Generic ELF target group signature symbol

[Alan Modra]

Even though the generic ELF target doesn't handle groups correctly,
this helps avoid a segfault in bfd_elf_set_group_contents seen on
d30v-elf, dlx-elf, pj-elf, and xgate-elf when linking the pr22836
testcase.

	PR 24596
bfd/
	* linker.c (_bfd_generic_link_output_symbols): Heed BSF_KEEP.
ld/
	* emultempl/genelf.em (gld${EMULATION_NAME}_after_open): Set
	BFS_KEEP on group signature symbol.

diff --git a/bfd/linker.c b/bfd/linker.c
index 9e89c84d15..1b71fcf8f0 100644
--- a/bfd/linker.c
+++ b/bfd/linker.c
@@ -2112,12 +2112,11 @@ _bfd_generic_link_output_symbols (bfd *output_bfd,
 	    }
 	}
 
-      /* This switch is straight from the old code in
-	 write_file_locals in ldsym.c.  */
-      if (info->strip == strip_all
-	  || (info->strip == strip_some
-	      && bfd_hash_lookup (info->keep_hash, bfd_asymbol_name (sym),
-				  FALSE, FALSE) == NULL))
+      if ((sym->flags & BSF_KEEP) == 0
+	  && (info->strip == strip_all
+	      || (info->strip == strip_some
+		  && bfd_hash_lookup (info->keep_hash, bfd_asymbol_name (sym),
+				      FALSE, FALSE) == NULL)))
 	output = FALSE;
       else if ((sym->flags & (BSF_GLOBAL | BSF_WEAK | BSF_GNU_UNIQUE)) != 0)
 	{
@@ -2131,6 +2130,8 @@ _bfd_generic_link_output_symbols (bfd *output_bfd,
 	  else
 	    output = FALSE;
 	}
+      else if ((sym->flags & BSF_KEEP) != 0)
+	output = TRUE;
       else if (bfd_is_ind_section (sym->section))
 	output = FALSE;
       else if ((sym->flags & BSF_DEBUGGING) != 0)
diff --git a/ld/emultempl/genelf.em b/ld/emultempl/genelf.em
index 472f701dbe..664a5b1804 100644
--- a/ld/emultempl/genelf.em
+++ b/ld/emultempl/genelf.em
@@ -45,7 +45,9 @@ gld${EMULATION_NAME}_after_open (void)
 	  if ((sec->flags & (SEC_GROUP | SEC_LINKER_CREATED)) == SEC_GROUP)
 	    {
 	      struct bfd_elf_section_data *sec_data = elf_section_data (sec);
-	      elf_group_id (sec) = syms[sec_data->this_hdr.sh_info - 1];
+	      struct bfd_symbol *sym = syms[sec_data->this_hdr.sh_info - 1];
+	      elf_group_id (sec) = sym;
+	      sym->flags |= BSF_KEEP;
 	    }
 }
 

-- 
Alan Modra
Australia Development Lab, IBM