[lldb-dev] python SBBreakpoint questions

Bill Terwilliger sideshowtwig at gmail.com
Fri Oct 19 13:48:33 PDT 2012


I'm an idiot. My iterator issue was because I was also checking that bp.GetNumResolvedLocations > 0. And of course that would fail if the breakpoint was disabled.

Thank you everyone for your help. :)


On Oct 19, 2012, at 4:21 PM, Greg Clayton <gclayton at apple.com> wrote:

> You can always just use the actual API:
> 
>    uint32_t
>    SBTarget::GetNumBreakpoints () const;
> 
>    lldb::SBBreakpoint
>    SBTarget::GetBreakpointAtIndex (uint32_t idx) const;
> 
> "breakpoint_iter" should be doing the right thing as it is defined in lldb.py (which is in LLDB.framework/Resources/python/lldb):
> 
> 
>    def breakpoint_iter(self): return lldb_iter(self, 'GetNumBreakpoints', 'GetBreakpointAtIndex')
> 
> This calls lldb_iter:
> 
> # Iterator for lldb container objects
> # ===================================
> def lldb_iter(obj, getsize, getelem):
>    """A generator adaptor to support iteration for lldb container objects."""
>    size = getattr(obj, getsize)
>    elem = getattr(obj, getelem)
>    for i in range(size()):
>        yield elem(i)
> 
> 
> 
> On Oct 19, 2012, at 1:10 PM, Bill Terwilliger <sideshowtwig at gmail.com> wrote:
> 
>> Thanks Carlo! I am able to find the current breakpoint with GetStopReasonDataAtIndex(0).
>> 
>> New problem… when I find my breakpoint, I'm calling bp.SetEnabled(False) and then process.Continue(), and that seems to work as expected. But later when I use target.breakpoint_iter() to iterate over all of the breakpoints, it stops iterating after a single breakpoint.  The script is setting 12 breakpoints, 9 of them are being triggered (and disabled.) My understanding of the code is that all 12 breakpoints should still be there regardless of the their 'enabled' state. When I take out the bp.SetEnabled(False) line, the iterator continues to work as expected. Is this a bug or am I doing something else wrong?
>> 
>> --bill
>> 
>> On Oct 19, 2012, at 3:25 PM, Carlo Kok <ck at remobjects.com> wrote:
>> 
>>> Op 19-10-2012 20:26, Bill Terwilliger schreef:
>>>> Hi,
>>>> 
>>>> I'm having trouble using breakpoints with the python API... My script creates a bunch of breakpoints (by address), launches the target and then goes into an infinite loop checking 'process.GetState()'. The scripts checks for a state of 'eStateStopped', and then iterates through the threads until it finds a thread stop reason of 'eStopReasonBreakpoint'. The issue with that approach is that I can't figure out which breakpoint triggered the thread to stop. So I guess I have two questions, (1) how do I use SetCallback() to call a method when a breakpoint is triggered and (2) if I know which thread hit my breakpoint, how do I know which SBBreakpoint triggered?
>>>> 
>>>> BTW, I looked through all of the unit test for examples of how to do this but all I could find was a call to SetCallback(None, None). The documentation for SBBreakpoint gives a prototype of SetCallback(BreakpointHitCallback callback, void baton) but BreakpointHitCallback doesn't appear to be documented in the python docs.
>>>> 
>>>> Any help would be greatly appreciated. :-)
>>>> 
>>> 
>>> There's an events sample for python. Essentially you have a thread waiting for events on a listener, the wait call returns and the SBEvent you get then can be retrieved:
>>> 
>>> SBEvent data;
>>> while (!stop) {
>>> if (self->m_listener.WaitForEvent(UINT32_MAX, data)) {
>>> if (data.getType() == SBProcess::eBroadcastBitStateChanged && m_process.GetStateFromEvent (data) == eStateStopped) {
>>>  SBThread th = m_process.GetSelectedThread();
>>>  if (th.GetStopReason() == eStopReasonBreakpoint) {
>>>    // th.GetStopReasonDataAtIndex(0) should have the breakpoint id
>>>  }
>>> }
>>> }
>>> }
>>> 
>>> something like that
>>> _______________________________________________
>>> lldb-dev mailing list
>>> lldb-dev at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>> 
>> 
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> 





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