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
23using base::FilePath;
24
25CommandLine* CommandLine::current_process_commandline_ = NULL;
26
27namespace {
28const CommandLine::CharType kSwitchTerminator[] = FILE_PATH_LITERAL("--");
29const 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.
37const CommandLine::CharType* const kSwitchPrefixes[] = {L"--", L"-", L"/"};
38#elif defined(OS_POSIX)
39// Unixes don't use slash as a switch.
40const CommandLine::CharType* const kSwitchPrefixes[] = {"--", "-"};
41#endif
42size_t switch_prefix_count = arraysize(kSwitchPrefixes);
43
44size_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|.
55bool 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.
72void 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*.
95std::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*.
106std::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
151CommandLine::CommandLine(NoProgram no_program)
152    : argv_(1),
153      begin_args_(1) {
154}
155
156CommandLine::CommandLine(const FilePath& program)
157    : argv_(1),
158      begin_args_(1) {
159  SetProgram(program);
160}
161
162CommandLine::CommandLine(int argc, const CommandLine::CharType* const* argv)
163    : argv_(1),
164      begin_args_(1) {
165  InitFromArgv(argc, argv);
166}
167
168CommandLine::CommandLine(const StringVector& argv)
169    : argv_(1),
170      begin_args_(1) {
171  InitFromArgv(argv);
172}
173
174CommandLine::~CommandLine() {
175}
176
177#if defined(OS_WIN)
178// static
179void 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
187bool 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
206void CommandLine::Reset() {
207  DCHECK(current_process_commandline_);
208  delete current_process_commandline_;
209  current_process_commandline_ = NULL;
210}
211
212// static
213CommandLine* CommandLine::ForCurrentProcess() {
214  DCHECK(current_process_commandline_);
215  return current_process_commandline_;
216}
217
218// static
219bool CommandLine::InitializedForCurrentProcess() {
220  return !!current_process_commandline_;
221}
222
223#if defined(OS_WIN)
224// static
225CommandLine CommandLine::FromString(const std::wstring& command_line) {
226  CommandLine cmd(NO_PROGRAM);
227  cmd.ParseFromString(command_line);
228  return cmd;
229}
230#endif
231
232void 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
240void 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
248CommandLine::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
261CommandLine::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
291FilePath CommandLine::GetProgram() const {
292  return FilePath(argv_[0]);
293}
294
295void CommandLine::SetProgram(const FilePath& program) {
296  TrimWhitespace(program.value(), TRIM_ALL, &argv_[0]);
297}
298
299bool CommandLine::HasSwitch(const std::string& switch_string) const {
300  return switches_.find(LowerASCIIOnWindows(switch_string)) != switches_.end();
301}
302
303std::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
317FilePath CommandLine::GetSwitchValuePath(
318    const std::string& switch_string) const {
319  return FilePath(GetSwitchValueNative(switch_string));
320}
321
322CommandLine::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
329void CommandLine::AppendSwitch(const std::string& switch_string) {
330  AppendSwitchNative(switch_string, StringType());
331}
332
333void CommandLine::AppendSwitchPath(const std::string& switch_string,
334                                   const FilePath& path) {
335  AppendSwitchNative(switch_string, path.value());
336}
337
338void 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
357void 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
366void 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
375CommandLine::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
386void 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
395void CommandLine::AppendArgPath(const FilePath& path) {
396  AppendArgNative(path.value());
397}
398
399void CommandLine::AppendArgNative(const CommandLine::StringType& value) {
400  argv_.push_back(value);
401}
402
403void CommandLine::AppendArguments(const CommandLine& other,
404                                  bool include_program) {
405  if (include_program)
406    SetProgram(other.GetProgram());
407  AppendSwitchesAndArguments(*this, other.argv());
408}
409
410void 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)
423void 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