CMake/Modules/FindOpenThreads.cmake

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#.rst:
# FindOpenThreads
# ---------------
#
#
#
# OpenThreads is a C++ based threading library. Its largest userbase
# seems to OpenSceneGraph so you might notice I accept OSGDIR as an
# environment path. I consider this part of the Findosg* suite used to
# find OpenSceneGraph components. Each component is separate and you
# must opt in to each module.
#
# Locate OpenThreads This module defines OPENTHREADS_LIBRARY
# OPENTHREADS_FOUND, if false, do not try to link to OpenThreads
# OPENTHREADS_INCLUDE_DIR, where to find the headers
#
# $OPENTHREADS_DIR is an environment variable that would correspond to
# the ./configure --prefix=$OPENTHREADS_DIR used in building osg.
#
# [CMake 2.8.10]: The CMake variables OPENTHREADS_DIR or OSG_DIR can now
# be used as well to influence detection, instead of needing to specify
# an environment variable.
#
# Created by Eric Wing.
#=============================================================================
# Copyright 2007-2009 Kitware, Inc.
# Copyright 2012 Philip Lowman <philip@yhbt.com>
#
# 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.)
# Header files are presumed to be included like
# #include <OpenThreads/Thread>
# To make it easier for one-step automated configuration/builds,
# we leverage environmental paths. This is preferable
# to the -DVAR=value switches because it insulates the
# users from changes we may make in this script.
# It also offers a little more flexibility than setting
# the CMAKE_*_PATH since we can target specific components.
# However, the default CMake behavior will search system paths
# before anything else. This is problematic in the cases
# where you have an older (stable) version installed, but
# are trying to build a newer version.
# CMake doesn't offer a nice way to globally control this behavior
# so we have to do a nasty "double FIND_" in this module.
# The first FIND disables the CMAKE_ search paths and only checks
# the environmental paths.
# If nothing is found, then the second find will search the
# standard install paths.
# Explicit -DVAR=value arguments should still be able to override everything.
find_path(OPENTHREADS_INCLUDE_DIR OpenThreads/Thread
HINTS
ENV OPENTHREADS_INCLUDE_DIR
ENV OPENTHREADS_DIR
ENV OSG_INCLUDE_DIR
ENV OSG_DIR
ENV OSGDIR
ENV OpenThreads_ROOT
ENV OSG_ROOT
${OPENTHREADS_DIR}
${OSG_DIR}
PATHS
/sw # Fink
/opt/local # DarwinPorts
/opt/csw # Blastwave
/opt
/usr/freeware
PATH_SUFFIXES include
)
find_library(OPENTHREADS_LIBRARY
NAMES OpenThreads OpenThreadsWin32
HINTS
ENV OPENTHREADS_LIBRARY_DIR
ENV OPENTHREADS_DIR
ENV OSG_LIBRARY_DIR
ENV OSG_DIR
ENV OSGDIR
ENV OpenThreads_ROOT
ENV OSG_ROOT
${OPENTHREADS_DIR}
${OSG_DIR}
PATHS
/sw
/opt/local
/opt/csw
/opt
/usr/freeware
PATH_SUFFIXES lib
)
find_library(OPENTHREADS_LIBRARY_DEBUG
NAMES OpenThreadsd OpenThreadsWin32d
HINTS
ENV OPENTHREADS_DEBUG_LIBRARY_DIR
ENV OPENTHREADS_LIBRARY_DIR
ENV OPENTHREADS_DIR
ENV OSG_LIBRARY_DIR
ENV OSG_DIR
ENV OSGDIR
ENV OpenThreads_ROOT
ENV OSG_ROOT
${OPENTHREADS_DIR}
${OSG_DIR}
PATHS
/sw
/opt/local
/opt/csw
/opt
/usr/freeware
PATH_SUFFIXES lib
)
if(OPENTHREADS_LIBRARY_DEBUG)
set(OPENTHREADS_LIBRARIES
optimized ${OPENTHREADS_LIBRARY}
debug ${OPENTHREADS_LIBRARY_DEBUG})
else()
set(OPENTHREADS_LIBRARIES ${OPENTHREADS_LIBRARY})
endif()
Modules: Include builtin FindPackageHandleStandardArgs directly The FindPackageHandleStandardArgs module was originally created outside of CMake. It was added for CMake 2.6.0 by commit e118a627 (add a macro FIND_PACKAGE_HANDLE_STANDARD_ARGS..., 2007-07-18). However, it also proliferated into a number of other projects that at the time required only CMake 2.4 and thus could not depend on CMake to provide the module. CMake's own find modules started using the module in commit b5f656e0 (use the new FIND_PACKAGE_HANDLE_STANDARD_ARGS in some of the FindXXX modules..., 2007-07-18). Then commit d358cf5c (add 2nd, more powerful mode to find_package_handle_standard_args, 2010-07-29) added a new feature to the interface of the module that was fully optional and backward compatible with all existing users of the module. Later commit 5f183caa (FindZLIB: use the FPHSA version mode, 2010-08-04) and others shortly thereafter started using the new interface in CMake's own find modules. This change was also backward compatible because it was only an implementation detail within each module. Unforutnately these changes introduced a problem for projects that still have an old copy of FindPackageHandleStandardArgs in CMAKE_MODULE_PATH. When any such project uses one of CMake's builtin find modules the line include(FindPackageHandleStandardArgs) loads the copy from the project which does not have the new interface! Then the including find module tries to use the new interface with the old module and fails. Whether this breakage can be considered a backward incompatible change in CMake is debatable. The situation is analagous to copying a standard library header from one version of a compiler into a project and then observing problems when the next version of the compiler reports errors in its other headers that depend on its new version of the original header. Nevertheless it is a change to CMake that causes problems for projects that worked with previous versions. This problem was discovered during the 2.8.3 release candidate cycle. It is an instance of a more general problem with projects that provide their own versions of CMake modules when other CMake modules depend on them. At the time we resolved this instance of the problem with commit b0118402 (Use absolute path to FindPackageHandleStandardArgs.cmake everywhere, 2010-09-28) for the 2.8.3 release. In order to address the more general problem we introduced policy CMP0017 in commit db44848f (Prefer files from CMAKE_ROOT when including from CMAKE_ROOT, 2010-11-17). That change was followed by commit ce28737c (Remove usage of CMAKE_CURRENT_LIST_DIR now that we have CMP0017, 2010-12-20) which reverted the original workaround in favor of using the policy. However, existing project releases do not set the policy behavior to NEW and therefore still exhibit the problem. We introduced in commit a364daf1 (Allow users to specify defaults for unset policies, 2011-01-03) an option for users to build existing projects by adding -DCMAKE_POLICY_DEFAULT_CMP0017=NEW to the command line. Unfortunately this solution still does not allow such projects to build out of the box, and there is no good way to suggest the use of the new option. The only remaining solution to keep existing projects that exhibit this problem building is to restore the change originally made in commit b0118402 (Use absolute path to FindPackageHandleStandardArgs.cmake everywhere, 2010-09-28). This also avoids policy CMP0017 warnings for this particular instance of the problem the policy addresses.
2011-01-20 15:56:49 +00:00
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(OpenThreads DEFAULT_MSG
OPENTHREADS_LIBRARY OPENTHREADS_INCLUDE_DIR)