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

[Jeff Law]

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  <pola...@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