Summary:
With this change generating clang order files using dtrace uses the following workflow:
cmake <whatever options you want>
ninja generate-order-file
ninja clang
This patch works by setting a default path to the order file (which can be overridden by the user). If the order file doesn't exist during configuration CMake will create an empty one.
CMake then ties up the dependencies between the clang link job and the order file, and generate-order-file overwrites CLANG_ORDER_FILE with the new order file.
Reviewers: bogner
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D16896
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@259862
91177308-0d34-0410-b5e6-
96231b3b80d8
add_subdirectory(docs)
endif()
-set(CLANG_ORDER_FILE "" CACHE FILEPATH
+# this line is needed as a cleanup to ensure that any CMakeCaches with the old
+# default value get updated to the new default.
+if(CLANG_ORDER_FILE STREQUAL "")
+ unset(CLANG_ORDER_FILE CACHE)
+endif()
+
+set(CLANG_ORDER_FILE ${CMAKE_CURRENT_BINARY_DIR}/clang.order CACHE FILEPATH
"Order file to use when compiling clang in order to improve startup time.")
+if(NOT EXISTS ${CLANG_ORDER_FILE})
+ execute_process(COMMAND ${CMAKE_COMMAND} -E touch ${CLANG_ORDER_FILE})
+endif()
+
if (CLANG_BUILT_STANDALONE OR CMAKE_VERSION VERSION_EQUAL 3 OR
CMAKE_VERSION VERSION_GREATER 3)
# Generate a list of CMake library targets so that other CMake projects can
set(TOOL_INFO_BUILD_VERSION)
endif()
-if(CLANG_ORDER_FILE)
+check_cxx_compiler_flag("-Wl,-order_file,${CLANG_ORDER_FILE}"
+ LINKER_HAS_ORDER_FILE_FLAG)
+
+if(LINKER_HAS_ORDER_FILE_FLAG)
target_link_libraries(clang "-Wl,-order_file,${CLANG_ORDER_FILE}")
+ set_target_properties(clang PROPERTIES LINK_DEPENDS ${CLANG_ORDER_FILE})
endif()
if(WITH_POLLY AND LINK_POLLY_INTO_TOOLS)
COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py clean ${CMAKE_CURRENT_BINARY_DIR} dtrace
COMMENT "Clearing old dtrace data")
-
add_custom_target(generate-order-file
- COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py gen-order-file --binary $<TARGET_FILE:clang> --output ${CMAKE_CURRENT_BINARY_DIR}/clang.order ${CMAKE_CURRENT_BINARY_DIR}
+ COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py gen-order-file --binary $<TARGET_FILE:clang> --output ${CLANG_ORDER_FILE} ${CMAKE_CURRENT_BINARY_DIR}
COMMENT "Generating order file"
DEPENDS generate-dtrace-logs)
endif()