cmake/Modules/FindThreads.cmake

   1 # Updated FindThreads.cmake that supports pthread-win32
   2 # Downloaded from http://www.vtk.org/Bug/bug_view_advanced_page.php?bug_id=6399
   3
   4 # - This module determines the thread library of the system.
   5 #
   6 # The following variables are set
   7 #  CMAKE_THREAD_LIBS_INIT     - the thread library
   8 #  CMAKE_USE_SPROC_INIT       - are we using sproc?
   9 #  CMAKE_USE_WIN32_THREADS_INIT - using WIN32 threads?
  10 #  CMAKE_USE_PTHREADS_INIT    - are we using pthreads
  11 #  CMAKE_HP_PTHREADS_INIT     - are we using hp pthreads
  12 #
  13 # If use of pthreads-win32 is desired, the following variables
  14 # can be set.
  15 #
  16 #  THREADS_USE_PTHREADS_WIN32 -
  17 #    Setting this to true searches for the pthreads-win32
  18 #    port (since CMake 2.8.0)
  19 #
  20 #  THREADS_PTHREADS_WIN32_EXCEPTION_SCHEME
  21 #      C  = no exceptions (default)
  22 #         (NOTE: This is the default scheme on most POSIX thread
  23 #          implementations and what you should probably be using)
  24 #      CE = C++ Exception Handling
  25 #      SE = Structure Exception Handling (MSVC only)
  26 #      (NOTE: Changing this option from the default may affect
  27 #       the portability of your application.  See pthreads-win32
  28 #       documentation for more details.)
  29 #
  30 #======================================================
  31 # Example usage where threading library
  32 # is provided by the system:
  33 #
  34 #   find_package(Threads REQUIRED)
  35 #   add_executable(foo foo.cc)
  36 #   target_link_libraries(foo ${CMAKE_THREAD_LIBS_INIT})
  37 #
  38 # Example usage if pthreads-win32 is desired on Windows
  39 # or a system provided thread library:
  40 #
  41 #   set(THREADS_USE_PTHREADS_WIN32 true)
  42 #   find_package(Threads REQUIRED)
  43 #   include_directories(${THREADS_PTHREADS_INCLUDE_DIR})
  44 #
  45 #   add_executable(foo foo.cc)
  46 #   target_link_libraries(foo ${CMAKE_THREAD_LIBS_INIT})
  47 #
  48
  49 INCLUDE (CheckIncludeFiles)
  50 INCLUDE (CheckLibraryExists)
  51 SET(Threads_FOUND FALSE)
  52
  53 IF(WIN32 AND NOT CYGWIN AND THREADS_USE_PTHREADS_WIN32)
  54   SET(_Threads_ptwin32 true)
  55 ENDIF()
  56
  57 # Do we have sproc?
  58 IF(CMAKE_SYSTEM MATCHES IRIX)
  59   CHECK_INCLUDE_FILES("sys/types.h;sys/prctl.h"  CMAKE_HAVE_SPROC_H)
  60 ENDIF()
  61
  62 IF(CMAKE_HAVE_SPROC_H)
  63   # We have sproc
  64   SET(CMAKE_USE_SPROC_INIT 1)
  65
  66 ELSEIF(_Threads_ptwin32)
  67
  68   IF(NOT DEFINED THREADS_PTHREADS_WIN32_EXCEPTION_SCHEME)
  69     # Assign the default scheme
  70     SET(THREADS_PTHREADS_WIN32_EXCEPTION_SCHEME "C")
  71   ELSE()
  72     # Validate the scheme specified by the user
  73     IF(NOT THREADS_PTHREADS_WIN32_EXCEPTION_SCHEME STREQUAL "C" AND
  74        NOT THREADS_PTHREADS_WIN32_EXCEPTION_SCHEME STREQUAL "CE" AND
  75        NOT THREADS_PTHREADS_WIN32_EXCEPTION_SCHEME STREQUAL "SE")
  76          MESSAGE(FATAL_ERROR "See documentation for FindPthreads.cmake, only C, CE, and SE modes are allowed")
  77     ENDIF()
  78     IF(NOT MSVC AND THREADS_PTHREADS_WIN32_EXCEPTION_SCHEME STREQUAL "SE")
  79       MESSAGE(FATAL_ERROR "Structured Exception Handling is only allowed for MSVC")
  80     ENDIF(NOT MSVC AND THREADS_PTHREADS_WIN32_EXCEPTION_SCHEME STREQUAL "SE")
  81   ENDIF()
  82
  83   FIND_PATH(THREADS_PTHREADS_INCLUDE_DIR pthread.h)
  84
  85   # Determine the library filename
  86   IF(MSVC)
  87     SET(_Threads_pthreads_libname
  88         pthreadV${THREADS_PTHREADS_WIN32_EXCEPTION_SCHEME}2)
  89   ELSEIF(MINGW)
  90     SET(_Threads_pthreads_libname
  91         pthreadG${THREADS_PTHREADS_WIN32_EXCEPTION_SCHEME}2)
  92   ELSE()
  93     MESSAGE(FATAL_ERROR "This should never happen")
  94   ENDIF()
  95
  96   # Use the include path to help find the library if possible
  97   SET(_Threads_lib_paths "")
  98   IF(THREADS_PTHREADS_INCLUDE_DIR)
  99      GET_FILENAME_COMPONENT(_Threads_root_dir
 100                             ${THREADS_PTHREADS_INCLUDE_DIR} PATH)
 101      SET(_Threads_lib_paths ${_Threads_root_dir}/lib)
 102   ENDIF()
 103   FIND_LIBRARY(THREADS_PTHREADS_WIN32_LIBRARY
 104                NAMES ${_Threads_pthreads_libname}
 105                PATHS ${_Threads_lib_paths}
 106                DOC "The Portable Threads Library for Win32"
 107                NO_SYSTEM_PATH
 108                )
 109
 110   IF(THREADS_PTHREADS_INCLUDE_DIR AND THREADS_PTHREADS_WIN32_LIBRARY)
 111     MARK_AS_ADVANCED(THREADS_PTHREADS_INCLUDE_DIR)
 112     SET(CMAKE_THREAD_LIBS_INIT ${THREADS_PTHREADS_WIN32_LIBRARY})
 113     SET(CMAKE_HAVE_THREADS_LIBRARY 1)
 114     SET(Threads_FOUND TRUE)
 115   ENDIF()
 116
 117   MARK_AS_ADVANCED(THREADS_PTHREADS_WIN32_LIBRARY)
 118
 119 ELSE()
 120   # Do we have pthreads?
 121   CHECK_INCLUDE_FILES("pthread.h" CMAKE_HAVE_PTHREAD_H)
 122   IF(CMAKE_HAVE_PTHREAD_H)
 123
 124     #
 125     # We have pthread.h
 126     # Let's check for the library now.
 127     #
 128     SET(CMAKE_HAVE_THREADS_LIBRARY)
 129     IF(NOT THREADS_HAVE_PTHREAD_ARG)
 130
 131       # Do we have -lpthreads
 132       CHECK_LIBRARY_EXISTS(pthreads pthread_create "" CMAKE_HAVE_PTHREADS_CREATE)
 133       IF(CMAKE_HAVE_PTHREADS_CREATE)
 134         SET(CMAKE_THREAD_LIBS_INIT "-lpthreads")
 135         SET(CMAKE_HAVE_THREADS_LIBRARY 1)
 136         SET(Threads_FOUND TRUE)
 137       ENDIF()
 138
 139       # Ok, how about -lpthread
 140       CHECK_LIBRARY_EXISTS(pthread pthread_create "" CMAKE_HAVE_PTHREAD_CREATE)
 141       IF(CMAKE_HAVE_PTHREAD_CREATE)
 142         SET(CMAKE_THREAD_LIBS_INIT "-lpthread")
 143         SET(Threads_FOUND TRUE)
 144         SET(CMAKE_HAVE_THREADS_LIBRARY 1)
 145       ENDIF()
 146
 147       IF(CMAKE_SYSTEM MATCHES "SunOS.*")
 148         # On sun also check for -lthread
 149         CHECK_LIBRARY_EXISTS(thread thr_create "" CMAKE_HAVE_THR_CREATE)
 150         IF(CMAKE_HAVE_THR_CREATE)
 151           SET(CMAKE_THREAD_LIBS_INIT "-lthread")
 152           SET(CMAKE_HAVE_THREADS_LIBRARY 1)
 153           SET(Threads_FOUND TRUE)
 154         ENDIF()
 155       ENDIF(CMAKE_SYSTEM MATCHES "SunOS.*")
 156
 157     ENDIF(NOT THREADS_HAVE_PTHREAD_ARG)
 158
 159     IF(NOT CMAKE_HAVE_THREADS_LIBRARY)
 160       # If we did not found -lpthread, -lpthread, or -lthread, look for -pthread
 161       IF("THREADS_HAVE_PTHREAD_ARG" MATCHES "^THREADS_HAVE_PTHREAD_ARG")
 162         MESSAGE(STATUS "Check if compiler accepts -pthread")
 163         TRY_RUN(THREADS_PTHREAD_ARG THREADS_HAVE_PTHREAD_ARG
 164           ${CMAKE_BINARY_DIR}
 165           ${CMAKE_ROOT}/Modules/CheckForPthreads.c
 166           CMAKE_FLAGS -DLINK_LIBRARIES:STRING=-pthread
 167           COMPILE_OUTPUT_VARIABLE OUTPUT)
 168
 169         IF(THREADS_HAVE_PTHREAD_ARG)
 170           IF(THREADS_PTHREAD_ARG MATCHES "^2$")
 171             SET(Threads_FOUND TRUE)
 172             MESSAGE(STATUS "Check if compiler accepts -pthread - yes")
 173           ELSE()
 174             MESSAGE(STATUS "Check if compiler accepts -pthread - no")
 175             FILE(APPEND
 176               ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
 177               "Determining if compiler accepts -pthread returned ${THREADS_PTHREAD_ARG} instead of 2. The compiler had the following output:\n${OUTPUT}\n\n")
 178           ENDIF()
 179         ELSE()
 180           MESSAGE(STATUS "Check if compiler accepts -pthread - no")
 181           FILE(APPEND
 182             ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
 183             "Determining if compiler accepts -pthread failed with the following output:\n${OUTPUT}\n\n")
 184         ENDIF()
 185
 186       ENDIF("THREADS_HAVE_PTHREAD_ARG" MATCHES "^THREADS_HAVE_PTHREAD_ARG")
 187
 188       IF(THREADS_HAVE_PTHREAD_ARG)
 189         SET(Threads_FOUND TRUE)
 190         SET(CMAKE_THREAD_LIBS_INIT "-pthread")
 191       ENDIF()
 192
 193     ENDIF(NOT CMAKE_HAVE_THREADS_LIBRARY)
 194   ENDIF(CMAKE_HAVE_PTHREAD_H)
 195 ENDIF()
 196
 197 IF(CMAKE_THREAD_LIBS_INIT)
 198   SET(CMAKE_USE_PTHREADS_INIT 1)
 199   SET(Threads_FOUND TRUE)
 200 ENDIF()
 201
 202 IF(CMAKE_SYSTEM MATCHES "Windows"
 203    AND NOT THREADS_USE_PTHREADS_WIN32)
 204   SET(CMAKE_USE_WIN32_THREADS_INIT 1)
 205   SET(Threads_FOUND TRUE)
 206 ENDIF()
 207
 208 IF(CMAKE_USE_PTHREADS_INIT)
 209   IF(CMAKE_SYSTEM MATCHES "HP-UX-*")
 210     # Use libcma if it exists and can be used.  It provides more
 211     # symbols than the plain pthread library.  CMA threads
 212     # have actually been deprecated:
 213     #   http://docs.hp.com/en/B3920-90091/ch12s03.html#d0e11395
 214     #   http://docs.hp.com/en/947/d8.html
 215     # but we need to maintain compatibility here.
 216     # The CMAKE_HP_PTHREADS setting actually indicates whether CMA threads
 217     # are available.
 218     CHECK_LIBRARY_EXISTS(cma pthread_attr_create "" CMAKE_HAVE_HP_CMA)
 219     IF(CMAKE_HAVE_HP_CMA)
 220       SET(CMAKE_THREAD_LIBS_INIT "-lcma")
 221       SET(CMAKE_HP_PTHREADS_INIT 1)
 222       SET(Threads_FOUND TRUE)
 223     ENDIF(CMAKE_HAVE_HP_CMA)
 224     SET(CMAKE_USE_PTHREADS_INIT 1)
 225   ENDIF()
 226
 227   IF(CMAKE_SYSTEM MATCHES "OSF1-V*")
 228     SET(CMAKE_USE_PTHREADS_INIT 0)
 229     SET(CMAKE_THREAD_LIBS_INIT )
 230   ENDIF()
 231
 232   IF(CMAKE_SYSTEM MATCHES "CYGWIN_NT*")
 233     SET(CMAKE_USE_PTHREADS_INIT 1)
 234     SET(Threads_FOUND TRUE)
 235     SET(CMAKE_THREAD_LIBS_INIT )
 236     SET(CMAKE_USE_WIN32_THREADS_INIT 0)
 237   ENDIF()
 238 ENDIF(CMAKE_USE_PTHREADS_INIT)
 239
 240 INCLUDE(FindPackageHandleStandardArgs)
 241 IF(_Threads_ptwin32)
 242   FIND_PACKAGE_HANDLE_STANDARD_ARGS(Threads DEFAULT_MSG
 243     THREADS_PTHREADS_WIN32_LIBRARY THREADS_PTHREADS_INCLUDE_DIR)
 244 ELSE()
 245   FIND_PACKAGE_HANDLE_STANDARD_ARGS(Threads DEFAULT_MSG Threads_FOUND)
 246 ENDIF()