re PR ada/21937 (Member record alignment triggers an ICE)

PR ada/21937
	PR ada/22328
	PR ada/22381
	PR ada/22383
	PR ada/22419
	PR ada/22420
	* utils2.c (build_return_expr): New helper function.
	* gigi.h (build_return_expr): Declare it.
	* trans.c (Subprogram_Body_to_gnu): Use build_return_expr instead
	of manually building the RETURN_EXPR tree.
	(call_to_gnu): Pass MODIFY_EXPR through build_binary_op.
	(gnat_to_gnu) <N_Return_Statement>: Pass MODIFY_EXPR through
	build_binary_op for the "target pointer" case. �Use build_return_expr
	instead of manually building the RETURN_EXPR tree.

From-SVN: r105741

gcc/ada/ChangeLog

@@ -1,3 +1,20 @@
+2005-10-21  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR ada/21937
+	PR ada/22328
+	PR ada/22381
+	PR ada/22383
+	PR ada/22419
+	PR ada/22420
+	* utils2.c (build_return_expr): New helper function.
+	* gigi.h (build_return_expr): Declare it.
+	* trans.c (Subprogram_Body_to_gnu): Use build_return_expr instead
+	of manually building the RETURN_EXPR tree.
+	(call_to_gnu): Pass MODIFY_EXPR through build_binary_op.
+	(gnat_to_gnu) <N_Return_Statement>: Pass MODIFY_EXPR through
+	build_binary_op for the "target pointer" case.  Use build_return_expr
+	instead of manually building the RETURN_EXPR tree.
+
 2005-09-16  Laurent GUERBY  <laurent@guerby.net>
 
 	PR ada/23788

gcc/ada/gigi.h

@@ -678,6 +678,9 @@ extern tree build_unary_op (enum tree_code op_code, tree result_type,
 extern tree build_cond_expr (tree result_type, tree condition_operand,
                              tree true_operand, tree false_operand);
 
+/* Similar, but for RETURN_EXPR.  */
+extern tree build_return_expr (tree result_decl, tree ret_val);
+
 /* Build a CALL_EXPR to call FUNDECL with one argument, ARG.  Return
    the CALL_EXPR.  */
 extern tree build_call_1_expr (tree fundecl, tree arg);

gcc/ada/trans.c

@@ -1456,9 +1456,7 @@ Subprogram_Body_to_gnu (Node_Id gnat_node)
 	gnu_retval = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_retval);
 
       add_stmt_with_node
-	(build1 (RETURN_EXPR, void_type_node,
+	(build_return_expr (DECL_RESULT (current_function_decl), gnu_retval),
-		 build2 (MODIFY_EXPR, TREE_TYPE (gnu_retval),
-			 DECL_RESULT (current_function_decl), gnu_retval)),
 	 gnat_node);
       gnat_poplevel ();
       gnu_result = end_stmt_group ();
@@ -1685,8 +1683,8 @@ call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target)
 		}
 
 	      /* Set up to move the copy back to the original.  */
-	      gnu_temp = build2 (MODIFY_EXPR, TREE_TYPE (gnu_copy),
+	      gnu_temp = build_binary_op (MODIFY_EXPR, NULL_TREE,
-				 gnu_copy, gnu_actual);
+					  gnu_copy, gnu_actual);
 	      annotate_with_node (gnu_temp, gnat_actual);
 	      append_to_statement_list (gnu_temp, &gnu_after_list);
 	    }
@@ -3519,8 +3517,6 @@ gnat_to_gnu (Node_Id gnat_node)
 	tree gnu_ret_val = NULL_TREE;
 	/* The place to put the return value.  */
 	tree gnu_lhs;
-	/* Avoid passing error_mark_node to RETURN_EXPR.  */
-	gnu_result = NULL_TREE;
 
 	/* If we are dealing with a "return;" from an Ada procedure with
 	   parameters passed by copy in copy out, we need to return a record
@@ -3626,18 +3622,20 @@ gnat_to_gnu (Node_Id gnat_node)
 		  }
 	      }
 	  }
-
+	else
-	if (gnu_ret_val)
+	  /* If the Ada subprogram is a regular procedure, just return.  */
-	  gnu_result = build2 (MODIFY_EXPR, TREE_TYPE (gnu_ret_val),
+	  gnu_lhs = NULL_TREE;
-			       gnu_lhs, gnu_ret_val);
 
 	if (TYPE_RETURNS_BY_TARGET_PTR_P (gnu_subprog_type))
 	  {
+	    if (gnu_ret_val)
+	      gnu_result = build_binary_op (MODIFY_EXPR, NULL_TREE,
+					    gnu_lhs, gnu_ret_val);
 	    add_stmt_with_node (gnu_result, gnat_node);
-	    gnu_result = NULL_TREE;
+	    gnu_lhs = NULL_TREE;
 	  }
 
-	gnu_result = build1 (RETURN_EXPR, void_type_node, gnu_result);
+	gnu_result = build_return_expr (gnu_lhs, gnu_ret_val);
       }
       break;
 

gcc/ada/utils2.c

@@ -1378,8 +1378,50 @@ build_cond_expr (tree result_type, tree condition_operand,
 
   return result;
 }
-
 
+/* Similar, but for RETURN_EXPR.  If RESULT_DECL is non-zero, build
+   a RETURN_EXPR around the assignment of RET_VAL to RESULT_DECL.
+   If RESULT_DECL is zero, build a bare RETURN_EXPR.  */
+
+tree
+build_return_expr (tree result_decl, tree ret_val)
+{
+  tree result_expr;
+
+  if (result_decl)
+    {
+      /* The gimplifier explicitly enforces the following invariant:
+
+           RETURN_EXPR
+               |
+           MODIFY_EXPR
+           /        \
+          /          \
+      RESULT_DECL    ...
+
+      As a consequence, type-homogeneity dictates that we use the type
+      of the RESULT_DECL as the operation type.  */
+
+      tree operation_type = TREE_TYPE (result_decl);
+
+      /* Convert the right operand to the operation type.  Note that
+         it's the same transformation as in the MODIFY_EXPR case of
+         build_binary_op with the additional guarantee that the type
+         cannot involve a placeholder, since otherwise the function
+         would use the "target pointer" return mechanism.  */
+       
+      if (operation_type != TREE_TYPE (ret_val))
+	ret_val = convert (operation_type, ret_val);
+
+      result_expr
+	= build2 (MODIFY_EXPR, operation_type, result_decl, ret_val);
+    }
+  else
+    result_expr = NULL_TREE;
+
+  return build1 (RETURN_EXPR, void_type_node, result_expr);
+}
+
 /* Build a CALL_EXPR to call FUNDECL with one argument, ARG.  Return
    the CALL_EXPR.  */