re PR fortran/89646 (Spurious actual argument might interfere warning)

2019-06-14  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/89646
	* dependency.c (gfc_check_argument_var_dependency): Suppress spurious
	warnings by comparing variable names.

2019-06-14  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/89646
	* gfortran.dg/pr89646.f90: New test.

From-SVN: r272307

gcc/fortran/ChangeLog

-2019-06-12  Steven G. Kargl  <kargl@gcc.gnu.org>
+2019-06-14  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/89646
+	* dependency.c (gfc_check_argument_var_dependency): Suppress spurious
+	warnings by comparing variable names.
+
+2019-06-13  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/68544
 	* resolve.c (is_dt_name): New function to compare symbol name against

gcc/fortran/dependency.c

@@ -979,6 +979,10 @@ gfc_check_argument_var_dependency (gfc_expr *var, sym_intent intent,
 		     If a dependency is found in the case
 		     elemental == ELEM_CHECK_VARIABLE, we will generate
 		     a temporary, so we don't need to bother the user.  */
+
+		  if (var->expr_type == EXPR_VARIABLE
+		      && expr->expr_type == EXPR_VARIABLE
+		      && strcmp(var->symtree->name, expr->symtree->name) == 0)
 		    gfc_warning (0, "INTENT(%s) actual argument at %L might "
 				 "interfere with actual argument at %L.",
 				 intent == INTENT_OUT ? "OUT" : "INOUT",

gcc/testsuite/ChangeLog

+2019-06-14  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/89646
+	* gfortran.dg/pr89646.f90: New test.
+
 2019-06-14  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR rtl-optimization/90765

gcc/testsuite/gfortran.dg/pr89646.f90

+! { dg-do compile }
+! PR fortran/89646
+! Original testcase contributed by Ian Harvey <ian_harvey at bigpond dot com>
+!
+! This code use to give spurious warnings about aliasing.
+!
+module m
+   implicit none
+   type :: t
+   end type t
+   contains
+      ! To reproduce, both actual arguments must be TARGET, 
+      ! both arguments must be of derived type.
+      subroutine s
+         type(t), target :: a(5)
+         type(t), target :: b(5)
+         call move(a, b)
+      end subroutine s
+      ! To reproduce, called procedure must be elemental.
+      elemental subroutine move(x, y)
+         type(t), intent(inout) :: x
+         type(t), intent(out) :: y
+      end subroutine move
+end module m