diff options
Diffstat (limited to 'lib/relocatable.c')
| -rw-r--r-- | lib/relocatable.c | 69 |
1 files changed, 38 insertions, 31 deletions
diff --git a/lib/relocatable.c b/lib/relocatable.c index 15b3bc44..3483d0ad 100644 --- a/lib/relocatable.c +++ b/lib/relocatable.c @@ -1,5 +1,5 @@ /* Provide relocatable packages. - Copyright (C) 2003-2006, 2008-2025 Free Software Foundation, Inc. + Copyright (C) 2003-2006, 2008-2026 Free Software Foundation, Inc. Written by Bruno Haible <bruno@clisp.org>, 2003. This file is free software: you can redistribute it and/or modify @@ -55,6 +55,10 @@ # define strncmp strnicmp #endif +#if HAVE_DLADDR_IN_LIBC +# include <dlfcn.h> +#endif + #if DEPENDS_ON_LIBCHARSET # include <libcharset.h> #endif @@ -101,9 +105,8 @@ /* Whether to enable the more costly support for relocatable libraries. It allows libraries to be have been installed with a different original - prefix than the program. But it is quite costly, especially on Cygwin - platforms, see below. Therefore we enable it by default only on native - Windows platforms. */ + prefix than the program. But it is quite costly, see below. Therefore + we enable it by default only on native Windows platforms. */ #ifndef ENABLE_COSTLY_RELOCATABLE # if defined _WIN32 && !defined __CYGWIN__ # define ENABLE_COSTLY_RELOCATABLE 1 @@ -136,11 +139,9 @@ set_this_relocation_prefix (const char *orig_prefix_arg, && 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); + char *memory = (char *) xmalloc (orig_prefix_len + 1 + curr_prefix_len + 1); #ifdef NO_XMALLOC if (memory != NULL) #endif @@ -197,9 +198,6 @@ 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; @@ -210,9 +208,10 @@ compute_curr_prefix (const char *orig_installprefix, != 0) /* Shouldn't happen - nothing should be installed outside $(prefix). */ return NULL; - rel_installdir = orig_installdir + strlen (orig_installprefix); + const char *rel_installdir = orig_installdir + strlen (orig_installprefix); /* Determine the current installation directory. */ + char *curr_installdir; { const char *p_base = curr_pathname + FILE_SYSTEM_PREFIX_LEN (curr_pathname); const char *p = curr_pathname + strlen (curr_pathname); @@ -318,9 +317,9 @@ static char *shared_library_fullname; #if defined _WIN32 && !defined __CYGWIN__ /* Native Windows only. - On Cygwin, it is better to use the Cygwin provided /proc interface, than - to use native Windows API and cygwin_conv_to_posix_path, because it - supports longer file names + On Cygwin, it is better to use either dladdr() or the Cygwin provided /proc + interface, than to use native Windows API and cygwin_conv_to_posix_path, + because it supports longer file names (see <https://cygwin.com/ml/cygwin/2011-01/msg00410.html>). */ /* Determine the full pathname of the shared library when it is loaded. @@ -402,39 +401,44 @@ _DLL_InitTerm (unsigned long hModule, unsigned long ulFlag) static void find_shared_library_fullname () { -#if (defined __linux__ && (__GLIBC__ >= 2 || defined __UCLIBC__)) || defined __CYGWIN__ +#if HAVE_DLADDR_IN_LIBC + /* glibc >= 2.34, musl, macOS, FreeBSD, NetBSD, OpenBSD, Solaris, Cygwin, Minix */ + /* We can use dladdr() without introducing extra link dependencies. */ + Dl_info info; + /* It is OK to use a 'static' function — that does not appear in the + dynamic symbol table of any ELF object — as argument of dladdr() here, + because we don't access the fields info.dli_sname and info.dli_saddr. */ + int ret = dladdr (find_shared_library_fullname, &info); + if (ret != 0 && info.dli_fname != NULL) + shared_library_fullname = strdup (info.dli_fname); +#elif (defined __linux__ && (__GLIBC__ >= 2 || defined __UCLIBC__)) || defined __CYGWIN__ /* Linux has /proc/self/maps. glibc 2 and uClibc have the getline() function. - Cygwin >= 1.5 has /proc/self/maps and the getline() function too. - But it is costly: ca. 0.3 ms on Linux, 3 ms on Cygwin 1.5, and 5 ms on - Cygwin 1.7. */ - FILE *fp; + But it is costly: ca. 0.3 ms. */ /* Open the current process' maps file. It describes one VMA per line. */ - fp = fopen ("/proc/self/maps", "r"); + FILE *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. */ + int c; 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); + shared_library_fullname = NULL; + size_t size = 0; + int len = getline (&shared_library_fullname, &size, fp); if (len >= 0) { /* Success: filled shared_library_fullname. */ @@ -444,6 +448,7 @@ find_shared_library_fullname () } break; } + int c; while (c = getc (fp), c != EOF && c != '\n') continue; } @@ -452,15 +457,19 @@ find_shared_library_fullname () #endif } +# define find_shared_library_fullname find_shared_library_fullname + #endif /* Native Windows / EMX / Unix */ /* Return the full pathname of the current shared library. Return NULL if unknown. - Guaranteed to work only on Linux, EMX, Cygwin, and native Windows. */ + Guaranteed to work only on + glibc >= 2.34, Linux, macOS, FreeBSD, NetBSD, OpenBSD, Solaris, Cygwin, + Minix, native Windows, EMX. */ static char * get_shared_library_fullname () { -#if !(defined _WIN32 && !defined __CYGWIN__) && !defined __EMX__ +#if defined find_shared_library_fullname static bool tried_find_shared_library_fullname; if (!tried_find_shared_library_fullname) { @@ -496,9 +505,7 @@ relocate (const char *pathname) orig_prefix. */ const char *orig_installprefix = INSTALLPREFIX; const char *orig_installdir = INSTALLDIR; - char *curr_prefix_better; - - curr_prefix_better = + char *curr_prefix_better = compute_curr_prefix (orig_installprefix, orig_installdir, get_shared_library_fullname ()); |