Add Expat as a subdirectory instead of external.

  - This allows for a cleaner configuration.

  - There was a dependency on a non-existent (yet) target expatex.
    CMake used to issue a developer warning

      CMake Warning (dev) at Config.cmake/fmixml.cmake:185 (add_dependencies):
      Policy CMP0046 is not set: Error on non-existent dependency in
      add_dependencies.  Run "cmake --help-policy CMP0046" for policy details.
      Use the cmake_policy command to set the policy and suppress this warning.

      The dependency target "/home/mahge/fmi-library/build_cmake/CMakeCache.txt"
      of target "expatex" does not exist.

  This a problem for some build tools like "Ninja" which are more strict

  libexpat can instead be added as a subdirectory. Its build tree will be
  in <fmil_binary_dir>/ThirdParty/Expat/exapat-2.1.0.

  This also allows it to inherit common configurations (e.g. build type
  debug/release) from its parent FMI library settings.

Config.cmake/fmixml.cmake

@@ -139,71 +139,14 @@ set(FMIXMLSOURCE
 
 SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DXML_STATIC -DFMI_XML_QUERY")
 
-include(ExternalProject)
-
-set(EXPAT_SETTINGS
-		-DBUILD_tools:BOOLEAN=OFF
-		-DBUILD_examples:BOOLEAN=OFF
-		-DBUILD_tests:BOOLEAN=OFF
-		-DBUILD_shared:BOOLEAN=OFF
-		-DXML_DTD:BOOLEAN=OFF
-		-DXML_NS:BOOLEAN=OFF
-		-DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE}
-		-DCMAKE_C_FLAGS:STRING=${CMAKE_C_FLAGS}
-		-DCMAKE_C_FLAGS_DEBUG:STRING=${CMAKE_C_FLAGS_DEBUG}
-		-DCMAKE_C_FLAGS_RELEASE:STRING=${CMAKE_C_FLAGS_RELEASE}
-		-DCMAKE_C_FLAGS_MINSIZEREL:STRING=${CMAKE_C_FLAGS_MINSIZEREL}
-		-DCMAKE_C_FLAGS_RELWITHDEBINFO:STRING=${CMAKE_C_FLAGS_RELWITHDEBINFO}
-		-DCMAKE_EXE_LINKER_FLAGS:STRING=${CMAKE_EXE_LINKER_FLAGS}
-		-DCMAKE_LINK_LIBRARY_FLAG:STRING=${CMAKE_LINK_LIBRARY_FLAG}
-		-DCMAKE_MODULE_LINKER_FLAGS:STRING=${CMAKE_MODULE_LINKER_FLAGS}
-		-DCMAKE_SHARED_LINKER_FLAGS:STRING=${CMAKE_SHARED_LINKER_FLAGS}	
-		-DCMAKE_INSTALL_PREFIX:PATH=${CMAKE_BINARY_DIR}/ExpatEx/install
-)
-
-ExternalProject_Add(
-	expatex
-	PREFIX "${FMIXML_EXPAT_DIR}"
-	SOURCE_DIR "${FMIXML_EXPAT_DIR}"
-	CMAKE_CACHE_ARGS ${EXPAT_SETTINGS}
-	BINARY_DIR ${CMAKE_BINARY_DIR}/ExpatEx
-	INSTALL_DIR ${CMAKE_BINARY_DIR}/ExpatEx/install
-	TMP_DIR     ${CMAKE_BINARY_DIR}/ExpatEx/tmp
-    STAMP_DIR   ${CMAKE_BINARY_DIR}/ExpatEx/stamp
-)
-
-ExternalProject_Add_Step(
-	expatex dependent_reconfigure
-	DEPENDEES configure
-	DEPENDERS build
-	COMMAND ${CMAKE_COMMAND} -E echo "Running:  ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}"  ${EXPAT_SETTINGS} ${FMIXML_EXPAT_DIR}"
-	COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" ${EXPAT_SETTINGS} "${FMIXML_EXPAT_DIR}"
-	DEPENDS ${CMAKE_BINARY_DIR}/CMakeCache.txt
-	WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/ExpatEx
-)
-
-add_dependencies(expatex ${CMAKE_BINARY_DIR}/CMakeCache.txt ${FMILIBRARYHOME}/CMakeLists.txt)
-
-set(expatlib "${CMAKE_BINARY_DIR}/ExpatEx/${CMAKE_CFG_INTDIR}/${CMAKE_STATIC_LIBRARY_PREFIX}expat${CMAKE_STATIC_LIBRARY_SUFFIX}")
-
-add_library(expat STATIC IMPORTED)
-
-set_target_properties(
-	expat PROPERTIES 
-		IMPORTED_LOCATION "${expatlib}"
-)
-
-add_dependencies(expat expatex)
-
-if(FMILIB_INSTALL_SUBLIBS)
-	install(FILES 
-	"${CMAKE_BINARY_DIR}/ExpatEx/install/lib/${CMAKE_STATIC_LIBRARY_PREFIX}expat${CMAKE_STATIC_LIBRARY_SUFFIX}"
-	DESTINATION lib)
-endif()
-
-set(EXPAT_INCLUDE_DIRS ${CMAKE_BINARY_DIR}/ExpatEx/install/include)
-
-include_directories("${EXPAT_INCLUDE_DIRS}" "${FMILIB_THIRDPARTYLIBS}/FMI/" "${FMIXMLGENDIR}/FMI1" "${FMIXMLGENDIR}/FMI2")
+### Add the options of expat to the cache and add it as subdirectory.
+set(BUILD_tools OFF CACHE BOOL "build the xmlwf tool for expat library")
+set(BUILD_examples OFF CACHE BOOL "build the examples for expat library")
+set(BUILD_tests OFF CACHE BOOL "build the tests for expat library")
+set(BUILD_shared OFF CACHE BOOL "build a shared expat library")
+add_subdirectory(ThirdParty/Expat/expat-2.1.0)
+
+include_directories("${FMILIB_THIRDPARTYLIBS}/FMI/" "${FMIXMLGENDIR}/FMI1" "${FMIXMLGENDIR}/FMI2")
 
 PREFIXLIST(FMIXMLSOURCE  ${FMIXMLDIR}/)
 PREFIXLIST(FMIXMLHEADERS ${FMIXMLDIR}/)

ThirdParty/Expat/expat-2.1.0/CMakeLists.txt

@@ -37,7 +37,7 @@ endif(BUILD_tests)
 
 include(ConfigureChecks.cmake)
 
-include_directories(${CMAKE_BINARY_DIR} ${CMAKE_SOURCE_DIR}/lib)
+include_directories(${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_SOURCE_DIR}/lib)
 if(MSVC)
     add_definitions(-D_CRT_SECURE_NO_WARNINGS -wd4996)
 endif(MSVC)