[FOLD] fix pre-c++23 compat

Author: sdkrystian

clang/lib/Sema/SemaTemplate.cpp

@@ -410,6 +410,8 @@ bool Sema::LookupTemplateName(LookupResult &Found, Scope *S, CXXScopeSpec &SS,
   LookupParsedName(Found, S, &SS, ObjectType,
                    /*AllowBuiltinCreation=*/false, EnteringContext);
 
+  bool IsDependent = Found.wasNotFoundInCurrentInstantiation();
+
   bool ObjectTypeSearchedInScope = false;
 
   // C++ [basic.lookup.qual.general]p2:
@@ -428,8 +430,7 @@ bool Sema::LookupTemplateName(LookupResult &Found, Scope *S, CXXScopeSpec &SS,
   // we perform the unqualified lookup in the template definition context
   // and store the results so we can replicate the lookup during instantiation.
   if (MayBeNNS && Found.empty() && !ObjectType.isNull() &&
-      (!getLangOpts().CPlusPlus23 ||
-       !Found.wasNotFoundInCurrentInstantiation())) {
+      (!getLangOpts().CPlusPlus23 || !IsDependent)) {
     if (S) {
       LookupName(Found, S);
     } else if (!SS.getUnqualifiedLookups().empty()) {
@@ -503,7 +504,7 @@ bool Sema::LookupTemplateName(LookupResult &Found, Scope *S, CXXScopeSpec &SS,
     }
   }
 
-  if (Found.empty() && AllowTypoCorrection) {
+  if (Found.empty() && AllowTypoCorrection && !IsDependent) {
     // If we did not find any names, and this is not a disambiguation, attempt
     // to correct any typos.
     DeclarationName Name = Found.getLookupName();
@@ -544,14 +545,14 @@ bool Sema::LookupTemplateName(LookupResult &Found, Scope *S, CXXScopeSpec &SS,
 
   NamedDecl *ExampleLookupResult =
       Found.empty() ? nullptr : Found.getRepresentativeDecl();
-  FilterAcceptableTemplateNames(
-      Found,
-      /*AllowFunctionTemplates=*/getLangOpts().CPlusPlus23 ||
-          !ObjectTypeSearchedInScope);
+  FilterAcceptableTemplateNames(Found, getLangOpts().CPlusPlus23 ||
+                                           !ObjectTypeSearchedInScope);
   if (Found.empty()) {
-    // If a 'template' keyword was used, a lookup that finds only non-template
-    // names is an error.
-    if (ExampleLookupResult && RequiredTemplate) {
+    if (IsDependent) {
+      Found.setNotFoundInCurrentInstantiation();
+    } else if (ExampleLookupResult && RequiredTemplate) {
+      // If a 'template' keyword was used, a lookup that finds only non-template
+      // names is an error.
       Diag(Found.getNameLoc(), diag::err_template_kw_refers_to_non_template)
           << Found.getLookupName() << SS.getRange()
           << RequiredTemplate.hasTemplateKeyword()

clang/test/CXX/drs/cwg13xx.cpp

@@ -1,8 +1,8 @@
-// RUN: %clang_cc1 -std=c++98 %s -verify=expected,cxx98-14,cxx98-20,cxx98 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++11 %s -verify=expected,cxx11-20,cxx11-17,cxx11-14,cxx98-14,cxx98-20,since-cxx11,cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++14 %s -verify=expected,cxx11-20,cxx11-17,cxx11-14,since-cxx14,cxx98-14,cxx98-20,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++17 %s -verify=expected,cxx11-20,cxx11-17,cxx98-20,since-cxx14,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++20 %s -verify=expected,cxx11-20,cxx98-20,since-cxx14,since-cxx20,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++98 %s -verify=expected,cxx98-14,cxx98 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++11 %s -verify=expected,cxx11-20,cxx11-17,cxx11-14,cxx98-14,since-cxx11,cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++14 %s -verify=expected,cxx11-20,cxx11-17,cxx11-14,since-cxx14,cxx98-14,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++17 %s -verify=expected,cxx11-20,cxx11-17,since-cxx14,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++20 %s -verify=expected,cxx11-20,since-cxx14,since-cxx20,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -std=c++23 %s -verify=expected,since-cxx14,since-cxx20,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -std=c++2c %s -verify=expected,since-cxx14,since-cxx20,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
 
@@ -136,7 +136,6 @@ namespace cwg1310 { // cwg1310: 5
     // expected-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a template name in this context, despite preceding 'template' keyword}}
   }
   template<typename W>
-  // cxx98-20-note@-1 2{{declared as a non-template here}}
   void wt_test_good() {
     typename W::W::X w2ax;
     typename W::template W<int>::X w4x;
@@ -147,9 +146,7 @@ namespace cwg1310 { // cwg1310: 5
     (void)w.W::W::n;
     (void)w.W::template W<int>::n;
     (void)w.template W<int>::W::n;
-    // cxx98-20-error@-1 {{'W' following the 'template' keyword does not refer to a template}}
     (void)w.template W<int>::template W<int>::n;
-    // cxx98-20-error@-1 {{'W' following the 'template' keyword does not refer to a template}}
   }
   template void wt_test<W<int> >(); // #cwg1310-W-int
   template void wt_test_good<W<int> >();