Re: Current tip hang on bad syntax

[Jaroslav Hajek]

On Fri, Mar 26, 2010 at 7:39 AM, Michael D Godfrey
<address@hidden> wrote:
> I accidentally did:
>
> octave
> chirpm1
> ===============
> where the file chirpm1.m contained:
> % chirp defn:
>
> x(t) = sin(2\pi \int_0^t f(t')dt') = sin(2\pi(f_0 + (k/2)t)t)
> ============================
> The result was:
>
> octave:1> chirp1
> parse error near line 3 of file
> /home/godfrey/mdg/reps/noise_and_info/chirp1.m
>
>   syntax error
>
>>>> x(t) = sin(2\pi \int_0^t f(t')dt') = sin(2\pi(f_0 + (k/2)t)t)
>                            ^
>
> parse error near line 3 of file
> /home/godfrey/mdg/reps/noise_and_info/chirp1.m
>
>   syntax error
>
>>>> x(t) = sin(2\pi \int_0^t f(t')dt') = sin(2\pi(f_0 + (k/2)t)t)
>                            ^
>
>
>
> ^C^CPress Control-C again to abort.
> ^Cpanic: Interrupt -- stopping myself...
> ^C^C^C
> ^C^C^C^C^C^C^C
> ============================
> The only way to kill octave was with kill -9 from another window.
> Running under gdb shows a loop (after seg fault) like:
> (after SIGSEGV message)
> bt  command dumps trace, which drops into loop:
> #1040 0x00007ffff75901f0 in feval (name="unimplemented", args=...,
> nargout=0) at oct-parse.yy:4038
> #1041 0x00007ffff766738d in maybe_missing_function_hook (name=Traceback
> (most recent call last):
>   File "/usr/lib64/../share/gdb/python/libstdcxx/v6/printers.py", line 467,
> in to_string
>     header = ptr.cast(reptype) - 1
> RuntimeError: Cannot access memory at address 0x1000
> ) at variables.cc:2397
> #1042 0x00007ffff75901f0 in feval (name="unimplemented", args=...,
> nargout=0) at oct-parse.yy:4038
> ============================
> But, under gdb it did not print anything before SIGSEGV message.  I do not
> know
> where to start to diagnose this.
>
> The text which octave read is really TeX, but this should not lead to a dead
> hang.
> Michael
>
>


It works normally for me. Still I think that a guard against recursive
calls of the hook will do no harm.


-- 
RNDr. Jaroslav Hajek, PhD
computing expert & GNU Octave developer
Aeronautical Research and Test Institute (VZLU)
Prague, Czech Republic
url: www.highegg.matfyz.cz