From 83c02698258871896f3f173531ad6c8660ea1377 Mon Sep 17 00:00:00 2001
From: Bruno Cardoso Lopes <bruno.cardoso@gmail.com>
Date: Fri, 5 Feb 2016 19:36:39 +0000
Subject: [PATCH] [Parser] Perform CachedTokens update dependent on token
 consumption

In the context where we break one tok::greatergreater into two
tok::greater in order to correctly update the cached tokens; update the
CachedTokens with two tok::greater only if ParseGreaterThanInTemplateList
clients asks to consume the last token. Otherwise we only need to add
one because the second is already added later on, as a not yet cached token.

Differential Revision: http://reviews.llvm.org/D16906

rdar://problem/24488367

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@259910 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Parse/ParseTemplate.cpp                  |  8 ++++++--
 test/Parser/objcxx14-protocol-in-template.mm | 15 +++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)
 create mode 100644 test/Parser/objcxx14-protocol-in-template.mm

diff --git a/lib/Parse/ParseTemplate.cpp b/lib/Parse/ParseTemplate.cpp
index 9e68c4a15d..e6ce30a659 100644
--- a/lib/Parse/ParseTemplate.cpp
+++ b/lib/Parse/ParseTemplate.cpp
@@ -855,8 +855,12 @@ bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
       RemainingToken == tok::greater && PP.IsPreviousCachedToken(PrevTok)) {
     PrevTok.setKind(RemainingToken);
     PrevTok.setLength(1);
-    Token NewToks[] = {PrevTok, Tok};
-    PP.ReplacePreviousCachedToken(NewToks);
+    // Break tok::greatergreater into two tok::greater but only add the second
+    // one in case the client asks to consume the last token.
+    if (ConsumeLastToken)
+      PP.ReplacePreviousCachedToken({PrevTok, Tok});
+    else
+      PP.ReplacePreviousCachedToken({PrevTok});
   }
 
   if (!ConsumeLastToken) {
diff --git a/test/Parser/objcxx14-protocol-in-template.mm b/test/Parser/objcxx14-protocol-in-template.mm
new file mode 100644
index 0000000000..36da92e251
--- /dev/null
+++ b/test/Parser/objcxx14-protocol-in-template.mm
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++14 %s
+
+template<class T> class vector {};
+@protocol P @end
+
+// expected-no-diagnostics
+
+template <typename Functor> void F(Functor functor) {}
+
+// Test protocol in template within lambda capture initializer context.
+void z() {
+  id<P> x = 0;
+  (void)x;
+  F( [ x = vector<id<P>>{} ] {} );
+}
-- 
2.40.0