[PATCH] PR fortran/98307 - Dependency check fails when using "allocatable"

[Harald Anlauf via Gcc-patches]

Dear all,

since the introduction of check_forall_dependencies() we mishandled the
dependencies of ALLOCATABLE components of derived types, while POINTER
was dealt with.  Fix that.

Regtested on x86_64-pc-linux-gnu.

OK for master?  Since we generate wrong code under the given circumstances,
what do people think about backports?

Thanks,
Harald


PR fortran/98307 - Dependency check fails when using "allocatable"

The dependency check for FORALL constructs already handled pointer
components to derived types, but missed allocatables.  Fix that.

gcc/fortran/ChangeLog:

        PR fortran/98307
        * trans-stmt.c (check_forall_dependencies): Extend dependency
        check to allocatable components of derived types.

gcc/testsuite/ChangeLog:

        PR fortran/98307
        * gfortran.dg/forall_19.f90: New test.


diff --git a/gcc/fortran/trans-stmt.c b/gcc/fortran/trans-stmt.c
index adc6b8fefb5..112a4e8ead9 100644
--- a/gcc/fortran/trans-stmt.c
+++ b/gcc/fortran/trans-stmt.c
@@ -3949,9 +3949,10 @@ check_forall_dependencies (gfc_code *c, stmtblock_t *pre, stmtblock_t *post)
      point to the copy instead.  Note that the shallow copy of
      the variable will not suffice for derived types with
      pointer components.  We therefore leave these to their
-     own devices.  */
+     own devices.  Likewise for allocatable components.  */
   if (lsym->ts.type == BT_DERIVED
-	&& lsym->ts.u.derived->attr.pointer_comp)
+      && (lsym->ts.u.derived->attr.pointer_comp
+	  || lsym->ts.u.derived->attr.alloc_comp))
     return need_temp;

   new_symtree = NULL;
diff --git a/gcc/testsuite/gfortran.dg/forall_19.f90 b/gcc/testsuite/gfortran.dg/forall_19.f90
new file mode 100644
index 00000000000..ef05c97ab24
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/forall_19.f90
@@ -0,0 +1,32 @@
+! { dg-do run }
+! PR fortran/98307 - Dependency check fails when using "allocatable"
+
+program forall_deps
+  implicit none
+  type t
+    logical :: valid = .true.
+    integer :: s     = 0
+    integer, allocatable :: p(:)
+  end type
+  type(t) :: v(2)
+  integer :: i
+
+  allocate (v(1)%p(8))
+  allocate (v(2)%p(8))
+  v(1)%s    = 8
+  v(2)%s    = 6
+
+  v(1)%p(:) = [1, 2, 3, 4, 5, 6, 7, 8]
+  v(2)%p(:) = [13, 14, 15, 16, 17, 18, 19, 20]
+  forall (i=1:2)
+     v(i)%p(1:v(i)%s) = v(3-i)%p(1:v(i)%s)
+  end forall
+  if (any(v(2)%p(:) /= [1, 2, 3, 4, 5, 6, 19, 20])) stop 1
+
+  v(1)%p(:) = [1, 2, 3, 4, 5, 6, 7, 8]
+  v(2)%p(:) = [13, 14, 15, 16, 17, 18, 19, 20]
+  forall (i=1:2, v(i)%valid)
+     v(i)%p(1:v(i)%s) = v(3-i)%p(1:v(i)%s)
+  end forall
+  if (any(v(2)%p(:) /= [1, 2, 3, 4, 5, 6, 19, 20])) stop 2
+end