diff options
Diffstat (limited to 'llvm/cmake/modules/TableGen.cmake')
| -rw-r--r-- | llvm/cmake/modules/TableGen.cmake | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/llvm/cmake/modules/TableGen.cmake b/llvm/cmake/modules/TableGen.cmake index cf7cd1f62e5..bb8fc13c547 100644 --- a/llvm/cmake/modules/TableGen.cmake +++ b/llvm/cmake/modules/TableGen.cmake @@ -13,10 +13,19 @@ macro(tablegen ofn) ${CMAKE_CURRENT_SOURCE_DIR}/${LLVM_TARGET_DEFINITIONS}) endif() add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${ofn} + # Generate tablegen output in a temporary file. COMMAND ${LLVM_TABLEGEN_EXE} ${ARGN} -I ${CMAKE_CURRENT_SOURCE_DIR} -I ${LLVM_MAIN_SRC_DIR}/lib/Target -I ${LLVM_MAIN_INCLUDE_DIR} ${LLVM_TARGET_DEFINITIONS_ABSOLUTE} - -o ${CMAKE_CURRENT_BINARY_DIR}/${ofn} + -o ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp + # Only update the real output file if there are any differences. + # This prevents recompilation of all the files depending on it if there + # aren't any. + COMMAND ${CMAKE_COMMAND} -E copy_if_different + ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp + ${CMAKE_CURRENT_BINARY_DIR}/${ofn} + # Either way, we no longer need the temporary file. + COMMAND ${CMAKE_COMMAND} -E remove ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp DEPENDS tblgen ${local_tds} ${global_tds} COMMENT "Building ${ofn}..." ) |
