base/command_line.cc

   1 // Copyright (c) 2012 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 "base/command_line.h"
   6
   7 #include <algorithm>
   8 #include <ostream>
   9
  10 #include "base/basictypes.h"
  11 #include "base/file_path.h"
  12 #include "base/logging.h"
  13 #include "base/string_split.h"
  14 #include "base/string_util.h"
  15 #include "base/utf_string_conversions.h"
  16 #include "build/build_config.h"
  17
  18 #if defined(OS_WIN)
  19 #include <windows.h>
  20 #include <shellapi.h>
  21 #endif
  22
  23 CommandLine* CommandLine::current_process_commandline_ = NULL;
  24
  25 namespace {
  26 const CommandLine::CharType kSwitchTerminator[] = FILE_PATH_LITERAL("--");
  27 const CommandLine::CharType kSwitchValueSeparator[] = FILE_PATH_LITERAL("=");
  28 // Since we use a lazy match, make sure that longer versions (like "--") are
  29 // listed before shorter versions (like "-") of similar prefixes.
  30 #if defined(OS_WIN)
  31 const CommandLine::CharType* const kSwitchPrefixes[] = {L"--", L"-", L"/"};
  32 #elif defined(OS_POSIX)
  33 // Unixes don't use slash as a switch.
  34 const CommandLine::CharType* const kSwitchPrefixes[] = {"--", "-"};
  35 #endif
  36
  37 size_t GetSwitchPrefixLength(const CommandLine::StringType& string) {
  38   for (size_t i = 0; i < arraysize(kSwitchPrefixes); ++i) {
  39     CommandLine::StringType prefix(kSwitchPrefixes[i]);
  40     if (string.compare(0, prefix.length(), prefix) == 0)
  41       return prefix.length();
  42   }
  43   return 0;
  44 }
  45
  46 // Fills in |switch_string| and |switch_value| if |string| is a switch.
  47 // This will preserve the input switch prefix in the output |switch_string|.
  48 bool IsSwitch(const CommandLine::StringType& string,
  49               CommandLine::StringType* switch_string,
  50               CommandLine::StringType* switch_value) {
  51   switch_string->clear();
  52   switch_value->clear();
  53   if (GetSwitchPrefixLength(string) == 0)
  54     return false;
  55
  56   const size_t equals_position = string.find(kSwitchValueSeparator);
  57   *switch_string = string.substr(0, equals_position);
  58   if (equals_position != CommandLine::StringType::npos)
  59     *switch_value = string.substr(equals_position + 1);
  60   return true;
  61 }
  62
  63 // Append switches and arguments, keeping switches before arguments.
  64 void AppendSwitchesAndArguments(CommandLine& command_line,
  65                                 const CommandLine::StringVector& argv) {
  66   bool parse_switches = true;
  67   for (size_t i = 1; i < argv.size(); ++i) {
  68     CommandLine::StringType arg = argv[i];
  69     TrimWhitespace(arg, TRIM_ALL, &arg);
  70
  71     CommandLine::StringType switch_string;
  72     CommandLine::StringType switch_value;
  73     parse_switches &= (arg != kSwitchTerminator);
  74     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
  75 #if defined(OS_WIN)
  76       command_line.AppendSwitchNative(WideToASCII(switch_string), switch_value);
  77 #elif defined(OS_POSIX)
  78       command_line.AppendSwitchNative(switch_string, switch_value);
  79 #endif
  80     } else {
  81       command_line.AppendArgNative(arg);
  82     }
  83   }
  84 }
  85
  86 // Lowercase switches for backwards compatiblity *on Windows*.
  87 std::string LowerASCIIOnWindows(const std::string& string) {
  88 #if defined(OS_WIN)
  89   return StringToLowerASCII(string);
  90 #elif defined(OS_POSIX)
  91   return string;
  92 #endif
  93 }
  94
  95
  96 #if defined(OS_WIN)
  97 // Quote a string as necessary for CommandLineToArgvW compatiblity *on Windows*.
  98 std::wstring QuoteForCommandLineToArgvW(const std::wstring& arg) {
  99   // We follow the quoting rules of CommandLineToArgvW.
 100   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
 101   if (arg.find_first_of(L" \\\"") == std::wstring::npos) {
 102     // No quoting necessary.
 103     return arg;
 104   }
 105
 106   std::wstring out;
 107   out.push_back(L'"');
 108   for (size_t i = 0; i < arg.size(); ++i) {
 109     if (arg[i] == '\\') {
 110       // Find the extent of this run of backslashes.
 111       size_t start = i, end = start + 1;
 112       for (; end < arg.size() && arg[end] == '\\'; ++end)
 113         /* empty */;
 114       size_t backslash_count = end - start;
 115
 116       // Backslashes are escapes only if the run is followed by a double quote.
 117       // Since we also will end the string with a double quote, we escape for
 118       // either a double quote or the end of the string.
 119       if (end == arg.size() || arg[end] == '"') {
 120         // To quote, we need to output 2x as many backslashes.
 121         backslash_count *= 2;
 122       }
 123       for (size_t j = 0; j < backslash_count; ++j)
 124         out.push_back('\\');
 125
 126       // Advance i to one before the end to balance i++ in loop.
 127       i = end - 1;
 128     } else if (arg[i] == '"') {
 129       out.push_back('\\');
 130       out.push_back('"');
 131     } else {
 132       out.push_back(arg[i]);
 133     }
 134   }
 135   out.push_back('"');
 136
 137   return out;
 138 }
 139 #endif
 140
 141 }  // namespace
 142
 143 CommandLine::CommandLine(NoProgram no_program)
 144     : argv_(1),
 145       begin_args_(1) {
 146 }
 147
 148 CommandLine::CommandLine(const FilePath& program)
 149     : argv_(1),
 150       begin_args_(1) {
 151   SetProgram(program);
 152 }
 153
 154 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
 155     : argv_(1),
 156       begin_args_(1) {
 157   InitFromArgv(argc, argv);
 158 }
 159
 160 CommandLine::CommandLine(const StringVector& argv)
 161     : argv_(1),
 162       begin_args_(1) {
 163   InitFromArgv(argv);
 164 }
 165
 166 CommandLine::~CommandLine() {
 167 }
 168
 169 // static
 170 bool CommandLine::Init(int argc, const char* const* argv) {
 171   if (current_process_commandline_) {
 172     // If this is intentional, Reset() must be called first. If we are using
 173     // the shared build mode, we have to share a single object across multiple
 174     // shared libraries.
 175     return false;
 176   }
 177
 178   current_process_commandline_ = new CommandLine(NO_PROGRAM);
 179 #if defined(OS_WIN)
 180   current_process_commandline_->ParseFromString(::GetCommandLineW());
 181 #elif defined(OS_POSIX)
 182   current_process_commandline_->InitFromArgv(argc, argv);
 183 #endif
 184
 185   return true;
 186 }
 187
 188 // static
 189 void CommandLine::Reset() {
 190   DCHECK(current_process_commandline_);
 191   delete current_process_commandline_;
 192   current_process_commandline_ = NULL;
 193 }
 194
 195 // static
 196 CommandLine* CommandLine::ForCurrentProcess() {
 197   DCHECK(current_process_commandline_);
 198   return current_process_commandline_;
 199 }
 200
 201 #if defined(OS_WIN)
 202 // static
 203 CommandLine CommandLine::FromString(const std::wstring& command_line) {
 204   CommandLine cmd(NO_PROGRAM);
 205   cmd.ParseFromString(command_line);
 206   return cmd;
 207 }
 208 #endif
 209
 210 void CommandLine::InitFromArgv(int argc,
 211                                const CommandLine::CharType* const* argv) {
 212   StringVector new_argv;
 213   for (int i = 0; i < argc; ++i)
 214     new_argv.push_back(argv[i]);
 215   InitFromArgv(new_argv);
 216 }
 217
 218 void CommandLine::InitFromArgv(const StringVector& argv) {
 219   argv_ = StringVector(1);
 220   begin_args_ = 1;
 221   SetProgram(argv.empty() ? FilePath() : FilePath(argv[0]));
 222   AppendSwitchesAndArguments(*this, argv);
 223 }
 224
 225 CommandLine::StringType CommandLine::GetCommandLineString() const {
 226   StringType string(argv_[0]);
 227 #if defined(OS_WIN)
 228   string = QuoteForCommandLineToArgvW(string);
 229 #endif
 230   // Append switches and arguments.
 231   bool parse_switches = true;
 232   for (size_t i = 1; i < argv_.size(); ++i) {
 233     CommandLine::StringType arg = argv_[i];
 234     CommandLine::StringType switch_string;
 235     CommandLine::StringType switch_value;
 236     parse_switches &= arg != kSwitchTerminator;
 237     string.append(StringType(FILE_PATH_LITERAL(" ")));
 238     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
 239       string.append(switch_string);
 240       if (!switch_value.empty()) {
 241 #if defined(OS_WIN)
 242         switch_value = QuoteForCommandLineToArgvW(switch_value);
 243 #endif
 244         string.append(kSwitchValueSeparator + switch_value);
 245       }
 246     }
 247     else {
 248 #if defined(OS_WIN)
 249       arg = QuoteForCommandLineToArgvW(arg);
 250 #endif
 251       string.append(arg);
 252     }
 253   }
 254   return string;
 255 }
 256
 257 FilePath CommandLine::GetProgram() const {
 258   return FilePath(argv_[0]);
 259 }
 260
 261 void CommandLine::SetProgram(const FilePath& program) {
 262   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
 263 }
 264
 265 bool CommandLine::HasSwitch(const std::string& switch_string) const {
 266   return switches_.find(LowerASCIIOnWindows(switch_string)) != switches_.end();
 267 }
 268
 269 std::string CommandLine::GetSwitchValueASCII(
 270     const std::string& switch_string) const {
 271   StringType value = GetSwitchValueNative(switch_string);
 272   if (!IsStringASCII(value)) {
 273     DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
 274     return std::string();
 275   }
 276 #if defined(OS_WIN)
 277   return WideToASCII(value);
 278 #else
 279   return value;
 280 #endif
 281 }
 282
 283 FilePath CommandLine::GetSwitchValuePath(
 284     const std::string& switch_string) const {
 285   return FilePath(GetSwitchValueNative(switch_string));
 286 }
 287
 288 CommandLine::StringType CommandLine::GetSwitchValueNative(
 289     const std::string& switch_string) const {
 290   SwitchMap::const_iterator result = switches_.end();
 291   result = switches_.find(LowerASCIIOnWindows(switch_string));
 292   return result == switches_.end() ? StringType() : result->second;
 293 }
 294
 295 void CommandLine::AppendSwitch(const std::string& switch_string) {
 296   AppendSwitchNative(switch_string, StringType());
 297 }
 298
 299 void CommandLine::AppendSwitchPath(const std::string& switch_string,
 300                                    const FilePath& path) {
 301   AppendSwitchNative(switch_string, path.value());
 302 }
 303
 304 void CommandLine::AppendSwitchNative(const std::string& switch_string,
 305                                      const CommandLine::StringType& value) {
 306   std::string switch_key(LowerASCIIOnWindows(switch_string));
 307 #if defined(OS_WIN)
 308   StringType combined_switch_string(ASCIIToWide(switch_key));
 309 #elif defined(OS_POSIX)
 310   StringType combined_switch_string(switch_string);
 311 #endif
 312   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
 313   switches_[switch_key.substr(prefix_length)] = value;
 314   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
 315   if (prefix_length == 0)
 316     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
 317   if (!value.empty())
 318     combined_switch_string += kSwitchValueSeparator + value;
 319   // Append the switch and update the switches/arguments divider |begin_args_|.
 320   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
 321 }
 322
 323 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
 324                                     const std::string& value_string) {
 325 #if defined(OS_WIN)
 326   AppendSwitchNative(switch_string, ASCIIToWide(value_string));
 327 #elif defined(OS_POSIX)
 328   AppendSwitchNative(switch_string, value_string);
 329 #endif
 330 }
 331
 332 void CommandLine::CopySwitchesFrom(const CommandLine& source,
 333                                    const char* const switches[],
 334                                    size_t count) {
 335   for (size_t i = 0; i < count; ++i) {
 336     if (source.HasSwitch(switches[i]))
 337       AppendSwitchNative(switches[i], source.GetSwitchValueNative(switches[i]));
 338   }
 339 }
 340
 341 CommandLine::StringVector CommandLine::GetArgs() const {
 342   // Gather all arguments after the last switch (may include kSwitchTerminator).
 343   StringVector args(argv_.begin() + begin_args_, argv_.end());
 344   // Erase only the first kSwitchTerminator (maybe "--" is a legitimate page?)
 345   StringVector::iterator switch_terminator =
 346       std::find(args.begin(), args.end(), kSwitchTerminator);
 347   if (switch_terminator != args.end())
 348     args.erase(switch_terminator);
 349   return args;
 350 }
 351
 352 void CommandLine::AppendArg(const std::string& value) {
 353 #if defined(OS_WIN)
 354   DCHECK(IsStringUTF8(value));
 355   AppendArgNative(UTF8ToWide(value));
 356 #elif defined(OS_POSIX)
 357   AppendArgNative(value);
 358 #endif
 359 }
 360
 361 void CommandLine::AppendArgPath(const FilePath& path) {
 362   AppendArgNative(path.value());
 363 }
 364
 365 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
 366   argv_.push_back(value);
 367 }
 368
 369 void CommandLine::AppendArguments(const CommandLine& other,
 370                                   bool include_program) {
 371   if (include_program)
 372     SetProgram(other.GetProgram());
 373   AppendSwitchesAndArguments(*this, other.argv());
 374 }
 375
 376 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
 377   if (wrapper.empty())
 378     return;
 379   // The wrapper may have embedded arguments (like "gdb --args"). In this case,
 380   // we don't pretend to do anything fancy, we just split on spaces.
 381   StringVector wrapper_argv;
 382   base::SplitString(wrapper, FILE_PATH_LITERAL(' '), &wrapper_argv);
 383   // Prepend the wrapper and update the switches/arguments |begin_args_|.
 384   argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
 385   begin_args_ += wrapper_argv.size();
 386 }
 387
 388 #if defined(OS_WIN)
 389 void CommandLine::ParseFromString(const std::wstring& command_line) {
 390   std::wstring command_line_string;
 391   TrimWhitespace(command_line, TRIM_ALL, &command_line_string);
 392   if (command_line_string.empty())
 393     return;
 394
 395   int num_args = 0;
 396   wchar_t** args = NULL;
 397   args = ::CommandLineToArgvW(command_line_string.c_str(), &num_args);
 398
 399   DPLOG_IF(FATAL, !args) << "CommandLineToArgvW failed on command line: "
 400                          << command_line;
 401   InitFromArgv(num_args, args);
 402   LocalFree(args);
 403 }
 404 #endif