dlls/jscript/jsval.h

   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 /*
  23  * jsval_t structure is used to represent JavaScript dynamically-typed values.
  24  * It's a (type,value) pair, usually represented as a structure of enum (type)
  25  * and union (value of given type). For both memory and speed performance, we
  26  * use tricks allowing storing both values as a struct with size equal to
  27  * size of double (that is 64-bit) on 32-bit systems. For that, we use the fact
  28  * that NaN value representation has 52 (almost) free bits.
  29  */
  30
  31 #ifdef __i386__
  32 #define JSVAL_DOUBLE_LAYOUT_PTR32
  33 #endif
  34
  35 #ifdef JSVAL_DOUBLE_LAYOUT_PTR32
  36 /* NaN exponent and our 0x80000 marker */
  37 #define JSV_VAL(x) (0x7ff80000|x)
  38 #else
  39 #define JSV_VAL(x) x
  40 #endif
  41
  42 typedef enum {
  43     JSV_UNDEFINED = JSV_VAL(1),
  44     JSV_NULL      = JSV_VAL(2),
  45     JSV_OBJECT    = JSV_VAL(3),
  46     JSV_STRING    = JSV_VAL(4),
  47     JSV_NUMBER    = JSV_VAL(5),
  48     JSV_BOOL      = JSV_VAL(6),
  49     JSV_VARIANT   = JSV_VAL(7)
  50 } jsval_type_t;
  51
  52 struct _jsval_t {
  53 #ifdef JSVAL_DOUBLE_LAYOUT_PTR32
  54     union {
  55         double n;
  56         struct {
  57             union {
  58                 IDispatch *obj;
  59                 BSTR str;
  60                 BOOL b;
  61                 VARIANT *v;
  62                 UINT_PTR as_uintptr;
  63             } u;
  64             jsval_type_t tag;
  65         } s;
  66     } u;
  67 #else
  68     jsval_type_t type;
  69     union {
  70         IDispatch *obj;
  71         BSTR str;
  72         double n;
  73         BOOL b;
  74         VARIANT *v;
  75     } u;
  76 #endif
  77 };
  78
  79 #ifdef JSVAL_DOUBLE_LAYOUT_PTR32
  80
  81 C_ASSERT(sizeof(jsval_t) == sizeof(double));
  82
  83 #define __JSVAL_TYPE(x) ((x).u.s.tag)
  84 #define __JSVAL_BOOL(x) ((x).u.s.u.b)
  85 #define __JSVAL_STR(x)  ((x).u.s.u.str)
  86 #define __JSVAL_OBJ(x)  ((x).u.s.u.obj)
  87 #define __JSVAL_VAR(x)  ((x).u.s.u.v)
  88
  89 #else
  90
  91 #define __JSVAL_TYPE(x) ((x).type)
  92 #define __JSVAL_BOOL(x) ((x).u.b)
  93 #define __JSVAL_STR(x)  ((x).u.str)
  94 #define __JSVAL_OBJ(x)  ((x).u.obj)
  95 #define __JSVAL_VAR(x)  ((x).u.v)
  96
  97 #endif
  98
  99 static inline jsval_t jsval_bool(BOOL b)
 100 {
 101     jsval_t ret;
 102     __JSVAL_TYPE(ret) = JSV_BOOL;
 103     __JSVAL_BOOL(ret) = b;
 104     return ret;
 105 }
 106
 107 static inline jsval_t jsval_string(BSTR str)
 108 {
 109     jsval_t ret;
 110     __JSVAL_TYPE(ret) = JSV_STRING;
 111     __JSVAL_STR(ret) = str;
 112     return ret;
 113 }
 114
 115 static inline jsval_t jsval_disp(IDispatch *obj)
 116 {
 117     jsval_t ret;
 118     __JSVAL_TYPE(ret) = JSV_OBJECT;
 119     __JSVAL_OBJ(ret) = obj;
 120     return ret;
 121 }
 122
 123 static inline jsval_t jsval_obj(jsdisp_t *obj)
 124 {
 125     return jsval_disp(to_disp(obj));
 126 }
 127
 128 static inline jsval_t jsval_null(void)
 129 {
 130     jsval_t ret;
 131     __JSVAL_TYPE(ret) = JSV_NULL;
 132     return ret;
 133 }
 134
 135 static inline jsval_t jsval_undefined(void)
 136 {
 137     jsval_t ret;
 138     __JSVAL_TYPE(ret) = JSV_UNDEFINED;
 139     return ret;
 140 }
 141
 142 static inline jsval_t jsval_number(double n)
 143 {
 144     jsval_t ret;
 145 #ifdef JSVAL_DOUBLE_LAYOUT_PTR32
 146     ret.u.n = n;
 147     /* normalize NaN value */
 148     if((ret.u.s.tag & 0x7ff00000) == 0x7ff00000) {
 149         /* isinf */
 150         if(ret.u.s.tag & 0xfffff) {
 151             ret.u.s.tag = 0x7ff00000;
 152             ret.u.s.u.as_uintptr = ~0;
 153         }else if(ret.u.s.u.as_uintptr) {
 154             ret.u.s.tag = 0x7ff00000;
 155         }
 156     }
 157     return ret;
 158 #else
 159     ret.type = JSV_NUMBER;
 160     ret.u.n = n;
 161 #endif
 162     return ret;
 163 }
 164
 165 static inline BOOL is_object_instance(jsval_t v)
 166 {
 167     return __JSVAL_TYPE(v) == JSV_OBJECT;
 168 }
 169
 170 static inline BOOL is_undefined(jsval_t v)
 171 {
 172     return __JSVAL_TYPE(v) == JSV_UNDEFINED;
 173 }
 174
 175 static inline BOOL is_null(jsval_t v)
 176 {
 177     return __JSVAL_TYPE(v) == JSV_NULL;
 178 }
 179
 180 static inline BOOL is_null_instance(jsval_t v)
 181 {
 182     return is_null(v) || (is_object_instance(v) && !__JSVAL_OBJ(v));
 183 }
 184
 185 static inline BOOL is_string(jsval_t v)
 186 {
 187     return __JSVAL_TYPE(v) == JSV_STRING;
 188 }
 189
 190 static inline BOOL is_number(jsval_t v)
 191 {
 192 #ifdef JSVAL_DOUBLE_LAYOUT_PTR32
 193     return (v.u.s.tag & 0x7ff80000) != 0x7ff80000;
 194 #else
 195     return v.type == JSV_NUMBER;
 196 #endif
 197 }
 198
 199 static inline BOOL is_variant(jsval_t v)
 200 {
 201     return __JSVAL_TYPE(v) == JSV_VARIANT;
 202 }
 203
 204 static inline BOOL is_bool(jsval_t v)
 205 {
 206     return __JSVAL_TYPE(v) == JSV_BOOL;
 207 }
 208
 209 static inline jsval_type_t jsval_type(jsval_t v)
 210 {
 211 #ifdef JSVAL_DOUBLE_LAYOUT_PTR32
 212     return is_number(v) ? JSV_NUMBER : v.u.s.tag;
 213 #else
 214     return v.type;
 215 #endif
 216 }
 217
 218 static inline IDispatch *get_object(jsval_t v)
 219 {
 220     return __JSVAL_OBJ(v);
 221 }
 222
 223 static inline double get_number(jsval_t v)
 224 {
 225     return v.u.n;
 226 }
 227
 228 static inline BSTR get_string(jsval_t v)
 229 {
 230     return __JSVAL_STR(v);
 231 }
 232
 233 static inline VARIANT *get_variant(jsval_t v)
 234 {
 235     return __JSVAL_VAR(v);
 236 }
 237
 238 static inline BOOL get_bool(jsval_t v)
 239 {
 240     return __JSVAL_BOOL(v);
 241 }
 242
 243 HRESULT variant_to_jsval(VARIANT*,jsval_t*) DECLSPEC_HIDDEN;
 244 HRESULT jsval_to_variant(jsval_t,VARIANT*) DECLSPEC_HIDDEN;
 245 void jsval_release(jsval_t) DECLSPEC_HIDDEN;
 246 HRESULT jsval_copy(jsval_t,jsval_t*) DECLSPEC_HIDDEN;
 247
 248 #endif