[LLVMdev] DWARF 2/3 backwards compatibility?

[Rick Foos]

The error we are getting is:
"Undefined Form Value: 25"

We have customers that have a variety of debuggers, and we need to be 
able to preserve Dwarf3 compatibility. GDB, Lauterbach, etc.

The patch that caused a problem for us is:
https://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp?r1=162493&r2=162526&pathrev=162526&diff_format=h

DW_FORM_flag_present caused the problem. The old DW_FORM_flag works for us.

While the DD->useDarwinGDBCompat() option is a workaround in this case, 
Darwin GDB is a specific version of GDB.
http://sourceware.org/gdb/onlinedocs/gdb/Darwin.html

So useDarwinGDBCompat means Darwin GDB Compatibility, not GDB 
Compatibility or Dwarf xxx Compatibility, etc.

Going in that direction for now means that we will hit this problem 
again. Eventually useDarwinGDBCompat should diverge to things that don't 
apply to all GDB's.

Would like to discuss:
1) What level of interest is there in Dwarf backward compatibility;
2) What levels of Debugger backward compatibility are needed.
3) What framework of flags/options would be a container for specific 
backward compatibility features.
4) What type of testing to ensure backward compatibility, GDB Testsuite?

Thank you!
-rick


On 10/17/2012 10:53 AM, Pranav Bhandarkar wrote:
>
>> My GDB Testsuite runs have been failing more tests, and now an internal
> test
>> has started failing on some missing dwarf 3 records.
> What is the error message or the nature of the failures you are seeing ?
>
> Pranav
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by
> The Linux Foundation
>
>
>


-- 
Rick Foos
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

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