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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 | 8a116e0b3efdd18f65e17bc7133a94a008c17235 (patch) | |
| tree | b792d915cdb63ef45a6f9a2d02ec69ceb8acc7c7 /cmake/modules | |
| parent | eecb858ca86fa949c06f819d6127e2ac68d165c8 (diff) | |
| download | llvm-8a116e0b3efdd18f65e17bc7133a94a008c17235.tar.gz llvm-8a116e0b3efdd18f65e17bc7133a94a008c17235.tar.bz2 llvm-8a116e0b3efdd18f65e17bc7133a94a008c17235.tar.xz | |
Teach CMake to only touch tablegen-generated files if anything
actually changed.
Patch by Frits van Bommel!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117102 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'cmake/modules')
| -rw-r--r-- | cmake/modules/TableGen.cmake | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/cmake/modules/TableGen.cmake b/cmake/modules/TableGen.cmake index cf7cd1f62e..bb8fc13c54 100644 --- a/cmake/modules/TableGen.cmake +++ b/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}..." ) |