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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225269 91177308-0d34-0410-b5e6-96231b3b80d8

lib/DebugInfo/CMakeLists.txt

@@ -15,4 +15,5 @@ add_llvm_library(LLVMDebugInfo
   DWARFFormValue.cpp
   DWARFTypeUnit.cpp
   DWARFUnit.cpp
+  SyntaxHighlighting.cpp
   )

lib/DebugInfo/DWARFDebugInfoEntry.cpp

@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "SyntaxHighlighting.h"
 #include "llvm/DebugInfo/DWARFDebugInfoEntry.h"
 #include "llvm/DebugInfo/DWARFCompileUnit.h"
 #include "llvm/DebugInfo/DWARFContext.h"
@@ -19,6 +20,7 @@
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 using namespace dwarf;
+using namespace syntax;
 
 // Small helper to extract a DIE pointed by a reference
 // attribute. It looks up the Unit containing the DIE and calls
@@ -39,15 +41,17 @@ void DWARFDebugInfoEntryMinimal::dump(raw_ostream &OS, DWARFUnit *u,
 
   if (debug_info_data.isValidOffset(offset)) {
     uint32_t abbrCode = debug_info_data.getULEB128(&offset);
+    WithColor(OS, syntax::Address).get() << format("\n0x%8.8x: ", Offset);
 
-    OS << format("\n0x%8.8x: ", Offset);
     if (abbrCode) {
       if (AbbrevDecl) {
-        const char *tagString = TagString(getTag());
-        if (tagString)
-          OS.indent(indent) << tagString;
-        else
-          OS.indent(indent) << format("DW_TAG_Unknown_%x", getTag());
+          const char *tagString = TagString(getTag());
+          if (tagString)
+            WithColor(OS, syntax::Tag).get().indent(indent) << tagString;
+          else
+            WithColor(OS, syntax::Tag).get().indent(indent) <<
+              format("DW_TAG_Unknown_%x", getTag());
+
         OS << format(" [%u] %c\n", abbrCode,
                      AbbrevDecl->hasChildren() ? '*' : ' ');
 
@@ -114,9 +118,10 @@ void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
   OS.indent(indent+2);
   const char *attrString = AttributeString(attr);
   if (attrString)
-    OS << attrString;
+    WithColor(OS, syntax::Attribute) << attrString;
   else
-    OS << format("DW_AT_Unknown_%x", attr);
+    WithColor(OS, syntax::Attribute).get() << format("DW_AT_Unknown_%x", attr);
+
   const char *formString = FormEncodingString(form);
   if (formString)
     OS << " [" << formString << ']';
@@ -132,7 +137,9 @@ void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
   
   const char *Name = nullptr;
   std::string File;
+  auto Color = syntax::Enumerator;
   if (attr == DW_AT_decl_file || attr == DW_AT_call_file) {
+  Color = syntax::String;
     if (const auto *LT = u->getContext().getLineTableForUnit(u))
       if (LT->getFileNameByIndex(
              formValue.getAsUnsignedConstant().getValue(),
@@ -144,13 +151,12 @@ void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
   } else if (Optional<uint64_t> Val = formValue.getAsUnsignedConstant())
     Name = AttributeValueString(attr, *Val);
 
-  if (Name) {
-    OS << Name;
-  } else if (attr == DW_AT_decl_line || attr == DW_AT_call_line) {
+  if (Name)
+    WithColor(OS, Color) << Name;
+  else if (attr == DW_AT_decl_line || attr == DW_AT_call_line)
     OS << *formValue.getAsUnsignedConstant();
-  } else {
+  else
     formValue.dump(OS, u);
-  }
 
   // We have dumped the attribute raw value. For some attributes
   // having both the raw value and the pretty-printed value is

lib/DebugInfo/DWARFFormValue.cpp

@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "SyntaxHighlighting.h"
 #include "llvm/DebugInfo/DWARFFormValue.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringRef.h"
@@ -19,6 +20,7 @@
 #include <cassert>
 using namespace llvm;
 using namespace dwarf;
+using namespace syntax;
 
 namespace {
 uint8_t getRefAddrSize(uint8_t AddrSize, uint16_t Version) {
@@ -423,9 +425,10 @@ DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
     OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
     Optional<const char *> DbgStr = getAsCString(cu);
     if (DbgStr.hasValue()) {
-      OS << '"';
-      OS.write_escaped(DbgStr.getValue());
-      OS << '"';
+      raw_ostream &COS = WithColor(OS, syntax::String);
+      COS << '"';
+      COS.write_escaped(DbgStr.getValue());
+      COS << '"';
     }
     break;
   }
@@ -433,9 +436,10 @@ DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
     OS << format(" indexed (%8.8x) string = ", (uint32_t)uvalue);
     Optional<const char *> DbgStr = getAsCString(cu);
     if (DbgStr.hasValue()) {
-      OS << '"';
-      OS.write_escaped(DbgStr.getValue());
-      OS << '"';
+      raw_ostream &COS = WithColor(OS, syntax::String);
+      COS << '"';
+      COS.write_escaped(DbgStr.getValue());
+      COS << '"';
     }
     break;
   }
@@ -479,8 +483,12 @@ DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
     break;
   }
 
-  if (cu_relative_offset)
-    OS << format(" => {0x%8.8" PRIx64 "}", uvalue + (cu ? cu->getOffset() : 0));
+  if (cu_relative_offset) {
+    OS << " => {";
+    WithColor(OS, syntax::Address).get()
+      << format("0x%8.8" PRIx64, uvalue + (cu ? cu->getOffset() : 0));
+    OS << "}";
+  }
 }
 
 Optional<const char *> DWARFFormValue::getAsCString(const DWARFUnit *U) const {

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();
+}

lib/DebugInfo/SyntaxHighlighting.h

@@ -0,0 +1,39 @@
+//===-- SyntaxHighlighting.h ------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_DEBUGINFO_SYNTAXHIGHLIGHTING_H
+#define LLVM_LIB_DEBUGINFO_SYNTAXHIGHLIGHTING_H
+
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+namespace dwarf {
+namespace syntax {
+
+// Symbolic names for various syntax elements.
+enum HighlightColor { Address, String, Tag, Attribute, Enumerator };
+
+/// An RAII object that temporarily switches an output stream to a
+/// specific color.
+class WithColor {
+  llvm::raw_ostream &OS;
+
+public:
+  /// To be used like this: WithColor(OS, syntax::String) << "text";
+  WithColor(llvm::raw_ostream &OS, enum HighlightColor Type);
+  ~WithColor();
+
+  llvm::raw_ostream& get() { return OS; }
+  operator llvm::raw_ostream& () { return OS; }
+};
+}
+}
+}
+
+#endif