Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -1334,6 +1334,10 @@
 def fno_diagnostics_show_option : Flag<["-"], "fno-diagnostics-show-option">, Group<f_Group>;
 def fno_diagnostics_show_note_include_stack : Flag<["-"], "fno-diagnostics-show-note-include-stack">,
     Flags<[CC1Option]>, Group<f_Group>;
+def fdigraphs : Flag<["-"], "fdigraphs">, Group<f_Group>, Flags<[CC1Option]>,
+  HelpText<"Enable alternative token representations '<:', ':>', '<%', '%>', '%:' (default)">;
+def fno_digraphs : Flag<["-"], "fno-digraphs">, Group<f_Group>, Flags<[CC1Option]>,
+  HelpText<"Disallow alternative token representations '<:', ':>', '<%', '%>', '%:'">;
 def fno_declspec : Flag<["-"], "fno-declspec">, Group<f_clang_Group>,
   HelpText<"Disallow __declspec as a keyword">, Flags<[CC1Option]>;
 def fno_dollars_in_identifiers : Flag<["-"], "fno-dollars-in-identifiers">, Group<f_Group>,
Index: lib/Driver/ToolChains/Clang.cpp
===================================================================
--- lib/Driver/ToolChains/Clang.cpp
+++ lib/Driver/ToolChains/Clang.cpp
@@ -3970,6 +3970,7 @@
   // Forward -f (flag) options which we can pass directly.
   Args.AddLastArg(CmdArgs, options::OPT_femit_all_decls);
   Args.AddLastArg(CmdArgs, options::OPT_fheinous_gnu_extensions);
+  Args.AddLastArg(CmdArgs, options::OPT_fdigraphs, options::OPT_fno_digraphs);
   Args.AddLastArg(CmdArgs, options::OPT_fno_operator_names);
   Args.AddLastArg(CmdArgs, options::OPT_femulated_tls,
                   options::OPT_fno_emulated_tls);
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -2080,6 +2080,7 @@
                           DiagnosticsEngine &Diags) {
   // FIXME: Cleanup per-file based stuff.
   LangStandard::Kind LangStd = LangStandard::lang_unspecified;
+  const Arg *LangStdArg;
   if (const Arg *A = Args.getLastArg(OPT_std_EQ)) {
     LangStd = llvm::StringSwitch<LangStandard::Kind>(A->getValue())
 #define LANGSTANDARD(id, name, lang, desc, features) \
@@ -2117,6 +2118,7 @@
     } else {
       // Valid standard, check to make sure language and standard are
       // compatible.
+      LangStdArg = A;
       const LangStandard &Std = LangStandard::getLangStandardForKind(LangStd);
       if (!IsInputCompatibleWithStandard(IK, Std)) {
         Diags.Report(diag::err_drv_argument_not_allowed_with)
@@ -2147,8 +2149,10 @@
       Diags.Report(diag::err_drv_invalid_value)
         << A->getAsString(Args) << A->getValue();
     }
-    else
+    else {
       LangStd = OpenCLLangStd;
+      LangStdArg = A;
+    }
   }
 
   Opts.IncludeDefaultHeader = Args.hasArg(OPT_finclude_default_header);
@@ -2174,6 +2178,16 @@
   Opts.GNUKeywords = Args.hasFlag(OPT_fgnu_keywords, OPT_fno_gnu_keywords,
                                   Opts.GNUKeywords);
 
+  if (const Arg* A = Args.getLastArg(OPT_fdigraphs, OPT_fno_digraphs)) {
+    // Prevent the user from enabling or disabling digraphs when they are not supported.
+    if (!Opts.Digraphs && LangStdArg)
+      Diags.Report(diag::err_drv_argument_not_allowed_with)
+          << A->getSpelling() << LangStdArg->getAsString(Args);
+
+    if (A->getOption().matches(OPT_fno_digraphs))
+      Opts.Digraphs = 0;
+  }
+
   if (Args.hasArg(OPT_fno_operator_names))
     Opts.CXXOperatorNames = 0;
 
Index: test/Lexer/digraph.c
===================================================================
--- test/Lexer/digraph.c
+++ test/Lexer/digraph.c
@@ -1,6 +1,17 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -ffreestanding %s
-// expected-no-diagnostics
+// RUN: %clang_cc1 -DDIGRAPHS=1 -fsyntax-only -verify -ffreestanding %s
+// RUN: %clang_cc1 -DDIGRAPHS=1 -fno-digraphs -fdigraphs -fsyntax-only -verify -ffreestanding %s
+// RUN: %clang_cc1 -fno-digraphs -fsyntax-only -verify -ffreestanding %s
+// RUN: %clang_cc1 -fdigraphs -fno-digraphs -fsyntax-only -verify -ffreestanding %s
+
+// RUN: not %clang_cc1 -std=c89 -fdigraphs -fsyntax-only -ffreestanding %s 2>&1 | FileCheck -check-prefix=CHECK1 %s
+// RUN: not %clang_cc1 -std=c89 -fno-digraphs -fsyntax-only -ffreestanding %s 2>&1 | FileCheck -check-prefix=CHECK2 %s
+
+// CHECK1: error: invalid argument '-fdigraphs' not allowed with '-std=c89'
+// CHECK2: error: invalid argument '-fno-digraphs' not allowed with '-std=c89'
 
+#if DIGRAPHS
+
+// expected-no-diagnostics
 %:include <stdint.h>
 
     %:ifndef BUFSIZE
@@ -14,3 +25,15 @@
             d<:len:> = s<:len:>;
         %>
     %>
+#else
+
+// expected-error@+1 {{expected identifier or '('}}
+%:include <stdint.h>
+;
+// expected-error@+1 {{expected ')'}} expected-note@+1{{to match this '('}}
+void copy(char d<::>);
+
+// expected-error@+1 {{expected function body}}
+void copy() <% %>
+
+#endif