[ Was: Re: [PR65637][PATCH][1/3] Fix gcc_assert in 
expand_omp_for_static_chunk ]

On 15/04/15 15:15, Tom de Vries wrote:
> On 15-04-15 15:10, Tom de Vries wrote:
>> Hi,
>>
>> This patch series fixes PR65637.
>>

<SNIP>

> This patch fixes a segfault in an gcc_assert in expand_omp_for_static_chunk
> while compiling autopar/pr46099.c.
>
> When compiling f1 from autopar/pr46099.c using
> expand_omp_for_static_chunk, we
> redirect the edge (trip_update_bb -> fin_bb) to point to iter_part_bb:
> ...
>        redirect_edge_and_branch (single_succ_edge (trip_update_bb),
> iter_part_bb);
> ...
>
> And fin_bb is an empty block without any phis, so during the redirect we
> don't
> store any entries in the edge_var_map:
> ...
> (gdb) call debug_bb (fin_bb)
> ;; basic block 18, loop depth 0, count 0, freq 0, maybe hot
> ;;  prev block 21, next block 16, flags: (NEW)
> ;;  pred:       21 [100.0%]  (FALLTHRU)
> ;;              19 (FALSE_VALUE)
> ;;  succ:       16 [100.0%]  (FALLTHRU)
> ...
>
> Consequently, head will be NULL.
> ...
>        vec<edge_var_map> *head = redirect_edge_var_map_vector (re);
> ...
>
> And because head is NULL, this assert causes a segfault:
> ...
>    gcc_assert (gsi_end_p (psi) && i == head->length ());
> ...
>
> This patch fixes that, by handling the case that head is NULL in the
> assert.
>

This updated patch includes a test-case.

OK for trunk?

Thanks,
- Tom