PR 15891 infrastructure

[Alan Modra <amodra at gmail dot com>]

This cleanup puts into place machinery necessary to fix PR15891.  Not
that I'm promising to fix the PR.  I may, but it would be nice if
Intel pulled their weight in support.

	* elf-bfd.h (struct elf_backend_data): Remove as_needed_cleanup.
	Add notice_as_needed.
	* elf64-ppc.c (elf_backend_as_needed_cleanup): Don't define.
	(elf_backend_notice_as_needed): Define.
	(ppc64_elf_as_needed_cleanup): Rename and adjust..
	(ppc64_elf_notice_as_needed): ..to this.
	* elflink.c (_bfd_elf_notice_as_needed): New function, extracted..
	(elf_link_add_object_symbols): ..from here.
	* elfxx-target.h (elf_backend_as_needed_cleanup): Don't define.
	(elf_backend_notice_as_needed): Define..
	(elfNN_bed): ..and use here.

Index: bfd/elf-bfd.h
===================================================================
RCS file: /cvs/src/src/bfd/elf-bfd.h,v
retrieving revision 1.372
diff -u -p -r1.372 elf-bfd.h
--- bfd/elf-bfd.h	7 May 2013 17:03:51 -0000	1.372
+++ bfd/elf-bfd.h	26 Aug 2013 23:24:35 -0000
@@ -881,12 +881,12 @@ struct elf_backend_data
   bfd_boolean (*check_directives)
     (bfd *abfd, struct bfd_link_info *info);
 
-  /* The AS_NEEDED_CLEANUP function is called once per --as-needed
-     input file that was not needed by the add_symbols phase of the
-     ELF backend linker.  The function must undo any target specific
-     changes in the symbol hash table.  */
-  bfd_boolean (*as_needed_cleanup)
-    (bfd *abfd, struct bfd_link_info *info);
+  /* The NOTICE_AS_NEEDED function is called as the linker is about to
+     handle an as-needed lib (ACT = notice_as_needed), and after the
+     linker has decided to keep the lib (ACT = notice_needed) or when
+     the lib is not needed (ACT = notice_not_needed).  */
+  bfd_boolean (*notice_as_needed)
+    (bfd *abfd, struct bfd_link_info *info, enum notice_asneeded_action act);
 
   /* The ADJUST_DYNAMIC_SYMBOL function is called by the ELF backend
      linker for every symbol which is defined by a dynamic object and
@@ -2139,6 +2139,8 @@ extern bfd_boolean _bfd_elf_default_relo
 
 extern bfd_boolean _bfd_elf_relocs_compatible
   (const bfd_target *, const bfd_target *);
+extern bfd_boolean _bfd_elf_notice_as_needed
+  (bfd *, struct bfd_link_info *, enum notice_asneeded_action);
 
 extern struct elf_link_hash_entry *_bfd_elf_archive_symbol_lookup
   (bfd *, struct bfd_link_info *, const char *);
Index: bfd/elf64-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf64-ppc.c,v
retrieving revision 1.417
diff -u -p -r1.417 elf64-ppc.c
--- bfd/elf64-ppc.c	25 Jul 2013 15:18:26 -0000	1.417
+++ bfd/elf64-ppc.c	26 Aug 2013 23:24:35 -0000
@@ -96,7 +96,7 @@ static bfd_vma opd_entry_value
 #define elf_backend_copy_indirect_symbol      ppc64_elf_copy_indirect_symbol
 #define elf_backend_add_symbol_hook	      ppc64_elf_add_symbol_hook
 #define elf_backend_check_directives	      ppc64_elf_process_dot_syms
-#define elf_backend_as_needed_cleanup	      ppc64_elf_as_needed_cleanup
+#define elf_backend_notice_as_needed	      ppc64_elf_notice_as_needed
 #define elf_backend_archive_symbol_lookup     ppc64_elf_archive_symbol_lookup
 #define elf_backend_check_relocs	      ppc64_elf_check_relocs
 #define elf_backend_gc_keep		      ppc64_elf_gc_keep
@@ -4806,16 +4806,20 @@ ppc64_elf_process_dot_syms (bfd *ibfd, s
    not to be needed.  */
 
 static bfd_boolean
-ppc64_elf_as_needed_cleanup (bfd *ibfd ATTRIBUTE_UNUSED,
-			     struct bfd_link_info *info)
+ppc64_elf_notice_as_needed (bfd *ibfd,
+			    struct bfd_link_info *info,
+			    enum notice_asneeded_action act)
 {
-  struct ppc_link_hash_table *htab = ppc_hash_table (info);
+  if (act == notice_not_needed)
+    {
+      struct ppc_link_hash_table *htab = ppc_hash_table (info);
 
-  if (htab == NULL)
-    return FALSE;
+      if (htab == NULL)
+	return FALSE;
 
-  htab->dot_syms = NULL;
-  return TRUE;
+      htab->dot_syms = NULL;
+    }
+  return _bfd_elf_notice_as_needed (ibfd, info, act);
 }
 
 /* If --just-symbols against a final linked binary, then assume we need
Index: bfd/elflink.c
===================================================================
RCS file: /cvs/src/src/bfd/elflink.c,v
retrieving revision 1.498
diff -u -p -r1.498 elflink.c
--- bfd/elflink.c	21 Aug 2013 04:09:30 -0000	1.498
+++ bfd/elflink.c	26 Aug 2013 23:24:36 -0000
@@ -3309,6 +3309,18 @@ _bfd_elf_relocs_compatible (const bfd_ta
   return ibed->relocs_compatible == obed->relocs_compatible;
 }
 
+/* Make a special call to the linker "notice" function to tell it that
+   we are about to handle an as-needed lib, or have finished
+   processing the lib.  */ 
+
+bfd_boolean
+_bfd_elf_notice_as_needed (bfd *ibfd,
+			   struct bfd_link_info *info,
+			   enum notice_asneeded_action act)
+{
+  return (*info->callbacks->notice) (info, NULL, ibfd, NULL, act, 0, NULL);
+}
+
 /* Add symbols from an ELF object file to the linker hash table.  */
 
 static bfd_boolean
@@ -3766,8 +3778,7 @@ error_free_dyn:
 
       /* Make a special call to the linker "notice" function to
 	 tell it that we are about to handle an as-needed lib.  */
-      if (!(*info->callbacks->notice) (info, NULL, abfd, NULL,
-				       notice_as_needed, 0, NULL))
+      if (!(*bed->notice_as_needed) (abfd, info, notice_as_needed))
 	goto error_free_vers;
 
       /* Clone the symbol table.  Remember some pointers into the
@@ -4461,8 +4472,6 @@ error_free_dyn:
       unsigned int i;
 
       /* Restore the symbol table.  */
-      if (bed->as_needed_cleanup)
-	(*bed->as_needed_cleanup) (abfd, info);
       old_ent = (char *) old_tab + tabsize;
       memset (elf_sym_hashes (abfd), 0,
 	      extsymcount * sizeof (struct elf_link_hash_entry *));
@@ -4524,8 +4533,7 @@ error_free_dyn:
 
       /* Make a special call to the linker "notice" function to
 	 tell it that symbols added for crefs may need to be removed.  */
-      if (!(*info->callbacks->notice) (info, NULL, abfd, NULL,
-				       notice_not_needed, 0, NULL))
+      if (!(*bed->notice_as_needed) (abfd, info, notice_not_needed))
 	goto error_free_vers;
 
       free (old_tab);
@@ -4538,8 +4546,7 @@ error_free_dyn:
 
   if (old_tab != NULL)
     {
-      if (!(*info->callbacks->notice) (info, NULL, abfd, NULL,
-				       notice_needed, 0, NULL))
+      if (!(*bed->notice_as_needed) (abfd, info, notice_needed))
 	goto error_free_vers;
       free (old_tab);
       old_tab = NULL;
Index: bfd/elfxx-target.h
===================================================================
RCS file: /cvs/src/src/bfd/elfxx-target.h,v
retrieving revision 1.132
diff -u -p -r1.132 elfxx-target.h
--- bfd/elfxx-target.h	11 Feb 2013 22:15:53 -0000	1.132
+++ bfd/elfxx-target.h	26 Aug 2013 23:24:36 -0000
@@ -424,8 +424,8 @@
 #ifndef elf_backend_check_directives
 #define elf_backend_check_directives	0
 #endif
-#ifndef elf_backend_as_needed_cleanup
-#define elf_backend_as_needed_cleanup	0
+#ifndef elf_backend_notice_as_needed
+#define elf_backend_notice_as_needed	_bfd_elf_notice_as_needed
 #endif
 #ifndef elf_backend_adjust_dynamic_symbol
 #define elf_backend_adjust_dynamic_symbol 0
@@ -705,7 +705,7 @@ static struct elf_backend_data elfNN_bed
   elf_backend_relocs_compatible,
   elf_backend_check_relocs,
   elf_backend_check_directives,
-  elf_backend_as_needed_cleanup,
+  elf_backend_notice_as_needed,
   elf_backend_adjust_dynamic_symbol,
   elf_backend_always_size_sections,
   elf_backend_size_dynamic_sections,

-- 
Alan Modra
Australia Development Lab, IBM