Return to relocatable.h CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / libiconv / lib

libiconv 1.16

    1: /* Provide relocatable packages.
    2:    Copyright (C) 2003, 2005, 2008-2017 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 License
   16:    along with this program; if not, see <https://www.gnu.org/licenses/>.  */
   17: 
   18: #ifndef _RELOCATABLE_H
   19: #define _RELOCATABLE_H
   20: 
   21: #ifdef __cplusplus
   22: extern "C" {
   23: #endif
   24: 
   25: 
   26: /* This can be enabled through the configure --enable-relocatable option.  */
   27: #if ENABLE_RELOCATABLE
   28: 
   29: /* When building a DLL, we must export some functions.  Note that because
   30:    this is a private .h file, we don't need to use __declspec(dllimport)
   31:    in any case.  */
   32: #if HAVE_VISIBILITY && BUILDING_DLL
   33: # define RELOCATABLE_DLL_EXPORTED __attribute__((__visibility__("default")))
   34: #elif 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:    The returned string is either PATHNAME unmodified or a freshly allocated
   52:    string that you can free with free() after casting it to 'char *'.  */
   53: extern const char * relocate (const char *pathname);
   54: 
   55: /* Returns the pathname, relocated according to the current installation
   56:    directory.
   57:    This function sets *ALLOCATEDP to the allocated memory, or to NULL if
   58:    no memory allocation occurs.  So that, after you're done with the return
   59:    value, to reclaim allocated memory, you can do: free (*ALLOCATEDP).  */
   60: extern const char * relocate2 (const char *pathname, char **allocatedp);
   61: 
   62: /* Memory management: relocate() potentially allocates memory, because it has
   63:    to construct a fresh pathname.  If this is a problem because your program
   64:    calls relocate() frequently or because you want to fix all potential memory
   65:    leaks anyway, you have three options:
   66:    1) Use this idiom:
   67:         const char *pathname = ...;
   68:         const char *rel_pathname = relocate (pathname);
   69:         ...
   70:         if (rel_pathname != pathname)
   71:           free ((char *) rel_pathname);
   72:    2) Use this idiom:
   73:         char *allocated;
   74:         const char *rel_pathname = relocate2 (..., &allocated);
   75:         ...
   76:         free (allocated);
   77:    3) Think about caching the result.  */
   78: 
   79: /* Convenience function:
   80:    Computes the current installation prefix, based on the original
   81:    installation prefix, the original installation directory of a particular
   82:    file, and the current pathname of this file.
   83:    Returns it, freshly allocated.  Returns NULL upon failure.  */
   84: extern char * compute_curr_prefix (const char *orig_installprefix,
   85:                                    const char *orig_installdir,
   86:                                    const char *curr_pathname);
   87: 
   88: #else
   89: 
   90: /* By default, we use the hardwired pathnames.  */
   91: #define relocate(pathname) (pathname)
   92: #define relocate2(pathname,allocatedp) (*(allocatedp) = NULL, (pathname))
   93: 
   94: #endif
   95: 
   96: 
   97: #ifdef __cplusplus
   98: }
   99: #endif
  100: 
  101: #endif /* _RELOCATABLE_H */