/*

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

   | 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: Ilija Tovilo <ilutov@php.net>                               |

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

*/

#include "zend.h"

#include "zend_API.h"

#include "zend_compile.h"

#include "zend_enum_arginfo.h"

#include "zend_interfaces.h"

#include "zend_enum.h"

#include "zend_extensions.h"

#include "zend_observer.h"

#define ZEND_ENUM_DISALLOW_MAGIC_METHOD(propertyName, methodName) \

  do { \

    if (ce->propertyName) { \

      zend_error_noreturn(E_COMPILE_ERROR, "Enum %s cannot include magic method %s", ZSTR_VAL(ce->name), methodName); \

    } \

  } while (0);

ZEND_API zend_class_entry *zend_ce_unit_enum;

ZEND_API zend_class_entry *zend_ce_backed_enum;

ZEND_API zend_object_handlers zend_enum_object_handlers;

static zend_arg_info zarginfo_class_UnitEnum_cases[sizeof(arginfo_class_UnitEnum_cases)/sizeof(zend_internal_arg_info)];

static zend_arg_info zarginfo_class_BackedEnum_from[sizeof(arginfo_class_BackedEnum_from)/sizeof(zend_internal_arg_info)];

static zend_arg_info zarginfo_class_BackedEnum_tryFrom[sizeof(arginfo_class_BackedEnum_tryFrom)/sizeof(zend_internal_arg_info)];

zend_object *zend_enum_new(zval *result, zend_class_entry *ce, int case_id, zend_string *case_name, zval *backing_value_zv)

{

  zend_enum_obj *intern = zend_object_alloc(sizeof(*intern), ce);

  zend_object_std_init(&intern->std, ce);

  object_properties_init(&intern->std, ce);

  intern->case_id = case_id;

  zend_object *zobj = &intern->std;

  GC_ADD_FLAGS(zobj, GC_NOT_COLLECTABLE);

  ZVAL_OBJ(result, zobj);

  zval *zname = OBJ_PROP_NUM(zobj, 0);

  ZVAL_STR_COPY(zname, case_name);

  /* ZVAL_COPY does not set Z_PROP_FLAG, this needs to be cleared to avoid leaving IS_PROP_REINITABLE set */

  Z_PROP_FLAG_P(zname) = 0;

  if (backing_value_zv != NULL) {

    zval *prop = OBJ_PROP_NUM(zobj, 1);

    ZVAL_COPY(prop, backing_value_zv);

    /* ZVAL_COPY does not set Z_PROP_FLAG, this needs to be cleared to avoid leaving IS_PROP_REINITABLE set */

    Z_PROP_FLAG_P(prop) = 0;

  }

  return zobj;

}

static void zend_verify_enum_properties(const zend_class_entry *ce)

{

  const zend_property_info *property_info;

  ZEND_HASH_MAP_FOREACH_PTR(&ce->properties_info, property_info) {

    if (zend_string_equals(property_info->name, ZSTR_KNOWN(ZEND_STR_NAME))) {

      continue;

    }

    if (

      ce->enum_backing_type != IS_UNDEF

      && zend_string_equals(property_info->name, ZSTR_KNOWN(ZEND_STR_VALUE))

    ) {

      continue;

    }

    // FIXME: File/line number for traits?

    zend_error_noreturn(E_COMPILE_ERROR, "Enum %s cannot include properties",

      ZSTR_VAL(ce->name));

  } ZEND_HASH_FOREACH_END();

}

static void zend_verify_enum_magic_methods(const zend_class_entry *ce)

{

  // Only __get, __call, __debugInfo and __invoke are allowed

  ZEND_ENUM_DISALLOW_MAGIC_METHOD(constructor, "__construct");

  ZEND_ENUM_DISALLOW_MAGIC_METHOD(destructor, "__destruct");

  ZEND_ENUM_DISALLOW_MAGIC_METHOD(clone, "__clone");

  ZEND_ENUM_DISALLOW_MAGIC_METHOD(__get, "__get");

  ZEND_ENUM_DISALLOW_MAGIC_METHOD(__set, "__set");

  ZEND_ENUM_DISALLOW_MAGIC_METHOD(__unset, "__unset");

  ZEND_ENUM_DISALLOW_MAGIC_METHOD(__isset, "__isset");

  ZEND_ENUM_DISALLOW_MAGIC_METHOD(__tostring, "__toString");

  ZEND_ENUM_DISALLOW_MAGIC_METHOD(__serialize, "__serialize");

  ZEND_ENUM_DISALLOW_MAGIC_METHOD(__unserialize, "__unserialize");

  static const char *const forbidden_methods[] = {

    "__sleep",

    "__wakeup",

    "__set_state",

  };

  uint32_t forbidden_methods_length = sizeof(forbidden_methods) / sizeof(forbidden_methods[0]);

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

    const char *forbidden_method = forbidden_methods[i];

    if (zend_hash_str_exists(&ce->function_table, forbidden_method, strlen(forbidden_method))) {

      zend_error_noreturn(E_COMPILE_ERROR, "Enum %s cannot include magic method %s", ZSTR_VAL(ce->name), forbidden_method);

    }

  }

}

static void zend_verify_enum_interfaces(const zend_class_entry *ce)

{

  if (zend_class_implements_interface(ce, zend_ce_serializable)) {

    zend_error_noreturn(E_COMPILE_ERROR,

      "Enum %s cannot implement the Serializable interface", ZSTR_VAL(ce->name));

  }

}

void zend_verify_enum(const zend_class_entry *ce)

{

  zend_verify_enum_properties(ce);

  zend_verify_enum_magic_methods(ce);

  zend_verify_enum_interfaces(ce);

}

static int zend_implement_unit_enum(zend_class_entry *interface, zend_class_entry *class_type)

{

  if (class_type->ce_flags & ZEND_ACC_ENUM) {

    return SUCCESS;

  }

  zend_error_noreturn(E_ERROR, "Non-enum class %s cannot implement interface %s",

    ZSTR_VAL(class_type->name),

    ZSTR_VAL(interface->name));

  return FAILURE;

}

static int zend_implement_backed_enum(zend_class_entry *interface, zend_class_entry *class_type)

{

  if (!(class_type->ce_flags & ZEND_ACC_ENUM)) {

    zend_error_noreturn(E_ERROR, "Non-enum class %s cannot implement interface %s",

      ZSTR_VAL(class_type->name),

      ZSTR_VAL(interface->name));

    return FAILURE;

  }

  if (class_type->enum_backing_type == IS_UNDEF) {

    zend_error_noreturn(E_ERROR, "Non-backed enum %s cannot implement interface %s",

      ZSTR_VAL(class_type->name),

      ZSTR_VAL(interface->name));

    return FAILURE;

  }

  return SUCCESS;

}

void zend_register_enum_ce(void)

{

  zend_ce_unit_enum = register_class_UnitEnum();

  zend_ce_unit_enum->interface_gets_implemented = zend_implement_unit_enum;

  zend_ce_backed_enum = register_class_BackedEnum(zend_ce_unit_enum);

  zend_ce_backed_enum->interface_gets_implemented = zend_implement_backed_enum;

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

  zend_enum_object_handlers.offset = offsetof(zend_enum_obj, std);

  zend_enum_object_handlers.clone_obj = NULL;

  zend_enum_object_handlers.compare = zend_objects_not_comparable;

}

void zend_enum_add_interfaces(zend_class_entry *ce)

{

  uint32_t num_interfaces_before = ce->num_interfaces;

  ce->num_interfaces++;

  if (ce->enum_backing_type != IS_UNDEF) {

    ce->num_interfaces++;

  }

  ZEND_ASSERT(!(ce->ce_flags & ZEND_ACC_RESOLVED_INTERFACES));

  ce->interface_names = erealloc(ce->interface_names, sizeof(zend_class_name) * ce->num_interfaces);

  ce->interface_names[num_interfaces_before].name = zend_string_copy(zend_ce_unit_enum->name);

  ce->interface_names[num_interfaces_before].lc_name = ZSTR_INIT_LITERAL("unitenum", 0);

  if (ce->enum_backing_type != IS_UNDEF) {

    ce->interface_names[num_interfaces_before + 1].name = zend_string_copy(zend_ce_backed_enum->name);

    ce->interface_names[num_interfaces_before + 1].lc_name = ZSTR_INIT_LITERAL("backedenum", 0);

  }

  ce->default_object_handlers = &zend_enum_object_handlers;

}

zend_result zend_enum_build_backed_enum_table(zend_class_entry *ce)

{

  ZEND_ASSERT(ce->ce_flags & ZEND_ACC_ENUM);

  ZEND_ASSERT(ce->type == ZEND_USER_CLASS);

  uint32_t backing_type = ce->enum_backing_type;

  ZEND_ASSERT(backing_type != IS_UNDEF);

  HashTable *backed_enum_table = emalloc(sizeof(HashTable));

  zend_hash_init(backed_enum_table, 0, NULL, ZVAL_PTR_DTOR, 0);

  zend_class_set_backed_enum_table(ce, backed_enum_table);

  const zend_string *enum_class_name = ce->name;

  zend_string *name;

  zval *val;

  ZEND_HASH_MAP_FOREACH_STR_KEY_VAL(CE_CONSTANTS_TABLE(ce), name, val) {

    zend_class_constant *c = Z_PTR_P(val);

    if ((ZEND_CLASS_CONST_FLAGS(c) & ZEND_CLASS_CONST_IS_CASE) == 0) {

      continue;

    }

    zval *c_value = &c->value;

    zval *case_name = zend_enum_fetch_case_name(Z_OBJ_P(c_value));

    zval *case_value = zend_enum_fetch_case_value(Z_OBJ_P(c_value));

    if (ce->enum_backing_type != Z_TYPE_P(case_value)) {

      zend_type_error("Enum case type %s does not match enum backing type %s",

        zend_get_type_by_const(Z_TYPE_P(case_value)),

        zend_get_type_by_const(ce->enum_backing_type));

      goto failure;

    }

    if (ce->enum_backing_type == IS_LONG) {

      zend_long long_key = Z_LVAL_P(case_value);

      const zval *existing_case_name = zend_hash_index_find(backed_enum_table, long_key);

      if (existing_case_name) {

        zend_throw_error(NULL, "Duplicate value in enum %s for cases %s and %s",

          ZSTR_VAL(enum_class_name),

          Z_STRVAL_P(existing_case_name),

          ZSTR_VAL(name));

        goto failure;

      }

      Z_TRY_ADDREF_P(case_name);

      zend_hash_index_add_new(backed_enum_table, long_key, case_name);

    } else {

      ZEND_ASSERT(ce->enum_backing_type == IS_STRING);

      zend_string *string_key = Z_STR_P(case_value);

      const zval *existing_case_name = zend_hash_find(backed_enum_table, string_key);

      if (existing_case_name != NULL) {

        zend_throw_error(NULL, "Duplicate value in enum %s for cases %s and %s",

          ZSTR_VAL(enum_class_name),

          Z_STRVAL_P(existing_case_name),

          ZSTR_VAL(name));

        goto failure;

      }

      Z_TRY_ADDREF_P(case_name);

      zend_hash_add_new(backed_enum_table, string_key, case_name);

    }

  } ZEND_HASH_FOREACH_END();

  return SUCCESS;

failure:

  zend_hash_release(backed_enum_table);

  zend_class_set_backed_enum_table(ce, NULL);

  return FAILURE;

}

static ZEND_NAMED_FUNCTION(zend_enum_cases_func)

{

  zend_class_entry *ce = execute_data->func->common.scope;

  zend_class_constant *c;

  ZEND_PARSE_PARAMETERS_NONE();

  array_init(return_value);

  ZEND_HASH_MAP_FOREACH_PTR(CE_CONSTANTS_TABLE(ce), c) {

    if (!(ZEND_CLASS_CONST_FLAGS(c) & ZEND_CLASS_CONST_IS_CASE)) {

      continue;

    }

    zval *zv = &c->value;

    if (Z_TYPE_P(zv) == IS_CONSTANT_AST) {

      if (zval_update_constant_ex(zv, c->ce) == FAILURE) {

        RETURN_THROWS();

      }

    }

    Z_ADDREF_P(zv);

    zend_hash_next_index_insert_new(Z_ARRVAL_P(return_value), zv);

  } ZEND_HASH_FOREACH_END();

}

ZEND_API zend_result zend_enum_get_case_by_value(zend_object **result, zend_class_entry *ce, zend_long long_key, zend_string *string_key, bool try_from)

{

  if (ce->type == ZEND_USER_CLASS && !(ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {

    if (zend_update_class_constants(ce) == FAILURE) {

      return FAILURE;

    }

  }

  const HashTable *backed_enum_table = CE_BACKED_ENUM_TABLE(ce);

  if (!backed_enum_table) {

    goto not_found;

  }

  zval *case_name_zv;

  if (ce->enum_backing_type == IS_LONG) {

    case_name_zv = zend_hash_index_find(backed_enum_table, long_key);

  } else {

    ZEND_ASSERT(ce->enum_backing_type == IS_STRING);

    ZEND_ASSERT(string_key != NULL);

    case_name_zv = zend_hash_find(backed_enum_table, string_key);

  }

  if (case_name_zv == NULL) {

not_found:

    if (try_from) {

      *result = NULL;

      return SUCCESS;

    }

    if (ce->enum_backing_type == IS_LONG) {

      zend_value_error(ZEND_LONG_FMT " is not a valid backing value for enum %s", long_key, ZSTR_VAL(ce->name));

    } else {

      ZEND_ASSERT(ce->enum_backing_type == IS_STRING);

      zend_value_error("\"%s\" is not a valid backing value for enum %s", ZSTR_VAL(string_key), ZSTR_VAL(ce->name));

    }

    return FAILURE;

  }

  // TODO: We might want to store pointers to constants in backed_enum_table instead of names,

  // to make this lookup more efficient.

  ZEND_ASSERT(Z_TYPE_P(case_name_zv) == IS_STRING);

  zend_class_constant *c = zend_hash_find_ptr(CE_CONSTANTS_TABLE(ce), Z_STR_P(case_name_zv));

  ZEND_ASSERT(c != NULL);

  zval *case_zv = &c->value;

  if (Z_TYPE_P(case_zv) == IS_CONSTANT_AST) {

    if (zval_update_constant_ex(case_zv, c->ce) == FAILURE) {

      return FAILURE;

    }

  }

  *result = Z_OBJ_P(case_zv);

  return SUCCESS;

}

static void zend_enum_from_base(INTERNAL_FUNCTION_PARAMETERS, bool try_from)

{

  zend_class_entry *ce = execute_data->func->common.scope;

  bool release_string = false;

  zend_string *string_key = NULL;

  zend_long long_key = 0;

  if (ce->enum_backing_type == IS_LONG) {

    ZEND_PARSE_PARAMETERS_START(1, 1)

      Z_PARAM_LONG(long_key)

    ZEND_PARSE_PARAMETERS_END();

  } else {

    ZEND_ASSERT(ce->enum_backing_type == IS_STRING);

    if (ZEND_ARG_USES_STRICT_TYPES()) {

      ZEND_PARSE_PARAMETERS_START(1, 1)

        Z_PARAM_STR(string_key)

      ZEND_PARSE_PARAMETERS_END();

    } else {

      // We allow long keys so that coercion to string doesn't happen implicitly. The JIT

      // skips deallocation of params that don't require it. In the case of from/tryFrom

      // passing int to from(int|string) looks like no coercion will happen, so the JIT

      // won't emit a dtor call. Thus we allocate/free the string manually.

      ZEND_PARSE_PARAMETERS_START(1, 1)

        Z_PARAM_STR_OR_LONG(string_key, long_key)

      ZEND_PARSE_PARAMETERS_END();

      if (string_key == NULL) {

        release_string = true;

        string_key = zend_long_to_str(long_key);

      }

    }

  }

  zend_object *case_obj;

  if (zend_enum_get_case_by_value(&case_obj, ce, long_key, string_key, try_from) == FAILURE) {

    goto throw;

  }

  if (case_obj == NULL) {

    ZEND_ASSERT(try_from);

    goto return_null;

  }

  if (release_string) {

    zend_string_release(string_key);

  }

  RETURN_OBJ_COPY(case_obj);

throw:

  if (release_string) {

    zend_string_release(string_key);

  }

  RETURN_THROWS();

return_null:

  if (release_string) {

    zend_string_release(string_key);

  }

  RETURN_NULL();

}

static ZEND_NAMED_FUNCTION(zend_enum_from_func)

{

  zend_enum_from_base(INTERNAL_FUNCTION_PARAM_PASSTHRU, 0);

}

static ZEND_NAMED_FUNCTION(zend_enum_try_from_func)

{

  zend_enum_from_base(INTERNAL_FUNCTION_PARAM_PASSTHRU, 1);

}

static void zend_enum_register_func(zend_class_entry *ce, zend_known_string_id name_id, zend_internal_function *zif) {

  zend_string *name = ZSTR_KNOWN(name_id);

  zif->type = ZEND_INTERNAL_FUNCTION;

  zif->module = EG(current_module);

  zif->scope = ce;

  zif->T = ZEND_OBSERVER_ENABLED;

  if (EG(active)) { // at run-time

    if (CG(compiler_options) & ZEND_COMPILE_PRELOAD) {

      zif->fn_flags |= ZEND_ACC_PRELOADED;

    }

    ZEND_MAP_PTR_INIT(zif->run_time_cache, zend_arena_calloc(&CG(arena), 1, zend_internal_run_time_cache_reserved_size()));

  } else {

#ifdef ZTS

    ZEND_MAP_PTR_NEW_STATIC(zif->run_time_cache);

#else

    ZEND_MAP_PTR_INIT(zif->run_time_cache, NULL);

#endif

  }

  if (!zend_hash_add_ptr(&ce->function_table, name, zif)) {

    zend_error_noreturn(E_COMPILE_ERROR, "Cannot redeclare %s::%s()", ZSTR_VAL(ce->name), ZSTR_VAL(name));

  }

}

void zend_enum_register_funcs(zend_class_entry *ce)

{

  const uint32_t fn_flags =

    ZEND_ACC_PUBLIC|ZEND_ACC_STATIC|ZEND_ACC_HAS_RETURN_TYPE|ZEND_ACC_ARENA_ALLOCATED;

  zend_internal_function *cases_function = zend_arena_calloc(&CG(arena), sizeof(zend_internal_function), 1);

  cases_function->handler = zend_enum_cases_func;

  cases_function->function_name = ZSTR_KNOWN(ZEND_STR_CASES);

  cases_function->fn_flags = fn_flags;

  cases_function->doc_comment = NULL;

  cases_function->arg_info = zarginfo_class_UnitEnum_cases + 1;

  zend_enum_register_func(ce, ZEND_STR_CASES, cases_function);

  if (ce->enum_backing_type != IS_UNDEF) {

    zend_internal_function *from_function = zend_arena_calloc(&CG(arena), sizeof(zend_internal_function), 1);

    from_function->handler = zend_enum_from_func;

    from_function->function_name = ZSTR_KNOWN(ZEND_STR_FROM);

    from_function->fn_flags = fn_flags;

    from_function->doc_comment = NULL;

    from_function->num_args = 1;

    from_function->required_num_args = 1;

    from_function->arg_info = zarginfo_class_BackedEnum_from + 1;

    zend_enum_register_func(ce, ZEND_STR_FROM, from_function);

    zend_internal_function *try_from_function = zend_arena_calloc(&CG(arena), sizeof(zend_internal_function), 1);

    try_from_function->handler = zend_enum_try_from_func;

    try_from_function->function_name = ZSTR_KNOWN(ZEND_STR_TRYFROM);

    try_from_function->fn_flags = fn_flags;

    try_from_function->doc_comment = NULL;

    try_from_function->num_args = 1;

    try_from_function->required_num_args = 1;

    try_from_function->arg_info = zarginfo_class_BackedEnum_tryFrom + 1;

    zend_enum_register_func(ce, ZEND_STR_TRYFROM_LOWERCASE, try_from_function);

  }

}

void zend_enum_register_props(zend_class_entry *ce)

{

  ce->ce_flags |= ZEND_ACC_NO_DYNAMIC_PROPERTIES;

  zval name_default_value;

  ZVAL_UNDEF(&name_default_value);

  zend_type name_type = ZEND_TYPE_INIT_CODE(IS_STRING, 0, 0);

  zend_declare_typed_property(ce, ZSTR_KNOWN(ZEND_STR_NAME), &name_default_value, ZEND_ACC_PUBLIC | ZEND_ACC_READONLY, NULL, name_type);

  if (ce->enum_backing_type != IS_UNDEF) {

    zval value_default_value;

    ZVAL_UNDEF(&value_default_value);

    zend_type value_type = ZEND_TYPE_INIT_CODE(ce->enum_backing_type, 0, 0);

    zend_declare_typed_property(ce, ZSTR_KNOWN(ZEND_STR_VALUE), &value_default_value, ZEND_ACC_PUBLIC | ZEND_ACC_READONLY, NULL, value_type);

  }

}

static const zend_function_entry unit_enum_methods[] = {

  ZEND_NAMED_ME(cases, zend_enum_cases_func, arginfo_class_UnitEnum_cases, ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)

  ZEND_FE_END

};

static const zend_function_entry backed_enum_methods[] = {

  ZEND_NAMED_ME(cases, zend_enum_cases_func, arginfo_class_UnitEnum_cases, ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)

  ZEND_NAMED_ME(from, zend_enum_from_func, arginfo_class_BackedEnum_from, ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)

  ZEND_NAMED_ME(tryFrom, zend_enum_try_from_func, arginfo_class_BackedEnum_tryFrom, ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)

  ZEND_FE_END

};

ZEND_API zend_class_entry *zend_register_internal_enum(

  const char *name, uint8_t type, const zend_function_entry *functions)

{

  ZEND_ASSERT(type == IS_UNDEF || type == IS_LONG || type == IS_STRING);

  zend_class_entry tmp_ce;

  INIT_CLASS_ENTRY_EX(tmp_ce, name, strlen(name), functions);

  zend_class_entry *ce = zend_register_internal_class(&tmp_ce);

  ce->ce_flags |= ZEND_ACC_ENUM;

  ce->enum_backing_type = type;

  if (type != IS_UNDEF) {

    HashTable *backed_enum_table = pemalloc(sizeof(HashTable), 1);

    zend_hash_init(backed_enum_table, 0, NULL, ZVAL_PTR_DTOR, 1);

    zend_class_set_backed_enum_table(ce, backed_enum_table);

  }

  zend_enum_register_props(ce);

  if (type == IS_UNDEF) {

    zend_register_functions(

      ce, unit_enum_methods, &ce->function_table, EG(current_module)->type);

    zend_class_implements(ce, 1, zend_ce_unit_enum);

  } else {

    zend_register_functions(

      ce, backed_enum_methods, &ce->function_table, EG(current_module)->type);

    zend_class_implements(ce, 1, zend_ce_backed_enum);

  }

  ce->default_object_handlers = &zend_enum_object_handlers;

  return ce;

}

static zend_ast_ref *create_enum_case_ast(

    zend_string *class_name, int case_id, zend_string *case_name,

    zval *value) {

  // TODO: Use custom node type for enum cases?

  const size_t num_children = ZEND_AST_CONST_ENUM_INIT >> ZEND_AST_NUM_CHILDREN_SHIFT;

  size_t size = sizeof(zend_ast_ref) + zend_ast_size(num_children)

    + (value ? num_children : num_children-1) * sizeof(zend_ast_zval);

  char *p = pemalloc(size, 1);

  zend_ast_ref *ref = (zend_ast_ref *) p; p += sizeof(zend_ast_ref);

  GC_SET_REFCOUNT(ref, 1);

  GC_TYPE_INFO(ref) = GC_CONSTANT_AST | GC_PERSISTENT | GC_IMMUTABLE;

  zend_ast *ast = (zend_ast *) p; p += zend_ast_size(num_children);

  ast->kind = ZEND_AST_CONST_ENUM_INIT;

  ast->attr = 0;

  ast->lineno = 0;

  ast->child[0] = (zend_ast *) p; p += sizeof(zend_ast_zval);

  ast->child[0]->kind = ZEND_AST_ZVAL;

  ast->child[0]->attr = 0;

  ZEND_ASSERT(ZSTR_IS_INTERNED(class_name));

  ZVAL_STR(zend_ast_get_zval(ast->child[0]), class_name);

  Z_LINENO_P(zend_ast_get_zval(ast->child[0])) = 0;

  ast->child[1] = (zend_ast *) p; p += sizeof(zend_ast_zval);

  ast->child[1]->kind = ZEND_AST_ZVAL;

  ast->child[1]->attr = 0;

  ZVAL_LONG(zend_ast_get_zval(ast->child[1]), case_id);

  Z_LINENO_P(zend_ast_get_zval(ast->child[1])) = 0;

  ast->child[2] = (zend_ast *) p; p += sizeof(zend_ast_zval);

  ast->child[2]->kind = ZEND_AST_ZVAL;

  ast->child[2]->attr = 0;

  ZEND_ASSERT(ZSTR_IS_INTERNED(case_name));

  ZVAL_STR(zend_ast_get_zval(ast->child[2]), case_name);

  Z_LINENO_P(zend_ast_get_zval(ast->child[2])) = 0;

  if (value) {

    ast->child[3] = (zend_ast *) p; p += sizeof(zend_ast_zval);

    ast->child[3]->kind = ZEND_AST_ZVAL;

    ast->child[3]->attr = 0;

    ZEND_ASSERT(!Z_REFCOUNTED_P(value));

    ZVAL_COPY_VALUE(zend_ast_get_zval(ast->child[3]), value);

    Z_LINENO_P(zend_ast_get_zval(ast->child[3])) = 0;

  } else {

    ast->child[3] = NULL;

  }

  return ref;

}

int zend_enum_next_case_id(zend_class_entry *enum_class)

{

  ZEND_HASH_REVERSE_FOREACH_VAL(&enum_class->constants_table, zval *zv) {

    zend_class_constant *c = Z_PTR_P(zv);

    if (!(ZEND_CLASS_CONST_FLAGS(c) & ZEND_CLASS_CONST_IS_CASE)) {

      continue;

    }

    ZEND_ASSERT(Z_TYPE(c->value) == IS_CONSTANT_AST);

    zend_ast *ast = Z_ASTVAL(c->value);

    ZEND_ASSERT(ast->kind == ZEND_AST_CONST_ENUM_INIT);

    return Z_LVAL_P(zend_ast_get_zval(ast->child[1])) + 1;

  } ZEND_HASH_FOREACH_END();

  return 1;

}

ZEND_API void zend_enum_add_case(zend_class_entry *ce, zend_string *case_name, zval *value)

{

  if (value) {

    ZEND_ASSERT(ce->enum_backing_type == Z_TYPE_P(value));

    if (Z_TYPE_P(value) == IS_STRING && !ZSTR_IS_INTERNED(Z_STR_P(value))) {

      zval_make_interned_string(value);

    }

    HashTable *backed_enum_table = CE_BACKED_ENUM_TABLE(ce);

    zval case_name_zv;

    ZVAL_STR(&case_name_zv, case_name);

    if (Z_TYPE_P(value) == IS_LONG) {

      zend_hash_index_add_new(backed_enum_table, Z_LVAL_P(value), &case_name_zv);

    } else {

      zend_hash_add_new(backed_enum_table, Z_STR_P(value), &case_name_zv);

    }

  } else {

    ZEND_ASSERT(ce->enum_backing_type == IS_UNDEF);

  }

  int case_id = zend_enum_next_case_id(ce);

  zval ast_zv;

  Z_TYPE_INFO(ast_zv) = IS_CONSTANT_AST;

  Z_AST(ast_zv) = create_enum_case_ast(ce->name, case_id, case_name, value);

  zend_class_constant *c = zend_declare_class_constant_ex(

    ce, case_name, &ast_zv, ZEND_ACC_PUBLIC, NULL);

  ZEND_CLASS_CONST_FLAGS(c) |= ZEND_CLASS_CONST_IS_CASE;

}

ZEND_API void zend_enum_add_case_cstr(zend_class_entry *ce, const char *name, zval *value)

{

  zend_string *name_str = zend_string_init_interned(name, strlen(name), 1);

  zend_enum_add_case(ce, name_str, value);

  zend_string_release(name_str);

}

static zend_object *zend_enum_case_from_class_constant(zend_class_constant *c) {

  ZEND_ASSERT(c && "Must be a valid enum case");

  ZEND_ASSERT(ZEND_CLASS_CONST_FLAGS(c) & ZEND_CLASS_CONST_IS_CASE);

  if (Z_TYPE(c->value) == IS_CONSTANT_AST) {

    if (zval_update_constant_ex(&c->value, c->ce) == FAILURE) {

      ZEND_UNREACHABLE();

    }

  }

  ZEND_ASSERT(Z_TYPE(c->value) == IS_OBJECT);

  return Z_OBJ(c->value);

}

ZEND_API zend_object *zend_enum_get_case(zend_class_entry *ce, zend_string *name) {

  zend_class_constant *c = zend_hash_find_ptr(CE_CONSTANTS_TABLE(ce), name);

  return zend_enum_case_from_class_constant(c);

}

ZEND_API zend_object *zend_enum_get_case_cstr(zend_class_entry *ce, const char *name) {

  zend_class_constant *c = zend_hash_str_find_ptr(CE_CONSTANTS_TABLE(ce), name, strlen(name));

  return zend_enum_case_from_class_constant(c);

}

void zend_enum_startup(void)

{

  for (size_t i = 0; i < sizeof(zarginfo_class_UnitEnum_cases)/sizeof(zend_arg_info); i++) {

    zend_convert_internal_arg_info(&zarginfo_class_UnitEnum_cases[i], &arginfo_class_UnitEnum_cases[i], i == 0, true);

  }

  for (size_t i = 0; i < sizeof(zarginfo_class_BackedEnum_from)/sizeof(zend_arg_info); i++) {

    zend_convert_internal_arg_info(&zarginfo_class_BackedEnum_from[i], &arginfo_class_BackedEnum_from[i], i == 0, true);

  }

  for (size_t i = 0; i < sizeof(zarginfo_class_BackedEnum_tryFrom)/sizeof(zend_arg_info); i++) {

    zend_convert_internal_arg_info(&zarginfo_class_BackedEnum_tryFrom[i], &arginfo_class_BackedEnum_tryFrom[i], i == 0, true);

  }

}