From 7a11603dc6bde67066ce6f8d4c5f6b86bebaf3c1 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Sat, 18 Sep 2004 06:46:52 +0000 Subject: Update. 2004-09-17 Ulrich Drepper * include/link.h (struct link_map): Add l_used element. * sysdeps/generic/ldsodefs.h: Define DL_DEBUG_UNUSED. * elf/rtld.c (process_dl_debug): Recognize unused. (dl_main): When unused debug flag is set check for unused direct dependencies. When printing dependencies and SONAME starts with /, omit the SONAME => part. * elf/dl-lookup.c (_dl_lookup_symbol_x): Mark object in which the symbol has been found as used. * elf/ldd.bash.in: Add -u option. --- elf/dl-lookup.c | 3 +++ elf/ldd.bash.in | 7 +++++++ elf/rtld.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 54 insertions(+) (limited to 'elf') diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c index 2b73da591a..d2a6976e4e 100644 --- a/elf/dl-lookup.c +++ b/elf/dl-lookup.c @@ -344,6 +344,9 @@ _dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map, symbol_scope, version, type_class, flags, skip_map); + /* The object is used. */ + current_value.m->l_used = 1; + if (__builtin_expect (GLRO(dl_debug_mask) & (DL_DEBUG_BINDINGS|DL_DEBUG_PRELINK), 0)) _dl_debug_bindings (undef_name, undef_map, ref, symbol_scope, diff --git a/elf/ldd.bash.in b/elf/ldd.bash.in index 8867211109..6ee9b60e51 100644 --- a/elf/ldd.bash.in +++ b/elf/ldd.bash.in @@ -50,6 +50,7 @@ warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. --version print version information and exit -d, --data-relocs process data relocations -r, --function-relocs process data and function relocations + -u, --unused print unused direct dependencies -v, --verbose print all information For bug reporting instructions, please see: ." @@ -71,6 +72,9 @@ For bug reporting instructions, please see: verbose=yes shift ;; + -u | --u | --un | --unu | --unus | --unuse | --unused) + unused=yes + shift --v | --ve | --ver) echo >&2 $"ldd: option \`$1' is ambiguous" exit 1 @@ -97,6 +101,9 @@ nonelf () add_env="LD_TRACE_LOADED_OBJECTS=1 LD_WARN=$warn LD_BIND_NOW=$bind_now" add_env="$add_env LD_VERBOSE=$verbose" +if test "$unused" = yes; then + add_env="$add_env LD_DEBUG="$LD_DEBUG${LD_DEBUG:+,}unused" +fi case $# in 0) echo >&2 'ldd:' $"missing file arguments" diff --git a/elf/rtld.c b/elf/rtld.c index e015477c19..93c45311d4 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1526,6 +1526,44 @@ cannot allocate TLS data structures for initial thread"); _dl_printf ("\n"); } } + else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED) + { + /* Look through the dependencies of the main executable + and determine which of them is not actually + required. */ + struct link_map *l = GL(dl_loaded); + + /* Relocate the main executable. */ + struct relocate_args args = { .l = l, .lazy = GLRO(dl_lazy) }; + _dl_receive_error (print_unresolved, relocate_doit, &args); + + /* This loop depends on the dependencies of the executable to + correspond in number and order to the DT_NEEDED entries. */ + ElfW(Dyn) *dyn = GL(dl_loaded)->l_ld; + bool first = true; + while (dyn->d_tag != DT_NULL) + { + if (dyn->d_tag == DT_NEEDED) + { + l = l->l_next; + + if (!l->l_used) + { + if (first) + { + _dl_printf ("Unused direct dependencies:\n"); + first = false; + } + + _dl_printf ("\t%s\n", l->l_name); + } + } + + ++dyn; + } + + _exit (first != true); + } else if (! GL(dl_loaded)->l_info[DT_NEEDED]) _dl_printf ("\tstatically linked\n"); else @@ -1534,6 +1572,10 @@ cannot allocate TLS data structures for initial thread"); if (l->l_faked) /* The library was not found. */ _dl_printf ("\t%s => not found\n", l->l_libname->name); + else if (l->l_libname->name[0] == '/') + _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name, + (int) sizeof l->l_map_start * 2, + (size_t) l->l_map_start); else _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name, l->l_name, (int) sizeof l->l_map_start * 2, @@ -1962,6 +2004,8 @@ process_dl_debug (const char *dl_debug) | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS }, { LEN_AND_STR ("statistics"), "display relocation statistics", DL_DEBUG_STATISTICS }, + { LEN_AND_STR ("unused"), "determined unused DSOs", + DL_DEBUG_UNUSED }, { LEN_AND_STR ("help"), "display this help message and exit", DL_DEBUG_HELP }, }; -- cgit 1.4.1