release/src/router/libiconv/lib/relocatable.h

   1 /* Provide relocatable packages.
   2    Copyright (C) 2003, 2005, 2008-2011 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 HAVE_VISIBILITY && BUILDING_DLL
  35 # define RELOCATABLE_DLL_EXPORTED __attribute__((__visibility__("default")))
  36 #elif defined _MSC_VER && BUILDING_DLL
  37 # define RELOCATABLE_DLL_EXPORTED __declspec(dllexport)
  38 #else
  39 # define RELOCATABLE_DLL_EXPORTED
  40 #endif
  41
  42 /* Sets the original and the current installation prefix of the package.
  43    Relocation simply replaces a pathname starting with the original prefix
  44    by the corresponding pathname with the current prefix instead.  Both
  45    prefixes should be directory names without trailing slash (i.e. use ""
  46    instead of "/").  */
  47 extern RELOCATABLE_DLL_EXPORTED void
  48        set_relocation_prefix (const char *orig_prefix,
  49                               const char *curr_prefix);
  50
  51 /* Returns the pathname, relocated according to the current installation
  52    directory.
  53    The returned string is either PATHNAME unmodified or a freshly allocated
  54    string that you can free with free() after casting it to 'char *'.  */
  55 extern const char * relocate (const char *pathname);
  56
  57 /* Memory management: relocate() potentially allocates memory, because it has
  58    to construct a fresh pathname.  If this is a problem because your program
  59    calls relocate() frequently, think about caching the result.  Or free the
  60    return value if it was different from the argument pathname.  */
  61
  62 /* Convenience function:
  63    Computes the current installation prefix, based on the original
  64    installation prefix, the original installation directory of a particular
  65    file, and the current pathname of this file.
  66    Returns it, freshly allocated.  Returns NULL upon failure.  */
  67 extern char * compute_curr_prefix (const char *orig_installprefix,
  68                                    const char *orig_installdir,
  69                                    const char *curr_pathname);
  70
  71 #else
  72
  73 /* By default, we use the hardwired pathnames.  */
  74 #define relocate(pathname) (pathname)
  75
  76 #endif
  77
  78
  79 #ifdef __cplusplus
  80 }
  81 #endif
  82
  83 #endif /* _RELOCATABLE_H */