/src/php-src/Zend/zend_opcode.c

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/*
   +----------------------------------------------------------------------+
   | Zend Engine                                                          |
   +----------------------------------------------------------------------+
   | Copyright (c) Zend Technologies Ltd. (http://www.zend.com)           |
   +----------------------------------------------------------------------+
   | This source file is subject to version 2.00 of the Zend license,     |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.zend.com/license/2_00.txt.                                |
   | If you did not receive a copy of the Zend license and are unable to  |
   | obtain it through the world-wide-web, please send a note to          |
   | license@zend.com so we can mail you a copy immediately.              |
   +----------------------------------------------------------------------+
   | Authors: Andi Gutmans <andi@php.net>                                 |
   |          Zeev Suraski <zeev@php.net>                                 |
   |          Dmitry Stogov <dmitry@php.net>                              |
   +----------------------------------------------------------------------+
*/

#include <stdio.h>

#include "zend.h"
#include "zend_alloc.h"
#include "zend_compile.h"
#include "zend_extensions.h"
#include "zend_API.h"
#include "zend_sort.h"
#include "zend_constants.h"
#include "zend_observer.h"

#include "zend_vm.h"

static void zend_extension_op_array_ctor_handler(zend_extension *extension, zend_op_array *op_array)
{
  if (extension->op_array_ctor) {
    extension->op_array_ctor(op_array);
  }
}

static void zend_extension_op_array_dtor_handler(zend_extension *extension, zend_op_array *op_array)
{
  if (extension->op_array_dtor) {
    extension->op_array_dtor(op_array);
  }
}

void init_op_array(zend_op_array *op_array, uint8_t type, int initial_ops_size)
{
  op_array->type = type;
  op_array->arg_flags[0] = 0;
  op_array->arg_flags[1] = 0;
  op_array->arg_flags[2] = 0;

  op_array->refcount = (uint32_t *) emalloc(sizeof(uint32_t));
  *op_array->refcount = 1;
  op_array->last = 0;
  op_array->opcodes = emalloc(initial_ops_size * sizeof(zend_op));

  op_array->last_var = 0;
  op_array->vars = NULL;

  op_array->T = 0;

  op_array->function_name = NULL;
  op_array->filename = zend_string_copy(zend_get_compiled_filename());
  op_array->doc_comment = NULL;
  op_array->attributes = NULL;

  op_array->arg_info = NULL;
  op_array->num_args = 0;
  op_array->required_num_args = 0;

  op_array->scope = NULL;
  op_array->prototype = NULL;
  op_array->prop_info = NULL;

  op_array->live_range = NULL;
  op_array->try_catch_array = NULL;
  op_array->last_live_range = 0;

  op_array->static_variables = NULL;
  ZEND_MAP_PTR_INIT(op_array->static_variables_ptr, NULL);
  op_array->last_try_catch = 0;

  op_array->fn_flags = 0;

  op_array->last_literal = 0;
  op_array->literals = NULL;

  op_array->num_dynamic_func_defs = 0;
  op_array->dynamic_func_defs = NULL;

  ZEND_MAP_PTR_INIT(op_array->run_time_cache, NULL);
  op_array->cache_size = zend_op_array_extension_handles * sizeof(void*);

  memset(op_array->reserved, 0, ZEND_MAX_RESERVED_RESOURCES * sizeof(void*));

  if (zend_extension_flags & ZEND_EXTENSIONS_HAVE_OP_ARRAY_CTOR) {
    zend_llist_apply_with_argument(&zend_extensions, (llist_apply_with_arg_func_t) zend_extension_op_array_ctor_handler, op_array);
  }
}

ZEND_API void destroy_zend_function(zend_function *function)
{
  zval tmp;

  ZVAL_PTR(&tmp, function);
  zend_function_dtor(&tmp);
}

ZEND_API void zend_type_release(zend_type type, bool persistent) {
  if (ZEND_TYPE_HAS_LIST(type)) {
    zend_type *list_type;
    ZEND_TYPE_LIST_FOREACH_MUTABLE(ZEND_TYPE_LIST(type), list_type) {
      zend_type_release(*list_type, persistent);
    } ZEND_TYPE_LIST_FOREACH_END();
    if (!ZEND_TYPE_USES_ARENA(type)) {
      pefree(ZEND_TYPE_LIST(type), persistent);
    }
  } else if (ZEND_TYPE_HAS_NAME(type)) {
    zend_string_release(ZEND_TYPE_NAME(type));
  }
}

void zend_free_internal_arg_info(zend_internal_function *function) {
  if ((function->fn_flags & (ZEND_ACC_HAS_RETURN_TYPE|ZEND_ACC_HAS_TYPE_HINTS)) &&
    function->arg_info) {

    uint32_t i;
    uint32_t num_args = function->num_args + 1;
    zend_internal_arg_info *arg_info = function->arg_info - 1;

    if (function->fn_flags & ZEND_ACC_VARIADIC) {
      num_args++;
    }
    for (i = 0 ; i < num_args; i++) {
      zend_type_release(arg_info[i].type, /* persistent */ 1);
    }
    free(arg_info);
  }
}

ZEND_API void zend_function_dtor(zval *zv)
{
  zend_function *function = Z_PTR_P(zv);

  if (function->type == ZEND_USER_FUNCTION) {
    ZEND_ASSERT(function->common.function_name);
    destroy_op_array(&function->op_array);
    /* op_arrays are allocated on arena, so we don't have to free them */
  } else {
    ZEND_ASSERT(function->type == ZEND_INTERNAL_FUNCTION);
    ZEND_ASSERT(function->common.function_name);
    zend_string_release_ex(function->common.function_name, 1);

    /* For methods this will be called explicitly. */
    if (!function->common.scope) {
      zend_free_internal_arg_info(&function->internal_function);

      if (function->common.attributes) {
        zend_hash_release(function->common.attributes);
        function->common.attributes = NULL;
      }
    }

    if (function->common.doc_comment) {
      zend_string_release_ex(function->common.doc_comment, 1);
      function->common.doc_comment = NULL;
    }

    if (!(function->common.fn_flags & ZEND_ACC_ARENA_ALLOCATED)) {
      pefree(function, 1);
    }
  }
}

ZEND_API void zend_cleanup_internal_class_data(zend_class_entry *ce)
{
  if (ZEND_MAP_PTR(ce->static_members_table) && CE_STATIC_MEMBERS(ce)) {
    zval *static_members = CE_STATIC_MEMBERS(ce);
    zval *p = static_members;
    zval *end = p + ce->default_static_members_count;
    ZEND_MAP_PTR_SET(ce->static_members_table, NULL);
    while (p != end) {
      if (UNEXPECTED(Z_ISREF_P(p))) {
        zend_property_info *prop_info;
        ZEND_REF_FOREACH_TYPE_SOURCES(Z_REF_P(p), prop_info) {
          if (prop_info->ce == ce && p - static_members == prop_info->offset) {
            ZEND_REF_DEL_TYPE_SOURCE(Z_REF_P(p), prop_info);
            break; /* stop iteration here, the array might be realloc()'ed */
          }
        } ZEND_REF_FOREACH_TYPE_SOURCES_END();
      }
      i_zval_ptr_dtor(p);
      p++;
    }
    efree(static_members);
  }
}

static void _destroy_zend_class_traits_info(zend_class_entry *ce)
{
  uint32_t i;

  for (i = 0; i < ce->num_traits; i++) {
    zend_string_release_ex(ce->trait_names[i].name, 0);
    zend_string_release_ex(ce->trait_names[i].lc_name, 0);
  }
  efree(ce->trait_names);

  if (ce->trait_aliases) {
    i = 0;
    while (ce->trait_aliases[i]) {
      if (ce->trait_aliases[i]->trait_method.method_name) {
        zend_string_release_ex(ce->trait_aliases[i]->trait_method.method_name, 0);
      }
      if (ce->trait_aliases[i]->trait_method.class_name) {
        zend_string_release_ex(ce->trait_aliases[i]->trait_method.class_name, 0);
      }

      if (ce->trait_aliases[i]->alias) {
        zend_string_release_ex(ce->trait_aliases[i]->alias, 0);
      }

      efree(ce->trait_aliases[i]);
      i++;
    }

    efree(ce->trait_aliases);
  }

  if (ce->trait_precedences) {
    uint32_t j;

    i = 0;
    while (ce->trait_precedences[i]) {
      zend_string_release_ex(ce->trait_precedences[i]->trait_method.method_name, 0);
      zend_string_release_ex(ce->trait_precedences[i]->trait_method.class_name, 0);

      for (j = 0; j < ce->trait_precedences[i]->num_excludes; j++) {
        zend_string_release_ex(ce->trait_precedences[i]->exclude_class_names[j], 0);
      }
      efree(ce->trait_precedences[i]);
      i++;
    }
    efree(ce->trait_precedences);
  }
}

ZEND_API void zend_cleanup_mutable_class_data(zend_class_entry *ce)
{
  zend_class_mutable_data *mutable_data = ZEND_MAP_PTR_GET_IMM(ce->mutable_data);

  if (mutable_data) {
    HashTable *constants_table;
    zval *p;

    constants_table = mutable_data->constants_table;
    if (constants_table && constants_table != &ce->constants_table) {
      zend_class_constant *c;

      ZEND_HASH_MAP_FOREACH_PTR(constants_table, c) {
        if (c->ce == ce || (Z_CONSTANT_FLAGS(c->value) & CONST_OWNED)) {
          zval_ptr_dtor_nogc(&c->value);
        }
      } ZEND_HASH_FOREACH_END();
      zend_hash_destroy(constants_table);
      mutable_data->constants_table = NULL;
    }

    p = mutable_data->default_properties_table;
    if (p && p != ce->default_properties_table) {
      zval *end = p + ce->default_properties_count;

      while (p < end) {
        zval_ptr_dtor_nogc(p);
        p++;
      }
      mutable_data->default_properties_table = NULL;
    }

    if (mutable_data->backed_enum_table) {
      zend_hash_release(mutable_data->backed_enum_table);
      mutable_data->backed_enum_table = NULL;
    }

    ZEND_MAP_PTR_SET_IMM(ce->mutable_data, NULL);
  }
}

ZEND_API void destroy_zend_class(zval *zv)
{
  zend_property_info *prop_info;
  zend_class_entry *ce = Z_PTR_P(zv);
  zend_function *fn;

  if (ce->ce_flags & ZEND_ACC_IMMUTABLE) {
    return;
  }

  /* We don't increase the refcount for class aliases,
   * skip the destruction of aliases entirely. */
  if (UNEXPECTED(Z_TYPE_INFO_P(zv) == IS_ALIAS_PTR)) {
    return;
  }

  if (ce->ce_flags & ZEND_ACC_FILE_CACHED) {
    zend_class_constant *c;
    zval *p, *end;

    ZEND_HASH_MAP_FOREACH_PTR(&ce->constants_table, c) {
      if (c->ce == ce) {
        zval_ptr_dtor_nogc(&c->value);
      }
    } ZEND_HASH_FOREACH_END();

    if (ce->default_properties_table) {
      p = ce->default_properties_table;
      end = p + ce->default_properties_count;

      while (p < end) {
        zval_ptr_dtor_nogc(p);
        p++;
      }
    }
    return;
  }

  ZEND_ASSERT(ce->refcount > 0);

  if (--ce->refcount > 0) {
    return;
  }

  switch (ce->type) {
    case ZEND_USER_CLASS:
      if (!(ce->ce_flags & ZEND_ACC_CACHED)) {
        if (ce->parent_name && !(ce->ce_flags & ZEND_ACC_RESOLVED_PARENT)) {
          zend_string_release_ex(ce->parent_name, 0);
        }

        zend_string_release_ex(ce->name, 0);
        zend_string_release_ex(ce->info.user.filename, 0);

        if (ce->doc_comment) {
          zend_string_release_ex(ce->doc_comment, 0);
        }

        if (ce->attributes) {
          zend_hash_release(ce->attributes);
        }

        if (ce->num_interfaces > 0 && !(ce->ce_flags & ZEND_ACC_RESOLVED_INTERFACES)) {
          uint32_t i;

          for (i = 0; i < ce->num_interfaces; i++) {
            zend_string_release_ex(ce->interface_names[i].name, 0);
            zend_string_release_ex(ce->interface_names[i].lc_name, 0);
          }
          efree(ce->interface_names);
        }

        if (ce->num_traits > 0) {
          _destroy_zend_class_traits_info(ce);
        }
      }

      if (ce->default_properties_table) {
        zval *p = ce->default_properties_table;
        zval *end = p + ce->default_properties_count;

        while (p != end) {
          i_zval_ptr_dtor(p);
          p++;
        }
        efree(ce->default_properties_table);
      }
      if (ce->default_static_members_table) {
        zval *p = ce->default_static_members_table;
        zval *end = p + ce->default_static_members_count;

        while (p != end) {
          ZEND_ASSERT(!Z_ISREF_P(p));
          i_zval_ptr_dtor(p);
          p++;
        }
        efree(ce->default_static_members_table);
      }
      ZEND_HASH_MAP_FOREACH_PTR(&ce->properties_info, prop_info) {
        if (prop_info->ce == ce) {
          zend_string_release_ex(prop_info->name, 0);
          if (prop_info->doc_comment) {
            zend_string_release_ex(prop_info->doc_comment, 0);
          }
          if (prop_info->attributes) {
            zend_hash_release(prop_info->attributes);
          }
          zend_type_release(prop_info->type, /* persistent */ 0);
          if (prop_info->hooks) {
            for (uint32_t i = 0; i < ZEND_PROPERTY_HOOK_COUNT; i++) {
              if (prop_info->hooks[i]) {
                destroy_op_array(&prop_info->hooks[i]->op_array);
              }
            }
          }
        }
      } ZEND_HASH_FOREACH_END();
      zend_hash_destroy(&ce->properties_info);
      zend_hash_destroy(&ce->function_table);
      if (zend_hash_num_elements(&ce->constants_table)) {
        zend_class_constant *c;

        ZEND_HASH_MAP_FOREACH_PTR(&ce->constants_table, c) {
          if (c->ce == ce || (Z_CONSTANT_FLAGS(c->value) & CONST_OWNED)) {
            zval_ptr_dtor_nogc(&c->value);
            if (c->doc_comment) {
              zend_string_release_ex(c->doc_comment, 0);
            }
            if (c->attributes) {
              zend_hash_release(c->attributes);
            }
          }
        } ZEND_HASH_FOREACH_END();
      }
      zend_hash_destroy(&ce->constants_table);
      if (ce->num_interfaces > 0 && (ce->ce_flags & ZEND_ACC_RESOLVED_INTERFACES)) {
        efree(ce->interfaces);
      }
      if (ce->backed_enum_table) {
        zend_hash_release(ce->backed_enum_table);
      }
      break;
    case ZEND_INTERNAL_CLASS:
      if (ce->doc_comment) {
        zend_string_release_ex(ce->doc_comment, 1);
      }

      if (ce->backed_enum_table) {
        zend_hash_release(ce->backed_enum_table);
      }
      if (ce->default_properties_table) {
        zval *p = ce->default_properties_table;
        zval *end = p + ce->default_properties_count;

        while (p != end) {
          zval_internal_ptr_dtor(p);
          p++;
        }
        free(ce->default_properties_table);
      }
      if (ce->default_static_members_table) {
        zval *p = ce->default_static_members_table;
        zval *end = p + ce->default_static_members_count;

        while (p != end) {
          zval_internal_ptr_dtor(p);
          p++;
        }
        free(ce->default_static_members_table);
      }

      ZEND_HASH_MAP_FOREACH_PTR(&ce->properties_info, prop_info) {
        if (prop_info->ce == ce) {
          zend_string_release(prop_info->name);
          zend_type_release(prop_info->type, /* persistent */ 1);
          if (prop_info->attributes) {
            zend_hash_release(prop_info->attributes);
          }
          free(prop_info);
        }
      } ZEND_HASH_FOREACH_END();
      zend_hash_destroy(&ce->properties_info);
      zend_string_release_ex(ce->name, 1);

      /* TODO: eliminate this loop for classes without functions with arg_info / attributes */
      ZEND_HASH_MAP_FOREACH_PTR(&ce->function_table, fn) {
        if (fn->common.scope == ce) {
          if (fn->common.fn_flags & (ZEND_ACC_HAS_RETURN_TYPE|ZEND_ACC_HAS_TYPE_HINTS)) {
            zend_free_internal_arg_info(&fn->internal_function);
          }

          if (fn->common.attributes) {
            zend_hash_release(fn->common.attributes);
            fn->common.attributes = NULL;
          }
        }
      } ZEND_HASH_FOREACH_END();

      zend_hash_destroy(&ce->function_table);
      if (zend_hash_num_elements(&ce->constants_table)) {
        zend_class_constant *c;

        ZEND_HASH_MAP_FOREACH_PTR(&ce->constants_table, c) {
          if (c->ce == ce) {
            if (Z_TYPE(c->value) == IS_CONSTANT_AST) {
              /* We marked this as IMMUTABLE, but do need to free it when the
               * class is destroyed. */
              ZEND_ASSERT(Z_ASTVAL(c->value)->kind == ZEND_AST_CONST_ENUM_INIT);
              free(Z_AST(c->value));
            } else {
              zval_internal_ptr_dtor(&c->value);
            }
            if (c->doc_comment) {
              zend_string_release_ex(c->doc_comment, 1);
            }
            if (c->attributes) {
              zend_hash_release(c->attributes);
            }
          }
          free(c);
        } ZEND_HASH_FOREACH_END();
        zend_hash_destroy(&ce->constants_table);
      }
      if (ce->iterator_funcs_ptr) {
        free(ce->iterator_funcs_ptr);
      }
      if (ce->arrayaccess_funcs_ptr) {
        free(ce->arrayaccess_funcs_ptr);
      }
      if (ce->num_interfaces > 0) {
        free(ce->interfaces);
      }
      if (ce->properties_info_table) {
        free(ce->properties_info_table);
      }
      if (ce->attributes) {
        zend_hash_release(ce->attributes);
      }
      free(ce);
      break;
  }
}

void zend_class_add_ref(zval *zv)
{
  zend_class_entry *ce = Z_PTR_P(zv);

  if (Z_TYPE_P(zv) != IS_ALIAS_PTR && !(ce->ce_flags & ZEND_ACC_IMMUTABLE)) {
    ce->refcount++;
  }
}

ZEND_API void zend_destroy_static_vars(zend_op_array *op_array)
{
  if (ZEND_MAP_PTR(op_array->static_variables_ptr)) {
    HashTable *ht = ZEND_MAP_PTR_GET(op_array->static_variables_ptr);
    if (ht) {
      zend_array_destroy(ht);
      ZEND_MAP_PTR_SET(op_array->static_variables_ptr, NULL);
    }
  }
}

ZEND_API void destroy_op_array(zend_op_array *op_array)
{
  uint32_t i;

  if ((op_array->fn_flags & ZEND_ACC_HEAP_RT_CACHE)
   && ZEND_MAP_PTR(op_array->run_time_cache)) {
    efree(ZEND_MAP_PTR(op_array->run_time_cache));
  }

  if (op_array->function_name) {
    zend_string_release_ex(op_array->function_name, 0);
  }

  if (!op_array->refcount || --(*op_array->refcount) > 0) {
    return;
  }

  efree_size(op_array->refcount, sizeof(*(op_array->refcount)));

  if (op_array->vars) {
    i = op_array->last_var;
    while (i > 0) {
      i--;
      zend_string_release_ex(op_array->vars[i], 0);
    }
    efree(op_array->vars);
  }

  /* ZEND_ACC_PTR_OPS and ZEND_ACC_OVERRIDE use the same value */
  if ((op_array->fn_flags & ZEND_ACC_PTR_OPS) && !op_array->function_name) {
    zend_op *op = op_array->opcodes;
    zend_op *end = op + op_array->last;
    while (op < end) {
      if (op->opcode == ZEND_DECLARE_ATTRIBUTED_CONST) {
        HashTable *attributes = Z_PTR_P(RT_CONSTANT(op+1, (op+1)->op1));
        zend_hash_release(attributes);
      }
      op++;
    }
  }
  if (op_array->literals) {
    zval *literal = op_array->literals;
    zval *end = literal + op_array->last_literal;
    while (literal < end) {
      zval_ptr_dtor_nogc(literal);
      literal++;
    }
    if (ZEND_USE_ABS_CONST_ADDR
     || !(op_array->fn_flags & ZEND_ACC_DONE_PASS_TWO)) {
      efree(op_array->literals);
    }
  }
  efree(op_array->opcodes);

  zend_string_release_ex(op_array->filename, 0);
  if (op_array->doc_comment) {
    zend_string_release_ex(op_array->doc_comment, 0);
  }
  if (op_array->attributes) {
    zend_hash_release(op_array->attributes);
  }
  if (op_array->live_range) {
    efree(op_array->live_range);
  }
  if (op_array->try_catch_array) {
    efree(op_array->try_catch_array);
  }
  if (zend_extension_flags & ZEND_EXTENSIONS_HAVE_OP_ARRAY_DTOR) {
    if (op_array->fn_flags & ZEND_ACC_DONE_PASS_TWO) {
      zend_llist_apply_with_argument(&zend_extensions, (llist_apply_with_arg_func_t) zend_extension_op_array_dtor_handler, op_array);
    }
  }
  if (op_array->arg_info) {
    uint32_t num_args = op_array->num_args;
    zend_arg_info *arg_info = op_array->arg_info;

    if (op_array->fn_flags & ZEND_ACC_HAS_RETURN_TYPE) {
      arg_info--;
      num_args++;
    }
    if (op_array->fn_flags & ZEND_ACC_VARIADIC) {
      num_args++;
    }
    for (i = 0 ; i < num_args; i++) {
      if (arg_info[i].name) {
        zend_string_release_ex(arg_info[i].name, 0);
      }
      zend_type_release(arg_info[i].type, /* persistent */ 0);
    }
    efree(arg_info);
  }
  if (op_array->static_variables) {
    zend_array_destroy(op_array->static_variables);
  }
  if (op_array->num_dynamic_func_defs) {
    for (i = 0; i < op_array->num_dynamic_func_defs; i++) {
      destroy_op_array(op_array->dynamic_func_defs[i]);
    }
    efree(op_array->dynamic_func_defs);
  }
}

static void zend_update_extended_stmts(zend_op_array *op_array)
{
  zend_op *opline = op_array->opcodes, *end=opline+op_array->last;

  while (opline<end) {
    if (opline->opcode == ZEND_EXT_STMT) {
      if (opline+1<end) {
        if ((opline+1)->opcode == ZEND_EXT_STMT) {
          opline->opcode = ZEND_NOP;
          opline++;
          continue;
        }
        if (opline+1<end) {
          opline->lineno = (opline+1)->lineno;
        }
      } else {
        opline->opcode = ZEND_NOP;
      }
    }
    opline++;
  }
}

static void zend_extension_op_array_handler(zend_extension *extension, zend_op_array *op_array)
{
  if (extension->op_array_handler) {
    extension->op_array_handler(op_array);
  }
}

static void zend_check_finally_breakout(zend_op_array *op_array, uint32_t op_num, uint32_t dst_num)
{
  int i;

  for (i = 0; i < op_array->last_try_catch; i++) {
    if ((op_num < op_array->try_catch_array[i].finally_op ||
          op_num >= op_array->try_catch_array[i].finally_end)
        && (dst_num >= op_array->try_catch_array[i].finally_op &&
           dst_num <= op_array->try_catch_array[i].finally_end)) {
      CG(in_compilation) = 1;
      CG(active_op_array) = op_array;
      CG(zend_lineno) = op_array->opcodes[op_num].lineno;
      zend_error_noreturn(E_COMPILE_ERROR, "jump into a finally block is disallowed");
    } else if ((op_num >= op_array->try_catch_array[i].finally_op
          && op_num <= op_array->try_catch_array[i].finally_end)
        && (dst_num > op_array->try_catch_array[i].finally_end
          || dst_num < op_array->try_catch_array[i].finally_op)) {
      CG(in_compilation) = 1;
      CG(active_op_array) = op_array;
      CG(zend_lineno) = op_array->opcodes[op_num].lineno;
      zend_error_noreturn(E_COMPILE_ERROR, "jump out of a finally block is disallowed");
    }
  }
}

static uint32_t zend_get_brk_cont_target(const zend_op_array *op_array, const zend_op *opline) {
  int nest_levels = opline->op2.num;
  int array_offset = opline->op1.num;
  zend_brk_cont_element *jmp_to;
  do {
    jmp_to = &CG(context).brk_cont_array[array_offset];
    if (nest_levels > 1) {
      array_offset = jmp_to->parent;
    }
  } while (--nest_levels > 0);

  return opline->opcode == ZEND_BRK ? jmp_to->brk : jmp_to->cont;
}

static void emit_live_range_raw(
    zend_op_array *op_array, uint32_t var_num, uint32_t kind, uint32_t start, uint32_t end) {
  zend_live_range *range;

  op_array->last_live_range++;
  op_array->live_range = erealloc(op_array->live_range,
    sizeof(zend_live_range) * op_array->last_live_range);

  ZEND_ASSERT(start < end);
  range = &op_array->live_range[op_array->last_live_range - 1];
  range->var = EX_NUM_TO_VAR(op_array->last_var + var_num);
  range->var |= kind;
  range->start = start;
  range->end = end;
}

static void emit_live_range(
    zend_op_array *op_array, uint32_t var_num, uint32_t start, uint32_t end,
    zend_needs_live_range_cb needs_live_range) {
  zend_op *def_opline = &op_array->opcodes[start], *orig_def_opline = def_opline;
  zend_op *use_opline = &op_array->opcodes[end];
  uint32_t kind;

  switch (def_opline->opcode) {
    /* These should never be the first def. */
    case ZEND_ADD_ARRAY_ELEMENT:
    case ZEND_ADD_ARRAY_UNPACK:
    case ZEND_ROPE_ADD:
      ZEND_UNREACHABLE();
      return;
    /* Result is boolean, it doesn't have to be destroyed. */
    case ZEND_JMPZ_EX:
    case ZEND_JMPNZ_EX:
    case ZEND_BOOL:
    case ZEND_BOOL_NOT:
    /* Classes don't have to be destroyed. */
    case ZEND_FETCH_CLASS:
    case ZEND_DECLARE_ANON_CLASS:
    /* FAST_CALLs don't have to be destroyed. */
    case ZEND_FAST_CALL:
      return;
    case ZEND_BEGIN_SILENCE:
      kind = ZEND_LIVE_SILENCE;
      start++;
      break;
    case ZEND_ROPE_INIT:
      kind = ZEND_LIVE_ROPE;
      /* ROPE live ranges include the generating opcode. */
      def_opline--;
      break;
    case ZEND_FE_RESET_R:
    case ZEND_FE_RESET_RW:
      kind = ZEND_LIVE_LOOP;
      start++;
      break;
    /* Objects created via ZEND_NEW are only fully initialized
     * after the DO_FCALL (constructor call).
     * We are creating two live-ranges: ZEND_LINE_NEW for uninitialized
     * part, and ZEND_LIVE_TMPVAR for initialized.
     */
    case ZEND_NEW:
    {
      int level = 0;
      uint32_t orig_start = start;

      while (def_opline + 1 < use_opline) {
        def_opline++;
        start++;
        switch (def_opline->opcode) {
          case ZEND_INIT_FCALL:
          case ZEND_INIT_FCALL_BY_NAME:
          case ZEND_INIT_NS_FCALL_BY_NAME:
          case ZEND_INIT_DYNAMIC_CALL:
          case ZEND_INIT_USER_CALL:
          case ZEND_INIT_METHOD_CALL:
          case ZEND_INIT_STATIC_METHOD_CALL:
          case ZEND_INIT_PARENT_PROPERTY_HOOK_CALL:
          case ZEND_NEW:
            level++;
            break;
          case ZEND_DO_FCALL:
          case ZEND_DO_FCALL_BY_NAME:
          case ZEND_DO_ICALL:
          case ZEND_DO_UCALL:
            if (level == 0) {
              goto done;
            }
            level--;
            break;
        }
      }
done:
      emit_live_range_raw(op_array, var_num, ZEND_LIVE_NEW, orig_start + 1, start + 1);
      if (start + 1 == end) {
        /* Trivial live-range, no need to store it. */
        return;
      }
    }
    ZEND_FALLTHROUGH;
    default:
      start++;
      kind = ZEND_LIVE_TMPVAR;

      /* Check hook to determine whether a live range is necessary,
       * e.g. based on type info. */
      if (needs_live_range && !needs_live_range(op_array, orig_def_opline)) {
        return;
      }
      break;
    case ZEND_COPY_TMP:
    {
      /* COPY_TMP has a split live-range: One from the definition until the use in
       * "null" branch, and another from the start of the "non-null" branch to the
       * FREE opcode. */
      uint32_t rt_var_num = EX_NUM_TO_VAR(op_array->last_var + var_num);
      if (needs_live_range && !needs_live_range(op_array, orig_def_opline)) {
        return;
      }

      kind = ZEND_LIVE_TMPVAR;
      if (use_opline->opcode != ZEND_FREE) {
        /* This can happen if one branch of the coalesce has been optimized away.
         * In this case we should emit a normal live-range instead. */
        start++;
        break;
      }

      zend_op *block_start_op = use_opline;
      while ((block_start_op-1)->opcode == ZEND_FREE) {
        block_start_op--;
      }

      start = block_start_op - op_array->opcodes;
      if (start != end) {
        emit_live_range_raw(op_array, var_num, kind, start, end);
      }

      do {
        use_opline--;

        /* The use might have been optimized away, in which case we will hit the def
         * instead. */
        if (use_opline->opcode == ZEND_COPY_TMP && use_opline->result.var == rt_var_num) {
          start = def_opline + 1 - op_array->opcodes;
          emit_live_range_raw(op_array, var_num, kind, start, end);
          return;
        }
      } while (!(
        ((use_opline->op1_type & (IS_TMP_VAR|IS_VAR)) && use_opline->op1.var == rt_var_num) ||
        ((use_opline->op2_type & (IS_TMP_VAR|IS_VAR)) && use_opline->op2.var == rt_var_num)
      ));

      start = def_opline + 1 - op_array->opcodes;
      end = use_opline - op_array->opcodes;
      emit_live_range_raw(op_array, var_num, kind, start, end);
      return;
    }
  }

  emit_live_range_raw(op_array, var_num, kind, start, end);
}

static bool is_fake_def(zend_op *opline) {
  /* These opcodes only modify the result, not create it. */
  return opline->opcode == ZEND_ROPE_ADD
    || opline->opcode == ZEND_ADD_ARRAY_ELEMENT
    || opline->opcode == ZEND_ADD_ARRAY_UNPACK;
}

static bool keeps_op1_alive(zend_op *opline) {
  /* These opcodes don't consume their OP1 operand,
   * it is later freed by something else. */
  if (opline->opcode == ZEND_CASE
   || opline->opcode == ZEND_CASE_STRICT
   || opline->opcode == ZEND_SWITCH_LONG
   || opline->opcode == ZEND_SWITCH_STRING
   || opline->opcode == ZEND_MATCH
   || opline->opcode == ZEND_MATCH_ERROR
   || opline->opcode == ZEND_FETCH_LIST_R
   || opline->opcode == ZEND_FETCH_LIST_W
   || opline->opcode == ZEND_COPY_TMP) {
    return 1;
  }
  ZEND_ASSERT(opline->opcode != ZEND_FE_FETCH_R
    && opline->opcode != ZEND_FE_FETCH_RW
    && opline->opcode != ZEND_VERIFY_RETURN_TYPE
    && opline->opcode != ZEND_BIND_LEXICAL
    && opline->opcode != ZEND_ROPE_ADD);
  return 0;
}

/* Live ranges must be sorted by increasing start opline */
static int cmp_live_range(const zend_live_range *a, const zend_live_range *b) {
  return a->start - b->start;
}
static void swap_live_range(zend_live_range *a, zend_live_range *b) {
  uint32_t tmp;
  tmp = a->var;
  a->var = b->var;
  b->var = tmp;
  tmp = a->start;
  a->start = b->start;
  b->start = tmp;
  tmp = a->end;
  a->end = b->end;
  b->end = tmp;
}

static void zend_calc_live_ranges(
    zend_op_array *op_array, zend_needs_live_range_cb needs_live_range) {
  uint32_t opnum = op_array->last;
  zend_op *opline = &op_array->opcodes[opnum];
  ALLOCA_FLAG(use_heap)
  uint32_t var_offset = op_array->last_var;
  uint32_t *last_use = do_alloca(sizeof(uint32_t) * op_array->T, use_heap);
  memset(last_use, -1, sizeof(uint32_t) * op_array->T);

  ZEND_ASSERT(!op_array->live_range);
  while (opnum > 0) {
    opnum--;
    opline--;

    /* SEPARATE always redeclares its op1. For the purposes of live-ranges,
     * its declaration is irrelevant. Don't terminate the current live-range
     * to avoid breaking special handling of COPY_TMP. */
    if (opline->opcode == ZEND_SEPARATE) {
      ZEND_ASSERT(opline->op1.var == opline->result.var);
      continue;
    }

    if ((opline->result_type & (IS_TMP_VAR|IS_VAR)) && !is_fake_def(opline)) {
      uint32_t var_num = EX_VAR_TO_NUM(opline->result.var) - var_offset;
      /* Defs without uses can occur for two reasons: Either because the result is
       * genuinely unused (e.g. omitted FREE opcode for an unused boolean result), or
       * because there are multiple defining opcodes (e.g. JMPZ_EX and QM_ASSIGN), in
       * which case the last one starts the live range. As such, we can simply ignore
       * missing uses here. */
      if (EXPECTED(last_use[var_num] != (uint32_t) -1)) {
        /* Skip trivial live-range */
        if (opnum + 1 != last_use[var_num]) {
          uint32_t num;

#if 1
          /* OP_DATA uses only op1 operand */
          ZEND_ASSERT(opline->opcode != ZEND_OP_DATA);
          num = opnum;
#else
          /* OP_DATA is really part of the previous opcode. */
          num = opnum - (opline->opcode == ZEND_OP_DATA);
#endif
          emit_live_range(op_array, var_num, num, last_use[var_num], needs_live_range);
        }
        last_use[var_num] = (uint32_t) -1;
      }
    }

    if ((opline->op1_type & (IS_TMP_VAR|IS_VAR))) {
      uint32_t var_num = EX_VAR_TO_NUM(opline->op1.var) - var_offset;
      if (EXPECTED(last_use[var_num] == (uint32_t) -1)) {
        if (EXPECTED(!keeps_op1_alive(opline))) {
          /* OP_DATA is really part of the previous opcode. */
          last_use[var_num] = opnum - (opline->opcode == ZEND_OP_DATA);
        }
      }
    }
    if (opline->op2_type & (IS_TMP_VAR|IS_VAR)) {
      uint32_t var_num = EX_VAR_TO_NUM(opline->op2.var) - var_offset;
      if (UNEXPECTED(opline->opcode == ZEND_FE_FETCH_R
          || opline->opcode == ZEND_FE_FETCH_RW)) {
        /* OP2 of FE_FETCH is actually a def, not a use. */
        if (last_use[var_num] != (uint32_t) -1) {
          if (opnum + 1 != last_use[var_num]) {
            emit_live_range(
              op_array, var_num, opnum, last_use[var_num], needs_live_range);
          }
          last_use[var_num] = (uint32_t) -1;
        }
      } else if (EXPECTED(last_use[var_num] == (uint32_t) -1)) {
#if 1
        /* OP_DATA uses only op1 operand */
        ZEND_ASSERT(opline->opcode != ZEND_OP_DATA);
        last_use[var_num] = opnum;
#else
        /* OP_DATA is really part of the previous opcode. */
        last_use[var_num] = opnum - (opline->opcode == ZEND_OP_DATA);
#endif
      }
    }
  }

  if (op_array->last_live_range > 1) {
    zend_live_range *r1 = op_array->live_range;
    zend_live_range *r2 = r1 + op_array->last_live_range - 1;

    /* In most cases we need just revert the array */
    while (r1 < r2) {
      swap_live_range(r1, r2);
      r1++;
      r2--;
    }

    r1 = op_array->live_range;
    r2 = r1 + op_array->last_live_range - 1;
    while (r1 < r2) {
      if (r1->start > (r1+1)->start) {
        zend_sort(r1, r2 - r1 + 1, sizeof(zend_live_range),
          (compare_func_t) cmp_live_range, (swap_func_t) swap_live_range);
        break;
      }
      r1++;
    }
  }

  free_alloca(last_use, use_heap);
}

ZEND_API void zend_recalc_live_ranges(
    zend_op_array *op_array, zend_needs_live_range_cb needs_live_range) {
  /* We assume that we never create live-ranges where there were none before. */
  ZEND_ASSERT(op_array->live_range);
  efree(op_array->live_range);
  op_array->live_range = NULL;
  op_array->last_live_range = 0;
  zend_calc_live_ranges(op_array, needs_live_range);
}

ZEND_API void pass_two(zend_op_array *op_array)
{
  zend_op *opline, *end;

  if (!ZEND_USER_CODE(op_array->type)) {
    return;
  }
  if (CG(compiler_options) & ZEND_COMPILE_EXTENDED_STMT) {
    zend_update_extended_stmts(op_array);
  }
  if (CG(compiler_options) & ZEND_COMPILE_HANDLE_OP_ARRAY) {
    if (zend_extension_flags & ZEND_EXTENSIONS_HAVE_OP_ARRAY_HANDLER) {
      zend_llist_apply_with_argument(&zend_extensions, (llist_apply_with_arg_func_t) zend_extension_op_array_handler, op_array);
    }
  }

  if (CG(context).vars_size != op_array->last_var) {
    op_array->vars = (zend_string**) erealloc(op_array->vars, sizeof(zend_string*)*op_array->last_var);
    CG(context).vars_size = op_array->last_var;
  }

#if ZEND_USE_ABS_CONST_ADDR
  if (CG(context).opcodes_size != op_array->last) {
    op_array->opcodes = (zend_op *) erealloc(op_array->opcodes, sizeof(zend_op)*op_array->last);
    CG(context).opcodes_size = op_array->last;
  }
  if (CG(context).literals_size != op_array->last_literal) {
    op_array->literals = (zval*)erealloc(op_array->literals, sizeof(zval) * op_array->last_literal);
    CG(context).literals_size = op_array->last_literal;
  }
#else
  op_array->opcodes = (zend_op *) erealloc(op_array->opcodes,
    ZEND_MM_ALIGNED_SIZE_EX(sizeof(zend_op) * op_array->last, 16) +
    sizeof(zval) * op_array->last_literal);
  if (op_array->literals) {
    memcpy(((char*)op_array->opcodes) + ZEND_MM_ALIGNED_SIZE_EX(sizeof(zend_op) * op_array->last, 16),
      op_array->literals, sizeof(zval) * op_array->last_literal);
    efree(op_array->literals);
    op_array->literals = (zval*)(((char*)op_array->opcodes) + ZEND_MM_ALIGNED_SIZE_EX(sizeof(zend_op) * op_array->last, 16));
  }
  CG(context).opcodes_size = op_array->last;
  CG(context).literals_size = op_array->last_literal;
#endif

    op_array->T += ZEND_OBSERVER_ENABLED; // reserve last temporary for observers if enabled

  /* Needs to be set directly after the opcode/literal reallocation, to ensure destruction
   * happens correctly if any of the following fixups generate a fatal error. */
  op_array->fn_flags |= ZEND_ACC_DONE_PASS_TWO;

  opline = op_array->opcodes;
  end = opline + op_array->last;
  while (opline < end) {
    switch (opline->opcode) {
      case ZEND_RECV_INIT:
        {
          zval *val = CT_CONSTANT(opline->op2);
          if (Z_TYPE_P(val) == IS_CONSTANT_AST) {
            uint32_t slot = ZEND_MM_ALIGNED_SIZE_EX(op_array->cache_size, 8);
            Z_CACHE_SLOT_P(val) = slot;
            op_array->cache_size += sizeof(zval);
          }
        }
        break;
      case ZEND_FAST_CALL:
        opline->op1.opline_num = op_array->try_catch_array[opline->op1.num].finally_op;
        ZEND_PASS_TWO_UPDATE_JMP_TARGET(op_array, opline, opline->op1);
        break;
      case ZEND_BRK:
      case ZEND_CONT:
        {
          uint32_t jmp_target = zend_get_brk_cont_target(op_array, opline);

          if (op_array->fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK) {
            zend_check_finally_breakout(op_array, opline - op_array->opcodes, jmp_target);
          }
          opline->opcode = ZEND_JMP;
          opline->op1.opline_num = jmp_target;
          opline->op2.num = 0;
          ZEND_PASS_TWO_UPDATE_JMP_TARGET(op_array, opline, opline->op1);
        }
        break;
      case ZEND_GOTO:
        zend_resolve_goto_label(op_array, opline);
        if (op_array->fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK) {
          zend_check_finally_breakout(op_array, opline - op_array->opcodes, opline->op1.opline_num);
        }
        ZEND_FALLTHROUGH;
      case ZEND_JMP:
        ZEND_PASS_TWO_UPDATE_JMP_TARGET(op_array, opline, opline->op1);
        break;
      case ZEND_JMPZ:
      case ZEND_JMPNZ:
      case ZEND_JMPZ_EX:
      case ZEND_JMPNZ_EX:
      case ZEND_JMP_SET:
      case ZEND_COALESCE:
      case ZEND_FE_RESET_R:
      case ZEND_FE_RESET_RW:
      case ZEND_JMP_NULL:
      case ZEND_BIND_INIT_STATIC_OR_JMP:
      case ZEND_JMP_FRAMELESS:
        ZEND_PASS_TWO_UPDATE_JMP_TARGET(op_array, opline, opline->op2);
        break;
      case ZEND_ASSERT_CHECK:
      {
        /* If result of assert is unused, result of check is unused as well */
        zend_op *call = &op_array->opcodes[opline->op2.opline_num - 1];
        if (call->opcode == ZEND_EXT_FCALL_END) {
          call--;
        }
        if (call->result_type == IS_UNUSED) {
          opline->result_type = IS_UNUSED;
        }
        ZEND_PASS_TWO_UPDATE_JMP_TARGET(op_array, opline, opline->op2);
        break;
      }
      case ZEND_FE_FETCH_R:
      case ZEND_FE_FETCH_RW:
        /* absolute index to relative offset */
        opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, opline, opline->extended_value);
        break;
      case ZEND_CATCH:
        if (!(opline->extended_value & ZEND_LAST_CATCH)) {
          ZEND_PASS_TWO_UPDATE_JMP_TARGET(op_array, opline, opline->op2);
        }
        break;
      case ZEND_RETURN:
      case ZEND_RETURN_BY_REF:
        if (op_array->fn_flags & ZEND_ACC_GENERATOR) {
          opline->opcode = ZEND_GENERATOR_RETURN;
        }
        break;
      case ZEND_SWITCH_LONG:
      case ZEND_SWITCH_STRING:
      case ZEND_MATCH:
      {
        /* absolute indexes to relative offsets */
        HashTable *jumptable = Z_ARRVAL_P(CT_CONSTANT(opline->op2));
        zval *zv;
        ZEND_HASH_FOREACH_VAL(jumptable, zv) {
          Z_LVAL_P(zv) = ZEND_OPLINE_NUM_TO_OFFSET(op_array, opline, Z_LVAL_P(zv));
        } ZEND_HASH_FOREACH_END();

        opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, opline, opline->extended_value);
        break;
      }
    }
    if (opline->op1_type == IS_CONST) {
      ZEND_PASS_TWO_UPDATE_CONSTANT(op_array, opline, opline->op1);
    } else if (opline->op1_type & (IS_VAR|IS_TMP_VAR)) {
      opline->op1.var = EX_NUM_TO_VAR(op_array->last_var + opline->op1.var);
    }
    if (opline->op2_type == IS_CONST) {
      ZEND_PASS_TWO_UPDATE_CONSTANT(op_array, opline, opline->op2);
    } else if (opline->op2_type & (IS_VAR|IS_TMP_VAR)) {
      opline->op2.var = EX_NUM_TO_VAR(op_array->last_var + opline->op2.var);
    }
    if (opline->result_type & (IS_VAR|IS_TMP_VAR)) {
      opline->result.var = EX_NUM_TO_VAR(op_array->last_var + opline->result.var);
    }
    ZEND_VM_SET_OPCODE_HANDLER(opline);
    opline++;
  }

  zend_calc_live_ranges(op_array, NULL);

  return;
}

ZEND_API unary_op_type get_unary_op(int opcode)
{
  switch (opcode) {
    case ZEND_BW_NOT:
      return (unary_op_type) bitwise_not_function;
    case ZEND_BOOL_NOT:
      return (unary_op_type) boolean_not_function;
    default:
      return (unary_op_type) NULL;
  }
}

ZEND_API binary_op_type get_binary_op(int opcode)
{
  switch (opcode) {
    case ZEND_ADD:
      return (binary_op_type) add_function;
    case ZEND_SUB:
      return (binary_op_type) sub_function;
    case ZEND_MUL:
      return (binary_op_type) mul_function;
    case ZEND_POW:
      return (binary_op_type) pow_function;
    case ZEND_DIV:
      return (binary_op_type) div_function;
    case ZEND_MOD:
      return (binary_op_type) mod_function;
    case ZEND_SL:
      return (binary_op_type) shift_left_function;
    case ZEND_SR:
      return (binary_op_type) shift_right_function;
    case ZEND_FAST_CONCAT:
    case ZEND_CONCAT:
      return (binary_op_type) concat_function;
    case ZEND_IS_IDENTICAL:
    case ZEND_CASE_STRICT:
      return (binary_op_type) is_identical_function;
    case ZEND_IS_NOT_IDENTICAL:
      return (binary_op_type) is_not_identical_function;
    case ZEND_IS_EQUAL:
    case ZEND_CASE:
      return (binary_op_type) is_equal_function;
    case ZEND_IS_NOT_EQUAL:
      return (binary_op_type) is_not_equal_function;
    case ZEND_IS_SMALLER:
      return (binary_op_type) is_smaller_function;
    case ZEND_IS_SMALLER_OR_EQUAL:
      return (binary_op_type) is_smaller_or_equal_function;
    case ZEND_SPACESHIP:
      return (binary_op_type) compare_function;
    case ZEND_BW_OR:
      return (binary_op_type) bitwise_or_function;
    case ZEND_BW_AND:
      return (binary_op_type) bitwise_and_function;
    case ZEND_BW_XOR:
      return (binary_op_type) bitwise_xor_function;
    case ZEND_BOOL_XOR:
      return (binary_op_type) boolean_xor_function;
    default:
      ZEND_UNREACHABLE();
      return (binary_op_type) NULL;
  }
}

Coverage Report

Created: 2025-06-13 06:43