/src/php-src/Zend/zend_closures.c

Source
/*
   +----------------------------------------------------------------------+
   | 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: 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"

typedef struct _zend_closure {
  zend_object       std;
  zend_function     func;
  zval              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);

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);

  /* 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, zval *newthis, zend_class_entry *scope) /* {{{ */
{
  zend_function *func = &closure->func;
  bool is_fake_closure = (func->common.fn_flags & ZEND_ACC_FAKE_CLOSURE) != 0;
  if (newthis) {
    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(Z_OBJCE_P(newthis), 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(Z_OBJCE_P(newthis)->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 && !Z_ISUNDEF(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 *newthis, closure_result;
  zend_closure *closure;
  zend_fcall_info fci;
  zend_fcall_info_cache fci_cache;
  zend_object *newobj;
  zend_class_entry *newclass;

  fci.param_count = 0;
  fci.params = NULL;

  ZEND_PARSE_PARAMETERS_START(1, -1)
    Z_PARAM_OBJECT(newthis)
    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);

  newobj = Z_OBJ_P(newthis);
  newclass = newobj->ce;

  if (!zend_valid_closure_binding(closure, newthis, newclass)) {
    return;
  }

  fci_cache.called_scope = newclass;
  fci_cache.object = fci.object = newobj;

  fci.size = sizeof(fci);
  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(&new_closure, &closure->func, newclass, closure->called_scope, newthis);
    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;
    ZVAL_UNDEF(&fake_closure->this_ptr);
    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 void do_closure_bind(zval *return_value, zval *zclosure, zval *newthis, 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));
      RETURN_NULL();
    }
  } else {
    ce = NULL;
  }

  if (!zend_valid_closure_binding(closure, newthis, ce)) {
    return;
  }

  if (newthis) {
    called_scope = Z_OBJCE_P(newthis);
  } else {
    called_scope = ce;
  }

  zend_create_closure(return_value, &closure->func, ce, called_scope, newthis);
}

/* {{{ Create a closure from another one and bind to another object and scope */
ZEND_METHOD(Closure, bind)
{
  zval *zclosure, *newthis;
  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_OBJECT_OR_NULL(newthis)
    Z_PARAM_OPTIONAL
    Z_PARAM_OBJ_OR_STR_OR_NULL(scope_obj, scope_str)
  ZEND_PARSE_PARAMETERS_END();

  do_closure_bind(return_value, zclosure, newthis, scope_obj, scope_str);
}

/* {{{ Create a closure from another one and bind to another object and scope */
ZEND_METHOD(Closure, bindTo)
{
  zval *newthis;
  zend_object *scope_obj = NULL;
  zend_string *scope_str = ZSTR_KNOWN(ZEND_STR_STATIC);

  ZEND_PARSE_PARAMETERS_START(1, 2)
    Z_PARAM_OBJECT_OR_NULL(newthis)
    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, newthis, 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 = fci.object = Z_OBJ_P(ZEND_THIS);
  fcc.called_scope = zend_get_called_scope(EG(current_execute_data));

  zend_call_function(&fci, &fcc);

  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;
  zval instance;
  zend_internal_function call;

  if (!zend_is_callable_ex(callable, NULL, 0, NULL, &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;
  }

  if (fcc.object) {
    ZVAL_OBJ(&instance, fcc.object);
    zend_create_fake_closure(return_value, mptr, mptr->common.scope, fcc.called_scope, &instance);
  } else {
    zend_create_fake_closure(return_value, mptr, mptr->common.scope, fcc.called_scope, NULL);
  }

  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 (Z_TYPE(lhs->this_ptr) != Z_TYPE(rhs->this_ptr)) {
    return ZEND_UNCOMPARABLE;
  }

  if (Z_TYPE(lhs->this_ptr) == IS_OBJECT && Z_OBJ(lhs->this_ptr) != Z_OBJ(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 | (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 zval* zend_get_closure_this_ptr(zval *obj) /* {{{ */
{
  zend_closure *closure = (zend_closure *)Z_OBJ_P(obj);
  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 (Z_TYPE(closure->this_ptr) != IS_UNDEF) {
    zval_ptr_dtor(&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(&result, &closure->func,
    closure->func.common.scope, closure->called_scope, &closure->this_ptr);
  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;

  if (Z_TYPE(closure->this_ptr) != IS_UNDEF) {
    *obj_ptr = Z_OBJ(closure->this_ptr);
  } else {
    *obj_ptr = NULL;
  }

  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;
  bool zstr_args = (closure->func.type == ZEND_USER_FUNCTION) || (closure->func.common.fn_flags & ZEND_ACC_USER_ARG_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 (Z_TYPE(closure->this_ptr) != IS_UNDEF) {
    Z_ADDREF(closure->this_ptr);
    zend_hash_update(debug_info, ZSTR_KNOWN(ZEND_STR_THIS), &closure->this_ptr);
  }

  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");
      if (zstr_args) {
        name = zend_strpprintf(0, "%s$%s",
            ZEND_ARG_SEND_MODE(arg_info) ? "&" : "",
            ZSTR_VAL(arg_info->name));
      } else {
        name = zend_strpprintf(0, "%s$%s",
            ZEND_ARG_SEND_MODE(arg_info) ? "&" : "",
            ((zend_internal_arg_info*)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;

  *table = Z_TYPE(closure->this_ptr) != IS_NULL ? &closure->this_ptr : NULL;
  *n = Z_TYPE(closure->this_ptr) != IS_NULL ? 1 : 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);
  // 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, zval *this_ptr, bool is_fake) /* {{{ */
{
  zend_closure *closure;
  void *ptr;

  object_init_ex(res, zend_ce_closure);

  closure = (zend_closure *)Z_OBJ_P(res);

  if ((scope == NULL) && this_ptr && (Z_TYPE_P(this_ptr) != IS_UNDEF)) {
    /* 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_closure*)((char*)func - XtOffsetOf(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;
    }
  }

  ZVAL_UNDEF(&closure->this_ptr);
  /* 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 && Z_TYPE_P(this_ptr) == IS_OBJECT && (closure->func.common.fn_flags & ZEND_ACC_STATIC) == 0) {
      ZVAL_OBJ_COPY(&closure->this_ptr, Z_OBJ_P(this_ptr));
    }
  }
}
/* }}} */

ZEND_API void zend_create_closure(zval *res, zend_function *func, zend_class_entry *scope, zend_class_entry *called_scope, zval *this_ptr)
{
  zend_create_closure_ex(res, func, scope, called_scope, this_ptr,
    /* is_fake */ (func->common.fn_flags & ZEND_ACC_FAKE_CLOSURE) != 0);
}

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

  zend_create_closure_ex(res, func, scope, called_scope, this_ptr, /* is_fake */ true);

  closure = (zend_closure *)Z_OBJ_P(res);
  closure->func.common.fn_flags |= ZEND_ACC_FAKE_CLOSURE;
  if (Z_TYPE(closure->this_ptr) != IS_OBJECT) {
    GC_ADD_FLAGS(&closure->std, GC_NOT_COLLECTABLE);
  }
}
/* }}} */

/* __call and __callStatic name the arguments "$arguments" in the docs. */
static zend_internal_arg_info trampoline_arg_info[] = {ZEND_ARG_VARIADIC_TYPE_INFO(false, arguments, IS_MIXED, false)};

void zend_closure_from_frame(zval *return_value, const zend_execute_data *call) { /* {{{ */
  zval instance;
  zend_internal_function trampoline;
  zend_function *mptr = call->func;

  if (ZEND_CALL_INFO(call) & ZEND_CALL_CLOSURE) {
    RETURN_OBJ(ZEND_CLOSURE_OBJECT(mptr));
  }

  if (mptr->common.fn_flags & ZEND_ACC_CALL_VIA_TRAMPOLINE) {
    if ((ZEND_CALL_INFO(call) & ZEND_CALL_HAS_THIS) &&
      (Z_OBJCE(call->This) == zend_ce_closure)
      && zend_string_equals(mptr->common.function_name, ZSTR_KNOWN(ZEND_STR_MAGIC_INVOKE))) {
          zend_free_trampoline(mptr);
          RETURN_OBJ_COPY(Z_OBJ(call->This));
      }

    memset(&trampoline, 0, sizeof(zend_internal_function));
    trampoline.type = ZEND_INTERNAL_FUNCTION;
    trampoline.fn_flags = mptr->common.fn_flags & (ZEND_ACC_STATIC | ZEND_ACC_VARIADIC | ZEND_ACC_RETURN_REFERENCE | ZEND_ACC_DEPRECATED);
    trampoline.handler = zend_closure_call_magic;
    trampoline.function_name = mptr->common.function_name;
    trampoline.scope = mptr->common.scope;
    trampoline.doc_comment = NULL;
    if (trampoline.fn_flags & ZEND_ACC_VARIADIC) {
      trampoline.arg_info = trampoline_arg_info;
    }
    trampoline.attributes = mptr->common.attributes;

    zend_free_trampoline(mptr);
    mptr = (zend_function *) &trampoline;
  }

  if (ZEND_CALL_INFO(call) & ZEND_CALL_HAS_THIS) {
    ZVAL_OBJ(&instance, Z_OBJ(call->This));

    zend_create_fake_closure(return_value, mptr, mptr->common.scope, Z_OBJCE(instance), &instance);
  } else {
    zend_create_fake_closure(return_value, mptr, mptr->common.scope, Z_CE(call->This), NULL);
  }

  if (&mptr->internal_function == &trampoline) {
    zend_string_release(mptr->common.function_name);
  }
} /* }}} */

void zend_closure_bind_var(zval *closure_zv, zend_string *var_name, zval *var) /* {{{ */
{
  zend_closure *closure = (zend_closure *) Z_OBJ_P(closure_zv);
  HashTable *static_variables = ZEND_MAP_PTR_GET(closure->func.op_array.static_variables_ptr);
  zend_hash_update(static_variables, var_name, var);
}
/* }}} */

void zend_closure_bind_var_ex(zval *closure_zv, uint32_t offset, zval *val) /* {{{ */
{
  zend_closure *closure = (zend_closure *) Z_OBJ_P(closure_zv);
  HashTable *static_variables = ZEND_MAP_PTR_GET(closure->func.op_array.static_variables_ptr);
  zval *var = (zval*)((char*)static_variables->arData + offset);
  zval_ptr_dtor(var);
  ZVAL_COPY_VALUE(var, val);
}
/* }}} */

Coverage Report

Created: 2025-12-14 06:06