/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	5.32k	{
34	5.32k	int i;
35
36	198k	for (i = 0; i < count; i++) {
37	193k	parent[i] = i;
38	193k	size[i] = 1;
39	193k	}
40	5.32k	}
41		/* }}} */
42
43		static zend_always_inline int union_find_root(int parent, int i) / {{{ */
44	398k	{
45	398k	int p = parent[i];
46
47	549k	while (i != p) {
48	151k	p = parent[p];
49	151k	parent[i] = p;
50	151k	i = p;
51	151k	p = parent[i];
52	151k	}
53	398k	return i;
54	398k	}
55		/* }}} */
56
57		static zend_always_inline void union_find_unite(int parent, int size, int i, int j) /* {{{ */
58	102k	{
59	102k	int r1 = union_find_root(parent, i);
60	102k	int r2 = union_find_root(parent, j);
61
62	102k	if (r1 != r2) {
63	74.1k	if (size[r1] < size[r2]) {
64	33.1k	parent[r1] = r2;
65	33.1k	size[r2] += size[r1];
66	41.0k	} else {
67	41.0k	parent[r2] = r1;
68	41.0k	size[r1] += size[r2];
69	41.0k	}
70	74.1k	}
71	102k	}
72		/* }}} */
73
74		static zend_result zend_build_equi_escape_sets(int parent, zend_op_array op_array, zend_ssa ssa) / {{{ */
75	5.32k	{
76	5.32k	zend_ssa_var *ssa_vars = ssa->vars;
77	5.32k	int ssa_vars_count = ssa->vars_count;
78	5.32k	zend_ssa_phi *p;
79	5.32k	int i;
80	5.32k	int *size;
81	5.32k	ALLOCA_FLAG(use_heap)
82
83	5.32k	size = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
84	5.32k	if (!size) {
85	0	return FAILURE;
86	0	}
87	5.32k	union_find_init(parent, size, ssa_vars_count);
88
89	198k	for (i = 0; i < ssa_vars_count; i++) {
90	193k	if (ssa_vars[i].definition_phi) {
91	29.5k	p = ssa_vars[i].definition_phi;
92	29.5k	if (p->pi >= 0) {
93	8.11k	union_find_unite(parent, size, i, p->sources[0]);
94	21.4k	} else {
95	66.0k	for (uint32_t j = 0; j < ssa->cfg.blocks[p->block].predecessors_count; j++) {
96	44.6k	union_find_unite(parent, size, i, p->sources[j]);
97	44.6k	}
98	21.4k	}
99	163k	} else if (ssa_vars[i].definition >= 0) {
100	145k	int def = ssa_vars[i].definition;
101	145k	zend_ssa_op *op = ssa->ops + def;
102	145k	zend_op *opline = op_array->opcodes + def;
103
104	145k	if (op->op1_def >= 0) {
105	36.4k	if (op->op1_use >= 0) {
106	36.4k	if (opline->opcode != ZEND_ASSIGN) {
107	18.1k	union_find_unite(parent, size, op->op1_def, op->op1_use);
108	18.1k	}
109	36.4k	}
110	36.4k	if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
111	13.0k	union_find_unite(parent, size, op->op1_def, op->op2_use);
112	13.0k	}
113	36.4k	}
114	145k	if (op->op2_def >= 0) {
115	2.76k	if (op->op2_use >= 0) {
116	2.61k	union_find_unite(parent, size, op->op2_def, op->op2_use);
117	2.61k	}
118	2.76k	}
119	145k	if (op->result_def >= 0) {
120	121k	if (op->result_use >= 0) {
121	5.81k	if (opline->opcode != ZEND_QM_ASSIGN) {
122	5.81k	union_find_unite(parent, size, op->result_def, op->result_use);
123	5.81k	}
124	5.81k	}
125	121k	if (opline->opcode == ZEND_QM_ASSIGN && op->op1_use >= 0) {
126	674	union_find_unite(parent, size, op->result_def, op->op1_use);
127	674	}
128	121k	if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
129	4.48k	union_find_unite(parent, size, op->result_def, op->op2_use);
130	4.48k	}
131	121k	if (opline->opcode == ZEND_ASSIGN && op->op1_def >= 0) {
132	5.00k	union_find_unite(parent, size, op->result_def, op->op1_def);
133	5.00k	}
134	121k	}
135	145k	}
136	193k	}
137
138	198k	for (i = 0; i < ssa_vars_count; i++) {
139	193k	parent[i] = union_find_root(parent, i);
140	193k	}
141
142	5.32k	free_alloca(size, use_heap);
143
144	5.32k	return SUCCESS;
145	5.32k	}
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	116k	{
150	116k	zend_ssa_op *ssa_op = ssa->ops + def;
151	116k	zend_op *opline = op_array->opcodes + def;
152
153	116k	if (ssa_op->result_def == var) {
154	83.1k	switch (opline->opcode) {
155	2.84k	case ZEND_INIT_ARRAY:
156	2.84k	return true;
157	11.8k	case ZEND_NEW: {
158		/* objects with destructors should escape */
159	11.8k	zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
160	11.8k	script, op_array, opline);
161	11.8k	uint32_t forbidden_flags =
162		/* These flags will always cause an exception */
163	11.8k	ZEND_ACC_IMPLICIT_ABSTRACT_CLASS \| ZEND_ACC_EXPLICIT_ABSTRACT_CLASS
164	11.8k	\| ZEND_ACC_INTERFACE \| ZEND_ACC_TRAIT;
165	11.8k	if (ce
166	10.4k	&& !ce->parent
167	9.50k	&& !ce->create_object
168	7.29k	&& ce->default_object_handlers->get_constructor == zend_std_get_constructor
169	7.29k	&& ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
170	7.29k	&& !ce->constructor
171	6.31k	&& !ce->destructor
172	5.72k	&& !ce->__get
173	5.50k	&& !ce->__set
174	5.45k	&& !(ce->ce_flags & forbidden_flags)
175	5.45k	&& (ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
176	5.43k	return true;
177	5.43k	}
178	6.38k	break;
179	11.8k	}
180	6.38k	case ZEND_QM_ASSIGN:
181	674	if (opline->op1_type == IS_CONST
182	6	&& Z_TYPE_P(CRT_CONSTANT(opline->op1)) == IS_ARRAY) {
183	6	return true;
184	6	}
185	668	if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
186	117	return true;
187	117	}
188	551	break;
189	551	case ZEND_ASSIGN:
190	336	if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
191	93	return true;
192	93	}
193	243	break;
194	83.1k	}
195	83.1k	} else if (ssa_op->op1_def == var) {
196	32.4k	switch (opline->opcode) {
197	18.8k	case ZEND_ASSIGN:
198	18.8k	if (opline->op2_type == IS_CONST
199	8.47k	&& Z_TYPE_P(CRT_CONSTANT(opline->op2)) == IS_ARRAY) {
200	3.23k	return true;
201	3.23k	}
202	15.5k	if (opline->op2_type == IS_CV && (OP2_INFO() & MAY_BE_ARRAY)) {
203	360	return true;
204	360	}
205	15.2k	break;
206	15.2k	case ZEND_ASSIGN_DIM:
207	1.32k	if (OP1_INFO() & (MAY_BE_UNDEF \| MAY_BE_NULL \| MAY_BE_FALSE)) {
208		/* implicit object/array allocation */
209	1.30k	return true;
210	1.30k	}
211	26	break;
212	32.4k	}
213	32.4k	}
214
215	103k	return false;
216	116k	}
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	54.3k	{
221	54.3k	zend_ssa_op *op = ssa->ops + def;
222	54.3k	zend_op *opline = op_array->opcodes + def;
223
224	54.3k	if (op->result_def == var) {
225	39.3k	switch (opline->opcode) {
226	1.86k	case ZEND_INIT_ARRAY:
227	7.52k	case ZEND_ADD_ARRAY_ELEMENT:
228	7.67k	case ZEND_QM_ASSIGN:
229	8.04k	case ZEND_ASSIGN:
230	8.04k	return true;
231	5.19k	case ZEND_NEW: {
232		/* objects with destructors should escape */
233	5.19k	zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
234	5.19k	script, op_array, opline);
235	5.19k	if (ce
236	4.76k	&& !ce->create_object
237	3.93k	&& ce->default_object_handlers->get_constructor == zend_std_get_constructor
238	3.93k	&& ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
239	3.93k	&& !ce->constructor
240	3.66k	&& !ce->destructor
241	3.55k	&& !ce->__get
242	3.52k	&& !ce->__set
243	3.52k	&& !ce->parent) {
244	3.40k	return true;
245	3.40k	}
246	1.79k	break;
247	5.19k	}
248	39.3k	}
249	39.3k	} else if (op->op1_def == var) {
250	13.8k	switch (opline->opcode) {
251	6.85k	case ZEND_ASSIGN:
252	9.49k	case ZEND_ASSIGN_DIM:
253	10.4k	case ZEND_ASSIGN_OBJ:
254	10.4k	case ZEND_ASSIGN_OBJ_REF:
255	10.5k	case ZEND_ASSIGN_DIM_OP:
256	10.5k	case ZEND_ASSIGN_OBJ_OP:
257	10.6k	case ZEND_PRE_INC_OBJ:
258	10.6k	case ZEND_PRE_DEC_OBJ:
259	10.6k	case ZEND_POST_INC_OBJ:
260	10.6k	case ZEND_POST_DEC_OBJ:
261	10.6k	return true;
262	13.8k	}
263	13.8k	}
264
265	32.2k	return false;
266	54.3k	}
267		/* }}} */
268
269		static bool is_escape_use(zend_op_array op_array, zend_ssa ssa, int use, int var) /* {{{ */
270	12.6k	{
271	12.6k	zend_ssa_op *ssa_op = ssa->ops + use;
272	12.6k	zend_op *opline = op_array->opcodes + use;
273
274	12.6k	if (ssa_op->op1_use == var) {
275	7.18k	switch (opline->opcode) {
276	303	case ZEND_ASSIGN:
277		/* no_val */
278	303	break;
279	89	case ZEND_QM_ASSIGN:
280	89	if (opline->op1_type == IS_CV) {
281	89	if (OP1_INFO() & MAY_BE_OBJECT) {
282		/* object aliasing */
283	87	return true;
284	87	}
285	89	}
286	2	break;
287	35	case ZEND_ISSET_ISEMPTY_DIM_OBJ:
288	43	case ZEND_ISSET_ISEMPTY_PROP_OBJ:
289	710	case ZEND_FETCH_DIM_R:
290	748	case ZEND_FETCH_OBJ_R:
291	997	case ZEND_FETCH_DIM_IS:
292	997	case ZEND_FETCH_OBJ_IS:
293	997	break;
294	0	case ZEND_ASSIGN_OP:
295	0	return true;
296	14	case ZEND_ASSIGN_DIM_OP:
297	14	case ZEND_ASSIGN_OBJ_OP:
298	14	case ZEND_ASSIGN_STATIC_PROP_OP:
299	2.30k	case ZEND_ASSIGN_DIM:
300	2.51k	case ZEND_ASSIGN_OBJ:
301	2.52k	case ZEND_ASSIGN_OBJ_REF:
302	2.52k	break;
303	2	case ZEND_PRE_INC_OBJ:
304	2	case ZEND_PRE_DEC_OBJ:
305	2	case ZEND_POST_INC_OBJ:
306	2	case ZEND_POST_DEC_OBJ:
307	2	break;
308	187	case ZEND_INIT_ARRAY:
309	503	case ZEND_ADD_ARRAY_ELEMENT:
310	503	if (opline->extended_value & ZEND_ARRAY_ELEMENT_REF) {
311	0	return true;
312	0	}
313	503	if (OP1_INFO() & MAY_BE_OBJECT) {
314		/* object aliasing */
315	289	return true;
316	289	}
317		/* reference dependencies processed separately */
318	214	break;
319	461	case ZEND_OP_DATA:
320	461	if ((opline-1)->opcode != ZEND_ASSIGN_DIM
321	350	&& (opline-1)->opcode != ZEND_ASSIGN_OBJ) {
322	40	return true;
323	40	}
324	421	if (OP1_INFO() & MAY_BE_OBJECT) {
325		/* object aliasing */
326	354	return true;
327	354	}
328	67	opline--;
329	67	ssa_op--;
330	67	if (opline->op1_type != IS_CV
331	52	\|\| (OP1_INFO() & MAY_BE_REF)
332	55	\|\| (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
333		/* assignment into escaping structure */
334	55	return true;
335	55	}
336		/* reference dependencies processed separately */
337	12	break;
338	2.30k	default:
339	2.30k	return true;
340	7.18k	}
341	7.18k	}
342
343	9.56k	if (ssa_op->op2_use == var) {
344	2.44k	switch (opline->opcode) {
345	2.17k	case ZEND_ASSIGN:
346	2.17k	if (opline->op1_type != IS_CV
347	2.17k	\|\| (OP1_INFO() & MAY_BE_REF)
348	1.70k	\|\| (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
349		/* assignment into escaping variable */
350	1.70k	return true;
351	1.70k	}
352	475	if (opline->op2_type == IS_CV \|\| opline->result_type != IS_UNUSED) {
353	78	if (OP2_INFO() & MAY_BE_OBJECT) {
354		/* object aliasing */
355	60	return true;
356	60	}
357	78	}
358	415	break;
359	415	default:
360	268	return true;
361	2.44k	}
362	2.44k	}
363
364	7.53k	if (ssa_op->result_use == var) {
365	3.07k	switch (opline->opcode) {
366	0	case ZEND_ASSIGN:
367	0	case ZEND_QM_ASSIGN:
368	0	case ZEND_INIT_ARRAY:
369	3.07k	case ZEND_ADD_ARRAY_ELEMENT:
370	3.07k	break;
371	0	default:
372	0	return true;
373	3.07k	}
374	3.07k	}
375
376	7.53k	return false;
377	7.53k	}
378		/* }}} */
379
380		zend_result zend_ssa_escape_analysis(const zend_script script, zend_op_array op_array, zend_ssa ssa) / {{{ */
381	34.0k	{
382	34.0k	zend_ssa_var *ssa_vars = ssa->vars;
383	34.0k	int ssa_vars_count = ssa->vars_count;
384	34.0k	int i, root, use;
385	34.0k	int *ees;
386	34.0k	bool has_allocations;
387	34.0k	int num_non_escaped;
388	34.0k	ALLOCA_FLAG(use_heap)
389
390	34.0k	if (!ssa_vars) {
391	0	return SUCCESS;
392	0	}
393
394	34.0k	has_allocations = false;
395	401k	for (i = op_array->last_var; i < ssa_vars_count; i++) {
396	373k	if (ssa_vars[i].definition >= 0
397	330k	&& (ssa->var_info[i].type & (MAY_BE_ARRAY\|MAY_BE_OBJECT))
398	106k	&& is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
399	5.32k	has_allocations = true;
400	5.32k	break;
401	5.32k	}
402	373k	}
403	34.0k	if (!has_allocations) {
404	28.7k	return SUCCESS;
405	28.7k	}
406
407
408		/* 1. Build EES (Equi-Escape Sets) */
409	5.32k	ees = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
410	5.32k	if (!ees) {
411	0	return FAILURE;
412	0	}
413
414	5.32k	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	5.32k	num_non_escaped = 0;
421	180k	for (i = op_array->last_var; i < ssa_vars_count; i++) {
422	175k	root = ees[i];
423	175k	if (ssa_vars[root].escape_state > ESCAPE_STATE_NO_ESCAPE) {
424		/* already escape. skip */
425	153k	} 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	153k	} else if (ssa_vars[i].definition >= 0
431	131k	&& (ssa->var_info[i].type & (MAY_BE_ARRAY\|MAY_BE_OBJECT))) {
432	54.3k	if (!is_local_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
433	32.2k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
434	1.57k	num_non_escaped--;
435	1.57k	}
436	32.2k	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
437	32.2k	} else if (ssa_vars[root].escape_state == ESCAPE_STATE_UNKNOWN
438	10.2k	&& is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
439	8.06k	ssa_vars[root].escape_state = ESCAPE_STATE_NO_ESCAPE;
440	8.06k	num_non_escaped++;
441	8.06k	}
442	54.3k	}
443	175k	}
444
445		/* 3. Mark escaped EES */
446	5.32k	if (num_non_escaped) {
447	122k	for (i = 0; i < ssa_vars_count; i++) {
448	118k	if (ssa_vars[i].use_chain >= 0) {
449	98.0k	root = ees[i];
450	98.0k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
451	24.4k	FOREACH_USE(ssa_vars + i, use) {
452	24.4k	if (is_escape_use(op_array, ssa, use, i)) {
453	5.15k	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
454	5.15k	num_non_escaped--;
455	5.15k	if (num_non_escaped == 0) {
456	3.04k	i = ssa_vars_count;
457	3.04k	}
458	5.15k	break;
459	5.15k	}
460	24.4k	} FOREACH_USE_END();
461	11.7k	}
462	98.0k	}
463	118k	}
464	3.96k	}
465
466		/* 4. Process referential dependencies */
467	5.32k	if (num_non_escaped) {
468	920	bool changed;
469
470	944	do {
471	944	changed = false;
472	57.4k	for (i = 0; i < ssa_vars_count; i++) {
473	56.4k	if (ssa_vars[i].use_chain >= 0) {
474	45.3k	root = ees[i];
475	45.3k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
476	7.82k	FOREACH_USE(ssa_vars + i, use) {
477	7.82k	zend_ssa_op *op = ssa->ops + use;
478	7.82k	zend_op *opline = op_array->opcodes + use;
479	7.82k	int enclosing_root;
480
481	7.82k	if (opline->opcode == ZEND_OP_DATA &&
482	10	((opline-1)->opcode == ZEND_ASSIGN_DIM \|\|
483	8	(opline-1)->opcode == ZEND_ASSIGN_OBJ \|\|
484	0	(opline-1)->opcode == ZEND_ASSIGN_OBJ_REF) &&
485	10	op->op1_use == i &&
486	10	(op-1)->op1_use >= 0) {
487	10	enclosing_root = ees[(op-1)->op1_use];
488	4.26k	} else if ((opline->opcode == ZEND_INIT_ARRAY \|\|
489	4.21k	opline->opcode == ZEND_ADD_ARRAY_ELEMENT) &&
490	1.04k	op->op1_use == i &&
491	404	op->result_def >= 0) {
492	404	enclosing_root = ees[op->result_def];
493	3.86k	} else {
494	3.86k	continue;
495	3.86k	}
496
497	414	if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN \|\|
498	412	ssa_vars[enclosing_root].escape_state > ssa_vars[root].escape_state) {
499	222	if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN) {
500	2	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
501	220	} else {
502	220	ssa_vars[root].escape_state = ssa_vars[enclosing_root].escape_state;
503	220	}
504	222	if (ssa_vars[root].escape_state == ESCAPE_STATE_GLOBAL_ESCAPE) {
505	222	num_non_escaped--;
506	222	if (num_non_escaped == 0) {
507	70	changed = false;
508	152	} else {
509	152	changed = true;
510	152	}
511	222	break;
512	222	} else {
513	0	changed = true;
514	0	}
515	222	}
516	414	} FOREACH_USE_END();
517	3.55k	}
518	45.3k	}
519	56.4k	}
520	944	} while (changed);
521	920	}
522
523		/* 5. Propagate values of escape sets to variables */
524	198k	for (i = 0; i < ssa_vars_count; i++) {
525	193k	root = ees[i];
526	193k	if (i != root) {
527	74.1k	ssa_vars[i].escape_state = ssa_vars[root].escape_state;
528	74.1k	}
529	193k	}
530
531	5.32k	free_alloca(ees, use_heap);
532
533	5.32k	return SUCCESS;
534	5.32k	}
535		/* }}} */