For PR java/4509:

	* parse.y (java_complete_lhs) [COMPOUND_EXPR]: Correctly compute
	CAN_COMPLETE_NORMALLY for the node.
	* jcf-write.c (generate_bytecode_insns) [COMPOUND_EXPR]: Don't
	generate code for second branch if first branch can't complete
	normally.
	(generate_bytecode_insns) [LOOP_EXPR]: Don't generate `goto' to
	the loop head if the loop body can't complete normally.

From-SVN: r48233

gcc/java/ChangeLog

 2001-12-20  Tom Tromey  <tromey@redhat.com>
 
+	For PR java/4509:
+	* parse.y (java_complete_lhs) [COMPOUND_EXPR]: Correctly compute
+	CAN_COMPLETE_NORMALLY for the node.
+	* jcf-write.c (generate_bytecode_insns) [COMPOUND_EXPR]: Don't
+	generate code for second branch if first branch can't complete
+	normally.
+	(generate_bytecode_insns) [LOOP_EXPR]: Don't generate `goto' to
+	the loop head if the loop body can't complete normally.
+
+2001-12-20  Tom Tromey  <tromey@redhat.com>
+
 	For PR java/4766:
 	* jcf-write.c (generate_bytecode_insns) [TRY_FINALLY_EXPR]: Handle
 	case where `finally' clause can't complete normally.

gcc/java/jcf-write.c

@@ -1483,7 +1483,11 @@ generate_bytecode_insns (exp, target, state)
       break;
     case COMPOUND_EXPR:	
       generate_bytecode_insns (TREE_OPERAND (exp, 0), IGNORE_TARGET, state);
-      generate_bytecode_insns (TREE_OPERAND (exp, 1), target, state);
+      /* Normally the first operand to a COMPOUND_EXPR must complete
+	 normally.  However, in the special case of a do-while
+	 statement this is not necessarily the case.  */
+      if (CAN_COMPLETE_NORMALLY (TREE_OPERAND (exp, 0)))
+	generate_bytecode_insns (TREE_OPERAND (exp, 1), target, state);
       break;
     case EXPR_WITH_FILE_LOCATION:
       {
@@ -1880,7 +1884,8 @@ generate_bytecode_insns (exp, target, state)
 	  {
 	    struct jcf_block *head_label = get_jcf_label_here (state);
 	    generate_bytecode_insns (body, IGNORE_TARGET, state);
-	    emit_goto (head_label, state);
+	    if (CAN_COMPLETE_NORMALLY (body))
+	      emit_goto (head_label, state);
 	  }
       }
       break;

gcc/java/parse.y

@@ -11776,8 +11776,12 @@ java_complete_lhs (node)
 	  TREE_OPERAND (node, 1) = java_complete_tree (TREE_OPERAND (node, 1));
 	  if (TREE_OPERAND (node, 1) == error_mark_node)
 	    return error_mark_node;
+	  /* Even though we might allow the case where the first
+	     operand doesn't return normally, we still should compute
+	     CAN_COMPLETE_NORMALLY correctly.  */
 	  CAN_COMPLETE_NORMALLY (node)
-	    = CAN_COMPLETE_NORMALLY (TREE_OPERAND (node, 1));
+	    = (CAN_COMPLETE_NORMALLY (TREE_OPERAND (node, 0))
+	       && CAN_COMPLETE_NORMALLY (TREE_OPERAND (node, 1)));
 	}
       TREE_TYPE (node) = TREE_TYPE (TREE_OPERAND (node, 1));
       break;