xref: /dragonfly/contrib/diffutils/lib/allocator.h (revision 0de61e28)
1 /* Memory allocators such as malloc+free.
2 
3    Copyright (C) 2011-2018 Free Software Foundation, Inc.
4 
5    This program is free software: you can redistribute it and/or modify
6    it under the terms of the GNU General Public License as published by
7    the Free Software Foundation; either version 3 of the License, or
8    (at your option) any later version.
9 
10    This program 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 General Public License for more details.
14 
15    You should have received a copy of the GNU General Public License
16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
17 
18 /* Written by Paul Eggert.  */
19 
20 #ifndef _GL_ALLOCATOR_H
21 #define _GL_ALLOCATOR_H
22 
23 #include <stddef.h>
24 
25 /* An object describing a memory allocator family.  */
26 
27 struct allocator
28 {
29   /* Do not use GCC attributes such as __attribute__ ((malloc)) with
30      the function types pointed at by these members, because these
31      attributes do not work with pointers to functions.  See
32      <https://lists.gnu.org/r/bug-gnulib/2011-04/msg00007.html>.  */
33 
34   /* Call ALLOCATE to allocate memory, like 'malloc'.  On failure ALLOCATE
35      should return NULL, though not necessarily set errno.  When given
36      a zero size it may return NULL even if successful.  */
37   void *(*allocate) (size_t);
38 
39   /* If nonnull, call REALLOCATE to reallocate memory, like 'realloc'.
40      On failure REALLOCATE should return NULL, though not necessarily set
41      errno.  When given a zero size it may return NULL even if
42      successful.  */
43   void *(*reallocate) (void *, size_t);
44 
45   /* Call FREE to free memory, like 'free'.  */
46   void (*free) (void *);
47 
48   /* If nonnull, call DIE (SIZE) if MALLOC (SIZE) or REALLOC (...,
49      SIZE) fails.  DIE should not return.  SIZE should equal SIZE_MAX
50      if size_t overflow was detected while calculating sizes to be
51      passed to MALLOC or REALLOC.  */
52   void (*die) (size_t);
53 };
54 
55 /* An allocator using the stdlib functions and a null DIE function.  */
56 extern struct allocator const stdlib_allocator;
57 
58 #endif /* _GL_ALLOCATOR_H */
59