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      1 // Copyright 2008, Google Inc.
      2 // All rights reserved.
      3 //
      4 // Redistribution and use in source and binary forms, with or without
      5 // modification, are permitted provided that the following conditions are
      6 // met:
      7 //
      8 //     * Redistributions of source code must retain the above copyright
      9 // notice, this list of conditions and the following disclaimer.
     10 //     * Redistributions in binary form must reproduce the above
     11 // copyright notice, this list of conditions and the following disclaimer
     12 // in the documentation and/or other materials provided with the
     13 // distribution.
     14 //     * Neither the name of Google Inc. nor the names of its
     15 // contributors may be used to endorse or promote products derived from
     16 // this software without specific prior written permission.
     17 //
     18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29 //
     30 // Author: wan (at) google.com (Zhanyong Wan)
     31 
     32 #include <gtest/internal/gtest-port.h>
     33 
     34 #include <limits.h>
     35 #include <stdlib.h>
     36 #include <stdio.h>
     37 
     38 #if GTEST_OS_WINDOWS_MOBILE
     39 #include <windows.h>  // For TerminateProcess()
     40 #elif GTEST_OS_WINDOWS
     41 #include <io.h>
     42 #include <sys/stat.h>
     43 #else
     44 #include <unistd.h>
     45 #endif  // GTEST_OS_WINDOWS_MOBILE
     46 
     47 #if GTEST_OS_MAC
     48 #include <mach/mach_init.h>
     49 #include <mach/task.h>
     50 #include <mach/vm_map.h>
     51 #endif  // GTEST_OS_MAC
     52 
     53 #include <gtest/gtest-spi.h>
     54 #include <gtest/gtest-message.h>
     55 #include <gtest/internal/gtest-string.h>
     56 
     57 // Indicates that this translation unit is part of Google Test's
     58 // implementation.  It must come before gtest-internal-inl.h is
     59 // included, or there will be a compiler error.  This trick is to
     60 // prevent a user from accidentally including gtest-internal-inl.h in
     61 // his code.
     62 #define GTEST_IMPLEMENTATION_ 1
     63 #include "src/gtest-internal-inl.h"
     64 #undef GTEST_IMPLEMENTATION_
     65 
     66 namespace testing {
     67 namespace internal {
     68 
     69 #if defined(_MSC_VER) || defined(__BORLANDC__)
     70 // MSVC and C++Builder do not provide a definition of STDERR_FILENO.
     71 const int kStdErrFileno = 2;
     72 #else
     73 const int kStdErrFileno = STDERR_FILENO;
     74 #endif  // _MSC_VER
     75 
     76 #if GTEST_OS_MAC
     77 
     78 // Returns the number of threads running in the process, or 0 to indicate that
     79 // we cannot detect it.
     80 size_t GetThreadCount() {
     81   const task_t task = mach_task_self();
     82   mach_msg_type_number_t thread_count;
     83   thread_act_array_t thread_list;
     84   const kern_return_t status = task_threads(task, &thread_list, &thread_count);
     85   if (status == KERN_SUCCESS) {
     86     // task_threads allocates resources in thread_list and we need to free them
     87     // to avoid leaks.
     88     vm_deallocate(task,
     89                   reinterpret_cast<vm_address_t>(thread_list),
     90                   sizeof(thread_t) * thread_count);
     91     return static_cast<size_t>(thread_count);
     92   } else {
     93     return 0;
     94   }
     95 }
     96 
     97 #else
     98 
     99 size_t GetThreadCount() {
    100   // There's no portable way to detect the number of threads, so we just
    101   // return 0 to indicate that we cannot detect it.
    102   return 0;
    103 }
    104 
    105 #endif  // GTEST_OS_MAC
    106 
    107 #if GTEST_USES_POSIX_RE
    108 
    109 // Implements RE.  Currently only needed for death tests.
    110 
    111 RE::~RE() {
    112   regfree(&partial_regex_);
    113   regfree(&full_regex_);
    114   free(const_cast<char*>(pattern_));
    115 }
    116 
    117 // Returns true iff regular expression re matches the entire str.
    118 bool RE::FullMatch(const char* str, const RE& re) {
    119   if (!re.is_valid_) return false;
    120 
    121   regmatch_t match;
    122   return regexec(&re.full_regex_, str, 1, &match, 0) == 0;
    123 }
    124 
    125 // Returns true iff regular expression re matches a substring of str
    126 // (including str itself).
    127 bool RE::PartialMatch(const char* str, const RE& re) {
    128   if (!re.is_valid_) return false;
    129 
    130   regmatch_t match;
    131   return regexec(&re.partial_regex_, str, 1, &match, 0) == 0;
    132 }
    133 
    134 // Initializes an RE from its string representation.
    135 void RE::Init(const char* regex) {
    136   pattern_ = posix::StrDup(regex);
    137 
    138   // Reserves enough bytes to hold the regular expression used for a
    139   // full match.
    140   const size_t full_regex_len = strlen(regex) + 10;
    141   char* const full_pattern = new char[full_regex_len];
    142 
    143   snprintf(full_pattern, full_regex_len, "^(%s)$", regex);
    144   is_valid_ = regcomp(&full_regex_, full_pattern, REG_EXTENDED) == 0;
    145   // We want to call regcomp(&partial_regex_, ...) even if the
    146   // previous expression returns false.  Otherwise partial_regex_ may
    147   // not be properly initialized can may cause trouble when it's
    148   // freed.
    149   //
    150   // Some implementation of POSIX regex (e.g. on at least some
    151   // versions of Cygwin) doesn't accept the empty string as a valid
    152   // regex.  We change it to an equivalent form "()" to be safe.
    153   const char* const partial_regex = (*regex == '\0') ? "()" : regex;
    154   is_valid_ = (regcomp(&partial_regex_, partial_regex, REG_EXTENDED) == 0)
    155       && is_valid_;
    156   EXPECT_TRUE(is_valid_)
    157       << "Regular expression \"" << regex
    158       << "\" is not a valid POSIX Extended regular expression.";
    159 
    160   delete[] full_pattern;
    161 }
    162 
    163 #elif GTEST_USES_SIMPLE_RE
    164 
    165 // Returns true iff ch appears anywhere in str (excluding the
    166 // terminating '\0' character).
    167 bool IsInSet(char ch, const char* str) {
    168   return ch != '\0' && strchr(str, ch) != NULL;
    169 }
    170 
    171 // Returns true iff ch belongs to the given classification.  Unlike
    172 // similar functions in <ctype.h>, these aren't affected by the
    173 // current locale.
    174 bool IsDigit(char ch) { return '0' <= ch && ch <= '9'; }
    175 bool IsPunct(char ch) {
    176   return IsInSet(ch, "^-!\"#$%&'()*+,./:;<=>?@[\\]_`{|}~");
    177 }
    178 bool IsRepeat(char ch) { return IsInSet(ch, "?*+"); }
    179 bool IsWhiteSpace(char ch) { return IsInSet(ch, " \f\n\r\t\v"); }
    180 bool IsWordChar(char ch) {
    181   return ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') ||
    182       ('0' <= ch && ch <= '9') || ch == '_';
    183 }
    184 
    185 // Returns true iff "\\c" is a supported escape sequence.
    186 bool IsValidEscape(char c) {
    187   return (IsPunct(c) || IsInSet(c, "dDfnrsStvwW"));
    188 }
    189 
    190 // Returns true iff the given atom (specified by escaped and pattern)
    191 // matches ch.  The result is undefined if the atom is invalid.
    192 bool AtomMatchesChar(bool escaped, char pattern_char, char ch) {
    193   if (escaped) {  // "\\p" where p is pattern_char.
    194     switch (pattern_char) {
    195       case 'd': return IsDigit(ch);
    196       case 'D': return !IsDigit(ch);
    197       case 'f': return ch == '\f';
    198       case 'n': return ch == '\n';
    199       case 'r': return ch == '\r';
    200       case 's': return IsWhiteSpace(ch);
    201       case 'S': return !IsWhiteSpace(ch);
    202       case 't': return ch == '\t';
    203       case 'v': return ch == '\v';
    204       case 'w': return IsWordChar(ch);
    205       case 'W': return !IsWordChar(ch);
    206     }
    207     return IsPunct(pattern_char) && pattern_char == ch;
    208   }
    209 
    210   return (pattern_char == '.' && ch != '\n') || pattern_char == ch;
    211 }
    212 
    213 // Helper function used by ValidateRegex() to format error messages.
    214 String FormatRegexSyntaxError(const char* regex, int index) {
    215   return (Message() << "Syntax error at index " << index
    216           << " in simple regular expression \"" << regex << "\": ").GetString();
    217 }
    218 
    219 // Generates non-fatal failures and returns false if regex is invalid;
    220 // otherwise returns true.
    221 bool ValidateRegex(const char* regex) {
    222   if (regex == NULL) {
    223     // TODO(wan (at) google.com): fix the source file location in the
    224     // assertion failures to match where the regex is used in user
    225     // code.
    226     ADD_FAILURE() << "NULL is not a valid simple regular expression.";
    227     return false;
    228   }
    229 
    230   bool is_valid = true;
    231 
    232   // True iff ?, *, or + can follow the previous atom.
    233   bool prev_repeatable = false;
    234   for (int i = 0; regex[i]; i++) {
    235     if (regex[i] == '\\') {  // An escape sequence
    236       i++;
    237       if (regex[i] == '\0') {
    238         ADD_FAILURE() << FormatRegexSyntaxError(regex, i - 1)
    239                       << "'\\' cannot appear at the end.";
    240         return false;
    241       }
    242 
    243       if (!IsValidEscape(regex[i])) {
    244         ADD_FAILURE() << FormatRegexSyntaxError(regex, i - 1)
    245                       << "invalid escape sequence \"\\" << regex[i] << "\".";
    246         is_valid = false;
    247       }
    248       prev_repeatable = true;
    249     } else {  // Not an escape sequence.
    250       const char ch = regex[i];
    251 
    252       if (ch == '^' && i > 0) {
    253         ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
    254                       << "'^' can only appear at the beginning.";
    255         is_valid = false;
    256       } else if (ch == '$' && regex[i + 1] != '\0') {
    257         ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
    258                       << "'$' can only appear at the end.";
    259         is_valid = false;
    260       } else if (IsInSet(ch, "()[]{}|")) {
    261         ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
    262                       << "'" << ch << "' is unsupported.";
    263         is_valid = false;
    264       } else if (IsRepeat(ch) && !prev_repeatable) {
    265         ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
    266                       << "'" << ch << "' can only follow a repeatable token.";
    267         is_valid = false;
    268       }
    269 
    270       prev_repeatable = !IsInSet(ch, "^$?*+");
    271     }
    272   }
    273 
    274   return is_valid;
    275 }
    276 
    277 // Matches a repeated regex atom followed by a valid simple regular
    278 // expression.  The regex atom is defined as c if escaped is false,
    279 // or \c otherwise.  repeat is the repetition meta character (?, *,
    280 // or +).  The behavior is undefined if str contains too many
    281 // characters to be indexable by size_t, in which case the test will
    282 // probably time out anyway.  We are fine with this limitation as
    283 // std::string has it too.
    284 bool MatchRepetitionAndRegexAtHead(
    285     bool escaped, char c, char repeat, const char* regex,
    286     const char* str) {
    287   const size_t min_count = (repeat == '+') ? 1 : 0;
    288   const size_t max_count = (repeat == '?') ? 1 :
    289       static_cast<size_t>(-1) - 1;
    290   // We cannot call numeric_limits::max() as it conflicts with the
    291   // max() macro on Windows.
    292 
    293   for (size_t i = 0; i <= max_count; ++i) {
    294     // We know that the atom matches each of the first i characters in str.
    295     if (i >= min_count && MatchRegexAtHead(regex, str + i)) {
    296       // We have enough matches at the head, and the tail matches too.
    297       // Since we only care about *whether* the pattern matches str
    298       // (as opposed to *how* it matches), there is no need to find a
    299       // greedy match.
    300       return true;
    301     }
    302     if (str[i] == '\0' || !AtomMatchesChar(escaped, c, str[i]))
    303       return false;
    304   }
    305   return false;
    306 }
    307 
    308 // Returns true iff regex matches a prefix of str.  regex must be a
    309 // valid simple regular expression and not start with "^", or the
    310 // result is undefined.
    311 bool MatchRegexAtHead(const char* regex, const char* str) {
    312   if (*regex == '\0')  // An empty regex matches a prefix of anything.
    313     return true;
    314 
    315   // "$" only matches the end of a string.  Note that regex being
    316   // valid guarantees that there's nothing after "$" in it.
    317   if (*regex == '$')
    318     return *str == '\0';
    319 
    320   // Is the first thing in regex an escape sequence?
    321   const bool escaped = *regex == '\\';
    322   if (escaped)
    323     ++regex;
    324   if (IsRepeat(regex[1])) {
    325     // MatchRepetitionAndRegexAtHead() calls MatchRegexAtHead(), so
    326     // here's an indirect recursion.  It terminates as the regex gets
    327     // shorter in each recursion.
    328     return MatchRepetitionAndRegexAtHead(
    329         escaped, regex[0], regex[1], regex + 2, str);
    330   } else {
    331     // regex isn't empty, isn't "$", and doesn't start with a
    332     // repetition.  We match the first atom of regex with the first
    333     // character of str and recurse.
    334     return (*str != '\0') && AtomMatchesChar(escaped, *regex, *str) &&
    335         MatchRegexAtHead(regex + 1, str + 1);
    336   }
    337 }
    338 
    339 // Returns true iff regex matches any substring of str.  regex must be
    340 // a valid simple regular expression, or the result is undefined.
    341 //
    342 // The algorithm is recursive, but the recursion depth doesn't exceed
    343 // the regex length, so we won't need to worry about running out of
    344 // stack space normally.  In rare cases the time complexity can be
    345 // exponential with respect to the regex length + the string length,
    346 // but usually it's must faster (often close to linear).
    347 bool MatchRegexAnywhere(const char* regex, const char* str) {
    348   if (regex == NULL || str == NULL)
    349     return false;
    350 
    351   if (*regex == '^')
    352     return MatchRegexAtHead(regex + 1, str);
    353 
    354   // A successful match can be anywhere in str.
    355   do {
    356     if (MatchRegexAtHead(regex, str))
    357       return true;
    358   } while (*str++ != '\0');
    359   return false;
    360 }
    361 
    362 // Implements the RE class.
    363 
    364 RE::~RE() {
    365   free(const_cast<char*>(pattern_));
    366   free(const_cast<char*>(full_pattern_));
    367 }
    368 
    369 // Returns true iff regular expression re matches the entire str.
    370 bool RE::FullMatch(const char* str, const RE& re) {
    371   return re.is_valid_ && MatchRegexAnywhere(re.full_pattern_, str);
    372 }
    373 
    374 // Returns true iff regular expression re matches a substring of str
    375 // (including str itself).
    376 bool RE::PartialMatch(const char* str, const RE& re) {
    377   return re.is_valid_ && MatchRegexAnywhere(re.pattern_, str);
    378 }
    379 
    380 // Initializes an RE from its string representation.
    381 void RE::Init(const char* regex) {
    382   pattern_ = full_pattern_ = NULL;
    383   if (regex != NULL) {
    384     pattern_ = posix::StrDup(regex);
    385   }
    386 
    387   is_valid_ = ValidateRegex(regex);
    388   if (!is_valid_) {
    389     // No need to calculate the full pattern when the regex is invalid.
    390     return;
    391   }
    392 
    393   const size_t len = strlen(regex);
    394   // Reserves enough bytes to hold the regular expression used for a
    395   // full match: we need space to prepend a '^', append a '$', and
    396   // terminate the string with '\0'.
    397   char* buffer = static_cast<char*>(malloc(len + 3));
    398   full_pattern_ = buffer;
    399 
    400   if (*regex != '^')
    401     *buffer++ = '^';  // Makes sure full_pattern_ starts with '^'.
    402 
    403   // We don't use snprintf or strncpy, as they trigger a warning when
    404   // compiled with VC++ 8.0.
    405   memcpy(buffer, regex, len);
    406   buffer += len;
    407 
    408   if (len == 0 || regex[len - 1] != '$')
    409     *buffer++ = '$';  // Makes sure full_pattern_ ends with '$'.
    410 
    411   *buffer = '\0';
    412 }
    413 
    414 #endif  // GTEST_USES_POSIX_RE
    415 
    416 
    417 GTestLog::GTestLog(GTestLogSeverity severity, const char* file, int line)
    418     : severity_(severity) {
    419   const char* const marker =
    420       severity == GTEST_INFO ?    "[  INFO ]" :
    421       severity == GTEST_WARNING ? "[WARNING]" :
    422       severity == GTEST_ERROR ?   "[ ERROR ]" : "[ FATAL ]";
    423   GetStream() << ::std::endl << marker << " "
    424               << FormatFileLocation(file, line).c_str() << ": ";
    425 }
    426 
    427 // Flushes the buffers and, if severity is GTEST_FATAL, aborts the program.
    428 GTestLog::~GTestLog() {
    429   GetStream() << ::std::endl;
    430   if (severity_ == GTEST_FATAL) {
    431     fflush(stderr);
    432     posix::Abort();
    433   }
    434 }
    435 // Disable Microsoft deprecation warnings for POSIX functions called from
    436 // this class (creat, dup, dup2, and close)
    437 #ifdef _MSC_VER
    438 #pragma warning(push)
    439 #pragma warning(disable: 4996)
    440 #endif  // _MSC_VER
    441 
    442 // Defines the stderr capturer.
    443 
    444 class CapturedStderr {
    445  public:
    446   // The ctor redirects stderr to a temporary file.
    447   CapturedStderr() {
    448 #if GTEST_OS_WINDOWS_MOBILE
    449     // Not supported on Windows CE.
    450     posix::Abort();
    451 #else
    452     uncaptured_fd_ = dup(kStdErrFileno);
    453 
    454 #if GTEST_OS_WINDOWS
    455     char temp_dir_path[MAX_PATH + 1] = { '\0' };  // NOLINT
    456     char temp_file_path[MAX_PATH + 1] = { '\0' };  // NOLINT
    457 
    458     ::GetTempPathA(sizeof(temp_dir_path), temp_dir_path);
    459     ::GetTempFileNameA(temp_dir_path, "gtest_redir", 0, temp_file_path);
    460     const int captured_fd = creat(temp_file_path, _S_IREAD | _S_IWRITE);
    461     filename_ = temp_file_path;
    462 #else
    463     // There's no guarantee that a test has write access to the
    464     // current directory, so we create the temporary file in the /tmp
    465     // directory instead.
    466     char name_template[] = "/tmp/captured_stderr.XXXXXX";
    467     const int captured_fd = mkstemp(name_template);
    468     filename_ = name_template;
    469 #endif  // GTEST_OS_WINDOWS
    470     fflush(NULL);
    471     dup2(captured_fd, kStdErrFileno);
    472     close(captured_fd);
    473 #endif  // GTEST_OS_WINDOWS_MOBILE
    474   }
    475 
    476   ~CapturedStderr() {
    477 #if !GTEST_OS_WINDOWS_MOBILE
    478     remove(filename_.c_str());
    479 #endif  // !GTEST_OS_WINDOWS_MOBILE
    480   }
    481 
    482   // Stops redirecting stderr.
    483   void StopCapture() {
    484 #if !GTEST_OS_WINDOWS_MOBILE
    485     // Restores the original stream.
    486     fflush(NULL);
    487     dup2(uncaptured_fd_, kStdErrFileno);
    488     close(uncaptured_fd_);
    489     uncaptured_fd_ = -1;
    490 #endif  // !GTEST_OS_WINDOWS_MOBILE
    491   }
    492 
    493   // Returns the name of the temporary file holding the stderr output.
    494   // GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we
    495   // can use it here.
    496   ::std::string filename() const { return filename_; }
    497 
    498  private:
    499   int uncaptured_fd_;
    500   ::std::string filename_;
    501 };
    502 
    503 #ifdef _MSC_VER
    504 #pragma warning(pop)
    505 #endif  // _MSC_VER
    506 
    507 static CapturedStderr* g_captured_stderr = NULL;
    508 
    509 // Returns the size (in bytes) of a file.
    510 static size_t GetFileSize(FILE * file) {
    511   fseek(file, 0, SEEK_END);
    512   return static_cast<size_t>(ftell(file));
    513 }
    514 
    515 // Reads the entire content of a file as a string.
    516 static String ReadEntireFile(FILE * file) {
    517   const size_t file_size = GetFileSize(file);
    518   char* const buffer = new char[file_size];
    519 
    520   size_t bytes_last_read = 0;  // # of bytes read in the last fread()
    521   size_t bytes_read = 0;       // # of bytes read so far
    522 
    523   fseek(file, 0, SEEK_SET);
    524 
    525   // Keeps reading the file until we cannot read further or the
    526   // pre-determined file size is reached.
    527   do {
    528     bytes_last_read = fread(buffer+bytes_read, 1, file_size-bytes_read, file);
    529     bytes_read += bytes_last_read;
    530   } while (bytes_last_read > 0 && bytes_read < file_size);
    531 
    532   const String content(buffer, bytes_read);
    533   delete[] buffer;
    534 
    535   return content;
    536 }
    537 
    538 // Starts capturing stderr.
    539 void CaptureStderr() {
    540   if (g_captured_stderr != NULL) {
    541     GTEST_LOG_(FATAL) << "Only one stderr capturer can exist at one time.";
    542   }
    543   g_captured_stderr = new CapturedStderr;
    544 }
    545 
    546 // Stops capturing stderr and returns the captured string.
    547 // GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we can
    548 // use it here.
    549 String GetCapturedStderr() {
    550   g_captured_stderr->StopCapture();
    551 
    552   FILE* const file = posix::FOpen(g_captured_stderr->filename().c_str(), "r");
    553   const String content = ReadEntireFile(file);
    554   posix::FClose(file);
    555 
    556   delete g_captured_stderr;
    557   g_captured_stderr = NULL;
    558 
    559   return content;
    560 }
    561 
    562 #if GTEST_HAS_DEATH_TEST
    563 
    564 // A copy of all command line arguments.  Set by InitGoogleTest().
    565 ::std::vector<String> g_argvs;
    566 
    567 // Returns the command line as a vector of strings.
    568 const ::std::vector<String>& GetArgvs() { return g_argvs; }
    569 
    570 #endif  // GTEST_HAS_DEATH_TEST
    571 
    572 #if GTEST_OS_WINDOWS_MOBILE
    573 namespace posix {
    574 void Abort() {
    575   DebugBreak();
    576   TerminateProcess(GetCurrentProcess(), 1);
    577 }
    578 }  // namespace posix
    579 #endif  // GTEST_OS_WINDOWS_MOBILE
    580 
    581 // Returns the name of the environment variable corresponding to the
    582 // given flag.  For example, FlagToEnvVar("foo") will return
    583 // "GTEST_FOO" in the open-source version.
    584 static String FlagToEnvVar(const char* flag) {
    585   const String full_flag =
    586       (Message() << GTEST_FLAG_PREFIX_ << flag).GetString();
    587 
    588   Message env_var;
    589   for (size_t i = 0; i != full_flag.length(); i++) {
    590     env_var << static_cast<char>(toupper(full_flag.c_str()[i]));
    591   }
    592 
    593   return env_var.GetString();
    594 }
    595 
    596 // Parses 'str' for a 32-bit signed integer.  If successful, writes
    597 // the result to *value and returns true; otherwise leaves *value
    598 // unchanged and returns false.
    599 bool ParseInt32(const Message& src_text, const char* str, Int32* value) {
    600   // Parses the environment variable as a decimal integer.
    601   char* end = NULL;
    602   const long long_value = strtol(str, &end, 10);  // NOLINT
    603 
    604   // Has strtol() consumed all characters in the string?
    605   if (*end != '\0') {
    606     // No - an invalid character was encountered.
    607     Message msg;
    608     msg << "WARNING: " << src_text
    609         << " is expected to be a 32-bit integer, but actually"
    610         << " has value \"" << str << "\".\n";
    611     printf("%s", msg.GetString().c_str());
    612     fflush(stdout);
    613     return false;
    614   }
    615 
    616   // Is the parsed value in the range of an Int32?
    617   const Int32 result = static_cast<Int32>(long_value);
    618   if (long_value == LONG_MAX || long_value == LONG_MIN ||
    619       // The parsed value overflows as a long.  (strtol() returns
    620       // LONG_MAX or LONG_MIN when the input overflows.)
    621       result != long_value
    622       // The parsed value overflows as an Int32.
    623       ) {
    624     Message msg;
    625     msg << "WARNING: " << src_text
    626         << " is expected to be a 32-bit integer, but actually"
    627         << " has value " << str << ", which overflows.\n";
    628     printf("%s", msg.GetString().c_str());
    629     fflush(stdout);
    630     return false;
    631   }
    632 
    633   *value = result;
    634   return true;
    635 }
    636 
    637 // Reads and returns the Boolean environment variable corresponding to
    638 // the given flag; if it's not set, returns default_value.
    639 //
    640 // The value is considered true iff it's not "0".
    641 bool BoolFromGTestEnv(const char* flag, bool default_value) {
    642   const String env_var = FlagToEnvVar(flag);
    643   const char* const string_value = posix::GetEnv(env_var.c_str());
    644   return string_value == NULL ?
    645       default_value : strcmp(string_value, "0") != 0;
    646 }
    647 
    648 // Reads and returns a 32-bit integer stored in the environment
    649 // variable corresponding to the given flag; if it isn't set or
    650 // doesn't represent a valid 32-bit integer, returns default_value.
    651 Int32 Int32FromGTestEnv(const char* flag, Int32 default_value) {
    652   const String env_var = FlagToEnvVar(flag);
    653   const char* const string_value = posix::GetEnv(env_var.c_str());
    654   if (string_value == NULL) {
    655     // The environment variable is not set.
    656     return default_value;
    657   }
    658 
    659   Int32 result = default_value;
    660   if (!ParseInt32(Message() << "Environment variable " << env_var,
    661                   string_value, &result)) {
    662     printf("The default value %s is used.\n",
    663            (Message() << default_value).GetString().c_str());
    664     fflush(stdout);
    665     return default_value;
    666   }
    667 
    668   return result;
    669 }
    670 
    671 // Reads and returns the string environment variable corresponding to
    672 // the given flag; if it's not set, returns default_value.
    673 const char* StringFromGTestEnv(const char* flag, const char* default_value) {
    674   const String env_var = FlagToEnvVar(flag);
    675   const char* const value = posix::GetEnv(env_var.c_str());
    676   return value == NULL ? default_value : value;
    677 }
    678 
    679 }  // namespace internal
    680 }  // namespace testing
    681