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_util.h"
  14 #include "base/strings/string_split.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   size_t prefix_length = GetSwitchPrefixLength(string);
  54   if (prefix_length == 0 || prefix_length == string.length())
  55     return false;
  56
  57   const size_t equals_position = string.find(kSwitchValueSeparator);
  58   *switch_string = string.substr(0, equals_position);
  59   if (equals_position != CommandLine::StringType::npos)
  60     *switch_value = string.substr(equals_position + 1);
  61   return true;
  62 }
  63
  64 // Append switches and arguments, keeping switches before arguments.
  65 void AppendSwitchesAndArguments(CommandLine& command_line,
  66                                 const CommandLine::StringVector& argv) {
  67   bool parse_switches = true;
  68   for (size_t i = 1; i < argv.size(); ++i) {
  69     CommandLine::StringType arg = argv[i];
  70     TrimWhitespace(arg, TRIM_ALL, &arg);
  71
  72     CommandLine::StringType switch_string;
  73     CommandLine::StringType switch_value;
  74     parse_switches &= (arg != kSwitchTerminator);
  75     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
  76 #if defined(OS_WIN)
  77       command_line.AppendSwitchNative(WideToASCII(switch_string), switch_value);
  78 #elif defined(OS_POSIX)
  79       command_line.AppendSwitchNative(switch_string, switch_value);
  80 #endif
  81     } else {
  82       command_line.AppendArgNative(arg);
  83     }
  84   }
  85 }
  86
  87 // Lowercase switches for backwards compatiblity *on Windows*.
  88 std::string LowerASCIIOnWindows(const std::string& string) {
  89 #if defined(OS_WIN)
  90   return StringToLowerASCII(string);
  91 #elif defined(OS_POSIX)
  92   return string;
  93 #endif
  94 }
  95
  96
  97 #if defined(OS_WIN)
  98 // Quote a string as necessary for CommandLineToArgvW compatiblity *on Windows*.
  99 std::wstring QuoteForCommandLineToArgvW(const std::wstring& arg) {
 100   // We follow the quoting rules of CommandLineToArgvW.
 101   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
 102   if (arg.find_first_of(L" \\\"") == std::wstring::npos) {
 103     // No quoting necessary.
 104     return arg;
 105   }
 106
 107   std::wstring out;
 108   out.push_back(L'"');
 109   for (size_t i = 0; i < arg.size(); ++i) {
 110     if (arg[i] == '\\') {
 111       // Find the extent of this run of backslashes.
 112       size_t start = i, end = start + 1;
 113       for (; end < arg.size() && arg[end] == '\\'; ++end)
 114         /* empty */;
 115       size_t backslash_count = end - start;
 116
 117       // Backslashes are escapes only if the run is followed by a double quote.
 118       // Since we also will end the string with a double quote, we escape for
 119       // either a double quote or the end of the string.
 120       if (end == arg.size() || arg[end] == '"') {
 121         // To quote, we need to output 2x as many backslashes.
 122         backslash_count *= 2;
 123       }
 124       for (size_t j = 0; j < backslash_count; ++j)
 125         out.push_back('\\');
 126
 127       // Advance i to one before the end to balance i++ in loop.
 128       i = end - 1;
 129     } else if (arg[i] == '"') {
 130       out.push_back('\\');
 131       out.push_back('"');
 132     } else {
 133       out.push_back(arg[i]);
 134     }
 135   }
 136   out.push_back('"');
 137
 138   return out;
 139 }
 140 #endif
 141
 142 }  // namespace
 143
 144 CommandLine::CommandLine(NoProgram no_program)
 145     : argv_(1),
 146       begin_args_(1) {
 147 }
 148
 149 CommandLine::CommandLine(const FilePath& program)
 150     : argv_(1),
 151       begin_args_(1) {
 152   SetProgram(program);
 153 }
 154
 155 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
 156     : argv_(1),
 157       begin_args_(1) {
 158   InitFromArgv(argc, argv);
 159 }
 160
 161 CommandLine::CommandLine(const StringVector& argv)
 162     : argv_(1),
 163       begin_args_(1) {
 164   InitFromArgv(argv);
 165 }
 166
 167 CommandLine::~CommandLine() {
 168 }
 169
 170 // static
 171 bool CommandLine::Init(int argc, const char* const* argv) {
 172   if (current_process_commandline_) {
 173     // If this is intentional, Reset() must be called first. If we are using
 174     // the shared build mode, we have to share a single object across multiple
 175     // shared libraries.
 176     return false;
 177   }
 178
 179   current_process_commandline_ = new CommandLine(NO_PROGRAM);
 180 #if defined(OS_WIN)
 181   current_process_commandline_->ParseFromString(::GetCommandLineW());
 182 #elif defined(OS_POSIX)
 183   current_process_commandline_->InitFromArgv(argc, argv);
 184 #endif
 185
 186   return true;
 187 }
 188
 189 // static
 190 void CommandLine::Reset() {
 191   DCHECK(current_process_commandline_);
 192   delete current_process_commandline_;
 193   current_process_commandline_ = NULL;
 194 }
 195
 196 // static
 197 CommandLine* CommandLine::ForCurrentProcess() {
 198   DCHECK(current_process_commandline_);
 199   return current_process_commandline_;
 200 }
 201
 202 #if defined(OS_WIN)
 203 // static
 204 CommandLine CommandLine::FromString(const std::wstring& command_line) {
 205   CommandLine cmd(NO_PROGRAM);
 206   cmd.ParseFromString(command_line);
 207   return cmd;
 208 }
 209 #endif
 210
 211 void CommandLine::InitFromArgv(int argc,
 212                                const CommandLine::CharType* const* argv) {
 213   StringVector new_argv;
 214   for (int i = 0; i < argc; ++i)
 215     new_argv.push_back(argv[i]);
 216   InitFromArgv(new_argv);
 217 }
 218
 219 void CommandLine::InitFromArgv(const StringVector& argv) {
 220   argv_ = StringVector(1);
 221   begin_args_ = 1;
 222   SetProgram(argv.empty() ? FilePath() : FilePath(argv[0]));
 223   AppendSwitchesAndArguments(*this, argv);
 224 }
 225
 226 CommandLine::StringType CommandLine::GetCommandLineString() const {
 227   StringType string(argv_[0]);
 228 #if defined(OS_WIN)
 229   string = QuoteForCommandLineToArgvW(string);
 230 #endif
 231   StringType params(GetArgumentsString());
 232   if (!params.empty()) {
 233     string.append(StringType(FILE_PATH_LITERAL(" ")));
 234     string.append(params);
 235   }
 236   return string;
 237 }
 238
 239 CommandLine::StringType CommandLine::GetArgumentsString() const {
 240   StringType params;
 241   // Append switches and arguments.
 242   bool parse_switches = true;
 243   for (size_t i = 1; i < argv_.size(); ++i) {
 244     StringType arg = argv_[i];
 245     StringType switch_string;
 246     StringType switch_value;
 247     parse_switches &= arg != kSwitchTerminator;
 248     if (i > 1)
 249       params.append(StringType(FILE_PATH_LITERAL(" ")));
 250     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
 251       params.append(switch_string);
 252       if (!switch_value.empty()) {
 253 #if defined(OS_WIN)
 254         switch_value = QuoteForCommandLineToArgvW(switch_value);
 255 #endif
 256         params.append(kSwitchValueSeparator + switch_value);
 257       }
 258     }
 259     else {
 260 #if defined(OS_WIN)
 261       arg = QuoteForCommandLineToArgvW(arg);
 262 #endif
 263       params.append(arg);
 264     }
 265   }
 266   return params;
 267 }
 268
 269 FilePath CommandLine::GetProgram() const {
 270   return FilePath(argv_[0]);
 271 }
 272
 273 void CommandLine::SetProgram(const FilePath& program) {
 274   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
 275 }
 276
 277 bool CommandLine::HasSwitch(const std::string& switch_string) const {
 278   return switches_.find(LowerASCIIOnWindows(switch_string)) != switches_.end();
 279 }
 280
 281 std::string CommandLine::GetSwitchValueASCII(
 282     const std::string& switch_string) const {
 283   StringType value = GetSwitchValueNative(switch_string);
 284   if (!IsStringASCII(value)) {
 285     DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
 286     return std::string();
 287   }
 288 #if defined(OS_WIN)
 289   return WideToASCII(value);
 290 #else
 291   return value;
 292 #endif
 293 }
 294
 295 FilePath CommandLine::GetSwitchValuePath(
 296     const std::string& switch_string) const {
 297   return FilePath(GetSwitchValueNative(switch_string));
 298 }
 299
 300 CommandLine::StringType CommandLine::GetSwitchValueNative(
 301     const std::string& switch_string) const {
 302   SwitchMap::const_iterator result = switches_.end();
 303   result = switches_.find(LowerASCIIOnWindows(switch_string));
 304   return result == switches_.end() ? StringType() : result->second;
 305 }
 306
 307 void CommandLine::AppendSwitch(const std::string& switch_string) {
 308   AppendSwitchNative(switch_string, StringType());
 309 }
 310
 311 void CommandLine::AppendSwitchPath(const std::string& switch_string,
 312                                    const FilePath& path) {
 313   AppendSwitchNative(switch_string, path.value());
 314 }
 315
 316 void CommandLine::AppendSwitchNative(const std::string& switch_string,
 317                                      const CommandLine::StringType& value) {
 318   std::string switch_key(LowerASCIIOnWindows(switch_string));
 319 #if defined(OS_WIN)
 320   StringType combined_switch_string(ASCIIToWide(switch_key));
 321 #elif defined(OS_POSIX)
 322   StringType combined_switch_string(switch_string);
 323 #endif
 324   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
 325   switches_[switch_key.substr(prefix_length)] = value;
 326   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
 327   if (prefix_length == 0)
 328     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
 329   if (!value.empty())
 330     combined_switch_string += kSwitchValueSeparator + value;
 331   // Append the switch and update the switches/arguments divider |begin_args_|.
 332   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
 333 }
 334
 335 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
 336                                     const std::string& value_string) {
 337 #if defined(OS_WIN)
 338   AppendSwitchNative(switch_string, ASCIIToWide(value_string));
 339 #elif defined(OS_POSIX)
 340   AppendSwitchNative(switch_string, value_string);
 341 #endif
 342 }
 343
 344 void CommandLine::CopySwitchesFrom(const CommandLine& source,
 345                                    const char* const switches[],
 346                                    size_t count) {
 347   for (size_t i = 0; i < count; ++i) {
 348     if (source.HasSwitch(switches[i]))
 349       AppendSwitchNative(switches[i], source.GetSwitchValueNative(switches[i]));
 350   }
 351 }
 352
 353 CommandLine::StringVector CommandLine::GetArgs() const {
 354   // Gather all arguments after the last switch (may include kSwitchTerminator).
 355   StringVector args(argv_.begin() + begin_args_, argv_.end());
 356   // Erase only the first kSwitchTerminator (maybe "--" is a legitimate page?)
 357   StringVector::iterator switch_terminator =
 358       std::find(args.begin(), args.end(), kSwitchTerminator);
 359   if (switch_terminator != args.end())
 360     args.erase(switch_terminator);
 361   return args;
 362 }
 363
 364 void CommandLine::AppendArg(const std::string& value) {
 365 #if defined(OS_WIN)
 366   DCHECK(IsStringUTF8(value));
 367   AppendArgNative(UTF8ToWide(value));
 368 #elif defined(OS_POSIX)
 369   AppendArgNative(value);
 370 #endif
 371 }
 372
 373 void CommandLine::AppendArgPath(const FilePath& path) {
 374   AppendArgNative(path.value());
 375 }
 376
 377 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
 378   argv_.push_back(value);
 379 }
 380
 381 void CommandLine::AppendArguments(const CommandLine& other,
 382                                   bool include_program) {
 383   if (include_program)
 384     SetProgram(other.GetProgram());
 385   AppendSwitchesAndArguments(*this, other.argv());
 386 }
 387
 388 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
 389   if (wrapper.empty())
 390     return;
 391   // The wrapper may have embedded arguments (like "gdb --args"). In this case,
 392   // we don't pretend to do anything fancy, we just split on spaces.
 393   StringVector wrapper_argv;
 394   base::SplitString(wrapper, FILE_PATH_LITERAL(' '), &wrapper_argv);
 395   // Prepend the wrapper and update the switches/arguments |begin_args_|.
 396   argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
 397   begin_args_ += wrapper_argv.size();
 398 }
 399
 400 #if defined(OS_WIN)
 401 void CommandLine::ParseFromString(const std::wstring& command_line) {
 402   std::wstring command_line_string;
 403   TrimWhitespace(command_line, TRIM_ALL, &command_line_string);
 404   if (command_line_string.empty())
 405     return;
 406
 407   int num_args = 0;
 408   wchar_t** args = NULL;
 409   args = ::CommandLineToArgvW(command_line_string.c_str(), &num_args);
 410
 411   DPLOG_IF(FATAL, !args) << "CommandLineToArgvW failed on command line: "
 412                          << command_line;
 413   InitFromArgv(num_args, args);
 414   LocalFree(args);
 415 }
 416 #endif