Define Stringable with __toString():string method

17 files changed, 75 insertions, 56 deletions

diff --git a/Zend/tests/bug26166.phpt b/Zend/tests/bug26166.phpt
index 7e5668e47f..4a5a30f5b2 100644
--- a/Zend/tests/bug26166.phpt
+++ b/Zend/tests/bug26166.phpt
@@ -64,6 +64,6 @@ try {
 --EXPECT--
 Hello World!
 ===NONE===
-Method NoneTest::__toString() must return a string value
+Return value of NoneTest::__toString() must be of type string, none returned
 ===THROW===
 This is an error!
diff --git a/Zend/tests/list_keyed_evaluation_order.inc b/Zend/tests/list_keyed_evaluation_order.inc
index d4ee778b63..577a19a838 100644
--- a/Zend/tests/list_keyed_evaluation_order.inc
+++ b/Zend/tests/list_keyed_evaluation_order.inc
@@ -2,7 +2,7 @@
 
 // Observer objects for the Zend/tests/list_keyed_evaluation_order.* tests
 
-class Stringable
+class StringCapable
 {
     private $name;
     public function __construct(string $name) {
diff --git a/Zend/tests/list_keyed_evaluation_order.phpt b/Zend/tests/list_keyed_evaluation_order.phpt
index 0f0652b6a9..3c5fb7e877 100644
--- a/Zend/tests/list_keyed_evaluation_order.phpt
+++ b/Zend/tests/list_keyed_evaluation_order.phpt
@@ -5,8 +5,8 @@ list() with keys, evaluation order
 
 require_once "list_keyed_evaluation_order.inc";
 
-$a = new Stringable("A");
-$c = new Stringable("C");
+$a = new StringCapable("A");
+$c = new StringCapable("C");
 
 $e = new IndexableRetrievable("E", new Indexable(["A" => "value for offset A", "C" => "value for offset C"]));
 
diff --git a/Zend/tests/list_keyed_evaluation_order_nested.phpt b/Zend/tests/list_keyed_evaluation_order_nested.phpt
index 8a7725d4ea..496deefbb9 100644
--- a/Zend/tests/list_keyed_evaluation_order_nested.phpt
+++ b/Zend/tests/list_keyed_evaluation_order_nested.phpt
@@ -5,11 +5,11 @@ list() with keys, evaluation order: nested
 
 require_once "list_keyed_evaluation_order.inc";
 
-$a = new Stringable("A");
-$c = new Stringable("C");
-$f = new Stringable("F");
-$g = new Stringable("G");
-$i = new Stringable("I");
+$a = new StringCapable("A");
+$c = new StringCapable("C");
+$f = new StringCapable("F");
+$g = new StringCapable("G");
+$i = new StringCapable("I");
 
 $k = new IndexableRetrievable("K", new Indexable([
     "A" => "offset value for A",
diff --git a/Zend/tests/type_declarations/scalar_basic.phpt b/Zend/tests/type_declarations/scalar_basic.phpt
index e4b8ab5c51..c3f06c5bbd 100644
--- a/Zend/tests/type_declarations/scalar_basic.phpt
+++ b/Zend/tests/type_declarations/scalar_basic.phpt
@@ -19,7 +19,7 @@ $functions = [
     'bool' => function (bool $b) { return $b; }
 ];
 
-class Stringable {
+class StringCapable implements Stringable {
     public function __toString() {
         return "foobar";
     }
@@ -40,7 +40,7 @@ $values = [
     NULL,
     [],
     new StdClass,
-    new Stringable,
+    new StringCapable,
     fopen("data:text/plain,foobar", "r")
 ];
 
@@ -106,7 +106,7 @@ int(0)
 }
 *** Caught {closure}(): Argument #1 ($i) must be of type int, object given, called in %s on line %d
 
-*** Trying object(Stringable)#%s (0) {
+*** Trying object(StringCapable)#%s (0) {
 }
 *** Caught {closure}(): Argument #1 ($i) must be of type int, object given, called in %s on line %d
 
@@ -160,7 +160,7 @@ float(0)
 }
 *** Caught {closure}(): Argument #1 ($f) must be of type float, object given, called in %s on line %d
 
-*** Trying object(Stringable)#%s (0) {
+*** Trying object(StringCapable)#%s (0) {
 }
 *** Caught {closure}(): Argument #1 ($f) must be of type float, object given, called in %s on line %d
 
@@ -213,7 +213,7 @@ string(0) ""
 }
 *** Caught {closure}(): Argument #1 ($s) must be of type string, object given, called in %s on line %d
 
-*** Trying object(Stringable)#%s (0) {
+*** Trying object(StringCapable)#%s (0) {
 }
 string(6) "foobar"
 
@@ -266,7 +266,7 @@ bool(false)
 }
 *** Caught {closure}(): Argument #1 ($b) must be of type bool, object given, called in %s on line %d
 
-*** Trying object(Stringable)#%s (0) {
+*** Trying object(StringCapable)#%s (0) {
 }
 *** Caught {closure}(): Argument #1 ($b) must be of type bool, object given, called in %s on line %d
 
diff --git a/Zend/tests/type_declarations/scalar_return_basic.phpt b/Zend/tests/type_declarations/scalar_return_basic.phpt
index 9ee50f8457..c0b0df6829 100644
--- a/Zend/tests/type_declarations/scalar_return_basic.phpt
+++ b/Zend/tests/type_declarations/scalar_return_basic.phpt
@@ -21,7 +21,7 @@ $functions = [
     'bool' => function ($b): bool { return $b; }
 ];
 
-class Stringable {
+class StringCapable {
     public function __toString() {
         return "foobar";
     }
@@ -42,7 +42,7 @@ $values = [
     NULL,
     [],
     new StdClass,
-    new Stringable,
+    new StringCapable,
     fopen("data:text/plain,foobar", "r")
 ];
 
@@ -94,7 +94,7 @@ int(0)
 *** Trying object(stdClass)#6 (0) {
 }
 *** Caught Return value of {closure}() must be of type int, object returned in %s on line %d
-*** Trying object(Stringable)#7 (0) {
+*** Trying object(StringCapable)#7 (0) {
 }
 *** Caught Return value of {closure}() must be of type int, object returned in %s on line %d
 *** Trying resource(5) of type (stream)
@@ -132,7 +132,7 @@ float(0)
 *** Trying object(stdClass)#6 (0) {
 }
 *** Caught Return value of {closure}() must be of type float, object returned in %s on line %d
-*** Trying object(Stringable)#7 (0) {
+*** Trying object(StringCapable)#7 (0) {
 }
 *** Caught Return value of {closure}() must be of type float, object returned in %s on line %d
 *** Trying resource(5) of type (stream)
@@ -169,7 +169,7 @@ string(0) ""
 *** Trying object(stdClass)#6 (0) {
 }
 *** Caught Return value of {closure}() must be of type string, object returned in %s on line %d
-*** Trying object(Stringable)#7 (0) {
+*** Trying object(StringCapable)#7 (0) {
 }
 string(6) "foobar"
 *** Trying resource(5) of type (stream)
@@ -206,7 +206,7 @@ bool(false)
 *** Trying object(stdClass)#6 (0) {
 }
 *** Caught Return value of {closure}() must be of type bool, object returned in %s on line %d
-*** Trying object(Stringable)#7 (0) {
+*** Trying object(StringCapable)#7 (0) {
 }
 *** Caught Return value of {closure}() must be of type bool, object returned in %s on line %d
 *** Trying resource(5) of type (stream)
diff --git a/Zend/tests/type_declarations/scalar_return_basic_64bit.phpt b/Zend/tests/type_declarations/scalar_return_basic_64bit.phpt
index ad987e58da..5e387c45c8 100644
--- a/Zend/tests/type_declarations/scalar_return_basic_64bit.phpt
+++ b/Zend/tests/type_declarations/scalar_return_basic_64bit.phpt
@@ -21,7 +21,7 @@ $functions = [
     'bool' => function ($b): bool { return $b; }
 ];
 
-class Stringable {
+class StringCapable {
     public function __toString() {
         return "foobar";
     }
@@ -42,7 +42,7 @@ $values = [
     NULL,
     [],
     new StdClass,
-    new Stringable,
+    new StringCapable,
     fopen("data:text/plain,foobar", "r")
 ];
 
@@ -94,7 +94,7 @@ int(0)
 *** Trying object(stdClass)#6 (0) {
 }
 *** Caught Return value of {closure}() must be of type int, object returned in %s on line %d
-*** Trying object(Stringable)#7 (0) {
+*** Trying object(StringCapable)#7 (0) {
 }
 *** Caught Return value of {closure}() must be of type int, object returned in %s on line %d
 *** Trying resource(5) of type (stream)
@@ -132,7 +132,7 @@ float(0)
 *** Trying object(stdClass)#6 (0) {
 }
 *** Caught Return value of {closure}() must be of type float, object returned in %s on line %d
-*** Trying object(Stringable)#7 (0) {
+*** Trying object(StringCapable)#7 (0) {
 }
 *** Caught Return value of {closure}() must be of type float, object returned in %s on line %d
 *** Trying resource(5) of type (stream)
@@ -169,7 +169,7 @@ string(0) ""
 *** Trying object(stdClass)#6 (0) {
 }
 *** Caught Return value of {closure}() must be of type string, object returned in %s on line %d
-*** Trying object(Stringable)#7 (0) {
+*** Trying object(StringCapable)#7 (0) {
 }
 string(6) "foobar"
 *** Trying resource(5) of type (stream)
@@ -206,7 +206,7 @@ bool(false)
 *** Trying object(stdClass)#6 (0) {
 }
 *** Caught Return value of {closure}() must be of type bool, object returned in %s on line %d
-*** Trying object(Stringable)#7 (0) {
+*** Trying object(StringCapable)#7 (0) {
 }
 *** Caught Return value of {closure}() must be of type bool, object returned in %s on line %d
 *** Trying resource(5) of type (stream)
diff --git a/Zend/tests/type_declarations/scalar_strict.phpt b/Zend/tests/type_declarations/scalar_strict.phpt
index 032fd3d301..3c420ed455 100644
--- a/Zend/tests/type_declarations/scalar_strict.phpt
+++ b/Zend/tests/type_declarations/scalar_strict.phpt
@@ -13,7 +13,7 @@ $functions = [
     'bool' => function (bool $b) { return $b; }
 ];
 
-class Stringable {
+class StringCapable {
     public function __toString() {
         return "foobar";
     }
@@ -34,7 +34,7 @@ $values = [
     NULL,
     [],
     new StdClass,
-    new Stringable,
+    new StringCapable,
     fopen("data:text/plain,foobar", "r")
 ];
 
@@ -100,7 +100,7 @@ int(2147483647)
 }
 *** Caught {closure}(): Argument #1 ($i) must be of type int, object given, called in %s on line %d
 
-*** Trying object(Stringable)#6 (0) {
+*** Trying object(StringCapable)#6 (0) {
 }
 *** Caught {closure}(): Argument #1 ($i) must be of type int, object given, called in %s on line %d
 
@@ -153,7 +153,7 @@ float(NAN)
 }
 *** Caught {closure}(): Argument #1 ($f) must be of type float, object given, called in %s on line %d
 
-*** Trying object(Stringable)#6 (0) {
+*** Trying object(StringCapable)#6 (0) {
 }
 *** Caught {closure}(): Argument #1 ($f) must be of type float, object given, called in %s on line %d
 
@@ -206,7 +206,7 @@ string(0) ""
 }
 *** Caught {closure}(): Argument #1 ($s) must be of type string, object given, called in %s on line %d
 
-*** Trying object(Stringable)#6 (0) {
+*** Trying object(StringCapable)#6 (0) {
 }
 *** Caught {closure}(): Argument #1 ($s) must be of type string, object given, called in %s on line %d
 
@@ -259,7 +259,7 @@ bool(false)
 }
 *** Caught {closure}(): Argument #1 ($b) must be of type bool, object given, called in %s on line %d
 
-*** Trying object(Stringable)#6 (0) {
+*** Trying object(StringCapable)#6 (0) {
 }
 *** Caught {closure}(): Argument #1 ($b) must be of type bool, object given, called in %s on line %d
 
diff --git a/Zend/tests/type_declarations/scalar_strict_64bit.phpt b/Zend/tests/type_declarations/scalar_strict_64bit.phpt
index 5818606b4c..6f8504c16c 100644
--- a/Zend/tests/type_declarations/scalar_strict_64bit.phpt
+++ b/Zend/tests/type_declarations/scalar_strict_64bit.phpt
@@ -13,7 +13,7 @@ $functions = [
     'bool' => function (bool $b) { return $b; }
 ];
 
-class Stringable {
+class StringCapable {
     public function __toString() {
         return "foobar";
     }
@@ -34,7 +34,7 @@ $values = [
     NULL,
     [],
     new StdClass,
-    new Stringable,
+    new StringCapable,
     fopen("data:text/plain,foobar", "r")
 ];
 
@@ -100,7 +100,7 @@ int(9223372036854775807)
 }
 *** Caught {closure}(): Argument #1 ($i) must be of type int, object given, called in %s on line %d
 
-*** Trying object(Stringable)#6 (0) {
+*** Trying object(StringCapable)#6 (0) {
 }
 *** Caught {closure}(): Argument #1 ($i) must be of type int, object given, called in %s on line %d
 
@@ -153,7 +153,7 @@ float(NAN)
 }
 *** Caught {closure}(): Argument #1 ($f) must be of type float, object given, called in %s on line %d
 
-*** Trying object(Stringable)#6 (0) {
+*** Trying object(StringCapable)#6 (0) {
 }
 *** Caught {closure}(): Argument #1 ($f) must be of type float, object given, called in %s on line %d
 
@@ -206,7 +206,7 @@ string(0) ""
 }
 *** Caught {closure}(): Argument #1 ($s) must be of type string, object given, called in %s on line %d
 
-*** Trying object(Stringable)#6 (0) {
+*** Trying object(StringCapable)#6 (0) {
 }
 *** Caught {closure}(): Argument #1 ($s) must be of type string, object given, called in %s on line %d
 
@@ -259,7 +259,7 @@ bool(false)
 }
 *** Caught {closure}(): Argument #1 ($b) must be of type bool, object given, called in %s on line %d
 
-*** Trying object(Stringable)#6 (0) {
+*** Trying object(StringCapable)#6 (0) {
 }
 *** Caught {closure}(): Argument #1 ($b) must be of type bool, object given, called in %s on line %d
 
diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index f7ba3acf9d..cbf5ebfc02 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -5714,7 +5714,7 @@ static zend_bool zend_is_valid_default_value(zend_type type, zval *value)
 	return 0;
 }
 
-void zend_compile_params(zend_ast *ast, zend_ast *return_type_ast) /* {{{ */
+void zend_compile_params(zend_ast *ast, zend_ast *return_type_ast, uint32_t fallback_return_type) /* {{{ */
 {
 	zend_ast_list *list = zend_ast_get_list(ast);
 	uint32_t i;
@@ -5722,14 +5722,18 @@ void zend_compile_params(zend_ast *ast, zend_ast *return_type_ast) /* {{{ */
 	zend_arg_info *arg_infos;
 	zend_string *optional_param = NULL;
 
-	if (return_type_ast) {
+	if (return_type_ast || fallback_return_type) {
 		/* Use op_array->arg_info[-1] for return type */
 		arg_infos = safe_emalloc(sizeof(zend_arg_info), list->children + 1, 0);
 		arg_infos->name = NULL;
-		arg_infos->type = zend_compile_typename(
-			return_type_ast, /* force_allow_null */ 0, /* use_arena */ 0);
-		ZEND_TYPE_FULL_MASK(arg_infos->type) |= _ZEND_ARG_INFO_FLAGS(
-			(op_array->fn_flags & ZEND_ACC_RETURN_REFERENCE) != 0, /* is_variadic */ 0);
+		if (return_type_ast) {
+			arg_infos->type = zend_compile_typename(
+				return_type_ast, /* force_allow_null */ 0, /* use_arena */ 0);
+			ZEND_TYPE_FULL_MASK(arg_infos->type) |= _ZEND_ARG_INFO_FLAGS(
+				(op_array->fn_flags & ZEND_ACC_RETURN_REFERENCE) != 0, /* is_variadic */ 0);
+		} else {
+			arg_infos->type = (zend_type) ZEND_TYPE_INIT_CODE(fallback_return_type, 0, 0);
+		}
 		arg_infos++;
 		op_array->fn_flags |= ZEND_ACC_HAS_RETURN_TYPE;
 	} else {
@@ -6294,7 +6298,8 @@ void zend_compile_func_decl(znode *result, zend_ast *ast, zend_bool toplevel) /*
 		zend_stack_push(&CG(loop_var_stack), (void *) &dummy_var);
 	}
 
-	zend_compile_params(params_ast, return_type_ast);
+	zend_compile_params(params_ast, return_type_ast,
+		is_method && zend_string_equals_literal_ci(decl->name, "__toString") ? IS_STRING : 0);
 	if (CG(active_op_array)->fn_flags & ZEND_ACC_GENERATOR) {
 		zend_mark_function_as_generator();
 		zend_emit_op(NULL, ZEND_GENERATOR_CREATE, NULL, NULL);
diff --git a/Zend/zend_exceptions.c b/Zend/zend_exceptions.c
index f3846d326b..fb48d34bdf 100644
--- a/Zend/zend_exceptions.c
+++ b/Zend/zend_exceptions.c
@@ -763,7 +763,6 @@ static const zend_function_entry zend_funcs_throwable[] = {
 	ZEND_ABSTRACT_ME(throwable, getTrace,         arginfo_class_Throwable_getTrace)
 	ZEND_ABSTRACT_ME(throwable, getPrevious,      arginfo_class_Throwable_getPrevious)
 	ZEND_ABSTRACT_ME(throwable, getTraceAsString, arginfo_class_Throwable_getTraceAsString)
-	ZEND_ABSTRACT_ME(throwable, __toString,       arginfo_class_Throwable___toString)
 	ZEND_FE_END
 };
 /* }}} */
@@ -805,6 +804,7 @@ void zend_register_default_exception(void) /* {{{ */
 	zend_class_entry ce;
 
 	REGISTER_MAGIC_INTERFACE(throwable, Throwable);
+	zend_class_implements(zend_ce_throwable, 1, zend_ce_stringable);
 
 	memcpy(&default_exception_handlers, &std_object_handlers, sizeof(zend_object_handlers));
 	default_exception_handlers.clone_obj = NULL;
diff --git a/Zend/zend_exceptions.stub.php b/Zend/zend_exceptions.stub.php
index 96d581caf9..12255df3f6 100644
--- a/Zend/zend_exceptions.stub.php
+++ b/Zend/zend_exceptions.stub.php
@@ -1,6 +1,6 @@
 <?php
 
-interface Throwable
+interface Throwable extends Stringable
 {
     /** @return string */
     function getMessage();
@@ -22,9 +22,6 @@ interface Throwable
 
     /** @return string */
     function getTraceAsString();
-
-    /** @return string */
-    function __toString();
 }
 
 class Exception implements Throwable
@@ -56,8 +53,7 @@ class Exception implements Throwable
     /** @return string */
     final function getTraceAsString() {}
 
-    /** @return string */
-    function __toString() {}
+    function __toString(): string {}
 }
 
 class ErrorException extends Exception
diff --git a/Zend/zend_exceptions_arginfo.h b/Zend/zend_exceptions_arginfo.h
index c2f83e47e5..93badb6652 100644
--- a/Zend/zend_exceptions_arginfo.h
+++ b/Zend/zend_exceptions_arginfo.h
@@ -15,8 +15,6 @@ ZEND_END_ARG_INFO()
 
 #define arginfo_class_Throwable_getTraceAsString arginfo_class_Throwable_getMessage
 
-#define arginfo_class_Throwable___toString arginfo_class_Throwable_getMessage
-
 #define arginfo_class_Exception___clone arginfo_class_Throwable_getMessage
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_Exception___construct, 0, 0, 0)
@@ -41,7 +39,8 @@ ZEND_END_ARG_INFO()
 
 #define arginfo_class_Exception_getTraceAsString arginfo_class_Throwable_getMessage
 
-#define arginfo_class_Exception___toString arginfo_class_Throwable_getMessage
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_class_Exception___toString, 0, 0, IS_STRING, 0)
+ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_ErrorException___construct, 0, 0, 0)
 	ZEND_ARG_TYPE_INFO(0, message, IS_STRING, 0)
diff --git a/Zend/zend_interfaces.c b/Zend/zend_interfaces.c
index b6fdec95be..db42202571 100644
--- a/Zend/zend_interfaces.c
+++ b/Zend/zend_interfaces.c
@@ -28,6 +28,7 @@ ZEND_API zend_class_entry *zend_ce_iterator;
 ZEND_API zend_class_entry *zend_ce_arrayaccess;
 ZEND_API zend_class_entry *zend_ce_serializable;
 ZEND_API zend_class_entry *zend_ce_countable;
+ZEND_API zend_class_entry *zend_ce_stringable;
 
 /* {{{ zend_call_method
  Only returns the returned zval if retval_ptr != NULL */
@@ -567,6 +568,11 @@ static const zend_function_entry zend_funcs_countable[] = {
 	ZEND_ABSTRACT_ME(Countable, count, arginfo_class_Countable_count)
 	ZEND_FE_END
 };
+
+static const zend_function_entry zend_funcs_stringable[] = {
+	ZEND_ABSTRACT_ME(Stringable, __toString, arginfo_class_Stringable___toString)
+	ZEND_FE_END
+};
 /* }}} */
 
 /* {{{ zend_register_interfaces */
@@ -585,5 +591,9 @@ ZEND_API void zend_register_interfaces(void)
 	REGISTER_MAGIC_INTERFACE(serializable, Serializable);
 
 	REGISTER_MAGIC_INTERFACE(countable, Countable);
+
+	zend_class_entry ce;
+	INIT_CLASS_ENTRY(ce, "Stringable", zend_funcs_stringable);
+	zend_ce_stringable = zend_register_internal_interface(&ce);
 }
 /* }}} */
diff --git a/Zend/zend_interfaces.h b/Zend/zend_interfaces.h
index e7d0315ac5..c79495eca3 100644
--- a/Zend/zend_interfaces.h
+++ b/Zend/zend_interfaces.h
@@ -30,6 +30,7 @@ extern ZEND_API zend_class_entry *zend_ce_iterator;
 extern ZEND_API zend_class_entry *zend_ce_arrayaccess;
 extern ZEND_API zend_class_entry *zend_ce_serializable;
 extern ZEND_API zend_class_entry *zend_ce_countable;
+extern ZEND_API zend_class_entry *zend_ce_stringable;
 
 typedef struct _zend_user_iterator {
 	zend_object_iterator     it;
diff --git a/Zend/zend_interfaces.stub.php b/Zend/zend_interfaces.stub.php
index 882a21e600..3a908212a4 100644
--- a/Zend/zend_interfaces.stub.php
+++ b/Zend/zend_interfaces.stub.php
@@ -49,3 +49,8 @@ interface Countable
     /** @return int */
     function count();
 }
+
+interface Stringable
+{
+    function __toString(): string;
+}
diff --git a/Zend/zend_interfaces_arginfo.h b/Zend/zend_interfaces_arginfo.h
index fee57057af..e96104719a 100644
--- a/Zend/zend_interfaces_arginfo.h
+++ b/Zend/zend_interfaces_arginfo.h
@@ -33,3 +33,6 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_class_Serializable_unserialize, 0, 0, 1)
 ZEND_END_ARG_INFO()
 
 #define arginfo_class_Countable_count arginfo_class_IteratorAggregate_getIterator
+
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_class_Stringable___toString, 0, 0, IS_STRING, 0)
+ZEND_END_ARG_INFO()