2 Commits

Author	SHA1	Message	Date
Younan Zhang	b412ec5d39	[Clang][Sema] Revisit the fix for the lambda within a type alias template decl (#89934) ... In the last patch #82310, we used template depths to tell if such alias decls contain lambdas, which is wrong because the lambda can also appear as a part of the default argument, and that would make `getTemplateInstantiationArgs` provide extra template arguments in undesired contexts. This leads to issue #89853. Moreover, our approach for https://github.com/llvm/llvm-project/issues/82104 was sadly wrong. We tried to teach `DeduceReturnType` to consider alias template arguments; however, giving these arguments in the context where they should have been substituted in a `TransformCallExpr` call is never correct. This patch addresses such problems by using a `RecursiveASTVisitor` to check if the lambda is contained by an alias `Decl`, as well as twiddling the lambda dependencies - we should also build a dependent lambda expression if the surrounding alias template arguments were dependent. Fixes #89853 Fixes #102760 Fixes #105885	2024-08-27 09:25:53 +08:00
Younan Zhang	843cc474fa	[Clang][Sema] Fix the lambda call expression inside of a type alias declaration (#82310) ... This patch attempts to fix the lambda call expression inside of a type alias declaration from two aspects: 1. Defer the lambda call expression building until after we have sufficient template arguments. This avoids the overeager (and often wrong) semantic checking before the type alias instantiation. 2. Properly obtain template arguments involving a template type alias for constraint checking. It is unfortunate that a `TypeAliasTemplateDecl` (or a `TypeAliasDecl`) is never a `DeclContext`, nor does it have an associated specialization Decl from which we could collect these template arguments. Thus, I added a new CodeSynthesisContext to record template arguments for alias declarations. Fixes https://github.com/llvm/llvm-project/issues/70601 Fixes https://github.com/llvm/llvm-project/issues/76674 Fixes https://github.com/llvm/llvm-project/issues/79555 Fixes https://github.com/llvm/llvm-project/issues/81145 Fixes https://github.com/llvm/llvm-project/issues/82104 Note that this doesn't involve the fix for https://github.com/llvm/llvm-project/issues/28461. That seems different, and I'd like to leave it as a follow-up.	2024-04-05 11:09:33 +08:00