pjs/js/ref/jsparse.h

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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#ifndef jsparse_h___
#define jsparse_h___
/*
* JS parser definitions.
*/
#include "jsprvtd.h"
#include "jspubtd.h"
#include "jsscan.h"
PR_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_fun: function, contains arg and var properties
* pn_body: TOK_LC node for function body
* NB: We define or create the function object at
* parse (not emit) time, in order to specialize arg
* and var bytecodes early.
* 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 ternary pn_kid1: discriminant
* pn_kid2: list of TOK_CASE nodes
* pn_kid3: TOK_LC node for default statements or null
* TOK_CASE binary pn_left: case expr
* pn_right: TOK_LC node for case 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_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 and
* 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>
* TOK_COMMA list pn_head: list of pn_count comma-separated exprs
* TOK_ASSIGN binary pn_left: lvalue, pn_right: rvalue
* 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
* 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 pn_num: arg or local var slot if non-negative
* 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=
* TOK_USESHARP nullary pn_num: jsint value of n in #n#
* TOK_RP unary pn_kid: parenthesized expression
* TOK_NAME, name pn_atom: name, string, or object atom
* TOK_STRING, pn_op: JSOP_NAME, JSOP_STRING, or JSOP_OBJECT
* TOK_OBJECT pn_op may be *ARG or *VAR with pn_slot >= 0
* TOK_NUMBER dval pn_dval: double value of numeric literal
* TOK_PRIMARY nullary pn_op: JSOp bytecode
*/
typedef enum JSParseNodeArity {
PN_FUNC = -3,
PN_LIST = -2,
PN_TERNARY = 3,
PN_BINARY = 2,
PN_UNARY = 1,
PN_NAME = -1,
PN_NULLARY = 0
} JSParseNodeArity;
struct JSParseNode {
JSTokenType pn_type;
JSTokenPos pn_pos;
JSOp pn_op;
ptrdiff_t pn_offset; /* first generated bytecode offset */
JSParseNodeArity pn_arity;
union {
struct { /* TOK_FUNCTION node */
JSFunction *fun; /* function object private data */
JSParseNode *body; /* TOK_LC list of statements */
uint32 tryCount; /* try statement count */
} func;
struct { /* list of next-linked nodes */
JSParseNode *head; /* first node in list */
JSParseNode **tail; /* ptr to ptr to last node in list */
uint32 count; /* number of nodes in list */
JSBool extra; /* extra comma flag for [1,2,,] */
} list;
struct { /* ternary: if, switch, for(;;), ?: */
JSParseNode *kid1; /* condition, discriminant, etc. */
JSParseNode *kid2; /* then-part, case list, etc. */
JSParseNode *kid3; /* else-part, default case, etc. */
} ternary;
struct { /* two kids if binary */
JSParseNode *left;
JSParseNode *right;
jsval val; /* switch case value */
} binary;
struct { /* one kid if unary */
JSParseNode *kid;
jsint num; /* -1 or arg or local/sharp var num */
} unary;
struct { /* name, labeled statement, etc. */
JSAtom *atom; /* name or label atom, null if slot */
JSParseNode *expr; /* object or initializer */
jsint slot; /* -1 or arg or local var slot */
} name;
jsdouble dval; /* aligned numeric literal value */
} pn_u;
JSParseNode *pn_next; /* here to align dval and pn_u on RISCs */
};
#define pn_fun pn_u.func.fun
#define pn_body pn_u.func.body
#define pn_tryCount pn_u.func.tryCount
#define pn_head pn_u.list.head
#define pn_tail pn_u.list.tail
#define pn_count pn_u.list.count
#define pn_extra pn_u.list.extra
#define pn_kid1 pn_u.ternary.kid1
#define pn_kid2 pn_u.ternary.kid2
#define pn_kid3 pn_u.ternary.kid3
#define pn_left pn_u.binary.left
#define pn_right pn_u.binary.right
#define pn_val pn_u.binary.val
#define pn_kid pn_u.unary.kid
#define pn_num pn_u.unary.num
#define pn_atom pn_u.name.atom
#define pn_expr pn_u.name.expr
#define pn_slot pn_u.name.slot
#define pn_dval pn_u.dval
/*
* Compute a pointer to the last JSParseNode element in a singly-linked list.
* NB: list must be non-empty for correct PN_LAST usage!
*/
#define PN_LAST(list) \
((JSParseNode *)((char *)(list)->pn_tail - offsetof(JSParseNode, pn_next)))
#define PN_INIT_LIST(list) \
PR_BEGIN_MACRO \
(list)->pn_head = NULL; \
(list)->pn_tail = &(list)->pn_head; \
(list)->pn_count = 0; \
PR_END_MACRO
#define PN_INIT_LIST_1(list, pn) \
PR_BEGIN_MACRO \
(list)->pn_head = (pn); \
(list)->pn_tail = &(pn)->pn_next; \
(list)->pn_count = 1; \
PR_END_MACRO
#define PN_APPEND(list, pn) \
PR_BEGIN_MACRO \
*(list)->pn_tail = (pn); \
(list)->pn_tail = &(pn)->pn_next; \
(list)->pn_count++; \
PR_END_MACRO
/* New names to connote code generation in addition to parse tree gen. */
#define js_CompileTokenStream js_Parse
#define js_CompileFunctionBody js_ParseFunctionBody
extern JS_FRIEND_API(JSBool)
js_CompileTokenStream(JSContext *cx, JSObject *chain, JSTokenStream *ts,
JSCodeGenerator *cg);
extern JSBool
js_CompileFunctionBody(JSContext *cx, JSTokenStream *ts, JSFunction *fun);
/* XXXbe expose js_Parse{TokenStream,FunctionBody} that return trees? */
extern JSBool
js_FoldConstants(JSContext *cx, JSParseNode *pn);
PR_END_EXTERN_C
#endif /* jsparse_h___ */