doc
c_macro.h
Go to the documentation of this file.
1 /*
2  * cynapses libc functions
3  *
4  * Copyright (c) 2008-2013 by Andreas Schneider <asn@cryptomilk.org>
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file c_macro.h
23  *
24  * @brief cynapses libc macro definitions
25  *
26  * @defgroup cynMacroInternals cynapses libc macro definitions
27  * @ingroup cynLibraryAPI
28  *
29  * @{
30  */
31 #ifndef _C_MACRO_H
32 #define _C_MACRO_H
33 
34 #include <stdint.h>
35 #include <string.h>
36 
37 #define INT_TO_POINTER(i) (void *) i
38 #define POINTER_TO_INT(p) *((int *) (p))
39 
40 /** Zero a structure */
41 #define ZERO_STRUCT(x) memset((char *)&(x), 0, sizeof(x))
42 
43 /** Zero a structure given a pointer to the structure */
44 #define ZERO_STRUCTP(x) do { if ((x) != NULL) memset((char *)(x), 0, sizeof(*(x))); } while(0)
45 
46 /** Free memory and zero the pointer */
47 #define SAFE_FREE(x) do { if ((x) != NULL) {free(x); x=NULL;} } while(0)
48 
49 /** Get the smaller value */
50 #define MIN(a,b) ((a) < (b) ? (a) : (b))
51 
52 /** Get the bigger value */
53 #define MAX(a,b) ((a) < (b) ? (b) : (a))
54 
55 /** Get the size of an array */
56 #define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
57 
58 /**
59  * This is a hack to fix warnings. The idea is to use this everywhere that we
60  * get the "discarding const" warning by the compiler. That doesn't actually
61  * fix the real issue, but marks the place and you can search the code for
62  * discard_const.
63  *
64  * Please use this macro only when there is no other way to fix the warning.
65  * We should use this function in only in a very few places.
66  *
67  * Also, please call this via the discard_const_p() macro interface, as that
68  * makes the return type safe.
69  */
70 #define discard_const(ptr) ((void *)((uintptr_t)(ptr)))
71 
72 /**
73  * Type-safe version of discard_const
74  */
75 #define discard_const_p(type, ptr) ((type *)discard_const(ptr))
76 
77 #if (__GNUC__ >= 3)
78 # ifndef likely
79 # define likely(x) __builtin_expect(!!(x), 1)
80 # endif
81 # ifndef unlikely
82 # define unlikely(x) __builtin_expect(!!(x), 0)
83 # endif
84 #else /* __GNUC__ */
85 # ifndef likely
86 # define likely(x) (x)
87 # endif
88 # ifndef unlikely
89 # define unlikely(x) (x)
90 # endif
91 #endif /* __GNUC__ */
92 
93 /**
94  * }@
95  */
96 #endif /* _C_MACRO_H */
97