Zend: Resolve self and parent types at compile time

Zend/tests/magic_methods/magic_methods_021.phpt

@@ -12,7 +12,7 @@ class Foo2 {
 }
 
 class Foo3 {
-    public static function __set_state(array $data): Foo3|self {}
+    public static function __set_state(array $data): Foo3|Foo2 {}
 }
 
 ?>

Zend/tests/type_declarations/intersection_types/relative_types/relative_parent_type_is_allow_when_compile_time_resolve.phpt

@@ -0,0 +1,15 @@
+--TEST--
+parent type can take part in an intersection type is resolvable at compile time
+--FILE--
+<?php
+
+class A {}
+
+class B extends A {
+    public function foo(): parent&Iterator {}
+}
+
+?>
+DONE
+--EXPECT--
+DONE

Zend/tests/type_declarations/intersection_types/invalid_types/invalid_parent_type.phpt → Zend/tests/type_declarations/intersection_types/relative_types/relative_parent_type_is_not_allow_if_not_compile_time_resolve.phpt

@@ -1,14 +1,13 @@
 --TEST--
-parent type cannot take part in an intersection type
+parent type cannot take part in an intersection type if not resolvable at compile time
 --FILE--
 <?php
 
-class A {}
-
-class B extends A {
+trait T {
     public function foo(): parent&Iterator {}
 }
 
 ?>
+DONE
 --EXPECTF--
 Fatal error: Type parent cannot be part of an intersection type in %s on line %d

Zend/tests/type_declarations/intersection_types/relative_types/relative_parent_type_is_not_allow_if_not_compile_time_resolve2.phpt

@@ -0,0 +1,13 @@
+--TEST--
+parent type cannot take part in an intersection type if not resolvable at compile time
+--FILE--
+<?php
+
+trait T {
+    public function foo(): PARENT&Iterator {}
+}
+
+?>
+DONE
+--EXPECTF--
+Fatal error: Type PARENT cannot be part of an intersection type in %s on line %d

Zend/tests/type_declarations/intersection_types/relative_types/relative_self_type_is_allow_when_compile_time_resolve.phpt

@@ -0,0 +1,13 @@
+--TEST--
+self type can take part in an intersection type is resolvable at compile time
+--FILE--
+<?php
+
+class A {
+    public function foo(): self&Iterator {}
+}
+
+?>
+DONE
+--EXPECT--
+DONE

Zend/tests/type_declarations/intersection_types/invalid_types/invalid_self_type.phpt → Zend/tests/type_declarations/intersection_types/relative_types/relative_self_type_is_not_allow_if_not_compile_time_resolve.phpt

@@ -1,12 +1,13 @@
 --TEST--
-self type cannot take part in an intersection type
+self type cannot take part in an intersection type if not resolvable at compile time
 --FILE--
 <?php
 
-class A {
+trait T {
     public function foo(): self&Iterator {}
 }
 
 ?>
+DONE
 --EXPECTF--
 Fatal error: Type self cannot be part of an intersection type in %s on line %d

Zend/tests/type_declarations/intersection_types/relative_types/relative_self_type_is_not_allow_if_not_compile_time_resolve2.phpt

@@ -0,0 +1,13 @@
+--TEST--
+self type cannot take part in an intersection type if not resolvable at compile time
+--FILE--
+<?php
+
+trait T {
+    public function foo(): SELF&Iterator {}
+}
+
+?>
+DONE
+--EXPECTF--
+Fatal error: Type SELF cannot be part of an intersection type in %s on line %d

Zend/tests/type_declarations/union_types/redundant_types/duplicate_case_sensitive_relative_class_parent_type.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Duplicate parent type in different cases
+--FILE--
+<?php
+
+class Foo {
+    public function method(array $data) {}
+}
+class Bar extends Foo {
+    public function method(array $data): parent|PARENT {}
+}
+
+?>
+--EXPECTF--
+Fatal error: Duplicate type Foo is redundant in %s on line %d

Zend/tests/type_declarations/union_types/redundant_types/duplicate_case_sensitive_relative_class_self_type.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Duplicate self type in different cases
+--FILE--
+<?php
+
+class Foo {
+    public function method(array $data): self|SELF {}
+}
+
+?>
+--EXPECTF--
+Fatal error: Duplicate type Foo is redundant in %s on line %d

Zend/tests/type_declarations/union_types/redundant_types/duplicate_relative_class_parent_type.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Duplicate parent type
+--FILE--
+<?php
+
+class Foo {
+    public function method(array $data) {}
+}
+class Bar extends Foo {
+    public function method(array $data): parent|parent {}
+}
+
+?>
+--EXPECTF--
+Fatal error: Duplicate type Foo is redundant in %s on line %d

Zend/tests/type_declarations/union_types/redundant_types/duplicate_relative_class_self_type.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Duplicate self type
+--FILE--
+<?php
+
+class Foo {
+    public function method(array $data): self|self {}
+}
+
+?>
+--EXPECTF--
+Fatal error: Duplicate type Foo is redundant in %s on line %d

Zend/tests/type_declarations/union_types/redundant_types/duplicate_relative_class_static_type.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Duplicate static type
+--FILE--
+<?php
+
+class Foo {
+    public function method(array $data): static|static {}
+}
+
+?>
+--EXPECTF--
+Fatal error: Duplicate type static is redundant in %s on line %d

Zend/tests/type_declarations/union_types/redundant_types/duplicate_resolved_relative_class_type_variation1.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Relative class type self resolving to an existing entry (after variation)
+--FILE--
+<?php
+
+class Foo {
+    public function method(array $data): Foo|self {}
+}
+
+?>
+DONE
+--EXPECTF--
+Fatal error: Duplicate type Foo is redundant in %s on line %d

Zend/tests/type_declarations/union_types/redundant_types/duplicate_resolved_relative_class_type_variation2.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Relative class type self resolving to an existing entry (before variation)
+--FILE--
+<?php
+
+class Foo {
+    public function method(array $data): self|Foo {}
+}
+
+?>
+DONE
+--EXPECTF--
+Fatal error: Duplicate type Foo is redundant in %s on line %d

Zend/tests/type_declarations/union_types/redundant_types/duplicate_resolved_relative_class_type_variation3.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Relative class type parent resolving to an existing entry (after variation)
+--FILE--
+<?php
+
+class Foo {
+    public function method(array $data) {}
+}
+class Bar extends Foo {
+    public function method(array $data): Foo|parent {}
+}
+
+?>
+DONE
+--EXPECTF--
+Fatal error: Duplicate type Foo is redundant in %s on line %d

Zend/tests/type_declarations/union_types/redundant_types/duplicate_resolved_relative_class_type_variation4.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Relative class type parent resolving to an existing entry (before variation)
+--FILE--
+<?php
+
+class Foo {
+    public function method(array $data) {}
+}
+class Bar extends Foo {
+    public function method(array $data): parent|Foo {}
+}
+
+?>
+DONE
+--EXPECTF--
+Fatal error: Duplicate type Foo is redundant in %s on line %d

Zend/zend_compile.c

@@ -1409,10 +1409,8 @@ static zend_string *add_intersection_type(zend_string *str,
 	ZEND_TYPE_LIST_FOREACH(intersection_type_list, single_type) {
 		ZEND_ASSERT(!ZEND_TYPE_HAS_LIST(*single_type));
 		ZEND_ASSERT(ZEND_TYPE_HAS_NAME(*single_type));
-		zend_string *name = ZEND_TYPE_NAME(*single_type);
-		zend_string *resolved = resolve_class_name(name, scope);
-		intersection_str = add_type_string(intersection_str, resolved, /* is_intersection */ true);
-		zend_string_release(resolved);
+
+		intersection_str = add_type_string(intersection_str, ZEND_TYPE_NAME(*single_type), /* is_intersection */ true);
 	} ZEND_TYPE_LIST_FOREACH_END();
 
 	ZEND_ASSERT(intersection_str);
@@ -1444,6 +1442,7 @@ zend_string *zend_type_to_string_resolved(zend_type type, zend_class_entry *scop
 			}
 			ZEND_ASSERT(!ZEND_TYPE_HAS_LIST(*list_type));
 			ZEND_ASSERT(ZEND_TYPE_HAS_NAME(*list_type));
+
 			zend_string *name = ZEND_TYPE_NAME(*list_type);
 			zend_string *resolved = resolve_class_name(name, scope);
 			str = add_type_string(str, resolved, /* is_intersection */ false);
@@ -6957,14 +6956,14 @@ static zend_type zend_compile_single_typename(zend_ast *ast)
 
 		return (zend_type) ZEND_TYPE_INIT_CODE(ast->attr, 0, 0);
 	} else {
-		zend_string *class_name = zend_ast_get_str(ast);
-		uint8_t type_code = zend_lookup_builtin_type_by_name(class_name);
+		zend_string *type_name = zend_ast_get_str(ast);
+		uint8_t type_code = zend_lookup_builtin_type_by_name(type_name);
 
 		if (type_code != 0) {
 			if ((ast->attr & ZEND_NAME_NOT_FQ) != ZEND_NAME_NOT_FQ) {
 				zend_error_noreturn(E_COMPILE_ERROR,
 					"Type declaration '%s' must be unqualified",
-					ZSTR_VAL(zend_string_tolower(class_name)));
+					ZSTR_VAL(zend_string_tolower(type_name)));
 			}
 
 			/* Transform iterable into a type union alias */
@@ -6978,38 +6977,55 @@ static zend_type zend_compile_single_typename(zend_ast *ast)
 			return (zend_type) ZEND_TYPE_INIT_CODE(type_code, 0, 0);
 		} else {
 			const char *correct_name;
-			zend_string *orig_name = zend_ast_get_str(ast);
 			uint32_t fetch_type = zend_get_class_fetch_type_ast(ast);
+			zend_string *class_name = type_name;
+
 			if (fetch_type == ZEND_FETCH_CLASS_DEFAULT) {
 				class_name = zend_resolve_class_name_ast(ast);
 				zend_assert_valid_class_name(class_name, "a type name");
 			} else {
+				ZEND_ASSERT(fetch_type == ZEND_FETCH_CLASS_SELF || fetch_type == ZEND_FETCH_CLASS_PARENT);
+
 				zend_ensure_valid_class_fetch_type(fetch_type);
+				if (fetch_type == ZEND_FETCH_CLASS_SELF) {
+					/* Scope might be unknown for unbound closures and traits */
+					if (zend_is_scope_known()) {
+						class_name = CG(active_class_entry)->name;
+						ZEND_ASSERT(class_name && "must know class name when resolving self type at compile time");
+					}
+				} else {
+					ZEND_ASSERT(fetch_type == ZEND_FETCH_CLASS_PARENT);
+					/* Scope might be unknown for unbound closures and traits */
+					if (zend_is_scope_known()) {
+						class_name = CG(active_class_entry)->parent_name;
+						ZEND_ASSERT(class_name && "must know class name when resolving parent type at compile time");
+					}
+				}
 				zend_string_addref(class_name);
 			}
 
 			if (ast->attr == ZEND_NAME_NOT_FQ
-					&& zend_is_confusable_type(orig_name, &correct_name)
-					&& zend_is_not_imported(orig_name)) {
+					&& zend_is_confusable_type(type_name, &correct_name)
+					&& zend_is_not_imported(type_name)) {
 				const char *extra =
 					FC(current_namespace) ? " or import the class with \"use\"" : "";
 				if (correct_name) {
 					zend_error(E_COMPILE_WARNING,
 						"\"%s\" will be interpreted as a class name. Did you mean \"%s\"? "
 						"Write \"\\%s\"%s to suppress this warning",
-						ZSTR_VAL(orig_name), correct_name, ZSTR_VAL(class_name), extra);
+						ZSTR_VAL(type_name), correct_name, ZSTR_VAL(class_name), extra);
 				} else {
 					zend_error(E_COMPILE_WARNING,
 						"\"%s\" is not a supported builtin type "
 						"and will be interpreted as a class name. "
 						"Write \"\\%s\"%s to suppress this warning",
-						ZSTR_VAL(orig_name), ZSTR_VAL(class_name), extra);
+						ZSTR_VAL(type_name), ZSTR_VAL(class_name), extra);
 				}
 			}
 
 			class_name = zend_new_interned_string(class_name);
 			zend_alloc_ce_cache(class_name);
-			return (zend_type) ZEND_TYPE_INIT_CLASS(class_name, 0, 0);
+			return (zend_type) ZEND_TYPE_INIT_CLASS(class_name, /* allow null */ false, 0);
 		}
 	}
 }
@@ -7132,6 +7148,7 @@ static zend_type zend_compile_typename_ex(
 					/* Switch from single name to name list. */
 					type_list->num_types = 1;
 					type_list->types[0] = type;
+					/* Clear MAY_BE_* type flags */
 					ZEND_TYPE_FULL_MASK(type_list->types[0]) &= ~_ZEND_TYPE_MAY_BE_MASK;
 				}
 				/* Mark type as list type */
@@ -7178,6 +7195,7 @@ static zend_type zend_compile_typename_ex(
 					"Type contains both true and false, bool must be used instead");
 			}
 			ZEND_TYPE_FULL_MASK(type) |= ZEND_TYPE_PURE_MASK(single_type);
+			/* Clear MAY_BE_* type flags */
 			ZEND_TYPE_FULL_MASK(single_type) &= ~_ZEND_TYPE_MAY_BE_MASK;
 
 			if (ZEND_TYPE_IS_COMPLEX(single_type)) {
@@ -7190,6 +7208,7 @@ static zend_type zend_compile_typename_ex(
 						/* Switch from single name to name list. */
 						type_list->num_types = 1;
 						type_list->types[0] = type;
+						/* Clear MAY_BE_* type flags */
 						ZEND_TYPE_FULL_MASK(type_list->types[0]) &= ~_ZEND_TYPE_MAY_BE_MASK;
 						ZEND_TYPE_SET_LIST(type, type_list);
 					}
@@ -7253,8 +7272,10 @@ static zend_type zend_compile_typename_ex(
 				zend_string_release_ex(standard_type_str, false);
 			}
 			/* Check for "self" and "parent" too */
-			if (zend_string_equals_literal_ci(ZEND_TYPE_NAME(single_type), "self")
-					|| zend_string_equals_literal_ci(ZEND_TYPE_NAME(single_type), "parent")) {
+			if (
+				zend_string_equals_ci(ZEND_TYPE_NAME(single_type), ZSTR_KNOWN(ZEND_STR_SELF))
+				|| zend_string_equals_ci(ZEND_TYPE_NAME(single_type), ZSTR_KNOWN(ZEND_STR_PARENT))
+			) {
 				zend_error_noreturn(E_COMPILE_ERROR,
 					"Type %s cannot be part of an intersection type", ZSTR_VAL(ZEND_TYPE_NAME(single_type)));
 			}

Zend/zend_string.h

@@ -624,6 +624,8 @@ EMPTY_SWITCH_DEFAULT_CASE()
 	_(ZEND_STR_NULL_LOWERCASE,         "null") \
 	_(ZEND_STR_MIXED,                  "mixed") \
 	_(ZEND_STR_TRAVERSABLE,            "Traversable") \
+	_(ZEND_STR_SELF,                   "self") \
+	_(ZEND_STR_PARENT,                 "parent") \
 	_(ZEND_STR_SLEEP,                  "__sleep") \
 	_(ZEND_STR_WAKEUP,                 "__wakeup") \
 	_(ZEND_STR_CASES,                  "cases") \