xref: /PHP-7.0/Zend/zend_constants.c (revision 478f119a)
1 /*
2    +----------------------------------------------------------------------+
3    | Zend Engine                                                          |
4    +----------------------------------------------------------------------+
5    | Copyright (c) 1998-2017 Zend Technologies Ltd. (http://www.zend.com) |
6    +----------------------------------------------------------------------+
7    | This source file is subject to version 2.00 of the Zend license,     |
8    | that is bundled with this package in the file LICENSE, and is        |
9    | available through the world-wide-web at the following url:           |
10    | http://www.zend.com/license/2_00.txt.                                |
11    | If you did not receive a copy of the Zend license and are unable to  |
12    | obtain it through the world-wide-web, please send a note to          |
13    | license@zend.com so we can mail you a copy immediately.              |
14    +----------------------------------------------------------------------+
15    | Authors: Andi Gutmans <andi@zend.com>                                |
16    |          Zeev Suraski <zeev@zend.com>                                |
17    +----------------------------------------------------------------------+
18 */
19 
20 /* $Id$ */
21 
22 #include "zend.h"
23 #include "zend_constants.h"
24 #include "zend_exceptions.h"
25 #include "zend_execute.h"
26 #include "zend_variables.h"
27 #include "zend_operators.h"
28 #include "zend_globals.h"
29 #include "zend_API.h"
30 
free_zend_constant(zval * zv)31 void free_zend_constant(zval *zv)
32 {
33 	zend_constant *c = Z_PTR_P(zv);
34 
35 	if (!(c->flags & CONST_PERSISTENT)) {
36 		zval_dtor(&c->value);
37 	} else {
38 		zval_internal_dtor(&c->value);
39 	}
40 	if (c->name) {
41 		zend_string_release(c->name);
42 	}
43 	pefree(c, c->flags & CONST_PERSISTENT);
44 }
45 
46 
copy_zend_constant(zval * zv)47 static void copy_zend_constant(zval *zv)
48 {
49 	zend_constant *c = Z_PTR_P(zv);
50 
51 	Z_PTR_P(zv) = pemalloc(sizeof(zend_constant), c->flags & CONST_PERSISTENT);
52 	memcpy(Z_PTR_P(zv), c, sizeof(zend_constant));
53 
54 	c = Z_PTR_P(zv);
55 	c->name = zend_string_copy(c->name);
56 	if (!(c->flags & CONST_PERSISTENT)) {
57 		zval_copy_ctor(&c->value);
58 	} else {
59 		if (Z_TYPE(c->value) == IS_STRING) {
60 			Z_STR(c->value) = zend_string_dup(Z_STR(c->value), 1);
61 		}
62 	}
63 }
64 
65 
zend_copy_constants(HashTable * target,HashTable * source)66 void zend_copy_constants(HashTable *target, HashTable *source)
67 {
68 	zend_hash_copy(target, source, copy_zend_constant);
69 }
70 
71 
clean_non_persistent_constant(zval * zv)72 static int clean_non_persistent_constant(zval *zv)
73 {
74 	zend_constant *c = Z_PTR_P(zv);
75 	return (c->flags & CONST_PERSISTENT) ? ZEND_HASH_APPLY_STOP : ZEND_HASH_APPLY_REMOVE;
76 }
77 
78 
clean_non_persistent_constant_full(zval * zv)79 static int clean_non_persistent_constant_full(zval *zv)
80 {
81 	zend_constant *c = Z_PTR_P(zv);
82 	return (c->flags & CONST_PERSISTENT) ? 0 : 1;
83 }
84 
85 
clean_module_constant(zval * el,void * arg)86 static int clean_module_constant(zval *el, void *arg)
87 {
88 	zend_constant *c = (zend_constant *)Z_PTR_P(el);
89 	int module_number = *(int *)arg;
90 
91 	if (c->module_number == module_number) {
92 		return 1;
93 	} else {
94 		return 0;
95 	}
96 }
97 
98 
clean_module_constants(int module_number)99 void clean_module_constants(int module_number)
100 {
101 	zend_hash_apply_with_argument(EG(zend_constants), clean_module_constant, (void *) &module_number);
102 }
103 
104 
zend_startup_constants(void)105 int zend_startup_constants(void)
106 {
107 	EG(zend_constants) = (HashTable *) malloc(sizeof(HashTable));
108 
109 	zend_hash_init(EG(zend_constants), 128, NULL, ZEND_CONSTANT_DTOR, 1);
110 	return SUCCESS;
111 }
112 
113 
114 
zend_register_standard_constants(void)115 void zend_register_standard_constants(void)
116 {
117 	REGISTER_MAIN_LONG_CONSTANT("E_ERROR", E_ERROR, CONST_PERSISTENT | CONST_CS);
118 	REGISTER_MAIN_LONG_CONSTANT("E_RECOVERABLE_ERROR", E_RECOVERABLE_ERROR, CONST_PERSISTENT | CONST_CS);
119 	REGISTER_MAIN_LONG_CONSTANT("E_WARNING", E_WARNING, CONST_PERSISTENT | CONST_CS);
120 	REGISTER_MAIN_LONG_CONSTANT("E_PARSE", E_PARSE, CONST_PERSISTENT | CONST_CS);
121 	REGISTER_MAIN_LONG_CONSTANT("E_NOTICE", E_NOTICE, CONST_PERSISTENT | CONST_CS);
122 	REGISTER_MAIN_LONG_CONSTANT("E_STRICT", E_STRICT, CONST_PERSISTENT | CONST_CS);
123 	REGISTER_MAIN_LONG_CONSTANT("E_DEPRECATED", E_DEPRECATED, CONST_PERSISTENT | CONST_CS);
124 	REGISTER_MAIN_LONG_CONSTANT("E_CORE_ERROR", E_CORE_ERROR, CONST_PERSISTENT | CONST_CS);
125 	REGISTER_MAIN_LONG_CONSTANT("E_CORE_WARNING", E_CORE_WARNING, CONST_PERSISTENT | CONST_CS);
126 	REGISTER_MAIN_LONG_CONSTANT("E_COMPILE_ERROR", E_COMPILE_ERROR, CONST_PERSISTENT | CONST_CS);
127 	REGISTER_MAIN_LONG_CONSTANT("E_COMPILE_WARNING", E_COMPILE_WARNING, CONST_PERSISTENT | CONST_CS);
128 	REGISTER_MAIN_LONG_CONSTANT("E_USER_ERROR", E_USER_ERROR, CONST_PERSISTENT | CONST_CS);
129 	REGISTER_MAIN_LONG_CONSTANT("E_USER_WARNING", E_USER_WARNING, CONST_PERSISTENT | CONST_CS);
130 	REGISTER_MAIN_LONG_CONSTANT("E_USER_NOTICE", E_USER_NOTICE, CONST_PERSISTENT | CONST_CS);
131 	REGISTER_MAIN_LONG_CONSTANT("E_USER_DEPRECATED", E_USER_DEPRECATED, CONST_PERSISTENT | CONST_CS);
132 
133 	REGISTER_MAIN_LONG_CONSTANT("E_ALL", E_ALL, CONST_PERSISTENT | CONST_CS);
134 
135 	REGISTER_MAIN_LONG_CONSTANT("DEBUG_BACKTRACE_PROVIDE_OBJECT", DEBUG_BACKTRACE_PROVIDE_OBJECT, CONST_PERSISTENT | CONST_CS);
136 	REGISTER_MAIN_LONG_CONSTANT("DEBUG_BACKTRACE_IGNORE_ARGS", DEBUG_BACKTRACE_IGNORE_ARGS, CONST_PERSISTENT | CONST_CS);
137 	/* true/false constants */
138 	{
139 		REGISTER_MAIN_BOOL_CONSTANT("TRUE", 1, CONST_PERSISTENT | CONST_CT_SUBST);
140 		REGISTER_MAIN_BOOL_CONSTANT("FALSE", 0, CONST_PERSISTENT | CONST_CT_SUBST);
141 		REGISTER_MAIN_BOOL_CONSTANT("ZEND_THREAD_SAFE", ZTS_V, CONST_PERSISTENT | CONST_CS);
142 		REGISTER_MAIN_BOOL_CONSTANT("ZEND_DEBUG_BUILD", ZEND_DEBUG, CONST_PERSISTENT | CONST_CS);
143 	}
144 	REGISTER_MAIN_NULL_CONSTANT("NULL", CONST_PERSISTENT | CONST_CT_SUBST);
145 }
146 
147 
zend_shutdown_constants(void)148 int zend_shutdown_constants(void)
149 {
150 	zend_hash_destroy(EG(zend_constants));
151 	free(EG(zend_constants));
152 	return SUCCESS;
153 }
154 
155 
clean_non_persistent_constants(void)156 void clean_non_persistent_constants(void)
157 {
158 	if (EG(full_tables_cleanup)) {
159 		zend_hash_apply(EG(zend_constants), clean_non_persistent_constant_full);
160 	} else {
161 		zend_hash_reverse_apply(EG(zend_constants), clean_non_persistent_constant);
162 	}
163 }
164 
zend_register_null_constant(const char * name,size_t name_len,int flags,int module_number)165 ZEND_API void zend_register_null_constant(const char *name, size_t name_len, int flags, int module_number)
166 {
167 	zend_constant c;
168 
169 	ZVAL_NULL(&c.value);
170 	c.flags = flags;
171 	c.name = zend_string_init(name, name_len, flags & CONST_PERSISTENT);
172 	c.module_number = module_number;
173 	zend_register_constant(&c);
174 }
175 
zend_register_bool_constant(const char * name,size_t name_len,zend_bool bval,int flags,int module_number)176 ZEND_API void zend_register_bool_constant(const char *name, size_t name_len, zend_bool bval, int flags, int module_number)
177 {
178 	zend_constant c;
179 
180 	ZVAL_BOOL(&c.value, bval);
181 	c.flags = flags;
182 	c.name = zend_string_init(name, name_len, flags & CONST_PERSISTENT);
183 	c.module_number = module_number;
184 	zend_register_constant(&c);
185 }
186 
zend_register_long_constant(const char * name,size_t name_len,zend_long lval,int flags,int module_number)187 ZEND_API void zend_register_long_constant(const char *name, size_t name_len, zend_long lval, int flags, int module_number)
188 {
189 	zend_constant c;
190 
191 	ZVAL_LONG(&c.value, lval);
192 	c.flags = flags;
193 	c.name = zend_string_init(name, name_len, flags & CONST_PERSISTENT);
194 	c.module_number = module_number;
195 	zend_register_constant(&c);
196 }
197 
198 
zend_register_double_constant(const char * name,size_t name_len,double dval,int flags,int module_number)199 ZEND_API void zend_register_double_constant(const char *name, size_t name_len, double dval, int flags, int module_number)
200 {
201 	zend_constant c;
202 
203 	ZVAL_DOUBLE(&c.value, dval);
204 	c.flags = flags;
205 	c.name = zend_string_init(name, name_len, flags & CONST_PERSISTENT);
206 	c.module_number = module_number;
207 	zend_register_constant(&c);
208 }
209 
210 
zend_register_stringl_constant(const char * name,size_t name_len,char * strval,size_t strlen,int flags,int module_number)211 ZEND_API void zend_register_stringl_constant(const char *name, size_t name_len, char *strval, size_t strlen, int flags, int module_number)
212 {
213 	zend_constant c;
214 
215 	ZVAL_NEW_STR(&c.value, zend_string_init(strval, strlen, flags & CONST_PERSISTENT));
216 	c.flags = flags;
217 	c.name = zend_string_init(name, name_len, flags & CONST_PERSISTENT);
218 	c.module_number = module_number;
219 	zend_register_constant(&c);
220 }
221 
222 
zend_register_string_constant(const char * name,size_t name_len,char * strval,int flags,int module_number)223 ZEND_API void zend_register_string_constant(const char *name, size_t name_len, char *strval, int flags, int module_number)
224 {
225 	zend_register_stringl_constant(name, name_len, strval, strlen(strval), flags, module_number);
226 }
227 
zend_get_special_constant(const char * name,size_t name_len)228 static zend_constant *zend_get_special_constant(const char *name, size_t name_len)
229 {
230 	zend_constant *c;
231 	static char haltoff[] = "__COMPILER_HALT_OFFSET__";
232 
233 	if (!EG(current_execute_data)) {
234 		return NULL;
235 	} else if (name_len == sizeof("__COMPILER_HALT_OFFSET__")-1 &&
236 	          !memcmp(name, "__COMPILER_HALT_OFFSET__", sizeof("__COMPILER_HALT_OFFSET__")-1)) {
237 		const char *cfilename;
238 		zend_string *haltname;
239 		size_t clen;
240 
241 		cfilename = zend_get_executed_filename();
242 		clen = strlen(cfilename);
243 		/* check for __COMPILER_HALT_OFFSET__ */
244 		haltname = zend_mangle_property_name(haltoff,
245 			sizeof("__COMPILER_HALT_OFFSET__") - 1, cfilename, clen, 0);
246 		c = zend_hash_find_ptr(EG(zend_constants), haltname);
247 		zend_string_free(haltname);
248 		return c;
249 	} else {
250 		return NULL;
251 	}
252 }
253 
254 
zend_get_constant_str(const char * name,size_t name_len)255 ZEND_API zval *zend_get_constant_str(const char *name, size_t name_len)
256 {
257 	zend_constant *c;
258 	ALLOCA_FLAG(use_heap)
259 
260 	if ((c = zend_hash_str_find_ptr(EG(zend_constants), name, name_len)) == NULL) {
261 		char *lcname = do_alloca(name_len + 1, use_heap);
262 		zend_str_tolower_copy(lcname, name, name_len);
263 		if ((c = zend_hash_str_find_ptr(EG(zend_constants), lcname, name_len)) != NULL) {
264 			if (c->flags & CONST_CS) {
265 				c = NULL;
266 			}
267 		} else {
268 			c = zend_get_special_constant(name, name_len);
269 		}
270 		free_alloca(lcname, use_heap);
271 	}
272 
273 	return c ? &c->value : NULL;
274 }
275 
zend_get_constant(zend_string * name)276 ZEND_API zval *zend_get_constant(zend_string *name)
277 {
278 	zend_constant *c;
279 	ALLOCA_FLAG(use_heap)
280 
281 	if ((c = zend_hash_find_ptr(EG(zend_constants), name)) == NULL) {
282 		char *lcname = do_alloca(ZSTR_LEN(name) + 1, use_heap);
283 		zend_str_tolower_copy(lcname, ZSTR_VAL(name), ZSTR_LEN(name));
284 		if ((c = zend_hash_str_find_ptr(EG(zend_constants), lcname, ZSTR_LEN(name))) != NULL) {
285 			if (c->flags & CONST_CS) {
286 				c = NULL;
287 			}
288 		} else {
289 			c = zend_get_special_constant(ZSTR_VAL(name), ZSTR_LEN(name));
290 		}
291 		free_alloca(lcname, use_heap);
292 	}
293 
294 	return c ? &c->value : NULL;
295 }
296 
zend_get_constant_ex(zend_string * cname,zend_class_entry * scope,zend_ulong flags)297 ZEND_API zval *zend_get_constant_ex(zend_string *cname, zend_class_entry *scope, zend_ulong flags)
298 {
299 	zend_constant *c;
300 	const char *colon;
301 	zend_class_entry *ce = NULL;
302 	const char *name = ZSTR_VAL(cname);
303 	size_t name_len = ZSTR_LEN(cname);
304 
305 	/* Skip leading \\ */
306 	if (name[0] == '\\') {
307 		name += 1;
308 		name_len -= 1;
309 		cname = NULL;
310 	}
311 
312 	if ((colon = zend_memrchr(name, ':', name_len)) &&
313 	    colon > name && (*(colon - 1) == ':')) {
314 		int class_name_len = colon - name - 1;
315 		size_t const_name_len = name_len - class_name_len - 2;
316 		zend_string *constant_name = zend_string_init(colon + 1, const_name_len, 0);
317 		zend_string *class_name = zend_string_init(name, class_name_len, 0);
318 		zval *ret_constant = NULL;
319 
320 		if (!scope) {
321 			if (EG(current_execute_data)) {
322 				scope = EG(scope);
323 			} else {
324 				scope = CG(active_class_entry);
325 			}
326 		}
327 
328 		if (zend_string_equals_literal_ci(class_name, "self")) {
329 			if (UNEXPECTED(!scope)) {
330 				zend_throw_error(NULL, "Cannot access self:: when no class scope is active");
331 				goto failure;
332 			}
333 			ce = scope;
334 		} else if (zend_string_equals_literal_ci(class_name, "parent")) {
335 			if (UNEXPECTED(!scope)) {
336 				zend_throw_error(NULL, "Cannot access parent:: when no class scope is active");
337 				goto failure;
338 			} else if (UNEXPECTED(!scope->parent)) {
339 				zend_throw_error(NULL, "Cannot access parent:: when current class scope has no parent");
340 				goto failure;
341 			} else {
342 				ce = scope->parent;
343 			}
344 		} else if (zend_string_equals_literal_ci(class_name, "static")) {
345 			ce = zend_get_called_scope(EG(current_execute_data));
346 			if (UNEXPECTED(!ce)) {
347 				zend_throw_error(NULL, "Cannot access static:: when no class scope is active");
348 				goto failure;
349 			}
350 		} else {
351 			ce = zend_fetch_class(class_name, flags);
352 		}
353 		if (ce) {
354 			ret_constant = zend_hash_find(&ce->constants_table, constant_name);
355 			if (ret_constant == NULL) {
356 				if ((flags & ZEND_FETCH_CLASS_SILENT) == 0) {
357 					zend_throw_error(NULL, "Undefined class constant '%s::%s'", ZSTR_VAL(class_name), ZSTR_VAL(constant_name));
358 				}
359 			} else if (Z_ISREF_P(ret_constant)) {
360 				ret_constant = Z_REFVAL_P(ret_constant);
361 			}
362 		}
363 
364 failure:
365 		zend_string_release(class_name);
366 		zend_string_free(constant_name);
367 		if (ret_constant && Z_CONSTANT_P(ret_constant)) {
368 			if (UNEXPECTED(zval_update_constant_ex(ret_constant, 1, ce) != SUCCESS)) {
369 				return NULL;
370 			}
371 		}
372 		return ret_constant;
373 	}
374 
375 	/* non-class constant */
376 	if ((colon = zend_memrchr(name, '\\', name_len)) != NULL) {
377 		/* compound constant name */
378 		int prefix_len = colon - name;
379 		size_t const_name_len = name_len - prefix_len - 1;
380 		const char *constant_name = colon + 1;
381 		char *lcname;
382 		size_t lcname_len;
383 		ALLOCA_FLAG(use_heap)
384 
385 		lcname_len = prefix_len + 1 + const_name_len;
386 		lcname = do_alloca(lcname_len + 1, use_heap);
387 		zend_str_tolower_copy(lcname, name, prefix_len);
388 		/* Check for namespace constant */
389 
390 		lcname[prefix_len] = '\\';
391 		memcpy(lcname + prefix_len + 1, constant_name, const_name_len + 1);
392 
393 		if ((c = zend_hash_str_find_ptr(EG(zend_constants), lcname, lcname_len)) == NULL) {
394 			/* try lowercase */
395 			zend_str_tolower(lcname + prefix_len + 1, const_name_len);
396 			if ((c = zend_hash_str_find_ptr(EG(zend_constants), lcname, lcname_len)) != NULL) {
397 				if ((c->flags & CONST_CS) != 0) {
398 					c = NULL;
399 				}
400 			}
401 		}
402 		free_alloca(lcname, use_heap);
403 		if (c) {
404 			return &c->value;
405 		}
406 		/* name requires runtime resolution, need to check non-namespaced name */
407 		if ((flags & IS_CONSTANT_UNQUALIFIED) != 0) {
408 			return zend_get_constant_str(constant_name, const_name_len);
409 		}
410 		return NULL;
411 	}
412 
413 	if (cname) {
414 		return zend_get_constant(cname);
415 	} else {
416 		return zend_get_constant_str(name, name_len);
417 	}
418 }
419 
zend_quick_get_constant(const zval * key,zend_ulong flags)420 zend_constant *zend_quick_get_constant(const zval *key, zend_ulong flags)
421 {
422 	zend_constant *c;
423 
424 	if ((c = zend_hash_find_ptr(EG(zend_constants), Z_STR_P(key))) == NULL) {
425 		key++;
426 		if ((c = zend_hash_find_ptr(EG(zend_constants), Z_STR_P(key))) == NULL ||
427 		    (c->flags & CONST_CS) != 0) {
428 			if ((flags & (IS_CONSTANT_IN_NAMESPACE|IS_CONSTANT_UNQUALIFIED)) == (IS_CONSTANT_IN_NAMESPACE|IS_CONSTANT_UNQUALIFIED)) {
429 				key++;
430 				if ((c = zend_hash_find_ptr(EG(zend_constants), Z_STR_P(key))) == NULL) {
431 				    key++;
432 					if ((c = zend_hash_find_ptr(EG(zend_constants), Z_STR_P(key))) == NULL ||
433 					    (c->flags & CONST_CS) != 0) {
434 
435 						key--;
436 						c = NULL;
437 					}
438 				}
439 			} else {
440 				key--;
441 				c = NULL;
442 			}
443 		}
444 	}
445 	return c;
446 }
447 
zend_hash_add_constant(HashTable * ht,zend_string * key,zend_constant * c)448 static void* zend_hash_add_constant(HashTable *ht, zend_string *key, zend_constant *c)
449 {
450 	void *ret;
451 	zend_constant *copy = pemalloc(sizeof(zend_constant), c->flags & CONST_PERSISTENT);
452 
453 	memcpy(copy, c, sizeof(zend_constant));
454 	ret = zend_hash_add_ptr(ht, key, copy);
455 	if (!ret) {
456 		pefree(copy, c->flags & CONST_PERSISTENT);
457 	}
458 	return ret;
459 }
460 
zend_register_constant(zend_constant * c)461 ZEND_API int zend_register_constant(zend_constant *c)
462 {
463 	zend_string *lowercase_name = NULL;
464 	zend_string *name;
465 	int ret = SUCCESS;
466 
467 #if 0
468 	printf("Registering constant for module %d\n", c->module_number);
469 #endif
470 
471 	if (!(c->flags & CONST_CS)) {
472 		lowercase_name = zend_string_alloc(ZSTR_LEN(c->name), c->flags & CONST_PERSISTENT);
473 		zend_str_tolower_copy(ZSTR_VAL(lowercase_name), ZSTR_VAL(c->name), ZSTR_LEN(c->name));
474 		lowercase_name = zend_new_interned_string(lowercase_name);
475 		name = lowercase_name;
476 	} else {
477 		char *slash = strrchr(ZSTR_VAL(c->name), '\\');
478 		if (slash) {
479 			lowercase_name = zend_string_init(ZSTR_VAL(c->name), ZSTR_LEN(c->name), c->flags & CONST_PERSISTENT);
480 			zend_str_tolower(ZSTR_VAL(lowercase_name), slash - ZSTR_VAL(c->name));
481 			lowercase_name = zend_new_interned_string(lowercase_name);
482 			name = lowercase_name;
483 		} else {
484 			name = c->name;
485 		}
486 	}
487 
488 	/* Check if the user is trying to define the internal pseudo constant name __COMPILER_HALT_OFFSET__ */
489 	if ((ZSTR_LEN(c->name) == sizeof("__COMPILER_HALT_OFFSET__")-1
490 		&& !memcmp(ZSTR_VAL(name), "__COMPILER_HALT_OFFSET__", sizeof("__COMPILER_HALT_OFFSET__")-1))
491 		|| zend_hash_add_constant(EG(zend_constants), name, c) == NULL) {
492 
493 		/* The internal __COMPILER_HALT_OFFSET__ is prefixed by NULL byte */
494 		if (ZSTR_VAL(c->name)[0] == '\0' && ZSTR_LEN(c->name) > sizeof("\0__COMPILER_HALT_OFFSET__")-1
495 			&& memcmp(ZSTR_VAL(name), "\0__COMPILER_HALT_OFFSET__", sizeof("\0__COMPILER_HALT_OFFSET__")) == 0) {
496 		}
497 		zend_error(E_NOTICE,"Constant %s already defined", ZSTR_VAL(name));
498 		zend_string_release(c->name);
499 		if (!(c->flags & CONST_PERSISTENT)) {
500 			zval_dtor(&c->value);
501 		}
502 		ret = FAILURE;
503 	}
504 	if (lowercase_name) {
505 		zend_string_release(lowercase_name);
506 	}
507 	return ret;
508 }
509 
510 
511 /*
512  * Local variables:
513  * tab-width: 4
514  * c-basic-offset: 4
515  * indent-tabs-mode: t
516  * End:
517  */
518