xref: /PHP-8.2/Zend/Optimizer/pass1.c (revision 631bc816) 
1 /*
2    +----------------------------------------------------------------------+
3    | Zend OPcache                                                         |
4    +----------------------------------------------------------------------+
5    | Copyright (c) The PHP Group                                          |
6    +----------------------------------------------------------------------+
7    | This source file is subject to version 3.01 of the PHP 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    | https://www.php.net/license/3_01.txt                                 |
11    | If you did not receive a copy of the PHP license and are unable to   |
12    | obtain it through the world-wide-web, please send a note to          |
13    | license@php.net so we can mail you a copy immediately.               |
14    +----------------------------------------------------------------------+
15    | Authors: Andi Gutmans <andi@php.net>                                 |
16    |          Zeev Suraski <zeev@php.net>                                 |
17    |          Stanislav Malyshev <stas@zend.com>                          |
18    |          Dmitry Stogov <dmitry@php.net>                              |
19    +----------------------------------------------------------------------+
20 */
21 
22 /* pass 1 (Simple local optimizations)
23  * - persistent constant substitution (true, false, null, etc)
24  * - constant casting (ADD expects numbers, CONCAT strings, etc)
25  * - constant expression evaluation
26  * - optimize constant conditional JMPs
27  * - pre-evaluate constant function calls
28  */
29 
30 #include "Optimizer/zend_optimizer.h"
31 #include "Optimizer/zend_optimizer_internal.h"
32 #include "zend_API.h"
33 #include "zend_constants.h"
34 #include "zend_execute.h"
35 #include "zend_vm.h"
36 
replace_by_const_or_qm_assign(zend_op_array * op_array,zend_op * opline,zval * result)37 static void replace_by_const_or_qm_assign(zend_op_array *op_array, zend_op *opline, zval *result) {
38 	if (opline->op1_type == IS_CONST) {
39 		literal_dtor(&ZEND_OP1_LITERAL(opline));
40 	}
41 	if (opline->op2_type == IS_CONST) {
42 		literal_dtor(&ZEND_OP2_LITERAL(opline));
43 	}
44 	if (zend_optimizer_replace_by_const(op_array, opline + 1, opline->result_type, opline->result.var, result)) {
45 		MAKE_NOP(opline);
46 	} else {
47 		opline->opcode = ZEND_QM_ASSIGN;
48 		opline->extended_value = 0;
49 		SET_UNUSED(opline->op2);
50 		zend_optimizer_update_op1_const(op_array, opline, result);
51 	}
52 }
53 
zend_optimizer_pass1(zend_op_array * op_array,zend_optimizer_ctx * ctx)54 void zend_optimizer_pass1(zend_op_array *op_array, zend_optimizer_ctx *ctx)
55 {
56 	zend_op *opline = op_array->opcodes;
57 	zend_op *end = opline + op_array->last;
58 	bool collect_constants = (ZEND_OPTIMIZER_PASS_15 & ctx->optimization_level)?
59 		(op_array == &ctx->script->main_op_array) : 0;
60 	zval result;
61 
62 	while (opline < end) {
63 		switch (opline->opcode) {
64 		case ZEND_CONCAT:
65 		case ZEND_FAST_CONCAT:
66 			if (opline->op1_type == IS_CONST && Z_TYPE(ZEND_OP1_LITERAL(opline)) != IS_STRING) {
67 				convert_to_string(&ZEND_OP1_LITERAL(opline));
68 			}
69 			if (opline->op2_type == IS_CONST && Z_TYPE(ZEND_OP2_LITERAL(opline)) != IS_STRING) {
70 				convert_to_string(&ZEND_OP2_LITERAL(opline));
71 			}
72 			ZEND_FALLTHROUGH;
73 		case ZEND_ADD:
74 		case ZEND_SUB:
75 		case ZEND_MUL:
76 		case ZEND_DIV:
77 		case ZEND_POW:
78 		case ZEND_MOD:
79 		case ZEND_SL:
80 		case ZEND_SR:
81 		case ZEND_BW_OR:
82 		case ZEND_BW_AND:
83 		case ZEND_BW_XOR:
84 		case ZEND_IS_EQUAL:
85 		case ZEND_IS_NOT_EQUAL:
86 		case ZEND_IS_SMALLER:
87 		case ZEND_IS_SMALLER_OR_EQUAL:
88 		case ZEND_IS_IDENTICAL:
89 		case ZEND_IS_NOT_IDENTICAL:
90 		case ZEND_BOOL_XOR:
91 		case ZEND_SPACESHIP:
92 		case ZEND_CASE:
93 		case ZEND_CASE_STRICT:
94 			if (opline->op1_type == IS_CONST && opline->op2_type == IS_CONST &&
95 					zend_optimizer_eval_binary_op(&result, opline->opcode, &ZEND_OP1_LITERAL(opline), &ZEND_OP2_LITERAL(opline)) == SUCCESS) {
96 				replace_by_const_or_qm_assign(op_array, opline, &result);
97 			}
98 			break;
99 
100 		case ZEND_ASSIGN_OP:
101 			if (opline->extended_value == ZEND_CONCAT && opline->op2_type == IS_CONST
102 					&& Z_TYPE(ZEND_OP2_LITERAL(opline)) != IS_STRING) {
103 				convert_to_string(&ZEND_OP2_LITERAL(opline));
104 			}
105 			break;
106 
107 		case ZEND_CAST:
108 			if (opline->op1_type == IS_CONST &&
109 					zend_optimizer_eval_cast(&result, opline->extended_value, &ZEND_OP1_LITERAL(opline)) == SUCCESS) {
110 				replace_by_const_or_qm_assign(op_array, opline, &result);
111 			}
112 			break;
113 
114 		case ZEND_BW_NOT:
115 		case ZEND_BOOL_NOT:
116 			if (opline->op1_type == IS_CONST &&
117 					zend_optimizer_eval_unary_op(&result, opline->opcode, &ZEND_OP1_LITERAL(opline)) == SUCCESS) {
118 				replace_by_const_or_qm_assign(op_array, opline, &result);
119 			}
120 			break;
121 
122 		case ZEND_FETCH_CONSTANT:
123 			if (opline->op2_type == IS_CONST &&
124 				Z_TYPE(ZEND_OP2_LITERAL(opline)) == IS_STRING &&
125 				zend_string_equals_literal(Z_STR(ZEND_OP2_LITERAL(opline)), "__COMPILER_HALT_OFFSET__")) {
126 				/* substitute __COMPILER_HALT_OFFSET__ constant */
127 				zend_execute_data *orig_execute_data = EG(current_execute_data);
128 				zend_execute_data fake_execute_data;
129 				zval *offset;
130 
131 				memset(&fake_execute_data, 0, sizeof(zend_execute_data));
132 				fake_execute_data.func = (zend_function*)op_array;
133 				EG(current_execute_data) = &fake_execute_data;
134 				if ((offset = zend_get_constant_str("__COMPILER_HALT_OFFSET__", sizeof("__COMPILER_HALT_OFFSET__") - 1)) != NULL) {
135 
136 					literal_dtor(&ZEND_OP2_LITERAL(opline));
137 					replace_by_const_or_qm_assign(op_array, opline, offset);
138 				}
139 				EG(current_execute_data) = orig_execute_data;
140 				break;
141 			}
142 
143 			if (opline->op2_type == IS_CONST &&
144 				Z_TYPE(ZEND_OP2_LITERAL(opline)) == IS_STRING) {
145 				/* substitute persistent constants */
146 				if (!zend_optimizer_get_persistent_constant(Z_STR(ZEND_OP2_LITERAL(opline)), &result, 1)) {
147 					if (!ctx->constants || !zend_optimizer_get_collected_constant(ctx->constants, &ZEND_OP2_LITERAL(opline), &result)) {
148 						break;
149 					}
150 				}
151 				if (Z_TYPE(result) == IS_CONSTANT_AST) {
152 					break;
153 				}
154 				replace_by_const_or_qm_assign(op_array, opline, &result);
155 			}
156 			break;
157 
158 		case ZEND_FETCH_CLASS_CONSTANT:
159 			if (opline->op2_type == IS_CONST &&
160 				Z_TYPE(ZEND_OP2_LITERAL(opline)) == IS_STRING) {
161 
162 				zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
163 					ctx->script, op_array, opline);
164 				if (ce) {
165 					zend_class_constant *cc = zend_hash_find_ptr(
166 						&ce->constants_table, Z_STR(ZEND_OP2_LITERAL(opline)));
167 					if (cc && !(ZEND_CLASS_CONST_FLAGS(cc) & ZEND_ACC_DEPRECATED) && (ZEND_CLASS_CONST_FLAGS(cc) & ZEND_ACC_PPP_MASK) == ZEND_ACC_PUBLIC && !(ce->ce_flags & ZEND_ACC_TRAIT)) {
168 						zval *c = &cc->value;
169 						if (Z_TYPE_P(c) == IS_CONSTANT_AST) {
170 							zend_ast *ast = Z_ASTVAL_P(c);
171 							if (ast->kind != ZEND_AST_CONSTANT
172 							 || !zend_optimizer_get_persistent_constant(zend_ast_get_constant_name(ast), &result, 1)
173 							 || Z_TYPE(result) == IS_CONSTANT_AST) {
174 								break;
175 							}
176 						} else {
177 							ZVAL_COPY_OR_DUP(&result, c);
178 						}
179 
180 						replace_by_const_or_qm_assign(op_array, opline, &result);
181 					}
182 				}
183 			}
184 			break;
185 
186 		case ZEND_DO_ICALL: {
187 			zend_op *send1_opline = opline - 1;
188 			zend_op *send2_opline = NULL;
189 			zend_op *init_opline = NULL;
190 
191 			while (send1_opline->opcode == ZEND_NOP) {
192 				send1_opline--;
193 			}
194 			if (send1_opline->opcode != ZEND_SEND_VAL ||
195 			    send1_opline->op1_type != IS_CONST) {
196 				/* don't collect constants after unknown function call */
197 				collect_constants = 0;
198 				break;
199 			}
200 			if (send1_opline->op2.num == 2) {
201 				send2_opline = send1_opline;
202 				send1_opline--;
203 				while (send1_opline->opcode == ZEND_NOP) {
204 					send1_opline--;
205 				}
206 				if (send1_opline->opcode != ZEND_SEND_VAL ||
207 				    send1_opline->op1_type != IS_CONST) {
208 					/* don't collect constants after unknown function call */
209 					collect_constants = 0;
210 					break;
211 				}
212 			}
213 			init_opline = send1_opline - 1;
214 			while (init_opline->opcode == ZEND_NOP) {
215 				init_opline--;
216 			}
217 			if (init_opline->opcode != ZEND_INIT_FCALL ||
218 			    init_opline->op2_type != IS_CONST ||
219 			    Z_TYPE(ZEND_OP2_LITERAL(init_opline)) != IS_STRING) {
220 				/* don't collect constants after unknown function call */
221 				collect_constants = 0;
222 				break;
223 			}
224 
225 			/* define("name", scalar); */
226 			if (zend_string_equals_literal_ci(Z_STR(ZEND_OP2_LITERAL(init_opline)), "define")) {
227 
228 				if (Z_TYPE(ZEND_OP1_LITERAL(send1_opline)) == IS_STRING && send2_opline) {
229 
230 					if (collect_constants) {
231 						zend_optimizer_collect_constant(ctx, &ZEND_OP1_LITERAL(send1_opline), &ZEND_OP1_LITERAL(send2_opline));
232 					}
233 
234 					if (RESULT_UNUSED(opline) &&
235 					    !zend_memnstr(Z_STRVAL(ZEND_OP1_LITERAL(send1_opline)), "::", sizeof("::") - 1, Z_STRVAL(ZEND_OP1_LITERAL(send1_opline)) + Z_STRLEN(ZEND_OP1_LITERAL(send1_opline)))) {
236 
237 						opline->opcode = ZEND_DECLARE_CONST;
238 						opline->op1_type = IS_CONST;
239 						opline->op2_type = IS_CONST;
240 						opline->result_type = IS_UNUSED;
241 						opline->op1.constant = send1_opline->op1.constant;
242 						opline->op2.constant = send2_opline->op1.constant;
243 						opline->result.num = 0;
244 
245 						literal_dtor(&ZEND_OP2_LITERAL(init_opline));
246 						MAKE_NOP(init_opline);
247 						MAKE_NOP(send1_opline);
248 						MAKE_NOP(send2_opline);
249 					}
250 					break;
251 				}
252 			}
253 
254 			if (!send2_opline && Z_TYPE(ZEND_OP1_LITERAL(send1_opline)) == IS_STRING &&
255 					zend_optimizer_eval_special_func_call(&result, Z_STR(ZEND_OP2_LITERAL(init_opline)), Z_STR(ZEND_OP1_LITERAL(send1_opline))) == SUCCESS) {
256 				literal_dtor(&ZEND_OP2_LITERAL(init_opline));
257 				MAKE_NOP(init_opline);
258 				literal_dtor(&ZEND_OP1_LITERAL(send1_opline));
259 				MAKE_NOP(send1_opline);
260 				replace_by_const_or_qm_assign(op_array, opline, &result);
261 				break;
262 			}
263 
264 			/* don't collect constants after any other function call */
265 			collect_constants = 0;
266 			break;
267 		}
268 		case ZEND_STRLEN:
269 			if (opline->op1_type == IS_CONST &&
270 					zend_optimizer_eval_strlen(&result, &ZEND_OP1_LITERAL(opline)) == SUCCESS) {
271 				replace_by_const_or_qm_assign(op_array, opline, &result);
272 			}
273 			break;
274 		case ZEND_DEFINED:
275 			if (!zend_optimizer_get_persistent_constant(Z_STR(ZEND_OP1_LITERAL(opline)), &result, 0)) {
276 				break;
277 			}
278 			ZVAL_TRUE(&result);
279 			literal_dtor(&ZEND_OP1_LITERAL(opline));
280 			replace_by_const_or_qm_assign(op_array, opline, &result);
281 			break;
282 		case ZEND_DECLARE_CONST:
283 			if (collect_constants &&
284 			    Z_TYPE(ZEND_OP1_LITERAL(opline)) == IS_STRING &&
285 			    Z_TYPE(ZEND_OP2_LITERAL(opline)) != IS_CONSTANT_AST) {
286 				zend_optimizer_collect_constant(ctx, &ZEND_OP1_LITERAL(opline), &ZEND_OP2_LITERAL(opline));
287 			}
288 			break;
289 
290 		case ZEND_JMPZ_EX:
291 		case ZEND_JMPNZ_EX:
292 			/* convert Ti = JMPZ_EX(C, L) => Ti = QM_ASSIGN(C)
293 			   in case we know it wouldn't jump */
294 			if (opline->op1_type == IS_CONST) {
295 				if (zend_is_true(&ZEND_OP1_LITERAL(opline))) {
296 					if (opline->opcode == ZEND_JMPZ_EX) {
297 						opline->opcode = ZEND_QM_ASSIGN;
298 						zval_ptr_dtor_nogc(&ZEND_OP1_LITERAL(opline));
299 						ZVAL_TRUE(&ZEND_OP1_LITERAL(opline));
300 						opline->op2.num = 0;
301 						break;
302 					}
303 				} else {
304 					if (opline->opcode == ZEND_JMPNZ_EX) {
305 						opline->opcode = ZEND_QM_ASSIGN;
306 						zval_ptr_dtor_nogc(&ZEND_OP1_LITERAL(opline));
307 						ZVAL_FALSE(&ZEND_OP1_LITERAL(opline));
308 						opline->op2.num = 0;
309 						break;
310 					}
311 				}
312 			}
313 			collect_constants = 0;
314 			break;
315 
316 		case ZEND_JMPZ:
317 		case ZEND_JMPNZ:
318 			if (opline->op1_type == IS_CONST) {
319 				int should_jmp = zend_is_true(&ZEND_OP1_LITERAL(opline));
320 
321 				if (opline->opcode == ZEND_JMPZ) {
322 					should_jmp = !should_jmp;
323 				}
324 				literal_dtor(&ZEND_OP1_LITERAL(opline));
325 				opline->op1_type = IS_UNUSED;
326 				if (should_jmp) {
327 					opline->opcode = ZEND_JMP;
328 					COPY_NODE(opline->op1, opline->op2);
329 					opline->op2.num = 0;
330 				} else {
331 					MAKE_NOP(opline);
332 					break;
333 				}
334 			}
335 			collect_constants = 0;
336 			break;
337 
338 		case ZEND_RETURN:
339 		case ZEND_RETURN_BY_REF:
340 		case ZEND_GENERATOR_RETURN:
341 		case ZEND_EXIT:
342 		case ZEND_THROW:
343 		case ZEND_MATCH_ERROR:
344 		case ZEND_CATCH:
345 		case ZEND_FAST_CALL:
346 		case ZEND_FAST_RET:
347 		case ZEND_JMP:
348 		case ZEND_FE_RESET_R:
349 		case ZEND_FE_RESET_RW:
350 		case ZEND_FE_FETCH_R:
351 		case ZEND_FE_FETCH_RW:
352 		case ZEND_JMP_SET:
353 		case ZEND_COALESCE:
354 		case ZEND_ASSERT_CHECK:
355 		case ZEND_JMP_NULL:
356 		case ZEND_VERIFY_NEVER_TYPE:
357 		case ZEND_BIND_INIT_STATIC_OR_JMP:
358 		case ZEND_JMP_FRAMELESS:
359 			collect_constants = 0;
360 			break;
361 		}
362 		opline++;
363 	}
364 }
365