diff --git a/lib/AST/ExprClassification.cpp b/lib/AST/ExprClassification.cpp
index f5ee3e5..60e6f96 100644
--- a/lib/AST/ExprClassification.cpp
+++ b/lib/AST/ExprClassification.cpp
@@ -247,7 +247,7 @@
   case Expr::ParenExprClass:
     return ClassifyInternal(Ctx, cast<ParenExpr>(E)->getSubExpr());
 
-    // C1X 6.5.1.1p4: [A generic selection] is an lvalue, a function designator,
+    // C11 6.5.1.1p4: [A generic selection] is an lvalue, a function designator,
     // or a void expression if its result expression is, respectively, an
     // lvalue, a function designator, or a void expression.
   case Expr::GenericSelectionExprClass:
diff --git a/lib/Basic/IdentifierTable.cpp b/lib/Basic/IdentifierTable.cpp
index f5b417c..690a1f5 100644
--- a/lib/Basic/IdentifierTable.cpp
+++ b/lib/Basic/IdentifierTable.cpp
@@ -95,7 +95,7 @@
     KEYNOCXX = 0x80,
     KEYBORLAND = 0x100,
     KEYOPENCL = 0x200,
-    KEYC1X = 0x400,
+    KEYC11 = 0x400,
     KEYARC = 0x800,
     KEYALL = 0x0fff
   };
@@ -124,7 +124,7 @@
   else if (LangOpts.AltiVec && (Flags & KEYALTIVEC)) AddResult = 2;
   else if (LangOpts.OpenCL && (Flags & KEYOPENCL)) AddResult = 2;
   else if (!LangOpts.CPlusPlus && (Flags & KEYNOCXX)) AddResult = 2;
-  else if (LangOpts.C1X && (Flags & KEYC1X)) AddResult = 2;
+  else if (LangOpts.C11 && (Flags & KEYC11)) AddResult = 2;
   // We treat bridge casts as objective-C keywords so we can warn on them
   // in non-arc mode.
   else if (LangOpts.ObjC2 && (Flags & KEYARC)) AddResult = 2;
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 18b247c..caeb416 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -1615,7 +1615,7 @@
   const LangStandard &Std = LangStandard::getLangStandardForKind(LangStd);
   Opts.BCPLComment = Std.hasBCPLComments();
   Opts.C99 = Std.isC99();
-  Opts.C1X = Std.isC1X();
+  Opts.C11 = Std.isC11();
   Opts.CPlusPlus = Std.isCPlusPlus();
   Opts.CPlusPlus0x = Std.isCPlusPlus0x();
   Opts.Digraphs = Std.hasDigraphs();
diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index 61d1748..ad12e3d 100644
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -270,7 +270,7 @@
     // FIXME: C1x doesn't have a defined version number yet, so pick something
     // that is the minimum possible according to their placeholder scheme
     // 201ymmL.
-    if (LangOpts.C1X)
+    if (LangOpts.C11)
       Builder.defineMacro("__STDC_VERSION__", "201001L");
     else if (LangOpts.C99)
       Builder.defineMacro("__STDC_VERSION__", "199901L");
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index c5041dd..a0d203f 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -621,10 +621,10 @@
            .Case("ownership_returns", true)
            .Case("ownership_takes", true)
            .Case("arc_cf_code_audited", true)
-           // C1X features
-           .Case("c_alignas", LangOpts.C1X)
-           .Case("c_generic_selections", LangOpts.C1X)
-           .Case("c_static_assert", LangOpts.C1X)
+           // C11 features
+           .Case("c_alignas", LangOpts.C11)
+           .Case("c_generic_selections", LangOpts.C11)
+           .Case("c_static_assert", LangOpts.C11)
            // C++0x features
            .Case("cxx_access_control_sfinae", LangOpts.CPlusPlus0x)
            .Case("cxx_alias_templates", LangOpts.CPlusPlus0x)
@@ -718,7 +718,7 @@
   // Because we inherit the feature list from HasFeature, this string switch
   // must be less restrictive than HasFeature's.
   return llvm::StringSwitch<bool>(II->getName())
-           // C1X features supported by other languages as extensions.
+           // C11 features supported by other languages as extensions.
            .Case("c_alignas", true)
            .Case("c_generic_selections", true)
            .Case("c_static_assert", true)
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 9644d62..94f7b9b 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -883,7 +883,7 @@
 /// [C++]   namespace-definition
 /// [C++]   using-directive
 /// [C++]   using-declaration
-/// [C++0x/C1X] static_assert-declaration
+/// [C++0x/C11] static_assert-declaration
 ///         others... [FIXME]
 ///
 Parser::DeclGroupPtrTy Parser::ParseDeclaration(StmtVector &Stmts,
@@ -1566,8 +1566,8 @@
 /// FIXME: Simply returns an alignof() expression if the argument is a
 /// type. Ideally, the type should be propagated directly into Sema.
 ///
-/// [C1X]   type-id
-/// [C1X]   constant-expression
+/// [C11]   type-id
+/// [C11]   constant-expression
 /// [C++0x] type-id ...[opt]
 /// [C++0x] assignment-expression ...[opt]
 ExprResult Parser::ParseAlignArgument(SourceLocation Start,
@@ -1592,8 +1592,8 @@
 /// attribute to Attrs.
 ///
 /// alignment-specifier:
-/// [C1X]   '_Alignas' '(' type-id ')'
-/// [C1X]   '_Alignas' '(' constant-expression ')'
+/// [C11]   '_Alignas' '(' type-id ')'
+/// [C11]   '_Alignas' '(' constant-expression ')'
 /// [C++0x] 'alignas' '(' type-id ...[opt] ')'
 /// [C++0x] 'alignas' '(' assignment-expression ...[opt] ')'
 void Parser::ParseAlignmentSpecifier(ParsedAttributes &Attrs,
@@ -1636,7 +1636,7 @@
 ///         storage-class-specifier declaration-specifiers[opt]
 ///         type-specifier declaration-specifiers[opt]
 /// [C99]   function-specifier declaration-specifiers[opt]
-/// [C1X]   alignment-specifier declaration-specifiers[opt]
+/// [C11]   alignment-specifier declaration-specifiers[opt]
 /// [GNU]   attributes declaration-specifiers[opt]
 /// [Clang] '__module_private__' declaration-specifiers[opt]
 ///
@@ -2085,8 +2085,8 @@
 
     // alignment-specifier
     case tok::kw__Alignas:
-      if (!getLang().C1X)
-        Diag(Tok, diag::ext_c1x_alignas);
+      if (!getLang().C11)
+        Diag(Tok, diag::ext_c11_alignas);
       ParseAlignmentSpecifier(DS.getAttributes());
       continue;
 
@@ -3341,7 +3341,7 @@
   case tok::kw_private:
     return getLang().OpenCL;
 
-  // C1x _Atomic()
+  // C11 _Atomic()
   case tok::kw__Atomic:
     return true;
   }
@@ -3465,7 +3465,7 @@
   case tok::annot_decltype:
     return true;
 
-    // C1x _Atomic()
+    // C11 _Atomic()
   case tok::kw__Atomic:
     return true;
 
@@ -4670,7 +4670,7 @@
     Diag(StartLoc, DiagID) << PrevSpec;
 }
 
-/// [C1X]   atomic-specifier:
+/// [C11]   atomic-specifier:
 ///           _Atomic ( type-name )
 ///
 void Parser::ParseAtomicSpecifier(DeclSpec &DS) {
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index 58e16bf..5bae0e4 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -573,20 +573,20 @@
                                        IsTypeName, TypenameLoc);
 }
 
-/// ParseStaticAssertDeclaration - Parse C++0x or C1X static_assert-declaration.
+/// ParseStaticAssertDeclaration - Parse C++0x or C11 static_assert-declaration.
 ///
 /// [C++0x] static_assert-declaration:
 ///           static_assert ( constant-expression  ,  string-literal  ) ;
 ///
-/// [C1X]   static_assert-declaration:
+/// [C11]   static_assert-declaration:
 ///           _Static_assert ( constant-expression  ,  string-literal  ) ;
 ///
 Decl *Parser::ParseStaticAssertDeclaration(SourceLocation &DeclEnd){
   assert((Tok.is(tok::kw_static_assert) || Tok.is(tok::kw__Static_assert)) &&
          "Not a static_assert declaration");
 
-  if (Tok.is(tok::kw__Static_assert) && !getLang().C1X)
-    Diag(Tok, diag::ext_c1x_static_assert);
+  if (Tok.is(tok::kw__Static_assert) && !getLang().C11)
+    Diag(Tok, diag::ext_c11_static_assert);
   if (Tok.is(tok::kw_static_assert))
     Diag(Tok, diag::warn_cxx98_compat_static_assert);
 
diff --git a/lib/Parse/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp
index 8af7204..0dd48a2 100644
--- a/lib/Parse/ParseExpr.cpp
+++ b/lib/Parse/ParseExpr.cpp
@@ -466,7 +466,7 @@
 /// [C++]   boolean-literal  [C++ 2.13.5]
 /// [C++0x] 'nullptr'        [C++0x 2.14.7]
 ///         '(' expression ')'
-/// [C1X]   generic-selection
+/// [C11]   generic-selection
 ///         '__func__'        [C99 6.4.2.2]
 /// [GNU]   '__FUNCTION__'
 /// [GNU]   '__PRETTY_FUNCTION__'
@@ -794,7 +794,7 @@
   case tok::utf32_string_literal:
     Res = ParseStringLiteralExpression();
     break;
-  case tok::kw__Generic:   // primary-expression: generic-selection [C1X 6.5.1]
+  case tok::kw__Generic:   // primary-expression: generic-selection [C11 6.5.1]
     Res = ParseGenericSelectionExpression();
     break;
   case tok::kw___builtin_va_arg:
@@ -2050,8 +2050,8 @@
   return Actions.ActOnStringLiteral(&StringToks[0], StringToks.size());
 }
 
-/// ParseGenericSelectionExpression - Parse a C1X generic-selection
-/// [C1X 6.5.1.1].
+/// ParseGenericSelectionExpression - Parse a C11 generic-selection
+/// [C11 6.5.1.1].
 ///
 ///    generic-selection:
 ///           _Generic ( assignment-expression , generic-assoc-list )
@@ -2065,8 +2065,8 @@
   assert(Tok.is(tok::kw__Generic) && "_Generic keyword expected");
   SourceLocation KeyLoc = ConsumeToken();
 
-  if (!getLang().C1X)
-    Diag(KeyLoc, diag::ext_c1x_generic_selection);
+  if (!getLang().C11)
+    Diag(KeyLoc, diag::ext_c11_generic_selection);
 
   BalancedDelimiterTracker T(*this, tok::l_paren);
   if (T.expectAndConsume(diag::err_expected_lparen))
@@ -2074,7 +2074,7 @@
 
   ExprResult ControllingExpr;
   {
-    // C1X 6.5.1.1p3 "The controlling expression of a generic selection is
+    // C11 6.5.1.1p3 "The controlling expression of a generic selection is
     // not evaluated."
     EnterExpressionEvaluationContext Unevaluated(Actions, Sema::Unevaluated);
     ControllingExpr = ParseAssignmentExpression();
@@ -2095,7 +2095,7 @@
   while (1) {
     ParsedType Ty;
     if (Tok.is(tok::kw_default)) {
-      // C1X 6.5.1.1p2 "A generic selection shall have no more than one default
+      // C11 6.5.1.1p2 "A generic selection shall have no more than one default
       // generic association."
       if (!DefaultLoc.isInvalid()) {
         Diag(Tok, diag::err_duplicate_default_assoc);
diff --git a/lib/Parse/ParseTentative.cpp b/lib/Parse/ParseTentative.cpp
index 2c90183..fe46456 100644
--- a/lib/Parse/ParseTentative.cpp
+++ b/lib/Parse/ParseTentative.cpp
@@ -1046,7 +1046,7 @@
   case tok::kw___underlying_type:
     return TPResult::True();
 
-  // C1x _Atomic
+  // C11 _Atomic
   case tok::kw__Atomic:
     return TPResult::True();
 
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 9d2298a..126468e 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -1015,7 +1015,7 @@
       if (Types[i]->getType()->isDependentType()) {
         IsResultDependent = true;
       } else {
-        // C1X 6.5.1.1p2 "The type name in a generic association shall specify a
+        // C11 6.5.1.1p2 "The type name in a generic association shall specify a
         // complete object type other than a variably modified type."
         unsigned D = 0;
         if (Types[i]->getType()->isIncompleteType())
@@ -1032,7 +1032,7 @@
           TypeErrorFound = true;
         }
 
-        // C1X 6.5.1.1p2 "No two generic associations in the same generic
+        // C11 6.5.1.1p2 "No two generic associations in the same generic
         // selection shall specify compatible types."
         for (unsigned j = i+1; j < NumAssocs; ++j)
           if (Types[j] && !Types[j]->getType()->isDependentType() &&
@@ -1073,7 +1073,7 @@
       CompatIndices.push_back(i);
   }
 
-  // C1X 6.5.1.1p2 "The controlling expression of a generic selection shall have
+  // C11 6.5.1.1p2 "The controlling expression of a generic selection shall have
   // type compatible with at most one of the types named in its generic
   // association list."
   if (CompatIndices.size() > 1) {
@@ -1093,7 +1093,7 @@
     return ExprError();
   }
 
-  // C1X 6.5.1.1p2 "If a generic selection has no default generic association,
+  // C11 6.5.1.1p2 "If a generic selection has no default generic association,
   // its controlling expression shall have type compatible with exactly one of
   // the types named in its generic association list."
   if (DefaultIndex == -1U && CompatIndices.size() == 0) {
@@ -1105,7 +1105,7 @@
     return ExprError();
   }
 
-  // C1X 6.5.1.1p3 "If a generic selection has a generic association with a
+  // C11 6.5.1.1p3 "If a generic selection has a generic association with a
   // type name that is compatible with the type of the controlling expression,
   // then the result expression of the generic selection is the expression
   // in that generic association. Otherwise, the result expression of the