[binutils-gdb] Generic ELF target group signature symbol

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=3d7d6a6ff4678685f86976f08ab4c9c639e262e1

commit 3d7d6a6ff4678685f86976f08ab4c9c639e262e1
Author: Alan Modra <amodra@gmail.com>
Date:   Mon May 27 09:38:42 2019 +0930

    Generic ELF target group signature symbol
    
    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:
---
 bfd/ChangeLog          |  5 +++++
 bfd/linker.c           | 13 +++++++------
 ld/ChangeLog           |  6 ++++++
 ld/emultempl/genelf.em |  4 +++-
 4 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index a7603da..3f7f174 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,8 @@
+2019-05-27  Alan Modra  <amodra@gmail.com>
+
+	PR 24596
+	* linker.c (_bfd_generic_link_output_symbols): Heed BSF_KEEP.
+
 2019-05-24  Szabolcs Nagy  <szabolcs.nagy@arm.com>
 
 	* elfnn-aarch64.c (elfNN_aarch64_merge_symbol_attribute): New function.
diff --git a/bfd/linker.c b/bfd/linker.c
index 9e89c84..1b71fcf 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/ChangeLog b/ld/ChangeLog
index 4de04b6..36d866f 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,9 @@
+2019-05-27  Alan Modra  <amodra@gmail.com>
+
+	PR 24596
+	* emultempl/genelf.em (gld${EMULATION_NAME}_after_open): Set
+	BFS_KEEP on group signature symbol.
+
 2019-04-24  Szabolcs Nagy  <szabolcs.nagy@arm.com>
 
 	* testsuite/ld-aarch64/aarch64-elf.exp: Add new tests.
diff --git a/ld/emultempl/genelf.em b/ld/emultempl/genelf.em
index 472f701..664a5b1 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;
 	    }
 }