1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
|
/* Provide relocatable packages.
Copyright (C) 2003, 2005, 2008-2017 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2003.
This program is free software: you can redistribute it and/or
modify it under the terms of either:
* the GNU Lesser General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at your
option) any later version.
or
* the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version.
or both in parallel, as here.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
#ifndef _RELOCATABLE_H
#define _RELOCATABLE_H
#ifdef __cplusplus
extern "C" {
#endif
/* This can be enabled through the configure --enable-relocatable option. */
#if ENABLE_RELOCATABLE
/* When building a DLL, we must export some functions. Note that because
this is a private .h file, we don't need to use __declspec(dllimport)
in any case. */
#if HAVE_VISIBILITY && BUILDING_DLL
# define RELOCATABLE_DLL_EXPORTED __attribute__((__visibility__("default")))
#elif defined _MSC_VER && BUILDING_DLL
# define RELOCATABLE_DLL_EXPORTED __declspec(dllexport)
#else
# define RELOCATABLE_DLL_EXPORTED
#endif
/* Sets the original and the current installation prefix of the package.
Relocation simply replaces a pathname starting with the original prefix
by the corresponding pathname with the current prefix instead. Both
prefixes should be directory names without trailing slash (i.e. use ""
instead of "/"). */
extern RELOCATABLE_DLL_EXPORTED void
set_relocation_prefix (const char *orig_prefix,
const char *curr_prefix);
/* Returns the pathname, relocated according to the current installation
directory.
The returned string is either PATHNAME unmodified or a freshly allocated
string that you can free with free() after casting it to 'char *'. */
extern const char * relocate (const char *pathname);
/* Returns the pathname, relocated according to the current installation
directory.
This function sets *ALLOCATEDP to the allocated memory, or to NULL if
no memory allocation occurs. So that, after you're done with the return
value, to reclaim allocated memory, you can do: free (*ALLOCATEDP). */
extern const char * relocate2 (const char *pathname, char **allocatedp);
/* Memory management: relocate() potentially allocates memory, because it has
to construct a fresh pathname. If this is a problem because your program
calls relocate() frequently or because you want to fix all potential memory
leaks anyway, you have three options:
1) Use this idiom:
const char *pathname = ...;
const char *rel_pathname = relocate (pathname);
...
if (rel_pathname != pathname)
free ((char *) rel_pathname);
2) Use this idiom:
char *allocated;
const char *rel_pathname = relocate2 (..., &allocated);
...
free (allocated);
3) Think about caching the result. */
/* Convenience function:
Computes the current installation prefix, based on the original
installation prefix, the original installation directory of a particular
file, and the current pathname of this file.
Returns it, freshly allocated. Returns NULL upon failure. */
extern char * compute_curr_prefix (const char *orig_installprefix,
const char *orig_installdir,
const char *curr_pathname);
#else
/* By default, we use the hardwired pathnames. */
#define relocate(pathname) (pathname)
#define relocate2(pathname,allocatedp) (*(allocatedp) = NULL, (pathname))
#endif
#ifdef __cplusplus
}
#endif
#endif /* _RELOCATABLE_H */
|
