[clangd] Suppress unwritten scopes when expanding auto.

[hokein]

Summary

otherwise the replacement will break the code.

[ilya-biryukov]

LGTM

clang-tools-extra/trunk/clangd/AST.h

 /// FIXME: the USR semantics might not be stable enough as the ID for index
 /// macro (e.g. a change in definition offset can result in a different USR). We
 /// could change these semantics in the future by reimplementing this funcure
 /// (e.g. avoid USR for macros).
 llvm::Optional<SymbolID> getSymbolID(const IdentifierInfo &II,
                                      const MacroInfo *MI,
                                      const SourceManager &SM);
 
-/// Returns a QualType as string.
+/// Returns a QualType as string. The result doesn't contain unwritten scopes
+/// like annoymous/inline namespace.
 std::string printType(const QualType QT, const DeclContext & Context);
 
 /// Try to shorten the OriginalName by removing namespaces from the left of
 /// the string that are redundant in the CurrentNamespace. This way the type
 /// idenfier become shorter and easier to read.
 /// Limitation: It only handles the qualifier of the type itself, not that of
 /// templates.
 /// FIXME: change type of parameter CurrentNamespace to DeclContext ,

clang-tools-extra/trunk/clangd/AST.cpp

std::string shortenNamespace(const llvm::StringRef OriginalName,
   for (unsigned i = DifferentAt; i < OriginalParts.size(); ++i) {
     Result.push_back(OriginalParts[i]);
   }
   return join(Result, "::");
 }
 
 std::string printType(const QualType QT, const DeclContext & Context){
   PrintingPolicy PP(Context.getParentASTContext().getPrintingPolicy());
+  PP.SuppressUnwrittenScope = 1;
   PP.SuppressTagKeyword = 1;
   return shortenNamespace(
       QT.getAsString(PP),
       printNamespaceScope(Context) );
 }
 
 
 } // namespace clangd
 } // namespace clang

clang-tools-extra/trunk/clangd/unittests/TweakTests.cpp

TEST(TweakTest, ExpandAutoType) {
   // replace array types
   Input = R"cpp(
     au^to x = "test";
   )cpp";
   Output = R"cpp(
     const char * x = "test";
   )cpp";
   checkTransform(ID, Input, Output);
+
+  Input = R"cpp(
+  namespace {
+  class Foo {};
+  }
+  au^to f = Foo();
+  )cpp";
+  Output = R"cpp(
+  namespace {
+  class Foo {};
+  }
+  Foo f = Foo();
+  )cpp";
+  checkTransform(ID, Input, Output);
 }
 
 } // namespace
 } // namespace clangd
 } // namespace clang