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

[Doug Snyder]

what if the logic was changed to do what it does now, but if the "set
breakpoint" returns 0 locations, then try again with
target.inline-breakpoint-strategy set?




On Thu, Sep 18, 2014 at 3:41 PM, Greg Clayton <gclayton at apple.com> wrote:

> Because it vastly improves performance for large Objective C and C++
> projects when setting file and line breakpoints. See our troubleshooting
> page for more details:
>
> http://lldb.llvm.org/troubleshooting.html
>
>
> > On Sep 18, 2014, at 3:38 PM, Doug Snyder <dsnyder at blueshiftinc.com>
> wrote:
> >
> > adding that setting to .lldbinit appears to fix all three cases (ccache,
> preprocess and include).  this was tested in xcode with individual test
> cases that i created.
> >
> > i wonder why that setting is not on by default?
> >
> >
> >
> >
> > 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
> >
> >
> > _______________________________________________
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> > lldb-dev at cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>
>
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