1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 *
3 * ***** BEGIN LICENSE BLOCK *****
4 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
5 *
6 * The contents of this file are subject to the Mozilla Public License Version
7 * 1.1 (the "License"); you may not use this file except in compliance with
8 * the License. You may obtain a copy of the License at
9 * http://www.mozilla.org/MPL/
10 *
11 * Software distributed under the License is distributed on an "AS IS" basis,
12 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13 * for the specific language governing rights and limitations under the
14 * License.
15 *
16 * The Original Code is Mozilla Communicator client code, released
17 * March 31, 1998.
18 *
19 * The Initial Developer of the Original Code is
20 * Netscape Communications Corporation.
21 * Portions created by the Initial Developer are Copyright (C) 1998
22 * the Initial Developer. All Rights Reserved.
23 *
24 * Contributor(s):
25 *
26 * Alternatively, the contents of this file may be used under the terms of
27 * either of the GNU General Public License Version 2 or later (the "GPL"),
28 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
29 * in which case the provisions of the GPL or the LGPL are applicable instead
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34 * and other provisions required by the GPL or the LGPL. If you do not delete
35 * the provisions above, a recipient may use your version of this file under
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37 *
38 * ***** END LICENSE BLOCK ***** */
40 #ifndef jsparse_h___
41 #define jsparse_h___
42 /*
43 * JS parser definitions.
44 */
45 #include "jsprvtd.h"
46 #include "jspubtd.h"
47 #include "jsscan.h"
49 JS_BEGIN_EXTERN_C
51 /*
52 * Parsing builds a tree of nodes that directs code generation. This tree is
53 * not a concrete syntax tree in all respects (for example, || and && are left
54 * associative, but (A && B && C) translates into the right-associated tree
55 * <A && <B && C>> so that code generation can emit a left-associative branch
56 * around <B && C> when A is false). Nodes are labeled by token type, with a
57 * JSOp secondary label when needed:
58 *
59 * Label Variant Members
60 * ----- ------- -------
61 * <Definitions>
62 * TOK_FUNCTION func pn_funAtom: atom holding function object containing
63 * arg and var properties. We create the function
64 * object at parse (not emit) time to specialize arg
65 * and var bytecodes early.
66 * pn_body: TOK_LC node for function body statements
67 * pn_flags: TCF_FUN_* flags (see jsemit.h) collected
68 * while parsing the function's body
69 * pn_tryCount: of try statements in function
70 *
71 * <Statements>
72 * TOK_LC list pn_head: list of pn_count statements
73 * TOK_EXPORT list pn_head: list of pn_count TOK_NAMEs or one TOK_STAR
74 * (which is not a multiply node)
75 * TOK_IMPORT list pn_head: list of pn_count sub-trees of the form
76 * a.b.*, a[b].*, a.*, a.b, or a[b] -- but never a.
77 * Each member is expressed with TOK_DOT or TOK_LB.
78 * Each sub-tree's root node has a pn_op in the set
79 * JSOP_IMPORT{ALL,PROP,ELEM}
80 * TOK_IF ternary pn_kid1: cond, pn_kid2: then, pn_kid3: else or null
81 * TOK_SWITCH binary pn_left: discriminant
82 * pn_right: list of TOK_CASE nodes, with at most one
83 * TOK_DEFAULT node
84 * TOK_CASE, binary pn_left: case expr or null if TOK_DEFAULT
85 * TOK_DEFAULT pn_right: TOK_LC node for this case's statements
86 * pn_val: constant value if lookup or table switch
87 * TOK_WHILE binary pn_left: cond, pn_right: body
88 * TOK_DO binary pn_left: body, pn_right: cond
89 * TOK_FOR binary pn_left: either
90 * for/in loop: a binary TOK_IN node with
91 * pn_left: TOK_VAR or TOK_NAME to left of 'in'
92 * if TOK_VAR, its pn_extra may have PNX_POPVAR
93 * and PNX_FORINVAR bits set
94 * pn_right: object expr to right of 'in'
95 * for(;;) loop: a ternary TOK_RESERVED node with
96 * pn_kid1: init expr before first ';'
97 * pn_kid2: cond expr before second ';'
98 * pn_kid3: update expr after second ';'
99 * any kid may be null
100 * pn_right: body
101 * TOK_THROW unary pn_op: JSOP_THROW, pn_kid: exception
102 * TOK_TRY ternary pn_kid1: try block
103 * pn_kid2: catch blocks or null
104 * pn_kid3: finally block or null
105 * TOK_CATCH ternary pn_kid1: PN_NAME node for catch var (with pn_expr
106 * null or the catch guard expression)
107 * pn_kid2: more catch blocks or null
108 * pn_kid3: catch block statements
109 * TOK_BREAK name pn_atom: label or null
110 * TOK_CONTINUE name pn_atom: label or null
111 * TOK_WITH binary pn_left: head expr, pn_right: body
112 * TOK_VAR list pn_head: list of pn_count TOK_NAME nodes
113 * each name node has
114 * pn_atom: variable name
115 * pn_expr: initializer or null
116 * TOK_RETURN unary pn_kid: return expr or null
117 * TOK_SEMI unary pn_kid: expr or null statement
118 * TOK_COLON name pn_atom: label, pn_expr: labeled statement
119 *
120 * <Expressions>
121 * All left-associated binary trees of the same type are optimized into lists
122 * to avoid recursion when processing expression chains.
123 * TOK_COMMA list pn_head: list of pn_count comma-separated exprs
124 * TOK_ASSIGN binary pn_left: lvalue, pn_right: rvalue
125 * pn_op: JSOP_ADD for +=, etc.
126 * TOK_HOOK ternary pn_kid1: cond, pn_kid2: then, pn_kid3: else
127 * TOK_OR binary pn_left: first in || chain, pn_right: rest of chain
128 * TOK_AND binary pn_left: first in && chain, pn_right: rest of chain
129 * TOK_BITOR binary pn_left: left-assoc | expr, pn_right: ^ expr
130 * TOK_BITXOR binary pn_left: left-assoc ^ expr, pn_right: & expr
131 * TOK_BITAND binary pn_left: left-assoc & expr, pn_right: EQ expr
132 * TOK_EQOP binary pn_left: left-assoc EQ expr, pn_right: REL expr
133 * pn_op: JSOP_EQ, JSOP_NE, JSOP_NEW_EQ, JSOP_NEW_NE
134 * TOK_RELOP binary pn_left: left-assoc REL expr, pn_right: SH expr
135 * pn_op: JSOP_LT, JSOP_LE, JSOP_GT, JSOP_GE
136 * TOK_SHOP binary pn_left: left-assoc SH expr, pn_right: ADD expr
137 * pn_op: JSOP_LSH, JSOP_RSH, JSOP_URSH
138 * TOK_PLUS, binary pn_left: left-assoc ADD expr, pn_right: MUL expr
139 * pn_extra: if a left-associated binary TOK_PLUS
140 * tree has been flattened into a list (see above
141 * under <Expressions>), pn_extra will contain
142 * PNX_STRCAT if at least one list element is a
143 * string literal (TOK_STRING); if such a list has
144 * any non-string, non-number term, pn_extra will
145 * contain PNX_CANTFOLD.
146 * pn_
147 * TOK_MINUS pn_op: JSOP_ADD, JSOP_SUB
148 * TOK_STAR, binary pn_left: left-assoc MUL expr, pn_right: UNARY expr
149 * TOK_DIVOP pn_op: JSOP_MUL, JSOP_DIV, JSOP_MOD
150 * TOK_UNARYOP unary pn_kid: UNARY expr, pn_op: JSOP_NEG, JSOP_POS,
151 * JSOP_NOT, JSOP_BITNOT, JSOP_TYPEOF, JSOP_VOID
152 * TOK_INC, unary pn_kid: MEMBER expr
153 * TOK_DEC
154 * TOK_NEW list pn_head: list of ctor, arg1, arg2, ... argN
155 * pn_count: 1 + N (where N is number of args)
156 * ctor is a MEMBER expr
157 * TOK_DELETE unary pn_kid: MEMBER expr
158 * TOK_DOT name pn_expr: MEMBER expr to left of .
159 * pn_atom: name to right of .
160 * TOK_LB binary pn_left: MEMBER expr to left of [
161 * pn_right: expr between [ and ]
162 * TOK_LP list pn_head: list of call, arg1, arg2, ... argN
163 * pn_count: 1 + N (where N is number of args)
164 * call is a MEMBER expr naming a callable object
165 * TOK_RB list pn_head: list of pn_count array element exprs
166 * [,,] holes are represented by TOK_COMMA nodes
167 * #n=[...] produces TOK_DEFSHARP at head of list
168 * pn_extra: PN_ENDCOMMA if extra comma at end
169 * TOK_RC list pn_head: list of pn_count TOK_COLON nodes where
170 * each has pn_left: property id, pn_right: value
171 * #n={...} produces TOK_DEFSHARP at head of list
172 * TOK_DEFSHARP unary pn_num: jsint value of n in #n=
173 * pn_kid: null for #n=[...] and #n={...}, primary
174 * if #n=primary for function, paren, name, object
175 * literal expressions
176 * TOK_USESHARP nullary pn_num: jsint value of n in #n#
177 * TOK_RP unary pn_kid: parenthesized expression
178 * TOK_NAME, name pn_atom: name, string, or object atom
179 * TOK_STRING, pn_op: JSOP_NAME, JSOP_STRING, or JSOP_OBJECT, or
180 * JSOP_REGEXP
181 * TOK_OBJECT If JSOP_NAME, pn_op may be JSOP_*ARG or JSOP_*VAR
182 * with pn_slot >= 0 and pn_attrs telling const-ness
183 * TOK_NUMBER dval pn_dval: double value of numeric literal
184 * TOK_PRIMARY nullary pn_op: JSOp bytecode
185 */
186 typedef enum JSParseNodeArity {
187 PN_FUNC = -3,
188 PN_LIST = -2,
189 PN_TERNARY = 3,
190 PN_BINARY = 2,
191 PN_UNARY = 1,
192 PN_NAME = -1,
193 PN_NULLARY = 0
194 } JSParseNodeArity;
196 struct JSParseNode {
197 JSTokenType pn_type;
198 JSTokenPos pn_pos;
199 JSOp pn_op;
200 ptrdiff_t pn_offset; /* first generated bytecode offset */
201 JSParseNodeArity pn_arity;
202 union {
203 struct { /* TOK_FUNCTION node */
204 JSAtom *funAtom; /* atomized function object */
205 JSParseNode *body; /* TOK_LC list of statements */
206 uint32 flags; /* accumulated tree context flags */
207 uint32 tryCount; /* count of try statements in body */
208 } func;
209 struct { /* list of next-linked nodes */
210 JSParseNode *head; /* first node in list */
211 JSParseNode **tail; /* ptr to ptr to last node in list */
212 uint32 count; /* number of nodes in list */
213 uint32 extra; /* extra comma flag for [1,2,,] */
214 } list;
215 struct { /* ternary: if, for(;;), ?: */
216 JSParseNode *kid1; /* condition, discriminant, etc. */
217 JSParseNode *kid2; /* then-part, case list, etc. */
218 JSParseNode *kid3; /* else-part, default case, etc. */
219 } ternary;
220 struct { /* two kids if binary */
221 JSParseNode *left;
222 JSParseNode *right;
223 jsval val; /* switch case value */
224 } binary;
225 struct { /* one kid if unary */
226 JSParseNode *kid;
227 jsint num; /* -1 or sharp variable number */
228 } unary;
229 struct { /* name, labeled statement, etc. */
230 JSAtom *atom; /* name or label atom, null if slot */
231 JSParseNode *expr; /* object or initializer */
232 jsint slot; /* -1 or arg or local var slot */
233 uintN attrs; /* attributes if local var or const */
234 } name;
235 jsdouble dval; /* aligned numeric literal value */
236 } pn_u;
237 JSParseNode *pn_next; /* to align dval and pn_u on RISCs */
238 };
240 #define pn_funAtom pn_u.func.funAtom
241 #define pn_body pn_u.func.body
242 #define pn_flags pn_u.func.flags
243 #define pn_tryCount pn_u.func.tryCount
244 #define pn_head pn_u.list.head
245 #define pn_tail pn_u.list.tail
246 #define pn_count pn_u.list.count
247 #define pn_extra pn_u.list.extra
248 #define pn_kid1 pn_u.ternary.kid1
249 #define pn_kid2 pn_u.ternary.kid2
250 #define pn_kid3 pn_u.ternary.kid3
251 #define pn_left pn_u.binary.left
252 #define pn_right pn_u.binary.right
253 #define pn_val pn_u.binary.val
254 #define pn_kid pn_u.unary.kid
255 #define pn_num pn_u.unary.num
256 #define pn_atom pn_u.name.atom
257 #define pn_expr pn_u.name.expr
258 #define pn_slot pn_u.name.slot
259 #define pn_attrs pn_u.name.attrs
260 #define pn_dval pn_u.dval
262 /* PN_LIST pn_extra flags. */
263 #define PNX_STRCAT 0x01 /* TOK_PLUS list has string term */
264 #define PNX_CANTFOLD 0x02 /* TOK_PLUS list has unfoldable term */
265 #define PNX_POPVAR 0x04 /* TOK_VAR last result needs popping */
266 #define PNX_FORINVAR 0x08 /* TOK_VAR is left kid of TOK_IN node,
267 which is left kid of TOK_FOR */
268 #define PNX_ENDCOMMA 0x10 /* array literal has comma at end */
270 /*
271 * Move pn2 into pn, preserving pn->pn_pos and pn->pn_offset and handing off
272 * any kids in pn2->pn_u, by clearing pn2.
273 */
274 #define PN_MOVE_NODE(pn, pn2) \
275 JS_BEGIN_MACRO \
276 (pn)->pn_type = (pn2)->pn_type; \
277 (pn)->pn_op = (pn2)->pn_op; \
278 (pn)->pn_arity = (pn2)->pn_arity; \
279 (pn)->pn_u = (pn2)->pn_u; \
280 PN_CLEAR_NODE(pn2); \
281 JS_END_MACRO
283 #define PN_CLEAR_NODE(pn) \
284 JS_BEGIN_MACRO \
285 (pn)->pn_type = TOK_EOF; \
286 (pn)->pn_op = JSOP_NOP; \
287 (pn)->pn_arity = PN_NULLARY; \
288 JS_END_MACRO
290 /* True if pn is a parsenode representing a literal constant. */
291 #define PN_IS_CONSTANT(pn) \
292 ((pn)->pn_type == TOK_NUMBER || \
293 (pn)->pn_type == TOK_STRING || \
294 ((pn)->pn_type == TOK_PRIMARY && (pn)->pn_op != JSOP_THIS))
296 /*
297 * Compute a pointer to the last JSParseNode element in a singly-linked list.
298 * NB: list must be non-empty for correct PN_LAST usage!
299 */
300 #define PN_LAST(list) \
301 ((JSParseNode *)((char *)(list)->pn_tail - offsetof(JSParseNode, pn_next)))
303 #define PN_INIT_LIST(list) \
304 JS_BEGIN_MACRO \
305 (list)->pn_head = NULL; \
306 (list)->pn_tail = &(list)->pn_head; \
307 (list)->pn_count = 0; \
308 JS_END_MACRO
310 #define PN_INIT_LIST_1(list, pn) \
311 JS_BEGIN_MACRO \
312 (list)->pn_head = (pn); \
313 (list)->pn_tail = &(pn)->pn_next; \
314 (list)->pn_count = 1; \
315 JS_END_MACRO
317 #define PN_APPEND(list, pn) \
318 JS_BEGIN_MACRO \
319 *(list)->pn_tail = (pn); \
320 (list)->pn_tail = &(pn)->pn_next; \
321 (list)->pn_count++; \
322 JS_END_MACRO
324 /*
325 * Parse a top-level JS script.
326 *
327 * The caller must prevent the GC from running while this function is active,
328 * because atoms and function newborns are not rooted yet.
329 */
330 extern JS_FRIEND_API(JSParseNode *)
331 js_ParseTokenStream(JSContext *cx, JSObject *chain, JSTokenStream *ts);
333 extern JS_FRIEND_API(JSBool)
334 js_CompileTokenStream(JSContext *cx, JSObject *chain, JSTokenStream *ts,
335 JSCodeGenerator *cg);
337 extern JSBool
338 js_CompileFunctionBody(JSContext *cx, JSTokenStream *ts, JSFunction *fun);
340 extern JSBool
341 js_FoldConstants(JSContext *cx, JSParseNode *pn, JSTreeContext *tc);
343 JS_END_EXTERN_C
345 #endif /* jsparse_h___ */