[PATCH 09/18] convert cp IF_STMTs to use private scope fields

[Nathan Froyd <froydnj@codesourcery.com>]

Just like the previous *FOR_STMT conversions, except with IF_STMTs.

-Nathan

gcc/cp/
	* cp-tree.def (IF_STMT): Add an extra operand.
	* cp-objcp-common.c (cp_common_init_ts): Mark it as TS_TYPED.
	* cp-tree.h (IF_SCOPE): Define.
	* semantics.c (begin_if_stmt): Pass scope to build_stmt.
	(finish_if_stmt): Use IF_SCOPE instead of TREE_CHAIN.

diff --git a/gcc/cp/cp-objcp-common.c b/gcc/cp/cp-objcp-common.c
index 21fa57f..d602dfe 100644
--- a/gcc/cp/cp-objcp-common.c
+++ b/gcc/cp/cp-objcp-common.c
@@ -236,7 +236,6 @@ cp_common_init_ts (void)
   MARK_TS_COMMON (TEMPLATE_INFO);
   MARK_TS_COMMON (TYPENAME_TYPE);
   MARK_TS_COMMON (TYPEOF_TYPE);
-  MARK_TS_COMMON (IF_STMT);
   MARK_TS_COMMON (BASELINK);
   MARK_TS_COMMON (SWITCH_STMT);
   MARK_TS_COMMON (TYPE_PACK_EXPANSION);
@@ -245,6 +244,7 @@ cp_common_init_ts (void)
   MARK_TS_COMMON (BOUND_TEMPLATE_TEMPLATE_PARM);
   MARK_TS_COMMON (UNBOUND_CLASS_TEMPLATE);
 
+  MARK_TS_TYPED (IF_STMT);
   MARK_TS_TYPED (FOR_STMT);
   MARK_TS_TYPED (RANGE_FOR_STMT);
   MARK_TS_TYPED (AGGR_INIT_EXPR);
diff --git a/gcc/cp/cp-tree.def b/gcc/cp/cp-tree.def
index fdfe9b5..59f89b8 100644
--- a/gcc/cp/cp-tree.def
+++ b/gcc/cp/cp-tree.def
@@ -284,10 +284,10 @@ DEFTREECODE (MUST_NOT_THROW_EXPR, "must_not_throw_expr", tcc_expression, 1)
 DEFTREECODE (CLEANUP_STMT, "cleanup_stmt", tcc_statement, 3)
 
 /* Represents an 'if' statement. The operands are IF_COND,
-   THEN_CLAUSE, and ELSE_CLAUSE, respectively.  */
+   THEN_CLAUSE, and ELSE_CLAUSE, and the current scope, respectively.  */
 /* ??? It is currently still necessary to distinguish between IF_STMT
    and COND_EXPR for the benefit of templates.  */
-DEFTREECODE (IF_STMT, "if_stmt", tcc_statement, 3)
+DEFTREECODE (IF_STMT, "if_stmt", tcc_statement, 4)
 
 /* Used to represent a `for' statement. The operands are
    FOR_INIT_STMT, FOR_COND, FOR_EXPR, and FOR_BODY, respectively.  */
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index e542388..2340812 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -3781,6 +3781,7 @@ more_aggr_init_expr_args_p (const aggr_init_expr_arg_iterator *iter)
 #define IF_COND(NODE)		TREE_OPERAND (IF_STMT_CHECK (NODE), 0)
 #define THEN_CLAUSE(NODE)	TREE_OPERAND (IF_STMT_CHECK (NODE), 1)
 #define ELSE_CLAUSE(NODE)	TREE_OPERAND (IF_STMT_CHECK (NODE), 2)
+#define IF_SCOPE(NODE)		TREE_OPERAND (IF_STMT_CHECK (NODE), 3)
 
 /* WHILE_STMT accessors. These give access to the condition of the
    while statement and the body of the while statement, respectively.  */
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index c8e5619..4071494 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -662,8 +662,8 @@ begin_if_stmt (void)
 {
   tree r, scope;
   scope = do_pushlevel (sk_block);
-  r = build_stmt (input_location, IF_STMT, NULL_TREE, NULL_TREE, NULL_TREE);
-  TREE_CHAIN (r) = scope;
+  r = build_stmt (input_location, IF_STMT, NULL_TREE,
+		  NULL_TREE, NULL_TREE, scope);
   begin_cond (&IF_COND (r));
   return r;
 }
@@ -711,8 +711,8 @@ finish_else_clause (tree if_stmt)
 void
 finish_if_stmt (tree if_stmt)
 {
-  tree scope = TREE_CHAIN (if_stmt);
-  TREE_CHAIN (if_stmt) = NULL;
+  tree scope = IF_SCOPE (if_stmt);
+  IF_SCOPE (if_stmt) = NULL;
   add_stmt (do_poplevel (scope));
   finish_stmt ();
 }
-- 
1.7.0.4