add hg and python

cinap_lenrek committed 15 years ago

Commit 4bb9e221 parent 987265c3706 files · +1228772 −-233Browse files

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	1	+/* parsermodule.c
	2	+ *
	3	+ * Copyright 1995-1996 by Fred L. Drake, Jr. and Virginia Polytechnic
	4	+ * Institute and State University, Blacksburg, Virginia, USA.
	5	+ * Portions copyright 1991-1995 by Stichting Mathematisch Centrum,
	6	+ * Amsterdam, The Netherlands. Copying is permitted under the terms
	7	+ * associated with the main Python distribution, with the additional
	8	+ * restriction that this additional notice be included and maintained
	9	+ * on all distributed copies.
	10	+ *
	11	+ * This module serves to replace the original parser module written
	12	+ * by Guido. The functionality is not matched precisely, but the
	13	+ * original may be implemented on top of this. This is desirable
	14	+ * since the source of the text to be parsed is now divorced from
	15	+ * this interface.
	16	+ *
	17	+ * Unlike the prior interface, the ability to give a parse tree
	18	+ * produced by Python code as a tuple to the compiler is enabled by
	19	+ * this module. See the documentation for more details.
	20	+ *
	21	+ * I've added some annotations that help with the lint code-checking
	22	+ * program, but they're not complete by a long shot. The real errors
	23	+ * that lint detects are gone, but there are still warnings with
	24	+ * Py_[X]DECREF() and Py_[X]INCREF() macros. The lint annotations
	25	+ * look like "NOTE(...)".
	26	+ */
	27	+
	28	+#include "Python.h" /* general Python API */
	29	+#include "graminit.h" /* symbols defined in the grammar */
	30	+#include "node.h" /* internal parser structure */
	31	+#include "errcode.h" /* error codes for PyNode_() /
	32	+#include "token.h" /* token definitions */
	33	+ /* ISTERMINAL() / ISNONTERMINAL() */
	34	+#include "compile.h" /* PyNode_Compile() */
	35	+
	36	+#ifdef lint
	37	+#include <note.h>
	38	+#else
	39	+#define NOTE(x)
	40	+#endif
	41	+
	42	+/* String constants used to initialize module attributes.
	43	+ *
	44	+ */
	45	+static char parser_copyright_string[] =
	46	+"Copyright 1995-1996 by Virginia Polytechnic Institute & State\n\
	47	+University, Blacksburg, Virginia, USA, and Fred L. Drake, Jr., Reston,\n\
	48	+Virginia, USA. Portions copyright 1991-1995 by Stichting Mathematisch\n\
	49	+Centrum, Amsterdam, The Netherlands.";
	50	+
	51	+
	52	+PyDoc_STRVAR(parser_doc_string,
	53	+"This is an interface to Python's internal parser.");
	54	+
	55	+static char parser_version_string[] = "0.5";
	56	+
	57	+
	58	+typedef PyObject* (*SeqMaker) (Py_ssize_t length);
	59	+typedef int (SeqInserter) (PyObject sequence,
	60	+ Py_ssize_t index,
	61	+ PyObject* element);
	62	+
	63	+/* The function below is copyrighted by Stichting Mathematisch Centrum. The
	64	+ * original copyright statement is included below, and continues to apply
	65	+ * in full to the function immediately following. All other material is
	66	+ * original, copyrighted by Fred L. Drake, Jr. and Virginia Polytechnic
	67	+ * Institute and State University. Changes were made to comply with the
	68	+ * new naming conventions. Added arguments to provide support for creating
	69	+ * lists as well as tuples, and optionally including the line numbers.
	70	+ */
	71	+
	72	+
	73	+static PyObject*
	74	+node2tuple(node n, / node to convert */
	75	+ SeqMaker mkseq, /* create sequence */
	76	+ SeqInserter addelem, /* func. to add elem. in seq. */
	77	+ int lineno) /* include line numbers? */
	78	+{
	79	+ if (n == NULL) {
	80	+ Py_INCREF(Py_None);
	81	+ return (Py_None);
	82	+ }
	83	+ if (ISNONTERMINAL(TYPE(n))) {
	84	+ int i;
	85	+ PyObject *v;
	86	+ PyObject *w;
	87	+
	88	+ v = mkseq(1 + NCH(n) + (TYPE(n) == encoding_decl));
	89	+ if (v == NULL)
	90	+ return (v);
	91	+ w = PyInt_FromLong(TYPE(n));
	92	+ if (w == NULL) {
	93	+ Py_DECREF(v);
	94	+ return ((PyObject*) NULL);
	95	+ }
	96	+ (void) addelem(v, 0, w);
	97	+ for (i = 0; i < NCH(n); i++) {
	98	+ w = node2tuple(CHILD(n, i), mkseq, addelem, lineno);
	99	+ if (w == NULL) {
	100	+ Py_DECREF(v);
	101	+ return ((PyObject*) NULL);
	102	+ }
	103	+ (void) addelem(v, i+1, w);
	104	+ }
	105	+
	106	+ if (TYPE(n) == encoding_decl)
	107	+ (void) addelem(v, i+1, PyString_FromString(STR(n)));
	108	+ return (v);
	109	+ }
	110	+ else if (ISTERMINAL(TYPE(n))) {
	111	+ PyObject *result = mkseq(2 + lineno);
	112	+ if (result != NULL) {
	113	+ (void) addelem(result, 0, PyInt_FromLong(TYPE(n)));
	114	+ (void) addelem(result, 1, PyString_FromString(STR(n)));
	115	+ if (lineno == 1)
	116	+ (void) addelem(result, 2, PyInt_FromLong(n->n_lineno));
	117	+ }
	118	+ return (result);
	119	+ }
	120	+ else {
	121	+ PyErr_SetString(PyExc_SystemError,
	122	+ "unrecognized parse tree node type");
	123	+ return ((PyObject*) NULL);
	124	+ }
	125	+}
	126	+/*
	127	+ * End of material copyrighted by Stichting Mathematisch Centrum.
	128	+ */
	129	+
	130	+
	131	+
	132	+/* There are two types of intermediate objects we're interested in:
	133	+ * 'eval' and 'exec' types. These constants can be used in the st_type
	134	+ * field of the object type to identify which any given object represents.
	135	+ * These should probably go in an external header to allow other extensions
	136	+ * to use them, but then, we really should be using C++ too. ;-)
	137	+ */
	138	+
	139	+#define PyST_EXPR 1
	140	+#define PyST_SUITE 2
	141	+
	142	+
	143	+/* These are the internal objects and definitions required to implement the
	144	+ * ST type. Most of the internal names are more reminiscent of the 'old'
	145	+ * naming style, but the code uses the new naming convention.
	146	+ */
	147	+
	148	+static PyObject*
	149	+parser_error = 0;
	150	+
	151	+
	152	+typedef struct {
	153	+ PyObject_HEAD /* standard object header */
	154	+ node* st_node; /* the node* returned by the parser */
	155	+ int st_type; /* EXPR or SUITE ? */
	156	+} PyST_Object;
	157	+
	158	+
	159	+static void parser_free(PyST_Object *st);
	160	+static int parser_compare(PyST_Object left, PyST_Object right);
	161	+static PyObject parser_getattr(PyObject self, char *name);
	162	+
	163	+
	164	+static
	165	+PyTypeObject PyST_Type = {
	166	+ PyObject_HEAD_INIT(NULL)
	167	+ 0,
	168	+ "parser.st", /* tp_name */
	169	+ (int) sizeof(PyST_Object), /* tp_basicsize */
	170	+ 0, /* tp_itemsize */
	171	+ (destructor)parser_free, /* tp_dealloc */
	172	+ 0, /* tp_print */
	173	+ parser_getattr, /* tp_getattr */
	174	+ 0, /* tp_setattr */
	175	+ (cmpfunc)parser_compare, /* tp_compare */
	176	+ 0, /* tp_repr */
	177	+ 0, /* tp_as_number */
	178	+ 0, /* tp_as_sequence */
	179	+ 0, /* tp_as_mapping */
	180	+ 0, /* tp_hash */
	181	+ 0, /* tp_call */
	182	+ 0, /* tp_str */
	183	+ 0, /* tp_getattro */
	184	+ 0, /* tp_setattro */
	185	+
	186	+ /* Functions to access object as input/output buffer */
	187	+ 0, /* tp_as_buffer */
	188	+
	189	+ Py_TPFLAGS_DEFAULT, /* tp_flags */
	190	+
	191	+ /* __doc__ */
	192	+ "Intermediate representation of a Python parse tree."
	193	+}; /* PyST_Type */
	194	+
	195	+
	196	+static int
	197	+parser_compare_nodes(node left, node right)
	198	+{
	199	+ int j;
	200	+
	201	+ if (TYPE(left) < TYPE(right))
	202	+ return (-1);
	203	+
	204	+ if (TYPE(right) < TYPE(left))
	205	+ return (1);
	206	+
	207	+ if (ISTERMINAL(TYPE(left)))
	208	+ return (strcmp(STR(left), STR(right)));
	209	+
	210	+ if (NCH(left) < NCH(right))
	211	+ return (-1);
	212	+
	213	+ if (NCH(right) < NCH(left))
	214	+ return (1);
	215	+
	216	+ for (j = 0; j < NCH(left); ++j) {
	217	+ int v = parser_compare_nodes(CHILD(left, j), CHILD(right, j));
	218	+
	219	+ if (v != 0)
	220	+ return (v);
	221	+ }
	222	+ return (0);
	223	+}
	224	+
	225	+
	226	+/* int parser_compare(PyST_Object* left, PyST_Object* right)
	227	+ *
	228	+ * Comparison function used by the Python operators ==, !=, <, >, <=, >=
	229	+ * This really just wraps a call to parser_compare_nodes() with some easy
	230	+ * checks and protection code.
	231	+ *
	232	+ */
	233	+static int
	234	+parser_compare(PyST_Object left, PyST_Object right)
	235	+{
	236	+ if (left == right)
	237	+ return (0);
	238	+
	239	+ if ((left == 0) \|\| (right == 0))
	240	+ return (-1);
	241	+
	242	+ return (parser_compare_nodes(left->st_node, right->st_node));
	243	+}
	244	+
	245	+
	246	+/* parser_newstobject(node* st)
	247	+ *
	248	+ * Allocates a new Python object representing an ST. This is simply the
	249	+ * 'wrapper' object that holds a node* and allows it to be passed around in
	250	+ * Python code.
	251	+ *
	252	+ */
	253	+static PyObject*
	254	+parser_newstobject(node *st, int type)
	255	+{
	256	+ PyST_Object* o = PyObject_New(PyST_Object, &PyST_Type);
	257	+
	258	+ if (o != 0) {
	259	+ o->st_node = st;
	260	+ o->st_type = type;
	261	+ }
	262	+ else {
	263	+ PyNode_Free(st);
	264	+ }
	265	+ return ((PyObject*)o);
	266	+}
	267	+
	268	+
	269	+/* void parser_free(PyST_Object* st)
	270	+ *
	271	+ * This is called by a del statement that reduces the reference count to 0.
	272	+ *
	273	+ */
	274	+static void
	275	+parser_free(PyST_Object *st)
	276	+{
	277	+ PyNode_Free(st->st_node);
	278	+ PyObject_Del(st);
	279	+}
	280	+
	281	+
	282	+/* parser_st2tuple(PyObject* self, PyObject* args, PyObject* kw)
	283	+ *
	284	+ * This provides conversion from a node* to a tuple object that can be
	285	+ * returned to the Python-level caller. The ST object is not modified.
	286	+ *
	287	+ */
	288	+static PyObject*
	289	+parser_st2tuple(PyST_Object self, PyObject args, PyObject *kw)
	290	+{
	291	+ PyObject *line_option = 0;
	292	+ PyObject *res = 0;
	293	+ int ok;
	294	+
	295	+ static char *keywords[] = {"ast", "line_info", NULL};
	296	+
	297	+ if (self == NULL) {
	298	+ ok = PyArg_ParseTupleAndKeywords(args, kw, "O!\|O:st2tuple", keywords,
	299	+ &PyST_Type, &self, &line_option);
	300	+ }
	301	+ else
	302	+ ok = PyArg_ParseTupleAndKeywords(args, kw, "\|O:totuple", &keywords[1],
	303	+ &line_option);
	304	+ if (ok != 0) {
	305	+ int lineno = 0;
	306	+ if (line_option != NULL) {
	307	+ lineno = (PyObject_IsTrue(line_option) != 0) ? 1 : 0;
	308	+ }
	309	+ /*
	310	+ * Convert ST into a tuple representation. Use Guido's function,
	311	+ * since it's known to work already.
	312	+ */
	313	+ res = node2tuple(((PyST_Object*)self)->st_node,
	314	+ PyTuple_New, PyTuple_SetItem, lineno);
	315	+ }
	316	+ return (res);
	317	+}
	318	+
	319	+
	320	+/* parser_st2list(PyObject* self, PyObject* args, PyObject* kw)
	321	+ *
	322	+ * This provides conversion from a node* to a list object that can be
	323	+ * returned to the Python-level caller. The ST object is not modified.
	324	+ *
	325	+ */
	326	+static PyObject*
	327	+parser_st2list(PyST_Object self, PyObject args, PyObject *kw)
	328	+{
	329	+ PyObject *line_option = 0;
	330	+ PyObject *res = 0;
	331	+ int ok;
	332	+
	333	+ static char *keywords[] = {"ast", "line_info", NULL};
	334	+
	335	+ if (self == NULL)
	336	+ ok = PyArg_ParseTupleAndKeywords(args, kw, "O!\|O:st2list", keywords,
	337	+ &PyST_Type, &self, &line_option);
	338	+ else
	339	+ ok = PyArg_ParseTupleAndKeywords(args, kw, "\|O:tolist", &keywords[1],
	340	+ &line_option);
	341	+ if (ok) {
	342	+ int lineno = 0;
	343	+ if (line_option != 0) {
	344	+ lineno = PyObject_IsTrue(line_option) ? 1 : 0;
	345	+ }
	346	+ /*
	347	+ * Convert ST into a tuple representation. Use Guido's function,
	348	+ * since it's known to work already.
	349	+ */
	350	+ res = node2tuple(self->st_node,
	351	+ PyList_New, PyList_SetItem, lineno);
	352	+ }
	353	+ return (res);
	354	+}
	355	+
	356	+
	357	+/* parser_compilest(PyObject* self, PyObject* args)
	358	+ *
	359	+ * This function creates code objects from the parse tree represented by
	360	+ * the passed-in data object. An optional file name is passed in as well.
	361	+ *
	362	+ */
	363	+static PyObject*
	364	+parser_compilest(PyST_Object self, PyObject args, PyObject *kw)
	365	+{
	366	+ PyObject* res = 0;
	367	+ char* str = "<syntax-tree>";
	368	+ int ok;
	369	+
	370	+ static char *keywords[] = {"ast", "filename", NULL};
	371	+
	372	+ if (self == NULL)
	373	+ ok = PyArg_ParseTupleAndKeywords(args, kw, "O!\|s:compilest", keywords,
	374	+ &PyST_Type, &self, &str);
	375	+ else
	376	+ ok = PyArg_ParseTupleAndKeywords(args, kw, "\|s:compile", &keywords[1],
	377	+ &str);
	378	+
	379	+ if (ok)
	380	+ res = (PyObject *)PyNode_Compile(self->st_node, str);
	381	+
	382	+ return (res);
	383	+}
	384	+
	385	+
	386	+/* PyObject* parser_isexpr(PyObject* self, PyObject* args)
	387	+ * PyObject* parser_issuite(PyObject* self, PyObject* args)
	388	+ *
	389	+ * Checks the passed-in ST object to determine if it is an expression or
	390	+ * a statement suite, respectively. The return is a Python truth value.
	391	+ *
	392	+ */
	393	+static PyObject*
	394	+parser_isexpr(PyST_Object self, PyObject args, PyObject *kw)
	395	+{
	396	+ PyObject* res = 0;
	397	+ int ok;
	398	+
	399	+ static char *keywords[] = {"ast", NULL};
	400	+
	401	+ if (self == NULL)
	402	+ ok = PyArg_ParseTupleAndKeywords(args, kw, "O!:isexpr", keywords,
	403	+ &PyST_Type, &self);
	404	+ else
	405	+ ok = PyArg_ParseTupleAndKeywords(args, kw, ":isexpr", &keywords[1]);
	406	+
	407	+ if (ok) {
	408	+ /* Check to see if the ST represents an expression or not. */
	409	+ res = (self->st_type == PyST_EXPR) ? Py_True : Py_False;
	410	+ Py_INCREF(res);
	411	+ }
	412	+ return (res);
	413	+}
	414	+
	415	+
	416	+static PyObject*
	417	+parser_issuite(PyST_Object self, PyObject args, PyObject *kw)
	418	+{
	419	+ PyObject* res = 0;
	420	+ int ok;
	421	+
	422	+ static char *keywords[] = {"ast", NULL};
	423	+
	424	+ if (self == NULL)
	425	+ ok = PyArg_ParseTupleAndKeywords(args, kw, "O!:issuite", keywords,
	426	+ &PyST_Type, &self);
	427	+ else
	428	+ ok = PyArg_ParseTupleAndKeywords(args, kw, ":issuite", &keywords[1]);
	429	+
	430	+ if (ok) {
	431	+ /* Check to see if the ST represents an expression or not. */
	432	+ res = (self->st_type == PyST_EXPR) ? Py_False : Py_True;
	433	+ Py_INCREF(res);
	434	+ }
	435	+ return (res);
	436	+}
	437	+
	438	+
	439	+#define PUBLIC_METHOD_TYPE (METH_VARARGS\|METH_KEYWORDS)
	440	+
	441	+static PyMethodDef
	442	+parser_methods[] = {
	443	+ {"compile", (PyCFunction)parser_compilest, PUBLIC_METHOD_TYPE,
	444	+ PyDoc_STR("Compile this ST object into a code object.")},
	445	+ {"isexpr", (PyCFunction)parser_isexpr, PUBLIC_METHOD_TYPE,
	446	+ PyDoc_STR("Determines if this ST object was created from an expression.")},
	447	+ {"issuite", (PyCFunction)parser_issuite, PUBLIC_METHOD_TYPE,
	448	+ PyDoc_STR("Determines if this ST object was created from a suite.")},
	449	+ {"tolist", (PyCFunction)parser_st2list, PUBLIC_METHOD_TYPE,
	450	+ PyDoc_STR("Creates a list-tree representation of this ST.")},
	451	+ {"totuple", (PyCFunction)parser_st2tuple, PUBLIC_METHOD_TYPE,
	452	+ PyDoc_STR("Creates a tuple-tree representation of this ST.")},
	453	+
	454	+ {NULL, NULL, 0, NULL}
	455	+};
	456	+
	457	+
	458	+static PyObject*
	459	+parser_getattr(PyObject self, char name)
	460	+{
	461	+ return (Py_FindMethod(parser_methods, self, name));
	462	+}
	463	+
	464	+
	465	+/* err_string(char* message)
	466	+ *
	467	+ * Sets the error string for an exception of type ParserError.
	468	+ *
	469	+ */
	470	+static void
	471	+err_string(char *message)
	472	+{
	473	+ PyErr_SetString(parser_error, message);
	474	+}
	475	+
	476	+
	477	+/* PyObject* parser_do_parse(PyObject* args, int type)
	478	+ *
	479	+ * Internal function to actually execute the parse and return the result if
	480	+ * successful or set an exception if not.
	481	+ *
	482	+ */
	483	+static PyObject*
	484	+parser_do_parse(PyObject args, PyObject kw, char *argspec, int type)
	485	+{
	486	+ char* string = 0;
	487	+ PyObject* res = 0;
	488	+
	489	+ static char *keywords[] = {"source", NULL};
	490	+
	491	+ if (PyArg_ParseTupleAndKeywords(args, kw, argspec, keywords, &string)) {
	492	+ node* n = PyParser_SimpleParseString(string,
	493	+ (type == PyST_EXPR)
	494	+ ? eval_input : file_input);
	495	+
	496	+ if (n)
	497	+ res = parser_newstobject(n, type);
	498	+ }
	499	+ return (res);
	500	+}
	501	+
	502	+
	503	+/* PyObject* parser_expr(PyObject* self, PyObject* args)
	504	+ * PyObject* parser_suite(PyObject* self, PyObject* args)
	505	+ *
	506	+ * External interfaces to the parser itself. Which is called determines if
	507	+ * the parser attempts to recognize an expression ('eval' form) or statement
	508	+ * suite ('exec' form). The real work is done by parser_do_parse() above.
	509	+ *
	510	+ */
	511	+static PyObject*
	512	+parser_expr(PyST_Object self, PyObject args, PyObject *kw)
	513	+{
	514	+ NOTE(ARGUNUSED(self))
	515	+ return (parser_do_parse(args, kw, "s:expr", PyST_EXPR));
	516	+}
	517	+
	518	+
	519	+static PyObject*
	520	+parser_suite(PyST_Object self, PyObject args, PyObject *kw)
	521	+{
	522	+ NOTE(ARGUNUSED(self))
	523	+ return (parser_do_parse(args, kw, "s:suite", PyST_SUITE));
	524	+}
	525	+
	526	+
	527	+
	528	+/* This is the messy part of the code. Conversion from a tuple to an ST
	529	+ * object requires that the input tuple be valid without having to rely on
	530	+ * catching an exception from the compiler. This is done to allow the
	531	+ * compiler itself to remain fast, since most of its input will come from
	532	+ * the parser directly, and therefore be known to be syntactically correct.
	533	+ * This validation is done to ensure that we don't core dump the compile
	534	+ * phase, returning an exception instead.
	535	+ *
	536	+ * Two aspects can be broken out in this code: creating a node tree from
	537	+ * the tuple passed in, and verifying that it is indeed valid. It may be
	538	+ * advantageous to expand the number of ST types to include funcdefs and
	539	+ * lambdadefs to take advantage of the optimizer, recognizing those STs
	540	+ * here. They are not necessary, and not quite as useful in a raw form.
	541	+ * For now, let's get expressions and suites working reliably.
	542	+ */
	543	+
	544	+
	545	+static node* build_node_tree(PyObject *tuple);
	546	+static int validate_expr_tree(node *tree);
	547	+static int validate_file_input(node *tree);
	548	+static int validate_encoding_decl(node *tree);
	549	+
	550	+/* PyObject* parser_tuple2st(PyObject* self, PyObject* args)
	551	+ *
	552	+ * This is the public function, called from the Python code. It receives a
	553	+ * single tuple object from the caller, and creates an ST object if the
	554	+ * tuple can be validated. It does this by checking the first code of the
	555	+ * tuple, and, if acceptable, builds the internal representation. If this
	556	+ * step succeeds, the internal representation is validated as fully as
	557	+ * possible with the various validate_*() routines defined below.
	558	+ *
	559	+ * This function must be changed if support is to be added for PyST_FRAGMENT
	560	+ * ST objects.
	561	+ *
	562	+ */
	563	+static PyObject*
	564	+parser_tuple2st(PyST_Object self, PyObject args, PyObject *kw)
	565	+{
	566	+ NOTE(ARGUNUSED(self))
	567	+ PyObject *st = 0;
	568	+ PyObject *tuple;
	569	+ node *tree;
	570	+
	571	+ static char *keywords[] = {"sequence", NULL};
	572	+
	573	+ if (!PyArg_ParseTupleAndKeywords(args, kw, "O:sequence2st", keywords,
	574	+ &tuple))
	575	+ return (0);
	576	+ if (!PySequence_Check(tuple)) {
	577	+ PyErr_SetString(PyExc_ValueError,
	578	+ "sequence2st() requires a single sequence argument");
	579	+ return (0);
	580	+ }
	581	+ /*
	582	+ * Convert the tree to the internal form before checking it.
	583	+ */
	584	+ tree = build_node_tree(tuple);
	585	+ if (tree != 0) {
	586	+ int start_sym = TYPE(tree);
	587	+ if (start_sym == eval_input) {
	588	+ /* Might be an eval form. */
	589	+ if (validate_expr_tree(tree))
	590	+ st = parser_newstobject(tree, PyST_EXPR);
	591	+ else
	592	+ PyNode_Free(tree);
	593	+ }
	594	+ else if (start_sym == file_input) {
	595	+ /* This looks like an exec form so far. */
	596	+ if (validate_file_input(tree))
	597	+ st = parser_newstobject(tree, PyST_SUITE);
	598	+ else
	599	+ PyNode_Free(tree);
	600	+ }
	601	+ else if (start_sym == encoding_decl) {
	602	+ /* This looks like an encoding_decl so far. */
	603	+ if (validate_encoding_decl(tree))
	604	+ st = parser_newstobject(tree, PyST_SUITE);
	605	+ else
	606	+ PyNode_Free(tree);
	607	+ }
	608	+ else {
	609	+ /* This is a fragment, at best. */
	610	+ PyNode_Free(tree);
	611	+ err_string("parse tree does not use a valid start symbol");
	612	+ }
	613	+ }
	614	+ /* Make sure we throw an exception on all errors. We should never
	615	+ * get this, but we'd do well to be sure something is done.
	616	+ */
	617	+ if (st == NULL && !PyErr_Occurred())
	618	+ err_string("unspecified ST error occurred");
	619	+
	620	+ return st;
	621	+}
	622	+
	623	+
	624	+/* node* build_node_children()
	625	+ *
	626	+ * Iterate across the children of the current non-terminal node and build
	627	+ * their structures. If successful, return the root of this portion of
	628	+ * the tree, otherwise, 0. Any required exception will be specified already,
	629	+ * and no memory will have been deallocated.
	630	+ *
	631	+ */
	632	+static node*
	633	+build_node_children(PyObject tuple, node root, int *line_num)
	634	+{
	635	+ Py_ssize_t len = PyObject_Size(tuple);
	636	+ Py_ssize_t i;
	637	+ int err;
	638	+
	639	+ for (i = 1; i < len; ++i) {
	640	+ /* elem must always be a sequence, however simple */
	641	+ PyObject* elem = PySequence_GetItem(tuple, i);
	642	+ int ok = elem != NULL;
	643	+ long type = 0;
	644	+ char *strn = 0;
	645	+
	646	+ if (ok)
	647	+ ok = PySequence_Check(elem);
	648	+ if (ok) {
	649	+ PyObject *temp = PySequence_GetItem(elem, 0);
	650	+ if (temp == NULL)
	651	+ ok = 0;
	652	+ else {
	653	+ ok = PyInt_Check(temp);
	654	+ if (ok)
	655	+ type = PyInt_AS_LONG(temp);
	656	+ Py_DECREF(temp);
	657	+ }
	658	+ }
	659	+ if (!ok) {
	660	+ PyObject *err = Py_BuildValue("os", elem,
	661	+ "Illegal node construct.");
	662	+ PyErr_SetObject(parser_error, err);
	663	+ Py_XDECREF(err);
	664	+ Py_XDECREF(elem);
	665	+ return (0);
	666	+ }
	667	+ if (ISTERMINAL(type)) {
	668	+ Py_ssize_t len = PyObject_Size(elem);
	669	+ PyObject *temp;
	670	+
	671	+ if ((len != 2) && (len != 3)) {
	672	+ err_string("terminal nodes must have 2 or 3 entries");
	673	+ return 0;
	674	+ }
	675	+ temp = PySequence_GetItem(elem, 1);
	676	+ if (temp == NULL)
	677	+ return 0;
	678	+ if (!PyString_Check(temp)) {
	679	+ PyErr_Format(parser_error,
	680	+ "second item in terminal node must be a string,"
	681	+ " found %s",
	682	+ temp->ob_type->tp_name);
	683	+ Py_DECREF(temp);
	684	+ return 0;
	685	+ }
	686	+ if (len == 3) {
	687	+ PyObject *o = PySequence_GetItem(elem, 2);
	688	+ if (o != NULL) {
	689	+ if (PyInt_Check(o))
	690	+ *line_num = PyInt_AS_LONG(o);
	691	+ else {
	692	+ PyErr_Format(parser_error,
	693	+ "third item in terminal node must be an"
	694	+ " integer, found %s",
	695	+ temp->ob_type->tp_name);
	696	+ Py_DECREF(o);
	697	+ Py_DECREF(temp);
	698	+ return 0;
	699	+ }
	700	+ Py_DECREF(o);
	701	+ }
	702	+ }
	703	+ len = PyString_GET_SIZE(temp) + 1;
	704	+ strn = (char *)PyObject_MALLOC(len);
	705	+ if (strn != NULL)
	706	+ (void) memcpy(strn, PyString_AS_STRING(temp), len);
	707	+ Py_DECREF(temp);
	708	+ }
	709	+ else if (!ISNONTERMINAL(type)) {
	710	+ /*
	711	+ * It has to be one or the other; this is an error.
	712	+ * Throw an exception.
	713	+ */
	714	+ PyObject *err = Py_BuildValue("os", elem, "unknown node type.");
	715	+ PyErr_SetObject(parser_error, err);
	716	+ Py_XDECREF(err);
	717	+ Py_XDECREF(elem);
	718	+ return (0);
	719	+ }
	720	+ err = PyNode_AddChild(root, type, strn, *line_num, 0);
	721	+ if (err == E_NOMEM) {
	722	+ PyObject_FREE(strn);
	723	+ return (node *) PyErr_NoMemory();
	724	+ }
	725	+ if (err == E_OVERFLOW) {
	726	+ PyObject_FREE(strn);
	727	+ PyErr_SetString(PyExc_ValueError,
	728	+ "unsupported number of child nodes");
	729	+ return NULL;
	730	+ }
	731	+
	732	+ if (ISNONTERMINAL(type)) {
	733	+ node* new_child = CHILD(root, i - 1);
	734	+
	735	+ if (new_child != build_node_children(elem, new_child, line_num)) {
	736	+ Py_XDECREF(elem);
	737	+ return (0);
	738	+ }
	739	+ }
	740	+ else if (type == NEWLINE) { /* It's true: we increment the */
	741	+ ++(line_num); / line number after the newline! */
	742	+ }
	743	+ Py_XDECREF(elem);
	744	+ }
	745	+ return root;
	746	+}
	747	+
	748	+
	749	+static node*
	750	+build_node_tree(PyObject *tuple)
	751	+{
	752	+ node* res = 0;
	753	+ PyObject *temp = PySequence_GetItem(tuple, 0);
	754	+ long num = -1;
	755	+
	756	+ if (temp != NULL)
	757	+ num = PyInt_AsLong(temp);
	758	+ Py_XDECREF(temp);
	759	+ if (ISTERMINAL(num)) {
	760	+ /*
	761	+ * The tuple is simple, but it doesn't start with a start symbol.
	762	+ * Throw an exception now and be done with it.
	763	+ */
	764	+ tuple = Py_BuildValue("os", tuple,
	765	+ "Illegal syntax-tree; cannot start with terminal symbol.");
	766	+ PyErr_SetObject(parser_error, tuple);
	767	+ Py_XDECREF(tuple);
	768	+ }
	769	+ else if (ISNONTERMINAL(num)) {
	770	+ /*
	771	+ * Not efficient, but that can be handled later.
	772	+ */
	773	+ int line_num = 0;
	774	+ PyObject *encoding = NULL;
	775	+
	776	+ if (num == encoding_decl) {
	777	+ encoding = PySequence_GetItem(tuple, 2);
	778	+ /* tuple isn't borrowed anymore here, need to DECREF */
	779	+ tuple = PySequence_GetSlice(tuple, 0, 2);
	780	+ }
	781	+ res = PyNode_New(num);
	782	+ if (res != NULL) {
	783	+ if (res != build_node_children(tuple, res, &line_num)) {
	784	+ PyNode_Free(res);
	785	+ res = NULL;
	786	+ }
	787	+ if (res && encoding) {
	788	+ Py_ssize_t len;
	789	+ len = PyString_GET_SIZE(encoding) + 1;
	790	+ res->n_str = (char *)PyObject_MALLOC(len);
	791	+ if (res->n_str != NULL)
	792	+ (void) memcpy(res->n_str, PyString_AS_STRING(encoding), len);
	793	+ Py_DECREF(encoding);
	794	+ Py_DECREF(tuple);
	795	+ }
	796	+ }
	797	+ }
	798	+ else {
	799	+ /* The tuple is illegal -- if the number is neither TERMINAL nor
	800	+ * NONTERMINAL, we can't use it. Not sure the implementation
	801	+ * allows this condition, but the API doesn't preclude it.
	802	+ */
	803	+ PyObject *err = Py_BuildValue("os", tuple,
	804	+ "Illegal component tuple.");
	805	+ PyErr_SetObject(parser_error, err);
	806	+ Py_XDECREF(err);
	807	+ }
	808	+
	809	+ return (res);
	810	+}
	811	+
	812	+
	813	+/*
	814	+ * Validation routines used within the validation section:
	815	+ */
	816	+static int validate_terminal(node terminal, int type, char string);
	817	+
	818	+#define validate_ampersand(ch) validate_terminal(ch, AMPER, "&")
	819	+#define validate_circumflex(ch) validate_terminal(ch, CIRCUMFLEX, "^")
	820	+#define validate_colon(ch) validate_terminal(ch, COLON, ":")
	821	+#define validate_comma(ch) validate_terminal(ch, COMMA, ",")
	822	+#define validate_dedent(ch) validate_terminal(ch, DEDENT, "")
	823	+#define validate_equal(ch) validate_terminal(ch, EQUAL, "=")
	824	+#define validate_indent(ch) validate_terminal(ch, INDENT, (char*)NULL)
	825	+#define validate_lparen(ch) validate_terminal(ch, LPAR, "(")
	826	+#define validate_newline(ch) validate_terminal(ch, NEWLINE, (char*)NULL)
	827	+#define validate_rparen(ch) validate_terminal(ch, RPAR, ")")
	828	+#define validate_semi(ch) validate_terminal(ch, SEMI, ";")
	829	+#define validate_star(ch) validate_terminal(ch, STAR, "*")
	830	+#define validate_vbar(ch) validate_terminal(ch, VBAR, "\|")
	831	+#define validate_doublestar(ch) validate_terminal(ch, DOUBLESTAR, "**")
	832	+#define validate_dot(ch) validate_terminal(ch, DOT, ".")
	833	+#define validate_at(ch) validate_terminal(ch, AT, "@")
	834	+#define validate_name(ch, str) validate_terminal(ch, NAME, str)
	835	+
	836	+#define VALIDATER(n) static int validate_##n(node *tree)
	837	+
	838	+VALIDATER(node); VALIDATER(small_stmt);
	839	+VALIDATER(class); VALIDATER(node);
	840	+VALIDATER(parameters); VALIDATER(suite);
	841	+VALIDATER(testlist); VALIDATER(varargslist);
	842	+VALIDATER(fpdef); VALIDATER(fplist);
	843	+VALIDATER(stmt); VALIDATER(simple_stmt);
	844	+VALIDATER(expr_stmt); VALIDATER(power);
	845	+VALIDATER(print_stmt); VALIDATER(del_stmt);
	846	+VALIDATER(return_stmt); VALIDATER(list_iter);
	847	+VALIDATER(raise_stmt); VALIDATER(import_stmt);
	848	+VALIDATER(import_name); VALIDATER(import_from);
	849	+VALIDATER(global_stmt); VALIDATER(list_if);
	850	+VALIDATER(assert_stmt); VALIDATER(list_for);
	851	+VALIDATER(exec_stmt); VALIDATER(compound_stmt);
	852	+VALIDATER(while); VALIDATER(for);
	853	+VALIDATER(try); VALIDATER(except_clause);
	854	+VALIDATER(test); VALIDATER(and_test);
	855	+VALIDATER(not_test); VALIDATER(comparison);
	856	+VALIDATER(comp_op); VALIDATER(expr);
	857	+VALIDATER(xor_expr); VALIDATER(and_expr);
	858	+VALIDATER(shift_expr); VALIDATER(arith_expr);
	859	+VALIDATER(term); VALIDATER(factor);
	860	+VALIDATER(atom); VALIDATER(lambdef);
	861	+VALIDATER(trailer); VALIDATER(subscript);
	862	+VALIDATER(subscriptlist); VALIDATER(sliceop);
	863	+VALIDATER(exprlist); VALIDATER(dictmaker);
	864	+VALIDATER(arglist); VALIDATER(argument);
	865	+VALIDATER(listmaker); VALIDATER(yield_stmt);
	866	+VALIDATER(testlist1); VALIDATER(gen_for);
	867	+VALIDATER(gen_iter); VALIDATER(gen_if);
	868	+VALIDATER(testlist_gexp); VALIDATER(yield_expr);
	869	+VALIDATER(yield_or_testlist); VALIDATER(or_test);
	870	+VALIDATER(old_test); VALIDATER(old_lambdef);
	871	+
	872	+#undef VALIDATER
	873	+
	874	+#define is_even(n) (((n) & 1) == 0)
	875	+#define is_odd(n) (((n) & 1) == 1)
	876	+
	877	+
	878	+static int
	879	+validate_ntype(node *n, int t)
	880	+{
	881	+ if (TYPE(n) != t) {
	882	+ PyErr_Format(parser_error, "Expected node type %d, got %d.",
	883	+ t, TYPE(n));
	884	+ return 0;
	885	+ }
	886	+ return 1;
	887	+}
	888	+
	889	+
	890	+/* Verifies that the number of child nodes is exactly 'num', raising
	891	+ * an exception if it isn't. The exception message does not indicate
	892	+ * the exact number of nodes, allowing this to be used to raise the
	893	+ * "right" exception when the wrong number of nodes is present in a
	894	+ * specific variant of a statement's syntax. This is commonly used
	895	+ * in that fashion.
	896	+ */
	897	+static int
	898	+validate_numnodes(node n, int num, const char const name)
	899	+{
	900	+ if (NCH(n) != num) {
	901	+ PyErr_Format(parser_error,
	902	+ "Illegal number of children for %s node.", name);
	903	+ return 0;
	904	+ }
	905	+ return 1;
	906	+}
	907	+
	908	+
	909	+static int
	910	+validate_terminal(node terminal, int type, char string)
	911	+{
	912	+ int res = (validate_ntype(terminal, type)
	913	+ && ((string == 0) \|\| (strcmp(string, STR(terminal)) == 0)));
	914	+
	915	+ if (!res && !PyErr_Occurred()) {
	916	+ PyErr_Format(parser_error,
	917	+ "Illegal terminal: expected \"%s\"", string);
	918	+ }
	919	+ return (res);
	920	+}
	921	+
	922	+
	923	+/* X (',' X) [',']
	924	+ */
	925	+static int
	926	+validate_repeating_list(node tree, int ntype, int (vfunc)(node *),
	927	+ const char *const name)
	928	+{
	929	+ int nch = NCH(tree);
	930	+ int res = (nch && validate_ntype(tree, ntype)
	931	+ && vfunc(CHILD(tree, 0)));
	932	+
	933	+ if (!res && !PyErr_Occurred())
	934	+ (void) validate_numnodes(tree, 1, name);
	935	+ else {
	936	+ if (is_even(nch))
	937	+ res = validate_comma(CHILD(tree, --nch));
	938	+ if (res && nch > 1) {
	939	+ int pos = 1;
	940	+ for ( ; res && pos < nch; pos += 2)
	941	+ res = (validate_comma(CHILD(tree, pos))
	942	+ && vfunc(CHILD(tree, pos + 1)));
	943	+ }
	944	+ }
	945	+ return (res);
	946	+}
	947	+
	948	+
	949	+/* validate_class()
	950	+ *
	951	+ * classdef:
	952	+ * 'class' NAME ['(' testlist ')'] ':' suite
	953	+ */
	954	+static int
	955	+validate_class(node *tree)
	956	+{
	957	+ int nch = NCH(tree);
	958	+ int res = (validate_ntype(tree, classdef) &&
	959	+ ((nch == 4) \|\| (nch == 6) \|\| (nch == 7)));
	960	+
	961	+ if (res) {
	962	+ res = (validate_name(CHILD(tree, 0), "class")
	963	+ && validate_ntype(CHILD(tree, 1), NAME)
	964	+ && validate_colon(CHILD(tree, nch - 2))
	965	+ && validate_suite(CHILD(tree, nch - 1)));
	966	+ }
	967	+ else {
	968	+ (void) validate_numnodes(tree, 4, "class");
	969	+ }
	970	+
	971	+ if (res) {
	972	+ if (nch == 7) {
	973	+ res = ((validate_lparen(CHILD(tree, 2)) &&
	974	+ validate_testlist(CHILD(tree, 3)) &&
	975	+ validate_rparen(CHILD(tree, 4))));
	976	+ }
	977	+ else if (nch == 6) {
	978	+ res = (validate_lparen(CHILD(tree,2)) &&
	979	+ validate_rparen(CHILD(tree,3)));
	980	+ }
	981	+ }
	982	+ return (res);
	983	+}
	984	+
	985	+
	986	+/* if_stmt:
	987	+ * 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
	988	+ */
	989	+static int
	990	+validate_if(node *tree)
	991	+{
	992	+ int nch = NCH(tree);
	993	+ int res = (validate_ntype(tree, if_stmt)
	994	+ && (nch >= 4)
	995	+ && validate_name(CHILD(tree, 0), "if")
	996	+ && validate_test(CHILD(tree, 1))
	997	+ && validate_colon(CHILD(tree, 2))
	998	+ && validate_suite(CHILD(tree, 3)));
	999	+
	1000	+ if (res && ((nch % 4) == 3)) {
	1001	+ /* ... 'else' ':' suite */
	1002	+ res = (validate_name(CHILD(tree, nch - 3), "else")
	1003	+ && validate_colon(CHILD(tree, nch - 2))
	1004	+ && validate_suite(CHILD(tree, nch - 1)));
	1005	+ nch -= 3;
	1006	+ }
	1007	+ else if (!res && !PyErr_Occurred())
	1008	+ (void) validate_numnodes(tree, 4, "if");
	1009	+ if ((nch % 4) != 0)
	1010	+ /* Will catch the case for nch < 4 */
	1011	+ res = validate_numnodes(tree, 0, "if");
	1012	+ else if (res && (nch > 4)) {
	1013	+ /* ... ('elif' test ':' suite)+ ... */
	1014	+ int j = 4;
	1015	+ while ((j < nch) && res) {
	1016	+ res = (validate_name(CHILD(tree, j), "elif")
	1017	+ && validate_colon(CHILD(tree, j + 2))
	1018	+ && validate_test(CHILD(tree, j + 1))
	1019	+ && validate_suite(CHILD(tree, j + 3)));
	1020	+ j += 4;
	1021	+ }
	1022	+ }
	1023	+ return (res);
	1024	+}
	1025	+
	1026	+
	1027	+/* parameters:
	1028	+ * '(' [varargslist] ')'
	1029	+ *
	1030	+ */
	1031	+static int
	1032	+validate_parameters(node *tree)
	1033	+{
	1034	+ int nch = NCH(tree);
	1035	+ int res = validate_ntype(tree, parameters) && ((nch == 2) \|\| (nch == 3));
	1036	+
	1037	+ if (res) {
	1038	+ res = (validate_lparen(CHILD(tree, 0))
	1039	+ && validate_rparen(CHILD(tree, nch - 1)));
	1040	+ if (res && (nch == 3))
	1041	+ res = validate_varargslist(CHILD(tree, 1));
	1042	+ }
	1043	+ else {
	1044	+ (void) validate_numnodes(tree, 2, "parameters");
	1045	+ }
	1046	+ return (res);
	1047	+}
	1048	+
	1049	+
	1050	+/* validate_suite()
	1051	+ *
	1052	+ * suite:
	1053	+ * simple_stmt
	1054	+ * \| NEWLINE INDENT stmt+ DEDENT
	1055	+ */
	1056	+static int
	1057	+validate_suite(node *tree)
	1058	+{
	1059	+ int nch = NCH(tree);
	1060	+ int res = (validate_ntype(tree, suite) && ((nch == 1) \|\| (nch >= 4)));
	1061	+
	1062	+ if (res && (nch == 1))
	1063	+ res = validate_simple_stmt(CHILD(tree, 0));
	1064	+ else if (res) {
	1065	+ /* NEWLINE INDENT stmt+ DEDENT */
	1066	+ res = (validate_newline(CHILD(tree, 0))
	1067	+ && validate_indent(CHILD(tree, 1))
	1068	+ && validate_stmt(CHILD(tree, 2))
	1069	+ && validate_dedent(CHILD(tree, nch - 1)));
	1070	+
	1071	+ if (res && (nch > 4)) {
	1072	+ int i = 3;
	1073	+ --nch; /* forget the DEDENT */
	1074	+ for ( ; res && (i < nch); ++i)
	1075	+ res = validate_stmt(CHILD(tree, i));
	1076	+ }
	1077	+ else if (nch < 4)
	1078	+ res = validate_numnodes(tree, 4, "suite");
	1079	+ }
	1080	+ return (res);
	1081	+}
	1082	+
	1083	+
	1084	+static int
	1085	+validate_testlist(node *tree)
	1086	+{
	1087	+ return (validate_repeating_list(tree, testlist,
	1088	+ validate_test, "testlist"));
	1089	+}
	1090	+
	1091	+
	1092	+static int
	1093	+validate_testlist1(node *tree)
	1094	+{
	1095	+ return (validate_repeating_list(tree, testlist1,
	1096	+ validate_test, "testlist1"));
	1097	+}
	1098	+
	1099	+
	1100	+static int
	1101	+validate_testlist_safe(node *tree)
	1102	+{
	1103	+ return (validate_repeating_list(tree, testlist_safe,
	1104	+ validate_old_test, "testlist_safe"));
	1105	+}
	1106	+
	1107	+
	1108	+/* '' NAME [',' '' NAME] \| '*' NAME
	1109	+ */
	1110	+static int
	1111	+validate_varargslist_trailer(node *tree, int start)
	1112	+{
	1113	+ int nch = NCH(tree);
	1114	+ int res = 0;
	1115	+ int sym;
	1116	+
	1117	+ if (nch <= start) {
	1118	+ err_string("expected variable argument trailer for varargslist");
	1119	+ return 0;
	1120	+ }
	1121	+ sym = TYPE(CHILD(tree, start));
	1122	+ if (sym == STAR) {
	1123	+ /*
	1124	+ * ('' NAME [',' '*' NAME]
	1125	+ */
	1126	+ if (nch-start == 2)
	1127	+ res = validate_name(CHILD(tree, start+1), NULL);
	1128	+ else if (nch-start == 5)
	1129	+ res = (validate_name(CHILD(tree, start+1), NULL)
	1130	+ && validate_comma(CHILD(tree, start+2))
	1131	+ && validate_doublestar(CHILD(tree, start+3))
	1132	+ && validate_name(CHILD(tree, start+4), NULL));
	1133	+ }
	1134	+ else if (sym == DOUBLESTAR) {
	1135	+ /*
	1136	+ * '**' NAME
	1137	+ */
	1138	+ if (nch-start == 2)
	1139	+ res = validate_name(CHILD(tree, start+1), NULL);
	1140	+ }
	1141	+ if (!res)
	1142	+ err_string("illegal variable argument trailer for varargslist");
	1143	+ return res;
	1144	+}
	1145	+
	1146	+
	1147	+/* validate_varargslist()
	1148	+ *
	1149	+ * varargslist:
	1150	+ * (fpdef ['=' test] ',')*
	1151	+ * ('' NAME [',' '*' NAME]
	1152	+ * \| '**' NAME)
	1153	+ * \| fpdef ['=' test] (',' fpdef ['=' test])* [',']
	1154	+ *
	1155	+ */
	1156	+static int
	1157	+validate_varargslist(node *tree)
	1158	+{
	1159	+ int nch = NCH(tree);
	1160	+ int res = validate_ntype(tree, varargslist) && (nch != 0);
	1161	+ int sym;
	1162	+
	1163	+ if (!res)
	1164	+ return 0;
	1165	+ if (nch < 1) {
	1166	+ err_string("varargslist missing child nodes");
	1167	+ return 0;
	1168	+ }
	1169	+ sym = TYPE(CHILD(tree, 0));
	1170	+ if (sym == STAR \|\| sym == DOUBLESTAR)
	1171	+ /* whole thing matches:
	1172	+ * '' NAME [',' '' NAME] \| '*' NAME
	1173	+ */
	1174	+ res = validate_varargslist_trailer(tree, 0);
	1175	+ else if (sym == fpdef) {
	1176	+ int i = 0;
	1177	+
	1178	+ sym = TYPE(CHILD(tree, nch-1));
	1179	+ if (sym == NAME) {
	1180	+ /*
	1181	+ * (fpdef ['=' test] ',')+
	1182	+ * ('' NAME [',' '*' NAME]
	1183	+ * \| '**' NAME)
	1184	+ */
	1185	+ /* skip over (fpdef ['=' test] ',')+ */
	1186	+ while (res && (i+2 <= nch)) {
	1187	+ res = validate_fpdef(CHILD(tree, i));
	1188	+ ++i;
	1189	+ if (res && TYPE(CHILD(tree, i)) == EQUAL && (i+2 <= nch)) {
	1190	+ res = (validate_equal(CHILD(tree, i))
	1191	+ && validate_test(CHILD(tree, i+1)));
	1192	+ if (res)
	1193	+ i += 2;
	1194	+ }
	1195	+ if (res && i < nch) {
	1196	+ res = validate_comma(CHILD(tree, i));
	1197	+ ++i;
	1198	+ if (res && i < nch
	1199	+ && (TYPE(CHILD(tree, i)) == DOUBLESTAR
	1200	+ \|\| TYPE(CHILD(tree, i)) == STAR))
	1201	+ break;
	1202	+ }
	1203	+ }
	1204	+ /* ... '' NAME [',' '' NAME] \| '*' NAME
	1205	+ * i --^^^
	1206	+ */
	1207	+ if (res)
	1208	+ res = validate_varargslist_trailer(tree, i);
	1209	+ }
	1210	+ else {
	1211	+ /*
	1212	+ * fpdef ['=' test] (',' fpdef ['=' test])* [',']
	1213	+ */
	1214	+ /* strip trailing comma node */
	1215	+ if (sym == COMMA) {
	1216	+ res = validate_comma(CHILD(tree, nch-1));
	1217	+ if (!res)
	1218	+ return 0;
	1219	+ --nch;
	1220	+ }
	1221	+ /*
	1222	+ * fpdef ['=' test] (',' fpdef ['=' test])*
	1223	+ */
	1224	+ res = validate_fpdef(CHILD(tree, 0));
	1225	+ ++i;
	1226	+ if (res && (i+2 <= nch) && TYPE(CHILD(tree, i)) == EQUAL) {
	1227	+ res = (validate_equal(CHILD(tree, i))
	1228	+ && validate_test(CHILD(tree, i+1)));
	1229	+ i += 2;
	1230	+ }
	1231	+ /*
	1232	+ * ... (',' fpdef ['=' test])*
	1233	+ * i ---^^^
	1234	+ */
	1235	+ while (res && (nch - i) >= 2) {
	1236	+ res = (validate_comma(CHILD(tree, i))
	1237	+ && validate_fpdef(CHILD(tree, i+1)));
	1238	+ i += 2;
	1239	+ if (res && (nch - i) >= 2 && TYPE(CHILD(tree, i)) == EQUAL) {
	1240	+ res = (validate_equal(CHILD(tree, i))
	1241	+ && validate_test(CHILD(tree, i+1)));
	1242	+ i += 2;
	1243	+ }
	1244	+ }
	1245	+ if (res && nch - i != 0) {
	1246	+ res = 0;
	1247	+ err_string("illegal formation for varargslist");
	1248	+ }
	1249	+ }
	1250	+ }
	1251	+ return res;
	1252	+}
	1253	+
	1254	+
	1255	+/* list_iter: list_for \| list_if
	1256	+ */
	1257	+static int
	1258	+validate_list_iter(node *tree)
	1259	+{
	1260	+ int res = (validate_ntype(tree, list_iter)
	1261	+ && validate_numnodes(tree, 1, "list_iter"));
	1262	+ if (res && TYPE(CHILD(tree, 0)) == list_for)
	1263	+ res = validate_list_for(CHILD(tree, 0));
	1264	+ else
	1265	+ res = validate_list_if(CHILD(tree, 0));
	1266	+
	1267	+ return res;
	1268	+}
	1269	+
	1270	+/* gen_iter: gen_for \| gen_if
	1271	+ */
	1272	+static int
	1273	+validate_gen_iter(node *tree)
	1274	+{
	1275	+ int res = (validate_ntype(tree, gen_iter)
	1276	+ && validate_numnodes(tree, 1, "gen_iter"));
	1277	+ if (res && TYPE(CHILD(tree, 0)) == gen_for)
	1278	+ res = validate_gen_for(CHILD(tree, 0));
	1279	+ else
	1280	+ res = validate_gen_if(CHILD(tree, 0));
	1281	+
	1282	+ return res;
	1283	+}
	1284	+
	1285	+/* list_for: 'for' exprlist 'in' testlist [list_iter]
	1286	+ */
	1287	+static int
	1288	+validate_list_for(node *tree)
	1289	+{
	1290	+ int nch = NCH(tree);
	1291	+ int res;
	1292	+
	1293	+ if (nch == 5)
	1294	+ res = validate_list_iter(CHILD(tree, 4));
	1295	+ else
	1296	+ res = validate_numnodes(tree, 4, "list_for");
	1297	+
	1298	+ if (res)
	1299	+ res = (validate_name(CHILD(tree, 0), "for")
	1300	+ && validate_exprlist(CHILD(tree, 1))
	1301	+ && validate_name(CHILD(tree, 2), "in")
	1302	+ && validate_testlist_safe(CHILD(tree, 3)));
	1303	+
	1304	+ return res;
	1305	+}
	1306	+
	1307	+/* gen_for: 'for' exprlist 'in' test [gen_iter]
	1308	+ */
	1309	+static int
	1310	+validate_gen_for(node *tree)
	1311	+{
	1312	+ int nch = NCH(tree);
	1313	+ int res;
	1314	+
	1315	+ if (nch == 5)
	1316	+ res = validate_gen_iter(CHILD(tree, 4));
	1317	+ else
	1318	+ res = validate_numnodes(tree, 4, "gen_for");
	1319	+
	1320	+ if (res)
	1321	+ res = (validate_name(CHILD(tree, 0), "for")
	1322	+ && validate_exprlist(CHILD(tree, 1))
	1323	+ && validate_name(CHILD(tree, 2), "in")
	1324	+ && validate_or_test(CHILD(tree, 3)));
	1325	+
	1326	+ return res;
	1327	+}
	1328	+
	1329	+/* list_if: 'if' old_test [list_iter]
	1330	+ */
	1331	+static int
	1332	+validate_list_if(node *tree)
	1333	+{
	1334	+ int nch = NCH(tree);
	1335	+ int res;
	1336	+
	1337	+ if (nch == 3)
	1338	+ res = validate_list_iter(CHILD(tree, 2));
	1339	+ else
	1340	+ res = validate_numnodes(tree, 2, "list_if");
	1341	+
	1342	+ if (res)
	1343	+ res = (validate_name(CHILD(tree, 0), "if")
	1344	+ && validate_old_test(CHILD(tree, 1)));
	1345	+
	1346	+ return res;
	1347	+}
	1348	+
	1349	+/* gen_if: 'if' old_test [gen_iter]
	1350	+ */
	1351	+static int
	1352	+validate_gen_if(node *tree)
	1353	+{
	1354	+ int nch = NCH(tree);
	1355	+ int res;
	1356	+
	1357	+ if (nch == 3)
	1358	+ res = validate_gen_iter(CHILD(tree, 2));
	1359	+ else
	1360	+ res = validate_numnodes(tree, 2, "gen_if");
	1361	+
	1362	+ if (res)
	1363	+ res = (validate_name(CHILD(tree, 0), "if")
	1364	+ && validate_old_test(CHILD(tree, 1)));
	1365	+
	1366	+ return res;
	1367	+}
	1368	+
	1369	+/* validate_fpdef()
	1370	+ *
	1371	+ * fpdef:
	1372	+ * NAME
	1373	+ * \| '(' fplist ')'
	1374	+ */
	1375	+static int
	1376	+validate_fpdef(node *tree)
	1377	+{
	1378	+ int nch = NCH(tree);
	1379	+ int res = validate_ntype(tree, fpdef);
	1380	+
	1381	+ if (res) {
	1382	+ if (nch == 1)
	1383	+ res = validate_ntype(CHILD(tree, 0), NAME);
	1384	+ else if (nch == 3)
	1385	+ res = (validate_lparen(CHILD(tree, 0))
	1386	+ && validate_fplist(CHILD(tree, 1))
	1387	+ && validate_rparen(CHILD(tree, 2)));
	1388	+ else
	1389	+ res = validate_numnodes(tree, 1, "fpdef");
	1390	+ }
	1391	+ return (res);
	1392	+}
	1393	+
	1394	+
	1395	+static int
	1396	+validate_fplist(node *tree)
	1397	+{
	1398	+ return (validate_repeating_list(tree, fplist,
	1399	+ validate_fpdef, "fplist"));
	1400	+}
	1401	+
	1402	+
	1403	+/* simple_stmt \| compound_stmt
	1404	+ *
	1405	+ */
	1406	+static int
	1407	+validate_stmt(node *tree)
	1408	+{
	1409	+ int res = (validate_ntype(tree, stmt)
	1410	+ && validate_numnodes(tree, 1, "stmt"));
	1411	+
	1412	+ if (res) {
	1413	+ tree = CHILD(tree, 0);
	1414	+
	1415	+ if (TYPE(tree) == simple_stmt)
	1416	+ res = validate_simple_stmt(tree);
	1417	+ else
	1418	+ res = validate_compound_stmt(tree);
	1419	+ }
	1420	+ return (res);
	1421	+}
	1422	+
	1423	+
	1424	+/* small_stmt (';' small_stmt)* [';'] NEWLINE
	1425	+ *
	1426	+ */
	1427	+static int
	1428	+validate_simple_stmt(node *tree)
	1429	+{
	1430	+ int nch = NCH(tree);
	1431	+ int res = (validate_ntype(tree, simple_stmt)
	1432	+ && (nch >= 2)
	1433	+ && validate_small_stmt(CHILD(tree, 0))
	1434	+ && validate_newline(CHILD(tree, nch - 1)));
	1435	+
	1436	+ if (nch < 2)
	1437	+ res = validate_numnodes(tree, 2, "simple_stmt");
	1438	+ --nch; /* forget the NEWLINE */
	1439	+ if (res && is_even(nch))
	1440	+ res = validate_semi(CHILD(tree, --nch));
	1441	+ if (res && (nch > 2)) {
	1442	+ int i;
	1443	+
	1444	+ for (i = 1; res && (i < nch); i += 2)
	1445	+ res = (validate_semi(CHILD(tree, i))
	1446	+ && validate_small_stmt(CHILD(tree, i + 1)));
	1447	+ }
	1448	+ return (res);
	1449	+}
	1450	+
	1451	+
	1452	+static int
	1453	+validate_small_stmt(node *tree)
	1454	+{
	1455	+ int nch = NCH(tree);
	1456	+ int res = validate_numnodes(tree, 1, "small_stmt");
	1457	+
	1458	+ if (res) {
	1459	+ int ntype = TYPE(CHILD(tree, 0));
	1460	+
	1461	+ if ( (ntype == expr_stmt)
	1462	+ \|\| (ntype == print_stmt)
	1463	+ \|\| (ntype == del_stmt)
	1464	+ \|\| (ntype == pass_stmt)
	1465	+ \|\| (ntype == flow_stmt)
	1466	+ \|\| (ntype == import_stmt)
	1467	+ \|\| (ntype == global_stmt)
	1468	+ \|\| (ntype == assert_stmt)
	1469	+ \|\| (ntype == exec_stmt))
	1470	+ res = validate_node(CHILD(tree, 0));
	1471	+ else {
	1472	+ res = 0;
	1473	+ err_string("illegal small_stmt child type");
	1474	+ }
	1475	+ }
	1476	+ else if (nch == 1) {
	1477	+ res = 0;
	1478	+ PyErr_Format(parser_error,
	1479	+ "Unrecognized child node of small_stmt: %d.",
	1480	+ TYPE(CHILD(tree, 0)));
	1481	+ }
	1482	+ return (res);
	1483	+}
	1484	+
	1485	+
	1486	+/* compound_stmt:
	1487	+ * if_stmt \| while_stmt \| for_stmt \| try_stmt \| funcdef \| classdef
	1488	+ */
	1489	+static int
	1490	+validate_compound_stmt(node *tree)
	1491	+{
	1492	+ int res = (validate_ntype(tree, compound_stmt)
	1493	+ && validate_numnodes(tree, 1, "compound_stmt"));
	1494	+ int ntype;
	1495	+
	1496	+ if (!res)
	1497	+ return (0);
	1498	+
	1499	+ tree = CHILD(tree, 0);
	1500	+ ntype = TYPE(tree);
	1501	+ if ( (ntype == if_stmt)
	1502	+ \|\| (ntype == while_stmt)
	1503	+ \|\| (ntype == for_stmt)
	1504	+ \|\| (ntype == try_stmt)
	1505	+ \|\| (ntype == funcdef)
	1506	+ \|\| (ntype == classdef))
	1507	+ res = validate_node(tree);
	1508	+ else {
	1509	+ res = 0;
	1510	+ PyErr_Format(parser_error,
	1511	+ "Illegal compound statement type: %d.", TYPE(tree));
	1512	+ }
	1513	+ return (res);
	1514	+}
	1515	+
	1516	+
	1517	+static int
	1518	+validate_yield_or_testlist(node *tree)
	1519	+{
	1520	+ if (TYPE(tree) == yield_expr)
	1521	+ return validate_yield_expr(tree);
	1522	+ else
	1523	+ return validate_testlist(tree);
	1524	+}
	1525	+
	1526	+static int
	1527	+validate_expr_stmt(node *tree)
	1528	+{
	1529	+ int j;
	1530	+ int nch = NCH(tree);
	1531	+ int res = (validate_ntype(tree, expr_stmt)
	1532	+ && is_odd(nch)
	1533	+ && validate_testlist(CHILD(tree, 0)));
	1534	+
	1535	+ if (res && nch == 3
	1536	+ && TYPE(CHILD(tree, 1)) == augassign) {
	1537	+ res = validate_numnodes(CHILD(tree, 1), 1, "augassign")
	1538	+ && validate_yield_or_testlist(CHILD(tree, 2));
	1539	+
	1540	+ if (res) {
	1541	+ char *s = STR(CHILD(CHILD(tree, 1), 0));
	1542	+
	1543	+ res = (strcmp(s, "+=") == 0
	1544	+ \|\| strcmp(s, "-=") == 0
	1545	+ \|\| strcmp(s, "*=") == 0
	1546	+ \|\| strcmp(s, "/=") == 0
	1547	+ \|\| strcmp(s, "//=") == 0
	1548	+ \|\| strcmp(s, "%=") == 0
	1549	+ \|\| strcmp(s, "&=") == 0
	1550	+ \|\| strcmp(s, "\|=") == 0
	1551	+ \|\| strcmp(s, "^=") == 0
	1552	+ \|\| strcmp(s, "<<=") == 0
	1553	+ \|\| strcmp(s, ">>=") == 0
	1554	+ \|\| strcmp(s, "**=") == 0);
	1555	+ if (!res)
	1556	+ err_string("illegal augmmented assignment operator");
	1557	+ }
	1558	+ }
	1559	+ else {
	1560	+ for (j = 1; res && (j < nch); j += 2)
	1561	+ res = validate_equal(CHILD(tree, j))
	1562	+ && validate_yield_or_testlist(CHILD(tree, j + 1));
	1563	+ }
	1564	+ return (res);
	1565	+}
	1566	+
	1567	+
	1568	+/* print_stmt:
	1569	+ *
	1570	+ * 'print' ( [ test (',' test)* [','] ]
	1571	+ * \| '>>' test [ (',' test)+ [','] ] )
	1572	+ */
	1573	+static int
	1574	+validate_print_stmt(node *tree)
	1575	+{
	1576	+ int nch = NCH(tree);
	1577	+ int res = (validate_ntype(tree, print_stmt)
	1578	+ && (nch > 0)
	1579	+ && validate_name(CHILD(tree, 0), "print"));
	1580	+
	1581	+ if (res && nch > 1) {
	1582	+ int sym = TYPE(CHILD(tree, 1));
	1583	+ int i = 1;
	1584	+ int allow_trailing_comma = 1;
	1585	+
	1586	+ if (sym == test)
	1587	+ res = validate_test(CHILD(tree, i++));
	1588	+ else {
	1589	+ if (nch < 3)
	1590	+ res = validate_numnodes(tree, 3, "print_stmt");
	1591	+ else {
	1592	+ res = (validate_ntype(CHILD(tree, i), RIGHTSHIFT)
	1593	+ && validate_test(CHILD(tree, i+1)));
	1594	+ i += 2;
	1595	+ allow_trailing_comma = 0;
	1596	+ }
	1597	+ }
	1598	+ if (res) {
	1599	+ /* ... (',' test)* [','] */
	1600	+ while (res && i+2 <= nch) {
	1601	+ res = (validate_comma(CHILD(tree, i))
	1602	+ && validate_test(CHILD(tree, i+1)));
	1603	+ allow_trailing_comma = 1;
	1604	+ i += 2;
	1605	+ }
	1606	+ if (res && !allow_trailing_comma)
	1607	+ res = validate_numnodes(tree, i, "print_stmt");
	1608	+ else if (res && i < nch)
	1609	+ res = validate_comma(CHILD(tree, i));
	1610	+ }
	1611	+ }
	1612	+ return (res);
	1613	+}
	1614	+
	1615	+
	1616	+static int
	1617	+validate_del_stmt(node *tree)
	1618	+{
	1619	+ return (validate_numnodes(tree, 2, "del_stmt")
	1620	+ && validate_name(CHILD(tree, 0), "del")
	1621	+ && validate_exprlist(CHILD(tree, 1)));
	1622	+}
	1623	+
	1624	+
	1625	+static int
	1626	+validate_return_stmt(node *tree)
	1627	+{
	1628	+ int nch = NCH(tree);
	1629	+ int res = (validate_ntype(tree, return_stmt)
	1630	+ && ((nch == 1) \|\| (nch == 2))
	1631	+ && validate_name(CHILD(tree, 0), "return"));
	1632	+
	1633	+ if (res && (nch == 2))
	1634	+ res = validate_testlist(CHILD(tree, 1));
	1635	+
	1636	+ return (res);
	1637	+}
	1638	+
	1639	+
	1640	+static int
	1641	+validate_raise_stmt(node *tree)
	1642	+{
	1643	+ int nch = NCH(tree);
	1644	+ int res = (validate_ntype(tree, raise_stmt)
	1645	+ && ((nch == 1) \|\| (nch == 2) \|\| (nch == 4) \|\| (nch == 6)));
	1646	+
	1647	+ if (res) {
	1648	+ res = validate_name(CHILD(tree, 0), "raise");
	1649	+ if (res && (nch >= 2))
	1650	+ res = validate_test(CHILD(tree, 1));
	1651	+ if (res && nch > 2) {
	1652	+ res = (validate_comma(CHILD(tree, 2))
	1653	+ && validate_test(CHILD(tree, 3)));
	1654	+ if (res && (nch > 4))
	1655	+ res = (validate_comma(CHILD(tree, 4))
	1656	+ && validate_test(CHILD(tree, 5)));
	1657	+ }
	1658	+ }
	1659	+ else
	1660	+ (void) validate_numnodes(tree, 2, "raise");
	1661	+ if (res && (nch == 4))
	1662	+ res = (validate_comma(CHILD(tree, 2))
	1663	+ && validate_test(CHILD(tree, 3)));
	1664	+
	1665	+ return (res);
	1666	+}
	1667	+
	1668	+
	1669	+/* yield_expr: 'yield' [testlist]
	1670	+ */
	1671	+static int
	1672	+validate_yield_expr(node *tree)
	1673	+{
	1674	+ int nch = NCH(tree);
	1675	+ int res = (validate_ntype(tree, yield_expr)
	1676	+ && ((nch == 1) \|\| (nch == 2))
	1677	+ && validate_name(CHILD(tree, 0), "yield"));
	1678	+
	1679	+ if (res && (nch == 2))
	1680	+ res = validate_testlist(CHILD(tree, 1));
	1681	+
	1682	+ return (res);
	1683	+}
	1684	+
	1685	+
	1686	+/* yield_stmt: yield_expr
	1687	+ */
	1688	+static int
	1689	+validate_yield_stmt(node *tree)
	1690	+{
	1691	+ return (validate_ntype(tree, yield_stmt)
	1692	+ && validate_numnodes(tree, 1, "yield_stmt")
	1693	+ && validate_yield_expr(CHILD(tree, 0)));
	1694	+}
	1695	+
	1696	+
	1697	+static int
	1698	+validate_import_as_name(node *tree)
	1699	+{
	1700	+ int nch = NCH(tree);
	1701	+ int ok = validate_ntype(tree, import_as_name);
	1702	+
	1703	+ if (ok) {
	1704	+ if (nch == 1)
	1705	+ ok = validate_name(CHILD(tree, 0), NULL);
	1706	+ else if (nch == 3)
	1707	+ ok = (validate_name(CHILD(tree, 0), NULL)
	1708	+ && validate_name(CHILD(tree, 1), "as")
	1709	+ && validate_name(CHILD(tree, 2), NULL));
	1710	+ else
	1711	+ ok = validate_numnodes(tree, 3, "import_as_name");
	1712	+ }
	1713	+ return ok;
	1714	+}
	1715	+
	1716	+
	1717	+/* dotted_name: NAME ("." NAME)*
	1718	+ */
	1719	+static int
	1720	+validate_dotted_name(node *tree)
	1721	+{
	1722	+ int nch = NCH(tree);
	1723	+ int res = (validate_ntype(tree, dotted_name)
	1724	+ && is_odd(nch)
	1725	+ && validate_name(CHILD(tree, 0), NULL));
	1726	+ int i;
	1727	+
	1728	+ for (i = 1; res && (i < nch); i += 2) {
	1729	+ res = (validate_dot(CHILD(tree, i))
	1730	+ && validate_name(CHILD(tree, i+1), NULL));
	1731	+ }
	1732	+ return res;
	1733	+}
	1734	+
	1735	+
	1736	+/* dotted_as_name: dotted_name [NAME NAME]
	1737	+ */
	1738	+static int
	1739	+validate_dotted_as_name(node *tree)
	1740	+{
	1741	+ int nch = NCH(tree);
	1742	+ int res = validate_ntype(tree, dotted_as_name);
	1743	+
	1744	+ if (res) {
	1745	+ if (nch == 1)
	1746	+ res = validate_dotted_name(CHILD(tree, 0));
	1747	+ else if (nch == 3)
	1748	+ res = (validate_dotted_name(CHILD(tree, 0))
	1749	+ && validate_name(CHILD(tree, 1), "as")
	1750	+ && validate_name(CHILD(tree, 2), NULL));
	1751	+ else {
	1752	+ res = 0;
	1753	+ err_string("illegal number of children for dotted_as_name");
	1754	+ }
	1755	+ }
	1756	+ return res;
	1757	+}
	1758	+
	1759	+
	1760	+/* dotted_as_name (',' dotted_as_name)* */
	1761	+static int
	1762	+validate_dotted_as_names(node *tree)
	1763	+{
	1764	+ int nch = NCH(tree);
	1765	+ int res = is_odd(nch) && validate_dotted_as_name(CHILD(tree, 0));
	1766	+ int i;
	1767	+
	1768	+ for (i = 1; res && (i < nch); i += 2)
	1769	+ res = (validate_comma(CHILD(tree, i))
	1770	+ && validate_dotted_as_name(CHILD(tree, i + 1)));
	1771	+ return (res);
	1772	+}
	1773	+
	1774	+
	1775	+/* import_as_name (',' import_as_name)* [','] */
	1776	+static int
	1777	+validate_import_as_names(node *tree)
	1778	+{
	1779	+ int nch = NCH(tree);
	1780	+ int res = validate_import_as_name(CHILD(tree, 0));
	1781	+ int i;
	1782	+
	1783	+ for (i = 1; res && (i + 1 < nch); i += 2)
	1784	+ res = (validate_comma(CHILD(tree, i))
	1785	+ && validate_import_as_name(CHILD(tree, i + 1)));
	1786	+ return (res);
	1787	+}
	1788	+
	1789	+
	1790	+/* 'import' dotted_as_names */
	1791	+static int
	1792	+validate_import_name(node *tree)
	1793	+{
	1794	+ return (validate_ntype(tree, import_name)
	1795	+ && validate_numnodes(tree, 2, "import_name")
	1796	+ && validate_name(CHILD(tree, 0), "import")
	1797	+ && validate_dotted_as_names(CHILD(tree, 1)));
	1798	+}
	1799	+
	1800	+/* Helper function to count the number of leading dots in
	1801	+ * 'from ...module import name'
	1802	+ */
	1803	+static int
	1804	+count_from_dots(node *tree)
	1805	+{
	1806	+ int i;
	1807	+ for (i = 0; i < NCH(tree); i++)
	1808	+ if (TYPE(CHILD(tree, i)) != DOT)
	1809	+ break;
	1810	+ return i;
	1811	+}
	1812	+
	1813	+/* 'from' ('.'* dotted_name \| '.') 'import' ('*' \| '(' import_as_names ')' \|
	1814	+ * import_as_names
	1815	+ */
	1816	+static int
	1817	+validate_import_from(node *tree)
	1818	+{
	1819	+ int nch = NCH(tree);
	1820	+ int ndots = count_from_dots(tree);
	1821	+ int havename = (TYPE(CHILD(tree, ndots + 1)) == dotted_name);
	1822	+ int offset = ndots + havename;
	1823	+ int res = validate_ntype(tree, import_from)
	1824	+ && (nch >= 4 + ndots)
	1825	+ && validate_name(CHILD(tree, 0), "from")
	1826	+ && (!havename \|\| validate_dotted_name(CHILD(tree, ndots + 1)))
	1827	+ && validate_name(CHILD(tree, offset + 1), "import");
	1828	+
	1829	+ if (res && TYPE(CHILD(tree, offset + 2)) == LPAR)
	1830	+ res = ((nch == offset + 5)
	1831	+ && validate_lparen(CHILD(tree, offset + 2))
	1832	+ && validate_import_as_names(CHILD(tree, offset + 3))
	1833	+ && validate_rparen(CHILD(tree, offset + 4)));
	1834	+ else if (res && TYPE(CHILD(tree, offset + 2)) != STAR)
	1835	+ res = validate_import_as_names(CHILD(tree, offset + 2));
	1836	+ return (res);
	1837	+}
	1838	+
	1839	+
	1840	+/* import_stmt: import_name \| import_from */
	1841	+static int
	1842	+validate_import_stmt(node *tree)
	1843	+{
	1844	+ int nch = NCH(tree);
	1845	+ int res = validate_numnodes(tree, 1, "import_stmt");
	1846	+
	1847	+ if (res) {
	1848	+ int ntype = TYPE(CHILD(tree, 0));
	1849	+
	1850	+ if (ntype == import_name \|\| ntype == import_from)
	1851	+ res = validate_node(CHILD(tree, 0));
	1852	+ else {
	1853	+ res = 0;
	1854	+ err_string("illegal import_stmt child type");
	1855	+ }
	1856	+ }
	1857	+ else if (nch == 1) {
	1858	+ res = 0;
	1859	+ PyErr_Format(parser_error,
	1860	+ "Unrecognized child node of import_stmt: %d.",
	1861	+ TYPE(CHILD(tree, 0)));
	1862	+ }
	1863	+ return (res);
	1864	+}
	1865	+
	1866	+
	1867	+
	1868	+
	1869	+static int
	1870	+validate_global_stmt(node *tree)
	1871	+{
	1872	+ int j;
	1873	+ int nch = NCH(tree);
	1874	+ int res = (validate_ntype(tree, global_stmt)
	1875	+ && is_even(nch) && (nch >= 2));
	1876	+
	1877	+ if (!res && !PyErr_Occurred())
	1878	+ err_string("illegal global statement");
	1879	+
	1880	+ if (res)
	1881	+ res = (validate_name(CHILD(tree, 0), "global")
	1882	+ && validate_ntype(CHILD(tree, 1), NAME));
	1883	+ for (j = 2; res && (j < nch); j += 2)
	1884	+ res = (validate_comma(CHILD(tree, j))
	1885	+ && validate_ntype(CHILD(tree, j + 1), NAME));
	1886	+
	1887	+ return (res);
	1888	+}
	1889	+
	1890	+
	1891	+/* exec_stmt:
	1892	+ *
	1893	+ * 'exec' expr ['in' test [',' test]]
	1894	+ */
	1895	+static int
	1896	+validate_exec_stmt(node *tree)
	1897	+{
	1898	+ int nch = NCH(tree);
	1899	+ int res = (validate_ntype(tree, exec_stmt)
	1900	+ && ((nch == 2) \|\| (nch == 4) \|\| (nch == 6))
	1901	+ && validate_name(CHILD(tree, 0), "exec")
	1902	+ && validate_expr(CHILD(tree, 1)));
	1903	+
	1904	+ if (!res && !PyErr_Occurred())
	1905	+ err_string("illegal exec statement");
	1906	+ if (res && (nch > 2))
	1907	+ res = (validate_name(CHILD(tree, 2), "in")
	1908	+ && validate_test(CHILD(tree, 3)));
	1909	+ if (res && (nch == 6))
	1910	+ res = (validate_comma(CHILD(tree, 4))
	1911	+ && validate_test(CHILD(tree, 5)));
	1912	+
	1913	+ return (res);
	1914	+}
	1915	+
	1916	+
	1917	+/* assert_stmt:
	1918	+ *
	1919	+ * 'assert' test [',' test]
	1920	+ */
	1921	+static int
	1922	+validate_assert_stmt(node *tree)
	1923	+{
	1924	+ int nch = NCH(tree);
	1925	+ int res = (validate_ntype(tree, assert_stmt)
	1926	+ && ((nch == 2) \|\| (nch == 4))
	1927	+ && (validate_name(CHILD(tree, 0), "assert"))
	1928	+ && validate_test(CHILD(tree, 1)));
	1929	+
	1930	+ if (!res && !PyErr_Occurred())
	1931	+ err_string("illegal assert statement");
	1932	+ if (res && (nch > 2))
	1933	+ res = (validate_comma(CHILD(tree, 2))
	1934	+ && validate_test(CHILD(tree, 3)));
	1935	+
	1936	+ return (res);
	1937	+}
	1938	+
	1939	+
	1940	+static int
	1941	+validate_while(node *tree)
	1942	+{
	1943	+ int nch = NCH(tree);
	1944	+ int res = (validate_ntype(tree, while_stmt)
	1945	+ && ((nch == 4) \|\| (nch == 7))
	1946	+ && validate_name(CHILD(tree, 0), "while")
	1947	+ && validate_test(CHILD(tree, 1))
	1948	+ && validate_colon(CHILD(tree, 2))
	1949	+ && validate_suite(CHILD(tree, 3)));
	1950	+
	1951	+ if (res && (nch == 7))
	1952	+ res = (validate_name(CHILD(tree, 4), "else")
	1953	+ && validate_colon(CHILD(tree, 5))
	1954	+ && validate_suite(CHILD(tree, 6)));
	1955	+
	1956	+ return (res);
	1957	+}
	1958	+
	1959	+
	1960	+static int
	1961	+validate_for(node *tree)
	1962	+{
	1963	+ int nch = NCH(tree);
	1964	+ int res = (validate_ntype(tree, for_stmt)
	1965	+ && ((nch == 6) \|\| (nch == 9))
	1966	+ && validate_name(CHILD(tree, 0), "for")
	1967	+ && validate_exprlist(CHILD(tree, 1))
	1968	+ && validate_name(CHILD(tree, 2), "in")
	1969	+ && validate_testlist(CHILD(tree, 3))
	1970	+ && validate_colon(CHILD(tree, 4))
	1971	+ && validate_suite(CHILD(tree, 5)));
	1972	+
	1973	+ if (res && (nch == 9))
	1974	+ res = (validate_name(CHILD(tree, 6), "else")
	1975	+ && validate_colon(CHILD(tree, 7))
	1976	+ && validate_suite(CHILD(tree, 8)));
	1977	+
	1978	+ return (res);
	1979	+}
	1980	+
	1981	+
	1982	+/* try_stmt:
	1983	+ * 'try' ':' suite (except_clause ':' suite)+ ['else' ':' suite]
	1984	+ * \| 'try' ':' suite 'finally' ':' suite
	1985	+ *
	1986	+ */
	1987	+static int
	1988	+validate_try(node *tree)
	1989	+{
	1990	+ int nch = NCH(tree);
	1991	+ int pos = 3;
	1992	+ int res = (validate_ntype(tree, try_stmt)
	1993	+ && (nch >= 6) && ((nch % 3) == 0));
	1994	+
	1995	+ if (res)
	1996	+ res = (validate_name(CHILD(tree, 0), "try")
	1997	+ && validate_colon(CHILD(tree, 1))
	1998	+ && validate_suite(CHILD(tree, 2))
	1999	+ && validate_colon(CHILD(tree, nch - 2))
	2000	+ && validate_suite(CHILD(tree, nch - 1)));
	2001	+ else if (!PyErr_Occurred()) {
	2002	+ const char* name = "except";
	2003	+ if (TYPE(CHILD(tree, nch - 3)) != except_clause)
	2004	+ name = STR(CHILD(tree, nch - 3));
	2005	+
	2006	+ PyErr_Format(parser_error,
	2007	+ "Illegal number of children for try/%s node.", name);
	2008	+ }
	2009	+ /* Skip past except_clause sections: */
	2010	+ while (res && (TYPE(CHILD(tree, pos)) == except_clause)) {
	2011	+ res = (validate_except_clause(CHILD(tree, pos))
	2012	+ && validate_colon(CHILD(tree, pos + 1))
	2013	+ && validate_suite(CHILD(tree, pos + 2)));
	2014	+ pos += 3;
	2015	+ }
	2016	+ if (res && (pos < nch)) {
	2017	+ res = validate_ntype(CHILD(tree, pos), NAME);
	2018	+ if (res && (strcmp(STR(CHILD(tree, pos)), "finally") == 0))
	2019	+ res = (validate_numnodes(tree, 6, "try/finally")
	2020	+ && validate_colon(CHILD(tree, 4))
	2021	+ && validate_suite(CHILD(tree, 5)));
	2022	+ else if (res) {
	2023	+ if (nch == (pos + 3)) {
	2024	+ res = ((strcmp(STR(CHILD(tree, pos)), "except") == 0)
	2025	+ \|\| (strcmp(STR(CHILD(tree, pos)), "else") == 0));
	2026	+ if (!res)
	2027	+ err_string("illegal trailing triple in try statement");
	2028	+ }
	2029	+ else if (nch == (pos + 6)) {
	2030	+ res = (validate_name(CHILD(tree, pos), "except")
	2031	+ && validate_colon(CHILD(tree, pos + 1))
	2032	+ && validate_suite(CHILD(tree, pos + 2))
	2033	+ && validate_name(CHILD(tree, pos + 3), "else"));
	2034	+ }
	2035	+ else
	2036	+ res = validate_numnodes(tree, pos + 3, "try/except");
	2037	+ }
	2038	+ }
	2039	+ return (res);
	2040	+}
	2041	+
	2042	+
	2043	+static int
	2044	+validate_except_clause(node *tree)
	2045	+{
	2046	+ int nch = NCH(tree);
	2047	+ int res = (validate_ntype(tree, except_clause)
	2048	+ && ((nch == 1) \|\| (nch == 2) \|\| (nch == 4))
	2049	+ && validate_name(CHILD(tree, 0), "except"));
	2050	+
	2051	+ if (res && (nch > 1))
	2052	+ res = validate_test(CHILD(tree, 1));
	2053	+ if (res && (nch == 4))
	2054	+ res = (validate_comma(CHILD(tree, 2))
	2055	+ && validate_test(CHILD(tree, 3)));
	2056	+
	2057	+ return (res);
	2058	+}
	2059	+
	2060	+
	2061	+static int
	2062	+validate_test(node *tree)
	2063	+{
	2064	+ int nch = NCH(tree);
	2065	+ int res = validate_ntype(tree, test) && is_odd(nch);
	2066	+
	2067	+ if (res && (TYPE(CHILD(tree, 0)) == lambdef))
	2068	+ res = ((nch == 1)
	2069	+ && validate_lambdef(CHILD(tree, 0)));
	2070	+ else if (res) {
	2071	+ res = validate_or_test(CHILD(tree, 0));
	2072	+ res = (res && (nch == 1 \|\| (nch == 5 &&
	2073	+ validate_name(CHILD(tree, 1), "if") &&
	2074	+ validate_or_test(CHILD(tree, 2)) &&
	2075	+ validate_name(CHILD(tree, 3), "else") &&
	2076	+ validate_test(CHILD(tree, 4)))));
	2077	+ }
	2078	+ return (res);
	2079	+}
	2080	+
	2081	+static int
	2082	+validate_old_test(node *tree)
	2083	+{
	2084	+ int nch = NCH(tree);
	2085	+ int res = validate_ntype(tree, old_test) && (nch == 1);
	2086	+
	2087	+ if (res && (TYPE(CHILD(tree, 0)) == old_lambdef))
	2088	+ res = (validate_old_lambdef(CHILD(tree, 0)));
	2089	+ else if (res) {
	2090	+ res = (validate_or_test(CHILD(tree, 0)));
	2091	+ }
	2092	+ return (res);
	2093	+}
	2094	+
	2095	+static int
	2096	+validate_or_test(node *tree)
	2097	+{
	2098	+ int nch = NCH(tree);
	2099	+ int res = validate_ntype(tree, or_test) && is_odd(nch);
	2100	+
	2101	+ if (res) {
	2102	+ int pos;
	2103	+ res = validate_and_test(CHILD(tree, 0));
	2104	+ for (pos = 1; res && (pos < nch); pos += 2)
	2105	+ res = (validate_name(CHILD(tree, pos), "or")
	2106	+ && validate_and_test(CHILD(tree, pos + 1)));
	2107	+ }
	2108	+ return (res);
	2109	+}
	2110	+
	2111	+
	2112	+static int
	2113	+validate_and_test(node *tree)
	2114	+{
	2115	+ int pos;
	2116	+ int nch = NCH(tree);
	2117	+ int res = (validate_ntype(tree, and_test)
	2118	+ && is_odd(nch)
	2119	+ && validate_not_test(CHILD(tree, 0)));
	2120	+
	2121	+ for (pos = 1; res && (pos < nch); pos += 2)
	2122	+ res = (validate_name(CHILD(tree, pos), "and")
	2123	+ && validate_not_test(CHILD(tree, 0)));
	2124	+
	2125	+ return (res);
	2126	+}
	2127	+
	2128	+
	2129	+static int
	2130	+validate_not_test(node *tree)
	2131	+{
	2132	+ int nch = NCH(tree);
	2133	+ int res = validate_ntype(tree, not_test) && ((nch == 1) \|\| (nch == 2));
	2134	+
	2135	+ if (res) {
	2136	+ if (nch == 2)
	2137	+ res = (validate_name(CHILD(tree, 0), "not")
	2138	+ && validate_not_test(CHILD(tree, 1)));
	2139	+ else if (nch == 1)
	2140	+ res = validate_comparison(CHILD(tree, 0));
	2141	+ }
	2142	+ return (res);
	2143	+}
	2144	+
	2145	+
	2146	+static int
	2147	+validate_comparison(node *tree)
	2148	+{
	2149	+ int pos;
	2150	+ int nch = NCH(tree);
	2151	+ int res = (validate_ntype(tree, comparison)
	2152	+ && is_odd(nch)
	2153	+ && validate_expr(CHILD(tree, 0)));
	2154	+
	2155	+ for (pos = 1; res && (pos < nch); pos += 2)
	2156	+ res = (validate_comp_op(CHILD(tree, pos))
	2157	+ && validate_expr(CHILD(tree, pos + 1)));
	2158	+
	2159	+ return (res);
	2160	+}
	2161	+
	2162	+
	2163	+static int
	2164	+validate_comp_op(node *tree)
	2165	+{
	2166	+ int res = 0;
	2167	+ int nch = NCH(tree);
	2168	+
	2169	+ if (!validate_ntype(tree, comp_op))
	2170	+ return (0);
	2171	+ if (nch == 1) {
	2172	+ /*
	2173	+ * Only child will be a terminal with a well-defined symbolic name
	2174	+ * or a NAME with a string of either 'is' or 'in'
	2175	+ */
	2176	+ tree = CHILD(tree, 0);
	2177	+ switch (TYPE(tree)) {
	2178	+ case LESS:
	2179	+ case GREATER:
	2180	+ case EQEQUAL:
	2181	+ case EQUAL:
	2182	+ case LESSEQUAL:
	2183	+ case GREATEREQUAL:
	2184	+ case NOTEQUAL:
	2185	+ res = 1;
	2186	+ break;
	2187	+ case NAME:
	2188	+ res = ((strcmp(STR(tree), "in") == 0)
	2189	+ \|\| (strcmp(STR(tree), "is") == 0));
	2190	+ if (!res) {
	2191	+ PyErr_Format(parser_error,
	2192	+ "illegal operator '%s'", STR(tree));
	2193	+ }
	2194	+ break;
	2195	+ default:
	2196	+ err_string("illegal comparison operator type");
	2197	+ break;
	2198	+ }
	2199	+ }
	2200	+ else if ((res = validate_numnodes(tree, 2, "comp_op")) != 0) {
	2201	+ res = (validate_ntype(CHILD(tree, 0), NAME)
	2202	+ && validate_ntype(CHILD(tree, 1), NAME)
	2203	+ && (((strcmp(STR(CHILD(tree, 0)), "is") == 0)
	2204	+ && (strcmp(STR(CHILD(tree, 1)), "not") == 0))
	2205	+ \|\| ((strcmp(STR(CHILD(tree, 0)), "not") == 0)
	2206	+ && (strcmp(STR(CHILD(tree, 1)), "in") == 0))));
	2207	+ if (!res && !PyErr_Occurred())
	2208	+ err_string("unknown comparison operator");
	2209	+ }
	2210	+ return (res);
	2211	+}
	2212	+
	2213	+
	2214	+static int
	2215	+validate_expr(node *tree)
	2216	+{
	2217	+ int j;
	2218	+ int nch = NCH(tree);
	2219	+ int res = (validate_ntype(tree, expr)
	2220	+ && is_odd(nch)
	2221	+ && validate_xor_expr(CHILD(tree, 0)));
	2222	+
	2223	+ for (j = 2; res && (j < nch); j += 2)
	2224	+ res = (validate_xor_expr(CHILD(tree, j))
	2225	+ && validate_vbar(CHILD(tree, j - 1)));
	2226	+
	2227	+ return (res);
	2228	+}
	2229	+
	2230	+
	2231	+static int
	2232	+validate_xor_expr(node *tree)
	2233	+{
	2234	+ int j;
	2235	+ int nch = NCH(tree);
	2236	+ int res = (validate_ntype(tree, xor_expr)
	2237	+ && is_odd(nch)
	2238	+ && validate_and_expr(CHILD(tree, 0)));
	2239	+
	2240	+ for (j = 2; res && (j < nch); j += 2)
	2241	+ res = (validate_circumflex(CHILD(tree, j - 1))
	2242	+ && validate_and_expr(CHILD(tree, j)));
	2243	+
	2244	+ return (res);
	2245	+}
	2246	+
	2247	+
	2248	+static int
	2249	+validate_and_expr(node *tree)
	2250	+{
	2251	+ int pos;
	2252	+ int nch = NCH(tree);
	2253	+ int res = (validate_ntype(tree, and_expr)
	2254	+ && is_odd(nch)
	2255	+ && validate_shift_expr(CHILD(tree, 0)));
	2256	+
	2257	+ for (pos = 1; res && (pos < nch); pos += 2)
	2258	+ res = (validate_ampersand(CHILD(tree, pos))
	2259	+ && validate_shift_expr(CHILD(tree, pos + 1)));
	2260	+
	2261	+ return (res);
	2262	+}
	2263	+
	2264	+
	2265	+static int
	2266	+validate_chain_two_ops(node tree, int (termvalid)(node *), int op1, int op2)
	2267	+ {
	2268	+ int pos = 1;
	2269	+ int nch = NCH(tree);
	2270	+ int res = (is_odd(nch)
	2271	+ && (*termvalid)(CHILD(tree, 0)));
	2272	+
	2273	+ for ( ; res && (pos < nch); pos += 2) {
	2274	+ if (TYPE(CHILD(tree, pos)) != op1)
	2275	+ res = validate_ntype(CHILD(tree, pos), op2);
	2276	+ if (res)
	2277	+ res = (*termvalid)(CHILD(tree, pos + 1));
	2278	+ }
	2279	+ return (res);
	2280	+}
	2281	+
	2282	+
	2283	+static int
	2284	+validate_shift_expr(node *tree)
	2285	+{
	2286	+ return (validate_ntype(tree, shift_expr)
	2287	+ && validate_chain_two_ops(tree, validate_arith_expr,
	2288	+ LEFTSHIFT, RIGHTSHIFT));
	2289	+}
	2290	+
	2291	+
	2292	+static int
	2293	+validate_arith_expr(node *tree)
	2294	+{
	2295	+ return (validate_ntype(tree, arith_expr)
	2296	+ && validate_chain_two_ops(tree, validate_term, PLUS, MINUS));
	2297	+}
	2298	+
	2299	+
	2300	+static int
	2301	+validate_term(node *tree)
	2302	+{
	2303	+ int pos = 1;
	2304	+ int nch = NCH(tree);
	2305	+ int res = (validate_ntype(tree, term)
	2306	+ && is_odd(nch)
	2307	+ && validate_factor(CHILD(tree, 0)));
	2308	+
	2309	+ for ( ; res && (pos < nch); pos += 2)
	2310	+ res = (((TYPE(CHILD(tree, pos)) == STAR)
	2311	+ \|\| (TYPE(CHILD(tree, pos)) == SLASH)
	2312	+ \|\| (TYPE(CHILD(tree, pos)) == DOUBLESLASH)
	2313	+ \|\| (TYPE(CHILD(tree, pos)) == PERCENT))
	2314	+ && validate_factor(CHILD(tree, pos + 1)));
	2315	+
	2316	+ return (res);
	2317	+}
	2318	+
	2319	+
	2320	+/* factor:
	2321	+ *
	2322	+ * factor: ('+'\|'-'\|'~') factor \| power
	2323	+ */
	2324	+static int
	2325	+validate_factor(node *tree)
	2326	+{
	2327	+ int nch = NCH(tree);
	2328	+ int res = (validate_ntype(tree, factor)
	2329	+ && (((nch == 2)
	2330	+ && ((TYPE(CHILD(tree, 0)) == PLUS)
	2331	+ \|\| (TYPE(CHILD(tree, 0)) == MINUS)
	2332	+ \|\| (TYPE(CHILD(tree, 0)) == TILDE))
	2333	+ && validate_factor(CHILD(tree, 1)))
	2334	+ \|\| ((nch == 1)
	2335	+ && validate_power(CHILD(tree, 0)))));
	2336	+ return (res);
	2337	+}
	2338	+
	2339	+
	2340	+/* power:
	2341	+ *
	2342	+ * power: atom trailer* ('*' factor)
	2343	+ */
	2344	+static int
	2345	+validate_power(node *tree)
	2346	+{
	2347	+ int pos = 1;
	2348	+ int nch = NCH(tree);
	2349	+ int res = (validate_ntype(tree, power) && (nch >= 1)
	2350	+ && validate_atom(CHILD(tree, 0)));
	2351	+
	2352	+ while (res && (pos < nch) && (TYPE(CHILD(tree, pos)) == trailer))
	2353	+ res = validate_trailer(CHILD(tree, pos++));
	2354	+ if (res && (pos < nch)) {
	2355	+ if (!is_even(nch - pos)) {
	2356	+ err_string("illegal number of nodes for 'power'");
	2357	+ return (0);
	2358	+ }
	2359	+ for ( ; res && (pos < (nch - 1)); pos += 2)
	2360	+ res = (validate_doublestar(CHILD(tree, pos))
	2361	+ && validate_factor(CHILD(tree, pos + 1)));
	2362	+ }
	2363	+ return (res);
	2364	+}
	2365	+
	2366	+
	2367	+static int
	2368	+validate_atom(node *tree)
	2369	+{
	2370	+ int pos;
	2371	+ int nch = NCH(tree);
	2372	+ int res = validate_ntype(tree, atom);
	2373	+
	2374	+ if (res && nch < 1)
	2375	+ res = validate_numnodes(tree, nch+1, "atom");
	2376	+ if (res) {
	2377	+ switch (TYPE(CHILD(tree, 0))) {
	2378	+ case LPAR:
	2379	+ res = ((nch <= 3)
	2380	+ && (validate_rparen(CHILD(tree, nch - 1))));
	2381	+
	2382	+ if (res && (nch == 3)) {
	2383	+ if (TYPE(CHILD(tree, 1))==yield_expr)
	2384	+ res = validate_yield_expr(CHILD(tree, 1));
	2385	+ else
	2386	+ res = validate_testlist_gexp(CHILD(tree, 1));
	2387	+ }
	2388	+ break;
	2389	+ case LSQB:
	2390	+ if (nch == 2)
	2391	+ res = validate_ntype(CHILD(tree, 1), RSQB);
	2392	+ else if (nch == 3)
	2393	+ res = (validate_listmaker(CHILD(tree, 1))
	2394	+ && validate_ntype(CHILD(tree, 2), RSQB));
	2395	+ else {
	2396	+ res = 0;
	2397	+ err_string("illegal list display atom");
	2398	+ }
	2399	+ break;
	2400	+ case LBRACE:
	2401	+ res = ((nch <= 3)
	2402	+ && validate_ntype(CHILD(tree, nch - 1), RBRACE));
	2403	+
	2404	+ if (res && (nch == 3))
	2405	+ res = validate_dictmaker(CHILD(tree, 1));
	2406	+ break;
	2407	+ case BACKQUOTE:
	2408	+ res = ((nch == 3)
	2409	+ && validate_testlist1(CHILD(tree, 1))
	2410	+ && validate_ntype(CHILD(tree, 2), BACKQUOTE));
	2411	+ break;
	2412	+ case NAME:
	2413	+ case NUMBER:
	2414	+ res = (nch == 1);
	2415	+ break;
	2416	+ case STRING:
	2417	+ for (pos = 1; res && (pos < nch); ++pos)
	2418	+ res = validate_ntype(CHILD(tree, pos), STRING);
	2419	+ break;
	2420	+ default:
	2421	+ res = 0;
	2422	+ break;
	2423	+ }
	2424	+ }
	2425	+ return (res);
	2426	+}
	2427	+
	2428	+
	2429	+/* listmaker:
	2430	+ * test ( list_for \| (',' test)* [','] )
	2431	+ */
	2432	+static int
	2433	+validate_listmaker(node *tree)
	2434	+{
	2435	+ int nch = NCH(tree);
	2436	+ int ok = nch;
	2437	+
	2438	+ if (nch == 0)
	2439	+ err_string("missing child nodes of listmaker");
	2440	+ else
	2441	+ ok = validate_test(CHILD(tree, 0));
	2442	+
	2443	+ /*
	2444	+ * list_for \| (',' test)* [',']
	2445	+ */
	2446	+ if (nch == 2 && TYPE(CHILD(tree, 1)) == list_for)
	2447	+ ok = validate_list_for(CHILD(tree, 1));
	2448	+ else {
	2449	+ /* (',' test)* [','] */
	2450	+ int i = 1;
	2451	+ while (ok && nch - i >= 2) {
	2452	+ ok = (validate_comma(CHILD(tree, i))
	2453	+ && validate_test(CHILD(tree, i+1)));
	2454	+ i += 2;
	2455	+ }
	2456	+ if (ok && i == nch-1)
	2457	+ ok = validate_comma(CHILD(tree, i));
	2458	+ else if (i != nch) {
	2459	+ ok = 0;
	2460	+ err_string("illegal trailing nodes for listmaker");
	2461	+ }
	2462	+ }
	2463	+ return ok;
	2464	+}
	2465	+
	2466	+/* testlist_gexp:
	2467	+ * test ( gen_for \| (',' test)* [','] )
	2468	+ */
	2469	+static int
	2470	+validate_testlist_gexp(node *tree)
	2471	+{
	2472	+ int nch = NCH(tree);
	2473	+ int ok = nch;
	2474	+
	2475	+ if (nch == 0)
	2476	+ err_string("missing child nodes of testlist_gexp");
	2477	+ else {
	2478	+ ok = validate_test(CHILD(tree, 0));
	2479	+ }
	2480	+
	2481	+ /*
	2482	+ * gen_for \| (',' test)* [',']
	2483	+ */
	2484	+ if (nch == 2 && TYPE(CHILD(tree, 1)) == gen_for)
	2485	+ ok = validate_gen_for(CHILD(tree, 1));
	2486	+ else {
	2487	+ /* (',' test)* [','] */
	2488	+ int i = 1;
	2489	+ while (ok && nch - i >= 2) {
	2490	+ ok = (validate_comma(CHILD(tree, i))
	2491	+ && validate_test(CHILD(tree, i+1)));
	2492	+ i += 2;
	2493	+ }
	2494	+ if (ok && i == nch-1)
	2495	+ ok = validate_comma(CHILD(tree, i));
	2496	+ else if (i != nch) {
	2497	+ ok = 0;
	2498	+ err_string("illegal trailing nodes for testlist_gexp");
	2499	+ }
	2500	+ }
	2501	+ return ok;
	2502	+}
	2503	+
	2504	+/* decorator:
	2505	+ * '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
	2506	+ */
	2507	+static int
	2508	+validate_decorator(node *tree)
	2509	+{
	2510	+ int ok;
	2511	+ int nch = NCH(tree);
	2512	+ ok = (validate_ntype(tree, decorator) &&
	2513	+ (nch == 3 \|\| nch == 5 \|\| nch == 6) &&
	2514	+ validate_at(CHILD(tree, 0)) &&
	2515	+ validate_dotted_name(CHILD(tree, 1)) &&
	2516	+ validate_newline(RCHILD(tree, -1)));
	2517	+
	2518	+ if (ok && nch != 3) {
	2519	+ ok = (validate_lparen(CHILD(tree, 2)) &&
	2520	+ validate_rparen(RCHILD(tree, -2)));
	2521	+
	2522	+ if (ok && nch == 6)
	2523	+ ok = validate_arglist(CHILD(tree, 3));
	2524	+ }
	2525	+
	2526	+ return ok;
	2527	+}
	2528	+
	2529	+/* decorators:
	2530	+ * decorator+
	2531	+ */
	2532	+static int
	2533	+validate_decorators(node *tree)
	2534	+{
	2535	+ int i, nch, ok;
	2536	+ nch = NCH(tree);
	2537	+ ok = validate_ntype(tree, decorators) && nch >= 1;
	2538	+
	2539	+ for (i = 0; ok && i < nch; ++i)
	2540	+ ok = validate_decorator(CHILD(tree, i));
	2541	+
	2542	+ return ok;
	2543	+}
	2544	+
	2545	+/* funcdef:
	2546	+ *
	2547	+ * -6 -5 -4 -3 -2 -1
	2548	+ * [decorators] 'def' NAME parameters ':' suite
	2549	+ */
	2550	+static int
	2551	+validate_funcdef(node *tree)
	2552	+{
	2553	+ int nch = NCH(tree);
	2554	+ int ok = (validate_ntype(tree, funcdef)
	2555	+ && ((nch == 5) \|\| (nch == 6))
	2556	+ && validate_name(RCHILD(tree, -5), "def")
	2557	+ && validate_ntype(RCHILD(tree, -4), NAME)
	2558	+ && validate_colon(RCHILD(tree, -2))
	2559	+ && validate_parameters(RCHILD(tree, -3))
	2560	+ && validate_suite(RCHILD(tree, -1)));
	2561	+
	2562	+ if (ok && (nch == 6))
	2563	+ ok = validate_decorators(CHILD(tree, 0));
	2564	+
	2565	+ return ok;
	2566	+}
	2567	+
	2568	+
	2569	+static int
	2570	+validate_lambdef(node *tree)
	2571	+{
	2572	+ int nch = NCH(tree);
	2573	+ int res = (validate_ntype(tree, lambdef)
	2574	+ && ((nch == 3) \|\| (nch == 4))
	2575	+ && validate_name(CHILD(tree, 0), "lambda")
	2576	+ && validate_colon(CHILD(tree, nch - 2))
	2577	+ && validate_test(CHILD(tree, nch - 1)));
	2578	+
	2579	+ if (res && (nch == 4))
	2580	+ res = validate_varargslist(CHILD(tree, 1));
	2581	+ else if (!res && !PyErr_Occurred())
	2582	+ (void) validate_numnodes(tree, 3, "lambdef");
	2583	+
	2584	+ return (res);
	2585	+}
	2586	+
	2587	+
	2588	+static int
	2589	+validate_old_lambdef(node *tree)
	2590	+{
	2591	+ int nch = NCH(tree);
	2592	+ int res = (validate_ntype(tree, old_lambdef)
	2593	+ && ((nch == 3) \|\| (nch == 4))
	2594	+ && validate_name(CHILD(tree, 0), "lambda")
	2595	+ && validate_colon(CHILD(tree, nch - 2))
	2596	+ && validate_test(CHILD(tree, nch - 1)));
	2597	+
	2598	+ if (res && (nch == 4))
	2599	+ res = validate_varargslist(CHILD(tree, 1));
	2600	+ else if (!res && !PyErr_Occurred())
	2601	+ (void) validate_numnodes(tree, 3, "old_lambdef");
	2602	+
	2603	+ return (res);
	2604	+}
	2605	+
	2606	+
	2607	+/* arglist:
	2608	+ *
	2609	+ * (argument ',')* (argument [','] \| '' test [',' '' test] \| '*' test)
	2610	+ */
	2611	+static int
	2612	+validate_arglist(node *tree)
	2613	+{
	2614	+ int nch = NCH(tree);
	2615	+ int i = 0;
	2616	+ int ok = 1;
	2617	+
	2618	+ if (nch <= 0)
	2619	+ /* raise the right error from having an invalid number of children */
	2620	+ return validate_numnodes(tree, nch + 1, "arglist");
	2621	+
	2622	+ if (nch > 1) {
	2623	+ for (i=0; i<nch; i++) {
	2624	+ if (TYPE(CHILD(tree, i)) == argument) {
	2625	+ node *ch = CHILD(tree, i);
	2626	+ if (NCH(ch) == 2 && TYPE(CHILD(ch, 1)) == gen_for) {
	2627	+ err_string("need '(', ')' for generator expression");
	2628	+ return 0;
	2629	+ }
	2630	+ }
	2631	+ }
	2632	+ }
	2633	+
	2634	+ while (ok && nch-i >= 2) {
	2635	+ /* skip leading (argument ',') */
	2636	+ ok = (validate_argument(CHILD(tree, i))
	2637	+ && validate_comma(CHILD(tree, i+1)));
	2638	+ if (ok)
	2639	+ i += 2;
	2640	+ else
	2641	+ PyErr_Clear();
	2642	+ }
	2643	+ ok = 1;
	2644	+ if (nch-i > 0) {
	2645	+ /*
	2646	+ * argument \| '' test [',' '' test] \| '*' test
	2647	+ */
	2648	+ int sym = TYPE(CHILD(tree, i));
	2649	+
	2650	+ if (sym == argument) {
	2651	+ ok = validate_argument(CHILD(tree, i));
	2652	+ if (ok && i+1 != nch) {
	2653	+ err_string("illegal arglist specification"
	2654	+ " (extra stuff on end)");
	2655	+ ok = 0;
	2656	+ }
	2657	+ }
	2658	+ else if (sym == STAR) {
	2659	+ ok = validate_star(CHILD(tree, i));
	2660	+ if (ok && (nch-i == 2))
	2661	+ ok = validate_test(CHILD(tree, i+1));
	2662	+ else if (ok && (nch-i == 5))
	2663	+ ok = (validate_test(CHILD(tree, i+1))
	2664	+ && validate_comma(CHILD(tree, i+2))
	2665	+ && validate_doublestar(CHILD(tree, i+3))
	2666	+ && validate_test(CHILD(tree, i+4)));
	2667	+ else {
	2668	+ err_string("illegal use of '*' in arglist");
	2669	+ ok = 0;
	2670	+ }
	2671	+ }
	2672	+ else if (sym == DOUBLESTAR) {
	2673	+ if (nch-i == 2)
	2674	+ ok = (validate_doublestar(CHILD(tree, i))
	2675	+ && validate_test(CHILD(tree, i+1)));
	2676	+ else {
	2677	+ err_string("illegal use of '**' in arglist");
	2678	+ ok = 0;
	2679	+ }
	2680	+ }
	2681	+ else {
	2682	+ err_string("illegal arglist specification");
	2683	+ ok = 0;
	2684	+ }
	2685	+ }
	2686	+ return (ok);
	2687	+}
	2688	+
	2689	+
	2690	+
	2691	+/* argument:
	2692	+ *
	2693	+ * [test '='] test [gen_for]
	2694	+ */
	2695	+static int
	2696	+validate_argument(node *tree)
	2697	+{
	2698	+ int nch = NCH(tree);
	2699	+ int res = (validate_ntype(tree, argument)
	2700	+ && ((nch == 1) \|\| (nch == 2) \|\| (nch == 3))
	2701	+ && validate_test(CHILD(tree, 0)));
	2702	+
	2703	+ if (res && (nch == 2))
	2704	+ res = validate_gen_for(CHILD(tree, 1));
	2705	+ else if (res && (nch == 3))
	2706	+ res = (validate_equal(CHILD(tree, 1))
	2707	+ && validate_test(CHILD(tree, 2)));
	2708	+
	2709	+ return (res);
	2710	+}
	2711	+
	2712	+
	2713	+
	2714	+/* trailer:
	2715	+ *
	2716	+ * '(' [arglist] ')' \| '[' subscriptlist ']' \| '.' NAME
	2717	+ */
	2718	+static int
	2719	+validate_trailer(node *tree)
	2720	+{
	2721	+ int nch = NCH(tree);
	2722	+ int res = validate_ntype(tree, trailer) && ((nch == 2) \|\| (nch == 3));
	2723	+
	2724	+ if (res) {
	2725	+ switch (TYPE(CHILD(tree, 0))) {
	2726	+ case LPAR:
	2727	+ res = validate_rparen(CHILD(tree, nch - 1));
	2728	+ if (res && (nch == 3))
	2729	+ res = validate_arglist(CHILD(tree, 1));
	2730	+ break;
	2731	+ case LSQB:
	2732	+ res = (validate_numnodes(tree, 3, "trailer")
	2733	+ && validate_subscriptlist(CHILD(tree, 1))
	2734	+ && validate_ntype(CHILD(tree, 2), RSQB));
	2735	+ break;
	2736	+ case DOT:
	2737	+ res = (validate_numnodes(tree, 2, "trailer")
	2738	+ && validate_ntype(CHILD(tree, 1), NAME));
	2739	+ break;
	2740	+ default:
	2741	+ res = 0;
	2742	+ break;
	2743	+ }
	2744	+ }
	2745	+ else {
	2746	+ (void) validate_numnodes(tree, 2, "trailer");
	2747	+ }
	2748	+ return (res);
	2749	+}
	2750	+
	2751	+
	2752	+/* subscriptlist:
	2753	+ *
	2754	+ * subscript (',' subscript)* [',']
	2755	+ */
	2756	+static int
	2757	+validate_subscriptlist(node *tree)
	2758	+{
	2759	+ return (validate_repeating_list(tree, subscriptlist,
	2760	+ validate_subscript, "subscriptlist"));
	2761	+}
	2762	+
	2763	+
	2764	+/* subscript:
	2765	+ *
	2766	+ * '.' '.' '.' \| test \| [test] ':' [test] [sliceop]
	2767	+ */
	2768	+static int
	2769	+validate_subscript(node *tree)
	2770	+{
	2771	+ int offset = 0;
	2772	+ int nch = NCH(tree);
	2773	+ int res = validate_ntype(tree, subscript) && (nch >= 1) && (nch <= 4);
	2774	+
	2775	+ if (!res) {
	2776	+ if (!PyErr_Occurred())
	2777	+ err_string("invalid number of arguments for subscript node");
	2778	+ return (0);
	2779	+ }
	2780	+ if (TYPE(CHILD(tree, 0)) == DOT)
	2781	+ /* take care of ('.' '.' '.') possibility */
	2782	+ return (validate_numnodes(tree, 3, "subscript")
	2783	+ && validate_dot(CHILD(tree, 0))
	2784	+ && validate_dot(CHILD(tree, 1))
	2785	+ && validate_dot(CHILD(tree, 2)));
	2786	+ if (nch == 1) {
	2787	+ if (TYPE(CHILD(tree, 0)) == test)
	2788	+ res = validate_test(CHILD(tree, 0));
	2789	+ else
	2790	+ res = validate_colon(CHILD(tree, 0));
	2791	+ return (res);
	2792	+ }
	2793	+ /* Must be [test] ':' [test] [sliceop],
	2794	+ * but at least one of the optional components will
	2795	+ * be present, but we don't know which yet.
	2796	+ */
	2797	+ if ((TYPE(CHILD(tree, 0)) != COLON) \|\| (nch == 4)) {
	2798	+ res = validate_test(CHILD(tree, 0));
	2799	+ offset = 1;
	2800	+ }
	2801	+ if (res)
	2802	+ res = validate_colon(CHILD(tree, offset));
	2803	+ if (res) {
	2804	+ int rem = nch - ++offset;
	2805	+ if (rem) {
	2806	+ if (TYPE(CHILD(tree, offset)) == test) {
	2807	+ res = validate_test(CHILD(tree, offset));
	2808	+ ++offset;
	2809	+ --rem;
	2810	+ }
	2811	+ if (res && rem)
	2812	+ res = validate_sliceop(CHILD(tree, offset));
	2813	+ }
	2814	+ }
	2815	+ return (res);
	2816	+}
	2817	+
	2818	+
	2819	+static int
	2820	+validate_sliceop(node *tree)
	2821	+{
	2822	+ int nch = NCH(tree);
	2823	+ int res = ((nch == 1) \|\| validate_numnodes(tree, 2, "sliceop"))
	2824	+ && validate_ntype(tree, sliceop);
	2825	+ if (!res && !PyErr_Occurred()) {
	2826	+ res = validate_numnodes(tree, 1, "sliceop");
	2827	+ }
	2828	+ if (res)
	2829	+ res = validate_colon(CHILD(tree, 0));
	2830	+ if (res && (nch == 2))
	2831	+ res = validate_test(CHILD(tree, 1));
	2832	+
	2833	+ return (res);
	2834	+}
	2835	+
	2836	+
	2837	+static int
	2838	+validate_exprlist(node *tree)
	2839	+{
	2840	+ return (validate_repeating_list(tree, exprlist,
	2841	+ validate_expr, "exprlist"));
	2842	+}
	2843	+
	2844	+
	2845	+static int
	2846	+validate_dictmaker(node *tree)
	2847	+{
	2848	+ int nch = NCH(tree);
	2849	+ int res = (validate_ntype(tree, dictmaker)
	2850	+ && (nch >= 3)
	2851	+ && validate_test(CHILD(tree, 0))
	2852	+ && validate_colon(CHILD(tree, 1))
	2853	+ && validate_test(CHILD(tree, 2)));
	2854	+
	2855	+ if (res && ((nch % 4) == 0))
	2856	+ res = validate_comma(CHILD(tree, --nch));
	2857	+ else if (res)
	2858	+ res = ((nch % 4) == 3);
	2859	+
	2860	+ if (res && (nch > 3)) {
	2861	+ int pos = 3;
	2862	+ /* ( ',' test ':' test )* */
	2863	+ while (res && (pos < nch)) {
	2864	+ res = (validate_comma(CHILD(tree, pos))
	2865	+ && validate_test(CHILD(tree, pos + 1))
	2866	+ && validate_colon(CHILD(tree, pos + 2))
	2867	+ && validate_test(CHILD(tree, pos + 3)));
	2868	+ pos += 4;
	2869	+ }
	2870	+ }
	2871	+ return (res);
	2872	+}
	2873	+
	2874	+
	2875	+static int
	2876	+validate_eval_input(node *tree)
	2877	+{
	2878	+ int pos;
	2879	+ int nch = NCH(tree);
	2880	+ int res = (validate_ntype(tree, eval_input)
	2881	+ && (nch >= 2)
	2882	+ && validate_testlist(CHILD(tree, 0))
	2883	+ && validate_ntype(CHILD(tree, nch - 1), ENDMARKER));
	2884	+
	2885	+ for (pos = 1; res && (pos < (nch - 1)); ++pos)
	2886	+ res = validate_ntype(CHILD(tree, pos), NEWLINE);
	2887	+
	2888	+ return (res);
	2889	+}
	2890	+
	2891	+
	2892	+static int
	2893	+validate_node(node *tree)
	2894	+{
	2895	+ int nch = 0; /* num. children on current node */
	2896	+ int res = 1; /* result value */
	2897	+ node* next = 0; /* node to process after this one */
	2898	+
	2899	+ while (res && (tree != 0)) {
	2900	+ nch = NCH(tree);
	2901	+ next = 0;
	2902	+ switch (TYPE(tree)) {
	2903	+ /*
	2904	+ * Definition nodes.
	2905	+ */
	2906	+ case funcdef:
	2907	+ res = validate_funcdef(tree);
	2908	+ break;
	2909	+ case classdef:
	2910	+ res = validate_class(tree);
	2911	+ break;
	2912	+ /*
	2913	+ * "Trivial" parse tree nodes.
	2914	+ * (Why did I call these trivial?)
	2915	+ */
	2916	+ case stmt:
	2917	+ res = validate_stmt(tree);
	2918	+ break;
	2919	+ case small_stmt:
	2920	+ /*
	2921	+ * expr_stmt \| print_stmt \| del_stmt \| pass_stmt \| flow_stmt
	2922	+ * \| import_stmt \| global_stmt \| exec_stmt \| assert_stmt
	2923	+ */
	2924	+ res = validate_small_stmt(tree);
	2925	+ break;
	2926	+ case flow_stmt:
	2927	+ res = (validate_numnodes(tree, 1, "flow_stmt")
	2928	+ && ((TYPE(CHILD(tree, 0)) == break_stmt)
	2929	+ \|\| (TYPE(CHILD(tree, 0)) == continue_stmt)
	2930	+ \|\| (TYPE(CHILD(tree, 0)) == yield_stmt)
	2931	+ \|\| (TYPE(CHILD(tree, 0)) == return_stmt)
	2932	+ \|\| (TYPE(CHILD(tree, 0)) == raise_stmt)));
	2933	+ if (res)
	2934	+ next = CHILD(tree, 0);
	2935	+ else if (nch == 1)
	2936	+ err_string("illegal flow_stmt type");
	2937	+ break;
	2938	+ case yield_stmt:
	2939	+ res = validate_yield_stmt(tree);
	2940	+ break;
	2941	+ /*
	2942	+ * Compound statements.
	2943	+ */
	2944	+ case simple_stmt:
	2945	+ res = validate_simple_stmt(tree);
	2946	+ break;
	2947	+ case compound_stmt:
	2948	+ res = validate_compound_stmt(tree);
	2949	+ break;
	2950	+ /*
	2951	+ * Fundamental statements.
	2952	+ */
	2953	+ case expr_stmt:
	2954	+ res = validate_expr_stmt(tree);
	2955	+ break;
	2956	+ case print_stmt:
	2957	+ res = validate_print_stmt(tree);
	2958	+ break;
	2959	+ case del_stmt:
	2960	+ res = validate_del_stmt(tree);
	2961	+ break;
	2962	+ case pass_stmt:
	2963	+ res = (validate_numnodes(tree, 1, "pass")
	2964	+ && validate_name(CHILD(tree, 0), "pass"));
	2965	+ break;
	2966	+ case break_stmt:
	2967	+ res = (validate_numnodes(tree, 1, "break")
	2968	+ && validate_name(CHILD(tree, 0), "break"));
	2969	+ break;
	2970	+ case continue_stmt:
	2971	+ res = (validate_numnodes(tree, 1, "continue")
	2972	+ && validate_name(CHILD(tree, 0), "continue"));
	2973	+ break;
	2974	+ case return_stmt:
	2975	+ res = validate_return_stmt(tree);
	2976	+ break;
	2977	+ case raise_stmt:
	2978	+ res = validate_raise_stmt(tree);
	2979	+ break;
	2980	+ case import_stmt:
	2981	+ res = validate_import_stmt(tree);
	2982	+ break;
	2983	+ case import_name:
	2984	+ res = validate_import_name(tree);
	2985	+ break;
	2986	+ case import_from:
	2987	+ res = validate_import_from(tree);
	2988	+ break;
	2989	+ case global_stmt:
	2990	+ res = validate_global_stmt(tree);
	2991	+ break;
	2992	+ case exec_stmt:
	2993	+ res = validate_exec_stmt(tree);
	2994	+ break;
	2995	+ case assert_stmt:
	2996	+ res = validate_assert_stmt(tree);
	2997	+ break;
	2998	+ case if_stmt:
	2999	+ res = validate_if(tree);
	3000	+ break;
	3001	+ case while_stmt:
	3002	+ res = validate_while(tree);
	3003	+ break;
	3004	+ case for_stmt:
	3005	+ res = validate_for(tree);
	3006	+ break;
	3007	+ case try_stmt:
	3008	+ res = validate_try(tree);
	3009	+ break;
	3010	+ case suite:
	3011	+ res = validate_suite(tree);
	3012	+ break;
	3013	+ /*
	3014	+ * Expression nodes.
	3015	+ */
	3016	+ case testlist:
	3017	+ res = validate_testlist(tree);
	3018	+ break;
	3019	+ case yield_expr:
	3020	+ res = validate_yield_expr(tree);
	3021	+ break;
	3022	+ case testlist1:
	3023	+ res = validate_testlist1(tree);
	3024	+ break;
	3025	+ case test:
	3026	+ res = validate_test(tree);
	3027	+ break;
	3028	+ case and_test:
	3029	+ res = validate_and_test(tree);
	3030	+ break;
	3031	+ case not_test:
	3032	+ res = validate_not_test(tree);
	3033	+ break;
	3034	+ case comparison:
	3035	+ res = validate_comparison(tree);
	3036	+ break;
	3037	+ case exprlist:
	3038	+ res = validate_exprlist(tree);
	3039	+ break;
	3040	+ case comp_op:
	3041	+ res = validate_comp_op(tree);
	3042	+ break;
	3043	+ case expr:
	3044	+ res = validate_expr(tree);
	3045	+ break;
	3046	+ case xor_expr:
	3047	+ res = validate_xor_expr(tree);
	3048	+ break;
	3049	+ case and_expr:
	3050	+ res = validate_and_expr(tree);
	3051	+ break;
	3052	+ case shift_expr:
	3053	+ res = validate_shift_expr(tree);
	3054	+ break;
	3055	+ case arith_expr:
	3056	+ res = validate_arith_expr(tree);
	3057	+ break;
	3058	+ case term:
	3059	+ res = validate_term(tree);
	3060	+ break;
	3061	+ case factor:
	3062	+ res = validate_factor(tree);
	3063	+ break;
	3064	+ case power:
	3065	+ res = validate_power(tree);
	3066	+ break;
	3067	+ case atom:
	3068	+ res = validate_atom(tree);
	3069	+ break;
	3070	+
	3071	+ default:
	3072	+ /* Hopefully never reached! */
	3073	+ err_string("unrecognized node type");
	3074	+ res = 0;
	3075	+ break;
	3076	+ }
	3077	+ tree = next;
	3078	+ }
	3079	+ return (res);
	3080	+}
	3081	+
	3082	+
	3083	+static int
	3084	+validate_expr_tree(node *tree)
	3085	+{
	3086	+ int res = validate_eval_input(tree);
	3087	+
	3088	+ if (!res && !PyErr_Occurred())
	3089	+ err_string("could not validate expression tuple");
	3090	+
	3091	+ return (res);
	3092	+}
	3093	+
	3094	+
	3095	+/* file_input:
	3096	+ * (NEWLINE \| stmt)* ENDMARKER
	3097	+ */
	3098	+static int
	3099	+validate_file_input(node *tree)
	3100	+{
	3101	+ int j;
	3102	+ int nch = NCH(tree) - 1;
	3103	+ int res = ((nch >= 0)
	3104	+ && validate_ntype(CHILD(tree, nch), ENDMARKER));
	3105	+
	3106	+ for (j = 0; res && (j < nch); ++j) {
	3107	+ if (TYPE(CHILD(tree, j)) == stmt)
	3108	+ res = validate_stmt(CHILD(tree, j));
	3109	+ else
	3110	+ res = validate_newline(CHILD(tree, j));
	3111	+ }
	3112	+ /* This stays in to prevent any internal failures from getting to the
	3113	+ * user. Hopefully, this won't be needed. If a user reports getting
	3114	+ * this, we have some debugging to do.
	3115	+ */
	3116	+ if (!res && !PyErr_Occurred())
	3117	+ err_string("VALIDATION FAILURE: report this to the maintainer!");
	3118	+
	3119	+ return (res);
	3120	+}
	3121	+
	3122	+static int
	3123	+validate_encoding_decl(node *tree)
	3124	+{
	3125	+ int nch = NCH(tree);
	3126	+ int res = ((nch == 1)
	3127	+ && validate_file_input(CHILD(tree, 0)));
	3128	+
	3129	+ if (!res && !PyErr_Occurred())
	3130	+ err_string("Error Parsing encoding_decl");
	3131	+
	3132	+ return res;
	3133	+}
	3134	+
	3135	+static PyObject*
	3136	+pickle_constructor = NULL;
	3137	+
	3138	+
	3139	+static PyObject*
	3140	+parser__pickler(PyObject self, PyObject args)
	3141	+{
	3142	+ NOTE(ARGUNUSED(self))
	3143	+ PyObject *result = NULL;
	3144	+ PyObject *st = NULL;
	3145	+ PyObject *empty_dict = NULL;
	3146	+
	3147	+ if (PyArg_ParseTuple(args, "O!:_pickler", &PyST_Type, &st)) {
	3148	+ PyObject *newargs;
	3149	+ PyObject *tuple;
	3150	+
	3151	+ if ((empty_dict = PyDict_New()) == NULL)
	3152	+ goto finally;
	3153	+ if ((newargs = Py_BuildValue("Oi", st, 1)) == NULL)
	3154	+ goto finally;
	3155	+ tuple = parser_st2tuple((PyST_Object*)NULL, newargs, empty_dict);
	3156	+ if (tuple != NULL) {
	3157	+ result = Py_BuildValue("O(O)", pickle_constructor, tuple);
	3158	+ Py_DECREF(tuple);
	3159	+ }
	3160	+ Py_DECREF(empty_dict);
	3161	+ Py_DECREF(newargs);
	3162	+ }
	3163	+ finally:
	3164	+ Py_XDECREF(empty_dict);
	3165	+
	3166	+ return (result);
	3167	+}
	3168	+
	3169	+
	3170	+/* Functions exported by this module. Most of this should probably
	3171	+ * be converted into an ST object with methods, but that is better
	3172	+ * done directly in Python, allowing subclasses to be created directly.
	3173	+ * We'd really have to write a wrapper around it all anyway to allow
	3174	+ * inheritance.
	3175	+ */
	3176	+static PyMethodDef parser_functions[] = {
	3177	+ {"ast2tuple", (PyCFunction)parser_st2tuple, PUBLIC_METHOD_TYPE,
	3178	+ PyDoc_STR("Creates a tuple-tree representation of an ST.")},
	3179	+ {"ast2list", (PyCFunction)parser_st2list, PUBLIC_METHOD_TYPE,
	3180	+ PyDoc_STR("Creates a list-tree representation of an ST.")},
	3181	+ {"compileast", (PyCFunction)parser_compilest, PUBLIC_METHOD_TYPE,
	3182	+ PyDoc_STR("Compiles an ST object into a code object.")},
	3183	+ {"compilest", (PyCFunction)parser_compilest, PUBLIC_METHOD_TYPE,
	3184	+ PyDoc_STR("Compiles an ST object into a code object.")},
	3185	+ {"expr", (PyCFunction)parser_expr, PUBLIC_METHOD_TYPE,
	3186	+ PyDoc_STR("Creates an ST object from an expression.")},
	3187	+ {"isexpr", (PyCFunction)parser_isexpr, PUBLIC_METHOD_TYPE,
	3188	+ PyDoc_STR("Determines if an ST object was created from an expression.")},
	3189	+ {"issuite", (PyCFunction)parser_issuite, PUBLIC_METHOD_TYPE,
	3190	+ PyDoc_STR("Determines if an ST object was created from a suite.")},
	3191	+ {"suite", (PyCFunction)parser_suite, PUBLIC_METHOD_TYPE,
	3192	+ PyDoc_STR("Creates an ST object from a suite.")},
	3193	+ {"sequence2ast", (PyCFunction)parser_tuple2st, PUBLIC_METHOD_TYPE,
	3194	+ PyDoc_STR("Creates an ST object from a tree representation.")},
	3195	+ {"sequence2st", (PyCFunction)parser_tuple2st, PUBLIC_METHOD_TYPE,
	3196	+ PyDoc_STR("Creates an ST object from a tree representation.")},
	3197	+ {"st2tuple", (PyCFunction)parser_st2tuple, PUBLIC_METHOD_TYPE,
	3198	+ PyDoc_STR("Creates a tuple-tree representation of an ST.")},
	3199	+ {"st2list", (PyCFunction)parser_st2list, PUBLIC_METHOD_TYPE,
	3200	+ PyDoc_STR("Creates a list-tree representation of an ST.")},
	3201	+ {"tuple2ast", (PyCFunction)parser_tuple2st, PUBLIC_METHOD_TYPE,
	3202	+ PyDoc_STR("Creates an ST object from a tree representation.")},
	3203	+ {"tuple2st", (PyCFunction)parser_tuple2st, PUBLIC_METHOD_TYPE,
	3204	+ PyDoc_STR("Creates an ST object from a tree representation.")},
	3205	+
	3206	+ /* private stuff: support pickle module */
	3207	+ {"_pickler", (PyCFunction)parser__pickler, METH_VARARGS,
	3208	+ PyDoc_STR("Returns the pickle magic to allow ST objects to be pickled.")},
	3209	+
	3210	+ {NULL, NULL, 0, NULL}
	3211	+ };
	3212	+
	3213	+
	3214	+PyMODINIT_FUNC initparser(void); /* supply a prototype */
	3215	+
	3216	+PyMODINIT_FUNC
	3217	+initparser(void)
	3218	+{
	3219	+ PyObject module, copyreg;
	3220	+
	3221	+ PyST_Type.ob_type = &PyType_Type;
	3222	+ module = Py_InitModule("parser", parser_functions);
	3223	+ if (module == NULL)
	3224	+ return;
	3225	+
	3226	+ if (parser_error == 0)
	3227	+ parser_error = PyErr_NewException("parser.ParserError", NULL, NULL);
	3228	+
	3229	+ if (parser_error == 0)
	3230	+ /* caller will check PyErr_Occurred() */
	3231	+ return;
	3232	+ /* CAUTION: The code next used to skip bumping the refcount on
	3233	+ * parser_error. That's a disaster if initparser() gets called more
	3234	+ * than once. By incref'ing, we ensure that each module dict that
	3235	+ * gets created owns its reference to the shared parser_error object,
	3236	+ * and the file static parser_error vrbl owns a reference too.
	3237	+ */
	3238	+ Py_INCREF(parser_error);
	3239	+ if (PyModule_AddObject(module, "ParserError", parser_error) != 0)
	3240	+ return;
	3241	+
	3242	+ Py_INCREF(&PyST_Type);
	3243	+ PyModule_AddObject(module, "ASTType", (PyObject*)&PyST_Type);
	3244	+ Py_INCREF(&PyST_Type);
	3245	+ PyModule_AddObject(module, "STType", (PyObject*)&PyST_Type);
	3246	+
	3247	+ PyModule_AddStringConstant(module, "__copyright__",
	3248	+ parser_copyright_string);
	3249	+ PyModule_AddStringConstant(module, "__doc__",
	3250	+ parser_doc_string);
	3251	+ PyModule_AddStringConstant(module, "__version__",
	3252	+ parser_version_string);
	3253	+
	3254	+ /* Register to support pickling.
	3255	+ * If this fails, the import of this module will fail because an
	3256	+ * exception will be raised here; should we clear the exception?
	3257	+ */
	3258	+ copyreg = PyImport_ImportModule("copy_reg");
	3259	+ if (copyreg != NULL) {
	3260	+ PyObject func, pickler;
	3261	+
	3262	+ func = PyObject_GetAttrString(copyreg, "pickle");
	3263	+ pickle_constructor = PyObject_GetAttrString(module, "sequence2st");
	3264	+ pickler = PyObject_GetAttrString(module, "_pickler");
	3265	+ Py_XINCREF(pickle_constructor);
	3266	+ if ((func != NULL) && (pickle_constructor != NULL)
	3267	+ && (pickler != NULL)) {
	3268	+ PyObject *res;
	3269	+
	3270	+ res = PyObject_CallFunctionObjArgs(func, &PyST_Type, pickler,
	3271	+ pickle_constructor, NULL);
	3272	+ Py_XDECREF(res);
	3273	+ }
	3274	+ Py_XDECREF(func);
	3275	+ Py_XDECREF(pickle_constructor);
	3276	+ Py_XDECREF(pickler);
	3277	+ Py_DECREF(copyreg);
	3278	+ }
	3279	+}