Hi Mikael,
Am 25.11.21 um 22:02 schrieb Mikael Morin:
> 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.
well, that one is actually better valid, since b=[2,2].
> So yes, I was wrong; b has been expanded to an array before.
Motivated by your reasoning I tried gfc_reduce_init_expr. That attempt
failed miserably (many regressions), and I think it is not right.
Then I found that array sections posed a problem that wasn't detected
before. gfc_simplify_expr seemed to be a better choice that makes more
sense for the present situations and seems to work here. And it even
detects many more invalid cases now than e.g. Intel ;-)
I've updated the patch and testcase accordingly.
> Can you add an assert or a comment saying that the parameter value has
> been expanded to a constant array?
>
> Ok with that change.
>
Given the above discussion, I'll give you another day or two to have a
further look. Otherwise Gerhard will... ;-)
Cheers,
Harald
From 56fd0d23ac0a5bda802e5cce3024b947e497555a Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Thu, 25 Nov 2021 22:39:44 +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. Try other simplifications
of shape.
gcc/testsuite/ChangeLog:
PR fortran/103411
* gfortran.dg/pr68153.f90: Adjust test to improved check.
* gfortran.dg/reshape_7.f90: Likewise.
* gfortran.dg/reshape_9.f90: New test.
---
gcc/fortran/check.c | 22 +++++++++++++++++-----
gcc/testsuite/gfortran.dg/pr68153.f90 | 2 +-
gcc/testsuite/gfortran.dg/reshape_7.f90 | 2 +-
gcc/testsuite/gfortran.dg/reshape_9.f90 | 24 ++++++++++++++++++++++++
4 files changed, 43 insertions(+), 7 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;
@@ -4732,10 +4733,14 @@ gfc_check_reshape (gfc_expr *source, gfc_expr *shape,
"than %d elements", &shape->where, GFC_MAX_DIMENSIONS);
return false;
}
- else if (shape->expr_type == EXPR_ARRAY && gfc_is_constant_expr (shape))
+
+ gfc_simplify_expr (shape, 0);
+
+ if (shape->expr_type == EXPR_ARRAY && gfc_is_constant_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 +4753,7 @@ 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 +4771,7 @@ 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 +4862,7 @@ 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 +4871,17 @@ 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);
@@ -5,5 +5,5 @@
!
program foo
integer, parameter :: a(2) = [2, -2]
- integer, parameter :: b(2,2) = reshape([1, 2, 3, 4], a) ! { dg-error "cannot be negative" }
+ integer, parameter :: b(2,2) = reshape([1, 2, 3, 4], a) ! { dg-error "negative" }
end program foo
@@ -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 +1,24 @@
+! { dg-do compile }
+! PR fortran/103411 - ICE in gfc_conv_array_initializer
+! Based on testcase by G. Steinmetz
+! Test simplifications for checks of shape argument to reshape intrinsic
+
+program p
+ integer :: i
+ integer, parameter :: a(2) = [2,2]
+ integer, parameter :: u(5) = [1,2,2,42,2]
+ integer, parameter :: v(1,2) = 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
+ print *, reshape([1,2,3], [(u(i),i=1,2)])
+ print *, reshape([1,2,3], [(u(i),i=2,3)]) ! { dg-error "not enough elements" }
+ print *, reshape([1,2,3,4], u(5:3:-2))
+ print *, reshape([1,2,3], u(5:3:-2)) ! { dg-error "not enough elements" }
+ print *, reshape([1,2,3], v(1,:)) ! { dg-error "not enough elements" }
+end
--
2.26.2