[clang] [clang] print correct context for diagnostics suppressed by deduction (PR #125453)

[Matheus Izvekov via cfe-commits]

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@@ -1909,7 +1909,19 @@ class Sema final : public SemaBase {
   /// '\#pragma clang attribute push' directives to the given declaration.
   void AddPragmaAttributes(Scope *S, Decl *D);
 
-  void PrintPragmaAttributeInstantiationPoint();
+  using DiagFuncRef =
+      llvm::function_ref<void(SourceLocation, PartialDiagnostic)>;
+  auto getDefaultDiagFunc() {
+    return [this](SourceLocation Loc, PartialDiagnostic PD) {
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mizvekov wrote:

Yeah I know, but nothing we are using takes it, so it doesn't buy much.

I am passing both things for consistency with existing practice, but I don't understand why we have PartialDiagnosticsAt if the PartialDiagnostic already has a SourceLocation. I may look into that at some point.

https://github.com/llvm/llvm-project/pull/125453