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+/* Provide relocatable packages.
+ Copyright (C) 2003-2006, 2008 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
+
+#include <config.h>
+
+/* 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 "xalloc.h"
+#endif
+
+#if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__
+# define WIN32_LEAN_AND_MEAN
+# include <windows.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 __CYGWIN__ || defined __EMX__ || defined __DJGPP__
+ /* Win32, Cygwin, 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 FILE_SYSTEM_PREFIX_LEN(P) (HAS_DEVICE (P) ? 2 : 0)
+#else
+ /* Unix */
+# define ISSLASH(C) ((C) == '/')
+# define IS_PATH_WITH_DIR(P) (strchr (P, '/') != NULL)
+# define FILE_SYSTEM_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
+}
+
+#if !defined IN_LIBRARY || (defined PIC && defined INSTALLDIR)
+
+/* 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 it, freshly allocated. Returns NULL upon failure. */
+#ifdef IN_LIBRARY
+#define compute_curr_prefix local_compute_curr_prefix
+static
+#endif
+char *
+compute_curr_prefix (const char *orig_installprefix,
+ const char *orig_installdir,
+ const char *curr_pathname)
+{
+ 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 + FILE_SYSTEM_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 + FILE_SYSTEM_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;
+ }
+ /* Do case-insensitive comparison if the filesystem is always or
+ often case-insensitive. It's better to accept the comparison
+ if the difference is only in case, rather than to fail. */
+#if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__
+ /* Win32, Cygwin, 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. */
+ free (curr_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)
+ {
+ free (curr_installdir);
+ return NULL;
+ }
+#endif
+ memcpy (curr_prefix, curr_installdir, curr_prefix_len);
+ curr_prefix[curr_prefix_len] = '\0';
+
+ free (curr_installdir);
+
+ return curr_prefix;
+ }
+ }
+}
+
+#endif /* !IN_LIBRARY || PIC */
+
+#if defined PIC && defined INSTALLDIR
+
+/* Full pathname of shared library, or NULL. */
+static char *shared_library_fullname;
+
+#if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__
+
+/* 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;
+
+ {
+#if defined __CYGWIN__
+ /* On Cygwin, we need to convert paths coming from Win32 system calls
+ to the Unix-like slashified notation. */
+ static char location_as_posix_path[2 * MAX_PATH];
+ /* There's no error return defined for cygwin_conv_to_posix_path.
+ See cygwin-api/func-cygwin-conv-to-posix-path.html.
+ Does it overflow the buffer of expected size MAX_PATH or does it
+ truncate the path? I don't know. Let's catch both. */
+ cygwin_conv_to_posix_path (location, location_as_posix_path);
+ location_as_posix_path[MAX_PATH - 1] = '\0';
+ if (strlen (location_as_posix_path) >= MAX_PATH - 1)
+ /* A sign of buffer overflow or path truncation. */
+ return FALSE;
+ shared_library_fullname = strdup (location_as_posix_path);
+#else
+ shared_library_fullname = strdup (location);
+#endif
+ }
+ }
+
+ return TRUE;
+}
+
+#else /* Unix except Cygwin */
+
+static void
+find_shared_library_fullname ()
+{
+#if defined __linux__ && __GLIBC__ >= 2
+ /* Linux has /proc/self/maps. glibc 2 has the getline() function. */
+ 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 or Cygwin) / (Unix except Cygwin) */
+
+/* Return the full pathname of the current shared library.
+ Return NULL if unknown.
+ Guaranteed to work only on Linux, Cygwin and Woe32. */
+static char *
+get_shared_library_fullname ()
+{
+#if !(defined _WIN32 || defined __WIN32__ || defined __CYGWIN__)
+ 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.
+ The returned string is either PATHNAME unmodified or a freshly allocated
+ string that you can free with free() after casting it to 'char *'. */
+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;
+ char *curr_prefix_better;
+
+ curr_prefix_better =
+ compute_curr_prefix (orig_installprefix, orig_installdir,
+ get_shared_library_fullname ());
+
+ set_relocation_prefix (orig_installprefix,
+ curr_prefix_better != NULL
+ ? curr_prefix_better
+ : curr_prefix);
+
+ if (curr_prefix_better != NULL)
+ free (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. */
+ char *result = (char *) xmalloc (strlen (curr_prefix) + 1);
+
+#ifdef NO_XMALLOC
+ if (result != NULL)
+#endif
+ {
+ strcpy (result, curr_prefix);
+ return result;
+ }
+ }
+ else 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