[PATCH] java/12739: Reduce try/finally expr with empty blocks

[Jeff Sturm]

Fixes slight regression caused by my unit-at-a-time patches.  The parser
used to substitute empty BLOCK nodes with an empty_stmt_node, but it was
awkward handling these in places that expected a BLOCK node.

Tested by rebuilding libjava and running testsuite.  OK for mainline?

Jeff


2003-10-26  Jeff Sturm  <jsturm@one-point.com>

	Fix PR java/12739.
	* java-tree.h (BLOCK_EMPTY_P): Define.
	* parse.y (java_complete_lhs): Check for empty blocks
	in TRY_FINALLY_EXPR case.

Index: java-tree.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/java/java-tree.h,v
retrieving revision 1.186
diff -u -p -r1.186 java-tree.h
--- java-tree.h	24 Oct 2003 09:29:40 -0000	1.186
+++ java-tree.h	27 Oct 2003 17:41:01 -0000
@@ -1727,6 +1727,8 @@ while (0)
 #define BLOCK_EXPR_BODY(NODE)   BLOCK_SUBBLOCKS(NODE)
 /* True for an implicit block surrounding declaration not at start of {...}. */
 #define BLOCK_IS_IMPLICIT(NODE) TREE_LANG_FLAG_1 (NODE)
+#define BLOCK_EMPTY_P(NODE) \
+  (TREE_CODE (NODE) == BLOCK && BLOCK_EXPR_BODY (NODE) == empty_stmt_node)

 #define BUILD_MONITOR_ENTER(WHERE, ARG)				\
   {								\
Index: parse.y
===================================================================
RCS file: /cvs/gcc/gcc/gcc/java/parse.y,v
retrieving revision 1.451
diff -u -p -r1.451 parse.y
--- parse.y	22 Oct 2003 18:06:38 -0000	1.451
+++ parse.y	27 Oct 2003 17:41:05 -0000
@@ -11720,9 +11720,13 @@ java_complete_lhs (tree node)
     case TRY_FINALLY_EXPR:
       COMPLETE_CHECK_OP_0 (node);
       COMPLETE_CHECK_OP_1 (node);
-      if (TREE_OPERAND (node, 0) == empty_stmt_node)
+      /* Reduce try/finally nodes with an empty try block.  */
+      if (TREE_OPERAND (node, 0) == empty_stmt_node ||
+	  BLOCK_EMPTY_P (TREE_OPERAND (node, 0)))
 	return TREE_OPERAND (node, 1);
-      if (TREE_OPERAND (node, 1) == empty_stmt_node)
+      /* Likewise for an empty finally block.  */
+      if (TREE_OPERAND (node, 1) == empty_stmt_node ||
+	  BLOCK_EMPTY_P (TREE_OPERAND (node, 1)))
 	return TREE_OPERAND (node, 0);
       CAN_COMPLETE_NORMALLY (node)
 	= (CAN_COMPLETE_NORMALLY (TREE_OPERAND (node, 0))