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Reactos
1/*
2 * Copyright 2012 Jacek Caban for CodeWeavers
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
17 */
18
19#ifndef JSVAL_H
20#define JSVAL_H
21
22#include "jsstr.h"
23
24/*
25 * jsval_t structure is used to represent JavaScript dynamically-typed values.
26 * It's a (type,value) pair, usually represented as a structure of enum (type)
27 * and union (value of given type). For both memory and speed performance, we
28 * use tricks allowing storing both values as a struct with size equal to
29 * size of double (that is 64-bit) on 32-bit systems. For that, we use the fact
30 * that NaN value representation has 52 (almost) free bits.
31 */
32
33#ifdef __i386__
34#define JSVAL_DOUBLE_LAYOUT_PTR32
35#endif
36
37#ifdef JSVAL_DOUBLE_LAYOUT_PTR32
38/* NaN exponent and our 0x80000 marker */
39#define JSV_VAL(x) (0x7ff80000|x)
40#else
41#define JSV_VAL(x) x
42#endif
43
44typedef enum {
45 JSV_UNDEFINED = JSV_VAL(1),
46 JSV_NULL = JSV_VAL(2),
47 JSV_OBJECT = JSV_VAL(3),
48 JSV_STRING = JSV_VAL(4),
49 JSV_NUMBER = JSV_VAL(5),
50 JSV_BOOL = JSV_VAL(6),
51 JSV_VARIANT = JSV_VAL(7)
52} jsval_type_t;
53
54struct _jsval_t {
55#ifdef JSVAL_DOUBLE_LAYOUT_PTR32
56 union {
57 double n;
58 struct {
59 union {
60 IDispatch *obj;
61 jsstr_t *str;
62 BOOL b;
63 VARIANT *v;
64 UINT_PTR as_uintptr;
65 } u;
66 jsval_type_t tag;
67 } s;
68 } u;
69#else
70 jsval_type_t type;
71 union {
72 IDispatch *obj;
73 jsstr_t *str;
74 double n;
75 BOOL b;
76 VARIANT *v;
77 } u;
78#endif
79};
80
81#ifdef JSVAL_DOUBLE_LAYOUT_PTR32
82
83C_ASSERT(sizeof(jsval_t) == sizeof(double));
84
85#define __JSVAL_TYPE(x) ((x).u.s.tag)
86#define __JSVAL_BOOL(x) ((x).u.s.u.b)
87#define __JSVAL_STR(x) ((x).u.s.u.str)
88#define __JSVAL_OBJ(x) ((x).u.s.u.obj)
89#define __JSVAL_VAR(x) ((x).u.s.u.v)
90
91#else
92
93#define __JSVAL_TYPE(x) ((x).type)
94#define __JSVAL_BOOL(x) ((x).u.b)
95#define __JSVAL_STR(x) ((x).u.str)
96#define __JSVAL_OBJ(x) ((x).u.obj)
97#define __JSVAL_VAR(x) ((x).u.v)
98
99#endif
100
101static inline jsval_t jsval_bool(BOOL b)
102{
103 jsval_t ret;
104 __JSVAL_TYPE(ret) = JSV_BOOL;
105 __JSVAL_BOOL(ret) = b;
106 return ret;
107}
108
109static inline jsval_t jsval_string(jsstr_t *str)
110{
111 jsval_t ret;
112 __JSVAL_TYPE(ret) = JSV_STRING;
113 __JSVAL_STR(ret) = str;
114 return ret;
115}
116
117static inline jsval_t jsval_disp(IDispatch *obj)
118{
119 jsval_t ret;
120 __JSVAL_TYPE(ret) = JSV_OBJECT;
121 __JSVAL_OBJ(ret) = obj;
122 return ret;
123}
124
125static inline jsval_t jsval_obj(jsdisp_t *obj)
126{
127 return jsval_disp(to_disp(obj));
128}
129
130static inline jsval_t jsval_null(void)
131{
132 jsval_t ret;
133 __JSVAL_TYPE(ret) = JSV_NULL;
134 return ret;
135}
136
137static inline jsval_t jsval_undefined(void)
138{
139 jsval_t ret;
140 __JSVAL_TYPE(ret) = JSV_UNDEFINED;
141 return ret;
142}
143
144static inline jsval_t jsval_number(double n)
145{
146 jsval_t ret;
147#ifdef JSVAL_DOUBLE_LAYOUT_PTR32
148 ret.u.n = n;
149 /* normalize NaN value */
150 if((ret.u.s.tag & 0x7ff00000) == 0x7ff00000) {
151 /* isinf */
152 if(ret.u.s.tag & 0xfffff) {
153 ret.u.s.tag = 0x7ff00000;
154 ret.u.s.u.as_uintptr = ~0;
155 }else if(ret.u.s.u.as_uintptr) {
156 ret.u.s.tag = 0x7ff00000;
157 }
158 }
159#else
160 ret.type = JSV_NUMBER;
161 ret.u.n = n;
162#endif
163 return ret;
164}
165
166static inline BOOL is_object_instance(jsval_t v)
167{
168 return __JSVAL_TYPE(v) == JSV_OBJECT;
169}
170
171static inline BOOL is_undefined(jsval_t v)
172{
173 return __JSVAL_TYPE(v) == JSV_UNDEFINED;
174}
175
176static inline BOOL is_null(jsval_t v)
177{
178 return __JSVAL_TYPE(v) == JSV_NULL;
179}
180
181static inline BOOL is_null_instance(jsval_t v)
182{
183 return is_null(v) || (is_object_instance(v) && !__JSVAL_OBJ(v));
184}
185
186static inline BOOL is_string(jsval_t v)
187{
188 return __JSVAL_TYPE(v) == JSV_STRING;
189}
190
191static inline BOOL is_number(jsval_t v)
192{
193#ifdef JSVAL_DOUBLE_LAYOUT_PTR32
194 return (v.u.s.tag & 0x7ff80000) != 0x7ff80000;
195#else
196 return v.type == JSV_NUMBER;
197#endif
198}
199
200static inline BOOL is_variant(jsval_t v)
201{
202 return __JSVAL_TYPE(v) == JSV_VARIANT;
203}
204
205static inline BOOL is_bool(jsval_t v)
206{
207 return __JSVAL_TYPE(v) == JSV_BOOL;
208}
209
210static inline jsval_type_t jsval_type(jsval_t v)
211{
212#ifdef JSVAL_DOUBLE_LAYOUT_PTR32
213 return is_number(v) ? JSV_NUMBER : v.u.s.tag;
214#else
215 return v.type;
216#endif
217}
218
219static inline IDispatch *get_object(jsval_t v)
220{
221 return __JSVAL_OBJ(v);
222}
223
224static inline double get_number(jsval_t v)
225{
226 return v.u.n;
227}
228
229static inline jsstr_t *get_string(jsval_t v)
230{
231 return __JSVAL_STR(v);
232}
233
234static inline VARIANT *get_variant(jsval_t v)
235{
236 return __JSVAL_VAR(v);
237}
238
239static inline BOOL get_bool(jsval_t v)
240{
241 return __JSVAL_BOOL(v);
242}
243
244HRESULT variant_to_jsval(VARIANT*,jsval_t*) DECLSPEC_HIDDEN;
245HRESULT jsval_to_variant(jsval_t,VARIANT*) DECLSPEC_HIDDEN;
246void jsval_release(jsval_t) DECLSPEC_HIDDEN;
247HRESULT jsval_copy(jsval_t,jsval_t*) DECLSPEC_HIDDEN;
248
249#endif