1/*
2   Unix SMB/CIFS implementation.
3   Samba utility functions
4   Copyright (C) Andrew Tridgell 1992-1999
5   Copyright (C) Jelmer Vernooij <jelmer@samba.org> 2008
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.
19*/
20
21#ifndef _SAMBA_MEMORY_H_
22#define _SAMBA_MEMORY_H_
23
24#ifndef SAFE_FREE /* Oh no this is also defined in tdb.h */
25/**
26 * Free memory if the pointer and zero the pointer.
27 *
28 * @note You are explicitly allowed to pass NULL pointers -- they will
29 * always be ignored.
30 **/
31#define SAFE_FREE(x) do { if ((x) != NULL) {free(discard_const_p(void *, (x))); (x)=NULL;} } while(0)
32#endif
33
34/**
35 * Type-safe version of malloc. Allocated one copy of the
36 * specified data type.
37 */
38#define malloc_p(type) (type *)malloc(sizeof(type))
39
40/**
41 * Allocate an array of elements of one data type. Does type-checking.
42 */
43#define malloc_array_p(type, count) (type *)realloc_array(NULL, sizeof(type), count, false)
44
45/**
46 * Resize an array of elements of one data type. Does type-checking.
47 */
48#define realloc_p(p, type, count) (type *)realloc_array(p, sizeof(type), count, false)
49
50/**
51 * zero a structure
52 */
53#ifndef ZERO_STRUCT
54#define ZERO_STRUCT(x) memset((char *)&(x), 0, sizeof(x))
55#endif
56
57/**
58 * zero a structure given a pointer to the structure
59 */
60#ifndef ZERO_STRUCTP
61#define ZERO_STRUCTP(x) do { if ((x) != NULL) memset((char *)(x), 0, sizeof(*(x))); } while(0)
62#endif
63
64/**
65 * zero a structure given a pointer to the structure - no zero check
66 */
67#ifndef ZERO_STRUCTPN
68#define ZERO_STRUCTPN(x) memset((char *)(x), 0, sizeof(*(x)))
69#endif
70
71/* zero an array - note that sizeof(array) must work - ie. it must not be a
72   pointer */
73#ifndef ZERO_ARRAY
74#define ZERO_ARRAY(x) memset((char *)(x), 0, sizeof(x))
75#endif
76
77/**
78 * work out how many elements there are in a static array
79 */
80#ifndef ARRAY_SIZE
81#define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
82#endif
83
84/**
85 * pointer difference macro
86 */
87#ifndef PTR_DIFF
88#define PTR_DIFF(p1,p2) ((ptrdiff_t)(((const char *)(p1)) - (const char *)(p2)))
89#endif
90
91/**
92  this is a warning hack. The idea is to use this everywhere that we
93  get the "discarding const" warning from gcc. That doesn't actually
94  fix the problem of course, but it means that when we do get to
95  cleaning them up we can do it by searching the code for
96  discard_const.
97
98  It also means that other error types aren't as swamped by the noise
99  of hundreds of const warnings, so we are more likely to notice when
100  we get new errors.
101
102  Please only add more uses of this macro when you find it
103  _really_ hard to fix const warnings. Our aim is to eventually use
104  this function in only a very few places.
105
106  Also, please call this via the discard_const_p() macro interface, as that
107  makes the return type safe.
108*/
109#ifndef discard_const
110#define discard_const(ptr) ((void *)((uintptr_t)(ptr)))
111#endif
112
113/** Type-safe version of discard_const */
114#ifndef discard_const_p
115#define discard_const_p(type, ptr) ((type *)discard_const(ptr))
116#endif
117
118#endif /* _SAMBA_MEMORY_H_ */
119