1 //===- WithColor.h ----------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLVM_SUPPORT_WITHCOLOR_H
10 #define LLVM_SUPPORT_WITHCOLOR_H
11 
12 #include "llvm/Support/raw_ostream.h"
13 
14 namespace llvm {
15 
16 class Error;
17 class StringRef;
18 
19 namespace cl {
20 class OptionCategory;
21 }
22 
23 extern cl::OptionCategory &getColorCategory();
24 
25 // Symbolic names for various syntax elements.
26 enum class HighlightColor {
27   Address,
28   String,
29   Tag,
30   Attribute,
31   Enumerator,
32   Macro,
33   Error,
34   Warning,
35   Note,
36   Remark
37 };
38 
39 enum class ColorMode {
40   /// Determine whether to use color based on the command line argument and the
41   /// raw_ostream.
42   Auto,
43   /// Enable colors. Because raw_ostream is the one implementing colors, this
44   /// has no effect if the stream does not support colors or has colors
45   /// disabled.
46   Enable,
47   /// Disable colors.
48   Disable,
49 };
50 
51 /// An RAII object that temporarily switches an output stream to a specific
52 /// color.
53 class WithColor {
54   raw_ostream &OS;
55   ColorMode Mode;
56 
57 public:
58   /// To be used like this: WithColor(OS, HighlightColor::String) << "text";
59   /// @param OS The output stream
60   /// @param S Symbolic name for syntax element to color
61   /// @param Mode Enable, disable or compute whether to use colors.
62   WithColor(raw_ostream &OS, HighlightColor S,
63             ColorMode Mode = ColorMode::Auto);
64   /// To be used like this: WithColor(OS, raw_ostream::Black) << "text";
65   /// @param OS The output stream
66   /// @param Color ANSI color to use, the special SAVEDCOLOR can be used to
67   /// change only the bold attribute, and keep colors untouched
68   /// @param Bold Bold/brighter text, default false
69   /// @param BG If true, change the background, default: change foreground
70   /// @param Mode Enable, disable or compute whether to use colors.
71   WithColor(raw_ostream &OS,
72             raw_ostream::Colors Color = raw_ostream::SAVEDCOLOR,
73             bool Bold = false, bool BG = false,
74             ColorMode Mode = ColorMode::Auto)
75       : OS(OS), Mode(Mode) {
76     changeColor(Color, Bold, BG);
77   }
78   ~WithColor();
79 
80   raw_ostream &get() { return OS; }
81   operator raw_ostream &() { return OS; }
82   template <typename T> WithColor &operator<<(T &O) {
83     OS << O;
84     return *this;
85   }
86   template <typename T> WithColor &operator<<(const T &O) {
87     OS << O;
88     return *this;
89   }
90 
91   /// Convenience method for printing "error: " to stderr.
92   static raw_ostream &error();
93   /// Convenience method for printing "warning: " to stderr.
94   static raw_ostream &warning();
95   /// Convenience method for printing "note: " to stderr.
96   static raw_ostream &note();
97   /// Convenience method for printing "remark: " to stderr.
98   static raw_ostream &remark();
99 
100   /// Convenience method for printing "error: " to the given stream.
101   static raw_ostream &error(raw_ostream &OS, StringRef Prefix = "",
102                             bool DisableColors = false);
103   /// Convenience method for printing "warning: " to the given stream.
104   static raw_ostream &warning(raw_ostream &OS, StringRef Prefix = "",
105                               bool DisableColors = false);
106   /// Convenience method for printing "note: " to the given stream.
107   static raw_ostream &note(raw_ostream &OS, StringRef Prefix = "",
108                            bool DisableColors = false);
109   /// Convenience method for printing "remark: " to the given stream.
110   static raw_ostream &remark(raw_ostream &OS, StringRef Prefix = "",
111                              bool DisableColors = false);
112 
113   /// Determine whether colors are displayed.
114   bool colorsEnabled();
115 
116   /// Change the color of text that will be output from this point forward.
117   /// @param Color ANSI color to use, the special SAVEDCOLOR can be used to
118   /// change only the bold attribute, and keep colors untouched
119   /// @param Bold Bold/brighter text, default false
120   /// @param BG If true, change the background, default: change foreground
121   WithColor &changeColor(raw_ostream::Colors Color, bool Bold = false,
122                          bool BG = false);
123 
124   /// Reset the colors to terminal defaults. Call this when you are done
125   /// outputting colored text, or before program exit.
126   WithColor &resetColor();
127 
128   /// Implement default handling for Error.
129   /// Print "error: " to stderr.
130   static void defaultErrorHandler(Error Err);
131 
132   /// Implement default handling for Warning.
133   /// Print "warning: " to stderr.
134   static void defaultWarningHandler(Error Warning);
135 };
136 
137 } // end namespace llvm
138 
139 #endif // LLVM_SUPPORT_WITHCOLOR_H
140