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