Invalid yul generated for references unwrapped in a match block

[d-xo]

The following snippet results in yul that is rejected by solc:

data Wrapper = Wrapper(word);
contract C {
    function main() -> word {
        return foo(Wrapper(1));
    }
    function foo(w:Wrapper) -> word {
        let result : word;
        match w {
            | Wrapper(ptr) =>
                //let ptr2 : word = ptr;
                assembly { result := calldataload(ptr) }
        }
        return result;
    }
}

Error: Identifier "ptr" not found.
 --> bug.yul:7:30:
  |
7 |       result := calldataload(ptr)
  |                              ^^^

uncommenting the let ptr2 ... line and using ptr2 as the arg to calldataload fixes the error.

[mbenke]

Match compilation result:

data Wrapper = Wrapper(word) ;
data CCxt = CCxt  ;
forall self args ret . class  self : invokable (args, ret) {
   forall self args . function invoke (self<self> : self, args<args> : args) -> ret;
}
contract C {
   function foo (w<Wrapper> : Wrapper) -> word {
      let result<word> : word ;
      match (w<Wrapper>) {
      | Wrapper<word -> Wrapper>(var_1<word>) =>
         let var_2<word> : word = var_1<word> ;
         assembly {
            result := calldataload(ptr)
         }
      }
      return result<word>;
   }
   function main () -> word {
      return foo<Wrapper -> word>(Wrapper<word -> Wrapper>(1));
   }
}

Probably the match compiler should rename variables in assembly blocks too.

[rodrigogribeiro]

Fixed by pattern wildcard desugaring.

[mbenke]

It's still an issue with nested match:

data Wrapper(a) = Wrapper(a);

contract C {
    function main() -> word {
        return foo(Wrapper(Wrapper(1)));
    }
    function foo(w:Wrapper(Wrapper(word))) -> word {
        let result : word;
        match w {
            | Wrapper(w2) =>
	    match w2 {
              | Wrapper(ptr) =>
                //let ptr2 : word = ptr;
                assembly { result := calldataload(ptr) }
            }
        }
        return result;
    }
}

Error: Compiler run failed:
Error (8198): Identifier "ptr" not found.
  --> Output.sol:14:40:
   |
14 |                 result := calldataload(ptr)
   |                                        ^^^

but this time the bug may be in EmitCore