1 /* Declarations for common convenience functions.
2    Copyright (C) 2006-2011 Red Hat, Inc.
3    This file is part of elfutils.
4 
5    This file is free software; you can redistribute it and/or modify
6    it under the terms of either
7 
8      * the GNU Lesser General Public License as published by the Free
9        Software Foundation; either version 3 of the License, or (at
10        your option) any later version
11 
12    or
13 
14      * the GNU General Public License as published by the Free
15        Software Foundation; either version 2 of the License, or (at
16        your option) any later version
17 
18    or both in parallel, as here.
19 
20    elfutils is distributed in the hope that it will be useful, but
21    WITHOUT ANY WARRANTY; without even the implied warranty of
22    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
23    General Public License for more details.
24 
25    You should have received copies of the GNU General Public License and
26    the GNU Lesser General Public License along with this program.  If
27    not, see <http://www.gnu.org/licenses/>.  */
28 
29 #ifndef LIB_SYSTEM_H
30 #define LIB_SYSTEM_H	1
31 
32 #include <errno.h>
33 #include <error.h>
34 #include <stddef.h>
35 #include <stdint.h>
36 #include <sys/param.h>
37 #include <endian.h>
38 #include <byteswap.h>
39 #include <unistd.h>
40 
41 #if __BYTE_ORDER == __LITTLE_ENDIAN
42 # define LE32(n)	(n)
43 # define LE64(n)	(n)
44 # define BE32(n)	bswap_32 (n)
45 # define BE64(n)	bswap_64 (n)
46 #elif __BYTE_ORDER == __BIG_ENDIAN
47 # define BE32(n)	(n)
48 # define BE64(n)	(n)
49 # define LE32(n)	bswap_32 (n)
50 # define LE64(n)	bswap_64 (n)
51 #else
52 # error "Unknown byte order"
53 #endif
54 
55 #ifndef MAX
56 #define MAX(m, n) ((m) < (n) ? (n) : (m))
57 #endif
58 
59 #ifndef MIN
60 #define MIN(m, n) ((m) < (n) ? (m) : (n))
61 #endif
62 
63 #if !HAVE_DECL_POWEROF2
64 #define powerof2(x) (((x) & ((x) - 1)) == 0)
65 #endif
66 
67 #if !HAVE_DECL_MEMPCPY
68 #define mempcpy(dest, src, n) \
69     ((void *) ((char *) memcpy (dest, src, n) + (size_t) n))
70 #endif
71 
72 /* A special gettext function we use if the strings are too short.  */
73 #define sgettext(Str) \
74   ({ const char *__res = strrchr (gettext (Str), '|');			      \
75      __res ? __res + 1 : Str; })
76 
77 #define gettext_noop(Str) Str
78 
79 #ifndef TEMP_FAILURE_RETRY
80 #define TEMP_FAILURE_RETRY(expression) \
81   ({ ssize_t __res; \
82      do \
83        __res = expression; \
84      while (__res == -1 && errno == EINTR); \
85      __res; })
86 #endif
87 
88 static inline ssize_t __attribute__ ((unused))
pwrite_retry(int fd,const void * buf,size_t len,off_t off)89 pwrite_retry (int fd, const void *buf, size_t len, off_t off)
90 {
91   ssize_t recvd = 0;
92 
93   do
94     {
95       ssize_t ret = TEMP_FAILURE_RETRY (pwrite (fd, buf + recvd, len - recvd,
96 						off + recvd));
97       if (ret <= 0)
98 	return ret < 0 ? ret : recvd;
99 
100       recvd += ret;
101     }
102   while ((size_t) recvd < len);
103 
104   return recvd;
105 }
106 
107 static inline ssize_t __attribute__ ((unused))
write_retry(int fd,const void * buf,size_t len)108 write_retry (int fd, const void *buf, size_t len)
109 {
110   ssize_t recvd = 0;
111 
112   do
113     {
114       ssize_t ret = TEMP_FAILURE_RETRY (write (fd, buf + recvd, len - recvd));
115       if (ret <= 0)
116 	return ret < 0 ? ret : recvd;
117 
118       recvd += ret;
119     }
120   while ((size_t) recvd < len);
121 
122   return recvd;
123 }
124 
125 static inline ssize_t __attribute__ ((unused))
pread_retry(int fd,void * buf,size_t len,off_t off)126 pread_retry (int fd, void *buf, size_t len, off_t off)
127 {
128   ssize_t recvd = 0;
129 
130   do
131     {
132       ssize_t ret = TEMP_FAILURE_RETRY (pread (fd, buf + recvd, len - recvd,
133 					       off + recvd));
134       if (ret <= 0)
135 	return ret < 0 ? ret : recvd;
136 
137       recvd += ret;
138     }
139   while ((size_t) recvd < len);
140 
141   return recvd;
142 }
143 
144 /* The demangler from libstdc++.  */
145 extern char *__cxa_demangle (const char *mangled_name, char *output_buffer,
146 			     size_t *length, int *status);
147 
148 /* A static assertion.  This will cause a compile-time error if EXPR,
149    which must be a compile-time constant, is false.  */
150 
151 #define eu_static_assert(expr)						\
152   extern int never_defined_just_used_for_checking[(expr) ? 1 : -1]	\
153     __attribute__ ((unused))
154 
155 #endif /* system.h */
156