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

Source
/*
   +----------------------------------------------------------------------+
   | Zend OPcache, Escape Analysis                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | https://www.php.net/license/3_01.txt                                 |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | 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, j;
  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 (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: 2026-02-09 07:07

Line	Count	Source
1		/*
2		+----------------------------------------------------------------------+
3		\| Zend OPcache, Escape Analysis \|
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 "Optimizer/zend_optimizer.h"
20		#include "Optimizer/zend_optimizer_internal.h"
21		#include "zend_bitset.h"
22		#include "zend_cfg.h"
23		#include "zend_ssa.h"
24		#include "zend_inference.h"
25		#include "zend_dump.h"
26
27		/*
28		* T. Kotzmann and H. Mossenbock. Escape analysis in the context of dynamic
29		* compilation and deoptimization. In Proceedings of the International
30		* Conference on Virtual Execution Environments, pages 111-120, Chicago,
31		* June 2005
32		*/
33
34		static zend_always_inline void union_find_init(int parent, int size, int count) /* {{{ */
35	9.57k	{
36	9.57k	int i;
37
38	394k	for (i = 0; i < count; i++) {
39	384k	parent[i] = i;
40	384k	size[i] = 1;
41	384k	}
42	9.57k	}
43		/* }}} */
44
45		static zend_always_inline int union_find_root(int parent, int i) / {{{ */
46	776k	{
47	776k	int p = parent[i];
48
49	1.07M	while (i != p) {
50	295k	p = parent[p];
51	295k	parent[i] = p;
52	295k	i = p;
53	295k	p = parent[i];
54	295k	}
55	776k	return i;
56	776k	}
57		/* }}} */
58
59		static zend_always_inline void union_find_unite(int parent, int size, int i, int j) /* {{{ */
60	195k	{
61	195k	int r1 = union_find_root(parent, i);
62	195k	int r2 = union_find_root(parent, j);
63
64	195k	if (r1 != r2) {
65	146k	if (size[r1] < size[r2]) {
66	70.5k	parent[r1] = r2;
67	70.5k	size[r2] += size[r1];
68	75.7k	} else {
69	75.7k	parent[r2] = r1;
70	75.7k	size[r1] += size[r2];
71	75.7k	}
72	146k	}
73	195k	}
74		/* }}} */
75
76		static zend_result zend_build_equi_escape_sets(int parent, zend_op_array op_array, zend_ssa ssa) / {{{ */
77	9.57k	{
78	9.57k	zend_ssa_var *ssa_vars = ssa->vars;
79	9.57k	int ssa_vars_count = ssa->vars_count;
80	9.57k	zend_ssa_phi *p;
81	9.57k	int i, j;
82	9.57k	int *size;
83	9.57k	ALLOCA_FLAG(use_heap)
84
85	9.57k	size = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
86	9.57k	if (!size) {
87	0	return FAILURE;
88	0	}
89	9.57k	union_find_init(parent, size, ssa_vars_count);
90
91	394k	for (i = 0; i < ssa_vars_count; i++) {
92	384k	if (ssa_vars[i].definition_phi) {
93	62.0k	p = ssa_vars[i].definition_phi;
94	62.0k	if (p->pi >= 0) {
95	17.7k	union_find_unite(parent, size, i, p->sources[0]);
96	44.2k	} else {
97	135k	for (j = 0; j < ssa->cfg.blocks[p->block].predecessors_count; j++) {
98	91.3k	union_find_unite(parent, size, i, p->sources[j]);
99	91.3k	}
100	44.2k	}
101	322k	} else if (ssa_vars[i].definition >= 0) {
102	293k	int def = ssa_vars[i].definition;
103	293k	zend_ssa_op *op = ssa->ops + def;
104	293k	zend_op *opline = op_array->opcodes + def;
105
106	293k	if (op->op1_def >= 0) {
107	59.1k	if (op->op1_use >= 0) {
108	59.1k	if (opline->opcode != ZEND_ASSIGN) {
109	29.4k	union_find_unite(parent, size, op->op1_def, op->op1_use);
110	29.4k	}
111	59.1k	}
112	59.1k	if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
113	20.7k	union_find_unite(parent, size, op->op1_def, op->op2_use);
114	20.7k	}
115	59.1k	}
116	293k	if (op->op2_def >= 0) {
117	4.66k	if (op->op2_use >= 0) {
118	4.40k	union_find_unite(parent, size, op->op2_def, op->op2_use);
119	4.40k	}
120	4.66k	}
121	293k	if (op->result_def >= 0) {
122	253k	if (op->result_use >= 0) {
123	16.0k	if (opline->opcode != ZEND_QM_ASSIGN) {
124	16.0k	union_find_unite(parent, size, op->result_def, op->result_use);
125	16.0k	}
126	16.0k	}
127	253k	if (opline->opcode == ZEND_QM_ASSIGN && op->op1_use >= 0) {
128	1.17k	union_find_unite(parent, size, op->result_def, op->op1_use);
129	1.17k	}
130	253k	if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
131	6.75k	union_find_unite(parent, size, op->result_def, op->op2_use);
132	6.75k	}
133	253k	if (opline->opcode == ZEND_ASSIGN && op->op1_def >= 0) {
134	7.79k	union_find_unite(parent, size, op->result_def, op->op1_def);
135	7.79k	}
136	253k	}
137	293k	}
138	384k	}
139
140	394k	for (i = 0; i < ssa_vars_count; i++) {
141	384k	parent[i] = union_find_root(parent, i);
142	384k	}
143
144	9.57k	free_alloca(size, use_heap);
145
146	9.57k	return SUCCESS;
147	9.57k	}
148		/* }}} */
149
150		static bool is_allocation_def(zend_op_array op_array, zend_ssa ssa, int def, int var, const zend_script script) / {{{ */
151	231k	{
152	231k	zend_ssa_op *ssa_op = ssa->ops + def;
153	231k	zend_op *opline = op_array->opcodes + def;
154
155	231k	if (ssa_op->result_def == var) {
156	175k	switch (opline->opcode) {
157	4.82k	case ZEND_INIT_ARRAY:
158	4.82k	return true;
159	21.9k	case ZEND_NEW: {
160		/* objects with destructors should escape */
161	21.9k	zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
162	21.9k	script, op_array, opline);
163	21.9k	uint32_t forbidden_flags =
164		/* These flags will always cause an exception */
165	21.9k	ZEND_ACC_IMPLICIT_ABSTRACT_CLASS \| ZEND_ACC_EXPLICIT_ABSTRACT_CLASS
166	21.9k	\| ZEND_ACC_INTERFACE \| ZEND_ACC_TRAIT;
167	21.9k	if (ce
168	19.2k	&& !ce->parent
169	17.5k	&& !ce->create_object
170	12.9k	&& ce->default_object_handlers->get_constructor == zend_std_get_constructor
171	12.9k	&& ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
172	12.9k	&& !ce->constructor
173	11.0k	&& !ce->destructor
174	9.65k	&& !ce->__get
175	9.33k	&& !ce->__set
176	9.27k	&& !(ce->ce_flags & forbidden_flags)
177	9.26k	&& (ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
178	9.20k	return true;
179	9.20k	}
180	12.7k	break;
181	21.9k	}
182	12.7k	case ZEND_QM_ASSIGN:
183	808	if (opline->op1_type == IS_CONST
184	22	&& Z_TYPE_P(CRT_CONSTANT(opline->op1)) == IS_ARRAY) {
185	22	return true;
186	22	}
187	786	if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
188	198	return true;
189	198	}
190	588	break;
191	588	case ZEND_ASSIGN:
192	320	if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
193	184	return true;
194	184	}
195	136	break;
196	175k	}
197	175k	} else if (ssa_op->op1_def == var) {
198	54.3k	switch (opline->opcode) {
199	33.2k	case ZEND_ASSIGN:
200	33.2k	if (opline->op2_type == IS_CONST
201	15.1k	&& Z_TYPE_P(CRT_CONSTANT(opline->op2)) == IS_ARRAY) {
202	5.73k	return true;
203	5.73k	}
204	27.4k	if (opline->op2_type == IS_CV && (OP2_INFO() & MAY_BE_ARRAY)) {
205	490	return true;
206	490	}
207	26.9k	break;
208	26.9k	case ZEND_ASSIGN_DIM:
209	2.18k	if (OP1_INFO() & (MAY_BE_UNDEF \| MAY_BE_NULL \| MAY_BE_FALSE)) {
210		/* implicit object/array allocation */
211	2.11k	return true;
212	2.11k	}
213	72	break;
214	54.3k	}
215	54.3k	}
216
217	209k	return false;
218	231k	}
219		/* }}} */
220
221		static bool is_local_def(zend_op_array op_array, zend_ssa ssa, int def, int var, const zend_script script) / {{{ */
222	104k	{
223	104k	zend_ssa_op *op = ssa->ops + def;
224	104k	zend_op *opline = op_array->opcodes + def;
225
226	104k	if (op->result_def == var) {
227	79.3k	switch (opline->opcode) {
228	3.12k	case ZEND_INIT_ARRAY:
229	18.9k	case ZEND_ADD_ARRAY_ELEMENT:
230	19.2k	case ZEND_QM_ASSIGN:
231	19.5k	case ZEND_ASSIGN:
232	19.5k	return true;
233	8.52k	case ZEND_NEW: {
234		/* objects with destructors should escape */
235	8.52k	zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
236	8.52k	script, op_array, opline);
237	8.52k	if (ce
238	7.75k	&& !ce->create_object
239	6.44k	&& ce->default_object_handlers->get_constructor == zend_std_get_constructor
240	6.44k	&& ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
241	6.44k	&& !ce->constructor
242	5.97k	&& !ce->destructor
243	5.75k	&& !ce->__get
244	5.72k	&& !ce->__set
245	5.71k	&& !ce->parent) {
246	5.51k	return true;
247	5.51k	}
248	3.00k	break;
249	8.52k	}
250	79.3k	}
251	79.3k	} else if (op->op1_def == var) {
252	22.9k	switch (opline->opcode) {
253	11.9k	case ZEND_ASSIGN:
254	15.0k	case ZEND_ASSIGN_DIM:
255	16.7k	case ZEND_ASSIGN_OBJ:
256	16.7k	case ZEND_ASSIGN_OBJ_REF:
257	16.8k	case ZEND_ASSIGN_DIM_OP:
258	16.9k	case ZEND_ASSIGN_OBJ_OP:
259	16.9k	case ZEND_PRE_INC_OBJ:
260	17.0k	case ZEND_PRE_DEC_OBJ:
261	17.0k	case ZEND_POST_INC_OBJ:
262	17.0k	case ZEND_POST_DEC_OBJ:
263	17.0k	return true;
264	22.9k	}
265	22.9k	}
266
267	62.1k	return false;
268	104k	}
269		/* }}} */
270
271		static bool is_escape_use(zend_op_array op_array, zend_ssa ssa, int use, int var) /* {{{ */
272	19.3k	{
273	19.3k	zend_ssa_op *ssa_op = ssa->ops + use;
274	19.3k	zend_op *opline = op_array->opcodes + use;
275
276	19.3k	if (ssa_op->op1_use == var) {
277	10.7k	switch (opline->opcode) {
278	553	case ZEND_ASSIGN:
279		/* no_val */
280	553	break;
281	146	case ZEND_QM_ASSIGN:
282	146	if (opline->op1_type == IS_CV) {
283	146	if (OP1_INFO() & MAY_BE_OBJECT) {
284		/* object aliasing */
285	136	return true;
286	136	}
287	146	}
288	10	break;
289	56	case ZEND_ISSET_ISEMPTY_DIM_OBJ:
290	72	case ZEND_ISSET_ISEMPTY_PROP_OBJ:
291	1.22k	case ZEND_FETCH_DIM_R:
292	1.36k	case ZEND_FETCH_OBJ_R:
293	1.78k	case ZEND_FETCH_DIM_IS:
294	1.79k	case ZEND_FETCH_OBJ_IS:
295	1.79k	break;
296	0	case ZEND_ASSIGN_OP:
297	0	return true;
298	47	case ZEND_ASSIGN_DIM_OP:
299	99	case ZEND_ASSIGN_OBJ_OP:
300	99	case ZEND_ASSIGN_STATIC_PROP_OP:
301	2.72k	case ZEND_ASSIGN_DIM:
302	3.10k	case ZEND_ASSIGN_OBJ:
303	3.11k	case ZEND_ASSIGN_OBJ_REF:
304	3.11k	break;
305	0	case ZEND_PRE_INC_OBJ:
306	8	case ZEND_PRE_DEC_OBJ:
307	8	case ZEND_POST_INC_OBJ:
308	8	case ZEND_POST_DEC_OBJ:
309	8	break;
310	316	case ZEND_INIT_ARRAY:
311	839	case ZEND_ADD_ARRAY_ELEMENT:
312	839	if (opline->extended_value & ZEND_ARRAY_ELEMENT_REF) {
313	0	return true;
314	0	}
315	839	if (OP1_INFO() & MAY_BE_OBJECT) {
316		/* object aliasing */
317	487	return true;
318	487	}
319		/* reference dependencies processed separately */
320	352	break;
321	643	case ZEND_OP_DATA:
322	643	if ((opline-1)->opcode != ZEND_ASSIGN_DIM
323	475	&& (opline-1)->opcode != ZEND_ASSIGN_OBJ) {
324	93	return true;
325	93	}
326	550	if (OP1_INFO() & MAY_BE_OBJECT) {
327		/* object aliasing */
328	439	return true;
329	439	}
330	111	opline--;
331	111	ssa_op--;
332	111	if (opline->op1_type != IS_CV
333	75	\|\| (OP1_INFO() & MAY_BE_REF)
334	99	\|\| (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
335		/* assignment into escaping structure */
336	99	return true;
337	99	}
338		/* reference dependencies processed separately */
339	12	break;
340	3.63k	default:
341	3.63k	return true;
342	10.7k	}
343	10.7k	}
344
345	14.4k	if (ssa_op->op2_use == var) {
346	4.09k	switch (opline->opcode) {
347	3.62k	case ZEND_ASSIGN:
348	3.62k	if (opline->op1_type != IS_CV
349	3.59k	\|\| (OP1_INFO() & MAY_BE_REF)
350	2.80k	\|\| (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
351		/* assignment into escaping variable */
352	2.80k	return true;
353	2.80k	}
354	827	if (opline->op2_type == IS_CV \|\| opline->result_type != IS_UNUSED) {
355	137	if (OP2_INFO() & MAY_BE_OBJECT) {
356		/* object aliasing */
357	61	return true;
358	61	}
359	137	}
360	766	break;
361	766	default:
362	470	return true;
363	4.09k	}
364	4.09k	}
365
366	11.1k	if (ssa_op->result_use == var) {
367	4.49k	switch (opline->opcode) {
368	0	case ZEND_ASSIGN:
369	0	case ZEND_QM_ASSIGN:
370	0	case ZEND_INIT_ARRAY:
371	4.49k	case ZEND_ADD_ARRAY_ELEMENT:
372	4.49k	break;
373	0	default:
374	0	return true;
375	4.49k	}
376	4.49k	}
377
378	11.1k	return false;
379	11.1k	}
380		/* }}} */
381
382		zend_result zend_ssa_escape_analysis(const zend_script script, zend_op_array op_array, zend_ssa ssa) / {{{ */
383	66.0k	{
384	66.0k	zend_ssa_var *ssa_vars = ssa->vars;
385	66.0k	int ssa_vars_count = ssa->vars_count;
386	66.0k	int i, root, use;
387	66.0k	int *ees;
388	66.0k	bool has_allocations;
389	66.0k	int num_non_escaped;
390	66.0k	ALLOCA_FLAG(use_heap)
391
392	66.0k	if (!ssa_vars) {
393	0	return SUCCESS;
394	0	}
395
396	66.0k	has_allocations = false;
397	808k	for (i = op_array->last_var; i < ssa_vars_count; i++) {
398	752k	if (ssa_vars[i].definition >= 0
399	642k	&& (ssa->var_info[i].type & (MAY_BE_ARRAY\|MAY_BE_OBJECT))
400	214k	&& is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
401	9.57k	has_allocations = true;
402	9.57k	break;
403	9.57k	}
404	752k	}
405	66.0k	if (!has_allocations) {
406	56.4k	return SUCCESS;
407	56.4k	}
408
409
410		/* 1. Build EES (Equi-Escape Sets) */
411	9.57k	ees = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
412	9.57k	if (!ees) {
413	0	return FAILURE;
414	0	}
415
416	9.57k	if (zend_build_equi_escape_sets(ees, op_array, ssa) == FAILURE) {
417	0	free_alloca(ees, use_heap);
418	0	return FAILURE;
419	0	}
420
421		/* 2. Identify Allocations */
422	9.57k	num_non_escaped = 0;
423	365k	for (i = op_array->last_var; i < ssa_vars_count; i++) {
424	355k	root = ees[i];
425	355k	if (ssa_vars[root].escape_state > ESCAPE_STATE_NO_ESCAPE) {
426		/* already escape. skip */
427	314k	} else if (ssa_vars[i].alias && (ssa->var_info[i].type & MAY_BE_REF)) {
428	0	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
429	0	num_non_escaped--;
430	0	}
431	0	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
432	314k	} else if (ssa_vars[i].definition >= 0
433	270k	&& (ssa->var_info[i].type & (MAY_BE_ARRAY\|MAY_BE_OBJECT))) {
434	104k	if (!is_local_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
435	62.1k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
436	2.91k	num_non_escaped--;
437	2.91k	}
438	62.1k	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
439	62.1k	} else if (ssa_vars[root].escape_state == ESCAPE_STATE_UNKNOWN
440	17.0k	&& is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
441	13.1k	ssa_vars[root].escape_state = ESCAPE_STATE_NO_ESCAPE;
442	13.1k	num_non_escaped++;
443	13.1k	}
444	104k	}
445	355k	}
446
447		/* 3. Mark escaped EES */
448	9.57k	if (num_non_escaped) {
449	232k	for (i = 0; i < ssa_vars_count; i++) {
450	226k	if (ssa_vars[i].use_chain >= 0) {
451	184k	root = ees[i];
452	184k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
453	36.9k	FOREACH_USE(ssa_vars + i, use) {
454	36.9k	if (is_escape_use(op_array, ssa, use, i)) {
455	8.21k	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
456	8.21k	num_non_escaped--;
457	8.21k	if (num_non_escaped == 0) {
458	5.47k	i = ssa_vars_count;
459	5.47k	}
460	8.21k	break;
461	8.21k	}
462	36.9k	} FOREACH_USE_END();
463	17.6k	}
464	184k	}
465	226k	}
466	6.93k	}
467
468		/* 4. Process referential dependencies */
469	9.57k	if (num_non_escaped) {
470	1.46k	bool changed;
471
472	1.47k	do {
473	1.47k	changed = false;
474	64.4k	for (i = 0; i < ssa_vars_count; i++) {
475	62.9k	if (ssa_vars[i].use_chain >= 0) {
476	49.2k	root = ees[i];
477	49.2k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
478	10.8k	FOREACH_USE(ssa_vars + i, use) {
479	10.8k	zend_ssa_op *op = ssa->ops + use;
480	10.8k	zend_op *opline = op_array->opcodes + use;
481	10.8k	int enclosing_root;
482
483	10.8k	if (opline->opcode == ZEND_OP_DATA &&
484	8	((opline-1)->opcode == ZEND_ASSIGN_DIM \|\|
485	2	(opline-1)->opcode == ZEND_ASSIGN_OBJ \|\|
486	0	(opline-1)->opcode == ZEND_ASSIGN_OBJ_REF) &&
487	8	op->op1_use == i &&
488	8	(op-1)->op1_use >= 0) {
489	8	enclosing_root = ees[(op-1)->op1_use];
490	6.03k	} else if ((opline->opcode == ZEND_INIT_ARRAY \|\|
491	5.95k	opline->opcode == ZEND_ADD_ARRAY_ELEMENT) &&
492	1.63k	op->op1_use == i &&
493	654	op->result_def >= 0) {
494	654	enclosing_root = ees[op->result_def];
495	5.38k	} else {
496	5.38k	continue;
497	5.38k	}
498
499	662	if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN \|\|
500	660	ssa_vars[enclosing_root].escape_state > ssa_vars[root].escape_state) {
501	338	if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN) {
502	2	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
503	336	} else {
504	336	ssa_vars[root].escape_state = ssa_vars[enclosing_root].escape_state;
505	336	}
506	338	if (ssa_vars[root].escape_state == ESCAPE_STATE_GLOBAL_ESCAPE) {
507	338	num_non_escaped--;
508	338	if (num_non_escaped == 0) {
509	98	changed = false;
510	240	} else {
511	240	changed = true;
512	240	}
513	338	break;
514	338	} else {
515	0	changed = true;
516	0	}
517	338	}
518	662	} FOREACH_USE_END();
519	4.78k	}
520	49.2k	}
521	62.9k	}
522	1.47k	} while (changed);
523	1.46k	}
524
525		/* 5. Propagate values of escape sets to variables */
526	394k	for (i = 0; i < ssa_vars_count; i++) {
527	384k	root = ees[i];
528	384k	if (i != root) {
529	146k	ssa_vars[i].escape_state = ssa_vars[root].escape_state;
530	146k	}
531	384k	}
532
533	9.57k	free_alloca(ees, use_heap);
534
535	9.57k	return SUCCESS;
536	9.57k	}
537		/* }}} */