1 /*
2 +----------------------------------------------------------------------+
3 | Zend Engine, Call Graph |
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: Dmitry Stogov <dmitry@php.net> |
16 +----------------------------------------------------------------------+
17 */
18
19 #include "zend_compile.h"
20 #include "zend_extensions.h"
21 #include "Optimizer/zend_optimizer.h"
22 #include "zend_optimizer_internal.h"
23 #include "zend_inference.h"
24 #include "zend_call_graph.h"
25 #include "zend_func_info.h"
26 #include "zend_inference.h"
27 #include "zend_call_graph.h"
28
zend_op_array_calc(zend_op_array * op_array,void * context)29 static void zend_op_array_calc(zend_op_array *op_array, void *context)
30 {
31 zend_call_graph *call_graph = context;
32 call_graph->op_arrays_count++;
33 }
34
zend_op_array_collect(zend_op_array * op_array,void * context)35 static void zend_op_array_collect(zend_op_array *op_array, void *context)
36 {
37 zend_call_graph *call_graph = context;
38 zend_func_info *func_info = call_graph->func_infos + call_graph->op_arrays_count;
39
40 ZEND_SET_FUNC_INFO(op_array, func_info);
41 call_graph->op_arrays[call_graph->op_arrays_count] = op_array;
42 func_info->num = call_graph->op_arrays_count;
43 call_graph->op_arrays_count++;
44 }
45
zend_analyze_calls(zend_arena ** arena,zend_script * script,uint32_t build_flags,zend_op_array * op_array,zend_func_info * func_info)46 ZEND_API void zend_analyze_calls(zend_arena **arena, zend_script *script, uint32_t build_flags, zend_op_array *op_array, zend_func_info *func_info)
47 {
48 zend_op *opline = op_array->opcodes;
49 zend_op *end = opline + op_array->last;
50 zend_function *func;
51 zend_call_info *call_info;
52 int call = 0;
53 zend_call_info **call_stack;
54 ALLOCA_FLAG(use_heap);
55 bool is_prototype;
56
57 call_stack = do_alloca((op_array->last / 2) * sizeof(zend_call_info*), use_heap);
58 call_info = NULL;
59 while (opline != end) {
60 switch (opline->opcode) {
61 case ZEND_INIT_FCALL:
62 case ZEND_INIT_METHOD_CALL:
63 case ZEND_INIT_STATIC_METHOD_CALL:
64 call_stack[call] = call_info;
65 func = zend_optimizer_get_called_func(
66 script, op_array, opline, &is_prototype);
67 if (func) {
68 call_info = zend_arena_calloc(arena, 1, sizeof(zend_call_info) + (sizeof(zend_send_arg_info) * ((int)opline->extended_value - 1)));
69 call_info->caller_op_array = op_array;
70 call_info->caller_init_opline = opline;
71 call_info->caller_call_opline = NULL;
72 call_info->callee_func = func;
73 call_info->num_args = opline->extended_value;
74 call_info->next_callee = func_info->callee_info;
75 call_info->is_prototype = is_prototype;
76 func_info->callee_info = call_info;
77
78 if (build_flags & ZEND_CALL_TREE) {
79 call_info->next_caller = NULL;
80 } else if (func->type == ZEND_INTERNAL_FUNCTION) {
81 call_info->next_caller = NULL;
82 } else {
83 zend_func_info *callee_func_info = ZEND_FUNC_INFO(&func->op_array);
84 if (callee_func_info) {
85 call_info->next_caller = callee_func_info->caller_info;
86 callee_func_info->caller_info = call_info;
87 } else {
88 call_info->next_caller = NULL;
89 }
90 }
91 } else {
92 call_info = NULL;
93 }
94 call++;
95 break;
96 case ZEND_INIT_FCALL_BY_NAME:
97 case ZEND_INIT_NS_FCALL_BY_NAME:
98 case ZEND_INIT_DYNAMIC_CALL:
99 case ZEND_NEW:
100 case ZEND_INIT_USER_CALL:
101 call_stack[call] = call_info;
102 call_info = NULL;
103 call++;
104 break;
105 case ZEND_DO_FCALL:
106 case ZEND_DO_ICALL:
107 case ZEND_DO_UCALL:
108 case ZEND_DO_FCALL_BY_NAME:
109 case ZEND_CALLABLE_CONVERT:
110 func_info->flags |= ZEND_FUNC_HAS_CALLS;
111 if (call_info) {
112 call_info->caller_call_opline = opline;
113 }
114 call--;
115 call_info = call_stack[call];
116 break;
117 case ZEND_SEND_VAL:
118 case ZEND_SEND_VAR:
119 case ZEND_SEND_VAL_EX:
120 case ZEND_SEND_VAR_EX:
121 case ZEND_SEND_FUNC_ARG:
122 case ZEND_SEND_REF:
123 case ZEND_SEND_VAR_NO_REF:
124 case ZEND_SEND_VAR_NO_REF_EX:
125 case ZEND_SEND_USER:
126 if (call_info) {
127 if (opline->op2_type == IS_CONST) {
128 call_info->named_args = 1;
129 break;
130 }
131
132 uint32_t num = opline->op2.num;
133 if (num > 0) {
134 num--;
135 }
136 call_info->arg_info[num].opline = opline;
137 }
138 break;
139 case ZEND_SEND_ARRAY:
140 case ZEND_SEND_UNPACK:
141 if (call_info) {
142 call_info->send_unpack = 1;
143 }
144 break;
145 case ZEND_EXIT:
146 /* In this case the DO_CALL opcode may have been dropped
147 * and caller_call_opline will be NULL. */
148 break;
149 }
150 opline++;
151 }
152 free_alloca(call_stack, use_heap);
153 }
154
zend_is_indirectly_recursive(zend_op_array * root,zend_op_array * op_array,zend_bitset visited)155 static bool zend_is_indirectly_recursive(zend_op_array *root, zend_op_array *op_array, zend_bitset visited)
156 {
157 zend_func_info *func_info;
158 zend_call_info *call_info;
159 bool ret = 0;
160
161 if (op_array == root) {
162 return 1;
163 }
164
165 func_info = ZEND_FUNC_INFO(op_array);
166 if (zend_bitset_in(visited, func_info->num)) {
167 return 0;
168 }
169 zend_bitset_incl(visited, func_info->num);
170 call_info = func_info->caller_info;
171 while (call_info) {
172 if (zend_is_indirectly_recursive(root, call_info->caller_op_array, visited)) {
173 call_info->recursive = 1;
174 ret = 1;
175 }
176 call_info = call_info->next_caller;
177 }
178 return ret;
179 }
180
zend_analyze_recursion(zend_call_graph * call_graph)181 static void zend_analyze_recursion(zend_call_graph *call_graph)
182 {
183 zend_op_array *op_array;
184 zend_func_info *func_info;
185 zend_call_info *call_info;
186 int i;
187 int set_len = zend_bitset_len(call_graph->op_arrays_count);
188 zend_bitset visited;
189 ALLOCA_FLAG(use_heap);
190
191 visited = ZEND_BITSET_ALLOCA(set_len, use_heap);
192 for (i = 0; i < call_graph->op_arrays_count; i++) {
193 op_array = call_graph->op_arrays[i];
194 func_info = call_graph->func_infos + i;
195 call_info = func_info->caller_info;
196 for (; call_info; call_info = call_info->next_caller) {
197 if (call_info->is_prototype) {
198 /* Might be calling an overridden child method and not actually recursive. */
199 continue;
200 }
201 if (call_info->caller_op_array == op_array) {
202 call_info->recursive = 1;
203 func_info->flags |= ZEND_FUNC_RECURSIVE | ZEND_FUNC_RECURSIVE_DIRECTLY;
204 } else {
205 memset(visited, 0, sizeof(zend_ulong) * set_len);
206 if (zend_is_indirectly_recursive(op_array, call_info->caller_op_array, visited)) {
207 call_info->recursive = 1;
208 func_info->flags |= ZEND_FUNC_RECURSIVE | ZEND_FUNC_RECURSIVE_INDIRECTLY;
209 }
210 }
211 }
212 }
213
214 free_alloca(visited, use_heap);
215 }
216
zend_sort_op_arrays(zend_call_graph * call_graph)217 static void zend_sort_op_arrays(zend_call_graph *call_graph)
218 {
219 (void) call_graph;
220
221 // TODO: perform topological sort of cyclic call graph
222 }
223
zend_build_call_graph(zend_arena ** arena,zend_script * script,zend_call_graph * call_graph)224 ZEND_API void zend_build_call_graph(zend_arena **arena, zend_script *script, zend_call_graph *call_graph) /* {{{ */
225 {
226 call_graph->op_arrays_count = 0;
227 zend_foreach_op_array(script, zend_op_array_calc, call_graph);
228
229 call_graph->op_arrays = (zend_op_array**)zend_arena_calloc(arena, call_graph->op_arrays_count, sizeof(zend_op_array*));
230 call_graph->func_infos = (zend_func_info*)zend_arena_calloc(arena, call_graph->op_arrays_count, sizeof(zend_func_info));
231 call_graph->op_arrays_count = 0;
232 zend_foreach_op_array(script, zend_op_array_collect, call_graph);
233 }
234 /* }}} */
235
zend_analyze_call_graph(zend_arena ** arena,zend_script * script,zend_call_graph * call_graph)236 ZEND_API void zend_analyze_call_graph(zend_arena **arena, zend_script *script, zend_call_graph *call_graph) /* {{{ */
237 {
238 int i;
239
240 for (i = 0; i < call_graph->op_arrays_count; i++) {
241 zend_analyze_calls(arena, script, 0, call_graph->op_arrays[i], call_graph->func_infos + i);
242 }
243 zend_analyze_recursion(call_graph);
244 zend_sort_op_arrays(call_graph);
245 }
246 /* }}} */
247
zend_build_call_map(zend_arena ** arena,zend_func_info * info,const zend_op_array * op_array)248 ZEND_API zend_call_info **zend_build_call_map(zend_arena **arena, zend_func_info *info, const zend_op_array *op_array) /* {{{ */
249 {
250 zend_call_info **map, *call;
251 if (!info->callee_info) {
252 /* Don't build call map if function contains no calls */
253 return NULL;
254 }
255
256 map = zend_arena_calloc(arena, sizeof(zend_call_info *), op_array->last);
257 for (call = info->callee_info; call; call = call->next_callee) {
258 int i;
259 map[call->caller_init_opline - op_array->opcodes] = call;
260 if (call->caller_call_opline) {
261 map[call->caller_call_opline - op_array->opcodes] = call;
262 }
263 for (i = 0; i < call->num_args; i++) {
264 if (call->arg_info[i].opline) {
265 map[call->arg_info[i].opline - op_array->opcodes] = call;
266 }
267 }
268 }
269 return map;
270 }
271 /* }}} */
272
