tests/test-perror2.c

   1 /* Test of perror() function.
   2    Copyright (C) 2011-2024 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, see <https://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18
  19 #include <stdio.h>
  20
  21 #include <errno.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24
  25 /* Tell GCC not to warn about myerr being leaked.  */
  26 #if __GNUC__ >= 13
  27 # pragma GCC diagnostic ignored "-Wanalyzer-fd-leak"
  28 #endif
  29
  30 /* This test intentionally parses stderr.  So, we arrange to have fd 10
  31    (outside the range of interesting fd's during the test) set up to
  32    duplicate the original stderr.  */
  33 #define BACKUP_STDERR_FILENO 10
  34 #define ASSERT_STREAM myerr
  35 #include "macros.h"
  36
  37 static FILE *myerr;
  38
  39 #define BASE "test-perror2"
  40
  41 int
  42 main (void)
  43 {
  44   /* We change fd 2 later, so save it in fd 10.  */
  45   if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
  46       || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
  47     return 2;
  48
  49   ASSERT (freopen (BASE ".tmp", "w+", stderr) == stderr);
  50
  51   /* Test that perror does not clobber strerror buffer.  */
  52   {
  53     const char *msg1;
  54     const char *msg2;
  55     const char *msg3;
  56     const char *msg4;
  57     char *str1;
  58     char *str2;
  59     char *str3;
  60     char *str4;
  61
  62     msg1 = strerror (ENOENT);
  63     ASSERT (msg1);
  64     str1 = strdup (msg1);
  65     ASSERT (str1);
  66
  67     msg2 = strerror (ERANGE);
  68     ASSERT (msg2);
  69     str2 = strdup (msg2);
  70     ASSERT (str2);
  71
  72     msg3 = strerror (-4);
  73     ASSERT (msg3);
  74     str3 = strdup (msg3);
  75     ASSERT (str3);
  76
  77     msg4 = strerror (1729576);
  78     ASSERT (msg4);
  79     str4 = strdup (msg4);
  80     ASSERT (str4);
  81
  82     errno = EACCES;
  83     perror ("");
  84     errno = -5;
  85     perror ("");
  86     ASSERT (!ferror (stderr));
  87     ASSERT (STREQ (msg4, str4));
  88
  89     free (str1);
  90     free (str2);
  91     free (str3);
  92     free (str4);
  93   }
  94
  95   /* Test that perror uses the same message as strerror.  */
  96   {
  97     int errs[] = { EACCES, 0, -3, };
  98     int i;
  99     for (i = 0; i < SIZEOF (errs); i++)
 100       {
 101         char buf[256];
 102         const char *err = strerror (errs[i]);
 103
 104         ASSERT (err);
 105         ASSERT (strlen (err) < sizeof buf);
 106         rewind (stderr);
 107         ASSERT (ftruncate (fileno (stderr), 0) == 0);
 108         errno = errs[i];
 109         perror (NULL);
 110         ASSERT (!ferror (stderr));
 111         rewind (stderr);
 112         ASSERT (fgets (buf, sizeof buf, stderr) == buf);
 113         ASSERT (strstr (buf, err));
 114       }
 115   }
 116
 117   /* Test that perror reports write failure.  */
 118   {
 119     ASSERT (freopen (BASE ".tmp", "r", stderr) == stderr);
 120     ASSERT (setvbuf (stderr, NULL, _IONBF, BUFSIZ) == 0);
 121     errno = -1;
 122     ASSERT (!ferror (stderr));
 123     perror (NULL);
 124 #if 0
 125     /* Commented out until cygwin behaves:
 126        https://sourceware.org/ml/newlib/2011/msg00228.html */
 127     ASSERT (errno > 0);
 128     /* Commented out until glibc behaves:
 129        https://sourceware.org/bugzilla/show_bug.cgi?id=12792 */
 130     ASSERT (ferror (stderr));
 131 #endif
 132   }
 133
 134   ASSERT (fclose (stderr) == 0);
 135   ASSERT (remove (BASE ".tmp") == 0);
 136
 137   return test_exit_status;
 138 }