[Driver] Fix driver support for color diagnostics

Diagnostics that happen during driver time do not have color output support
unless -fcolor-diagonostic is explicitly passed into the driver.  This is not a
problem for cc1 since dianostic arguments are properly handled and color is
enabled by default if the terminal supports it.

Make the driver behave like CC1. There are tests that already check for these
flags, but for the color itself there's no sensible way to test it.

Differential Revision: http://reviews.llvm.org/D20404

rdar://problem/26290980

llvm-svn: 271042

1 files changed, 47 insertions, 3 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index a37e1cecae8..3b4c50b8356 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -860,8 +860,51 @@ static void ParseDependencyOutputArgs(DependencyOutputOptions &Opts,
                         ModuleFiles.end());
 }
 
+static bool parseShowColorsArgs(const ArgList &Args, bool DefaultColor) {
+  // Color diagnostics default to auto ("on" if terminal supports) in the driver
+  // but default to off in cc1, needing an explicit OPT_fdiagnostics_color.
+  // Support both clang's -f[no-]color-diagnostics and gcc's
+  // -f[no-]diagnostics-colors[=never|always|auto].
+  enum {
+    Colors_On,
+    Colors_Off,
+    Colors_Auto
+  } ShowColors = DefaultColor ? Colors_Auto : Colors_Off;
+  for (Arg *A : Args) {
+    const Option &O = A->getOption();
+    if (!O.matches(options::OPT_fcolor_diagnostics) &&
+        !O.matches(options::OPT_fdiagnostics_color) &&
+        !O.matches(options::OPT_fno_color_diagnostics) &&
+        !O.matches(options::OPT_fno_diagnostics_color) &&
+        !O.matches(options::OPT_fdiagnostics_color_EQ))
+      continue;
+
+    if (O.matches(options::OPT_fcolor_diagnostics) ||
+        O.matches(options::OPT_fdiagnostics_color)) {
+      ShowColors = Colors_On;
+    } else if (O.matches(options::OPT_fno_color_diagnostics) ||
+               O.matches(options::OPT_fno_diagnostics_color)) {
+      ShowColors = Colors_Off;
+    } else {
+      assert(O.matches(options::OPT_fdiagnostics_color_EQ));
+      StringRef Value(A->getValue());
+      if (Value == "always")
+        ShowColors = Colors_On;
+      else if (Value == "never")
+        ShowColors = Colors_Off;
+      else if (Value == "auto")
+        ShowColors = Colors_Auto;
+    }
+  }
+  if (ShowColors == Colors_On ||
+      (ShowColors == Colors_Auto && llvm::sys::Process::StandardErrHasColors()))
+    return true;
+  return false;
+}
+
 bool clang::ParseDiagnosticArgs(DiagnosticOptions &Opts, ArgList &Args,
-                                DiagnosticsEngine *Diags) {
+                                DiagnosticsEngine *Diags,
+                                bool DefaultDiagColor) {
   using namespace options;
   bool Success = true;
 
@@ -874,7 +917,7 @@ bool clang::ParseDiagnosticArgs(DiagnosticOptions &Opts, ArgList &Args,
   Opts.Pedantic = Args.hasArg(OPT_pedantic);
   Opts.PedanticErrors = Args.hasArg(OPT_pedantic_errors);
   Opts.ShowCarets = !Args.hasArg(OPT_fno_caret_diagnostics);
-  Opts.ShowColors = Args.hasArg(OPT_fcolor_diagnostics);
+  Opts.ShowColors = parseShowColorsArgs(Args, DefaultDiagColor);
   Opts.ShowColumn = Args.hasFlag(OPT_fshow_column,
                                  OPT_fno_show_column,
                                  /*Default=*/true);
@@ -2240,7 +2283,8 @@ bool CompilerInvocation::CreateFromArgs(CompilerInvocation &Res,
   Success &= ParseAnalyzerArgs(*Res.getAnalyzerOpts(), Args, Diags);
   Success &= ParseMigratorArgs(Res.getMigratorOpts(), Args);
   ParseDependencyOutputArgs(Res.getDependencyOutputOpts(), Args);
-  Success &= ParseDiagnosticArgs(Res.getDiagnosticOpts(), Args, &Diags);
+  Success &= ParseDiagnosticArgs(Res.getDiagnosticOpts(), Args, &Diags,
+                                 false /*DefaultDiagColor*/);
   ParseCommentArgs(LangOpts.CommentOpts, Args);
   ParseFileSystemArgs(Res.getFileSystemOpts(), Args);
   // FIXME: We shouldn't have to pass the DashX option around here