Re: Dwarf expertise needed

[Sami Wagiaalla <swagiaal@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 1017 bytes --]

This is a run of the above test-case with more details:

There are two issues:
get_addrdie() does not return the correct die:

calling get_addrdie() with address 0x8048369
returned die: DW_TAG_compile_unit name: 
/to/scratch/swagiaal/frysks/frysk.patches/frysk-core/frysk/pkglibdir/funit-scopes.c

But it can be seen from the attached relevenat debug info that the 
address actually falls within the expanded instance of the inlined function.

The other issue is that in the test case where it works the complete 
hierarchy of scopes is not returned. Is there a bug or what is the 
correct way of getting the hierarchy of scopes that a die belongs to ? 
Frysk uses dwarf_getscopes()
>>   
>> ------------------------------------------------------------------------
>>
>> #include <stdlib.h>
>>
>> void crash(int param1){
>>   int* a = 0;
>>   a[0] = param1;
>> }
>>
>> inline void second(int w){
>>   crash(0);
>> }
>>
>> void first(){
>>   second(0);
>> }
>>
>> int main(){
>>
>>   first(0);
>>
>>   return 0;
>> }


[-- Attachment #2: debug_info --]
[-- Type: text/plain, Size: 1406 bytes --]


The section .debug_info contains:

  Compilation Unit @ offset 0x0:
   Length:        227
   Version:       2
   Abbrev Offset: 0
   Pointer Size:  4
 <0><b>: Abbrev Number: 1 (DW_TAG_compile_unit)
     DW_AT_stmt_list   : 0	
     DW_AT_high_pc     : 0x80483aa	
     DW_AT_low_pc      : 0x8048344	
     DW_AT_producer    : (indirect string, offset: 0xbc): GNU C 4.1.1 20070105 (Red Hat 4.1.1-51)	
     DW_AT_language    : 1	(ANSI C)
     DW_AT_name        : (indirect string, offset: 0x62): /to/scratch/swagiaal/frysks/frysk.patches/frysk-core/frysk/pkglibdir/funit-scopes.c	
[...]

 <1><9d>: Abbrev Number: 7 (DW_TAG_subprogram)
     DW_AT_external    : 1	
     DW_AT_name        : (indirect string, offset: 0x5b): second	
     DW_AT_decl_file   : 1	
     DW_AT_decl_line   : 8	
     DW_AT_inline      : 3	(declared as inline and inlined)
 <1><a6>: Abbrev Number: 4 (DW_TAG_subprogram)
     DW_AT_sibling     : <ce>	
     DW_AT_external    : 1	
     DW_AT_name        : (indirect string, offset: 0xb6): first	
     DW_AT_decl_file   : 1	
     DW_AT_decl_line   : 12	
     DW_AT_low_pc      : 0x8048353	
     DW_AT_high_pc     : 0x8048370	
     DW_AT_frame_base  : 0x2c	(location list)
 <2><be>: Abbrev Number: 8 (DW_TAG_inlined_subroutine)
     DW_AT_abstract_origin: <9d>	
     DW_AT_low_pc      : 0x8048365	
     DW_AT_high_pc     : 0x804836a	
     DW_AT_call_file   : 1	
     DW_AT_call_line   : 13