[clang-repl] Disambiguate global namespace identifiers

[Hahnfeld]

Summary

A double colon starts an identifier name in the global namespace and must be tentatively parsed as such.

[v.g.vassilev]

clang/test/Interpreter/global-namespace-disambiguate.cpp

6

Can we add this test to disambiguate-decl-stmt.cpp instead where we track these things?

[Hahnfeld]

clang/test/Interpreter/global-namespace-disambiguate.cpp

6

done

[v.g.vassilev]

LGTM!

clang/lib/Parse/ParseTentative.cpp

bool Parser::isCXXDeclarationStatement(
   case tok::kw_namespace:
     // using-declaration
     // using-directive
   case tok::kw_using:
     // static_assert-declaration
   case tok::kw_static_assert:
   case tok::kw__Static_assert:
     return true;
+  case tok::coloncolon:
   case tok::identifier: {
     if (DisambiguatingWithExpression) {
       RevertingTentativeParsingAction TPA(*this);
       // Parse the C++ scope specifier.
       CXXScopeSpec SS;
       ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/nullptr,
                                      /*ObjectHasErrors=*/false,
                                      /*EnteringContext=*/true);

clang/test/Interpreter/global-namespace-disambiguate.cpp

+// UNSUPPORTED: system-aix
+
+// RUN: cat %s | clang-repl 2>&1 | FileCheck %s
+
+struct A { ~A(); };
+::A::~A() {}
+
+// CHECK-NOT: error