[change-namespace] correctly shorten namespace when references have leading '::'

[bkramer]

lg

clang-tools-extra/trunk/change-namespace/ChangeNamespace.cpp

void ChangeNamespaceTool::replaceQualifiedSymbolInDeclContext(
   (void)Consumed;
   const std::string NewNs = (NewNamespace + Postfix).str();
 
   llvm::StringRef NestedName = Lexer::getSourceText(
       CharSourceRange::getTokenRange(
           Result.SourceManager->getSpellingLoc(Start),
           Result.SourceManager->getSpellingLoc(End)),
       *Result.SourceManager, Result.Context->getLangOpts());
-  // If the symbol is already fully qualified, no change needs to be make.
-  if (NestedName.startswith("::"))
-    return;
   std::string FromDeclName = FromDecl->getQualifiedNameAsString();
   std::string ReplaceName =
       getShortestQualifiedNameInNamespace(FromDeclName, NewNs);
   // Checks if there is any using namespace declarations that can shorten the
   // qualified name.
   for (const auto *UsingNamespace : UsingNamespaceDecls) {
     if (!isDeclVisibleAtLocation(*Result.SourceManager, UsingNamespace, DeclCtx,
                                  Start))
if (isDeclVisibleAtLocation(*Result.SourceManager, Using, DeclCtx, Start)) {
           Matched = true;
           break;
         }
       }
     }
   }
   // If the new nested name in the new namespace is the same as it was in the
   // old namespace, we don't create replacement.
-  if (NestedName == ReplaceName)
+  if (NestedName == ReplaceName ||
+      (NestedName.startswith("::") && NestedName.drop_front(2) == ReplaceName))
     return;
   // If the reference need to be fully-qualified, add a leading "::" unless
   // NewNamespace is the global namespace.
   if (ReplaceName == FromDeclName && !NewNamespace.empty())
     ReplaceName = "::" + ReplaceName;
   addReplacementOrDie(Start, End, ReplaceName, *Result.SourceManager,
                       &FileToReplacements);
 }

clang-tools-extra/trunk/unittests/change-namespace/ChangeNamespaceTests.cpp

std::string Expected = "class G {};\n"
                          "class X {\n"
                          " G g; Y y; A a; nc::C c;\n"
                          "};\n"
                          "} // namespace na\n"
                          "} // namespace ny\n";
   EXPECT_EQ(format(Expected), runChangeNamespaceOnCode(Code));
 }
 
+TEST_F(ChangeNamespaceTest, ShortenNamespaceSpecifierInAnonymousNamespace) {
+  OldNamespace = "nx";
+  NewNamespace = "ny::na";
+  std::string Code = "class G {};\n"
+                     "namespace ny {\n"
+                     "class Y {};\n"
+                     "namespace na {\n"
+                     "class A {};\n"
+                     "namespace nc { class C {}; } // namespace nc\n"
+                     "}\n // namespace na\n"
+                     "}\n // namespace ny\n"
+                     "namespace nx {\n"
+                     "namespace {\n"
+                     "class X {\n"
+                     " G g; ::ny::Y y; ::ny::na::A a; ::ny::na::nc::C c;\n"
+                     "};\n"
+                     "} // namespace\n"
+                     "} // namespace nx\n";
+  std::string Expected = "class G {};\n"
+                         "namespace ny {\n"
+                         "class Y {};\n"
+                         "namespace na {\n"
+                         "class A {};\n"
+                         "namespace nc { class C {}; } // namespace nc\n"
+                         "}\n // namespace na\n"
+                         "}\n // namespace ny\n"
+                         "\n"
+                         "namespace ny {\n"
+                         "namespace na {\n"
+                         "namespace {\n"
+                         "class X {\n"
+                         " G g; Y y; A a; nc::C c;\n"
+                         "};\n"
+                         "} // namespace\n"
+                         "} // namespace na\n"
+                         "} // namespace ny\n";
+  EXPECT_EQ(format(Expected), runChangeNamespaceOnCode(Code));
+}
+
 } // anonymous namespace
 } // namespace change_namespace
 } // namespace clang