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Diffstat (limited to 'Modules/FindThreads.cmake')
| -rw-r--r-- | Modules/FindThreads.cmake | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/Modules/FindThreads.cmake b/Modules/FindThreads.cmake new file mode 100644 index 0000000..a0148dd --- /dev/null +++ b/Modules/FindThreads.cmake @@ -0,0 +1,217 @@ +# Distributed under the OSI-approved BSD 3-Clause License. See accompanying +# file Copyright.txt or https://cmake.org/licensing for details. + +#.rst: +# FindThreads +# ----------- +# +# This module determines the thread library of the system. +# +# The following variables are set +# +# :: +# +# CMAKE_THREAD_LIBS_INIT - the thread library +# CMAKE_USE_SPROC_INIT - are we using sproc? +# CMAKE_USE_WIN32_THREADS_INIT - using WIN32 threads? +# CMAKE_USE_PTHREADS_INIT - are we using pthreads +# CMAKE_HP_PTHREADS_INIT - are we using hp pthreads +# +# The following import target is created +# +# :: +# +# Threads::Threads +# +# For systems with multiple thread libraries, caller can set +# +# :: +# +# CMAKE_THREAD_PREFER_PTHREAD +# +# If the use of the -pthread compiler and linker flag is preferred then the +# caller can set +# +# :: +# +# THREADS_PREFER_PTHREAD_FLAG +# +# Please note that the compiler flag can only be used with the imported +# target. Use of both the imported target as well as this switch is highly +# recommended for new code. + +include (CheckLibraryExists) +include (CheckSymbolExists) +set(Threads_FOUND FALSE) +set(CMAKE_REQUIRED_QUIET_SAVE ${CMAKE_REQUIRED_QUIET}) +set(CMAKE_REQUIRED_QUIET ${Threads_FIND_QUIETLY}) + +if(CMAKE_C_COMPILER_LOADED) + include (CheckIncludeFile) +elseif(CMAKE_CXX_COMPILER_LOADED) + include (CheckIncludeFileCXX) +else() + message(FATAL_ERROR "FindThreads only works if either C or CXX language is enabled") +endif() + +# Do we have sproc? +if(CMAKE_SYSTEM_NAME MATCHES IRIX AND NOT CMAKE_THREAD_PREFER_PTHREAD) + include (CheckIncludeFiles) + CHECK_INCLUDE_FILES("sys/types.h;sys/prctl.h" CMAKE_HAVE_SPROC_H) +endif() + +# Internal helper macro. +# Do NOT even think about using it outside of this file! +macro(_check_threads_lib LIBNAME FUNCNAME VARNAME) + if(NOT Threads_FOUND) + CHECK_LIBRARY_EXISTS(${LIBNAME} ${FUNCNAME} "" ${VARNAME}) + if(${VARNAME}) + set(CMAKE_THREAD_LIBS_INIT "-l${LIBNAME}") + set(CMAKE_HAVE_THREADS_LIBRARY 1) + set(Threads_FOUND TRUE) + endif() + endif () +endmacro() + +# Internal helper macro. +# Do NOT even think about using it outside of this file! +macro(_check_pthreads_flag) + if(NOT Threads_FOUND) + # If we did not found -lpthread, -lpthread, or -lthread, look for -pthread + if(NOT DEFINED THREADS_HAVE_PTHREAD_ARG) + message(STATUS "Check if compiler accepts -pthread") + if(CMAKE_C_COMPILER_LOADED) + set(_threads_src ${CMAKE_CURRENT_LIST_DIR}/CheckForPthreads.c) + elseif(CMAKE_CXX_COMPILER_LOADED) + set(_threads_src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/FindThreads/CheckForPthreads.cxx) + configure_file(${CMAKE_CURRENT_LIST_DIR}/CheckForPthreads.c "${_threads_src}" COPYONLY) + endif() + try_compile(THREADS_HAVE_PTHREAD_ARG + ${CMAKE_BINARY_DIR} + ${_threads_src} + CMAKE_FLAGS -DLINK_LIBRARIES:STRING=-pthread + OUTPUT_VARIABLE OUTPUT) + unset(_threads_src) + + if(THREADS_HAVE_PTHREAD_ARG) + set(Threads_FOUND TRUE) + message(STATUS "Check if compiler accepts -pthread - yes") + else() + message(STATUS "Check if compiler accepts -pthread - no") + file(APPEND + ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log + "Determining if compiler accepts -pthread failed with the following output:\n${OUTPUT}\n\n") + endif() + + endif() + + if(THREADS_HAVE_PTHREAD_ARG) + set(Threads_FOUND TRUE) + set(CMAKE_THREAD_LIBS_INIT "-pthread") + endif() + endif() +endmacro() + +if(CMAKE_HAVE_SPROC_H AND NOT CMAKE_THREAD_PREFER_PTHREAD) + # We have sproc + set(CMAKE_USE_SPROC_INIT 1) +else() + # Do we have pthreads? + if(CMAKE_C_COMPILER_LOADED) + CHECK_INCLUDE_FILE("pthread.h" CMAKE_HAVE_PTHREAD_H) + else() + CHECK_INCLUDE_FILE_CXX("pthread.h" CMAKE_HAVE_PTHREAD_H) + endif() + if(CMAKE_HAVE_PTHREAD_H) + + # + # We have pthread.h + # Let's check for the library now. + # + set(CMAKE_HAVE_THREADS_LIBRARY) + if(NOT THREADS_HAVE_PTHREAD_ARG) + # Check if pthread functions are in normal C library + CHECK_SYMBOL_EXISTS(pthread_create pthread.h CMAKE_HAVE_LIBC_CREATE) + if(CMAKE_HAVE_LIBC_CREATE) + set(CMAKE_THREAD_LIBS_INIT "") + set(CMAKE_HAVE_THREADS_LIBRARY 1) + set(Threads_FOUND TRUE) + else() + + # Check for -pthread first if enabled. This is the recommended + # way, but not backwards compatible as one must also pass -pthread + # as compiler flag then. + if (THREADS_PREFER_PTHREAD_FLAG) + _check_pthreads_flag() + endif () + + _check_threads_lib(pthreads pthread_create CMAKE_HAVE_PTHREADS_CREATE) + _check_threads_lib(pthread pthread_create CMAKE_HAVE_PTHREAD_CREATE) + if(CMAKE_SYSTEM_NAME MATCHES "SunOS") + # On sun also check for -lthread + _check_threads_lib(thread thr_create CMAKE_HAVE_THR_CREATE) + endif() + endif() + endif() + + _check_pthreads_flag() + endif() +endif() + +if(CMAKE_THREAD_LIBS_INIT OR CMAKE_HAVE_LIBC_CREATE) + set(CMAKE_USE_PTHREADS_INIT 1) + set(Threads_FOUND TRUE) +endif() + +if(CMAKE_SYSTEM_NAME MATCHES "Windows") + set(CMAKE_USE_WIN32_THREADS_INIT 1) + set(Threads_FOUND TRUE) +endif() + +if(CMAKE_USE_PTHREADS_INIT) + if(CMAKE_SYSTEM_NAME MATCHES "HP-UX") + # Use libcma if it exists and can be used. It provides more + # symbols than the plain pthread library. CMA threads + # have actually been deprecated: + # http://docs.hp.com/en/B3920-90091/ch12s03.html#d0e11395 + # http://docs.hp.com/en/947/d8.html + # but we need to maintain compatibility here. + # The CMAKE_HP_PTHREADS setting actually indicates whether CMA threads + # are available. + CHECK_LIBRARY_EXISTS(cma pthread_attr_create "" CMAKE_HAVE_HP_CMA) + if(CMAKE_HAVE_HP_CMA) + set(CMAKE_THREAD_LIBS_INIT "-lcma") + set(CMAKE_HP_PTHREADS_INIT 1) + set(Threads_FOUND TRUE) + endif() + set(CMAKE_USE_PTHREADS_INIT 1) + endif() + + if(CMAKE_SYSTEM MATCHES "OSF1-V") + set(CMAKE_USE_PTHREADS_INIT 0) + set(CMAKE_THREAD_LIBS_INIT ) + endif() + + if(CMAKE_SYSTEM MATCHES "CYGWIN_NT") + set(CMAKE_USE_PTHREADS_INIT 1) + set(Threads_FOUND TRUE) + set(CMAKE_THREAD_LIBS_INIT ) + set(CMAKE_USE_WIN32_THREADS_INIT 0) + endif() +endif() + +set(CMAKE_REQUIRED_QUIET ${CMAKE_REQUIRED_QUIET_SAVE}) +include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake) +FIND_PACKAGE_HANDLE_STANDARD_ARGS(Threads DEFAULT_MSG Threads_FOUND) + +if(THREADS_FOUND AND NOT TARGET Threads::Threads) + add_library(Threads::Threads INTERFACE IMPORTED) + + if(THREADS_HAVE_PTHREAD_ARG) + set_property(TARGET Threads::Threads PROPERTY INTERFACE_COMPILE_OPTIONS "-pthread") + endif() + + if(CMAKE_THREAD_LIBS_INIT) + set_property(TARGET Threads::Threads PROPERTY INTERFACE_LINK_LIBRARIES "${CMAKE_THREAD_LIBS_INIT}") + endif() +endif() |