tests/test-inttostr.c

   1 /* Test inttostr functions, and incidentally, INT_BUFSIZE_BOUND
   2    Copyright (C) 2010-2024 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 of the License, or
   7    (at your option) 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 /* Written by Jim Meyering.  */
  18
  19 #include <config.h>
  20
  21 #include "inttostr.h"
  22 #include "intprops.h"
  23 #include <inttypes.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #include "macros.h"
  29
  30 #define STREQ(a, b) (strcmp (a, b) == 0)
  31 #define IS_TIGHT(T) (_GL_SIGNED_TYPE_OR_EXPR (T) == TYPE_SIGNED (T))
  32 #define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
  33
  34 /* Verify that an inttostr function works as advertised.
  35    Convert maximum and minimum (per-type, T) values using both snprintf --
  36    with a cast to intmax_t or uintmax_t -- and FN, and compare the
  37    resulting strings.  Use malloc for the inttostr buffer, so that if
  38    we ever exceed the usually-tight INT_BUFSIZE_BOUND, tools like
  39    valgrind will detect the failure. */
  40 #define CK(T, Fn)                                                       \
  41   do                                                                    \
  42     {                                                                   \
  43       char ref[100];                                                    \
  44       char *buf = malloc (INT_BUFSIZE_BOUND (T));                       \
  45       char const *p;                                                    \
  46       ASSERT (buf);                                                     \
  47       *buf = '\0';                                                      \
  48       ASSERT                                                            \
  49         ((TYPE_SIGNED (T)                                               \
  50           ? snprintf (ref, sizeof ref, "%jd", (intmax_t) TYPE_MINIMUM (T)) \
  51           : snprintf (ref, sizeof ref, "%ju", (uintmax_t) TYPE_MINIMUM (T))) \
  52          < sizeof ref);                                                 \
  53       ASSERT (STREQ ((p = Fn (TYPE_MINIMUM (T), buf)), ref));           \
  54       /* Ensure that INT_BUFSIZE_BOUND is tight for signed types.  */   \
  55       ASSERT (! TYPE_SIGNED (T) || (p == buf && *p == '-'));            \
  56       ASSERT                                                            \
  57         ((TYPE_SIGNED (T)                                               \
  58           ? snprintf (ref, sizeof ref, "%jd", (intmax_t) TYPE_MAXIMUM (T)) \
  59           : snprintf (ref, sizeof ref, "%ju", (uintmax_t) TYPE_MAXIMUM (T))) \
  60          < sizeof ref);                                                 \
  61       ASSERT (STREQ ((p = Fn (TYPE_MAXIMUM (T), buf)), ref));           \
  62       /* For unsigned types, the bound is not always tight.  */         \
  63       ASSERT (! IS_TIGHT (T) || TYPE_SIGNED (T)                         \
  64               || (p == buf && ISDIGIT (*p)));                           \
  65       free (buf);                                                       \
  66     }                                                                   \
  67   while (0)
  68
  69 int
  70 main (void)
  71 {
  72   size_t b_size = 2;
  73   char *b = malloc (b_size);
  74   ASSERT (b);
  75
  76   /* Ideally we would rely on the snprintf-posix module, in which case
  77      this guard would not be required, but due to limitations in gnulib's
  78      implementation (see modules/snprintf-posix), we cannot.  */
  79   if (!(snprintf (b, b_size, "%ju", (uintmax_t) 3) == 1
  80         && b[0] == '3' && b[1] == '\0'))
  81     {
  82       /* snprintf doesn't accept %ju; skip this test.  */
  83       free (b);
  84       fputs ("Skipping test: %ju format directive not supported\n", stderr);
  85       return 77;
  86     }
  87
  88   CK (int,          inttostr);
  89   CK (unsigned int, uinttostr);
  90   CK (off_t,        offtostr);
  91   CK (uintmax_t,    umaxtostr);
  92   CK (intmax_t,     imaxtostr);
  93   free (b);
  94   return test_exit_status;
  95 }