This is the mail archive of the
binutils@sources.redhat.com
mailing list for the binutils project.
RFC: Implement --no-add-needed/--add-needed for ld
- From: "H. J. Lu" <hjl at lucon dot org>
- To: binutils at sources dot redhat dot com
- Date: Thu, 8 Jul 2004 00:51:58 -0700
- Subject: RFC: Implement --no-add-needed/--add-needed for ld
I am working on the gcc unwind library bug:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14925
A propposed fix requires adding --no-add-needed/--add-needed for ld:
http://gcc.gnu.org/ml/gcc/2004-04/msg01130.html
Here is something I have been working on. Any comments?
H.J.
----
--- binutils/bfd/bfd-in.h.needed 2004-07-06 16:10:22.000000000 -0700
+++ binutils/bfd/bfd-in.h 2004-07-07 23:53:41.676387892 -0700
@@ -628,7 +628,9 @@ struct bfd_link_needed_list
enum dynamic_lib_link_class {
DYN_NORMAL = 0,
DYN_AS_NEEDED = 1,
- DYN_DT_NEEDED = 2
+ DYN_DT_NEEDED = 2,
+ DYN_NO_ADD_NEEDED = 4,
+ DYN_NO_NEEDED = 8
};
extern bfd_boolean bfd_elf_record_link_assignment
@@ -646,6 +648,8 @@ extern const char *bfd_elf_get_dt_soname
(bfd *);
extern void bfd_elf_set_dyn_lib_class
(bfd *, int);
+extern int bfd_elf_get_dyn_lib_class
+ (bfd *);
extern struct bfd_link_needed_list *bfd_elf_get_runpath_list
(bfd *, struct bfd_link_info *);
extern bfd_boolean bfd_elf_discard_info
--- binutils/bfd/elf.c.needed 2004-07-06 16:10:22.000000000 -0700
+++ binutils/bfd/elf.c 2004-07-08 00:15:25.164802381 -0700
@@ -1562,6 +1562,18 @@ bfd_elf_set_dt_needed_name (bfd *abfd, c
elf_dt_name (abfd) = name;
}
+int
+bfd_elf_get_dyn_lib_class (bfd *abfd)
+{
+ int lib_class;
+ if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
+ && bfd_get_format (abfd) == bfd_object)
+ lib_class = elf_dyn_lib_class (abfd);
+ else
+ lib_class = 0;
+ return lib_class;
+}
+
void
bfd_elf_set_dyn_lib_class (bfd *abfd, int lib_class)
{
--- binutils/bfd/elflink.c.needed 2004-07-07 15:53:14.000000000 -0700
+++ binutils/bfd/elflink.c 2004-07-08 00:38:04.197520901 -0700
@@ -3064,8 +3064,13 @@ elf_link_add_object_symbols (bfd *abfd,
/* If this dynamic lib was specified on the command line with
--as-needed in effect, then we don't want to add a DT_NEEDED
tag unless the lib is actually used. Similary for libs brought
- in by another lib's DT_NEEDED. */
- add_needed = elf_dyn_lib_class (abfd) == DYN_NORMAL;
+ in by another lib's DT_NEEDED. When --no-add-needed is used
+ on a dynamic lib, we don't want to add a DT_NEEDED entry for
+ any dynamic library in DT_NEEDED tags in the dynamic lib at
+ all. */
+ add_needed = (elf_dyn_lib_class (abfd)
+ & (DYN_AS_NEEDED | DYN_DT_NEEDED
+ | DYN_NO_NEEDED)) == 0;
s = bfd_get_section_by_name (abfd, ".dynamic");
if (s != NULL)
@@ -3846,7 +3851,17 @@ elf_link_add_object_symbols (bfd *abfd,
/* A symbol from a library loaded via DT_NEEDED of some
other library is referenced by a regular object.
- Add a DT_NEEDED entry for it. */
+ Add a DT_NEEDED entry for it. Issue an error if
+ --no-add-needed is used. */
+ if ((elf_dyn_lib_class (abfd) & DYN_NO_NEEDED) != 0)
+ {
+ (*_bfd_error_handler)
+ (_("%s: invalid DSO for symbol `%s' definition"),
+ bfd_archive_filename (abfd), name);
+ bfd_set_error (bfd_error_bad_value);
+ goto error_free_vers;
+ }
+
add_needed = TRUE;
ret = elf_add_dt_needed_tag (info, soname, add_needed);
if (ret < 0)
@@ -5818,7 +5833,7 @@ elf_link_check_versioned_symbol (struct
case bfd_link_hash_undefweak:
abfd = h->root.u.undef.abfd;
if ((abfd->flags & DYNAMIC) == 0
- || elf_dyn_lib_class (abfd) != DYN_DT_NEEDED)
+ || (elf_dyn_lib_class (abfd) & DYN_DT_NEEDED) == 0)
return FALSE;
break;
--- binutils/ld/emultempl/elf32.em.needed 2004-06-24 08:35:38.000000000 -0700
+++ binutils/ld/emultempl/elf32.em 2004-07-08 00:32:45.139790857 -0700
@@ -96,14 +96,25 @@ cat >>e${EMULATION_NAME}.c <<EOF
static bfd_boolean
gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *entry)
{
- if (!entry->as_needed
- || (bfd_get_file_flags (entry->the_bfd) & DYNAMIC) == 0)
- return FALSE;
+ int class = 0;
/* Tell the ELF linker that we don't want the output file to have a
DT_NEEDED entry for this file, unless it is used to resolve
references in a regular object. */
- bfd_elf_set_dyn_lib_class (entry->the_bfd, DYN_AS_NEEDED);
+ if (entry->as_needed)
+ class = DYN_AS_NEEDED;
+
+ /* Tell the ELF linker that we don't want the output file to have a
+ DT_NEEDED entry for any dynamic library in DT_NEEDED tags from
+ this file at all. */
+ if (!entry->add_needed)
+ class |= DYN_NO_ADD_NEEDED;
+
+ if (!class
+ || (bfd_get_file_flags (entry->the_bfd) & DYNAMIC) == 0)
+ return FALSE;
+
+ bfd_elf_set_dyn_lib_class (entry->the_bfd, class);
/* Continue on with normal load_symbols processing. */
return FALSE;
@@ -242,16 +253,24 @@ gld${EMULATION_NAME}_stat_needed (lang_i
global_needed->name, global_needed->by, soname);
}
+struct dt_needed
+{
+ bfd *by;
+ const char *name;
+};
/* This function is called for each possible name for a dynamic object
named by a DT_NEEDED entry. The FORCE parameter indicates whether
to skip the check for a conflicting version. */
static bfd_boolean
-gld${EMULATION_NAME}_try_needed (const char *name, int force)
+gld${EMULATION_NAME}_try_needed (struct dt_needed *needed,
+ int force)
{
bfd *abfd;
+ const char *name = needed->name;
const char *soname;
+ int class;
abfd = bfd_openr (name, bfd_get_target (output_bfd));
if (abfd == NULL)
@@ -364,7 +383,16 @@ cat >>e${EMULATION_NAME}.c <<EOF
/* Tell the ELF linker that we don't want the output file to have a
DT_NEEDED entry for this file, unless it is used to resolve
references in a regular object. */
- bfd_elf_set_dyn_lib_class (abfd, DYN_DT_NEEDED);
+ class = DYN_DT_NEEDED;
+
+ /* Tell the ELF linker that we don't want the output file to have a
+ DT_NEEDED entry for this file at all. */
+ if (needed->by
+ && (bfd_elf_get_dyn_lib_class (needed->by)
+ & DYN_NO_ADD_NEEDED) != 0)
+ class |= DYN_NO_NEEDED;
+
+ bfd_elf_set_dyn_lib_class (abfd, class);
/* Add this file into the symbol table. */
if (! bfd_link_add_symbols (abfd, &link_info))
@@ -377,16 +405,23 @@ cat >>e${EMULATION_NAME}.c <<EOF
/* Search for a needed file in a path. */
static bfd_boolean
-gld${EMULATION_NAME}_search_needed (const char *path, const char *name, int force)
+gld${EMULATION_NAME}_search_needed (const char *path,
+ struct dt_needed *n, int force)
{
const char *s;
+ const char *name = n->name;
size_t len;
+ struct dt_needed needed;
if (name[0] == '/')
- return gld${EMULATION_NAME}_try_needed (name, force);
+ return gld${EMULATION_NAME}_try_needed (n, force);
if (path == NULL || *path == '\0')
return FALSE;
+
+ needed.by = n->by;
+ needed.name = n->name;
+
len = strlen (name);
while (1)
{
@@ -407,7 +442,8 @@ gld${EMULATION_NAME}_search_needed (cons
}
strcpy (sset, name);
- if (gld${EMULATION_NAME}_try_needed (filename, force))
+ needed.name = filename;
+ if (gld${EMULATION_NAME}_try_needed (&needed, force))
return TRUE;
free (filename);
@@ -474,6 +510,7 @@ gld${EMULATION_NAME}_check_ld_so_conf (c
{
static bfd_boolean initialized;
static char *ld_so_conf;
+ struct dt_needed needed;
if (! initialized)
{
@@ -548,7 +585,10 @@ gld${EMULATION_NAME}_check_ld_so_conf (c
if (ld_so_conf == NULL)
return FALSE;
- return gld${EMULATION_NAME}_search_needed (ld_so_conf, name, force);
+
+ needed.by = NULL;
+ needed.name = name;
+ return gld${EMULATION_NAME}_search_needed (ld_so_conf, &needed, force);
}
EOF
@@ -631,6 +671,7 @@ gld${EMULATION_NAME}_after_open (void)
for (l = needed; l != NULL; l = l->next)
{
struct bfd_link_needed_list *ll;
+ struct dt_needed n, nn;
int force;
/* If we've already seen this file, skip it. */
@@ -647,6 +688,9 @@ gld${EMULATION_NAME}_after_open (void)
if (global_found)
continue;
+ n.by = l->by;
+ n.name = l->name;
+ nn.by = l->by;
if (trace_file_tries)
info_msg (_("%s needed by %B\n"), l->name, l->by);
@@ -676,13 +720,13 @@ fi
cat >>e${EMULATION_NAME}.c <<EOF
if (gld${EMULATION_NAME}_search_needed (command_line.rpath_link,
- l->name, force))
+ &n, force))
break;
EOF
if [ "x${USE_LIBPATH}" = xyes ] ; then
cat >>e${EMULATION_NAME}.c <<EOF
if (gld${EMULATION_NAME}_search_needed (command_line.rpath,
- l->name, force))
+ &n, force))
break;
EOF
fi
@@ -692,12 +736,12 @@ cat >>e${EMULATION_NAME}.c <<EOF
&& command_line.rpath == NULL)
{
lib_path = (const char *) getenv ("LD_RUN_PATH");
- if (gld${EMULATION_NAME}_search_needed (lib_path, l->name,
+ if (gld${EMULATION_NAME}_search_needed (lib_path, &n,
force))
break;
}
lib_path = (const char *) getenv ("LD_LIBRARY_PATH");
- if (gld${EMULATION_NAME}_search_needed (lib_path, l->name, force))
+ if (gld${EMULATION_NAME}_search_needed (lib_path, &n, force))
break;
EOF
fi
@@ -710,7 +754,7 @@ cat >>e${EMULATION_NAME}.c <<EOF
char *tmpname = gld${EMULATION_NAME}_add_sysroot (rp->name);
found = (rp->by == l->by
&& gld${EMULATION_NAME}_search_needed (tmpname,
- l->name,
+ &n,
force));
free (tmpname);
}
@@ -729,7 +773,8 @@ cat >>e${EMULATION_NAME}.c <<EOF
continue;
filename = (char *) xmalloc (strlen (search->name) + len + 2);
sprintf (filename, "%s/%s", search->name, l->name);
- if (gld${EMULATION_NAME}_try_needed (filename, force))
+ nn.name = filename;
+ if (gld${EMULATION_NAME}_try_needed (&nn, force))
break;
free (filename);
}
--- binutils/ld/ld.texinfo.needed 2004-07-06 08:36:55.000000000 -0700
+++ binutils/ld/ld.texinfo 2004-07-07 14:42:25.000000000 -0700
@@ -984,6 +984,17 @@ needed. @option{--as-needed} causes DT_N
for libraries that satisfy some reference from regular objects.
@option{--no-as-needed} restores the default behaviour.
+@kindex --add-needed
+@kindex --no-add-needed
+@item --add-needed
+@itemx --no-add-needed
+This option affects the treatment of dynamic libraries from ELF
+DT_NEEDED tags in dynamic libraries mentioned on the command line after
+the @option{--no-add-needed} option. Normally, the linker will load
+each dynamic library from DT_NEEDED tags. @option{--no-add-needed}
+causes those libraries from DT_NEEDED tags to be ignored.
+@option{--add-needed} restores the default behaviour.
+
@kindex -assert @var{keyword}
@item -assert @var{keyword}
This option is ignored for SunOS compatibility.
--- binutils/ld/ldlang.c.needed 2004-07-06 16:10:22.000000000 -0700
+++ binutils/ld/ldlang.c 2004-07-07 22:43:07.000000000 -0700
@@ -454,6 +454,7 @@ new_afile (const char *name,
p->next = NULL;
p->symbol_count = 0;
p->dynamic = config.dynamic_link;
+ p->add_needed = add_needed;
p->as_needed = as_needed;
p->whole_archive = whole_archive;
p->loaded = FALSE;
--- binutils/ld/ldlang.h.needed 2004-05-19 08:24:36.000000000 -0700
+++ binutils/ld/ldlang.h 2004-07-07 15:30:50.000000000 -0700
@@ -266,6 +266,10 @@ typedef struct lang_input_statement_stru
/* Whether to search for this entry as a dynamic archive. */
bfd_boolean dynamic;
+ /* Whether dynamic libraries in DT_NEEDED tags in this entry should
+ be loaded. */
+ bfd_boolean add_needed;
+
/* Whether this entry should cause a DT_NEEDED tag only when
satisfying references from regular files, or always. */
bfd_boolean as_needed;
--- binutils/ld/ldmain.c.needed 2004-05-25 22:35:42.000000000 -0700
+++ binutils/ld/ldmain.c 2004-07-07 14:46:06.000000000 -0700
@@ -97,6 +97,9 @@ bfd_boolean whole_archive;
actually satisfies some reference in a regular object. */
bfd_boolean as_needed;
+/* Nonzero means load DT_NEEDED entries. */
+bfd_boolean add_needed = TRUE;
+
/* TRUE if we should demangle symbol names. */
bfd_boolean demangling;
--- binutils/ld/ldmain.h.needed 2004-03-18 10:11:56.000000000 -0800
+++ binutils/ld/ldmain.h 2004-07-07 14:46:21.000000000 -0700
@@ -33,6 +33,7 @@ extern bfd_boolean trace_file_tries;
extern bfd_boolean version_printed;
extern bfd_boolean whole_archive;
extern bfd_boolean as_needed;
+extern bfd_boolean add_needed;
extern bfd_boolean demangling;
extern int g_switch_value;
extern const char *output_filename;
--- binutils/ld/lexsup.c.needed 2004-05-28 12:50:30.000000000 -0700
+++ binutils/ld/lexsup.c 2004-07-07 15:07:21.000000000 -0700
@@ -113,6 +113,8 @@ enum option_values
OPTION_SPLIT_BY_RELOC,
OPTION_SPLIT_BY_FILE ,
OPTION_WHOLE_ARCHIVE,
+ OPTION_ADD_NEEDED,
+ OPTION_NO_ADD_NEEDED,
OPTION_AS_NEEDED,
OPTION_NO_AS_NEEDED,
OPTION_WRAP,
@@ -486,6 +488,12 @@ static const struct ld_option ld_options
{ {"whole-archive", no_argument, NULL, OPTION_WHOLE_ARCHIVE},
'\0', NULL, N_("Include all objects from following archives"),
TWO_DASHES },
+ { {"add-needed", no_argument, NULL, OPTION_ADD_NEEDED},
+ '\0', NULL, N_("Load DT_NEEDED tags for following dynamic libs"),
+ TWO_DASHES },
+ { {"no-add-needed", no_argument, NULL, OPTION_NO_ADD_NEEDED},
+ '\0', NULL, N_("Do not load DT_NEEDED tags for following dynamic libs"),
+ TWO_DASHES },
{ {"as-needed", no_argument, NULL, OPTION_AS_NEEDED},
'\0', NULL, N_("Only set DT_NEEDED for following dynamic libs if used"),
TWO_DASHES },
@@ -1196,6 +1204,12 @@ parse_args (unsigned argc, char **argv)
case OPTION_WHOLE_ARCHIVE:
whole_archive = TRUE;
break;
+ case OPTION_ADD_NEEDED:
+ add_needed = TRUE;
+ break;
+ case OPTION_NO_ADD_NEEDED:
+ add_needed = FALSE;
+ break;
case OPTION_AS_NEEDED:
as_needed = TRUE;
break;