Re: compiling development sources

[Carlo de Falco]

On 10 Feb 2010, at 18:46, John W. Eaton wrote:

> OK, then try running Octave with
>
>  ./run-octave -g
>
> then at the (gdb) prompt, type "run", then at the Octave prompt, cd to
> the src/DLD-FUNCTIONS directory and type "test lu".  That should
> result in the same segfault and you should be able to get information
> about where the crash happens and examine the variables in scope at
> the time of the crash.
>
> jwe

running the tests manually I found where the crash is:

>> [l, u, p] = lu ([1, 2; 3, 4]);
Reading symbols for shared libraries . done
>> p
p =

Permutation Matrix

   0   1
   1   0

>> assert(p(:,:), [0, 1; 1, 0], sqrt (eps));

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x9b12d1e0
get_dispatch_type (address@hidden, address@hidden) at  
symtab.cc:528
528                 btyp = sup_table[btyp][args(i).builtin_type ()];
(gdb)


It seems that the problem is in comparing the permutation matrix p  
with the full matrix [0, 1; 1, 0]

Indeed, changing the test to:

>> [l, u, p] = lu ([1, 2; 3, 4]);
>> assert(full(p), [0, 1; 1, 0], sqrt (eps));
>>


I don't get the crash anymore...
c.