[binutils-gdb/binutils-2_31-branch] Correct removal of .gnu.attributes

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e89e89c9f8ceced99ebad21c045d7203939a5e33

commit e89e89c9f8ceced99ebad21c045d7203939a5e33
Author: Alan Modra <amodra@gmail.com>
Date:   Tue Jul 3 17:57:36 2018 +0930

    Correct removal of .gnu.attributes
    
    Setting SEC_EXCLUDE for empty .gnu.attributes is too late in the link
    process for the linker to remove the section.  That must be done in
    bfd_elf_final_link, as we do for removed group sections.
    
    	* elflink.c (bfd_elf_final_link): Remove zero size .gnu.attributes
    	sections.
    
    (cherry picked from commit b8a6ced79668ec8af3180e50b76f7517ebbab0d9)

Diff:
---
 bfd/ChangeLog |  5 +++++
 bfd/elflink.c | 18 +++++++++++-------
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index ebf032b..355f657 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,10 @@
 2018-07-03  Alan Modra  <amodra@gmail.com>
 
+	* elflink.c (bfd_elf_final_link): Remove zero size .gnu.attributes
+	sections.
+
+2018-07-03  Alan Modra  <amodra@gmail.com>
+
 	* elf-bfd.h (ATTR_TYPE_FLAG_ERROR, ATTR_TYPE_HAS_ERROR): Define.
 	* elf-attrs.c (is_default_attr): Handle ATTR_TYPE_HAS_ERROR.
 	* elf32-ppc.c (_bfd_elf_ppc_merge_fp_attributes): Use
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 36e0c37..138efac 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -11715,6 +11715,8 @@ bfd_elf_final_link (bfd *abfd, struct bfd_link_info *info)
   std_attrs_section = get_elf_backend_data (abfd)->obj_attrs_section;
   for (o = abfd->sections; o != NULL; o = o->next)
     {
+      bfd_boolean remove = FALSE;
+
       if ((std_attrs_section && strcmp (o->name, std_attrs_section) == 0)
 	  || strcmp (o->name, ".gnu.attributes") == 0)
 	{
@@ -11731,19 +11733,21 @@ bfd_elf_final_link (bfd *abfd, struct bfd_link_info *info)
 	    }
 
 	  attr_size = bfd_elf_obj_attr_size (abfd);
+	  bfd_set_section_size (abfd, o, attr_size);
+	  /* Skip this section later on.  */
+	  o->map_head.link_order = NULL;
 	  if (attr_size)
-	    {
-	      bfd_set_section_size (abfd, o, attr_size);
-	      attr_section = o;
-	      /* Skip this section later on.  */
-	      o->map_head.link_order = NULL;
-	    }
+	    attr_section = o;
 	  else
-	    o->flags |= SEC_EXCLUDE;
+	    remove = TRUE;
 	}
       else if ((o->flags & SEC_GROUP) != 0 && o->size == 0)
 	{
 	  /* Remove empty group section from linker output.  */
+	  remove = TRUE;
+	}
+      if (remove)
+	{
 	  o->flags |= SEC_EXCLUDE;
 	  bfd_section_list_remove (abfd, o);
 	  abfd->section_count--;