From 57c13008c634f47d8ca1b6aa9d7965d82a05c502 Mon Sep 17 00:00:00 2001
From: John McCall <rjmccall@apple.com>
Date: Wed, 6 Jul 2011 05:58:41 +0000
Subject: [PATCH] Properly protect colons when parsing a nested-name-specifier
 as part of an enum specifier in dialects which permit fixed underlying types.
 Fixes the rejects-valid part of PR10264.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134468 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Parse/ParseDecl.cpp      | 27 ++++++++++++++++-----------
 test/SemaCXX/enum-scoped.cpp | 11 +++++++++++
 2 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 022fe36157..f2588c875f 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -2450,13 +2450,29 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
     Actions.CodeCompleteTag(getCurScope(), DeclSpec::TST_enum);
     ConsumeCodeCompletionToken();
   }
+
+  bool IsScopedEnum = false;
+  bool IsScopedUsingClassTag = false;
+
+  if (getLang().CPlusPlus0x &&
+      (Tok.is(tok::kw_class) || Tok.is(tok::kw_struct))) {
+    IsScopedEnum = true;
+    IsScopedUsingClassTag = Tok.is(tok::kw_class);
+    ConsumeToken();
+  }
   
   // If attributes exist after tag, parse them.
   ParsedAttributes attrs(AttrFactory);
   MaybeParseGNUAttributes(attrs);
 
+  bool AllowFixedUnderlyingType = getLang().CPlusPlus0x || getLang().Microsoft;
+
   CXXScopeSpec &SS = DS.getTypeSpecScope();
   if (getLang().CPlusPlus) {
+    // "enum foo : bar;" is not a potential typo for "enum foo::bar;"
+    // if a fixed underlying type is allowed.
+    ColonProtectionRAIIObject X(*this, AllowFixedUnderlyingType);
+    
     if (ParseOptionalCXXScopeSpecifier(SS, ParsedType(), false))
       return;
 
@@ -2471,17 +2487,6 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
     }
   }
 
-  bool AllowFixedUnderlyingType = getLang().CPlusPlus0x || getLang().Microsoft;
-  bool IsScopedEnum = false;
-  bool IsScopedUsingClassTag = false;
-
-  if (getLang().CPlusPlus0x &&
-      (Tok.is(tok::kw_class) || Tok.is(tok::kw_struct))) {
-    IsScopedEnum = true;
-    IsScopedUsingClassTag = Tok.is(tok::kw_class);
-    ConsumeToken();
-  }
-
   // Must have either 'enum name' or 'enum {...}'.
   if (Tok.isNot(tok::identifier) && Tok.isNot(tok::l_brace) &&
       (AllowFixedUnderlyingType && Tok.isNot(tok::colon))) {
diff --git a/test/SemaCXX/enum-scoped.cpp b/test/SemaCXX/enum-scoped.cpp
index fc871cf379..2c3537e163 100644
--- a/test/SemaCXX/enum-scoped.cpp
+++ b/test/SemaCXX/enum-scoped.cpp
@@ -119,3 +119,14 @@ namespace rdar9366066 {
     x % 8; // expected-error{{invalid operands to binary expression ('rdar9366066::X' and 'int')}}
   }
 }
+
+// Part of PR10264
+namespace test5 {
+  namespace ns {
+    typedef unsigned Atype;
+    enum A : Atype;
+  }
+  enum ns::A : ns::Atype {
+    x, y, z
+  };
+}
-- 
2.40.0