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ast.c
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/*
* This file includes functions to transform a concrete syntax tree (CST) to
* an abstract syntax tree (AST). The main function is PyAST_FromNode().
*
*/
#include "Python.h"
#include "Python-ast.h"
#include "node.h"
#include "ast.h"
#include "token.h"
#include <assert.h>
static int validate_stmts(asdl_seq *);
static int validate_exprs(asdl_seq *, expr_context_ty, int);
static int validate_nonempty_seq(asdl_seq *, const char *, const char *);
static int validate_stmt(stmt_ty);
static int validate_expr(expr_ty, expr_context_ty);
static int
validate_comprehension(asdl_seq *gens)
{
int i;
if (!asdl_seq_LEN(gens)) {
PyErr_SetString(PyExc_ValueError, "comprehension with no generators");
return 0;
}
for (i = 0; i < asdl_seq_LEN(gens); i++) {
comprehension_ty comp = asdl_seq_GET(gens, i);
if (!validate_expr(comp->target, Store) ||
!validate_expr(comp->iter, Load) ||
!validate_exprs(comp->ifs, Load, 0))
return 0;
}
return 1;
}
static int
validate_slice(slice_ty slice)
{
switch (slice->kind) {
case Slice_kind:
return (!slice->v.Slice.lower || validate_expr(slice->v.Slice.lower, Load)) &&
(!slice->v.Slice.upper || validate_expr(slice->v.Slice.upper, Load)) &&
(!slice->v.Slice.step || validate_expr(slice->v.Slice.step, Load));
case ExtSlice_kind: {
int i;
if (!validate_nonempty_seq(slice->v.ExtSlice.dims, "dims", "ExtSlice"))
return 0;
for (i = 0; i < asdl_seq_LEN(slice->v.ExtSlice.dims); i++)
if (!validate_slice(asdl_seq_GET(slice->v.ExtSlice.dims, i)))
return 0;
return 1;
}
case Index_kind:
return validate_expr(slice->v.Index.value, Load);
default:
PyErr_SetString(PyExc_SystemError, "unknown slice node");
return 0;
}
}
static int
validate_keywords(asdl_seq *keywords)
{
int i;
for (i = 0; i < asdl_seq_LEN(keywords); i++)
if (!validate_expr(((keyword_ty)asdl_seq_GET(keywords, i))->value, Load))
return 0;
return 1;
}
static int
validate_args(asdl_seq *args)
{
int i;
for (i = 0; i < asdl_seq_LEN(args); i++) {
arg_ty arg = asdl_seq_GET(args, i);
if (arg->annotation && !validate_expr(arg->annotation, Load))
return 0;
}
return 1;
}
static const char *
expr_context_name(expr_context_ty ctx)
{
switch (ctx) {
case Load:
return "Load";
case Store:
return "Store";
case Del:
return "Del";
case AugLoad:
return "AugLoad";
case AugStore:
return "AugStore";
case Param:
return "Param";
default:
assert(0);
return "(unknown)";
}
}
static int
validate_arguments(arguments_ty args)
{
if (!validate_args(args->args))
return 0;
if (args->vararg && args->vararg->annotation
&& !validate_expr(args->vararg->annotation, Load)) {
return 0;
}
if (!validate_args(args->kwonlyargs))
return 0;
if (args->kwarg && args->kwarg->annotation
&& !validate_expr(args->kwarg->annotation, Load)) {
return 0;
}
if (asdl_seq_LEN(args->defaults) > asdl_seq_LEN(args->args)) {
PyErr_SetString(PyExc_ValueError, "more positional defaults than args on arguments");
return 0;
}
if (asdl_seq_LEN(args->kw_defaults) != asdl_seq_LEN(args->kwonlyargs)) {
PyErr_SetString(PyExc_ValueError, "length of kwonlyargs is not the same as "
"kw_defaults on arguments");
return 0;
}
return validate_exprs(args->defaults, Load, 0) && validate_exprs(args->kw_defaults, Load, 1);
}
static int
validate_constant(PyObject *value)
{
if (value == Py_None || value == Py_Ellipsis)
return 1;
if (PyLong_CheckExact(value)
|| PyFloat_CheckExact(value)
|| PyComplex_CheckExact(value)
|| PyBool_Check(value)
|| PyUnicode_CheckExact(value)
|| PyBytes_CheckExact(value))
return 1;
if (PyTuple_CheckExact(value) || PyFrozenSet_CheckExact(value)) {
PyObject *it;
it = PyObject_GetIter(value);
if (it == NULL)
return 0;
while (1) {
PyObject *item = PyIter_Next(it);
if (item == NULL) {
if (PyErr_Occurred()) {
Py_DECREF(it);
return 0;
}
break;
}
if (!validate_constant(item)) {
Py_DECREF(it);
Py_DECREF(item);
return 0;
}
Py_DECREF(item);
}
Py_DECREF(it);
return 1;
}
return 0;
}
static int
validate_expr(expr_ty exp, expr_context_ty ctx)
{
int check_ctx = 1;
expr_context_ty actual_ctx;
/* First check expression context. */
switch (exp->kind) {
case Attribute_kind:
actual_ctx = exp->v.Attribute.ctx;
break;
case Subscript_kind:
actual_ctx = exp->v.Subscript.ctx;
break;
case Starred_kind:
actual_ctx = exp->v.Starred.ctx;
break;
case Name_kind:
actual_ctx = exp->v.Name.ctx;
break;
case List_kind:
actual_ctx = exp->v.List.ctx;
break;
case Tuple_kind:
actual_ctx = exp->v.Tuple.ctx;
break;
default:
if (ctx != Load) {
PyErr_Format(PyExc_ValueError, "expression which can't be "
"assigned to in %s context", expr_context_name(ctx));
return 0;
}
check_ctx = 0;
/* set actual_ctx to prevent gcc warning */
actual_ctx = 0;
}
if (check_ctx && actual_ctx != ctx) {
PyErr_Format(PyExc_ValueError, "expression must have %s context but has %s instead",
expr_context_name(ctx), expr_context_name(actual_ctx));
return 0;
}
/* Now validate expression. */
switch (exp->kind) {
case BoolOp_kind:
if (asdl_seq_LEN(exp->v.BoolOp.values) < 2) {
PyErr_SetString(PyExc_ValueError, "BoolOp with less than 2 values");
return 0;
}
return validate_exprs(exp->v.BoolOp.values, Load, 0);
case BinOp_kind:
return validate_expr(exp->v.BinOp.left, Load) &&
validate_expr(exp->v.BinOp.right, Load);
case UnaryOp_kind:
return validate_expr(exp->v.UnaryOp.operand, Load);
case Lambda_kind:
return validate_arguments(exp->v.Lambda.args) &&
validate_expr(exp->v.Lambda.body, Load);
case IfExp_kind:
return validate_expr(exp->v.IfExp.test, Load) &&
validate_expr(exp->v.IfExp.body, Load) &&
validate_expr(exp->v.IfExp.orelse, Load);
case Dict_kind:
if (asdl_seq_LEN(exp->v.Dict.keys) != asdl_seq_LEN(exp->v.Dict.values)) {
PyErr_SetString(PyExc_ValueError,
"Dict doesn't have the same number of keys as values");
return 0;
}
/* null_ok=1 for keys expressions to allow dict unpacking to work in
dict literals, i.e. ``{**{a:b}}`` */
return validate_exprs(exp->v.Dict.keys, Load, /*null_ok=*/ 1) &&
validate_exprs(exp->v.Dict.values, Load, /*null_ok=*/ 0);
case Set_kind:
return validate_exprs(exp->v.Set.elts, Load, 0);
#define COMP(NAME) \
case NAME ## _kind: \
return validate_comprehension(exp->v.NAME.generators) && \
validate_expr(exp->v.NAME.elt, Load);
COMP(ListComp)
COMP(SetComp)
COMP(GeneratorExp)
#undef COMP
case DictComp_kind:
return validate_comprehension(exp->v.DictComp.generators) &&
validate_expr(exp->v.DictComp.key, Load) &&
validate_expr(exp->v.DictComp.value, Load);
case Yield_kind:
return !exp->v.Yield.value || validate_expr(exp->v.Yield.value, Load);
case YieldFrom_kind:
return validate_expr(exp->v.YieldFrom.value, Load);
case Await_kind:
return validate_expr(exp->v.Await.value, Load);
case Compare_kind:
if (!asdl_seq_LEN(exp->v.Compare.comparators)) {
PyErr_SetString(PyExc_ValueError, "Compare with no comparators");
return 0;
}
if (asdl_seq_LEN(exp->v.Compare.comparators) !=
asdl_seq_LEN(exp->v.Compare.ops)) {
PyErr_SetString(PyExc_ValueError, "Compare has a different number "
"of comparators and operands");
return 0;
}
return validate_exprs(exp->v.Compare.comparators, Load, 0) &&
validate_expr(exp->v.Compare.left, Load);
case Call_kind:
return validate_expr(exp->v.Call.func, Load) &&
validate_exprs(exp->v.Call.args, Load, 0) &&
validate_keywords(exp->v.Call.keywords);
case Constant_kind:
if (!validate_constant(exp->v.Constant.value)) {
PyErr_Format(PyExc_TypeError,
"got an invalid type in Constant: %s",
Py_TYPE(exp->v.Constant.value)->tp_name);
return 0;
}
return 1;
case Num_kind: {
PyObject *n = exp->v.Num.n;
if (!PyLong_CheckExact(n) && !PyFloat_CheckExact(n) &&
!PyComplex_CheckExact(n)) {
PyErr_SetString(PyExc_TypeError, "non-numeric type in Num");
return 0;
}
return 1;
}
case Str_kind: {
PyObject *s = exp->v.Str.s;
if (!PyUnicode_CheckExact(s)) {
PyErr_SetString(PyExc_TypeError, "non-string type in Str");
return 0;
}
return 1;
}
case JoinedStr_kind:
return validate_exprs(exp->v.JoinedStr.values, Load, 0);
case FormattedValue_kind:
if (validate_expr(exp->v.FormattedValue.value, Load) == 0)
return 0;
if (exp->v.FormattedValue.format_spec)
return validate_expr(exp->v.FormattedValue.format_spec, Load);
return 1;
case Bytes_kind: {
PyObject *b = exp->v.Bytes.s;
if (!PyBytes_CheckExact(b)) {
PyErr_SetString(PyExc_TypeError, "non-bytes type in Bytes");
return 0;
}
return 1;
}
case Attribute_kind:
return validate_expr(exp->v.Attribute.value, Load);
case Subscript_kind:
return validate_slice(exp->v.Subscript.slice) &&
validate_expr(exp->v.Subscript.value, Load);
case Starred_kind:
return validate_expr(exp->v.Starred.value, ctx);
case List_kind:
return validate_exprs(exp->v.List.elts, ctx, 0);
case Tuple_kind:
return validate_exprs(exp->v.Tuple.elts, ctx, 0);
/* These last cases don't have any checking. */
case Name_kind:
case NameConstant_kind:
case Ellipsis_kind:
return 1;
default:
PyErr_SetString(PyExc_SystemError, "unexpected expression");
return 0;
}
}
static int
validate_nonempty_seq(asdl_seq *seq, const char *what, const char *owner)
{
if (asdl_seq_LEN(seq))
return 1;
PyErr_Format(PyExc_ValueError, "empty %s on %s", what, owner);
return 0;
}
static int
validate_assignlist(asdl_seq *targets, expr_context_ty ctx)
{
return validate_nonempty_seq(targets, "targets", ctx == Del ? "Delete" : "Assign") &&
validate_exprs(targets, ctx, 0);
}
static int
validate_body(asdl_seq *body, const char *owner)
{
return validate_nonempty_seq(body, "body", owner) && validate_stmts(body);
}
static int
validate_stmt(stmt_ty stmt)
{
int i;
switch (stmt->kind) {
case FunctionDef_kind:
return validate_body(stmt->v.FunctionDef.body, "FunctionDef") &&
validate_arguments(stmt->v.FunctionDef.args) &&
validate_exprs(stmt->v.FunctionDef.decorator_list, Load, 0) &&
(!stmt->v.FunctionDef.returns ||
validate_expr(stmt->v.FunctionDef.returns, Load));
case ClassDef_kind:
return validate_body(stmt->v.ClassDef.body, "ClassDef") &&
validate_exprs(stmt->v.ClassDef.bases, Load, 0) &&
validate_keywords(stmt->v.ClassDef.keywords) &&
validate_exprs(stmt->v.ClassDef.decorator_list, Load, 0);
case Return_kind:
return !stmt->v.Return.value || validate_expr(stmt->v.Return.value, Load);
case Delete_kind:
return validate_assignlist(stmt->v.Delete.targets, Del);
case Assign_kind:
return validate_assignlist(stmt->v.Assign.targets, Store) &&
validate_expr(stmt->v.Assign.value, Load);
case AugAssign_kind:
return validate_expr(stmt->v.AugAssign.target, Store) &&
validate_expr(stmt->v.AugAssign.value, Load);
case AnnAssign_kind:
if (stmt->v.AnnAssign.target->kind != Name_kind &&
stmt->v.AnnAssign.simple) {
PyErr_SetString(PyExc_TypeError,
"AnnAssign with simple non-Name target");
return 0;
}
return validate_expr(stmt->v.AnnAssign.target, Store) &&
(!stmt->v.AnnAssign.value ||
validate_expr(stmt->v.AnnAssign.value, Load)) &&
validate_expr(stmt->v.AnnAssign.annotation, Load);
case For_kind:
return validate_expr(stmt->v.For.target, Store) &&
validate_expr(stmt->v.For.iter, Load) &&
validate_body(stmt->v.For.body, "For") &&
validate_stmts(stmt->v.For.orelse);
case AsyncFor_kind:
return validate_expr(stmt->v.AsyncFor.target, Store) &&
validate_expr(stmt->v.AsyncFor.iter, Load) &&
validate_body(stmt->v.AsyncFor.body, "AsyncFor") &&
validate_stmts(stmt->v.AsyncFor.orelse);
case While_kind:
return validate_expr(stmt->v.While.test, Load) &&
validate_body(stmt->v.While.body, "While") &&
validate_stmts(stmt->v.While.orelse);
case If_kind:
return validate_expr(stmt->v.If.test, Load) &&
validate_body(stmt->v.If.body, "If") &&
validate_stmts(stmt->v.If.orelse);
case With_kind:
if (!validate_nonempty_seq(stmt->v.With.items, "items", "With"))
return 0;
for (i = 0; i < asdl_seq_LEN(stmt->v.With.items); i++) {
withitem_ty item = asdl_seq_GET(stmt->v.With.items, i);
if (!validate_expr(item->context_expr, Load) ||
(item->optional_vars && !validate_expr(item->optional_vars, Store)))
return 0;
}
return validate_body(stmt->v.With.body, "With");
case AsyncWith_kind:
if (!validate_nonempty_seq(stmt->v.AsyncWith.items, "items", "AsyncWith"))
return 0;
for (i = 0; i < asdl_seq_LEN(stmt->v.AsyncWith.items); i++) {
withitem_ty item = asdl_seq_GET(stmt->v.AsyncWith.items, i);
if (!validate_expr(item->context_expr, Load) ||
(item->optional_vars && !validate_expr(item->optional_vars, Store)))
return 0;
}
return validate_body(stmt->v.AsyncWith.body, "AsyncWith");
case Raise_kind:
if (stmt->v.Raise.exc) {
return validate_expr(stmt->v.Raise.exc, Load) &&
(!stmt->v.Raise.cause || validate_expr(stmt->v.Raise.cause, Load));
}
if (stmt->v.Raise.cause) {
PyErr_SetString(PyExc_ValueError, "Raise with cause but no exception");
return 0;
}
return 1;
case Try_kind:
if (!validate_body(stmt->v.Try.body, "Try"))
return 0;
if (!asdl_seq_LEN(stmt->v.Try.handlers) &&
!asdl_seq_LEN(stmt->v.Try.finalbody)) {
PyErr_SetString(PyExc_ValueError, "Try has neither except handlers nor finalbody");
return 0;
}
if (!asdl_seq_LEN(stmt->v.Try.handlers) &&
asdl_seq_LEN(stmt->v.Try.orelse)) {
PyErr_SetString(PyExc_ValueError, "Try has orelse but no except handlers");
return 0;
}
for (i = 0; i < asdl_seq_LEN(stmt->v.Try.handlers); i++) {
excepthandler_ty handler = asdl_seq_GET(stmt->v.Try.handlers, i);
if ((handler->v.ExceptHandler.type &&
!validate_expr(handler->v.ExceptHandler.type, Load)) ||
!validate_body(handler->v.ExceptHandler.body, "ExceptHandler"))
return 0;
}
return (!asdl_seq_LEN(stmt->v.Try.finalbody) ||
validate_stmts(stmt->v.Try.finalbody)) &&
(!asdl_seq_LEN(stmt->v.Try.orelse) ||
validate_stmts(stmt->v.Try.orelse));
case Assert_kind:
return validate_expr(stmt->v.Assert.test, Load) &&
(!stmt->v.Assert.msg || validate_expr(stmt->v.Assert.msg, Load));
case Import_kind:
return validate_nonempty_seq(stmt->v.Import.names, "names", "Import");
case ImportFrom_kind:
if (stmt->v.ImportFrom.level < 0) {
PyErr_SetString(PyExc_ValueError, "Negative ImportFrom level");
return 0;
}
return validate_nonempty_seq(stmt->v.ImportFrom.names, "names", "ImportFrom");
case Global_kind:
return validate_nonempty_seq(stmt->v.Global.names, "names", "Global");
case Nonlocal_kind:
return validate_nonempty_seq(stmt->v.Nonlocal.names, "names", "Nonlocal");
case Expr_kind:
return validate_expr(stmt->v.Expr.value, Load);
case AsyncFunctionDef_kind:
return validate_body(stmt->v.AsyncFunctionDef.body, "AsyncFunctionDef") &&
validate_arguments(stmt->v.AsyncFunctionDef.args) &&
validate_exprs(stmt->v.AsyncFunctionDef.decorator_list, Load, 0) &&
(!stmt->v.AsyncFunctionDef.returns ||
validate_expr(stmt->v.AsyncFunctionDef.returns, Load));
case Pass_kind:
case Break_kind:
case Continue_kind:
return 1;
default:
PyErr_SetString(PyExc_SystemError, "unexpected statement");
return 0;
}
}
static int
validate_stmts(asdl_seq *seq)
{
int i;
for (i = 0; i < asdl_seq_LEN(seq); i++) {
stmt_ty stmt = asdl_seq_GET(seq, i);
if (stmt) {
if (!validate_stmt(stmt))
return 0;
}
else {
PyErr_SetString(PyExc_ValueError,
"None disallowed in statement list");
return 0;
}
}
return 1;
}
static int
validate_exprs(asdl_seq *exprs, expr_context_ty ctx, int null_ok)
{
int i;
for (i = 0; i < asdl_seq_LEN(exprs); i++) {
expr_ty expr = asdl_seq_GET(exprs, i);
if (expr) {
if (!validate_expr(expr, ctx))
return 0;
}
else if (!null_ok) {
PyErr_SetString(PyExc_ValueError,
"None disallowed in expression list");
return 0;
}
}
return 1;
}
int
PyAST_Validate(mod_ty mod)
{
int res = 0;
switch (mod->kind) {
case Module_kind:
res = validate_stmts(mod->v.Module.body);
break;
case Interactive_kind:
res = validate_stmts(mod->v.Interactive.body);
break;
case Expression_kind:
res = validate_expr(mod->v.Expression.body, Load);
break;
case Suite_kind:
PyErr_SetString(PyExc_ValueError, "Suite is not valid in the CPython compiler");
break;
default:
PyErr_SetString(PyExc_SystemError, "impossible module node");
res = 0;
break;
}
return res;
}
/* This is done here, so defines like "test" don't interfere with AST use above. */
#include "grammar.h"
#include "parsetok.h"
#include "graminit.h"
/* Data structure used internally */
struct compiling {
PyArena *c_arena; /* Arena for allocating memory. */
PyObject *c_filename; /* filename */
PyObject *c_normalize; /* Normalization function from unicodedata. */
PyObject *c_normalize_args; /* Normalization argument tuple. */
};
static asdl_seq *seq_for_testlist(struct compiling *, const node *);
static expr_ty ast_for_expr(struct compiling *, const node *);
static stmt_ty ast_for_stmt(struct compiling *, const node *);
static asdl_seq *ast_for_suite(struct compiling *, const node *);
static asdl_seq *ast_for_exprlist(struct compiling *, const node *,
expr_context_ty);
static expr_ty ast_for_testlist(struct compiling *, const node *);
static stmt_ty ast_for_classdef(struct compiling *, const node *, asdl_seq *);
static stmt_ty ast_for_with_stmt(struct compiling *, const node *, int);
static stmt_ty ast_for_for_stmt(struct compiling *, const node *, int);
/* Note different signature for ast_for_call */
static expr_ty ast_for_call(struct compiling *, const node *, expr_ty);
static PyObject *parsenumber(struct compiling *, const char *);
static expr_ty parsestrplus(struct compiling *, const node *n);
#define COMP_GENEXP 0
#define COMP_LISTCOMP 1
#define COMP_SETCOMP 2
static int
init_normalization(struct compiling *c)
{
PyObject *m = PyImport_ImportModuleNoBlock("unicodedata");
if (!m)
return 0;
c->c_normalize = PyObject_GetAttrString(m, "normalize");
Py_DECREF(m);
if (!c->c_normalize)
return 0;
c->c_normalize_args = Py_BuildValue("(sN)", "NFKC", Py_None);
if (!c->c_normalize_args) {
Py_CLEAR(c->c_normalize);
return 0;
}
PyTuple_SET_ITEM(c->c_normalize_args, 1, NULL);
return 1;
}
static identifier
new_identifier(const char *n, struct compiling *c)
{
PyObject *id = PyUnicode_DecodeUTF8(n, strlen(n), NULL);
if (!id)
return NULL;
/* PyUnicode_DecodeUTF8 should always return a ready string. */
assert(PyUnicode_IS_READY(id));
/* Check whether there are non-ASCII characters in the
identifier; if so, normalize to NFKC. */
if (!PyUnicode_IS_ASCII(id)) {
PyObject *id2;
if (!c->c_normalize && !init_normalization(c)) {
Py_DECREF(id);
return NULL;
}
PyTuple_SET_ITEM(c->c_normalize_args, 1, id);
id2 = PyObject_Call(c->c_normalize, c->c_normalize_args, NULL);
Py_DECREF(id);
if (!id2)
return NULL;
id = id2;
}
PyUnicode_InternInPlace(&id);
if (PyArena_AddPyObject(c->c_arena, id) < 0) {
Py_DECREF(id);
return NULL;
}
return id;
}
#define NEW_IDENTIFIER(n) new_identifier(STR(n), c)
static int
ast_error(struct compiling *c, const node *n, const char *errmsg)
{
PyObject *value, *errstr, *loc, *tmp;
loc = PyErr_ProgramTextObject(c->c_filename, LINENO(n));
if (!loc) {
Py_INCREF(Py_None);
loc = Py_None;
}
tmp = Py_BuildValue("(OiiN)", c->c_filename, LINENO(n), n->n_col_offset, loc);
if (!tmp)
return 0;
errstr = PyUnicode_FromString(errmsg);
if (!errstr) {
Py_DECREF(tmp);
return 0;
}
value = PyTuple_Pack(2, errstr, tmp);
Py_DECREF(errstr);
Py_DECREF(tmp);
if (value) {
PyErr_SetObject(PyExc_SyntaxError, value);
Py_DECREF(value);
}
return 0;
}
/* num_stmts() returns number of contained statements.
Use this routine to determine how big a sequence is needed for
the statements in a parse tree. Its raison d'etre is this bit of
grammar:
stmt: simple_stmt | compound_stmt
simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
A simple_stmt can contain multiple small_stmt elements joined
by semicolons. If the arg is a simple_stmt, the number of
small_stmt elements is returned.
*/
static int
num_stmts(const node *n)
{
int i, l;
node *ch;
switch (TYPE(n)) {
case single_input:
if (TYPE(CHILD(n, 0)) == NEWLINE)
return 0;
else
return num_stmts(CHILD(n, 0));
case file_input:
l = 0;
for (i = 0; i < NCH(n); i++) {
ch = CHILD(n, i);
if (TYPE(ch) == stmt)
l += num_stmts(ch);
}
return l;
case stmt:
return num_stmts(CHILD(n, 0));
case compound_stmt:
return 1;
case simple_stmt:
return NCH(n) / 2; /* Divide by 2 to remove count of semi-colons */
case suite:
if (NCH(n) == 1)
return num_stmts(CHILD(n, 0));
else {
l = 0;
for (i = 2; i < (NCH(n) - 1); i++)
l += num_stmts(CHILD(n, i));
return l;
}
default: {
char buf[128];
sprintf(buf, "Non-statement found: %d %d",
TYPE(n), NCH(n));
Py_FatalError(buf);
}
}
assert(0);
return 0;
}
/* Transform the CST rooted at node * to the appropriate AST
*/
mod_ty
PyAST_FromNodeObject(const node *n, PyCompilerFlags *flags,
PyObject *filename, PyArena *arena)
{
int i, j, k, num;
asdl_seq *stmts = NULL;
stmt_ty s;
node *ch;
struct compiling c;
mod_ty res = NULL;
c.c_arena = arena;
/* borrowed reference */
c.c_filename = filename;
c.c_normalize = NULL;
c.c_normalize_args = NULL;
if (TYPE(n) == encoding_decl)
n = CHILD(n, 0);
k = 0;
switch (TYPE(n)) {
case file_input:
stmts = _Py_asdl_seq_new(num_stmts(n), arena);
if (!stmts)
goto out;
for (i = 0; i < NCH(n) - 1; i++) {
ch = CHILD(n, i);
if (TYPE(ch) == NEWLINE)
continue;
REQ(ch, stmt);
num = num_stmts(ch);
if (num == 1) {
s = ast_for_stmt(&c, ch);
if (!s)
goto out;
asdl_seq_SET(stmts, k++, s);
}
else {
ch = CHILD(ch, 0);
REQ(ch, simple_stmt);
for (j = 0; j < num; j++) {
s = ast_for_stmt(&c, CHILD(ch, j * 2));
if (!s)
goto out;
asdl_seq_SET(stmts, k++, s);
}
}
}
res = Module(stmts, arena);
break;
case eval_input: {
expr_ty testlist_ast;
/* XXX Why not comp_for here? */
testlist_ast = ast_for_testlist(&c, CHILD(n, 0));
if (!testlist_ast)
goto out;
res = Expression(testlist_ast, arena);
break;
}
case single_input:
if (TYPE(CHILD(n, 0)) == NEWLINE) {
stmts = _Py_asdl_seq_new(1, arena);
if (!stmts)
goto out;
asdl_seq_SET(stmts, 0, Pass(n->n_lineno, n->n_col_offset,
arena));
if (!asdl_seq_GET(stmts, 0))
goto out;
res = Interactive(stmts, arena);
}
else {
n = CHILD(n, 0);
num = num_stmts(n);
stmts = _Py_asdl_seq_new(num, arena);
if (!stmts)
goto out;
if (num == 1) {
s = ast_for_stmt(&c, n);
if (!s)
goto out;
asdl_seq_SET(stmts, 0, s);
}
else {
/* Only a simple_stmt can contain multiple statements. */
REQ(n, simple_stmt);
for (i = 0; i < NCH(n); i += 2) {
if (TYPE(CHILD(n, i)) == NEWLINE)
break;
s = ast_for_stmt(&c, CHILD(n, i));
if (!s)
goto out;
asdl_seq_SET(stmts, i / 2, s);
}
}
res = Interactive(stmts, arena);
}
break;
default:
PyErr_Format(PyExc_SystemError,
"invalid node %d for PyAST_FromNode", TYPE(n));
goto out;
}
out:
if (c.c_normalize) {
Py_DECREF(c.c_normalize);
PyTuple_SET_ITEM(c.c_normalize_args, 1, NULL);
Py_DECREF(c.c_normalize_args);
}
return res;
}
mod_ty
PyAST_FromNode(const node *n, PyCompilerFlags *flags, const char *filename_str,
PyArena *arena)
{
mod_ty mod;
PyObject *filename;
filename = PyUnicode_DecodeFSDefault(filename_str);
if (filename == NULL)
return NULL;
mod = PyAST_FromNodeObject(n, flags, filename, arena);
Py_DECREF(filename);
return mod;
}
/* Return the AST repr. of the operator represented as syntax (|, ^, etc.)
*/
static operator_ty
get_operator(const node *n)
{
switch (TYPE(n)) {
case VBAR:
return BitOr;
case CIRCUMFLEX:
return BitXor;
case AMPER:
return BitAnd;
case LEFTSHIFT:
return LShift;
case RIGHTSHIFT:
return RShift;
case PLUS:
return Add;
case MINUS:
return Sub;
case STAR:
return Mult;
case AT:
return MatMult;
case SLASH:
return Div;
case DOUBLESLASH:
return FloorDiv;
case PERCENT:
return Mod;
default:
return (operator_ty)0;
}
}
static const char * const FORBIDDEN[] = {
"None",
"True",
"False",
NULL,
};
static int
forbidden_name(struct compiling *c, identifier name, const node *n,
int full_checks)
{
assert(PyUnicode_Check(name));
if (_PyUnicode_EqualToASCIIString(name, "__debug__")) {
ast_error(c, n, "assignment to keyword");
return 1;
}
if (_PyUnicode_EqualToASCIIString(name, "async") ||
_PyUnicode_EqualToASCIIString(name, "await"))
{
PyObject *message = PyUnicode_FromString(
"'async' and 'await' will become reserved keywords"
" in Python 3.7");
int ret;
if (message == NULL) {
return 1;
}
ret = PyErr_WarnExplicitObject(
PyExc_DeprecationWarning,
message,
c->c_filename,
LINENO(n),
NULL,
NULL);
Py_DECREF(message);
if (ret < 0) {
return 1;
}
}
if (full_checks) {
const char * const *p;
for (p = FORBIDDEN; *p; p++) {
if (_PyUnicode_EqualToASCIIString(name, *p)) {
ast_error(c, n, "assignment to keyword");
return 1;
}
}
}
return 0;
}
/* Set the context ctx for expr_ty e, recursively traversing e.
Only sets context for expr kinds that "can appear in assignment context"
(according to ../Parser/Python.asdl). For other expr kinds, it sets
an appropriate syntax error and returns false.
*/
static int
set_context(struct compiling *c, expr_ty e, expr_context_ty ctx, const node *n)
{
asdl_seq *s = NULL;
/* If a particular expression type can't be used for assign / delete,
set expr_name to its name and an error message will be generated.
*/
const char* expr_name = NULL;
/* The ast defines augmented store and load contexts, but the
implementation here doesn't actually use them. The code may be
a little more complex than necessary as a result. It also means
that expressions in an augmented assignment have a Store context.
Consider restructuring so that augmented assignment uses
set_context(), too.
*/
assert(ctx != AugStore && ctx != AugLoad);
switch (e->kind) {