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cpython/Modules/parsermodule.c
Fred Drake 711370831a Fix problems with validation of import statement parse trees. 
This closes SF bug #127271.
2001-01-07 05:59:59 +00:00

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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 "graminit.h" /* symbols defined in the grammar */
#include "node.h" /* internal parser structure */
#include "token.h" /* token definitions */
/* ISTERMINAL() / ISNONTERMINAL() */
#include "compile.h" /* PyNode_Compile() */
#ifdef lint
#include <note.h>
#else
#define NOTE(x)
#endif
#ifdef macintosh
char *strdup(char *);
#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.";
static char*
parser_doc_string
= "This is an interface to Python's internal parser.";
static char*
parser_version_string = "0.5";
typedef PyObject* (*SeqMaker) (int length);
typedef int (*SeqInserter) (PyObject* sequence,
int 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? */
{
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));
if (v == NULL)
return (v);
w = PyInt_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);
if (w == NULL) {
Py_DECREF(v);
return ((PyObject*) NULL);
}
(void) addelem(v, i+1, w);
}
return (v);
}
else if (ISTERMINAL(TYPE(n))) {
PyObject *result = mkseq(2 + lineno);
if (result != NULL) {
(void) addelem(result, 0, PyInt_FromLong(TYPE(n)));
(void) addelem(result, 1, PyString_FromString(STR(n)));
if (lineno == 1)
(void) addelem(result, 2, PyInt_FromLong(n->n_lineno));
}
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 ast_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. ;-)
*
* The PyAST_FRAGMENT type is not currently supported. Maybe not useful?
* Haven't decided yet.
*/
#define PyAST_EXPR 1
#define PyAST_SUITE 2
#define PyAST_FRAGMENT 3
/* These are the internal objects and definitions required to implement the
* AST 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 _PyAST_Object {
PyObject_HEAD /* standard object header */
node* ast_node; /* the node* returned by the parser */
int ast_type; /* EXPR or SUITE ? */
} PyAST_Object;
staticforward void
parser_free(PyAST_Object *ast);
staticforward int
parser_compare(PyAST_Object *left, PyAST_Object *right);
staticforward PyObject *
parser_getattr(PyObject *self, char *name);
static
PyTypeObject PyAST_Type = {
PyObject_HEAD_INIT(NULL)
0,
"ast", /* tp_name */
(int) sizeof(PyAST_Object), /* tp_basicsize */
0, /* tp_itemsize */
(destructor)parser_free, /* tp_dealloc */
0, /* tp_print */
parser_getattr, /* tp_getattr */
0, /* tp_setattr */
(cmpfunc)parser_compare, /* tp_compare */
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."
}; /* PyAST_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);
}
/* int parser_compare(PyAST_Object* left, PyAST_Object* right)
*
* Comparison function used by the Python operators ==, !=, <, >, <=, >=
* This really just wraps a call to parser_compare_nodes() with some easy
* checks and protection code.
*
*/
static int
parser_compare(PyAST_Object *left, PyAST_Object *right)
{
if (left == right)
return (0);
if ((left == 0) || (right == 0))
return (-1);
return (parser_compare_nodes(left->ast_node, right->ast_node));
}
/* parser_newastobject(node* ast)
*
* Allocates a new Python object representing an AST. This is simply the
* 'wrapper' object that holds a node* and allows it to be passed around in
* Python code.
*
*/
static PyObject*
parser_newastobject(node *ast, int type)
{
PyAST_Object* o = PyObject_New(PyAST_Object, &PyAST_Type);
if (o != 0) {
o->ast_node = ast;
o->ast_type = type;
}
else {
PyNode_Free(ast);
}
return ((PyObject*)o);
}
/* void parser_free(PyAST_Object* ast)
*
* This is called by a del statement that reduces the reference count to 0.
*
*/
static void
parser_free(PyAST_Object *ast)
{
PyNode_Free(ast->ast_node);
PyObject_Del(ast);
}
/* parser_ast2tuple(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 AST object is not modified.
*
*/
static PyObject*
parser_ast2tuple(PyAST_Object *self, PyObject *args, PyObject *kw)
{
PyObject *line_option = 0;
PyObject *res = 0;
int ok;
static char *keywords[] = {"ast", "line_info", NULL};
if (self == NULL) {
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!|O:ast2tuple", keywords,
&PyAST_Type, &self, &line_option);
}
else
ok = PyArg_ParseTupleAndKeywords(args, kw, "|O:totuple", &keywords[1],
&line_option);
if (ok != 0) {
int lineno = 0;
if (line_option != NULL) {
lineno = (PyObject_IsTrue(line_option) != 0) ? 1 : 0;
}
/*
* Convert AST into a tuple representation. Use Guido's function,
* since it's known to work already.
*/
res = node2tuple(((PyAST_Object*)self)->ast_node,
PyTuple_New, PyTuple_SetItem, lineno);
}
return (res);
}
/* parser_ast2list(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 AST object is not modified.
*
*/
static PyObject*
parser_ast2list(PyAST_Object *self, PyObject *args, PyObject *kw)
{
PyObject *line_option = 0;
PyObject *res = 0;
int ok;
static char *keywords[] = {"ast", "line_info", NULL};
if (self == NULL)
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!|O:ast2list", keywords,
&PyAST_Type, &self, &line_option);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, "|O:tolist", &keywords[1],
&line_option);
if (ok) {
int lineno = 0;
if (line_option != 0) {
lineno = PyObject_IsTrue(line_option) ? 1 : 0;
}
/*
* Convert AST into a tuple representation. Use Guido's function,
* since it's known to work already.
*/
res = node2tuple(self->ast_node,
PyList_New, PyList_SetItem, lineno);
}
return (res);
}
/* parser_compileast(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_compileast(PyAST_Object *self, PyObject *args, PyObject *kw)
{
PyObject* res = 0;
char* str = "<ast>";
int ok;
static char *keywords[] = {"ast", "filename", NULL};
if (self == NULL)
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!|s:compileast", keywords,
&PyAST_Type, &self, &str);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, "|s:compile", &keywords[1],
&str);
if (ok)
res = (PyObject *)PyNode_Compile(self->ast_node, str);
return (res);
}
/* PyObject* parser_isexpr(PyObject* self, PyObject* args)
* PyObject* parser_issuite(PyObject* self, PyObject* args)
*
* Checks the passed-in AST object to determine if it is an expression or
* a statement suite, respectively. The return is a Python truth value.
*
*/
static PyObject*
parser_isexpr(PyAST_Object *self, PyObject *args, PyObject *kw)
{
PyObject* res = 0;
int ok;
static char *keywords[] = {"ast", NULL};
if (self == NULL)
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!:isexpr", keywords,
&PyAST_Type, &self);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, ":isexpr", &keywords[1]);
if (ok) {
/* Check to see if the AST represents an expression or not. */
res = (self->ast_type == PyAST_EXPR) ? Py_True : Py_False;
Py_INCREF(res);
}
return (res);
}
static PyObject*
parser_issuite(PyAST_Object *self, PyObject *args, PyObject *kw)
{
PyObject* res = 0;
int ok;
static char *keywords[] = {"ast", NULL};
if (self == NULL)
ok = PyArg_ParseTupleAndKeywords(args, kw, "O!:issuite", keywords,
&PyAST_Type, &self);
else
ok = PyArg_ParseTupleAndKeywords(args, kw, ":issuite", &keywords[1]);
if (ok) {
/* Check to see if the AST represents an expression or not. */
res = (self->ast_type == PyAST_EXPR) ? Py_False : Py_True;
Py_INCREF(res);
}
return (res);
}
#define PUBLIC_METHOD_TYPE (METH_VARARGS|METH_KEYWORDS)
static PyMethodDef
parser_methods[] = {
{"compile", (PyCFunction)parser_compileast, PUBLIC_METHOD_TYPE,
"Compile this AST object into a code object."},
{"isexpr", (PyCFunction)parser_isexpr, PUBLIC_METHOD_TYPE,
"Determines if this AST object was created from an expression."},
{"issuite", (PyCFunction)parser_issuite, PUBLIC_METHOD_TYPE,
"Determines if this AST object was created from a suite."},
{"tolist", (PyCFunction)parser_ast2list, PUBLIC_METHOD_TYPE,
"Creates a list-tree representation of this AST."},
{"totuple", (PyCFunction)parser_ast2tuple, PUBLIC_METHOD_TYPE,
"Creates a tuple-tree representation of this AST."},
{NULL, NULL, 0, NULL}
};
static PyObject*
parser_getattr(PyObject *self, char *name)
{
return (Py_FindMethod(parser_methods, self, name));
}
/* 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;
static char *keywords[] = {"source", NULL};
if (PyArg_ParseTupleAndKeywords(args, kw, argspec, keywords, &string)) {
node* n = PyParser_SimpleParseString(string,
(type == PyAST_EXPR)
? eval_input : file_input);
if (n != 0)
res = parser_newastobject(n, type);
else
err_string("could not parse string");
}
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(PyAST_Object *self, PyObject *args, PyObject *kw)
{
NOTE(ARGUNUSED(self))
return (parser_do_parse(args, kw, "s:expr", PyAST_EXPR));
}
static PyObject*
parser_suite(PyAST_Object *self, PyObject *args, PyObject *kw)
{
NOTE(ARGUNUSED(self))
return (parser_do_parse(args, kw, "s:suite", PyAST_SUITE));
}
/* This is the messy part of the code. Conversion from a tuple to an AST
* 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 AST types to include funcdefs and
* lambdadefs to take advantage of the optimizer, recognizing those ASTs
* here. They are not necessary, and not quite as useful in a raw form.
* For now, let's get expressions and suites working reliably.
*/
staticforward node* build_node_tree(PyObject *tuple);
staticforward int validate_expr_tree(node *tree);
staticforward int validate_file_input(node *tree);
/* PyObject* parser_tuple2ast(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 AST 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 PyAST_FRAGMENT
* AST objects.
*
*/
static PyObject*
parser_tuple2ast(PyAST_Object *self, PyObject *args, PyObject *kw)
{
NOTE(ARGUNUSED(self))
PyObject *ast = 0;
PyObject *tuple;
node *tree;
static char *keywords[] = {"sequence", NULL};
if (!PyArg_ParseTupleAndKeywords(args, kw, "O:sequence2ast", keywords,
&tuple))
return (0);
if (!PySequence_Check(tuple)) {
PyErr_SetString(PyExc_ValueError,
"sequence2ast() 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))
ast = parser_newastobject(tree, PyAST_EXPR);
}
else if (start_sym == file_input) {
/* This looks like an exec form so far. */
if (validate_file_input(tree))
ast = parser_newastobject(tree, PyAST_SUITE);
}
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 ((ast == 0) && !PyErr_Occurred())
err_string("unspecified AST error occurred");
return (ast);
}
/* 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)
{
int len = PyObject_Size(tuple);
int i;
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 = PyInt_Check(temp);
if (ok)
type = PyInt_AS_LONG(temp);
Py_DECREF(temp);
}
}
if (!ok) {
PyErr_SetObject(parser_error,
Py_BuildValue("os", elem,
"Illegal node construct."));
Py_XDECREF(elem);
return (0);
}
if (ISTERMINAL(type)) {
int len = PyObject_Size(elem);
PyObject *temp;
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 (!PyString_Check(temp)) {
PyErr_Format(parser_error,
"second item in terminal node must be a string,"
" found %s",
((PyTypeObject*)PyObject_Type(temp))->tp_name);
Py_DECREF(temp);
return 0;
}
if (len == 3) {
PyObject *o = PySequence_GetItem(elem, 2);
if (o != NULL) {
if (PyInt_Check(o))
*line_num = PyInt_AS_LONG(o);
else {
PyErr_Format(parser_error,
"third item in terminal node must be an"
" integer, found %s",
((PyTypeObject*)PyObject_Type(temp))->tp_name);
Py_DECREF(o);
Py_DECREF(temp);
return 0;
}
Py_DECREF(o);
}
}
len = PyString_GET_SIZE(temp) + 1;
strn = (char *)PyMem_MALLOC(len);
if (strn != NULL)
(void) memcpy(strn, PyString_AS_STRING(temp), len);
Py_DECREF(temp);
}
else if (!ISNONTERMINAL(type)) {
/*
* It has to be one or the other; this is an error.
* Throw an exception.
*/
PyErr_SetObject(parser_error,
Py_BuildValue("os", elem, "unknown node type."));
Py_XDECREF(elem);
return (0);
}
PyNode_AddChild(root, type, strn, *line_num);
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 = PyInt_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 ast tuple; cannot start with terminal symbol.");
PyErr_SetObject(parser_error, tuple);
}
else if (ISNONTERMINAL(num)) {
/*
* Not efficient, but that can be handled later.
*/
int line_num = 0;
res = PyNode_New(num);
if (res != build_node_children(tuple, res, &line_num)) {
PyNode_Free(res);
res = 0;
}
}
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.
*/
PyErr_SetObject(parser_error,
Py_BuildValue("os", tuple,
"Illegal component tuple."));
return (res);
}
/*
* Validation routines used within the validation section:
*/
staticforward 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_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(fpdef); VALIDATER(fplist);
VALIDATER(stmt); VALIDATER(simple_stmt);
VALIDATER(expr_stmt); VALIDATER(power);
VALIDATER(print_stmt); VALIDATER(del_stmt);
VALIDATER(return_stmt); VALIDATER(list_iter);
VALIDATER(raise_stmt); VALIDATER(import_stmt);
VALIDATER(global_stmt); VALIDATER(list_if);
VALIDATER(assert_stmt); VALIDATER(list_for);
VALIDATER(exec_stmt); VALIDATER(compound_stmt);
VALIDATER(while); VALIDATER(for);
VALIDATER(try); VALIDATER(except_clause);
VALIDATER(test); VALIDATER(and_test);
VALIDATER(not_test); VALIDATER(comparison);
VALIDATER(comp_op); 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(dictmaker);
VALIDATER(arglist); VALIDATER(argument);
VALIDATER(listmaker);
#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 == 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 && (nch == 7)) {
res = (validate_lparen(CHILD(tree, 2))
&& validate_testlist(CHILD(tree, 3))
&& validate_rparen(CHILD(tree, 4)));
}
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"));
}
/* '*' NAME [',' '**' NAME] | '**' NAME
*/
static int
validate_varargslist_trailer(node *tree, int start)
{
int nch = NCH(tree);
int res = 0;
int sym;
if (nch <= start) {
err_string("expected variable argument trailer for varargslist");
return 0;
}
sym = TYPE(CHILD(tree, start));
if (sym == STAR) {
/*
* ('*' NAME [',' '**' NAME]
*/
if (nch-start == 2)
res = validate_name(CHILD(tree, start+1), NULL);
else if (nch-start == 5)
res = (validate_name(CHILD(tree, start+1), NULL)
&& validate_comma(CHILD(tree, start+2))
&& validate_doublestar(CHILD(tree, start+3))
&& validate_name(CHILD(tree, start+4), NULL));
}
else if (sym == DOUBLESTAR) {
/*
* '**' NAME
*/
if (nch-start == 2)
res = validate_name(CHILD(tree, start+1), NULL);
}
if (!res)
err_string("illegal variable argument trailer for varargslist");
return res;
}
/* validate_varargslist()
*
* varargslist:
* (fpdef ['=' test] ',')*
* ('*' NAME [',' '**' NAME]
* | '**' NAME)
* | fpdef ['=' test] (',' fpdef ['=' test])* [',']
*
*/
static int
validate_varargslist(node *tree)
{
int nch = NCH(tree);
int res = validate_ntype(tree, varargslist) && (nch != 0);
int sym;
if (!res)
return 0;
if (nch < 1) {
err_string("varargslist missing child nodes");
return 0;
}
sym = TYPE(CHILD(tree, 0));
if (sym == STAR || sym == DOUBLESTAR)
/* whole thing matches:
* '*' NAME [',' '**' NAME] | '**' NAME
*/
res = validate_varargslist_trailer(tree, 0);
else if (sym == fpdef) {
int i = 0;
sym = TYPE(CHILD(tree, nch-1));
if (sym == NAME) {
/*
* (fpdef ['=' test] ',')+
* ('*' NAME [',' '**' NAME]
* | '**' NAME)
*/
/* skip over (fpdef ['=' test] ',')+ */
while (res && (i+2 <= nch)) {
res = validate_fpdef(CHILD(tree, i));
++i;
if (res && TYPE(CHILD(tree, i)) == EQUAL && (i+2 <= nch)) {
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;
if (res && i < nch
&& (TYPE(CHILD(tree, i)) == DOUBLESTAR
|| TYPE(CHILD(tree, i)) == STAR))
break;
}
}
/* ... '*' NAME [',' '**' NAME] | '**' NAME
* i --^^^
*/
if (res)
res = validate_varargslist_trailer(tree, i);
}
else {
/*
* fpdef ['=' test] (',' fpdef ['=' test])* [',']
*/
/* strip trailing comma node */
if (sym == COMMA) {
res = validate_comma(CHILD(tree, nch-1));
if (!res)
return 0;
--nch;
}
/*
* fpdef ['=' test] (',' fpdef ['=' test])*
*/
res = validate_fpdef(CHILD(tree, 0));
++i;
if (res && (i+2 <= nch) && TYPE(CHILD(tree, i)) == EQUAL) {
res = (validate_equal(CHILD(tree, i))
&& validate_test(CHILD(tree, i+1)));
i += 2;
}
/*
* ... (',' fpdef ['=' test])*
* i ---^^^
*/
while (res && (nch - i) >= 2) {
res = (validate_comma(CHILD(tree, i))
&& validate_fpdef(CHILD(tree, i+1)));
i += 2;
if (res && (nch - i) >= 2 && TYPE(CHILD(tree, i)) == EQUAL) {
res = (validate_equal(CHILD(tree, i))
&& validate_test(CHILD(tree, i+1)));
i += 2;
}
}
if (res && nch - i != 0) {
res = 0;
err_string("illegal formation for varargslist");
}
}
}
return res;
}
/* list_iter: list_for | list_if
*/
static int
validate_list_iter(node *tree)
{
int res = (validate_ntype(tree, list_iter)
&& validate_numnodes(tree, 1, "list_iter"));
if (res && TYPE(CHILD(tree, 0)) == list_for)
res = validate_list_for(CHILD(tree, 0));
else
res = validate_list_if(CHILD(tree, 0));
return res;
}
/* list_for: 'for' exprlist 'in' testlist [list_iter]
*/
static int
validate_list_for(node *tree)
{
int nch = NCH(tree);
int res;
if (nch == 5)
res = validate_list_iter(CHILD(tree, 4));
else
res = validate_numnodes(tree, 4, "list_for");
if (res)
res = (validate_name(CHILD(tree, 0), "for")
&& validate_exprlist(CHILD(tree, 1))
&& validate_name(CHILD(tree, 2), "in")
&& validate_testlist(CHILD(tree, 3)));
return res;
}
/* list_if: 'if' test [list_iter]
*/
static int
validate_list_if(node *tree)
{
int nch = NCH(tree);
int res;
if (nch == 3)
res = validate_list_iter(CHILD(tree, 2));
else
res = validate_numnodes(tree, 2, "list_if");
if (res)
res = (validate_name(CHILD(tree, 0), "if")
&& validate_test(CHILD(tree, 1)));
return res;
}
/* validate_fpdef()
*
* fpdef:
* NAME
* | '(' fplist ')'
*/
static int
validate_fpdef(node *tree)
{
int nch = NCH(tree);
int res = validate_ntype(tree, fpdef);
if (res) {
if (nch == 1)
res = validate_ntype(CHILD(tree, 0), NAME);
else if (nch == 3)
res = (validate_lparen(CHILD(tree, 0))
&& validate_fplist(CHILD(tree, 1))
&& validate_rparen(CHILD(tree, 2)));
else
res = validate_numnodes(tree, 1, "fpdef");
}
return (res);
}
static int
validate_fplist(node *tree)
{
return (validate_repeating_list(tree, fplist,
validate_fpdef, "fplist"));
}
/* 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 == print_stmt)
|| (ntype == del_stmt)
|| (ntype == pass_stmt)
|| (ntype == flow_stmt)
|| (ntype == import_stmt)
|| (ntype == global_stmt)
|| (ntype == assert_stmt)
|| (ntype == exec_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 | funcdef | classdef
*/
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 == funcdef)
|| (ntype == classdef))
res = validate_node(tree);
else {
res = 0;
PyErr_Format(parser_error,
"Illegal compound statement type: %d.", TYPE(tree));
}
return (res);
}
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(CHILD(tree, 0)));
if (res && nch == 3
&& TYPE(CHILD(tree, 1)) == augassign) {
res = (validate_numnodes(CHILD(tree, 1), 1, "augassign")
&& validate_testlist(CHILD(tree, 2)));
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);
if (!res)
err_string("illegal augmmented assignment operator");
}
}
else {
for (j = 1; res && (j < nch); j += 2)
res = (validate_equal(CHILD(tree, j))
&& validate_testlist(CHILD(tree, j + 1)));
}
return (res);
}
/* print_stmt:
*
* 'print' ( [ test (',' test)* [','] ]
* | '>>' test [ (',' test)+ [','] ] )
*/
static int
validate_print_stmt(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, print_stmt)
&& (nch > 0)
&& validate_name(CHILD(tree, 0), "print"));
if (res && nch > 1) {
int sym = TYPE(CHILD(tree, 1));
int i = 1;
int allow_trailing_comma = 1;
if (sym == test)
res = validate_test(CHILD(tree, i++));
else {
if (nch < 3)
res = validate_numnodes(tree, 3, "print_stmt");
else {
res = (validate_ntype(CHILD(tree, i), RIGHTSHIFT)
&& validate_test(CHILD(tree, i+1)));
i += 2;
allow_trailing_comma = 0;
}
}
if (res) {
/* ... (',' test)* [','] */
while (res && i+2 <= nch) {
res = (validate_comma(CHILD(tree, i))
&& validate_test(CHILD(tree, i+1)));
allow_trailing_comma = 1;
i += 2;
}
if (res && !allow_trailing_comma)
res = validate_numnodes(tree, i, "print_stmt");
else if (res && i < nch)
res = validate_comma(CHILD(tree, i));
}
}
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);
}
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;
}
/* import_stmt:
*
* 'import' dotted_as_name (',' dotted_as_name)*
* | 'from' dotted_name 'import' ('*' | import_as_name (',' import_as_name)*)
*/
static int
validate_import_stmt(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, import_stmt)
&& (nch >= 2) && is_even(nch)
&& validate_ntype(CHILD(tree, 0), NAME));
if (res && (strcmp(STR(CHILD(tree, 0)), "import") == 0)) {
int j;
res = validate_dotted_as_name(CHILD(tree, 1));
for (j = 2; res && (j < nch); j += 2)
res = (validate_comma(CHILD(tree, j))
&& validate_dotted_as_name(CHILD(tree, j + 1)));
}
else if (res && (res = validate_name(CHILD(tree, 0), "from"))) {
res = ((nch >= 4) && is_even(nch)
&& validate_dotted_name(CHILD(tree, 1))
&& validate_name(CHILD(tree, 2), "import"));
if (nch == 4) {
if (TYPE(CHILD(tree, 3)) == import_as_name)
res = validate_import_as_name(CHILD(tree, 3));
else
res = validate_star(CHILD(tree, 3));
}
else {
/* 'from' dotted_name 'import' import_as_name
* (',' import_as_name)+
*/
int j;
res = validate_import_as_name(CHILD(tree, 3));
for (j = 4; res && (j < nch); j += 2)
res = (validate_comma(CHILD(tree, j))
&& validate_import_as_name(CHILD(tree, j + 1)));
}
}
else
res = 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)
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);
}
/* exec_stmt:
*
* 'exec' expr ['in' test [',' test]]
*/
static int
validate_exec_stmt(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, exec_stmt)
&& ((nch == 2) || (nch == 4) || (nch == 6))
&& validate_name(CHILD(tree, 0), "exec")
&& validate_expr(CHILD(tree, 1)));
if (!res && !PyErr_Occurred())
err_string("illegal exec statement");
if (res && (nch > 2))
res = (validate_name(CHILD(tree, 2), "in")
&& validate_test(CHILD(tree, 3)));
if (res && (nch == 6))
res = (validate_comma(CHILD(tree, 4))
&& validate_test(CHILD(tree, 5)));
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_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]
* | '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);
}
/* Skip past except_clause sections: */
while (res && (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;
}
if (res && (pos < nch)) {
res = validate_ntype(CHILD(tree, pos), NAME);
if (res && (strcmp(STR(CHILD(tree, pos)), "finally") == 0))
res = (validate_numnodes(tree, 6, "try/finally")
&& validate_colon(CHILD(tree, 4))
&& validate_suite(CHILD(tree, 5)));
else if (res) {
if (nch == (pos + 3)) {
res = ((strcmp(STR(CHILD(tree, pos)), "except") == 0)
|| (strcmp(STR(CHILD(tree, pos)), "else") == 0));
if (!res)
err_string("illegal trailing triple in try statement");
}
else if (nch == (pos + 6)) {
res = (validate_name(CHILD(tree, pos), "except")
&& validate_colon(CHILD(tree, pos + 1))
&& validate_suite(CHILD(tree, pos + 2))
&& validate_name(CHILD(tree, pos + 3), "else"));
}
else
res = validate_numnodes(tree, pos + 3, "try/except");
}
}
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_comma(CHILD(tree, 2))
&& validate_test(CHILD(tree, 3)));
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) {
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_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)) == 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))
res = validate_testlist(CHILD(tree, 1));
break;
case LSQB:
if (nch == 2)
res = validate_ntype(CHILD(tree, 1), RSQB);
else if (nch == 3)
res = (validate_listmaker(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_dictmaker(CHILD(tree, 1));
break;
case BACKQUOTE:
res = ((nch == 3)
&& validate_testlist(CHILD(tree, 1))
&& validate_ntype(CHILD(tree, 2), BACKQUOTE));
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;
default:
res = 0;
break;
}
}
return (res);
}
/* listmaker:
* test ( list_for | (',' test)* [','] )
*/
static int
validate_listmaker(node *tree)
{
int nch = NCH(tree);
int ok = nch;
if (nch == 0)
err_string("missing child nodes of listmaker");
else
ok = validate_test(CHILD(tree, 0));
/*
* list_iter | (',' test)* [',']
*/
if (nch == 2 && TYPE(CHILD(tree, 1)) == list_for)
ok = validate_list_for(CHILD(tree, 1));
else {
/* (',' test)* [','] */
int i = 1;
while (ok && nch - i >= 2) {
ok = (validate_comma(CHILD(tree, i))
&& validate_test(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 listmaker");
}
}
return ok;
}
/* funcdef:
* 'def' NAME parameters ':' suite
*
*/
static int
validate_funcdef(node *tree)
{
return (validate_ntype(tree, funcdef)
&& validate_numnodes(tree, 5, "funcdef")
&& validate_name(CHILD(tree, 0), "def")
&& validate_ntype(CHILD(tree, 1), NAME)
&& validate_colon(CHILD(tree, 3))
&& validate_parameters(CHILD(tree, 2))
&& validate_suite(CHILD(tree, 4)));
}
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);
}
/* 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");
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
*/
static int
validate_argument(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, argument)
&& ((nch == 1) || (nch == 3))
&& validate_test(CHILD(tree, 0)));
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_exprlist(node *tree)
{
return (validate_repeating_list(tree, exprlist,
validate_expr, "exprlist"));
}
static int
validate_dictmaker(node *tree)
{
int nch = NCH(tree);
int res = (validate_ntype(tree, dictmaker)
&& (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 classdef:
res = validate_class(tree);
break;
/*
* "Trivial" parse tree nodes.
* (Why did I call these trivial?)
*/
case stmt:
res = validate_stmt(tree);
break;
case small_stmt:
/*
* expr_stmt | print_stmt | del_stmt | pass_stmt | flow_stmt
* | import_stmt | global_stmt | exec_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)) == 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;
/*
* 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 print_stmt:
res = validate_print_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 global_stmt:
res = validate_global_stmt(tree);
break;
case exec_stmt:
res = validate_exec_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 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 = 0;
int nch = NCH(tree) - 1;
int res = ((nch >= 0)
&& validate_ntype(CHILD(tree, nch), ENDMARKER));
for ( ; 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 PyObject*
pickle_constructor = NULL;
static PyObject*
parser__pickler(PyObject *self, PyObject *args)
{
NOTE(ARGUNUSED(self))
PyObject *result = NULL;
PyObject *ast = NULL;
PyObject *empty_dict = NULL;
if (PyArg_ParseTuple(args, "O!:_pickler", &PyAST_Type, &ast)) {
PyObject *newargs;
PyObject *tuple;
if ((empty_dict = PyDict_New()) == NULL)
goto finally;
if ((newargs = Py_BuildValue("Oi", ast, 1)) == NULL)
goto finally;
tuple = parser_ast2tuple((PyAST_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 AST 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[] = {
{"ast2tuple", (PyCFunction)parser_ast2tuple, PUBLIC_METHOD_TYPE,
"Creates a tuple-tree representation of an AST."},
{"ast2list", (PyCFunction)parser_ast2list, PUBLIC_METHOD_TYPE,
"Creates a list-tree representation of an AST."},
{"compileast", (PyCFunction)parser_compileast, PUBLIC_METHOD_TYPE,
"Compiles an AST object into a code object."},
{"expr", (PyCFunction)parser_expr, PUBLIC_METHOD_TYPE,
"Creates an AST object from an expression."},
{"isexpr", (PyCFunction)parser_isexpr, PUBLIC_METHOD_TYPE,
"Determines if an AST object was created from an expression."},
{"issuite", (PyCFunction)parser_issuite, PUBLIC_METHOD_TYPE,
"Determines if an AST object was created from a suite."},
{"suite", (PyCFunction)parser_suite, PUBLIC_METHOD_TYPE,
"Creates an AST object from a suite."},
{"sequence2ast", (PyCFunction)parser_tuple2ast, PUBLIC_METHOD_TYPE,
"Creates an AST object from a tree representation."},
{"tuple2ast", (PyCFunction)parser_tuple2ast, PUBLIC_METHOD_TYPE,
"Creates an AST object from a tree representation."},
/* private stuff: support pickle module */
{"_pickler", (PyCFunction)parser__pickler, METH_VARARGS,
"Returns the pickle magic to allow ast objects to be pickled."},
{NULL, NULL, 0, NULL}
};
DL_EXPORT(void) initparser(void); /* supply a prototype */
DL_EXPORT(void)
initparser(void)
{
PyObject* module;
PyObject* dict;
PyAST_Type.ob_type = &PyType_Type;
module = Py_InitModule("parser", parser_functions);
dict = PyModule_GetDict(module);
if (parser_error == 0)
parser_error = PyErr_NewException("parser.ParserError", NULL, NULL);
if ((parser_error == 0)
|| (PyDict_SetItemString(dict, "ParserError", parser_error) != 0))
{
/* caller will check PyErr_Occurred() */
return;
}
/*
* Nice to have, but don't cry if we fail.
*/
Py_INCREF(&PyAST_Type);
PyDict_SetItemString(dict, "ASTType", (PyObject*)&PyAST_Type);
PyDict_SetItemString(dict, "__copyright__",
PyString_FromString(parser_copyright_string));
PyDict_SetItemString(dict, "__doc__",
PyString_FromString(parser_doc_string));
PyDict_SetItemString(dict, "__version__",
PyString_FromString(parser_version_string));
/* register to support pickling */
module = PyImport_ImportModule("copy_reg");
if (module != NULL) {
PyObject *func, *pickler;
func = PyObject_GetAttrString(module, "pickle");
pickle_constructor = PyDict_GetItemString(dict, "sequence2ast");
pickler = PyDict_GetItemString(dict, "_pickler");
Py_XINCREF(pickle_constructor);
if ((func != NULL) && (pickle_constructor != NULL)
&& (pickler != NULL)) {
PyObject *res;
res = PyObject_CallFunction(
func, "OOO", &PyAST_Type, pickler, pickle_constructor);
Py_XDECREF(res);
}
Py_XDECREF(func);
Py_DECREF(module);
}
}
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