support/support_test_compare_string.c

   1 /* Check two strings for equality.
   2    Copyright (C) 2018-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <support/check.h>
  23 #include <support/support.h>
  24 #include <support/xmemstream.h>
  25
  26 static void
  27 report_length (const char *what, const char *str, size_t length)
  28 {
  29   if (str == NULL)
  30     printf ("  %s string: NULL\n", what);
  31   else
  32     printf ("  %s string: %zu bytes\n", what, length);
  33 }
  34
  35 static void
  36 report_string (const char *what, const unsigned char *blob,
  37                size_t length, const char *expr)
  38 {
  39   if (length > 0)
  40     {
  41       printf ("  %s (evaluated from %s):\n", what, expr);
  42       char *quoted = support_quote_blob (blob, length);
  43       printf ("      \"%s\"\n", quoted);
  44       free (quoted);
  45
  46       fputs ("     ", stdout);
  47       for (size_t i = 0; i < length; ++i)
  48         printf (" %02X", blob[i]);
  49       putc ('\n', stdout);
  50     }
  51 }
  52
  53 static size_t
  54 string_length_or_zero (const char *str)
  55 {
  56   if (str == NULL)
  57     return 0;
  58   else
  59     return strlen (str);
  60 }
  61
  62 void
  63 support_test_compare_string (const char *left, const char *right,
  64                              const char *file, int line,
  65                              const char *left_expr, const char *right_expr)
  66 {
  67   /* Two null pointers are accepted.  */
  68   if (left == NULL && right == NULL)
  69     return;
  70
  71   size_t left_length = string_length_or_zero (left);
  72   size_t right_length = string_length_or_zero (right);
  73
  74   if (left_length != right_length || left == NULL || right == NULL
  75       || memcmp (left, right, left_length) != 0)
  76     {
  77       support_record_failure ();
  78       printf ("%s:%d: error: string comparison failed\n", file, line);
  79       if (left_length == right_length && right != NULL && left != NULL)
  80         printf ("  string length: %zu bytes\n", left_length);
  81       else
  82         {
  83           report_length ("left", left, left_length);
  84           report_length ("right", right, right_length);
  85         }
  86       report_string ("left", (const unsigned char *) left,
  87                      left_length, left_expr);
  88       report_string ("right", (const unsigned char *) right,
  89                      right_length, right_expr);
  90     }
  91 }