[lldb-dev] Fwd: inability to set breakpoints in lldb

[Todd Fiala]

Or should I say "suggesti'n?"  Er, hmm... Suggestion ;-)

On Thu, Sep 18, 2014 at 1:42 PM, Todd Fiala <tfiala at google.com> wrote:

> Hey Doug,
>
> Can you give Jim's suggestin a try and see if that affects anything?
>
> Thanks,
> Todd
>
> On Wed, Sep 17, 2014 at 2:39 PM, <jingham at apple.com> wrote:
>
>> Are any of these bugs fixed by setting:
>>
>> settings set target.inline-breakpoint-strategy always
>>
>> in your .lldbinit file?
>>
>> Jim
>>
>> > On Sep 17, 2014, at 10:34 AM, Doug Snyder <dsnyder at blueshiftinc.com>
>> wrote:
>> >
>> > i have been investigating several lldb bugs that seem to be related.
>> >
>> > bug 19974 describes lldb's inability to set a breakpoint in an included
>> file and bug 20297 describes lldb's inability to set a breakpoint when
>> using ccache.  i have also found a similar case where lldb is unable to set
>> a breakpoint when a separate preprocess step has been used before compiling.
>> >
>> > note: ccache uses a preprocess step to determine which source files
>> need to be rebuilt so using ccache could be considered the same as using a
>> separate preprocess step.
>> >
>> > all three cases are similar in that the c/c++ preprocessor is involved
>> and alters the way symbols are added to the object files.
>> >
>> > the following attached files are write-ups of some of my findings for
>> the different cases
>> >     ccache - "lldb and ccache.rtf"
>> >     preprocessed files - "lldb and preprocessed files.rtf"
>> >     include files - "lldb and include files.rtf"
>> >
>> > all three cases generate the inability to set breakpoints
>> >
>> > on the Mac, all three cases create object files with "SOL" symbols for
>> preprocessed or included source files.
>> >
>> > the following attached file describes the object files created for the
>> preprocessed test case on the Mac:
>> >     "preprocessed object files.rtf"
>> >
>> > on ubuntu, it is not as obvious to spot differences in the object files
>> when examining object files that that lldb is unable to set breakpoints.
>> >
>> > lldb is unable to set breakpoints on both OSX and ubuntu for all three
>> cases.   gdb is able to set breakpoints on both OSX and ubuntu for all
>> three cases.
>> >
>> > using XCode, i have tried a couple different ways of stepping through
>> lldb to see why it is having trouble setting breakpoints.
>> >
>> > From top-down, i have traced setting breakpoints in Breakpoint.cpp down
>> thru BreakpointResolver.cpp.  The intended source file does not seem to be
>> in the list of compute units, but i don't know why.
>> >
>> > From bottom-up, i have tried to follow how ObjectFileMachO.cpp parses
>> symbols, but i'm not sure that this is the correct place to look.  Also,
>> since this is both a MachO problem and an Elf problem, the problem isn't
>> likely to be here anyway.
>> >
>> > Does anyone familiar with lldb's architecture have any ideas where in
>> the code i should be looking or have a plan-of-attack to suggest?
>> >
>> > thanks,
>> > doug
>> >
>> >
>> >
>> >
>> > <lldb and ccache.rtf><lldb and preprocessed files.rtf><preprocessed
>> object files.rtf><lldb and include
>> files.rtf>_______________________________________________
>> > lldb-dev mailing list
>> > lldb-dev at cs.uiuc.edu
>> > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>>
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>
>
>
> --
> Todd Fiala | Software Engineer | tfiala at google.com | 650-943-3180
>



-- 
Todd Fiala | Software Engineer | tfiala at google.com | 650-943-3180
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