lib/util/memory.h

   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(x); (x)=NULL;} } while(0)
  32 #endif
  33
  34 /**
  35  * Zero string and free memory if the pointer and zero the pointer.
  36  *
  37  * @note You are explicitly allowed to pass NULL pointers -- they will
  38  * always be ignored.
  39  **/
  40 #define BURN_FREE_STR(x) do { \
  41                                 if ((x) != NULL) { \
  42                                         size_t s = strlen(x); \
  43                                         memset_s((x), s, 0, s); \
  44                                         free(x); (x) = NULL; \
  45                                 } \
  46                         } while(0)
  47
  48 /**
  49  * Zero and free memory if the pointer and zero the pointer.
  50  *
  51  * @note You are explicitly allowed to pass NULL pointers -- they will
  52  * always be ignored.
  53  **/
  54 #define BURN_FREE(x, s) do { \
  55                                 if ((x) != NULL) { \
  56                                         memset_s((x), (s), 0, (s)); \
  57                                         free(x); (x) = NULL; \
  58                                 } \
  59                         } while(0)
  60
  61 /**
  62  * Type-safe version of malloc. Allocated one copy of the
  63  * specified data type.
  64  */
  65 #define malloc_p(type) (type *)malloc(sizeof(type))
  66
  67 /**
  68  * Allocate an array of elements of one data type. Does type-checking.
  69  */
  70 #define malloc_array_p(type, count) (type *)realloc_array(NULL, sizeof(type), count, false)
  71
  72 /**
  73  * Resize an array of elements of one data type. Does type-checking.
  74  */
  75 #define realloc_p(p, type, count) (type *)realloc_array(p, sizeof(type), count, false)
  76
  77 /**
  78  * Zero a structure.
  79  */
  80 #ifndef ZERO_STRUCT
  81 #define ZERO_STRUCT(x) memset_s((char *)&(x), sizeof(x), 0, sizeof(x))
  82 #endif
  83
  84 /**
  85  * Zero a structure given a pointer to the structure.
  86  */
  87 #ifndef ZERO_STRUCTP
  88 #define ZERO_STRUCTP(x) do { \
  89         if ((x) != NULL) { \
  90                 memset_s((char *)(x), sizeof(*(x)), 0, sizeof(*(x))); \
  91         } \
  92 } while(0)
  93 #endif
  94
  95 /**
  96  * Zero a structure given a pointer to the structure - no zero check.
  97  */
  98 #ifndef ZERO_STRUCTPN
  99 #define ZERO_STRUCTPN(x) memset_s((char *)(x), sizeof(*(x)), 0, sizeof(*(x)))
 100 #endif
 101
 102 /**
 103  * Zero an array - note that sizeof(array) must work - ie. it must not be a
 104  * pointer.
 105  */
 106 #ifndef ZERO_ARRAY
 107 #define ZERO_ARRAY(x) memset_s((char *)(x), sizeof(x), 0, sizeof(x))
 108 #endif
 109
 110 /**
 111  * Zero a given len of an array
 112  */
 113 #define ZERO_ARRAY_LEN(x, l) memset_s((char *)(x), (l), 0, (l))
 114
 115 /**
 116  * Work out how many elements there are in a static array
 117  */
 118 #ifndef ARRAY_SIZE
 119 #define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
 120 #endif
 121
 122 /**
 123  * Pointer difference macro.
 124  */
 125 #ifndef PTR_DIFF
 126 #define PTR_DIFF(p1,p2) ((ptrdiff_t)(((const char *)(p1)) - (const char *)(p2)))
 127 #endif
 128
 129 #endif /* _SAMBA_MEMORY_H_ */