/*

   +----------------------------------------------------------------------+

   | Zend Engine                                                          |

   +----------------------------------------------------------------------+

   | Copyright © Zend Technologies Ltd., a subsidiary company of          |

   |     Perforce Software, Inc., and Contributors.                       |

   +----------------------------------------------------------------------+

   | This source file is subject to the Modified BSD License that is      |

   | bundled with this package in the file LICENSE, and is available      |

   | through the World Wide Web at <https://www.php.net/license/>.        |

   |                                                                      |

   | SPDX-License-Identifier: BSD-3-Clause                                |

   +----------------------------------------------------------------------+

   | Authors: Christian Seiler <chris_se@gmx.net>                         |

   |          Dmitry Stogov <dmitry@php.net>                              |

   |          Marcus Boerger <helly@php.net>                              |

   +----------------------------------------------------------------------+

*/

#include "zend.h"

#include "zend_API.h"

#include "zend_closures.h"

#include "zend_exceptions.h"

#include "zend_interfaces.h"

#include "zend_objects.h"

#include "zend_objects_API.h"

#include "zend_globals.h"

#include "zend_closures_arginfo.h"

/* Closure is a PFA */

#define ZEND_PARTIAL            OBJ_EXTRA_FLAG_PRIV_1

/* Closure is a PFA of a Closure. Rebinding the PFA requires rebinding the inner Closure. */

#define ZEND_PARTIAL_OF_CLOSURE OBJ_EXTRA_FLAG_PRIV_2

typedef struct _zend_closure {

  zend_object       std;

  zend_function     func;

  zend_object      *this_ptr;

  zend_class_entry *called_scope;

  zif_handler       orig_internal_handler;

} zend_closure;

/* non-static since it needs to be referenced */

ZEND_API zend_class_entry *zend_ce_closure;

static zend_object_handlers closure_handlers;

static zend_result zend_closure_get_closure(zend_object *obj, zend_class_entry **ce_ptr, zend_function **fptr_ptr, zend_object **obj_ptr, bool check_only);

static void zend_create_closure_ex(zval *res, zend_function *func, zend_class_entry *scope, zend_class_entry *called_scope, zend_object *this_ptr, bool is_fake, uint32_t flags);

static inline uint32_t zend_closure_flags(const zend_closure *closure)

{

  return closure->std.extra_flags & (ZEND_PARTIAL|ZEND_PARTIAL_OF_CLOSURE);

}

static inline bool zend_closure_is_fake(const zend_closure *closure)

{

  return closure->func.common.fn_flags & ZEND_ACC_FAKE_CLOSURE;

}

ZEND_METHOD(Closure, __invoke) /* {{{ */

{

  zend_function *func = EX(func);

  zval *args;

  uint32_t num_args;

  HashTable *named_args;

  ZEND_PARSE_PARAMETERS_START(0, -1)

    Z_PARAM_VARIADIC_WITH_NAMED(args, num_args, named_args)

  ZEND_PARSE_PARAMETERS_END();

  zend_fcall_info_cache fcc = {

    .closure = Z_OBJ_P(ZEND_THIS),

  };

  zend_closure_get_closure(Z_OBJ_P(ZEND_THIS), &fcc.calling_scope, &fcc.function_handler, &fcc.object, false);

  fcc.called_scope = fcc.calling_scope;

  zend_call_known_fcc(&fcc, return_value, num_args, args, named_args);

  zend_return_unwrap_ref(execute_data, return_value);

  /* destruct the function also, then - we have allocated it in get_method */

  zend_string_release_ex(func->internal_function.function_name, 0);

  efree(func);

  /* Set the func pointer to NULL. Prior to PHP 8.3, this was only done for debug builds,

   * because debug builds check certain properties after the call and needed to know this

   * had been freed.

   * However, extensions can proxy zend_execute_internal, and it's a bit surprising to have

   * an invalid func pointer sitting on there, so this was changed in PHP 8.3.

   */

  execute_data->func = NULL;

}

/* }}} */

static bool zend_valid_closure_binding(

    zend_closure *closure, zend_object *new_this, zend_class_entry *scope) /* {{{ */

{

  zend_function *func = &closure->func;

  // TODO: rename variable

  bool is_fake_closure = (func->common.fn_flags & ZEND_ACC_FAKE_CLOSURE) != 0

    || (closure->std.extra_flags & ZEND_PARTIAL);

  if (new_this) {

    if (func->common.fn_flags & ZEND_ACC_STATIC) {

      zend_error(E_WARNING, "Cannot bind an instance to a static closure, this will be an error in PHP 9");

      return false;

    }

    if (is_fake_closure && func->common.scope &&

        !instanceof_function(new_this->ce, func->common.scope)) {

      /* Binding incompatible $this to an internal method is not supported. */

      zend_error(E_WARNING, "Cannot bind method %s::%s() to object of class %s, this will be an error in PHP 9",

          ZSTR_VAL(func->common.scope->name),

          ZSTR_VAL(func->common.function_name),

          ZSTR_VAL(new_this->ce->name));

      return false;

    }

  } else if (is_fake_closure && func->common.scope

      && !(func->common.fn_flags & ZEND_ACC_STATIC)) {

    zend_error(E_WARNING, "Cannot unbind $this of method, this will be an error in PHP 9");

    return false;

  } else if (!is_fake_closure && closure->this_ptr

      && (func->common.fn_flags & ZEND_ACC_USES_THIS)) {

    zend_error(E_WARNING, "Cannot unbind $this of closure using $this, this will be an error in PHP 9");

    return false;

  }

  if (scope && scope != func->common.scope && scope->type == ZEND_INTERNAL_CLASS) {

    /* rebinding to internal class is not allowed */

    zend_error(E_WARNING, "Cannot bind closure to scope of internal class %s, this will be an error in PHP 9",

        ZSTR_VAL(scope->name));

    return false;

  }

  if (is_fake_closure && scope != func->common.scope) {

    if (func->common.scope == NULL) {

      zend_error(E_WARNING, "Cannot rebind scope of closure created from function, this will be an error in PHP 9");

    } else {

      zend_error(E_WARNING, "Cannot rebind scope of closure created from method, this will be an error in PHP 9");

    }

    return false;

  }

  return true;

}

/* }}} */

/* {{{ Call closure, binding to a given object with its class as the scope */

ZEND_METHOD(Closure, call)

{

  zval closure_result;

  zend_closure *closure;

  zend_fcall_info fci;

  zend_fcall_info_cache fci_cache;

  zend_object *new_this;

  zend_class_entry *newclass;

  fci.param_count = 0;

  fci.params = NULL;

  ZEND_PARSE_PARAMETERS_START(1, -1)

    Z_PARAM_OBJ(new_this)

    Z_PARAM_VARIADIC_WITH_NAMED(fci.params, fci.param_count, fci.named_params)

  ZEND_PARSE_PARAMETERS_END();

  closure = (zend_closure *) Z_OBJ_P(ZEND_THIS);

  newclass = new_this->ce;

  if (!zend_valid_closure_binding(closure, new_this, newclass)) {

    return;

  }

  fci_cache.called_scope = newclass;

  fci_cache.object = new_this;

  fci.size = sizeof(fci);

  fci.consumed_args = 0;

  ZVAL_OBJ(&fci.function_name, &closure->std);

  ZVAL_UNDEF(&closure_result);

  fci.retval = &closure_result;

  if (closure->func.common.fn_flags & ZEND_ACC_GENERATOR) {

    zval new_closure;

    zend_create_closure_ex(&new_closure, &closure->func, newclass,

        closure->called_scope, new_this,

        zend_closure_is_fake(closure), zend_closure_flags(closure));

    closure = (zend_closure *) Z_OBJ(new_closure);

    fci_cache.function_handler = &closure->func;

    zend_call_function(&fci, &fci_cache);

    /* copied upon generator creation */

    GC_DELREF(&closure->std);

  } else {

    zend_closure *fake_closure;

    zend_function *my_function;

    fake_closure = emalloc(sizeof(zend_closure));

    memset(&fake_closure->std, 0, sizeof(fake_closure->std));

    fake_closure->std.gc.refcount = 1;

    fake_closure->std.gc.u.type_info = GC_NULL;

    fake_closure->std.extra_flags = zend_closure_flags(closure);

    fake_closure->this_ptr = NULL;

    fake_closure->called_scope = NULL;

    my_function = &fake_closure->func;

    if (ZEND_USER_CODE(closure->func.type)) {

      memcpy(my_function, &closure->func, sizeof(zend_op_array));

    } else {

      memcpy(my_function, &closure->func, sizeof(zend_internal_function));

    }

    /* use scope of passed object */

    my_function->common.scope = newclass;

    if (closure->func.type == ZEND_INTERNAL_FUNCTION) {

      my_function->internal_function.handler = closure->orig_internal_handler;

    }

    fci_cache.function_handler = my_function;

    /* Runtime cache relies on bound scope to be immutable, hence we need a separate rt cache in case scope changed */

    if (ZEND_USER_CODE(my_function->type)

     && (closure->func.common.scope != newclass

      || (closure->func.common.fn_flags & ZEND_ACC_HEAP_RT_CACHE))) {

      void *ptr;

      my_function->op_array.fn_flags |= ZEND_ACC_HEAP_RT_CACHE;

      ptr = emalloc(my_function->op_array.cache_size);

      ZEND_MAP_PTR_INIT(my_function->op_array.run_time_cache, ptr);

      memset(ptr, 0, my_function->op_array.cache_size);

    }

    zend_call_function(&fci, &fci_cache);

    if (ZEND_USER_CODE(my_function->type)) {

      if (fci_cache.function_handler->common.fn_flags & ZEND_ACC_HEAP_RT_CACHE) {

        efree(ZEND_MAP_PTR(my_function->op_array.run_time_cache));

      }

    }

    efree_size(fake_closure, sizeof(zend_closure));

  }

  if (Z_TYPE(closure_result) != IS_UNDEF) {

    if (Z_ISREF(closure_result)) {

      zend_unwrap_reference(&closure_result);

    }

    ZVAL_COPY_VALUE(return_value, &closure_result);

  }

}

/* }}} */

static zend_result do_closure_bind(zval *return_value, zval *zclosure, zend_object *new_this, zend_object *scope_obj, zend_string *scope_str)

{

  zend_class_entry *ce, *called_scope;

  zend_closure *closure = (zend_closure *) Z_OBJ_P(zclosure);

  if (scope_obj) {

    ce = scope_obj->ce;

  } else if (scope_str) {

    if (zend_string_equals(scope_str, ZSTR_KNOWN(ZEND_STR_STATIC))) {

      ce = closure->func.common.scope;

    } else if ((ce = zend_lookup_class(scope_str)) == NULL) {

      zend_error(E_WARNING, "Class \"%s\" not found", ZSTR_VAL(scope_str));

      RETVAL_NULL();

      return FAILURE;

    }

  } else {

    ce = NULL;

  }

  if (!zend_valid_closure_binding(closure, new_this, ce)) {

    return FAILURE;

  }

  if (new_this) {

    called_scope = new_this->ce;

  } else {

    called_scope = ce;

  }

  zend_create_closure_ex(return_value, &closure->func, ce, called_scope, new_this,

    zend_closure_is_fake(closure), zend_closure_flags(closure));

  if (zend_closure_flags(closure) & ZEND_PARTIAL_OF_CLOSURE) {

    /* Re-bind the inner closure */

    zend_closure *new_closure = (zend_closure*)Z_OBJ_P(return_value);

    HashTable *static_variables = ZEND_MAP_PTR_GET(new_closure->func.op_array.static_variables_ptr);

    ZEND_ASSERT(static_variables->nNumOfElements > 0);

    zval *inner = &static_variables->arData[0].val;

    ZEND_ASSERT(Z_TYPE_P(inner) == IS_OBJECT && Z_OBJCE_P(inner) == zend_ce_closure);

    zval new_inner;

    if (do_closure_bind(&new_inner, inner, new_this, scope_obj, scope_str) != SUCCESS) {

      /* Should not happen, as we have already validated arguments and the

       * inner closure should have the same constraints. */

      ZEND_UNREACHABLE();

      zval_ptr_dtor(return_value);

      ZVAL_NULL(return_value);

      return FAILURE;

    }

    zend_object *garbage = Z_OBJ_P(inner);

    ZVAL_COPY_VALUE(inner, &new_inner);

    zend_object_release(garbage);

  }

  return SUCCESS;

}

/* {{{ Create a closure from another one and bind to another object and scope */

ZEND_METHOD(Closure, bind)

{

  zval *zclosure;

  zend_object *new_this;

  zend_object *scope_obj = NULL;

  zend_string *scope_str = ZSTR_KNOWN(ZEND_STR_STATIC);

  ZEND_PARSE_PARAMETERS_START(2, 3)

    Z_PARAM_OBJECT_OF_CLASS(zclosure, zend_ce_closure)

    Z_PARAM_OBJ_OR_NULL(new_this)

    Z_PARAM_OPTIONAL

    Z_PARAM_OBJ_OR_STR_OR_NULL(scope_obj, scope_str)

  ZEND_PARSE_PARAMETERS_END();

  do_closure_bind(return_value, zclosure, new_this, scope_obj, scope_str);

}

/* {{{ Create a closure from another one and bind to another object and scope */

ZEND_METHOD(Closure, bindTo)

{

  zend_object *new_this;

  zend_object *scope_obj = NULL;

  zend_string *scope_str = ZSTR_KNOWN(ZEND_STR_STATIC);

  ZEND_PARSE_PARAMETERS_START(1, 2)

    Z_PARAM_OBJ_OR_NULL(new_this)

    Z_PARAM_OPTIONAL

    Z_PARAM_OBJ_OR_STR_OR_NULL(scope_obj, scope_str)

  ZEND_PARSE_PARAMETERS_END();

  do_closure_bind(return_value, ZEND_THIS, new_this, scope_obj, scope_str);

}

static void zend_copy_parameters_array(const uint32_t param_count, HashTable *argument_array) /* {{{ */

{

  zval *param_ptr = ZEND_CALL_ARG(EG(current_execute_data), 1);

  ZEND_ASSERT(param_count <= ZEND_CALL_NUM_ARGS(EG(current_execute_data)));

  for (uint32_t i = 0; i < param_count; i++) {

    Z_TRY_ADDREF_P(param_ptr);

    zend_hash_next_index_insert_new(argument_array, param_ptr);

    param_ptr++;

  }

}

static ZEND_NAMED_FUNCTION(zend_closure_call_magic) /* {{{ */ {

  zend_fcall_info fci;

  zend_fcall_info_cache fcc;

  zval params[2];

  memset(&fci, 0, sizeof(zend_fcall_info));

  memset(&fcc, 0, sizeof(zend_fcall_info_cache));

  fci.size = sizeof(zend_fcall_info);

  fci.retval = return_value;

  fcc.function_handler = (EX(func)->internal_function.fn_flags & ZEND_ACC_STATIC) ?

    EX(func)->internal_function.scope->__callstatic : EX(func)->internal_function.scope->__call;

  fci.named_params = NULL;

  fci.params = params;

  fci.param_count = 2;

  ZVAL_STR(&fci.params[0], EX(func)->common.function_name);

  if (EX_CALL_INFO() & ZEND_CALL_HAS_EXTRA_NAMED_PARAMS) {

    zend_string *name;

    zval *named_param_zval;

    array_init_size(&fci.params[1], ZEND_NUM_ARGS() + zend_hash_num_elements(EX(extra_named_params)));

    /* Avoid conversion from packed to mixed later. */

    zend_hash_real_init_mixed(Z_ARRVAL(fci.params[1]));

    zend_copy_parameters_array(ZEND_NUM_ARGS(), Z_ARRVAL(fci.params[1]));

    ZEND_HASH_MAP_FOREACH_STR_KEY_VAL(EX(extra_named_params), name, named_param_zval) {

      Z_TRY_ADDREF_P(named_param_zval);

      zend_hash_add_new(Z_ARRVAL(fci.params[1]), name, named_param_zval);

    } ZEND_HASH_FOREACH_END();

  } else if (ZEND_NUM_ARGS()) {

    array_init_size(&fci.params[1], ZEND_NUM_ARGS());

    zend_copy_parameters_array(ZEND_NUM_ARGS(), Z_ARRVAL(fci.params[1]));

  } else {

    ZVAL_EMPTY_ARRAY(&fci.params[1]);

  }

  fcc.object = Z_OBJ_P(ZEND_THIS);

  fcc.called_scope = zend_get_called_scope(EG(current_execute_data));

  zend_call_function(&fci, &fcc);

  zend_return_unwrap_ref(EG(current_execute_data), return_value);

  zval_ptr_dtor(&fci.params[1]);

}

/* }}} */

static zend_result zend_create_closure_from_callable(zval *return_value, zval *callable, char **error) /* {{{ */ {

  zend_fcall_info_cache fcc;

  zend_function *mptr;

  zend_internal_function call;

  if (!zend_is_callable(callable, &fcc, error)) {

    return FAILURE;

  }

  mptr = fcc.function_handler;

  if (mptr->common.fn_flags & ZEND_ACC_CALL_VIA_TRAMPOLINE) {

    /* For Closure::fromCallable([$closure, "__invoke"]) return $closure. */

    if (fcc.object && fcc.object->ce == zend_ce_closure

        && zend_string_equals(mptr->common.function_name, ZSTR_KNOWN(ZEND_STR_MAGIC_INVOKE))) {

      RETVAL_OBJ_COPY(fcc.object);

      zend_free_trampoline(mptr);

      return SUCCESS;

    }

    if (!mptr->common.scope) {

      return FAILURE;

    }

    if (mptr->common.fn_flags & ZEND_ACC_STATIC) {

      if (!mptr->common.scope->__callstatic) {

        return FAILURE;

      }

    } else {

      if (!mptr->common.scope->__call) {

        return FAILURE;

      }

    }

    memset(&call, 0, sizeof(zend_internal_function));

    call.type = ZEND_INTERNAL_FUNCTION;

    call.fn_flags = mptr->common.fn_flags & (ZEND_ACC_STATIC | ZEND_ACC_DEPRECATED);

    call.handler = zend_closure_call_magic;

    call.function_name = mptr->common.function_name;

    call.scope = mptr->common.scope;

    call.doc_comment = NULL;

    call.attributes = mptr->common.attributes;

    zend_free_trampoline(mptr);

    mptr = (zend_function *) &call;

  }

  zend_create_fake_closure(return_value, mptr, mptr->common.scope, fcc.called_scope, fcc.object);

  if (&mptr->internal_function == &call) {

    zend_string_release(mptr->common.function_name);

  }

  return SUCCESS;

}

/* }}} */

/* {{{ Create a closure from a callable using the current scope. */

ZEND_METHOD(Closure, fromCallable)

{

  zval *callable;

  char *error = NULL;

  ZEND_PARSE_PARAMETERS_START(1, 1)

    Z_PARAM_ZVAL(callable)

  ZEND_PARSE_PARAMETERS_END();

  if (Z_TYPE_P(callable) == IS_OBJECT && instanceof_function(Z_OBJCE_P(callable), zend_ce_closure)) {

    /* It's already a closure */

    RETURN_COPY(callable);

  }

  if (zend_create_closure_from_callable(return_value, callable, &error) == FAILURE) {

    if (error) {

      zend_type_error("Failed to create closure from callable: %s", error);

      efree(error);

    } else {

      zend_type_error("Failed to create closure from callable");

    }

  }

}

/* }}} */

ZEND_METHOD(Closure, getCurrent)

{

  ZEND_PARSE_PARAMETERS_NONE();

  zend_execute_data *prev_ex = EX(prev_execute_data);

  if (!prev_ex

   || !prev_ex->func

   || (prev_ex->func->common.fn_flags & (ZEND_ACC_CLOSURE|ZEND_ACC_FAKE_CLOSURE)) != ZEND_ACC_CLOSURE) {

      zend_throw_error(NULL, "Current function is not a closure");

      RETURN_THROWS();

  }

  zend_object *obj = ZEND_CLOSURE_OBJECT(prev_ex->func);

  RETURN_OBJ_COPY(obj);

}

static ZEND_COLD zend_function *zend_closure_get_constructor(zend_object *object) /* {{{ */

{

  zend_throw_error(NULL, "Instantiation of class Closure is not allowed");

  return NULL;

}

/* }}} */

/* int return due to Object Handler API */

static int zend_closure_compare(zval *o1, zval *o2) /* {{{ */

{

  ZEND_COMPARE_OBJECTS_FALLBACK(o1, o2);

  zend_closure *lhs = (zend_closure*) Z_OBJ_P(o1);

  zend_closure *rhs = (zend_closure*) Z_OBJ_P(o2);

  if (!((lhs->func.common.fn_flags & ZEND_ACC_FAKE_CLOSURE) && (rhs->func.common.fn_flags & ZEND_ACC_FAKE_CLOSURE))) {

    return ZEND_UNCOMPARABLE;

  }

  if (lhs->this_ptr != rhs->this_ptr) {

    return ZEND_UNCOMPARABLE;

  }

  if (lhs->called_scope != rhs->called_scope) {

    return ZEND_UNCOMPARABLE;

  }

  if (lhs->func.type != rhs->func.type) {

    return ZEND_UNCOMPARABLE;

  }

  if (lhs->func.common.scope != rhs->func.common.scope) {

    return ZEND_UNCOMPARABLE;

  }

  if (!zend_string_equals(lhs->func.common.function_name, rhs->func.common.function_name)) {

    return ZEND_UNCOMPARABLE;

  }

  return 0;

}

/* }}} */

ZEND_API zend_function *zend_get_closure_invoke_method(zend_object *object) /* {{{ */

{

  zend_closure *closure = (zend_closure *)object;

  zend_function *invoke = (zend_function*)emalloc(sizeof(zend_function));

  const uint32_t keep_flags =

    ZEND_ACC_RETURN_REFERENCE | ZEND_ACC_VARIADIC | ZEND_ACC_HAS_RETURN_TYPE | ZEND_ACC_DEPRECATED;

  invoke->common = closure->func.common;

  /* We return ZEND_INTERNAL_FUNCTION, but arg_info representation is the

   * same as for ZEND_USER_FUNCTION (uses zend_string* instead of char*).

   * This is not a problem, because ZEND_ACC_HAS_TYPE_HINTS is never set,

   * and we won't check arguments on internal function. We also set

   * ZEND_ACC_USER_ARG_INFO flag to prevent invalid usage by Reflection */

  invoke->type = ZEND_INTERNAL_FUNCTION;

  invoke->internal_function.fn_flags =

    ZEND_ACC_PUBLIC | ZEND_ACC_CALL_VIA_HANDLER | ZEND_ACC_NEVER_CACHE | (closure->func.common.fn_flags & keep_flags);

  if (closure->func.type != ZEND_INTERNAL_FUNCTION || (closure->func.common.fn_flags & ZEND_ACC_USER_ARG_INFO)) {

    invoke->internal_function.fn_flags |=

      ZEND_ACC_USER_ARG_INFO;

  }

  invoke->internal_function.handler = ZEND_MN(Closure___invoke);

  invoke->internal_function.doc_comment = NULL;

  invoke->internal_function.module = 0;

  invoke->internal_function.scope = zend_ce_closure;

  invoke->internal_function.function_name = ZSTR_KNOWN(ZEND_STR_MAGIC_INVOKE);

  return invoke;

}

/* }}} */

ZEND_API const zend_function *zend_get_closure_method_def(zend_object *obj) /* {{{ */

{

  zend_closure *closure = (zend_closure *) obj;

  return &closure->func;

}

/* }}} */

ZEND_API zend_object* zend_get_closure_this_ptr(zend_object *closure_zobj) /* {{{ */

{

  zend_closure *closure = (zend_closure *)closure_zobj;

  return closure->this_ptr;

}

/* }}} */

static zend_function *zend_closure_get_method(zend_object **object, zend_string *method, const zval *key) /* {{{ */

{

  if (zend_string_equals_literal_ci(method, ZEND_INVOKE_FUNC_NAME)) {

    return zend_get_closure_invoke_method(*object);

  }

  return zend_std_get_method(object, method, key);

}

/* }}} */

static void zend_closure_free_storage(zend_object *object) /* {{{ */

{

  zend_closure *closure = (zend_closure *)object;

  zend_object_std_dtor(&closure->std);

  if (closure->func.type == ZEND_USER_FUNCTION) {

    /* We don't own the static variables of fake closures. */

    if (!(closure->func.op_array.fn_flags & ZEND_ACC_FAKE_CLOSURE)) {

      zend_destroy_static_vars(&closure->func.op_array);

    }

    destroy_op_array(&closure->func.op_array);

  } else if (closure->func.type == ZEND_INTERNAL_FUNCTION) {

    zend_string_release(closure->func.common.function_name);

  }

  if (closure->this_ptr) {

    OBJ_RELEASE(closure->this_ptr);

  }

}

/* }}} */

static zend_object *zend_closure_new(zend_class_entry *class_type) /* {{{ */

{

  zend_closure *closure;

  closure = emalloc(sizeof(zend_closure));

  memset(closure, 0, sizeof(zend_closure));

  zend_object_std_init(&closure->std, class_type);

  return (zend_object*)closure;

}

/* }}} */

static zend_object *zend_closure_clone(zend_object *zobject) /* {{{ */

{

  zend_closure *closure = (zend_closure *)zobject;

  zval result;

  zend_create_closure_ex(&result, &closure->func,

    closure->func.common.scope, closure->called_scope,

    closure->this_ptr,

    zend_closure_is_fake(closure), zend_closure_flags(closure));

  return Z_OBJ(result);

}

/* }}} */

static zend_result zend_closure_get_closure(zend_object *obj, zend_class_entry **ce_ptr, zend_function **fptr_ptr, zend_object **obj_ptr, bool check_only) /* {{{ */

{

  zend_closure *closure = (zend_closure*)obj;

  *fptr_ptr = &closure->func;

  *ce_ptr = closure->called_scope;

  *obj_ptr = closure->this_ptr;

  return SUCCESS;

}

/* }}} */

/* *is_temp is int due to Object Handler API */

static HashTable *zend_closure_get_debug_info(zend_object *object, int *is_temp) /* {{{ */

{

  zend_closure *closure = (zend_closure *)object;

  zval val;

  struct _zend_arg_info *arg_info = closure->func.common.arg_info;

  HashTable *debug_info;

  *is_temp = 1;

  debug_info = zend_new_array(8);

  if (closure->func.op_array.fn_flags & ZEND_ACC_FAKE_CLOSURE) {

    if (closure->func.common.scope) {

      zend_string *class_name = closure->func.common.scope->name;

      zend_string *func_name = closure->func.common.function_name;

      zend_string *combined = zend_string_concat3(

        ZSTR_VAL(class_name), ZSTR_LEN(class_name),

        "::", strlen("::"),

        ZSTR_VAL(func_name), ZSTR_LEN(func_name)

      );

      ZVAL_STR(&val, combined);

    } else {

      ZVAL_STR_COPY(&val, closure->func.common.function_name);

    }

    zend_hash_update(debug_info, ZSTR_KNOWN(ZEND_STR_FUNCTION), &val);

  } else {

    ZVAL_STR_COPY(&val, closure->func.common.function_name);

    zend_hash_update(debug_info, ZSTR_KNOWN(ZEND_STR_NAME), &val);

    ZVAL_STR_COPY(&val, closure->func.op_array.filename);

    zend_hash_update(debug_info, ZSTR_KNOWN(ZEND_STR_FILE), &val);

    ZVAL_LONG(&val, closure->func.op_array.line_start);

    zend_hash_update(debug_info, ZSTR_KNOWN(ZEND_STR_LINE), &val);

  }

  if (closure->func.type == ZEND_USER_FUNCTION && closure->func.op_array.static_variables) {

    zval *var;

    zend_string *key;

    HashTable *static_variables = ZEND_MAP_PTR_GET(closure->func.op_array.static_variables_ptr);

    array_init(&val);

    ZEND_HASH_MAP_FOREACH_STR_KEY_VAL(static_variables, key, var) {

      zval copy;

      if (Z_ISREF_P(var) && Z_REFCOUNT_P(var) == 1) {

        var = Z_REFVAL_P(var);

      }

      ZVAL_COPY(&copy, var);

      zend_hash_add_new(Z_ARRVAL(val), key, &copy);

    } ZEND_HASH_FOREACH_END();

    if (zend_hash_num_elements(Z_ARRVAL(val))) {

      zend_hash_update(debug_info, ZSTR_KNOWN(ZEND_STR_STATIC), &val);

    } else {

      zval_ptr_dtor(&val);

    }

  }

  if (closure->this_ptr) {

    zval tmp;

    ZVAL_OBJ_COPY(&tmp, closure->this_ptr);

    zend_hash_update(debug_info, ZSTR_KNOWN(ZEND_STR_THIS), &tmp);

  }

  if (arg_info &&

    (closure->func.common.num_args ||

     (closure->func.common.fn_flags & ZEND_ACC_VARIADIC))) {

    uint32_t i, num_args, required = closure->func.common.required_num_args;

    array_init(&val);

    num_args = closure->func.common.num_args;

    if (closure->func.common.fn_flags & ZEND_ACC_VARIADIC) {

      num_args++;

    }

    for (i = 0; i < num_args; i++) {

      zend_string *name;

      zval info;

      ZEND_ASSERT(arg_info->name && "Argument should have name");

      name = zend_strpprintf(0, "%s$%s",

          ZEND_ARG_SEND_MODE(arg_info) ? "&" : "",

          ZSTR_VAL(arg_info->name));

      ZVAL_NEW_STR(&info, zend_strpprintf(0, "%s", i >= required ? "<optional>" : "<required>"));

      zend_hash_update(Z_ARRVAL(val), name, &info);

      zend_string_release_ex(name, 0);

      arg_info++;

    }

    zend_hash_str_update(debug_info, "parameter", sizeof("parameter")-1, &val);

  }

  return debug_info;

}

/* }}} */

static HashTable *zend_closure_get_gc(zend_object *obj, zval **table, int *n) /* {{{ */

{

  zend_closure *closure = (zend_closure *)obj;

  if (closure->this_ptr) {

    zend_get_gc_buffer *gc_buffer = zend_get_gc_buffer_create();

    zend_get_gc_buffer_add_obj(gc_buffer, closure->this_ptr);

    zend_get_gc_buffer_use(gc_buffer, table, n);

  } else {

    *table = NULL;

    *n = 0;

  }

  /* Fake closures don't own the static variables they reference. */

  return (closure->func.type == ZEND_USER_FUNCTION

      && !(closure->func.op_array.fn_flags & ZEND_ACC_FAKE_CLOSURE)) ?

    ZEND_MAP_PTR_GET(closure->func.op_array.static_variables_ptr) : NULL;

}

/* }}} */

/* {{{ Private constructor preventing instantiation */

ZEND_COLD ZEND_METHOD(Closure, __construct)

{

  zend_throw_error(NULL, "Instantiation of class Closure is not allowed");

}

/* }}} */

void zend_register_closure_ce(void) /* {{{ */

{

  zend_ce_closure = register_class_Closure();

  zend_ce_closure->create_object = zend_closure_new;

  zend_ce_closure->default_object_handlers = &closure_handlers;

  memcpy(&closure_handlers, &std_object_handlers, sizeof(zend_object_handlers));

  closure_handlers.free_obj = zend_closure_free_storage;

  closure_handlers.get_constructor = zend_closure_get_constructor;

  closure_handlers.get_method = zend_closure_get_method;

  closure_handlers.compare = zend_closure_compare;

  closure_handlers.clone_obj = zend_closure_clone;

  closure_handlers.get_debug_info = zend_closure_get_debug_info;

  closure_handlers.get_closure = zend_closure_get_closure;

  closure_handlers.get_gc = zend_closure_get_gc;

}

/* }}} */

static ZEND_NAMED_FUNCTION(zend_closure_internal_handler) /* {{{ */

{

  zend_closure *closure = (zend_closure*)ZEND_CLOSURE_OBJECT(EX(func));

  closure->orig_internal_handler(INTERNAL_FUNCTION_PARAM_PASSTHRU);

  ZEND_ASSERT(!(closure->func.common.fn_flags2 & ZEND_ACC2_FORBID_DYN_CALLS) || EG(exception));

  // Assign to EX(this) so that it is released after observer checks etc.

  ZEND_ADD_CALL_FLAG(execute_data, ZEND_CALL_RELEASE_THIS);

  Z_OBJ(EX(This)) = &closure->std;

}

/* }}} */

static void zend_create_closure_ex(

  zval *res, zend_function *func,

  zend_class_entry *scope, zend_class_entry *called_scope,

  zend_object *this_ptr, bool is_fake, uint32_t flags) /* {{{ */

{

  zend_closure *closure;

  void *ptr;

  object_init_ex(res, zend_ce_closure);

  closure = (zend_closure *)Z_OBJ_P(res);

  closure->std.extra_flags = flags;

  if ((scope == NULL) && this_ptr) {

    /* use dummy scope if we're binding an object without specifying a scope */

    /* maybe it would be better to create one for this purpose */

    scope = zend_ce_closure;

  }

  if (func->type == ZEND_USER_FUNCTION) {

    memcpy(&closure->func, func, sizeof(zend_op_array));

    closure->func.common.fn_flags |= ZEND_ACC_CLOSURE;

    closure->func.common.fn_flags &= ~ZEND_ACC_IMMUTABLE;

    zend_string_addref(closure->func.op_array.function_name);

    if (closure->func.op_array.refcount) {

      (*closure->func.op_array.refcount)++;

    }

    /* For fake closures, we want to reuse the static variables of the original function. */

    HashTable *ht = ZEND_MAP_PTR_GET(func->op_array.static_variables_ptr);

    if (!is_fake) {

      if (!ht) {

        ht = closure->func.op_array.static_variables;

      }

      ZEND_MAP_PTR_INIT(closure->func.op_array.static_variables_ptr,

        ht ? zend_array_dup(ht) : NULL);

    } else if (func->op_array.static_variables) {

      if (!ht) {

        ht = zend_array_dup(func->op_array.static_variables);

        ZEND_MAP_PTR_SET(func->op_array.static_variables_ptr, ht);

      }

      ZEND_MAP_PTR_INIT(closure->func.op_array.static_variables_ptr, ht);

    }

    /* Runtime cache is scope-dependent, so we cannot reuse it if the scope changed */

    ptr = ZEND_MAP_PTR_GET(func->op_array.run_time_cache);

    if (!ptr

      || func->common.scope != scope

      || (func->common.fn_flags & ZEND_ACC_HEAP_RT_CACHE)

    ) {

      if (!ptr

       && (func->common.fn_flags & ZEND_ACC_CLOSURE)

       && (func->common.scope == scope ||

           !(func->common.fn_flags & ZEND_ACC_IMMUTABLE))) {

        /* If a real closure is used for the first time, we create a shared runtime cache

         * and remember which scope it is for. */

        if (func->common.scope != scope) {

          func->common.scope = scope;

        }

        ptr = zend_arena_alloc(&CG(arena), func->op_array.cache_size);

        ZEND_MAP_PTR_SET(func->op_array.run_time_cache, ptr);

        closure->func.op_array.fn_flags &= ~ZEND_ACC_HEAP_RT_CACHE;

      } else {

        /* Otherwise, we use a non-shared runtime cache */

        ptr = emalloc(func->op_array.cache_size);

        closure->func.op_array.fn_flags |= ZEND_ACC_HEAP_RT_CACHE;

      }

      memset(ptr, 0, func->op_array.cache_size);

    }

    ZEND_MAP_PTR_INIT(closure->func.op_array.run_time_cache, ptr);

  } else {

    memcpy(&closure->func, func, sizeof(zend_internal_function));

    closure->func.common.fn_flags |= ZEND_ACC_CLOSURE;

    /* wrap internal function handler to avoid memory leak */

    if (UNEXPECTED(closure->func.internal_function.handler == zend_closure_internal_handler)) {

      /* avoid infinity recursion, by taking handler from nested closure */

      zend_closure *nested = ZEND_CONTAINER_OF(func, zend_closure, func);

      ZEND_ASSERT(nested->std.ce == zend_ce_closure);

      closure->orig_internal_handler = nested->orig_internal_handler;

    } else {

      closure->orig_internal_handler = closure->func.internal_function.handler;

    }

    closure->func.internal_function.handler = zend_closure_internal_handler;

    zend_string_addref(closure->func.op_array.function_name);

    if (!func->common.scope) {

      /* if it's a free function, we won't set scope & this since they're meaningless */

      this_ptr = NULL;

      scope = NULL;

    }

  }

  closure->this_ptr = NULL;

  /* Invariant:

   * If the closure is unscoped or static, it has no bound object. */

  closure->func.common.scope = scope;

  closure->called_scope = called_scope;

  if (scope) {

    closure->func.common.fn_flags |= ZEND_ACC_PUBLIC;

    if (this_ptr && (closure->func.common.fn_flags & ZEND_ACC_STATIC) == 0) {

      closure->this_ptr = zend_object_copy(this_ptr);

    }

  }

}

/* }}} */

ZEND_API void zend_create_closure(zval *res, zend_function *func, zend_class_entry *scope, zend_class_entry *called_scope, zend_object *this_ptr)

{

  zend_create_closure_ex(res, func, scope, called_scope, this_ptr,

    /* is_fake */ (func->common.fn_flags & ZEND_ACC_FAKE_CLOSURE) != 0,

    /* flags */ 0);

}

ZEND_API void zend_create_fake_closure(zval *res, zend_function *func, zend_class_entry *scope, zend_class_entry *called_scope, zend_object *this_ptr) /* {{{ */

{

  zend_closure *closure;

  zend_create_closure_ex(res, func, scope, called_scope, this_ptr,

      /* is_fake */ true, /* flags */ 0);

  closure = (zend_closure *)Z_OBJ_P(res);

  closure->func.common.fn_flags |= ZEND_ACC_FAKE_CLOSURE;

  if (!closure->this_ptr) {

    GC_ADD_FLAGS(&closure->std, GC_NOT_COLLECTABLE);

  }

}

/* }}} */

ZEND_API void zend_create_partial_closure(zval *res, zend_function *func, zend_class_entry *scope, zend_class_entry *called_scope, zend_object *this_ptr, bool partial_of_closure)

{

  uint32_t flags = ZEND_PARTIAL;

  if (partial_of_closure) {

    flags |= ZEND_PARTIAL_OF_CLOSURE;

  }