Edit File: relocatable.c
/* Provide relocatable packages. Copyright (C) 2003-2006 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 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 + 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. */ 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; } } } #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. */ 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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