/* relocatable.h - Provide relocatable packages. */

/* Copyright (C) 2003, 2005-2009 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2003.

   This file is part of GNU Bash.

   Bash is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   Bash 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 Bash.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef _RELOCATABLE_H
#define _RELOCATABLE_H

/* 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 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

#endif /* _RELOCATABLE_H */
