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