[patch bfd]: Some adjustments on coff-link.c

[Kai Tietz <ktietz70 at googlemail dot com>]

Hello,

Now at right ML.
This patch improves COFF linker for undefined weak symbols
and avoids writing symbols for discarded sections - if linker tells so
-, and for IR generated sections.

ChangeLog

2011-10-09 ?Kai Tietz ?<ktietz@redhat.com>

? ? ? ?* cofflink.c (coff_link_check_ar_symbols): Allow
? ? ? ?adding of archive-file if symbol was undefined weak.
? ? ? ?(_bfd_coff_write_global_sym): Skip write for symbol
? ? ? ?in discared section, or if section is coming from IR, or
? ? ? ?if input section has explicit SEC_EXCLUDED set.
? ? ? ?(_bfd_coff_generic_relocate_section): For undefined weak
? ? ? ?symbol and replacing it by another undefined weak, mark
? ? ? ?section as absolute.

Regression tested for i686-w64-mingw32, x86_64-w64-mingw32, and
i686-pc-cygwin. ?Ok for apply?

Regards,
Kai


Index: src/bfd/cofflink.c
===================================================================
--- src.orig/bfd/cofflink.c
+++ src/bfd/cofflink.c
@@ -242,7 +242,8 @@ coff_link_check_ar_symbols (bfd *abfd,
? ? ? ? ? ? COFF linkers do not bring in an object file which defines
? ? ? ? ? ? it. ?*/
? ? ? ? ?if (h != (struct bfd_link_hash_entry *) NULL
- ? ? ? ? ? ? && h->type == bfd_link_hash_undefined)
+ ? ? ? ? ? ? && (h->type == bfd_link_hash_undefined
+ ? ? ? ? ? ? ? ? || h->type == bfd_link_hash_undefweak))
? ? ? ? ? ?{
? ? ? ? ? ? ?if (!(*info->callbacks
? ? ? ? ? ? ? ? ? ?->add_archive_element) (info, abfd, name, subsbfd))
@@ -2527,6 +2528,7 @@ _bfd_coff_write_global_sym (struct bfd_h
? bfd_size_type symesz;
? unsigned int i;
? file_ptr pos;
+ ?asection *input_sec;

? output_bfd = finfo->output_bfd;

@@ -2547,6 +2549,21 @@ _bfd_coff_write_global_sym (struct bfd_h
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? h->root.root.string, FALSE, FALSE)
? ? ? ? ? ? ? ? ?== NULL))))
? ? return TRUE;
+ ?else if (h->indx != -2
+ ? ? ? ? ? && (h->root.type == bfd_link_hash_defined
+ ? ? ? ? ? ? ?|| h->root.type == bfd_link_hash_defweak)
+ ? ? ? ? ?&& ((finfo->info->strip_discarded
+ ? ? ? ? ? ? ? && !bfd_is_abs_section (h->root.u.def.section)
+ ? ? ? ? ? ? ? && bfd_is_abs_section (h->root.u.def.section->output_section))
+ ? ? ? ? ? ? ?|| (h->root.u.def.section->owner != NULL
+ ? ? ? ? ? ? ? ? ?&& (h->root.u.def.section->owner->flags & BFD_PLUGIN) != 0)))
+ ? ?return TRUE;
+ ?else if (h->indx != -2
+ ? ? ? ? ? && (h->root.type == bfd_link_hash_undefined
+ ? ? ? ? ? ? ?|| h->root.type == bfd_link_hash_undefweak)
+ ? ? ? ? ?&& h->root.u.undef.abfd != NULL
+ ? ? ? ? ?&& (h->root.u.undef.abfd->flags & BFD_PLUGIN) != 0)
+ ? ?return TRUE;

? switch (h->root.type)
? ? {
@@ -2560,26 +2577,37 @@ _bfd_coff_write_global_sym (struct bfd_h
? ? case bfd_link_hash_undefweak:
? ? ? isym.n_scnum = N_UNDEF;
? ? ? isym.n_value = 0;
+ ? ? ?input_sec = bfd_und_section_ptr;
? ? ? break;

? ? case bfd_link_hash_defined:
? ? case bfd_link_hash_defweak:
- ? ? ?{
- ? ? ? asection *sec;
+ ? ? ?input_sec = h->root.u.def.section;
+ ? ? ?if (input_sec->output_section != NULL)
+ ? ? ? {
+ ? ? ? ? asection *sec;

- ? ? ? sec = h->root.u.def.section->output_section;
- ? ? ? if (bfd_is_abs_section (sec))
- ? ? ? ? isym.n_scnum = N_ABS;
- ? ? ? else
- ? ? ? ? isym.n_scnum = sec->target_index;
- ? ? ? isym.n_value = (h->root.u.def.value
- ? ? ? ? ? ? ? ? ? ? ? + h->root.u.def.section->output_offset);
- ? ? ? if (! obj_pe (finfo->output_bfd))
- ? ? ? ? isym.n_value += sec->vma;
- ? ? ?}
+ ? ? ? ? sec = h->root.u.def.section->output_section;
+ ? ? ? ? if (bfd_is_abs_section (sec))
+ ? ? ? ? ? isym.n_scnum = N_ABS;
+ ? ? ? ? else
+ ? ? ? ? ? isym.n_scnum = sec->target_index;
+ ? ? ? ? isym.n_value = (h->root.u.def.value
+ ? ? ? ? ? ? ? ? ? ? ? ? + h->root.u.def.section->output_offset);
+ ? ? ? ? if (! obj_pe (finfo->output_bfd))
+ ? ? ? ? ? isym.n_value += sec->vma;
+ ? ? ? }
+ ? ? ?else
+ ? ? ? ?{
+ ? ? ? ? BFD_ASSERT (input_sec->owner == NULL);
+ ? ? ? ? isym.n_scnum = N_UNDEF;
+ ? ? ? ? isym.n_value = 0;
+ ? ? ? ? input_sec = bfd_und_section_ptr;
+ ? ? ? }
? ? ? break;

? ? case bfd_link_hash_common:
+ ? ? ?input_sec = h->root.u.c.p->section;
? ? ? isym.n_scnum = N_UNDEF;
? ? ? isym.n_value = h->root.u.c.size;
? ? ? break;
@@ -2589,6 +2617,9 @@ _bfd_coff_write_global_sym (struct bfd_h
? ? ? return TRUE;
? ? }

+ ?if ((input_sec->flags & SEC_EXCLUDE) != 0)
+ ? ?return TRUE;
+
? if (strlen (h->root.root.string) <= SYMNMLEN)
? ? strncpy (isym._n._n_name, h->root.root.string, SYMNMLEN);
? else
@@ -3013,7 +3044,8 @@ _bfd_coff_generic_relocate_section (bfd
? ? ? ? ? ? ? ? ? ?h->auxbfd->tdata.coff_obj_data->sym_hashes[
? ? ? ? ? ? ? ? ? ?h->aux->x_sym.x_tagndx.l];

- ? ? ? ? ? ? ? ? if (!h2 || h2->root.type == bfd_link_hash_undefined)
+ ? ? ? ? ? ? ? ? if (!h2 || h2->root.type == bfd_link_hash_undefined
+ ? ? ? ? ? ? ? ? ? ? || h2->root.type == bfd_link_hash_undefweak)
? ? ? ? ? ? ? ? ? ?{
? ? ? ? ? ? ? ? ? ? ?sec = bfd_abs_section_ptr;
? ? ? ? ? ? ? ? ? ? ?val = 0;



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