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/* 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. */
/* Tell glibc's <stdio.h> to provide a prototype for getline().
This must come before <config.h> because <config.h> may include
<features.h>, and once <features.h> has been included, it's too late. */
#ifndef _GNU_SOURCE
# define _GNU_SOURCE 1
#endif
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
/* Specification. */
#include "relocatable.h"
#if ENABLE_RELOCATABLE
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef NO_XMALLOC
# define xmalloc malloc
#else
# include "xmalloc.h"
#endif
#if DEPENDS_ON_LIBCHARSET
# include <libcharset.h>
#endif
#if DEPENDS_ON_LIBICONV && HAVE_ICONV
# include <iconv.h>
#endif
#if DEPENDS_ON_LIBINTL && ENABLE_NLS
# include <libintl.h>
#endif
/* Faked cheap 'bool'. */
#undef bool
#undef false
#undef true
#define bool int
#define false 0
#define true 1
/* Pathname support.
ISSLASH(C) tests whether C is a directory separator character.
IS_PATH_WITH_DIR(P) tests whether P contains a directory specification.
*/
#if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__
/* Win32, OS/2, DOS */
# define ISSLASH(C) ((C) == '/' || (C) == '\\')
# define HAS_DEVICE(P) \
((((P)[0] >= 'A' && (P)[0] <= 'Z') || ((P)[0] >= 'a' && (P)[0] <= 'z')) \
&& (P)[1] == ':')
# define IS_PATH_WITH_DIR(P) \
(strchr (P, '/') != NULL || strchr (P, '\\') != NULL || HAS_DEVICE (P))
# define FILESYSTEM_PREFIX_LEN(P) (HAS_DEVICE (P) ? 2 : 0)
#else
/* Unix */
# define ISSLASH(C) ((C) == '/')
# define IS_PATH_WITH_DIR(P) (strchr (P, '/') != NULL)
# define FILESYSTEM_PREFIX_LEN(P) 0
#endif
/* Original installation prefix. */
static char *orig_prefix;
static size_t orig_prefix_len;
/* Current installation prefix. */
static char *curr_prefix;
static size_t curr_prefix_len;
/* These prefixes do not end in a slash. Anything that will be concatenated
to them must start with a slash. */
/* Sets the original and the current installation prefix of this module.
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 "/"). */
static void
set_this_relocation_prefix (const char *orig_prefix_arg,
const char *curr_prefix_arg)
{
if (orig_prefix_arg != NULL && curr_prefix_arg != NULL
/* Optimization: if orig_prefix and curr_prefix are equal, the
relocation is a nop. */
&& strcmp (orig_prefix_arg, curr_prefix_arg) != 0)
{
/* Duplicate the argument strings. */
char *memory;
orig_prefix_len = strlen (orig_prefix_arg);
curr_prefix_len = strlen (curr_prefix_arg);
memory = (char *) xmalloc (orig_prefix_len + 1 + curr_prefix_len + 1);
#ifdef NO_XMALLOC
if (memory != NULL)
#endif
{
memcpy (memory, orig_prefix_arg, orig_prefix_len + 1);
orig_prefix = memory;
memory += orig_prefix_len + 1;
memcpy (memory, curr_prefix_arg, curr_prefix_len + 1);
curr_prefix = memory;
return;
}
}
orig_prefix = NULL;
curr_prefix = NULL;
/* Don't worry about wasted memory here - this function is usually only
called once. */
}
/* 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 "/"). */
void
set_relocation_prefix (const char *orig_prefix_arg, const char *curr_prefix_arg)
{
set_this_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
/* Now notify all dependent libraries. */
#if DEPENDS_ON_LIBCHARSET
libcharset_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
#endif
#if DEPENDS_ON_LIBICONV && HAVE_ICONV && _LIBICONV_VERSION >= 0x0109
libiconv_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
#endif
#if DEPENDS_ON_LIBINTL && ENABLE_NLS && defined libintl_set_relocation_prefix
libintl_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
#endif
}
/* 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. */
#ifdef IN_LIBRARY
#define compute_curr_prefix local_compute_curr_prefix
static
#endif
const char *
compute_curr_prefix (const char *orig_installprefix,
const char *orig_installdir,
const char *curr_pathname)
{
const char *curr_installdir;
const char *rel_installdir;
if (curr_pathname == NULL)
return NULL;
/* Determine the relative installation directory, relative to the prefix.
This is simply the difference between orig_installprefix and
orig_installdir. */
if (strncmp (orig_installprefix, orig_installdir, strlen (orig_installprefix))
!= 0)
/* Shouldn't happen - nothing should be installed outside $(prefix). */
return NULL;
rel_installdir = orig_installdir + strlen (orig_installprefix);
/* Determine the current installation directory. */
{
const char *p_base = curr_pathname + FILESYSTEM_PREFIX_LEN (curr_pathname);
const char *p = curr_pathname + strlen (curr_pathname);
char *q;
while (p > p_base)
{
p--;
if (ISSLASH (*p))
break;
}
q = (char *) xmalloc (p - curr_pathname + 1);
#ifdef NO_XMALLOC
if (q == NULL)
return NULL;
#endif
memcpy (q, curr_pathname, p - curr_pathname);
q[p - curr_pathname] = '\0';
curr_installdir = q;
}
/* Compute the current installation prefix by removing the trailing
rel_installdir from it. */
{
const char *rp = rel_installdir + strlen (rel_installdir);
const char *cp = curr_installdir + strlen (curr_installdir);
const char *cp_base =
curr_installdir + FILESYSTEM_PREFIX_LEN (curr_installdir);
while (rp > rel_installdir && cp > cp_base)
{
bool same = false;
const char *rpi = rp;
const char *cpi = cp;
while (rpi > rel_installdir && cpi > cp_base)
{
rpi--;
cpi--;
if (ISSLASH (*rpi) || ISSLASH (*cpi))
{
if (ISSLASH (*rpi) && ISSLASH (*cpi))
same = true;
break;
}
#if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__
/* Win32, OS/2, DOS - case insignificant filesystem */
if ((*rpi >= 'a' && *rpi <= 'z' ? *rpi - 'a' + 'A' : *rpi)
!= (*cpi >= 'a' && *cpi <= 'z' ? *cpi - 'a' + 'A' : *cpi))
break;
#else
if (*rpi != *cpi)
break;
#endif
}
if (!same)
break;
/* The last pathname component was the same. opi and cpi now point
to the slash before it. */
rp = rpi;
cp = cpi;
}
if (rp > rel_installdir)
/* Unexpected: The curr_installdir does not end with rel_installdir. */
return NULL;
{
size_t curr_prefix_len = cp - curr_installdir;
char *curr_prefix;
curr_prefix = (char *) xmalloc (curr_prefix_len + 1);
#ifdef NO_XMALLOC
if (curr_prefix == NULL)
return NULL;
#endif
memcpy (curr_prefix, curr_installdir, curr_prefix_len);
curr_prefix[curr_prefix_len] = '\0';
return curr_prefix;
}
}
}
#if defined PIC && defined INSTALLDIR
/* Full pathname of shared library, or NULL. */
static char *shared_library_fullname;
#if defined _WIN32 || defined __WIN32__
/* Determine the full pathname of the shared library when it is loaded. */
BOOL WINAPI
DllMain (HINSTANCE module_handle, DWORD event, LPVOID reserved)
{
(void) reserved;
if (event == DLL_PROCESS_ATTACH)
{
/* The DLL is being loaded into an application's address range. */
static char location[MAX_PATH];
if (!GetModuleFileName (module_handle, location, sizeof (location)))
/* Shouldn't happen. */
return FALSE;
if (!IS_PATH_WITH_DIR (location))
/* Shouldn't happen. */
return FALSE;
shared_library_fullname = strdup (location);
}
return TRUE;
}
#else /* Unix */
static void
find_shared_library_fullname ()
{
#ifdef __linux__
FILE *fp;
/* Open the current process' maps file. It describes one VMA per line. */
fp = fopen ("/proc/self/maps", "r");
if (fp)
{
unsigned long address = (unsigned long) &find_shared_library_fullname;
for (;;)
{
unsigned long start, end;
int c;
if (fscanf (fp, "%lx-%lx", &start, &end) != 2)
break;
if (address >= start && address <= end - 1)
{
/* Found it. Now see if this line contains a filename. */
while (c = getc (fp), c != EOF && c != '\n' && c != '/')
continue;
if (c == '/')
{
size_t size;
int len;
ungetc (c, fp);
shared_library_fullname = NULL; size = 0;
len = getline (&shared_library_fullname, &size, fp);
if (len >= 0)
{
/* Success: filled shared_library_fullname. */
if (len > 0 && shared_library_fullname[len - 1] == '\n')
shared_library_fullname[len - 1] = '\0';
}
}
break;
}
while (c = getc (fp), c != EOF && c != '\n')
continue;
}
fclose (fp);
}
#endif
}
#endif /* WIN32 / Unix */
/* Return the full pathname of the current shared library.
Return NULL if unknown.
Guaranteed to work only on Linux and Woe32. */
static char *
get_shared_library_fullname ()
{
#if !(defined _WIN32 || defined __WIN32__)
static bool tried_find_shared_library_fullname;
if (!tried_find_shared_library_fullname)
{
find_shared_library_fullname ();
tried_find_shared_library_fullname = true;
}
#endif
return shared_library_fullname;
}
#endif /* PIC */
/* Returns the pathname, relocated according to the current installation
directory. */
const char *
relocate (const char *pathname)
{
#if defined PIC && defined INSTALLDIR
static int initialized;
/* Initialization code for a shared library. */
if (!initialized)
{
/* At this point, orig_prefix and curr_prefix likely have already been
set through the main program's set_program_name_and_installdir
function. This is sufficient in the case that the library has
initially been installed in the same orig_prefix. But we can do
better, to also cover the cases that 1. it has been installed
in a different prefix before being moved to orig_prefix and (later)
to curr_prefix, 2. unlike the program, it has not moved away from
orig_prefix. */
const char *orig_installprefix = INSTALLPREFIX;
const char *orig_installdir = INSTALLDIR;
const char *curr_prefix_better;
curr_prefix_better =
compute_curr_prefix (orig_installprefix, orig_installdir,
get_shared_library_fullname ());
if (curr_prefix_better == NULL)
curr_prefix_better = curr_prefix;
set_relocation_prefix (orig_installprefix, curr_prefix_better);
initialized = 1;
}
#endif
/* Note: It is not necessary to perform case insensitive comparison here,
even for DOS-like filesystems, because the pathname argument was
typically created from the same Makefile variable as orig_prefix came
from. */
if (orig_prefix != NULL && curr_prefix != NULL
&& strncmp (pathname, orig_prefix, orig_prefix_len) == 0)
{
if (pathname[orig_prefix_len] == '\0')
/* pathname equals orig_prefix. */
return curr_prefix;
if (ISSLASH (pathname[orig_prefix_len]))
{
/* pathname starts with orig_prefix. */
const char *pathname_tail = &pathname[orig_prefix_len];
char *result =
(char *) xmalloc (curr_prefix_len + strlen (pathname_tail) + 1);
#ifdef NO_XMALLOC
if (result != NULL)
#endif
{
memcpy (result, curr_prefix, curr_prefix_len);
strcpy (result + curr_prefix_len, pathname_tail);
return result;
}
}
}
/* Nothing to relocate. */
return pathname;
}
#endif
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