add ydb deps

1 files changed, 1110 insertions, 0 deletions

diff --git a/contrib/tools/python3/src/Python/ast_opt.c b/contrib/tools/python3/src/Python/ast_opt.c
new file mode 100644
index 0000000000..77ed29d0cd
--- /dev/null
+++ b/contrib/tools/python3/src/Python/ast_opt.c
@@ -0,0 +1,1110 @@
+/* AST Optimizer */
+#include "Python.h"
+#include "pycore_ast.h"           // _PyAST_GetDocString()
+#include "pycore_compile.h"       // _PyASTOptimizeState
+#include "pycore_pystate.h"       // _PyThreadState_GET()
+#include "pycore_format.h"        // F_LJUST
+
+
+static int
+make_const(expr_ty node, PyObject *val, PyArena *arena)
+{
+    // Even if no new value was calculated, make_const may still
+    // need to clear an error (e.g. for division by zero)
+    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.kind = NULL;
+    node->v.Constant.value = val;
+    return 1;
+}
+
+#define COPY_NODE(TO, FROM) (memcpy((TO), (FROM), sizeof(struct _expr)))
+
+static int
+has_starred(asdl_expr_seq *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;
+        }
+    }
+    return 0;
+}
+
+
+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, _PyASTOptimizeState *state)
+{
+    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. */
+            cmpop_ty 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;
+            // The remaining comparison operators can't be safely inverted
+            case Eq:
+            case NotEq:
+            case Lt:
+            case LtE:
+            case Gt:
+            case GtE:
+                op = 0; // The AST enums leave "0" free as an "unused" marker
+                break;
+            // No default case, so the compiler will emit a warning if new
+            // comparison operators are added without being handled here
+            }
+            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 expr_ty
+parse_literal(PyObject *fmt, Py_ssize_t *ppos, PyArena *arena)
+{
+    const void *data = PyUnicode_DATA(fmt);
+    int kind = PyUnicode_KIND(fmt);
+    Py_ssize_t size = PyUnicode_GET_LENGTH(fmt);
+    Py_ssize_t start, pos;
+    int has_percents = 0;
+    start = pos = *ppos;
+    while (pos < size) {
+        if (PyUnicode_READ(kind, data, pos) != '%') {
+            pos++;
+        }
+        else if (pos+1 < size && PyUnicode_READ(kind, data, pos+1) == '%') {
+            has_percents = 1;
+            pos += 2;
+        }
+        else {
+            break;
+        }
+    }
+    *ppos = pos;
+    if (pos == start) {
+        return NULL;
+    }
+    PyObject *str = PyUnicode_Substring(fmt, start, pos);
+    /* str = str.replace('%%', '%') */
+    if (str && has_percents) {
+        _Py_DECLARE_STR(percent, "%");
+        _Py_DECLARE_STR(dbl_percent, "%%");
+        Py_SETREF(str, PyUnicode_Replace(str, &_Py_STR(dbl_percent),
+                                         &_Py_STR(percent), -1));
+    }
+    if (!str) {
+        return NULL;
+    }
+
+    if (_PyArena_AddPyObject(arena, str) < 0) {
+        Py_DECREF(str);
+        return NULL;
+    }
+    return _PyAST_Constant(str, NULL, -1, -1, -1, -1, arena);
+}
+
+#define MAXDIGITS 3
+
+static int
+simple_format_arg_parse(PyObject *fmt, Py_ssize_t *ppos,
+                        int *spec, int *flags, int *width, int *prec)
+{
+    Py_ssize_t pos = *ppos, len = PyUnicode_GET_LENGTH(fmt);
+    Py_UCS4 ch;
+
+#define NEXTC do {                      \
+    if (pos >= len) {                   \
+        return 0;                       \
+    }                                   \
+    ch = PyUnicode_READ_CHAR(fmt, pos); \
+    pos++;                              \
+} while (0)
+
+    *flags = 0;
+    while (1) {
+        NEXTC;
+        switch (ch) {
+            case '-': *flags |= F_LJUST; continue;
+            case '+': *flags |= F_SIGN; continue;
+            case ' ': *flags |= F_BLANK; continue;
+            case '#': *flags |= F_ALT; continue;
+            case '0': *flags |= F_ZERO; continue;
+        }
+        break;
+    }
+    if ('0' <= ch && ch <= '9') {
+        *width = 0;
+        int digits = 0;
+        while ('0' <= ch && ch <= '9') {
+            *width = *width * 10 + (ch - '0');
+            NEXTC;
+            if (++digits >= MAXDIGITS) {
+                return 0;
+            }
+        }
+    }
+
+    if (ch == '.') {
+        NEXTC;
+        *prec = 0;
+        if ('0' <= ch && ch <= '9') {
+            int digits = 0;
+            while ('0' <= ch && ch <= '9') {
+                *prec = *prec * 10 + (ch - '0');
+                NEXTC;
+                if (++digits >= MAXDIGITS) {
+                    return 0;
+                }
+            }
+        }
+    }
+    *spec = ch;
+    *ppos = pos;
+    return 1;
+
+#undef NEXTC
+}
+
+static expr_ty
+parse_format(PyObject *fmt, Py_ssize_t *ppos, expr_ty arg, PyArena *arena)
+{
+    int spec, flags, width = -1, prec = -1;
+    if (!simple_format_arg_parse(fmt, ppos, &spec, &flags, &width, &prec)) {
+        // Unsupported format.
+        return NULL;
+    }
+    if (spec == 's' || spec == 'r' || spec == 'a') {
+        char buf[1 + MAXDIGITS + 1 + MAXDIGITS + 1], *p = buf;
+        if (!(flags & F_LJUST) && width > 0) {
+            *p++ = '>';
+        }
+        if (width >= 0) {
+            p += snprintf(p, MAXDIGITS + 1, "%d", width);
+        }
+        if (prec >= 0) {
+            p += snprintf(p, MAXDIGITS + 2, ".%d", prec);
+        }
+        expr_ty format_spec = NULL;
+        if (p != buf) {
+            PyObject *str = PyUnicode_FromString(buf);
+            if (str == NULL) {
+                return NULL;
+            }
+            if (_PyArena_AddPyObject(arena, str) < 0) {
+                Py_DECREF(str);
+                return NULL;
+            }
+            format_spec = _PyAST_Constant(str, NULL, -1, -1, -1, -1, arena);
+            if (format_spec == NULL) {
+                return NULL;
+            }
+        }
+        return _PyAST_FormattedValue(arg, spec, format_spec,
+                                     arg->lineno, arg->col_offset,
+                                     arg->end_lineno, arg->end_col_offset,
+                                     arena);
+    }
+    // Unsupported format.
+    return NULL;
+}
+
+static int
+optimize_format(expr_ty node, PyObject *fmt, asdl_expr_seq *elts, PyArena *arena)
+{
+    Py_ssize_t pos = 0;
+    Py_ssize_t cnt = 0;
+    asdl_expr_seq *seq = _Py_asdl_expr_seq_new(asdl_seq_LEN(elts) * 2 + 1, arena);
+    if (!seq) {
+        return 0;
+    }
+    seq->size = 0;
+
+    while (1) {
+        expr_ty lit = parse_literal(fmt, &pos, arena);
+        if (lit) {
+            asdl_seq_SET(seq, seq->size++, lit);
+        }
+        else if (PyErr_Occurred()) {
+            return 0;
+        }
+
+        if (pos >= PyUnicode_GET_LENGTH(fmt)) {
+            break;
+        }
+        if (cnt >= asdl_seq_LEN(elts)) {
+            // More format units than items.
+            return 1;
+        }
+        assert(PyUnicode_READ_CHAR(fmt, pos) == '%');
+        pos++;
+        expr_ty expr = parse_format(fmt, &pos, asdl_seq_GET(elts, cnt), arena);
+        cnt++;
+        if (!expr) {
+            return !PyErr_Occurred();
+        }
+        asdl_seq_SET(seq, seq->size++, expr);
+    }
+    if (cnt < asdl_seq_LEN(elts)) {
+        // More items than format units.
+        return 1;
+    }
+    expr_ty res = _PyAST_JoinedStr(seq,
+                                   node->lineno, node->col_offset,
+                                   node->end_lineno, node->end_col_offset,
+                                   arena);
+    if (!res) {
+        return 0;
+    }
+    COPY_NODE(node, res);
+//     PySys_FormatStderr("format = %R\n", fmt);
+    return 1;
+}
+
+static int
+fold_binop(expr_ty node, PyArena *arena, _PyASTOptimizeState *state)
+{
+    expr_ty lhs, rhs;
+    lhs = node->v.BinOp.left;
+    rhs = node->v.BinOp.right;
+    if (lhs->kind != Constant_kind) {
+        return 1;
+    }
+    PyObject *lv = lhs->v.Constant.value;
+
+    if (node->v.BinOp.op == Mod &&
+        rhs->kind == Tuple_kind &&
+        PyUnicode_Check(lv) &&
+        !has_starred(rhs->v.Tuple.elts))
+    {
+        return optimize_format(node, lv, rhs->v.Tuple.elts, arena);
+    }
+
+    if (rhs->kind != Constant_kind) {
+        return 1;
+    }
+
+    PyObject *rv = rhs->v.Constant.value;
+    PyObject *newval = NULL;
+
+    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;
+    // No builtin constants implement the following operators
+    case MatMult:
+        return 1;
+    // No default case, so the compiler will emit a warning if new binary
+    // operators are added without being handled here
+    }
+
+    return make_const(node, newval, arena);
+}
+
+static PyObject*
+make_const_tuple(asdl_expr_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, _PyASTOptimizeState *state)
+{
+    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, _PyASTOptimizeState *state)
+{
+    PyObject *newval;
+    expr_ty arg, idx;
+
+    arg = node->v.Subscript.value;
+    idx = node->v.Subscript.slice;
+    if (node->v.Subscript.ctx != Load ||
+            arg->kind != Constant_kind ||
+            idx->kind != Constant_kind)
+    {
+        return 1;
+    }
+
+    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, _PyASTOptimizeState *state)
+{
+    PyObject *newval;
+    if (arg->kind == List_kind) {
+        /* First change a list into tuple. */
+        asdl_expr_seq *elts = arg->v.List.elts;
+        if (has_starred(elts)) {
+            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, _PyASTOptimizeState *state)
+{
+    asdl_int_seq *ops;
+    asdl_expr_seq *args;
+    Py_ssize_t i;
+
+    ops = node->v.Compare.ops;
+    args = node->v.Compare.comparators;
+    /* 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, state)) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+static int astfold_mod(mod_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+static int astfold_stmt(stmt_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+static int astfold_expr(expr_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+static int astfold_arguments(arguments_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+static int astfold_comprehension(comprehension_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+static int astfold_keyword(keyword_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+static int astfold_arg(arg_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+static int astfold_withitem(withitem_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+static int astfold_excepthandler(excepthandler_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+static int astfold_match_case(match_case_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+static int astfold_pattern(pattern_ty node_, PyArena *ctx_, _PyASTOptimizeState *state);
+
+#define CALL(FUNC, TYPE, ARG) \
+    if (!FUNC((ARG), ctx_, state)) \
+        return 0;
+
+#define CALL_OPT(FUNC, TYPE, ARG) \
+    if ((ARG) != NULL && !FUNC((ARG), ctx_, state)) \
+        return 0;
+
+#define CALL_SEQ(FUNC, TYPE, ARG) { \
+    int i; \
+    asdl_ ## TYPE ## _seq *seq = (ARG); /* avoid variable capture */ \
+    for (i = 0; i < asdl_seq_LEN(seq); i++) { \
+        TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, i); \
+        if (elt != NULL && !FUNC(elt, ctx_, state)) \
+            return 0; \
+    } \
+}
+
+
+static int
+astfold_body(asdl_stmt_seq *stmts, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    int docstring = _PyAST_GetDocString(stmts) != NULL;
+    CALL_SEQ(astfold_stmt, stmt, stmts);
+    if (!docstring && _PyAST_GetDocString(stmts) != NULL) {
+        stmt_ty st = (stmt_ty)asdl_seq_GET(stmts, 0);
+        asdl_expr_seq *values = _Py_asdl_expr_seq_new(1, ctx_);
+        if (!values) {
+            return 0;
+        }
+        asdl_seq_SET(values, 0, st->v.Expr.value);
+        expr_ty expr = _PyAST_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_, _PyASTOptimizeState *state)
+{
+    switch (node_->kind) {
+    case Module_kind:
+        CALL(astfold_body, asdl_seq, node_->v.Module.body);
+        break;
+    case Interactive_kind:
+        CALL_SEQ(astfold_stmt, stmt, node_->v.Interactive.body);
+        break;
+    case Expression_kind:
+        CALL(astfold_expr, expr_ty, node_->v.Expression.body);
+        break;
+    // The following top level nodes don't participate in constant folding
+    case FunctionType_kind:
+        break;
+    // No default case, so the compiler will emit a warning if new top level
+    // compilation nodes are added without being handled here
+    }
+    return 1;
+}
+
+static int
+astfold_expr(expr_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    if (++state->recursion_depth > state->recursion_limit) {
+        PyErr_SetString(PyExc_RecursionError,
+                        "maximum recursion depth exceeded during compilation");
+        return 0;
+    }
+    switch (node_->kind) {
+    case BoolOp_kind:
+        CALL_SEQ(astfold_expr, expr, 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, node_->v.Dict.keys);
+        CALL_SEQ(astfold_expr, expr, node_->v.Dict.values);
+        break;
+    case Set_kind:
+        CALL_SEQ(astfold_expr, expr, node_->v.Set.elts);
+        break;
+    case ListComp_kind:
+        CALL(astfold_expr, expr_ty, node_->v.ListComp.elt);
+        CALL_SEQ(astfold_comprehension, comprehension, node_->v.ListComp.generators);
+        break;
+    case SetComp_kind:
+        CALL(astfold_expr, expr_ty, node_->v.SetComp.elt);
+        CALL_SEQ(astfold_comprehension, comprehension, 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, node_->v.DictComp.generators);
+        break;
+    case GeneratorExp_kind:
+        CALL(astfold_expr, expr_ty, node_->v.GeneratorExp.elt);
+        CALL_SEQ(astfold_comprehension, comprehension, 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, 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, node_->v.Call.args);
+        CALL_SEQ(astfold_keyword, keyword, 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, 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_expr, expr_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 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 List_kind:
+        CALL_SEQ(astfold_expr, expr, node_->v.List.elts);
+        break;
+    case Tuple_kind:
+        CALL_SEQ(astfold_expr, expr, node_->v.Tuple.elts);
+        CALL(fold_tuple, expr_ty, node_);
+        break;
+    case Name_kind:
+        if (node_->v.Name.ctx == Load &&
+                _PyUnicode_EqualToASCIIString(node_->v.Name.id, "__debug__")) {
+            state->recursion_depth--;
+            return make_const(node_, PyBool_FromLong(!state->optimize), ctx_);
+        }
+        break;
+    case NamedExpr_kind:
+        CALL(astfold_expr, expr_ty, node_->v.NamedExpr.value);
+        break;
+    case Constant_kind:
+        // Already a constant, nothing further to do
+        break;
+    // No default case, so the compiler will emit a warning if new expression
+    // kinds are added without being handled here
+    }
+    state->recursion_depth--;
+    return 1;
+}
+
+static int
+astfold_keyword(keyword_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    CALL(astfold_expr, expr_ty, node_->value);
+    return 1;
+}
+
+static int
+astfold_comprehension(comprehension_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    CALL(astfold_expr, expr_ty, node_->target);
+    CALL(astfold_expr, expr_ty, node_->iter);
+    CALL_SEQ(astfold_expr, expr, node_->ifs);
+
+    CALL(fold_iter, expr_ty, node_->iter);
+    return 1;
+}
+
+static int
+astfold_arguments(arguments_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    CALL_SEQ(astfold_arg, arg, node_->posonlyargs);
+    CALL_SEQ(astfold_arg, arg, node_->args);
+    CALL_OPT(astfold_arg, arg_ty, node_->vararg);
+    CALL_SEQ(astfold_arg, arg, node_->kwonlyargs);
+    CALL_SEQ(astfold_expr, expr, node_->kw_defaults);
+    CALL_OPT(astfold_arg, arg_ty, node_->kwarg);
+    CALL_SEQ(astfold_expr, expr, node_->defaults);
+    return 1;
+}
+
+static int
+astfold_arg(arg_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    if (!(state->ff_features & CO_FUTURE_ANNOTATIONS)) {
+        CALL_OPT(astfold_expr, expr_ty, node_->annotation);
+    }
+    return 1;
+}
+
+static int
+astfold_stmt(stmt_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    if (++state->recursion_depth > state->recursion_limit) {
+        PyErr_SetString(PyExc_RecursionError,
+                        "maximum recursion depth exceeded during compilation");
+        return 0;
+    }
+    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, node_->v.FunctionDef.decorator_list);
+        if (!(state->ff_features & CO_FUTURE_ANNOTATIONS)) {
+            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, node_->v.AsyncFunctionDef.decorator_list);
+        if (!(state->ff_features & CO_FUTURE_ANNOTATIONS)) {
+            CALL_OPT(astfold_expr, expr_ty, node_->v.AsyncFunctionDef.returns);
+        }
+        break;
+    case ClassDef_kind:
+        CALL_SEQ(astfold_expr, expr, node_->v.ClassDef.bases);
+        CALL_SEQ(astfold_keyword, keyword, node_->v.ClassDef.keywords);
+        CALL(astfold_body, asdl_seq, node_->v.ClassDef.body);
+        CALL_SEQ(astfold_expr, expr, 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, node_->v.Delete.targets);
+        break;
+    case Assign_kind:
+        CALL_SEQ(astfold_expr, expr, 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);
+        if (!(state->ff_features & CO_FUTURE_ANNOTATIONS)) {
+            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, node_->v.For.body);
+        CALL_SEQ(astfold_stmt, stmt, 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, node_->v.AsyncFor.body);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.AsyncFor.orelse);
+        break;
+    case While_kind:
+        CALL(astfold_expr, expr_ty, node_->v.While.test);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.While.body);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.While.orelse);
+        break;
+    case If_kind:
+        CALL(astfold_expr, expr_ty, node_->v.If.test);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.If.body);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.If.orelse);
+        break;
+    case With_kind:
+        CALL_SEQ(astfold_withitem, withitem, node_->v.With.items);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.With.body);
+        break;
+    case AsyncWith_kind:
+        CALL_SEQ(astfold_withitem, withitem, node_->v.AsyncWith.items);
+        CALL_SEQ(astfold_stmt, stmt, 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, node_->v.Try.body);
+        CALL_SEQ(astfold_excepthandler, excepthandler, node_->v.Try.handlers);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.Try.orelse);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.Try.finalbody);
+        break;
+    case TryStar_kind:
+        CALL_SEQ(astfold_stmt, stmt, node_->v.TryStar.body);
+        CALL_SEQ(astfold_excepthandler, excepthandler, node_->v.TryStar.handlers);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.TryStar.orelse);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.TryStar.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;
+    case Match_kind:
+        CALL(astfold_expr, expr_ty, node_->v.Match.subject);
+        CALL_SEQ(astfold_match_case, match_case, node_->v.Match.cases);
+        break;
+    // The following statements don't contain any subexpressions to be folded
+    case Import_kind:
+    case ImportFrom_kind:
+    case Global_kind:
+    case Nonlocal_kind:
+    case Pass_kind:
+    case Break_kind:
+    case Continue_kind:
+        break;
+    // No default case, so the compiler will emit a warning if new statement
+    // kinds are added without being handled here
+    }
+    state->recursion_depth--;
+    return 1;
+}
+
+static int
+astfold_excepthandler(excepthandler_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    switch (node_->kind) {
+    case ExceptHandler_kind:
+        CALL_OPT(astfold_expr, expr_ty, node_->v.ExceptHandler.type);
+        CALL_SEQ(astfold_stmt, stmt, node_->v.ExceptHandler.body);
+        break;
+    // No default case, so the compiler will emit a warning if new handler
+    // kinds are added without being handled here
+    }
+    return 1;
+}
+
+static int
+astfold_withitem(withitem_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    CALL(astfold_expr, expr_ty, node_->context_expr);
+    CALL_OPT(astfold_expr, expr_ty, node_->optional_vars);
+    return 1;
+}
+
+static int
+astfold_pattern(pattern_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    // Currently, this is really only used to form complex/negative numeric
+    // constants in MatchValue and MatchMapping nodes
+    // We still recurse into all subexpressions and subpatterns anyway
+    if (++state->recursion_depth > state->recursion_limit) {
+        PyErr_SetString(PyExc_RecursionError,
+                        "maximum recursion depth exceeded during compilation");
+        return 0;
+    }
+    switch (node_->kind) {
+        case MatchValue_kind:
+            CALL(astfold_expr, expr_ty, node_->v.MatchValue.value);
+            break;
+        case MatchSingleton_kind:
+            break;
+        case MatchSequence_kind:
+            CALL_SEQ(astfold_pattern, pattern, node_->v.MatchSequence.patterns);
+            break;
+        case MatchMapping_kind:
+            CALL_SEQ(astfold_expr, expr, node_->v.MatchMapping.keys);
+            CALL_SEQ(astfold_pattern, pattern, node_->v.MatchMapping.patterns);
+            break;
+        case MatchClass_kind:
+            CALL(astfold_expr, expr_ty, node_->v.MatchClass.cls);
+            CALL_SEQ(astfold_pattern, pattern, node_->v.MatchClass.patterns);
+            CALL_SEQ(astfold_pattern, pattern, node_->v.MatchClass.kwd_patterns);
+            break;
+        case MatchStar_kind:
+            break;
+        case MatchAs_kind:
+            if (node_->v.MatchAs.pattern) {
+                CALL(astfold_pattern, pattern_ty, node_->v.MatchAs.pattern);
+            }
+            break;
+        case MatchOr_kind:
+            CALL_SEQ(astfold_pattern, pattern, node_->v.MatchOr.patterns);
+            break;
+    // No default case, so the compiler will emit a warning if new pattern
+    // kinds are added without being handled here
+    }
+    state->recursion_depth--;
+    return 1;
+}
+
+static int
+astfold_match_case(match_case_ty node_, PyArena *ctx_, _PyASTOptimizeState *state)
+{
+    CALL(astfold_pattern, expr_ty, node_->pattern);
+    CALL_OPT(astfold_expr, expr_ty, node_->guard);
+    CALL_SEQ(astfold_stmt, stmt, node_->body);
+    return 1;
+}
+
+#undef CALL
+#undef CALL_OPT
+#undef CALL_SEQ
+
+/* See comments in symtable.c. */
+#define COMPILER_STACK_FRAME_SCALE 3
+
+int
+_PyAST_Optimize(mod_ty mod, PyArena *arena, _PyASTOptimizeState *state)
+{
+    PyThreadState *tstate;
+    int recursion_limit = Py_GetRecursionLimit();
+    int starting_recursion_depth;
+
+    /* Setup recursion depth check counters */
+    tstate = _PyThreadState_GET();
+    if (!tstate) {
+        return 0;
+    }
+    /* Be careful here to prevent overflow. */
+    int recursion_depth = tstate->recursion_limit - tstate->recursion_remaining;
+    starting_recursion_depth = (recursion_depth < INT_MAX / COMPILER_STACK_FRAME_SCALE) ?
+        recursion_depth * COMPILER_STACK_FRAME_SCALE : recursion_depth;
+    state->recursion_depth = starting_recursion_depth;
+    state->recursion_limit = (recursion_limit < INT_MAX / COMPILER_STACK_FRAME_SCALE) ?
+        recursion_limit * COMPILER_STACK_FRAME_SCALE : recursion_limit;
+
+    int ret = astfold_mod(mod, arena, state);
+    assert(ret || PyErr_Occurred());
+
+    /* Check that the recursion depth counting balanced correctly */
+    if (ret && state->recursion_depth != starting_recursion_depth) {
+        PyErr_Format(PyExc_SystemError,
+            "AST optimizer recursion depth mismatch (before=%d, after=%d)",
+            starting_recursion_depth, state->recursion_depth);
+        return 0;
+    }
+
+    return ret;
+}