[lldb-dev] Missing function arguments in the backtrace

[jingham at apple.com]

Perhaps we should add a "settings reset" command that clears all settings values back to their defaults, and run that as part of the "lldbtest.setUp"?  I don't think there is much beyond settings that can persist from target to target.  That would be useful thing to add in any case.

Jim

On Sep 25, 2013, at 8:09 AM, Thirumurthi, Ashok <ashok.thirumurthi at intel.com> wrote:

> Bingo, thanks!  TestInferiorAssert.py passes for me with the attached patch.  Even better, it would be nice to cache the initial result of runCmd("settings show frame-format") so that this doesn't drift with changes to default settings...
> 
> - Ashok
> 
> -----Original Message-----
> From: lldb-dev-bounces at cs.uiuc.edu [mailto:lldb-dev-bounces at cs.uiuc.edu] On Behalf Of Richard Mitton
> Sent: Tuesday, September 24, 2013 10:24 PM
> To: lldb-dev at cs.uiuc.edu
> Subject: Re: [lldb-dev] Missing function arguments in the backtrace
> 
> I think you might be looking at the same bug that I am.
> 
> The problem is that TestSettings.py changes the frame format string, and doesn't restore it to the correct value.
> But I think the real problem is that dotest.py executes multiple tests using the same context (I just posted a mail about this).
> 
> Richard Mitton
> richard at codersnotes.com
> 
> On 09/24/2013 07:19 PM, Jason Molenda wrote:
>> Ashok, for what it's worth I can't see what would cause this difference between the two runs based on the log files.
>> 
>> Is it possible that lldb is stopped at different places when the thread backtrace all is invoked?  The lldb unwind log isn't printing the pc values of thread 1 frame 0.  thread 1 is clearly the same in both - we have the exact same pc value and we're using the same unwind instructions from the eh_frame.
>> 
>> This is a little odd  -
>> 
>>   th1/fr2 looking for register saved location for reg 2
>>  th1/fr1 did not supply reg location for 2 (rcx) because it is volatile
>>   th1/fr2 looking for register saved location for reg 16
>>  th1/fr1 supplying caller's saved reg 16's location, cached
>>   th1/fr2 looking for register saved location for reg 8
>>  th1/fr1 did not supply reg location for 8 (r8) because it is 
>> volatile
>> 
>> Why would lldb be trying to examine something in rcx or r8 in frame 2 here?  There must be a variable whose location list says it is live at the call site in that register - poor DWARF from the compiler.
>> 
>> The fact that we don't see the same thing in the bt-fail.log case makes me wonder if the debug info isn't different -- or absent?
>> 
>> 
>> On Sep 24, 2013, at 1:26 PM, Thirumurthi, Ashok <ashok.thirumurthi at intel.com> wrote:
>> 
>>> I have an Ubuntu 12.10 machine where inferior_asserting() succeeds when functionalities/inferior-asserting is run in isolation with either of clang or gcc, but fails when dotest.py is used to run the full suite.  When it fails, the backtrace is missing all function arguments.  A diff of the attached logs illustrates that RegisterContextLLDB comes up with a more complete register set in the passing case.
>>> 
>>> Note: th1/fr1 frame uses eh_frame CFI for full UnwindPlan
>>> 
>>> Any guesses from the logs where I'd be looking to root cause this funkiness??
>>> 
>>> - Ashok
>>> 
>>>  th1/fr2 looking for register saved location for reg 16
>>> th1/fr1 supplying caller's saved reg 16's location, cached
>>>  th1/fr2 looking for register saved location for reg 1
>>> th1/fr1 could not supply caller's reg 1 location
>>> th1/fr0 supplying caller's register 1 from the live RegisterContext 
>>> at frame 0
>>> th1/fr1 looking for register saved location for reg 1
>>> th1/fr0 supplying caller's saved reg 1's location, cached
>>> th1/fr0 looking for register saved location for reg 1
>>> th1/fr0 passing along to the live register context for reg 1
>>>  th1/fr2 looking for register saved location for reg 16
>>> th1/fr1 supplying caller's saved reg 16's location, cached
>>>  th1/fr2 looking for register saved location for reg 12
>>> th1/fr1 could not supply caller's reg 12 location
>>> th1/fr0 supplying caller's register 12 from the live RegisterContext 
>>> at frame 0
>>> th1/fr1 looking for register saved location for reg 12
>>> th1/fr0 supplying caller's saved reg 12's location, cached
>>> th1/fr0 looking for register saved location for reg 12
>>> th1/fr0 passing along to the live register context for reg 12
>>>  th1/fr2 looking for register saved location for reg 16
>>> th1/fr1 supplying caller's saved reg 16's location, cached
>>>  th1/fr2 looking for register saved location for reg 6
>>> th1/fr1 could not supply caller's reg 6 location
>>> th1/fr0 supplying caller's saved reg 6's location, cached
>>> th1/fr1 looking for register saved location for reg 6
>>> th1/fr0 supplying caller's saved reg 6's location, cached
>>> th1/fr0 looking for register saved location for reg 6
>>> th1/fr0 passing along to the live register context for reg 6
>>>  th1/fr2 looking for register saved location for reg 16
>>> th1/fr1 supplying caller's saved reg 16's location, cached
>>>  th1/fr2 looking for register saved location for reg 2
>>> th1/fr1 did not supply reg location for 2 (rcx) because it is volatile
>>>  th1/fr2 looking for register saved location for reg 16
>>> th1/fr1 supplying caller's saved reg 16's location, cached
>>>  th1/fr2 looking for register saved location for reg 8
>>> th1/fr1 did not supply reg location for 8 (r8) because it is volatile
>>> 
>>> 
>>> <bt-fail.log><bt-ok.log>_____________________________________________
>>> __
>>> lldb-dev mailing list
>>> lldb-dev at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>> _______________________________________________
>> lldb-dev mailing list
>> lldb-dev at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
> 
> _______________________________________________
> lldb-dev mailing list
> lldb-dev at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
> <TestSettings.patch>_______________________________________________
> lldb-dev mailing list
> lldb-dev at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev