+######
+# LLVMBuild Integration
+#
+# We use llvm-build to generate all the data required by the CMake based
+# build system in one swoop:
+#
+# - We generate a file (a CMake fragment) in the object root which contains
+# all the definitions that are required by CMake.
+#
+# - We generate the library table used by llvm-config.
+#
+# - We generate the dependencies for the CMake fragment, so that we will
+# automatically reconfigure outselves.
+
+set(LLVMBUILDTOOL "${LLVM_MAIN_SRC_DIR}/utils/llvm-build/llvm-build")
+set(LLVMCONFIGLIBRARYDEPENDENCIESINC
+ "${LLVM_BINARY_DIR}/tools/llvm-config/LibraryDependencies.inc")
+set(LLVMBUILDCMAKEFRAG
+ "${LLVM_BINARY_DIR}/LLVMBuild.cmake")
+message(STATUS "Constructing LLVMBuild project information")
+execute_process(
+ COMMAND ${PYTHON_EXECUTABLE} ${LLVMBUILDTOOL}
+ --native-target "${LLVM_NATIVE_ARCH}"
+ --enable-targets "${LLVM_TARGETS_TO_BUILD}"
+ --write-library-table ${LLVMCONFIGLIBRARYDEPENDENCIESINC}
+ --write-cmake-fragment ${LLVMBUILDCMAKEFRAG}
+ ERROR_VARIABLE LLVMBUILDOUTPUT
+ ERROR_VARIABLE LLVMBUILDERRORS
+ OUTPUT_STRIP_TRAILING_WHITESPACE
+ ERROR_STRIP_TRAILING_WHITESPACE
+ RESULT_VARIABLE LLVMBUILDRESULT)
+
+# On Win32, CMake doesn't properly handle piping the default output/error
+# streams into the GUI console. So, we explicitly catch and report them.
+if( NOT "${LLVMBUILDOUTPUT}" STREQUAL "")
+ message(STATUS "llvm-build output: ${LLVMBUILDOUTPUT}")
+endif()
+if( NOT "${LLVMBUILDRESULT}" STREQUAL "0" )
+ message(FATAL_ERROR
+ "Unexpected failure executing llvm-build: ${LLVMBUILDERRORS}")
+endif()