/* Provide relocatable packages.
  Copyright (C) 2003, 2005 Free Software Foundation, Inc.
  Written by Bruno Haible <[email protected]>, 2003.

  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU Library General Public License as published
  by the Free Software Foundation; either version 2, or (at your option)
  any later version.

  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
  Library General Public License for more details.

  You should have received a copy of the GNU Library General Public
  License along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  USA.  */

#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.  */
extern const char * relocate (const char *pathname);

/* Memory management: relocate() leaks memory, because it has to construct
  a fresh pathname.  If this is a problem because your program calls
  relocate() frequently, 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 NULL upon failure.  */
extern const 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)

#endif


#ifdef __cplusplus
}
#endif

#endif /* _RELOCATABLE_H */