llvm-project

f061a395 - [Clang][Sema][Parse] Delay parsing of noexcept-specifiers in friend function declarations (#90517)

[Clang][Sema][Parse] Delay parsing of noexcept-specifiers in friend function declarations (#90517) According to [class.mem.general] p8: > A complete-class context of a class (template) is a > - function body, > - default argument, > - default template argument, > - _noexcept-specifier_, or > - default member initializer > > within the member-specification of the class or class template. When testing #90152, it came to my attention that we do _not_ consider the _noexcept-specifier_ of a friend function declaration to be a complete-class context (something which the Microsoft standard library depends on). Although a comment states that this is "consistent with what other implementations do", the only other implementation that exhibits this behavior is GCC (MSVC and EDG both late-parse the _noexcept-specifier_). This patch changes _noexcept-specifiers_ of friend function declarations to be late parsed, which is in agreement with the standard & majority of implementations. Pre-#90152, our existing implementation falls "in between" the implementation consensus: within non-template classes, we would not find latter declared members (qualified and unqualified), while within class templates we would not find latter declared member when named with a unqualified name, we would find members named with a qualified name (even when lookup context is the current instantiation). Therefore, this _shouldn't_ be a breaking change -- any code that didn't compile will continue to not compile (since a _noexcept-specifier_ is not part of the deduction substitution loci (see [temp.deduct.general] p7), and any code which did compile should continue to do so.