jsparse.h

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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * ***** END LICENSE BLOCK ***** */

#ifndef jsparse_h___
#define jsparse_h___
/*
 * JS parser definitions.
 */
#include "jsprvtd.h"
#include "jspubtd.h"
#include "jsscan.h"

JS_BEGIN_EXTERN_C

/*
 * Parsing builds a tree of nodes that directs code generation.  This tree is
 * not a concrete syntax tree in all respects (for example, || and && are left
 * associative, but (A && B && C) translates into the right-associated tree
 * <A && <B && C>> so that code generation can emit a left-associative branch
 * around <B && C> when A is false).  Nodes are labeled by token type, with a
 * JSOp secondary label when needed:
 *
 * Label        Variant     Members
 * -----        -------     -------
 * <Definitions>
 * TOK_FUNCTION func        pn_funAtom: atom holding function object containing
 *                            arg and var properties.  We create the function
 *                            object at parse (not emit) time to specialize arg
 *                            and var bytecodes early.
 *                          pn_body: TOK_LC node for function body statements
 *                          pn_flags: TCF_FUN_* flags (see jsemit.h) collected
 *                            while parsing the function's body
 *                          pn_tryCount: of try statements in function
 *
 * <Statements>
 * TOK_LC       list        pn_head: list of pn_count statements
 * TOK_EXPORT   list        pn_head: list of pn_count TOK_NAMEs or one TOK_STAR
 *                            (which is not a multiply node)
 * TOK_IMPORT   list        pn_head: list of pn_count sub-trees of the form
 *                            a.b.*, a[b].*, a.*, a.b, or a[b] -- but never a.
 *                            Each member is expressed with TOK_DOT or TOK_LB.
 *                            Each sub-tree's root node has a pn_op in the set
 *                            JSOP_IMPORT{ALL,PROP,ELEM}
 * TOK_IF       ternary     pn_kid1: cond, pn_kid2: then, pn_kid3: else or null
 * TOK_SWITCH   binary      pn_left: discriminant
 *                          pn_right: list of TOK_CASE nodes, with at most one
 *                            TOK_DEFAULT node
 * TOK_CASE,    binary      pn_left: case expr or null if TOK_DEFAULT
 * TOK_DEFAULT              pn_right: TOK_LC node for this case's statements
 * TOK_WHILE    binary      pn_left: cond, pn_right: body
 * TOK_DO       binary      pn_left: body, pn_right: cond
 * TOK_FOR      binary      pn_left: either
 *                            for/in loop: a binary TOK_IN node with
 *                              pn_left:  TOK_VAR or TOK_NAME to left of 'in'
 *                              pn_right: object expr to right of 'in'
 *                            for(;;) loop: a ternary TOK_RESERVED node with
 *                              pn_kid1:  init expr before first ';'
 *                              pn_kid2:  cond expr before second ';'
 *                              pn_kid3:  update expr after second ';'
 *                              any kid may be null
 *                          pn_right: body
 * TOK_THROW    unary       pn_op: JSOP_THROW, pn_kid: exception
 * TOK_TRY      ternary     pn_kid1: try block
 *                          pn_kid2: catch blocks or null
 *                          pn_kid3: finally block or null
 * TOK_CATCH    ternary     pn_kid1: PN_NAME node for catch var (with pn_expr
 *                                   null or the catch guard expression)
 *                          pn_kid2: more catch blocks or null
 *                          pn_kid3: catch block statements
 * TOK_BREAK    name        pn_atom: label or null
 * TOK_CONTINUE name        pn_atom: label or null
 * TOK_WITH     binary      pn_left: head expr, pn_right: body
 * TOK_VAR      list        pn_head: list of pn_count TOK_NAME nodes
 *                                   each name node has
 *                                     pn_atom: variable name
 *                                     pn_expr: initializer or null
 * TOK_RETURN   unary       pn_kid: return expr or null
 * TOK_SEMI     unary       pn_kid: expr or null statement
 * TOK_COLON    name        pn_atom: label, pn_expr: labeled statement
 *
 * <Expressions>
 * All left-associated binary trees of the same type are optimized into lists
 * to avoid recursion when processing expression chains.
 * TOK_COMMA    list        pn_head: list of pn_count comma-separated exprs
 * TOK_ASSIGN   binary      pn_left: lvalue, pn_right: rvalue
 *                          pn_op: JSOP_ADD for +=, etc.
 * TOK_HOOK     ternary     pn_kid1: cond, pn_kid2: then, pn_kid3: else
 * TOK_OR       binary      pn_left: first in || chain, pn_right: rest of chain
 * TOK_AND      binary      pn_left: first in && chain, pn_right: rest of chain
 * TOK_BITOR    binary      pn_left: left-assoc | expr, pn_right: ^ expr
 * TOK_BITXOR   binary      pn_left: left-assoc ^ expr, pn_right: & expr
 * TOK_BITAND   binary      pn_left: left-assoc & expr, pn_right: EQ expr
 * TOK_EQOP     binary      pn_left: left-assoc EQ expr, pn_right: REL expr
 *                          pn_op: JSOP_EQ, JSOP_NE, JSOP_NEW_EQ, JSOP_NEW_NE
 * TOK_RELOP    binary      pn_left: left-assoc REL expr, pn_right: SH expr
 *                          pn_op: JSOP_LT, JSOP_LE, JSOP_GT, JSOP_GE
 * TOK_SHOP     binary      pn_left: left-assoc SH expr, pn_right: ADD expr
 *                          pn_op: JSOP_LSH, JSOP_RSH, JSOP_URSH
 * TOK_PLUS,    binary      pn_left: left-assoc ADD expr, pn_right: MUL expr
 *                          pn_extra: if a left-associated binary TOK_PLUS
 *                            tree has been flattened into a list (see above
 *                            under <Expressions>), pn_extra will contain
 *                            PNX_STRCAT if at least one list element is a
 *                            string literal (TOK_STRING); if such a list has
 *                            any non-string, non-number term, pn_extra will
 *                            contain PNX_CANTFOLD.
 *                          pn_
 * TOK_MINUS                pn_op: JSOP_ADD, JSOP_SUB
 * TOK_STAR,    binary      pn_left: left-assoc MUL expr, pn_right: UNARY expr
 * TOK_DIVOP                pn_op: JSOP_MUL, JSOP_DIV, JSOP_MOD
 * TOK_UNARYOP  unary       pn_kid: UNARY expr, pn_op: JSOP_NEG, JSOP_POS,
 *                          JSOP_NOT, JSOP_BITNOT, JSOP_TYPEOF, JSOP_VOID
 * TOK_INC,     unary       pn_kid: MEMBER expr
 * TOK_DEC
 * TOK_NEW      list        pn_head: list of ctor, arg1, arg2, ... argN
 *                          pn_count: 1 + N (where N is number of args)
 *                          ctor is a MEMBER expr
 * TOK_DELETE   unary       pn_kid: MEMBER expr
 * TOK_DOT      name        pn_expr: MEMBER expr to left of .
 *                          pn_atom: name to right of .
 * TOK_LB       binary      pn_left: MEMBER expr to left of [
 *                          pn_right: expr between [ and ]
 * TOK_LP       list        pn_head: list of call, arg1, arg2, ... argN
 *                          pn_count: 1 + N (where N is number of args)
 *                          call is a MEMBER expr naming a callable object
 * TOK_RB       list        pn_head: list of pn_count array element exprs
 *                          [,,] holes are represented by TOK_COMMA nodes
 *                          #n=[...] produces TOK_DEFSHARP at head of list
 *                          pn_extra: true if extra comma at end
 * TOK_RC       list        pn_head: list of pn_count TOK_COLON nodes where
 *                          each has pn_left: property id, pn_right: value
 *                          #n={...} produces TOK_DEFSHARP at head of list
 * TOK_DEFSHARP unary       pn_num: jsint value of n in #n=