lib/ialloc.h

   1 /* ialloc.h -- malloc with idx_t rather than size_t
   2
   3    Copyright 2021-2024 Free Software Foundation, Inc.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file 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
  13    GNU Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef IALLOC_H_
  19 #define IALLOC_H_
  20
  21 /* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE, _GL_ATTRIBUTE_COLD,
  22    _GL_ATTRIBUTE_MALLOC.  */
  23 #if !_GL_CONFIG_H_INCLUDED
  24  #error "Please include config.h first."
  25 #endif
  26
  27 #include "idx.h"
  28
  29 #include <errno.h>
  30 #include <stdint.h>
  31 #include <stdlib.h>
  32 #if defined __CHERI_PURE_CAPABILITY__
  33 # include <cheri.h>
  34 #endif
  35
  36 _GL_INLINE_HEADER_BEGIN
  37 #ifndef IALLOC_INLINE
  38 # define IALLOC_INLINE _GL_INLINE
  39 #endif
  40
  41 #ifdef __cplusplus
  42 extern "C" {
  43 #endif
  44
  45 IALLOC_INLINE void * _GL_ATTRIBUTE_COLD
  46 _gl_alloc_nomem (void)
  47 {
  48   errno = ENOMEM;
  49   return NULL;
  50 }
  51
  52 /* imalloc (size) is like malloc (size).
  53    It returns a non-NULL pointer to size bytes of memory.
  54    Upon failure, it returns NULL with errno set.  */
  55 IALLOC_INLINE
  56 _GL_ATTRIBUTE_MALLOC /*_GL_ATTRIBUTE_DEALLOC_FREE*/
  57 void *
  58 imalloc (idx_t s)
  59 {
  60   return s <= SIZE_MAX ? malloc (s) : _gl_alloc_nomem ();
  61 }
  62
  63 /* irealloc (ptr, size) is like realloc (ptr, size).
  64    It returns a non-NULL pointer to size bytes of memory.
  65    Upon failure, it returns NULL with errno set.  */
  66 IALLOC_INLINE
  67 /*_GL_ATTRIBUTE_DEALLOC_FREE*/
  68 void *
  69 irealloc (void *p, idx_t s)
  70 {
  71   if (s <= SIZE_MAX)
  72     {
  73       /* Work around GNU realloc glitch by treating a zero size as if it
  74          were 1, so that returning NULL is equivalent to failing.  */
  75       p = realloc (p, s | !s);
  76 #if defined __CHERI_PURE_CAPABILITY__
  77       if (p != NULL)
  78         p = cheri_bounds_set (p, s);
  79 #endif
  80       return p;
  81     }
  82   else
  83     return _gl_alloc_nomem ();
  84 }
  85
  86 /* icalloc (num, size) is like calloc (num, size).
  87    It returns a non-NULL pointer to num * size bytes of memory.
  88    Upon failure, it returns NULL with errno set.  */
  89 IALLOC_INLINE
  90 _GL_ATTRIBUTE_MALLOC /*_GL_ATTRIBUTE_DEALLOC_FREE*/
  91 void *
  92 icalloc (idx_t n, idx_t s)
  93 {
  94   if (SIZE_MAX < n)
  95     {
  96       if (s != 0)
  97         return _gl_alloc_nomem ();
  98       n = 0;
  99     }
 100   if (SIZE_MAX < s)
 101     {
 102       if (n != 0)
 103         return _gl_alloc_nomem ();
 104       s = 0;
 105     }
 106   return calloc (n, s);
 107 }
 108
 109 /* ireallocarray (ptr, num, size) is like reallocarray (ptr, num, size).
 110    It returns a non-NULL pointer to num * size bytes of memory.
 111    Upon failure, it returns NULL with errno set.  */
 112 IALLOC_INLINE void *
 113 ireallocarray (void *p, idx_t n, idx_t s)
 114 {
 115   if (n <= SIZE_MAX && s <= SIZE_MAX)
 116     {
 117       /* Work around GNU reallocarray glitch by treating a zero size as if
 118          it were 1, so that returning NULL is equivalent to failing.  */
 119       size_t nx = n;
 120       size_t sx = s;
 121       if (n == 0 || s == 0)
 122         nx = sx = 1;
 123       p = reallocarray (p, nx, sx);
 124 #if defined __CHERI_PURE_CAPABILITY__
 125       if (p != NULL && (n == 0 || s == 0))
 126         p = cheri_bounds_set (p, 0);
 127 #endif
 128       return p;
 129     }
 130   else
 131     return _gl_alloc_nomem ();
 132 }
 133
 134 #ifdef __cplusplus
 135 }
 136 #endif
 137
 138 _GL_INLINE_HEADER_END
 139
 140 #endif