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/files/file_path.h"
  12 #include "base/logging.h"
  13 #include "base/strings/string_split.h"
  14 #include "base/strings/string_util.h"
  15 #include "base/strings/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 namespace base {
  24
  25 CommandLine* CommandLine::current_process_commandline_ = NULL;
  26
  27 namespace {
  28
  29 const CommandLine::CharType kSwitchTerminator[] = FILE_PATH_LITERAL("--");
  30 const CommandLine::CharType kSwitchValueSeparator[] = FILE_PATH_LITERAL("=");
  31
  32 // Since we use a lazy match, make sure that longer versions (like "--") are
  33 // listed before shorter versions (like "-") of similar prefixes.
  34 #if defined(OS_WIN)
  35 // By putting slash last, we can control whether it is treaded as a switch
  36 // value by changing the value of switch_prefix_count to be one less than
  37 // the array size.
  38 const CommandLine::CharType* const kSwitchPrefixes[] = {L"--", L"-", L"/"};
  39 #elif defined(OS_POSIX)
  40 // Unixes don't use slash as a switch.
  41 const CommandLine::CharType* const kSwitchPrefixes[] = {"--", "-"};
  42 #endif
  43 size_t switch_prefix_count = arraysize(kSwitchPrefixes);
  44
  45 size_t GetSwitchPrefixLength(const CommandLine::StringType& string) {
  46   for (size_t i = 0; i < switch_prefix_count; ++i) {
  47     CommandLine::StringType prefix(kSwitchPrefixes[i]);
  48     if (string.compare(0, prefix.length(), prefix) == 0)
  49       return prefix.length();
  50   }
  51   return 0;
  52 }
  53
  54 // Fills in |switch_string| and |switch_value| if |string| is a switch.
  55 // This will preserve the input switch prefix in the output |switch_string|.
  56 bool IsSwitch(const CommandLine::StringType& string,
  57               CommandLine::StringType* switch_string,
  58               CommandLine::StringType* switch_value) {
  59   switch_string->clear();
  60   switch_value->clear();
  61   size_t prefix_length = GetSwitchPrefixLength(string);
  62   if (prefix_length == 0 || prefix_length == string.length())
  63     return false;
  64
  65   const size_t equals_position = string.find(kSwitchValueSeparator);
  66   *switch_string = string.substr(0, equals_position);
  67   if (equals_position != CommandLine::StringType::npos)
  68     *switch_value = string.substr(equals_position + 1);
  69   return true;
  70 }
  71
  72 // Append switches and arguments, keeping switches before arguments.
  73 void AppendSwitchesAndArguments(CommandLine* command_line,
  74                                 const CommandLine::StringVector& argv) {
  75   bool parse_switches = true;
  76   for (size_t i = 1; i < argv.size(); ++i) {
  77     CommandLine::StringType arg = argv[i];
  78     TrimWhitespace(arg, TRIM_ALL, &arg);
  79
  80     CommandLine::StringType switch_string;
  81     CommandLine::StringType switch_value;
  82     parse_switches &= (arg != kSwitchTerminator);
  83     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
  84 #if defined(OS_WIN)
  85       command_line->AppendSwitchNative(UTF16ToASCII(switch_string),
  86                                        switch_value);
  87 #elif defined(OS_POSIX)
  88       command_line->AppendSwitchNative(switch_string, switch_value);
  89 #endif
  90     } else {
  91       command_line->AppendArgNative(arg);
  92     }
  93   }
  94 }
  95
  96 #if defined(OS_WIN)
  97 // Quote a string as necessary for CommandLineToArgvW compatiblity *on Windows*.
  98 string16 QuoteForCommandLineToArgvW(const string16& arg,
  99                                     bool quote_placeholders) {
 100   // We follow the quoting rules of CommandLineToArgvW.
 101   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
 102   string16 quotable_chars(L" \\\"");
 103   // We may also be required to quote '%', which is commonly used in a command
 104   // line as a placeholder. (It may be substituted for a string with spaces.)
 105   if (quote_placeholders)
 106     quotable_chars.push_back(L'%');
 107   if (arg.find_first_of(quotable_chars) == string16::npos) {
 108     // No quoting necessary.
 109     return arg;
 110   }
 111
 112   string16 out;
 113   out.push_back(L'"');
 114   for (size_t i = 0; i < arg.size(); ++i) {
 115     if (arg[i] == '\\') {
 116       // Find the extent of this run of backslashes.
 117       size_t start = i, end = start + 1;
 118       for (; end < arg.size() && arg[end] == '\\'; ++end) {}
 119       size_t backslash_count = end - start;
 120
 121       // Backslashes are escapes only if the run is followed by a double quote.
 122       // Since we also will end the string with a double quote, we escape for
 123       // either a double quote or the end of the string.
 124       if (end == arg.size() || arg[end] == '"') {
 125         // To quote, we need to output 2x as many backslashes.
 126         backslash_count *= 2;
 127       }
 128       for (size_t j = 0; j < backslash_count; ++j)
 129         out.push_back('\\');
 130
 131       // Advance i to one before the end to balance i++ in loop.
 132       i = end - 1;
 133     } else if (arg[i] == '"') {
 134       out.push_back('\\');
 135       out.push_back('"');
 136     } else {
 137       out.push_back(arg[i]);
 138     }
 139   }
 140   out.push_back('"');
 141
 142   return out;
 143 }
 144 #endif
 145
 146 }  // namespace
 147
 148 CommandLine::CommandLine(NoProgram no_program)
 149     : argv_(1),
 150       begin_args_(1) {
 151 }
 152
 153 CommandLine::CommandLine(const FilePath& program)
 154     : argv_(1),
 155       begin_args_(1) {
 156   SetProgram(program);
 157 }
 158
 159 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
 160     : argv_(1),
 161       begin_args_(1) {
 162   InitFromArgv(argc, argv);
 163 }
 164
 165 CommandLine::CommandLine(const StringVector& argv)
 166     : argv_(1),
 167       begin_args_(1) {
 168   InitFromArgv(argv);
 169 }
 170
 171 CommandLine::CommandLine(const CommandLine& other)
 172     : argv_(other.argv_),
 173       switches_(other.switches_),
 174       begin_args_(other.begin_args_) {
 175   ResetStringPieces();
 176 }
 177
 178 CommandLine& CommandLine::operator=(const CommandLine& other) {
 179   argv_ = other.argv_;
 180   switches_ = other.switches_;
 181   begin_args_ = other.begin_args_;
 182   ResetStringPieces();
 183   return *this;
 184 }
 185
 186 CommandLine::~CommandLine() {
 187 }
 188
 189 #if defined(OS_WIN)
 190 // static
 191 void CommandLine::set_slash_is_not_a_switch() {
 192   // The last switch prefix should be slash, so adjust the size to skip it.
 193   DCHECK_EQ(wcscmp(kSwitchPrefixes[arraysize(kSwitchPrefixes) - 1], L"/"), 0);
 194   switch_prefix_count = arraysize(kSwitchPrefixes) - 1;
 195 }
 196 #endif
 197
 198 // static
 199 bool CommandLine::Init(int argc, const char* const* argv) {
 200   if (current_process_commandline_) {
 201     // If this is intentional, Reset() must be called first. If we are using
 202     // the shared build mode, we have to share a single object across multiple
 203     // shared libraries.
 204     return false;
 205   }
 206
 207   current_process_commandline_ = new CommandLine(NO_PROGRAM);
 208 #if defined(OS_WIN)
 209   current_process_commandline_->ParseFromString(::GetCommandLineW());
 210 #elif defined(OS_POSIX)
 211   current_process_commandline_->InitFromArgv(argc, argv);
 212 #endif
 213
 214   return true;
 215 }
 216
 217 // static
 218 void CommandLine::Reset() {
 219   DCHECK(current_process_commandline_);
 220   delete current_process_commandline_;
 221   current_process_commandline_ = NULL;
 222 }
 223
 224 // static
 225 CommandLine* CommandLine::ForCurrentProcess() {
 226   DCHECK(current_process_commandline_);
 227   return current_process_commandline_;
 228 }
 229
 230 // static
 231 bool CommandLine::InitializedForCurrentProcess() {
 232   return !!current_process_commandline_;
 233 }
 234
 235 #if defined(OS_WIN)
 236 // static
 237 CommandLine CommandLine::FromString(const string16& command_line) {
 238   CommandLine cmd(NO_PROGRAM);
 239   cmd.ParseFromString(command_line);
 240   return cmd;
 241 }
 242 #endif
 243
 244 void CommandLine::InitFromArgv(int argc,
 245                                const CommandLine::CharType* const* argv) {
 246   StringVector new_argv;
 247   for (int i = 0; i < argc; ++i)
 248     new_argv.push_back(argv[i]);
 249   InitFromArgv(new_argv);
 250 }
 251
 252 void CommandLine::InitFromArgv(const StringVector& argv) {
 253   argv_ = StringVector(1);
 254   switches_.clear();
 255   switches_by_stringpiece_.clear();
 256   begin_args_ = 1;
 257   SetProgram(argv.empty() ? FilePath() : FilePath(argv[0]));
 258   AppendSwitchesAndArguments(this, argv);
 259 }
 260
 261 FilePath CommandLine::GetProgram() const {
 262   return FilePath(argv_[0]);
 263 }
 264
 265 void CommandLine::SetProgram(const FilePath& program) {
 266   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
 267 }
 268
 269 bool CommandLine::HasSwitch(const base::StringPiece& switch_string) const {
 270   DCHECK_EQ(StringToLowerASCII(switch_string.as_string()), switch_string);
 271   return switches_by_stringpiece_.find(switch_string) !=
 272          switches_by_stringpiece_.end();
 273 }
 274
 275 bool CommandLine::HasSwitch(const char switch_constant[]) const {
 276   return HasSwitch(base::StringPiece(switch_constant));
 277 }
 278
 279 std::string CommandLine::GetSwitchValueASCII(
 280     const base::StringPiece& switch_string) const {
 281   StringType value = GetSwitchValueNative(switch_string);
 282   if (!IsStringASCII(value)) {
 283     DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
 284     return std::string();
 285   }
 286 #if defined(OS_WIN)
 287   return UTF16ToASCII(value);
 288 #else
 289   return value;
 290 #endif
 291 }
 292
 293 FilePath CommandLine::GetSwitchValuePath(
 294     const base::StringPiece& switch_string) const {
 295   return FilePath(GetSwitchValueNative(switch_string));
 296 }
 297
 298 CommandLine::StringType CommandLine::GetSwitchValueNative(
 299     const base::StringPiece& switch_string) const {
 300   DCHECK_EQ(StringToLowerASCII(switch_string.as_string()), switch_string);
 301   auto result = switches_by_stringpiece_.find(switch_string);
 302   return result == switches_by_stringpiece_.end() ? StringType()
 303                                                   : *(result->second);
 304 }
 305
 306 void CommandLine::AppendSwitch(const std::string& switch_string) {
 307   AppendSwitchNative(switch_string, StringType());
 308 }
 309
 310 void CommandLine::AppendSwitchPath(const std::string& switch_string,
 311                                    const FilePath& path) {
 312   AppendSwitchNative(switch_string, path.value());
 313 }
 314
 315 void CommandLine::AppendSwitchNative(const std::string& switch_string,
 316                                      const CommandLine::StringType& value) {
 317 #if defined(OS_WIN)
 318   const std::string switch_key = StringToLowerASCII(switch_string);
 319   StringType combined_switch_string(ASCIIToUTF16(switch_key));
 320 #elif defined(OS_POSIX)
 321   const std::string& switch_key = switch_string;
 322   StringType combined_switch_string(switch_key);
 323 #endif
 324   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
 325   auto insertion =
 326       switches_.insert(make_pair(switch_key.substr(prefix_length), value));
 327   if (!insertion.second)
 328     insertion.first->second = value;
 329   switches_by_stringpiece_[insertion.first->first] = &(insertion.first->second);
 330   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
 331   if (prefix_length == 0)
 332     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
 333   if (!value.empty())
 334     combined_switch_string += kSwitchValueSeparator + value;
 335   // Append the switch and update the switches/arguments divider |begin_args_|.
 336   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
 337 }
 338
 339 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
 340                                     const std::string& value_string) {
 341 #if defined(OS_WIN)
 342   AppendSwitchNative(switch_string, ASCIIToUTF16(value_string));
 343 #elif defined(OS_POSIX)
 344   AppendSwitchNative(switch_string, value_string);
 345 #endif
 346 }
 347
 348 void CommandLine::CopySwitchesFrom(const CommandLine& source,
 349                                    const char* const switches[],
 350                                    size_t count) {
 351   for (size_t i = 0; i < count; ++i) {
 352     if (source.HasSwitch(switches[i]))
 353       AppendSwitchNative(switches[i], source.GetSwitchValueNative(switches[i]));
 354   }
 355 }
 356
 357 CommandLine::StringVector CommandLine::GetArgs() const {
 358   // Gather all arguments after the last switch (may include kSwitchTerminator).
 359   StringVector args(argv_.begin() + begin_args_, argv_.end());
 360   // Erase only the first kSwitchTerminator (maybe "--" is a legitimate page?)
 361   StringVector::iterator switch_terminator =
 362       std::find(args.begin(), args.end(), kSwitchTerminator);
 363   if (switch_terminator != args.end())
 364     args.erase(switch_terminator);
 365   return args;
 366 }
 367
 368 void CommandLine::AppendArg(const std::string& value) {
 369 #if defined(OS_WIN)
 370   DCHECK(IsStringUTF8(value));
 371   AppendArgNative(UTF8ToWide(value));
 372 #elif defined(OS_POSIX)
 373   AppendArgNative(value);
 374 #endif
 375 }
 376
 377 void CommandLine::AppendArgPath(const FilePath& path) {
 378   AppendArgNative(path.value());
 379 }
 380
 381 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
 382   argv_.push_back(value);
 383 }
 384
 385 void CommandLine::AppendArguments(const CommandLine& other,
 386                                   bool include_program) {
 387   if (include_program)
 388     SetProgram(other.GetProgram());
 389   AppendSwitchesAndArguments(this, other.argv());
 390 }
 391
 392 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
 393   if (wrapper.empty())
 394     return;
 395   // The wrapper may have embedded arguments (like "gdb --args"). In this case,
 396   // we don't pretend to do anything fancy, we just split on spaces.
 397   StringVector wrapper_argv;
 398   SplitString(wrapper, FILE_PATH_LITERAL(' '), &wrapper_argv);
 399   // Prepend the wrapper and update the switches/arguments |begin_args_|.
 400   argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
 401   begin_args_ += wrapper_argv.size();
 402 }
 403
 404 #if defined(OS_WIN)
 405 void CommandLine::ParseFromString(const string16& command_line) {
 406   string16 command_line_string;
 407   TrimWhitespace(command_line, TRIM_ALL, &command_line_string);
 408   if (command_line_string.empty())
 409     return;
 410
 411   int num_args = 0;
 412   wchar_t** args = NULL;
 413   args = ::CommandLineToArgvW(command_line_string.c_str(), &num_args);
 414
 415   DPLOG_IF(FATAL, !args) << "CommandLineToArgvW failed on command line: "
 416                          << UTF16ToUTF8(command_line);
 417   InitFromArgv(num_args, args);
 418   LocalFree(args);
 419 }
 420 #endif
 421
 422 CommandLine::StringType CommandLine::GetCommandLineStringInternal(
 423     bool quote_placeholders) const {
 424   StringType string(argv_[0]);
 425 #if defined(OS_WIN)
 426   string = QuoteForCommandLineToArgvW(string, quote_placeholders);
 427 #endif
 428   StringType params(GetArgumentsStringInternal(quote_placeholders));
 429   if (!params.empty()) {
 430     string.append(StringType(FILE_PATH_LITERAL(" ")));
 431     string.append(params);
 432   }
 433   return string;
 434 }
 435
 436 CommandLine::StringType CommandLine::GetArgumentsStringInternal(
 437     bool quote_placeholders) const {
 438   StringType params;
 439   // Append switches and arguments.
 440   bool parse_switches = true;
 441   for (size_t i = 1; i < argv_.size(); ++i) {
 442     StringType arg = argv_[i];
 443     StringType switch_string;
 444     StringType switch_value;
 445     parse_switches &= arg != kSwitchTerminator;
 446     if (i > 1)
 447       params.append(StringType(FILE_PATH_LITERAL(" ")));
 448     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
 449       params.append(switch_string);
 450       if (!switch_value.empty()) {
 451 #if defined(OS_WIN)
 452         switch_value =
 453             QuoteForCommandLineToArgvW(switch_value, quote_placeholders);
 454 #endif
 455         params.append(kSwitchValueSeparator + switch_value);
 456       }
 457     } else {
 458 #if defined(OS_WIN)
 459       arg = QuoteForCommandLineToArgvW(arg, quote_placeholders);
 460 #endif
 461       params.append(arg);
 462     }
 463   }
 464   return params;
 465 }
 466
 467 void CommandLine::ResetStringPieces() {
 468   switches_by_stringpiece_.clear();
 469   for (const auto& entry : switches_)
 470     switches_by_stringpiece_[entry.first] = &(entry.second);
 471 }
 472
 473 }  // namespace base