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