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| author | Oscar Fuentes <ofv@wanadoo.es> | 2010-10-22 16:20:10 +0000 |
|---|---|---|
| committer | Oscar Fuentes <ofv@wanadoo.es> | 2010-10-22 16:20:10 +0000 |
| commit | 861e51a244d25e645538c9657a18ad04797b924a (patch) | |
| tree | 7097db947404799495e719ea7c382e0651f37de3 | |
| parent | 962b799070c3c29c524064df3bdf4e6781f18c72 (diff) | |
| download | bcm5719-llvm-861e51a244d25e645538c9657a18ad04797b924a.tar.gz bcm5719-llvm-861e51a244d25e645538c9657a18ad04797b924a.zip | |
Teach CMake to only touch tablegen-generated files if anything
actually changed.
Patch by Frits van Bommel!
llvm-svn: 117102
| -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}..." ) |
