[mlir] Build a native mlir-linalg-ods-gen when cross-compiling

[isuruf]

Summary

This builds the mlir-linalg-ods-gen tool natively in the same way as tablegen

[stephenneuendorffer]

My sense is that this could be done more simply? Seems like complex code that shouldn't be proliferated in other places if we can avoid it.

mlir/CMakeLists.txt

58

Is there a particular reason for moving this from the sub-directory? Can you comment on it in the commit log, if so? I suspect it's because of all the PARENT_SCOPE variable sets below?

mlir/tools/mlir-linalg-ods-gen/CMakeLists.txt

22

I assume ${target} here is copy-paste from add_tablegen()? it seems to me like this concept of "A host-tools executable' should be factored out... In fact, maybe this could be accomplished with add_tablegen(mlir-linalg-ods-gen MLIR_LINALG_ODS_GEN .....)?

mlir/CMakeLists.txt

 
 include_directories( "include")
 include_directories( ${MLIR_INCLUDE_DIR})
 
 # Adding tools/mlir-tblgen here as calling add_tablegen sets some variables like
 # MLIR_TABLEGEN_EXE in PARENT_SCOPE which gets lost if that folder is included
 # from another directory like tools
 add_subdirectory(tools/mlir-tblgen)
+add_subdirectory(tools/mlir-linalg-ods-gen)
 
 add_subdirectory(include/mlir)
 add_subdirectory(lib)
 if (MLIR_INCLUDE_TESTS)
   add_definitions(-DMLIR_INCLUDE_TESTS)
   add_subdirectory(unittests)
   add_subdirectory(test)
 endif()

mlir/include/mlir/Dialect/Linalg/IR/CMakeLists.txt

 # Declare a function to generate ODS with mlir-linalg-ods-gen
 function(add_linalg_ods_gen tc_filename output_file)
   set(TC_SOURCE ${CMAKE_CURRENT_SOURCE_DIR}/${tc_filename})
   set(GEN_ODS_FILE ${CMAKE_CURRENT_BINARY_DIR}/${output_file}.td)
   set(GEN_CPP_FILE ${CMAKE_CURRENT_BINARY_DIR}/${output_file}.cpp.inc)
   set_source_files_properties(
     ${GEN_ODS_FILE}
     PROPERTIES GENERATED TRUE)
   set_source_files_properties(
     ${GEN_CPP_FILE}
     PROPERTIES GENERATED TRUE)
   add_custom_command(
     OUTPUT ${GEN_ODS_FILE} ${GEN_CPP_FILE}
-    COMMAND mlir-linalg-ods-gen -gen-ods-decl ${TC_SOURCE} > ${GEN_ODS_FILE}
-    COMMAND mlir-linalg-ods-gen -gen-impl ${TC_SOURCE} > ${GEN_CPP_FILE}
+    COMMAND ${MLIR_LINALG_ODS_GEN_EXE} -gen-ods-decl ${TC_SOURCE} > ${GEN_ODS_FILE}
+    COMMAND ${MLIR_LINALG_ODS_GEN_EXE} -gen-impl ${TC_SOURCE} > ${GEN_CPP_FILE}
     MAIN_DEPENDENCY
     ${TC_SOURCE}
     DEPENDS
-    mlir-linalg-ods-gen
+    ${MLIR_LINALG_ODS_GEN_TARGET}
     VERBATIM)
   add_custom_target(
     MLIR${output_file}IncGen
     DEPENDS
-    mlir-linalg-ods-gen
+    ${MLIR_LINALG_ODS_GEN_TARGET}
     ${GEN_ODS_FILE} ${GEN_CPP_FILE})
 endfunction()
 
 add_linalg_ods_gen(LinalgNamedStructuredOpsSpec.tc LinalgNamedStructuredOps)
 # Provide a short name for all external dependency that needs to
 # include Linalg in ODS
 add_custom_target(LinalgOdsGen DEPENDS MLIRLinalgNamedStructuredOpsIncGen)
 add_dependencies(mlir-headers LinalgOdsGen)

mlir/tools/CMakeLists.txt

 add_subdirectory(mlir-cuda-runner)
 add_subdirectory(mlir-cpu-runner)
-add_subdirectory(mlir-linalg-ods-gen)
 add_subdirectory(mlir-opt)
 add_subdirectory(mlir-rocm-runner)
 add_subdirectory(mlir-translate)
 add_subdirectory(mlir-vulkan-runner)
 add_subdirectory(mlir-shlib)

mlir/tools/mlir-linalg-ods-gen/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   Core
   Support
   )
 add_llvm_tool(mlir-linalg-ods-gen
   mlir-linalg-ods-gen.cpp
 )
 llvm_update_compile_flags(mlir-linalg-ods-gen)
 target_link_libraries(mlir-linalg-ods-gen PRIVATE
   MLIRParser
   MLIRSupport
   )
+
+
+set(MLIR_LINALG_ODS_GEN "mlir-linalg-ods-gen" CACHE
+      STRING "Native mlir-linalg-ods-gen executable. Saves building one when cross-compiling.")
+
+set(MLIR_LINALG_ODS_GEN_EXE "${MLIR_LINALG_ODS_GEN}" PARENT_SCOPE)
+set(MLIR_LINALG_ODS_GEN_TARGET "${MLIR_LINALG_ODS_GEN}" PARENT_SCOPE)
+
+if(LLVM_USE_HOST_TOOLS)
+  if( "${MLIR_LINALG_ODS_GEN}" STREQUAL "${target}" )
+    # The NATIVE executable *must* depend on the current target one
+    # otherwise the native one won't get rebuilt when the sources
+    # change, and we end up with incorrect builds.
+    build_native_tool(mlir-linalg-ods-gen MLIR_LINALG_ODS_GEN_EXE DEPENDS mlir-linalg-ods-gen)
+    set(MLIR_LINALG_ODS_GEN_EXE ${MLIR_LINALG_ODS_GEN_EXE} PARENT_SCOPE)
+
+    add_custom_target(mlir-linalg-ods-gen-host DEPENDS ${MLIR_LINALG_ODS_GEN_EXE})
+    set(MLIR_LINALG_ODS_GEN_TARGET mlir-linalg-ods-gen-host PARENT_SCOPE)
+
+    # If we're using the host tool, and utils were not requested, we have no
+    # need to build this tool.
+    if ( NOT LLVM_BUILD_UTILS )
+      set_target_properties(mlir-linalg-ods-gen PROPERTIES EXCLUDE_FROM_ALL ON)
+    endif()
+  endif()
+endif()