PR fortran/103411 - ICE in gfc_conv_array_initializer, at fortran/trans-array.c:6377
Commit Message
Dear all,
when checking the SOURCE and SHAPE arguments to the RESHAPE
intrinsic, for absent PAD argument we failed to handle the case
when SHAPE was a parameter.
Fortunately, the proper check was already there, and the code
just needs some tweaking, as well as one of the testcases.
Regtested on x86_64-pc-linux-gnu. OK for mainline?
Thanks,
Harald
Comments
Hello,
Le 24/11/2021 à 22:32, Harald Anlauf via Fortran a écrit :
> diff --git a/gcc/fortran/check.c b/gcc/fortran/check.c
> index 5a5aca10ebe..837eb0912c0 100644
> --- a/gcc/fortran/check.c
> +++ b/gcc/fortran/check.c
> @@ -4866,10 +4868,17 @@ gfc_check_reshape (gfc_expr *source, gfc_expr *shape,
> {
> gfc_constructor *c;
> bool test;
> + gfc_constructor_base b;
>
> + if (shape->expr_type == EXPR_ARRAY)
> + b = shape->value.constructor;
> + else if (shape->expr_type == EXPR_VARIABLE)
> + b = shape->symtree->n.sym->value->value.constructor;
This misses a check that shape->symtree->n.sym->value is an array, so
that it makes sense to access its constructor.
Actually, this only supports the case where the parameter value is
defined by an array; but it could be an intrinsic call, a sum of
parameters, a reference to an other parameter, etc.
The usual way to handle this is to call gfc_reduce_init_expr which (pray
for it) will make an array out of whatever the shape expression is.
The rest looks good.
In the test, can you add a comment telling what it is testing?
Something like: "This tests that constant shape expressions passed to
the reshape intrinsic are properly simplified before being used to
diagnose invalid values"
We also used to put a comment mentioning the person who submitted the
test, but not everybody seems to do it these days.
Mikael
Hi Mikael,
Am 25.11.21 um 17:46 schrieb Mikael Morin:
> Hello,
>
> Le 24/11/2021 à 22:32, Harald Anlauf via Fortran a écrit :
>> diff --git a/gcc/fortran/check.c b/gcc/fortran/check.c
>> index 5a5aca10ebe..837eb0912c0 100644
>> --- a/gcc/fortran/check.c
>> +++ b/gcc/fortran/check.c
>> @@ -4866,10 +4868,17 @@ gfc_check_reshape (gfc_expr *source, gfc_expr
>> *shape,
>> {
>> gfc_constructor *c;
>> bool test;
>> + gfc_constructor_base b;
>>
>> + if (shape->expr_type == EXPR_ARRAY)
>> + b = shape->value.constructor;
>> + else if (shape->expr_type == EXPR_VARIABLE)
>> + b = shape->symtree->n.sym->value->value.constructor;
>
> This misses a check that shape->symtree->n.sym->value is an array, so
> that it makes sense to access its constructor.
there are checks further above for the cases
shape->expr_type == EXPR_ARRAY
and for
shape->expr_type == EXPR_VARIABLE
which look at the elements of array shape to see if they are
non-negative.
Only in those cases where the full "if ()'s" pass we set
shape_is_const = true; and proceed. The purpose of the auxiliary
bool shape_is_const is to avoid repeating the lengthy if's again.
Only then the above cited code segment should get executed.
For shape->expr_type == EXPR_ARRAY there is really no change in logic.
For shape->expr_type == EXPR_VARIABLE the above snipped is now executed,
but then we already had
else if (shape->expr_type == EXPR_VARIABLE && shape->ref
&& shape->ref->u.ar.type == AR_FULL && shape->ref->u.ar.dimen == 1
&& shape->ref->u.ar.as
&& shape->ref->u.ar.as->lower[0]->expr_type == EXPR_CONSTANT
&& shape->ref->u.ar.as->lower[0]->ts.type == BT_INTEGER
&& shape->ref->u.ar.as->upper[0]->expr_type == EXPR_CONSTANT
&& shape->ref->u.ar.as->upper[0]->ts.type == BT_INTEGER
&& shape->symtree->n.sym->attr.flavor == FL_PARAMETER
&& shape->symtree->n.sym->value)
In which situations do I miss anything new?
> Actually, this only supports the case where the parameter value is
> defined by an array; but it could be an intrinsic call, a sum of
> parameters, a reference to an other parameter, etc.
E.g. the following (still) does get rejected:
print *, reshape([1,2,3,4,5], a+1)
print *, reshape([1,2,3,4,5], a+a)
print *, reshape([1,2,3,4,5], 2*a)
print *, reshape([1,2,3,4,5], [3,3])
print *, reshape([1,2,3,4,5], spread(3,dim=1,ncopies=2))
and has been rejected before.
> The usual way to handle this is to call gfc_reduce_init_expr which (pray
> for it) will make an array out of whatever the shape expression is.
Can you give an example where it fails?
I think the current code would almost certainly fail, too.
> The rest looks good.
> In the test, can you add a comment telling what it is testing?
> Something like: "This tests that constant shape expressions passed to
> the reshape intrinsic are properly simplified before being used to
> diagnose invalid values"
Can do.
> We also used to put a comment mentioning the person who submitted the
> test, but not everybody seems to do it these days.
Can do.
> Mikael
>
Harald
Le 25/11/2021 à 21:03, Harald Anlauf a écrit :
> Hi Mikael,
>
> Am 25.11.21 um 17:46 schrieb Mikael Morin:
>> Hello,
>>
>> Le 24/11/2021 à 22:32, Harald Anlauf via Fortran a écrit :
>>> diff --git a/gcc/fortran/check.c b/gcc/fortran/check.c
>>> index 5a5aca10ebe..837eb0912c0 100644
>>> --- a/gcc/fortran/check.c
>>> +++ b/gcc/fortran/check.c
>>> @@ -4866,10 +4868,17 @@ gfc_check_reshape (gfc_expr *source, gfc_expr
>>> *shape,
>>> {
>>> gfc_constructor *c;
>>> bool test;
>>> + gfc_constructor_base b;
>>>
>>> + if (shape->expr_type == EXPR_ARRAY)
>>> + b = shape->value.constructor;
>>> + else if (shape->expr_type == EXPR_VARIABLE)
>>> + b = shape->symtree->n.sym->value->value.constructor;
>>
>> This misses a check that shape->symtree->n.sym->value is an array, so
>> that it makes sense to access its constructor.
>
> there are checks further above for the cases
> shape->expr_type == EXPR_ARRAY
> and for
> shape->expr_type == EXPR_VARIABLE
> which look at the elements of array shape to see if they are
> non-negative.
>
> Only in those cases where the full "if ()'s" pass we set
> shape_is_const = true; and proceed. The purpose of the auxiliary
> bool shape_is_const is to avoid repeating the lengthy if's again.
> Only then the above cited code segment should get executed.
>
> For shape->expr_type == EXPR_ARRAY there is really no change in logic.
> For shape->expr_type == EXPR_VARIABLE the above snipped is now executed,
> but then we already had
>
> else if (shape->expr_type == EXPR_VARIABLE && shape->ref
> && shape->ref->u.ar.type == AR_FULL && shape->ref->u.ar.dimen == 1
> && shape->ref->u.ar.as
> && shape->ref->u.ar.as->lower[0]->expr_type == EXPR_CONSTANT
> && shape->ref->u.ar.as->lower[0]->ts.type == BT_INTEGER
> && shape->ref->u.ar.as->upper[0]->expr_type == EXPR_CONSTANT
> && shape->ref->u.ar.as->upper[0]->ts.type == BT_INTEGER
> && shape->symtree->n.sym->attr.flavor == FL_PARAMETER
> && shape->symtree->n.sym->value)
>
> In which situations do I miss anything new?
>
Yes, I agree with all of this.
My comment wasn’t about a check on shape->expr_type, but on
shape->value->expr_type if shape->expr_type is a (parameter) variable.
>> Actually, this only supports the case where the parameter value is
>> defined by an array; but it could be an intrinsic call, a sum of
>> parameters, a reference to an other parameter, etc.
>
> E.g. the following (still) does get rejected:
>
> print *, reshape([1,2,3,4,5], a+1)
> print *, reshape([1,2,3,4,5], a+a)
> print *, reshape([1,2,3,4,5], 2*a)
> print *, reshape([1,2,3,4,5], [3,3])
> print *, reshape([1,2,3,4,5], spread(3,dim=1,ncopies=2))
>
> and has been rejected before.
>
>> The usual way to handle this is to call gfc_reduce_init_expr which (pray
>> for it) will make an array out of whatever the shape expression is.
>
> Can you give an example where it fails?
>
> I think the current code would almost certainly fail, too.
>
Probably, I was just trying to avoid followup bugs. ;-)
I have checked the following:
integer, parameter :: a(2) = [1,1]
integer, parameter :: b(2) = a + 1
print *, reshape([1,2,3,4], b)
end
and it doesn’t fail as I thought it would.
So yes, I was wrong; b has been expanded to an array before.
Can you add an assert or a comment saying that the parameter value has
been expanded to a constant array?
Ok with that change.
From d6af2a33bad852bcea39b8c5b2e7c27976bde2a1 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Wed, 24 Nov 2021 22:22:24 +0100
Subject: [PATCH] Fortran: improve check of arguments to the RESHAPE intrinsic
gcc/fortran/ChangeLog:
PR fortran/103411
* check.c (gfc_check_reshape): Improve check of size of source
array for the RESHAPE intrinsic against the given shape when pad
is not given, and shape is a parameter.
gcc/testsuite/ChangeLog:
PR fortran/103411
* gfortran.dg/reshape_7.f90: Adjust test to improved check.
* gfortran.dg/reshape_9.f90: New test.
---
gcc/fortran/check.c | 17 +++++++++++++----
gcc/testsuite/gfortran.dg/reshape_7.f90 | 2 +-
gcc/testsuite/gfortran.dg/reshape_9.f90 | 14 ++++++++++++++
3 files changed, 28 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gfortran.dg/reshape_9.f90
@@ -4699,6 +4699,7 @@ gfc_check_reshape (gfc_expr *source, gfc_expr *shape,
mpz_t size;
mpz_t nelems;
int shape_size;
+ bool shape_is_const = false;
if (!array_check (source, 0))
return false;
@@ -4736,6 +4737,7 @@ gfc_check_reshape (gfc_expr *source, gfc_expr *shape,
{
gfc_expr *e;
int i, extent;
+ shape_is_const = true;
for (i = 0; i < shape_size; ++i)
{
e = gfc_constructor_lookup_expr (shape->value.constructor, i);
@@ -4748,7 +4750,7 @@ gfc_check_reshape (gfc_expr *source, gfc_expr *shape,
gfc_error ("%qs argument of %qs intrinsic at %L has "
"negative element (%d)",
gfc_current_intrinsic_arg[1]->name,
- gfc_current_intrinsic, &e->where, extent);
+ gfc_current_intrinsic, &shape->where, extent);
return false;
}
}
@@ -4766,6 +4768,7 @@ gfc_check_reshape (gfc_expr *source, gfc_expr *shape,
int i, extent;
gfc_expr *e, *v;
+ shape_is_const = true;
v = shape->symtree->n.sym->value;
for (i = 0; i < shape_size; i++)
@@ -4856,8 +4859,7 @@ gfc_check_reshape (gfc_expr *source, gfc_expr *shape,
}
}
- if (pad == NULL && shape->expr_type == EXPR_ARRAY
- && gfc_is_constant_expr (shape)
+ if (pad == NULL && shape_is_const
&& !(source->expr_type == EXPR_VARIABLE && source->symtree->n.sym->as
&& source->symtree->n.sym->as->type == AS_ASSUMED_SIZE))
{
@@ -4866,10 +4868,17 @@ gfc_check_reshape (gfc_expr *source, gfc_expr *shape,
{
gfc_constructor *c;
bool test;
+ gfc_constructor_base b;
+ if (shape->expr_type == EXPR_ARRAY)
+ b = shape->value.constructor;
+ else if (shape->expr_type == EXPR_VARIABLE)
+ b = shape->symtree->n.sym->value->value.constructor;
+ else
+ gcc_unreachable ();
mpz_init_set_ui (size, 1);
- for (c = gfc_constructor_first (shape->value.constructor);
+ for (c = gfc_constructor_first (b);
c; c = gfc_constructor_next (c))
mpz_mul (size, size, c->expr->value.integer);
@@ -4,7 +4,7 @@
subroutine p0
integer, parameter :: sh(2) = [2, 3]
integer, parameter :: &
- & a(2,2) = reshape([1, 2, 3, 4], sh) ! { dg-error "Different shape" }
+ & a(2,2) = reshape([1, 2, 3, 4], sh) ! { dg-error "not enough elements" }
if (a(1,1) /= 0) STOP 1
end subroutine p0
new file mode 100644
@@ -0,0 +1,14 @@
+! { dg-do compile }
+! PR fortran/103411 - ICE in gfc_conv_array_initializer
+
+program p
+ integer, parameter :: a(2) = [2,2]
+ integer, parameter :: d(2,2) = reshape([1,2,3,4,5], a)
+ integer, parameter :: c(2,2) = reshape([1,2,3,4], a)
+ integer, parameter :: b(2,2) = &
+ reshape([1,2,3], a) ! { dg-error "not enough elements" }
+ print *, reshape([1,2,3], a) ! { dg-error "not enough elements" }
+ print *, reshape([1,2,3,4], a)
+ print *, reshape([1,2,3,4,5], a)
+ print *, b, c, d
+end
--
2.26.2