1 /* Common operations. 2 3 Copyright (C) 2015, 2016, 2017 Paul Boddie <paul@boddie.org.uk> 4 5 This program is free software; you can redistribute it and/or modify it under 6 the terms of the GNU General Public License as published by the Free Software 7 Foundation; either version 3 of the License, or (at your option) any later 8 version. 9 10 This program is distributed in the hope that it will be useful, but WITHOUT 11 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 12 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 13 details. 14 15 You should have received a copy of the GNU General Public License along with 16 this program. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #include "gc.h" /* GC_MALLOC, GC_REALLOC */ 20 #include "ops.h" 21 #include "progops.h" /* for raising errors */ 22 #include "progconsts.h" 23 #include "progtypes.h" 24 #include <stdio.h> 25 26 /* Direct access and manipulation of static objects. */ 27 28 __attr __load_static_ignore(__ref obj) 29 { 30 return (__attr) {.value=obj}; 31 } 32 33 __attr __load_static_replace(__ref context, __ref obj) 34 { 35 return __update_context(context, (__attr) {.value=obj}); 36 } 37 38 __attr __load_static_test(__ref context, __ref obj) 39 { 40 return __test_context(context, (__attr) {.value=obj}); 41 } 42 43 /* Direct retrieval operations, returning and setting attributes. */ 44 45 __attr __load_via_object(__ref obj, int pos) 46 { 47 return obj->attrs[pos]; 48 } 49 50 __attr __load_via_class(__ref obj, int pos) 51 { 52 return __load_via_object(__get_class(obj), pos); 53 } 54 55 __attr __get_class_and_load(__ref obj, int pos) 56 { 57 if (__is_instance(obj)) 58 return __load_via_class(obj, pos); 59 else 60 return __load_via_object(obj, pos); 61 } 62 63 /* Direct storage operations. */ 64 65 int __store_via_object(__ref obj, int pos, __attr value) 66 { 67 obj->attrs[pos] = value; 68 return 1; 69 } 70 71 int __get_class_and_store(__ref obj, int pos, __attr value) 72 { 73 /* Forbid class-relative assignments. */ 74 75 __raise_type_error(); 76 return 0; 77 } 78 79 /* Introspection. */ 80 81 int __is_instance(__ref obj) 82 { 83 return obj->pos == __INSTANCEPOS; 84 } 85 86 int __is_type_instance(__ref obj) 87 { 88 return __HASATTR(__get_class(obj), __TYPE_CLASS_POS, __TYPE_CLASS_CODE); 89 } 90 91 __ref __get_class(__ref obj) 92 { 93 return __load_via_object(obj, __pos___class__).value; 94 } 95 96 __attr __get_class_attr(__ref obj) 97 { 98 return __load_via_object(obj, __pos___class__); 99 } 100 101 /* Attribute testing operations. */ 102 103 __ref __test_specific_instance(__ref obj, __ref type) 104 { 105 return __get_class(obj) == type ? obj : 0; 106 } 107 108 __ref __test_specific_object(__ref obj, __ref type) 109 { 110 return __test_specific_type(obj, type) || __test_specific_instance(obj, type) ? obj : 0; 111 } 112 113 __ref __test_specific_type(__ref obj, __ref type) 114 { 115 return obj == type ? obj : 0; 116 } 117 118 __ref __test_common_instance(__ref obj, int pos, int code) 119 { 120 return __HASATTR(__get_class(obj), pos, code) ? obj : 0; 121 } 122 123 __ref __test_common_object(__ref obj, int pos, int code) 124 { 125 return __test_common_type(obj, pos, code) || __test_common_instance(obj, pos, code) ? obj : 0; 126 } 127 128 __ref __test_common_type(__ref obj, int pos, int code) 129 { 130 return __HASATTR(obj, pos, code) ? obj : 0; 131 } 132 133 /* Attribute testing and retrieval operations. */ 134 135 __attr __check_and_load_via_object_null(__ref obj, int pos, int code) 136 { 137 if (__HASATTR(obj, pos, code)) 138 return __load_via_object(obj, pos); 139 else 140 return __NULL; 141 } 142 143 __attr __check_and_load_via_class(__ref obj, int pos, int code) 144 { 145 return __check_and_load_via_object(__get_class(obj), pos, code); 146 } 147 148 __attr __check_and_load_via_object(__ref obj, int pos, int code) 149 { 150 if (__HASATTR(obj, pos, code)) 151 return __load_via_object(obj, pos); 152 153 __raise_type_error(); 154 return __NULL; 155 } 156 157 __attr __check_and_load_via_any(__ref obj, int pos, int code) 158 { 159 __attr out = __check_and_load_via_object_null(obj, pos, code); 160 if (out.value == 0) 161 out = __check_and_load_via_class(obj, pos, code); 162 return out; 163 } 164 165 /* Attribute testing and storage operations. */ 166 167 int __check_and_store_via_class(__ref obj, int pos, int code, __attr value) 168 { 169 /* Forbid class-relative assignments. */ 170 171 __raise_type_error(); 172 return 0; 173 } 174 175 int __check_and_store_via_object(__ref obj, int pos, int code, __attr value) 176 { 177 if (__HASATTR(obj, pos, code)) 178 { 179 __store_via_object(obj, pos, value); 180 return 1; 181 } 182 183 /* No suitable attribute. */ 184 185 __raise_type_error(); 186 return 0; 187 } 188 189 int __check_and_store_via_any(__ref obj, int pos, int code, __attr value) 190 { 191 if (__check_and_store_via_object(obj, pos, code, value)) 192 return 1; 193 194 /* Forbid class-relative assignments. */ 195 196 __raise_type_error(); 197 return 0; 198 } 199 200 /* Context-related operations. */ 201 202 __attr __test_context(__ref context, __attr attr) 203 { 204 __ref attrcontext = __CONTEXT_AS_VALUE(attr).value; 205 206 /* Preserve any existing null or instance context. */ 207 208 if ((attrcontext == 0) || __is_instance(attrcontext)) 209 return attr; 210 211 /* Test any instance context against the context employed by the 212 attribute. */ 213 214 if (__is_instance(context)) 215 { 216 if (__test_common_instance(context, __TYPEPOS(attrcontext), __TYPECODE(attrcontext))) 217 return __update_context(context, attr); 218 else 219 __raise_type_error(); 220 } 221 222 /* Test for access to a type class attribute using a type instance. */ 223 224 if (__test_specific_type(attrcontext, &__TYPE_CLASS_TYPE) && __is_type_instance(context)) 225 return __update_context(context, attr); 226 227 /* Otherwise, preserve the attribute as retrieved. */ 228 229 return attr; 230 } 231 232 __attr __update_context(__ref context, __attr attr) 233 { 234 return __new_wrapper(context, attr); 235 } 236 237 /* Context testing for invocations. */ 238 239 int __type_method_invocation(__ref context, __attr target) 240 { 241 __ref targetcontext = __CONTEXT_AS_VALUE(target).value; 242 243 /* Require instances, not classes, where methods are function instances. */ 244 245 if (!__is_instance(target.value)) 246 return 0; 247 248 /* Access the context of the callable and test if it is the type object. */ 249 250 return ((targetcontext != 0) && __test_specific_type(targetcontext, &__TYPE_CLASS_TYPE) && __is_type_instance(context)); 251 } 252 253 __attr __unwrap_callable(__attr callable) 254 { 255 __attr value = __check_and_load_via_object_null(callable.value, __ATTRPOS(__value__), __ATTRCODE(__value__)); 256 return value.value ? value : callable; 257 } 258 259 __attr (*__get_function(__ref context, __attr target))(__attr[]) 260 { 261 target = __unwrap_callable(target); 262 263 /* Require null or instance contexts for functions and methods respectively, 264 or type instance contexts for type methods. */ 265 266 if ((context == 0) || __is_instance(context) || __type_method_invocation(context, target)) 267 return __load_via_object(target.value, __ATTRPOS(__fn__)).fn; 268 else 269 return __unbound_method; 270 } 271 272 __attr (*__check_and_get_function(__ref context, __attr target))(__attr[]) 273 { 274 target = __unwrap_callable(target); 275 276 /* Require null or instance contexts for functions and methods respectively, 277 or type instance contexts for type methods. */ 278 279 if ((context == 0) || __is_instance(context) || __type_method_invocation(context, target)) 280 return __check_and_load_via_object(target.value, __ATTRPOS(__fn__), __ATTRCODE(__fn__)).fn; 281 else 282 return __unbound_method; 283 } 284 285 /* Basic structure tests. */ 286 287 int __WITHIN(__ref obj, int pos) 288 { 289 return pos < obj->table->size; 290 } 291 292 int __HASATTR(__ref obj, int pos, int code) 293 { 294 return __WITHIN(obj, pos) && (obj->table->attrs[pos] == code); 295 } 296 297 /* Parameter position operations. */ 298 299 int __HASPARAM(const __ptable *ptable, int ppos, int pcode) 300 { 301 __param param; 302 303 if (ppos < ptable->size) 304 { 305 param = ptable->params[ppos]; 306 if (param.code == pcode) 307 return param.pos; 308 } 309 310 return -1; 311 } 312 313 /* Conversions. */ 314 315 __attr __CONTEXT_AS_VALUE(__attr attr) 316 { 317 return __check_and_load_via_object_null(attr.value, __ATTRPOS(__context__), __ATTRCODE(__context__)); 318 } 319 320 /* Type testing. */ 321 322 __ref __ISFUNC(__ref obj) 323 { 324 return __test_specific_instance(obj, &__FUNCTION_TYPE); 325 } 326 327 int __ISNULL(__attr value) 328 { 329 return (value.value == 0); /* __NULL.value */ 330 } 331 332 /* Attribute codes and positions for type objects. */ 333 334 unsigned int __TYPECODE(__ref obj) 335 { 336 return obj->table->attrs[obj->pos]; 337 } 338 339 unsigned int __TYPEPOS(__ref obj) 340 { 341 return obj->pos; 342 } 343 344 /* Memory allocation. */ 345 346 void *__ALLOCATE(size_t nmemb, size_t size) 347 { 348 void *ptr = GC_MALLOC(nmemb * size); /* sets memory to zero */ 349 if (ptr == NULL) 350 __raise_memory_error(); 351 return ptr; 352 } 353 354 void *__REALLOCATE(void *ptr, size_t size) 355 { 356 void *nptr = GC_REALLOC(ptr, size); 357 if (nptr == NULL) 358 __raise_memory_error(); 359 return nptr; 360 } 361 362 /* Copying of structures. */ 363 364 __ref __COPY(__ref obj, int size) 365 { 366 __ref copy = (__ref) __ALLOCATE(1, size); 367 memcpy(copy, obj, size); 368 return copy; 369 }