[lldb-dev] No stopping event during launch(stop_at_entry=True) on Linux?

Jim Ingham via lldb-dev lldb-dev at lists.llvm.org
Tue Feb 23 17:10:19 PST 2016


That also is a bug.  If it is going to do a public stop, it has to send a stop event.

Jim

> On Feb 23, 2016, at 2:52 PM, Jeffrey Tan <jeffrey.fudan at gmail.com> wrote:
> 
> I am not sure. From the output, it seems lldb does stop at the entry point(because you can issue "bt" command to dump the stack) in both platforms; the problem seems to be that it did not emit the stopped event for its stop on linux.  
> 
> On Tue, Feb 23, 2016 at 2:03 PM, Jim Ingham <jingham at apple.com> wrote:
> If the linux side is not obeying "stop_at_entry" then that is a bug.
> 
> Jim
> 
> 
> > On Feb 23, 2016, at 1:49 PM, Jeffrey Tan via lldb-dev <lldb-dev at lists.llvm.org> wrote:
> >
> > Hi,
> >
> > I have got lldb launch working fine on my macbook for sometime. But when I try the same code on Linux, it failed to emit any stopping events during initial launch.
> >
> > When I run the reproduce code(listed at the end), I got the following different results:
> >
> > The key difference is that Macbook will emit a stopped event which caused our IDE UI to enter break mode, while Linux violates this assumption. Is this a bug?
> >
> > ======================Mac======================
> > lldb_pythonpath: /Applications/Xcode.app/Contents/Developer/../SharedFrameworks/LLDB.framework/Resources/Python
> > Launch result: success
> > <Listener> Listening Thread ID: 4610625536
> > dbg> Target event: ModulesLoaded
> > Process event: StateChanged, Stopped
> > Stop reason: 5
> > dbg> bt
> > * thread #1: tid = 0x101f01d, 0x00007fff6401a000 dyld`_dyld_start, stop reason = signal SIGSTOP
> >   * frame #0: 0x00007fff6401a000 dyld`_dyld_start
> > ======================Mac======================
> >
> > ======================Linux======================
> > python linux_launch.py
> > find_lldb: <module 'lldb' from '/home/jeffreytan/project/llvm-bin/Debug+Asserts/lib/python2.7/site-packages/lldb/__init__.pyc'>
> > Launch result: success
> > <Listener> Listening Thread ID: 140316621375232
> > dbg> bt
> > * thread #1: tid = 2794520, 0x00007f6165b7bb00, name = 'foo', stop reason = signal SIGSTOP
> >   * frame #0: 0x00007f6165b7bb00
> > ======================Linux======================
> >
> > ============================Repro main.py============================
> > # Should be first for LLDB package to be added to search path.
> > from find_lldb import lldb
> > import sys
> > import os
> > import time
> > from sys import stdin, stdout
> > from event_thread import LLDBListenerThread
> > import threading
> >
> >
> > def interctive_loop(debugger):
> >     while (True):
> >         stdout.write('dbg> ')
> >         command = stdin.readline().rstrip()
> >         if len(command) == 0:
> >             continue
> >         if command == 'q':
> >             return
> >         debugger.HandleCommand(command)
> >
> > def do_test():
> >     debugger = lldb.SBDebugger.Create()
> >     debugger.SetAsync(True)
> >     executable_path = '~/Personal/compiler/CompilerConstruction/code/compiler'
> >     target = debugger.CreateTargetWithFileAndArch(executable_path, lldb.LLDB_ARCH_DEFAULT)
> >
> >     listener = lldb.SBListener('Event Listener')
> >     error = lldb.SBError()
> >     process = target.Launch (listener,
> >                              None,      # argv
> >                              None,      # envp
> >                              None,      # stdin_path
> >                              None,      # stdout_path
> >                              None,      # stderr_path
> >                              None,      # working directory
> >                              0,         # launch flags
> >                              True,     # Stop at entry
> >                              error)     # error
> >     print 'Launch result: %s' % str(error)
> >
> >     running_signal = threading.Event()
> >     stopped_signal = threading.Event()
> >     event_thread = LLDBListenerThread(debugger, running_signal, stopped_signal)
> >     event_thread.start()
> >
> >     interctive_loop(debugger)
> >
> >     event_thread.should_quit = True
> >     event_thread.join()
> >
> >     lldb.SBDebugger.Destroy(debugger)
> >     return debugger
> >
> > def main():
> >     debugger = do_test()
> >
> > if __name__ == '__main__':
> >     main()
> >
> > ============================Event_thread============================
> > class LLDBListenerThread(Thread):
> >     should_quit = False
> >
> >     def __init__(self, debugger, running_signal=None, stopped_sigal=None):
> >       Thread.__init__(self)
> >       self._running_signal = running_signal
> >       self._stopped_sigal = stopped_sigal
> >       process = debugger.GetSelectedTarget().process
> >       self.listener = debugger.GetListener()
> >       self._add_listener_to_process(process)
> >       self._add_listener_to_target(process.target)
> >
> >
> >     def _add_listener_to_target(self, target):
> >         # Listen for breakpoint/watchpoint events (Added/Removed/Disabled/etc).
> >         broadcaster = target.GetBroadcaster()
> >         mask = lldb.SBTarget.eBroadcastBitBreakpointChanged | lldb.SBTarget.eBroadcastBitWatchpointChanged | lldb.SBTarget.eBroadcastBitModulesLoaded
> >         broadcaster.AddListener(self.listener, mask)
> >
> >     def _add_listener_to_process(self, process):
> >         # Listen for process events (Start/Stop/Interrupt/etc).
> >         broadcaster = process.GetBroadcaster()
> >         mask = lldb.SBProcess.eBroadcastBitStateChanged | lldb.SBProcess.eBroadcastBitSTDOUT | lldb.SBProcess.eBroadcastBitSTDERR | lldb.SBProcess.eBroadcastBitInterrupt
> >         broadcaster.AddListener(self.listener, mask)
> >
> >     def run(self):
> >         print '<Listener> Listening Thread ID: %d' % thread.get_ident()
> >         while not self.should_quit:
> >             event = lldb.SBEvent()
> >             if self.listener.WaitForEvent(1, event):
> >                 if lldb.SBTarget.EventIsTargetEvent(event):
> >                     self._handle_target_event(event)
> >                 elif lldb.SBProcess.EventIsProcessEvent(event):
> >                     self._handle_process_event(event)
> >                 elif lldb.SBBreakpoint.EventIsBreakpointEvent(event):
> >                     self._handle_breakpoint_event(event)
> >                 elif lldb.SBThread.EventIsThreadEvent(event):
> >                     self._handle_thread_event(event)
> >                 else:
> >                     self._handle_unknown_event(event)
> >         print '<Listener> Exiting listener thread'
> >
> >     def _handle_target_event(self, event):
> >         event_type = event.GetType()
> >         print 'Target event: %s' % target_event_type_to_name_map[event_type]
> >
> >     def _handle_process_event(self, event):
> >         if lldb.SBProcess.GetRestartedFromEvent(event):
> >             print 'Non stopping event: %s' % str(event)
> >             return
> >         process = lldb.SBProcess.GetProcessFromEvent(event)
> >         event_type = event.GetType()
> >         print 'Process event: %s, %s' % (process_event_type_to_name_map[event_type], process_state_name_map[process.state])
> >         if process.state == lldb.eStateExited:
> >             self.should_quit = True
> >         elif process.state == lldb.eStateStopped:
> >             if self._stopped_sigal:
> >                 self._stopped_sigal.set()
> >         else:
> >             if self._running_signal:
> >                 self._running_signal.set()
> >
> >         thread = process.selected_thread
> >         print 'Stop reason: %d' % thread.GetStopReason()
> >         if event_type == lldb.SBProcess.eBroadcastBitSTDOUT:
> >             print 'Stdout:'
> >             while True:
> >                 output = process.GetSTDOUT(1024)
> >                 if len(output) == 0:
> >                     break
> >                 stdout.write(output)
> >
> >     def _handle_breakpoint_event(self, event):
> >         breakpoint = lldb.SBBreakpoint.GetBreakpointFromEvent(event)
> >         event_type = lldb.SBBreakpoint.GetBreakpointEventTypeFromEvent(event)
> >         print 'Breakpoint event: [%s] %s' % (breakpoint_event_type_to_name_map[event_type], str(breakpoint))
> >
> >     def _handle_unknown_event(self, event):
> >         print 'Unknown event'
> >
> > _______________________________________________
> > lldb-dev mailing list
> > lldb-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
> 
> 



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