PR fortran/95053 - division by zero constants

	Partially revert the fix for PR93499.  Replace by checks for valid
	expressions in the declaration of array shape and PDT KIND and LEN
	expressions at a later stage.

gcc/fortran/

2020-05-18  Harald Anlauf  <anlauf@gmx.de>

	PR fortran/95053
	* arith.c (gfc_divide): Revert hunk introduced by patch for
	PR93499.
	* decl.c (variable_decl): Generate error for array shape not being
	an INTEGER constant.
	(gfc_get_pdt_instance): Generate error if KIND or LEN expressions
	in declaration of a PDT instance do not simplify to INTEGER
	constants.

gcc/testsuite/

2020-05-18  Harald Anlauf  <anlauf@gmx.de>

	PR fortran/95053
	* gfortran.dg/dec_structure_23.f90: Adjust to new error messages.
	* gfortran.dg/pr93499.f90: Adjust to new error messages.
	* gfortran.dg/pr95053_2.f90: New test.
	* gfortran.dg/pr95053_3.f90: New test.

3 files changed, 27 insertions, 33 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 1434022..ab79158 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,14 @@
+2020-05-18  Harald Anlauf  <anlauf@gmx.de>
+
+	PR fortran/95053
+	* arith.c (gfc_divide): Revert hunk introduced by patch for
+	PR93499.
+	* decl.c (variable_decl): Generate error for array shape not being
+	an INTEGER constant.
+	(gfc_get_pdt_instance): Generate error if KIND or LEN expressions
+	in declaration of a PDT instance do not simplify to INTEGER
+	constants.
+
 2020-05-15  Tobias Burnus  <tobias@codesourcery.com>
 
 	PR fortran/94690
diff --git a/gcc/fortran/arith.c b/gcc/fortran/arith.c
index dd72f44..c770569 100644
--- a/gcc/fortran/arith.c
+++ b/gcc/fortran/arith.c
@@ -1806,38 +1806,6 @@ gfc_multiply (gfc_expr *op1, gfc_expr *op2)
 gfc_expr *
 gfc_divide (gfc_expr *op1, gfc_expr *op2)
 {
-  if (op2 && op2->expr_type == EXPR_CONSTANT)
-    {
-      arith rc = ARITH_OK;
-      switch (op2->ts.type)
-	{
-	case BT_INTEGER:
-	  /* non-integer divided by integer 0 is handled elsewhere.  */
-	  if (mpz_sgn (op2->value.integer) == 0
-	      && op1->ts.type == BT_INTEGER)
-	    rc = ARITH_DIV0;
-	  break;
-	case BT_REAL:
-	  if (mpfr_sgn (op2->value.real) == 0
-	      && flag_range_check == 1)
-	    rc = ARITH_DIV0;
-	  break;
-	case BT_COMPLEX:
-	  if (mpc_cmp_si_si (op2->value.complex, 0, 0) == 0
-	      && flag_range_check == 1)
-	    rc = ARITH_DIV0;
-	  break;
-	default:
-	  /* basic type is non-numeric, handle this elsewhere.  */
-	  break;
-	}
-      if (rc == ARITH_DIV0)
-	{
-	  gfc_seen_div0 = true;
-	  gfc_error ("Division by zero at %L", &op2->where);
-	  return NULL;
-	}
-    }
   return eval_intrinsic_f3 (INTRINSIC_DIVIDE, gfc_arith_divide, op1, op2);
 }
 
diff --git a/gcc/fortran/decl.c b/gcc/fortran/decl.c
index 9cc8136..3ad5559 100644
--- a/gcc/fortran/decl.c
+++ b/gcc/fortran/decl.c
@@ -2607,6 +2607,14 @@ variable_decl (int elem)
 	      gfc_free_expr (e);
 	    }
 
+	  if (not_constant && e->ts.type != BT_INTEGER)
+	    {
+	      gfc_error ("Explicit array shape at %C must be constant of "
+			 "INTEGER type and not %s type",
+			 gfc_basic_typename (e->ts.type));
+	      m = MATCH_ERROR;
+	      goto cleanup;
+	    }
 	  if (not_constant)
 	    {
 	      gfc_error ("Explicit shaped array with nonconstant bounds at %C");
@@ -3741,8 +3749,9 @@ gfc_get_pdt_instance (gfc_actual_arglist *param_list, gfc_symbol **sym,
       if (kind_expr)
 	{
 	  /* Try simplification even for LEN expressions.  */
+	  bool ok;
 	  gfc_resolve_expr (kind_expr);
-	  gfc_simplify_expr (kind_expr, 1);
+	  ok = gfc_simplify_expr (kind_expr, 1);
 	  /* Variable expressions seem to default to BT_PROCEDURE.
 	     TODO find out why this is and fix it.  */
 	  if (kind_expr->ts.type != BT_INTEGER
@@ -3753,6 +3762,12 @@ gfc_get_pdt_instance (gfc_actual_arglist *param_list, gfc_symbol **sym,
 			 gfc_basic_typename (kind_expr->ts.type));
 	      goto error_return;
 	    }
+	  if (kind_expr->ts.type == BT_INTEGER && !ok)
+	    {
+	      gfc_error ("The parameter expression at %C does not "
+			 "simplify to an INTEGER constant");
+	      goto error_return;
+	    }
 
 	  tail->expr = gfc_copy_expr (kind_expr);
 	}