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      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/files/file_path.h"
     11 #include "base/logging.h"
     12 #include "base/macros.h"
     13 #include "base/strings/string_split.h"
     14 #include "base/strings/string_tokenizer.h"
     15 #include "base/strings/string_util.h"
     16 #include "base/strings/utf_string_conversions.h"
     17 #include "build/build_config.h"
     18 
     19 #if defined(OS_WIN)
     20 #include <windows.h>
     21 #include <shellapi.h>
     22 #endif
     23 
     24 namespace base {
     25 
     26 CommandLine* CommandLine::current_process_commandline_ = NULL;
     27 
     28 namespace {
     29 
     30 const CommandLine::CharType kSwitchTerminator[] = FILE_PATH_LITERAL("--");
     31 const CommandLine::CharType kSwitchValueSeparator[] = FILE_PATH_LITERAL("=");
     32 
     33 // Since we use a lazy match, make sure that longer versions (like "--") are
     34 // listed before shorter versions (like "-") of similar prefixes.
     35 #if defined(OS_WIN)
     36 // By putting slash last, we can control whether it is treaded as a switch
     37 // value by changing the value of switch_prefix_count to be one less than
     38 // the array size.
     39 const CommandLine::CharType* const kSwitchPrefixes[] = {L"--", L"-", L"/"};
     40 #elif defined(OS_POSIX)
     41 // Unixes don't use slash as a switch.
     42 const CommandLine::CharType* const kSwitchPrefixes[] = {"--", "-"};
     43 #endif
     44 size_t switch_prefix_count = arraysize(kSwitchPrefixes);
     45 
     46 size_t GetSwitchPrefixLength(const CommandLine::StringType& string) {
     47   for (size_t i = 0; i < switch_prefix_count; ++i) {
     48     CommandLine::StringType prefix(kSwitchPrefixes[i]);
     49     if (string.compare(0, prefix.length(), prefix) == 0)
     50       return prefix.length();
     51   }
     52   return 0;
     53 }
     54 
     55 // Fills in |switch_string| and |switch_value| if |string| is a switch.
     56 // This will preserve the input switch prefix in the output |switch_string|.
     57 bool IsSwitch(const CommandLine::StringType& string,
     58               CommandLine::StringType* switch_string,
     59               CommandLine::StringType* switch_value) {
     60   switch_string->clear();
     61   switch_value->clear();
     62   size_t prefix_length = GetSwitchPrefixLength(string);
     63   if (prefix_length == 0 || prefix_length == string.length())
     64     return false;
     65 
     66   const size_t equals_position = string.find(kSwitchValueSeparator);
     67   *switch_string = string.substr(0, equals_position);
     68   if (equals_position != CommandLine::StringType::npos)
     69     *switch_value = string.substr(equals_position + 1);
     70   return true;
     71 }
     72 
     73 // Append switches and arguments, keeping switches before arguments.
     74 void AppendSwitchesAndArguments(CommandLine* command_line,
     75                                 const CommandLine::StringVector& argv) {
     76   bool parse_switches = true;
     77   for (size_t i = 1; i < argv.size(); ++i) {
     78     CommandLine::StringType arg = argv[i];
     79 #if defined(OS_WIN)
     80     TrimWhitespace(arg, TRIM_ALL, &arg);
     81 #else
     82     TrimWhitespaceASCII(arg, TRIM_ALL, &arg);
     83 #endif
     84 
     85     CommandLine::StringType switch_string;
     86     CommandLine::StringType switch_value;
     87     parse_switches &= (arg != kSwitchTerminator);
     88     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
     89 #if defined(OS_WIN)
     90       command_line->AppendSwitchNative(UTF16ToASCII(switch_string),
     91                                        switch_value);
     92 #elif defined(OS_POSIX)
     93       command_line->AppendSwitchNative(switch_string, switch_value);
     94 #endif
     95     } else {
     96       command_line->AppendArgNative(arg);
     97     }
     98   }
     99 }
    100 
    101 #if defined(OS_WIN)
    102 // Quote a string as necessary for CommandLineToArgvW compatiblity *on Windows*.
    103 string16 QuoteForCommandLineToArgvW(const string16& arg,
    104                                     bool quote_placeholders) {
    105   // We follow the quoting rules of CommandLineToArgvW.
    106   // http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
    107   string16 quotable_chars(L" \\\"");
    108   // We may also be required to quote '%', which is commonly used in a command
    109   // line as a placeholder. (It may be substituted for a string with spaces.)
    110   if (quote_placeholders)
    111     quotable_chars.push_back(L'%');
    112   if (arg.find_first_of(quotable_chars) == string16::npos) {
    113     // No quoting necessary.
    114     return arg;
    115   }
    116 
    117   string16 out;
    118   out.push_back(L'"');
    119   for (size_t i = 0; i < arg.size(); ++i) {
    120     if (arg[i] == '\\') {
    121       // Find the extent of this run of backslashes.
    122       size_t start = i, end = start + 1;
    123       for (; end < arg.size() && arg[end] == '\\'; ++end) {}
    124       size_t backslash_count = end - start;
    125 
    126       // Backslashes are escapes only if the run is followed by a double quote.
    127       // Since we also will end the string with a double quote, we escape for
    128       // either a double quote or the end of the string.
    129       if (end == arg.size() || arg[end] == '"') {
    130         // To quote, we need to output 2x as many backslashes.
    131         backslash_count *= 2;
    132       }
    133       for (size_t j = 0; j < backslash_count; ++j)
    134         out.push_back('\\');
    135 
    136       // Advance i to one before the end to balance i++ in loop.
    137       i = end - 1;
    138     } else if (arg[i] == '"') {
    139       out.push_back('\\');
    140       out.push_back('"');
    141     } else {
    142       out.push_back(arg[i]);
    143     }
    144   }
    145   out.push_back('"');
    146 
    147   return out;
    148 }
    149 #endif
    150 
    151 }  // namespace
    152 
    153 CommandLine::CommandLine(NoProgram no_program)
    154     : argv_(1),
    155       begin_args_(1) {
    156 }
    157 
    158 CommandLine::CommandLine(const FilePath& program)
    159     : argv_(1),
    160       begin_args_(1) {
    161   SetProgram(program);
    162 }
    163 
    164 CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
    165     : argv_(1),
    166       begin_args_(1) {
    167   InitFromArgv(argc, argv);
    168 }
    169 
    170 CommandLine::CommandLine(const StringVector& argv)
    171     : argv_(1),
    172       begin_args_(1) {
    173   InitFromArgv(argv);
    174 }
    175 
    176 CommandLine::CommandLine(const CommandLine& other)
    177     : argv_(other.argv_),
    178       switches_(other.switches_),
    179       begin_args_(other.begin_args_) {
    180   ResetStringPieces();
    181 }
    182 
    183 CommandLine& CommandLine::operator=(const CommandLine& other) {
    184   argv_ = other.argv_;
    185   switches_ = other.switches_;
    186   begin_args_ = other.begin_args_;
    187   ResetStringPieces();
    188   return *this;
    189 }
    190 
    191 CommandLine::~CommandLine() {
    192 }
    193 
    194 #if defined(OS_WIN)
    195 // static
    196 void CommandLine::set_slash_is_not_a_switch() {
    197   // The last switch prefix should be slash, so adjust the size to skip it.
    198   DCHECK_EQ(wcscmp(kSwitchPrefixes[arraysize(kSwitchPrefixes) - 1], L"/"), 0);
    199   switch_prefix_count = arraysize(kSwitchPrefixes) - 1;
    200 }
    201 
    202 // static
    203 void CommandLine::InitUsingArgvForTesting(int argc, const char* const* argv) {
    204   DCHECK(!current_process_commandline_);
    205   current_process_commandline_ = new CommandLine(NO_PROGRAM);
    206   // On Windows we need to convert the command line arguments to string16.
    207   base::CommandLine::StringVector argv_vector;
    208   for (int i = 0; i < argc; ++i)
    209     argv_vector.push_back(UTF8ToUTF16(argv[i]));
    210   current_process_commandline_->InitFromArgv(argv_vector);
    211 }
    212 #endif
    213 
    214 // static
    215 bool CommandLine::Init(int argc, const char* const* argv) {
    216   if (current_process_commandline_) {
    217     // If this is intentional, Reset() must be called first. If we are using
    218     // the shared build mode, we have to share a single object across multiple
    219     // shared libraries.
    220     return false;
    221   }
    222 
    223   current_process_commandline_ = new CommandLine(NO_PROGRAM);
    224 #if defined(OS_WIN)
    225   current_process_commandline_->ParseFromString(::GetCommandLineW());
    226 #elif defined(OS_POSIX)
    227   current_process_commandline_->InitFromArgv(argc, argv);
    228 #endif
    229 
    230   return true;
    231 }
    232 
    233 // static
    234 void CommandLine::Reset() {
    235   DCHECK(current_process_commandline_);
    236   delete current_process_commandline_;
    237   current_process_commandline_ = NULL;
    238 }
    239 
    240 // static
    241 CommandLine* CommandLine::ForCurrentProcess() {
    242   DCHECK(current_process_commandline_);
    243   return current_process_commandline_;
    244 }
    245 
    246 // static
    247 bool CommandLine::InitializedForCurrentProcess() {
    248   return !!current_process_commandline_;
    249 }
    250 
    251 #if defined(OS_WIN)
    252 // static
    253 CommandLine CommandLine::FromString(const string16& command_line) {
    254   CommandLine cmd(NO_PROGRAM);
    255   cmd.ParseFromString(command_line);
    256   return cmd;
    257 }
    258 #endif
    259 
    260 void CommandLine::InitFromArgv(int argc,
    261                                const CommandLine::CharType* const* argv) {
    262   StringVector new_argv;
    263   for (int i = 0; i < argc; ++i)
    264     new_argv.push_back(argv[i]);
    265   InitFromArgv(new_argv);
    266 }
    267 
    268 void CommandLine::InitFromArgv(const StringVector& argv) {
    269   argv_ = StringVector(1);
    270   switches_.clear();
    271   switches_by_stringpiece_.clear();
    272   begin_args_ = 1;
    273   SetProgram(argv.empty() ? FilePath() : FilePath(argv[0]));
    274   AppendSwitchesAndArguments(this, argv);
    275 }
    276 
    277 FilePath CommandLine::GetProgram() const {
    278   return FilePath(argv_[0]);
    279 }
    280 
    281 void CommandLine::SetProgram(const FilePath& program) {
    282 #if defined(OS_WIN)
    283   TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
    284 #else
    285   TrimWhitespaceASCII(program.value(), TRIM_ALL, &argv_[0]);
    286 #endif
    287 }
    288 
    289 bool CommandLine::HasSwitch(const base::StringPiece& switch_string) const {
    290   DCHECK_EQ(ToLowerASCII(switch_string), switch_string);
    291   return switches_by_stringpiece_.find(switch_string) !=
    292          switches_by_stringpiece_.end();
    293 }
    294 
    295 bool CommandLine::HasSwitch(const char switch_constant[]) const {
    296   return HasSwitch(base::StringPiece(switch_constant));
    297 }
    298 
    299 std::string CommandLine::GetSwitchValueASCII(
    300     const base::StringPiece& switch_string) const {
    301   StringType value = GetSwitchValueNative(switch_string);
    302   if (!IsStringASCII(value)) {
    303     DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
    304     return std::string();
    305   }
    306 #if defined(OS_WIN)
    307   return UTF16ToASCII(value);
    308 #else
    309   return value;
    310 #endif
    311 }
    312 
    313 FilePath CommandLine::GetSwitchValuePath(
    314     const base::StringPiece& switch_string) const {
    315   return FilePath(GetSwitchValueNative(switch_string));
    316 }
    317 
    318 CommandLine::StringType CommandLine::GetSwitchValueNative(
    319     const base::StringPiece& switch_string) const {
    320   DCHECK_EQ(ToLowerASCII(switch_string), switch_string);
    321   auto result = switches_by_stringpiece_.find(switch_string);
    322   return result == switches_by_stringpiece_.end() ? StringType()
    323                                                   : *(result->second);
    324 }
    325 
    326 void CommandLine::AppendSwitch(const std::string& switch_string) {
    327   AppendSwitchNative(switch_string, StringType());
    328 }
    329 
    330 void CommandLine::AppendSwitchPath(const std::string& switch_string,
    331                                    const FilePath& path) {
    332   AppendSwitchNative(switch_string, path.value());
    333 }
    334 
    335 void CommandLine::AppendSwitchNative(const std::string& switch_string,
    336                                      const CommandLine::StringType& value) {
    337 #if defined(OS_WIN)
    338   const std::string switch_key = ToLowerASCII(switch_string);
    339   StringType combined_switch_string(ASCIIToUTF16(switch_key));
    340 #elif defined(OS_POSIX)
    341   const std::string& switch_key = switch_string;
    342   StringType combined_switch_string(switch_key);
    343 #endif
    344   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
    345   auto insertion =
    346       switches_.insert(make_pair(switch_key.substr(prefix_length), value));
    347   if (!insertion.second)
    348     insertion.first->second = value;
    349   switches_by_stringpiece_[insertion.first->first] = &(insertion.first->second);
    350   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
    351   if (prefix_length == 0)
    352     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
    353   if (!value.empty())
    354     combined_switch_string += kSwitchValueSeparator + value;
    355   // Append the switch and update the switches/arguments divider |begin_args_|.
    356   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
    357 }
    358 
    359 void CommandLine::AppendSwitchASCII(const std::string& switch_string,
    360                                     const std::string& value_string) {
    361 #if defined(OS_WIN)
    362   AppendSwitchNative(switch_string, ASCIIToUTF16(value_string));
    363 #elif defined(OS_POSIX)
    364   AppendSwitchNative(switch_string, value_string);
    365 #endif
    366 }
    367 
    368 void CommandLine::CopySwitchesFrom(const CommandLine& source,
    369                                    const char* const switches[],
    370                                    size_t count) {
    371   for (size_t i = 0; i < count; ++i) {
    372     if (source.HasSwitch(switches[i]))
    373       AppendSwitchNative(switches[i], source.GetSwitchValueNative(switches[i]));
    374   }
    375 }
    376 
    377 CommandLine::StringVector CommandLine::GetArgs() const {
    378   // Gather all arguments after the last switch (may include kSwitchTerminator).
    379   StringVector args(argv_.begin() + begin_args_, argv_.end());
    380   // Erase only the first kSwitchTerminator (maybe "--" is a legitimate page?)
    381   StringVector::iterator switch_terminator =
    382       std::find(args.begin(), args.end(), kSwitchTerminator);
    383   if (switch_terminator != args.end())
    384     args.erase(switch_terminator);
    385   return args;
    386 }
    387 
    388 void CommandLine::AppendArg(const std::string& value) {
    389 #if defined(OS_WIN)
    390   DCHECK(IsStringUTF8(value));
    391   AppendArgNative(UTF8ToWide(value));
    392 #elif defined(OS_POSIX)
    393   AppendArgNative(value);
    394 #endif
    395 }
    396 
    397 void CommandLine::AppendArgPath(const FilePath& path) {
    398   AppendArgNative(path.value());
    399 }
    400 
    401 void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
    402   argv_.push_back(value);
    403 }
    404 
    405 void CommandLine::AppendArguments(const CommandLine& other,
    406                                   bool include_program) {
    407   if (include_program)
    408     SetProgram(other.GetProgram());
    409   AppendSwitchesAndArguments(this, other.argv());
    410 }
    411 
    412 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
    413   if (wrapper.empty())
    414     return;
    415   // Split the wrapper command based on whitespace (with quoting).
    416   using CommandLineTokenizer =
    417       StringTokenizerT<StringType, StringType::const_iterator>;
    418   CommandLineTokenizer tokenizer(wrapper, FILE_PATH_LITERAL(" "));
    419   tokenizer.set_quote_chars(FILE_PATH_LITERAL("'\""));
    420   std::vector<StringType> wrapper_argv;
    421   while (tokenizer.GetNext())
    422     wrapper_argv.emplace_back(tokenizer.token());
    423 
    424   // Prepend the wrapper and update the switches/arguments |begin_args_|.
    425   argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
    426   begin_args_ += wrapper_argv.size();
    427 }
    428 
    429 #if defined(OS_WIN)
    430 void CommandLine::ParseFromString(const string16& command_line) {
    431   string16 command_line_string;
    432   TrimWhitespace(command_line, TRIM_ALL, &command_line_string);
    433   if (command_line_string.empty())
    434     return;
    435 
    436   int num_args = 0;
    437   wchar_t** args = NULL;
    438   args = ::CommandLineToArgvW(command_line_string.c_str(), &num_args);
    439 
    440   DPLOG_IF(FATAL, !args) << "CommandLineToArgvW failed on command line: "
    441                          << UTF16ToUTF8(command_line);
    442   InitFromArgv(num_args, args);
    443   LocalFree(args);
    444 }
    445 #endif
    446 
    447 CommandLine::StringType CommandLine::GetCommandLineStringInternal(
    448     bool quote_placeholders) const {
    449   StringType string(argv_[0]);
    450 #if defined(OS_WIN)
    451   string = QuoteForCommandLineToArgvW(string, quote_placeholders);
    452 #endif
    453   StringType params(GetArgumentsStringInternal(quote_placeholders));
    454   if (!params.empty()) {
    455     string.append(StringType(FILE_PATH_LITERAL(" ")));
    456     string.append(params);
    457   }
    458   return string;
    459 }
    460 
    461 CommandLine::StringType CommandLine::GetArgumentsStringInternal(
    462     bool quote_placeholders) const {
    463   StringType params;
    464   // Append switches and arguments.
    465   bool parse_switches = true;
    466   for (size_t i = 1; i < argv_.size(); ++i) {
    467     StringType arg = argv_[i];
    468     StringType switch_string;
    469     StringType switch_value;
    470     parse_switches &= arg != kSwitchTerminator;
    471     if (i > 1)
    472       params.append(StringType(FILE_PATH_LITERAL(" ")));
    473     if (parse_switches && IsSwitch(arg, &switch_string, &switch_value)) {
    474       params.append(switch_string);
    475       if (!switch_value.empty()) {
    476 #if defined(OS_WIN)
    477         switch_value =
    478             QuoteForCommandLineToArgvW(switch_value, quote_placeholders);
    479 #endif
    480         params.append(kSwitchValueSeparator + switch_value);
    481       }
    482     } else {
    483 #if defined(OS_WIN)
    484       arg = QuoteForCommandLineToArgvW(arg, quote_placeholders);
    485 #endif
    486       params.append(arg);
    487     }
    488   }
    489   return params;
    490 }
    491 
    492 void CommandLine::ResetStringPieces() {
    493   switches_by_stringpiece_.clear();
    494   for (const auto& entry : switches_)
    495     switches_by_stringpiece_[entry.first] = &(entry.second);
    496 }
    497 
    498 }  // namespace base
    499