vcs-svn/compat-util.h

   1 /*
   2  * Licensed under a two-clause BSD-style license.
   3  * See LICENSE for details.
   4  */
   5
   6 #ifndef COMPAT_UTIL_H
   7 #define COMPAT_UTIL_H
   8
   9 #define _POSIX_C_SOURCE 200809L
  10 #define _XOPEN_SOURCE 700
  11 #include <sys/types.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <inttypes.h>
  16 #include <errno.h>
  17
  18 #define error(...) (fprintf(stderr, "error: " __VA_ARGS__), -1)
  19 #define warning(...) (fprintf(stderr, "warning: " __VA_ARGS__), -1)
  20 #define die(...) \
  21         do { \
  22                 fprintf(stderr, "fatal: " __VA_ARGS__); \
  23                 exit(128); \
  24         } while (0)
  25 #define die_errno(...) \
  26         do { \
  27                 int _err = errno; \
  28                 fprintf(stderr, __VA_ARGS__); \
  29                 fprintf(stderr, ": %s", strerror(_err)); \
  30                 exit(128); \
  31         } while (0)
  32
  33 #define maximum_signed_value_of_type(a) \
  34         (INTMAX_MAX >> (8 * (sizeof(intmax_t) - sizeof(a))))
  35 #define signed_add_overflows(a, b) \
  36         ((b) > maximum_signed_value_of_type(a) - (a))
  37 #define unsigned_add_overflows(a, b) ((a) + (b) < (a))
  38
  39 /* rate of growth taken from git. */
  40 static inline void alloc_grow(void **array, size_t nmemb,
  41                                 size_t *alloc, size_t elemsize)
  42 {
  43         const size_t newalloc = (*alloc + 16) * 3 / 2;
  44
  45         if (nmemb <= *alloc)
  46                 return;
  47         *alloc = newalloc < nmemb ? nmemb : newalloc;
  48         *array = realloc(*array, *alloc * elemsize);
  49 }
  50
  51 #define ALLOC_GROW(array, sz, alloc) \
  52         alloc_grow((void **) &array, sz, &alloc, sizeof(*array))
  53
  54 #endif