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Annotation of embedaddon/libiconv/srclib/relocatable.h, revision 1.1.1.3

1.1       misho       1: /* Provide relocatable packages.
1.1.1.3 ! misho       2:    Copyright (C) 2003, 2005, 2008-2019 Free Software Foundation, Inc.
1.1       misho       3:    Written by Bruno Haible <bruno@clisp.org>, 2003.
                      4: 
1.1.1.2   misho       5:    This program is free software: you can redistribute it and/or modify
                      6:    it under the terms of the GNU General Public License as published by
                      7:    the Free Software Foundation; either version 3 of the License, or
                      8:    (at your option) any later version.
1.1       misho       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
1.1.1.2   misho      12:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     13:    GNU General Public License for more details.
1.1       misho      14: 
1.1.1.2   misho      15:    You should have received a copy of the GNU General Public License
1.1.1.3 ! misho      16:    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
1.1       misho      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,
1.1.1.2   misho      47:                               const char *curr_prefix);
1.1       misho      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: 
1.1.1.3 ! misho      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: 
1.1       misho      62: /* Memory management: relocate() potentially allocates memory, because it has
                     63:    to construct a fresh pathname.  If this is a problem because your program
1.1.1.3 ! misho      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.  */
1.1       misho      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,
1.1.1.2   misho      85:                                    const char *orig_installdir,
                     86:                                    const char *curr_pathname);
1.1       misho      87: 
                     88: #else
                     89: 
                     90: /* By default, we use the hardwired pathnames.  */
                     91: #define relocate(pathname) (pathname)
1.1.1.3 ! misho      92: #define relocate2(pathname,allocatedp) (*(allocatedp) = NULL, (pathname))
1.1       misho      93: 
                     94: #endif
                     95: 
                     96: 
                     97: #ifdef __cplusplus
                     98: }
                     99: #endif
                    100: 
                    101: #endif /* _RELOCATABLE_H */