Bug 21992 – importC: Error: variable is used as a type

The parser is unable to handle ambiguity well for cast expressions. --- int test() { int i = 1; int j = (i) * 2; }

Unfortunately, the (i)*2 can be parsed as either a multiply of i*2 or a cast of *2 to type i. This can only be distinguished in the semantic phase when what i is is known.

Because ( ) are not seen by the semantic code, the best solution is for the parser to turn (i)*2 into a cast expression. Then, if the semantic pass determines that i is a variable, rewrite the cast expression into a multiply. Do the analogous thing for -, +, and & operators.

(In reply to Walter Bright from comment #2) > Because ( ) are not seen by the semantic code, the best solution is for the > parser to turn (i)*2 into a cast expression. Then, if the semantic pass > determines that i is a variable, rewrite the cast expression into a multiply. > > Do the analogous thing for -, +, and & operators. Yes, this is what I have in the pipeline already.

At the moment I do have some lvalue checking in the parser, this'll have to be moved to semantic as well. But there are some hurdles to overcome - mostly from the semantic lowering rvalues into lvalues. For example, this nudges support in the right direction: https://github.com/dlang/dmd/pull/12752

@ibuclaw created dlang/dmd pull request #12808 "fix Issue 21992 - importC: Error: variable is used as a type" fixing this issue: - fix Issue 21992 - importC: Error: variable is used as a type https://github.com/dlang/dmd/pull/12808

dlang/dmd pull request #12808 "fix Issue 21992 - importC: Error: variable is used as a type" was merged into master: - fb4583eb93aba712bcbcda5d7bdf6303d6c1416e by Iain Buclaw: fix Issue 21992 - importC: Error: variable is used as a type https://github.com/dlang/dmd/pull/12808