Move -fcolor-diagnostics logic to driver.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86014 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 04463be..808c31c 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -955,9 +955,14 @@
   if (Args.hasFlag(options::OPT_fdiagnostics_show_option,
                    options::OPT_fno_diagnostics_show_option))
     CmdArgs.push_back("-fdiagnostics-show-option");
-  if (!Args.hasFlag(options::OPT_fcolor_diagnostics,
-                    options::OPT_fno_color_diagnostics))
-    CmdArgs.push_back("-fno-color-diagnostics");
+
+  // Color diagnostics are the default, unless the terminal doesn't support
+  // them.
+  if (Args.hasFlag(options::OPT_fcolor_diagnostics,
+                   options::OPT_fno_color_diagnostics) &&
+      llvm::sys::Process::StandardErrHasColors())
+    CmdArgs.push_back("-fcolor-diagnostics");
+
   if (!Args.hasFlag(options::OPT_fshow_source_location,
                     options::OPT_fno_show_source_location))
     CmdArgs.push_back("-fno-show-source-location");
diff --git a/tools/clang-cc/clang-cc.cpp b/tools/clang-cc/clang-cc.cpp
index c09f44b..671fc35 100644
--- a/tools/clang-cc/clang-cc.cpp
+++ b/tools/clang-cc/clang-cc.cpp
@@ -70,7 +70,6 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/System/Host.h"
 #include "llvm/System/Path.h"
-#include "llvm/System/Process.h"
 #include "llvm/System/Program.h"
 #include "llvm/System/Signals.h"
 #include "llvm/Target/TargetSelect.h"
@@ -284,10 +283,9 @@
               llvm::cl::value_desc("N"));
 
 static llvm::cl::opt<bool>
-NoColorDiagnostic("fno-color-diagnostics",
-                  llvm::cl::desc("Don't use colors when showing diagnostics "
-                             "(automatically turned off if output is not a "
-                             "terminal)."));
+PrintColorDiagnostic("fcolor-diagnostics",
+                     llvm::cl::desc("Use colors in diagnostics"));
+
 //===----------------------------------------------------------------------===//
 // C++ Visualization.
 //===----------------------------------------------------------------------===//
@@ -2160,8 +2158,7 @@
   DiagOpts.ShowFixits = !NoDiagnosticsFixIt;
   DiagOpts.ShowSourceRanges = PrintSourceRangeInfo;
   DiagOpts.ShowOptionNames = PrintDiagnosticOption;
-  DiagOpts.ShowColors = (!NoColorDiagnostic &&
-                         llvm::sys::Process::StandardErrHasColors());
+  DiagOpts.ShowColors = PrintColorDiagnostic;
   DiagOpts.MessageLength = MessageLength;
 
   // Create the diagnostic client for reporting errors or for