/src/php-src/Zend/Optimizer/zend_call_graph.c

Source
/*
   +----------------------------------------------------------------------+
   | Zend Engine, Call Graph                                              |
   +----------------------------------------------------------------------+
   | Copyright © The PHP Group and Contributors.                          |
   +----------------------------------------------------------------------+
   | This source file is subject to the Modified BSD License that is      |
   | bundled with this package in the file LICENSE, and is available      |
   | through the World Wide Web at <https://www.php.net/license/>.        |
   |                                                                      |
   | SPDX-License-Identifier: BSD-3-Clause                                |
   +----------------------------------------------------------------------+
   | Authors: Dmitry Stogov <dmitry@php.net>                              |
   +----------------------------------------------------------------------+
*/

#include "zend_compile.h"
#include "zend_extensions.h"
#include "Optimizer/zend_optimizer.h"
#include "zend_optimizer_internal.h"
#include "zend_inference.h"
#include "zend_call_graph.h"
#include "zend_func_info.h"

static void zend_op_array_calc(zend_op_array *op_array, void *context)
{
  zend_call_graph *call_graph = context;
  call_graph->op_arrays_count++;
}

static void zend_op_array_collect(zend_op_array *op_array, void *context)
{
  zend_call_graph *call_graph = context;
  zend_func_info *func_info = call_graph->func_infos + call_graph->op_arrays_count;

  ZEND_SET_FUNC_INFO(op_array, func_info);
  call_graph->op_arrays[call_graph->op_arrays_count] = op_array;
  func_info->num = call_graph->op_arrays_count;
  call_graph->op_arrays_count++;
}

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)
{
  zend_op *opline = op_array->opcodes;
  zend_op *end = opline + op_array->last;
  zend_function *func;
  zend_call_info *call_info;
  int call = 0;
  zend_call_info **call_stack;
  ALLOCA_FLAG(use_heap);
  bool is_prototype;

  // Note: Reserve one call stack slot per operation. Each opcode pushes at
  // most one entry to the call stack, and (with dead code elimination) it's
  // possible to never pop from the stack.
  call_stack = do_alloca(op_array->last * sizeof(zend_call_info*), use_heap);
  call_info = NULL;
  while (opline != end) {
    switch (opline->opcode) {
      case ZEND_INIT_FCALL:
      case ZEND_INIT_METHOD_CALL:
      case ZEND_INIT_STATIC_METHOD_CALL:
      case ZEND_INIT_PARENT_PROPERTY_HOOK_CALL:
        call_stack[call] = call_info;
        func = zend_optimizer_get_called_func(
          script, op_array, opline, &is_prototype);
        if (func) {
          call_info = zend_arena_calloc(arena, 1, sizeof(zend_call_info) + (sizeof(zend_send_arg_info) * ((int)opline->extended_value - 1)));
          call_info->caller_op_array = op_array;
          call_info->caller_init_opline = opline;
          call_info->caller_call_opline = NULL;
          call_info->callee_func = func;
          call_info->num_args = opline->extended_value;
          call_info->next_callee = func_info->callee_info;
          call_info->is_prototype = is_prototype;
          call_info->is_frameless = false;
          func_info->callee_info = call_info;

          if (build_flags & ZEND_CALL_TREE) {
            call_info->next_caller = NULL;
          } else if (func->type == ZEND_INTERNAL_FUNCTION
           || func->op_array.filename != script->filename) {
            call_info->next_caller = NULL;
          } else {
            zend_func_info *callee_func_info = ZEND_FUNC_INFO(&func->op_array);
            if (callee_func_info) {
              call_info->next_caller = callee_func_info->caller_info;
              callee_func_info->caller_info = call_info;
            } else {
              call_info->next_caller = NULL;
            }
          }
        } else {
          call_info = NULL;
        }
        call++;
        break;
      case ZEND_INIT_FCALL_BY_NAME:
      case ZEND_INIT_NS_FCALL_BY_NAME:
      case ZEND_INIT_DYNAMIC_CALL:
      case ZEND_NEW:
      case ZEND_INIT_USER_CALL:
        call_stack[call] = call_info;
        call_info = NULL;
        call++;
        break;
      case ZEND_FRAMELESS_ICALL_0:
      case ZEND_FRAMELESS_ICALL_1:
      case ZEND_FRAMELESS_ICALL_2:
      case ZEND_FRAMELESS_ICALL_3: {
        func = ZEND_FLF_FUNC(opline);
        zend_call_info *call_info = zend_arena_calloc(arena, 1, sizeof(zend_call_info));
        call_info->caller_op_array = op_array;
        call_info->caller_init_opline = opline;
        call_info->caller_call_opline = NULL;
        call_info->callee_func = func;
        call_info->num_args = ZEND_FLF_NUM_ARGS(opline->opcode);
        call_info->next_callee = func_info->callee_info;
        call_info->is_prototype = false;
        call_info->is_frameless = true;
        call_info->next_caller = NULL;
        func_info->callee_info = call_info;
        break;
      }
      case ZEND_DO_FCALL:
      case ZEND_DO_ICALL:
      case ZEND_DO_UCALL:
      case ZEND_DO_FCALL_BY_NAME:
      case ZEND_CALLABLE_CONVERT:
      case ZEND_CALLABLE_CONVERT_PARTIAL:
        func_info->flags |= ZEND_FUNC_HAS_CALLS;
        if (call_info) {
          call_info->caller_call_opline = opline;
        }
        call--;
        call_info = call_stack[call];
        break;
      case ZEND_SEND_VAL:
      case ZEND_SEND_VAR:
      case ZEND_SEND_VAL_EX:
      case ZEND_SEND_VAR_EX:
      case ZEND_SEND_FUNC_ARG:
      case ZEND_SEND_REF:
      case ZEND_SEND_VAR_NO_REF:
      case ZEND_SEND_VAR_NO_REF_EX:
      case ZEND_SEND_USER:
      case ZEND_SEND_PLACEHOLDER:
        if (call_info) {
          if (opline->op2_type == IS_CONST) {
            call_info->named_args = true;
            break;
          }

          uint32_t num = opline->op2.num;
          if (num > 0) {
            num--;
          }
          call_info->arg_info[num].opline = opline;
        }
        break;
      case ZEND_SEND_ARRAY:
      case ZEND_SEND_UNPACK:
        if (call_info) {
          call_info->send_unpack = true;
        }
        break;
    }
    opline++;
  }
  free_alloca(call_stack, use_heap);
}

static bool zend_is_indirectly_recursive(const zend_op_array *root, const zend_op_array *op_array, zend_bitset visited)
{
  const zend_func_info *func_info;
  zend_call_info *call_info;
  bool ret = false;

  if (op_array == root) {
    return true;
  }

  func_info = ZEND_FUNC_INFO(op_array);
  if (zend_bitset_in(visited, func_info->num)) {
    return false;
  }
  zend_bitset_incl(visited, func_info->num);
  call_info = func_info->caller_info;
  while (call_info) {
    if (zend_is_indirectly_recursive(root, call_info->caller_op_array, visited)) {
      call_info->recursive = true;
      ret = true;
    }
    call_info = call_info->next_caller;
  }
  return ret;
}

static void zend_analyze_recursion(zend_call_graph *call_graph)
{
  const zend_op_array *op_array;
  zend_func_info *func_info;
  zend_call_info *call_info;
  uint32_t set_len = zend_bitset_len(call_graph->op_arrays_count);
  zend_bitset visited;
  ALLOCA_FLAG(use_heap);

  visited = ZEND_BITSET_ALLOCA(set_len, use_heap);
  for (uint32_t i = 0; i < call_graph->op_arrays_count; i++) {
    op_array = call_graph->op_arrays[i];
    func_info = call_graph->func_infos + i;
    call_info = func_info->caller_info;
    for (; call_info; call_info = call_info->next_caller) {
      if (call_info->is_prototype) {
        /* Might be calling an overridden child method and not actually recursive. */
        continue;
      }
      if (call_info->caller_op_array == op_array) {
        call_info->recursive = true;
        func_info->flags |= ZEND_FUNC_RECURSIVE | ZEND_FUNC_RECURSIVE_DIRECTLY;
      } else {
        memset(visited, 0, sizeof(zend_ulong) * set_len);
        if (zend_is_indirectly_recursive(op_array, call_info->caller_op_array, visited)) {
          call_info->recursive = true;
          func_info->flags |= ZEND_FUNC_RECURSIVE | ZEND_FUNC_RECURSIVE_INDIRECTLY;
        }
      }
    }
  }

  free_alloca(visited, use_heap);
}

static void zend_sort_op_arrays(zend_call_graph *call_graph)
{
  (void) call_graph;

  // TODO: perform topological sort of cyclic call graph
}

ZEND_API void zend_build_call_graph(zend_arena **arena, zend_script *script, zend_call_graph *call_graph) /* {{{ */
{
  call_graph->op_arrays_count = 0;
  zend_foreach_op_array(script, zend_op_array_calc, call_graph);

  call_graph->op_arrays = (zend_op_array**)zend_arena_calloc(arena, call_graph->op_arrays_count, sizeof(zend_op_array*));
  call_graph->func_infos = (zend_func_info*)zend_arena_calloc(arena, call_graph->op_arrays_count, sizeof(zend_func_info));
  call_graph->op_arrays_count = 0;
  zend_foreach_op_array(script, zend_op_array_collect, call_graph);
}
/* }}} */

ZEND_API void zend_analyze_call_graph(zend_arena **arena, zend_script *script, zend_call_graph *call_graph) /* {{{ */
{
  for (uint32_t i = 0; i < call_graph->op_arrays_count; i++) {
    zend_analyze_calls(arena, script, 0, call_graph->op_arrays[i], call_graph->func_infos + i);
  }
  zend_analyze_recursion(call_graph);
  zend_sort_op_arrays(call_graph);
}
/* }}} */

ZEND_API zend_call_info **zend_build_call_map(zend_arena **arena, const zend_func_info *info, const zend_op_array *op_array) /* {{{ */
{
  zend_call_info **map, *call;
  if (!info->callee_info) {
    /* Don't build call map if function contains no calls */
    return NULL;
  }

  map = zend_arena_calloc(arena, sizeof(zend_call_info *), op_array->last);
  for (call = info->callee_info; call; call = call->next_callee) {
    map[call->caller_init_opline - op_array->opcodes] = call;
    if (call->caller_call_opline) {
      map[call->caller_call_opline - op_array->opcodes] = call;
    }
    if (!call->is_frameless) {
      for (uint32_t i = 0; i < call->num_args; i++) {
        if (call->arg_info[i].opline) {
          map[call->arg_info[i].opline - op_array->opcodes] = call;
        }
      }
    }
  }
  return map;
}
/* }}} */

Coverage Report

Created: 2026-10-28 06:20

Line	Count	Source
1		/*
2		+----------------------------------------------------------------------+
3		\| Zend Engine, Call Graph \|
4		+----------------------------------------------------------------------+
5		\| Copyright © The PHP Group and Contributors. \|
6		+----------------------------------------------------------------------+
7		\| This source file is subject to the Modified BSD License that is \|
8		\| bundled with this package in the file LICENSE, and is available \|
9		\| through the World Wide Web at <https://www.php.net/license/>. \|
10		\| \|
11		\| SPDX-License-Identifier: BSD-3-Clause \|
12		+----------------------------------------------------------------------+
13		\| Authors: Dmitry Stogov <dmitry@php.net> \|
14		+----------------------------------------------------------------------+
15		*/
16
17		#include "zend_compile.h"
18		#include "zend_extensions.h"
19		#include "Optimizer/zend_optimizer.h"
20		#include "zend_optimizer_internal.h"
21		#include "zend_inference.h"
22		#include "zend_call_graph.h"
23		#include "zend_func_info.h"
24
25		static void zend_op_array_calc(zend_op_array op_array, void context)
26	33.3k	{
27	33.3k	zend_call_graph *call_graph = context;
28	33.3k	call_graph->op_arrays_count++;
29	33.3k	}
30
31		static void zend_op_array_collect(zend_op_array op_array, void context)
32	33.3k	{
33	33.3k	zend_call_graph *call_graph = context;
34	33.3k	zend_func_info *func_info = call_graph->func_infos + call_graph->op_arrays_count;
35
36	33.3k	ZEND_SET_FUNC_INFO(op_array, func_info);
37	33.3k	call_graph->op_arrays[call_graph->op_arrays_count] = op_array;
38	33.3k	func_info->num = call_graph->op_arrays_count;
39	33.3k	call_graph->op_arrays_count++;
40	33.3k	}
41
42		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)
43	35.8k	{
44	35.8k	zend_op *opline = op_array->opcodes;
45	35.8k	zend_op *end = opline + op_array->last;
46	35.8k	zend_function *func;
47	35.8k	zend_call_info *call_info;
48	35.8k	int call = 0;
49	35.8k	zend_call_info **call_stack;
50	35.8k	ALLOCA_FLAG(use_heap);
51	35.8k	bool is_prototype;
52
53		// Note: Reserve one call stack slot per operation. Each opcode pushes at
54		// most one entry to the call stack, and (with dead code elimination) it's
55		// possible to never pop from the stack.
56	35.8k	call_stack = do_alloca(op_array->last * sizeof(zend_call_info*), use_heap);
57	35.8k	call_info = NULL;
58	246k	while (opline != end) {
59	210k	switch (opline->opcode) {
60	2.53k	case ZEND_INIT_FCALL:
61	2.60k	case ZEND_INIT_METHOD_CALL:
62	2.73k	case ZEND_INIT_STATIC_METHOD_CALL:
63	2.73k	case ZEND_INIT_PARENT_PROPERTY_HOOK_CALL:
64	2.73k	call_stack[call] = call_info;
65	2.73k	func = zend_optimizer_get_called_func(
66	2.73k	script, op_array, opline, &is_prototype);
67	2.73k	if (func) {
68	2.54k	call_info = zend_arena_calloc(arena, 1, sizeof(zend_call_info) + (sizeof(zend_send_arg_info) * ((int)opline->extended_value - 1)));
69	2.54k	call_info->caller_op_array = op_array;
70	2.54k	call_info->caller_init_opline = opline;
71	2.54k	call_info->caller_call_opline = NULL;
72	2.54k	call_info->callee_func = func;
73	2.54k	call_info->num_args = opline->extended_value;
74	2.54k	call_info->next_callee = func_info->callee_info;
75	2.54k	call_info->is_prototype = is_prototype;
76	2.54k	call_info->is_frameless = false;
77	2.54k	func_info->callee_info = call_info;
78
79	2.54k	if (build_flags & ZEND_CALL_TREE) {
80	208	call_info->next_caller = NULL;
81	2.33k	} else if (func->type == ZEND_INTERNAL_FUNCTION
82	2.18k	\|\| func->op_array.filename != script->filename) {
83	2.18k	call_info->next_caller = NULL;
84	2.18k	} else {
85	148	zend_func_info *callee_func_info = ZEND_FUNC_INFO(&func->op_array);
86	148	if (callee_func_info) {
87	148	call_info->next_caller = callee_func_info->caller_info;
88	148	callee_func_info->caller_info = call_info;
89	148	} else {
90	0	call_info->next_caller = NULL;
91	0	}
92	148	}
93	2.54k	} else {
94	190	call_info = NULL;
95	190	}
96	2.73k	call++;
97	2.73k	break;
98	1.65k	case ZEND_INIT_FCALL_BY_NAME:
99	1.68k	case ZEND_INIT_NS_FCALL_BY_NAME:
100	1.93k	case ZEND_INIT_DYNAMIC_CALL:
101	9.99k	case ZEND_NEW:
102	9.99k	case ZEND_INIT_USER_CALL:
103	9.99k	call_stack[call] = call_info;
104	9.99k	call_info = NULL;
105	9.99k	call++;
106	9.99k	break;
107	0	case ZEND_FRAMELESS_ICALL_0:
108	0	case ZEND_FRAMELESS_ICALL_1:
109	0	case ZEND_FRAMELESS_ICALL_2:
110	0	case ZEND_FRAMELESS_ICALL_3: {
111	0	func = ZEND_FLF_FUNC(opline);
112	0	zend_call_info *call_info = zend_arena_calloc(arena, 1, sizeof(zend_call_info));
113	0	call_info->caller_op_array = op_array;
114	0	call_info->caller_init_opline = opline;
115	0	call_info->caller_call_opline = NULL;
116	0	call_info->callee_func = func;
117	0	call_info->num_args = ZEND_FLF_NUM_ARGS(opline->opcode);
118	0	call_info->next_callee = func_info->callee_info;
119	0	call_info->is_prototype = false;
120	0	call_info->is_frameless = true;
121	0	call_info->next_caller = NULL;
122	0	func_info->callee_info = call_info;
123	0	break;
124	0	}
125	12.4k	case ZEND_DO_FCALL:
126	12.4k	case ZEND_DO_ICALL:
127	12.5k	case ZEND_DO_UCALL:
128	12.5k	case ZEND_DO_FCALL_BY_NAME:
129	12.6k	case ZEND_CALLABLE_CONVERT:
130	12.7k	case ZEND_CALLABLE_CONVERT_PARTIAL:
131	12.7k	func_info->flags \|= ZEND_FUNC_HAS_CALLS;
132	12.7k	if (call_info) {
133	2.54k	call_info->caller_call_opline = opline;
134	2.54k	}
135	12.7k	call--;
136	12.7k	call_info = call_stack[call];
137	12.7k	break;
138	10.6k	case ZEND_SEND_VAL:
139	10.7k	case ZEND_SEND_VAR:
140	12.3k	case ZEND_SEND_VAL_EX:
141	12.4k	case ZEND_SEND_VAR_EX:
142	12.6k	case ZEND_SEND_FUNC_ARG:
143	12.6k	case ZEND_SEND_REF:
144	12.6k	case ZEND_SEND_VAR_NO_REF:
145	12.7k	case ZEND_SEND_VAR_NO_REF_EX:
146	12.7k	case ZEND_SEND_USER:
147	12.8k	case ZEND_SEND_PLACEHOLDER:
148	12.8k	if (call_info) {
149	3.25k	if (opline->op2_type == IS_CONST) {
150	84	call_info->named_args = true;
151	84	break;
152	84	}
153
154	3.17k	uint32_t num = opline->op2.num;
155	3.17k	if (num > 0) {
156	3.17k	num--;
157	3.17k	}
158	3.17k	call_info->arg_info[num].opline = opline;
159	3.17k	}
160	12.7k	break;
161	12.7k	case ZEND_SEND_ARRAY:
162	14	case ZEND_SEND_UNPACK:
163	14	if (call_info) {
164	6	call_info->send_unpack = true;
165	6	}
166	14	break;
167	210k	}
168	210k	opline++;
169	210k	}
170	35.8k	free_alloca(call_stack, use_heap);
171	35.8k	}
172
173		static bool zend_is_indirectly_recursive(const zend_op_array root, const zend_op_array op_array, zend_bitset visited)
174	142	{
175	142	const zend_func_info *func_info;
176	142	zend_call_info *call_info;
177	142	bool ret = false;
178
179	142	if (op_array == root) {
180	0	return true;
181	0	}
182
183	142	func_info = ZEND_FUNC_INFO(op_array);
184	142	if (zend_bitset_in(visited, func_info->num)) {
185	0	return false;
186	0	}
187	142	zend_bitset_incl(visited, func_info->num);
188	142	call_info = func_info->caller_info;
189	142	while (call_info) {
190	0	if (zend_is_indirectly_recursive(root, call_info->caller_op_array, visited)) {
191	0	call_info->recursive = true;
192	0	ret = true;
193	0	}
194	0	call_info = call_info->next_caller;
195	0	}
196	142	return ret;
197	142	}
198
199		static void zend_analyze_recursion(zend_call_graph *call_graph)
200	32.5k	{
201	32.5k	const zend_op_array *op_array;
202	32.5k	zend_func_info *func_info;
203	32.5k	zend_call_info *call_info;
204	32.5k	uint32_t set_len = zend_bitset_len(call_graph->op_arrays_count);
205	32.5k	zend_bitset visited;
206	32.5k	ALLOCA_FLAG(use_heap);
207
208	32.5k	visited = ZEND_BITSET_ALLOCA(set_len, use_heap);
209	65.8k	for (uint32_t i = 0; i < call_graph->op_arrays_count; i++) {
210	33.3k	op_array = call_graph->op_arrays[i];
211	33.3k	func_info = call_graph->func_infos + i;
212	33.3k	call_info = func_info->caller_info;
213	33.4k	for (; call_info; call_info = call_info->next_caller) {
214	148	if (call_info->is_prototype) {
215		/* Might be calling an overridden child method and not actually recursive. */
216	0	continue;
217	0	}
218	148	if (call_info->caller_op_array == op_array) {
219	6	call_info->recursive = true;
220	6	func_info->flags \|= ZEND_FUNC_RECURSIVE \| ZEND_FUNC_RECURSIVE_DIRECTLY;
221	142	} else {
222	142	memset(visited, 0, sizeof(zend_ulong) * set_len);
223	142	if (zend_is_indirectly_recursive(op_array, call_info->caller_op_array, visited)) {
224	0	call_info->recursive = true;
225	0	func_info->flags \|= ZEND_FUNC_RECURSIVE \| ZEND_FUNC_RECURSIVE_INDIRECTLY;
226	0	}
227	142	}
228	148	}
229	33.3k	}
230
231	32.5k	free_alloca(visited, use_heap);
232	32.5k	}
233
234		static void zend_sort_op_arrays(zend_call_graph *call_graph)
235	32.5k	{
236	32.5k	(void) call_graph;
237
238		// TODO: perform topological sort of cyclic call graph
239	32.5k	}
240
241		ZEND_API void zend_build_call_graph(zend_arena *arena, zend_script script, zend_call_graph call_graph) / {{{ */
242	32.5k	{
243	32.5k	call_graph->op_arrays_count = 0;
244	32.5k	zend_foreach_op_array(script, zend_op_array_calc, call_graph);
245
246	32.5k	call_graph->op_arrays = (zend_op_array*)zend_arena_calloc(arena, call_graph->op_arrays_count, sizeof(zend_op_array));
247	32.5k	call_graph->func_infos = (zend_func_info*)zend_arena_calloc(arena, call_graph->op_arrays_count, sizeof(zend_func_info));
248	32.5k	call_graph->op_arrays_count = 0;
249	32.5k	zend_foreach_op_array(script, zend_op_array_collect, call_graph);
250	32.5k	}
251		/* }}} */
252
253		ZEND_API void zend_analyze_call_graph(zend_arena *arena, zend_script script, zend_call_graph call_graph) / {{{ */
254	32.5k	{
255	65.8k	for (uint32_t i = 0; i < call_graph->op_arrays_count; i++) {
256	33.3k	zend_analyze_calls(arena, script, 0, call_graph->op_arrays[i], call_graph->func_infos + i);
257	33.3k	}
258	32.5k	zend_analyze_recursion(call_graph);
259	32.5k	zend_sort_op_arrays(call_graph);
260	32.5k	}
261		/* }}} */
262
263		ZEND_API zend_call_info zend_build_call_map(zend_arena arena, const zend_func_info info, const zend_op_array op_array) /* {{{ */
264	35.8k	{
265	35.8k	zend_call_info *map, call;
266	35.8k	if (!info->callee_info) {
267		/* Don't build call map if function contains no calls */
268	33.4k	return NULL;
269	33.4k	}
270
271	2.34k	map = zend_arena_calloc(arena, sizeof(zend_call_info *), op_array->last);
272	4.89k	for (call = info->callee_info; call; call = call->next_callee) {
273	2.54k	map[call->caller_init_opline - op_array->opcodes] = call;
274	2.54k	if (call->caller_call_opline) {
275	2.54k	map[call->caller_call_opline - op_array->opcodes] = call;
276	2.54k	}
277	2.54k	if (!call->is_frameless) {
278	5.71k	for (uint32_t i = 0; i < call->num_args; i++) {
279	3.17k	if (call->arg_info[i].opline) {
280	3.17k	map[call->arg_info[i].opline - op_array->opcodes] = call;
281	3.17k	}
282	3.17k	}
283	2.54k	}
284	2.54k	}
285	2.34k	return map;
286	35.8k	}
287		/* }}} */