2005-07-25 H.J. Lu <hongjiu.lu@intel.com>

	* elf-bfd.h (elf_backend_data): Add common_definition,
	common_section_index, common_section, and merge_symbol.
	(_bfd_elf_common_definition): New.
	(_bfd_elf_common_section_index): New.
	(_bfd_elf_common_section): New.

	* elf.c (elf_fake_sections): Don't clear sh_flags.

	* elflink.c (_bfd_elf_merge_symbol): Call backend merge_symbol
	if it is available.
	(is_global_data_symbol_definition): Call backend
	common_definition instead of checking SHN_COMMON.
	(elf_link_add_object_symbols): Likewise.
	(elf_link_output_extsym): Call backend common_section_index
	for common section index.
	(_bfd_elf_common_definition): New.
	(_bfd_elf_common_section_index): New.
	(_bfd_elf_common_section): New.

	* elfxx-target.h (elf_backend_common_definition): New.
	(elf_backend_common_section_index): New.
	(elf_backend_common_section): New.
	(elf_backend_merge_symbol): New.
	(elfNN_bed): Initialize common_definition, common_section_index,
	common_section, and merge_symbol.

	* section.c (BFD_FAKE_SECTION): New.
	(STD_SECTION): Use it.
	* bfd-in2.h: Regenerated.

7 files changed, 214 insertions, 50 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 495ea95..64d9817 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,35 @@
+2005-07-25  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* elf-bfd.h (elf_backend_data): Add common_definition,
+	common_section_index, common_section, and merge_symbol.
+	(_bfd_elf_common_definition): New.
+	(_bfd_elf_common_section_index): New.
+	(_bfd_elf_common_section): New.
+
+	* elf.c (elf_fake_sections): Don't clear sh_flags.
+
+	* elflink.c (_bfd_elf_merge_symbol): Call backend merge_symbol
+	if it is available.
+	(is_global_data_symbol_definition): Call backend
+	common_definition instead of checking SHN_COMMON.
+	(elf_link_add_object_symbols): Likewise.
+	(elf_link_output_extsym): Call backend common_section_index
+	for common section index.
+	(_bfd_elf_common_definition): New.
+	(_bfd_elf_common_section_index): New.
+	(_bfd_elf_common_section): New.
+
+	* elfxx-target.h (elf_backend_common_definition): New.
+	(elf_backend_common_section_index): New.
+	(elf_backend_common_section): New.
+	(elf_backend_merge_symbol): New.
+	(elfNN_bed): Initialize common_definition, common_section_index,
+	common_section, and merge_symbol.
+
+	* section.c (BFD_FAKE_SECTION): New.
+	(STD_SECTION): Use it.
+	* bfd-in2.h: Regenerated.
+
 2005-07-23  Olaf Hering <olh@suse.de>
 
 	* elflink.c (elf_link_input_bfd): Add '\n' for linker einfo
diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h
index c9c75c2..7dbfe95 100644
--- a/bfd/bfd-in2.h
+++ b/bfd/bfd-in2.h
@@ -1551,6 +1551,47 @@ extern const struct bfd_symbol * const bfd_ind_symbol;
 #define bfd_section_removed_from_list(ABFD, S) \
   ((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
 
+#define BFD_FAKE_SECTION(SEC, FLAGS, SYM, SYM_PTR, NAME, IDX)          \
+  /* name, id,  index, next, prev, flags, user_set_vma,            */  \
+  { NAME,  IDX, 0,     NULL, NULL, FLAGS, 0,                           \
+                                                                       \
+  /* linker_mark, linker_has_input, gc_mark, gc_mark_from_eh,      */  \
+     0,           0,                1,       0,                        \
+                                                                       \
+  /* segment_mark, sec_info_type, use_rela_p, has_tls_reloc,       */  \
+     0,            0,             0,          0,                       \
+                                                                       \
+  /* has_gp_reloc, need_finalize_relax, reloc_done,                */  \
+     0,            0,                   0,                             \
+                                                                       \
+  /* vma, lma, size, rawsize                                       */  \
+     0,   0,   0,    0,                                                \
+                                                                       \
+  /* output_offset, output_section,              alignment_power,  */  \
+     0,             (struct bfd_section *) &SEC, 0,                    \
+                                                                       \
+  /* relocation, orelocation, reloc_count, filepos, rel_filepos,   */  \
+     NULL,       NULL,        0,           0,       0,                 \
+                                                                       \
+  /* line_filepos, userdata, contents, lineno, lineno_count,       */  \
+     0,            NULL,     NULL,     NULL,   0,                      \
+                                                                       \
+  /* entsize, kept_section, moving_line_filepos,                    */ \
+     0,       NULL,          0,                                        \
+                                                                       \
+  /* target_index, used_by_bfd, constructor_chain, owner,          */  \
+     0,            NULL,        NULL,              NULL,               \
+                                                                       \
+  /* symbol,                                                       */  \
+     (struct bfd_symbol *) SYM,                                        \
+                                                                       \
+  /* symbol_ptr_ptr,                                               */  \
+     (struct bfd_symbol **) SYM_PTR,                                   \
+                                                                       \
+  /* map_head, map_tail                                            */  \
+     { NULL }, { NULL }                                                \
+    }
+
 void bfd_section_list_clear (bfd *);
 
 asection *bfd_get_section_by_name (bfd *abfd, const char *name);
diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
index 2bbc1c9..f7bab5c 100644
--- a/bfd/elf-bfd.h
+++ b/bfd/elf-bfd.h
@@ -969,6 +969,30 @@ struct elf_backend_data
      see elf.c.  */
   bfd_vma (*plt_sym_val) (bfd_vma, const asection *, const arelent *);
 
+  /* Is symbol defined in common section?  */
+  bfd_boolean (*common_definition) (Elf_Internal_Sym *);
+
+  /* Return a common section index for section.  */
+  unsigned int (*common_section_index) (asection *);
+
+  /* Return a common section for section.  */
+  asection *(*common_section) (asection *);
+
+  /* Return TRUE if we can merge 2 definitions.  */
+  bfd_boolean (*merge_symbol) (struct bfd_link_info *,
+			       struct elf_link_hash_entry **,
+			       struct elf_link_hash_entry *,
+			       Elf_Internal_Sym *, asection **,
+			       bfd_vma *, unsigned int *,
+			       bfd_boolean *, bfd_boolean *,
+			       bfd_boolean *, bfd_boolean *,
+			       bfd_boolean *, bfd_boolean *,
+			       bfd_boolean *, bfd_boolean *,
+			       bfd *, asection **,
+			       bfd_boolean *, bfd_boolean *,
+			       bfd_boolean *, bfd_boolean *,
+			       bfd *, asection **);
+
   /* Used to handle bad SHF_LINK_ORDER input.  */
   bfd_error_handler_type link_order_error_handler;
 
@@ -1741,6 +1765,15 @@ extern int bfd_elf_link_record_local_dynamic_symbol
 extern bfd_boolean _bfd_elf_close_and_cleanup
   (bfd *);
 
+extern bfd_boolean _bfd_elf_common_definition
+  (Elf_Internal_Sym *);
+
+extern unsigned int _bfd_elf_common_section_index
+  (asection *);
+
+extern asection *_bfd_elf_common_section
+  (asection *);
+
 extern void _bfd_dwarf2_cleanup_debug_info
   (bfd *);
 
diff --git a/bfd/elf.c b/bfd/elf.c
index ff46a5e..3e47b02 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -2618,7 +2618,7 @@ elf_fake_sections (bfd *abfd, asection *asect, void *failedptrarg)
       return;
     }
 
-  this_hdr->sh_flags = 0;
+  /* Don't clear sh_flags. Assembler may set additional bits.  */
 
   if ((asect->flags & SEC_ALLOC) != 0
       || asect->user_set_vma)
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 901b528..f52d307 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -780,6 +780,7 @@ _bfd_elf_merge_symbol (bfd *abfd,
   bfd *oldbfd;
   bfd_boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
   bfd_boolean newweak, oldweak;
+  const struct elf_backend_data *bed;
 
   *skip = FALSE;
   *override = FALSE;
@@ -1121,6 +1122,19 @@ _bfd_elf_merge_symbol (bfd *abfd,
   else
     olddyncommon = FALSE;
 
+  /* We now know everything about the old and new symbols.  We ask the
+     backend to check if we can merge them.  */
+  bed = get_elf_backend_data (abfd);
+  if (bed->merge_symbol
+      && !bed->merge_symbol (info, sym_hash, h, sym, psec, pvalue,
+			     pold_alignment, skip, override,
+			     type_change_ok, size_change_ok,
+			     &newdyn, &newdef, &newdyncommon, &newweak,
+			     abfd, &sec,
+			     &olddyn, &olddef, &olddyncommon, &oldweak,
+			     oldbfd, &oldsec))
+    return FALSE;
+
   /* If both the old and the new symbols look like common symbols in a
      dynamic object, set the size of the symbol to the larger of the
      two.  */
@@ -1197,7 +1211,7 @@ _bfd_elf_merge_symbol (bfd *abfd,
       newdef = FALSE;
       newdyncommon = FALSE;
       *pvalue = sym->st_size;
-      *psec = sec = bfd_com_section_ptr;
+      *psec = sec = bed->common_section (oldsec);
       *size_change_ok = TRUE;
     }
 
@@ -2641,6 +2655,8 @@ static bfd_boolean
 is_global_data_symbol_definition (bfd *abfd ATTRIBUTE_UNUSED,
 				  Elf_Internal_Sym *sym)
 {
+  const struct elf_backend_data *bed;
+
   /* Local symbols do not count, but target specific ones might.  */
   if (ELF_ST_BIND (sym->st_info) != STB_GLOBAL
       && ELF_ST_BIND (sym->st_info) < STB_LOOS)
@@ -2656,7 +2672,8 @@ is_global_data_symbol_definition (bfd *abfd ATTRIBUTE_UNUSED,
 
   /* If the symbol is defined in the common section, then
      it is a common definition and so does not count.  */
-  if (sym->st_shndx == SHN_COMMON)
+  bed = get_elf_backend_data (abfd);
+  if (bed->common_definition (sym))
     return FALSE;
 
   /* If the symbol is in a target specific section then we
@@ -3548,6 +3565,7 @@ elf_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
       bfd_boolean type_change_ok;
       bfd_boolean new_weakdef;
       bfd_boolean override;
+      bfd_boolean common;
       unsigned int old_alignment;
       bfd *old_bfd;
 
@@ -3557,6 +3575,7 @@ elf_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
       sec = NULL;
       value = isym->st_value;
       *sym_hash = NULL;
+      common = bed->common_definition (isym);
 
       bind = ELF_ST_BIND (isym->st_info);
       if (bind == STB_LOCAL)
@@ -3569,8 +3588,7 @@ elf_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
 	}
       else if (bind == STB_GLOBAL)
 	{
-	  if (isym->st_shndx != SHN_UNDEF
-	      && isym->st_shndx != SHN_COMMON)
+	  if (isym->st_shndx != SHN_UNDEF && !common)
 	    flags = BSF_GLOBAL;
 	}
       else if (bind == STB_WEAK)
@@ -3861,13 +3879,12 @@ elf_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
 	}
 
       /* Set the alignment of a common symbol.  */
-      if ((isym->st_shndx == SHN_COMMON
-	   || bfd_is_com_section (sec))
+      if ((common || bfd_is_com_section (sec))
 	  && h->root.type == bfd_link_hash_common)
 	{
 	  unsigned int align;
 
-	  if (isym->st_shndx == SHN_COMMON)
+	  if (common)
 	    align = bfd_log2 (isym->st_value);
 	  else
 	    {
@@ -3893,7 +3910,7 @@ elf_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
 	     definition or a common symbol is ignored due to the old
 	     normal definition. We need to make sure the maximum
 	     alignment is maintained.  */
-	  if ((old_alignment || isym->st_shndx == SHN_COMMON)
+	  if ((old_alignment || common)
 	      && h->root.type != bfd_link_hash_common)
 	    {
 	      unsigned int common_align;
@@ -6498,7 +6515,7 @@ elf_link_output_extsym (struct elf_link_hash_entry *h, void *data)
 
     case bfd_link_hash_common:
       input_sec = h->root.u.c.p->section;
-      sym.st_shndx = SHN_COMMON;
+      sym.st_shndx = bed->common_section_index (input_sec);
       sym.st_value = 1 << h->root.u.c.p->alignment_power;
       break;
 
@@ -9900,3 +9917,21 @@ _bfd_elf_fix_excluded_sec_syms (bfd *obfd, struct bfd_link_info *info)
 {
   bfd_link_hash_traverse (info->hash, fix_syms, obfd);
 }
+
+bfd_boolean
+_bfd_elf_common_definition (Elf_Internal_Sym *sym)
+{
+  return sym->st_shndx == SHN_COMMON;
+}
+
+unsigned int
+_bfd_elf_common_section_index (asection *sec ATTRIBUTE_UNUSED)
+{
+  return SHN_COMMON;
+}
+
+asection *
+_bfd_elf_common_section (asection *sec ATTRIBUTE_UNUSED)
+{
+  return bfd_com_section_ptr;
+}
diff --git a/bfd/elfxx-target.h b/bfd/elfxx-target.h
index cd63244..0268e62 100644
--- a/bfd/elfxx-target.h
+++ b/bfd/elfxx-target.h
@@ -521,6 +521,22 @@
 #define elf_backend_link_order_error_handler _bfd_default_error_handler
 #endif
 
+#ifndef elf_backend_common_definition
+#define elf_backend_common_definition _bfd_elf_common_definition
+#endif
+
+#ifndef elf_backend_common_section_index
+#define elf_backend_common_section_index _bfd_elf_common_section_index
+#endif
+
+#ifndef elf_backend_common_section
+#define elf_backend_common_section _bfd_elf_common_section
+#endif
+
+#ifndef elf_backend_merge_symbol
+#define elf_backend_merge_symbol NULL
+#endif
+
 extern const struct elf_size_info _bfd_elfNN_size_info;
 
 #ifndef INCLUDED_TARGET_FILE
@@ -590,6 +606,10 @@ static const struct elf_backend_data elfNN_bed =
   elf_backend_ecoff_debug_swap,
   elf_backend_bfd_from_remote_memory,
   elf_backend_plt_sym_val,
+  elf_backend_common_definition,
+  elf_backend_common_section_index,
+  elf_backend_common_section,
+  elf_backend_merge_symbol,
   elf_backend_link_order_error_handler,
   elf_backend_relplt_name,
   ELF_MACHINE_ALT1,
diff --git a/bfd/section.c b/bfd/section.c
index aeb63a6..42554b9 100644
--- a/bfd/section.c
+++ b/bfd/section.c
@@ -635,6 +635,47 @@ CODE_FRAGMENT
 .#define bfd_section_removed_from_list(ABFD, S) \
 .  ((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
 .
+.#define BFD_FAKE_SECTION(SEC, FLAGS, SYM, SYM_PTR, NAME, IDX)		\
+.  {* name, id,  index, next, prev, flags, user_set_vma,            *}	\
+.  { NAME,  IDX, 0,     NULL, NULL, FLAGS, 0,				\
+.									\
+.  {* linker_mark, linker_has_input, gc_mark, gc_mark_from_eh,      *}	\
+.     0,           0,                1,       0,			\
+.									\
+.  {* segment_mark, sec_info_type, use_rela_p, has_tls_reloc,       *}	\
+.     0,            0,             0,          0,			\
+.									\
+.  {* has_gp_reloc, need_finalize_relax, reloc_done,                *}	\
+.     0,            0,                   0,				\
+.									\
+.  {* vma, lma, size, rawsize                                       *}	\
+.     0,   0,   0,    0,						\
+.									\
+.  {* output_offset, output_section,              alignment_power,  *}	\
+.     0,             (struct bfd_section *) &SEC, 0,			\
+.									\
+.  {* relocation, orelocation, reloc_count, filepos, rel_filepos,   *}	\
+.     NULL,       NULL,        0,           0,       0,			\
+.									\
+.  {* line_filepos, userdata, contents, lineno, lineno_count,       *}	\
+.     0,            NULL,     NULL,     NULL,   0,			\
+.									\
+.  {* entsize, kept_section, moving_line_filepos,		     *}	\
+.     0,       NULL,	      0,					\
+.									\
+.  {* target_index, used_by_bfd, constructor_chain, owner,          *}	\
+.     0,            NULL,        NULL,              NULL,		\
+.									\
+.  {* symbol,                                                       *}	\
+.     (struct bfd_symbol *) SYM,					\
+.									\
+.  {* symbol_ptr_ptr,                                               *}	\
+.     (struct bfd_symbol **) SYM_PTR,					\
+.									\
+.  {* map_head, map_tail                                            *}	\
+.     { NULL }, { NULL }						\
+.    }
+.
 */
 
 /* We use a macro to initialize the static asymbol structures because
@@ -662,46 +703,8 @@ static const asymbol global_syms[] =
 
 #define STD_SECTION(SEC, FLAGS, SYM, NAME, IDX)				\
   const asymbol * const SYM = (asymbol *) &global_syms[IDX]; 		\
-  asection SEC =							\
-    /* name, id,  index, next, prev, flags, user_set_vma,            */	\
-    { NAME,  IDX, 0,     NULL, NULL, FLAGS, 0,				\
-									\
-    /* linker_mark, linker_has_input, gc_mark, gc_mark_from_eh,      */	\
-       0,           0,                1,       0,			\
-									\
-    /* segment_mark, sec_info_type, use_rela_p, has_tls_reloc,       */	\
-       0,            0,             0,          0,			\
-									\
-    /* has_gp_reloc, need_finalize_relax, reloc_done,                */	\
-       0,            0,                   0,				\
-									\
-    /* vma, lma, size, rawsize                                       */	\
-       0,   0,   0,    0,						\
-									\
-    /* output_offset, output_section,              alignment_power,  */	\
-       0,             (struct bfd_section *) &SEC, 0,			\
-									\
-    /* relocation, orelocation, reloc_count, filepos, rel_filepos,   */	\
-       NULL,       NULL,        0,           0,       0,		\
-									\
-    /* line_filepos, userdata, contents, lineno, lineno_count,       */	\
-       0,            NULL,     NULL,     NULL,   0,			\
-									\
-    /* entsize, kept_section, moving_line_filepos,                   */	\
-       0,       NULL,         0,					\
-									\
-    /* target_index, used_by_bfd, constructor_chain, owner,          */	\
-       0,            NULL,        NULL,              NULL,		\
-									\
-    /* symbol,                                                       */	\
-       (struct bfd_symbol *) &global_syms[IDX],				\
-									\
-    /* symbol_ptr_ptr,                                               */	\
-       (struct bfd_symbol **) &SYM,					\
-									\
-    /* map_head, map_tail                                            */	\
-       { NULL }, { NULL }						\
-    }
+  asection SEC = BFD_FAKE_SECTION(SEC, FLAGS, &global_syms[IDX], &SYM,	\
+				  NAME, IDX)
 
 STD_SECTION (bfd_com_section, SEC_IS_COMMON, bfd_com_symbol,
 	     BFD_COM_SECTION_NAME, 0);