/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: 2025-12-31 07:28

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	999	{
36	999	int i;
37
38	223k	for (i = 0; i < count; i++) {
39	222k	parent[i] = i;
40	222k	size[i] = 1;
41	222k	}
42	999	}
43		/* }}} */
44
45		static zend_always_inline int union_find_root(int parent, int i) / {{{ */
46	421k	{
47	421k	int p = parent[i];
48
49	582k	while (i != p) {
50	160k	p = parent[p];
51	160k	parent[i] = p;
52	160k	i = p;
53	160k	p = parent[i];
54	160k	}
55	421k	return i;
56	421k	}
57		/* }}} */
58
59		static zend_always_inline void union_find_unite(int parent, int size, int i, int j) /* {{{ */
60	99.7k	{
61	99.7k	int r1 = union_find_root(parent, i);
62	99.7k	int r2 = union_find_root(parent, j);
63
64	99.7k	if (r1 != r2) {
65	77.4k	if (size[r1] < size[r2]) {
66	42.4k	parent[r1] = r2;
67	42.4k	size[r2] += size[r1];
68	42.4k	} else {
69	35.0k	parent[r2] = r1;
70	35.0k	size[r1] += size[r2];
71	35.0k	}
72	77.4k	}
73	99.7k	}
74		/* }}} */
75
76		static zend_result zend_build_equi_escape_sets(int parent, zend_op_array op_array, zend_ssa ssa) / {{{ */
77	999	{
78	999	zend_ssa_var *ssa_vars = ssa->vars;
79	999	int ssa_vars_count = ssa->vars_count;
80	999	zend_ssa_phi *p;
81	999	int i, j;
82	999	int *size;
83	999	ALLOCA_FLAG(use_heap)
84
85	999	size = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
86	999	if (!size) {
87	0	return FAILURE;
88	0	}
89	999	union_find_init(parent, size, ssa_vars_count);
90
91	223k	for (i = 0; i < ssa_vars_count; i++) {
92	222k	if (ssa_vars[i].definition_phi) {
93	41.0k	p = ssa_vars[i].definition_phi;
94	41.0k	if (p->pi >= 0) {
95	12.8k	union_find_unite(parent, size, i, p->sources[0]);
96	28.2k	} else {
97	85.4k	for (j = 0; j < ssa->cfg.blocks[p->block].predecessors_count; j++) {
98	57.2k	union_find_unite(parent, size, i, p->sources[j]);
99	57.2k	}
100	28.2k	}
101	181k	} else if (ssa_vars[i].definition >= 0) {
102	174k	int def = ssa_vars[i].definition;
103	174k	zend_ssa_op *op = ssa->ops + def;
104	174k	zend_op *opline = op_array->opcodes + def;
105
106	174k	if (op->op1_def >= 0) {
107	14.7k	if (op->op1_use >= 0) {
108	14.7k	if (opline->opcode != ZEND_ASSIGN) {
109	7.76k	union_find_unite(parent, size, op->op1_def, op->op1_use);
110	7.76k	}
111	14.7k	}
112	14.7k	if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
113	5.05k	union_find_unite(parent, size, op->op1_def, op->op2_use);
114	5.05k	}
115	14.7k	}
116	174k	if (op->op2_def >= 0) {
117	773	if (op->op2_use >= 0) {
118	753	union_find_unite(parent, size, op->op2_def, op->op2_use);
119	753	}
120	773	}
121	174k	if (op->result_def >= 0) {
122	166k	if (op->result_use >= 0) {
123	10.3k	if (opline->opcode != ZEND_QM_ASSIGN) {
124	10.3k	union_find_unite(parent, size, op->result_def, op->result_use);
125	10.3k	}
126	10.3k	}
127	166k	if (opline->opcode == ZEND_QM_ASSIGN && op->op1_use >= 0) {
128	215	union_find_unite(parent, size, op->result_def, op->op1_use);
129	215	}
130	166k	if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
131	2.48k	union_find_unite(parent, size, op->result_def, op->op2_use);
132	2.48k	}
133	166k	if (opline->opcode == ZEND_ASSIGN && op->op1_def >= 0) {
134	3.08k	union_find_unite(parent, size, op->result_def, op->op1_def);
135	3.08k	}
136	166k	}
137	174k	}
138	222k	}
139
140	223k	for (i = 0; i < ssa_vars_count; i++) {
141	222k	parent[i] = union_find_root(parent, i);
142	222k	}
143
144	999	free_alloca(size, use_heap);
145
146	999	return SUCCESS;
147	999	}
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	93.6k	{
152	93.6k	zend_ssa_op *ssa_op = ssa->ops + def;
153	93.6k	zend_op *opline = op_array->opcodes + def;
154
155	93.6k	if (ssa_op->result_def == var) {
156	86.1k	switch (opline->opcode) {
157	1.05k	case ZEND_INIT_ARRAY:
158	1.05k	return true;
159	2.36k	case ZEND_NEW: {
160		/* objects with destructors should escape */
161	2.36k	zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
162	2.36k	script, op_array, opline);
163	2.36k	uint32_t forbidden_flags =
164		/* These flags will always cause an exception */
165	2.36k	ZEND_ACC_IMPLICIT_ABSTRACT_CLASS \| ZEND_ACC_EXPLICIT_ABSTRACT_CLASS
166	2.36k	\| ZEND_ACC_INTERFACE \| ZEND_ACC_TRAIT;
167	2.36k	if (ce
168	2.00k	&& !ce->parent
169	1.83k	&& !ce->create_object
170	1.53k	&& ce->default_object_handlers->get_constructor == zend_std_get_constructor
171	1.53k	&& ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
172	1.53k	&& !ce->constructor
173	1.43k	&& !ce->destructor
174	916	&& !ce->__get
175	908	&& !ce->__set
176	906	&& !(ce->ce_flags & forbidden_flags)
177	906	&& (ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
178	906	return true;
179	906	}
180	1.46k	break;
181	2.36k	}
182	1.46k	case ZEND_QM_ASSIGN:
183	334	if (opline->op1_type == IS_CONST
184	0	&& Z_TYPE_P(CRT_CONSTANT(opline->op1)) == IS_ARRAY) {
185	0	return true;
186	0	}
187	334	if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
188	0	return true;
189	0	}
190	334	break;
191	334	case ZEND_ASSIGN:
192	126	if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
193	54	return true;
194	54	}
195	72	break;
196	86.1k	}
197	86.1k	} else if (ssa_op->op1_def == var) {
198	7.46k	switch (opline->opcode) {
199	3.59k	case ZEND_ASSIGN:
200	3.59k	if (opline->op2_type == IS_CONST
201	1.70k	&& Z_TYPE_P(CRT_CONSTANT(opline->op2)) == IS_ARRAY) {
202	494	return true;
203	494	}
204	3.09k	if (opline->op2_type == IS_CV && (OP2_INFO() & MAY_BE_ARRAY)) {
205	44	return true;
206	44	}
207	3.05k	break;
208	3.05k	case ZEND_ASSIGN_DIM:
209	426	if (OP1_INFO() & (MAY_BE_UNDEF \| MAY_BE_NULL \| MAY_BE_FALSE)) {
210		/* implicit object/array allocation */
211	412	return true;
212	412	}
213	14	break;
214	7.46k	}
215	7.46k	}
216
217	90.6k	return false;
218	93.6k	}
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	46.7k	{
223	46.7k	zend_ssa_op *op = ssa->ops + def;
224	46.7k	zend_op *opline = op_array->opcodes + def;
225
226	46.7k	if (op->result_def == var) {
227	42.3k	switch (opline->opcode) {
228	766	case ZEND_INIT_ARRAY:
229	11.1k	case ZEND_ADD_ARRAY_ELEMENT:
230	11.1k	case ZEND_QM_ASSIGN:
231	11.2k	case ZEND_ASSIGN:
232	11.2k	return true;
233	1.01k	case ZEND_NEW: {
234		/* objects with destructors should escape */
235	1.01k	zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
236	1.01k	script, op_array, opline);
237	1.01k	if (ce
238	919	&& !ce->create_object
239	751	&& ce->default_object_handlers->get_constructor == zend_std_get_constructor
240	751	&& ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
241	751	&& !ce->constructor
242	702	&& !ce->destructor
243	700	&& !ce->__get
244	700	&& !ce->__set
245	700	&& !ce->parent) {
246	660	return true;
247	660	}
248	354	break;
249	1.01k	}
250	42.3k	}
251	42.3k	} else if (op->op1_def == var) {
252	4.16k	switch (opline->opcode) {
253	1.77k	case ZEND_ASSIGN:
254	2.68k	case ZEND_ASSIGN_DIM:
255	2.99k	case ZEND_ASSIGN_OBJ:
256	2.99k	case ZEND_ASSIGN_OBJ_REF:
257	3.01k	case ZEND_ASSIGN_DIM_OP:
258	3.09k	case ZEND_ASSIGN_OBJ_OP:
259	3.09k	case ZEND_PRE_INC_OBJ:
260	3.09k	case ZEND_PRE_DEC_OBJ:
261	3.09k	case ZEND_POST_INC_OBJ:
262	3.10k	case ZEND_POST_DEC_OBJ:
263	3.10k	return true;
264	4.16k	}
265	4.16k	}
266
267	31.7k	return false;
268	46.7k	}
269		/* }}} */
270
271		static bool is_escape_use(zend_op_array op_array, zend_ssa ssa, int use, int var) /* {{{ */
272	4.50k	{
273	4.50k	zend_ssa_op *ssa_op = ssa->ops + use;
274	4.50k	zend_op *opline = op_array->opcodes + use;
275
276	4.50k	if (ssa_op->op1_use == var) {
277	2.99k	switch (opline->opcode) {
278	242	case ZEND_ASSIGN:
279		/* no_val */
280	242	break;
281	0	case ZEND_QM_ASSIGN:
282	0	if (opline->op1_type == IS_CV) {
283	0	if (OP1_INFO() & MAY_BE_OBJECT) {
284		/* object aliasing */
285	0	return true;
286	0	}
287	0	}
288	0	break;
289	0	case ZEND_ISSET_ISEMPTY_DIM_OBJ:
290	0	case ZEND_ISSET_ISEMPTY_PROP_OBJ:
291	460	case ZEND_FETCH_DIM_R:
292	562	case ZEND_FETCH_OBJ_R:
293	642	case ZEND_FETCH_DIM_IS:
294	646	case ZEND_FETCH_OBJ_IS:
295	646	break;
296	0	case ZEND_ASSIGN_OP:
297	0	return true;
298	2	case ZEND_ASSIGN_DIM_OP:
299	104	case ZEND_ASSIGN_OBJ_OP:
300	104	case ZEND_ASSIGN_STATIC_PROP_OP:
301	996	case ZEND_ASSIGN_DIM:
302	1.24k	case ZEND_ASSIGN_OBJ:
303	1.25k	case ZEND_ASSIGN_OBJ_REF:
304	1.25k	break;
305	0	case ZEND_PRE_INC_OBJ:
306	0	case ZEND_PRE_DEC_OBJ:
307	0	case ZEND_POST_INC_OBJ:
308	0	case ZEND_POST_DEC_OBJ:
309	0	break;
310	86	case ZEND_INIT_ARRAY:
311	213	case ZEND_ADD_ARRAY_ELEMENT:
312	213	if (opline->extended_value & ZEND_ARRAY_ELEMENT_REF) {
313	0	return true;
314	0	}
315	213	if (OP1_INFO() & MAY_BE_OBJECT) {
316		/* object aliasing */
317	77	return true;
318	77	}
319		/* reference dependencies processed separately */
320	136	break;
321	136	case ZEND_OP_DATA:
322	34	if ((opline-1)->opcode != ZEND_ASSIGN_DIM
323	9	&& (opline-1)->opcode != ZEND_ASSIGN_OBJ) {
324	2	return true;
325	2	}
326	32	if (OP1_INFO() & MAY_BE_OBJECT) {
327		/* object aliasing */
328	8	return true;
329	8	}
330	24	opline--;
331	24	ssa_op--;
332	24	if (opline->op1_type != IS_CV
333	20	\|\| (OP1_INFO() & MAY_BE_REF)
334	20	\|\| (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
335		/* assignment into escaping structure */
336	4	return true;
337	4	}
338		/* reference dependencies processed separately */
339	20	break;
340	607	default:
341	607	return true;
342	2.99k	}
343	2.99k	}
344
345	3.81k	if (ssa_op->op2_use == var) {
346	514	switch (opline->opcode) {
347	448	case ZEND_ASSIGN:
348	448	if (opline->op1_type != IS_CV
349	436	\|\| (OP1_INFO() & MAY_BE_REF)
350	262	\|\| (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
351		/* assignment into escaping variable */
352	186	return true;
353	186	}
354	262	if (opline->op2_type == IS_CV \|\| opline->result_type != IS_UNUSED) {
355	18	if (OP2_INFO() & MAY_BE_OBJECT) {
356		/* object aliasing */
357	14	return true;
358	14	}
359	18	}
360	248	break;
361	248	default:
362	66	return true;
363	514	}
364	514	}
365
366	3.54k	if (ssa_op->result_use == var) {
367	997	switch (opline->opcode) {
368	0	case ZEND_ASSIGN:
369	0	case ZEND_QM_ASSIGN:
370	0	case ZEND_INIT_ARRAY:
371	997	case ZEND_ADD_ARRAY_ELEMENT:
372	997	break;
373	0	default:
374	0	return true;
375	997	}
376	997	}
377
378	3.54k	return false;
379	3.54k	}
380		/* }}} */
381
382		zend_result zend_ssa_escape_analysis(const zend_script script, zend_op_array op_array, zend_ssa ssa) / {{{ */
383	6.78k	{
384	6.78k	zend_ssa_var *ssa_vars = ssa->vars;
385	6.78k	int ssa_vars_count = ssa->vars_count;
386	6.78k	int i, root, use;
387	6.78k	int *ees;
388	6.78k	bool has_allocations;
389	6.78k	int num_non_escaped;
390	6.78k	ALLOCA_FLAG(use_heap)
391
392	6.78k	if (!ssa_vars) {
393	0	return SUCCESS;
394	0	}
395
396	6.78k	has_allocations = false;
397	389k	for (i = op_array->last_var; i < ssa_vars_count; i++) {
398	383k	if (ssa_vars[i].definition >= 0
399	308k	&& (ssa->var_info[i].type & (MAY_BE_ARRAY\|MAY_BE_OBJECT))
400	90.9k	&& is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
401	999	has_allocations = true;
402	999	break;
403	999	}
404	383k	}
405	6.78k	if (!has_allocations) {
406	5.78k	return SUCCESS;
407	5.78k	}
408
409
410		/* 1. Build EES (Equi-Escape Sets) */
411	999	ees = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
412	999	if (!ees) {
413	0	return FAILURE;
414	0	}
415
416	999	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	999	num_non_escaped = 0;
423	216k	for (i = op_array->last_var; i < ssa_vars_count; i++) {
424	215k	root = ees[i];
425	215k	if (ssa_vars[root].escape_state > ESCAPE_STATE_NO_ESCAPE) {
426		/* already escape. skip */
427	197k	} 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	197k	} else if (ssa_vars[i].definition >= 0
433	169k	&& (ssa->var_info[i].type & (MAY_BE_ARRAY\|MAY_BE_OBJECT))) {
434	46.7k	if (!is_local_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
435	31.7k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
436	457	num_non_escaped--;
437	457	}
438	31.7k	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
439	31.7k	} else if (ssa_vars[root].escape_state == ESCAPE_STATE_UNKNOWN
440	2.71k	&& is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
441	1.96k	ssa_vars[root].escape_state = ESCAPE_STATE_NO_ESCAPE;
442	1.96k	num_non_escaped++;
443	1.96k	}
444	46.7k	}
445	215k	}
446
447		/* 3. Mark escaped EES */
448	999	if (num_non_escaped) {
449	135k	for (i = 0; i < ssa_vars_count; i++) {
450	134k	if (ssa_vars[i].use_chain >= 0) {
451	108k	root = ees[i];
452	108k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
453	8.39k	FOREACH_USE(ssa_vars + i, use) {
454	8.39k	if (is_escape_use(op_array, ssa, use, i)) {
455	964	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
456	964	num_non_escaped--;
457	964	if (num_non_escaped == 0) {
458	424	i = ssa_vars_count;
459	424	}
460	964	break;
461	964	}
462	8.39k	} FOREACH_USE_END();
463	3.88k	}
464	108k	}
465	134k	}
466	638	}
467
468		/* 4. Process referential dependencies */
469	999	if (num_non_escaped) {
470	214	bool changed;
471
472	222	do {
473	222	changed = false;
474	20.8k	for (i = 0; i < ssa_vars_count; i++) {
475	20.5k	if (ssa_vars[i].use_chain >= 0) {
476	16.6k	root = ees[i];
477	16.6k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
478	5.32k	FOREACH_USE(ssa_vars + i, use) {
479	5.32k	zend_ssa_op *op = ssa->ops + use;
480	5.32k	zend_op *opline = op_array->opcodes + use;
481	5.32k	int enclosing_root;
482
483	5.32k	if (opline->opcode == ZEND_OP_DATA &&
484	20	((opline-1)->opcode == ZEND_ASSIGN_DIM \|\|
485	0	(opline-1)->opcode == ZEND_ASSIGN_OBJ \|\|
486	0	(opline-1)->opcode == ZEND_ASSIGN_OBJ_REF) &&
487	20	op->op1_use == i &&
488	20	(op-1)->op1_use >= 0) {
489	20	enclosing_root = ees[(op-1)->op1_use];
490	2.88k	} else if ((opline->opcode == ZEND_INIT_ARRAY \|\|
491	2.84k	opline->opcode == ZEND_ADD_ARRAY_ELEMENT) &&
492	868	op->op1_use == i &&
493	302	op->result_def >= 0) {
494	302	enclosing_root = ees[op->result_def];
495	2.58k	} else {
496	2.58k	continue;
497	2.58k	}
498
499	322	if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN \|\|
500	322	ssa_vars[enclosing_root].escape_state > ssa_vars[root].escape_state) {
501	128	if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN) {
502	0	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
503	128	} else {
504	128	ssa_vars[root].escape_state = ssa_vars[enclosing_root].escape_state;
505	128	}
506	128	if (ssa_vars[root].escape_state == ESCAPE_STATE_GLOBAL_ESCAPE) {
507	128	num_non_escaped--;
508	128	if (num_non_escaped == 0) {
509	8	changed = false;
510	120	} else {
511	120	changed = true;
512	120	}
513	128	break;
514	128	} else {
515	0	changed = true;
516	0	}
517	128	}
518	322	} FOREACH_USE_END();
519	2.41k	}
520	16.6k	}
521	20.5k	}
522	222	} while (changed);
523	214	}
524
525		/* 5. Propagate values of escape sets to variables */
526	223k	for (i = 0; i < ssa_vars_count; i++) {
527	222k	root = ees[i];
528	222k	if (i != root) {
529	77.4k	ssa_vars[i].escape_state = ssa_vars[root].escape_state;
530	77.4k	}
531	222k	}
532
533	999	free_alloca(ees, use_heap);
534
535	999	return SUCCESS;
536	999	}
537		/* }}} */