DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (c68fe15a81fc)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

#ifndef mozilla_CmdLineAndEnvUtils_h
#define mozilla_CmdLineAndEnvUtils_h

// NB: This code may be used outside of xul and thus must not depend on XPCOM

#if defined(MOZILLA_INTERNAL_API)
#  include "prenv.h"
#  include "prprf.h"
#  include <string.h>
#elif defined(XP_WIN)
#  include <stdlib.h>
#endif

#if defined(XP_WIN)
#  include "mozilla/UniquePtr.h"
#  include "mozilla/Vector.h"
#  include "mozilla/WinHeaderOnlyUtils.h"

#  include <wchar.h>
#  include <windows.h>
#endif  // defined(XP_WIN)

#include "mozilla/MemoryChecking.h"
#include "mozilla/TypedEnumBits.h"

#include <ctype.h>
#include <stdint.h>

#ifndef NS_NO_XPCOM
#  include "nsIFile.h"
#  include "mozilla/AlreadyAddRefed.h"
#endif

// Undo X11/X.h's definition of None
#undef None

namespace mozilla {

enum ArgResult {
  ARG_NONE = 0,
  ARG_FOUND = 1,
  ARG_BAD = 2  // you wanted a param, but there isn't one
};

template <typename CharT>
inline void RemoveArg(int& argc, CharT** argv) {
  do {
    *argv = *(argv + 1);
    ++argv;
  } while (*argv);

  --argc;
}

namespace internal {

template <typename FuncT, typename CharT>
static inline bool strimatch(FuncT aToLowerFn, const CharT* lowerstr,
                             const CharT* mixedstr) {
  while (*lowerstr) {
    if (!*mixedstr) return false;  // mixedstr is shorter
    if (static_cast<CharT>(aToLowerFn(*mixedstr)) != *lowerstr)
      return false;  // no match

    ++lowerstr;
    ++mixedstr;
  }

  if (*mixedstr) return false;  // lowerstr is shorter

  return true;
}

}  // namespace internal

inline bool strimatch(const char* lowerstr, const char* mixedstr) {
  return internal::strimatch(&tolower, lowerstr, mixedstr);
}

inline bool strimatch(const wchar_t* lowerstr, const wchar_t* mixedstr) {
  return internal::strimatch(&towlower, lowerstr, mixedstr);
}

enum class FlagLiteral { osint, safemode };

template <typename CharT, FlagLiteral Literal>
inline const CharT* GetLiteral();

#define DECLARE_FLAG_LITERAL(enum_name, literal)                        \
  template <>                                                           \
  inline const char* GetLiteral<char, FlagLiteral::enum_name>() {       \
    return literal;                                                     \
  }                                                                     \
                                                                        \
  template <>                                                           \
  inline const wchar_t* GetLiteral<wchar_t, FlagLiteral::enum_name>() { \
    return L##literal;                                                  \
  }

DECLARE_FLAG_LITERAL(osint, "osint")
DECLARE_FLAG_LITERAL(safemode, "safe-mode")

enum class CheckArgFlag : uint32_t {
  None = 0,
  // (1 << 0) Used to be CheckOSInt
  RemoveArg = (1 << 1)  // Remove the argument from the argv array.
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(CheckArgFlag)

/**
 * Check for a commandline flag. If the flag takes a parameter, the
 * parameter is returned in aParam. Flags may be in the form -arg or
 * --arg (or /arg on win32).
 *
 * @param aArgc The argc value.
 * @param aArgv The original argv.
 * @param aArg the parameter to check. Must be lowercase.
 * @param aParam if non-null, the -arg <data> will be stored in this pointer.
 *        This is *not* allocated, but rather a pointer to the argv data.
 * @param aFlags Flags @see CheckArgFlag
 */
template <typename CharT>
inline ArgResult CheckArg(int& aArgc, CharT** aArgv, const CharT* aArg,
                          const CharT** aParam = nullptr,
                          CheckArgFlag aFlags = CheckArgFlag::RemoveArg) {
  MOZ_ASSERT(aArgv && aArg);

  CharT** curarg = aArgv + 1;  // skip argv[0]
  ArgResult ar = ARG_NONE;

  while (*curarg) {
    CharT* arg = curarg[0];

    if (arg[0] == '-'
#if defined(XP_WIN)
        || *arg == '/'
#endif
    ) {
      ++arg;

      if (*arg == '-') {
        ++arg;
      }

      if (strimatch(aArg, arg)) {
        if (aFlags & CheckArgFlag::RemoveArg) {
          RemoveArg(aArgc, curarg);
        } else {
          ++curarg;
        }

        if (!aParam) {
          ar = ARG_FOUND;
          break;
        }

        if (*curarg) {
          if (**curarg == '-'
#if defined(XP_WIN)
              || **curarg == '/'
#endif
          ) {
            return ARG_BAD;
          }

          *aParam = *curarg;

          if (aFlags & CheckArgFlag::RemoveArg) {
            RemoveArg(aArgc, curarg);
          }

          ar = ARG_FOUND;
          break;
        }

        return ARG_BAD;
      }
    }

    ++curarg;
  }

  return ar;
}

template <typename CharT>
inline void EnsureCommandlineSafe(int& aArgc, CharT** aArgv,
                                  const CharT** aAcceptableArgs) {
  // We expect either no -osint, or the full commandline to be:
  // app -osint
  // followed by one of the arguments listed in aAcceptableArgs,
  // followed by one parameter for that arg.
  // If this varies, we abort to avoid abuse of other commandline handlers
  // from apps that do a poor job escaping links they give to the OS.

  const CharT* osintLit = GetLiteral<CharT, FlagLiteral::osint>();

  if (CheckArg(aArgc, aArgv, osintLit, static_cast<const CharT**>(nullptr),
               CheckArgFlag::None) == ARG_FOUND) {
    // There should be 4 items left (app name + -osint + (acceptable arg) +
    // param)
    if (aArgc != 4) {
      exit(127);
    }

    // The first should be osint.
    CharT* arg = aArgv[1];
    if (*arg != '-'
#ifdef XP_WIN
        && *arg != '/'
#endif
    ) {
      exit(127);
    }
    ++arg;
    if (*arg == '-') {
      ++arg;
    }
    if (!strimatch(osintLit, arg)) {
      exit(127);
    }
    // Strip it:
    RemoveArg(aArgc, aArgv + 1);

    // Now only an acceptable argument and a parameter for it should be left:
    arg = aArgv[1];
    if (*arg != '-'
#ifdef XP_WIN
        && *arg != '/'
#endif
    ) {
      exit(127);
    }
    ++arg;
    if (*arg == '-') {
      ++arg;
    }
    bool haveAcceptableArg = false;
    const CharT** acceptableArg = aAcceptableArgs;
    while (*acceptableArg) {
      if (strimatch(*acceptableArg, arg)) {
        haveAcceptableArg = true;
        break;
      }
      acceptableArg++;
    }
    if (!haveAcceptableArg) {
      exit(127);
    }
    // The param that is passed afterwards shouldn't be another switch:
    arg = aArgv[2];
    if (*arg == '-'
#ifdef XP_WIN
        || *arg == '/'
#endif
    ) {
      exit(127);
    }
  }
  // Either no osint, so nothing to do, or we ensured nothing nefarious was
  // passed.
}

#if defined(XP_WIN)

namespace internal {

/**
 * Get the length that the string will take and takes into account the
 * additional length if the string needs to be quoted and if characters need to
 * be escaped.
 */
inline int ArgStrLen(const wchar_t* s) {
  int backslashes = 0;
  int i = wcslen(s);
  bool hasDoubleQuote = wcschr(s, L'"') != nullptr;
  // Only add doublequotes if the string contains a space or a tab
  bool addDoubleQuotes = wcspbrk(s, L" \t") != nullptr;

  if (addDoubleQuotes) {
    i += 2;  // initial and final duoblequote
  }

  if (hasDoubleQuote) {
    while (*s) {
      if (*s == '\\') {
        ++backslashes;
      } else {
        if (*s == '"') {
          // Escape the doublequote and all backslashes preceding the
          // doublequote
          i += backslashes + 1;
        }

        backslashes = 0;
      }

      ++s;
    }
  }

  return i;
}

/**
 * Copy string "s" to string "d", quoting the argument as appropriate and
 * escaping doublequotes along with any backslashes that immediately precede
 * doublequotes.
 * The CRT parses this to retrieve the original argc/argv that we meant,
 * see STDARGV.C in the MSVC CRT sources.
 *
 * @return the end of the string
 */
inline wchar_t* ArgToString(wchar_t* d, const wchar_t* s) {
  int backslashes = 0;
  bool hasDoubleQuote = wcschr(s, L'"') != nullptr;
  // Only add doublequotes if the string contains a space or a tab
  bool addDoubleQuotes = wcspbrk(s, L" \t") != nullptr;

  if (addDoubleQuotes) {
    *d = '"';  // initial doublequote
    ++d;
  }

  if (hasDoubleQuote) {
    int i;
    while (*s) {
      if (*s == '\\') {
        ++backslashes;
      } else {
        if (*s == '"') {
          // Escape the doublequote and all backslashes preceding the
          // doublequote
          for (i = 0; i <= backslashes; ++i) {
            *d = '\\';
            ++d;
          }
        }

        backslashes = 0;
      }

      *d = *s;
      ++d;
      ++s;
    }
  } else {
    wcscpy(d, s);
    d += wcslen(s);
  }

  if (addDoubleQuotes) {
    *d = '"';  // final doublequote
    ++d;
  }

  return d;
}

}  // namespace internal

/**
 * Creates a command line from a list of arguments.
 *
 * @param argc Number of elements in |argv|
 * @param argv Array of arguments
 * @param aArgcExtra Number of elements in |aArgvExtra|
 * @param aArgvExtra Optional array of arguments to be appended to the resulting
 *                   command line after those provided by |argv|.
 */
inline UniquePtr<wchar_t[]> MakeCommandLine(
    int argc, const wchar_t* const* argv, int aArgcExtra = 0,
    const wchar_t* const* aArgvExtra = nullptr) {
  int i;
  int len = 0;

  // The + 1 for each argument reserves space for either a ' ' or the null
  // terminator, depending on the position of the argument.
  for (i = 0; i < argc; ++i) {
    len += internal::ArgStrLen(argv[i]) + 1;
  }

  for (i = 0; i < aArgcExtra; ++i) {
    len += internal::ArgStrLen(aArgvExtra[i]) + 1;
  }

  // Protect against callers that pass 0 arguments
  if (len == 0) {
    len = 1;
  }

  auto s = MakeUnique<wchar_t[]>(len);
  if (!s) {
    return s;
  }

  int totalArgc = argc + aArgcExtra;

  wchar_t* c = s.get();
  for (i = 0; i < argc; ++i) {
    c = internal::ArgToString(c, argv[i]);
    if (i + 1 != totalArgc) {
      *c = ' ';
      ++c;
    }
  }

  for (i = 0; i < aArgcExtra; ++i) {
    c = internal::ArgToString(c, aArgvExtra[i]);
    if (i + 1 != aArgcExtra) {
      *c = ' ';
      ++c;
    }
  }

  *c = '\0';

  return s;
}

inline bool SetArgv0ToFullBinaryPath(wchar_t* aArgv[]) {
  if (!aArgv) {
    return false;
  }

  UniquePtr<wchar_t[]> newArgv_0(GetFullBinaryPath());
  if (!newArgv_0) {
    return false;
  }

  // We intentionally leak newArgv_0 into argv[0]
  aArgv[0] = newArgv_0.release();
  MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(aArgv[0]);
  return true;
}

#endif  // defined(XP_WIN)

// SaveToEnv and EnvHasValue are only available on Windows or when
// MOZILLA_INTERNAL_API is defined
#if defined(MOZILLA_INTERNAL_API) || defined(XP_WIN)

// Save literal putenv string to environment variable.
MOZ_NEVER_INLINE inline void SaveToEnv(const char* aEnvString) {
#  if defined(MOZILLA_INTERNAL_API)
  char* expr = strdup(aEnvString);
  if (expr) {
    PR_SetEnv(expr);
  }

  // We intentionally leak |expr| here since it is required by PR_SetEnv.
  MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(expr);
#  elif defined(XP_WIN)
  // This is the same as the NSPR implementation
  // (Note that we don't need to do a strdup for this case; the CRT makes a
  // copy)
  _putenv(aEnvString);
#  endif
}

inline bool EnvHasValue(const char* aVarName) {
#  if defined(MOZILLA_INTERNAL_API)
  const char* val = PR_GetEnv(aVarName);
  return val && *val;
#  elif defined(XP_WIN)
  // This is the same as the NSPR implementation
  const char* val = getenv(aVarName);
  return val && *val;
#  endif
}

#endif  // end windows/internal_api-only definitions

#ifndef NS_NO_XPCOM
already_AddRefed<nsIFile> GetFileFromEnv(const char* name);
#endif

}  // namespace mozilla

#endif  // mozilla_CmdLineAndEnvUtils_h