Re: [PATCH] Fix ICE with -Walloca-larger-than=[>INT_MAX] (PR middle-end/79809)

[Jeff Law <law at redhat dot com>]

On 03/02/2017 05:32 AM, Marek Polacek wrote:
> As demonstrated by this test, we can crash on the assert in alloca_call_type:
> gcc_assert (is_vla || warn_alloca_limit > 0);
> when -Walloca-larger-than= receives an argument greater than INT_MAX.  Even
> though warn_vla_limit is marked as UInteger in c.opt, those are still
> represented as ints; opt-functions.awk has
>
> 202         else if (flag_set_p("UInteger", flags))
> 203                 return "int "
> ...
> 213         if (flag_set_p("UInteger", flags))
> 214                 return "int "
>
> So 4207115063 is converted to int which is some negative value.
>
> It's probably too late to change opt-functions.awk now, so the following
> is a badn aid fix.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2017-03-02  Marek Polacek  <polacek@redhat.com>
>
> 	PR middle-end/79809
> 	* gimple-ssa-warn-alloca.c (pass_walloca::gate): Use HOST_WIDE_INT.
> 	(alloca_call_type): Likewise.
>
> 	* g++.dg/Walloca1.C: New test.
OK.
jeff