Fortran: fix NULL without MOLD argument to scalar DT pointer dummy [PR118179]

Commit r15-6408 overlooked the case of passing NULL without MOLD argument
to a derived type pointer dummy argument without specified intent.  Since
it is prohibited to modify the dummy argument, we treat it as if intent(in)
were specified and suppress copying back of the pointer address.

	PR fortran/118179

gcc/fortran/ChangeLog:

	* trans-expr.cc (conv_null_actual): Suppress copying back of
	pointer address for unspecified intent.

gcc/testsuite/ChangeLog:

	* gfortran.dg/null_actual_7.f90: Extend testcase to also cover
	scalar variants with pointer or allocatable dummy with or without
	specified intent.

2 files changed, 79 insertions, 1 deletions

diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index 9aedecb..4b02298 100644
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -6488,7 +6488,8 @@ conv_null_actual (gfc_se * parmse, gfc_expr * e, gfc_symbol * fsym)
 	  int dummy_rank;
 	  tree tmp = parmse->expr;
 
-	  if (fsym->attr.allocatable && fsym->attr.intent == INTENT_UNKNOWN)
+	  if ((fsym->attr.allocatable || fsym->attr.pointer)
+	      && fsym->attr.intent == INTENT_UNKNOWN)
 	    fsym->attr.intent = INTENT_IN;
 	  tmp = gfc_conv_scalar_to_descriptor (parmse, tmp, fsym->attr);
 	  dummy_rank = fsym->as ? fsym->as->rank : 0;
diff --git a/gcc/testsuite/gfortran.dg/null_actual_7.f90 b/gcc/testsuite/gfortran.dg/null_actual_7.f90
index ba3cd10..8891a36 100644
--- a/gcc/testsuite/gfortran.dg/null_actual_7.f90
+++ b/gcc/testsuite/gfortran.dg/null_actual_7.f90
@@ -10,6 +10,8 @@ program null_actual
   end type t
   type(t), pointer     :: p2(:,:) => NULL()
   type(t), allocatable :: a2(:,:)
+  type(t), pointer     :: p0 => NULL ()
+  type(t), allocatable :: a0
 
   ! Basic tests passing unallocated allocatable / disassociated pointer
   stop_base = 0
@@ -27,6 +29,16 @@ program null_actual
   call chk2_t_p (p2)
   call opt2_t_a (a2)
   call opt2_t_p (p2)
+  ! ... to rank-0 dummy:
+  stop_base = 60
+  call chk0_t_a (a0)
+  call chk0_t_p (p0)
+  call opt0_t_a (a0)
+  call opt0_t_p (p0)
+  call chk0_t_a_i (a0)
+  call chk0_t_p_i (p0)
+  call opt0_t_a_i (a0)
+  call opt0_t_p_i (p0)
 
   ! Test NULL with MOLD argument
   stop_base = 20
@@ -43,6 +55,16 @@ program null_actual
   call opt2_t_a (null(a2))
   call opt2_t_p (null(p2))
 
+  stop_base = 80
+  call chk0_t_a (null(a0))
+  call chk0_t_p (null(p0))
+  call opt0_t_a (null(a0))
+  call opt0_t_p (null(p0))
+  call chk0_t_a_i (null(a0))
+  call chk0_t_p_i (null(p0))
+  call opt0_t_a_i (null(a0))
+  call opt0_t_p_i (null(p0))
+
   ! Test NULL without MOLD argument
   stop_base = 40
   call chk2_t_a (null())
@@ -50,6 +72,16 @@ program null_actual
   call opt2_t_a (null())
   call opt2_t_p (null())
 
+  stop_base = 100
+  call chk0_t_a (null())
+  call chk0_t_p (null())
+  call opt0_t_a (null())
+  call opt0_t_p (null())
+  call chk0_t_a_i (null())
+  call chk0_t_p_i (null())
+  call opt0_t_a_i (null())
+  call opt0_t_p_i (null())
+
 contains
   ! Check assumed-rank dummy:
   subroutine chk_t_a (x)
@@ -120,4 +152,49 @@ contains
     if (.not. present (x)) stop stop_base + 19
     if (associated (x))    stop stop_base + 20
   end subroutine opt2_t_p
+
+  ! Checks for rank-0 dummy:
+  subroutine chk0_t_p (x)
+    type(t), pointer :: x
+    if (associated (x)) stop stop_base + 1
+  end subroutine chk0_t_p
+
+  subroutine chk0_t_p_i (x)
+    type(t), pointer, intent(in) :: x
+    if (associated (x)) stop stop_base + 2
+  end subroutine chk0_t_p_i
+
+  subroutine opt0_t_p (x)
+    type(t), pointer, optional :: x
+    if (.not. present (x)) stop stop_base + 3
+    if (associated (x))    stop stop_base + 4
+  end subroutine opt0_t_p
+
+  subroutine opt0_t_p_i (x)
+    type(t), pointer, optional, intent(in) :: x
+    if (.not. present (x)) stop stop_base + 5
+    if (associated (x))    stop stop_base + 6
+  end subroutine opt0_t_p_i
+
+  subroutine chk0_t_a (x)
+    type(t), allocatable :: x
+    if (allocated (x)) stop stop_base + 7
+  end subroutine chk0_t_a
+
+  subroutine chk0_t_a_i (x)
+    type(t), allocatable, intent(in) :: x
+    if (allocated (x)) stop stop_base + 8
+  end subroutine chk0_t_a_i
+
+  subroutine opt0_t_a (x)
+    type(t), allocatable, optional :: x
+    if (.not. present (x)) stop stop_base +  9
+    if (allocated (x))     stop stop_base + 10
+  end subroutine opt0_t_a
+
+  subroutine opt0_t_a_i (x)
+    type(t), allocatable, optional, intent(in) :: x
+    if (.not. present (x)) stop stop_base + 11
+    if (allocated (x))     stop stop_base + 12
+  end subroutine opt0_t_a_i
 end