Check*.cmake: Expand imported targets in CMAKE_REQUIRED_LIBRARIES

Add the function cmake_expand_imported_targets() to expand imported
targets in a list of libraries into their on-disk file names for a
particular configuration.  Adapt the implementation from KDE's
HANDLE_IMPORTED_TARGETS_IN_CMAKE_REQUIRED_LIBRARIES which has been in
use for over 2 years.  Call the function from all the Check*.cmake
macros to handle imported targets named in CMAKE_REQUIRED_LIBRARIES.

Alex

1 files changed, 129 insertions, 0 deletions

diff --git a/Modules/CMakeExpandImportedTargets.cmake b/Modules/CMakeExpandImportedTargets.cmake
new file mode 100644
index 0000000..fba071a
--- /dev/null
+++ b/Modules/CMakeExpandImportedTargets.cmake
@@ -0,0 +1,129 @@
+# CMAKE_EXPAND_IMPORTED_TARGETS(<var> LIBRARIES lib1 lib2...libN
+#                                     [CONFIGURATION <config>] )
+#
+# CMAKE_EXPAND_IMPORTED_TARGETS() takes a list of libraries and replaces
+# all imported targets contained in this list with their actual file paths
+# of the referenced libraries on disk, including the libraries from their
+# link interfaces.
+# If a CONFIGURATION is given, it uses the respective configuration of the
+# imported targets if it exists. If no CONFIGURATION is given, it uses
+# the first configuration from ${CMAKE_CONFIGURATION_TYPES} if set, otherwise
+# ${CMAKE_BUILD_TYPE}.
+# This macro is used by all Check*.cmake files which use
+# TRY_COMPILE() or TRY_RUN() and support CMAKE_REQUIRED_LIBRARIES , so that
+# these checks support imported targets in CMAKE_REQUIRED_LIBRARIES:
+#    cmake_expand_imported_targets(expandedLibs LIBRARIES ${CMAKE_REQUIRED_LIBRARIES}
+#                                               CONFIGURATION "${CMAKE_TRY_COMPILE_CONFIGURATION}" )
+
+
+#=============================================================================
+# Copyright 2012 Kitware, Inc.
+# Copyright 2009-2012 Alexander Neundorf <neundorf@kde.org>
+#
+# 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.)
+
+include(CMakeParseArguments)
+
+function(CMAKE_EXPAND_IMPORTED_TARGETS _RESULT )
+
+   set(options )
+   set(oneValueArgs CONFIGURATION )
+   set(multiValueArgs LIBRARIES )
+
+   cmake_parse_arguments(CEIT "${options}" "${oneValueArgs}" "${multiValueArgs}"  ${ARGN})
+
+   if(CEIT_UNPARSED_ARGUMENTS)
+      message(FATAL_ERROR "Unknown keywords given to CMAKE_EXPAND_IMPORTED_TARGETS(): \"${CEIT_UNPARSED_ARGUMENTS}\"")
+   endif()
+
+   if(NOT CEIT_CONFIGURATION)
+      if(CMAKE_CONFIGURATION_TYPES)
+         list(GET CMAKE_CONFIGURATION_TYPES 0 CEIT_CONFIGURATION)
+      else()
+         set(CEIT_CONFIGURATION ${CMAKE_BUILD_TYPE})
+      endif()
+   endif()
+
+   # handle imported library targets
+
+   set(_CCSR_REQ_LIBS ${CEIT_LIBRARIES})
+
+   set(_CHECK_FOR_IMPORTED_TARGETS TRUE)
+   set(_CCSR_LOOP_COUNTER 0)
+   while(_CHECK_FOR_IMPORTED_TARGETS)
+      math(EXPR _CCSR_LOOP_COUNTER "${_CCSR_LOOP_COUNTER} + 1 ")
+      set(_CCSR_NEW_REQ_LIBS )
+      set(_CHECK_FOR_IMPORTED_TARGETS FALSE)
+      foreach(_CURRENT_LIB ${_CCSR_REQ_LIBS})
+         get_target_property(_importedConfigs "${_CURRENT_LIB}" IMPORTED_CONFIGURATIONS)
+         if (_importedConfigs)
+#            message(STATUS "Detected imported target ${_CURRENT_LIB}")
+            # Ok, so this is an imported target.
+            # First we get the imported configurations.
+            # Then we get the location of the actual library on disk of the first configuration.
+            # then we'll get its link interface libraries property,
+            # iterate through it and replace all imported targets we find there
+            # with there actual location.
+
+            # guard against infinite loop: abort after 100 iterations ( 100 is arbitrary chosen)
+            if ("${_CCSR_LOOP_COUNTER}" LESS 100)
+               set(_CHECK_FOR_IMPORTED_TARGETS TRUE)
+#                else ("${_CCSR_LOOP_COUNTER}" LESS 1)
+#                   message(STATUS "********* aborting loop, counter : ${_CCSR_LOOP_COUNTER}")
+            endif ("${_CCSR_LOOP_COUNTER}" LESS 100)
+
+            # if one of the imported configurations equals ${CMAKE_TRY_COMPILE_CONFIGURATION},
+            # use it, otherwise simply use the first one:
+            list(FIND _importedConfigs "${CEIT_CONFIGURATION}" _configIndexToUse)
+            if("${_configIndexToUse}" EQUAL -1)
+              set(_configIndexToUse 0)
+            endif("${_configIndexToUse}" EQUAL -1)
+            list(GET _importedConfigs ${_configIndexToUse} _importedConfigToUse)
+
+            get_target_property(_importedLocation "${_CURRENT_LIB}" IMPORTED_LOCATION_${_importedConfigToUse})
+            get_target_property(_linkInterfaceLibs "${_CURRENT_LIB}" IMPORTED_LINK_INTERFACE_LIBRARIES_${_importedConfigToUse} )
+
+            list(APPEND _CCSR_NEW_REQ_LIBS  "${_importedLocation}")
+#            message(STATUS "Appending lib ${_CURRENT_LIB} as ${_importedLocation}")
+            if(_linkInterfaceLibs)
+               foreach(_currentLinkInterfaceLib ${_linkInterfaceLibs})
+#                  message(STATUS "Appending link interface lib ${_currentLinkInterfaceLib}")
+                  if(_currentLinkInterfaceLib)
+                     list(APPEND _CCSR_NEW_REQ_LIBS "${_currentLinkInterfaceLib}" )
+                  endif(_currentLinkInterfaceLib)
+               endforeach(_currentLinkInterfaceLib "${_linkInterfaceLibs}")
+            endif(_linkInterfaceLibs)
+         else(_importedConfigs)
+            # "Normal" libraries are just used as they are.
+            list(APPEND _CCSR_NEW_REQ_LIBS "${_CURRENT_LIB}" )
+#            message(STATUS "Appending lib directly: ${_CURRENT_LIB}")
+         endif(_importedConfigs)
+      endforeach(_CURRENT_LIB ${_CCSR_REQ_LIBS})
+
+      set(_CCSR_REQ_LIBS ${_CCSR_NEW_REQ_LIBS} )
+   endwhile(_CHECK_FOR_IMPORTED_TARGETS)
+
+   # Finally we iterate once more over all libraries. This loop only removes
+   # all remaining imported target names (there shouldn't be any left anyway).
+   set(_CCSR_NEW_REQ_LIBS )
+   foreach(_CURRENT_LIB ${_CCSR_REQ_LIBS})
+      get_target_property(_importedConfigs "${_CURRENT_LIB}" IMPORTED_CONFIGURATIONS)
+      if (NOT _importedConfigs)
+         list(APPEND _CCSR_NEW_REQ_LIBS "${_CURRENT_LIB}" )
+#         message(STATUS "final: appending ${_CURRENT_LIB}")
+      else (NOT _importedConfigs)
+#             message(STATUS "final: skipping ${_CURRENT_LIB}")
+      endif (NOT _importedConfigs)
+   endforeach(_CURRENT_LIB ${_CCSR_REQ_LIBS})
+#   message(STATUS "setting -${_RESULT}- to -${_CCSR_NEW_REQ_LIBS}-")
+   set(${_RESULT} "${_CCSR_NEW_REQ_LIBS}" PARENT_SCOPE)
+
+endfunction()