(CMAKE_C_STANDARD_LIBRARIES_INIT)
set(CMAKE_C_STANDARD_LIBRARIES "${CMAKE_C_STANDARD_LIBRARIES_INIT}"
CACHE STRING "Libraries linked by default with all C applications.")
mark_as_advanced(CMAKE_C_STANDARD_LIBRARIES)
endif()
include(CMakeCommonLanguageInclude)
# now define the following rule variables
# CMAKE_C_CREATE_SHARED_LIBRARY
# CMAKE_C_CREATE_SHARED_MODULE
# CMAKE_C_COMPILE_OBJECT
# CMAKE_C_LINK_EXECUTABLE
# variables supplied by the generator at use time
# <TARGET>
# <TARGET_BASE> the target without the suffix
# <OBJECTS>
# <OBJECT>
# <LINK_LIBRARIES>
# <FLAGS>
# <LINK_FLAGS>
# C compiler information
# <CMAKE_C_COMPILER>
# <CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS>
# <CMAKE_SHARED_MODULE_CREATE_C_FLAGS>
# <CMAKE_C_LINK_FLAGS>
# Static library tools
# <CMAKE_AR>
# <CMAKE_RANLIB>
# create a C shared library
if(NOT CMAKE_C_CREATE_SHARED_LIBRARY)
set(CMAKE_C_CREATE_SHARED_LIBRARY
"<CMAKE_C_COMPILER> <CMAKE_SHARED_LIBRARY_C_FLAGS> <LANGUAGE_COMPILE_FLAGS> <LINK_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS> <SONAME_FLAG><TARGET_SONAME> -o <TARGET> <OBJECTS> <LINK_LIBRARIES>")
endif()
# create a C shared module just copy the shared library rule
if(NOT CMAKE_C_CREATE_SHARED_MODULE)
set(CMAKE_C_CREATE_SHARED_MODULE ${CMAKE_C_CREATE_SHARED_LIBRARY})
endif()
# Create a static archive incrementally for large object file counts.
# If CMAKE_C_CREATE_STATIC_LIBRARY is set it will override these.
if(NOT DEFINED CMAKE_C_ARCHIVE_CREATE)
set(CMAKE_C_ARCHIVE_CREATE "<CMAKE_AR> qc <TARGET> <LINK_FLAGS> <OBJECTS>")
endif()
if(NOT DEFINED CMAKE_C_ARCHIVE_APPEND)
set(CMAKE_C_ARCHIVE_APPEND "<CMAKE_AR> q <TARGET> <LINK_FLAGS> <OBJECTS>")
endif()
if(NOT DEFINED CMAKE_C_ARCHIVE_FINISH)
set(CMAKE_C_ARCHIVE_FINISH "<CMAKE_RANLIB> <TARGET>")
endif()
# compile a C file into an object file
if(NOT CMAKE_C_COMPILE_OBJECT)
set(CMAKE_C_COMPILE_OBJECT
"<CMAKE_C_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT> -c <SOURCE>")
endif()
if(NOT CMAKE_C_LINK_EXECUTABLE)
set(CMAKE_C_LINK_EXECUTABLE
"<CMAKE_C_COMPILER> <FLAGS> <CMAKE_C_LINK_FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
endif()
if(NOT CMAKE_EXECUTABLE_RUNTIME_C_FLAG)
set(CMAKE_EXECUTABLE_RUNTIME_C_FLAG ${CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG})
endif()
if(NOT CMAKE_EXECUTABLE_RUNTIME_C_FLAG_SEP)
set(CMAKE_EXECUTABLE_RUNTIME_C_FLAG_SEP ${CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG_SEP})
endif()
if(NOT CMAKE_EXECUTABLE_RPATH_LINK_C_FLAG)
set(CMAKE_EXECUTABLE_RPATH_LINK_C_FLAG ${CMAKE_SHARED_LIBRARY_RPATH_LINK_C_FLAG})
endif()
mark_as_advanced(
CMAKE_C_FLAGS
CMAKE_C_FLAGS_DEBUG
CMAKE_C_FLAGS_MINSIZEREL
CMAKE_C_FLAGS_RELEASE
CMAKE_C_FLAGS_RELWITHDEBINFO
)
set(CMAKE_C_INFORMATION_LOADED 1)