add a AST validator (closes #12575)
diff --git a/Python/ast.c b/Python/ast.c
index 0d4d9ee..14500ee 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -1,19 +1,497 @@
/*
* This file includes functions to transform a concrete syntax tree (CST) to
- * an abstract syntax tree (AST). The main function is PyAST_FromNode().
+ * an abstract syntax tree (AST). The main function is PyAST_FromNode().
*
*/
#include "Python.h"
#include "Python-ast.h"
-#include "grammar.h"
#include "node.h"
#include "ast.h"
#include "token.h"
-#include "parsetok.h"
-#include "graminit.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->varargannotation) {
+ if (!args->vararg) {
+ PyErr_SetString(PyExc_ValueError, "varargannotation but no vararg on arguments");
+ return 0;
+ }
+ if (!validate_expr(args->varargannotation, Load))
+ return 0;
+ }
+ if (!validate_args(args->kwonlyargs))
+ return 0;
+ if (args->kwargannotation) {
+ if (!args->kwarg) {
+ PyErr_SetString(PyExc_ValueError, "kwargannotation but no kwarg on arguments");
+ return 0;
+ }
+ if (!validate_expr(args->kwargannotation, 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_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;
+ }
+ 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;
+ }
+ return validate_exprs(exp->v.Dict.keys, Load, 0) &&
+ validate_exprs(exp->v.Dict.values, Load, 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 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) &&
+ (!exp->v.Call.starargs || validate_expr(exp->v.Call.starargs, Load)) &&
+ (!exp->v.Call.kwargs || validate_expr(exp->v.Call.kwargs, Load));
+ 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 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 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) &&
+ (!stmt->v.ClassDef.starargs || validate_expr(stmt->v.ClassDef.starargs, Load)) &&
+ (!stmt->v.ClassDef.kwargs || validate_expr(stmt->v.ClassDef.kwargs, Load));
+ 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 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 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 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 < -1) {
+ PyErr_SetString(PyExc_ValueError, "ImportFrom level less than -1");
+ 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 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 down here, so defines like "test" don't intefere with access AST above. */
+#include "grammar.h"
+#include "parsetok.h"
+#include "graminit.h"
+
/* Data structure used internally */
struct compiling {
char *c_encoding; /* source encoding */