[Sema] Avoid attaching 'noreturn' attribute to explicit function template specializations

Author: snarang181

clang/lib/Sema/SemaDecl.cpp

@@ -3267,6 +3267,14 @@ void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
     if (isa<UsedAttr>(I) || isa<RetainAttr>(I))
       continue;
 
+    if (isa<InferredNoReturnAttr>(I)) {
+      if (auto *FD = dyn_cast<FunctionDecl>(New)) {
+        if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
+          continue; // Don't propagate inferred noreturn attributes to explicit
+                    // specializations.
+      }
+    }
+
     if (mergeDeclAttribute(*this, New, I, LocalAMK))
       foundAny = true;
   }

clang/lib/Sema/SemaDeclAttr.cpp

@@ -1970,6 +1970,9 @@ void clang::inferNoReturnAttr(Sema &S, const Decl *D) {
   if (!FD)
     return;
 
+  if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
+    return; // Don't infer noreturn for explicit specializations.
+
   auto *NonConstFD = const_cast<FunctionDecl *>(FD);
   DiagnosticsEngine &Diags = S.getDiagnostics();
   if (Diags.isIgnored(diag::warn_falloff_nonvoid, FD->getLocation()) &&