[clang] [Clang] prevent recovery call expression from proceeding with explicit attributes and undeclared templates (PR #107786)

[Oleksandr T. via cfe-commits]

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@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+
+namespace GH49093 {
+  class B {
+  public:
+    static int a() { return 0; } // expected-note {{member is declared here}}
+    decltype(a< 0 >(0)) test;    // expected-error {{member 'a' used before its declaration}}
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a-tarasyuk wrote:

@erichkeane @AaronBallman Thanks for the feedback. @AaronBallman The recovery checker attempts to diagnose an empty lookup and also tries to handle dependent member lookups, which detect them as being used before declarations

https://github.com/llvm/llvm-project/blob/df935ff4eca91013553edbf3ca1d45b568f6709f/clang/lib/Sema/SemaExpr.cpp#L2473-L2490

https://github.com/llvm/llvm-project/blob/df935ff4eca91013553edbf3ca1d45b568f6709f/clang/lib/Sema/SemaExpr.cpp#L2425

Is it acceptable to handle a lookup result that isn’t a template but uses explicit templated arguments at this stage?


https://github.com/llvm/llvm-project/pull/107786