TableGen.cmake: Use DEPFILE for Ninja Generator with CMake>=3.7.

chapuni · chapuni · commit 1b587358be64 · 2017-06-21T22:04:07.000Z
CMake emits build targets as relative paths (from build.ninja) but Ninja doesn't identify absolute path (in *.d) as relative path (in build.ninja). So, let file names, in the command line, relative from ${CMAKE_BINARY_DIR}, where build.ninja is. Note that tblgen is executed on ${CMAKE_BINARY_DIR} as working directory. Differential Revision: https://reviews.llvm.org/D33707 llvm-svn: 305961
diff --git a/llvm/cmake/modules/TableGen.cmake b/llvm/cmake/modules/TableGen.cmake
@@ -14,8 +14,31 @@ function(tablegen project ofn)
     message(FATAL_ERROR "${project}_TABLEGEN_EXE not set")
   endif()
 
-  file(GLOB local_tds "*.td")
-  file(GLOB_RECURSE global_tds "${LLVM_MAIN_INCLUDE_DIR}/llvm/*.td")
+  # Use depfile instead of globbing arbitrary *.td(s)
+  # DEPFILE is available for Ninja Generator with CMake>=3.7.
+  if(CMAKE_GENERATOR STREQUAL "Ninja" AND NOT CMAKE_VERSION VERSION_LESS 3.7)
+    # Make output path relative to build.ninja, assuming located on
+    # ${CMAKE_BINARY_DIR}.
+    # CMake emits build targets as relative paths but Ninja doesn't identify
+    # absolute path (in *.d) as relative path (in build.ninja)
+    # Note that tblgen is executed on ${CMAKE_BINARY_DIR} as working directory.
+    file(RELATIVE_PATH ofn_rel
+      ${CMAKE_BINARY_DIR} ${CMAKE_CURRENT_BINARY_DIR}/${ofn})
+    set(additional_cmdline
+      -o ${ofn_rel}.tmp
+      -d ${ofn_rel}.d
+      WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+      DEPFILE ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.d
+      )
+    set(local_tds)
+    set(global_tds)
+  else()
+    file(GLOB local_tds "*.td")
+    file(GLOB_RECURSE global_tds "${LLVM_MAIN_INCLUDE_DIR}/llvm/*.td")
+    set(additional_cmdline
+      -o ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp
+      )
+  endif()
 
   if (IS_ABSOLUTE ${LLVM_TARGET_DEFINITIONS})
     set(LLVM_TARGET_DEFINITIONS_ABSOLUTE ${LLVM_TARGET_DEFINITIONS})
@@ -44,7 +67,7 @@ function(tablegen project ofn)
     COMMAND ${${project}_TABLEGEN_EXE} ${ARGN} -I ${CMAKE_CURRENT_SOURCE_DIR}
     ${LLVM_TABLEGEN_FLAGS}
     ${LLVM_TARGET_DEFINITIONS_ABSOLUTE}
-    -o ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp
+    ${additional_cmdline}
     # The file in LLVM_TARGET_DEFINITIONS may be not in the current
     # directory and local_tds may not contain it, so we must
     # explicitly list it here:
