125 lines
4.9 KiB
C
Executable File
125 lines
4.9 KiB
C
Executable File
/* Provide relocatable packages.
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Copyright (C) 2003, 2005, 2008-2024 Free Software Foundation, Inc.
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Written by Bruno Haible <bruno@clisp.org>, 2003.
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This file is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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This file is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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#ifndef _RELOCATABLE_H
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#define _RELOCATABLE_H
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/* This file uses _GL_ATTRIBUTE_MALLOC, HAVE_VISIBILITY. */
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#if !_GL_CONFIG_H_INCLUDED
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#error "Please include config.h first."
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#endif
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#include <stdlib.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* This can be enabled through the configure --enable-relocatable option. */
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#if ENABLE_RELOCATABLE
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/* When building a shared library, we must export some functions.
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Note that because this is a private .h file, we don't need to use
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__declspec(dllimport) in any case. */
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#if HAVE_VISIBILITY && BUILDING_DLL
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# define RELOCATABLE_SHLIB_EXPORTED __attribute__((__visibility__("default")))
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#elif defined _MSC_VER && BUILDING_DLL
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/* When building with MSVC, exporting a symbol means that the object file
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contains a "linker directive" of the form /EXPORT:symbol. This can be
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inspected through the "objdump -s --section=.drectve FILE" or
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"dumpbin /directives FILE" commands.
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The symbols from this file should be exported if and only if the object
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file gets included in a DLL. Libtool, on Windows platforms, defines
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the C macro DLL_EXPORT (together with PIC) when compiling for a shared
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library (called DLL under Windows) and does not define it when compiling
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an object file meant to be linked statically into some executable. */
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# if defined DLL_EXPORT
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# define RELOCATABLE_SHLIB_EXPORTED __declspec(dllexport)
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# else
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# define RELOCATABLE_SHLIB_EXPORTED
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# endif
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#else
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# define RELOCATABLE_SHLIB_EXPORTED
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#endif
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/* Sets the original and the current installation prefix of the package.
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Relocation simply replaces a pathname starting with the original prefix
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by the corresponding pathname with the current prefix instead. Both
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prefixes should be directory names without trailing slash (i.e. use ""
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instead of "/"). */
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extern RELOCATABLE_SHLIB_EXPORTED void
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set_relocation_prefix (const char *orig_prefix,
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const char *curr_prefix);
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/* Returns the pathname, relocated according to the current installation
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directory.
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The returned string is either PATHNAME unmodified or a freshly allocated
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string that you can free with free() after casting it to 'char *'. */
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extern const char * relocate (const char *pathname);
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/* Returns the pathname, relocated according to the current installation
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directory.
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This function sets *ALLOCATEDP to the allocated memory, or to NULL if
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no memory allocation occurs. So that, after you're done with the return
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value, to reclaim allocated memory, you can do: free (*ALLOCATEDP). */
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extern const char * relocate2 (const char *pathname, char **allocatedp);
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/* Memory management: relocate() potentially allocates memory, because it has
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to construct a fresh pathname. If this is a problem because your program
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calls relocate() frequently or because you want to fix all potential memory
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leaks anyway, you have three options:
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1) Use this idiom:
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const char *pathname = ...;
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const char *rel_pathname = relocate (pathname);
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...
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if (rel_pathname != pathname)
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free ((char *) rel_pathname);
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2) Use this idiom:
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char *allocated;
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const char *rel_pathname = relocate2 (..., &allocated);
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...
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free (allocated);
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3) Think about caching the result. */
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/* Convenience function:
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Computes the current installation prefix, based on the original
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installation prefix, the original installation directory of a particular
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file, and the current pathname of this file.
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Returns it, freshly allocated. Returns NULL upon failure. */
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extern char * compute_curr_prefix (const char *orig_installprefix,
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const char *orig_installdir,
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const char *curr_pathname)
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_GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE;
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#else
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/* By default, we use the hardwired pathnames. */
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#define set_relocation_prefix(orig_prefix, curr_prefix) \
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((void) (orig_prefix), (void) (curr_prefix))
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#define relocate(pathname) (pathname)
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#define relocate2(pathname,allocatedp) (*(allocatedp) = NULL, (pathname))
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#endif
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#ifdef __cplusplus
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}
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#endif
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#endif /* _RELOCATABLE_H */
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