Properly merge hidden versioned symbol
The hidden versioned symbol can only be merged with the versioned symbol with the same symbol version. _bfd_elf_merge_symbol should check the symbol version before merging the new hidden versioned symbol with the existing symbol. _bfd_elf_link_hash_copy_indirect can't copy any references to the hidden versioned symbol. We need to bind a symbol locally when linking executable if it is locally defined, hidden versioned, not referenced by shared library and not exported. bfd/ PR ld/18720 * elflink.c (_bfd_elf_merge_symbol): Add a parameter to indicate if the new symbol matches the existing one. The new hidden versioned symbol matches the existing symbol if they have the same symbol version. Update the existing symbol only if they match. (_bfd_elf_add_default_symbol): Update call to _bfd_elf_merge_symbol. (_bfd_elf_link_assign_sym_version): Don't set the hidden field here. (elf_link_add_object_symbols): Override a definition only if the new symbol matches the existing one. (_bfd_elf_link_hash_copy_indirect): Don't copy any references to the hidden versioned symbol. (elf_link_output_extsym): Bind a symbol locally when linking executable if it is locally defined, hidden versioned, not referenced by shared library and not exported. Turn on VERSYM_HIDDEN only if the hidden vesioned symbol is defined locally. ld/testsuite/ PR ld/18720 * ld-elf/indirect.exp: Run tests for PR ld/18720. * ld-elf/pr18720.out: New file. * ld-elf/pr18720a.c: Likewise. * ld-elf/pr18720b.c: Likewise. * ld-elf/pr18720c.c: Likewise.
This commit is contained in:
H.J. Lu
parent
060967202b
commit
6e33951edc
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@ -1,3 +1,25 @@
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2015-08-07 H.J. Lu <hongjiu.lu@intel.com>
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PR ld/18720
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* elflink.c (_bfd_elf_merge_symbol): Add a parameter to indicate
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if the new symbol matches the existing one. The new hidden
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versioned symbol matches the existing symbol if they have the
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same symbol version. Update the existing symbol only if they
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match.
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(_bfd_elf_add_default_symbol): Update call to
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_bfd_elf_merge_symbol.
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(_bfd_elf_link_assign_sym_version): Don't set the hidden field
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here.
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(elf_link_add_object_symbols): Override a definition only if the
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new symbol matches the existing one.
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(_bfd_elf_link_hash_copy_indirect): Don't copy any references to
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the hidden versioned symbol.
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(elf_link_output_extsym): Bind a symbol locally when linking
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executable if it is locally defined, hidden versioned, not
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referenced by shared library and not exported. Turn on
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VERSYM_HIDDEN only if the hidden vesioned symbol is defined
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locally.
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2015-08-05 Nick Clifton <nickc@redhat.com>
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* elf.c (_bfd_elf_copy_private_bfd_data): Copy the sh_link and
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134
bfd/elflink.c
134
bfd/elflink.c
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@ -939,7 +939,8 @@ _bfd_elf_merge_symbol (bfd *abfd,
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bfd_boolean *skip,
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bfd_boolean *override,
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bfd_boolean *type_change_ok,
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bfd_boolean *size_change_ok)
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bfd_boolean *size_change_ok,
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bfd_boolean *matched)
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{
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asection *sec, *oldsec;
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struct elf_link_hash_entry *h;
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@ -950,6 +951,7 @@ _bfd_elf_merge_symbol (bfd *abfd,
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bfd_boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
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bfd_boolean newweak, oldweak, newfunc, oldfunc;
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const struct elf_backend_data *bed;
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char *new_version;
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*skip = FALSE;
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*override = FALSE;
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@ -968,6 +970,17 @@ _bfd_elf_merge_symbol (bfd *abfd,
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bed = get_elf_backend_data (abfd);
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/* NEW_VERSION is the symbol version of the new symbol. */
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new_version = strrchr (name, ELF_VER_CHR);
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if (new_version)
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{
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if (new_version > name && new_version[-1] != ELF_VER_CHR)
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h->hidden = 1;
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new_version += 1;
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if (new_version[0] == '\0')
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new_version = NULL;
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}
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/* For merging, we only care about real symbols. But we need to make
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sure that indirect symbol dynamic flags are updated. */
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hi = h;
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@ -975,6 +988,45 @@ _bfd_elf_merge_symbol (bfd *abfd,
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|| h->root.type == bfd_link_hash_warning)
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h = (struct elf_link_hash_entry *) h->root.u.i.link;
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if (!*matched)
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{
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if (hi == h || h->root.type == bfd_link_hash_new)
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*matched = TRUE;
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else
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{
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/* OLD_HIDDEN is true if the existing symbol is only visibile
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to the symbol with the same symbol version. NEW_HIDDEN is
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true if the new symbol is only visibile to the symbol with
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the same symbol version. */
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bfd_boolean old_hidden = h->hidden;
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bfd_boolean new_hidden = hi->hidden;
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if (!old_hidden && !new_hidden)
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/* The new symbol matches the existing symbol if both
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aren't hidden. */
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*matched = TRUE;
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else
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{
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/* OLD_VERSION is the symbol version of the existing
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symbol. */
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char *old_version = strrchr (h->root.root.string,
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ELF_VER_CHR);
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if (old_version)
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{
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old_version += 1;
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if (old_version[0] == '\0')
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old_version = NULL;
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}
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/* The new symbol matches the existing symbol if they
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have the same symbol version. */
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*matched = (old_version == new_version
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|| (old_version != NULL
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&& new_version != NULL
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&& strcmp (old_version, new_version) == 0));
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}
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}
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}
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/* OLDBFD and OLDSEC are a BFD and an ASECTION associated with the
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existing symbol. */
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@ -1047,7 +1099,9 @@ _bfd_elf_merge_symbol (bfd *abfd,
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}
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else
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{
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h->dynamic_def = 1;
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/* Update the existing symbol only if they match. */
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if (*matched)
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h->dynamic_def = 1;
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hi->dynamic_def = 1;
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}
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}
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@ -1618,6 +1672,7 @@ _bfd_elf_add_default_symbol (bfd *abfd,
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char *p;
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size_t len, shortlen;
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asection *tmp_sec;
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bfd_boolean matched;
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/* If this symbol has a version, and it is the default version, we
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create an indirect symbol from the default name to the fully
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@ -1644,10 +1699,11 @@ _bfd_elf_add_default_symbol (bfd *abfd,
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actually going to define an indirect symbol. */
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type_change_ok = FALSE;
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size_change_ok = FALSE;
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matched = TRUE;
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tmp_sec = sec;
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if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &tmp_sec, &value,
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&hi, poldbfd, NULL, NULL, &skip, &override,
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&type_change_ok, &size_change_ok))
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&type_change_ok, &size_change_ok, &matched))
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return FALSE;
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if (skip)
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@ -1767,7 +1823,7 @@ nondefault:
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tmp_sec = sec;
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if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &tmp_sec, &value,
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&hi, poldbfd, NULL, NULL, &skip, &override,
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&type_change_ok, &size_change_ok))
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&type_change_ok, &size_change_ok, &matched))
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return FALSE;
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if (skip)
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@ -1977,26 +2033,14 @@ _bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data)
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if (p != NULL && h->verinfo.vertree == NULL)
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{
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struct bfd_elf_version_tree *t;
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bfd_boolean hidden;
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hidden = TRUE;
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/* There are two consecutive ELF_VER_CHR characters if this is
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not a hidden symbol. */
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++p;
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if (*p == ELF_VER_CHR)
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{
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hidden = FALSE;
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++p;
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}
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++p;
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/* If there is no version string, we can just return out. */
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if (*p == '\0')
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{
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if (hidden)
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h->hidden = 1;
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return TRUE;
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}
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return TRUE;
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/* Look for the version. If we find it, it is no longer weak. */
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for (t = sinfo->info->version_info; t != NULL; t = t->next)
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@ -2092,9 +2136,6 @@ _bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data)
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sinfo->failed = TRUE;
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return FALSE;
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}
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if (hidden)
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h->hidden = 1;
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}
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/* If we don't have a version for this symbol, see if we can find
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@ -3885,6 +3926,7 @@ error_free_dyn:
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bfd_boolean common;
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unsigned int old_alignment;
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bfd *old_bfd;
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bfd_boolean matched;
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override = FALSE;
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@ -4019,6 +4061,7 @@ error_free_dyn:
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size_change_ok = FALSE;
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type_change_ok = bed->type_change_ok;
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old_weak = FALSE;
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matched = FALSE;
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old_alignment = 0;
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old_bfd = NULL;
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new_sec = sec;
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@ -4148,13 +4191,16 @@ error_free_dyn:
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if (!_bfd_elf_merge_symbol (abfd, info, name, isym, &sec, &value,
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sym_hash, &old_bfd, &old_weak,
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&old_alignment, &skip, &override,
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&type_change_ok, &size_change_ok))
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&type_change_ok, &size_change_ok,
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&matched))
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goto error_free_vers;
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if (skip)
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continue;
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if (override)
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/* Override a definition only if the new symbol matches the
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existing one. */
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if (override && matched)
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definition = FALSE;
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h = *sym_hash;
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@ -6810,14 +6856,18 @@ _bfd_elf_link_hash_copy_indirect (struct bfd_link_info *info,
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struct elf_link_hash_table *htab;
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/* Copy down any references that we may have already seen to the
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symbol which just became indirect. */
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symbol which just became indirect if DIR isn't a hidden versioned
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symbol. */
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dir->ref_dynamic |= ind->ref_dynamic;
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dir->ref_regular |= ind->ref_regular;
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dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
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dir->non_got_ref |= ind->non_got_ref;
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dir->needs_plt |= ind->needs_plt;
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dir->pointer_equality_needed |= ind->pointer_equality_needed;
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if (!dir->hidden)
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{
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dir->ref_dynamic |= ind->ref_dynamic;
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dir->ref_regular |= ind->ref_regular;
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dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
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dir->non_got_ref |= ind->non_got_ref;
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dir->needs_plt |= ind->needs_plt;
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dir->pointer_equality_needed |= ind->pointer_equality_needed;
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}
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if (ind->root.type != bfd_link_hash_indirect)
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return;
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@ -8904,6 +8954,16 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
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const struct elf_backend_data *bed;
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long indx;
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int ret;
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/* A symbol is bound locally if it is forced local or it is locally
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defined, hidden versioned, not referenced by shared library and
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not exported when linking executable. */
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bfd_boolean local_bind = (h->forced_local
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|| (flinfo->info->executable
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&& !flinfo->info->export_dynamic
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&& !h->dynamic
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&& !h->ref_dynamic
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&& h->def_regular
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&& h->hidden));
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if (h->root.type == bfd_link_hash_warning)
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{
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@ -8915,12 +8975,12 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
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/* Decide whether to output this symbol in this pass. */
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if (eoinfo->localsyms)
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{
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if (!h->forced_local)
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if (!local_bind)
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return TRUE;
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}
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else
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{
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if (h->forced_local)
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if (local_bind)
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return TRUE;
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}
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@ -9041,7 +9101,7 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
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sym.st_value = 0;
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sym.st_size = h->size;
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sym.st_other = h->other;
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if (h->forced_local)
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if (local_bind)
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{
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sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
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/* Turn off visibility on local symbol. */
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@ -9223,8 +9283,10 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
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/* Since there is no version information in the dynamic string,
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if there is no version info in symbol version section, we will
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have a run-time problem if not linking executable, referenced
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by shared library, or not locally defined. */
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by shared library, not locally defined, or not bound locally.
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*/
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if (h->verinfo.verdef == NULL
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&& !local_bind
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&& (!flinfo->info->executable
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|| h->ref_dynamic
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|| !h->def_regular))
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@ -9297,7 +9359,9 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
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iversym.vs_vers++;
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}
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if (h->hidden)
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/* Turn on VERSYM_HIDDEN only if the hidden vesioned symbol is
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defined locally. */
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if (h->hidden && h->def_regular)
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iversym.vs_vers |= VERSYM_HIDDEN;
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eversym = (Elf_External_Versym *) flinfo->symver_sec->contents;
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@ -1,3 +1,12 @@
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2015-08-07 H.J. Lu <hongjiu.lu@intel.com>
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PR ld/18720
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* ld-elf/indirect.exp: Run tests for PR ld/18720.
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* ld-elf/pr18720.out: New file.
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* ld-elf/pr18720a.c: Likewise.
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* ld-elf/pr18720b.c: Likewise.
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* ld-elf/pr18720c.c: Likewise.
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2015-08-04 Andrew Burgess <andrew.burgess@embecosm.com>
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* ld/ld-lib.exp (run_dump_test): When using the map option, no
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@ -64,7 +64,9 @@ if { ![ld_compile $CC $srcdir/$subdir/indirect1a.c tmpdir/indirect1a.o]
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|| ![ld_compile $CC $srcdir/$subdir/indirect3a.c tmpdir/indirect3a.o]
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|| ![ld_compile $CC $srcdir/$subdir/indirect3b.c tmpdir/indirect3b.o]
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|| ![ld_compile $CC $srcdir/$subdir/indirect4a.c tmpdir/indirect4a.o]
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|| ![ld_compile $CC $srcdir/$subdir/indirect4b.c tmpdir/indirect4b.o] } {
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|| ![ld_compile $CC $srcdir/$subdir/indirect4b.c tmpdir/indirect4b.o]
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|| ![ld_compile "$CC -O2 -fPIC -I../bfd" $srcdir/$subdir/pr18720a.c tmpdir/pr18720a.o]
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|| ![ld_compile $CC $srcdir/$subdir/pr18720b.c tmpdir/pr18720b.o] } {
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unresolved "Indirect symbol tests"
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return
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}
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@ -79,6 +81,12 @@ set build_tests {
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{"Build libindirect4c.so"
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"-shared" "-fPIC"
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{indirect4c.c} {} "libindirect4c.so"}
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{"Build libpr18720c.so"
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"-shared" "-fPIC"
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{pr18720c.c} {} "libpr18720c.so"}
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{"Build pr18720b1.o"
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"-r -nostdlib tmpdir/pr18720b.o" ""
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{dummy.c} {} "pr18720b1.o"}
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}
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run_cc_link_tests $build_tests
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@ -132,6 +140,21 @@ set run_tests {
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{"Run with libindirect4c.so 4"
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"tmpdir/libindirect4c.so tmpdir/indirect4b.o tmpdir/indirect4a.o" ""
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{dummy.c} "indirect4d" "indirect4.out"}
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{"Run with libpr18720c.so 1"
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"tmpdir/pr18720a.o tmpdir/pr18720b.o tmpdir/libpr18720c.so" ""
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{check-ptr-eq.c} "pr18720a" "pr18720.out"}
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{"Run with libpr18720c.so 2"
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"tmpdir/pr18720a.o tmpdir/libpr18720c.so tmpdir/pr18720b.o" ""
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{check-ptr-eq.c} "pr18720b" "pr18720.out"}
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{"Run with libpr18720c.so 3"
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"tmpdir/pr18720b.o tmpdir/libpr18720c.so tmpdir/pr18720a.o" ""
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{check-ptr-eq.c} "pr18720c" "pr18720.out"}
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{"Run with libpr18720c.so 4"
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"tmpdir/libpr18720c.so tmpdir/pr18720b.o tmpdir/pr18720a.o" ""
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{check-ptr-eq.c} "pr18720d" "pr18720.out"}
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{"Run with libpr18720c.so 5"
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"tmpdir/libpr18720c.so tmpdir/pr18720b1.o tmpdir/pr18720a.o" ""
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{check-ptr-eq.c} "pr18720d" "pr18720.out"}
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}
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run_ld_link_exec_tests [] $run_tests
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@ -0,0 +1,2 @@
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MAIN
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DSO
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@ -0,0 +1,27 @@
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#include <bfd_stdint.h>
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extern void bar (void);
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extern void foo (void);
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extern void foo_alias (void);
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extern void check_ptr_eq (void *, void *);
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#if defined(__GNUC__) && (__GNUC__ * 1000 + __GNUC_MINOR__) >= 4005
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__attribute__ ((noinline, noclone))
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#else
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__attribute__ ((noinline))
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#endif
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int
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foo_p (void)
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{
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return (intptr_t) &foo == 0x12345678 ? 1 : 0;
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}
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||||
|
||||
int
|
||||
main (void)
|
||||
{
|
||||
foo ();
|
||||
foo_p ();
|
||||
bar ();
|
||||
check_ptr_eq (&foo, &foo_alias);
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -0,0 +1,11 @@
|
|||
#include <stdio.h>
|
||||
|
||||
void
|
||||
foo (void)
|
||||
{
|
||||
printf ("MAIN\n");
|
||||
}
|
||||
|
||||
asm (".symver foo,foo@FOO");
|
||||
asm (".set foo_alias,foo");
|
||||
asm (".global foo_alias");
|
||||
|
|
@ -0,0 +1,15 @@
|
|||
#include <stdio.h>
|
||||
|
||||
extern void foo (void);
|
||||
|
||||
void
|
||||
foo (void)
|
||||
{
|
||||
printf ("DSO\n");
|
||||
}
|
||||
|
||||
void
|
||||
bar (void)
|
||||
{
|
||||
foo ();
|
||||
}
|
||||
Loading…
Reference in New Issue