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cpython/Modules/parsermodule.c
Benjamin Peterson 4905e80c3d fix an ambiguity in the grammar from the implementation of extended unpacking 
(one which was strangely "resolved" by pgen)

This also kills the unused testlist1 rule and fixes parse tree validation of
extended unpacking.
2009-09-27 02:43:28 +00:00

3249 lines
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/* parsermodule.c
*
* Copyright 1995-1996 by Fred L. Drake, Jr. and Virginia Polytechnic
* Institute and State University, Blacksburg, Virginia, USA.
* Portions copyright 1991-1995 by Stichting Mathematisch Centrum,
* Amsterdam, The Netherlands. Copying is permitted under the terms
* associated with the main Python distribution, with the additional
* restriction that this additional notice be included and maintained
* on all distributed copies.
*
* This module serves to replace the original parser module written
* by Guido. The functionality is not matched precisely, but the
* original may be implemented on top of this. This is desirable
* since the source of the text to be parsed is now divorced from
* this interface.
*
* Unlike the prior interface, the ability to give a parse tree
* produced by Python code as a tuple to the compiler is enabled by
* this module. See the documentation for more details.
*
* I've added some annotations that help with the lint code-checking
* program, but they're not complete by a long shot. The real errors
* that lint detects are gone, but there are still warnings with
* Py_[X]DECREF() and Py_[X]INCREF() macros. The lint annotations
* look like "NOTE(...)".
*/
#include "Python.h" /* general Python API */
#include "Python-ast.h" /* mod_ty */
#include "graminit.h" /* symbols defined in the grammar */
#include "node.h" /* internal parser structure */
#include "errcode.h" /* error codes for PyNode_*() */
#include "token.h" /* token definitions */
#include "grammar.h"
#include "parsetok.h"
/* ISTERMINAL() / ISNONTERMINAL() */
#include "compile.h"
#undef Yield
#include "ast.h"
#include "pyarena.h"
extern grammar _PyParser_Grammar; /* From graminit.c */
#ifdef lint
#include <note.h>
#else
#define NOTE(x)
#endif
/* String constants used to initialize module attributes.
*
*/
static char parser_copyright_string[] =
"Copyright 1995-1996 by Virginia Polytechnic Institute & State\n\
University, Blacksburg, Virginia, USA, and Fred L. Drake, Jr., Reston,\n\
Virginia, USA. Portions copyright 1991-1995 by Stichting Mathematisch\n\
Centrum, Amsterdam, The Netherlands.";
PyDoc_STRVAR(parser_doc_string,
"This is an interface to Python's internal parser.");
static char parser_version_string[] = "0.5";
typedef PyObject* (*SeqMaker) (Py_ssize_t length);
typedef int (*SeqInserter) (PyObject* sequence,
Py_ssize_t index,
PyObject* element);
/* The function below is copyrighted by Stichting Mathematisch Centrum. The
* original copyright statement is included below, and continues to apply
* in full to the function immediately following. All other material is
* original, copyrighted by Fred L. Drake, Jr. and Virginia Polytechnic
* Institute and State University. Changes were made to comply with the
* new naming conventions. Added arguments to provide support for creating
* lists as well as tuples, and optionally including the line numbers.
*/
static PyObject*
node2tuple(node *n, /* node to convert */
SeqMaker mkseq, /* create sequence */
SeqInserter addelem, /* func. to add elem. in seq. */
int lineno, /* include line numbers? */
int col_offset) /* include column offsets? */
{
if (n == NULL) {
Py_INCREF(Py_None);
return (Py_None);
}
if (ISNONTERMINAL(TYPE(n))) {
int i;
PyObject *v;
PyObject *w;
v = mkseq(1 + NCH(n) + (TYPE(n) == encoding_decl));
if (v == NULL)
return (v);
w = PyLong_FromLong(TYPE(n));
if (w == NULL) {
Py_DECREF(v);
return ((PyObject*) NULL);
}
(void) addelem(v, 0, w);
for (i = 0; i < NCH(n); i++) {
w = node2tuple(CHILD(n, i), mkseq, addelem, lineno, col_offset);
if (w == NULL) {
Py_DECREF(v);
return ((PyObject*) NULL);
}
(void) addelem(v, i+1, w);
}
if (TYPE(n) == encoding_decl)
(void) addelem(v, i+1, PyUnicode_FromString(STR(n)));
return (v);
}
else if (ISTERMINAL(TYPE(n))) {
PyObject *result = mkseq(2 + lineno + col_offset);
if (result != NULL) {
(void) addelem(result, 0, PyLong_FromLong(TYPE(n)));
(void) addelem(result, 1, PyUnicode_FromString(STR(n)));
if (lineno == 1)
(void) addelem(result, 2, PyLong_FromLong(n->n_lineno));
if (col_offset == 1)
(void) addelem(result, 3, PyLong_FromLong(n->n_col_offset));
}
return (result);
}
else {
PyErr_SetString(PyExc_SystemError,
"unrecognized parse tree node type");
return ((PyObject*) NULL);
}
}
/*
* End of material copyrighted by Stichting Mathematisch Centrum.
*/
/* There are two types of intermediate objects we're interested in:
* 'eval' and 'exec' types. These constants can be used in the st_type
* field of the object type to identify which any given object represents.
* These should probably go in an external header to allow other extensions
* to use them, but then, we really should be using C++ too. ;-)
*/
#define PyST_EXPR 1
#define PyST_SUITE 2
/* These are the internal objects and definitions required to implement the
* ST type. Most of the internal names are more reminiscent of the 'old'
* naming style, but the code uses the new naming convention.
*/
static PyObject*
parser_error = 0;
typedef struct {
PyObject_HEAD /* standard object header */
node* st_node; /* the node* returned by the parser */
int st_type; /* EXPR or SUITE ? */
PyCompilerFlags st_flags; /* Parser and compiler flags */
} PyST_Object;
static void parser_free(PyST_Object *st);
static PyObject* parser_richcompare(PyObject *left, PyObject *right, int op);
static PyObject* parser_compilest(PyST_Object *, PyObject *, PyObject *);
static PyObject* parser_isexpr(PyST_Object *, PyObject *, PyObject *);
static PyObject* parser_issuite(PyST_Object *, PyObject *, PyObject *);
static PyObject* parser_st2list(PyST_Object *, PyObject *, PyObject *);
static PyObject* parser_st2tuple(PyST_Object *, PyObject *, PyObject *);
#define PUBLIC_METHOD_TYPE (METH_VARARGS|METH_KEYWORDS)
static PyMethodDef parser_methods[] = {
{"compile", (PyCFunction)parser_compilest, PUBLIC_METHOD_TYPE,
PyDoc_STR("Compile this ST object into a code object.")},
{"isexpr", (PyCFunction)parser_isexpr, PUBLIC_METHOD_TYPE,
PyDoc_STR("Determines if this ST object was created from an expression.")},
{"issuite", (PyCFunction)parser_issuite, PUBLIC_METHOD_TYPE,
PyDoc_STR("Determines if this ST object was created from a suite.")},
{"tolist", (PyCFunction)parser_st2list, PUBLIC_METHOD_TYPE,
PyDoc_STR("Creates a list-tree representation of this ST.")},
{"totuple", (PyCFunction)parser_st2tuple, PUBLIC_METHOD_TYPE,
PyDoc_STR("Creates a tuple-tree representation of this ST.")},
{NULL, NULL, 0, NULL}
};
static
PyTypeObject PyST_Type = {
PyVarObject_HEAD_INIT(NULL, 0)
"parser.st", /* tp_name */
(int) sizeof(PyST_Object), /* tp_basicsize */
0, /* tp_itemsize */
(destructor)parser_free, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
0, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
/* Functions to access object as input/output buffer */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT, /* tp_flags */
/* __doc__ */
"Intermediate representation of a Python parse tree.",
0, /* tp_traverse */
0, /* tp_clear */
parser_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
parser_methods, /* tp_methods */
}; /* PyST_Type */
/* PyST_Type isn't subclassable, so just check ob_type */
#define PyST_Object_Check(v) ((v)->ob_type == &PyST_Type)
static int
parser_compare_nodes(node *left, node *right)
{
int j;
if (TYPE(left) < TYPE(right))
return (-1);
if (TYPE(right) < TYPE(left))
return (1);
if (ISTERMINAL(TYPE(left)))
return (strcmp(STR(left), STR(right)));
if (NCH(left) < NCH(right))
return (-1);
if (NCH(right) < NCH(left))
return (1);
for (j = 0; j < NCH(left); ++j) {
int v = parser_compare_nodes(CHILD(left, j), CHILD(right, j));
if (v != 0)
return (v);
}
return (0);
}
/* parser_richcompare(PyObject* left, PyObject* right, int op)
*
* Comparison function used by the Python operators ==, !=, <, >, <=, >=
* This really just wraps a call to parser_compare_nodes() with some easy
* checks and protection code.
*
*/
#define TEST_COND(cond) ((cond) ? Py_True : Py_False)
static PyObject *
parser_richcompare(PyObject *left, PyObject *right, int op)
{
int result;
PyObject *v;
/* neither argument should be NULL, unless something's gone wrong */
if (left == NULL || right == NULL) {
PyErr_BadInternalCall();
return NULL;
}
/* both arguments should be instances of PyST_Object */
if (!PyST_Object_Check(left) || !PyST_Object_Check(right)) {
v = Py_NotImplemented;
goto finished;
}
if (left == right)
/* if arguments are identical, they're equal */
result = 0;
else
result = parser_compare_nodes(((PyST_Object *)left)->st_node,
((PyST_Object *)right)->st_node);
/* Convert return value to a Boolean */
switch (op) {
case Py_EQ:
v = TEST_COND(result == 0);
break;
case Py_NE:
v = TEST_COND(result != 0);
break;
case Py_LE:
v = TEST_COND(result <= 0);
break;
case Py_GE:
v = TEST_COND(result >= 0);
break;
case Py_LT:
v = TEST_COND(result < 0);
break;
case Py_GT:
v = TEST_COND(result > 0);
break;
default:
PyErr_BadArgument();
return NULL;
}
finished:
Py_INCREF(v);
return v;
}
/* parser_newstobject(node* st)
*
* Allocates a new Python object representing an ST. This is simply the
* 'wrapper' object that holds a node* and allows it to be passed around in
* Python code.
*
*/
static PyObject*
parser_newstobject(node *st, int type)
{
PyST_Object* o = PyObject_New(PyST_Object, &PyST_Type);
if (o != 0) {
o->st_node = st;
o->st_type = type;
o->st_flags.cf_flags = 0;
}
else {
PyNode_Free(st);
}
return ((PyObject*)o);
}
/* void parser_free(PyST_Object* st)
*
* This is called by a del statement that reduces the reference count to 0.
*
*/
static void
parser_free(PyST_Object *st)
{
PyNode_Free(st->st_node);
PyObject_Del(st);
}
/* parser_st2tuple(PyObject* self, PyObject* args, PyObject* kw)
*
* This provides conversion from a node* to a tuple object that can be
* returned to the Python-level caller. The ST object is not modified.
*
*/
static PyObject*
parser_st2tuple(PyST_Object *self, PyObject *args, PyObject *kw)
{
PyObject *line_option = 0;
PyObject *col_option = 0;
PyObject *res = 0;
int ok;
static char *keywords[] = {"st", "line_info", "col_info", NULL};
if (self == NULL || PyModule_Check(self)) {
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!|OO:st2tuple", keywords,
&PyST_Type, &self, &line_option,
&col_option);
}
else
ok = PyArg_ParseTupleAndKeywords(args, kw, "|OO:totuple", &keywords[1],
&line_option, &col_option);
if (ok != 0) {
int lineno = 0;
int col_offset = 0;
if (line_option != NULL) {
lineno = (PyObject_IsTrue(line_option) != 0) ? 1 : 0;
}
if (col_option != NULL) {
col_offset = (PyObject_IsTrue(col_option) != 0) ? 1 : 0;
}
/*
* Convert ST into a tuple representation. Use Guido's function,
* since it's known to work already.
*/
res = node2tuple(((PyST_Object*)self)->st_node,
PyTuple_New, PyTuple_SetItem, lineno, col_offset);
}
return (res);
}
/* parser_st2list(PyObject* self, PyObject* args, PyObject* kw)
*
* This provides conversion from a node* to a list object that can be
* returned to the Python-level caller. The ST object is not modified.
*
*/
static PyObject*
parser_st2list(PyST_Object *self, PyObject *args, PyObject *kw)
{
PyObject *line_option = 0;
PyObject *col_option = 0;
PyObject *res = 0;
int ok;
static char *keywords[] = {"st", "line_info", "col_info", NULL};
if (self == NULL || PyModule_Check(self))
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!|OO:st2list", keywords,
&PyST_Type, &self, &line_option,
&col_option);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, "|OO:tolist", &keywords[1],
&line_option, &col_option);
if (ok) {
int lineno = 0;
int col_offset = 0;
if (line_option != 0) {
lineno = PyObject_IsTrue(line_option) ? 1 : 0;
}
if (col_option != NULL) {
col_offset = (PyObject_IsTrue(col_option) != 0) ? 1 : 0;
}
/*
* Convert ST into a tuple representation. Use Guido's function,
* since it's known to work already.
*/
res = node2tuple(self->st_node,
PyList_New, PyList_SetItem, lineno, col_offset);
}
return (res);
}
/* parser_compilest(PyObject* self, PyObject* args)
*
* This function creates code objects from the parse tree represented by
* the passed-in data object. An optional file name is passed in as well.
*
*/
static PyObject*
parser_compilest(PyST_Object *self, PyObject *args, PyObject *kw)
{
PyObject* res = 0;
PyArena* arena;
mod_ty mod;
char* str = "<syntax-tree>";
int ok;
static char *keywords[] = {"st", "filename", NULL};
if (self == NULL || PyModule_Check(self))
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!|s:compilest", keywords,
&PyST_Type, &self, &str);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, "|s:compile", &keywords[1],
&str);
if (ok) {
arena = PyArena_New();
if (arena) {
mod = PyAST_FromNode(self->st_node, &(self->st_flags), str, arena);
if (mod) {
res = (PyObject *)PyAST_Compile(mod, str, &(self->st_flags), arena);
}
PyArena_Free(arena);
}
}
return (res);
}
/* PyObject* parser_isexpr(PyObject* self, PyObject* args)
* PyObject* parser_issuite(PyObject* self, PyObject* args)
*
* Checks the passed-in ST object to determine if it is an expression or
* a statement suite, respectively. The return is a Python truth value.
*
*/
static PyObject*
parser_isexpr(PyST_Object *self, PyObject *args, PyObject *kw)
{
PyObject* res = 0;
int ok;
static char *keywords[] = {"st", NULL};
if (self == NULL || PyModule_Check(self))
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!:isexpr", keywords,
&PyST_Type, &self);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, ":isexpr", &keywords[1]);
if (ok) {
/* Check to see if the ST represents an expression or not. */
res = (self->st_type == PyST_EXPR) ? Py_True : Py_False;
Py_INCREF(res);
}
return (res);
}
static PyObject*
parser_issuite(PyST_Object *self, PyObject *args, PyObject *kw)
{
PyObject* res = 0;
int ok;
static char *keywords[] = {"st", NULL};
if (self == NULL || PyModule_Check(self))
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!:issuite", keywords,
&PyST_Type, &self);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, ":issuite", &keywords[1]);
if (ok) {
/* Check to see if the ST represents an expression or not. */
res = (self->st_type == PyST_EXPR) ? Py_False : Py_True;
Py_INCREF(res);
}
return (res);
}
/* err_string(char* message)
*
* Sets the error string for an exception of type ParserError.
*
*/
static void
err_string(char *message)
{
PyErr_SetString(parser_error, message);
}
/* PyObject* parser_do_parse(PyObject* args, int type)
*
* Internal function to actually execute the parse and return the result if
* successful or set an exception if not.
*
*/
static PyObject*
parser_do_parse(PyObject *args, PyObject *kw, char *argspec, int type)
{
char* string = 0;
PyObject* res = 0;
int flags = 0;
perrdetail err;
static char *keywords[] = {"source", NULL};
if (PyArg_ParseTupleAndKeywords(args, kw, argspec, keywords, &string)) {
node* n = PyParser_ParseStringFlagsFilenameEx(string, NULL,
&_PyParser_Grammar,
(type == PyST_EXPR)
? eval_input : file_input,
&err, &flags);
if (n) {
res = parser_newstobject(n, type);
if (res)
((PyST_Object *)res)->st_flags.cf_flags = flags & PyCF_MASK;
}
else
PyParser_SetError(&err);
}
return (res);
}
/* PyObject* parser_expr(PyObject* self, PyObject* args)
* PyObject* parser_suite(PyObject* self, PyObject* args)
*
* External interfaces to the parser itself. Which is called determines if
* the parser attempts to recognize an expression ('eval' form) or statement
* suite ('exec' form). The real work is done by parser_do_parse() above.
*
*/
static PyObject*
parser_expr(PyST_Object *self, PyObject *args, PyObject *kw)
{
NOTE(ARGUNUSED(self))
return (parser_do_parse(args, kw, "s:expr", PyST_EXPR));
}
static PyObject*
parser_suite(PyST_Object *self, PyObject *args, PyObject *kw)
{
NOTE(ARGUNUSED(self))
return (parser_do_parse(args, kw, "s:suite", PyST_SUITE));
}
/* This is the messy part of the code. Conversion from a tuple to an ST
* object requires that the input tuple be valid without having to rely on
* catching an exception from the compiler. This is done to allow the
* compiler itself to remain fast, since most of its input will come from
* the parser directly, and therefore be known to be syntactically correct.
* This validation is done to ensure that we don't core dump the compile
* phase, returning an exception instead.
*
* Two aspects can be broken out in this code: creating a node tree from
* the tuple passed in, and verifying that it is indeed valid. It may be
* advantageous to expand the number of ST types to include funcdefs and
* lambdadefs to take advantage of the optimizer, recognizing those STs
* here. They are not necessary, and not quite as useful in a raw form.
* For now, let's get expressions and suites working reliably.
*/
static node* build_node_tree(PyObject *tuple);
static int validate_expr_tree(node *tree);
static int validate_file_input(node *tree);
static int validate_encoding_decl(node *tree);
/* PyObject* parser_tuple2st(PyObject* self, PyObject* args)
*
* This is the public function, called from the Python code. It receives a
* single tuple object from the caller, and creates an ST object if the
* tuple can be validated. It does this by checking the first code of the
* tuple, and, if acceptable, builds the internal representation. If this
* step succeeds, the internal representation is validated as fully as
* possible with the various validate_*() routines defined below.
*
* This function must be changed if support is to be added for PyST_FRAGMENT
* ST objects.
*
*/
static PyObject*
parser_tuple2st(PyST_Object *self, PyObject *args, PyObject *kw)
{
NOTE(ARGUNUSED(self))
PyObject *st = 0;
PyObject *tuple;
node *tree;
static char *keywords[] = {"sequence", NULL};
if (!PyArg_ParseTupleAndKeywords(args, kw, "O:sequence2st", keywords,
&tuple))
return (0);
if (!PySequence_Check(tuple)) {
PyErr_SetString(PyExc_ValueError,
"sequence2st() requires a single sequence argument");
return (0);
}
/*
* Convert the tree to the internal form before checking it.
*/
tree = build_node_tree(tuple);
if (tree != 0) {
int start_sym = TYPE(tree);
if (start_sym == eval_input) {
/* Might be an eval form. */
if (validate_expr_tree(tree))
st = parser_newstobject(tree, PyST_EXPR);
else
PyNode_Free(tree);
}
else if (start_sym == file_input) {
/* This looks like an exec form so far. */
if (validate_file_input(tree))
st = parser_newstobject(tree, PyST_SUITE);
else
PyNode_Free(tree);
}
else if (start_sym == encoding_decl) {
/* This looks like an encoding_decl so far. */
if (validate_encoding_decl(tree))
st = parser_newstobject(tree, PyST_SUITE);
else
PyNode_Free(tree);
}
else {
/* This is a fragment, at best. */
PyNode_Free(tree);
err_string("parse tree does not use a valid start symbol");
}
}
/* Make sure we throw an exception on all errors. We should never
* get this, but we'd do well to be sure something is done.
*/
if (st == NULL && !PyErr_Occurred())
err_string("unspecified ST error occurred");
return st;
}
/* node* build_node_children()
*
* Iterate across the children of the current non-terminal node and build
* their structures. If successful, return the root of this portion of
* the tree, otherwise, 0. Any required exception will be specified already,
* and no memory will have been deallocated.
*
*/
static node*
build_node_children(PyObject *tuple, node *root, int *line_num)
{
Py_ssize_t len = PyObject_Size(tuple);
Py_ssize_t i;
int err;
for (i = 1; i < len; ++i) {
/* elem must always be a sequence, however simple */
PyObject* elem = PySequence_GetItem(tuple, i);
int ok = elem != NULL;
long type = 0;
char *strn = 0;
if (ok)
ok = PySequence_Check(elem);
if (ok) {
PyObject *temp = PySequence_GetItem(elem, 0);
if (temp == NULL)
ok = 0;
else {
ok = PyLong_Check(temp);
if (ok)
type = PyLong_AS_LONG(temp);
Py_DECREF(temp);
}
}
if (!ok) {
PyObject *err = Py_BuildValue("os", elem,
"Illegal node construct.");
PyErr_SetObject(parser_error, err);
Py_XDECREF(err);
Py_XDECREF(elem);
return (0);
}
if (ISTERMINAL(type)) {
Py_ssize_t len = PyObject_Size(elem);
PyObject *temp;
const char *temp_str;
if ((len != 2) && (len != 3)) {
err_string("terminal nodes must have 2 or 3 entries");
return 0;
}
temp = PySequence_GetItem(elem, 1);
if (temp == NULL)
return 0;
if (!PyUnicode_Check(temp)) {
PyErr_Format(parser_error,
"second item in terminal node must be a string,"
" found %s",
Py_TYPE(temp)->tp_name);
Py_DECREF(temp);
Py_DECREF(elem);
return 0;
}
if (len == 3) {
PyObject *o = PySequence_GetItem(elem, 2);
if (o != NULL) {
if (PyLong_Check(o))
*line_num = PyLong_AS_LONG(o);
else {
PyErr_Format(parser_error,
"third item in terminal node must be an"
" integer, found %s",
Py_TYPE(temp)->tp_name);
Py_DECREF(o);
Py_DECREF(temp);
Py_DECREF(elem);
return 0;
}
Py_DECREF(o);
}
}
temp_str = _PyUnicode_AsStringAndSize(temp, &len);
strn = (char *)PyObject_MALLOC(len + 1);
if (strn != NULL)
(void) memcpy(strn, temp_str, len + 1);
Py_DECREF(temp);
}
else if (!ISNONTERMINAL(type)) {
/*
* It has to be one or the other; this is an error.
* Throw an exception.
*/
PyObject *err = Py_BuildValue("os", elem, "unknown node type.");
PyErr_SetObject(parser_error, err);
Py_XDECREF(err);
Py_XDECREF(elem);
return (0);
}
err = PyNode_AddChild(root, type, strn, *line_num, 0);
if (err == E_NOMEM) {
Py_XDECREF(elem);
PyObject_FREE(strn);
return (node *) PyErr_NoMemory();
}
if (err == E_OVERFLOW) {
Py_XDECREF(elem);
PyObject_FREE(strn);
PyErr_SetString(PyExc_ValueError,
"unsupported number of child nodes");
return NULL;
}
if (ISNONTERMINAL(type)) {
node* new_child = CHILD(root, i - 1);
if (new_child != build_node_children(elem, new_child, line_num)) {
Py_XDECREF(elem);
return (0);
}
}
else if (type == NEWLINE) { /* It's true: we increment the */
++(*line_num); /* line number *after* the newline! */
}
Py_XDECREF(elem);
}
return root;
}
static node*
build_node_tree(PyObject *tuple)
{
node* res = 0;
PyObject *temp = PySequence_GetItem(tuple, 0);
long num = -1;
if (temp != NULL)
num = PyLong_AsLong(temp);
Py_XDECREF(temp);
if (ISTERMINAL(num)) {
/*
* The tuple is simple, but it doesn't start with a start symbol.
* Throw an exception now and be done with it.
*/
tuple = Py_BuildValue("os", tuple,
"Illegal syntax-tree; cannot start with terminal symbol.");
PyErr_SetObject(parser_error, tuple);
Py_XDECREF(tuple);
}
else if (ISNONTERMINAL(num)) {
/*
* Not efficient, but that can be handled later.
*/
int line_num = 0;
PyObject *encoding = NULL;
if (num == encoding_decl) {
encoding = PySequence_GetItem(tuple, 2);
/* tuple isn't borrowed anymore here, need to DECREF */
tuple = PySequence_GetSlice(tuple, 0, 2);
}
res = PyNode_New(num);
if (res != NULL) {
if (res != build_node_children(tuple, res, &line_num)) {
PyNode_Free(res);
res = NULL;
}
if (res && encoding) {
Py_ssize_t len;
const char *temp;
temp = _PyUnicode_AsStringAndSize(encoding, &len);
res->n_str = (char *)PyObject_MALLOC(len + 1);
if (res->n_str != NULL && temp != NULL)
(void) memcpy(res->n_str, temp, len + 1);
Py_DECREF(encoding);
Py_DECREF(tuple);
}
}
}
else {
/* The tuple is illegal -- if the number is neither TERMINAL nor
* NONTERMINAL, we can't use it. Not sure the implementation
* allows this condition, but the API doesn't preclude it.
*/
PyObject *err = Py_BuildValue("os", tuple,
"Illegal component tuple.");
PyErr_SetObject(parser_error, err);
Py_XDECREF(err);
}
return (res);
}
/*
* Validation routines used within the validation section:
*/
static int validate_terminal(node *terminal, int type, char *string);
#define validate_ampersand(ch) validate_terminal(ch, AMPER, "&")
#define validate_circumflex(ch) validate_terminal(ch, CIRCUMFLEX, "^")
#define validate_colon(ch) validate_terminal(ch, COLON, ":")
#define validate_comma(ch) validate_terminal(ch, COMMA, ",")
#define validate_dedent(ch) validate_terminal(ch, DEDENT, "")
#define validate_equal(ch) validate_terminal(ch, EQUAL, "=")
#define validate_indent(ch) validate_terminal(ch, INDENT, (char*)NULL)
#define validate_lparen(ch) validate_terminal(ch, LPAR, "(")
#define validate_newline(ch) validate_terminal(ch, NEWLINE, (char*)NULL)
#define validate_rparen(ch) validate_terminal(ch, RPAR, ")")
#define validate_semi(ch) validate_terminal(ch, SEMI, ";")
#define validate_star(ch) validate_terminal(ch, STAR, "*")
#define validate_vbar(ch) validate_terminal(ch, VBAR, "|")
#define validate_doublestar(ch) validate_terminal(ch, DOUBLESTAR, "**")
#define validate_dot(ch) validate_terminal(ch, DOT, ".")
#define validate_at(ch) validate_terminal(ch, AT, "@")
#define validate_name(ch, str) validate_terminal(ch, NAME, str)
#define VALIDATER(n) static int validate_##n(node *tree)
VALIDATER(node); VALIDATER(small_stmt);
VALIDATER(class); VALIDATER(node);
VALIDATER(parameters); VALIDATER(suite);
VALIDATER(testlist); VALIDATER(varargslist);
VALIDATER(vfpdef);
VALIDATER(stmt); VALIDATER(simple_stmt);
VALIDATER(expr_stmt); VALIDATER(power);
VALIDATER(del_stmt);
VALIDATER(return_stmt); VALIDATER(raise_stmt);
VALIDATER(import_stmt); VALIDATER(import_stmt);
VALIDATER(import_name); VALIDATER(yield_stmt);
VALIDATER(global_stmt); VALIDATER(assert_stmt);
VALIDATER(compound_stmt); VALIDATER(test_or_star_expr);
VALIDATER(while); VALIDATER(for);
VALIDATER(try); VALIDATER(except_clause);
VALIDATER(test); VALIDATER(and_test);
VALIDATER(not_test); VALIDATER(comparison);
VALIDATER(comp_op);
VALIDATER(star_expr); VALIDATER(expr);
VALIDATER(xor_expr); VALIDATER(and_expr);
VALIDATER(shift_expr); VALIDATER(arith_expr);
VALIDATER(term); VALIDATER(factor);
VALIDATER(atom); VALIDATER(lambdef);
VALIDATER(trailer); VALIDATER(subscript);
VALIDATER(subscriptlist); VALIDATER(sliceop);
VALIDATER(exprlist); VALIDATER(dictorsetmaker);
VALIDATER(arglist); VALIDATER(argument);
VALIDATER(comp_for);
VALIDATER(comp_iter); VALIDATER(comp_if);
VALIDATER(testlist_comp); VALIDATER(yield_expr);
VALIDATER(or_test);
VALIDATER(test_nocond); VALIDATER(lambdef_nocond);
#undef VALIDATER
#define is_even(n) (((n) & 1) == 0)
#define is_odd(n) (((n) & 1) == 1)
static int
validate_ntype(node *n, int t)
{
if (TYPE(n) != t) {
PyErr_Format(parser_error, "Expected node type %d, got %d.",
t, TYPE(n));
return 0;
}
return 1;
}
/* Verifies that the number of child nodes is exactly 'num', raising
* an exception if it isn't. The exception message does not indicate
* the exact number of nodes, allowing this to be used to raise the
* "right" exception when the wrong number of nodes is present in a
* specific variant of a statement's syntax. This is commonly used
* in that fashion.
*/
static int
validate_numnodes(node *n, int num, const char *const name)
{
if (NCH(n) != num) {
PyErr_Format(parser_error,
"Illegal number of children for %s node.", name);
return 0;
}
return 1;
}
static int
validate_terminal(node *terminal, int type, char *string)
{
int res = (validate_ntype(terminal, type)
&& ((string == 0) || (strcmp(string, STR(terminal)) == 0)));
if (!res && !PyErr_Occurred()) {
PyErr_Format(parser_error,
"Illegal terminal: expected \"%s\"", string);
}
return (res);
}
/* X (',' X) [',']
*/
static int
validate_repeating_list(node *tree, int ntype, int (*vfunc)(node *),
const char *const name)
{
int nch = NCH(tree);
int res = (nch && validate_ntype(tree, ntype)
&& vfunc(CHILD(tree, 0)));
if (!res && !PyErr_Occurred())
(void) validate_numnodes(tree, 1, name);
else {
if (is_even(nch))
res = validate_comma(CHILD(tree, --nch));
if (res && nch > 1) {
int pos = 1;
for ( ; res && pos < nch; pos += 2)
res = (validate_comma(CHILD(tree, pos))
&& vfunc(CHILD(tree, pos + 1)));
}
}
return (res);
}
/* validate_class()
*
* classdef:
* 'class' NAME ['(' testlist ')'] ':' suite
*/
static int
validate_class(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, classdef) &&
((nch == 4) || (nch == 6) || (nch == 7)));
if (res) {
res = (validate_name(CHILD(tree, 0), "class")
&& validate_ntype(CHILD(tree, 1), NAME)
&& validate_colon(CHILD(tree, nch - 2))
&& validate_suite(CHILD(tree, nch - 1)));
}
else {
(void) validate_numnodes(tree, 4, "class");
}
if (res) {
if (nch == 7) {
res = ((validate_lparen(CHILD(tree, 2)) &&
validate_arglist(CHILD(tree, 3)) &&
validate_rparen(CHILD(tree, 4))));
}
else if (nch == 6) {
res = (validate_lparen(CHILD(tree,2)) &&
validate_rparen(CHILD(tree,3)));
}
}
return (res);
}
/* if_stmt:
* 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
*/
static int
validate_if(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, if_stmt)
&& (nch >= 4)
&& validate_name(CHILD(tree, 0), "if")
&& validate_test(CHILD(tree, 1))
&& validate_colon(CHILD(tree, 2))
&& validate_suite(CHILD(tree, 3)));
if (res && ((nch % 4) == 3)) {
/* ... 'else' ':' suite */
res = (validate_name(CHILD(tree, nch - 3), "else")
&& validate_colon(CHILD(tree, nch - 2))
&& validate_suite(CHILD(tree, nch - 1)));
nch -= 3;
}
else if (!res && !PyErr_Occurred())
(void) validate_numnodes(tree, 4, "if");
if ((nch % 4) != 0)
/* Will catch the case for nch < 4 */
res = validate_numnodes(tree, 0, "if");
else if (res && (nch > 4)) {
/* ... ('elif' test ':' suite)+ ... */
int j = 4;
while ((j < nch) && res) {
res = (validate_name(CHILD(tree, j), "elif")
&& validate_colon(CHILD(tree, j + 2))
&& validate_test(CHILD(tree, j + 1))
&& validate_suite(CHILD(tree, j + 3)));
j += 4;
}
}
return (res);
}
/* parameters:
* '(' [varargslist] ')'
*
*/
static int
validate_parameters(node *tree)
{
int nch = NCH(tree);
int res = validate_ntype(tree, parameters) && ((nch == 2) || (nch == 3));
if (res) {
res = (validate_lparen(CHILD(tree, 0))
&& validate_rparen(CHILD(tree, nch - 1)));
if (res && (nch == 3))
res = validate_varargslist(CHILD(tree, 1));
}
else {
(void) validate_numnodes(tree, 2, "parameters");
}
return (res);
}
/* validate_suite()
*
* suite:
* simple_stmt
* | NEWLINE INDENT stmt+ DEDENT
*/
static int
validate_suite(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, suite) && ((nch == 1) || (nch >= 4)));
if (res && (nch == 1))
res = validate_simple_stmt(CHILD(tree, 0));
else if (res) {
/* NEWLINE INDENT stmt+ DEDENT */
res = (validate_newline(CHILD(tree, 0))
&& validate_indent(CHILD(tree, 1))
&& validate_stmt(CHILD(tree, 2))
&& validate_dedent(CHILD(tree, nch - 1)));
if (res && (nch > 4)) {
int i = 3;
--nch; /* forget the DEDENT */
for ( ; res && (i < nch); ++i)
res = validate_stmt(CHILD(tree, i));
}
else if (nch < 4)
res = validate_numnodes(tree, 4, "suite");
}
return (res);
}
static int
validate_testlist(node *tree)
{
return (validate_repeating_list(tree, testlist,
validate_test, "testlist"));
}
static int
validate_testlist_star_expr(node *tl)
{
return (validate_repeating_list(tl, testlist_star_expr, validate_test_or_star_expr,
"testlist"));
}
/* validate either vfpdef or tfpdef.
* vfpdef: NAME
* tfpdef: NAME [':' test]
*/
static int
validate_vfpdef(node *tree)
{
int nch = NCH(tree);
if (TYPE(tree) == vfpdef) {
return nch == 1 && validate_name(CHILD(tree, 0), NULL);
}
else if (TYPE(tree) == tfpdef) {
if (nch == 1) {
return validate_name(CHILD(tree, 0), NULL);
}
else if (nch == 3) {
return validate_name(CHILD(tree, 0), NULL) &&
validate_colon(CHILD(tree, 1)) &&
validate_test(CHILD(tree, 2));
}
}
return 0;
}
/* '*' vfpdef (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef
* ..or tfpdef in place of vfpdef. vfpdef: NAME; tfpdef: NAME [':' test]
*/
static int
validate_varargslist_trailer(node *tree, int start)
{
int nch = NCH(tree);
int res = 0, i;
int sym;
if (nch <= start) {
err_string("expected variable argument trailer for varargslist");
return 0;
}
sym = TYPE(CHILD(tree, start));
if (sym == STAR) {
/*
* '*' vfpdef (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef
*/
if (nch-start == 2)
res = validate_vfpdef(CHILD(tree, start+1));
else if (nch-start == 5 && TYPE(CHILD(tree, start+2)) == COMMA)
res = (validate_vfpdef(CHILD(tree, start+1))
&& validate_comma(CHILD(tree, start+2))
&& validate_doublestar(CHILD(tree, start+3))
&& validate_vfpdef(CHILD(tree, start+4)));
else {
/* skip over vfpdef (',' vfpdef ['=' test])* */
i = start + 1;
if (TYPE(CHILD(tree, i)) == vfpdef ||
TYPE(CHILD(tree, i)) == tfpdef) { /* skip over vfpdef or tfpdef */
i += 1;
}
while (res && i+1 < nch) { /* validate (',' vfpdef ['=' test])* */
res = validate_comma(CHILD(tree, i));
if (TYPE(CHILD(tree, i+1)) == DOUBLESTAR)
break;
res = res && validate_vfpdef(CHILD(tree, i+1));
if (res && i+2 < nch && TYPE(CHILD(tree, i+2)) == EQUAL) {
res = res && (i+3 < nch)
&& validate_test(CHILD(tree, i+3));
i += 4;
}
else {
i += 2;
}
}
/* [',' '**' vfpdef] */
if (res && i+1 < nch && TYPE(CHILD(tree, i+1)) == DOUBLESTAR) {
res = validate_vfpdef(CHILD(tree, i+2));
}
}
}
else if (sym == DOUBLESTAR) {
/*
* '**' NAME
*/
if (nch-start == 2)
res = validate_vfpdef(CHILD(tree, start+1));
}
if (!res)
err_string("illegal variable argument trailer for varargslist");
return res;
}
/* validate_varargslist()
*
* Validate typedargslist or varargslist.
*
* typedargslist: ((tfpdef ['=' test] ',')*
* ('*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] |
* '**' tfpdef)
* | tfpdef ['=' test] (',' tfpdef ['=' test])* [','])
* tfpdef: NAME [':' test]
* varargslist: ((vfpdef ['=' test] ',')*
* ('*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] |
* '**' vfpdef)
* | vfpdef ['=' test] (',' vfpdef ['=' test])* [','])
* vfpdef: NAME
*
*/
static int
validate_varargslist(node *tree)
{
int nch = NCH(tree);
int res = (TYPE(tree) == varargslist ||
TYPE(tree) == typedargslist) &&
(nch != 0);
int sym;
node *ch;
int i = 0;
if (!res)
return 0;
if (nch < 1) {
err_string("varargslist missing child nodes");
return 0;
}
while (i < nch) {
ch = CHILD(tree, i);
sym = TYPE(ch);
if (sym == vfpdef || sym == tfpdef) {
/* validate (vfpdef ['=' test] ',')+ */
res = validate_vfpdef(ch);
++i;
if (res && (i+2 <= nch) && TYPE(CHILD(tree, i)) == EQUAL) {
res = (validate_equal(CHILD(tree, i))
&& validate_test(CHILD(tree, i+1)));
if (res)
i += 2;
}
if (res && i < nch) {
res = validate_comma(CHILD(tree, i));
++i;
}
} else if (sym == DOUBLESTAR || sym == STAR) {
res = validate_varargslist_trailer(tree, i);
break;
} else {
res = 0;
err_string("illegal formation for varargslist");
}
}
return res;
}
/* comp_iter: comp_for | comp_if
*/
static int
validate_comp_iter(node *tree)
{
int res = (validate_ntype(tree, comp_iter)
&& validate_numnodes(tree, 1, "comp_iter"));
if (res && TYPE(CHILD(tree, 0)) == comp_for)
res = validate_comp_for(CHILD(tree, 0));
else
res = validate_comp_if(CHILD(tree, 0));
return res;
}
/* comp_for: 'for' exprlist 'in' test [comp_iter]
*/
static int
validate_comp_for(node *tree)
{
int nch = NCH(tree);
int res;
if (nch == 5)
res = validate_comp_iter(CHILD(tree, 4));
else
res = validate_numnodes(tree, 4, "comp_for");
if (res)
res = (validate_name(CHILD(tree, 0), "for")
&& validate_exprlist(CHILD(tree, 1))
&& validate_name(CHILD(tree, 2), "in")
&& validate_or_test(CHILD(tree, 3)));
return res;
}
/* comp_if: 'if' test_nocond [comp_iter]
*/
static int
validate_comp_if(node *tree)
{
int nch = NCH(tree);
int res;
if (nch == 3)
res = validate_comp_iter(CHILD(tree, 2));
else
res = validate_numnodes(tree, 2, "comp_if");
if (res)
res = (validate_name(CHILD(tree, 0), "if")
&& validate_test_nocond(CHILD(tree, 1)));
return res;
}
/* simple_stmt | compound_stmt
*
*/
static int
validate_stmt(node *tree)
{
int res = (validate_ntype(tree, stmt)
&& validate_numnodes(tree, 1, "stmt"));
if (res) {
tree = CHILD(tree, 0);
if (TYPE(tree) == simple_stmt)
res = validate_simple_stmt(tree);
else
res = validate_compound_stmt(tree);
}
return (res);
}
/* small_stmt (';' small_stmt)* [';'] NEWLINE
*
*/
static int
validate_simple_stmt(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, simple_stmt)
&& (nch >= 2)
&& validate_small_stmt(CHILD(tree, 0))
&& validate_newline(CHILD(tree, nch - 1)));
if (nch < 2)
res = validate_numnodes(tree, 2, "simple_stmt");
--nch; /* forget the NEWLINE */
if (res && is_even(nch))
res = validate_semi(CHILD(tree, --nch));
if (res && (nch > 2)) {
int i;
for (i = 1; res && (i < nch); i += 2)
res = (validate_semi(CHILD(tree, i))
&& validate_small_stmt(CHILD(tree, i + 1)));
}
return (res);
}
static int
validate_small_stmt(node *tree)
{
int nch = NCH(tree);
int res = validate_numnodes(tree, 1, "small_stmt");
if (res) {
int ntype = TYPE(CHILD(tree, 0));
if ( (ntype == expr_stmt)
|| (ntype == del_stmt)
|| (ntype == pass_stmt)
|| (ntype == flow_stmt)
|| (ntype == import_stmt)
|| (ntype == global_stmt)
|| (ntype == assert_stmt))
res = validate_node(CHILD(tree, 0));
else {
res = 0;
err_string("illegal small_stmt child type");
}
}
else if (nch == 1) {
res = 0;
PyErr_Format(parser_error,
"Unrecognized child node of small_stmt: %d.",
TYPE(CHILD(tree, 0)));
}
return (res);
}
/* compound_stmt:
* if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
*/
static int
validate_compound_stmt(node *tree)
{
int res = (validate_ntype(tree, compound_stmt)
&& validate_numnodes(tree, 1, "compound_stmt"));
int ntype;
if (!res)
return (0);
tree = CHILD(tree, 0);
ntype = TYPE(tree);
if ( (ntype == if_stmt)
|| (ntype == while_stmt)
|| (ntype == for_stmt)
|| (ntype == try_stmt)
|| (ntype == with_stmt)
|| (ntype == funcdef)
|| (ntype == classdef)
|| (ntype == decorated))
res = validate_node(tree);
else {
res = 0;
PyErr_Format(parser_error,
"Illegal compound statement type: %d.", TYPE(tree));
}
return (res);
}
static int
validate_yield_or_testlist(node *tree, int tse)
{
if (TYPE(tree) == yield_expr) {
return validate_yield_expr(tree);
}
else {
if (tse)
return validate_testlist_star_expr(tree);
else
return validate_testlist(tree);
}
}
static int
validate_expr_stmt(node *tree)
{
int j;
int nch = NCH(tree);
int res = (validate_ntype(tree, expr_stmt)
&& is_odd(nch)
&& validate_testlist_star_expr(CHILD(tree, 0)));
if (res && nch == 3
&& TYPE(CHILD(tree, 1)) == augassign) {
res = validate_numnodes(CHILD(tree, 1), 1, "augassign")
&& validate_yield_or_testlist(CHILD(tree, 2), 0);
if (res) {
char *s = STR(CHILD(CHILD(tree, 1), 0));
res = (strcmp(s, "+=") == 0
|| strcmp(s, "-=") == 0
|| strcmp(s, "*=") == 0
|| strcmp(s, "/=") == 0
|| strcmp(s, "//=") == 0
|| strcmp(s, "%=") == 0
|| strcmp(s, "&=") == 0
|| strcmp(s, "|=") == 0
|| strcmp(s, "^=") == 0
|| strcmp(s, "<<=") == 0
|| strcmp(s, ">>=") == 0
|| strcmp(s, "**=") == 0);
if (!res)
err_string("illegal augmmented assignment operator");
}
}
else {
for (j = 1; res && (j < nch); j += 2)
res = validate_equal(CHILD(tree, j))
&& validate_yield_or_testlist(CHILD(tree, j + 1), 1);
}
return (res);
}
static int
validate_del_stmt(node *tree)
{
return (validate_numnodes(tree, 2, "del_stmt")
&& validate_name(CHILD(tree, 0), "del")
&& validate_exprlist(CHILD(tree, 1)));
}
static int
validate_return_stmt(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, return_stmt)
&& ((nch == 1) || (nch == 2))
&& validate_name(CHILD(tree, 0), "return"));
if (res && (nch == 2))
res = validate_testlist(CHILD(tree, 1));
return (res);
}
static int
validate_raise_stmt(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, raise_stmt)
&& ((nch == 1) || (nch == 2) || (nch == 4) || (nch == 6)));
if (res) {
res = validate_name(CHILD(tree, 0), "raise");
if (res && (nch >= 2))
res = validate_test(CHILD(tree, 1));
if (res && nch > 2) {
res = (validate_comma(CHILD(tree, 2))
&& validate_test(CHILD(tree, 3)));
if (res && (nch > 4))
res = (validate_comma(CHILD(tree, 4))
&& validate_test(CHILD(tree, 5)));
}
}
else
(void) validate_numnodes(tree, 2, "raise");
if (res && (nch == 4))
res = (validate_comma(CHILD(tree, 2))
&& validate_test(CHILD(tree, 3)));
return (res);
}
/* yield_expr: 'yield' [testlist]
*/
static int
validate_yield_expr(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, yield_expr)
&& ((nch == 1) || (nch == 2))
&& validate_name(CHILD(tree, 0), "yield"));
if (res && (nch == 2))
res = validate_testlist(CHILD(tree, 1));
return (res);
}
/* yield_stmt: yield_expr
*/
static int
validate_yield_stmt(node *tree)
{
return (validate_ntype(tree, yield_stmt)
&& validate_numnodes(tree, 1, "yield_stmt")
&& validate_yield_expr(CHILD(tree, 0)));
}
static int
validate_import_as_name(node *tree)
{
int nch = NCH(tree);
int ok = validate_ntype(tree, import_as_name);
if (ok) {
if (nch == 1)
ok = validate_name(CHILD(tree, 0), NULL);
else if (nch == 3)
ok = (validate_name(CHILD(tree, 0), NULL)
&& validate_name(CHILD(tree, 1), "as")
&& validate_name(CHILD(tree, 2), NULL));
else
ok = validate_numnodes(tree, 3, "import_as_name");
}
return ok;
}
/* dotted_name: NAME ("." NAME)*
*/
static int
validate_dotted_name(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, dotted_name)
&& is_odd(nch)
&& validate_name(CHILD(tree, 0), NULL));
int i;
for (i = 1; res && (i < nch); i += 2) {
res = (validate_dot(CHILD(tree, i))
&& validate_name(CHILD(tree, i+1), NULL));
}
return res;
}
/* dotted_as_name: dotted_name [NAME NAME]
*/
static int
validate_dotted_as_name(node *tree)
{
int nch = NCH(tree);
int res = validate_ntype(tree, dotted_as_name);
if (res) {
if (nch == 1)
res = validate_dotted_name(CHILD(tree, 0));
else if (nch == 3)
res = (validate_dotted_name(CHILD(tree, 0))
&& validate_name(CHILD(tree, 1), "as")
&& validate_name(CHILD(tree, 2), NULL));
else {
res = 0;
err_string("illegal number of children for dotted_as_name");
}
}
return res;
}
/* dotted_as_name (',' dotted_as_name)* */
static int
validate_dotted_as_names(node *tree)
{
int nch = NCH(tree);
int res = is_odd(nch) && validate_dotted_as_name(CHILD(tree, 0));
int i;
for (i = 1; res && (i < nch); i += 2)
res = (validate_comma(CHILD(tree, i))
&& validate_dotted_as_name(CHILD(tree, i + 1)));
return (res);
}
/* import_as_name (',' import_as_name)* [','] */
static int
validate_import_as_names(node *tree)
{
int nch = NCH(tree);
int res = validate_import_as_name(CHILD(tree, 0));
int i;
for (i = 1; res && (i + 1 < nch); i += 2)
res = (validate_comma(CHILD(tree, i))
&& validate_import_as_name(CHILD(tree, i + 1)));
return (res);
}
/* 'import' dotted_as_names */
static int
validate_import_name(node *tree)
{
return (validate_ntype(tree, import_name)
&& validate_numnodes(tree, 2, "import_name")
&& validate_name(CHILD(tree, 0), "import")
&& validate_dotted_as_names(CHILD(tree, 1)));
}
/* Helper function to count the number of leading dots in
* 'from ...module import name'
*/
static int
count_from_dots(node *tree)
{
int i;
for (i = 1; i < NCH(tree); i++)
if (TYPE(CHILD(tree, i)) != DOT)
break;
return i-1;
}
/* 'from' ('.'* dotted_name | '.') 'import' ('*' | '(' import_as_names ')' |
* import_as_names
*/
static int
validate_import_from(node *tree)
{
int nch = NCH(tree);
int ndots = count_from_dots(tree);
int havename = (TYPE(CHILD(tree, ndots + 1)) == dotted_name);
int offset = ndots + havename;
int res = validate_ntype(tree, import_from)
&& (nch >= 4 + ndots)
&& validate_name(CHILD(tree, 0), "from")
&& (!havename || validate_dotted_name(CHILD(tree, ndots + 1)))
&& validate_name(CHILD(tree, offset + 1), "import");
if (res && TYPE(CHILD(tree, offset + 2)) == LPAR)
res = ((nch == offset + 5)
&& validate_lparen(CHILD(tree, offset + 2))
&& validate_import_as_names(CHILD(tree, offset + 3))
&& validate_rparen(CHILD(tree, offset + 4)));
else if (res && TYPE(CHILD(tree, offset + 2)) != STAR)
res = validate_import_as_names(CHILD(tree, offset + 2));
return (res);
}
/* import_stmt: import_name | import_from */
static int
validate_import_stmt(node *tree)
{
int nch = NCH(tree);
int res = validate_numnodes(tree, 1, "import_stmt");
if (res) {
int ntype = TYPE(CHILD(tree, 0));
if (ntype == import_name || ntype == import_from)
res = validate_node(CHILD(tree, 0));
else {
res = 0;
err_string("illegal import_stmt child type");
}
}
else if (nch == 1) {
res = 0;
PyErr_Format(parser_error,
"Unrecognized child node of import_stmt: %d.",
TYPE(CHILD(tree, 0)));
}
return (res);
}
static int
validate_global_stmt(node *tree)
{
int j;
int nch = NCH(tree);
int res = (validate_ntype(tree, global_stmt)
&& is_even(nch) && (nch >= 2));
if (!res && !PyErr_Occurred())
err_string("illegal global statement");
if (res)
res = (validate_name(CHILD(tree, 0), "global")
&& validate_ntype(CHILD(tree, 1), NAME));
for (j = 2; res && (j < nch); j += 2)
res = (validate_comma(CHILD(tree, j))
&& validate_ntype(CHILD(tree, j + 1), NAME));
return (res);
}
/* assert_stmt:
*
* 'assert' test [',' test]
*/
static int
validate_assert_stmt(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, assert_stmt)
&& ((nch == 2) || (nch == 4))
&& (validate_name(CHILD(tree, 0), "assert"))
&& validate_test(CHILD(tree, 1)));
if (!res && !PyErr_Occurred())
err_string("illegal assert statement");
if (res && (nch > 2))
res = (validate_comma(CHILD(tree, 2))
&& validate_test(CHILD(tree, 3)));
return (res);
}
static int
validate_while(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, while_stmt)
&& ((nch == 4) || (nch == 7))
&& validate_name(CHILD(tree, 0), "while")
&& validate_test(CHILD(tree, 1))
&& validate_colon(CHILD(tree, 2))
&& validate_suite(CHILD(tree, 3)));
if (res && (nch == 7))
res = (validate_name(CHILD(tree, 4), "else")
&& validate_colon(CHILD(tree, 5))
&& validate_suite(CHILD(tree, 6)));
return (res);
}
static int
validate_for(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, for_stmt)
&& ((nch == 6) || (nch == 9))
&& validate_name(CHILD(tree, 0), "for")
&& validate_exprlist(CHILD(tree, 1))
&& validate_name(CHILD(tree, 2), "in")
&& validate_testlist(CHILD(tree, 3))
&& validate_colon(CHILD(tree, 4))
&& validate_suite(CHILD(tree, 5)));
if (res && (nch == 9))
res = (validate_name(CHILD(tree, 6), "else")
&& validate_colon(CHILD(tree, 7))
&& validate_suite(CHILD(tree, 8)));
return (res);
}
/* try_stmt:
* 'try' ':' suite (except_clause ':' suite)+ ['else' ':' suite]
['finally' ':' suite]
* | 'try' ':' suite 'finally' ':' suite
*
*/
static int
validate_try(node *tree)
{
int nch = NCH(tree);
int pos = 3;
int res = (validate_ntype(tree, try_stmt)
&& (nch >= 6) && ((nch % 3) == 0));
if (res)
res = (validate_name(CHILD(tree, 0), "try")
&& validate_colon(CHILD(tree, 1))
&& validate_suite(CHILD(tree, 2))
&& validate_colon(CHILD(tree, nch - 2))
&& validate_suite(CHILD(tree, nch - 1)));
else if (!PyErr_Occurred()) {
const char* name = "except";
if (TYPE(CHILD(tree, nch - 3)) != except_clause)
name = STR(CHILD(tree, nch - 3));
PyErr_Format(parser_error,
"Illegal number of children for try/%s node.", name);
}
/* Handle try/finally statement */
if (res && (TYPE(CHILD(tree, pos)) == NAME) &&
(strcmp(STR(CHILD(tree, pos)), "finally") == 0)) {
res = (validate_numnodes(tree, 6, "try/finally")
&& validate_colon(CHILD(tree, 4))
&& validate_suite(CHILD(tree, 5)));
return (res);
}
/* try/except statement: skip past except_clause sections */
while (res && pos < nch && (TYPE(CHILD(tree, pos)) == except_clause)) {
res = (validate_except_clause(CHILD(tree, pos))
&& validate_colon(CHILD(tree, pos + 1))
&& validate_suite(CHILD(tree, pos + 2)));
pos += 3;
}
/* skip else clause */
if (res && pos < nch && (TYPE(CHILD(tree, pos)) == NAME) &&
(strcmp(STR(CHILD(tree, pos)), "else") == 0)) {
res = (validate_colon(CHILD(tree, pos + 1))
&& validate_suite(CHILD(tree, pos + 2)));
pos += 3;
}
if (res && pos < nch) {
/* last clause must be a finally */
res = (validate_name(CHILD(tree, pos), "finally")
&& validate_numnodes(tree, pos + 3, "try/except/finally")
&& validate_colon(CHILD(tree, pos + 1))
&& validate_suite(CHILD(tree, pos + 2)));
}
return (res);
}
static int
validate_except_clause(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, except_clause)
&& ((nch == 1) || (nch == 2) || (nch == 4))
&& validate_name(CHILD(tree, 0), "except"));
if (res && (nch > 1))
res = validate_test(CHILD(tree, 1));
if (res && (nch == 4))
res = (validate_name(CHILD(tree, 2), "as")
&& validate_ntype(CHILD(tree, 3), NAME));
return (res);
}
static int
validate_test(node *tree)
{
int nch = NCH(tree);
int res = validate_ntype(tree, test) && is_odd(nch);
if (res && (TYPE(CHILD(tree, 0)) == lambdef))
res = ((nch == 1)
&& validate_lambdef(CHILD(tree, 0)));
else if (res) {
res = validate_or_test(CHILD(tree, 0));
res = (res && (nch == 1 || (nch == 5 &&
validate_name(CHILD(tree, 1), "if") &&
validate_or_test(CHILD(tree, 2)) &&
validate_name(CHILD(tree, 3), "else") &&
validate_test(CHILD(tree, 4)))));
}
return (res);
}
static int
validate_test_nocond(node *tree)
{
int nch = NCH(tree);
int res = validate_ntype(tree, test_nocond) && (nch == 1);
if (res && (TYPE(CHILD(tree, 0)) == lambdef_nocond))
res = (validate_lambdef_nocond(CHILD(tree, 0)));
else if (res) {
res = (validate_or_test(CHILD(tree, 0)));
}
return (res);
}
static int
validate_or_test(node *tree)
{
int nch = NCH(tree);
int res = validate_ntype(tree, or_test) && is_odd(nch);
if (res) {
int pos;
res = validate_and_test(CHILD(tree, 0));
for (pos = 1; res && (pos < nch); pos += 2)
res = (validate_name(CHILD(tree, pos), "or")
&& validate_and_test(CHILD(tree, pos + 1)));
}
return (res);
}
static int
validate_and_test(node *tree)
{
int pos;
int nch = NCH(tree);
int res = (validate_ntype(tree, and_test)
&& is_odd(nch)
&& validate_not_test(CHILD(tree, 0)));
for (pos = 1; res && (pos < nch); pos += 2)
res = (validate_name(CHILD(tree, pos), "and")
&& validate_not_test(CHILD(tree, 0)));
return (res);
}
static int
validate_not_test(node *tree)
{
int nch = NCH(tree);
int res = validate_ntype(tree, not_test) && ((nch == 1) || (nch == 2));
if (res) {
if (nch == 2)
res = (validate_name(CHILD(tree, 0), "not")
&& validate_not_test(CHILD(tree, 1)));
else if (nch == 1)
res = validate_comparison(CHILD(tree, 0));
}
return (res);
}
static int
validate_comparison(node *tree)
{
int pos;
int nch = NCH(tree);
int res = (validate_ntype(tree, comparison)
&& is_odd(nch)
&& validate_expr(CHILD(tree, 0)));
for (pos = 1; res && (pos < nch); pos += 2)
res = (validate_comp_op(CHILD(tree, pos))
&& validate_expr(CHILD(tree, pos + 1)));
return (res);
}
static int
validate_comp_op(node *tree)
{
int res = 0;
int nch = NCH(tree);
if (!validate_ntype(tree, comp_op))
return (0);
if (nch == 1) {
/*
* Only child will be a terminal with a well-defined symbolic name
* or a NAME with a string of either 'is' or 'in'
*/
tree = CHILD(tree, 0);
switch (TYPE(tree)) {
case LESS:
case GREATER:
case EQEQUAL:
case EQUAL:
case LESSEQUAL:
case GREATEREQUAL:
case NOTEQUAL:
res = 1;
break;
case NAME:
res = ((strcmp(STR(tree), "in") == 0)
|| (strcmp(STR(tree), "is") == 0));
if (!res) {
PyErr_Format(parser_error,
"illegal operator '%s'", STR(tree));
}
break;
default:
err_string("illegal comparison operator type");
break;
}
}
else if ((res = validate_numnodes(tree, 2, "comp_op")) != 0) {
res = (validate_ntype(CHILD(tree, 0), NAME)
&& validate_ntype(CHILD(tree, 1), NAME)
&& (((strcmp(STR(CHILD(tree, 0)), "is") == 0)
&& (strcmp(STR(CHILD(tree, 1)), "not") == 0))
|| ((strcmp(STR(CHILD(tree, 0)), "not") == 0)
&& (strcmp(STR(CHILD(tree, 1)), "in") == 0))));
if (!res && !PyErr_Occurred())
err_string("unknown comparison operator");
}
return (res);
}
static int
validate_star_expr(node *tree)
{
int res = validate_ntype(tree, star_expr);
if (!res) return res;
if (!validate_numnodes(tree, 2, "star_expr"))
return 0;
return validate_ntype(CHILD(tree, 0), STAR) && \
validate_expr(CHILD(tree, 1));
}
static int
validate_expr(node *tree)
{
int j;
int nch = NCH(tree);
int res = (validate_ntype(tree, expr)
&& is_odd(nch)
&& validate_xor_expr(CHILD(tree, 0)));
for (j = 2; res && (j < nch); j += 2)
res = (validate_xor_expr(CHILD(tree, j))
&& validate_vbar(CHILD(tree, j - 1)));
return (res);
}
static int
validate_xor_expr(node *tree)
{
int j;
int nch = NCH(tree);
int res = (validate_ntype(tree, xor_expr)
&& is_odd(nch)
&& validate_and_expr(CHILD(tree, 0)));
for (j = 2; res && (j < nch); j += 2)
res = (validate_circumflex(CHILD(tree, j - 1))
&& validate_and_expr(CHILD(tree, j)));
return (res);
}
static int
validate_and_expr(node *tree)
{
int pos;
int nch = NCH(tree);
int res = (validate_ntype(tree, and_expr)
&& is_odd(nch)
&& validate_shift_expr(CHILD(tree, 0)));
for (pos = 1; res && (pos < nch); pos += 2)
res = (validate_ampersand(CHILD(tree, pos))
&& validate_shift_expr(CHILD(tree, pos + 1)));
return (res);
}
static int
validate_chain_two_ops(node *tree, int (*termvalid)(node *), int op1, int op2)
{
int pos = 1;
int nch = NCH(tree);
int res = (is_odd(nch)
&& (*termvalid)(CHILD(tree, 0)));
for ( ; res && (pos < nch); pos += 2) {
if (TYPE(CHILD(tree, pos)) != op1)
res = validate_ntype(CHILD(tree, pos), op2);
if (res)
res = (*termvalid)(CHILD(tree, pos + 1));
}
return (res);
}
static int
validate_shift_expr(node *tree)
{
return (validate_ntype(tree, shift_expr)
&& validate_chain_two_ops(tree, validate_arith_expr,
LEFTSHIFT, RIGHTSHIFT));
}
static int
validate_arith_expr(node *tree)
{
return (validate_ntype(tree, arith_expr)
&& validate_chain_two_ops(tree, validate_term, PLUS, MINUS));
}
static int
validate_term(node *tree)
{
int pos = 1;
int nch = NCH(tree);
int res = (validate_ntype(tree, term)
&& is_odd(nch)
&& validate_factor(CHILD(tree, 0)));
for ( ; res && (pos < nch); pos += 2)
res = (((TYPE(CHILD(tree, pos)) == STAR)
|| (TYPE(CHILD(tree, pos)) == SLASH)
|| (TYPE(CHILD(tree, pos)) == DOUBLESLASH)
|| (TYPE(CHILD(tree, pos)) == PERCENT))
&& validate_factor(CHILD(tree, pos + 1)));
return (res);
}
/* factor:
*
* factor: ('+'|'-'|'~') factor | power
*/
static int
validate_factor(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, factor)
&& (((nch == 2)
&& ((TYPE(CHILD(tree, 0)) == PLUS)
|| (TYPE(CHILD(tree, 0)) == MINUS)
|| (TYPE(CHILD(tree, 0)) == TILDE))
&& validate_factor(CHILD(tree, 1)))
|| ((nch == 1)
&& validate_power(CHILD(tree, 0)))));
return (res);
}
/* power:
*
* power: atom trailer* ('**' factor)*
*/
static int
validate_power(node *tree)
{
int pos = 1;
int nch = NCH(tree);
int res = (validate_ntype(tree, power) && (nch >= 1)
&& validate_atom(CHILD(tree, 0)));
while (res && (pos < nch) && (TYPE(CHILD(tree, pos)) == trailer))
res = validate_trailer(CHILD(tree, pos++));
if (res && (pos < nch)) {
if (!is_even(nch - pos)) {
err_string("illegal number of nodes for 'power'");
return (0);
}
for ( ; res && (pos < (nch - 1)); pos += 2)
res = (validate_doublestar(CHILD(tree, pos))
&& validate_factor(CHILD(tree, pos + 1)));
}
return (res);
}
static int
validate_atom(node *tree)
{
int pos;
int nch = NCH(tree);
int res = validate_ntype(tree, atom);
if (res && nch < 1)
res = validate_numnodes(tree, nch+1, "atom");
if (res) {
switch (TYPE(CHILD(tree, 0))) {
case LPAR:
res = ((nch <= 3)
&& (validate_rparen(CHILD(tree, nch - 1))));
if (res && (nch == 3)) {
if (TYPE(CHILD(tree, 1))==yield_expr)
res = validate_yield_expr(CHILD(tree, 1));
else
res = validate_testlist_comp(CHILD(tree, 1));
}
break;
case LSQB:
if (nch == 2)
res = validate_ntype(CHILD(tree, 1), RSQB);
else if (nch == 3)
res = (validate_testlist_comp(CHILD(tree, 1))
&& validate_ntype(CHILD(tree, 2), RSQB));
else {
res = 0;
err_string("illegal list display atom");
}
break;
case LBRACE:
res = ((nch <= 3)
&& validate_ntype(CHILD(tree, nch - 1), RBRACE));
if (res && (nch == 3))
res = validate_dictorsetmaker(CHILD(tree, 1));
break;
case NAME:
case NUMBER:
res = (nch == 1);
break;
case STRING:
for (pos = 1; res && (pos < nch); ++pos)
res = validate_ntype(CHILD(tree, pos), STRING);
break;
case DOT:
res = (nch == 3 &&
validate_ntype(CHILD(tree, 1), DOT) &&
validate_ntype(CHILD(tree, 2), DOT));
break;
default:
res = 0;
break;
}
}
return (res);
}
/* testlist_comp:
* test ( comp_for | (',' test)* [','] )
*/
static int
validate_testlist_comp(node *tree)
{
int nch = NCH(tree);
int ok = nch;
if (nch == 0)
err_string("missing child nodes of testlist_comp");
else {
ok = validate_test_or_star_expr(CHILD(tree, 0));
}
/*
* comp_for | (',' test)* [',']
*/
if (nch == 2 && TYPE(CHILD(tree, 1)) == comp_for)
ok = validate_comp_for(CHILD(tree, 1));
else {
/* (',' test)* [','] */
int i = 1;
while (ok && nch - i >= 2) {
ok = (validate_comma(CHILD(tree, i))
&& validate_test_or_star_expr(CHILD(tree, i+1)));
i += 2;
}
if (ok && i == nch-1)
ok = validate_comma(CHILD(tree, i));
else if (i != nch) {
ok = 0;
err_string("illegal trailing nodes for testlist_comp");
}
}
return ok;
}
/* decorator:
* '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
*/
static int
validate_decorator(node *tree)
{
int ok;
int nch = NCH(tree);
ok = (validate_ntype(tree, decorator) &&
(nch == 3 || nch == 5 || nch == 6) &&
validate_at(CHILD(tree, 0)) &&
validate_dotted_name(CHILD(tree, 1)) &&
validate_newline(RCHILD(tree, -1)));
if (ok && nch != 3) {
ok = (validate_lparen(CHILD(tree, 2)) &&
validate_rparen(RCHILD(tree, -2)));
if (ok && nch == 6)
ok = validate_arglist(CHILD(tree, 3));
}
return ok;
}
/* decorators:
* decorator+
*/
static int
validate_decorators(node *tree)
{
int i, nch, ok;
nch = NCH(tree);
ok = validate_ntype(tree, decorators) && nch >= 1;
for (i = 0; ok && i < nch; ++i)
ok = validate_decorator(CHILD(tree, i));
return ok;
}
/* with_item:
* test ['as' expr]
*/
static int
validate_with_item(node *tree)
{
int nch = NCH(tree);
int ok = (validate_ntype(tree, with_item)
&& (nch == 1 || nch == 3)
&& validate_test(CHILD(tree, 0)));
if (ok && nch == 3)
ok = (validate_name(CHILD(tree, 1), "as")
&& validate_expr(CHILD(tree, 2)));
return ok;
}
/* with_stmt:
* 0 1 ... -2 -1
* 'with' with_item (',' with_item)* ':' suite
*/
static int
validate_with_stmt(node *tree)
{
int i;
int nch = NCH(tree);
int ok = (validate_ntype(tree, with_stmt)
&& (nch % 2 == 0)
&& validate_name(CHILD(tree, 0), "with")
&& validate_colon(RCHILD(tree, -2))
&& validate_suite(RCHILD(tree, -1)));
for (i = 1; ok && i < nch - 2; i += 2)
ok = validate_with_item(CHILD(tree, i));
return ok;
}
/* funcdef:
*
* -5 -4 -3 -2 -1
* 'def' NAME parameters ':' suite
*/
static int
validate_funcdef(node *tree)
{
int nch = NCH(tree);
int ok = (validate_ntype(tree, funcdef)
&& (nch == 5)
&& validate_name(RCHILD(tree, -5), "def")
&& validate_ntype(RCHILD(tree, -4), NAME)
&& validate_colon(RCHILD(tree, -2))
&& validate_parameters(RCHILD(tree, -3))
&& validate_suite(RCHILD(tree, -1)));
return ok;
}
/* decorated
* decorators (classdef | funcdef)
*/
static int
validate_decorated(node *tree)
{
int nch = NCH(tree);
int ok = (validate_ntype(tree, decorated)
&& (nch == 2)
&& validate_decorators(RCHILD(tree, -2))
&& (validate_funcdef(RCHILD(tree, -1))
|| validate_class(RCHILD(tree, -1)))
);
return ok;
}
static int
validate_lambdef(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, lambdef)
&& ((nch == 3) || (nch == 4))
&& validate_name(CHILD(tree, 0), "lambda")
&& validate_colon(CHILD(tree, nch - 2))
&& validate_test(CHILD(tree, nch - 1)));
if (res && (nch == 4))
res = validate_varargslist(CHILD(tree, 1));
else if (!res && !PyErr_Occurred())
(void) validate_numnodes(tree, 3, "lambdef");
return (res);
}
static int
validate_lambdef_nocond(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, lambdef_nocond)
&& ((nch == 3) || (nch == 4))
&& validate_name(CHILD(tree, 0), "lambda")
&& validate_colon(CHILD(tree, nch - 2))
&& validate_test(CHILD(tree, nch - 1)));
if (res && (nch == 4))
res = validate_varargslist(CHILD(tree, 1));
else if (!res && !PyErr_Occurred())
(void) validate_numnodes(tree, 3, "lambdef_nocond");
return (res);
}
/* arglist:
*
* (argument ',')* (argument [','] | '*' test [',' '**' test] | '**' test)
*/
static int
validate_arglist(node *tree)
{
int nch = NCH(tree);
int i = 0;
int ok = 1;
if (nch <= 0)
/* raise the right error from having an invalid number of children */
return validate_numnodes(tree, nch + 1, "arglist");
if (nch > 1) {
for (i=0; i<nch; i++) {
if (TYPE(CHILD(tree, i)) == argument) {
node *ch = CHILD(tree, i);
if (NCH(ch) == 2 && TYPE(CHILD(ch, 1)) == comp_for) {
err_string("need '(', ')' for generator expression");
return 0;
}
}
}
}
while (ok && nch-i >= 2) {
/* skip leading (argument ',') */
ok = (validate_argument(CHILD(tree, i))
&& validate_comma(CHILD(tree, i+1)));
if (ok)
i += 2;
else
PyErr_Clear();
}
ok = 1;
if (nch-i > 0) {
/*
* argument | '*' test [',' '**' test] | '**' test
*/
int sym = TYPE(CHILD(tree, i));
if (sym == argument) {
ok = validate_argument(CHILD(tree, i));
if (ok && i+1 != nch) {
err_string("illegal arglist specification"
" (extra stuff on end)");
ok = 0;
}
}
else if (sym == STAR) {
ok = validate_star(CHILD(tree, i));
if (ok && (nch-i == 2))
ok = validate_test(CHILD(tree, i+1));
else if (ok && (nch-i == 5))
ok = (validate_test(CHILD(tree, i+1))
&& validate_comma(CHILD(tree, i+2))
&& validate_doublestar(CHILD(tree, i+3))
&& validate_test(CHILD(tree, i+4)));
else {
err_string("illegal use of '*' in arglist");
ok = 0;
}
}
else if (sym == DOUBLESTAR) {
if (nch-i == 2)
ok = (validate_doublestar(CHILD(tree, i))
&& validate_test(CHILD(tree, i+1)));
else {
err_string("illegal use of '**' in arglist");
ok = 0;
}
}
else {
err_string("illegal arglist specification");
ok = 0;
}
}
return (ok);
}
/* argument:
*
* [test '='] test [comp_for]
*/
static int
validate_argument(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, argument)
&& ((nch == 1) || (nch == 2) || (nch == 3))
&& validate_test(CHILD(tree, 0)));
if (res && (nch == 2))
res = validate_comp_for(CHILD(tree, 1));
else if (res && (nch == 3))
res = (validate_equal(CHILD(tree, 1))
&& validate_test(CHILD(tree, 2)));
return (res);
}
/* trailer:
*
* '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
*/
static int
validate_trailer(node *tree)
{
int nch = NCH(tree);
int res = validate_ntype(tree, trailer) && ((nch == 2) || (nch == 3));
if (res) {
switch (TYPE(CHILD(tree, 0))) {
case LPAR:
res = validate_rparen(CHILD(tree, nch - 1));
if (res && (nch == 3))
res = validate_arglist(CHILD(tree, 1));
break;
case LSQB:
res = (validate_numnodes(tree, 3, "trailer")
&& validate_subscriptlist(CHILD(tree, 1))
&& validate_ntype(CHILD(tree, 2), RSQB));
break;
case DOT:
res = (validate_numnodes(tree, 2, "trailer")
&& validate_ntype(CHILD(tree, 1), NAME));
break;
default:
res = 0;
break;
}
}
else {
(void) validate_numnodes(tree, 2, "trailer");
}
return (res);
}
/* subscriptlist:
*
* subscript (',' subscript)* [',']
*/
static int
validate_subscriptlist(node *tree)
{
return (validate_repeating_list(tree, subscriptlist,
validate_subscript, "subscriptlist"));
}
/* subscript:
*
* '.' '.' '.' | test | [test] ':' [test] [sliceop]
*/
static int
validate_subscript(node *tree)
{
int offset = 0;
int nch = NCH(tree);
int res = validate_ntype(tree, subscript) && (nch >= 1) && (nch <= 4);
if (!res) {
if (!PyErr_Occurred())
err_string("invalid number of arguments for subscript node");
return (0);
}
if (TYPE(CHILD(tree, 0)) == DOT)
/* take care of ('.' '.' '.') possibility */
return (validate_numnodes(tree, 3, "subscript")
&& validate_dot(CHILD(tree, 0))
&& validate_dot(CHILD(tree, 1))
&& validate_dot(CHILD(tree, 2)));
if (nch == 1) {
if (TYPE(CHILD(tree, 0)) == test)
res = validate_test(CHILD(tree, 0));
else
res = validate_colon(CHILD(tree, 0));
return (res);
}
/* Must be [test] ':' [test] [sliceop],
* but at least one of the optional components will
* be present, but we don't know which yet.
*/
if ((TYPE(CHILD(tree, 0)) != COLON) || (nch == 4)) {
res = validate_test(CHILD(tree, 0));
offset = 1;
}
if (res)
res = validate_colon(CHILD(tree, offset));
if (res) {
int rem = nch - ++offset;
if (rem) {
if (TYPE(CHILD(tree, offset)) == test) {
res = validate_test(CHILD(tree, offset));
++offset;
--rem;
}
if (res && rem)
res = validate_sliceop(CHILD(tree, offset));
}
}
return (res);
}
static int
validate_sliceop(node *tree)
{
int nch = NCH(tree);
int res = ((nch == 1) || validate_numnodes(tree, 2, "sliceop"))
&& validate_ntype(tree, sliceop);
if (!res && !PyErr_Occurred()) {
res = validate_numnodes(tree, 1, "sliceop");
}
if (res)
res = validate_colon(CHILD(tree, 0));
if (res && (nch == 2))
res = validate_test(CHILD(tree, 1));
return (res);
}
static int
validate_test_or_star_expr(node *n)
{
if (TYPE(n) == test)
return validate_test(n);
return validate_star_expr(n);
}
static int
validate_expr_or_star_expr(node *n)
{
if (TYPE(n) == expr)
return validate_expr(n);
return validate_star_expr(n);
}
static int
validate_exprlist(node *tree)
{
return (validate_repeating_list(tree, exprlist,
validate_expr_or_star_expr, "exprlist"));
}
static int
validate_dictorsetmaker(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, dictorsetmaker)
&& (nch >= 3)
&& validate_test(CHILD(tree, 0))
&& validate_colon(CHILD(tree, 1))
&& validate_test(CHILD(tree, 2)));
if (res && ((nch % 4) == 0))
res = validate_comma(CHILD(tree, --nch));
else if (res)
res = ((nch % 4) == 3);
if (res && (nch > 3)) {
int pos = 3;
/* ( ',' test ':' test )* */
while (res && (pos < nch)) {
res = (validate_comma(CHILD(tree, pos))
&& validate_test(CHILD(tree, pos + 1))
&& validate_colon(CHILD(tree, pos + 2))
&& validate_test(CHILD(tree, pos + 3)));
pos += 4;
}
}
return (res);
}
static int
validate_eval_input(node *tree)
{
int pos;
int nch = NCH(tree);
int res = (validate_ntype(tree, eval_input)
&& (nch >= 2)
&& validate_testlist(CHILD(tree, 0))
&& validate_ntype(CHILD(tree, nch - 1), ENDMARKER));
for (pos = 1; res && (pos < (nch - 1)); ++pos)
res = validate_ntype(CHILD(tree, pos), NEWLINE);
return (res);
}
static int
validate_node(node *tree)
{
int nch = 0; /* num. children on current node */
int res = 1; /* result value */
node* next = 0; /* node to process after this one */
while (res && (tree != 0)) {
nch = NCH(tree);
next = 0;
switch (TYPE(tree)) {
/*
* Definition nodes.
*/
case funcdef:
res = validate_funcdef(tree);
break;
case with_stmt:
res = validate_with_stmt(tree);
break;
case classdef:
res = validate_class(tree);
break;
case decorated:
res = validate_decorated(tree);
break;
/*
* "Trivial" parse tree nodes.
* (Why did I call these trivial?)
*/
case stmt:
res = validate_stmt(tree);
break;
case small_stmt:
/*
* expr_stmt | del_stmt | pass_stmt | flow_stmt
* | import_stmt | global_stmt | assert_stmt
*/
res = validate_small_stmt(tree);
break;
case flow_stmt:
res = (validate_numnodes(tree, 1, "flow_stmt")
&& ((TYPE(CHILD(tree, 0)) == break_stmt)
|| (TYPE(CHILD(tree, 0)) == continue_stmt)
|| (TYPE(CHILD(tree, 0)) == yield_stmt)
|| (TYPE(CHILD(tree, 0)) == return_stmt)
|| (TYPE(CHILD(tree, 0)) == raise_stmt)));
if (res)
next = CHILD(tree, 0);
else if (nch == 1)
err_string("illegal flow_stmt type");
break;
case yield_stmt:
res = validate_yield_stmt(tree);
break;
/*
* Compound statements.
*/
case simple_stmt:
res = validate_simple_stmt(tree);
break;
case compound_stmt:
res = validate_compound_stmt(tree);
break;
/*
* Fundamental statements.
*/
case expr_stmt:
res = validate_expr_stmt(tree);
break;
case del_stmt:
res = validate_del_stmt(tree);
break;
case pass_stmt:
res = (validate_numnodes(tree, 1, "pass")
&& validate_name(CHILD(tree, 0), "pass"));
break;
case break_stmt:
res = (validate_numnodes(tree, 1, "break")
&& validate_name(CHILD(tree, 0), "break"));
break;
case continue_stmt:
res = (validate_numnodes(tree, 1, "continue")
&& validate_name(CHILD(tree, 0), "continue"));
break;
case return_stmt:
res = validate_return_stmt(tree);
break;
case raise_stmt:
res = validate_raise_stmt(tree);
break;
case import_stmt:
res = validate_import_stmt(tree);
break;
case import_name:
res = validate_import_name(tree);
break;
case import_from:
res = validate_import_from(tree);
break;
case global_stmt:
res = validate_global_stmt(tree);
break;
case assert_stmt:
res = validate_assert_stmt(tree);
break;
case if_stmt:
res = validate_if(tree);
break;
case while_stmt:
res = validate_while(tree);
break;
case for_stmt:
res = validate_for(tree);
break;
case try_stmt:
res = validate_try(tree);
break;
case suite:
res = validate_suite(tree);
break;
/*
* Expression nodes.
*/
case testlist:
res = validate_testlist(tree);
break;
case yield_expr:
res = validate_yield_expr(tree);
break;
case test:
res = validate_test(tree);
break;
case and_test:
res = validate_and_test(tree);
break;
case not_test:
res = validate_not_test(tree);
break;
case comparison:
res = validate_comparison(tree);
break;
case exprlist:
res = validate_exprlist(tree);
break;
case comp_op:
res = validate_comp_op(tree);
break;
case expr:
res = validate_expr(tree);
break;
case xor_expr:
res = validate_xor_expr(tree);
break;
case and_expr:
res = validate_and_expr(tree);
break;
case shift_expr:
res = validate_shift_expr(tree);
break;
case arith_expr:
res = validate_arith_expr(tree);
break;
case term:
res = validate_term(tree);
break;
case factor:
res = validate_factor(tree);
break;
case power:
res = validate_power(tree);
break;
case atom:
res = validate_atom(tree);
break;
default:
/* Hopefully never reached! */
err_string("unrecognized node type");
res = 0;
break;
}
tree = next;
}
return (res);
}
static int
validate_expr_tree(node *tree)
{
int res = validate_eval_input(tree);
if (!res && !PyErr_Occurred())
err_string("could not validate expression tuple");
return (res);
}
/* file_input:
* (NEWLINE | stmt)* ENDMARKER
*/
static int
validate_file_input(node *tree)
{
int j;
int nch = NCH(tree) - 1;
int res = ((nch >= 0)
&& validate_ntype(CHILD(tree, nch), ENDMARKER));
for (j = 0; res && (j < nch); ++j) {
if (TYPE(CHILD(tree, j)) == stmt)
res = validate_stmt(CHILD(tree, j));
else
res = validate_newline(CHILD(tree, j));
}
/* This stays in to prevent any internal failures from getting to the
* user. Hopefully, this won't be needed. If a user reports getting
* this, we have some debugging to do.
*/
if (!res && !PyErr_Occurred())
err_string("VALIDATION FAILURE: report this to the maintainer!");
return (res);
}
static int
validate_encoding_decl(node *tree)
{
int nch = NCH(tree);
int res = ((nch == 1)
&& validate_file_input(CHILD(tree, 0)));
if (!res && !PyErr_Occurred())
err_string("Error Parsing encoding_decl");
return res;
}
static PyObject*
pickle_constructor = NULL;
static PyObject*
parser__pickler(PyObject *self, PyObject *args)
{
NOTE(ARGUNUSED(self))
PyObject *result = NULL;
PyObject *st = NULL;
PyObject *empty_dict = NULL;
if (PyArg_ParseTuple(args, "O!:_pickler", &PyST_Type, &st)) {
PyObject *newargs;
PyObject *tuple;
if ((empty_dict = PyDict_New()) == NULL)
goto finally;
if ((newargs = Py_BuildValue("Oi", st, 1)) == NULL)
goto finally;
tuple = parser_st2tuple((PyST_Object*)NULL, newargs, empty_dict);
if (tuple != NULL) {
result = Py_BuildValue("O(O)", pickle_constructor, tuple);
Py_DECREF(tuple);
}
Py_DECREF(empty_dict);
Py_DECREF(newargs);
}
finally:
Py_XDECREF(empty_dict);
return (result);
}
/* Functions exported by this module. Most of this should probably
* be converted into an ST object with methods, but that is better
* done directly in Python, allowing subclasses to be created directly.
* We'd really have to write a wrapper around it all anyway to allow
* inheritance.
*/
static PyMethodDef parser_functions[] = {
{"compilest", (PyCFunction)parser_compilest, PUBLIC_METHOD_TYPE,
PyDoc_STR("Compiles an ST object into a code object.")},
{"expr", (PyCFunction)parser_expr, PUBLIC_METHOD_TYPE,
PyDoc_STR("Creates an ST object from an expression.")},
{"isexpr", (PyCFunction)parser_isexpr, PUBLIC_METHOD_TYPE,
PyDoc_STR("Determines if an ST object was created from an expression.")},
{"issuite", (PyCFunction)parser_issuite, PUBLIC_METHOD_TYPE,
PyDoc_STR("Determines if an ST object was created from a suite.")},
{"suite", (PyCFunction)parser_suite, PUBLIC_METHOD_TYPE,
PyDoc_STR("Creates an ST object from a suite.")},
{"sequence2st", (PyCFunction)parser_tuple2st, PUBLIC_METHOD_TYPE,
PyDoc_STR("Creates an ST object from a tree representation.")},
{"st2tuple", (PyCFunction)parser_st2tuple, PUBLIC_METHOD_TYPE,
PyDoc_STR("Creates a tuple-tree representation of an ST.")},
{"st2list", (PyCFunction)parser_st2list, PUBLIC_METHOD_TYPE,
PyDoc_STR("Creates a list-tree representation of an ST.")},
{"tuple2st", (PyCFunction)parser_tuple2st, PUBLIC_METHOD_TYPE,
PyDoc_STR("Creates an ST object from a tree representation.")},
/* private stuff: support pickle module */
{"_pickler", (PyCFunction)parser__pickler, METH_VARARGS,
PyDoc_STR("Returns the pickle magic to allow ST objects to be pickled.")},
{NULL, NULL, 0, NULL}
};
static struct PyModuleDef parsermodule = {
PyModuleDef_HEAD_INIT,
"parser",
NULL,
-1,
parser_functions,
NULL,
NULL,
NULL,
NULL
};
PyMODINIT_FUNC PyInit_parser(void); /* supply a prototype */
PyMODINIT_FUNC
PyInit_parser(void)
{
PyObject *module, *copyreg;
if (PyType_Ready(&PyST_Type) < 0)
return NULL;
module = PyModule_Create(&parsermodule);
if (module == NULL)
return NULL;
if (parser_error == 0)
parser_error = PyErr_NewException("parser.ParserError", NULL, NULL);
if (parser_error == 0)
return NULL;
/* CAUTION: The code next used to skip bumping the refcount on
* parser_error. That's a disaster if PyInit_parser() gets called more
* than once. By incref'ing, we ensure that each module dict that
* gets created owns its reference to the shared parser_error object,
* and the file static parser_error vrbl owns a reference too.
*/
Py_INCREF(parser_error);
if (PyModule_AddObject(module, "ParserError", parser_error) != 0)
return NULL;
Py_INCREF(&PyST_Type);
PyModule_AddObject(module, "STType", (PyObject*)&PyST_Type);
PyModule_AddStringConstant(module, "__copyright__",
parser_copyright_string);
PyModule_AddStringConstant(module, "__doc__",
parser_doc_string);
PyModule_AddStringConstant(module, "__version__",
parser_version_string);
/* Register to support pickling.
* If this fails, the import of this module will fail because an
* exception will be raised here; should we clear the exception?
*/
copyreg = PyImport_ImportModuleNoBlock("copyreg");
if (copyreg != NULL) {
PyObject *func, *pickler;
func = PyObject_GetAttrString(copyreg, "pickle");
pickle_constructor = PyObject_GetAttrString(module, "sequence2st");
pickler = PyObject_GetAttrString(module, "_pickler");
Py_XINCREF(pickle_constructor);
if ((func != NULL) && (pickle_constructor != NULL)
&& (pickler != NULL)) {
PyObject *res;
res = PyObject_CallFunctionObjArgs(func, &PyST_Type, pickler,
pickle_constructor, NULL);
Py_XDECREF(res);
}
Py_XDECREF(func);
Py_XDECREF(pickle_constructor);
Py_XDECREF(pickler);
Py_DECREF(copyreg);
}
return module;
}
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