MLIR CAPI: how to set function argument names %arg0

Beginners
3

Hi @mehdi_amini et al.

I’ve applied the arg_attrs attribute as suggested. I noticed arg_attrs is included suffixed with attributes:

  func @__match(%arg0: !llvm.ptr<i8>, %arg1: !llvm.ptr<i8>) -> i32 attributes 
      {arg_attrs = [{name = "str"}, {name = "pattern"}]}

unlike your original (and logical) exemplar:

func @__match(%arg0: !llvm.ptr<i8> { name = "str" }, %arg1: !llvm.ptr<i8> { name = "pattern" }) -> i32 {

Are both definitions equivalent?

I’ve extended the attributes to include an additional array attribute:

    MlirAttribute funcArgAttrs = mlirArrayAttrGet(ctx, arity, funcValueAttr);
    MlirNamedAttribute funcAttrs[] = {
        mlirNamedAttributeGet(
            mlirIdentifierGet(ctx, mlirStringRefCreateFromCString("type")),
            funcTypeAttr),
        mlirNamedAttributeGet(
            mlirIdentifierGet(ctx, mlirStringRefCreateFromCString("sym_name")),
            funcNameAttr),
        mlirNamedAttributeGet(
            mlirIdentifierGet(ctx, mlirStringRefCreateFromCString("arg_attrs")),
            funcArgAttrs)};

running the commands below lowers MLIR (thanks @ftynse):

mlir-opt -convert-std-to-llvm 1.mlir > 2.mlir
mlir-translate -mlir-to-llvmir 2.mlir

but the arg_attrs are not lowered:

define i32 @__match(i8* %0, i8* %1)  {

LLVM C API allows for argument naming:

define i32 @__match(i8* %"$str", i8* %"$pattern") {

Has optimisation taken out argument names here?

regards,
Arun