From: Eric Botcazou <ebotcazou@gcc.gnu.org>
Date: Mon, 16 Aug 2021 13:26:22 +0000 (+0200)
Subject: Fix regression in debug info for Ada with DWARF 5
X-Git-Tag: releases/gcc-11.3.0~1022
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0c0c320a6e6195e68a4e0e44378ccde3be2d998b;p=thirdparty%2Fgcc.git

Fix regression in debug info for Ada with DWARF 5

add_scalar_info can directly generate a reference to an existing DIE for a
scalar attribute, e.g the upper bound of a VLA, but it does so only if this
existing DIE has a location or is a constant:

              if (get_AT (decl_die, DW_AT_location)
                  || get_AT (decl_die, DW_AT_data_member_location)
                  || get_AT (decl_die, DW_AT_const_value))

Now, in DWARF 5, members of a structure that are bitfields no longer have a
DW_AT_data_member_location but a DW_AT_data_bit_offset attribute instead, so
the condition is bypassed.

gcc/
	* dwarf2out.c (add_scalar_info): Deal with DW_AT_data_bit_offset.
---

diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 7606371296ee..54c6c326d49e 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -21054,6 +21054,7 @@ add_scalar_info (dw_die_ref die, enum dwarf_attribute attr, tree value,
 	    {
 	      if (get_AT (decl_die, DW_AT_location)
 		  || get_AT (decl_die, DW_AT_data_member_location)
+		  || get_AT (decl_die, DW_AT_data_bit_offset)
 		  || get_AT (decl_die, DW_AT_const_value))
 		{
 		  add_AT_die_ref (die, attr, decl_die);