[lldb-dev] just me, or lldb 3.4 is very buggy?

Todd Fiala tfiala at google.com
Fri Jan 31 08:30:02 PST 2014


Here's what I'm seeing on Ubuntu 12.04 x86_64 (I'll hop over to Ubuntu
13.10 in a moment to see what it shows), using gcc 4.8.2:

Here is my hello.c:

#include <stdio.h>

int main(int argc, char **argv)
{
    printf("Hello, world\n");
    return 0;
}

Here is the output from compiling and running lldb:

tfiala at tfiala2:~/lldb/samples/hello$ gcc -g -O0 -o hello hello.c
tfiala at tfiala2:~/lldb/samples/hello$ ./hello
Hello, world
# the following is my top of tree build from lldb as of about 12 hours ago
tfiala at tfiala2:~/lldb/samples/hello$
~/lldb/svn/lgs/build2/Debug+Asserts/bin/lldb
(lldb) target create ./hello
Current executable set to './hello' (x86_64).
(lldb) b main
Breakpoint 1: where = hello`main + 15 at hello.c:5, address =
0x00000000004004df
(lldb) r
Process 11433 launching
Process 11433 stopped
* thread #1: tid = 11433, 0x00007faad38206b0, name = 'hello', stop reason =
trace
    frame #0: 0x00007faad38206b0
-> 0x7faad38206b0:  movq   %rsp, %rdi
   0x7faad38206b3:  callq  0x7faad3824010
   0x7faad38206b8:  movq   %rax, %r12
   0x7faad38206bb:  movl   0x2215ff(%rip), %eax
(lldb) Process 11433 launched: './hello' (x86_64)
Process 11433 stopped
* thread #1: tid = 11433, 0x00000000004004df hello`main(argc=1,
argv=0x00007fffa93f3ba8) + 15 at hello.c:5, name = 'hello', stop reason =
breakpoint 1.1
    frame #0: 0x00000000004004df hello`main(argc=1,
argv=0x00007fffa93f3ba8) + 15 at hello.c:5
   2
   3   int main(int argc, char **argv)
   4   {
-> 5       printf("Hello, world\n");
   6       return 0;
   7   }
(lldb)

I'll try it on Ubuntu 13.10 x86_64 next.  That one will be with a stock
system + packages for build-essential, libedit-dev, libpython-dev and swig
(I think that's it).

-Todd


On Fri, Jan 31, 2014 at 8:23 AM, Jun Koi <junkoi2004 at gmail.com> wrote:

>
>
>
> On Sat, Feb 1, 2014 at 12:19 AM, Todd Fiala <tfiala at google.com> wrote:
>
>> Hi Jun,
>>
>> Thanks again for the report.
>>
>> I'm hopping over to Ubuntu 13.10 and will have a look at this.  It would
>> definitely be helpful to know a few things (which I'm going to have to
>> guess about here):
>> * What compiler are you using?  gcc or clang?
>>
>
> i am using default CC, which is gcc
>
>
>> * What flags did you pass to the compiler when you compiled? Was it a
>> debug build? Was it optimized?
>>
>>
> it is also default compiler option. for example, with helloworld.c
> program, i simply compiled it with (without Makefile):
>
>      $ make helloworld
>
>
>
>> I'll file a bug if I'm able to cause a seg fault.  Yesterday I had a
>> check-in that fixed a seg fault under Linux - not sure if that's something
>> you were hitting.
>>
>>
> I'll post what I see.
>>
>>
> awesome, please keep us updating!
>
> thanks,
> Jun
>
>
>
>
> On Thu, Jan 30, 2014 at 7:00 AM, Jun Koi <junkoi2004 at gmail.com> wrote:
>
>> hi,
>>
>> i got lldb 3.5 from llvm.org/apt, and it is a bit better: it no longer
>> has issue with libedit, it seems.
>>
>> however, it crashes all the time. you can easily reproduce it like below:
>>
>> $ lldb-3.5 ./test
>> Current executable set to './test' (i386).
>> (lldb) b main
>> Breakpoint 1: where = test`main, address = 0x0804847d
>> (lldb) r
>> Segmentation fault (core dumped)
>>
>>
>> "test" can be any program. in my case, it is just a "hello world"
>> program, written in C.
>>
>> again, this is on Ubuntu 13.10 32bit. please try it, and confirm this is
>> indeed a bug.
>>
>> at this current status, lldb is really unusable :-((
>>
>> thanks.
>> Jun
>>
>>
>>
>> On Thu, Jan 30, 2014 at 2:06 AM, Todd Fiala <tfiala at google.com> wrote:
>>
>>> Hi Jun,
>>>
>>> Could you file a bug here<http://llvm.org/bugs/enter_bug.cgi?product=lldb>and attach your source?  Include how you compile it so we make sure we're
>>> all on the same page to reproduce it.  Then we can see what's going on.
>>>
>>> Thanks for reporting it!
>>>
>>> Sincerely,
>>> Todd Fiala
>>>
>>>
>>> On Wed, Jan 29, 2014 at 6:48 PM, Sylvestre Ledru <sylvestre at debian.org>wrote:
>>>
>>>> On 29/01/2014 09:42, Greg Clayton wrote:
>>>> > You will need to update the installed libedit on your machine.
>>>> "libedit" is the line reader program we use to get commands and the default
>>>> version on most linux's is quite old and out of date.
>>>> >
>>>> >
>>>> Ubuntu saucy (13.10) has libedit  v3.1-20130712. Not sure it is the
>>>> issue here...
>>>>
>>>> Sylvestre
>>>>
>>>> _______________________________________________
>>>> lldb-dev mailing list
>>>> lldb-dev at cs.uiuc.edu
>>>> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>>>>
>>>
>>>
>>>
>>> --
>>>  Todd Fiala | Software Engineer |  tfiala at google.com |  650-943-3180
>>>
>>> _______________________________________________
>>> lldb-dev mailing list
>>> lldb-dev at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>>>
>>>
>>
>
>
> --
> Todd Fiala | Software Engineer |  tfiala at google.com |  650-943-3180
>
>


-- 
Todd Fiala | Software Engineer | tfiala at google.com | 650-943-3180
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