[lldb-dev] Python example does not work with latest LLDBs
Roman Popov via lldb-dev
lldb-dev at lists.llvm.org
Mon Feb 13 11:45:43 PST 2017
I've noticed that apt created some invalid symlinks, but fixing them did
not helped. I have a gut feeling that the problem is with prebuilt packages
from http://apt.llvm.org/ , not with lldb sources .
But we need someone else with Ubuntu 16.04 to confirm.
2017-02-13 22:15 GMT+03:00 Greg Clayton <gclayton at apple.com>:
> Works for me with top of tree:
>
> % PYTHONPATH=/tmp/lldb/build/Debug/LLDB.framework/Resources/Python ;
> ./foo.py )
> Creating a target for './a.out'
> SBBreakpoint: id = 1, name = 'main', module = a.out, locations = 1
> SBProcess: pid = 62855, state = stopped, threads = 1, executable = a.out
> thread #1: tid = 0x558f56, 0x000000010226bf74 a.out`main(argc=1,
> argv=0x00007fff5d994ec8) at main.cpp:15, queue =
> 'com.apple.main-thread', stop reason = breakpoint 1.1
> frame #0: 0x000000010226bf74 a.out`main(argc=1, argv=0x00007fff5d994ec8)
> at main.cpp:15
> SBFunction: id = 0x0000004b, name = main, type = main
> a.out[0x100000f60]: pushq %rbp
> a.out[0x100000f61]: movq %rsp, %rbp
> a.out[0x100000f64]: xorl %eax, %eax
> a.out[0x100000f66]: movl $0x0, -0x4(%rbp)
> a.out[0x100000f6d]: movl %edi, -0x8(%rbp)
> a.out[0x100000f70]: movq %rsi, -0x10(%rbp)
> a.out[0x100000f74]: popq %rbp
> a.out[0x100000f75]: retq
>
> this is on a Mac though. Might be something specific to linux.
>
> Greg
>
> On Feb 13, 2017, at 10:23 AM, Roman Popov <ripopov at gmail.com> wrote:
>
> Do you mean you were able to reproduce it? Because it is used to work on
> trunk month ago, but since then I've switched from ubuntu 14.04 to fresh
> 16.04 and it no longer works for me.
>
> 2017-02-13 21:21 GMT+03:00 Greg Clayton <gclayton at apple.com>:
>
>> I would be probably best to just step through it and see why it is
>> incorrectly returning. We know it is broken. We should also add a test for
>> this so we don't regress again.
>>
>> Greg
>>
>> On Feb 13, 2017, at 10:19 AM, Roman Popov <ripopov at gmail.com> wrote:
>>
>> Yes Greg, this was my expectation that it should not return until stops
>> on break-point. But I had to downgrade sequentially from 5.0 to 4.0 to 3.9
>> to make it work as expected.
>>
>> Can I get some diagnostics? Any log files?
>>
>> 2017-02-13 20:11 GMT+03:00 Greg Clayton <gclayton at apple.com>:
>>
>>> 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
>>> (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/ llvm-toolchain-xenial main
>>>
>>> # 3.9 -- Works
>>>
>>> deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-3.9 main
>>>
>>> # 4.0 -- Does not work
>>>
>>> deb 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
>>>
>>>
>>>
>>
>>
>
>
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