llvm-project

48bda00b - [Clang] [Sema] Don't crash on unexpanded pack in invalid block literal (#110762)

[Clang] [Sema] Don't crash on unexpanded pack in invalid block literal (#110762) Consider #109148: ```c++ template <typename ...Ts> void f() { [] { (^Ts); }; } ``` When we encounter `^Ts`, we try to parse a block and subsequently call `DiagnoseUnexpandedParameterPack()` (in `ActOnBlockArguments()`), which sees `Ts` and sets `ContainsUnexpandedParameterPack` to `true` in the `LambdaScopeInfo` of the enclosing lambda. However, the entire block is subsequently discarded entirely because it isn’t even syntactically well-formed. As a result, `ContainsUnexpandedParameterPack` is `true` despite the lambda’s body no longer containing any unexpanded packs, which causes an assertion the next time `DiagnoseUnexpandedParameterPack()` is called. This pr moves handling of unexpanded parameter packs into `CapturingScopeInfo` instead so that the same logic is used for both blocks and lambdas. This fixes this issue since the `ContainsUnexpandedParameterPack` flag is now part of the block (and before that, its `CapturingScopeInfo`) and no longer affects the surrounding lambda directly when the block is parsed. Moreover, this change makes blocks actually usable with pack expansion. This fixes #109148.