[Concepts] Fix parsing of scope specifier in compound-requirements, add more tests for scope specifiers in type-constraints

The code for parsing of type-constraints in compound-requirements was not adapted for the new TryAnnotateTypeConstraint which
caused compound-requirements with scope specifiers to ignore them.

Also add regression tests for scope specifiers in type-constraints in more contexts.

(cherry picked from commit 5043962dd3150c6ac72b75174b9460a510d1b5c3)

1 files changed, 6 insertions, 20 deletions

diff --git a/clang/lib/Parse/ParseExprCXX.cpp b/clang/lib/Parse/ParseExprCXX.cpp
index 036eabb94dd..9f94e0dde3b 100644
--- a/clang/lib/Parse/ParseExprCXX.cpp
+++ b/clang/lib/Parse/ParseExprCXX.cpp
@@ -3374,25 +3374,6 @@ ExprResult Parser::ParseRequiresExpression() {
           Diag(Tok, diag::err_requires_expr_missing_arrow)
               << FixItHint::CreateInsertion(Tok.getLocation(), "->");
         // Try to parse a 'type-constraint'
-        CXXScopeSpec SS;
-        if (ParseOptionalCXXScopeSpecifier(SS, ParsedType(),
-                                           /*EnteringContext=*/false,
-                                           /*MayBePseudoDestructor=*/nullptr,
-                                           // If this is not a type-constraint,
-                                           // then this scope-spec is part of
-                                           // the typename of a non-type
-                                           // template parameter
-                                           /*IsTypename=*/true,
-                                           /*LastII=*/nullptr,
-                                           // We won't find concepts in
-                                           // non-namespaces anyway, so might as
-                                           // well parse this correctly for
-                                           // possible type names.
-                                           /*OnlyNamespace=*/false,
-                                           /*SuppressDiagnostic=*/true)) {
-          SkipUntil(tok::semi, tok::r_brace, SkipUntilFlags::StopBeforeMatch);
-          break;
-        }
         if (TryAnnotateTypeConstraint()) {
           SkipUntil(tok::semi, tok::r_brace, SkipUntilFlags::StopBeforeMatch);
           break;
@@ -3402,8 +3383,13 @@ ExprResult Parser::ParseRequiresExpression() {
           SkipUntil(tok::semi, tok::r_brace, SkipUntilFlags::StopBeforeMatch);
           break;
         }
-        if (Tok.is(tok::annot_cxxscope))
+        CXXScopeSpec SS;
+        if (Tok.is(tok::annot_cxxscope)) {
+          Actions.RestoreNestedNameSpecifierAnnotation(Tok.getAnnotationValue(),
+                                                       Tok.getAnnotationRange(),
+                                                       SS);
           ConsumeAnnotationToken();
+        }
 
         Req = Actions.ActOnCompoundRequirement(
             Expression.get(), NoexceptLoc, SS, takeTemplateIdAnnotation(Tok),