/*
   +----------------------------------------------------------------------+
   | 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>                                 |
   +----------------------------------------------------------------------+
*/

#include "zend.h"
#include "zend_API.h"
#include "zend_compile.h"
#include "zend_execute.h"
#include "zend_inheritance.h"
#include "zend_interfaces.h"
#include "zend_smart_str.h"
#include "zend_operators.h"

static void overridden_ptr_dtor(zval *zv) /* {{{ */
{
	efree_size(Z_PTR_P(zv), sizeof(zend_function));
}
/* }}} */

static zend_property_info *zend_duplicate_property_info_internal(zend_property_info *property_info) /* {{{ */
{
	zend_property_info* new_property_info = pemalloc(sizeof(zend_property_info), 1);
	memcpy(new_property_info, property_info, sizeof(zend_property_info));
	zend_string_addref(new_property_info->name);
	if (ZEND_TYPE_IS_NAME(new_property_info->type)) {
		zend_string_addref(ZEND_TYPE_NAME(new_property_info->type));
	}

	return new_property_info;
}
/* }}} */

static zend_function *zend_duplicate_function(zend_function *func, zend_class_entry *ce) /* {{{ */
{
	zend_function *new_function;

	if (UNEXPECTED(func->type == ZEND_INTERNAL_FUNCTION)) {
		if (UNEXPECTED(ce->type & ZEND_INTERNAL_CLASS)) {
			new_function = pemalloc(sizeof(zend_internal_function), 1);
			memcpy(new_function, func, sizeof(zend_internal_function));
		} else {
			new_function = zend_arena_alloc(&CG(arena), sizeof(zend_internal_function));
			memcpy(new_function, func, sizeof(zend_internal_function));
			new_function->common.fn_flags |= ZEND_ACC_ARENA_ALLOCATED;
		}
		if (EXPECTED(new_function->common.function_name)) {
			zend_string_addref(new_function->common.function_name);
		}
	} else {
		if (func->op_array.refcount) {
			(*func->op_array.refcount)++;
		}
		if (EXPECTED(!func->op_array.static_variables)) {
			/* reuse the same op_array structure */
			return func;
		}
		new_function = zend_arena_alloc(&CG(arena), sizeof(zend_op_array));
		memcpy(new_function, func, sizeof(zend_op_array));
		if (ZEND_MAP_PTR_GET(func->op_array.static_variables_ptr)) {
			/* See: Zend/tests/method_static_var.phpt */
			new_function->op_array.static_variables = ZEND_MAP_PTR_GET(func->op_array.static_variables_ptr);
		}
		if (!(GC_FLAGS(new_function->op_array.static_variables) & IS_ARRAY_IMMUTABLE)) {
			GC_ADDREF(new_function->op_array.static_variables);
		}
		ZEND_MAP_PTR_INIT(new_function->op_array.static_variables_ptr, &new_function->op_array.static_variables);
	}
	return new_function;
}
/* }}} */

static void do_inherit_parent_constructor(zend_class_entry *ce) /* {{{ */
{
	zend_class_entry *parent = ce->parent;

	ZEND_ASSERT(parent != NULL);

	/* You cannot change create_object */
	ce->create_object = parent->create_object;

	/* Inherit special functions if needed */
	if (EXPECTED(!ce->get_iterator)) {
		ce->get_iterator = parent->get_iterator;
	}
	if (parent->iterator_funcs_ptr) {
		/* Must be initialized through iface->interface_gets_implemented() */
		ZEND_ASSERT(ce->iterator_funcs_ptr);
	}
	if (EXPECTED(!ce->__get)) {
		ce->__get = parent->__get;
	}
	if (EXPECTED(!ce->__set)) {
		ce->__set = parent->__set;
	}
	if (EXPECTED(!ce->__unset)) {
		ce->__unset = parent->__unset;
	}
	if (EXPECTED(!ce->__isset)) {
		ce->__isset = parent->__isset;
	}
	if (EXPECTED(!ce->__call)) {
		ce->__call = parent->__call;
	}
	if (EXPECTED(!ce->__callstatic)) {
		ce->__callstatic = parent->__callstatic;
	}
	if (EXPECTED(!ce->__tostring)) {
		ce->__tostring = parent->__tostring;
	}
	if (EXPECTED(!ce->clone)) {
		ce->clone = parent->clone;
	}
	if (EXPECTED(!ce->serialize_func)) {
		ce->serialize_func = parent->serialize_func;
	}
	if (EXPECTED(!ce->serialize)) {
		ce->serialize = parent->serialize;
	}
	if (EXPECTED(!ce->unserialize_func)) {
		ce->unserialize_func = parent->unserialize_func;
	}
	if (EXPECTED(!ce->unserialize)) {
		ce->unserialize = parent->unserialize;
	}
	if (!ce->destructor) {
		ce->destructor = parent->destructor;
	}
	if (EXPECTED(!ce->__debugInfo)) {
		ce->__debugInfo = parent->__debugInfo;
	}

	if (ce->constructor) {
		if (parent->constructor && UNEXPECTED(parent->constructor->common.fn_flags & ZEND_ACC_FINAL)) {
			zend_error_noreturn(E_ERROR, "Cannot override final %s::%s() with %s::%s()",
				ZSTR_VAL(parent->name), ZSTR_VAL(parent->constructor->common.function_name),
				ZSTR_VAL(ce->name), ZSTR_VAL(ce->constructor->common.function_name));
		}
		return;
	}

	ce->constructor = parent->constructor;
}
/* }}} */

char *zend_visibility_string(uint32_t fn_flags) /* {{{ */
{
	if (fn_flags & ZEND_ACC_PUBLIC) {
		return "public";
	} else if (fn_flags & ZEND_ACC_PRIVATE) {
		return "private";
	} else {
		ZEND_ASSERT(fn_flags & ZEND_ACC_PROTECTED);
		return "protected";
	}
}
/* }}} */

static zend_string *resolve_class_name(const zend_function *fe, zend_string *name) {
	zend_class_entry *ce = fe->common.scope;
	ZEND_ASSERT(ce);
	if (zend_string_equals_literal_ci(name, "parent") && ce->parent) {
		if (ce->ce_flags & (ZEND_ACC_LINKED|ZEND_ACC_LINKING_IN_PROGRESS)) {
			return ce->parent->name;
		} else {
			return ce->parent_name;
		}
	} else if (zend_string_equals_literal_ci(name, "self")) {
		return ce->name;
	} else {
		return name;
	}
}

static zend_bool class_visible(zend_class_entry *ce) {
	if (ce->type == ZEND_INTERNAL_CLASS) {
		return !(CG(compiler_options) & ZEND_COMPILE_IGNORE_INTERNAL_CLASSES);
	} else {
		ZEND_ASSERT(ce->type == ZEND_USER_CLASS);
		return !(CG(compiler_options) & ZEND_COMPILE_IGNORE_OTHER_FILES)
			|| ce->info.user.filename == CG(compiled_filename);
	}
}

static zend_class_entry *lookup_class(const zend_function *fe, zend_string *name) {
	zend_class_entry *ce;
	if (!CG(in_compilation)) {
		ce = zend_lookup_class(name);
		if (ce) {
			return ce;
		}
	} else {
		ce = zend_lookup_class_ex(name, NULL, ZEND_FETCH_CLASS_NO_AUTOLOAD);
		if (ce && class_visible(ce)) {
			return ce;
		}
	}

	/* The current class may not be registered yet, so check for it explicitly. */
	if (zend_string_equals_ci(fe->common.scope->name, name)) {
		return fe->common.scope;
	}

	return NULL;
}

/* Instanceof that's safe to use on unlinked classes. For the unlinked case, we only handle
 * class identity here. */
static zend_bool unlinked_instanceof(zend_class_entry *ce1, zend_class_entry *ce2) {
	if ((ce1->ce_flags & (ZEND_ACC_LINKED|ZEND_ACC_LINKING_IN_PROGRESS))) {
		return instanceof_function(ce1, ce2);
	}
	return ce1 == ce2;
}

/* Unresolved means that class declarations that are currently not available are needed to
 * determine whether the inheritance is valid or not. At runtime UNRESOLVED should be treated
 * as an ERROR. */
typedef enum {
	INHERITANCE_UNRESOLVED = -1,
	INHERITANCE_ERROR = 0,
	INHERITANCE_SUCCESS = 1,
} inheritance_status;

static inheritance_status zend_perform_covariant_type_check(
		zend_string **unresolved_class,
		const zend_function *fe, zend_arg_info *fe_arg_info,
		const zend_function *proto, zend_arg_info *proto_arg_info) /* {{{ */
{
	zend_type fe_type = fe_arg_info->type, proto_type = proto_arg_info->type;
	ZEND_ASSERT(ZEND_TYPE_IS_SET(fe_type) && ZEND_TYPE_IS_SET(proto_type));

	if (ZEND_TYPE_ALLOW_NULL(fe_type) && !ZEND_TYPE_ALLOW_NULL(proto_type)) {
		return INHERITANCE_ERROR;
	}

	if (ZEND_TYPE_IS_CLASS(proto_type)) {
		zend_string *fe_class_name, *proto_class_name;
		zend_class_entry *fe_ce, *proto_ce;
		if (!ZEND_TYPE_IS_CLASS(fe_type)) {
			return INHERITANCE_ERROR;
		}

		fe_class_name = resolve_class_name(fe, ZEND_TYPE_NAME(fe_type));
		proto_class_name = resolve_class_name(proto, ZEND_TYPE_NAME(proto_type));
		if (zend_string_equals_ci(fe_class_name, proto_class_name)) {
			return INHERITANCE_SUCCESS;
		}

		fe_ce = lookup_class(fe, fe_class_name);
		if (!fe_ce) {
			*unresolved_class = fe_class_name;
			return INHERITANCE_UNRESOLVED;
		}

		proto_ce = lookup_class(proto, proto_class_name);
		if (!proto_ce) {
			*unresolved_class = proto_class_name;
			return INHERITANCE_UNRESOLVED;
		}

		return unlinked_instanceof(fe_ce, proto_ce) ? INHERITANCE_SUCCESS : INHERITANCE_ERROR;
	} else if (ZEND_TYPE_CODE(proto_type) == IS_ITERABLE) {
		if (ZEND_TYPE_IS_CLASS(fe_type)) {
			zend_string *fe_class_name = resolve_class_name(fe, ZEND_TYPE_NAME(fe_type));
			zend_class_entry *fe_ce = lookup_class(fe, fe_class_name);
			if (!fe_ce) {
				*unresolved_class = fe_class_name;
				return INHERITANCE_UNRESOLVED;
			}
			return unlinked_instanceof(fe_ce, zend_ce_traversable)
				? INHERITANCE_SUCCESS : INHERITANCE_ERROR;
		}

		return ZEND_TYPE_CODE(fe_type) == IS_ITERABLE || ZEND_TYPE_CODE(fe_type) == IS_ARRAY
			? INHERITANCE_SUCCESS : INHERITANCE_ERROR;
	} else if (ZEND_TYPE_CODE(proto_type) == IS_OBJECT) {
		if (ZEND_TYPE_IS_CLASS(fe_type)) {
			/* Currently, any class name would be allowed here. We still perform a class lookup
			 * for forward-compatibility reasons, as we may have named types in the future that
			 * are not classes (such as enums or typedefs). */
			zend_string *fe_class_name = resolve_class_name(fe, ZEND_TYPE_NAME(fe_type));
			zend_class_entry *fe_ce = lookup_class(fe, fe_class_name);
			if (!fe_ce) {
				*unresolved_class = fe_class_name;
				return INHERITANCE_UNRESOLVED;
			}
			return INHERITANCE_SUCCESS;
		}

		return ZEND_TYPE_CODE(fe_type) == IS_OBJECT ? INHERITANCE_SUCCESS : INHERITANCE_ERROR;
	} else {
		return ZEND_TYPE_CODE(fe_type) == ZEND_TYPE_CODE(proto_type)
			? INHERITANCE_SUCCESS : INHERITANCE_ERROR;
	}
}
/* }}} */

static inheritance_status zend_do_perform_arg_type_hint_check(
		zend_string **unresolved_class,
		const zend_function *fe, zend_arg_info *fe_arg_info,
		const zend_function *proto, zend_arg_info *proto_arg_info) /* {{{ */
{
	if (!ZEND_TYPE_IS_SET(fe_arg_info->type)) {
		/* Child with no type is always compatible */
		return INHERITANCE_SUCCESS;
	}

	if (!ZEND_TYPE_IS_SET(proto_arg_info->type)) {
		/* Child defines a type, but parent doesn't, violates LSP */
		return INHERITANCE_ERROR;
	}

	/* Contravariant type check is performed as a covariant type check with swapped
	 * argument order. */
	return zend_perform_covariant_type_check(
		unresolved_class, proto, proto_arg_info, fe, fe_arg_info);
}
/* }}} */

static inheritance_status zend_do_perform_implementation_check(
		zend_string **unresolved_class, const zend_function *fe, const zend_function *proto) /* {{{ */
{
	uint32_t i, num_args;
	inheritance_status status, local_status;

	/* If it's a user function then arg_info == NULL means we don't have any parameters but
	 * we still need to do the arg number checks.  We are only willing to ignore this for internal
	 * functions because extensions don't always define arg_info.
	 */
	if (!proto->common.arg_info && proto->common.type != ZEND_USER_FUNCTION) {
		return INHERITANCE_SUCCESS;
	}

	/* Checks for constructors only if they are declared in an interface,
	 * or explicitly marked as abstract
	 */
	if ((fe->common.fn_flags & ZEND_ACC_CTOR)
		&& ((proto->common.scope->ce_flags & ZEND_ACC_INTERFACE) == 0
			&& (proto->common.fn_flags & ZEND_ACC_ABSTRACT) == 0)) {
		return INHERITANCE_SUCCESS;
	}

	/* If the prototype method is private do not enforce a signature */
	if (proto->common.fn_flags & ZEND_ACC_PRIVATE) {
		return INHERITANCE_SUCCESS;
	}

	/* check number of arguments */
	if (proto->common.required_num_args < fe->common.required_num_args
		|| proto->common.num_args > fe->common.num_args) {
		return INHERITANCE_ERROR;
	}

	/* by-ref constraints on return values are covariant */
	if ((proto->common.fn_flags & ZEND_ACC_RETURN_REFERENCE)
		&& !(fe->common.fn_flags & ZEND_ACC_RETURN_REFERENCE)) {
		return INHERITANCE_ERROR;
	}

	if ((proto->common.fn_flags & ZEND_ACC_VARIADIC)
		&& !(fe->common.fn_flags & ZEND_ACC_VARIADIC)) {
		return INHERITANCE_ERROR;
	}

	/* For variadic functions any additional (optional) arguments that were added must be
	 * checked against the signature of the variadic argument, so in this case we have to
	 * go through all the parameters of the function and not just those present in the
	 * prototype. */
	num_args = proto->common.num_args;
	if (proto->common.fn_flags & ZEND_ACC_VARIADIC) {
		num_args++;
        if (fe->common.num_args >= proto->common.num_args) {
			num_args = fe->common.num_args;
			if (fe->common.fn_flags & ZEND_ACC_VARIADIC) {
				num_args++;
			}
		}
	}

	status = INHERITANCE_SUCCESS;
	for (i = 0; i < num_args; i++) {
		zend_arg_info *fe_arg_info = &fe->common.arg_info[i];

		zend_arg_info *proto_arg_info;
		if (i < proto->common.num_args) {
			proto_arg_info = &proto->common.arg_info[i];
		} else {
			proto_arg_info = &proto->common.arg_info[proto->common.num_args];
		}

		local_status = zend_do_perform_arg_type_hint_check(
			unresolved_class, fe, fe_arg_info, proto, proto_arg_info);
		if (local_status == INHERITANCE_ERROR) {
			return INHERITANCE_ERROR;
		}
		if (local_status == INHERITANCE_UNRESOLVED) {
			status = INHERITANCE_UNRESOLVED;
		}

		/* by-ref constraints on arguments are invariant */
		if (fe_arg_info->pass_by_reference != proto_arg_info->pass_by_reference) {
			return INHERITANCE_ERROR;
		}
	}

	/* Check return type compatibility, but only if the prototype already specifies
	 * a return type. Adding a new return type is always valid. */
	if (proto->common.fn_flags & ZEND_ACC_HAS_RETURN_TYPE) {
		/* Removing a return type is not valid. */
		if (!(fe->common.fn_flags & ZEND_ACC_HAS_RETURN_TYPE)) {
			return INHERITANCE_ERROR;
		}

		local_status = zend_perform_covariant_type_check(
			unresolved_class, fe, fe->common.arg_info - 1, proto, proto->common.arg_info - 1);
		if (local_status == INHERITANCE_ERROR) {
			return INHERITANCE_ERROR;
		}
		if (local_status == INHERITANCE_UNRESOLVED) {
			status = INHERITANCE_UNRESOLVED;
		}
	}

	return status;
}
/* }}} */

static ZEND_COLD void zend_append_type_hint(smart_str *str, const zend_function *fptr, zend_arg_info *arg_info, int return_hint) /* {{{ */
{

	if (ZEND_TYPE_IS_SET(arg_info->type) && ZEND_TYPE_ALLOW_NULL(arg_info->type)) {
		smart_str_appendc(str, '?');
	}

	if (ZEND_TYPE_IS_CLASS(arg_info->type)) {
		const char *class_name;
		size_t class_name_len;

		class_name = ZSTR_VAL(ZEND_TYPE_NAME(arg_info->type));
		class_name_len = ZSTR_LEN(ZEND_TYPE_NAME(arg_info->type));

		if (!strcasecmp(class_name, "self") && fptr->common.scope) {
			class_name = ZSTR_VAL(fptr->common.scope->name);
			class_name_len = ZSTR_LEN(fptr->common.scope->name);
		} else if (!strcasecmp(class_name, "parent") && fptr->common.scope && fptr->common.scope->parent) {
			class_name = ZSTR_VAL(fptr->common.scope->parent->name);
			class_name_len = ZSTR_LEN(fptr->common.scope->parent->name);
		}

		smart_str_appendl(str, class_name, class_name_len);
		if (!return_hint) {
			smart_str_appendc(str, ' ');
		}
	} else if (ZEND_TYPE_IS_CODE(arg_info->type)) {
		const char *type_name = zend_get_type_by_const(ZEND_TYPE_CODE(arg_info->type));
		smart_str_appends(str, type_name);
		if (!return_hint) {
			smart_str_appendc(str, ' ');
		}
	}
}
/* }}} */

static ZEND_COLD zend_string *zend_get_function_declaration(const zend_function *fptr) /* {{{ */
{
	smart_str str = {0};

	if (fptr->op_array.fn_flags & ZEND_ACC_RETURN_REFERENCE) {
		smart_str_appends(&str, "& ");
	}

	if (fptr->common.scope) {
		/* cut off on NULL byte ... class@anonymous */
		smart_str_appendl(&str, ZSTR_VAL(fptr->common.scope->name), strlen(ZSTR_VAL(fptr->common.scope->name)));
		smart_str_appends(&str, "::");
	}

	smart_str_append(&str, fptr->common.function_name);
	smart_str_appendc(&str, '(');

	if (fptr->common.arg_info) {
		uint32_t i, num_args, required;
		zend_arg_info *arg_info = fptr->common.arg_info;

		required = fptr->common.required_num_args;
		num_args = fptr->common.num_args;
		if (fptr->common.fn_flags & ZEND_ACC_VARIADIC) {
			num_args++;
		}
		for (i = 0; i < num_args;) {
			zend_append_type_hint(&str, fptr, arg_info, 0);

			if (arg_info->pass_by_reference) {
				smart_str_appendc(&str, '&');
			}

			if (arg_info->is_variadic) {
				smart_str_appends(&str, "...");
			}

			smart_str_appendc(&str, '$');

			if (arg_info->name) {
				if (fptr->type == ZEND_INTERNAL_FUNCTION) {
					smart_str_appends(&str, ((zend_internal_arg_info*)arg_info)->name);
				} else {
					smart_str_appendl(&str, ZSTR_VAL(arg_info->name), ZSTR_LEN(arg_info->name));
				}
			} else {
				smart_str_appends(&str, "param");
				smart_str_append_unsigned(&str, i);
			}

			if (i >= required && !arg_info->is_variadic) {
				smart_str_appends(&str, " = ");
				if (fptr->type == ZEND_USER_FUNCTION) {
					zend_op *precv = NULL;
					{
						uint32_t idx  = i;
						zend_op *op = fptr->op_array.opcodes;
						zend_op *end = op + fptr->op_array.last;

						++idx;
						while (op < end) {
							if ((op->opcode == ZEND_RECV || op->opcode == ZEND_RECV_INIT)
									&& op->op1.num == (zend_ulong)idx)
							{
								precv = op;
							}
							++op;
						}
					}
					if (precv && precv->opcode == ZEND_RECV_INIT && precv->op2_type != IS_UNUSED) {
						zval *zv = RT_CONSTANT(precv, precv->op2);

						if (Z_TYPE_P(zv) == IS_FALSE) {
							smart_str_appends(&str, "false");
						} else if (Z_TYPE_P(zv) == IS_TRUE) {
							smart_str_appends(&str, "true");
						} else if (Z_TYPE_P(zv) == IS_NULL) {
							smart_str_appends(&str, "NULL");
						} else if (Z_TYPE_P(zv) == IS_STRING) {
							smart_str_appendc(&str, '\'');
							smart_str_appendl(&str, Z_STRVAL_P(zv), MIN(Z_STRLEN_P(zv), 10));
							if (Z_STRLEN_P(zv) > 10) {
								smart_str_appends(&str, "...");
							}
							smart_str_appendc(&str, '\'');
						} else if (Z_TYPE_P(zv) == IS_ARRAY) {
							smart_str_appends(&str, "Array");
						} else if (Z_TYPE_P(zv) == IS_CONSTANT_AST) {
							zend_ast *ast = Z_ASTVAL_P(zv);
							if (ast->kind == ZEND_AST_CONSTANT) {
								smart_str_append(&str, zend_ast_get_constant_name(ast));
							} else {
								smart_str_appends(&str, "<expression>");
							}
						} else {
							zend_string *tmp_zv_str;
							zend_string *zv_str = zval_get_tmp_string(zv, &tmp_zv_str);
							smart_str_append(&str, zv_str);
							zend_tmp_string_release(tmp_zv_str);
						}
					}
				} else {
					smart_str_appends(&str, "NULL");
				}
			}

			if (++i < num_args) {
				smart_str_appends(&str, ", ");
			}
			arg_info++;
		}
	}

	smart_str_appendc(&str, ')');

	if (fptr->common.fn_flags & ZEND_ACC_HAS_RETURN_TYPE) {
		smart_str_appends(&str, ": ");
		zend_append_type_hint(&str, fptr, fptr->common.arg_info - 1, 1);
	}
	smart_str_0(&str);

	return str.s;
}
/* }}} */

static zend_always_inline uint32_t func_lineno(zend_function *fn) {
	return fn->common.type == ZEND_USER_FUNCTION ? fn->op_array.line_start : 0;
}

static void ZEND_COLD emit_incompatible_method_error(
		int error_level, const char *error_verb, zend_function *child, zend_function *parent,
		inheritance_status status, zend_string *unresolved_class) {
	zend_string *parent_prototype = zend_get_function_declaration(parent);
	zend_string *child_prototype = zend_get_function_declaration(child);
	if (status == INHERITANCE_UNRESOLVED) {
		zend_error_at(error_level, NULL, func_lineno(child),
			"Could not check compatibility between %s and %s, because class %s is not available",
			ZSTR_VAL(child_prototype), ZSTR_VAL(parent_prototype), ZSTR_VAL(unresolved_class));
	} else {
		zend_error_at(error_level, NULL, func_lineno(child),
			"Declaration of %s %s be compatible with %s",
			ZSTR_VAL(child_prototype), error_verb, ZSTR_VAL(parent_prototype));
	}
	zend_string_efree(child_prototype);
	zend_string_efree(parent_prototype);
}

static void do_inheritance_check_on_method(zend_function *child, zend_function *parent, zend_class_entry *ce, zval *child_zv) /* {{{ */
{
	uint32_t child_flags;
	uint32_t parent_flags = parent->common.fn_flags;
	inheritance_status status;
	zend_string *unresolved_class;

	if (UNEXPECTED(parent_flags & ZEND_ACC_FINAL)) {
		zend_error_at_noreturn(E_COMPILE_ERROR, NULL, func_lineno(child),
			"Cannot override final method %s::%s()",
			ZEND_FN_SCOPE_NAME(parent), ZSTR_VAL(child->common.function_name));
	}

	child_flags	= child->common.fn_flags;
	/* You cannot change from static to non static and vice versa.
	 */
	if (UNEXPECTED((child_flags & ZEND_ACC_STATIC) != (parent_flags & ZEND_ACC_STATIC))) {
		if (child_flags & ZEND_ACC_STATIC) {
			zend_error_at_noreturn(E_COMPILE_ERROR, NULL, func_lineno(child),
				"Cannot make non static method %s::%s() static in class %s",
				ZEND_FN_SCOPE_NAME(parent), ZSTR_VAL(child->common.function_name), ZEND_FN_SCOPE_NAME(child));
		} else {
			zend_error_at_noreturn(E_COMPILE_ERROR, NULL, func_lineno(child),
				"Cannot make static method %s::%s() non static in class %s",
				ZEND_FN_SCOPE_NAME(parent), ZSTR_VAL(child->common.function_name), ZEND_FN_SCOPE_NAME(child));
		}
	}

	/* Disallow making an inherited method abstract. */
	if (UNEXPECTED((child_flags & ZEND_ACC_ABSTRACT) > (parent_flags & ZEND_ACC_ABSTRACT))) {
		zend_error_at_noreturn(E_COMPILE_ERROR, NULL, func_lineno(child),
			"Cannot make non abstract method %s::%s() abstract in class %s",
			ZEND_FN_SCOPE_NAME(parent), ZSTR_VAL(child->common.function_name), ZEND_FN_SCOPE_NAME(child));
	}

	if (parent_flags & (ZEND_ACC_PRIVATE|ZEND_ACC_CHANGED)) {
		child->common.fn_flags |= ZEND_ACC_CHANGED;
	}

	do {
		if (!(parent_flags & ZEND_ACC_PRIVATE)) {
			zend_function *proto = parent->common.prototype ?
				parent->common.prototype : parent;

			if (!(parent_flags & ZEND_ACC_CTOR)) {
				if (!proto) {
					proto = parent;
				}
			} else if (proto) {
				/* ctors only have a prototype if is abstract (or comes from an interface) */
				/* and if that is the case, we want to check inheritance against it */
				if (proto->common.fn_flags & ZEND_ACC_ABSTRACT) {
					parent = proto;
				} else {
					break;
				}
			} else {
				break;
			}
			if (child_zv && child->common.prototype != proto) {
				do {
					if (child->common.scope != ce
					 && child->type == ZEND_USER_FUNCTION
					 && !child->op_array.static_variables) {
						if (ce->ce_flags & ZEND_ACC_INTERFACE) {
							/* Few parent interfaces contain the same method */
							break;
						} else {
							/* op_array wasn't duplicated yet */
							zend_function *new_function = zend_arena_alloc(&CG(arena), sizeof(zend_op_array));
							memcpy(new_function, child, sizeof(zend_op_array));
							Z_PTR_P(child_zv) = child = new_function;
						}
					}
					child->common.prototype = proto;
				} while (0);
			}
			/* Prevent derived classes from restricting access that was available in parent classes (except deriving from non-abstract ctors) */
			if ((child_flags & ZEND_ACC_PPP_MASK) > (parent_flags & ZEND_ACC_PPP_MASK)) {
				zend_error_at_noreturn(E_COMPILE_ERROR, NULL, func_lineno(child),
					"Access level to %s::%s() must be %s (as in class %s)%s",
					ZEND_FN_SCOPE_NAME(child), ZSTR_VAL(child->common.function_name), zend_visibility_string(parent_flags), ZEND_FN_SCOPE_NAME(parent), (parent_flags&ZEND_ACC_PUBLIC) ? "" : " or weaker");
			}

			status = zend_do_perform_implementation_check(&unresolved_class, child, parent);
			if (UNEXPECTED(status != INHERITANCE_SUCCESS)) {
				int error_level;
				const char *error_verb;
				if (child->common.prototype && (
					child->common.prototype->common.fn_flags & ZEND_ACC_ABSTRACT
				)) {
					error_level = E_COMPILE_ERROR;
					error_verb = "must";
				} else if ((parent->common.fn_flags & ZEND_ACC_HAS_RETURN_TYPE) &&
		                   (!(child->common.fn_flags & ZEND_ACC_HAS_RETURN_TYPE) ||
				            zend_perform_covariant_type_check(&unresolved_class, child, child->common.arg_info - 1, parent, parent->common.arg_info - 1) != INHERITANCE_SUCCESS)) {
					error_level = E_COMPILE_ERROR;
					error_verb = "must";
				} else {
					error_level = E_WARNING;
					error_verb = "should";
				}
				emit_incompatible_method_error(
					error_level, error_verb, child, parent, status, unresolved_class);
			}
		}
	} while (0);
}
/* }}} */

static zend_function *do_inherit_method(zend_string *key, zend_function *parent, zend_class_entry *ce) /* {{{ */
{
	zval *child = zend_hash_find_ex(&ce->function_table, key, 1);

	if (child) {
		zend_function *func = (zend_function*)Z_PTR_P(child);

		if (UNEXPECTED(func == parent)) {
			/* The same method in interface may be inherited few times */
			return NULL;
		}

		do_inheritance_check_on_method(func, parent, ce, child);
		return NULL;
	}

	if (parent->common.fn_flags & (ZEND_ACC_ABSTRACT)) {
		ce->ce_flags |= ZEND_ACC_IMPLICIT_ABSTRACT_CLASS;
	}

	return zend_duplicate_function(parent, ce);
}
/* }}} */

zend_string* zend_resolve_property_type(zend_string *type, zend_class_entry *scope) /* {{{ */
{
	if (zend_string_equals_literal_ci(type, "parent")) {
		if (scope && scope->parent) {
			return scope->parent->name;
		}
	}

	if (zend_string_equals_literal_ci(type, "self")) {
		if (scope) {
			return scope->name;
		}
	}

	return type;
} /* }}} */

zend_bool property_types_compatible(zend_property_info *parent_info, zend_property_info *child_info) {
	zend_string *parent_name, *child_name;
	zend_class_entry *parent_type_ce, *child_type_ce;
	if (parent_info->type == child_info->type) {
		return 1;
	}

	if (!ZEND_TYPE_IS_CLASS(parent_info->type) || !ZEND_TYPE_IS_CLASS(child_info->type) ||
			ZEND_TYPE_ALLOW_NULL(parent_info->type) != ZEND_TYPE_ALLOW_NULL(child_info->type)) {
		return 0;
	}

	parent_name = ZEND_TYPE_IS_CE(parent_info->type)
		? ZEND_TYPE_CE(parent_info->type)->name
		: zend_resolve_property_type(ZEND_TYPE_NAME(parent_info->type), parent_info->ce);
	child_name = ZEND_TYPE_IS_CE(child_info->type)
		? ZEND_TYPE_CE(child_info->type)->name
		: zend_resolve_property_type(ZEND_TYPE_NAME(child_info->type), child_info->ce);
	if (zend_string_equals_ci(parent_name, child_name)) {
		return 1;
	}

	/* Check for class aliases */
	parent_type_ce = ZEND_TYPE_IS_CE(parent_info->type)
		? ZEND_TYPE_CE(parent_info->type)
		: zend_lookup_class(parent_name);
	child_type_ce = ZEND_TYPE_IS_CE(child_info->type)
		? ZEND_TYPE_CE(child_info->type)
		: zend_lookup_class(child_name);
	return parent_type_ce && child_type_ce && parent_type_ce == child_type_ce;
}

static void do_inherit_property(zend_property_info *parent_info, zend_string *key, zend_class_entry *ce) /* {{{ */
{
	zval *child = zend_hash_find_ex(&ce->properties_info, key, 1);
	zend_property_info *child_info;

	if (UNEXPECTED(child)) {
		child_info = Z_PTR_P(child);
		if (parent_info->flags & (ZEND_ACC_PRIVATE|ZEND_ACC_CHANGED)) {
			child_info->flags |= ZEND_ACC_CHANGED;
		}
		if (!(parent_info->flags & ZEND_ACC_PRIVATE)) {
			if (UNEXPECTED((parent_info->flags & ZEND_ACC_STATIC) != (child_info->flags & ZEND_ACC_STATIC))) {
				zend_error_noreturn(E_COMPILE_ERROR, "Cannot redeclare %s%s::$%s as %s%s::$%s",
					(parent_info->flags & ZEND_ACC_STATIC) ? "static " : "non static ", ZSTR_VAL(ce->parent->name), ZSTR_VAL(key),
					(child_info->flags & ZEND_ACC_STATIC) ? "static " : "non static ", ZSTR_VAL(ce->name), ZSTR_VAL(key));
			}

			if (UNEXPECTED((child_info->flags & ZEND_ACC_PPP_MASK) > (parent_info->flags & ZEND_ACC_PPP_MASK))) {
				zend_error_noreturn(E_COMPILE_ERROR, "Access level to %s::$%s must be %s (as in class %s)%s", ZSTR_VAL(ce->name), ZSTR_VAL(key), zend_visibility_string(parent_info->flags), ZSTR_VAL(ce->parent->name), (parent_info->flags&ZEND_ACC_PUBLIC) ? "" : " or weaker");
			} else if ((child_info->flags & ZEND_ACC_STATIC) == 0) {
				int parent_num = OBJ_PROP_TO_NUM(parent_info->offset);
				int child_num = OBJ_PROP_TO_NUM(child_info->offset);

				/* Don't keep default properties in GC (they may be freed by opcache) */
				zval_ptr_dtor_nogc(&(ce->default_properties_table[parent_num]));
				ce->default_properties_table[parent_num] = ce->default_properties_table[child_num];
				ZVAL_UNDEF(&ce->default_properties_table[child_num]);
				child_info->offset = parent_info->offset;
			}

			if (UNEXPECTED(ZEND_TYPE_IS_SET(parent_info->type))) {
				if (!property_types_compatible(parent_info, child_info)) {
					zend_error_noreturn(E_COMPILE_ERROR,
					"Type of %s::$%s must be %s%s (as in class %s)",
						ZSTR_VAL(ce->name),
						ZSTR_VAL(key),
						ZEND_TYPE_ALLOW_NULL(parent_info->type) ? "?" : "",
						ZEND_TYPE_IS_CLASS(parent_info->type)
							? ZSTR_VAL(ZEND_TYPE_IS_CE(parent_info->type) ? ZEND_TYPE_CE(parent_info->type)->name : zend_resolve_property_type(ZEND_TYPE_NAME(parent_info->type), parent_info->ce))
							: zend_get_type_by_const(ZEND_TYPE_CODE(parent_info->type)),
						ZSTR_VAL(ce->parent->name));
				}
			} else if (UNEXPECTED(ZEND_TYPE_IS_SET(child_info->type) && !ZEND_TYPE_IS_SET(parent_info->type))) {
				zend_error_noreturn(E_COMPILE_ERROR,
						"Type of %s::$%s must not be defined (as in class %s)",
						ZSTR_VAL(ce->name),
						ZSTR_VAL(key),
						ZSTR_VAL(ce->parent->name));
			}
		}
	} else {
		if (UNEXPECTED(ce->type & ZEND_INTERNAL_CLASS)) {
			child_info = zend_duplicate_property_info_internal(parent_info);
		} else {
			child_info = parent_info;
		}
		_zend_hash_append_ptr(&ce->properties_info, key, child_info);
	}
}
/* }}} */

static inline void do_implement_interface(zend_class_entry *ce, zend_class_entry *iface) /* {{{ */
{
	if (!(ce->ce_flags & ZEND_ACC_INTERFACE) && iface->interface_gets_implemented && iface->interface_gets_implemented(iface, ce) == FAILURE) {
		zend_error_noreturn(E_CORE_ERROR, "Class %s could not implement interface %s", ZSTR_VAL(ce->name), ZSTR_VAL(iface->name));
	}
	if (UNEXPECTED(ce == iface)) {
		zend_error_noreturn(E_ERROR, "Interface %s cannot implement itself", ZSTR_VAL(ce->name));
	}
}
/* }}} */

static void zend_do_inherit_interfaces(zend_class_entry *ce, const zend_class_entry *iface) /* {{{ */
{
	/* expects interface to be contained in ce's interface list already */
	uint32_t i, ce_num, if_num = iface->num_interfaces;
	zend_class_entry *entry;

	ce_num = ce->num_interfaces;

	if (ce->type == ZEND_INTERNAL_CLASS) {
		ce->interfaces = (zend_class_entry **) realloc(ce->interfaces, sizeof(zend_class_entry *) * (ce_num + if_num));
	} else {
		ce->interfaces = (zend_class_entry **) erealloc(ce->interfaces, sizeof(zend_class_entry *) * (ce_num + if_num));
	}

	/* Inherit the interfaces, only if they're not already inherited by the class */
	while (if_num--) {
		entry = iface->interfaces[if_num];
		for (i = 0; i < ce_num; i++) {
			if (ce->interfaces[i] == entry) {
				break;
			}
		}
		if (i == ce_num) {
			ce->interfaces[ce->num_interfaces++] = entry;
		}
	}

	/* and now call the implementing handlers */
	while (ce_num < ce->num_interfaces) {
		do_implement_interface(ce, ce->interfaces[ce_num++]);
	}
}
/* }}} */

static void do_inherit_class_constant(zend_string *name, zend_class_constant *parent_const, zend_class_entry *ce) /* {{{ */
{
	zval *zv = zend_hash_find_ex(&ce->constants_table, name, 1);
	zend_class_constant *c;

	if (zv != NULL) {
		c = (zend_class_constant*)Z_PTR_P(zv);
		if (UNEXPECTED((Z_ACCESS_FLAGS(c->value) & ZEND_ACC_PPP_MASK) > (Z_ACCESS_FLAGS(parent_const->value) & ZEND_ACC_PPP_MASK))) {
			zend_error_noreturn(E_COMPILE_ERROR, "Access level to %s::%s must be %s (as in class %s)%s",
				ZSTR_VAL(ce->name), ZSTR_VAL(name), zend_visibility_string(Z_ACCESS_FLAGS(parent_const->value)), ZSTR_VAL(ce->parent->name), (Z_ACCESS_FLAGS(parent_const->value) & ZEND_ACC_PUBLIC) ? "" : " or weaker");
		}
	} else if (!(Z_ACCESS_FLAGS(parent_const->value) & ZEND_ACC_PRIVATE)) {
		if (Z_TYPE(parent_const->value) == IS_CONSTANT_AST) {
			ce->ce_flags &= ~ZEND_ACC_CONSTANTS_UPDATED;
		}
		if (ce->type & ZEND_INTERNAL_CLASS) {
			c = pemalloc(sizeof(zend_class_constant), 1);
			memcpy(c, parent_const, sizeof(zend_class_constant));
			parent_const = c;
		}
		_zend_hash_append_ptr(&ce->constants_table, name, parent_const);
	}
}
/* }}} */

void zend_build_properties_info_table(zend_class_entry *ce)
{
	zend_property_info **table, *prop;
	size_t size;
	if (ce->default_properties_count == 0) {
		return;
	}

	ZEND_ASSERT(ce->properties_info_table == NULL);
	size = sizeof(zend_property_info *) * ce->default_properties_count;
	if (ce->type == ZEND_USER_CLASS) {
		ce->properties_info_table = table = zend_arena_alloc(&CG(arena), size);
	} else {
		ce->properties_info_table = table = pemalloc(size, 1);
	}

	/* Dead slots may be left behind during inheritance. Make sure these are NULLed out. */
	memset(table, 0, size);

	if (ce->parent && ce->parent->default_properties_count != 0) {
		zend_property_info **parent_table = ce->parent->properties_info_table;
		memcpy(
			table, parent_table,
			sizeof(zend_property_info *) * ce->parent->default_properties_count
		);

		/* Child did not add any new properties, we are done */
		if (ce->default_properties_count == ce->parent->default_properties_count) {
			return;
		}
	}

	ZEND_HASH_FOREACH_PTR(&ce->properties_info, prop) {
		if (prop->ce == ce && (prop->flags & ZEND_ACC_STATIC) == 0) {
			table[OBJ_PROP_TO_NUM(prop->offset)] = prop;
		}
	} ZEND_HASH_FOREACH_END();
}

ZEND_API void zend_do_inheritance(zend_class_entry *ce, zend_class_entry *parent_ce) /* {{{ */
{
	zend_property_info *property_info;
	zend_function *func;
	zend_string *key;

	if (UNEXPECTED(ce->ce_flags & ZEND_ACC_INTERFACE)) {
		/* Interface can only inherit other interfaces */
		if (UNEXPECTED(!(parent_ce->ce_flags & ZEND_ACC_INTERFACE))) {
			zend_error_noreturn(E_COMPILE_ERROR, "Interface %s may not inherit from class (%s)", ZSTR_VAL(ce->name), ZSTR_VAL(parent_ce->name));
		}
	} else if (UNEXPECTED(parent_ce->ce_flags & (ZEND_ACC_INTERFACE|ZEND_ACC_TRAIT|ZEND_ACC_FINAL))) {
		/* Class declaration must not extend traits or interfaces */
		if (parent_ce->ce_flags & ZEND_ACC_INTERFACE) {
			zend_error_noreturn(E_COMPILE_ERROR, "Class %s cannot extend from interface %s", ZSTR_VAL(ce->name), ZSTR_VAL(parent_ce->name));
		} else if (parent_ce->ce_flags & ZEND_ACC_TRAIT) {
			zend_error_noreturn(E_COMPILE_ERROR, "Class %s cannot extend from trait %s", ZSTR_VAL(ce->name), ZSTR_VAL(parent_ce->name));
		}

		/* Class must not extend a final class */
		if (parent_ce->ce_flags & ZEND_ACC_FINAL) {
			zend_error_noreturn(E_COMPILE_ERROR, "Class %s may not inherit from final class (%s)", ZSTR_VAL(ce->name), ZSTR_VAL(parent_ce->name));
		}
	}

	if (ce->parent_name) {
		zend_string_release_ex(ce->parent_name, 0);
	}
	ce->parent = parent_ce;

	/* Inherit interfaces */
	if (parent_ce->num_interfaces) {
		if (!(ce->ce_flags & ZEND_ACC_IMPLEMENT_INTERFACES)) {
			zend_do_inherit_interfaces(ce, parent_ce);
		} else {
			uint32_t i;

			for (i = 0; i < parent_ce->num_interfaces; i++) {
				do_implement_interface(ce, parent_ce->interfaces[i]);
			}
		}
	}

	/* Inherit properties */
	if (parent_ce->default_properties_count) {
		zval *src, *dst, *end;

		if (ce->default_properties_count) {
			zval *table = pemalloc(sizeof(zval) * (ce->default_properties_count + parent_ce->default_properties_count), ce->type == ZEND_INTERNAL_CLASS);
			src = ce->default_properties_table + ce->default_properties_count;
			end = table + parent_ce->default_properties_count;
			dst = end + ce->default_properties_count;
			ce->default_properties_table = table;
			do {
				dst--;
				src--;
				ZVAL_COPY_VALUE(dst, src);
			} while (dst != end);
			pefree(src, ce->type == ZEND_INTERNAL_CLASS);
			end = ce->default_properties_table;
		} else {
			end = pemalloc(sizeof(zval) * parent_ce->default_properties_count, ce->type == ZEND_INTERNAL_CLASS);
			dst = end + parent_ce->default_properties_count;
			ce->default_properties_table = end;
		}
		src = parent_ce->default_properties_table + parent_ce->default_properties_count;
		if (UNEXPECTED(parent_ce->type != ce->type)) {
			/* User class extends internal */
			do {
				dst--;
				src--;
				ZVAL_COPY_OR_DUP(dst, src);
				if (Z_OPT_TYPE_P(dst) == IS_CONSTANT_AST) {
					ce->ce_flags &= ~ZEND_ACC_CONSTANTS_UPDATED;
				}
				continue;
			} while (dst != end);
		} else {
			do {
				dst--;
				src--;
				ZVAL_COPY(dst, src);
				if (Z_OPT_TYPE_P(dst) == IS_CONSTANT_AST) {
					ce->ce_flags &= ~ZEND_ACC_CONSTANTS_UPDATED;
				}
				continue;
			} while (dst != end);
		}
		ce->default_properties_count += parent_ce->default_properties_count;
	}

	if (parent_ce->default_static_members_count) {
		zval *src, *dst, *end;

		if (ce->default_static_members_count) {
			zval *table = pemalloc(sizeof(zval) * (ce->default_static_members_count + parent_ce->default_static_members_count), ce->type == ZEND_INTERNAL_CLASS);
			src = ce->default_static_members_table + ce->default_static_members_count;
			end = table + parent_ce->default_static_members_count;
			dst = end + ce->default_static_members_count;
			ce->default_static_members_table = table;
			do {
				dst--;
				src--;
				ZVAL_COPY_VALUE(dst, src);
			} while (dst != end);
			pefree(src, ce->type == ZEND_INTERNAL_CLASS);
			end = ce->default_static_members_table;
		} else {
			end = pemalloc(sizeof(zval) * parent_ce->default_static_members_count, ce->type == ZEND_INTERNAL_CLASS);
			dst = end + parent_ce->default_static_members_count;
			ce->default_static_members_table = end;
		}
		if (UNEXPECTED(parent_ce->type != ce->type)) {
			/* User class extends internal */
			if (CE_STATIC_MEMBERS(parent_ce) == NULL) {
				zend_class_init_statics(parent_ce);
			}
			if (UNEXPECTED(zend_update_class_constants(parent_ce) != SUCCESS)) {
				ZEND_ASSERT(0);
			}
			src = CE_STATIC_MEMBERS(parent_ce) + parent_ce->default_static_members_count;
			do {
				dst--;
				src--;
				if (Z_TYPE_P(src) == IS_INDIRECT) {
					ZVAL_INDIRECT(dst, Z_INDIRECT_P(src));
				} else {
					ZVAL_INDIRECT(dst, src);
				}
			} while (dst != end);
		} else if (ce->type == ZEND_USER_CLASS) {
			if (CE_STATIC_MEMBERS(parent_ce) == NULL) {
				ZEND_ASSERT(parent_ce->ce_flags & ZEND_ACC_IMMUTABLE);
				zend_class_init_statics(parent_ce);
			}
			src = CE_STATIC_MEMBERS(parent_ce) + parent_ce->default_static_members_count;
			do {
				dst--;
				src--;
				if (Z_TYPE_P(src) == IS_INDIRECT) {
					ZVAL_INDIRECT(dst, Z_INDIRECT_P(src));
				} else {
					ZVAL_INDIRECT(dst, src);
				}
				if (Z_TYPE_P(Z_INDIRECT_P(dst)) == IS_CONSTANT_AST) {
					ce->ce_flags &= ~ZEND_ACC_CONSTANTS_UPDATED;
				}
			} while (dst != end);
		} else {
			src = parent_ce->default_static_members_table + parent_ce->default_static_members_count;
			do {
				dst--;
				src--;
				if (Z_TYPE_P(src) == IS_INDIRECT) {
					ZVAL_INDIRECT(dst, Z_INDIRECT_P(src));
				} else {
					ZVAL_INDIRECT(dst, src);
				}
			} while (dst != end);
		}
		ce->default_static_members_count += parent_ce->default_static_members_count;
		if (!ZEND_MAP_PTR(ce->static_members_table)) {
			ZEND_ASSERT(ce->type == ZEND_INTERNAL_CLASS);
			if (!EG(current_execute_data)) {
				ZEND_MAP_PTR_NEW(ce->static_members_table);
			} else {
				/* internal class loaded by dl() */
				ZEND_MAP_PTR_INIT(ce->static_members_table, &ce->default_static_members_table);
			}
		}
	}

	ZEND_HASH_FOREACH_PTR(&ce->properties_info, property_info) {
		if (property_info->ce == ce) {
			if (property_info->flags & ZEND_ACC_STATIC) {
				property_info->offset += parent_ce->default_static_members_count;
			} else {
				property_info->offset += parent_ce->default_properties_count * sizeof(zval);
			}
		}
	} ZEND_HASH_FOREACH_END();

	if (zend_hash_num_elements(&parent_ce->properties_info)) {
		zend_hash_extend(&ce->properties_info,
			zend_hash_num_elements(&ce->properties_info) +
			zend_hash_num_elements(&parent_ce->properties_info), 0);

		ZEND_HASH_FOREACH_STR_KEY_PTR(&parent_ce->properties_info, key, property_info) {
			do_inherit_property(property_info, key, ce);
		} ZEND_HASH_FOREACH_END();
	}

	if (zend_hash_num_elements(&parent_ce->constants_table)) {
		zend_class_constant *c;

		zend_hash_extend(&ce->constants_table,
			zend_hash_num_elements(&ce->constants_table) +
			zend_hash_num_elements(&parent_ce->constants_table), 0);

		ZEND_HASH_FOREACH_STR_KEY_PTR(&parent_ce->constants_table, key, c) {
			do_inherit_class_constant(key, c, ce);
		} ZEND_HASH_FOREACH_END();
	}

	if (zend_hash_num_elements(&parent_ce->function_table)) {
		zend_hash_extend(&ce->function_table,
			zend_hash_num_elements(&ce->function_table) +
			zend_hash_num_elements(&parent_ce->function_table), 0);

		ZEND_HASH_FOREACH_STR_KEY_PTR(&parent_ce->function_table, key, func) {
			zend_function *new_func = do_inherit_method(key, func, ce);

			if (new_func) {
				_zend_hash_append_ptr(&ce->function_table, key, new_func);
			}
		} ZEND_HASH_FOREACH_END();
	}

	do_inherit_parent_constructor(ce);

	if (ce->type == ZEND_INTERNAL_CLASS) {
		if (ce->ce_flags & ZEND_ACC_IMPLICIT_ABSTRACT_CLASS) {
			ce->ce_flags |= ZEND_ACC_EXPLICIT_ABSTRACT_CLASS;
		}
	}
	ce->ce_flags |= parent_ce->ce_flags & (ZEND_HAS_STATIC_IN_METHODS | ZEND_ACC_HAS_TYPE_HINTS | ZEND_ACC_USE_GUARDS);
}
/* }}} */

static zend_bool do_inherit_constant_check(HashTable *child_constants_table, zend_class_constant *parent_constant, zend_string *name, const zend_class_entry *iface) /* {{{ */
{
	zval *zv = zend_hash_find_ex(child_constants_table, name, 1);
	zend_class_constant *old_constant;

	if (zv != NULL) {
		old_constant = (zend_class_constant*)Z_PTR_P(zv);
		if (old_constant->ce != parent_constant->ce) {
			zend_error_noreturn(E_COMPILE_ERROR, "Cannot inherit previously-inherited or override constant %s from interface %s", ZSTR_VAL(name), ZSTR_VAL(iface->name));
		}
		return 0;
	}
	return 1;
}
/* }}} */

static void do_inherit_iface_constant(zend_string *name, zend_class_constant *c, zend_class_entry *ce, zend_class_entry *iface) /* {{{ */
{
	if (do_inherit_constant_check(&ce->constants_table, c, name, iface)) {
		zend_class_constant *ct;
		if (Z_TYPE(c->value) == IS_CONSTANT_AST) {
			ce->ce_flags &= ~ZEND_ACC_CONSTANTS_UPDATED;
		}
		if (ce->type & ZEND_INTERNAL_CLASS) {
			ct = pemalloc(sizeof(zend_class_constant), 1);
			memcpy(ct, c, sizeof(zend_class_constant));
			c = ct;
		}
		zend_hash_update_ptr(&ce->constants_table, name, c);
	}
}
/* }}} */

ZEND_API void zend_do_implement_interface(zend_class_entry *ce, zend_class_entry *iface) /* {{{ */
{
	uint32_t i, ignore = 0;
	uint32_t current_iface_num = ce->num_interfaces;
	uint32_t parent_iface_num  = ce->parent ? ce->parent->num_interfaces : 0;
	zend_function *func;
	zend_string *key;
	zend_class_constant *c;

	ZEND_ASSERT(ce->ce_flags & ZEND_ACC_LINKED);

	for (i = 0; i < ce->num_interfaces; i++) {
		if (ce->interfaces[i] == NULL) {
			memmove(ce->interfaces + i, ce->interfaces + i + 1, sizeof(zend_class_entry*) * (--ce->num_interfaces - i));
			i--;
		} else if (ce->interfaces[i] == iface) {
			if (EXPECTED(i < parent_iface_num)) {
				ignore = 1;
			} else {
				zend_error_noreturn(E_COMPILE_ERROR, "Class %s cannot implement previously implemented interface %s", ZSTR_VAL(ce->name), ZSTR_VAL(iface->name));
			}
		}
	}
	if (ignore) {
		/* Check for attempt to redeclare interface constants */
		ZEND_HASH_FOREACH_STR_KEY_PTR(&ce->constants_table, key, c) {
			do_inherit_constant_check(&iface->constants_table, c, key, iface);
		} ZEND_HASH_FOREACH_END();
	} else {
		if (ce->num_interfaces >= current_iface_num) {
			if (ce->type == ZEND_INTERNAL_CLASS) {
				ce->interfaces = (zend_class_entry **) realloc(ce->interfaces, sizeof(zend_class_entry *) * (++current_iface_num));
			} else {
				ce->interfaces = (zend_class_entry **) erealloc(ce->interfaces, sizeof(zend_class_entry *) * (++current_iface_num));
			}
		}
		ce->interfaces[ce->num_interfaces++] = iface;

		ZEND_HASH_FOREACH_STR_KEY_PTR(&iface->constants_table, key, c) {
			do_inherit_iface_constant(key, c, ce, iface);
		} ZEND_HASH_FOREACH_END();

		ZEND_HASH_FOREACH_STR_KEY_PTR(&iface->function_table, key, func) {
			zend_function *new_func = do_inherit_method(key, func, ce);

			if (new_func) {
				zend_hash_add_new_ptr(&ce->function_table, key, new_func);
			}
		} ZEND_HASH_FOREACH_END();

		do_implement_interface(ce, iface);
		if (iface->num_interfaces) {
			zend_do_inherit_interfaces(ce, iface);
		}
	}
}
/* }}} */

static void zend_do_implement_interfaces(zend_class_entry *ce) /* {{{ */
{
	zend_class_entry **interfaces, *iface;
	uint32_t num_interfaces = 0;
	zend_function *func;
	zend_string *key;
	zend_class_constant *c;
	uint32_t i, j;

	if (ce->parent && ce->parent->num_interfaces) {
		interfaces = emalloc(sizeof(zend_class_entry*) * (ce->parent->num_interfaces + ce->num_interfaces));
		memcpy(interfaces, ce->parent->interfaces, sizeof(zend_class_entry*) * ce->parent->num_interfaces);
		num_interfaces = ce->parent->num_interfaces;
	} else {
		interfaces = emalloc(sizeof(zend_class_entry*) * ce->num_interfaces);
	}

	for (i = 0; i < ce->num_interfaces; i++) {
		iface = zend_fetch_class_by_name(ce->interface_names[i].name,
			ce->interface_names[i].lc_name, ZEND_FETCH_CLASS_INTERFACE);
		if (UNEXPECTED(iface == NULL)) {
			return;
		}
		if (UNEXPECTED(!(iface->ce_flags & ZEND_ACC_INTERFACE))) {
			efree(interfaces);
			zend_error_noreturn(E_ERROR, "%s cannot implement %s - it is not an interface", ZSTR_VAL(ce->name), ZSTR_VAL(iface->name));
			return;
		}
		for (j = 0; j < num_interfaces; j++) {
			if (interfaces[j] == iface) {
				if (!ce->parent || j >= ce->parent->num_interfaces) {
					efree(interfaces);
					zend_error_noreturn(E_COMPILE_ERROR, "Class %s cannot implement previously implemented interface %s", ZSTR_VAL(ce->name), ZSTR_VAL(iface->name));
					return;
				}
				/* skip duplications */
				ZEND_HASH_FOREACH_STR_KEY_PTR(&ce->constants_table, key, c) {
					do_inherit_constant_check(&iface->constants_table, c, key, iface);
				} ZEND_HASH_FOREACH_END();

				iface = NULL;
				break;
			}
		}
		if (iface) {
			interfaces[num_interfaces] = iface;
			num_interfaces++;
		}
	}

	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);

	ce->num_interfaces = num_interfaces;
	ce->interfaces = interfaces;

	i = ce->parent ? ce->parent->num_interfaces : 0;
	for (; i < ce->num_interfaces; i++) {
		iface = ce->interfaces[i];

		ZEND_HASH_FOREACH_STR_KEY_PTR(&iface->constants_table, key, c) {
			do_inherit_iface_constant(key, c, ce, iface);
		} ZEND_HASH_FOREACH_END();

		ZEND_HASH_FOREACH_STR_KEY_PTR(&iface->function_table, key, func) {
			zend_function *new_func = do_inherit_method(key, func, ce);

			if (new_func) {
				zend_hash_add_new_ptr(&ce->function_table, key, new_func);
			}
		} ZEND_HASH_FOREACH_END();

		do_implement_interface(ce, iface);
		if (iface->num_interfaces) {
			zend_do_inherit_interfaces(ce, iface);
		}
	}
}
/* }}} */

static void zend_add_magic_methods(zend_class_entry* ce, zend_string* mname, zend_function* fe) /* {{{ */
{
	if (zend_string_equals_literal(mname, "serialize")) {
		ce->serialize_func = fe;
	} else if (zend_string_equals_literal(mname, "unserialize")) {
		ce->unserialize_func = fe;
	} else if (ZSTR_LEN(ce->name) != ZSTR_LEN(mname) && (ZSTR_VAL(mname)[0] != '_' || ZSTR_VAL(mname)[1] != '_')) {
		/* pass */
	} else if (zend_string_equals_literal(mname, ZEND_CLONE_FUNC_NAME)) {
		ce->clone = fe;
	} else if (zend_string_equals_literal(mname, ZEND_CONSTRUCTOR_FUNC_NAME)) {
		if (ce->constructor && (!ce->parent || ce->constructor != ce->parent->constructor)) {
			zend_error_noreturn(E_COMPILE_ERROR, "%s has colliding constructor definitions coming from traits", ZSTR_VAL(ce->name));
		}
		ce->constructor = fe;
	} else if (zend_string_equals_literal(mname, ZEND_DESTRUCTOR_FUNC_NAME)) {
		ce->destructor = fe;
	} else if (zend_string_equals_literal(mname, ZEND_GET_FUNC_NAME)) {
		ce->__get = fe;
		ce->ce_flags |= ZEND_ACC_USE_GUARDS;
	} else if (zend_string_equals_literal(mname, ZEND_SET_FUNC_NAME)) {
		ce->__set = fe;
		ce->ce_flags |= ZEND_ACC_USE_GUARDS;
	} else if (zend_string_equals_literal(mname, ZEND_CALL_FUNC_NAME)) {
		ce->__call = fe;
	} else if (zend_string_equals_literal(mname, ZEND_UNSET_FUNC_NAME)) {
		ce->__unset = fe;
		ce->ce_flags |= ZEND_ACC_USE_GUARDS;
	} else if (zend_string_equals_literal(mname, ZEND_ISSET_FUNC_NAME)) {
		ce->__isset = fe;
		ce->ce_flags |= ZEND_ACC_USE_GUARDS;
	} else if (zend_string_equals_literal(mname, ZEND_CALLSTATIC_FUNC_NAME)) {
		ce->__callstatic = fe;
	} else if (zend_string_equals_literal(mname, ZEND_TOSTRING_FUNC_NAME)) {
		ce->__tostring = fe;
	} else if (zend_string_equals_literal(mname, ZEND_DEBUGINFO_FUNC_NAME)) {
		ce->__debugInfo = fe;
	} else if (ZSTR_LEN(ce->name) == ZSTR_LEN(mname)) {
		zend_string *lowercase_name = zend_string_tolower(ce->name);
		lowercase_name = zend_new_interned_string(lowercase_name);
		if (!memcmp(ZSTR_VAL(mname), ZSTR_VAL(lowercase_name), ZSTR_LEN(mname))) {
			if (ce->constructor && (!ce->parent || ce->constructor != ce->parent->constructor)) {
				zend_error_noreturn(E_COMPILE_ERROR, "%s has colliding constructor definitions coming from traits", ZSTR_VAL(ce->name));
			}
			ce->constructor = fe;
			fe->common.fn_flags |= ZEND_ACC_CTOR;
		}
		zend_string_release_ex(lowercase_name, 0);
	}
}
/* }}} */

static void zend_add_trait_method(zend_class_entry *ce, const char *name, zend_string *key, zend_function *fn, HashTable **overridden) /* {{{ */
{
	zend_function *existing_fn = NULL;
	zend_function *new_fn;
	zend_string *unresolved_class;
	inheritance_status status;

	if ((existing_fn = zend_hash_find_ptr(&ce->function_table, key)) != NULL) {
		/* if it is the same function with the same visibility and has not been assigned a class scope yet, regardless
		 * of where it is coming from there is no conflict and we do not need to add it again */
		if (existing_fn->op_array.opcodes == fn->op_array.opcodes &&
			(existing_fn->common.fn_flags & ZEND_ACC_PPP_MASK) == (fn->common.fn_flags & ZEND_ACC_PPP_MASK) &&
			(existing_fn->common.scope->ce_flags & ZEND_ACC_TRAIT) == ZEND_ACC_TRAIT) {
			return;
		}

		if (existing_fn->common.scope == ce) {
			/* members from the current class override trait methods */
			/* use temporary *overridden HashTable to detect hidden conflict */
			if (*overridden) {
				if ((existing_fn = zend_hash_find_ptr(*overridden, key)) != NULL) {
					if (existing_fn->common.fn_flags & ZEND_ACC_ABSTRACT) {
						/* Make sure the trait method is compatible with previosly declared abstract method */
						status = zend_do_perform_implementation_check(
							&unresolved_class, fn, existing_fn);
						if (status != INHERITANCE_SUCCESS) {
							emit_incompatible_method_error(
								E_COMPILE_ERROR, "must", fn, existing_fn, status, unresolved_class);
						}
					}
					if (fn->common.fn_flags & ZEND_ACC_ABSTRACT) {
						/* Make sure the abstract declaration is compatible with previous declaration */
						status = zend_do_perform_implementation_check(
							&unresolved_class, existing_fn, fn);
						if (status != INHERITANCE_SUCCESS) {
							emit_incompatible_method_error(
								E_COMPILE_ERROR, "must", existing_fn, fn, status, unresolved_class);
						}
						return;
					}
				}
			} else {
				ALLOC_HASHTABLE(*overridden);
				zend_hash_init_ex(*overridden, 8, NULL, overridden_ptr_dtor, 0, 0);
			}
			zend_hash_update_mem(*overridden, key, fn, sizeof(zend_function));
			return;
		} else if (existing_fn->common.fn_flags & ZEND_ACC_ABSTRACT &&
				(existing_fn->common.scope->ce_flags & ZEND_ACC_INTERFACE) == 0) {
			/* Make sure the trait method is compatible with previosly declared abstract method */
			status = zend_do_perform_implementation_check(&unresolved_class, fn, existing_fn);
			if (status != INHERITANCE_SUCCESS) {
				emit_incompatible_method_error(
					E_COMPILE_ERROR, "must", fn, existing_fn, status, unresolved_class);
			}
		} else if (fn->common.fn_flags & ZEND_ACC_ABSTRACT) {
			/* Make sure the abstract declaration is compatible with previous declaration */
			status = zend_do_perform_implementation_check(&unresolved_class, existing_fn, fn);
			if (status != INHERITANCE_SUCCESS) {
				emit_incompatible_method_error(
					E_COMPILE_ERROR, "must", existing_fn, fn, status, unresolved_class);
			}
			return;
		} else if (UNEXPECTED(existing_fn->common.scope->ce_flags & ZEND_ACC_TRAIT)) {
			/* two traits can't define the same non-abstract method */
#if 1
			zend_error_noreturn(E_COMPILE_ERROR, "Trait method %s has not been applied, because there are collisions with other trait methods on %s",
				name, ZSTR_VAL(ce->name));
#else		/* TODO: better error message */
			zend_error_noreturn(E_COMPILE_ERROR, "Trait method %s::%s has not been applied as %s::%s, because of collision with %s::%s",
				ZSTR_VAL(fn->common.scope->name), ZSTR_VAL(fn->common.function_name),
				ZSTR_VAL(ce->name), name,
				ZSTR_VAL(existing_fn->common.scope->name), ZSTR_VAL(existing_fn->common.function_name));
#endif
		} else {
			/* inherited members are overridden by members inserted by traits */
			/* check whether the trait method fulfills the inheritance requirements */
			do_inheritance_check_on_method(fn, existing_fn, ce, NULL);
			fn->common.prototype = NULL;
		}
	}

	if (UNEXPECTED(fn->type == ZEND_INTERNAL_FUNCTION)) {
		new_fn = zend_arena_alloc(&CG(arena), sizeof(zend_internal_function));
		memcpy(new_fn, fn, sizeof(zend_internal_function));
		new_fn->common.fn_flags |= ZEND_ACC_ARENA_ALLOCATED;
	} else {
		new_fn = zend_arena_alloc(&CG(arena), sizeof(zend_op_array));
		memcpy(new_fn, fn, sizeof(zend_op_array));
		new_fn->op_array.fn_flags |= ZEND_ACC_TRAIT_CLONE;
		new_fn->op_array.fn_flags &= ~ZEND_ACC_IMMUTABLE;
	}
	function_add_ref(new_fn);
	fn = zend_hash_update_ptr(&ce->function_table, key, new_fn);
	zend_add_magic_methods(ce, key, fn);
}
/* }}} */

static void zend_fixup_trait_method(zend_function *fn, zend_class_entry *ce) /* {{{ */
{
	if ((fn->common.scope->ce_flags & ZEND_ACC_TRAIT) == ZEND_ACC_TRAIT) {

		fn->common.scope = ce;

		if (fn->common.fn_flags & ZEND_ACC_ABSTRACT) {
			ce->ce_flags |= ZEND_ACC_IMPLICIT_ABSTRACT_CLASS;
		}
		if (fn->type == ZEND_USER_FUNCTION && fn->op_array.static_variables) {
			ce->ce_flags |= ZEND_HAS_STATIC_IN_METHODS;
		}
	}
}
/* }}} */

static void zend_traits_copy_functions(zend_string *fnname, zend_function *fn, zend_class_entry *ce, HashTable **overridden, HashTable *exclude_table, zend_class_entry **aliases) /* {{{ */
{
	zend_trait_alias  *alias, **alias_ptr;
	zend_string       *lcname;
	zend_function      fn_copy;
	int                i;

	/* apply aliases which are qualified with a class name, there should not be any ambiguity */
	if (ce->trait_aliases) {
		alias_ptr = ce->trait_aliases;
		alias = *alias_ptr;
		i = 0;
		while (alias) {
			/* Scope unset or equal to the function we compare to, and the alias applies to fn */
			if (alias->alias != NULL
				&& (!aliases[i] || fn->common.scope == aliases[i])
				&& ZSTR_LEN(alias->trait_method.method_name) == ZSTR_LEN(fnname)
				&& (zend_binary_strcasecmp(ZSTR_VAL(alias->trait_method.method_name), ZSTR_LEN(alias->trait_method.method_name), ZSTR_VAL(fnname), ZSTR_LEN(fnname)) == 0)) {
				fn_copy = *fn;

				/* if it is 0, no modifieres has been changed */
				if (alias->modifiers) {
					fn_copy.common.fn_flags = alias->modifiers | (fn->common.fn_flags ^ (fn->common.fn_flags & ZEND_ACC_PPP_MASK));
				}

				lcname = zend_string_tolower(alias->alias);
				zend_add_trait_method(ce, ZSTR_VAL(alias->alias), lcname, &fn_copy, overridden);
				zend_string_release_ex(lcname, 0);

				/* Record the trait from which this alias was resolved. */
				if (!aliases[i]) {
					aliases[i] = fn->common.scope;
				}
				if (!alias->trait_method.class_name) {
					/* TODO: try to avoid this assignment (it's necessary only for reflection) */
					alias->trait_method.class_name = zend_string_copy(fn->common.scope->name);
				}
			}
			alias_ptr++;
			alias = *alias_ptr;
			i++;
		}
	}

	if (exclude_table == NULL || zend_hash_find(exclude_table, fnname) == NULL) {
		/* is not in hashtable, thus, function is not to be excluded */
		/* And how about ZEND_OVERLOADED_FUNCTION? */
		memcpy(&fn_copy, fn, fn->type == ZEND_USER_FUNCTION? sizeof(zend_op_array) : sizeof(zend_internal_function));

		/* apply aliases which have not alias name, just setting visibility */
		if (ce->trait_aliases) {
			alias_ptr = ce->trait_aliases;
			alias = *alias_ptr;
			i = 0;
			while (alias) {
				/* Scope unset or equal to the function we compare to, and the alias applies to fn */
				if (alias->alias == NULL && alias->modifiers != 0
					&& (!aliases[i] || fn->common.scope == aliases[i])
					&& (ZSTR_LEN(alias->trait_method.method_name) == ZSTR_LEN(fnname))
					&& (zend_binary_strcasecmp(ZSTR_VAL(alias->trait_method.method_name), ZSTR_LEN(alias->trait_method.method_name), ZSTR_VAL(fnname), ZSTR_LEN(fnname)) == 0)) {

					fn_copy.common.fn_flags = alias->modifiers | (fn->common.fn_flags ^ (fn->common.fn_flags & ZEND_ACC_PPP_MASK));

					/** Record the trait from which this alias was resolved. */
					if (!aliases[i]) {
						aliases[i] = fn->common.scope;
					}
					if (!alias->trait_method.class_name) {
						/* TODO: try to avoid this assignment (it's necessary only for reflection) */
						alias->trait_method.class_name = zend_string_copy(fn->common.scope->name);
					}
				}
				alias_ptr++;
				alias = *alias_ptr;
				i++;
			}
		}

		zend_add_trait_method(ce, ZSTR_VAL(fn->common.function_name), fnname, &fn_copy, overridden);
	}
}
/* }}} */

static uint32_t zend_check_trait_usage(zend_class_entry *ce, zend_class_entry *trait, zend_class_entry **traits) /* {{{ */
{
	uint32_t i;

	if (UNEXPECTED((trait->ce_flags & ZEND_ACC_TRAIT) != ZEND_ACC_TRAIT)) {
		zend_error_noreturn(E_COMPILE_ERROR, "Class %s is not a trait, Only traits may be used in 'as' and 'insteadof' statements", ZSTR_VAL(trait->name));
		return 0;
	}

	for (i = 0; i < ce->num_traits; i++) {
		if (traits[i] == trait) {
			return i;
		}
	}
	zend_error_noreturn(E_COMPILE_ERROR, "Required Trait %s wasn't added to %s", ZSTR_VAL(trait->name), ZSTR_VAL(ce->name));
	return 0;
}
/* }}} */

static void zend_traits_init_trait_structures(zend_class_entry *ce, zend_class_entry **traits, HashTable ***exclude_tables_ptr, zend_class_entry ***aliases_ptr) /* {{{ */
{
	size_t i, j = 0;
	zend_trait_precedence **precedences;
	zend_trait_precedence *cur_precedence;
	zend_trait_method_reference *cur_method_ref;
	zend_string *lcname;
	HashTable **exclude_tables = NULL;
	zend_class_entry **aliases = NULL;
	zend_class_entry *trait;

	/* resolve class references */
	if (ce->trait_precedences) {
		exclude_tables = ecalloc(ce->num_traits, sizeof(HashTable*));
		i = 0;
		precedences = ce->trait_precedences;
		ce->trait_precedences = NULL;
		while ((cur_precedence = precedences[i])) {
			/** Resolve classes for all precedence operations. */
			cur_method_ref = &cur_precedence->trait_method;
			trait = zend_fetch_class(cur_method_ref->class_name,
							ZEND_FETCH_CLASS_TRAIT|ZEND_FETCH_CLASS_NO_AUTOLOAD);
			if (!trait) {
				zend_error_noreturn(E_COMPILE_ERROR, "Could not find trait %s", ZSTR_VAL(cur_method_ref->class_name));
			}
			zend_check_trait_usage(ce, trait, traits);

			/** Ensure that the preferred method is actually available. */
			lcname = zend_string_tolower(cur_method_ref->method_name);
			if (!zend_hash_exists(&trait->function_table, lcname)) {
				zend_error_noreturn(E_COMPILE_ERROR,
						   "A precedence rule was defined for %s::%s but this method does not exist",
						   ZSTR_VAL(trait->name),
						   ZSTR_VAL(cur_method_ref->method_name));
			}

			/** With the other traits, we are more permissive.
				We do not give errors for those. This allows to be more
				defensive in such definitions.
				However, we want to make sure that the insteadof declaration
				is consistent in itself.
			 */

			for (j = 0; j < cur_precedence->num_excludes; j++) {
				zend_string* class_name = cur_precedence->exclude_class_names[j];
				zend_class_entry *exclude_ce = zend_fetch_class(class_name, ZEND_FETCH_CLASS_TRAIT |ZEND_FETCH_CLASS_NO_AUTOLOAD);
				uint32_t trait_num;

				if (!exclude_ce) {
					zend_error_noreturn(E_COMPILE_ERROR, "Could not find trait %s", ZSTR_VAL(class_name));
				}
				trait_num = zend_check_trait_usage(ce, exclude_ce, traits);
				if (!exclude_tables[trait_num]) {
					ALLOC_HASHTABLE(exclude_tables[trait_num]);
					zend_hash_init(exclude_tables[trait_num], 0, NULL, NULL, 0);
				}
				if (zend_hash_add_empty_element(exclude_tables[trait_num], lcname) == NULL) {
					zend_error_noreturn(E_COMPILE_ERROR, "Failed to evaluate a trait precedence (%s). Method of trait %s was defined to be excluded multiple times", ZSTR_VAL(precedences[i]->trait_method.method_name), ZSTR_VAL(exclude_ce->name));
				}

				/* make sure that the trait method is not from a class mentioned in
				 exclude_from_classes, for consistency */
				if (trait == exclude_ce) {
					zend_error_noreturn(E_COMPILE_ERROR,
							   "Inconsistent insteadof definition. "
							   "The method %s is to be used from %s, but %s is also on the exclude list",
							   ZSTR_VAL(cur_method_ref->method_name),
							   ZSTR_VAL(trait->name),
							   ZSTR_VAL(trait->name));
				}
			}
			zend_string_release_ex(lcname, 0);
			i++;
		}
		ce->trait_precedences = precedences;
	}

	if (ce->trait_aliases) {
		i = 0;
		while (ce->trait_aliases[i]) {
			i++;
		}
		aliases = ecalloc(i, sizeof(zend_class_entry*));
		i = 0;
		while (ce->trait_aliases[i]) {
			/** For all aliases with an explicit class name, resolve the class now. */
			if (ce->trait_aliases[i]->trait_method.class_name) {
				cur_method_ref = &ce->trait_aliases[i]->trait_method;
				trait = zend_fetch_class(cur_method_ref->class_name, ZEND_FETCH_CLASS_TRAIT|ZEND_FETCH_CLASS_NO_AUTOLOAD);
				if (!trait) {
					zend_error_noreturn(E_COMPILE_ERROR, "Could not find trait %s", ZSTR_VAL(cur_method_ref->class_name));
				}
				zend_check_trait_usage(ce, trait, traits);
				aliases[i] = trait;

				/** And, ensure that the referenced method is resolvable, too. */
				lcname = zend_string_tolower(cur_method_ref->method_name);
				if (!zend_hash_exists(&trait->function_table, lcname)) {
					zend_error_noreturn(E_COMPILE_ERROR, "An alias was defined for %s::%s but this method does not exist", ZSTR_VAL(trait->name), ZSTR_VAL(cur_method_ref->method_name));
				}
				zend_string_release_ex(lcname, 0);
			}
			i++;
		}
	}

	*exclude_tables_ptr = exclude_tables;
	*aliases_ptr = aliases;
}
/* }}} */

static void zend_do_traits_method_binding(zend_class_entry *ce, zend_class_entry **traits, HashTable **exclude_tables, zend_class_entry **aliases) /* {{{ */
{
	uint32_t i;
	HashTable *overridden = NULL;
	zend_string *key;
	zend_function *fn;

	if (exclude_tables) {
		for (i = 0; i < ce->num_traits; i++) {
			if (traits[i]) {
				/* copies functions, applies defined aliasing, and excludes unused trait methods */
				ZEND_HASH_FOREACH_STR_KEY_PTR(&traits[i]->function_table, key, fn) {
					zend_traits_copy_functions(key, fn, ce, &overridden, exclude_tables[i], aliases);
				} ZEND_HASH_FOREACH_END();

				if (exclude_tables[i]) {
					zend_hash_destroy(exclude_tables[i]);
					FREE_HASHTABLE(exclude_tables[i]);
					exclude_tables[i] = NULL;
				}
			}
		}
	} else {
		for (i = 0; i < ce->num_traits; i++) {
			if (traits[i]) {
				ZEND_HASH_FOREACH_STR_KEY_PTR(&traits[i]->function_table, key, fn) {
					zend_traits_copy_functions(key, fn, ce, &overridden, NULL, aliases);
				} ZEND_HASH_FOREACH_END();
			}
		}
	}

	ZEND_HASH_FOREACH_PTR(&ce->function_table, fn) {
		zend_fixup_trait_method(fn, ce);
	} ZEND_HASH_FOREACH_END();

	if (overridden) {
		zend_hash_destroy(overridden);
		FREE_HASHTABLE(overridden);
	}
}
/* }}} */

static zend_class_entry* find_first_definition(zend_class_entry *ce, zend_class_entry **traits, size_t current_trait, zend_string *prop_name, zend_class_entry *coliding_ce) /* {{{ */
{
	size_t i;

	if (coliding_ce == ce) {
		for (i = 0; i < current_trait; i++) {
			if (traits[i]
			 && zend_hash_exists(&traits[i]->properties_info, prop_name)) {
				return traits[i];
			}
		}
	}

	return coliding_ce;
}
/* }}} */

static void zend_do_traits_property_binding(zend_class_entry *ce, zend_class_entry **traits) /* {{{ */
{
	size_t i;
	zend_property_info *property_info;
	zend_property_info *coliding_prop;
	zend_string* prop_name;
	const char* class_name_unused;
	zend_bool not_compatible;
	zval* prop_value;
	uint32_t flags;
	zend_string *doc_comment;

	/* In the following steps the properties are inserted into the property table
	 * for that, a very strict approach is applied:
	 * - check for compatibility, if not compatible with any property in class -> fatal
	 * - if compatible, then strict notice
	 */
	for (i = 0; i < ce->num_traits; i++) {
		if (!traits[i]) {
			continue;
		}
		ZEND_HASH_FOREACH_PTR(&traits[i]->properties_info, property_info) {
			/* first get the unmangeld name if necessary,
			 * then check whether the property is already there
			 */
			flags = property_info->flags;
			if (flags & ZEND_ACC_PUBLIC) {
				prop_name = zend_string_copy(property_info->name);
			} else {
				const char *pname;
				size_t pname_len;

				/* for private and protected we need to unmangle the names */
				zend_unmangle_property_name_ex(property_info->name,
											&class_name_unused, &pname, &pname_len);
				prop_name = zend_string_init(pname, pname_len, 0);
			}

			/* next: check for conflicts with current class */
			if ((coliding_prop = zend_hash_find_ptr(&ce->properties_info, prop_name)) != NULL) {
				if ((coliding_prop->flags & ZEND_ACC_PRIVATE) && coliding_prop->ce != ce) {
					zend_hash_del(&ce->properties_info, prop_name);
					flags |= ZEND_ACC_CHANGED;
				} else {
					not_compatible = 1;

					if ((coliding_prop->flags & (ZEND_ACC_PPP_MASK | ZEND_ACC_STATIC))
						== (flags & (ZEND_ACC_PPP_MASK | ZEND_ACC_STATIC)) &&
						property_types_compatible(property_info, coliding_prop)
					) {
						/* the flags are identical, thus, the properties may be compatible */
						zval *op1, *op2;
						zval op1_tmp, op2_tmp;

						if (flags & ZEND_ACC_STATIC) {
							op1 = &ce->default_static_members_table[coliding_prop->offset];
							op2 = &traits[i]->default_static_members_table[property_info->offset];
							ZVAL_DEINDIRECT(op1);
							ZVAL_DEINDIRECT(op2);
						} else {
							op1 = &ce->default_properties_table[OBJ_PROP_TO_NUM(coliding_prop->offset)];
							op2 = &traits[i]->default_properties_table[OBJ_PROP_TO_NUM(property_info->offset)];
						}

						/* if any of the values is a constant, we try to resolve it */
						if (UNEXPECTED(Z_TYPE_P(op1) == IS_CONSTANT_AST)) {
							ZVAL_COPY_OR_DUP(&op1_tmp, op1);
							zval_update_constant_ex(&op1_tmp, ce);
							op1 = &op1_tmp;
						}
						if (UNEXPECTED(Z_TYPE_P(op2) == IS_CONSTANT_AST)) {
							ZVAL_COPY_OR_DUP(&op2_tmp, op2);
							zval_update_constant_ex(&op2_tmp, ce);
							op2 = &op2_tmp;
						}

						not_compatible = fast_is_not_identical_function(op1, op2);

						if (op1 == &op1_tmp) {
							zval_ptr_dtor_nogc(&op1_tmp);
						}
						if (op2 == &op2_tmp) {
							zval_ptr_dtor_nogc(&op2_tmp);
						}
					}

					if (not_compatible) {
						zend_error_noreturn(E_COMPILE_ERROR,
							   "%s and %s define the same property ($%s) in the composition of %s. However, the definition differs and is considered incompatible. Class was composed",
								ZSTR_VAL(find_first_definition(ce, traits, i, prop_name, coliding_prop->ce)->name),
								ZSTR_VAL(property_info->ce->name),
								ZSTR_VAL(prop_name),
								ZSTR_VAL(ce->name));
					}

					zend_string_release_ex(prop_name, 0);
					continue;
				}
			}

			/* property not found, so lets add it */
			if (flags & ZEND_ACC_STATIC) {
				prop_value = &traits[i]->default_static_members_table[property_info->offset];
				ZEND_ASSERT(Z_TYPE_P(prop_value) != IS_INDIRECT);
			} else {
				prop_value = &traits[i]->default_properties_table[OBJ_PROP_TO_NUM(property_info->offset)];
			}

			Z_TRY_ADDREF_P(prop_value);
			doc_comment = property_info->doc_comment ? zend_string_copy(property_info->doc_comment) : NULL;
			if (ZEND_TYPE_IS_NAME(property_info->type)) {
				zend_string_addref(ZEND_TYPE_NAME(property_info->type));
			}
			zend_declare_typed_property(ce, prop_name, prop_value, flags, doc_comment, property_info->type);
			zend_string_release_ex(prop_name, 0);
		} ZEND_HASH_FOREACH_END();
	}
}
/* }}} */

static void zend_do_check_for_inconsistent_traits_aliasing(zend_class_entry *ce, zend_class_entry **aliases) /* {{{ */
{
	int i = 0;
	zend_trait_alias* cur_alias;
	zend_string* lc_method_name;

	if (ce->trait_aliases) {
		while (ce->trait_aliases[i]) {
			cur_alias = ce->trait_aliases[i];
			/** The trait for this alias has not been resolved, this means, this
				alias was not applied. Abort with an error. */
			if (!aliases[i]) {
				if (cur_alias->alias) {
					/** Plain old inconsistency/typo/bug */
					zend_error_noreturn(E_COMPILE_ERROR,
							   "An alias (%s) was defined for method %s(), but this method does not exist",
							   ZSTR_VAL(cur_alias->alias),
							   ZSTR_VAL(cur_alias->trait_method.method_name));
				} else {
					/** Here are two possible cases:
						1) this is an attempt to modify the visibility
						   of a method introduce as part of another alias.
						   Since that seems to violate the DRY principle,
						   we check against it and abort.
						2) it is just a plain old inconsitency/typo/bug
						   as in the case where alias is set. */

					lc_method_name = zend_string_tolower(
						cur_alias->trait_method.method_name);
					if (zend_hash_exists(&ce->function_table,
										 lc_method_name)) {
						zend_string_release_ex(lc_method_name, 0);
						zend_error_noreturn(E_COMPILE_ERROR,
								   "The modifiers for the trait alias %s() need to be changed in the same statement in which the alias is defined. Error",
								   ZSTR_VAL(cur_alias->trait_method.method_name));
					} else {
						zend_string_release_ex(lc_method_name, 0);
						zend_error_noreturn(E_COMPILE_ERROR,
								   "The modifiers of the trait method %s() are changed, but this method does not exist. Error",
								   ZSTR_VAL(cur_alias->trait_method.method_name));

					}
				}
			}
			i++;
		}
	}
}
/* }}} */

static void zend_do_bind_traits(zend_class_entry *ce) /* {{{ */
{
	HashTable **exclude_tables;
	zend_class_entry **aliases;
	zend_class_entry **traits, *trait;
	uint32_t i, j;

	ZEND_ASSERT(ce->num_traits > 0);

	traits = emalloc(sizeof(zend_class_entry*) * ce->num_traits);

	for (i = 0; i < ce->num_traits; i++) {
		trait = zend_fetch_class_by_name(ce->trait_names[i].name,
			ce->trait_names[i].lc_name, ZEND_FETCH_CLASS_TRAIT);
		if (UNEXPECTED(trait == NULL)) {
			return;
		}
		if (UNEXPECTED(!(trait->ce_flags & ZEND_ACC_TRAIT))) {
			zend_error_noreturn(E_ERROR, "%s cannot use %s - it is not a trait", ZSTR_VAL(ce->name), ZSTR_VAL(trait->name));
			return;
		}
		for (j = 0; j < i; j++) {
			if (traits[j] == trait) {
				/* skip duplications */
				trait = NULL;
				break;
			}
		}
		traits[i] = trait;
	}

	/* complete initialization of trait strutures in ce */
	zend_traits_init_trait_structures(ce, traits, &exclude_tables, &aliases);

	/* first care about all methods to be flattened into the class */
	zend_do_traits_method_binding(ce, traits, exclude_tables, aliases);

	/* Aliases which have not been applied indicate typos/bugs. */
	zend_do_check_for_inconsistent_traits_aliasing(ce, aliases);

	if (aliases) {
		efree(aliases);
	}

	if (exclude_tables) {
		efree(exclude_tables);
	}

	/* then flatten the properties into it, to, mostly to notfiy developer about problems */
	zend_do_traits_property_binding(ce, traits);

	efree(traits);

	/* Emit E_DEPRECATED for PHP 4 constructors */
	zend_check_deprecated_constructor(ce);
}
/* }}} */


static zend_bool zend_has_deprecated_constructor(const zend_class_entry *ce) /* {{{ */
{
	const zend_string *constructor_name;
	if (!ce->constructor) {
		return 0;
	}
	constructor_name = ce->constructor->common.function_name;
	return !zend_binary_strcasecmp(
		ZSTR_VAL(ce->name), ZSTR_LEN(ce->name),
		ZSTR_VAL(constructor_name), ZSTR_LEN(constructor_name)
	);
}
/* }}} */

void zend_check_deprecated_constructor(const zend_class_entry *ce) /* {{{ */
{
	if (zend_has_deprecated_constructor(ce)) {
		zend_error(E_DEPRECATED, "Methods with the same name as their class will not be constructors in a future version of PHP; %s has a deprecated constructor", ZSTR_VAL(ce->name));
	}
}
/* }}} */

#define MAX_ABSTRACT_INFO_CNT 3
#define MAX_ABSTRACT_INFO_FMT "%s%s%s%s"
#define DISPLAY_ABSTRACT_FN(idx) \
	ai.afn[idx] ? ZEND_FN_SCOPE_NAME(ai.afn[idx]) : "", \
	ai.afn[idx] ? "::" : "", \
	ai.afn[idx] ? ZSTR_VAL(ai.afn[idx]->common.function_name) : "", \
	ai.afn[idx] && ai.afn[idx + 1] ? ", " : (ai.afn[idx] && ai.cnt > MAX_ABSTRACT_INFO_CNT ? ", ..." : "")

typedef struct _zend_abstract_info {
	zend_function *afn[MAX_ABSTRACT_INFO_CNT + 1];
	int cnt;
	int ctor;
} zend_abstract_info;

static void zend_verify_abstract_class_function(zend_function *fn, zend_abstract_info *ai) /* {{{ */
{
	if (fn->common.fn_flags & ZEND_ACC_ABSTRACT) {
		if (ai->cnt < MAX_ABSTRACT_INFO_CNT) {
			ai->afn[ai->cnt] = fn;
		}
		if (fn->common.fn_flags & ZEND_ACC_CTOR) {
			if (!ai->ctor) {
				ai->cnt++;
				ai->ctor = 1;
			} else {
				ai->afn[ai->cnt] = NULL;
			}
		} else {
			ai->cnt++;
		}
	}
}
/* }}} */

void zend_verify_abstract_class(zend_class_entry *ce) /* {{{ */
{
	zend_function *func;
	zend_abstract_info ai;

	ZEND_ASSERT((ce->ce_flags & (ZEND_ACC_IMPLICIT_ABSTRACT_CLASS|ZEND_ACC_INTERFACE|ZEND_ACC_TRAIT|ZEND_ACC_EXPLICIT_ABSTRACT_CLASS)) == ZEND_ACC_IMPLICIT_ABSTRACT_CLASS);
	memset(&ai, 0, sizeof(ai));

	ZEND_HASH_FOREACH_PTR(&ce->function_table, func) {
		zend_verify_abstract_class_function(func, &ai);
	} ZEND_HASH_FOREACH_END();

	if (ai.cnt) {
		zend_error_noreturn(E_ERROR, "Class %s contains %d abstract method%s and must therefore be declared abstract or implement the remaining methods (" MAX_ABSTRACT_INFO_FMT MAX_ABSTRACT_INFO_FMT MAX_ABSTRACT_INFO_FMT ")",
			ZSTR_VAL(ce->name), ai.cnt,
			ai.cnt > 1 ? "s" : "",
			DISPLAY_ABSTRACT_FN(0),
			DISPLAY_ABSTRACT_FN(1),
			DISPLAY_ABSTRACT_FN(2)
			);
	} else {
		/* now everything should be fine and an added ZEND_ACC_IMPLICIT_ABSTRACT_CLASS should be removed */
		ce->ce_flags &= ~ZEND_ACC_IMPLICIT_ABSTRACT_CLASS;
	}
}
/* }}} */

ZEND_API void zend_do_link_class(zend_class_entry *ce, zend_class_entry *parent) /* {{{ */
{
	ce->ce_flags |= ZEND_ACC_LINKING_IN_PROGRESS;
	if (parent) {
		zend_do_inheritance(ce, parent);
	}
	if (ce->ce_flags & ZEND_ACC_IMPLEMENT_TRAITS) {
		zend_do_bind_traits(ce);
	}
	if (ce->ce_flags & ZEND_ACC_IMPLEMENT_INTERFACES) {
		zend_do_implement_interfaces(ce);
	}
	if ((ce->ce_flags & (ZEND_ACC_IMPLICIT_ABSTRACT_CLASS|ZEND_ACC_INTERFACE|ZEND_ACC_TRAIT|ZEND_ACC_EXPLICIT_ABSTRACT_CLASS)) == ZEND_ACC_IMPLICIT_ABSTRACT_CLASS) {
		zend_verify_abstract_class(ce);
	}

	zend_build_properties_info_table(ce);
	ce->ce_flags &= ~ZEND_ACC_LINKING_IN_PROGRESS;
	ce->ce_flags |= ZEND_ACC_LINKED;
}

/* Check whether early binding is prevented due to unresolved types in inheritance checks. */
zend_bool zend_can_early_bind(zend_class_entry *ce, zend_class_entry *parent_ce) {
	zend_string *key;
	zend_function *parent_func;
	ZEND_HASH_FOREACH_STR_KEY_PTR(&parent_ce->function_table, key, parent_func) {
		uint32_t parent_flags = parent_func->common.fn_flags;
		zend_function *func = zend_hash_find_ptr(&ce->function_table, key);
		zend_string *unresolved_class;
		if (!func || (parent_flags & ZEND_ACC_PRIVATE) ||
			((parent_flags & ZEND_ACC_CTOR) && !(parent_flags & ZEND_ACC_ABSTRACT))
		) {
			continue;
		}
		if (zend_do_perform_implementation_check(&unresolved_class, func, parent_func) == INHERITANCE_UNRESOLVED) {
			return 0;
		}
	} ZEND_HASH_FOREACH_END();
	return 1;
}
/* }}} */