further help on dwarf2 debug

[IainS]

I'm trying to formulate a bug report for tools used to examine/ 
process debug output.
looking specifically at the _debug_frame.

for this source:

---
int testfunc(void)
{
	int i;
	i = 1;
	return i;
}

===

using -save-temps -dA -g -O0 -fverbose-asm (-gstrict-dwarf, on 4.5)

comparing the output of gcc-4-4 and trunk.

The main difference (and the area causing the tool to barf) is that  
the FDE on 4.5 has some extra information not present in 4.4

	.byte	0x4	# DW_CFA_advance_loc4
	.set L$set$6,LCFI3-LCFI1
	.long L$set$6
	.byte	0xc5	# DW_CFA_restore, column 0x5
	.byte	0xc	# DW_CFA_def_cfa
	.byte	0x4	# uleb128 0x4
	.byte	0x4	# uleb128 0x4


whilst, with the aid of the dwarf3 spec, I can see that this is  
syntactically correct (and confirm that the object file contains the  
correct output).
I can't (at the moment) determine if it's logically correct.
What is the purpose of the addition?
(complete .s files attached)

TIA,
Iain

-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: simpl-4.4.s.txt
URL: <https://gcc.gnu.org/pipermail/gcc/attachments/20090924/5bea5fee/attachment.txt>
-------------- next part --------------

-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: simpl-4.5.s.txt
URL: <https://gcc.gnu.org/pipermail/gcc/attachments/20090924/5bea5fee/attachment-0001.txt>