[Patch] PR fortran/100218 - target of pointer from evaluation of function-reference

[Harald Anlauf via Gcc-patches]

Dear Fortranners,

while analyzing a different PR (PR100154), Tobias pointed out that the
target of a pointer from the evaluation of function-reference is allowed
to be used in a variable definition context and thus as an actual
argument to a function or subroutine.

This seems to be a more general issue that seems to have been overlooked.
The attached simple patch allows to compile and run the attached example,
which is by the way already yet rejected with -std=f2003.

Regtested on x86_64-pc-linux-gnu.  OK for mainline?
Shall we backport this to (at least) 11?

Thanks,
Harald


Fortran - allow target of pointer from evaluation of function-reference

Fortran allows the target of a pointer from the evaluation of a
function-reference in a variable definition context (e.g. F2018:R902).

gcc/fortran/ChangeLog:

        PR fortran/100218
        * expr.c (gfc_check_vardef_context): Extend check to allow pointer
        from a function reference.

gcc/testsuite/ChangeLog:

        PR fortran/100218
        * gfortran.dg/pr100218.f90: New test.


diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index 92a6700568d..696b9f1daac 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -6121,7 +6132,9 @@ gfc_check_vardef_context (gfc_expr* e, bool pointer, bool alloc_obj,
     }
   if (!pointer && sym->attr.flavor != FL_VARIABLE
       && !(sym->attr.flavor == FL_PROCEDURE && sym == sym->result)
-      && !(sym->attr.flavor == FL_PROCEDURE && sym->attr.proc_pointer))
+      && !(sym->attr.flavor == FL_PROCEDURE && sym->attr.proc_pointer)
+      && !(sym->attr.flavor == FL_PROCEDURE
+	   && sym->attr.function && sym->attr.pointer))
     {
       if (context)
 	gfc_error ("%qs in variable definition context (%s) at %L is not"
diff --git a/gcc/testsuite/gfortran.dg/pr100218.f90 b/gcc/testsuite/gfortran.dg/pr100218.f90
new file mode 100644
index 00000000000..62b18f6a935
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr100218.f90
@@ -0,0 +1,19 @@
+! { dg-do run }
+! { dg-options "-O2 -std=f2008" }
+! PR fortran/100218 - target of pointer from evaluation of function-reference
+
+program p
+  implicit none
+  integer, target :: z = 0
+  call g (f ())
+  if (z /= 1) stop 1
+contains
+  function f () result (r)
+    integer, pointer :: r
+    r => z
+  end function f
+  subroutine g (x)
+    integer, intent(out) :: x
+    x = 1
+  end subroutine g
+end program p