Implement a very basic colored syntax highlighting for llvm-dwarfdump.
The color scheme is the same as the one used by the colorize dwarfdump
script on Darwin.
A new --color option can be used to forcibly turn color on or off.

http://reviews.llvm.org/D6852

llvm-svn: 225269
diff --git a/llvm/lib/DebugInfo/SyntaxHighlighting.cpp b/llvm/lib/DebugInfo/SyntaxHighlighting.cpp
new file mode 100644
index 0000000..a6b4c65
--- /dev/null
+++ b/llvm/lib/DebugInfo/SyntaxHighlighting.cpp
@@ -0,0 +1,37 @@
+//===-- SyntaxHighlighting.cpp ----------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SyntaxHighlighting.h"
+#include "llvm/Support/CommandLine.h"
+using namespace llvm;
+using namespace dwarf;
+using namespace syntax;
+
+static cl::opt<cl::boolOrDefault>
+    UseColor("color",
+             cl::desc("use colored syntax highlighting (default=autodetect)"),
+             cl::init(cl::BOU_UNSET));
+
+WithColor::WithColor(llvm::raw_ostream &OS, enum HighlightColor Type) : OS(OS) {
+  // Detect color from terminal type unless the user passed the --color option.
+  if (UseColor == cl::BOU_UNSET ? OS.has_colors() : UseColor == cl::BOU_TRUE) {
+    switch (Type) {
+    case Address:    OS.changeColor(llvm::raw_ostream::YELLOW);  break;
+    case String:     OS.changeColor(llvm::raw_ostream::GREEN);   break;
+    case Tag:        OS.changeColor(llvm::raw_ostream::BLUE);    break;
+    case Attribute:  OS.changeColor(llvm::raw_ostream::CYAN);    break;
+    case Enumerator: OS.changeColor(llvm::raw_ostream::MAGENTA); break;
+    }
+  }
+}
+
+WithColor::~WithColor() {
+  if (UseColor == cl::BOU_UNSET ? OS.has_colors() : UseColor == cl::BOU_TRUE)
+    OS.resetColor();
+}