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digitalmars.D - Possible malformed DWARF debug object files.

reply Steve Teale <steve.teale britseyeview.com> writes:
Before I waste time trying to find a minimal example of this, let me ask if
anyone has seen similar behavior. The problems I've seen arise when using gtkD.

DMD(2) Linux X386 compiled with -g appears to produce flawed object files.
Either on starting GDB or when I try to set a breakpoint, I get:

Die: DW_TAG_type_unit (abbrev 4, offset 0x5b)
  parent at offset: 0xb
  has children: FALSE
  attributes:
    DW_AT_byte_size (DW_FORM_data1) constant: 8
    DW_AT_type (DW_FORM_ref4) constant ref: 0x53 (adjusted)
Dwarf Error: Missing children for type unit [in module /home/steve/tredit/tree]

It occurs to me to wonder if 'unit' is actually 'uint'.

If you use -gc it works, but then debugging with GDC is very flaky.
Jul 23 2011
parent Robert Clipsham <robert octarineparrot.com> writes:
On 23/07/2011 17:48, Steve Teale wrote:

 Before I waste time trying to find a minimal example of this, let me ask if
 anyone has seen similar behavior. The problems I've seen arise when using gtkD.

 DMD(2) Linux X386 compiled with -g appears to produce flawed object files.
 Either on starting GDB or when I try to set a breakpoint, I get:

 Die: DW_TAG_type_unit (abbrev 4, offset 0x5b)
    parent at offset: 0xb
    has children: FALSE
    attributes:
      DW_AT_byte_size (DW_FORM_data1) constant: 8
      DW_AT_type (DW_FORM_ref4) constant ref: 0x53 (adjusted)
 Dwarf Error: Missing children for type unit [in module /home/steve/tredit/tree]

 It occurs to me to wonder if 'unit' is actually 'uint'.

 If you use -gc it works, but then debugging with GDC is very flaky.


I assume you mean gdb here.

The -g switch isn't meant to work on linux - gdb doesn't support D's 
extensions to DWARF, nor will it ever, as they conflict with certain 
parts of DWARF 4. You should compile with -gc if you are using anything 
but windows.

There are several ways this situation could be fixed, which have been 
discussed, but someone needs to take on the task of actually 
implementing it. I was going to do it when I was busy making debug info 
actually work (there was a time not too long ago where anything that 
used phobos didn't produce working debug info), but unforunately I ran 
out of time.

-- 
Robert
http://octarineparrot.com/
Jul 23 2011