[PATCH] gas: Use DW_FORM_sec_offset for DWARF version 4 or higher.

[PATCH] gas: Use DW_FORM_sec_offset for DWARF version 4 or higher.

[Mark Wielaard]

Older DWARF versions used DW_FORM_data4 or DW_FORM_data8 for offsets
into sections for e.g. DW_AT_stmt_list ot DW_AT_ranges. But version 4
introduced a dedicated form for such section offsets. Make sure to emit
the proper form for newer DWARF versions.

gas/ChangeLog:

	* dwarf2dbg.c (out_debug_abbrev): Use DW_FORM_sec_offset for DWARF
	version 4 or higher.
---
 gas/ChangeLog   |  5 +++++
 gas/dwarf2dbg.c | 20 +++++++++++---------
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 45c89f5c97c..4655aa891f5 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,8 @@
+2020-09-01  Mark Wielaard  <mark@klomp.org>
+
+	* dwarf2dbg.c (out_debug_abbrev): Use DW_FORM_sec_offset for DWARF
+	version 4 or higher.
+
 2020-08-28  Mark Wielaard  <mark@klomp.org>
 
 	* dwarf2dbg.c (dwarf2_directive_filename): Initialize with_md5 to
diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
index 8a840d0cbf1..30a98e0fc54 100644
--- a/gas/dwarf2dbg.c
+++ b/gas/dwarf2dbg.c
@@ -2429,15 +2429,22 @@ out_debug_abbrev (segT abbrev_seg,
 		  segT info_seg ATTRIBUTE_UNUSED,
 		  segT line_seg ATTRIBUTE_UNUSED)
 {
+  int secoff_form;
   subseg_set (abbrev_seg, 0);
 
   out_uleb128 (1);
   out_uleb128 (DW_TAG_compile_unit);
   out_byte (DW_CHILDREN_no);
-  if (DWARF2_FORMAT (line_seg) == dwarf2_format_32bit)
-    out_abbrev (DW_AT_stmt_list, DW_FORM_data4);
+  if (DWARF2_VERSION < 4)
+    {
+      if (DWARF2_FORMAT (line_seg) == dwarf2_format_32bit)
+	secoff_form = DW_FORM_data4;
+      else
+	secoff_form = DW_FORM_data8;
+    }
   else
-    out_abbrev (DW_AT_stmt_list, DW_FORM_data8);
+    secoff_form = DW_FORM_sec_offset;
+  out_abbrev (DW_AT_stmt_list, secoff_form);
   if (all_segs->next == NULL)
     {
       out_abbrev (DW_AT_low_pc, DW_FORM_addr);
@@ -2447,12 +2454,7 @@ out_debug_abbrev (segT abbrev_seg,
 	out_abbrev (DW_AT_high_pc, DW_FORM_udata);
     }
   else
-    {
-      if (DWARF2_FORMAT (info_seg) == dwarf2_format_32bit)
-	out_abbrev (DW_AT_ranges, DW_FORM_data4);
-      else
-	out_abbrev (DW_AT_ranges, DW_FORM_data8);
-    }
+    out_abbrev (DW_AT_ranges, secoff_form);
   out_abbrev (DW_AT_name, DW_FORM_strp);
   out_abbrev (DW_AT_comp_dir, DW_FORM_strp);
   out_abbrev (DW_AT_producer, DW_FORM_strp);
-- 
2.18.4

Re: [PATCH] gas: Use DW_FORM_sec_offset for DWARF version 4 or higher.

[Nick Clifton]

Hi Mark,

> gas/ChangeLog:
> 
> 	* dwarf2dbg.c (out_debug_abbrev): Use DW_FORM_sec_offset for DWARF
> 	version 4 or higher.

Approved - please apply.

Cheers
  Nick