diff mbox series

Fix PR89514, -fdebug-types-section vs. LTO

Message ID alpine.LSU.2.20.1902271021380.23386@zhemvz.fhfr.qr
State New
Headers show
Series Fix PR89514, -fdebug-types-section vs. LTO | expand

Commit Message

Richard Biener Feb. 27, 2019, 9:27 a.m. UTC 
This fixes inconsistencies with respect to computing DIE sizes and
abbrevs when using -fdebug-types-section and LTO where we have
external refs that are _not_ refs to comdat_type_p's.  output_die
gets this correct but both size_of_die and value_format simply
key on use_debug_types which causes the LTO external refs to the
early debug represented as type signatures for DIE size accounting
and in the abbrev while then actually being output correctly.
This obviously corrupts the DWARF quite a bit.

Fixed by doing what output_die does, check AT_ref (a)->comdat_type_p
instead of use_debug_types.

Bootstrap and regtest running on x86_64-unknown-linux-gnu.

There's no way to scan ltrans assembly so no testcase.

I've refrained from "ignoring" -fdebug-types-section for the
late debug (where it doesn't make any sense), the above
inconsistency warrants fixing anyway.  But a followup could
adjust the use_debug_types #define to include && !in_lto_p
like I did for want_pubnames.

Richard.

2019-02-27  Richard Biener  <rguenther@suse.de>

	PR debug/89514
	* dwarf2out.c (size_of_die): Key on AT_ref (a)->comdat_type_p
	rather than on use_debug_types, doing what output_die does.
	(value_format): Likewise.
diff mbox series

Patch

Index: gcc/dwarf2out.c
===================================================================
--- gcc/dwarf2out.c	(revision 269204)
+++ gcc/dwarf2out.c	(working copy)
@@ -9425,7 +9425,7 @@  size_of_die (dw_die_ref die)
 		 we use DW_FORM_ref_addr.  In DWARF2, DW_FORM_ref_addr
 		 is sized by target address length, whereas in DWARF3
 		 it's always sized as an offset.  */
-	      if (use_debug_types)
+	      if (AT_ref (a)->comdat_type_p)
 		size += DWARF_TYPE_SIGNATURE_SIZE;
 	      else if (dwarf_version == 2)
 		size += DWARF2_ADDR_SIZE;
@@ -9869,7 +9869,12 @@  value_format (dw_attr_node *a)
       return DW_FORM_flag;
     case dw_val_class_die_ref:
       if (AT_ref_external (a))
-	return use_debug_types ? DW_FORM_ref_sig8 : DW_FORM_ref_addr;
+	{
+	  if (AT_ref (a)->comdat_type_p)
+	    return DW_FORM_ref_sig8;
+	  else
+	    return DW_FORM_ref_addr;
+	}
       else
 	return DW_FORM_ref;
     case dw_val_class_fde_ref: