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  * 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_s((char *)&(x), sizeof(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 { \
  62         if ((x) != NULL) { \
  63                 memset_s((char *)(x), sizeof(*(x)), 0, sizeof(*(x))); \
  64         } \
  65 } while(0)
  66 #endif
  67
  68 /**
  69  * Zero a structure given a pointer to the structure - no zero check.
  70  */
  71 #ifndef ZERO_STRUCTPN
  72 #define ZERO_STRUCTPN(x) memset_s((char *)(x), sizeof(*(x)), 0, sizeof(*(x)))
  73 #endif
  74
  75 /**
  76  * Zero an array - note that sizeof(array) must work - ie. it must not be a
  77  * pointer.
  78  */
  79 #ifndef ZERO_ARRAY
  80 #define ZERO_ARRAY(x) memset_s((char *)(x), sizeof(x), 0, sizeof(x))
  81 #endif
  82
  83 /**
  84  * Zero a given len of an array
  85  */
  86 #define ZERO_ARRAY_LEN(x, l) memset_s((char *)(x), (l), 0, (l))
  87
  88 /**
  89  * Work out how many elements there are in a static array
  90  */
  91 #ifndef ARRAY_SIZE
  92 #define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
  93 #endif
  94
  95 /**
  96  * Pointer difference macro.
  97  */
  98 #ifndef PTR_DIFF
  99 #define PTR_DIFF(p1,p2) ((ptrdiff_t)(((const char *)(p1)) - (const char *)(p2)))
 100 #endif
 101
 102 #endif /* _SAMBA_MEMORY_H_ */