[mlir] Printing types in dialect attributes

MLIR
1

I can write a custom dialect attribute printer for the following:

#foo.bar<0> : i32

The operation parser will look ahead and optionally parse the colon-type. But if my dialect attribute printer is just

printer << '<' << getValue() << '>';

The output is

#foo.bar<0>

I have to manually print the type, but there’s no way to print it the same way it’s parsed, because

printer << '<' << getValue() << "> : " << getType();

Results in

#foo<"bar<0> : i32">

Is this an oversight or an intentional design decision? The dialect attribute parser supports parsing ahead to get an optional type, but the printer does not.

2

The attribute isn’t in charge of printing the type, the framework is. The AsmPrinter code looks buggy:
https://github.com/llvm/llvm-project/blob/cb4a5eae1eb3fb8be8c0cf73aa9b1e6f9279eda6/mlir/lib/IR/AsmPrinter.cpp#L1761

We shouldn’t be returning early there, because it skips type handling.

1 Like
3

OK, that’s what I thought. Thanks for clarifying. I’ll fix that up in my patch for https://github.com/llvm/llvm-project/issues/55324