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

Source (jump to first uncovered line)
/*
   +----------------------------------------------------------------------+
   | 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 1;
      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 1;
        }
        break;
      }
      case ZEND_QM_ASSIGN:
        if (opline->op1_type == IS_CONST
         && Z_TYPE_P(CRT_CONSTANT(opline->op1)) == IS_ARRAY) {
          return 1;
        }
        if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
          return 1;
        }
        break;
      case ZEND_ASSIGN:
        if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
          return 1;
        }
        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 1;
        }
        if (opline->op2_type == IS_CV && (OP2_INFO() & MAY_BE_ARRAY)) {
          return 1;
        }
        break;
      case ZEND_ASSIGN_DIM:
        if (OP1_INFO() & (MAY_BE_UNDEF | MAY_BE_NULL | MAY_BE_FALSE)) {
          /* implicit object/array allocation */
          return 1;
        }
        break;
    }
  }

  return 0;
}
/* }}} */

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 1;
      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 1;
        }
        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 1;
    }
  }

  return 0;
}
/* }}} */

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 1;
          }
        }
        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 1;
      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 1;
        }
        if (OP1_INFO() & MAY_BE_OBJECT) {
          /* object aliasing */
          return 1;
        }
        /* reference dependencies processed separately */
        break;
      case ZEND_OP_DATA:
        if ((opline-1)->opcode != ZEND_ASSIGN_DIM
         && (opline-1)->opcode != ZEND_ASSIGN_OBJ) {
          return 1;
        }
        if (OP1_INFO() & MAY_BE_OBJECT) {
          /* object aliasing */
          return 1;
        }
        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 1;
        }
        /* reference dependencies processed separately */
        break;
      default:
        return 1;
    }
  }

  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 1;
        }
        if (opline->op2_type == IS_CV || opline->result_type != IS_UNUSED) {
          if (OP2_INFO() & MAY_BE_OBJECT) {
            /* object aliasing */
            return 1;
          }
        }
        break;
      default:
        return 1;
    }
  }

  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 1;
    }
  }

  return 0;
}
/* }}} */

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 = 0;
  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 = 1;
      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 = 0;
      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 = 0;
                  } else {
                    changed = 1;
                  }
                  break;
                } else {
                  changed = 1;
                }
              }
            } 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: 2025-06-13 06:43

Line	Count	Source (jump to first uncovered line)
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	9.80k	{
36	9.80k	int i;
37
38	429k	for (i = 0; i < count; i++) {
39	419k	parent[i] = i;
40	419k	size[i] = 1;
41	419k	}
42	9.80k	}
43		/* }}} */
44
45		static zend_always_inline int union_find_root(int parent, int i) / {{{ */
46	874k	{
47	874k	int p = parent[i];
48
49	1.22M	while (i != p) {
50	345k	p = parent[p];
51	345k	parent[i] = p;
52	345k	i = p;
53	345k	p = parent[i];
54	345k	}
55	874k	return i;
56	874k	}
57		/* }}} */
58
59		static zend_always_inline void union_find_unite(int parent, int size, int i, int j) /* {{{ */
60	227k	{
61	227k	int r1 = union_find_root(parent, i);
62	227k	int r2 = union_find_root(parent, j);
63
64	227k	if (r1 != r2) {
65	171k	if (size[r1] < size[r2]) {
66	83.7k	parent[r1] = r2;
67	83.7k	size[r2] += size[r1];
68	87.3k	} else {
69	87.3k	parent[r2] = r1;
70	87.3k	size[r1] += size[r2];
71	87.3k	}
72	171k	}
73	227k	}
74		/* }}} */
75
76		static zend_result zend_build_equi_escape_sets(int parent, zend_op_array op_array, zend_ssa ssa) / {{{ */
77	9.80k	{
78	9.80k	zend_ssa_var *ssa_vars = ssa->vars;
79	9.80k	int ssa_vars_count = ssa->vars_count;
80	9.80k	zend_ssa_phi *p;
81	9.80k	int i, j;
82	9.80k	int *size;
83	9.80k	ALLOCA_FLAG(use_heap)
84
85	9.80k	size = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
86	9.80k	if (!size) {
87	0	return FAILURE;
88	0	}
89	9.80k	union_find_init(parent, size, ssa_vars_count);
90
91	429k	for (i = 0; i < ssa_vars_count; i++) {
92	419k	if (ssa_vars[i].definition_phi) {
93	78.7k	p = ssa_vars[i].definition_phi;
94	78.7k	if (p->pi >= 0) {
95	23.6k	union_find_unite(parent, size, i, p->sources[0]);
96	55.0k	} else {
97	167k	for (j = 0; j < ssa->cfg.blocks[p->block].predecessors_count; j++) {
98	112k	union_find_unite(parent, size, i, p->sources[j]);
99	112k	}
100	55.0k	}
101	340k	} else if (ssa_vars[i].definition >= 0) {
102	311k	int def = ssa_vars[i].definition;
103	311k	zend_ssa_op *op = ssa->ops + def;
104	311k	zend_op *opline = op_array->opcodes + def;
105
106	311k	if (op->op1_def >= 0) {
107	61.6k	if (op->op1_use >= 0) {
108	61.6k	if (opline->opcode != ZEND_ASSIGN) {
109	30.9k	union_find_unite(parent, size, op->op1_def, op->op1_use);
110	30.9k	}
111	61.6k	}
112	61.6k	if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
113	21.3k	union_find_unite(parent, size, op->op1_def, op->op2_use);
114	21.3k	}
115	61.6k	}
116	311k	if (op->op2_def >= 0) {
117	4.21k	if (op->op2_use >= 0) {
118	4.02k	union_find_unite(parent, size, op->op2_def, op->op2_use);
119	4.02k	}
120	4.21k	}
121	311k	if (op->result_def >= 0) {
122	271k	if (op->result_use >= 0) {
123	17.6k	if (opline->opcode != ZEND_QM_ASSIGN) {
124	17.6k	union_find_unite(parent, size, op->result_def, op->result_use);
125	17.6k	}
126	17.6k	}
127	271k	if (opline->opcode == ZEND_QM_ASSIGN && op->op1_use >= 0) {
128	1.01k	union_find_unite(parent, size, op->result_def, op->op1_use);
129	1.01k	}
130	271k	if (opline->opcode == ZEND_ASSIGN && op->op2_use >= 0) {
131	7.59k	union_find_unite(parent, size, op->result_def, op->op2_use);
132	7.59k	}
133	271k	if (opline->opcode == ZEND_ASSIGN && op->op1_def >= 0) {
134	8.94k	union_find_unite(parent, size, op->result_def, op->op1_def);
135	8.94k	}
136	271k	}
137	311k	}
138	419k	}
139
140	429k	for (i = 0; i < ssa_vars_count; i++) {
141	419k	parent[i] = union_find_root(parent, i);
142	419k	}
143
144	9.80k	free_alloca(size, use_heap);
145
146	9.80k	return SUCCESS;
147	9.80k	}
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	255k	{
152	255k	zend_ssa_op *ssa_op = ssa->ops + def;
153	255k	zend_op *opline = op_array->opcodes + def;
154
155	255k	if (ssa_op->result_def == var) {
156	195k	switch (opline->opcode) {
157	5.56k	case ZEND_INIT_ARRAY:
158	5.56k	return 1;
159	27.2k	case ZEND_NEW: {
160		/* objects with destructors should escape */
161	27.2k	zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
162	27.2k	script, op_array, opline);
163	27.2k	uint32_t forbidden_flags =
164		/* These flags will always cause an exception */
165	27.2k	ZEND_ACC_IMPLICIT_ABSTRACT_CLASS \| ZEND_ACC_EXPLICIT_ABSTRACT_CLASS
166	27.2k	\| ZEND_ACC_INTERFACE \| ZEND_ACC_TRAIT;
167	27.2k	if (ce
168	27.2k	&& !ce->parent
169	27.2k	&& !ce->create_object
170	27.2k	&& ce->default_object_handlers->get_constructor == zend_std_get_constructor
171	27.2k	&& ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
172	27.2k	&& !ce->constructor
173	27.2k	&& !ce->destructor
174	27.2k	&& !ce->__get
175	27.2k	&& !ce->__set
176	27.2k	&& !(ce->ce_flags & forbidden_flags)
177	27.2k	&& (ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
178	9.53k	return 1;
179	9.53k	}
180	17.6k	break;
181	27.2k	}
182	17.6k	case ZEND_QM_ASSIGN:
183	444	if (opline->op1_type == IS_CONST
184	444	&& Z_TYPE_P(CRT_CONSTANT(opline->op1)) == IS_ARRAY) {
185	96	return 1;
186	96	}
187	348	if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
188	176	return 1;
189	176	}
190	172	break;
191	531	case ZEND_ASSIGN:
192	531	if (opline->op1_type == IS_CV && (OP1_INFO() & MAY_BE_ARRAY)) {
193	198	return 1;
194	198	}
195	333	break;
196	195k	}
197	195k	} else if (ssa_op->op1_def == var) {
198	57.9k	switch (opline->opcode) {
199	36.1k	case ZEND_ASSIGN:
200	36.1k	if (opline->op2_type == IS_CONST
201	36.1k	&& Z_TYPE_P(CRT_CONSTANT(opline->op2)) == IS_ARRAY) {
202	5.84k	return 1;
203	5.84k	}
204	30.2k	if (opline->op2_type == IS_CV && (OP2_INFO() & MAY_BE_ARRAY)) {
205	420	return 1;
206	420	}
207	29.8k	break;
208	29.8k	case ZEND_ASSIGN_DIM:
209	1.98k	if (OP1_INFO() & (MAY_BE_UNDEF \| MAY_BE_NULL \| MAY_BE_FALSE)) {
210		/* implicit object/array allocation */
211	1.88k	return 1;
212	1.88k	}
213	96	break;
214	57.9k	}
215	57.9k	}
216
217	231k	return 0;
218	255k	}
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	112k	{
223	112k	zend_ssa_op *op = ssa->ops + def;
224	112k	zend_op *opline = op_array->opcodes + def;
225
226	112k	if (op->result_def == var) {
227	87.0k	switch (opline->opcode) {
228	3.71k	case ZEND_INIT_ARRAY:
229	21.0k	case ZEND_ADD_ARRAY_ELEMENT:
230	21.2k	case ZEND_QM_ASSIGN:
231	21.6k	case ZEND_ASSIGN:
232	21.6k	return 1;
233	8.50k	case ZEND_NEW: {
234		/* objects with destructors should escape */
235	8.50k	zend_class_entry *ce = zend_optimizer_get_class_entry_from_op1(
236	8.50k	script, op_array, opline);
237	8.50k	if (ce
238	8.50k	&& !ce->create_object
239	8.50k	&& ce->default_object_handlers->get_constructor == zend_std_get_constructor
240	8.50k	&& ce->default_object_handlers->dtor_obj == zend_objects_destroy_object
241	8.50k	&& !ce->constructor
242	8.50k	&& !ce->destructor
243	8.50k	&& !ce->__get
244	8.50k	&& !ce->__set
245	8.50k	&& !ce->parent) {
246	5.73k	return 1;
247	5.73k	}
248	2.77k	break;
249	8.50k	}
250	87.0k	}
251	87.0k	} else if (op->op1_def == var) {
252	23.7k	switch (opline->opcode) {
253	12.3k	case ZEND_ASSIGN:
254	15.4k	case ZEND_ASSIGN_DIM:
255	17.0k	case ZEND_ASSIGN_OBJ:
256	17.0k	case ZEND_ASSIGN_OBJ_REF:
257	17.1k	case ZEND_ASSIGN_DIM_OP:
258	17.3k	case ZEND_ASSIGN_OBJ_OP:
259	17.3k	case ZEND_PRE_INC_OBJ:
260	17.4k	case ZEND_PRE_DEC_OBJ:
261	17.4k	case ZEND_POST_INC_OBJ:
262	17.5k	case ZEND_POST_DEC_OBJ:
263	17.5k	return 1;
264	23.7k	}
265	23.7k	}
266
267	67.7k	return 0;
268	112k	}
269		/* }}} */
270
271		static bool is_escape_use(zend_op_array op_array, zend_ssa ssa, int use, int var) /* {{{ */
272	21.2k	{
273	21.2k	zend_ssa_op *ssa_op = ssa->ops + use;
274	21.2k	zend_op *opline = op_array->opcodes + use;
275
276	21.2k	if (ssa_op->op1_use == var) {
277	11.4k	switch (opline->opcode) {
278	568	case ZEND_ASSIGN:
279		/* no_val */
280	568	break;
281	142	case ZEND_QM_ASSIGN:
282	142	if (opline->op1_type == IS_CV) {
283	142	if (OP1_INFO() & MAY_BE_OBJECT) {
284		/* object aliasing */
285	128	return 1;
286	128	}
287	142	}
288	14	break;
289	58	case ZEND_ISSET_ISEMPTY_DIM_OBJ:
290	86	case ZEND_ISSET_ISEMPTY_PROP_OBJ:
291	1.24k	case ZEND_FETCH_DIM_R:
292	1.41k	case ZEND_FETCH_OBJ_R:
293	1.74k	case ZEND_FETCH_DIM_IS:
294	1.75k	case ZEND_FETCH_OBJ_IS:
295	1.75k	break;
296	2	case ZEND_ASSIGN_OP:
297	2	return 1;
298	57	case ZEND_ASSIGN_DIM_OP:
299	151	case ZEND_ASSIGN_OBJ_OP:
300	151	case ZEND_ASSIGN_STATIC_PROP_OP:
301	2.82k	case ZEND_ASSIGN_DIM:
302	3.29k	case ZEND_ASSIGN_OBJ:
303	3.32k	case ZEND_ASSIGN_OBJ_REF:
304	3.32k	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	506	case ZEND_INIT_ARRAY:
311	1.22k	case ZEND_ADD_ARRAY_ELEMENT:
312	1.22k	if (opline->extended_value & ZEND_ARRAY_ELEMENT_REF) {
313	0	return 1;
314	0	}
315	1.22k	if (OP1_INFO() & MAY_BE_OBJECT) {
316		/* object aliasing */
317	599	return 1;
318	599	}
319		/* reference dependencies processed separately */
320	627	break;
321	627	case ZEND_OP_DATA:
322	622	if ((opline-1)->opcode != ZEND_ASSIGN_DIM
323	622	&& (opline-1)->opcode != ZEND_ASSIGN_OBJ) {
324	76	return 1;
325	76	}
326	546	if (OP1_INFO() & MAY_BE_OBJECT) {
327		/* object aliasing */
328	395	return 1;
329	395	}
330	151	opline--;
331	151	ssa_op--;
332	151	if (opline->op1_type != IS_CV
333	151	\|\| (OP1_INFO() & MAY_BE_REF)
334	151	\|\| (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
335		/* assignment into escaping structure */
336	99	return 1;
337	99	}
338		/* reference dependencies processed separately */
339	52	break;
340	3.84k	default:
341	3.84k	return 1;
342	11.4k	}
343	11.4k	}
344
345	16.0k	if (ssa_op->op2_use == var) {
346	4.10k	switch (opline->opcode) {
347	3.64k	case ZEND_ASSIGN:
348	3.64k	if (opline->op1_type != IS_CV
349	3.64k	\|\| (OP1_INFO() & MAY_BE_REF)
350	3.64k	\|\| (ssa_op->op1_def >= 0 && ssa->vars[ssa_op->op1_def].alias)) {
351		/* assignment into escaping variable */
352	2.74k	return 1;
353	2.74k	}
354	900	if (opline->op2_type == IS_CV \|\| opline->result_type != IS_UNUSED) {
355	132	if (OP2_INFO() & MAY_BE_OBJECT) {
356		/* object aliasing */
357	76	return 1;
358	76	}
359	132	}
360	824	break;
361	824	default:
362	457	return 1;
363	4.10k	}
364	4.10k	}
365
366	12.8k	if (ssa_op->result_use == var) {
367	5.65k	switch (opline->opcode) {
368	0	case ZEND_ASSIGN:
369	0	case ZEND_QM_ASSIGN:
370	0	case ZEND_INIT_ARRAY:
371	5.65k	case ZEND_ADD_ARRAY_ELEMENT:
372	5.65k	break;
373	0	default:
374	0	return 1;
375	5.65k	}
376	5.65k	}
377
378	12.8k	return 0;
379	12.8k	}
380		/* }}} */
381
382		zend_result zend_ssa_escape_analysis(const zend_script script, zend_op_array op_array, zend_ssa ssa) / {{{ */
383	74.1k	{
384	74.1k	zend_ssa_var *ssa_vars = ssa->vars;
385	74.1k	int ssa_vars_count = ssa->vars_count;
386	74.1k	int i, root, use;
387	74.1k	int *ees;
388	74.1k	bool has_allocations;
389	74.1k	int num_non_escaped;
390	74.1k	ALLOCA_FLAG(use_heap)
391
392	74.1k	if (!ssa_vars) {
393	0	return SUCCESS;
394	0	}
395
396	74.1k	has_allocations = 0;
397	818k	for (i = op_array->last_var; i < ssa_vars_count; i++) {
398	753k	if (ssa_vars[i].definition >= 0
399	753k	&& (ssa->var_info[i].type & (MAY_BE_ARRAY\|MAY_BE_OBJECT))
400	753k	&& is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
401	9.80k	has_allocations = 1;
402	9.80k	break;
403	9.80k	}
404	753k	}
405	74.1k	if (!has_allocations) {
406	64.3k	return SUCCESS;
407	64.3k	}
408
409
410		/* 1. Build EES (Equi-Escape Sets) */
411	9.80k	ees = do_alloca(sizeof(int) * ssa_vars_count, use_heap);
412	9.80k	if (!ees) {
413	0	return FAILURE;
414	0	}
415
416	9.80k	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	9.80k	num_non_escaped = 0;
423	399k	for (i = op_array->last_var; i < ssa_vars_count; i++) {
424	390k	root = ees[i];
425	390k	if (ssa_vars[root].escape_state > ESCAPE_STATE_NO_ESCAPE) {
426		/* already escape. skip */
427	344k	} 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	344k	} else if (ssa_vars[i].definition >= 0
433	344k	&& (ssa->var_info[i].type & (MAY_BE_ARRAY\|MAY_BE_OBJECT))) {
434	112k	if (!is_local_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
435	67.7k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
436	3.17k	num_non_escaped--;
437	3.17k	}
438	67.7k	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
439	67.7k	} else if (ssa_vars[root].escape_state == ESCAPE_STATE_UNKNOWN
440	44.9k	&& is_allocation_def(op_array, ssa, ssa_vars[i].definition, i, script)) {
441	13.9k	ssa_vars[root].escape_state = ESCAPE_STATE_NO_ESCAPE;
442	13.9k	num_non_escaped++;
443	13.9k	}
444	112k	}
445	390k	}
446
447		/* 3. Mark escaped EES */
448	9.80k	if (num_non_escaped) {
449	294k	for (i = 0; i < ssa_vars_count; i++) {
450	287k	if (ssa_vars[i].use_chain >= 0) {
451	236k	root = ees[i];
452	236k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
453	40.9k	FOREACH_USE(ssa_vars + i, use) {
454	40.9k	if (is_escape_use(op_array, ssa, use, i)) {
455	8.42k	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
456	8.42k	num_non_escaped--;
457	8.42k	if (num_non_escaped == 0) {
458	5.50k	i = ssa_vars_count;
459	5.50k	}
460	8.42k	break;
461	8.42k	}
462	40.9k	} FOREACH_USE_END();
463	19.6k	}
464	236k	}
465	287k	}
466	6.98k	}
467
468		/* 4. Process referential dependencies */
469	9.80k	if (num_non_escaped) {
470	1.48k	bool changed;
471
472	1.52k	do {
473	1.52k	changed = 0;
474	79.1k	for (i = 0; i < ssa_vars_count; i++) {
475	77.5k	if (ssa_vars[i].use_chain >= 0) {
476	61.9k	root = ees[i];
477	61.9k	if (ssa_vars[root].escape_state == ESCAPE_STATE_NO_ESCAPE) {
478	15.6k	FOREACH_USE(ssa_vars + i, use) {
479	15.6k	zend_ssa_op *op = ssa->ops + use;
480	15.6k	zend_op *opline = op_array->opcodes + use;
481	15.6k	int enclosing_root;
482
483	15.6k	if (opline->opcode == ZEND_OP_DATA &&
484	8.44k	((opline-1)->opcode == ZEND_ASSIGN_DIM \|\|
485	48	(opline-1)->opcode == ZEND_ASSIGN_OBJ \|\|
486	48	(opline-1)->opcode == ZEND_ASSIGN_OBJ_REF) &&
487	8.44k	op->op1_use == i &&
488	8.44k	(op-1)->op1_use >= 0) {
489	48	enclosing_root = ees[(op-1)->op1_use];
490	8.39k	} else if ((opline->opcode == ZEND_INIT_ARRAY \|\|
491	8.39k	opline->opcode == ZEND_ADD_ARRAY_ELEMENT) &&
492	8.39k	op->op1_use == i &&
493	8.39k	op->result_def >= 0) {
494	1.30k	enclosing_root = ees[op->result_def];
495	7.08k	} else {
496	7.08k	continue;
497	7.08k	}
498
499	1.35k	if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN \|\|
500	1.35k	ssa_vars[enclosing_root].escape_state > ssa_vars[root].escape_state) {
501	625	if (ssa_vars[enclosing_root].escape_state == ESCAPE_STATE_UNKNOWN) {
502	2	ssa_vars[root].escape_state = ESCAPE_STATE_GLOBAL_ESCAPE;
503	623	} else {
504	623	ssa_vars[root].escape_state = ssa_vars[enclosing_root].escape_state;
505	623	}
506	625	if (ssa_vars[root].escape_state == ESCAPE_STATE_GLOBAL_ESCAPE) {
507	625	num_non_escaped--;
508	625	if (num_non_escaped == 0) {
509	131	changed = 0;
510	494	} else {
511	494	changed = 1;
512	494	}
513	625	break;
514	625	} else {
515	0	changed = 1;
516	0	}
517	625	}
518	1.35k	} FOREACH_USE_END();
519	7.25k	}
520	61.9k	}
521	77.5k	}
522	1.52k	} while (changed);
523	1.48k	}
524
525		/* 5. Propagate values of escape sets to variables */
526	429k	for (i = 0; i < ssa_vars_count; i++) {
527	419k	root = ees[i];
528	419k	if (i != root) {
529	171k	ssa_vars[i].escape_state = ssa_vars[root].escape_state;
530	171k	}
531	419k	}
532
533	9.80k	free_alloca(ees, use_heap);
534
535	9.80k	return SUCCESS;
536	9.80k	}
537		/* }}} */