[lldb-dev] Python example does not work with latest LLDBs

[Greg Clayton via lldb-dev]

The example code is:

#!/usr/bin/python

import lldb
import os

def disassemble_instructions(insts):
    for i in insts:
        print i

# Set the path to the executable to debug
exe = "./a.out"

# Create a new debugger instance
debugger = lldb.SBDebugger.Create()

# When we step or continue, don't return from the function until the process 
# stops. Otherwise we would have to handle the process events ourselves which, while doable is
#a little tricky.  We do this by setting the async mode to false.
debugger.SetAsync (False)

# Create a target from a file and arch
print "Creating a target for '%s'" % exe

target = debugger.CreateTargetWithFileAndArch (exe, lldb.LLDB_ARCH_DEFAULT)

if target:
    # If the target is valid set a breakpoint at main
    main_bp = target.BreakpointCreateByName ("main", target.GetExecutable().GetFilename());

    print main_bp

    # Launch the process. Since we specified synchronous mode, we won't return
    # from this function until we hit the breakpoint at main
    process = target.LaunchSimple (None, None, os.getcwd())
    
    # Make sure the launch went ok
    if process:
        # Print some simple process info
        state = process.GetState ()
        print process
        if state == lldb.eStateStopped:
            # Get the first thread
            thread = process.GetThreadAtIndex (0)
            if thread:
                # Print some simple thread info
                print thread
                # Get the first frame
                frame = thread.GetFrameAtIndex (0)
                if frame:
                    # Print some simple frame info
                    print frame
                    function = frame.GetFunction()
                    # See if we have debug info (a function)
                    if function:
                        # We do have a function, print some info for the function
                        print function
                        # Now get all instructions for this function and print them
                        insts = function.GetInstructions(target)
                        disassemble_instructions (insts)
                    else:
                        # See if we have a symbol in the symbol table for where we stopped
                        symbol = frame.GetSymbol();
                        if symbol:
                            # We do have a symbol, print some info for the symbol
                            print symbol

We set the async mode to false, so target.LaunchSimple() should not return until the process is stopped or exited. Note in your example it is returning with "state = launching", so this is what is failing. For some reason synchronous mode is not being obeyed.

Greg

> On Feb 11, 2017, at 10:07 AM, Roman Popov via lldb-dev <lldb-dev at lists.llvm.org> wrote:
> 
> I'm testing example from https://lldb.llvm.org/python-reference.html <https://lldb.llvm.org/python-reference.html> (USING THE LLDB.PY MODULE IN PYTHON)  on Ubuntu 16.04
> 
> For some reason it works only with LLDB 3.9, is it because LLDB 4.0/5.0 are not stable yet?
> 
> #5.0   -- Does not work
> deb http://apt.llvm.org/xenial/ <http://apt.llvm.org/xenial/> llvm-toolchain-xenial main
> # 3.9  -- Works
> deb http://apt.llvm.org/xenial/ <http://apt.llvm.org/xenial/> llvm-toolchain-xenial-3.9 main
> # 4.0  -- Does not work
> deb http://apt.llvm.org/xenial/ <http://apt.llvm.org/xenial/> llvm-toolchain-xenial-4.0 main
> 
> >clang-5.0 -g test.cpp
> >./python_example.py
> Creating a target for './a.out'
> SBBreakpoint: id = 1, name = 'main', locations = 1
> SBProcess: pid = 0, state = launching, threads = 0, executable = a.out
> Thanks,
> Roman
> _______________________________________________
> lldb-dev mailing list
> lldb-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/lldb-dev/attachments/20170213/ea0174bc/attachment.html>