Improve raw_ostream so that you can "write" colors using operator<<

1. raw_ostream supports ANSI colors so that you can write messages to
the termina with colors. Previously, in order to change and reset
color, you had to call `changeColor` and `resetColor` functions,
respectively.

So, if you print out "error: " in red, for example, you had to do
something like this:

  OS.changeColor(raw_ostream::RED);
  OS << "error: ";
  OS.resetColor();

With this patch, you can write the same code as follows:

  OS << raw_ostream::RED << "error: " << raw_ostream::RESET;

2. Add a boolean flag to raw_ostream so that you can disable colored
output. If you disable colors, changeColor, operator<<(Color),
resetColor and other color-related functions have no effect.

Most LLVM tools automatically prints out messages using colors, and
you can disable it by passing a flag such as `--disable-colors`.
This new flag makes it easy to write code that works that way.

Differential Revision: https://reviews.llvm.org/D65564

llvm-svn: 367649

1 files changed, 2 insertions, 2 deletions

diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
index 0ed1e988a19..5db15077ce3 100644
--- a/clang/lib/Analysis/CFG.cpp
+++ b/clang/lib/Analysis/CFG.cpp
@@ -5509,7 +5509,7 @@ static void print_block(raw_ostream &OS, const CFG* cfg,
   if (print_edges) {
     // Print the predecessors of this block.
     if (!B.pred_empty()) {
-      const raw_ostream::Colors Color = raw_ostream::BLUE;
+      const raw_ostream::Color Color = raw_ostream::BLUE;
       if (ShowColors)
         OS.changeColor(Color);
       OS << "   Preds " ;
@@ -5546,7 +5546,7 @@ static void print_block(raw_ostream &OS, const CFG* cfg,
 
     // Print the successors of this block.
     if (!B.succ_empty()) {
-      const raw_ostream::Colors Color = raw_ostream::MAGENTA;
+      const raw_ostream::Color Color = raw_ostream::MAGENTA;
       if (ShowColors)
         OS.changeColor(Color);
       OS << "   Succs ";