libio/test-fputs-unbuffered-full.c

   1 /* Regression test for 20632.
   2    Copyright (C) 2024-2025 Free Software Foundation, Inc.
   3    Copyright The GNU Toolchain Authors.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <support/check.h>
  24 #include <support/xunistd.h>
  25 #include <unistd.h>
  26
  27 #ifndef WIDE
  28 # define TEST_NAME "fputs-unbuffered-full"
  29 # define CHAR char
  30 # define FPUTS fputs
  31 # define TEXT "0123456789ABCDEF"
  32 #else
  33 # include <wchar.h>
  34 # define TEST_NAME "fputws-unbuffered-full"
  35 # define CHAR wchar_t
  36 # define FPUTS fputws
  37 # define TEXT L"0123456789ABCDEF"
  38 #endif /* WIDE */
  39
  40
  41 static int
  42 do_test (void)
  43 {
  44   /* Open an unbuffered stream to /dev/full.  */
  45   FILE *fp = fopen ("/dev/full", "w");
  46   TEST_VERIFY_EXIT (fp != NULL);
  47   int ret = setvbuf (fp, NULL, _IONBF, 0);
  48   TEST_VERIFY_EXIT (ret == 0);
  49
  50   /* Output a long string. */
  51   const int sz = 4096;
  52   CHAR *buff = calloc (sz+1, sizeof *buff);
  53   for (int i=0; i < sz; i++)
  54     buff[i] = (CHAR) 'x';
  55   buff[sz] = (CHAR) '\0';
  56   errno = 0;
  57   ret = FPUTS (buff, fp);
  58   TEST_VERIFY (ret == EOF);
  59   TEST_VERIFY (errno == ENOSPC);
  60   free (buff);
  61
  62   /* Output shorter strings.   */
  63   for (int i=0; i < 1024; i++)
  64     {
  65       errno = 0;
  66       ret = FPUTS (TEXT, fp);
  67       TEST_VERIFY (ret == EOF);
  68       TEST_VERIFY (errno == ENOSPC);
  69
  70       /* Call malloc, triggering a crash if its
  71          function pointers have been overwritten.  */
  72       void *volatile ptr = malloc (1);
  73       free (ptr);
  74     }
  75   return 0;
  76 }
  77
  78 #include <support/test-driver.c>