make CASE_LABEL_EXPR not abuse TREE_CHAIN

make CASE_LABEL_EXPR not abuse TREE_CHAIN
	* tree.def (CASE_LABEL_EXPR): Add an operand.
	* tree.h (CASE_CHAIN): Use TREE_OPERAND instead of TREE_CHAIN.

From-SVN: r173633

gcc/ChangeLog

+2011-05-10  Nathan Froyd  <froydnj@codesourcery.com>
+
+	* tree.def (CASE_LABEL_EXPR): Add an operand.
+	* tree.h (CASE_CHAIN): Use TREE_OPERAND instead of TREE_CHAIN.
+
 2011-05-10  Joseph Myers  <joseph@codesourcery.com>
 
 	* c-decl.c (c_override_global_bindings_to_false): Remove.

gcc/tree.def

@@ -863,7 +863,7 @@ DEFTREECODE (SWITCH_EXPR, "switch_expr", tcc_statement, 3)
    CASE_HIGH, respectively. If CASE_LOW is NULL_TREE, the label is a
    'default' label. If CASE_HIGH is NULL_TREE, the label is a normal case
    label.  CASE_LABEL is the corresponding LABEL_DECL.  */
-DEFTREECODE (CASE_LABEL_EXPR, "case_label_expr", tcc_statement, 3)
+DEFTREECODE (CASE_LABEL_EXPR, "case_label_expr", tcc_statement, 4)
 
 /* Used to represent an inline assembly statement.  ASM_STRING returns a
    STRING_CST for the instruction (e.g., "mov x, y"). ASM_OUTPUTS,

gcc/tree.h

@@ -1689,7 +1689,7 @@ extern void protected_set_expr_location (tree, location_t);
 #define CASE_LOW(NODE)          	TREE_OPERAND (CASE_LABEL_EXPR_CHECK (NODE), 0)
 #define CASE_HIGH(NODE)         	TREE_OPERAND (CASE_LABEL_EXPR_CHECK (NODE), 1)
 #define CASE_LABEL(NODE)		TREE_OPERAND (CASE_LABEL_EXPR_CHECK (NODE), 2)
-#define CASE_CHAIN(NODE)		TREE_CHAIN (CASE_LABEL_EXPR_CHECK (NODE))
+#define CASE_CHAIN(NODE)		TREE_OPERAND (CASE_LABEL_EXPR_CHECK (NODE), 3)
 
 /* The operands of a TARGET_MEM_REF.  Operands 0 and 1 have to match
    corresponding MEM_REF operands.  */