tools/gn/standard_out.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "tools/gn/standard_out.h"
   6
   7 #include <vector>
   8
   9 #include "base/command_line.h"
  10 #include "base/logging.h"
  11 #include "base/strings/string_split.h"
  12 #include "build/build_config.h"
  13
  14 #if defined(OS_WIN)
  15 #include <windows.h>
  16 #else
  17 #include <stdio.h>
  18 #include <unistd.h>
  19 #endif
  20
  21 namespace {
  22
  23 bool initialized = false;
  24
  25 static const char kSwitchColor[] = "color";
  26 static const char kSwitchNoColor[] = "nocolor";
  27
  28 #if defined(OS_WIN)
  29 HANDLE hstdout;
  30 WORD default_attributes;
  31 #endif
  32 bool is_console = false;
  33
  34 void EnsureInitialized() {
  35   if (initialized)
  36     return;
  37   initialized = true;
  38
  39   const base::CommandLine* cmdline = base::CommandLine::ForCurrentProcess();
  40   if (cmdline->HasSwitch(kSwitchNoColor)) {
  41     // Force color off.
  42     is_console = false;
  43     return;
  44   }
  45
  46 #if defined(OS_WIN)
  47   // On Windows, we can't force the color on. If the output handle isn't a
  48   // console, there's nothing we can do about it.
  49   hstdout = ::GetStdHandle(STD_OUTPUT_HANDLE);
  50   CONSOLE_SCREEN_BUFFER_INFO info;
  51   is_console = !!::GetConsoleScreenBufferInfo(hstdout, &info);
  52   default_attributes = info.wAttributes;
  53 #else
  54   if (cmdline->HasSwitch(kSwitchColor))
  55     is_console = true;
  56   else
  57     is_console = isatty(fileno(stdout));
  58 #endif
  59 }
  60
  61 void WriteToStdOut(const std::string& output) {
  62   size_t written_bytes = fwrite(output.data(), 1, output.size(), stdout);
  63   DCHECK_EQ(output.size(), written_bytes);
  64 }
  65
  66 }  // namespace
  67
  68 #if defined(OS_WIN)
  69
  70 void OutputString(const std::string& output, TextDecoration dec) {
  71   EnsureInitialized();
  72   if (is_console) {
  73     switch (dec) {
  74       case DECORATION_NONE:
  75         break;
  76       case DECORATION_DIM:
  77         ::SetConsoleTextAttribute(hstdout, FOREGROUND_INTENSITY);
  78         break;
  79       case DECORATION_RED:
  80         ::SetConsoleTextAttribute(hstdout,
  81                                   FOREGROUND_RED | FOREGROUND_INTENSITY);
  82         break;
  83       case DECORATION_GREEN:
  84         // Keep green non-bold.
  85         ::SetConsoleTextAttribute(hstdout, FOREGROUND_GREEN);
  86         break;
  87       case DECORATION_BLUE:
  88         ::SetConsoleTextAttribute(hstdout,
  89                                   FOREGROUND_BLUE | FOREGROUND_INTENSITY);
  90         break;
  91       case DECORATION_YELLOW:
  92         ::SetConsoleTextAttribute(hstdout,
  93                                   FOREGROUND_RED | FOREGROUND_GREEN);
  94         break;
  95     }
  96   }
  97
  98   DWORD written = 0;
  99   ::WriteFile(hstdout, output.c_str(), static_cast<DWORD>(output.size()),
 100               &written, NULL);
 101
 102   if (is_console)
 103     ::SetConsoleTextAttribute(hstdout, default_attributes);
 104 }
 105
 106 #else
 107
 108 void OutputString(const std::string& output, TextDecoration dec) {
 109   EnsureInitialized();
 110   if (is_console) {
 111     switch (dec) {
 112       case DECORATION_NONE:
 113         break;
 114       case DECORATION_DIM:
 115         WriteToStdOut("\e[2m");
 116         break;
 117       case DECORATION_RED:
 118         WriteToStdOut("\e[31m\e[1m");
 119         break;
 120       case DECORATION_GREEN:
 121         WriteToStdOut("\e[32m");
 122         break;
 123       case DECORATION_BLUE:
 124         WriteToStdOut("\e[34m\e[1m");
 125         break;
 126       case DECORATION_YELLOW:
 127         WriteToStdOut("\e[33m\e[1m");
 128         break;
 129     }
 130   }
 131
 132   WriteToStdOut(output.data());
 133
 134   if (is_console && dec != DECORATION_NONE)
 135     WriteToStdOut("\e[0m");
 136 }
 137
 138 #endif
 139
 140 void PrintShortHelp(const std::string& line) {
 141   size_t colon_offset = line.find(':');
 142   size_t first_normal = 0;
 143   if (colon_offset != std::string::npos) {
 144     OutputString("  " + line.substr(0, colon_offset), DECORATION_YELLOW);
 145     first_normal = colon_offset;
 146   }
 147
 148   // See if the colon is followed by a " [" and if so, dim the contents of [ ].
 149   if (first_normal > 0 &&
 150       line.size() > first_normal + 2 &&
 151       line[first_normal + 1] == ' ' && line[first_normal + 2] == '[') {
 152     size_t begin_bracket = first_normal + 2;
 153     OutputString(": ");
 154     first_normal = line.find(']', begin_bracket);
 155     if (first_normal == std::string::npos)
 156       first_normal = line.size();
 157     else
 158       first_normal++;
 159     OutputString(line.substr(begin_bracket, first_normal - begin_bracket),
 160                  DECORATION_DIM);
 161   }
 162
 163   OutputString(line.substr(first_normal) + "\n");
 164 }
 165
 166 void PrintLongHelp(const std::string& text) {
 167   std::vector<std::string> lines;
 168   base::SplitStringDontTrim(text, '\n', &lines);
 169
 170   for (const auto& line : lines) {
 171     // Check for a heading line.
 172     if (!line.empty() && line[0] != ' ') {
 173       // Highlight up to the colon (if any).
 174       size_t chars_to_highlight = line.find(':');
 175       if (chars_to_highlight == std::string::npos)
 176         chars_to_highlight = line.size();
 177       OutputString(line.substr(0, chars_to_highlight), DECORATION_YELLOW);
 178       OutputString(line.substr(chars_to_highlight) + "\n");
 179       continue;
 180     }
 181
 182     // Check for a comment.
 183     TextDecoration dec = DECORATION_NONE;
 184     for (size_t char_i = 0; char_i < line.size(); char_i++) {
 185       if (line[char_i] == '#') {
 186         // Got a comment, draw dimmed.
 187         dec = DECORATION_DIM;
 188         break;
 189       } else if (line[char_i] != ' ') {
 190         break;
 191       }
 192     }
 193
 194     OutputString(line + "\n", dec);
 195   }
 196 }
 197