1 /* Provide relocatable packages.
2    Copyright (C) 2003 Free Software Foundation, Inc.
3    Written by Bruno Haible <bruno@clisp.org>, 2003.
4 
5    This program is free software; you can redistribute it and/or modify it
6    under the terms of the GNU Library General Public License as published
7    by the Free Software Foundation; either version 2, or (at your option)
8    any later version.
9 
10    This program is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Library General Public License for more details.
14 
15    You should have received a copy of the GNU Library General Public
16    License along with this program; if not, write to the Free Software
17    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
18    USA.  */
19 
20 #ifndef _RELOCATABLE_H
21 #define _RELOCATABLE_H
22 
23 #ifdef __cplusplus
24 extern "C" {
25 #endif
26 
27 
28 /* This can be enabled through the configure --enable-relocatable option.  */
29 #if ENABLE_RELOCATABLE
30 
31 /* When building a DLL, we must export some functions.  Note that because
32    this is a private .h file, we don't need to use __declspec(dllimport)
33    in any case.  */
34 #if defined _MSC_VER && BUILDING_DLL
35 # define RELOCATABLE_DLL_EXPORTED __declspec(dllexport)
36 #else
37 # define RELOCATABLE_DLL_EXPORTED
38 #endif
39 
40 /* Sets the original and the current installation prefix of the package.
41    Relocation simply replaces a pathname starting with the original prefix
42    by the corresponding pathname with the current prefix instead.  Both
43    prefixes should be directory names without trailing slash (i.e. use ""
44    instead of "/").  */
45 extern RELOCATABLE_DLL_EXPORTED void
46        set_relocation_prefix (const char *orig_prefix,
47 			      const char *curr_prefix);
48 
49 /* Returns the pathname, relocated according to the current installation
50    directory.  */
51 extern const char * relocate (const char *pathname);
52 
53 /* Memory management: relocate() leaks memory, because it has to construct
54    a fresh pathname.  If this is a problem because your program calls
55    relocate() frequently, think about caching the result.  */
56 
57 /* Convenience function:
58    Computes the current installation prefix, based on the original
59    installation prefix, the original installation directory of a particular
60    file, and the current pathname of this file.  Returns NULL upon failure.  */
61 extern const char * compute_curr_prefix (const char *orig_installprefix,
62 					 const char *orig_installdir,
63 					 const char *curr_pathname);
64 
65 #else
66 
67 /* By default, we use the hardwired pathnames.  */
68 #define relocate(pathname) (pathname)
69 
70 #endif
71 
72 
73 #ifdef __cplusplus
74 }
75 #endif
76 
77 #endif /* _RELOCATABLE_H */
78