cmake/FindThreadsCXX.cmake

   1 #.rst:
   2 # FindThreads
   3 # -----------
   4 #
   5 # This module determines the thread library of the system.
   6 #
   7 # The following variables are set
   8 #
   9 # ::
  10 #
  11 #   CMAKE_THREAD_LIBS_INIT     - the thread library
  12 #   CMAKE_USE_SPROC_INIT       - are we using sproc?
  13 #   CMAKE_USE_WIN32_THREADS_INIT - using WIN32 threads?
  14 #   CMAKE_USE_PTHREADS_INIT    - are we using pthreads
  15 #   CMAKE_HP_PTHREADS_INIT     - are we using hp pthreads
  16 #
  17 # For systems with multiple thread libraries, caller can set
  18 #
  19 # ::
  20 #
  21 #   CMAKE_THREAD_PREFER_PTHREAD
  22
  23 #=============================================================================
  24 # Copyright 2002-2009 Kitware, Inc.
  25 #
  26 # Distributed under the OSI-approved BSD License (the "License");
  27 # see accompanying file Copyright.txt for details.
  28 #
  29 # This software is distributed WITHOUT ANY WARRANTY; without even the
  30 # implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  31 # See the License for more information.
  32 #=============================================================================
  33 # (To distribute this file outside of CMake, substitute the full
  34 #  License text for the above reference.)
  35
  36 include (CheckIncludeFileCXX)
  37 include (CheckCXXLibraryExists)
  38 include (CheckCXXSymbolExists)
  39 set(Threads_FOUND FALSE)
  40
  41
  42 # Do we have sproc?
  43 if(CMAKE_SYSTEM MATCHES IRIX AND NOT CMAKE_THREAD_PREFER_PTHREAD)
  44   CHECK_INCLUDE_FILES_CXX("sys/types.h;sys/prctl.h"  CMAKE_HAVE_SPROC_H)
  45 endif()
  46
  47 if(CMAKE_HAVE_SPROC_H AND NOT CMAKE_THREAD_PREFER_PTHREAD)
  48   # We have sproc
  49   set(CMAKE_USE_SPROC_INIT 1)
  50 else()
  51   # Do we have pthreads?
  52   CHECK_INCLUDE_FILE_CXX("pthread.h" CMAKE_HAVE_PTHREAD_H)
  53   if(CMAKE_HAVE_PTHREAD_H)
  54
  55     #
  56     # We have pthread.h
  57     # Let's check for the library now.
  58     #
  59     set(CMAKE_HAVE_THREADS_LIBRARY)
  60     if(NOT THREADS_HAVE_PTHREAD_ARG)
  61       # Check if pthread functions are in normal C library
  62       CHECK_CXX_SYMBOL_EXISTS(pthread_create pthread.h CMAKE_HAVE_LIBC_CREATE)
  63       if(CMAKE_HAVE_LIBC_CREATE)
  64         set(CMAKE_THREAD_LIBS_INIT "")
  65         set(CMAKE_HAVE_THREADS_LIBRARY 1)
  66         set(Threads_FOUND TRUE)
  67       endif()
  68
  69       if(NOT CMAKE_HAVE_THREADS_LIBRARY)
  70         # Do we have -lpthreads
  71         CHECK_CXX_LIBRARY_EXISTS(pthreads pthread_create "" CMAKE_HAVE_PTHREADS_CREATE)
  72         if(CMAKE_HAVE_PTHREADS_CREATE)
  73           set(CMAKE_THREAD_LIBS_INIT "-lpthreads")
  74           set(CMAKE_HAVE_THREADS_LIBRARY 1)
  75           set(Threads_FOUND TRUE)
  76         endif()
  77
  78         # Ok, how about -lpthread
  79         CHECK_CXX_LIBRARY_EXISTS(pthread pthread_create "" CMAKE_HAVE_PTHREAD_CREATE)
  80         if(CMAKE_HAVE_PTHREAD_CREATE)
  81           set(CMAKE_THREAD_LIBS_INIT "-lpthread")
  82           set(CMAKE_HAVE_THREADS_LIBRARY 1)
  83           set(Threads_FOUND TRUE)
  84         endif()
  85
  86         if(CMAKE_SYSTEM MATCHES "SunOS.*")
  87           # On sun also check for -lthread
  88           CHECK_CXX_LIBRARY_EXISTS(thread thr_create "" CMAKE_HAVE_THR_CREATE)
  89           if(CMAKE_HAVE_THR_CREATE)
  90             set(CMAKE_THREAD_LIBS_INIT "-lthread")
  91             set(CMAKE_HAVE_THREADS_LIBRARY 1)
  92             set(Threads_FOUND TRUE)
  93           endif()
  94         endif()
  95       endif()
  96     endif()
  97
  98     if(NOT CMAKE_HAVE_THREADS_LIBRARY)
  99       # If we did not found -lpthread, -lpthreads, or -lthread, look for -pthread
 100       if("THREADS_HAVE_PTHREAD_ARG" MATCHES "^THREADS_HAVE_PTHREAD_ARG")
 101         message(STATUS "Check if compiler accepts -pthread")
 102         configure_file ("${CMAKE_CURRENT_LIST_DIR}/CheckForPthreads.cxx"
 103                         "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckForPthreads.cxx" COPYONLY)
 104         try_run(THREADS_PTHREAD_ARG THREADS_HAVE_PTHREAD_ARG
 105           ${CMAKE_BINARY_DIR}
 106           ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckForPthreads.cxx
 107           CMAKE_FLAGS "-DLINK_LIBRARIES:STRING=-pthread;-DCMAKE_CXX_FLAGS:STRING=-fpermissive"
 108           COMPILE_OUTPUT_VARIABLE OUTPUT)
 109
 110         if(THREADS_HAVE_PTHREAD_ARG)
 111           if(THREADS_PTHREAD_ARG STREQUAL "2")
 112             set(Threads_FOUND TRUE)
 113             message(STATUS "Check if compiler accepts -pthread - yes")
 114           else()
 115             message(STATUS "Check if compiler accepts -pthread - no")
 116             file(APPEND
 117               ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
 118               "Determining if compiler accepts -pthread returned ${THREADS_PTHREAD_ARG} instead of 2. The compiler had the following output:\n${OUTPUT}\n\n")
 119           endif()
 120         else()
 121           message(STATUS "Check if compiler accepts -pthread - no")
 122           file(APPEND
 123             ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
 124             "Determining if compiler accepts -pthread failed with the following output:\n${OUTPUT}\n\n")
 125         endif()
 126
 127       endif()
 128
 129       if(THREADS_HAVE_PTHREAD_ARG)
 130         set(Threads_FOUND TRUE)
 131         set(CMAKE_THREAD_LIBS_INIT "-pthread")
 132       endif()
 133
 134     endif()
 135   endif()
 136 endif()
 137
 138 if(CMAKE_THREAD_LIBS_INIT OR CMAKE_HAVE_LIBC_CREATE)
 139   set(CMAKE_USE_PTHREADS_INIT 1)
 140   set(Threads_FOUND TRUE)
 141 endif()
 142
 143 if(CMAKE_SYSTEM MATCHES "Windows")
 144   set(CMAKE_USE_WIN32_THREADS_INIT 1)
 145   set(Threads_FOUND TRUE)
 146 endif()
 147
 148 if(CMAKE_USE_PTHREADS_INIT)
 149   if(CMAKE_SYSTEM MATCHES "HP-UX-*")
 150     # Use libcma if it exists and can be used.  It provides more
 151     # symbols than the plain pthread library.  CMA threads
 152     # have actually been deprecated:
 153     #   http://docs.hp.com/en/B3920-90091/ch12s03.html#d0e11395
 154     #   http://docs.hp.com/en/947/d8.html
 155     # but we need to maintain compatibility here.
 156     # The CMAKE_HP_PTHREADS setting actually indicates whether CMA threads
 157     # are available.
 158     CHECK_CXX_LIBRARY_EXISTS(cma pthread_attr_create "" CMAKE_HAVE_HP_CMA)
 159     if(CMAKE_HAVE_HP_CMA)
 160       set(CMAKE_THREAD_LIBS_INIT "-lcma")
 161       set(CMAKE_HP_PTHREADS_INIT 1)
 162       set(Threads_FOUND TRUE)
 163     endif()
 164     set(CMAKE_USE_PTHREADS_INIT 1)
 165   endif()
 166
 167   if(CMAKE_SYSTEM MATCHES "OSF1-V*")
 168     set(CMAKE_USE_PTHREADS_INIT 0)
 169     set(CMAKE_THREAD_LIBS_INIT )
 170   endif()
 171
 172   if(CMAKE_SYSTEM MATCHES "CYGWIN_NT*")
 173     set(CMAKE_USE_PTHREADS_INIT 1)
 174     set(Threads_FOUND TRUE)
 175     set(CMAKE_THREAD_LIBS_INIT )
 176     set(CMAKE_USE_WIN32_THREADS_INIT 0)
 177   endif()
 178 endif()
 179
 180 include(FindPackageHandleStandardArgs)
 181 FIND_PACKAGE_HANDLE_STANDARD_ARGS(Threads DEFAULT_MSG Threads_FOUND)