From 5b7a0bb38f66a7f7803b4b1752a1c2d1d0b2a2d4 Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Wed, 11 Oct 1995 17:35:38 +0000 Subject: Fred Drake's new parser module --- Modules/parsermodule.c | 2171 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 2120 insertions(+), 51 deletions(-) (limited to 'Modules/parsermodule.c') diff --git a/Modules/parsermodule.c b/Modules/parsermodule.c index 1d2fe13a3b..db478ade95 100644 --- a/Modules/parsermodule.c +++ b/Modules/parsermodule.c @@ -1,3 +1,82 @@ +/* Parser.c + * + * Copyright 1995 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. + * + */ + +#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() */ + +/* + * All the "fudge" declarations are here: + */ + + +/* These appearantly aren't prototyped in any of the standard Python headers, + * either by this name or as 'parse_string()/compile().' This works at + * cutting out the warning, but needs to be done as part of the mainstream + * Python headers if this is going to be supported. It is being handled as + * part of the Great Renaming. + */ +extern node* PyParser_SimpleParseString(char*, int); +extern PyObject* PyNode_Compile(node*, char*); + + +/* This isn't part of the Python runtime, but it's in the library somewhere. + * Where it is varies a bit, so just declare it. + */ +extern char* strdup(const char*); + + +/* + * That's it! Now, on to the module.... + */ + + + +/* String constants used to initialize module attributes. + * + */ +static char* +parser_copyright_string += "Copyright 1995 by Virginia Polytechnic Institute & State University and\n" + "Fred L. Drake, Jr., Blacksburg, Virginia, USA. Portions copyright\n" + "1991-1995 by Stichting Mathematisch Centrum, Amsterdam, The Netherlands."; + + +static char* +parser_doc_string += "This is an interface to Python's internal parser."; + +static char* +parser_version_string = "0.1"; + + +/* The function below is copyrigthed by Stichting Mathematisch Centrum. + * 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. + */ + /*********************************************************** Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam, The Netherlands. @@ -22,86 +101,2076 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. ******************************************************************/ -/* Raw interface to the parser. */ - -#include "allobjects.h" -#include "node.h" -#include "token.h" -#include "pythonrun.h" -#include "graminit.h" -#include "errcode.h" - -static object * +static PyObject* node2tuple(n) node *n; { if (n == NULL) { - INCREF(None); - return None; + Py_INCREF(Py_None); + return Py_None; } if (ISNONTERMINAL(TYPE(n))) { int i; - object *v, *w; - v = newtupleobject(1 + NCH(n)); + PyObject *v, *w; + v = PyTuple_New(1 + NCH(n)); if (v == NULL) return v; - w = newintobject(TYPE(n)); + w = PyInt_FromLong(TYPE(n)); if (w == NULL) { - DECREF(v); + Py_DECREF(v); return NULL; } - settupleitem(v, 0, w); + PyTuple_SetItem(v, 0, w); for (i = 0; i < NCH(n); i++) { w = node2tuple(CHILD(n, i)); if (w == NULL) { - DECREF(v); + Py_DECREF(v); return NULL; } - settupleitem(v, i+1, w); + PyTuple_SetItem(v, i+1, w); } return v; } else if (ISTERMINAL(TYPE(n))) { - return mkvalue("(is)", TYPE(n), STR(n)); + return Py_BuildValue("(is)", TYPE(n), STR(n)); } else { - err_setstr(SystemError, "unrecognized parse tree node type"); + PyErr_SetString(PyExc_SystemError, + "unrecognized parse tree node type"); return 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. + */ + +#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 { -static object * -parser_parsefile(self, args) - object *self; - object *args; + 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 long parser_hash(PyAST_Object* ast); + + +/* static */ +PyTypeObject PyAST_Type = { + + PyObject_HEAD_INIT(&PyType_Type) + 0, + "ast", /* tp_name */ + sizeof(PyAST_Object), /* tp_basicsize */ + 0, /* tp_itemsize */ + (destructor)parser_free, /* tp_dealloc */ + 0, /* tp_print */ + 0, /* 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 */ + +}; /* PyAST_Type */ + + +static int +parser_compare_nodes(left, right) + node* left; + node* right; { - char *filename; - FILE *fp; - node *n = NULL; - object *res; - if (!getargs(args, "s", &filename)) - return NULL; - fp = fopen(filename, "r"); - if (fp == NULL) { - err_errno(IOError); - return NULL; + 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) + return (v); + } + return (0); + +} /* parser_compare_nodes() */ + + +/* 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(left, right) + 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_compare() */ + + +/* 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(ast, type) + node* ast; + int type; +{ + PyAST_Object* o = PyObject_NEW(PyAST_Object, &PyAST_Type); + + if (o != 0) { + o->ast_node = ast; + o->ast_type = type; + } + return ((PyObject*)o); + +} /* parser_newastobject() */ + + +/* void parser_free(PyAST_Object* ast) + * + * This is called by a del statement that reduces the reference count to 0. + * + */ +static void +parser_free(ast) + PyAST_Object* ast; +{ + PyNode_Free(ast->ast_node); + PyMem_DEL(ast); + +} /* parser_free() */ + + +/* parser_ast2tuple(PyObject* self, PyObject* args) + * + * 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(self, args) + PyObject* self; + PyObject* args; +{ + PyObject* ast; + PyObject* res = 0; + + if (PyArg_ParseTuple(args, "O!:ast2tuple", &PyAST_Type, &ast)) { + /* + * Convert AST into a tuple representation. Use Guido's function, + * since it's known to work already. + */ + res = node2tuple(((PyAST_Object*)ast)->ast_node); + } + return (res); + +} /* parser_ast2tuple() */ + + +/* 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(self, args) + PyObject* self; + PyObject* args; +{ + PyAST_Object* ast; + PyObject* res = 0; + char* str = ""; + + if (PyArg_ParseTuple(args, "O!|s", &PyAST_Type, &ast, &str)) + res = PyNode_Compile(ast->ast_node, str); + + return (res); + +} /* parser_compileast() */ + + +/* 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(self, args) + PyObject* self; + PyObject* args; +{ + PyAST_Object* ast; + PyObject* res = 0; + + if (PyArg_ParseTuple(args, "O!:isexpr", &PyAST_Type, &ast)) { + /* + * Check to see if the AST represents an expression or not. + */ + res = (ast->ast_type == PyAST_EXPR) ? Py_True : Py_False; + Py_INCREF(res); + } + return (res); + +} /* parser_isexpr() */ + + +static PyObject* +parser_issuite(self, args) + PyObject* self; + PyObject* args; +{ + PyAST_Object* ast; + PyObject* res = 0; + + if (PyArg_ParseTuple(args, "O!:isexpr", &PyAST_Type, &ast)) { + /* + * Check to see if the AST represents an expression or not. + */ + res = (ast->ast_type == PyAST_EXPR) ? Py_False : Py_True; + Py_INCREF(res); + } + return (res); + +} /* parser_issuite() */ + + +/* 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(args, type) + PyObject *args; + int type; +{ + char* string = 0; + PyObject* res = 0; + + if (PyArg_ParseTuple(args, "s", &string)) { + node* n = PyParser_SimpleParseString(string, + (type == PyAST_EXPR) + ? eval_input : file_input); + + if (n != 0) + res = parser_newastobject(n, type); + else + PyErr_SetString(parser_error, "Could not parse string."); + } + return (res); + +} /* parser_do_parse() */ + + +/* 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(self, args) + PyObject* self; + PyObject* args; +{ + return (parser_do_parse(args, PyAST_EXPR)); + +} /* parser_expr() */ + + +static PyObject* +parser_suite(self, args) + PyObject* self; + PyObject* args; +{ + return (parser_do_parse(args, PyAST_SUITE)); + +} /* parser_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*); +staticforward int validate_expr_tree(node*); +staticforward int validate_suite_tree(node*); + + +/* 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(self, args) + PyObject* self; + PyObject* args; +{ + PyObject* ast = 0; + PyObject* tuple = 0; + int start_sym; + int next_sym; + + if ((PyTuple_Size(args) == 1) + && (tuple = PyTuple_GetItem(args, 0)) + && PyTuple_Check(tuple) + && (PyTuple_Size(tuple) >= 2) + && PyInt_Check(PyTuple_GetItem(tuple, 0)) + && PyTuple_Check(PyTuple_GetItem(tuple, 1)) + && (PyTuple_Size(PyTuple_GetItem(tuple, 1)) >= 2) + && PyInt_Check(PyTuple_GetItem(PyTuple_GetItem(tuple, 1), 0))) { + + /* + * This might be a valid parse tree, but let's do a quick check + * before we jump the gun. + */ + + start_sym = PyInt_AsLong(PyTuple_GetItem(tuple, 0)); + next_sym = PyInt_AsLong(PyTuple_GetItem(PyTuple_GetItem(tuple, 1), 0)); + + if ((start_sym == eval_input) && (next_sym == testlist)) { + /* + * Might be an expression. + */ + node* expression = build_node_tree(PyTuple_GetItem(args, 0)); + + puts("Parser.tuple2ast: built eval input tree."); + if ((expression != 0) && validate_expr_tree(expression)) + ast = parser_newastobject(expression, PyAST_EXPR); } - n = parse_file(fp, filename, file_input); - fclose(fp); - if (n == NULL) - return NULL; - res = node2tuple(n); - freetree(n); - return res; -} + else if ((start_sym == file_input) && (next_sym == stmt)) { + /* + * This looks like a suite so far. + */ + node* suite_tree = build_node_tree(PyTuple_GetItem(args, 0)); -static struct methodlist parser_methods[] = { - {"parsefile", parser_parsefile}, - {0, 0} /* Sentinel */ -}; + puts("Parser.tuple2ast: built file input tree."); + if ((suite_tree != 0) && validate_suite_tree(suite_tree)) + ast = parser_newastobject(suite_tree, PyAST_SUITE); + } + /* + * 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()) { + PyErr_SetString(parser_error, "Unspecified ast error occurred."); + } + } + else { + PyErr_SetString(PyExc_TypeError, + "parser.tuple2ast(): expected single tuple."); + } + return (ast); -void -initparser() +} /* parser_tuple2ast() */ + + +/* int check_terminal_tuple() + * + * Check a tuple to determine that it is indeed a valid terminal node. The + * node is known to be required as a terminal, so we throw an exception if + * there is a failure. The portion of the resulting node tree already built + * is passed in so we can deallocate it in the event of a failure. + * + * The format of an acceptable terminal tuple is "(is)": the fact that elem + * is a tuple and the integer is a valid terminal symbol has been established + * before this function is called. We must check the length of the tuple and + * the type of the second element. We do *NOT* check the actual text of the + * string element, which we could do in many cases. This is done by the + * validate_*() functions which operate on the internal representation. + * + */ +static int +check_terminal_tuple(elem, result) + PyObject* elem; + node* result; { - initmodule("parser", parser_methods); -} + int res = 0; + char* str = 0; + + if (PyTuple_Size(elem) != 2) { + str = "Illegal terminal symbol; node too long."; + } + else if (!PyString_Check(PyTuple_GetItem(elem, 1))) { + str = "Illegal terminal symbol; expected a string."; + } + else + res = 1; + + if ((res == 0) && (result != 0)) { + elem = Py_BuildValue("(os)", elem, str); + PyErr_SetObject(parser_error, elem); + } + return (res); + +} /* check_terminal_tuple() */ + + +/* 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(tuple, root, line_num) + PyObject* tuple; + node* root; + int* line_num; +{ + int len = PyTuple_Size(tuple); + int i; + + for (i = 1; i < len; ++i) { + /* elem must always be a tuple, however simple */ + PyObject* elem = PyTuple_GetItem(tuple, i); + long type = 0; + char* strn = 0; + + if ((!PyTuple_Check(elem)) || !PyInt_Check(PyTuple_GetItem(elem, 0))) { + PyErr_SetObject(parser_error, + Py_BuildValue("(os)", elem, + "Illegal node construct.")); + return (0); + } + type = PyInt_AsLong(PyTuple_GetItem(elem, 0)); + + if (ISTERMINAL(type)) { + if (check_terminal_tuple(elem, root)) + strn = strdup(PyString_AsString(PyTuple_GetItem(elem, 1))); + else + return (0); + } + 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.")); + 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)) + return (0); + } + else if (type == NEWLINE) /* It's true: we increment the */ + ++(*line_num); /* line number *after* the newline! */ + } + return (root); + +} /* build_node_children() */ + + +static node* +build_node_tree(tuple) + PyObject* tuple; +{ + node* res = 0; + long num = PyInt_AsLong(PyTuple_GetItem(tuple, 0)); + + 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. + */ + PyErr_SetObject(parser_error, + Py_BuildValue("(os)", tuple, + "Illegal component tuple.")); + } + return (res); + +} /* build_node_tree() */ + + +#define VALIDATER(n) static int validate_##n(node*) +#define VALIDATE(n) static int validate_##n(node* tree) + + +/* + * Validation for the code above: + */ +VALIDATER(expr_tree); +VALIDATER(suite_tree); + + +/* + * Validation routines used within the validation section: + */ +staticforward int validate_terminal(node*, int, char*); + +#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, "") +#define validate_lparen(ch) validate_terminal(ch, LPAR, "(") +#define validate_newline(ch) validate_terminal(ch, NEWLINE, "") +#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_compound_stmt(ch) validate_node(ch) +#define validate_name(ch, str) validate_terminal(ch, NAME, str) +#define validate_small_stmt(ch) validate_node(ch) + +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(print_stmt); VALIDATER(del_stmt); +VALIDATER(return_stmt); +VALIDATER(raise_stmt); VALIDATER(import_stmt); +VALIDATER(global_stmt); +VALIDATER(access_stmt); VALIDATER(accesstype); +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(exprlist); VALIDATER(dictmaker); + + +#define is_even(n) (((n) & 1) == 0) +#define is_odd(n) (((n) & 1) == 1) + + +static int +validate_ntype(n, t) + node* n; + int t; +{ + int res = (TYPE(n) == t); + + if (!res) { + char buffer[128]; + + sprintf(buffer, "Expected node type %d, got %d.", t, TYPE(n)); + PyErr_SetString(parser_error, buffer); + } + return (res); + +} /* validate_ntype() */ + + +static int +validate_terminal(terminal, type, string) + node* terminal; + int type; + char* string; +{ + static char buffer[60]; + int res = ((TYPE(terminal) == type) + && (strcmp(string, STR(terminal)) == 0)); + + if (!res) { + sprintf(buffer, "Illegal NAME: expected \"%s\"", string); + PyErr_SetString(parser_error, buffer); + } + return (res); + +} /* validate_terminal() */ + + +VALIDATE(class) { + int nch = NCH(tree); + int res = (((nch == 4) + || ((nch == 7) + && validate_lparen(CHILD(tree, 2)) + && validate_ntype(CHILD(tree, 3), testlist) + && validate_testlist(CHILD(tree, 3)) + && validate_rparen(CHILD(tree, 4)))) + && validate_terminal(CHILD(tree, 0), NAME, "class") + && validate_ntype(CHILD(tree, 1), NAME) + && validate_colon(CHILD(tree, nch - 2)) + && validate_ntype(CHILD(tree, nch - 1), suite) + && validate_suite(CHILD(tree, nch - 1))); + + if (!res) { + if ((nch >= 2) + && validate_ntype(CHILD(tree, 1), NAME)) { + char buffer[128]; + + sprintf(buffer, "Illegal classdef tuple for %s", + STR(CHILD(tree, 1))); + PyErr_SetString(parser_error, buffer); + } + else { + PyErr_SetString(parser_error, "Illegal classdef tuple."); + } + } + return (res); + +} /* validate_class() */ + + +static int +validate_elif(elif_node, test_node, colon_node, suite_node) + node* elif_node; + node* test_node; + node* colon_node; + node* suite_node; +{ + return (validate_ntype(test_node, test) + && validate_ntype(suite_node, suite) + && validate_name(elif_node, "elif") + && validate_colon(colon_node) + && validate_node(test_node) + && validate_suite(suite_node)); + +} /* validate_elif() */ + + +static int +validate_else(else_node, colon_node, suite_node) + node* else_node; + node* colon_node; + node* suite_node; +{ + return (validate_ntype(suite_node, suite) + && validate_name(else_node, "else") + && validate_colon(colon_node) + && validate_suite(suite_node)); + +} /* validate_else() */ + + +VALIDATE(if) { + int nch = NCH(tree); + int res = ((nch >= 4) + && validate_ntype(CHILD(tree, 1), test) + && validate_ntype(CHILD(tree, 3), suite) + && validate_name(CHILD(tree, 0), "if") + && validate_colon(CHILD(tree, 2)) + && validate_parameters(CHILD(tree, 1)) + && validate_suite(CHILD(tree, 3))); + + if (res && ((nch % 4) == 3)) { + /* + * There must be a single 'else' clause, and maybe a series + * of 'elif' clauses. + */ + res = validate_else(CHILD(tree, nch-3), CHILD(tree, nch-2), + CHILD(tree, nch-1)); + nch -= 3; + } + if ((nch % 4) != 0) + res = 0; + else if (res && (nch > 4)) { + /* + * There might be a series of 'elif' clauses. + */ + int j = 4; + while ((j < nch) && res) { + res = validate_elif(CHILD(tree, j), CHILD(tree, j+1), + CHILD(tree, j+2), CHILD(tree, j+3)); + j += 4; + } + } + if (!res && !PyErr_Occurred()) { + PyErr_SetString(parser_error, "Illegal 'if' statement found."); + } + return (res); + +} /* validate_if() */ + + +VALIDATE(parameters) { + int res = 1; + int nch = NCH(tree); + + res = (((nch == 2) + || ((nch == 3) + && validate_varargslist(CHILD(tree, 1)))) + && validate_lparen(CHILD(tree, 0)) + && validate_rparen(CHILD(tree, nch - 1))); + + return (res); + +} /* validate_parameters() */ + + +VALIDATE(suite) { + int res = 1; + int nch = NCH(tree); + + if (nch == 1) { + res = (validate_ntype(CHILD(tree, 0), simple_stmt) + && validate_simple_stmt(CHILD(tree, 0))); + } + else { + res = ((nch >= 5) + && validate_newline(CHILD(tree, 0)) + && validate_indent(CHILD(tree, 1)) + && validate_dedent(CHILD(tree, nch - 1))); + + if (res) { + int i = 2; + + while (TYPE(CHILD(tree, i)) == NEWLINE) + ++i; + res = (validate_ntype(CHILD(tree, i), stmt) + && validate_stmt(CHILD(tree, i))); + + if (res) { + ++i; + while (TYPE(CHILD(tree, i)) == NEWLINE) + ++i; + + while (res && (TYPE(CHILD(tree, i)) != DEDENT)) { + res = (validate_ntype(CHILD(tree, i), stmt) + && validate_stmt(CHILD(tree, i))); + + if (res) { + ++i; + while (TYPE(CHILD(tree, i)) == NEWLINE) + ++i; + } + } + } + } + } + return (res); + +} /* validate_suite() */ + + +VALIDATE(testlist) { + int i; + int nch = NCH(tree); + int res = ((nch >= 1) + && (is_odd(nch) + || validate_comma(CHILD(tree, nch - 1)))); + + /* + * If there are an even, non-zero number of children, the last one + * absolutely must be a comma. Why the trailing comma is allowed, + * I have no idea! + */ + if ((res) && is_odd(nch)) { + /* + * If the number is odd, the last is a test, and can be + * verified. What's left, if anything, can be verified + * as a list of [test, comma] pairs. + */ + --nch; + res = (validate_ntype(CHILD(tree, nch), test) + && validate_test(CHILD(tree, nch))); + } + for (i = 0; res && (i < nch); i += 2) { + res = (validate_ntype(CHILD(tree, i), test) + && validate_test(CHILD(tree, i)) + && validate_comma(CHILD(tree, i + 1))); + } + return (res); + +} /* validate_testlist() */ + + +VALIDATE(varargslist) { + int nch = NCH(tree); + int res = (nch != 0); + + if (res && (TYPE(CHILD(tree, 0)) == fpdef)) { + int pos = 0; + + while (res && (pos < nch)) { + res = (validate_ntype(CHILD(tree, pos), fpdef) + && validate_fpdef(CHILD(tree, pos))); + ++pos; + if (res && (pos < nch) && (TYPE(CHILD(tree, pos)) == EQUAL)) { + res = ((pos + 1 < nch) + && validate_ntype(CHILD(tree, pos + 1), test) + && validate_test(CHILD(tree, pos + 1))); + pos += 2; + } + if (res && (pos < nch)) { + res = validate_comma(CHILD(tree, pos)); + ++pos; + } + } + } + else { + int pos = 0; + + res = ((nch > 1) + && ((nch & 1) == 0) + && validate_star(CHILD(tree, nch - 2)) + && validate_ntype(CHILD(tree, nch - 1), NAME)); + + nch -= 2; + while (res && (pos < nch)) { + /* + * Sequence of: fpdef ['=' test] ',' + */ + res = (validate_ntype(CHILD(tree, pos), fpdef) + && validate_fpdef(CHILD(tree, pos)) + && ((TYPE(CHILD(tree, pos + 1)) == COMMA) + || (((pos + 2) < nch) + && validate_equal(CHILD(tree, pos + 1)) + && validate_ntype(CHILD(tree, pos + 2), test) + && validate_test(CHILD(tree, pos + 2)) + && validate_comma(CHILD(tree, pos + 3))))); + } + } + return (res); + +} /* validate_varargslist() */ + + +VALIDATE(fpdef) { + int nch = NCH(tree); + + return (((nch == 1) + && validate_ntype(CHILD(tree, 0), NAME)) + || ((nch == 3) + && validate_lparen(CHILD(tree, 0)) + && validate_fplist(CHILD(tree, 1)) + && validate_rparen(CHILD(tree, 2)))); + +} /* validate_fpdef() */ + + +VALIDATE(fplist) { + int j; + int nch = NCH(tree); + int res = ((nch != 0) && validate_fpdef(CHILD(tree, 0))); + + if (res && is_even(nch)) { + res = validate_comma(CHILD(tree, nch - 1)); + --nch; + } + for (j = 1; res && (j < nch); j += 2) { + res = (validate_comma(CHILD(tree, j)) + && validate_fpdef(CHILD(tree, j + 1))); + } + return (res); + +} /* validate_fplist() */ + + +VALIDATE(stmt) { + int nch = NCH(tree); + + return ((nch == 1) + && (((TYPE(CHILD(tree, 0)) == simple_stmt) + && validate_simple_stmt(CHILD(tree, 0))) + || (validate_ntype(CHILD(tree, 0), compound_stmt) + && validate_compound_stmt(CHILD(tree, 0))))); + +} /* validate_stmt() */ + + +VALIDATE(simple_stmt) { + int nch = NCH(tree); + int res = ((nch >= 2) + && validate_ntype(CHILD(tree, 0), small_stmt) + && validate_small_stmt(CHILD(tree, 0)) + && validate_newline(CHILD(tree, nch - 1))); + + --nch; /* forget the NEWLINE */ + if (res && (nch >= 2)) { + if (TYPE(CHILD(tree, nch - 1)) == SEMI) + --nch; + } + if (res && (nch > 2)) { + int i; + + for (i = 1; res && (i < nch); i += 2) { + res = (validate_semi(CHILD(tree, i)) + && validate_ntype(CHILD(tree, i + 1), small_stmt) + && validate_small_stmt(CHILD(tree, i + 1))); + } + } + return (res); + +} /* validate_simple_stmt() */ + + +VALIDATE(expr_stmt) { + int j; + int nch = NCH(tree); + int res = (is_odd(nch) + && (validate_testlist(CHILD(tree, 0)))); + + for (j = 1; res && (j < nch); j += 2) { + res = (validate_equal(CHILD(tree, j)) + && validate_ntype(CHILD(tree, j + 1), testlist) + && validate_testlist(CHILD(tree, j + 1))); + } + return (res); + +} /* validate_expr_stmt() */ + + +VALIDATE(print_stmt) { + int j; + int nch = NCH(tree); + int res = ((nch != 0) + && is_even(nch) + && validate_name(CHILD(tree, 0), "print") + && validate_ntype(CHILD(tree, 1), test) + && validate_test(CHILD(tree, 1))); + + for (j = 2; res && (j < nch); j += 2) { + res = (validate_comma(CHILD(tree, j)) + && validate_ntype(CHILD(tree, j + 1), test) + && validate_test(CHILD(tree, 1))); + } + return (res); + +} /* validate_print_stmt() */ + + +VALIDATE(del_stmt) { + + return ((NCH(tree) == 2) + && validate_name(CHILD(tree, 0), "del") + && validate_ntype(CHILD(tree, 1), exprlist) + && validate_exprlist(CHILD(tree, 1))); + +} /* validate_del_stmt() */ + + +VALIDATE(return_stmt) { + int nch = NCH(tree); + int res = (((nch == 1) + || (nch == 2)) + && validate_name(CHILD(tree, 0), "return")); + + if (res && (nch == 2)) { + res = (validate_ntype(CHILD(tree, 1), testlist) + && validate_testlist(CHILD(tree, 1))); + } + return (res); + +} /* validate_return_stmt() */ + + +VALIDATE(raise_stmt) { + int nch = NCH(tree); + int res = (((nch == 2) || (nch == 4)) + && validate_name(CHILD(tree, 0), "raise") + && validate_ntype(CHILD(tree, 1), test) + && validate_test(CHILD(tree, 1))); + + if (res && (nch == 4)) { + res = (validate_comma(CHILD(tree, 2)) + && (TYPE(CHILD(tree, 3)) == test) + && validate_test(CHILD(tree, 3))); + } + return (res); + +} /* validate_raise_stmt() */ + + +VALIDATE(import_stmt) { + int nch = NCH(tree); + int res = ((nch >= 2) + && validate_ntype(CHILD(tree, 0), NAME) + && validate_ntype(CHILD(tree, 1), NAME)); + + if (res && (strcmp(STR(CHILD(tree, 0)), "import") == 0)) { + res = is_even(nch); + if (res) { + int j; + + for (j = 2; res && (j < nch); j += 2) { + res = (validate_comma(CHILD(tree, j)) + && validate_ntype(CHILD(tree, j + 1), NAME)); + } + } + } + else if (res && validate_name(CHILD(tree, 0), "from")) { + res = ((nch >= 4) + && is_even(nch) + && validate_name(CHILD(tree, 2), "import")); + if (nch == 4) { + res = ((TYPE(CHILD(tree, 3)) == NAME) + || validate_ntype(CHILD(tree, 3), STAR)); + } + else { + /* 'from' NAME 'import' NAME (',' NAME)* */ + int j; + + res = validate_ntype(CHILD(tree, 3), NAME); + for (j = 4; res && (j < nch); j += 2) { + res = (validate_comma(CHILD(tree, j)) + && validate_ntype(CHILD(tree, j + 1), NAME)); + } + } + } + else { + res = 0; + } + return (res); + +} /* validate_import_stmt() */ + + +VALIDATE(global_stmt) { + int j; + int nch = NCH(tree); + int res = (is_even(nch) + && 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); + +} /* validate_global_stmt() */ + + +VALIDATE(access_stmt) { + int pos = 3; + int nch = NCH(tree); + int res = ((nch >= 4) + && is_even(nch) + && validate_name(CHILD(tree, 0), "access") + && validate_accesstype(CHILD(tree, nch - 1))); + + if (res && (TYPE(CHILD(tree, 1)) != STAR)) { + int j; + + res = validate_ntype(CHILD(tree, 1), NAME); + for (j = 2; res && (j < (nch - 2)); j += 2) { + if (TYPE(CHILD(tree, j)) == COLON) + break; + res = (validate_comma(CHILD(tree, j)) + && validate_ntype(CHILD(tree, j + 1), NAME) + && (pos += 2)); + } + } + else { + res = validate_star(CHILD(tree, 1)); + } + res = (res && validate_colon(CHILD(tree, pos - 1))); + + for (; res && (pos < (nch - 1)); pos += 2) { + res = (validate_accesstype(CHILD(tree, pos)) + && validate_comma(CHILD(tree, pos + 1))); + } + return (res && (pos == (nch - 1))); + +} /* validate_access_stmt() */ + + +VALIDATE(accesstype) { + int nch = NCH(tree); + int res = (nch >= 1); + int i; + + for (i = 0; res && (i < nch); ++i) { + res = validate_ntype(CHILD(tree, i), NAME); + } + return (res); + +} /* validate_accesstype() */ + + +VALIDATE(exec_stmt) { + int nch = NCH(tree); + int res = (((nch == 2) || (nch == 4) || (nch == 6)) + && validate_name(CHILD(tree, 0), "exec") + && validate_expr(CHILD(tree, 1))); + + if (res && (nch > 2)) { + res = (validate_name(CHILD(tree, 2), "in") + && validate_test(CHILD(tree, 3))); + } + if (res && (nch > 4)) { + res = (validate_comma(CHILD(tree, 4)) + && validate_test(CHILD(tree, 5))); + } + return (res); + +} /* validate_exec_stmt() */ + + +VALIDATE(while) { + int nch = NCH(tree); + int res = (((nch == 4) || (nch == 7)) + && validate_name(CHILD(tree, 0), "while") + && validate_ntype(CHILD(tree, 1), test) + && validate_test(CHILD(tree, 1)) + && validate_colon(CHILD(tree, 2)) + && validate_ntype(CHILD(tree, 3), suite) + && validate_suite(CHILD(tree, 3))); + + if (res && (nch == 7)) { + res = (validate_name(CHILD(tree, 4), "else") + && validate_colon(CHILD(tree, 5)) + && validate_ntype(CHILD(tree, 6), suite) + && validate_suite(CHILD(tree, 6))); + } + return (res); + +} /* validate_while() */ + + +VALIDATE(for) { + int nch = NCH(tree); + int res = (((nch == 6) || (nch == 9)) + && validate_name(CHILD(tree, 0), "for") + && validate_ntype(CHILD(tree, 1), exprlist) + && validate_exprlist(CHILD(tree, 1)) + && validate_name(CHILD(tree, 2), "in") + && validate_ntype(CHILD(tree, 3), testlist) + && validate_testlist(CHILD(tree, 3)) + && validate_colon(CHILD(tree, 4)) + && validate_ntype(CHILD(tree, 5), suite) + && validate_suite(CHILD(tree, 5))); + + if (res && (nch == 9)) { + res = (validate_name(CHILD(tree, 6), "else") + && validate_colon(CHILD(tree, 7)) + && validate_ntype(CHILD(tree, 8), suite) + && validate_suite(CHILD(tree, 8))); + } + return (res); + +} /* validate_for() */ + + +VALIDATE(try) { + int nch = NCH(tree); + int res = ((nch >= 6) + && ((nch % 3) == 0) + && validate_name(CHILD(tree, 0), "try") + && validate_colon(CHILD(tree, 1)) + && validate_ntype(CHILD(tree, 2), suite) + && validate_suite(CHILD(tree, 2)) + && validate_colon(CHILD(tree, nch - 2)) + && validate_ntype(CHILD(tree, nch - 1), suite) + && validate_suite(CHILD(tree, nch - 1))); + + if (res && (TYPE(CHILD(tree, 3)) == except_clause)) { + int groups = (nch / 3) - 2; + + res = validate_except_clause(CHILD(tree, 3)); + + if (res && (groups != 0)) { + int cln_pos = 4; + int sui_pos = 5; + int nxt_pos = 6; + + while (res && groups--) { + res = (validate_colon(CHILD(tree, cln_pos)) + && validate_ntype(CHILD(tree, sui_pos), suite) + && validate_suite(CHILD(tree, sui_pos))); + + if (res && (TYPE(CHILD(tree, nxt_pos)) == NAME)) { + res = ((groups == 0) + && validate_name(CHILD(tree, nxt_pos), "else")); + } + else if (res) { + res = (validate_ntype(CHILD(tree, nxt_pos), except_clause) + && validate_except_clause(CHILD(tree, nxt_pos))); + } + /* Update for next group. */ + cln_pos += 3; + sui_pos += 3; + nxt_pos += 3; + } + } + } + else if (res) { + res = ((nch == 6) + && validate_name(CHILD(tree, 3), "finally")); + } + return (res); + +} /* validate_try() */ + + +VALIDATE(except_clause) { + int nch = NCH(tree); + int res = (((nch == 1) || (nch == 2) || (nch == 4)) + && validate_name(CHILD(tree, 0), "except")); + + if (res && (nch > 1)) { + res = (validate_ntype(CHILD(tree, 1), test) + && validate_test(CHILD(tree, 1))); + } + if (res && (nch == 4)) { + res = (validate_comma(CHILD(tree, 2)) + && validate_ntype(CHILD(tree, 3), test) + && validate_test(CHILD(tree, 3))); + } + return (res); + +} /* validate_except_clause() */ + + +VALIDATE(test) { + int nch = NCH(tree); + int res = 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_ntype(CHILD(tree, 0), and_test) + && validate_and_test(CHILD(tree, 0))); + + for (pos = 1; res && (pos < nch); pos += 2) { + res = (validate_comma(CHILD(tree, pos)) + && validate_ntype(CHILD(tree, pos + 1), and_test) + && validate_and_test(CHILD(tree, pos + 1))); + } + } + return (res); + +} /* validate_test() */ + + +VALIDATE(and_test) { + int pos; + int nch = NCH(tree); + int res = (is_odd(nch) + && validate_ntype(CHILD(tree, 0), not_test) + && validate_not_test(CHILD(tree, 0))); + + for (pos = 1; res && (pos < nch); pos += 2) { + res = (validate_name(CHILD(tree, pos), "and") + && validate_ntype(CHILD(tree, 0), not_test) + && validate_not_test(CHILD(tree, 0))); + } + return (res); + +} /* validate_and_test() */ + + +VALIDATE(not_test) { + int nch = NCH(tree); + + return (((nch == 2) + && validate_name(CHILD(tree, 0), "not") + && validate_ntype(CHILD(tree, 1), not_test) + && validate_not_test(CHILD(tree, 1))) + || ((nch == 1) + && validate_ntype(CHILD(tree, 0), comparison) + && validate_comparison(CHILD(tree, 0)))); + +} /* validate_not_test() */ + + +VALIDATE(comparison) { + int pos; + int nch = NCH(tree); + int res = (is_odd(nch) + && validate_ntype(CHILD(tree, 0), expr) + && validate_expr(CHILD(tree, 0))); + + for (pos = 1; res && (pos < nch); pos += 2) { + res = (validate_ntype(CHILD(tree, pos), comp_op) + && validate_comp_op(CHILD(tree, pos)) + && validate_ntype(CHILD(tree, pos + 1), expr) + && validate_expr(CHILD(tree, 1))); + } + return (res); + +} /* validate_comparison() */ + + +VALIDATE(comp_op) { + int res = 0; + int nch = NCH(tree); + + 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) { + char buffer[128]; + + sprintf(buffer, "Illegal comparison operator: '%s'.", + STR(tree)); + PyErr_SetString(parser_error, buffer); + } + break; + default: + PyErr_SetString(parser_error, + "Illegal comparison operator type."); + break; + } + } + else if (nch == 2) { + 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()) { + PyErr_SetString(parser_error, "Unknown comparison operator."); + } + return (res); + +} /* validate_comp_op() */ + + +VALIDATE(expr) { + int j; + int nch = NCH(tree); + int res = (is_odd(nch) + && validate_ntype(CHILD(tree, 0), xor_expr) + && validate_xor_expr(CHILD(tree, 0))); + + for (j = 2; res && (j < nch); j += 2) { + res = (validate_ntype(CHILD(tree, j), xor_expr) + && validate_xor_expr(CHILD(tree, j)) + && validate_vbar(CHILD(tree, j - 1))); + } + return (res); + +} /* validate_expr() */ + + +VALIDATE(xor_expr) { + int j; + int nch = NCH(tree); + int res = (is_odd(nch) + && validate_ntype(CHILD(tree, 0), and_expr) + && validate_and_expr(CHILD(tree, 0))); + + for (j = 2; res && (j < nch); j += 2) { + res = (validate_circumflex(CHILD(tree, j - 1)) + && validate_ntype(CHILD(tree, j), and_expr) + && validate_and_expr(CHILD(tree, j))); + } + return (res); + +} /* validate_xor_expr() */ + + +VALIDATE(and_expr) { + int pos; + int nch = NCH(tree); + int res = (is_odd(nch) + && validate_ntype(CHILD(tree, 0), shift_expr) + && validate_shift_expr(CHILD(tree, 0))); + + for (pos = 1; res && (pos < nch); pos += 2) { + res = (validate_ampersand(CHILD(tree, pos)) + && validate_ntype(CHILD(tree, pos + 1), shift_expr) + && validate_shift_expr(CHILD(tree, pos + 1))); + } + return (res); + +} /* validate_and_expr() */ + + +static int +validate_chain_two_ops(tree, termtype, termvalid, op1, op2) + node* tree; + int termtype; + int (*termvalid)(node*); + int op1, op2; +{ + int pos; + int nch = NCH(tree); + int res = (is_odd(nch) + && validate_ntype(CHILD(tree, 0), termtype) + && (*termvalid)(CHILD(tree, 0))); + + for (pos = 1; res && (pos < nch); pos += 2) { + res = (((TYPE(CHILD(tree, pos)) == op1) + || validate_ntype(CHILD(tree, pos), op2)) + && validate_ntype(CHILD(tree, pos + 1), termtype) + && (*termvalid)(CHILD(tree, pos + 1))); + } + return (res); + +} /* validate_chain_two_ops() */ + + +VALIDATE(shift_expr) { + + return (validate_chain_two_ops(tree, arith_expr, + validate_arith_expr, + LEFTSHIFT, RIGHTSHIFT)); + +} /* validate_shift_expr() */ + + +VALIDATE(arith_expr) { + + return (validate_chain_two_ops(tree, term, + validate_term, + PLUS, MINUS)); + +} /* validate_arith_expr() */ + + +VALIDATE(term) { + int pos; + int nch = NCH(tree); + int res = (is_odd(nch) + && validate_ntype(CHILD(tree, 0), factor) + && validate_factor(CHILD(tree, 0))); + + for (pos = 1; res && (pos < nch); pos += 2) { + res= (((TYPE(CHILD(tree, pos)) == STAR) + || (TYPE(CHILD(tree, pos)) == SLASH) + || validate_ntype(CHILD(tree, pos), PERCENT)) + && validate_ntype(CHILD(tree, pos + 1), factor) + && validate_factor(CHILD(tree, pos + 1))); + } + return (res); + +} /* validate_term() */ + + +VALIDATE(factor) { + int nch = NCH(tree); + int res = (((nch == 2) + && ((TYPE(CHILD(tree, 0)) == PLUS) + || (TYPE(CHILD(tree, 0)) == MINUS) + || validate_ntype(CHILD(tree, 0), TILDE)) + && validate_ntype(CHILD(tree, 1), factor) + && validate_factor(CHILD(tree, 1))) + || ((nch >= 1) + && validate_ntype(CHILD(tree, 0), atom) + && validate_atom(CHILD(tree, 0)))); + + if (res && (TYPE(CHILD(tree, 0)) == atom)) { + int pos; + + for (pos = 1; res && (pos < nch); ++pos) { + res = (validate_ntype(CHILD(tree, pos), trailer) + && validate_trailer(CHILD(tree, pos))); + } + } + return (res); + +} /* validate_factor() */ + + +VALIDATE(atom) { + int pos; + int nch = NCH(tree); + int res = (nch >= 1); + + if (res) { + switch (TYPE(CHILD(tree, 0))) { + case LPAR: + res = ((nch <= 3) + && (validate_rparen(CHILD(tree, nch - 1)))); + + if (res && (nch == 3)) { + res = (validate_ntype(CHILD(tree, 1), testlist) + && validate_testlist(CHILD(tree, 1))); + } + break; + case LSQB: + res = ((nch <= 3) + && validate_ntype(CHILD(tree, nch - 1), RSQB)); + + if (res && (nch == 3)) { + res = (validate_ntype(CHILD(tree, 1), testlist) + && validate_testlist(CHILD(tree, 1))); + } + break; + case LBRACE: + res = ((nch <= 3) + && validate_ntype(CHILD(tree, nch - 1), RBRACE)); + + if (res && (nch == 3)) { + res = (validate_ntype(CHILD(tree, 1), dictmaker) + && validate_dictmaker(CHILD(tree, 1))); + } + break; + case BACKQUOTE: + res = ((nch == 3) + && validate_ntype(CHILD(tree, 1), testlist) + && 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); + +} /* validate_atom() */ + + +VALIDATE(funcdef) { + + return ((NCH(tree) == 5) + && validate_name(CHILD(tree, 0), "def") + && validate_ntype(CHILD(tree, 1), NAME) + && validate_ntype(CHILD(tree, 2), parameters) + && validate_colon(CHILD(tree, 3)) + && validate_ntype(CHILD(tree, 4), suite) + && validate_parameters(CHILD(tree, 2)) + && validate_suite(CHILD(tree, 4))); + +} /* validate_funcdef() */ + + +VALIDATE(lambdef) { + int nch = NCH(tree); + int res = (((nch == 3) || (nch == 4)) + && validate_name(CHILD(tree, 0), "lambda") + && validate_colon(CHILD(tree, nch - 2)) + && validate_ntype(CHILD(tree, nch - 1), test) + && validate_testlist(CHILD(tree, nch - 1))); + + if (res && (nch == 4)) { + res = (validate_ntype(CHILD(tree, 1), varargslist) + && validate_varargslist(CHILD(tree, 1))); + } + return (res); + +} /* validate_lambdef() */ + + +VALIDATE(trailer) { + int nch = NCH(tree); + int res = ((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_ntype(CHILD(tree, 1), testlist) + && validate_testlist(CHILD(tree, 1))); + } + break; + case LSQB: + res = ((nch == 3) + && validate_ntype(CHILD(tree, 1), subscript) + && validate_subscript(CHILD(tree, 1)) + && validate_ntype(CHILD(tree, 2), RSQB)); + break; + case DOT: + res = ((nch == 2) + && validate_ntype(CHILD(tree, 1), NAME)); + break; + default: + res = 0; + break; + } + } + return (res); + +} /* validate_trailer() */ + + +VALIDATE(subscript) { + int nch = NCH(tree); + int res = ((nch >= 1) && (nch <= 3)); + + if (res && is_odd(nch)) { + res = (validate_ntype(CHILD(tree, 0), test) + && validate_test(CHILD(tree, 0))); + + if (res && (nch == 3)) { + res = (validate_colon(CHILD(tree, 1)) + && validate_ntype(CHILD(tree, 2), test) + && validate_test(CHILD(tree, 2))); + } + } + else if (res == 2) { + if (TYPE(CHILD(tree, 0)) == COLON) { + res = (validate_ntype(CHILD(tree, 1), test) + && validate_test(CHILD(tree, 1))); + } + else { + res = (validate_ntype(CHILD(tree, 0), test) + && validate_test(CHILD(tree, 0)) + && validate_colon(CHILD(tree, 1))); + } + } + return (res); + +} /* validate_subscript() */ + + +VALIDATE(exprlist) { + int nch = NCH(tree); + int res = ((nch >= 1) + && validate_ntype(CHILD(tree, 0), expr) + && validate_expr(CHILD(tree, 0))); + + if (res && is_even(nch)) { + res = validate_comma(CHILD(tree, --nch)); + } + if (res && (nch > 1)) { + int pos; + + for (pos = 1; res && (pos < nch); pos += 2) { + res = (validate_comma(CHILD(tree, pos)) + && validate_ntype(CHILD(tree, pos + 1), expr) + && validate_expr(CHILD(tree, pos + 1))); + } + } + return (res); + +} /* validate_exprlist() */ + + +VALIDATE(dictmaker) { + int nch = NCH(tree); + int res = ((nch >= 3) + && validate_ntype(CHILD(tree, 0), test) + && validate_test(CHILD(tree, 0)) + && validate_colon(CHILD(tree, 1)) + && validate_ntype(CHILD(tree, 2), test) + && 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; + + /* What's left are groups of: ',' test ':' test */ + while (res && (pos < nch)) { + res = (validate_comma(CHILD(tree, pos)) + && validate_ntype(CHILD(tree, pos + 1), test) + && validate_test(CHILD(tree, pos + 1)) + && validate_colon(CHILD(tree, pos + 2)) + && validate_ntype(CHILD(tree, pos + 3), test) + && validate_test(CHILD(tree, pos + 3))); + pos += 4; + } + } + return (res); + +} /* validate_dictmaker() */ + + +VALIDATE(eval_input) { + int pos; + int nch = NCH(tree); + int res = ((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); + +} /* validate_eval_input() */ + + +VALIDATE(node) { + 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. + */ + case stmt: + res = validate_stmt(tree); + break; + case small_stmt: + res = ((nch == 1) + && ((TYPE(CHILD(tree, 0)) == expr_stmt) + || (TYPE(CHILD(tree, 0)) == print_stmt) + || (TYPE(CHILD(tree, 0)) == del_stmt) + || (TYPE(CHILD(tree, 0)) == pass_stmt) + || (TYPE(CHILD(tree, 0)) == flow_stmt) + || (TYPE(CHILD(tree, 0)) == import_stmt) + || (TYPE(CHILD(tree, 0)) == global_stmt) + || (TYPE(CHILD(tree, 0)) == access_stmt) + || validate_ntype(CHILD(tree, 0), exec_stmt)) + && (next = CHILD(tree, 0))); + break; + case flow_stmt: + res = ((nch == 1) + && ((TYPE(CHILD(tree, 0)) == break_stmt) + || (TYPE(CHILD(tree, 0)) == continue_stmt) + || (TYPE(CHILD(tree, 0)) == return_stmt) + || validate_ntype(CHILD(tree, 0), raise_stmt)) + && (next = CHILD(tree, 0))); + break; + /* + * Compound statements. + */ + case simple_stmt: + res = validate_simple_stmt(tree); + break; + case compound_stmt: + res = ((NCH(tree) == 1) + && ((TYPE(CHILD(tree, 0)) == if_stmt) + || (TYPE(CHILD(tree, 0)) == while_stmt) + || (TYPE(CHILD(tree, 0)) == for_stmt) + || (TYPE(CHILD(tree, 0)) == try_stmt) + || (TYPE(CHILD(tree, 0)) == funcdef) + || validate_ntype(CHILD(tree, 0), classdef)) + && (next = CHILD(tree, 0))); + break; + /* + * Fundemental 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 = ((nch == 1) + && validate_name(CHILD(tree, 0), "pass")); + break; + case break_stmt: + res = ((nch == 1) + && validate_name(CHILD(tree, 0), "break")); + break; + case continue_stmt: + res = ((nch == 1) + && 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 access_stmt: + res = validate_access_stmt(tree); + break; + case exec_stmt: + res = validate_exec_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 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 atom: + res = validate_atom(tree); + break; + + default: + /* Hopefully never reached! */ + res = 0; + break; + } + tree = next; + } + return (res); + +} /* validate_node() */ + + +VALIDATE(expr_tree) { + return (validate_ntype(tree, eval_input) + && validate_eval_input(tree)); + +} /* validate_expr_tree() */ + + +VALIDATE(suite_tree) { + int j; + int nch = NCH(tree); + int res = ((nch >= 1) + && validate_ntype(CHILD(tree, nch - 1), ENDMARKER) + && nch--); + + for (j = 0; res && (j < nch); ++j) { + res = ((TYPE(CHILD(tree, j)) == NEWLINE) + || (validate_ntype(CHILD(tree, j), stmt) + && validate_stmt(CHILD(tree, j)))); + } + return (res); + +} /* validate_suite_tree() */ + + + +/* 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. + * + */ +static PyMethodDef parser_functions[] = { + {"ast2tuple", parser_ast2tuple, 1}, + {"compileast", parser_compileast, 1}, + {"expr", parser_expr, 1}, + {"isexpr", parser_isexpr, 1}, + {"issuite", parser_issuite, 1}, + {"suite", parser_suite, 1}, + {"tuple2ast", parser_tuple2ast, 1}, + + {0, 0, 0} + }; + + + +void +initparser() { + PyObject* module = Py_InitModule("parser", parser_functions); + PyObject* dict = PyModule_GetDict(module); + + parser_error = PyString_FromString("parser.ParserError"); + + if ((parser_error == 0) + || (PyDict_SetItemString(dict, "ParserError", parser_error) != 0)) { + /* + * This is serious. + */ + Py_FatalError("can't define parser.error"); + } + /* + * Nice to have, but don't cry if we fail. + */ + 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)); + +} /* initparser() */ + + +/* + * end of Parser.c + */ -- cgit v1.2.1