[mlir][linalg][python] Add auto-generated file warning (NFC).

[gysit]

Summary

Annotate LinalgNamedStructuredOps.yaml with a comment stating the file is auto-generated and should not be edited manually.

[Kayjukh]

If LinalgNamedStructuredOps.yaml is generated by a script, would it be possible to remove it from the repository entirely and regenerate it during the build process? I feel that checking out a generated file into the repository may lead to some inconsistencies between the script and the generated version upstream if someone forgets to commit an updated version of LinalgNamedStructuredOps.yaml after each update to dump_oplib.py.

[gysit]

In D105809#2870965, @Kayjukh wrote:

If LinalgNamedStructuredOps.yaml is generated by a script, would it be possible to remove it from the repository entirely and regenerate it during the build process? I feel that checking out a generated file into the repository may lead to some inconsistencies between the script and the generated version upstream if someone forgets to commit an updated version of LinalgNamedStructuredOps.yaml after each update to dump_oplib.py.

It is a known issue but a non-trivial one. Not everyone has Python enabled and specifying dependencies between custom cmake targets is notoriously buggy (see for example, https://reviews.llvm.org/D105272 and the associated discussion https://llvm.discourse.group/t/missing-build-cmake-tblgen-dependency/3727/10). Additionally, running dump_oplib.py would require a two stage build process since it depends on mlir. At least for now, committing LinalgNamedStructuredOps.yaml seems like the better choice.

[Kayjukh]

Right, seems reasonable enough until we figure out something better. Thanks for the clarification and the pointers!

mlir/include/mlir/Dialect/Linalg/IR/LinalgNamedStructuredOps.yaml

+# Auto-generated file. Do not edit!
 --- !LinalgOpConfig
 metadata: !LinalgOpMetadata
   name: matmul
   cpp_class_name: MatmulOp
   doc: |-
     Performs a matrix multiplication of two 2D inputs.
 
     Numeric casting is performed on the operands to the inner multiply, promoting

mlir/python/mlir/dialects/linalg/opdsl/dump_oplib.py

for attr_name, value in m.__dict__.items():
           linalg_config = LinalgOpConfig.from_linalg_op_def(value.model)
         except Exception as e:
           raise ValueError(
               f"Could not create LinalgOpConfig from {value.model}") from e
         configs.extend(linalg_config)
 
   # Print.
   if args.format == "yaml":
+    print("# Auto-generated file. Do not edit!")
     print(yaml_dump_all(configs))
   elif args.format == "repr":
     for config in configs:
       print(repr(config))
 
 
 if __name__ == "__main__":
   main(create_arg_parser().parse_args())