From 1e584697aa795f915cd46afefd4e1141ee356b8c Mon Sep 17 00:00:00 2001
From: Argyrios Kyrtzidis <akyrtzi@gmail.com>
Date: Fri, 26 Oct 2012 22:53:44 +0000
Subject: [PATCH] In Parser::ParseDecltypeSpecifier, make sure the end location
 it returns is at the end of parsed tokens when an error occurs, otherwise
 we'll hit an assertion when trying to annotate the decltype tokens.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166826 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Parse/ParseDeclCXX.cpp | 17 +++++++++++++++--
 test/SemaCXX/decltype.cpp  |  9 ++++++++-
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index e656a6bd76..492250da1d 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -696,9 +696,22 @@ SourceLocation Parser::ParseDecltypeSpecifier(DeclSpec &DS) {
                                                  0, /*IsDecltype=*/true);
     Result = ParseExpression();
     if (Result.isInvalid()) {
-      SkipUntil(tok::r_paren);
       DS.SetTypeSpecError();
-      return StartLoc;
+      if (SkipUntil(tok::r_paren, /*StopAtSemi=*/true, /*DontConsume=*/true)) {
+        EndLoc = ConsumeParen();
+      } else {
+        assert(Tok.is(tok::semi));
+        if (PP.isBacktrackEnabled()) {
+          // Backtrack to get the location of the last token before the semi.
+          PP.RevertCachedTokens(2);
+          ConsumeToken(); // the semi.
+          EndLoc = ConsumeAnyToken();
+          assert(Tok.is(tok::semi));
+        } else {
+          EndLoc = Tok.getLocation();
+        }
+      }
+      return EndLoc;
     }
 
     // Match the ')'
diff --git a/test/SemaCXX/decltype.cpp b/test/SemaCXX/decltype.cpp
index ef3103ded7..f9bdececc4 100644
--- a/test/SemaCXX/decltype.cpp
+++ b/test/SemaCXX/decltype.cpp
@@ -1,5 +1,4 @@
 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
-// expected-no-diagnostics
 
 // PR5290
 int const f0();
@@ -29,3 +28,11 @@ template<typename T> auto f(T t) -> decltype(S<int>(t)) {
   using U = S<int>;
   return S<int>(t);
 }
+
+struct B {
+  B(decltype(undeclared)); // expected-error {{undeclared identifier}}
+};
+struct C {
+  C(decltype(undeclared; // expected-error {{undeclared identifier}} \
+                         // expected-error {{expected ')'}} expected-note {{to match this '('}}
+};
-- 
2.50.1