This patch adds support for string literals as `custom` directive
arguments. This can be useful for re-using custom parsers and printers
when arguments have a known value. For example:
```
ParseResult parseTypedAttr(AsmParser &parser, Attribute &attr, Type type) {
return parser.parseAttribute(attr, type);
}
void printTypedAttr(AsmPrinter &printer, Attribute attr, Type type) {
return parser.printAttributeWithoutType(attr);
}
```
And in TableGen:
```
def FooOp : ... {
let arguments = (ins AnyAttr:$a);
let assemblyFormat = [{ custom<TypedAttr>($a, "$_builder.getI1Type()")
attr-dict }];
}
def BarOp : ... {
let arguments = (ins AnyAttr:$a);
let assemblyFormat = [{ custom<TypedAttr>($a, "$_builder.getIndexType()")
attr-dict }];
}
```
Instead of writing two separate sets of custom parsers and printers.
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D131603
a2ad3ec7ac