[patch, fortran] PR66310 Problems with intrinsic repeat for large number of copies

[Jerry DeLisle]

On 07/12/2016 06:26 AM, Dominique d'Humières wrote:
>>> 2016-07-11  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
>>>
>>> 	PR fortran/66310
>>> 	* simplify.c (gfc_simplify_repeat): Set max repeat to huge - 1 to allow
>>> 	one byte for null terminating the resulting string constant.
>>
>> OK, thanks
> Please hold on. I still see several problem with the patch applied. One is
> 
>    program p
>       character :: z = 'z'
>       print *, repeat(z, huge(1)-2**9)
>    end
> 
> a.out(67209,0x7fff77e0b000) malloc: *** mach_vm_map(size=18446744071562067968) failed (error code=3)
> *** error: can't allocate region
> *** set a breakpoint in malloc_error_break to debug
> Operating system error: Cannot allocate memory
> Memory allocation failure in realloc
> 
> on x86_64-apple-darwin15.5 with/without the patch. print *, repeat(z, huge(1)-2**9-1) "works".
> 
> I’ll try to report the other problems in the PR later today.
> 
> Dominique
> 
> 

I am holding. On my system I get:

Operating system error: Cannot allocate memory
Memory allocation failure in xrealloc

Which is what I expect.  The error is in trying to allocate the buffer in
write_blockm which it simply can not do.  If you think about it, the numbers are
hugely ridiculous.

Can you try ncopies = (huge(1)-1)/4 and see what you get?

Jerry