xref: /php-src/Zend/Optimizer/pass1.c (revision 56cf09f2) 
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 			bool is_prototype;
160 			const zend_class_constant *cc = zend_fetch_class_const_info(ctx->script, op_array, opline, &is_prototype);
161 			if (!cc || is_prototype) {
162 				break;
163 			}
164 			const zval *c = &cc->value;
165 			if (Z_TYPE_P(c) == IS_CONSTANT_AST) {
166 				zend_ast *ast = Z_ASTVAL_P(c);
167 				if (ast->kind != ZEND_AST_CONSTANT
168 				 || !zend_optimizer_get_persistent_constant(zend_ast_get_constant_name(ast), &result, 1)
169 				 || Z_TYPE(result) == IS_CONSTANT_AST) {
170 					break;
171 				}
172 			} else {
173 				ZVAL_COPY_OR_DUP(&result, c);
174 			}
175 			replace_by_const_or_qm_assign(op_array, opline, &result);
176 			break;
177 		}
178 
179 		case ZEND_DO_ICALL: {
180 			zend_op *send1_opline = opline - 1;
181 			zend_op *send2_opline = NULL;
182 			zend_op *init_opline = NULL;
183 
184 			while (send1_opline->opcode == ZEND_NOP) {
185 				send1_opline--;
186 			}
187 			if (send1_opline->opcode != ZEND_SEND_VAL ||
188 			    send1_opline->op1_type != IS_CONST) {
189 				/* don't collect constants after unknown function call */
190 				collect_constants = 0;
191 				break;
192 			}
193 			if (send1_opline->op2.num == 2) {
194 				send2_opline = send1_opline;
195 				send1_opline--;
196 				while (send1_opline->opcode == ZEND_NOP) {
197 					send1_opline--;
198 				}
199 				if (send1_opline->opcode != ZEND_SEND_VAL ||
200 				    send1_opline->op1_type != IS_CONST) {
201 					/* don't collect constants after unknown function call */
202 					collect_constants = 0;
203 					break;
204 				}
205 			}
206 			init_opline = send1_opline - 1;
207 			while (init_opline->opcode == ZEND_NOP) {
208 				init_opline--;
209 			}
210 			if (init_opline->opcode != ZEND_INIT_FCALL ||
211 			    init_opline->op2_type != IS_CONST ||
212 			    Z_TYPE(ZEND_OP2_LITERAL(init_opline)) != IS_STRING) {
213 				/* don't collect constants after unknown function call */
214 				collect_constants = 0;
215 				break;
216 			}
217 
218 			/* define("name", scalar); */
219 			if (zend_string_equals_literal_ci(Z_STR(ZEND_OP2_LITERAL(init_opline)), "define")) {
220 
221 				if (Z_TYPE(ZEND_OP1_LITERAL(send1_opline)) == IS_STRING && send2_opline) {
222 
223 					if (collect_constants) {
224 						zend_optimizer_collect_constant(ctx, &ZEND_OP1_LITERAL(send1_opline), &ZEND_OP1_LITERAL(send2_opline));
225 					}
226 
227 					if (RESULT_UNUSED(opline) &&
228 					    !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)))) {
229 
230 						opline->opcode = ZEND_DECLARE_CONST;
231 						opline->op1_type = IS_CONST;
232 						opline->op2_type = IS_CONST;
233 						opline->result_type = IS_UNUSED;
234 						opline->op1.constant = send1_opline->op1.constant;
235 						opline->op2.constant = send2_opline->op1.constant;
236 						opline->result.num = 0;
237 
238 						literal_dtor(&ZEND_OP2_LITERAL(init_opline));
239 						MAKE_NOP(init_opline);
240 						MAKE_NOP(send1_opline);
241 						MAKE_NOP(send2_opline);
242 					}
243 					break;
244 				}
245 			}
246 
247 			if (!send2_opline && Z_TYPE(ZEND_OP1_LITERAL(send1_opline)) == IS_STRING &&
248 					zend_optimizer_eval_special_func_call(&result, Z_STR(ZEND_OP2_LITERAL(init_opline)), Z_STR(ZEND_OP1_LITERAL(send1_opline))) == SUCCESS) {
249 				literal_dtor(&ZEND_OP2_LITERAL(init_opline));
250 				MAKE_NOP(init_opline);
251 				literal_dtor(&ZEND_OP1_LITERAL(send1_opline));
252 				MAKE_NOP(send1_opline);
253 				replace_by_const_or_qm_assign(op_array, opline, &result);
254 				break;
255 			}
256 
257 			/* don't collect constants after any other function call */
258 			collect_constants = 0;
259 			break;
260 		}
261 		case ZEND_STRLEN:
262 			if (opline->op1_type == IS_CONST &&
263 					zend_optimizer_eval_strlen(&result, &ZEND_OP1_LITERAL(opline)) == SUCCESS) {
264 				replace_by_const_or_qm_assign(op_array, opline, &result);
265 			}
266 			break;
267 		case ZEND_DEFINED:
268 			if (!zend_optimizer_get_persistent_constant(Z_STR(ZEND_OP1_LITERAL(opline)), &result, 0)) {
269 				break;
270 			}
271 			ZVAL_TRUE(&result);
272 			literal_dtor(&ZEND_OP1_LITERAL(opline));
273 			replace_by_const_or_qm_assign(op_array, opline, &result);
274 			break;
275 		case ZEND_DECLARE_CONST:
276 			if (collect_constants &&
277 			    Z_TYPE(ZEND_OP1_LITERAL(opline)) == IS_STRING &&
278 			    Z_TYPE(ZEND_OP2_LITERAL(opline)) != IS_CONSTANT_AST) {
279 				zend_optimizer_collect_constant(ctx, &ZEND_OP1_LITERAL(opline), &ZEND_OP2_LITERAL(opline));
280 			}
281 			break;
282 
283 		case ZEND_JMPZ_EX:
284 		case ZEND_JMPNZ_EX:
285 			/* convert Ti = JMPZ_EX(C, L) => Ti = QM_ASSIGN(C)
286 			   in case we know it wouldn't jump */
287 			if (opline->op1_type == IS_CONST) {
288 				if (zend_is_true(&ZEND_OP1_LITERAL(opline))) {
289 					if (opline->opcode == ZEND_JMPZ_EX) {
290 						opline->opcode = ZEND_QM_ASSIGN;
291 						zval_ptr_dtor_nogc(&ZEND_OP1_LITERAL(opline));
292 						ZVAL_TRUE(&ZEND_OP1_LITERAL(opline));
293 						opline->op2.num = 0;
294 						break;
295 					}
296 				} else {
297 					if (opline->opcode == ZEND_JMPNZ_EX) {
298 						opline->opcode = ZEND_QM_ASSIGN;
299 						zval_ptr_dtor_nogc(&ZEND_OP1_LITERAL(opline));
300 						ZVAL_FALSE(&ZEND_OP1_LITERAL(opline));
301 						opline->op2.num = 0;
302 						break;
303 					}
304 				}
305 			}
306 			collect_constants = 0;
307 			break;
308 
309 		case ZEND_JMPZ:
310 		case ZEND_JMPNZ:
311 			if (opline->op1_type == IS_CONST) {
312 				int should_jmp = zend_is_true(&ZEND_OP1_LITERAL(opline));
313 
314 				if (opline->opcode == ZEND_JMPZ) {
315 					should_jmp = !should_jmp;
316 				}
317 				literal_dtor(&ZEND_OP1_LITERAL(opline));
318 				opline->op1_type = IS_UNUSED;
319 				if (should_jmp) {
320 					opline->opcode = ZEND_JMP;
321 					COPY_NODE(opline->op1, opline->op2);
322 					opline->op2.num = 0;
323 				} else {
324 					MAKE_NOP(opline);
325 					break;
326 				}
327 			}
328 			collect_constants = 0;
329 			break;
330 
331 		case ZEND_RETURN:
332 		case ZEND_RETURN_BY_REF:
333 		case ZEND_GENERATOR_RETURN:
334 		case ZEND_EXIT:
335 		case ZEND_THROW:
336 		case ZEND_MATCH_ERROR:
337 		case ZEND_CATCH:
338 		case ZEND_FAST_CALL:
339 		case ZEND_FAST_RET:
340 		case ZEND_JMP:
341 		case ZEND_FE_RESET_R:
342 		case ZEND_FE_RESET_RW:
343 		case ZEND_FE_FETCH_R:
344 		case ZEND_FE_FETCH_RW:
345 		case ZEND_JMP_SET:
346 		case ZEND_COALESCE:
347 		case ZEND_ASSERT_CHECK:
348 		case ZEND_JMP_NULL:
349 		case ZEND_VERIFY_NEVER_TYPE:
350 		case ZEND_BIND_INIT_STATIC_OR_JMP:
351 		case ZEND_JMP_FRAMELESS:
352 			collect_constants = 0;
353 			break;
354 		}
355 		opline++;
356 	}
357 }
358