PR22150, ld keeps a version reference for gc'd symbols

elf_gc_sweep_symbol should run after verdefs are calculated, since
the verdef code creates symbols for the versions.  However,
elf_gc_sweep_symbol needs to run before verrefs so as to not emit
useless verrefs for symbols that are gc'd.

I've also removed a _bfd_elf_link_renumber_dynsyms calls added by
Maciej after I fussed about it when reviewing.  On further examination
the call appears to be unnecessary.  Looking at renumber_dynsyms also
made me realize that the test to exclude .gnu.version has been wrong
since 2016-04-26 (git commit d5486c4372), so fix that too.

	PR 22150
	* elflink.c (bfd_elf_size_dynamic_sections): Garbage collect
	symbols before calculating verrefs.  Don't renumber dynsyms
	after gc.  Exclude .gnu.version when zero or one dynsym.
	Localize some vars and reindent.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index c607549..eb62bc3 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2017-09-19  Alan Modra  <amodra@gmail.com>
+
+       PR 22150
+       * elflink.c (bfd_elf_size_dynamic_sections): Garbage collect
+       symbols before calculating verrefs.  Don't renumber dynsyms
+       after gc.  Exclude .gnu.version when zero or one dynsym.
+       Localize some vars and reindent.
+
 2017-09-18  H.J. Lu  <hongjiu.lu@intel.com>
 
        PR ld/22148

diff --git a/bfd/elflink.c b/bfd/elflink.c
index 58fb83b..ee5c01f 100644 (file)
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -6006,19 +6006,18 @@ bfd_elf_size_dynamic_sections (bfd *output_bfd,
       struct elf_info_failed asvinfo;
       struct bfd_elf_version_tree *t;
       struct bfd_elf_version_expr *d;
-      struct elf_info_failed eif;
-      bfd_boolean all_defined;
       asection *s;
       size_t soname_indx;
 
-      eif.info = info;
-      eif.failed = FALSE;
-
       /* If we are supposed to export all symbols into the dynamic symbol
         table (this is not the normal case), then do so.  */
       if (info->export_dynamic
          || (bfd_link_executable (info) && info->dynamic))
        {
+         struct elf_info_failed eif;
+
+         eif.info = info;
+         eif.failed = FALSE;
          elf_link_hash_traverse (elf_hash_table (info),
                                  _bfd_elf_export_symbol,
                                  &eif);
@@ -6102,7 +6101,7 @@ bfd_elf_size_dynamic_sections (bfd *output_bfd,
       if (!info->allow_undefined_version)
        {
          /* Check if all global versions have a definition.  */
-         all_defined = TRUE;
+         bfd_boolean all_defined = TRUE;
          for (t = info->version_info; t != NULL; t = t->next)
            for (d = t->globals.list; d != NULL; d = d->next)
              if (d->literal && !d->symver && !d->script)
@@ -6355,134 +6354,128 @@ bfd_elf_size_dynamic_sections (bfd *output_bfd,
 
          elf_tdata (output_bfd)->cverdefs = cdefs;
        }
+    }
+
+  bed = get_elf_backend_data (output_bfd);
+
+  if (info->gc_sections && bed->can_gc_sections)
+    {
+      struct elf_gc_sweep_symbol_info sweep_info;
+
+      /* Remove the symbols that were in the swept sections from the
+        dynamic symbol table.  */
+      sweep_info.info = info;
+      sweep_info.hide_symbol = bed->elf_backend_hide_symbol;
+      elf_link_hash_traverse (elf_hash_table (info), elf_gc_sweep_symbol,
+                             &sweep_info);
+    }
+
+  if (dynobj != NULL && elf_hash_table (info)->dynamic_sections_created)
+    {
+      asection *s;
+      struct elf_find_verdep_info sinfo;
 
       /* Work out the size of the version reference section.  */
 
       s = bfd_get_linker_section (dynobj, ".gnu.version_r");
       BFD_ASSERT (s != NULL);
-      {
-       struct elf_find_verdep_info sinfo;
-
-       sinfo.info = info;
-       sinfo.vers = elf_tdata (output_bfd)->cverdefs;
-       if (sinfo.vers == 0)
-         sinfo.vers = 1;
-       sinfo.failed = FALSE;
 
-       elf_link_hash_traverse (elf_hash_table (info),
-                               _bfd_elf_link_find_version_dependencies,
-                               &sinfo);
-       if (sinfo.failed)
-         return FALSE;
+      sinfo.info = info;
+      sinfo.vers = elf_tdata (output_bfd)->cverdefs;
+      if (sinfo.vers == 0)
+       sinfo.vers = 1;
+      sinfo.failed = FALSE;
 
-       if (elf_tdata (output_bfd)->verref == NULL)
-         s->flags |= SEC_EXCLUDE;
-       else
-         {
-           Elf_Internal_Verneed *vn;
-           unsigned int size;
-           unsigned int crefs;
-           bfd_byte *p;
-
-           /* Build the version dependency section.  */
-           size = 0;
-           crefs = 0;
-           for (vn = elf_tdata (output_bfd)->verref;
-                vn != NULL;
-                vn = vn->vn_nextref)
-             {
-               Elf_Internal_Vernaux *a;
+      elf_link_hash_traverse (elf_hash_table (info),
+                             _bfd_elf_link_find_version_dependencies,
+                             &sinfo);
+      if (sinfo.failed)
+       return FALSE;
 
-               size += sizeof (Elf_External_Verneed);
-               ++crefs;
-               for (a = vn->vn_auxptr; a != NULL; a = a->vna_nextptr)
-                 size += sizeof (Elf_External_Vernaux);
-             }
+      if (elf_tdata (output_bfd)->verref == NULL)
+       s->flags |= SEC_EXCLUDE;
+      else
+       {
+         Elf_Internal_Verneed *vn;
+         unsigned int size;
+         unsigned int crefs;
+         bfd_byte *p;
 
-           s->size = size;
-           s->contents = (unsigned char *) bfd_alloc (output_bfd, s->size);
-           if (s->contents == NULL)
-             return FALSE;
+         /* Build the version dependency section.  */
+         size = 0;
+         crefs = 0;
+         for (vn = elf_tdata (output_bfd)->verref;
+              vn != NULL;
+              vn = vn->vn_nextref)
+           {
+             Elf_Internal_Vernaux *a;
 
-           p = s->contents;
-           for (vn = elf_tdata (output_bfd)->verref;
-                vn != NULL;
-                vn = vn->vn_nextref)
-             {
-               unsigned int caux;
-               Elf_Internal_Vernaux *a;
-               size_t indx;
-
-               caux = 0;
-               for (a = vn->vn_auxptr; a != NULL; a = a->vna_nextptr)
-                 ++caux;
-
-               vn->vn_version = VER_NEED_CURRENT;
-               vn->vn_cnt = caux;
-               indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
-                                           elf_dt_name (vn->vn_bfd) != NULL
-                                           ? elf_dt_name (vn->vn_bfd)
-                                           : lbasename (vn->vn_bfd->filename),
-                                           FALSE);
-               if (indx == (size_t) -1)
-                 return FALSE;
-               vn->vn_file = indx;
-               vn->vn_aux = sizeof (Elf_External_Verneed);
-               if (vn->vn_nextref == NULL)
-                 vn->vn_next = 0;
-               else
-                 vn->vn_next = (sizeof (Elf_External_Verneed)
-                               + caux * sizeof (Elf_External_Vernaux));
+             size += sizeof (Elf_External_Verneed);
+             ++crefs;
+             for (a = vn->vn_auxptr; a != NULL; a = a->vna_nextptr)
+               size += sizeof (Elf_External_Vernaux);
+           }
 
-               _bfd_elf_swap_verneed_out (output_bfd, vn,
-                                          (Elf_External_Verneed *) p);
-               p += sizeof (Elf_External_Verneed);
+         s->size = size;
+         s->contents = (unsigned char *) bfd_alloc (output_bfd, s->size);
+         if (s->contents == NULL)
+           return FALSE;
 
-               for (a = vn->vn_auxptr; a != NULL; a = a->vna_nextptr)
-                 {
-                   a->vna_hash = bfd_elf_hash (a->vna_nodename);
-                   indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
-                                               a->vna_nodename, FALSE);
-                   if (indx == (size_t) -1)
-                     return FALSE;
-                   a->vna_name = indx;
-                   if (a->vna_nextptr == NULL)
-                     a->vna_next = 0;
-                   else
-                     a->vna_next = sizeof (Elf_External_Vernaux);
+         p = s->contents;
+         for (vn = elf_tdata (output_bfd)->verref;
+              vn != NULL;
+              vn = vn->vn_nextref)
+           {
+             unsigned int caux;
+             Elf_Internal_Vernaux *a;
+             size_t indx;
 
-                   _bfd_elf_swap_vernaux_out (output_bfd, a,
-                                              (Elf_External_Vernaux *) p);
-                   p += sizeof (Elf_External_Vernaux);
-                 }
-             }
+             caux = 0;
+             for (a = vn->vn_auxptr; a != NULL; a = a->vna_nextptr)
+               ++caux;
 
-           elf_tdata (output_bfd)->cverrefs = crefs;
-         }
-      }
-    }
+             vn->vn_version = VER_NEED_CURRENT;
+             vn->vn_cnt = caux;
+             indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
+                                         elf_dt_name (vn->vn_bfd) != NULL
+                                         ? elf_dt_name (vn->vn_bfd)
+                                         : lbasename (vn->vn_bfd->filename),
+                                         FALSE);
+             if (indx == (size_t) -1)
+               return FALSE;
+             vn->vn_file = indx;
+             vn->vn_aux = sizeof (Elf_External_Verneed);
+             if (vn->vn_nextref == NULL)
+               vn->vn_next = 0;
+             else
+               vn->vn_next = (sizeof (Elf_External_Verneed)
+                              + caux * sizeof (Elf_External_Vernaux));
 
-  bed = get_elf_backend_data (output_bfd);
+             _bfd_elf_swap_verneed_out (output_bfd, vn,
+                                        (Elf_External_Verneed *) p);
+             p += sizeof (Elf_External_Verneed);
 
-  if (info->gc_sections && bed->can_gc_sections)
-    {
-      struct elf_gc_sweep_symbol_info sweep_info;
-      unsigned long section_sym_count;
+             for (a = vn->vn_auxptr; a != NULL; a = a->vna_nextptr)
+               {
+                 a->vna_hash = bfd_elf_hash (a->vna_nodename);
+                 indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
+                                             a->vna_nodename, FALSE);
+                 if (indx == (size_t) -1)
+                   return FALSE;
+                 a->vna_name = indx;
+                 if (a->vna_nextptr == NULL)
+                   a->vna_next = 0;
+                 else
+                   a->vna_next = sizeof (Elf_External_Vernaux);
 
-      /* Remove the symbols that were in the swept sections from the
-        dynamic symbol table.  GCFIXME: Anyone know how to get them
-        out of the static symbol table as well?  */
-      sweep_info.info = info;
-      sweep_info.hide_symbol = bed->elf_backend_hide_symbol;
-      elf_link_hash_traverse (elf_hash_table (info), elf_gc_sweep_symbol,
-                             &sweep_info);
+                 _bfd_elf_swap_vernaux_out (output_bfd, a,
+                                            (Elf_External_Vernaux *) p);
+                 p += sizeof (Elf_External_Vernaux);
+               }
+           }
 
-      /* We need to reassign dynsym indices now that symbols may have
-        been removed.  See the call in `bfd_elf_size_dynsym_hash_dynstr'
-        for the details of the conditions used here.  */
-      if (elf_hash_table (info)->dynamic_sections_created
-         || bed->always_renumber_dynsyms)
-       _bfd_elf_link_renumber_dynsyms (output_bfd, info, &section_sym_count);
+         elf_tdata (output_bfd)->cverrefs = crefs;
+       }
     }
 
   /* Any syms created from now on start with -1 in
@@ -6792,7 +6785,7 @@ bfd_elf_size_dynamic_sections (bfd *output_bfd,
       if ((elf_tdata (output_bfd)->cverrefs == 0
           && elf_tdata (output_bfd)->cverdefs == 0)
          || _bfd_elf_link_renumber_dynsyms (output_bfd, info,
-                                            &section_sym_count) == 0)
+                                            &section_sym_count) <= 1)
        {
          asection *s;