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-rw-r--r--Modules/CheckVariableExists.cmake66
1 files changed, 66 insertions, 0 deletions
diff --git a/Modules/CheckVariableExists.cmake b/Modules/CheckVariableExists.cmake
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+++ b/Modules/CheckVariableExists.cmake
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+# - Check if the variable exists.
+# CHECK_VARIABLE_EXISTS(VAR VARIABLE)
+#
+# VAR - the name of the variable
+# VARIABLE - variable to store the result
+#
+# This macro is only for C variables.
+#
+# The following variables may be set before calling this macro to
+# modify the way the check is run:
+#
+# CMAKE_REQUIRED_FLAGS = string of compile command line flags
+# CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
+# CMAKE_REQUIRED_LIBRARIES = list of libraries to link
+
+#=============================================================================
+# Copyright 2002-2009 Kitware, Inc.
+#
+# 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("${CMAKE_CURRENT_LIST_DIR}/CMakeExpandImportedTargets.cmake")
+
+
+MACRO(CHECK_VARIABLE_EXISTS VAR VARIABLE)
+ IF("${VARIABLE}" MATCHES "^${VARIABLE}$")
+ SET(MACRO_CHECK_VARIABLE_DEFINITIONS
+ "-DCHECK_VARIABLE_EXISTS=${VAR} ${CMAKE_REQUIRED_FLAGS}")
+ MESSAGE(STATUS "Looking for ${VAR}")
+ IF(CMAKE_REQUIRED_LIBRARIES)
+ # this one translates potentially used imported library targets to their files on disk
+ CMAKE_EXPAND_IMPORTED_TARGETS(_ADJUSTED_CMAKE_REQUIRED_LIBRARIES LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} CONFIGURATION "${CMAKE_TRY_COMPILE_CONFIGURATION}")
+ SET(CHECK_VARIABLE_EXISTS_ADD_LIBRARIES
+ "-DLINK_LIBRARIES:STRING=${_ADJUSTED_CMAKE_REQUIRED_LIBRARIES}")
+ ELSE(CMAKE_REQUIRED_LIBRARIES)
+ SET(CHECK_VARIABLE_EXISTS_ADD_LIBRARIES)
+ ENDIF(CMAKE_REQUIRED_LIBRARIES)
+ TRY_COMPILE(${VARIABLE}
+ ${CMAKE_BINARY_DIR}
+ ${CMAKE_ROOT}/Modules/CheckVariableExists.c
+ COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
+ CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_VARIABLE_DEFINITIONS}
+ "${CHECK_VARIABLE_EXISTS_ADD_LIBRARIES}"
+ OUTPUT_VARIABLE OUTPUT)
+ IF(${VARIABLE})
+ SET(${VARIABLE} 1 CACHE INTERNAL "Have variable ${VAR}")
+ MESSAGE(STATUS "Looking for ${VAR} - found")
+ FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+ "Determining if the variable ${VAR} exists passed with the following output:\n"
+ "${OUTPUT}\n\n")
+ ELSE(${VARIABLE})
+ SET(${VARIABLE} "" CACHE INTERNAL "Have variable ${VAR}")
+ MESSAGE(STATUS "Looking for ${VAR} - not found")
+ FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+ "Determining if the variable ${VAR} exists failed with the following output:\n"
+ "${OUTPUT}\n\n")
+ ENDIF(${VARIABLE})
+ ENDIF("${VARIABLE}" MATCHES "^${VARIABLE}$")
+ENDMACRO(CHECK_VARIABLE_EXISTS)