/* Provide relocatable packages.

   Copyright (C) 2003 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 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 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 */