ABataev added a comment. In D80925#2067145 <https://reviews.llvm.org/D80925#2067145>, @rjmccall wrote:
> In D80925#2066915 <https://reviews.llvm.org/D80925#2066915>, @ABataev wrote: > > > In D80925#2066728 <https://reviews.llvm.org/D80925#2066728>, @rjmccall > > wrote: > > > > > Narrowly this seems to fix the immediate problem, but I feel like we're > > > in trouble if tentative parsing is changing the semantic context in ways > > > that persist. In particular, I'm concerned that we could end up > > > tentatively parsing an ODR use as part of an expression and then > > > completely discarding it, causing Sema to think that there's an ODR use > > > later because it never sees an L2R conversion (because the expression is > > > not actually used). Probably the most architectural thing would be for > > > tentative expression parsing to push a possibly-unevaluated context, and > > > then when we claim an expression annotation token we can do the > > > retroactive work necessary to make it an expression in the proper > > > context. We already have most of the logic to support that because of > > > C99 `sizeof`, which is usually not evaluated but can be in the narrow > > > circumstance of a VLA. > > > > > > If we do decide to solve this more narrowly, then we should audit our use > > > of the tentative-parsing queries to make sure that we're pushing contexts > > > consistently, and we should leave comments in places like this to make > > > sure that maintainers understand the subtleties. > > > > > > So, you suggest to not create annot_primary_expr during tentative parsing > > and revert parsing completely, right? > > > Not creating the annotation doesn't help if we're still making Sema calls. > Also, I assume we're making the annotation token intentionally, probably to > avoid re-doing the lookup. But I do think we could recognize that we're > doing this, push an unevaluated context in tentative parsing, and then call > `TransformToPotentiallyEvaluated` when we see the token in expression parsing. Ah, got it, will try to implement it. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D80925/new/ https://reviews.llvm.org/D80925 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
