From: Mikael Morin <morin-mikael@orange.fr>
To: Harald Anlauf <anlauf@gmx.de>, fortran <fortran@gcc.gnu.org>,
gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH, v2] Fortran: fix for absent array argument passed to optional dummy [PR101135]
Date: Mon, 18 Mar 2024 19:47:16 +0100 [thread overview]
Message-ID: <b0bd5678-4e45-4aa6-bc32-b04bb20f5a57@orange.fr> (raw)
In-Reply-To: <c370a6d3-0ac6-482d-8ca0-65d3f2932a8b@gmx.de>
Le 17/03/2024 à 23:10, Harald Anlauf a écrit :
> Hi Mikael,
>
> On 3/17/24 22:04, Mikael Morin wrote:
>>> diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc
>>> index 3673fa40720..a7717a8107e 100644
>>> --- a/gcc/fortran/trans-array.cc
>>> +++ b/gcc/fortran/trans-array.cc
>>> @@ -7526,6 +7526,17 @@ gfc_get_dataptr_offset (stmtblock_t *block,
>>> tree parm, tree desc, tree offset,
>>>
>>> /* Set the target data pointer. */
>>> offset = gfc_build_addr_expr (gfc_array_dataptr_type (desc), tmp);
>>> +
>>> + /* Check for optional dummy argument being present. Arguments of
>>> BIND(C)
>>> + procedures are excepted here since they are handled
>>> differently. */
>>> + if (expr->expr_type == EXPR_VARIABLE
>>> + && expr->symtree->n.sym->attr.dummy
>>> + && expr->symtree->n.sym->attr.optional
>>> + && !is_CFI_desc (NULL, expr))
>>
>> I think the condition could additionally check the lack of subreferences.
>> But it's maybe not worth the trouble, and the patch is conservatively
>> correct as is, so OK.
>
> I have thought about the conditions here for some time and did not
> find better ones. They need to be broad enough to catch the case
> in gfortran.dg/missing_optional_dummy_6a.f90 that (according to the
> tree-dump) was not properly handled previously and would have triggered
> ubsan at some point in the future when someone tried to change that
> testcase from currently dg-do compile to dg-do run...
No problem, as said it is conservatively correct.
> (After the patch it would pass, but I didn't dare to change the dg-do).
> Did it include cases not covered by the new testcase (which was quite
complete already)?
> I have pushed the patch as-is, but feel free to post testcases
> not covered (or improperly covered) to narrow this down further...
>
The case I had in mind would only be a missed optimization, and probably
not that important, so let's move on.
prev parent reply other threads:[~2024-03-18 18:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-29 21:41 [PATCH] PR/101135 - Load of null pointer when passing absent assumed-shape array argument for an optional dummy argument Harald Anlauf
2022-02-04 10:45 ` Mikael Morin
2022-02-06 21:04 ` Harald Anlauf
2024-03-15 19:32 ` [PATCH, v2] Fortran: fix for absent array argument passed to optional dummy [PR101135] Harald Anlauf
2024-03-17 21:04 ` Mikael Morin
2024-03-17 22:10 ` Harald Anlauf
2024-03-18 18:47 ` Mikael Morin [this message]
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