/* AST Optimizer */
#include "Python.h"
#include "Python-ast.h"
#include "ast.h"


static int
make_const(expr_ty node, PyObject *val, PyArena *arena)
{
 if (val == NULL) {
 if (PyErr_ExceptionMatches(PyExc_KeyboardInterrupt)) {
 return 0;
 }
 PyErr_Clear();
 return 1;
 }
 if (PyArena_AddPyObject(arena, val) < 0) {
 Py_DECREF(val);
 return 0;
 }
 node->kind = Constant_kind;
 node->v.Constant.value = val;
 return 1;
}

#define COPY_NODE(TO, FROM) (memcpy((TO), (FROM), sizeof(struct _expr)))

static PyObject*
unary_not(PyObject *v)
{
 int r = PyObject_IsTrue(v);
 if (r < 0)
 return NULL;
 return PyBool_FromLong(!r);
}

static int
fold_unaryop(expr_ty node, PyArena *arena, int optimize)
{
 expr_ty arg = node->v.UnaryOp.operand;

 if (arg->kind != Constant_kind) {
 /* Fold not into comparison */
 if (node->v.UnaryOp.op == Not && arg->kind == Compare_kind &&
 asdl_seq_LEN(arg->v.Compare.ops) == 1) {
 /* Eq and NotEq are often implemented in terms of one another, so
 folding not (self == other) into self != other breaks implementation
 of !=. Detecting such cases doesn't seem worthwhile.
 Python uses </> for 'is subset'/'is superset' operations on sets.
 They don't satisfy not folding laws. */
 int op = asdl_seq_GET(arg->v.Compare.ops, 0);
 switch (op) {
 case Is:
 op = IsNot;
 break;
 case IsNot:
 op = Is;
 break;
 case In:
 op = NotIn;
 break;
 case NotIn:
 op = In;
 break;
 default:
 op = 0;
 }
 if (op) {
 asdl_seq_SET(arg->v.Compare.ops, 0, op);
 COPY_NODE(node, arg);
 return 1;
 }
 }
 return 1;
 }

 typedef PyObject *(*unary_op)(PyObject*);
 static const unary_op ops[] = {
 [Invert] = PyNumber_Invert,
 [Not] = unary_not,
 [UAdd] = PyNumber_Positive,
 [USub] = PyNumber_Negative,
 };
 PyObject *newval = ops[node->v.UnaryOp.op](arg->v.Constant.value);
 return make_const(node, newval, arena);
}

/* Check whether a collection doesn't containing too much items (including
 subcollections). This protects from creating a constant that needs
 too much time for calculating a hash.
 "limit" is the maximal number of items.
 Returns the negative number if the total number of items exceeds the
 limit. Otherwise returns the limit minus the total number of items.
*/

static Py_ssize_t
check_complexity(PyObject *obj, Py_ssize_t limit)
{
 if (PyTuple_Check(obj)) {
 Py_ssize_t i;
 limit -= PyTuple_GET_SIZE(obj);
 for (i = 0; limit >= 0 && i < PyTuple_GET_SIZE(obj); i++) {
 limit = check_complexity(PyTuple_GET_ITEM(obj, i), limit);
 }
 return limit;
 }
 else if (PyFrozenSet_Check(obj)) {
 Py_ssize_t i = 0;
 PyObject *item;
 Py_hash_t hash;
 limit -= PySet_GET_SIZE(obj);
 while (limit >= 0 && _PySet_NextEntry(obj, &i, &item, &hash)) {
 limit = check_complexity(item, limit);
 }
 }
 return limit;
}

#define MAX_INT_SIZE 128 /* bits */
#define MAX_COLLECTION_SIZE 256 /* items */
#define MAX_STR_SIZE 4096 /* characters */
#define MAX_TOTAL_ITEMS 1024 /* including nested collections */

static PyObject *
safe_multiply(PyObject *v, PyObject *w)
{
 if (PyLong_Check(v) && PyLong_Check(w) && Py_SIZE(v) && Py_SIZE(w)) {
 size_t vbits = _PyLong_NumBits(v);
 size_t wbits = _PyLong_NumBits(w);
 if (vbits == (size_t)-1 || wbits == (size_t)-1) {
 return NULL;
 }
 if (vbits + wbits > MAX_INT_SIZE) {
 return NULL;
 }
 }
 else if (PyLong_Check(v) && (PyTuple_Check(w) || PyFrozenSet_Check(w))) {
 Py_ssize_t size = PyTuple_Check(w) ? PyTuple_GET_SIZE(w) :
 PySet_GET_SIZE(w);
 if (size) {
 long n = PyLong_AsLong(v);
 if (n < 0 || n > MAX_COLLECTION_SIZE / size) {
 return NULL;
 }
 if (n && check_complexity(w, MAX_TOTAL_ITEMS / n) < 0) {
 return NULL;
 }
 }
 }
 else if (PyLong_Check(v) && (PyUnicode_Check(w) || PyBytes_Check(w))) {
 Py_ssize_t size = PyUnicode_Check(w) ? PyUnicode_GET_LENGTH(w) :
 PyBytes_GET_SIZE(w);
 if (size) {
 long n = PyLong_AsLong(v);
 if (n < 0 || n > MAX_STR_SIZE / size) {
 return NULL;
 }
 }
 }
 else if (PyLong_Check(w) &&
 (PyTuple_Check(v) || PyFrozenSet_Check(v) ||
 PyUnicode_Check(v) || PyBytes_Check(v)))
 {
 return safe_multiply(w, v);
 }

 return PyNumber_Multiply(v, w);
}

static PyObject *
safe_power(PyObject *v, PyObject *w)
{
 if (PyLong_Check(v) && PyLong_Check(w) && Py_SIZE(v) && Py_SIZE(w) > 0) {
 size_t vbits = _PyLong_NumBits(v);
 size_t wbits = PyLong_AsSize_t(w);
 if (vbits == (size_t)-1 || wbits == (size_t)-1) {
 return NULL;
 }
 if (vbits > MAX_INT_SIZE / wbits) {
 return NULL;
 }
 }

 return PyNumber_Power(v, w, Py_None);
}

static PyObject *
safe_lshift(PyObject *v, PyObject *w)
{
 if (PyLong_Check(v) && PyLong_Check(w) && Py_SIZE(v) && Py_SIZE(w)) {
 size_t vbits = _PyLong_NumBits(v);
 size_t wbits = PyLong_AsSize_t(w);
 if (vbits == (size_t)-1 || wbits == (size_t)-1) {
 return NULL;
 }
 if (wbits > MAX_INT_SIZE || vbits > MAX_INT_SIZE - wbits) {
 return NULL;
 }
 }

 return PyNumber_Lshift(v, w);
}

static PyObject *
safe_mod(PyObject *v, PyObject *w)
{
 if (PyUnicode_Check(v) || PyBytes_Check(v)) {
 return NULL;
 }

 return PyNumber_Remainder(v, w);
}

static int
fold_binop(expr_ty node, PyArena *arena, int optimize)
{
 expr_ty lhs, rhs;
 lhs = node->v.BinOp.left;
 rhs = node->v.BinOp.right;
 if (lhs->kind != Constant_kind || rhs->kind != Constant_kind) {
 return 1;
 }

 PyObject *lv = lhs->v.Constant.value;
 PyObject *rv = rhs->v.Constant.value;
 PyObject *newval;

 switch (node->v.BinOp.op) {
 case Add:
 newval = PyNumber_Add(lv, rv);
 break;
 case Sub:
 newval = PyNumber_Subtract(lv, rv);
 break;
 case Mult:
 newval = safe_multiply(lv, rv);
 break;
 case Div:
 newval = PyNumber_TrueDivide(lv, rv);
 break;
 case FloorDiv:
 newval = PyNumber_FloorDivide(lv, rv);
 break;
 case Mod:
 newval = safe_mod(lv, rv);
 break;
 case Pow:
 newval = safe_power(lv, rv);
 break;
 case LShift:
 newval = safe_lshift(lv, rv);
 break;
 case RShift:
 newval = PyNumber_Rshift(lv, rv);
 break;
 case BitOr:
 newval = PyNumber_Or(lv, rv);
 break;
 case BitXor:
 newval = PyNumber_Xor(lv, rv);
 break;
 case BitAnd:
 newval = PyNumber_And(lv, rv);
 break;
 default: // Unknown operator
 return 1;
 }

 return make_const(node, newval, arena);
}

static PyObject*
make_const_tuple(asdl_seq *elts)
{
 for (int i = 0; i < asdl_seq_LEN(elts); i++) {
 expr_ty e = (expr_ty)asdl_seq_GET(elts, i);
 if (e->kind != Constant_kind) {
 return NULL;
 }
 }

 PyObject *newval = PyTuple_New(asdl_seq_LEN(elts));
 if (newval == NULL) {
 return NULL;
 }

 for (int i = 0; i < asdl_seq_LEN(elts); i++) {
 expr_ty e = (expr_ty)asdl_seq_GET(elts, i);
 PyObject *v = e->v.Constant.value;
 Py_INCREF(v);
 PyTuple_SET_ITEM(newval, i, v);
 }
 return newval;
}

static int
fold_tuple(expr_ty node, PyArena *arena, int optimize)
{
 PyObject *newval;

 if (node->v.Tuple.ctx != Load)
 return 1;

 newval = make_const_tuple(node->v.Tuple.elts);
 return make_const(node, newval, arena);
}

static int
fold_subscr(expr_ty node, PyArena *arena, int optimize)
{
 PyObject *newval;
 expr_ty arg, idx;
 slice_ty slice;

 arg = node->v.Subscript.value;
 slice = node->v.Subscript.slice;
 if (node->v.Subscript.ctx != Load ||
 arg->kind != Constant_kind ||
 /* TODO: handle other types of slices */
 slice->kind != Index_kind ||
 slice->v.Index.value->kind != Constant_kind)
 {
 return 1;
 }

 idx = slice->v.Index.value;
 newval = PyObject_GetItem(arg->v.Constant.value, idx->v.Constant.value);
 return make_const(node, newval, arena);
}

/* Change literal list or set of constants into constant
 tuple or frozenset respectively. Change literal list of
 non-constants into tuple.
 Used for right operand of "in" and "not in" tests and for iterable
 in "for" loop and comprehensions.
*/
static int
fold_iter(expr_ty arg, PyArena *arena, int optimize)
{
 PyObject *newval;
 if (arg->kind == List_kind) {
 /* First change a list into tuple. */
 asdl_seq *elts = arg->v.List.elts;
 Py_ssize_t n = asdl_seq_LEN(elts);
 for (Py_ssize_t i = 0; i < n; i++) {
 expr_ty e = (expr_ty)asdl_seq_GET(elts, i);
 if (e->kind == Starred_kind) {
 return 1;
 }
 }
 expr_context_ty ctx = arg->v.List.ctx;
 arg->kind = Tuple_kind;
 arg->v.Tuple.elts = elts;
 arg->v.Tuple.ctx = ctx;
 /* Try to create a constant tuple. */
 newval = make_const_tuple(elts);
 }
 else if (arg->kind == Set_kind) {
 newval = make_const_tuple(arg->v.Set.elts);
 if (newval) {
 Py_SETREF(newval, PyFrozenSet_New(newval));
 }
 }
 else {
 return 1;
 }
 return make_const(arg, newval, arena);
}

static int
fold_compare(expr_ty node, PyArena *arena, int optimize)
{
 asdl_int_seq *ops;
 asdl_seq *args;
 Py_ssize_t i;

 ops = node->v.Compare.ops;
 args = node->v.Compare.comparators;
 /* TODO: optimize cases with literal arguments. */
 /* Change literal list or set in 'in' or 'not in' into
 tuple or frozenset respectively. */
 i = asdl_seq_LEN(ops) - 1;
 int op = asdl_seq_GET(ops, i);
 if (op == In || op == NotIn) {
 if (!fold_iter((expr_ty)asdl_seq_GET(args, i), arena, optimize)) {
 return 0;
 }
 }
 return 1;
}

static int astfold_mod(mod_ty node_, PyArena *ctx_, int optimize_);
static int astfold_stmt(stmt_ty node_, PyArena *ctx_, int optimize_);
static int astfold_expr(expr_ty node_, PyArena *ctx_, int optimize_);
static int astfold_arguments(arguments_ty node_, PyArena *ctx_, int optimize_);
static int astfold_comprehension(comprehension_ty node_, PyArena *ctx_, int optimize_);
static int astfold_keyword(keyword_ty node_, PyArena *ctx_, int optimize_);
static int astfold_slice(slice_ty node_, PyArena *ctx_, int optimize_);
static int astfold_arg(arg_ty node_, PyArena *ctx_, int optimize_);
static int astfold_withitem(withitem_ty node_, PyArena *ctx_, int optimize_);
static int astfold_excepthandler(excepthandler_ty node_, PyArena *ctx_, int optimize_);
#define CALL(FUNC, TYPE, ARG) \
 if (!FUNC((ARG), ctx_, optimize_)) \
 return 0;

#define CALL_OPT(FUNC, TYPE, ARG) \
 if ((ARG) != NULL && !FUNC((ARG), ctx_, optimize_)) \
 return 0;

#define CALL_SEQ(FUNC, TYPE, ARG) { \
 int i; \
 asdl_seq *seq = (ARG); /* avoid variable capture */ \
 for (i = 0; i < asdl_seq_LEN(seq); i++) { \
 TYPE elt = (TYPE)asdl_seq_GET(seq, i); \
 if (elt != NULL && !FUNC(elt, ctx_, optimize_)) \
 return 0; \
 } \
}

#define CALL_INT_SEQ(FUNC, TYPE, ARG) { \
 int i; \
 asdl_int_seq *seq = (ARG); /* avoid variable capture */ \
 for (i = 0; i < asdl_seq_LEN(seq); i++) { \
 TYPE elt = (TYPE)asdl_seq_GET(seq, i); \
 if (!FUNC(elt, ctx_, optimize_)) \
 return 0; \
 } \
}

static int
astfold_body(asdl_seq *stmts, PyArena *ctx_, int optimize_)
{
 int docstring = _PyAST_GetDocString(stmts) != NULL;
 CALL_SEQ(astfold_stmt, stmt_ty, stmts);
 if (!docstring && _PyAST_GetDocString(stmts) != NULL) {
 stmt_ty st = (stmt_ty)asdl_seq_GET(stmts, 0);
 asdl_seq *values = _Py_asdl_seq_new(1, ctx_);
 if (!values) {
 return 0;
 }
 asdl_seq_SET(values, 0, st->v.Expr.value);
 expr_ty expr = JoinedStr(values, st->lineno, st->col_offset,
 st->end_lineno, st->end_col_offset, ctx_);
 if (!expr) {
 return 0;
 }
 st->v.Expr.value = expr;
 }
 return 1;
}

static int
astfold_mod(mod_ty node_, PyArena *ctx_, int optimize_)
{
 switch (node_->kind) {
 case Module_kind:
 CALL(astfold_body, asdl_seq, node_->v.Module.body);
 break;
 case Interactive_kind:
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.Interactive.body);
 break;
 case Expression_kind:
 CALL(astfold_expr, expr_ty, node_->v.Expression.body);
 break;
 case Suite_kind:
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.Suite.body);
 break;
 default:
 break;
 }
 return 1;
}

static int
astfold_expr(expr_ty node_, PyArena *ctx_, int optimize_)
{
 switch (node_->kind) {
 case BoolOp_kind:
 CALL_SEQ(astfold_expr, expr_ty, node_->v.BoolOp.values);
 break;
 case BinOp_kind:
 CALL(astfold_expr, expr_ty, node_->v.BinOp.left);
 CALL(astfold_expr, expr_ty, node_->v.BinOp.right);
 CALL(fold_binop, expr_ty, node_);
 break;
 case UnaryOp_kind:
 CALL(astfold_expr, expr_ty, node_->v.UnaryOp.operand);
 CALL(fold_unaryop, expr_ty, node_);
 break;
 case Lambda_kind:
 CALL(astfold_arguments, arguments_ty, node_->v.Lambda.args);
 CALL(astfold_expr, expr_ty, node_->v.Lambda.body);
 break;
 case IfExp_kind:
 CALL(astfold_expr, expr_ty, node_->v.IfExp.test);
 CALL(astfold_expr, expr_ty, node_->v.IfExp.body);
 CALL(astfold_expr, expr_ty, node_->v.IfExp.orelse);
 break;
 case Dict_kind:
 CALL_SEQ(astfold_expr, expr_ty, node_->v.Dict.keys);
 CALL_SEQ(astfold_expr, expr_ty, node_->v.Dict.values);
 break;
 case Set_kind:
 CALL_SEQ(astfold_expr, expr_ty, node_->v.Set.elts);
 break;
 case ListComp_kind:
 CALL(astfold_expr, expr_ty, node_->v.ListComp.elt);
 CALL_SEQ(astfold_comprehension, comprehension_ty, node_->v.ListComp.generators);
 break;
 case SetComp_kind:
 CALL(astfold_expr, expr_ty, node_->v.SetComp.elt);
 CALL_SEQ(astfold_comprehension, comprehension_ty, node_->v.SetComp.generators);
 break;
 case DictComp_kind:
 CALL(astfold_expr, expr_ty, node_->v.DictComp.key);
 CALL(astfold_expr, expr_ty, node_->v.DictComp.value);
 CALL_SEQ(astfold_comprehension, comprehension_ty, node_->v.DictComp.generators);
 break;
 case GeneratorExp_kind:
 CALL(astfold_expr, expr_ty, node_->v.GeneratorExp.elt);
 CALL_SEQ(astfold_comprehension, comprehension_ty, node_->v.GeneratorExp.generators);
 break;
 case Await_kind:
 CALL(astfold_expr, expr_ty, node_->v.Await.value);
 break;
 case Yield_kind:
 CALL_OPT(astfold_expr, expr_ty, node_->v.Yield.value);
 break;
 case YieldFrom_kind:
 CALL(astfold_expr, expr_ty, node_->v.YieldFrom.value);
 break;
 case Compare_kind:
 CALL(astfold_expr, expr_ty, node_->v.Compare.left);
 CALL_SEQ(astfold_expr, expr_ty, node_->v.Compare.comparators);
 CALL(fold_compare, expr_ty, node_);
 break;
 case Call_kind:
 CALL(astfold_expr, expr_ty, node_->v.Call.func);
 CALL_SEQ(astfold_expr, expr_ty, node_->v.Call.args);
 CALL_SEQ(astfold_keyword, keyword_ty, node_->v.Call.keywords);
 break;
 case FormattedValue_kind:
 CALL(astfold_expr, expr_ty, node_->v.FormattedValue.value);
 CALL_OPT(astfold_expr, expr_ty, node_->v.FormattedValue.format_spec);
 break;
 case JoinedStr_kind:
 CALL_SEQ(astfold_expr, expr_ty, node_->v.JoinedStr.values);
 break;
 case Attribute_kind:
 CALL(astfold_expr, expr_ty, node_->v.Attribute.value);
 break;
 case Subscript_kind:
 CALL(astfold_expr, expr_ty, node_->v.Subscript.value);
 CALL(astfold_slice, slice_ty, node_->v.Subscript.slice);
 CALL(fold_subscr, expr_ty, node_);
 break;
 case Starred_kind:
 CALL(astfold_expr, expr_ty, node_->v.Starred.value);
 break;
 case List_kind:
 CALL_SEQ(astfold_expr, expr_ty, node_->v.List.elts);
 break;
 case Tuple_kind:
 CALL_SEQ(astfold_expr, expr_ty, node_->v.Tuple.elts);
 CALL(fold_tuple, expr_ty, node_);
 break;
 case Name_kind:
 if (_PyUnicode_EqualToASCIIString(node_->v.Name.id, "__debug__")) {
 return make_const(node_, PyBool_FromLong(!optimize_), ctx_);
 }
 break;
 default:
 break;
 }
 return 1;
}

static int
astfold_slice(slice_ty node_, PyArena *ctx_, int optimize_)
{
 switch (node_->kind) {
 case Slice_kind:
 CALL_OPT(astfold_expr, expr_ty, node_->v.Slice.lower);
 CALL_OPT(astfold_expr, expr_ty, node_->v.Slice.upper);
 CALL_OPT(astfold_expr, expr_ty, node_->v.Slice.step);
 break;
 case ExtSlice_kind:
 CALL_SEQ(astfold_slice, slice_ty, node_->v.ExtSlice.dims);
 break;
 case Index_kind:
 CALL(astfold_expr, expr_ty, node_->v.Index.value);
 break;
 default:
 break;
 }
 return 1;
}

static int
astfold_keyword(keyword_ty node_, PyArena *ctx_, int optimize_)
{
 CALL(astfold_expr, expr_ty, node_->value);
 return 1;
}

static int
astfold_comprehension(comprehension_ty node_, PyArena *ctx_, int optimize_)
{
 CALL(astfold_expr, expr_ty, node_->target);
 CALL(astfold_expr, expr_ty, node_->iter);
 CALL_SEQ(astfold_expr, expr_ty, node_->ifs);

 CALL(fold_iter, expr_ty, node_->iter);
 return 1;
}

static int
astfold_arguments(arguments_ty node_, PyArena *ctx_, int optimize_)
{
 CALL_SEQ(astfold_arg, arg_ty, node_->posonlyargs);
 CALL_SEQ(astfold_arg, arg_ty, node_->args);
 CALL_OPT(astfold_arg, arg_ty, node_->vararg);
 CALL_SEQ(astfold_arg, arg_ty, node_->kwonlyargs);
 CALL_SEQ(astfold_expr, expr_ty, node_->kw_defaults);
 CALL_OPT(astfold_arg, arg_ty, node_->kwarg);
 CALL_SEQ(astfold_expr, expr_ty, node_->defaults);
 return 1;
}

static int
astfold_arg(arg_ty node_, PyArena *ctx_, int optimize_)
{
 CALL_OPT(astfold_expr, expr_ty, node_->annotation);
 return 1;
}

static int
astfold_stmt(stmt_ty node_, PyArena *ctx_, int optimize_)
{
 switch (node_->kind) {
 case FunctionDef_kind:
 CALL(astfold_arguments, arguments_ty, node_->v.FunctionDef.args);
 CALL(astfold_body, asdl_seq, node_->v.FunctionDef.body);
 CALL_SEQ(astfold_expr, expr_ty, node_->v.FunctionDef.decorator_list);
 CALL_OPT(astfold_expr, expr_ty, node_->v.FunctionDef.returns);
 break;
 case AsyncFunctionDef_kind:
 CALL(astfold_arguments, arguments_ty, node_->v.AsyncFunctionDef.args);
 CALL(astfold_body, asdl_seq, node_->v.AsyncFunctionDef.body);
 CALL_SEQ(astfold_expr, expr_ty, node_->v.AsyncFunctionDef.decorator_list);
 CALL_OPT(astfold_expr, expr_ty, node_->v.AsyncFunctionDef.returns);
 break;
 case ClassDef_kind:
 CALL_SEQ(astfold_expr, expr_ty, node_->v.ClassDef.bases);
 CALL_SEQ(astfold_keyword, keyword_ty, node_->v.ClassDef.keywords);
 CALL(astfold_body, asdl_seq, node_->v.ClassDef.body);
 CALL_SEQ(astfold_expr, expr_ty, node_->v.ClassDef.decorator_list);
 break;
 case Return_kind:
 CALL_OPT(astfold_expr, expr_ty, node_->v.Return.value);
 break;
 case Delete_kind:
 CALL_SEQ(astfold_expr, expr_ty, node_->v.Delete.targets);
 break;
 case Assign_kind:
 CALL_SEQ(astfold_expr, expr_ty, node_->v.Assign.targets);
 CALL(astfold_expr, expr_ty, node_->v.Assign.value);
 break;
 case AugAssign_kind:
 CALL(astfold_expr, expr_ty, node_->v.AugAssign.target);
 CALL(astfold_expr, expr_ty, node_->v.AugAssign.value);
 break;
 case AnnAssign_kind:
 CALL(astfold_expr, expr_ty, node_->v.AnnAssign.target);
 CALL(astfold_expr, expr_ty, node_->v.AnnAssign.annotation);
 CALL_OPT(astfold_expr, expr_ty, node_->v.AnnAssign.value);
 break;
 case For_kind:
 CALL(astfold_expr, expr_ty, node_->v.For.target);
 CALL(astfold_expr, expr_ty, node_->v.For.iter);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.For.body);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.For.orelse);

 CALL(fold_iter, expr_ty, node_->v.For.iter);
 break;
 case AsyncFor_kind:
 CALL(astfold_expr, expr_ty, node_->v.AsyncFor.target);
 CALL(astfold_expr, expr_ty, node_->v.AsyncFor.iter);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.AsyncFor.body);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.AsyncFor.orelse);
 break;
 case While_kind:
 CALL(astfold_expr, expr_ty, node_->v.While.test);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.While.body);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.While.orelse);
 break;
 case If_kind:
 CALL(astfold_expr, expr_ty, node_->v.If.test);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.If.body);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.If.orelse);
 break;
 case With_kind:
 CALL_SEQ(astfold_withitem, withitem_ty, node_->v.With.items);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.With.body);
 break;
 case AsyncWith_kind:
 CALL_SEQ(astfold_withitem, withitem_ty, node_->v.AsyncWith.items);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.AsyncWith.body);
 break;
 case Raise_kind:
 CALL_OPT(astfold_expr, expr_ty, node_->v.Raise.exc);
 CALL_OPT(astfold_expr, expr_ty, node_->v.Raise.cause);
 break;
 case Try_kind:
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.Try.body);
 CALL_SEQ(astfold_excepthandler, excepthandler_ty, node_->v.Try.handlers);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.Try.orelse);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.Try.finalbody);
 break;
 case Assert_kind:
 CALL(astfold_expr, expr_ty, node_->v.Assert.test);
 CALL_OPT(astfold_expr, expr_ty, node_->v.Assert.msg);
 break;
 case Expr_kind:
 CALL(astfold_expr, expr_ty, node_->v.Expr.value);
 break;
 default:
 break;
 }
 return 1;
}

static int
astfold_excepthandler(excepthandler_ty node_, PyArena *ctx_, int optimize_)
{
 switch (node_->kind) {
 case ExceptHandler_kind:
 CALL_OPT(astfold_expr, expr_ty, node_->v.ExceptHandler.type);
 CALL_SEQ(astfold_stmt, stmt_ty, node_->v.ExceptHandler.body);
 break;
 default:
 break;
 }
 return 1;
}

static int
astfold_withitem(withitem_ty node_, PyArena *ctx_, int optimize_)
{
 CALL(astfold_expr, expr_ty, node_->context_expr);
 CALL_OPT(astfold_expr, expr_ty, node_->optional_vars);
 return 1;
}

#undef CALL
#undef CALL_OPT
#undef CALL_SEQ
#undef CALL_INT_SEQ

int
_PyAST_Optimize(mod_ty mod, PyArena *arena, int optimize)
{
 int ret = astfold_mod(mod, arena, optimize);
 assert(ret || PyErr_Occurred());
 return ret;
}