re PR fortran/19239 ([4.0 only] gfortran ICE on vector subscript expressions)

	PR fortran/19239
	* Makefile.in (fortran/trans-expr.o): Depend on dependency.h.
	* dependency.h (gfc_ref_needs_temporary_p): Declare.
	* dependency.c (gfc_ref_needs_temporary_p): New function.
	(gfc_check_fncall_dependency): Use it instead of inlined check.
	By so doing, take advantage of the fact that character substrings
	within an array reference also need a temporary.
	* trans.h (GFC_SS_VECTOR): Adjust comment.
	* trans-array.c (gfc_free_ss): Remove GFC_SS_VECTOR case.
	(gfc_set_vector_loop_bounds): New function.
	(gfc_add_loop_ss_code): Call it after evaluating the subscripts of
	a GFC_SS_SECTION.  Deal with the GFC_SS_VECTOR case by evaluating
	the vector expression and caching its descriptor for use within
	the loop.
	(gfc_conv_array_index_ref, gfc_conv_vector_array_index): Delete.
	(gfc_conv_array_index_offset): Handle scalar, vector and range
	dimensions as separate cases of a switch statement.  In the vector
	case, use the loop variable to calculate a vector index and use the
	referenced element as the dimension's index.  Perform bounds checking
	on this final index.
	(gfc_conv_section_upper_bound): Return null for vector indexes.
	(gfc_conv_section_startstride): Give vector indexes a start value
	of 0 and a stride of 1.
	(gfc_conv_ss_startstride): Adjust for new GFC_SS_VECTOR representation.
	(gfc_conv_expr_descriptor): Expand comments.  Generalize the
	handling of the !want_pointer && !direct_byref case.  Use
	gfc_ref_needs_temporary_p to decide whether the variable case
	needs a temporary.
	(gfc_walk_variable_expr): Handle DIMEN_VECTOR by creating a
	GFC_SS_VECTOR index.
	* trans-expr.c: Include dependency.h.
	(gfc_trans_arrayfunc_assign): Fail if the target needs a temporary.

2005-09-09  Richard Sandiford  <richard@codesourcery.com>

	PR fortran/21104
	* trans.h (gfc_interface_sym_mapping, gfc_interface_mapping): Moved
	from trans-expr.c.
	(gfc_init_interface_mapping, gfc_free_interface_mapping)
	(gfc_add_interface_mapping, gfc_finish_interface_mapping)
	(gfc_apply_interface_mapping): Declare.
	* trans-array.h (gfc_set_loop_bounds_from_array_spec): Declare.
	(gfc_trans_allocate_temp_array): Add pre and post block arguments.
	* trans-array.c (gfc_set_loop_bounds_from_array_spec): New function.
	(gfc_trans_allocate_array_storage): Replace loop argument with
	separate pre and post blocks.
	(gfc_trans_allocate_temp_array): Add pre and post block arguments.
	Update call to gfc_trans_allocate_array_storage.
	(gfc_trans_array_constructor, gfc_conv_loop_setup): Adjust for new
	interface to gfc_trans_allocate_temp_array.
	* trans-expr.c (gfc_interface_sym_mapping, gfc_interface_mapping):
	Moved to trans.h.
	(gfc_init_interface_mapping, gfc_free_interface_mapping)
	(gfc_add_interface_mapping, gfc_finish_interface_mapping)
	(gfc_apply_interface_mapping): Make extern.
	(gfc_conv_function_call): Build an interface mapping for array
	return values too.  Call gfc_set_loop_bounds_from_array_spec.
	Adjust call to gfc_trans_allocate_temp_array so that code is
	added to SE rather than LOOP.

From-SVN: r104077

1 files changed, 41 insertions, 27 deletions

diff --git a/gcc/fortran/dependency.c b/gcc/fortran/dependency.c
index 5b0045e..9c6b4f6 100644
--- a/gcc/fortran/dependency.c
+++ b/gcc/fortran/dependency.c
@@ -175,6 +175,45 @@ gfc_is_same_range (gfc_array_ref * ar1, gfc_array_ref * ar2, int n, int def)
 }
 
 
+/* Return true if the result of reference REF can only be constructed
+   using a temporary array.  */
+
+bool
+gfc_ref_needs_temporary_p (gfc_ref *ref)
+{
+  int n;
+  bool subarray_p;
+
+  subarray_p = false;
+  for (; ref; ref = ref->next)
+    switch (ref->type)
+      {
+      case REF_ARRAY:
+	/* Vector dimensions are generally not monotonic and must be
+	   handled using a temporary.  */
+	if (ref->u.ar.type == AR_SECTION)
+	  for (n = 0; n < ref->u.ar.dimen; n++)
+	    if (ref->u.ar.dimen_type[n] == DIMEN_VECTOR)
+	      return true;
+
+	subarray_p = true;
+	break;
+
+      case REF_SUBSTRING:
+	/* Within an array reference, character substrings generally
+	   need a temporary.  Character array strides are expressed as
+	   multiples of the element size (consistent with other array
+	   types), not in characters.  */
+	return subarray_p;
+
+      case REF_COMPONENT:
+	break;
+      }
+
+  return false;
+}
+
+
 /* Dependency checking for direct function return by reference.
    Returns true if the arguments of the function depend on the
    destination.  This is considerably less conservative than other
@@ -185,9 +224,7 @@ int
 gfc_check_fncall_dependency (gfc_expr * dest, gfc_expr * fncall)
 {
   gfc_actual_arglist *actual;
-  gfc_ref *ref;
   gfc_expr *expr;
-  int n;
 
   gcc_assert (dest->expr_type == EXPR_VARIABLE
 	  && fncall->expr_type == EXPR_FUNCTION);
@@ -205,31 +242,8 @@ gfc_check_fncall_dependency (gfc_expr * dest, gfc_expr * fncall)
       switch (expr->expr_type)
 	{
 	case EXPR_VARIABLE:
-	  if (expr->rank > 1)
-	    {
-	      /* This is an array section.  */
-	      for (ref = expr->ref; ref; ref = ref->next)
-		{
-		  if (ref->type == REF_ARRAY && ref->u.ar.type != AR_ELEMENT)
-		    break;
-		}
-	      gcc_assert (ref);
-	      /* AR_FULL can't contain vector subscripts.  */
-	      if (ref->u.ar.type == AR_SECTION)
-		{
-		  for (n = 0; n < ref->u.ar.dimen; n++)
-		    {
-		      if (ref->u.ar.dimen_type[n] == DIMEN_VECTOR)
-			break;
-		    }
-		  /* Vector subscript array sections will be copied to a
-		     temporary.  */
-		  if (n != ref->u.ar.dimen)
-		    continue;
-		}
-	    }
-
-	  if (gfc_check_dependency (dest, actual->expr, NULL, 0))
+	  if (!gfc_ref_needs_temporary_p (expr->ref)
+	      && gfc_check_dependency (dest, expr, NULL, 0))
 	    return 1;
 	  break;