Re: [PATCH] PR fortran/101536 - ICE in gfc_conv_expr_descriptor, at fortran/trans-array.c:7324

[Harald Anlauf <anlauf@gmx.de>]

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Hi Tobias,

you are right in that I was barking up the wrong tree.
I was focussed too much on the testcase in the PR.

> I think that one is wrong. While CLASS_DATA (e) accesses e->ts.u.derived->components,
> which always works, your code assumes that there is only 'c' and not 'x%c' where
> 'c' is of type BT_CLASS and 'x' is of type BT_DERIVED.
>
> I wonder whether it works if you simply remove 'return true;'
> as gfc_add_class_array_ref sets 'e->rank = CLASS(e)->rank (and
> adds an AR_FULL ref, if needed). In the nonerror case, the
> 'return true' is obtained via:
>     if (e->rank != 0 && e->ts.type != BT_PROCEDURE)
>       return true;
> And, otherwise, it falls through to the error.
>
> OK if that works

Well, I tried and this does not work.

However, an additional plain check on e->rank != 0 also in the
CLASS cases fixes the original issue as well as your example:

> type t
>    class(*), allocatable :: c(:)
> end type t
> type(t) :: x
> x%c = [1,2,3,4]
> print *, size(x%c)
> print *, size(x%c(1)) ! { dg-error ... }
> end

And regtests ok. :-)

See attached updated patch.

Anything else I am missing?

Thanks for the constructive review!

Harald

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diff --git a/gcc/fortran/check.c b/gcc/fortran/check.c
index 27bf3a7eafe..b03d322ad9c 100644
--- a/gcc/fortran/check.c
+++ b/gcc/fortran/check.c
@@ -731,7 +731,7 @@ logical_array_check (gfc_expr *array, int n)
 static bool
 array_check (gfc_expr *e, int n)
 {
-  if (e->ts.type == BT_CLASS && gfc_expr_attr (e).class_ok
+  if (e->rank != 0 && e->ts.type == BT_CLASS && gfc_expr_attr (e).class_ok
 	&& CLASS_DATA (e)->attr.dimension
 	&& CLASS_DATA (e)->as->rank)
     {
diff --git a/gcc/testsuite/gfortran.dg/pr101536.f90 b/gcc/testsuite/gfortran.dg/pr101536.f90
new file mode 100644
index 00000000000..f8fa1dee639
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr101536.f90
@@ -0,0 +1,26 @@
+! { dg-do compile }
+! PR fortran/101536 - ICE in gfc_conv_expr_descriptor
+
+program p
+  type t
+     class(*), allocatable :: c(:)
+  end type t
+  type u
+     integer :: c(2)
+  end type
+  type(t) :: x
+  x%c = [1,2,3,4]
+  print *, size (x%c)
+  print *, size (x%c(1)) ! { dg-error "must be an array" }
+contains
+  integer function f(x, y)
+    class(t), allocatable :: x(:)
+    class(u)              :: y(:)
+    f = size (x)
+    f = size (x(1))      ! { dg-error "must be an array" }
+    f = size (y)
+    f = size (y%c(1))
+    f = size (y(2)%c)
+    f = size (y(2)%c(1)) ! { dg-error "must be an array" }
+  end
+end