This is the mail archive of the
binutils@sources.redhat.com
mailing list for the binutils project.
Re: [RFC] unify dynamic_symbol_p implementations
On Fri, Jul 18, 2003 at 11:21:06PM -0700, H. J. Lu wrote:
> That is not the problem. _bfd_elf_dynamic_symbol_p came from
> elfxx-ia64.c, which isn't symmetric with SYMBOL_REFERENCES_LOCAL.
> I don't know how we can get it both ways.
Yes, I see I agreed with Richard's patch too quickly.. The problem is
that SYMBOL_REFERENCES_LOCAL and SYMBOL_CALLS_LOCAL as used by ppc,
ppc64, x86, and x86_64 should only return true if we have a local
definition. Causes failures in ld tests of visibility (hidden_undef).
I do like the idea of a predicate function though.
* elf-bfd.h (SYMBOL_REFERENCES_LOCAL, SYMBOL_CALLS_LOCAL): Use..
(_bfd_elf_symbol_refs_local_p): ..this. Declare.
* elflink.c (_bfd_elf_symbol_refs_local_p): New function.
* elf32-i386.c (elf_i386_relocate_section): Remove h NULL test
now done in _bfd_elf_symbol_refs_local_p.
* elf32-ppc.c (ppc_elf_relocate_section): Likewise.
* elf64-ppc.c (ppc64_elf_relocate_section): Likewise.
* elf64-x86-64.c (elf64_x86_64_relocate_section): Likewise.
One interesting place that this differs from (the inverse of) Richard's
function is in the treatment of weak and undefweak dynamic syms. I
suspect I should allow a weak dynamic sym in an executable to be
overridden, even if we don't find a strong sym in a shared lib supplied
at link time. Comments?
Index: bfd/elf-bfd.h
===================================================================
RCS file: /cvs/src/src/bfd/elf-bfd.h,v
retrieving revision 1.105
diff -u -p -r1.105 elf-bfd.h
--- bfd/elf-bfd.h 19 Jul 2003 04:12:22 -0000 1.105
+++ bfd/elf-bfd.h 20 Jul 2003 13:45:36 -0000
@@ -212,11 +212,11 @@ struct elf_link_hash_entry
it's necessary for shared libs to also reference the .plt even
though the symbol is really local to the shared lib. */
#define SYMBOL_REFERENCES_LOCAL(INFO, H) \
- !_bfd_elf_dynamic_symbol_p (H, INFO, 1)
+ _bfd_elf_symbol_refs_local_p (H, INFO, 0)
/* Will _calls_ to this symbol always call the version in this object? */
#define SYMBOL_CALLS_LOCAL(INFO, H) \
- !_bfd_elf_dynamic_symbol_p (H, INFO, 0)
+ _bfd_elf_symbol_refs_local_p (H, INFO, 1)
/* Records local symbols to be emitted in the dynamic symbol table. */
@@ -1496,6 +1496,9 @@ extern bfd_boolean _bfd_elf_link_sec_mer
PARAMS ((struct elf_link_hash_entry *, PTR));
extern bfd_boolean _bfd_elf_dynamic_symbol_p
+ PARAMS ((struct elf_link_hash_entry *, struct bfd_link_info *, bfd_boolean));
+
+extern bfd_boolean _bfd_elf_symbol_refs_local_p
PARAMS ((struct elf_link_hash_entry *, struct bfd_link_info *, bfd_boolean));
extern const bfd_target *bfd_elf32_object_p
Index: bfd/elflink.c
===================================================================
RCS file: /cvs/src/src/bfd/elflink.c,v
retrieving revision 1.39
diff -u -p -r1.39 elflink.c
--- bfd/elflink.c 19 Jul 2003 06:41:42 -0000 1.39
+++ bfd/elflink.c 20 Jul 2003 13:45:46 -0000
@@ -2534,3 +2534,52 @@ _bfd_elf_dynamic_symbol_p (h, info, igno
us that it remains local. */
return !binding_stays_local_p;
}
+
+/* Return true if the symbol referred to by H should be considered
+ to resolve local to the current module, and false otherwise. Differs
+ from (the inverse of) _bfd_elf_dynamic_symbol_p in the treatment of
+ undefined symbols and weak symbols. */
+
+bfd_boolean
+_bfd_elf_symbol_refs_local_p (h, info, local_protected)
+ struct elf_link_hash_entry *h;
+ struct bfd_link_info *info;
+ bfd_boolean local_protected;
+{
+ /* If it's a local sym, of course we resolve locally. */
+ if (h == NULL)
+ return TRUE;
+
+ /* If we don't have a definition in a regular file, then we can't
+ resolve locally. The sym is either undefined or dynamic. */
+ if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
+ return FALSE;
+
+ /* Forced local symbols resolve locally. */
+ if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
+ return TRUE;
+
+ /* As do non-dynamic symbols. */
+ if (h->dynindx == -1)
+ return TRUE;
+
+ /* At this point, we know the symbol is defined and dynamic. In an
+ executable it must resolve locally, likewise when building symbolic
+ shared libraries. */
+ if (info->executable || info->symbolic)
+ return TRUE;
+
+ /* Now deal with defined dynamic symbols in shared libraries. Ones
+ with default visibility might not resolve locally. */
+ if (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
+ return FALSE;
+
+ /* However, STV_HIDDEN or STV_INTERNAL ones must be local. */
+ if (ELF_ST_VISIBILITY (h->other) != STV_PROTECTED)
+ return TRUE;
+
+ /* Function pointer equality tests may require that STV_PROTECTED
+ symbols be treated as dynamic symbols, even when we know that the
+ dynamic linker will resolve them locally. */
+ return local_protected;
+}
Index: bfd/elf32-i386.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-i386.c,v
retrieving revision 1.107
diff -u -p -r1.107 elf32-i386.c
--- bfd/elf32-i386.c 4 Jul 2003 13:53:37 -0000 1.107
+++ bfd/elf32-i386.c 20 Jul 2003 13:45:37 -0000
@@ -2338,8 +2338,7 @@ elf_i386_relocate_section (bfd *output_b
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak)
&& (r_type != R_386_PC32
- || (h != NULL
- && !SYMBOL_CALLS_LOCAL (info, h))))
+ || !SYMBOL_CALLS_LOCAL (info, h)))
|| (ELIMINATE_COPY_RELOCS
&& !info->shared
&& h != NULL
Index: bfd/elf32-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-ppc.c,v
retrieving revision 1.93
diff -u -p -r1.93 elf32-ppc.c
--- bfd/elf32-ppc.c 12 Jul 2003 11:16:46 -0000 1.93
+++ bfd/elf32-ppc.c 20 Jul 2003 13:45:39 -0000
@@ -5175,9 +5175,8 @@ ppc_elf_relocate_section (bfd *output_bf
case R_PPC_REL14_BRNTAKEN:
/* If these relocations are not to a named symbol, they can be
handled right here, no need to bother the dynamic linker. */
- if (h == NULL
- || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0
- || SYMBOL_REFERENCES_LOCAL (info, h))
+ if (SYMBOL_REFERENCES_LOCAL (info, h)
+ || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
break;
/* fall through */
@@ -5207,8 +5206,7 @@ ppc_elf_relocate_section (bfd *output_bf
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak)
&& (MUST_BE_DYN_RELOC (r_type)
- || (h != NULL
- && !SYMBOL_CALLS_LOCAL (info, h))))
+ || !SYMBOL_CALLS_LOCAL (info, h)))
|| (ELIMINATE_COPY_RELOCS
&& !info->shared
&& (input_section->flags & SEC_ALLOC) != 0
@@ -5263,8 +5261,7 @@ ppc_elf_relocate_section (bfd *output_bf
if (skip)
memset (&outrel, 0, sizeof outrel);
- else if (h != NULL
- && !SYMBOL_REFERENCES_LOCAL (info, h))
+ else if (!SYMBOL_REFERENCES_LOCAL (info, h))
{
unresolved_reloc = FALSE;
outrel.r_info = ELF32_R_INFO (h->dynindx, r_type);
Index: bfd/elf64-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf64-ppc.c,v
retrieving revision 1.118
diff -u -p -r1.118 elf64-ppc.c
--- bfd/elf64-ppc.c 10 Jul 2003 00:37:26 -0000 1.118
+++ bfd/elf64-ppc.c 20 Jul 2003 13:45:43 -0000
@@ -8159,8 +8159,7 @@ ppc64_elf_relocate_section (bfd *output_
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak)
&& (MUST_BE_DYN_RELOC (r_type)
- || (h != NULL
- && !SYMBOL_CALLS_LOCAL (info, h))))
+ || !SYMBOL_CALLS_LOCAL (info, h)))
|| (ELIMINATE_COPY_RELOCS
&& !info->shared
&& h != NULL
@@ -8206,8 +8205,7 @@ ppc64_elf_relocate_section (bfd *output_
if (skip)
memset (&outrel, 0, sizeof outrel);
- else if (h != NULL
- && !SYMBOL_REFERENCES_LOCAL (info, h)
+ else if (!SYMBOL_REFERENCES_LOCAL (info, h)
&& !is_opd
&& r_type != R_PPC64_TOC)
outrel.r_info = ELF64_R_INFO (h->dynindx, r_type);
Index: bfd/elf64-x86-64.c
===================================================================
RCS file: /cvs/src/src/bfd/elf64-x86-64.c,v
retrieving revision 1.63
diff -u -p -r1.63 elf64-x86-64.c
--- bfd/elf64-x86-64.c 4 Jul 2003 13:53:37 -0000 1.63
+++ bfd/elf64-x86-64.c 20 Jul 2003 13:45:45 -0000
@@ -2015,8 +2015,7 @@ elf64_x86_64_relocate_section (bfd *outp
&& ((r_type != R_X86_64_PC8
&& r_type != R_X86_64_PC16
&& r_type != R_X86_64_PC32)
- || (h != NULL
- && !SYMBOL_CALLS_LOCAL (info, h))))
+ || !SYMBOL_CALLS_LOCAL (info, h)))
|| (ELIMINATE_COPY_RELOCS
&& !info->shared
&& h != NULL
--
Alan Modra
IBM OzLabs - Linux Technology Centre