Merge topic 'FindThreads_overhaul'

b7e5c5a2 FindThreads: introduce THREADS_PREFER_PTHREAD_FLAG (#14767)
bcb0e387 FindThreads: introduce an imported target to link to
46368edd FindThreads: move checking of the -pthread compiler flag into a macro
This commit is contained in:
Brad King 2014-10-09 16:12:06 -04:00 committed by CMake Topic Stage
commit c0a4f59160
1 changed files with 78 additions and 36 deletions

View File

@ -14,14 +14,32 @@
# 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 prefered 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.
#=============================================================================
# Copyright 2002-2009 Kitware, Inc.
# Copyright 2011-2014 Rolf Eike Beer <eike@sf-mail.de>
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
@ -48,7 +66,7 @@ endif()
# Internal helper macro.
# Do NOT even think about using it outside of this file!
macro(_check_threads_lib LIBNAME FUNCNAME VARNAME)
if(NOT CMAKE_HAVE_THREADS_LIBRARY)
if(NOT Threads_FOUND)
CHECK_LIBRARY_EXISTS(${LIBNAME} ${FUNCNAME} "" ${VARNAME})
if(${VARNAME})
set(CMAKE_THREAD_LIBS_INIT "-l${LIBNAME}")
@ -58,6 +76,45 @@ macro(_check_threads_lib LIBNAME FUNCNAME VARNAME)
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")
try_run(THREADS_PTHREAD_ARG THREADS_HAVE_PTHREAD_ARG
${CMAKE_BINARY_DIR}
${CMAKE_CURRENT_LIST_DIR}/CheckForPthreads.c
CMAKE_FLAGS -DLINK_LIBRARIES:STRING=-pthread
COMPILE_OUTPUT_VARIABLE OUTPUT)
if(THREADS_HAVE_PTHREAD_ARG)
if(THREADS_PTHREAD_ARG STREQUAL "2")
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 returned ${THREADS_PTHREAD_ARG} instead of 2. The compiler had the following output:\n${OUTPUT}\n\n")
endif()
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${OUTPUT}\n\n")
endif()
endif()
if(THREADS_HAVE_PTHREAD_ARG)
set(Threads_FOUND TRUE)
set(CMAKE_THREAD_LIBS_INIT "-pthread")
endif()
endif()
endmacro()
if(CMAKE_HAVE_SPROC_H AND NOT CMAKE_THREAD_PREFER_PTHREAD)
# We have sproc
set(CMAKE_USE_SPROC_INIT 1)
@ -80,6 +137,13 @@ else()
set(Threads_FOUND TRUE)
else()
# Check for -pthread first if enabled. This is the recommended
# way, but not backwards compatible as one must also pass -pthread
# as compiler flag then.
if (THREADS_PREFER_PTHREAD_FLAG)
_check_pthreads_flag()
endif ()
_check_threads_lib(pthreads pthread_create CMAKE_HAVE_PTHREADS_CREATE)
_check_threads_lib(pthread pthread_create CMAKE_HAVE_PTHREAD_CREATE)
if(CMAKE_SYSTEM_NAME MATCHES "SunOS")
@ -89,41 +153,7 @@ else()
endif()
endif()
if(NOT CMAKE_HAVE_THREADS_LIBRARY)
# If we did not found -lpthread, -lpthread, or -lthread, look for -pthread
if("x${THREADS_HAVE_PTHREAD_ARG}" STREQUAL "x")
message(STATUS "Check if compiler accepts -pthread")
try_run(THREADS_PTHREAD_ARG THREADS_HAVE_PTHREAD_ARG
${CMAKE_BINARY_DIR}
${CMAKE_CURRENT_LIST_DIR}/CheckForPthreads.c
CMAKE_FLAGS -DLINK_LIBRARIES:STRING=-pthread
COMPILE_OUTPUT_VARIABLE OUTPUT)
if(THREADS_HAVE_PTHREAD_ARG)
if(THREADS_PTHREAD_ARG STREQUAL "2")
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 returned ${THREADS_PTHREAD_ARG} instead of 2. The compiler had the following output:\n${OUTPUT}\n\n")
endif()
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()
_check_pthreads_flag()
endif()
endif()
@ -172,3 +202,15 @@ 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()