PR ld/12762

bfd/
	* bfd-in.h (struct bfd_section_already_linked): Forward declare.
	(_bfd_handle_already_linked): Declare.
	* coff-alpha.c (_bfd_ecoff_section_already_linked): Define as
	_bfd_coff_section_already_linked.
	* coff-mips.c (_bfd_ecoff_section_already_linked): Likewise.
	* coffcode.h (coff_section_already_linked): Likewise.
	* cofflink.c (coff_link_add_symbols): Revert 2011-07-09 changes.
	* elf-bfd.h: Likewise.
	* libbfd-in.h: Likewise.
	* targets.c: Likewise.
	* linker.c (bfd_section_already_linked): Likewise.
	(bfd_section_already_linked_table_lookup): Likewise.
	(bfd_section_already_linked_table_insert): Likewise.
	(_bfd_generic_section_already_linked): Likewise.  Call
	_bfd_handle_already_linked.
	(_bfd_handle_already_linked): New function, split out from..
	* elflink.c (_bfd_elf_section_already_linked): ..here.  Revert
	2011-07-09 changes.  Avoid unnecessary strcmp when matching
	already_linked_list entries.  Match plugin linkonce section.
	(section_signature): Delete.
	* coffgen.c (_bfd_coff_section_already_linked): New function.
	* libcoff-in.h (_bfd_coff_section_already_linked): Declare.
	* libbfd.h: Regenerate.
	* libcoff.h: Regenerate.
	* bfd-in2.h: Regenerate.
ld/
	* ldlang.c (section_already_linked): Revert 2011-07-09 changes.
	* plugin.c: Likewise.
	(asymbol_from_plugin_symbol): Create linkonce section for syms
	with comdat_key.

1 files changed, 103 insertions, 268 deletions

diff --git a/bfd/elflink.c b/bfd/elflink.c
index 53765b626d..528f705e8a 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -12502,208 +12502,84 @@ bfd_elf_discard_info (bfd *output_bfd, struct bfd_link_info *info)
   return ret;
 }
 
-/* For a SHT_GROUP section, return the group signature.  For other
-   sections, return the normal section name.  */
-
-static const char *
-section_signature (asection *sec)
-{
-  if ((sec->flags & SEC_GROUP) != 0
-      && elf_next_in_group (sec) != NULL
-      && elf_group_name (elf_next_in_group (sec)) != NULL)
-    return elf_group_name (elf_next_in_group (sec));
-  return sec->name;
-}
-
 bfd_boolean
 _bfd_elf_section_already_linked (bfd *abfd,
-				 struct already_linked *linked,
+				 asection *sec,
 				 struct bfd_link_info *info)
 {
   flagword flags;
-  const char *name, *p;
+  const char *name, *key;
   struct bfd_section_already_linked *l;
   struct bfd_section_already_linked_hash_entry *already_linked_list;
-  asection *sec, *l_sec;
-  bfd_boolean matched;
-
-  p = name = linked->comdat_key;
-  if (name)
-    {
-      sec = NULL;
-      flags = SEC_GROUP | SEC_LINK_ONCE | SEC_LINK_DUPLICATES_DISCARD;
-    }
-  else
-    {
-      sec = linked->u.sec;
-      if (sec->output_section == bfd_abs_section_ptr)
-	return FALSE;
 
-      flags = sec->flags;
-
-      /* Return if it isn't a linkonce section.  A comdat group section
-	 also has SEC_LINK_ONCE set.  */
-      if ((flags & SEC_LINK_ONCE) == 0)
-	return FALSE;
-
-      /* Don't put group member sections on our list of already linked
-	 sections.  They are handled as a group via their group section.
-	 */
-      if (elf_sec_group (sec) != NULL)
-	return FALSE;
-
-      /* FIXME: When doing a relocatable link, we may have trouble
-	 copying relocations in other sections that refer to local symbols
-	 in the section being discarded.  Those relocations will have to
-	 be converted somehow; as of this writing I'm not sure that any of
-	 the backends handle that correctly.
+  if (sec->output_section == bfd_abs_section_ptr)
+    return FALSE;
 
-	 It is tempting to instead not discard link once sections when
-	 doing a relocatable link (technically, they should be discarded
-	 whenever we are building constructors).  However, that fails,
-	 because the linker winds up combining all the link once sections
-	 into a single large link once section, which defeats the purpose
-	 of having link once sections in the first place.
+  flags = sec->flags;
 
-	 Also, not merging link once sections in a relocatable link
-	 causes trouble for MIPS ELF, which relies on link once semantics
-	 to handle the .reginfo section correctly.  */
+  /* Return if it isn't a linkonce section.  A comdat group section
+     also has SEC_LINK_ONCE set.  */
+  if ((flags & SEC_LINK_ONCE) == 0)
+    return FALSE;
 
-      name = section_signature (sec);
+  /* Don't put group member sections on our list of already linked
+     sections.  They are handled as a group via their group section.  */
+  if (elf_sec_group (sec) != NULL)
+    return FALSE;
 
+  /* For a SHT_GROUP section, use the group signature as the key.  */
+  name = sec->name;
+  if ((flags & SEC_GROUP) != 0
+      && elf_next_in_group (sec) != NULL
+      && elf_group_name (elf_next_in_group (sec)) != NULL)
+    key = elf_group_name (elf_next_in_group (sec));
+  else
+    {
+      /* Otherwise we should have a .gnu.linkonce.<type>.<key> section.  */
       if (CONST_STRNEQ (name, ".gnu.linkonce.")
-	  && ((p = strchr (name + sizeof (".gnu.linkonce.") - 1, '.'))
-	      != NULL))
-	p++;
+	  && (key = strchr (name + sizeof (".gnu.linkonce.") - 1, '.')) != NULL)
+	key++;
       else
-	p = name;
+	/* Must be a user linkonce section that doesn't follow gcc's
+	   naming convention.  In this case we won't be matching
+	   single member groups.  */
+	key = name;
     }
 
-  already_linked_list = bfd_section_already_linked_table_lookup (p);
+  already_linked_list = bfd_section_already_linked_table_lookup (key);
 
   for (l = already_linked_list->entry; l != NULL; l = l->next)
     {
-      flagword l_flags;
-      bfd *l_owner;
-      const char *l_name = l->linked.comdat_key;
-      if (l_name)
-	{
-	  l_sec = NULL;
-	  l_owner = l->linked.u.abfd;
-	  l_flags = (SEC_GROUP
-		     | SEC_LINK_ONCE
-		     | SEC_LINK_DUPLICATES_DISCARD);
-	}
-      else
-	{
-	  l_sec = l->linked.u.sec;
-	  l_owner = l_sec->owner;
-	  l_flags = l_sec->flags;
-	  l_name = section_signature (l_sec);
-	}
-
       /* We may have 2 different types of sections on the list: group
-	 sections and linkonce sections.  Match like sections.  */
-      if ((flags & SEC_GROUP) == (l_flags & SEC_GROUP)
-	  && strcmp (name, l_name) == 0)
+	 sections with a signature of <key> (<key> is some string),
+	 and linkonce sections named .gnu.linkonce.<type>.<key>.
+	 Match like sections.  LTO plugin sections are an exception.
+	 They are always named .gnu.linkonce.t.<key> and match either
+	 type of section.  */
+      if (((flags & SEC_GROUP) == (l->sec->flags & SEC_GROUP)
+	   && ((flags & SEC_GROUP) != 0
+	       || strcmp (name, l->sec->name) == 0))
+	  || (l->sec->owner->flags & BFD_PLUGIN) != 0)
 	{
 	  /* The section has already been linked.  See if we should
 	     issue a warning.  */
-	  switch (flags & SEC_LINK_DUPLICATES)
-	    {
-	    default:
-	      abort ();
-
-	    case SEC_LINK_DUPLICATES_DISCARD:
-	      /* If we found an LTO IR match for this comdat group on
-		 the first pass, replace it with the LTO output on the
-		 second pass.  We can't simply choose real object
-		 files over IR because the first pass may contain a
-		 mix of LTO and normal objects and we must keep the
-		 first match, be it IR or real.  */
-	      if (info->loading_lto_outputs
-		  && (l_owner->flags & BFD_PLUGIN) != 0)
-		{
-		  l->linked = *linked;
-		  return FALSE;
-		}
-	      break;
-
-	    case SEC_LINK_DUPLICATES_ONE_ONLY:
-	      (*_bfd_error_handler)
-		(_("%B: ignoring duplicate section `%A'"),
-		 abfd, sec);
-	      break;
-
-	    case SEC_LINK_DUPLICATES_SAME_SIZE:
-	      if (!sec || !l_sec)
-		abort ();
-
-	      if (sec->size != l_sec->size)
-		(*_bfd_error_handler)
-		  (_("%B: duplicate section `%A' has different size"),
-		   abfd, sec);
-	      break;
-
-	    case SEC_LINK_DUPLICATES_SAME_CONTENTS:
-	      if (!sec || !l_sec)
-		abort ();
-
-	      if (sec->size != l_sec->size)
-		(*_bfd_error_handler)
-		  (_("%B: duplicate section `%A' has different size"),
-		   abfd, sec);
-	      else if (sec->size != 0)
-		{
-		  bfd_byte *sec_contents, *l_sec_contents;
-
-		  if (!bfd_malloc_and_get_section (abfd, sec, &sec_contents))
-		    (*_bfd_error_handler)
-		      (_("%B: warning: could not read contents of section `%A'"),
-		       abfd, sec);
-		  else if (!bfd_malloc_and_get_section (l_sec->owner, l_sec,
-							&l_sec_contents))
-		    (*_bfd_error_handler)
-		      (_("%B: warning: could not read contents of section `%A'"),
-		       l_sec->owner, l_sec);
-		  else if (memcmp (sec_contents, l_sec_contents, sec->size) != 0)
-		    (*_bfd_error_handler)
-		      (_("%B: warning: duplicate section `%A' has different contents"),
-		       abfd, sec);
-
-		  if (sec_contents)
-		    free (sec_contents);
-		  if (l_sec_contents)
-		    free (l_sec_contents);
-		}
-	      break;
-	    }
+	  if (!_bfd_handle_already_linked (sec, l, info))
+	    return FALSE;
 
-	  if (sec)
+	  if (flags & SEC_GROUP)
 	    {
-	      /* Set the output_section field so that lang_add_section
-		 does not create a lang_input_section structure for this
-		 section.  Since there might be a symbol in the section
-		 being discarded, we must retain a pointer to the section
-		 which we are really going to use.  */
-	      sec->output_section = bfd_abs_section_ptr;
-	      sec->kept_section = l_sec;
+	      asection *first = elf_next_in_group (sec);
+	      asection *s = first;
 
-	      if (flags & SEC_GROUP)
+	      while (s != NULL)
 		{
-		  asection *first = elf_next_in_group (sec);
-		  asection *s = first;
-
-		  while (s != NULL)
-		    {
-		      s->output_section = bfd_abs_section_ptr;
-		      /* Record which group discards it.  */
-		      s->kept_section = l_sec;
-		      s = elf_next_in_group (s);
-		      /* These lists are circular.  */
-		      if (s == first)
-			break;
-		    }
+		  s->output_section = bfd_abs_section_ptr;
+		  /* Record which group discards it.  */
+		  s->kept_section = l->sec;
+		  s = elf_next_in_group (s);
+		  /* These lists are circular.  */
+		  if (s == first)
+		    break;
 		}
 	    }
 
@@ -12711,108 +12587,67 @@ _bfd_elf_section_already_linked (bfd *abfd,
 	}
     }
 
-  matched = FALSE;
-  if (sec)
+  /* A single member comdat group section may be discarded by a
+     linkonce section and vice versa.  */
+  if ((flags & SEC_GROUP) != 0)
     {
-      /* A single member comdat group section may be discarded by a
-	 linkonce section and vice versa.  */
+      asection *first = elf_next_in_group (sec);
 
-      if ((flags & SEC_GROUP) != 0)
+      if (first != NULL && elf_next_in_group (first) == first)
+	/* Check this single member group against linkonce sections.  */
+	for (l = already_linked_list->entry; l != NULL; l = l->next)
+	  if ((l->sec->flags & SEC_GROUP) == 0
+	      && bfd_elf_match_symbols_in_sections (l->sec, first, info))
+	    {
+	      first->output_section = bfd_abs_section_ptr;
+	      first->kept_section = l->sec;
+	      sec->output_section = bfd_abs_section_ptr;
+	      break;
+	    }
+    }
+  else
+    /* Check this linkonce section against single member groups.  */
+    for (l = already_linked_list->entry; l != NULL; l = l->next)
+      if (l->sec->flags & SEC_GROUP)
 	{
-	  asection *first = elf_next_in_group (sec);
+	  asection *first = elf_next_in_group (l->sec);
 
-	  if (first != NULL && elf_next_in_group (first) == first)
-	    /* Check this single member group against linkonce sections.  */
-	    for (l = already_linked_list->entry; l != NULL; l = l->next)
-	      {
-		if (l->linked.comdat_key == NULL)
-		  {
-		    l_sec = l->linked.u.sec;
-
-		    if ((l_sec->flags & SEC_GROUP) == 0
-			&& bfd_coff_get_comdat_section (l_sec->owner,
-							l_sec) == NULL
-			&& bfd_elf_match_symbols_in_sections (l_sec,
-							      first,
-							      info))
-		      {
-			first->output_section = bfd_abs_section_ptr;
-			first->kept_section = l_sec;
-			sec->output_section = bfd_abs_section_ptr;
-			matched = TRUE;
-			break;
-		      }
-		  }
-	      }
+	  if (first != NULL
+	      && elf_next_in_group (first) == first
+	      && bfd_elf_match_symbols_in_sections (first, sec, info))
+	    {
+	      sec->output_section = bfd_abs_section_ptr;
+	      sec->kept_section = first;
+	      break;
+	    }
 	}
-      else
-	/* Check this linkonce section against single member groups.  */
-	for (l = already_linked_list->entry; l != NULL; l = l->next)
-	  {
-	    if (l->linked.comdat_key == NULL)
-	      {
-		l_sec = l->linked.u.sec;
-
-		if (l_sec->flags & SEC_GROUP)
-		  {
-		    asection *first = elf_next_in_group (l_sec);
-
-		    if (first != NULL
-			&& elf_next_in_group (first) == first
-			&& bfd_elf_match_symbols_in_sections (first,
-							      sec,
-							      info))
-		      {
-			sec->output_section = bfd_abs_section_ptr;
-			sec->kept_section = first;
-			matched = TRUE;
-			break;
-		      }
-		  }
-	      }
-	  }
 
-      /* Do not complain on unresolved relocations in `.gnu.linkonce.r.F'
-	 referencing its discarded `.gnu.linkonce.t.F' counterpart -
-	 g++-3.4 specific as g++-4.x is using COMDAT groups (without the
-	 `.gnu.linkonce' prefix) instead.  `.gnu.linkonce.r.*' were the
-	 `.rodata' part of its matching `.gnu.linkonce.t.*'.  If
-	 `.gnu.linkonce.r.F' is not discarded but its `.gnu.linkonce.t.F'
-	 is discarded means we chose one-only `.gnu.linkonce.t.F' section
-	 from a different bfd not requiring any `.gnu.linkonce.r.F'.
-	 Thus `.gnu.linkonce.r.F' should be discarded.  The reverse order
-	 cannot happen as there is never a bfd with only the
-	 `.gnu.linkonce.r.F' section.  The order of sections in a bfd
-	 does not matter as here were are looking only for cross-bfd
-	 sections.  */
-
-      if ((flags & SEC_GROUP) == 0
-	  && CONST_STRNEQ (name, ".gnu.linkonce.r."))
-	for (l = already_linked_list->entry; l != NULL; l = l->next)
-	  {
-	    if (l->linked.comdat_key == NULL)
-	      {
-		l_sec = l->linked.u.sec;
-
-		if ((l_sec->flags & SEC_GROUP) == 0
-		    && CONST_STRNEQ (l_sec->name, ".gnu.linkonce.t."))
-		  {
-		    if (abfd != l_sec->owner)
-		      {
-			sec->output_section = bfd_abs_section_ptr;
-			matched = TRUE;
-		      }
-		    break;
-		  }
-	      }
-	  }
-    }
+  /* Do not complain on unresolved relocations in `.gnu.linkonce.r.F'
+     referencing its discarded `.gnu.linkonce.t.F' counterpart - g++-3.4
+     specific as g++-4.x is using COMDAT groups (without the `.gnu.linkonce'
+     prefix) instead.  `.gnu.linkonce.r.*' were the `.rodata' part of its
+     matching `.gnu.linkonce.t.*'.  If `.gnu.linkonce.r.F' is not discarded
+     but its `.gnu.linkonce.t.F' is discarded means we chose one-only
+     `.gnu.linkonce.t.F' section from a different bfd not requiring any
+     `.gnu.linkonce.r.F'.  Thus `.gnu.linkonce.r.F' should be discarded.
+     The reverse order cannot happen as there is never a bfd with only the
+     `.gnu.linkonce.r.F' section.  The order of sections in a bfd does not
+     matter as here were are looking only for cross-bfd sections.  */
+
+  if ((flags & SEC_GROUP) == 0 && CONST_STRNEQ (name, ".gnu.linkonce.r."))
+    for (l = already_linked_list->entry; l != NULL; l = l->next)
+      if ((l->sec->flags & SEC_GROUP) == 0
+	  && CONST_STRNEQ (l->sec->name, ".gnu.linkonce.t."))
+	{
+	  if (abfd != l->sec->owner)
+	    sec->output_section = bfd_abs_section_ptr;
+	  break;
+	}
 
   /* This is the first section with this name.  Record it.  */
-  if (! bfd_section_already_linked_table_insert (already_linked_list,
-						 linked))
+  if (!bfd_section_already_linked_table_insert (already_linked_list, sec))
     info->callbacks->einfo (_("%F%P: already_linked_table: %E\n"));
-  return matched;
+  return sec->output_section == bfd_abs_section_ptr;
 }
 
 bfd_boolean