13 files changed, 42 insertions, 25 deletions
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 766c964284c..4cc3f64dde4 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -940,6 +940,10 @@ def freroll_loops : Flag<["-"], "freroll-loops">, Group<f_Group>,
   HelpText<"Turn on loop reroller">, Flags<[CC1Option]>;
 def fno_reroll_loops : Flag<["-"], "fno-reroll-loops">, Group<f_Group>,
   HelpText<"Turn off loop reroller">;
+def ftrigraphs : Flag<["-"], "ftrigraphs">, Group<f_Group>,
+  HelpText<"Process trigraph sequences">, Flags<[CC1Option]>;
+def fno_trigraphs : Flag<["-"], "fno-trigraphs">, Group<f_Group>,
+  HelpText<"Do not process trigraph sequences">, Flags<[CC1Option]>;
 def funsigned_bitfields : Flag<["-"], "funsigned-bitfields">, Group<f_Group>;
 def funsigned_char : Flag<["-"], "funsigned-char">, Group<f_Group>;
 def fno_unsigned_char : Flag<["-"], "fno-unsigned-char">, Group<clang_ignored_f_Group>;
@@ -1471,7 +1475,7 @@ def time : Flag<["-"], "time">,
 def traditional_cpp : Flag<["-", "--"], "traditional-cpp">, Flags<[CC1Option]>,
   HelpText<"Enable some traditional CPP emulation">;
 def traditional : Flag<["-", "--"], "traditional">;
-def trigraphs : Flag<["-", "--"], "trigraphs">, Flags<[CC1Option]>,
+def trigraphs : Flag<["-", "--"], "trigraphs">, Alias<ftrigraphs>,
   HelpText<"Process trigraph sequences">;
 def twolevel__namespace__hints : Flag<["-"], "twolevel_namespace_hints">;
 def twolevel__namespace : Flag<["-"], "twolevel_namespace">;
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 1c5a9aa4046..5212d46345a 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -3412,8 +3412,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     else
       Std->render(Args, CmdArgs);
 
+    // If -f(no-)trigraphs appears after the language standard flag, honor it.
     if (Arg *A = Args.getLastArg(options::OPT_std_EQ, options::OPT_ansi,
-                                 options::OPT_trigraphs))
+                                 options::OPT_ftrigraphs,
+                                 options::OPT_fno_trigraphs))
       if (A != Std)
         A->render(Args, CmdArgs);
   } else {
@@ -3429,7 +3431,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     else if (IsWindowsMSVC)
       CmdArgs.push_back("-std=c++11");
 
-    Args.AddLastArg(CmdArgs, options::OPT_trigraphs);
+    Args.AddLastArg(CmdArgs, options::OPT_ftrigraphs,
+                    options::OPT_fno_trigraphs);
   }
 
   // GCC's behavior for -Wwrite-strings is a bit strange:
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index f44a4fb8ae7..8d484a5479a 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1440,8 +1440,8 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   // is specified, or -std is set to a conforming mode.
   // Trigraphs are disabled by default in c++1z onwards.
   Opts.Trigraphs = !Opts.GNUMode && !Opts.MSVCCompat && !Opts.CPlusPlus1z;
-  if (Args.hasArg(OPT_trigraphs))
-    Opts.Trigraphs = 1;
+  Opts.Trigraphs =
+      Args.hasFlag(OPT_ftrigraphs, OPT_fno_trigraphs, Opts.Trigraphs);
 
   Opts.DollarIdents = Args.hasFlag(OPT_fdollars_in_identifiers,
                                    OPT_fno_dollars_in_identifiers,
diff --git a/clang/test/CXX/lex/lex.trigraph/p1.cpp b/clang/test/CXX/lex/lex.trigraph/p1.cpp
index aacbc55b28f..a80b00eabe7 100644
--- a/clang/test/CXX/lex/lex.trigraph/p1.cpp
+++ b/clang/test/CXX/lex/lex.trigraph/p1.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -trigraphs -Wtrigraphs -verify %s
+// RUN: %clang_cc1 -fsyntax-only -ftrigraphs -Wtrigraphs -verify %s
 
 ??=pragma // expected-warning {{trigraph converted to '#' character}}
 
diff --git a/clang/test/CXX/lex/lex.trigraph/p2.cpp b/clang/test/CXX/lex/lex.trigraph/p2.cpp
index 7d11d5bf5d5..6502aa8d792 100644
--- a/clang/test/CXX/lex/lex.trigraph/p2.cpp
+++ b/clang/test/CXX/lex/lex.trigraph/p2.cpp
@@ -1,3 +1,3 @@
-// RUN: %clang_cc1 -fsyntax-only -trigraphs -Wtrigraphs -verify %s
+// RUN: %clang_cc1 -fsyntax-only -ftrigraphs -Wtrigraphs -verify %s
 
 ??=define arraycheck(a,b) a??(b??) ??!??! b??(a??) // expected-warning {{trigraph converted to '#' character}} expected-warning {{trigraph converted to '[' character}} expected-warning {{trigraph converted to ']' character}} expected-warning {{trigraph converted to '|' character}} expected-warning {{trigraph converted to '|' character}} expected-warning {{trigraph converted to '[' character}} expected-warning {{trigraph converted to ']' character}}
diff --git a/clang/test/CXX/lex/lex.trigraph/p3.cpp b/clang/test/CXX/lex/lex.trigraph/p3.cpp
index c74d8f358d0..bf935708a24 100644
--- a/clang/test/CXX/lex/lex.trigraph/p3.cpp
+++ b/clang/test/CXX/lex/lex.trigraph/p3.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -trigraphs -Wtrigraphs -verify %s
+// RUN: %clang_cc1 -fsyntax-only -ftrigraphs -Wtrigraphs -verify %s
 // expected-no-diagnostics
 
 char a[] =
diff --git a/clang/test/Driver/std.c b/clang/test/Driver/std.c
index c82e9f15c7d..02dca6698d3 100644
--- a/clang/test/Driver/std.c
+++ b/clang/test/Driver/std.c
@@ -1,8 +1,18 @@
-// RUN: %clang -std=c99 -trigraphs -std=gnu99 %s -E -o - | FileCheck -check-prefix=OVERRIDE %s
+// RUN: %clang -w -std=c99 -trigraphs -std=gnu99 %s -E -o - | FileCheck -check-prefix=OVERRIDE %s
 // OVERRIDE: ??(??)
-// RUN: %clang -ansi %s -E -o - | FileCheck -check-prefix=ANSI %s
+// RUN: %clang -w -std=c99 -trigraphs -std=gnu99 %s -E -o - | FileCheck -check-prefix=FOVERRIDE %s
+// FOVERRIDE: ??(??)
+// RUN: %clang -w -ansi %s -E -o - | FileCheck -check-prefix=ANSI %s
 // ANSI: []
-// RUN: %clang -std=gnu99 -trigraphs %s -E -o - | FileCheck -check-prefix=EXPLICIT %s
+// RUN: %clang -w -ansi %s -fno-trigraphs -E -o - | FileCheck -check-prefix=ANSI-OVERRIDE %s
+// ANSI-OVERRIDE: ??(??)
+// RUN: %clang -w -std=gnu99 -trigraphs %s -E -o - | FileCheck -check-prefix=EXPLICIT %s
 // EXPLICIT: []
+// RUN: %clang -w -std=gnu99 -ftrigraphs %s -E -o - | FileCheck -check-prefix=FEXPLICIT %s
+// FEXPLICIT: []
+// RUN: %clang -w -ftrigraphs -fno-trigraphs %s -E -o - | FileCheck -check-prefix=ONOFF %s
+// ONOFF: ??(??)
+// RUN: %clang -w -fno-trigraphs -trigraphs %s -E -o - | FileCheck -check-prefix=OFFFON %s
+// OFFFON: []
 
 ??(??)
diff --git a/clang/test/Frontend/trigraphs.cpp b/clang/test/Frontend/trigraphs.cpp
index 4b04bcbe130..552078951ae 100644
--- a/clang/test/Frontend/trigraphs.cpp
+++ b/clang/test/Frontend/trigraphs.cpp
@@ -1,8 +1,8 @@
 // RUN: %clang_cc1 -DSTDCPP11 -std=c++11 -verify -fsyntax-only %s
 // RUN: %clang_cc1 -DSTDGNU11 -std=gnu++11 -verify -fsyntax-only %s
-// RUN: %clang_cc1 -DSTDGNU11TRI -trigraphs -std=gnu++11 -verify -fsyntax-only %s
+// RUN: %clang_cc1 -DSTDGNU11TRI -ftrigraphs -std=gnu++11 -verify -fsyntax-only %s
 // RUN: %clang_cc1 -DSTDCPP17 -std=c++1z -verify -fsyntax-only %s
-// RUN: %clang_cc1 -DSTDCPP17TRI -trigraphs -std=c++1z -verify -fsyntax-only %s
+// RUN: %clang_cc1 -DSTDCPP17TRI -ftrigraphs -std=c++1z -verify -fsyntax-only %s
 // RUN: %clang_cc1 -DMSCOMPAT -fms-compatibility -std=c++11 -verify -fsyntax-only %s
 
 void foo() {
diff --git a/clang/test/Lexer/bcpl-escaped-newline.c b/clang/test/Lexer/bcpl-escaped-newline.c
index 05d4773b87e..0883173b224 100644
--- a/clang/test/Lexer/bcpl-escaped-newline.c
+++ b/clang/test/Lexer/bcpl-escaped-newline.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -Eonly -trigraphs %s
+// RUN: %clang_cc1 -Eonly -ftrigraphs %s
 // RUN: %clang_cc1 -Eonly -verify %s
 
 //\
diff --git a/clang/test/Lexer/block_cmt_end.c b/clang/test/Lexer/block_cmt_end.c
index f54b6a4a21a..1d00137644c 100644
--- a/clang/test/Lexer/block_cmt_end.c
+++ b/clang/test/Lexer/block_cmt_end.c
@@ -1,9 +1,9 @@
 /*
-  RUN: %clang_cc1 -E -trigraphs %s | grep bar
-  RUN: %clang_cc1 -E -trigraphs %s | grep foo
-  RUN: %clang_cc1 -E -trigraphs %s | not grep qux
-  RUN: %clang_cc1 -E -trigraphs %s | not grep xyz
-  RUN: %clang_cc1 -fsyntax-only -trigraphs -verify %s  
+  RUN: %clang_cc1 -E -ftrigraphs %s | grep bar
+  RUN: %clang_cc1 -E -ftrigraphs %s | grep foo
+  RUN: %clang_cc1 -E -ftrigraphs %s | not grep qux
+  RUN: %clang_cc1 -E -ftrigraphs %s | not grep xyz
+  RUN: %clang_cc1 -fsyntax-only -ftrigraphs -verify %s  
 */
 
 // This is a simple comment, /*/ does not end a comment, the trailing */ does.
diff --git a/clang/test/Lexer/constants.c b/clang/test/Lexer/constants.c
index 267e75e64e1..9c84ddc0192 100644
--- a/clang/test/Lexer/constants.c
+++ b/clang/test/Lexer/constants.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -pedantic -trigraphs %s
+// RUN: %clang_cc1 -fsyntax-only -verify -pedantic -ftrigraphs %s
 
 int x = 000000080;  // expected-error {{invalid digit}}
 
diff --git a/clang/test/Lexer/cxx1z-trigraphs.cpp b/clang/test/Lexer/cxx1z-trigraphs.cpp
index 410626fd7bb..0ea2adbe1e0 100644
--- a/clang/test/Lexer/cxx1z-trigraphs.cpp
+++ b/clang/test/Lexer/cxx1z-trigraphs.cpp
@@ -1,5 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z %s -verify
-// RUN: %clang_cc1 -std=c++1z %s -trigraphs -fsyntax-only
+// RUN: %clang_cc1 -std=c++1z %s -ftrigraphs -fsyntax-only
 
 ??= define foo ; // expected-error {{}} expected-warning {{trigraph ignored}}
 
diff --git a/clang/test/Lexer/escape_newline.c b/clang/test/Lexer/escape_newline.c
index d0f27dffdf7..9fc73dc7a42 100644
--- a/clang/test/Lexer/escape_newline.c
+++ b/clang/test/Lexer/escape_newline.c
@@ -1,7 +1,7 @@
-// RUN: %clang_cc1 -E -trigraphs %s | grep -- ' ->'
-// RUN: %clang_cc1 -E -trigraphs %s 2>&1 | grep 'backslash and newline separated by space'
-// RUN: %clang_cc1 -E -trigraphs %s 2>&1 | grep 'trigraph converted'
-// RUN: %clang_cc1 -E -CC -trigraphs %s
+// RUN: %clang_cc1 -E -ftrigraphs %s | grep -- ' ->'
+// RUN: %clang_cc1 -E -ftrigraphs %s 2>&1 | grep 'backslash and newline separated by space'
+// RUN: %clang_cc1 -E -ftrigraphs %s 2>&1 | grep 'trigraph converted'
+// RUN: %clang_cc1 -E -CC -ftrigraphs %s
 
 // This is an ugly way to spell a -> token.
  -??/