aaronpuchert added inline comments.
================
Comment at: clang/lib/CodeGen/CGExprScalar.cpp:466-469
+ // [expr.type.conv]: if the type is cv void and the initializer is () or
{},
+ // the expression is a prvalue of type void that performs no
initialization.
+ QualType T = E->getType();
+ return T->isVoidType() ? nullptr : EmitNullValue(T);
----------------
rsmith wrote:
> Would it make sense to put this check in `EmitNullValue` instead? That would
> also cover an `InitListExpr` for `void{}` (which we currently appear to
> incorrectly reject), and an `ImplicitValueInit` for type `void` (which I
> don't think can be created legitimately at the moment, but that could just be
> a failure of imagination on my part).
You're right, we do reject `void{}`. Perhaps something I should address first,
so that we can have tests for both cases.
I was considering putting this in `EmitNullValue`, but then I read through the
standard and it seems `void` isn't value/zero-initializable. Then I found
[expr.type.conv] where it says `void()` is allowed and “performs no
initialization.” So if we stick close to the standard it seems we should catch
the special case here, but in `EmitNullValue` it would indeed cover both
`void()` and `void{}`.
Regarding `void{}`: you might know that `InitListExpr`s have `void` type
initially, and there is an assertion that it doesn't have `void` type after
Sema ran over it. I'd have to remove that assertion, unless we give
`InitListExpr`s a different initial type. Maybe you can comment on D98664 what
you think about this, where I'm trying to bring `ParenListExpr` in line with
`InitListExpr` regarding the initial type.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D99466/new/
https://reviews.llvm.org/D99466
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
