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

Source
/*
   +----------------------------------------------------------------------+
   | Zend OPcache, Escape Analysis                                        |
   +----------------------------------------------------------------------+
   | 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 "Optimizer/zend_optimizer.h"
#include "Optimizer/zend_optimizer_internal.h"
#include "zend_bitset.h"
#include "zend_cfg.h"
#include "zend_ssa.h"
#include "zend_inference.h"
#include "zend_dump.h"

/*
 * T. Kotzmann and H. Mossenbock. Escape analysis  in the context of dynamic
 * compilation and deoptimization. In Proceedings of the International
 * Conference on Virtual Execution Environments, pages 111-120, Chicago,
 * June 2005
 */

static zend_always_inline void union_find_init(int *parent, int *size, int count) /* {{{ */
{
  int i;

  for (i = 0; i < count; i++) {
    parent[i] = i;
    size[i] = 1;
  }
}
/* }}} */

static zend_always_inline int union_find_root(int *parent, int i) /* {{{ */
{
  int p = parent[i];

  while (i != p) {
    p = parent[p];
    parent[i] = p;
    i = p;
    p = parent[i];
  }
  return i;
}
/* }}} */

static zend_always_inline void union_find_unite(int *parent, int *size, int i, int j) /* {{{ */
{
  int r1 = union_find_root(parent, i);
  int r2 = union_find_root(parent, j);

  if (r1 != r2) {
    if (size[r1] < size[r2]) {
      parent[r1] = r2;
      size[r2] += size[r1];
    } else {
      parent[r2] = r1;
      size[r1] += size[r2];
    }
  }
}
/* }}} */

static zend_result zend_build_equi_escape_sets(int *parent, zend_op_array *op_array, zend_ssa *ssa) /* {{{ */
{
  zend_ssa_var *ssa_vars = ssa->vars;
  int ssa_vars_count = ssa->vars_count;
  zend_ssa_phi *p;
  int i;
  int *size;
  ALLOCA_FLAG(use_heap)

  size = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
  if (!size) {
    return FAILURE;
  }
  union_find_init(parent, size, ssa_vars_count);

  for (i = 0; i < ssa_vars_count; i++) {
    if (ssa_vars[i].definition_phi) {
      p = ssa_vars[i].definition_phi;
      if (p->pi >= 0) {
        union_find_unite(parent, size, i, p->sources[0]);
      } else {
        for (uint32_t j = 0; j < ssa->cfg.blocks[p->block].predecessors_count; j++) {
          union_find_unite(parent, size, i, p->sources[j]);
        }
      }
    } else if (ssa_vars[i].definition >= 0) {
      int def = ssa_vars[i].definition;
      zend_ssa_op *op = ssa->ops + def;
      zend_op *opline =  op_array->opcodes + def;

      if (op->op1_def >= 0) {
        if (op->op1_use >= 0) {
          if (opline->opcode != ZEND_ASSIGN) {
            union_find_unite(parent, size, op->op1_def, op->op1_use);
          }
        }
        if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
          union_find_unite(parent, size, op->op1_def, op->op2_use);
        }
      }
      if (op->op2_def >= 0) {
        if (op->op2_use >= 0) {
          union_find_unite(parent, size, op->op2_def, op->op2_use);
        }
      }
      if (op->result_def >= 0) {
        if (op->result_use >= 0) {
          if (opline->opcode != ZEND_QM_ASSIGN) {
            union_find_unite(parent, size, op->result_def, op->result_use);
          }
        }
        if (opline->opcode == ZEND_QM_ASSIGN && op->op1_use >= 0) {
          union_find_unite(parent, size, op->result_def, op->op1_use);
        }
        if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
          union_find_unite(parent, size, op->result_def, op->op2_use);
        }
        if (opline->opcode == ZEND_ASSIGN && op->op1_def >= 0) {
          union_find_unite(parent, size, op->result_def, op->op1_def);
        }
      }
    }
  }

  for (i = 0; i < ssa_vars_count; i++) {
    parent[i] = union_find_root(parent, i);
  }

  free_alloca(size, use_heap);

  return SUCCESS;
}
/* }}} */

static bool is_allocation_def(zend_op_array *op_array, zend_ssa *ssa, int def, int var, const zend_script *script) /* {{{ */
{
  zend_ssa_op *ssa_op = ssa->ops + def;
  zend_op *opline = op_array->opcodes + def;

  if (ssa_op->result_def == var) {
    switch (opline->opcode) {
      case ZEND_INIT_ARRAY:
        return true;
      case ZEND_NEW: {
          /* objects with destructors should escape */
        zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
          script, op_array, opline);
        uint32_t forbidden_flags =
          /* These flags will always cause an exception */
          ZEND_ACC_IMPLICIT_ABSTRACT_CLASS | ZEND_ACC_EXPLICIT_ABSTRACT_CLASS
          | ZEND_ACC_INTERFACE | ZEND_ACC_TRAIT;
        if (ce
         && !ce->parent
         && !ce->create_object
         && ce->default_object_handlers->get_constructor == zend_std_get_constructor
         && ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
         && !ce->constructor
         && !ce->destructor
         && !ce->__get
         && !ce->__set
         && !(ce->ce_flags & forbidden_flags)
         && (ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
          return true;
        }
        break;
      }
      case ZEND_QM_ASSIGN:
        if (opline->op1_type == IS_CONST
         && Z_TYPE_P(CRT_CONSTANT(opline->op1)) == IS_ARRAY) {
          return true;
        }
        if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
          return true;
        }
        break;
      case ZEND_ASSIGN:
        if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
          return true;
        }
        break;
    }
  } else if (ssa_op->op1_def == var) {
    switch (opline->opcode) {
      case ZEND_ASSIGN:
        if (opline->op2_type == IS_CONST
         && Z_TYPE_P(CRT_CONSTANT(opline->op2)) == IS_ARRAY) {
          return true;
        }
        if (opline->op2_type == IS_CV && (OP2_INFO() & MAY_BE_ARRAY)) {
          return true;
        }
        break;
      case ZEND_ASSIGN_DIM:
        if (OP1_INFO() & (MAY_BE_UNDEF | MAY_BE_NULL | MAY_BE_FALSE)) {
          /* implicit object/array allocation */
          return true;
        }
        break;
    }
  }

  return false;
}
/* }}} */

static bool is_local_def(zend_op_array *op_array, zend_ssa *ssa, int def, int var, const zend_script *script) /* {{{ */
{
  zend_ssa_op *op = ssa->ops + def;
  zend_op *opline = op_array->opcodes + def;

  if (op->result_def == var) {
    switch (opline->opcode) {
      case ZEND_INIT_ARRAY:
      case ZEND_ADD_ARRAY_ELEMENT:
      case ZEND_QM_ASSIGN:
      case ZEND_ASSIGN:
        return true;
      case ZEND_NEW: {
        /* objects with destructors should escape */
        zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
          script, op_array, opline);
        if (ce
         && !ce->create_object
         && ce->default_object_handlers->get_constructor == zend_std_get_constructor
         && ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
         && !ce->constructor
         && !ce->destructor
         && !ce->__get
         && !ce->__set
         && !ce->parent) {
          return true;
        }
        break;
      }
    }
  } else if (op->op1_def == var) {
    switch (opline->opcode) {
      case ZEND_ASSIGN:
      case ZEND_ASSIGN_DIM:
      case ZEND_ASSIGN_OBJ:
      case ZEND_ASSIGN_OBJ_REF:
      case ZEND_ASSIGN_DIM_OP:
      case ZEND_ASSIGN_OBJ_OP:
      case ZEND_PRE_INC_OBJ:
      case ZEND_PRE_DEC_OBJ:
      case ZEND_POST_INC_OBJ:
      case ZEND_POST_DEC_OBJ:
        return true;
    }
  }

  return false;
}
/* }}} */

static bool is_escape_use(zend_op_array *op_array, zend_ssa *ssa, int use, int var) /* {{{ */
{
  zend_ssa_op *ssa_op = ssa->ops + use;
  zend_op *opline = op_array->opcodes + use;

  if (ssa_op->op1_use == var) {
    switch (opline->opcode) {
      case ZEND_ASSIGN:
        /* no_val */
        break;
      case ZEND_QM_ASSIGN:
        if (opline->op1_type == IS_CV) {
          if (OP1_INFO() & MAY_BE_OBJECT) {
            /* object aliasing */
            return true;
          }
        }
        break;
      case ZEND_ISSET_ISEMPTY_DIM_OBJ:
      case ZEND_ISSET_ISEMPTY_PROP_OBJ:
      case ZEND_FETCH_DIM_R:
      case ZEND_FETCH_OBJ_R:
      case ZEND_FETCH_DIM_IS:
      case ZEND_FETCH_OBJ_IS:
        break;
      case ZEND_ASSIGN_OP:
        return true;
      case ZEND_ASSIGN_DIM_OP:
      case ZEND_ASSIGN_OBJ_OP:
      case ZEND_ASSIGN_STATIC_PROP_OP:
      case ZEND_ASSIGN_DIM:
      case ZEND_ASSIGN_OBJ:
      case ZEND_ASSIGN_OBJ_REF:
        break;
      case ZEND_PRE_INC_OBJ:
      case ZEND_PRE_DEC_OBJ:
      case ZEND_POST_INC_OBJ:
      case ZEND_POST_DEC_OBJ:
        break;
      case ZEND_INIT_ARRAY:
      case ZEND_ADD_ARRAY_ELEMENT:
        if (opline->extended_value & ZEND_ARRAY_ELEMENT_REF) {
          return true;
        }
        if (OP1_INFO() & MAY_BE_OBJECT) {
          /* object aliasing */
          return true;
        }
        /* reference dependencies processed separately */
        break;
      case ZEND_OP_DATA:
        if ((opline-1)->opcode != ZEND_ASSIGN_DIM
         && (opline-1)->opcode != ZEND_ASSIGN_OBJ) {
          return true;
        }
        if (OP1_INFO() & MAY_BE_OBJECT) {
          /* object aliasing */
          return true;
        }
        opline--;
        ssa_op--;
        if (opline->op1_type != IS_CV
         || (OP1_INFO() & MAY_BE_REF)
         || (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
          /* assignment into escaping structure */
          return true;
        }
        /* reference dependencies processed separately */
        break;
      default:
        return true;
    }
  }

  if (ssa_op->op2_use == var) {
    switch (opline->opcode) {
      case ZEND_ASSIGN:
        if (opline->op1_type != IS_CV
         || (OP1_INFO() & MAY_BE_REF)
         || (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
          /* assignment into escaping variable */
          return true;
        }
        if (opline->op2_type == IS_CV || opline->result_type != IS_UNUSED) {
          if (OP2_INFO() & MAY_BE_OBJECT) {
            /* object aliasing */
            return true;
          }
        }
        break;
      default:
        return true;
    }
  }

  if (ssa_op->result_use == var) {
    switch (opline->opcode) {
      case ZEND_ASSIGN:
      case ZEND_QM_ASSIGN:
      case ZEND_INIT_ARRAY:
      case ZEND_ADD_ARRAY_ELEMENT:
        break;
      default:
        return true;
    }
  }

  return false;
}
/* }}} */

zend_result zend_ssa_escape_analysis(const zend_script *script, zend_op_array *op_array, zend_ssa *ssa) /* {{{ */
{
  zend_ssa_var *ssa_vars = ssa->vars;
  int ssa_vars_count = ssa->vars_count;
  int i, root, use;
  int *ees;
  bool has_allocations;
  int num_non_escaped;
  ALLOCA_FLAG(use_heap)

  if (!ssa_vars) {
    return SUCCESS;
  }

  has_allocations = false;
  for (i = op_array->last_var; i < ssa_vars_count; i++) {
    if (ssa_vars[i].definition >= 0
      && (ssa->var_info[i].type & (MAY_BE_ARRAY|MAY_BE_OBJECT))
      && is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
      has_allocations = true;
      break;
    }
  }
  if (!has_allocations) {
    return SUCCESS;
  }


  /* 1. Build EES (Equi-Escape Sets) */
  ees = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
  if (!ees) {
    return FAILURE;
  }

  if (zend_build_equi_escape_sets(ees, op_array, ssa) == FAILURE) {
    free_alloca(ees, use_heap);
    return FAILURE;
  }

  /* 2. Identify Allocations */
  num_non_escaped = 0;
  for (i = op_array->last_var; i < ssa_vars_count; i++) {
    root = ees[i];
    if (ssa_vars[root].escape_state > ESCAPE_STATE_NO_ESCAPE) {
      /* already escape. skip */
    } else if (ssa_vars[i].alias && (ssa->var_info[i].type & MAY_BE_REF)) {
      if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
        num_non_escaped--;
      }
      ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
    } else if (ssa_vars[i].definition >= 0
       && (ssa->var_info[i].type & (MAY_BE_ARRAY|MAY_BE_OBJECT))) {
      if (!is_local_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
        if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
          num_non_escaped--;
        }
        ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
      } else if (ssa_vars[root].escape_state == ESCAPE_STATE_UNKNOWN
       && is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
        ssa_vars[root].escape_state = ESCAPE_STATE_NO_ESCAPE;
        num_non_escaped++;
      }
    }
  }

  /* 3. Mark escaped EES */
  if (num_non_escaped) {
    for (i = 0; i < ssa_vars_count; i++) {
      if (ssa_vars[i].use_chain >= 0) {
        root = ees[i];
        if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
          FOREACH_USE(ssa_vars + i, use) {
            if (is_escape_use(op_array, ssa, use, i)) {
              ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
              num_non_escaped--;
              if (num_non_escaped == 0) {
                i = ssa_vars_count;
              }
              break;
            }
          } FOREACH_USE_END();
        }
      }
    }
  }

  /* 4. Process referential dependencies */
  if (num_non_escaped) {
    bool changed;

    do {
      changed = false;
      for (i = 0; i < ssa_vars_count; i++) {
        if (ssa_vars[i].use_chain >= 0) {
          root = ees[i];
          if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
            FOREACH_USE(ssa_vars + i, use) {
              zend_ssa_op *op = ssa->ops + use;
              zend_op *opline = op_array->opcodes + use;
              int enclosing_root;

              if (opline->opcode == ZEND_OP_DATA &&
                  ((opline-1)->opcode == ZEND_ASSIGN_DIM ||
                   (opline-1)->opcode == ZEND_ASSIGN_OBJ ||
                   (opline-1)->opcode == ZEND_ASSIGN_OBJ_REF) &&
                  op->op1_use == i &&
                  (op-1)->op1_use >= 0) {
                enclosing_root = ees[(op-1)->op1_use];
              } else if ((opline->opcode == ZEND_INIT_ARRAY ||
                   opline->opcode == ZEND_ADD_ARRAY_ELEMENT) &&
                  op->op1_use == i &&
                  op->result_def >= 0) {
                enclosing_root = ees[op->result_def];
              } else {
                continue;
              }

              if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN ||
                  ssa_vars[enclosing_root].escape_state > ssa_vars[root].escape_state) {
                  if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN) {
                  ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
                  } else {
                  ssa_vars[root].escape_state = ssa_vars[enclosing_root].escape_state;
                }
                if (ssa_vars[root].escape_state == ESCAPE_STATE_GLOBAL_ESCAPE) {
                  num_non_escaped--;
                  if (num_non_escaped == 0) {
                    changed = false;
                  } else {
                    changed = true;
                  }
                  break;
                } else {
                  changed = true;
                }
              }
            } FOREACH_USE_END();
          }
        }
      }
    } while (changed);
  }

  /* 5. Propagate values of escape sets to variables */
  for (i = 0; i < ssa_vars_count; i++) {
    root = ees[i];
    if (i != root) {
      ssa_vars[i].escape_state = ssa_vars[root].escape_state;
    }
  }

  free_alloca(ees, use_heap);

  return SUCCESS;
}
/* }}} */

Coverage Report

Created: 2026-06-02 06:40

Line	Count	Source
1		/*
2		+----------------------------------------------------------------------+
3		\| Zend OPcache, Escape Analysis \|
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 "Optimizer/zend_optimizer.h"
18		#include "Optimizer/zend_optimizer_internal.h"
19		#include "zend_bitset.h"
20		#include "zend_cfg.h"
21		#include "zend_ssa.h"
22		#include "zend_inference.h"
23		#include "zend_dump.h"
24
25		/*
26		* T. Kotzmann and H. Mossenbock. Escape analysis in the context of dynamic
27		* compilation and deoptimization. In Proceedings of the International
28		* Conference on Virtual Execution Environments, pages 111-120, Chicago,
29		* June 2005
30		*/
31
32		static zend_always_inline void union_find_init(int parent, int size, int count) /* {{{ */
33	11.1k	{
34	11.1k	int i;
35
36	430k	for (i = 0; i < count; i++) {
37	418k	parent[i] = i;
38	418k	size[i] = 1;
39	418k	}
40	11.1k	}
41		/* }}} */
42
43		static zend_always_inline int union_find_root(int parent, int i) / {{{ */
44	856k	{
45	856k	int p = parent[i];
46
47	1.18M	while (i != p) {
48	327k	p = parent[p];
49	327k	parent[i] = p;
50	327k	i = p;
51	327k	p = parent[i];
52	327k	}
53	856k	return i;
54	856k	}
55		/* }}} */
56
57		static zend_always_inline void union_find_unite(int parent, int size, int i, int j) /* {{{ */
58	218k	{
59	218k	int r1 = union_find_root(parent, i);
60	218k	int r2 = union_find_root(parent, j);
61
62	218k	if (r1 != r2) {
63	159k	if (size[r1] < size[r2]) {
64	75.3k	parent[r1] = r2;
65	75.3k	size[r2] += size[r1];
66	84.6k	} else {
67	84.6k	parent[r2] = r1;
68	84.6k	size[r1] += size[r2];
69	84.6k	}
70	159k	}
71	218k	}
72		/* }}} */
73
74		static zend_result zend_build_equi_escape_sets(int parent, zend_op_array op_array, zend_ssa ssa) / {{{ */
75	11.1k	{
76	11.1k	zend_ssa_var *ssa_vars = ssa->vars;
77	11.1k	int ssa_vars_count = ssa->vars_count;
78	11.1k	zend_ssa_phi *p;
79	11.1k	int i;
80	11.1k	int *size;
81	11.1k	ALLOCA_FLAG(use_heap)
82
83	11.1k	size = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
84	11.1k	if (!size) {
85	0	return FAILURE;
86	0	}
87	11.1k	union_find_init(parent, size, ssa_vars_count);
88
89	430k	for (i = 0; i < ssa_vars_count; i++) {
90	418k	if (ssa_vars[i].definition_phi) {
91	64.6k	p = ssa_vars[i].definition_phi;
92	64.6k	if (p->pi >= 0) {
93	17.9k	union_find_unite(parent, size, i, p->sources[0]);
94	46.6k	} else {
95	143k	for (uint32_t j = 0; j < ssa->cfg.blocks[p->block].predecessors_count; j++) {
96	96.8k	union_find_unite(parent, size, i, p->sources[j]);
97	96.8k	}
98	46.6k	}
99	354k	} else if (ssa_vars[i].definition >= 0) {
100	318k	int def = ssa_vars[i].definition;
101	318k	zend_ssa_op *op = ssa->ops + def;
102	318k	zend_op *opline = op_array->opcodes + def;
103
104	318k	if (op->op1_def >= 0) {
105	72.9k	if (op->op1_use >= 0) {
106	72.9k	if (opline->opcode != ZEND_ASSIGN) {
107	36.8k	union_find_unite(parent, size, op->op1_def, op->op1_use);
108	36.8k	}
109	72.9k	}
110	72.9k	if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
111	25.7k	union_find_unite(parent, size, op->op1_def, op->op2_use);
112	25.7k	}
113	72.9k	}
114	318k	if (op->op2_def >= 0) {
115	5.32k	if (op->op2_use >= 0) {
116	5.00k	union_find_unite(parent, size, op->op2_def, op->op2_use);
117	5.00k	}
118	5.32k	}
119	318k	if (op->result_def >= 0) {
120	271k	if (op->result_use >= 0) {
121	15.4k	if (opline->opcode != ZEND_QM_ASSIGN) {
122	15.4k	union_find_unite(parent, size, op->result_def, op->result_use);
123	15.4k	}
124	15.4k	}
125	271k	if (opline->opcode == ZEND_QM_ASSIGN && op->op1_use >= 0) {
126	1.41k	union_find_unite(parent, size, op->result_def, op->op1_use);
127	1.41k	}
128	271k	if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
129	9.11k	union_find_unite(parent, size, op->result_def, op->op2_use);
130	9.11k	}
131	271k	if (opline->opcode == ZEND_ASSIGN && op->op1_def >= 0) {
132	10.3k	union_find_unite(parent, size, op->result_def, op->op1_def);
133	10.3k	}
134	271k	}
135	318k	}
136	418k	}
137
138	430k	for (i = 0; i < ssa_vars_count; i++) {
139	418k	parent[i] = union_find_root(parent, i);
140	418k	}
141
142	11.1k	free_alloca(size, use_heap);
143
144	11.1k	return SUCCESS;
145	11.1k	}
146		/* }}} */
147
148		static bool is_allocation_def(zend_op_array op_array, zend_ssa ssa, int def, int var, const zend_script script) / {{{ */
149	250k	{
150	250k	zend_ssa_op *ssa_op = ssa->ops + def;
151	250k	zend_op *opline = op_array->opcodes + def;
152
153	250k	if (ssa_op->result_def == var) {
154	186k	switch (opline->opcode) {
155	5.53k	case ZEND_INIT_ARRAY:
156	5.53k	return true;
157	23.7k	case ZEND_NEW: {
158		/* objects with destructors should escape */
159	23.7k	zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
160	23.7k	script, op_array, opline);
161	23.7k	uint32_t forbidden_flags =
162		/* These flags will always cause an exception */
163	23.7k	ZEND_ACC_IMPLICIT_ABSTRACT_CLASS \| ZEND_ACC_EXPLICIT_ABSTRACT_CLASS
164	23.7k	\| ZEND_ACC_INTERFACE \| ZEND_ACC_TRAIT;
165	23.7k	if (ce
166	20.9k	&& !ce->parent
167	19.1k	&& !ce->create_object
168	14.6k	&& ce->default_object_handlers->get_constructor == zend_std_get_constructor
169	14.6k	&& ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
170	14.6k	&& !ce->constructor
171	12.7k	&& !ce->destructor
172	11.4k	&& !ce->__get
173	10.9k	&& !ce->__set
174	10.8k	&& !(ce->ce_flags & forbidden_flags)
175	10.8k	&& (ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
176	10.8k	return true;
177	10.8k	}
178	12.9k	break;
179	23.7k	}
180	12.9k	case ZEND_QM_ASSIGN:
181	1.02k	if (opline->op1_type == IS_CONST
182	22	&& Z_TYPE_P(CRT_CONSTANT(opline->op1)) == IS_ARRAY) {
183	22	return true;
184	22	}
185	1.00k	if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
186	271	return true;
187	271	}
188	731	break;
189	731	case ZEND_ASSIGN:
190	573	if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
191	223	return true;
192	223	}
193	350	break;
194	186k	}
195	186k	} else if (ssa_op->op1_def == var) {
196	61.3k	switch (opline->opcode) {
197	36.6k	case ZEND_ASSIGN:
198	36.6k	if (opline->op2_type == IS_CONST
199	16.7k	&& Z_TYPE_P(CRT_CONSTANT(opline->op2)) == IS_ARRAY) {
200	6.67k	return true;
201	6.67k	}
202	29.9k	if (opline->op2_type == IS_CV && (OP2_INFO() & MAY_BE_ARRAY)) {
203	682	return true;
204	682	}
205	29.3k	break;
206	29.3k	case ZEND_ASSIGN_DIM:
207	2.68k	if (OP1_INFO() & (MAY_BE_UNDEF \| MAY_BE_NULL \| MAY_BE_FALSE)) {
208		/* implicit object/array allocation */
209	2.61k	return true;
210	2.61k	}
211	72	break;
212	61.3k	}
213	61.3k	}
214
215	223k	return false;
216	250k	}
217		/* }}} */
218
219		static bool is_local_def(zend_op_array op_array, zend_ssa ssa, int def, int var, const zend_script script) / {{{ */
220	118k	{
221	118k	zend_ssa_op *op = ssa->ops + def;
222	118k	zend_op *opline = op_array->opcodes + def;
223
224	118k	if (op->result_def == var) {
225	88.7k	switch (opline->opcode) {
226	3.59k	case ZEND_INIT_ARRAY:
227	18.7k	case ZEND_ADD_ARRAY_ELEMENT:
228	19.0k	case ZEND_QM_ASSIGN:
229	19.6k	case ZEND_ASSIGN:
230	19.6k	return true;
231	9.90k	case ZEND_NEW: {
232		/* objects with destructors should escape */
233	9.90k	zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
234	9.90k	script, op_array, opline);
235	9.90k	if (ce
236	9.08k	&& !ce->create_object
237	7.58k	&& ce->default_object_handlers->get_constructor == zend_std_get_constructor
238	7.58k	&& ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
239	7.58k	&& !ce->constructor
240	7.08k	&& !ce->destructor
241	6.86k	&& !ce->__get
242	6.80k	&& !ce->__set
243	6.79k	&& !ce->parent) {
244	6.56k	return true;
245	6.56k	}
246	3.33k	break;
247	9.90k	}
248	88.7k	}
249	88.7k	} else if (op->op1_def == var) {
250	27.8k	switch (opline->opcode) {
251	13.9k	case ZEND_ASSIGN:
252	18.4k	case ZEND_ASSIGN_DIM:
253	20.4k	case ZEND_ASSIGN_OBJ:
254	20.4k	case ZEND_ASSIGN_OBJ_REF:
255	20.6k	case ZEND_ASSIGN_DIM_OP:
256	20.7k	case ZEND_ASSIGN_OBJ_OP:
257	20.8k	case ZEND_PRE_INC_OBJ:
258	20.9k	case ZEND_PRE_DEC_OBJ:
259	20.9k	case ZEND_POST_INC_OBJ:
260	20.9k	case ZEND_POST_DEC_OBJ:
261	20.9k	return true;
262	27.8k	}
263	27.8k	}
264
265	71.7k	return false;
266	118k	}
267		/* }}} */
268
269		static bool is_escape_use(zend_op_array op_array, zend_ssa ssa, int use, int var) /* {{{ */
270	23.5k	{
271	23.5k	zend_ssa_op *ssa_op = ssa->ops + use;
272	23.5k	zend_op *opline = op_array->opcodes + use;
273
274	23.5k	if (ssa_op->op1_use == var) {
275	13.6k	switch (opline->opcode) {
276	665	case ZEND_ASSIGN:
277		/* no_val */
278	665	break;
279	189	case ZEND_QM_ASSIGN:
280	189	if (opline->op1_type == IS_CV) {
281	189	if (OP1_INFO() & MAY_BE_OBJECT) {
282		/* object aliasing */
283	177	return true;
284	177	}
285	189	}
286	12	break;
287	85	case ZEND_ISSET_ISEMPTY_DIM_OBJ:
288	109	case ZEND_ISSET_ISEMPTY_PROP_OBJ:
289	1.44k	case ZEND_FETCH_DIM_R:
290	1.58k	case ZEND_FETCH_OBJ_R:
291	2.05k	case ZEND_FETCH_DIM_IS:
292	2.06k	case ZEND_FETCH_OBJ_IS:
293	2.06k	break;
294	0	case ZEND_ASSIGN_OP:
295	0	return true;
296	56	case ZEND_ASSIGN_DIM_OP:
297	108	case ZEND_ASSIGN_OBJ_OP:
298	108	case ZEND_ASSIGN_STATIC_PROP_OP:
299	3.98k	case ZEND_ASSIGN_DIM:
300	4.49k	case ZEND_ASSIGN_OBJ:
301	4.52k	case ZEND_ASSIGN_OBJ_REF:
302	4.52k	break;
303	4	case ZEND_PRE_INC_OBJ:
304	12	case ZEND_PRE_DEC_OBJ:
305	14	case ZEND_POST_INC_OBJ:
306	14	case ZEND_POST_DEC_OBJ:
307	14	break;
308	358	case ZEND_INIT_ARRAY:
309	913	case ZEND_ADD_ARRAY_ELEMENT:
310	913	if (opline->extended_value & ZEND_ARRAY_ELEMENT_REF) {
311	0	return true;
312	0	}
313	913	if (OP1_INFO() & MAY_BE_OBJECT) {
314		/* object aliasing */
315	537	return true;
316	537	}
317		/* reference dependencies processed separately */
318	376	break;
319	784	case ZEND_OP_DATA:
320	784	if ((opline-1)->opcode != ZEND_ASSIGN_DIM
321	601	&& (opline-1)->opcode != ZEND_ASSIGN_OBJ) {
322	84	return true;
323	84	}
324	700	if (OP1_INFO() & MAY_BE_OBJECT) {
325		/* object aliasing */
326	583	return true;
327	583	}
328	117	opline--;
329	117	ssa_op--;
330	117	if (opline->op1_type != IS_CV
331	89	\|\| (OP1_INFO() & MAY_BE_REF)
332	91	\|\| (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
333		/* assignment into escaping structure */
334	91	return true;
335	91	}
336		/* reference dependencies processed separately */
337	26	break;
338	4.51k	default:
339	4.51k	return true;
340	13.6k	}
341	13.6k	}
342
343	17.5k	if (ssa_op->op2_use == var) {
344	4.75k	switch (opline->opcode) {
345	4.21k	case ZEND_ASSIGN:
346	4.21k	if (opline->op1_type != IS_CV
347	4.17k	\|\| (OP1_INFO() & MAY_BE_REF)
348	3.22k	\|\| (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
349		/* assignment into escaping variable */
350	3.22k	return true;
351	3.22k	}
352	983	if (opline->op2_type == IS_CV \|\| opline->result_type != IS_UNUSED) {
353	132	if (OP2_INFO() & MAY_BE_OBJECT) {
354		/* object aliasing */
355	94	return true;
356	94	}
357	132	}
358	889	break;
359	889	default:
360	542	return true;
361	4.75k	}
362	4.75k	}
363
364	13.6k	if (ssa_op->result_use == var) {
365	5.12k	switch (opline->opcode) {
366	0	case ZEND_ASSIGN:
367	0	case ZEND_QM_ASSIGN:
368	0	case ZEND_INIT_ARRAY:
369	5.12k	case ZEND_ADD_ARRAY_ELEMENT:
370	5.12k	break;
371	0	default:
372	0	return true;
373	5.12k	}
374	5.12k	}
375
376	13.6k	return false;
377	13.6k	}
378		/* }}} */
379
380		zend_result zend_ssa_escape_analysis(const zend_script script, zend_op_array op_array, zend_ssa ssa) / {{{ */
381	71.2k	{
382	71.2k	zend_ssa_var *ssa_vars = ssa->vars;
383	71.2k	int ssa_vars_count = ssa->vars_count;
384	71.2k	int i, root, use;
385	71.2k	int *ees;
386	71.2k	bool has_allocations;
387	71.2k	int num_non_escaped;
388	71.2k	ALLOCA_FLAG(use_heap)
389
390	71.2k	if (!ssa_vars) {
391	0	return SUCCESS;
392	0	}
393
394	71.2k	has_allocations = false;
395	811k	for (i = op_array->last_var; i < ssa_vars_count; i++) {
396	751k	if (ssa_vars[i].definition >= 0
397	649k	&& (ssa->var_info[i].type & (MAY_BE_ARRAY\|MAY_BE_OBJECT))
398	229k	&& is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
399	11.1k	has_allocations = true;
400	11.1k	break;
401	11.1k	}
402	751k	}
403	71.2k	if (!has_allocations) {
404	60.1k	return SUCCESS;
405	60.1k	}
406
407
408		/* 1. Build EES (Equi-Escape Sets) */
409	11.1k	ees = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
410	11.1k	if (!ees) {
411	0	return FAILURE;
412	0	}
413
414	11.1k	if (zend_build_equi_escape_sets(ees, op_array, ssa) == FAILURE) {
415	0	free_alloca(ees, use_heap);
416	0	return FAILURE;
417	0	}
418
419		/* 2. Identify Allocations */
420	11.1k	num_non_escaped = 0;
421	394k	for (i = op_array->last_var; i < ssa_vars_count; i++) {
422	383k	root = ees[i];
423	383k	if (ssa_vars[root].escape_state > ESCAPE_STATE_NO_ESCAPE) {
424		/* already escape. skip */
425	337k	} else if (ssa_vars[i].alias && (ssa->var_info[i].type & MAY_BE_REF)) {
426	0	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
427	0	num_non_escaped--;
428	0	}
429	0	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
430	337k	} else if (ssa_vars[i].definition >= 0
431	290k	&& (ssa->var_info[i].type & (MAY_BE_ARRAY\|MAY_BE_OBJECT))) {
432	118k	if (!is_local_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
433	71.7k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
434	3.28k	num_non_escaped--;
435	3.28k	}
436	71.7k	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
437	71.7k	} else if (ssa_vars[root].escape_state == ESCAPE_STATE_UNKNOWN
438	20.1k	&& is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
439	15.7k	ssa_vars[root].escape_state = ESCAPE_STATE_NO_ESCAPE;
440	15.7k	num_non_escaped++;
441	15.7k	}
442	118k	}
443	383k	}
444
445		/* 3. Mark escaped EES */
446	11.1k	if (num_non_escaped) {
447	250k	for (i = 0; i < ssa_vars_count; i++) {
448	242k	if (ssa_vars[i].use_chain >= 0) {
449	198k	root = ees[i];
450	198k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
451	45.1k	FOREACH_USE(ssa_vars + i, use) {
452	45.1k	if (is_escape_use(op_array, ssa, use, i)) {
453	9.85k	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
454	9.85k	num_non_escaped--;
455	9.85k	if (num_non_escaped == 0) {
456	6.33k	i = ssa_vars_count;
457	6.33k	}
458	9.85k	break;
459	9.85k	}
460	45.1k	} FOREACH_USE_END();
461	21.6k	}
462	198k	}
463	242k	}
464	8.19k	}
465
466		/* 4. Process referential dependencies */
467	11.1k	if (num_non_escaped) {
468	1.85k	bool changed;
469
470	1.88k	do {
471	1.88k	changed = false;
472	89.7k	for (i = 0; i < ssa_vars_count; i++) {
473	87.8k	if (ssa_vars[i].use_chain >= 0) {
474	69.6k	root = ees[i];
475	69.6k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
476	13.9k	FOREACH_USE(ssa_vars + i, use) {
477	13.9k	zend_ssa_op *op = ssa->ops + use;
478	13.9k	zend_op *opline = op_array->opcodes + use;
479	13.9k	int enclosing_root;
480
481	13.9k	if (opline->opcode == ZEND_OP_DATA &&
482	22	((opline-1)->opcode == ZEND_ASSIGN_DIM \|\|
483	14	(opline-1)->opcode == ZEND_ASSIGN_OBJ \|\|
484	0	(opline-1)->opcode == ZEND_ASSIGN_OBJ_REF) &&
485	22	op->op1_use == i &&
486	22	(op-1)->op1_use >= 0) {
487	22	enclosing_root = ees[(op-1)->op1_use];
488	7.68k	} else if ((opline->opcode == ZEND_INIT_ARRAY \|\|
489	7.59k	opline->opcode == ZEND_ADD_ARRAY_ELEMENT) &&
490	1.73k	op->op1_use == i &&
491	662	op->result_def >= 0) {
492	662	enclosing_root = ees[op->result_def];
493	7.02k	} else {
494	7.02k	continue;
495	7.02k	}
496
497	684	if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN \|\|
498	682	ssa_vars[enclosing_root].escape_state > ssa_vars[root].escape_state) {
499	374	if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN) {
500	2	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
501	372	} else {
502	372	ssa_vars[root].escape_state = ssa_vars[enclosing_root].escape_state;
503	372	}
504	374	if (ssa_vars[root].escape_state == ESCAPE_STATE_GLOBAL_ESCAPE) {
505	374	num_non_escaped--;
506	374	if (num_non_escaped == 0) {
507	136	changed = false;
508	238	} else {
509	238	changed = true;
510	238	}
511	374	break;
512	374	} else {
513	0	changed = true;
514	0	}
515	374	}
516	684	} FOREACH_USE_END();
517	6.27k	}
518	69.6k	}
519	87.8k	}
520	1.88k	} while (changed);
521	1.85k	}
522
523		/* 5. Propagate values of escape sets to variables */
524	430k	for (i = 0; i < ssa_vars_count; i++) {
525	418k	root = ees[i];
526	418k	if (i != root) {
527	159k	ssa_vars[i].escape_state = ssa_vars[root].escape_state;
528	159k	}
529	418k	}
530
531	11.1k	free_alloca(ees, use_heap);
532
533	11.1k	return SUCCESS;
534	11.1k	}
535		/* }}} */