Prevent associated type from being in a union or intersection type

Author: Girgias

Zend/tests/type_declarations/associated/associated_type_cannot_be_in_intersection1.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Associated type cannot be in intersection (simple intersection with class type)
+--FILE--
+<?php
+
+interface I {
+    type T;
+    public function foo(T&Traversable $param): T&Traversable;
+}
+
+?>
+--EXPECTF--
+Fatal error: Associated type cannot be part of an intersection type in %s on line %d

Zend/tests/type_declarations/associated/associated_type_cannot_be_in_intersection2.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Associated type cannot be in intersection (DNF type)
+--FILE--
+<?php
+
+interface I {
+    type T;
+    public function foo(stdClass|(T&Traversable) $param): stdClass|(T&Traversable);
+}
+
+?>
+--EXPECTF--
+Fatal error: Associated type cannot be part of an intersection type in %s on line %d

Zend/tests/type_declarations/associated/associated_type_cannot_be_in_union1.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Associated type cannot be in union (simple union with built-in type)
+--FILE--
+<?php
+
+interface I {
+    type T;
+    public function foo(T|int $param): T|int;
+}
+
+?>
+--EXPECTF--
+Fatal error: Associated type cannot be part of a union type in %s on line %d

Zend/tests/type_declarations/associated/associated_type_cannot_be_in_union2.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Associated type cannot be in union (simple union with class type)
+--FILE--
+<?php
+
+interface I {
+    type T;
+    public function foo(T|stdClass $param): T|stdClass;
+}
+
+?>
+--EXPECTF--
+Fatal error: Associated type cannot be part of a union type in %s on line %d

Zend/tests/type_declarations/associated/associated_type_cannot_be_in_union3.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Associated type cannot be in union (DNF type)
+--FILE--
+<?php
+
+interface I {
+    type T;
+    public function foo(T|(Traversable&Countable) $param): T|(Traversable&Countable);
+}
+
+?>
+--EXPECTF--
+Fatal error: Associated type cannot be part of a union type in %s on line %d

Zend/zend_compile.c

@@ -6966,9 +6966,11 @@ ZEND_API void zend_set_function_arg_flags(zend_function *func) /* {{{ */
 
 static zend_type zend_compile_single_typename(zend_ast *ast)
 {
+	zend_class_entry *ce = CG(active_class_entry);
+
 	ZEND_ASSERT(!(ast->attr & ZEND_TYPE_NULLABLE));
 	if (ast->kind == ZEND_AST_TYPE) {
-		if (ast->attr == IS_STATIC && !CG(active_class_entry) && zend_is_scope_known()) {
+		if (ast->attr == IS_STATIC && !ce && zend_is_scope_known()) {
 			zend_error_noreturn(E_COMPILE_ERROR,
 				"Cannot use \"static\" when no class scope is active");
 		}
@@ -6998,25 +7000,29 @@ static zend_type zend_compile_single_typename(zend_ast *ast)
 			const char *correct_name;
 			uint32_t fetch_type = zend_get_class_fetch_type_ast(ast);
 			zend_string *class_name = type_name;
+			uint32_t flags = 0;
 
 			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");
+				if (ce && ce->associated_types && zend_hash_exists(ce->associated_types, class_name)) {
+					flags = _ZEND_TYPE_ASSOCIATED_BIT;
+				}
 			} 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;
+						class_name = ce->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;
+						class_name = ce->parent_name;
 						ZEND_ASSERT(class_name && "must know class name when resolving parent type at compile time");
 					}
 				}
@@ -7044,7 +7050,7 @@ static zend_type zend_compile_single_typename(zend_ast *ast)
 
 			class_name = zend_new_interned_string(class_name);
 			zend_alloc_ce_cache(class_name);
-			return (zend_type) ZEND_TYPE_INIT_CLASS(class_name, /* allow null */ false, 0);
+			return (zend_type) ZEND_TYPE_INIT_CLASS(class_name, /* allow null */ false, flags);
 		}
 	}
 }
@@ -7193,6 +7199,9 @@ static zend_type zend_compile_typename_ex(
 			single_type = zend_compile_single_typename(type_ast);
 			uint32_t single_type_mask = ZEND_TYPE_PURE_MASK(single_type);
 
+			if (ZEND_TYPE_IS_ASSOCIATED(single_type)) {
+				zend_error_noreturn(E_COMPILE_ERROR, "Associated type cannot be part of a union type");
+			}
 			if (single_type_mask == MAY_BE_ANY) {
 				zend_error_noreturn(E_COMPILE_ERROR, "Type mixed can only be used as a standalone type");
 			}
@@ -7275,6 +7284,9 @@ static zend_type zend_compile_typename_ex(
 			zend_ast *type_ast = list->child[i];
 			zend_type single_type = zend_compile_single_typename(type_ast);
 
+			if (ZEND_TYPE_IS_ASSOCIATED(single_type)) {
+				zend_error_noreturn(E_COMPILE_ERROR, "Associated type cannot be part of an intersection type");
+			}
 			/* An intersection of union types cannot exist so invalidate it
 			 * Currently only can happen with iterable getting canonicalized to Traversable|array */
 			if (ZEND_TYPE_IS_ITERABLE_FALLBACK(single_type)) {

Zend/zend_types.h

@@ -142,14 +142,15 @@ typedef struct {
 	zend_type types[1];
 } zend_type_list;
 
-#define _ZEND_TYPE_EXTRA_FLAGS_SHIFT 25
-#define _ZEND_TYPE_MASK ((1u << 25) - 1)
+#define _ZEND_TYPE_EXTRA_FLAGS_SHIFT 26
+#define _ZEND_TYPE_MASK ((1u << 26) - 1)
 /* Only one of these bits may be set. */
+#define _ZEND_TYPE_ASSOCIATED_BIT (1u << 25)
 #define _ZEND_TYPE_NAME_BIT (1u << 24)
 // Used to signify that type.ptr is not a `zend_string*` but a `const char*`,
 #define _ZEND_TYPE_LITERAL_NAME_BIT (1u << 23)
 #define _ZEND_TYPE_LIST_BIT (1u << 22)
-#define _ZEND_TYPE_KIND_MASK (_ZEND_TYPE_LIST_BIT|_ZEND_TYPE_NAME_BIT|_ZEND_TYPE_LITERAL_NAME_BIT)
+#define _ZEND_TYPE_KIND_MASK (_ZEND_TYPE_LIST_BIT|_ZEND_TYPE_NAME_BIT|_ZEND_TYPE_LITERAL_NAME_BIT|_ZEND_TYPE_ASSOCIATED_BIT)
 /* For BC behaviour with iterable type */
 #define _ZEND_TYPE_ITERABLE_BIT (1u << 21)
 /* Whether the type list is arena allocated */
@@ -167,7 +168,7 @@ typedef struct {
 	(((t).type_mask & _ZEND_TYPE_MASK) != 0)
 
 /* If a type is complex it means it's either a list with a union or intersection,
- * or the void pointer is a class name */
+ * the void pointer is a class name, or the type is an associated type (which implies it is a name) */
 #define ZEND_TYPE_IS_COMPLEX(t) \
 	((((t).type_mask) & _ZEND_TYPE_KIND_MASK) != 0)
 
@@ -180,6 +181,9 @@ typedef struct {
 #define ZEND_TYPE_HAS_LIST(t) \
 	((((t).type_mask) & _ZEND_TYPE_LIST_BIT) != 0)
 
+#define ZEND_TYPE_IS_ASSOCIATED(t) \
+	((((t).type_mask) & _ZEND_TYPE_ASSOCIATED_BIT) != 0)
+
 #define ZEND_TYPE_IS_ITERABLE_FALLBACK(t) \
 	((((t).type_mask) & _ZEND_TYPE_ITERABLE_BIT) != 0)