Merge remote-tracking branch 'origin/master' into stub-fix-self-parent-static-class-const-ref

phpunit/code/constructor_visibility_inherited_private.php

@@ -0,0 +1,17 @@
+<?php
+
+class PrivateConstructorParent
+{
+    private function __construct()
+    {
+    }
+}
+
+class PrivateConstructorChild extends PrivateConstructorParent
+{
+}
+
+function main()
+{
+    new PrivateConstructorChild();
+}

phpunit/code/constructor_visibility_internal_private.php

@@ -0,0 +1,6 @@
+<?php
+
+function main()
+{
+    new Closure();
+}

phpunit/code/constructor_visibility_namespaced.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace ConstructorVisibility;
+
+class Hidden
+{
+    private function __construct()
+    {
+    }
+}
+
+function main()
+{
+    new Hidden();
+}

phpunit/code/constructor_visibility_private.php

@@ -0,0 +1,11 @@
+<?php
+
+class TestClass
+{
+    private function __construct(){}
+}
+
+function main()
+{
+    new TestClass;
+}

phpunit/code/constructor_visibility_protected.php

@@ -0,0 +1,11 @@
+<?php
+
+class TestClass
+{
+    protected function __construct(){}
+}
+
+function main()
+{
+    new TestClass;
+}

phpunit/code/constructor_visibility_protected_foreign_class.php

@@ -0,0 +1,19 @@
+<?php
+
+class Base
+{
+    protected function __construct(){}
+}
+
+class Other
+{
+    public static function make(): Base
+    {
+        return new Base();
+    }
+}
+
+function main()
+{
+    Other::make();
+}

phpunit/code/inheritance_error_generator_return_widened.php

@@ -0,0 +1,14 @@
+<?php
+
+interface GeneratorReturnContract
+{
+    public function values(): \Generator;
+}
+
+class GeneratorReturnImplementation implements GeneratorReturnContract
+{
+    public function values(): iterable
+    {
+        yield 1;
+    }
+}

phpunit/code/inheritance_error_return_intersection_missing.php

@@ -0,0 +1,23 @@
+<?php
+
+interface IntersectionLeft
+{
+}
+
+interface IntersectionRight
+{
+}
+
+interface IntersectionReturnParent
+{
+    public function value(): IntersectionLeft&IntersectionRight;
+}
+
+class IntersectionReturnChild implements IntersectionReturnParent
+{
+    public function value(): IntersectionLeft
+    {
+        return new class implements IntersectionLeft {
+        };
+    }
+}

phpunit/code/inheritance_error_return_never_widened.php

@@ -0,0 +1,13 @@
+<?php
+
+abstract class NeverReturnParent
+{
+    abstract public function stop(): never;
+}
+
+abstract class NeverReturnChild extends NeverReturnParent
+{
+    public function stop(): void
+    {
+    }
+}

phpunit/code/inheritance_error_return_static_widened.php

@@ -0,0 +1,17 @@
+<?php
+
+class StaticReturnParent
+{
+    public function value(): static
+    {
+        return $this;
+    }
+}
+
+class StaticReturnChild extends StaticReturnParent
+{
+    public function value(): self
+    {
+        return $this;
+    }
+}

phpunit/code/inheritance_error_return_union_widened.php

@@ -0,0 +1,14 @@
+<?php
+
+interface UnionReturnParent
+{
+    public function value(): int|string;
+}
+
+class UnionReturnChild implements UnionReturnParent
+{
+    public function value(): bool
+    {
+        return true;
+    }
+}

phpunit/code/preprocessor/namespace_ending_comment_unbracketed.php

@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace NamespaceEndingComment;
+
+const VALUE = 42;
+
+function value(): int
+{
+    return VALUE;
+}
+
+// unbracketed namespace trailing comment

phpunit/code/return_type_covariance_intersection.php

@@ -0,0 +1,39 @@
+<?php
+
+interface CovarianceLeft
+{
+}
+
+interface CovarianceRight
+{
+}
+
+class CovarianceBoth implements CovarianceLeft, CovarianceRight
+{
+}
+
+interface IntersectionNarrowingContract
+{
+    public function intersection(): CovarianceLeft;
+}
+
+class IntersectionNarrowingImpl implements IntersectionNarrowingContract
+{
+    public function intersection(): CovarianceLeft&CovarianceRight
+    {
+        return new CovarianceBoth();
+    }
+}
+
+interface IntersectionContract
+{
+    public function concrete(): CovarianceLeft&CovarianceRight;
+}
+
+class IntersectionImpl implements IntersectionContract
+{
+    public function concrete(): CovarianceBoth
+    {
+        return new CovarianceBoth();
+    }
+}

phpunit/code/trait_constructor_conflict.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+trait TraitA
+{
+    public function __construct()
+    {
+        echo "A\n";
+    }
+}
+
+trait TraitB
+{
+    public function __construct()
+    {
+        echo "B\n";
+    }
+}
+
+class TestClass
+{
+    use TraitA, TraitB;
+}
+
+function main()
+{
+    new TestClass();
+}

phpunit/code/trait_constructor_private.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+trait TestTrait
+{
+    private function __construct()
+    {
+        echo "trait ctor\n";
+    }
+}
+
+class TestClass
+{
+    use TestTrait;
+}
+
+function main()
+{
+    new TestClass();
+}

phpunit/code/trait_constructor_protected.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+trait TestTrait
+{
+    protected function __construct()
+    {
+        echo "trait ctor\n";
+    }
+}
+
+class TestClass
+{
+    use TestTrait;
+}
+
+function main()
+{
+    new TestClass();
+}

phpunit/src/ConstructorVisibilityTest.php

@@ -0,0 +1,78 @@
+<?php
+
+use TypePhp\Exception\TestError;
+
+class ConstructorVisibilityTest extends BaseTest
+{
+    /**
+     * 编译期错误在转换阶段直接以 TestError 抛出，而在桩文件生成阶段
+     * (gen_stub.php) 会被包成 RuntimeException，这里两者都要捕获。
+     */
+    protected function exec(string $expected, string $file): void
+    {
+        try {
+            $this->compile($file);
+        } catch (TestError|RuntimeException $exception) {
+            $this->assertStringContainsString($expected, $exception->getMessage());
+            return;
+        }
+        $this->fail('Expected compile-time error was not thrown');
+    }
+
+    public function testPrivateConstructorCannotBeCalledFromOutside(): void
+    {
+        // 私有构造器不能从类外部通过 `new` 调用
+        $this->exec('Cannot call private TestClass::__construct()', 'constructor_visibility_private.php');
+    }
+
+    public function testProtectedConstructorCannotBeCalledFromGlobalScope(): void
+    {
+        // 保护构造器不能从全局作用域调用
+        $this->exec('Cannot call protected TestClass::__construct()', 'constructor_visibility_protected.php');
+    }
+
+    public function testProtectedConstructorCannotBeCalledFromNonSubclass(): void
+    {
+        // 保护构造器不能从非子类的其它类内部调用
+        $this->exec('Cannot call protected Base::__construct()', 'constructor_visibility_protected_foreign_class.php');
+    }
+
+    public function testInheritedPrivateConstructorCannotBeCalledFromChildScope(): void
+    {
+        $this->exec(
+            'Cannot call private PrivateConstructorParent::__construct()',
+            'constructor_visibility_inherited_private.php'
+        );
+    }
+
+    public function testInternalPrivateConstructorCannotBeCalled(): void
+    {
+        $this->exec('Cannot call private Closure::__construct()', 'constructor_visibility_internal_private.php');
+    }
+
+    public function testNamespacedConstructorUsesPhpClassNameInDiagnostic(): void
+    {
+        $this->exec(
+            'Cannot call private ConstructorVisibility\Hidden::__construct()',
+            'constructor_visibility_namespaced.php'
+        );
+    }
+
+    public function testTraitPrivateConstructorCannotBeCalledFromGlobalScope(): void
+    {
+        // trait 提供的私有构造器扁平化后等价于类的私有构造器
+        $this->exec('Cannot call private TestClass::__construct()', 'trait_constructor_private.php');
+    }
+
+    public function testTraitProtectedConstructorCannotBeCalledFromGlobalScope(): void
+    {
+        // trait 提供的保护构造器扁平化后等价于类的保护构造器
+        $this->exec('Cannot call protected TestClass::__construct()', 'trait_constructor_protected.php');
+    }
+
+    public function testConflictingTraitConstructorMustBeResolved(): void
+    {
+        // 两个 trait 各自声明 __construct 时必须显式解决冲突
+        $this->exec('Trait `TraitB` method `__construct` already exists', 'trait_constructor_conflict.php');
+    }
+}

phpunit/src/InheritanceErrorTest.php

@@ -53,6 +53,36 @@ class InheritanceErrorTest extends TestCase
         $this->exec('must be compatible', 'inheritance_error_return_contravariant_class.php');
     }
 
+    public function testUnionReturnTypeCannotBeWidenedToUnrelatedType(): void
+    {
+        $this->exec('must be compatible', 'inheritance_error_return_union_widened.php');
+    }
+
+    public function testIntersectionReturnTypeCannotDropAMember(): void
+    {
+        $this->exec('must be compatible', 'inheritance_error_return_intersection_missing.php');
+    }
+
+    public function testStaticReturnTypeCannotBeWidenedToSelf(): void
+    {
+        $this->exec('must be compatible', 'inheritance_error_return_static_widened.php');
+    }
+
+    public function testNeverReturnTypeCannotBeWidenedToVoid(): void
+    {
+        $this->exec('must be compatible', 'inheritance_error_return_never_widened.php');
+    }
+
+    public function testGeneratorReturnTypeCannotBeWidenedToIterable(): void
+    {
+        $this->exec('must be compatible', 'inheritance_error_generator_return_widened.php');
+    }
+
+    public function testIntersectionReturnTypeCanNarrowToIntersectionOrConcreteSubtype(): void
+    {
+        $this->assertCompiles('return_type_covariance_intersection.php');
+    }
+
     public function testParameterTypeCannotBeCovariant()
     {
         $this->exec('must be compatible', 'inheritance_error_param_covariant_class.php');

phpunit/src/PreprocessorTest.php

@@ -321,6 +321,25 @@ class PreprocessorTest extends TestCase
         $this->assertSame('App\\VERSION', $constants['_const_var_App__VERSION']->name);
     }
 
+    public function testNamespaceEndingCommentWithUnbracketedSyntaxIsIgnored(): void
+    {
+        global $translator;
+        $file = __DIR__ . '/../code/preprocessor/namespace_ending_comment_unbracketed.php';
+        $previousTranslator = $translator ?? null;
+        $translator = $this->compiler;
+
+        try {
+            $this->compiler->addFiles([$file]);
+            $this->compiler->prepareFile($file);
+            $this->compiler->convertFile($file);
+        } finally {
+            $translator = $previousTranslator;
+        }
+
+        $constants = $this->getProperty('constants');
+        $this->assertArrayHasKey('_const_var_NamespaceEndingComment__VALUE', $constants);
+    }
+
     public function testSortFilesUsesImplementsAndTraitDependencies(): void
     {
         $classFile = realpath(__DIR__ . '/../code/preprocessor/deps_class_implements.php');

src/CompilerBase.php

@@ -3172,11 +3172,17 @@ class CompilerBase implements PropertyAccessContext
                         $className = $this->getNamespacedClassName($className);
                     }
                     $ctorClassName = $className;
-                    if ($this->hasClass($className)) {
-                        $classDef = $this->getClass($className);
-                        if ($classDef->flags & Modifiers::ABSTRACT) {
-                            $this->fatalError($expr, "abstract class `{$className}` cannot be instantiated");
-                        }
+                    if ($this->isAbstractClass($className)) {
+                        $this->fatalError($expr, "abstract class `{$className}` cannot be instantiated");
+                    }
+                    $constructor = $this->findConstructor($className);
+                    if ($constructor !== null
+                        && !$this->checkAccessibleByClassName($constructor['className'], $constructor['flags'])) {
+                        $this->fatalError(
+                            $expr,
+                            'Cannot call ' . $this->visibilityLabel($constructor['flags']) . ' '
+                            . $constructor['className'] . '::__construct()'
+                        );
                     }
                     $cePtr = $this->getClassEntryPtr($className);
                 }
@@ -3833,6 +3839,11 @@ class CompilerBase implements PropertyAccessContext
     }
 
     protected function checkAccessible(ClassDef $classDef, int $flags): bool
+    {
+        return $this->checkAccessibleByClassName($classDef->getNamespacedName(false), $flags);
+    }
+
+    protected function checkAccessibleByClassName(string $declaringClass, int $flags): bool
     {
         $scopeClassDef = $this->classDef;
         if ($this->functionDef !== null
@@ -3843,7 +3854,7 @@ class CompilerBase implements PropertyAccessContext
         // 私有方法，只能当前的类使用
         if ($flags & Modifiers::PRIVATE) {
             return $scopeClassDef !== null
-                && strcasecmp($classDef->getNamespacedName(false), $scopeClassDef->getNamespacedName(false)) === 0;
+                && $this->isSameClassName($declaringClass, $scopeClassDef->getNamespacedName(false));
         }
         // 保护方法，只能当前类和子类使用
         if ($flags & Modifiers::PROTECTED) {
@@ -3852,13 +3863,60 @@ class CompilerBase implements PropertyAccessContext
             }
             return $this->canAccessProtectedProperty(
                 $scopeClassDef->getNamespacedName(false),
-                $classDef->getNamespacedName(false)
+                $declaringClass
             );
         }
         // 类外部调用，只允许调用 public 方法
         return true;
     }
 
+    /**
+     * 沿继承链查找实际调用的构造函数，包括项目类继承的内部类构造函数。
+     *
+     * @return array{className: string, flags: int}|null
+     */
+    protected function findConstructor(string $className): ?array
+    {
+        $current = $className;
+        while ($current !== '') {
+            if ($this->hasClass($current)) {
+                $classDef = $this->getClass($current);
+                if ($classDef->hasMethod('__construct')) {
+                    return [
+                        'className' => $classDef->getNamespacedName(false),
+                        'flags' => $classDef->getMethod('__construct')->flags,
+                    ];
+                }
+                $current = $classDef->extends;
+                continue;
+            }
+            if (!$this->isInternalClass($current)) {
+                return null;
+            }
+
+            $constructor = Reflection::getClass($current)?->getConstructor();
+            if ($constructor === null) {
+                return null;
+            }
+            return [
+                'className' => $constructor->getDeclaringClass()->getName(),
+                'flags' => $constructor->getModifiers(),
+            ];
+        }
+        return null;
+    }
+
+    protected function visibilityLabel(int $flags): string
+    {
+        if ($flags & Modifiers::PRIVATE) {
+            return 'private';
+        }
+        if ($flags & Modifiers::PROTECTED) {
+            return 'protected';
+        }
+        return 'public';
+    }
+
     protected function genDebugInfo(?NodeAbstract $stmt = null, string $functionName = '', int $startLine = 0): string
     {
         $code = '';

src/Entity/FunctionDef.php

@@ -74,6 +74,20 @@ class FunctionDef
     /** Original union/nullable return type AST node. */
     public ?NodeAbstract $returnTypeNode = null;
 
+    /**
+     * Source-level return type declared on a generator method, preserved after
+     * `prepareGeneratorFunction()` neutralizes the runtime return type. A
+     * generator actually returns a `\FiberGenerator` (which implements
+     * `Iterator`), so the C++ return type and runtime type check are left
+     * neutral; this copy is only used by interface/abstract return-type
+     * covariance checks so a generator method can still satisfy a contract such
+     * as `: \Generator`.
+     */
+    public ?string $declaredReturnType = null;
+    public string $declaredReturnClass = '';
+    public ?array $declaredReturnTypeCheck = null;
+    public string $declaredReturnTypeStr = '';
+
     public function __construct(string $name, string $returnType, string $namespace)
     {
         $this->name = $name;

src/Generator/DefaultArgumentGenerator.php

@@ -88,7 +88,8 @@ trait DefaultArgumentGenerator
                         $code .= 'return ' . $plan->expr . ';' . PHP_EOL;
                     }
                 } else {
-                    $code .= 'return ' . $argInfo->default . ';' . PHP_EOL;
+                    $default = $this->convertRuntimeConstantDefault($type, $argInfo->default);
+                    $code .= 'return ' . $default . ';' . PHP_EOL;
                 }
 
                 $code .= '}' . PHP_EOL . PHP_EOL;
@@ -98,6 +99,28 @@ trait DefaultArgumentGenerator
         return $code;
     }
 
+    /**
+     * Runtime constant lookup returns Variant, but a typed default helper must
+     * return its native C++ type explicitly. Convert the complete expression so
+     * constants nested in expressions are covered as well.
+     */
+    private function convertRuntimeConstantDefault(string $type, string $default): string
+    {
+        if (!str_contains($default, 'php::constant(')) {
+            return $default;
+        }
+
+        return match ($type) {
+            Type::INT => 'php::toInt(' . $default . ')',
+            Type::FLOAT => 'php::toFloat(' . $default . ')',
+            Type::BOOL => 'php::toBool(' . $default . ')',
+            Type::STR => 'php::toString(' . $default . ')',
+            Type::ARRAY => 'php::toArray(' . $default . ')',
+            Type::OBJECT => 'php::toObject(' . $default . ')',
+            default => $default,
+        };
+    }
+
     private function shouldGenerateDefaultArgumentHelper(ArgInfo $argInfo): bool
     {
         if ($argInfo->variadic) {

src/Generator/FiberGenerator.php

@@ -72,6 +72,18 @@ trait FiberGenerator
         if (!$this->generatorReturnTypeAcceptsFiber($v->returnType)) {
             $this->fatalError($v, 'Generator return type must accept \\FiberGenerator; use Iterator, Traversable, iterable, object, mixed, or omit the return type');
         }
+        // Preserve the source-level declared return type before neutralizing the
+        // runtime return type. The override compatibility check still needs it so
+        // a generator method can satisfy an interface/abstract contract such as
+        // `: \Generator` (the runtime object is a `\FiberGenerator`, not a Zend
+        // `Generator`, so the C++ return type and runtime check stay neutral).
+        if ($v->returnType !== null) {
+            $declared = $this->buildTypeCheckFromNode($v->returnType);
+            $functionDef->declaredReturnTypeCheck = $declared['check'] ?: null;
+        }
+        $functionDef->declaredReturnType = $functionDef->returnType;
+        $functionDef->declaredReturnClass = $functionDef->returnClass;
+        $functionDef->declaredReturnTypeStr = $functionDef->returnTypeStr;
         $functionDef->generator = true;
         $functionDef->returnType = Type::VAR;
         $functionDef->returnClass = '';
@@ -112,7 +124,11 @@ trait FiberGenerator
 
         [, $class] = $this->resolveTypeDecl($type, self::DECL_TYPE_OF_RETURN);
         $class = strtolower(ltrim($class, '\\'));
-        return in_array($class, ['iterator', 'traversable', 'fibergenerator'], true);
+        // `\Generator` is the return type PHP programmers naturally write for a
+        // generator. TypePHP generators actually return a `\FiberGenerator`, so
+        // accepting the declared `Generator` type keeps PHP source compatible
+        // while the runtime object remains a `\FiberGenerator`.
+        return in_array($class, ['iterator', 'traversable', 'fibergenerator', 'generator'], true);
     }
 
     protected function parseYieldExpr(Yield_ $expr): string

src/Generator/TypeCheckGenerator.php

@@ -116,7 +116,7 @@ trait TypeCheckGenerator
         return $class ? [['kind' => 'instanceof', 'class' => $class]] : [];
     }
 
-    private function typeCheckNodeToString(NodeAbstract $typeNode): string
+    protected function typeCheckNodeToString(NodeAbstract $typeNode): string
     {
         if ($typeNode instanceof Node\Identifier) {
             return $typeNode->name;

src/Parser/AssignOpTrait.php

@@ -42,11 +42,27 @@ trait AssignOpTrait
         $tmp = $this->genTmpVarName();
         $this->addLocalVar($tmp, Type::VAR);
 
+        // item(dim, true) updates an existing reference's value, while offsetSet()
+        // replaces the array bucket and breaks the reference. Keep offsetSet() for
+        // ArrayAccess objects; dynamically typed/reference containers need a
+        // runtime array check because either representation is possible.
+        $arrayType = $this->getVarType($array);
+
         if ($left->dim === null) {
             return $code . '((' . $tmp . ' = ' . $value . ', ' . "{$array}.offsetSet(" . self::VALUE_NULL . ", {$tmp})" . '), ' . $tmp . ')';
         }
         $dim = $this->parseIdentifier($left->dim);
 
+        if ($arrayType === Type::ARRAY) {
+            return $code . '((' . $tmp . ' = ' . $value . ', ' . "{$array}.item({$dim}, true) = {$tmp}" . '), ' . $tmp . ')';
+        }
+        if ($arrayType === Type::VAR || $arrayType === Type::REF) {
+            $writeArray = "static_cast<void>({$array}.item({$dim}, true) = {$tmp})";
+            $writeOther = "{$array}.offsetSet({$dim}, {$tmp})";
+            return $code . '((' . $tmp . ' = ' . $value . ', '
+                . "({$array}.isArray() ? {$writeArray} : {$writeOther})"
+                . '), ' . $tmp . ')';
+        }
         return $code . '((' . $tmp . ' = ' . $value . ', ' . "{$array}.offsetSet({$dim}, {$tmp})" . '), ' . $tmp . ')';
     }
 
@@ -746,6 +762,9 @@ trait AssignOpTrait
         }
 
         $left = $this->parseWritableIdentifier($expr->var);
+        // Keep this write-context form for every RHS kind. Re-parsing it as a
+        // read later breaks append and missing-key targets such as
+        // `$array[] =& $source`.
 
         if ($this->isVarExpr($expr->var)) {
             if (!$this->hasVar($left)) {
@@ -822,13 +841,10 @@ trait AssignOpTrait
                 }
             }
         } elseif ($this->isPropertyFetch($expr->expr)) {
-            $left = $this->parseIdentifier($expr->var);
             $rightExpr = $tmpVar . ' = ' . $this->emitDynamicPropertyFetchRef($expr->expr, $expr);
         } elseif ($this->isStaticPropertyFetch($expr->expr)) {
-            $left = $this->parseIdentifier($expr->var);
             $rightExpr = $tmpVar . ' = ' . $this->emitStaticPropertyFetchRef($expr->expr, $expr);
         } elseif ($this->isArrayDimFetch($expr->expr)) {
-            $left = $this->parseIdentifier($expr->var);
             $array = $this->parseWritableIdentifier($expr->expr->var);
             if ($expr->expr->dim == null) {
                 $this->fatalError($expr, 'Cannot assign reference to array dim fetch without dim');

src/Preprocessor.php

@@ -321,6 +321,8 @@ class Preprocessor extends CompilerBase
                 case 'Stmt_Interface':
                     $this->parseInterface($v2);
                     break;
+                case 'Stmt_Nop':
+                    break;
                 default:
                     $this->foundStrayCode($v2);
                     break;
@@ -542,6 +544,9 @@ class Preprocessor extends CompilerBase
         }
         $functionDef->exported = !($this->classDef?->exported === false || $this->hasNoExportAttribute($v));
         $functionDef->returnClass = $class;
+        $functionDef->returnTypeStr = $v->returnType === null
+            ? ''
+            : $this->typeCheckNodeToString($v->returnType);
         // Record late-bound return type keywords so they can be re-resolved to
         // the consuming class when a trait method is flattened into a class.
         $functionDef->returnTypeKeyword = $returnTypeKeyword;
@@ -560,7 +565,6 @@ class Preprocessor extends CompilerBase
             $typeInfo = $this->buildTypeCheckFromNode($v->returnType);
             if (!empty($typeInfo['check'])) {
                 $functionDef->returnTypeCheck = $typeInfo['check'];
-                $functionDef->returnTypeStr = $typeInfo['typeStr'];
                 $functionDef->returnTypeNode = $v->returnType;
             }
         }

src/Translator.php

@@ -2514,6 +2514,8 @@ CODE;
                 case 'Stmt_Interface':
                     $this->validateInterfaceOverrideAttributes($v2);
                     break;
+                case 'Stmt_Nop':
+                    break;
                 default:
                     abort($v2);
                     break;
@@ -3624,7 +3626,12 @@ CODE;
             ));
         }
 
-        if (!$this->isReturnTypeOverrideCompatible($childFuncDef, $parentFuncDef)) {
+        if (!$this->isReturnTypeOverrideCompatible(
+            $childFuncDef,
+            $parentFuncDef,
+            $className,
+            $parentClass,
+        )) {
             $this->fatalMethodOverrideIncompatible($v, $className, $methodName, $parentClass);
         }
         if ($childFuncDef->returnsByRef !== $parentFuncDef->returnsByRef) {
@@ -3709,33 +3716,176 @@ CODE;
         ));
     }
 
-    private function isReturnTypeOverrideCompatible(FunctionDef $childFuncDef, FunctionDef $parentFuncDef): bool
-    {
+    private function isReturnTypeOverrideCompatible(
+        FunctionDef $childFuncDef,
+        FunctionDef $parentFuncDef,
+        string $childClass,
+        string $parentClass,
+    ): bool {
         if ($parentFuncDef->returnTypeUndeclared) {
             return true;
         }
         if ($childFuncDef->returnTypeUndeclared) {
             return false;
         }
-        if ($parentFuncDef->returnTypeCheck || $childFuncDef->returnTypeCheck) {
-            return $parentFuncDef->returnTypeStr === $childFuncDef->returnTypeStr;
+
+        $parentTypes = $this->getReturnAcceptedTypes($parentFuncDef, $parentClass);
+        $childTypes = $this->getReturnAcceptedTypes($childFuncDef, $childClass);
+
+        // Type checks are stored in disjunctive normal form: the outer list is
+        // a union, while an allOf entry is an intersection. Every child union
+        // branch must imply at least one complete parent branch.
+        foreach ($childTypes as $childType) {
+            if (!$this->isReturnTypeCoveredBy($childType, $parentTypes)) {
+                return false;
+            }
         }
-        if ($parentFuncDef->returnType === Type::VAR) {
-            return true;
+        return true;
+    }
+
+    private function getReturnAcceptedTypes(FunctionDef $functionDef, string $declaringClass): array
+    {
+        $returnTypeCheck = $functionDef->generator
+            ? $functionDef->declaredReturnTypeCheck
+            : $functionDef->returnTypeCheck;
+        $returnType = $functionDef->generator
+            ? $functionDef->declaredReturnType
+            : $functionDef->returnType;
+        $returnClass = $functionDef->generator
+            ? $functionDef->declaredReturnClass
+            : $functionDef->returnClass;
+        $returnTypeStr = $functionDef->generator
+            ? $functionDef->declaredReturnTypeStr
+            : $functionDef->returnTypeStr;
+
+        if (!empty($returnTypeCheck)) {
+            return array_map(
+                fn (array $type): array => $this->normalizeReturnTypeEntry($type, $declaringClass),
+                $returnTypeCheck,
+            );
         }
-        if ($childFuncDef->returnType !== $parentFuncDef->returnType) {
-            return false;
+
+        if ($functionDef->returnTypeKeyword === 'static') {
+            return [['kind' => 'isStatic', 'class' => $declaringClass]];
+        }
+        if ($returnType === Type::OBJECT && $returnClass !== '') {
+            return [['kind' => 'instanceof', 'class' => $returnClass]];
+        }
+
+        $declaredType = strtolower($returnTypeStr);
+        return match ($declaredType) {
+            'mixed' => [['kind' => 'isMixed']],
+            'never' => [['kind' => 'isNever']],
+            'void' => [['kind' => 'isVoid']],
+            'null' => [['kind' => 'isNull']],
+            'true' => [['kind' => 'isTrue']],
+            'false' => [['kind' => 'isFalse']],
+            'callable' => [['kind' => 'callable']],
+            'iterable' => [['kind' => 'iterable']],
+            'object' => [['kind' => 'isObject']],
+            default => match ($returnType) {
+                Type::INT => [['kind' => 'isInt']],
+                Type::FLOAT => [['kind' => 'isFloat']],
+                Type::BOOL => [['kind' => 'isBool']],
+                Type::STR => [['kind' => 'isString']],
+                Type::ARRAY => [['kind' => 'isArray']],
+                Type::RESOURCE => [['kind' => 'isResource']],
+                Type::OBJECT => [['kind' => 'isObject']],
+                default => [['kind' => 'isMixed']],
+            },
+        };
+    }
+
+    private function normalizeReturnTypeEntry(array $type, string $declaringClass): array
+    {
+        if (($type['kind'] ?? null) === 'allOf') {
+            $type['types'] = array_map(
+                fn (array $member): array => $this->normalizeReturnTypeEntry($member, $declaringClass),
+                $type['types'],
+            );
+        } elseif (($type['kind'] ?? null) === 'instanceof' && ($type['class'] ?? null) === 'static') {
+            $type = ['kind' => 'isStatic', 'class' => $declaringClass];
+        }
+        return $type;
+    }
+
+    private function isReturnTypeCoveredBy(array $childType, array $parentTypes): bool
+    {
+        $childClause = ($childType['kind'] ?? null) === 'allOf'
+            ? $childType['types']
+            : [$childType];
+
+        foreach ($parentTypes as $parentType) {
+            $parentClause = ($parentType['kind'] ?? null) === 'allOf'
+                ? $parentType['types']
+                : [$parentType];
+            if ($this->isReturnTypeClauseSubtype($childClause, $parentClause)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private function isReturnTypeClauseSubtype(array $childClause, array $parentClause): bool
+    {
+        foreach ($parentClause as $parentType) {
+            $covered = false;
+            foreach ($childClause as $childType) {
+                if ($this->isReturnTypeEntryCompatible($childType, $parentType)) {
+                    $covered = true;
+                    break;
+                }
+            }
+            if (!$covered) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private function isReturnTypeEntryCompatible(array $childType, array $parentType): bool
+    {
+        $childKind = $childType['kind'] ?? null;
+        $parentKind = $parentType['kind'] ?? null;
+
+        if ($childKind === 'isNever' || $parentKind === 'isMixed') {
+            return true;
         }
-        if ($parentFuncDef->returnType !== Type::OBJECT) {
+        if (($childKind === 'isTrue' || $childKind === 'isFalse') && $parentKind === 'isBool') {
             return true;
         }
-        if ($childFuncDef->returnClass === $parentFuncDef->returnClass) {
+        if ($childKind === 'isArray' && $parentKind === 'iterable') {
             return true;
         }
-        if (!$childFuncDef->returnClass || !$parentFuncDef->returnClass) {
+        if ($childKind === 'isStatic') {
+            if ($parentKind === 'isObject' || $parentKind === 'isStatic') {
+                return true;
+            }
+            if ($parentKind === 'instanceof') {
+                return $this->isInheritedFrom(
+                    $childType['class'] ?? '',
+                    $parentType['class'] ?? '',
+                );
+            }
+            return false;
+        }
+        if ($childKind === 'instanceof') {
+            if ($parentKind === 'isObject') {
+                return true;
+            }
+            $childClass = $childType['class'] ?? '';
+            if ($parentKind === 'iterable') {
+                return $childClass !== '' && $this->isInheritedFrom($childClass, 'Traversable');
+            }
+            if ($parentKind === 'instanceof') {
+                $parentClass = $parentType['class'] ?? '';
+                return $childClass !== ''
+                    && $parentClass !== ''
+                    && $this->isInheritedFrom($childClass, $parentClass);
+            }
             return false;
         }
-        return $this->isInheritedFrom($childFuncDef->returnClass, $parentFuncDef->returnClass);
+        return $childKind !== null && $childKind === $parentKind;
     }
 
     private function isParameterTypeOverrideCompatible(ArgInfo $childArg, ArgInfo $parentArg): bool

src/gen_stub.php

@@ -834,7 +834,10 @@ class ArgInfo {
 
     private function getDefaultValueAsArginfoString(): string {
         if ($this->hasProperDefaultValue()) {
-            return '"' . addslashes($this->defaultValue) . '"';
+            // The default value is a PHP expression embedded in a C string.
+            // Escape for the outer C layer only; addslashes() leaves line
+            // breaks and other control bytes untouched, producing invalid C++.
+            return '"' . getTranslator()->escapeString($this->defaultValue) . '"';
         }
 
         return "NULL";
@@ -2488,7 +2491,9 @@ class EvaluatedValue
                 if ($forStringDef === '') {
                     $forStringDef = "{$zvalName}_str";
                 }
-                $code .= "\tzend_string *$forStringDef = zend_string_init($cExpr, strlen($cExpr), 1);\n";
+                // getCExpr() emits a C string literal here. sizeof() preserves
+                // embedded NUL bytes, unlike strlen().
+                $code .= "\tzend_string *$forStringDef = zend_string_init($cExpr, sizeof($cExpr) - 1, 1);\n";
                 $code .= "\tZVAL_STR(&$zvalName, $forStringDef);\n";
             }
         } elseif ($this->type->isArray()) {
@@ -2518,14 +2523,12 @@ class EvaluatedValue
                 return '"' . getTranslator()->escapeString((string) $this->value) . '"';
             } elseif ($this->expr instanceof Expr\ConstFetch) {
                 return getTranslator()->getConstValue($this->expr->name->toString());
-            } elseif (!($this->expr instanceof String_)) {
-                // ConstExprEvaluator has already reduced concatenations and
-                // other constant string expressions to their PHP value. Emit
-                // that value as a C string literal instead of rejecting every
-                // non-literal string expression.
-                return '"' . getTranslator()->escapeString((string) $this->value) . '"';
             }
-            $expr = preg_replace("/(^'|'$)/", '"', getTranslator()->escapeString($expr));
+
+            // ConstExprEvaluator has already decoded literal syntax and
+            // reduced constant string expressions. Emitting that value avoids
+            // leaking heredoc/nowdoc source syntax into generated C++.
+            return '"' . getTranslator()->escapeString((string) $this->value) . '"';
         } elseif ($this->type->isInt() or $this->type->isFloat()) {
             return strval($this->value);
         } elseif ($this->type->isBool()) {
@@ -5110,6 +5113,10 @@ function parseFunctionLike(
             if ($param->default instanceof Expr\ClassConstFetch && $param->default->class->toLowerString() === "self") {
                 $defaultValue = getTranslator()->getClassConstValue($func, $name->className->name, $param->default->name->name);
                 $defaultValue = var_export($defaultValue, true);
+            } elseif ($param->default instanceof String_) {
+                // Keep this as a PHP expression. ArgInfo escapes the expression
+                // separately when embedding it in generated C++.
+                $defaultValue = var_export($param->default->value, true);
             } else {
                 $defaultValue = $param->default ? $prettyPrinter->prettyPrintExpr($param->default) : null;
             }

tests/compiler/class/interface-return-covariance.phpt

@@ -0,0 +1,47 @@
+--TEST--
+Interface return type covariance with nullable interface and anonymous class
+--FILE--
+<?php
+
+declare(strict_types=1);
+
+interface TestInterface1
+{
+}
+
+interface TestInterface2 extends TestInterface1
+{
+}
+
+interface TestInterface3
+{
+    public function test(): ?TestInterface1;
+}
+
+class TestClass implements TestInterface3
+{
+    // Covariant: ?TestInterface2 is a subtype of ?TestInterface1 because
+    // TestInterface2 extends TestInterface1.
+    public function test(): ?TestInterface2
+    {
+        return new class() implements TestInterface2 {
+            public function hello(): string {
+                return "anon";
+            }
+        };
+    }
+}
+
+function main()
+{
+    $test = new TestClass;
+    $result = $test->test();
+    var_dump($result instanceof TestInterface1);
+    var_dump($result instanceof TestInterface2);
+    var_dump($result === null);
+}
+?>
+--EXPECT--
+bool(true)
+bool(true)
+bool(false)

tests/compiler/const/class-const-default-value-typed.phpt

@@ -0,0 +1,30 @@
+--TEST--
+Typed parameter default value from an unresolvable (external) class constant
+--FILE--
+<?php
+
+class TypedDefault
+{
+    public function run(
+        int $value = \ArrayObject::ARRAY_AS_PROPS,
+        float $floatValue = \ArrayObject::ARRAY_AS_PROPS,
+        string $format = \DateTime::ATOM,
+        int $composite = 1 | \ArrayObject::ARRAY_AS_PROPS,
+        mixed $variant = \ArrayObject::STD_PROP_LIST,
+    )
+    {
+        var_dump($value, $floatValue, $format, $composite, $variant);
+    }
+}
+
+function main()
+{
+    (new TypedDefault)->run();
+}
+?>
+--EXPECT--
+int(2)
+float(2)
+string(13) "Y-m-d\TH:i:sP"
+int(3)
+int(1)

tests/compiler/const/class-const-heredoc-nowdoc.phpt

@@ -0,0 +1,23 @@
+--TEST--
+class constants with heredoc and nowdoc syntax
+--FILE--
+<?php
+
+class Test
+{
+    const VALUE1 = <<<ABC
+    quote " slash \\ nul \0 tab \t ??
+    ABC;
+    const VALUE2 = <<<'DEF'
+    $value ?? "quoted" \n \path
+    DEF;
+}
+
+function main()
+{
+    var_dump(bin2hex(Test::VALUE1), bin2hex(Test::VALUE2));
+}
+?>
+--EXPECT--
+string(60) "71756f7465202220736c617368205c206e756c2000207461622009203f3f"
+string(54) "2476616c7565203f3f202271756f74656422205c6e205c70617468"

tests/compiler/const/heredoc-nowdoc-const-defaults.phpt

@@ -0,0 +1,51 @@
+--TEST--
+global constants, property defaults and parameter defaults with heredoc/nowdoc syntax
+--FILE--
+<?php
+
+const G_HEREDOC = <<<ABC
+    abc
+    ABC;
+const G_NOWDOC = <<<'DEF'
+    def
+    DEF;
+
+class WithProp
+{
+    public string $p = <<<ABC
+    xyz
+    ABC;
+}
+
+function with_default(string $x = <<<'ABC'
+$value ?? "quoted" \n \path
+ABC): string {
+    return $x;
+}
+
+function with_binary_default(string $x = <<<ABC
+A\0B
+ABC): string {
+    return $x;
+}
+
+function main()
+{
+    var_dump(G_HEREDOC, G_NOWDOC);
+    $o = new WithProp();
+    var_dump($o->p);
+    var_dump(bin2hex(with_default()), bin2hex(with_binary_default()));
+
+    $default = (new ReflectionFunction('with_default'))->getParameters()[0]->getDefaultValue();
+    $binaryDefault = (new ReflectionFunction('with_binary_default'))->getParameters()[0]->getDefaultValue();
+    var_dump(bin2hex($default), bin2hex($binaryDefault));
+}
+?>
+--EXPECT--
+string(3) "abc"
+string(3) "def"
+string(3) "xyz"
+string(54) "2476616c7565203f3f202271756f74656422205c6e205c70617468"
+string(6) "410042"
+string(54) "2476616c7565203f3f202271756f74656422205c6e205c70617468"
+string(6) "410042"

tests/compiler/generator/generator-foreach-yield.phpt

@@ -0,0 +1,57 @@
+--TEST--
+generator re-yielding array elements via foreach with \Generator return type
+--FILE--
+<?php
+
+function main()
+{
+    $g = test([1, 2, 3]);
+    var_dump($g);
+    foreach ($g as $value)
+    {
+        var_dump($value);
+    }
+}
+
+function test(array $array): \Generator
+{
+    foreach ($array as $value)
+    {
+        yield $value;
+    }
+}
+
+// main();
+?>
+--EXPECTF--
+object(FiberGenerator)#%d (9) {
+  ["callback":"FiberGenerator":private]=>
+  object(Closure)#%d (2) {
+    ["function"]=>
+    string(19) "stdClass::{closure}"
+    ["this"]=>
+    object(stdClass)#%d (1) {
+      ["box"]=>
+      resource(%d) of type (php::box)
+    }
+  }
+  ["fiber":"FiberGenerator":private]=>
+  NULL
+  ["current":"FiberGenerator":private]=>
+  NULL
+  ["key":"FiberGenerator":private]=>
+  NULL
+  ["valid":"FiberGenerator":private]=>
+  bool(false)
+  ["state":"FiberGenerator":private]=>
+  int(0)
+  ["yield_count":"FiberGenerator":private]=>
+  int(0)
+  ["next_index":"FiberGenerator":private]=>
+  int(0)
+  ["return_value":"FiberGenerator":private]=>
+  NULL
+}
+int(1)
+int(2)
+int(3)

tests/compiler/generator/generator-return-type-generator.phpt

@@ -0,0 +1,53 @@
+--TEST--
+generator return type accepts \Generator for methods, nullable and union variants
+--FILE--
+<?php
+
+class Box
+{
+    public function gen(array $array): \Generator
+    {
+        foreach ($array as $value) {
+            yield $value * 2;
+        }
+    }
+}
+
+function nullableGen(array $array): ?\Generator
+{
+    foreach ($array as $value) {
+        yield $value;
+    }
+}
+
+function unionGen(array $array): \Generator|\Iterator
+{
+    foreach ($array as $value) {
+        yield $value;
+    }
+}
+
+function main()
+{
+    $b = new Box();
+    foreach ($b->gen([1, 2, 3]) as $v) {
+        var_dump($v);
+    }
+    $g = nullableGen([4, 5]);
+    foreach ($g as $v) {
+        var_dump($v);
+    }
+    $u = unionGen([6, 7]);
+    foreach ($u as $v) {
+        var_dump($v);
+    }
+}
+?>
+--EXPECT--
+int(2)
+int(4)
+int(6)
+int(4)
+int(5)
+int(6)
+int(7)

tests/compiler/generator/interface-return-type-variants.phpt

@@ -0,0 +1,96 @@
+--TEST--
+generator methods implementing interfaces with iterable, nullable and union return types
+--FILE--
+<?php
+interface GenInterface
+{
+    public function gen(array $array): \Generator;
+}
+
+interface IterableInterface
+{
+    public function it(array $array): iterable;
+
+    public function narrowed(array $array): iterable;
+}
+
+interface NullableInterface
+{
+    public function nullable(array $array): ?\Generator;
+}
+
+interface UnionInterface
+{
+    public function union(array $array): \Generator|\Iterator;
+}
+
+class Box implements GenInterface, IterableInterface, NullableInterface, UnionInterface
+{
+    public function gen(array $array): \Generator
+    {
+        foreach ($array as $value) {
+            yield $value * 2;
+        }
+    }
+
+    public function it(array $array): iterable
+    {
+        foreach ($array as $value) {
+            yield $value;
+        }
+    }
+
+    public function narrowed(array $array): \Generator
+    {
+        foreach ($array as $value) {
+            yield $value;
+        }
+    }
+
+    public function nullable(array $array): ?\Generator
+    {
+        foreach ($array as $value) {
+            yield $value;
+        }
+    }
+
+    public function union(array $array): \Generator|\Iterator
+    {
+        foreach ($array as $value) {
+            yield $value;
+        }
+    }
+}
+
+function main()
+{
+    $box = new Box();
+    foreach ($box->gen([1, 2, 3]) as $v) {
+        var_dump($v);
+    }
+    foreach ($box->it([4, 5]) as $v) {
+        var_dump($v);
+    }
+    foreach ($box->narrowed([10, 11]) as $v) {
+        var_dump($v);
+    }
+    foreach ($box->nullable([6, 7]) as $v) {
+        var_dump($v);
+    }
+    foreach ($box->union([8, 9]) as $v) {
+        var_dump($v);
+    }
+}
+?>
+--EXPECT--
+int(2)
+int(4)
+int(6)
+int(4)
+int(5)
+int(10)
+int(11)
+int(6)
+int(7)
+int(8)
+int(9)

tests/compiler/generator/interface-return-type.phpt

@@ -0,0 +1,38 @@
+--TEST--
+generator method implementing an interface that declares \Generator return type
+--FILE--
+<?php
+interface T
+{
+    public function test(array $array): \Generator;
+}
+
+class TestClass implements T
+{
+    public function test(array $array): \Generator
+    {
+        foreach ($array as $value) {
+            yield $value;
+        }
+    }
+}
+
+function main()
+{
+    $test = new TestClass;
+    $g = $test->test([1, 2, 3]);
+    // TypePHP generators return a \FiberGenerator which implements Iterator
+    // but is NOT the Zend \Generator class.
+    var_dump($g instanceof \Generator);
+    var_dump($g instanceof \Iterator);
+    foreach ($g as $value) {
+        var_dump($value);
+    }
+}
+?>
+--EXPECT--
+bool(false)
+bool(true)
+int(1)
+int(2)
+int(3)

tests/compiler/namespace/namespace-ending-comment.phpt

@@ -0,0 +1,22 @@
+--TEST--
+A namespace block ending with a comment must not be treated as stray code
+--FILE--
+<?php
+
+declare(strict_types=1);
+
+namespace Test {
+    /* named namespace trailing block comment */
+}
+
+namespace {
+    function main()
+    {
+        var_dump('done');
+    }
+
+    // global namespace trailing line comment
+}
+?>
+--EXPECT--
+string(4) "done"

tests/compiler/object_ctor/ctor-visibility-protected-subclass.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Constructor visibility - protected constructor accessible from subclass
+--FILE--
+<?php
+
+class Base
+{
+    protected function __construct(){}
+}
+
+class Sub extends Base
+{
+    public static function make(): Base
+    {
+        return new Base();
+    }
+}
+
+function main()
+{
+    $obj = Sub::make();
+    var_dump($obj instanceof Base);
+}
+?>
+--EXPECT--
+bool(true)

tests/compiler/ref/array-ref-assign-001.phpt

@@ -0,0 +1,29 @@
+--TEST--
+array reference assignment: append and element assignment write back through reference
+--FILE--
+<?php
+function main()
+{
+    $arr1 = [1, 2, 3];
+    $arr2 = [&$arr1[0]];
+    $arr2[0] = 123;
+    $arr2[] = &$arr1[1];
+    $arr2[1] = 456;
+    var_dump($arr1, $arr2);
+}
+?>
+--EXPECT--
+array(3) {
+  [0]=>
+  &int(123)
+  [1]=>
+  &int(456)
+  [2]=>
+  int(3)
+}
+array(2) {
+  [0]=>
+  &int(123)
+  [1]=>
+  &int(456)
+}

tests/compiler/ref/array-ref-assign-002.phpt

@@ -0,0 +1,51 @@
+--TEST--
+array reference assignment to element: $arr[$k] = &$v writes back through reference
+--FILE--
+<?php
+class RefSource
+{
+    public $value = 30;
+    public static $staticValue = 40;
+}
+
+function main()
+{
+    $x = 10;
+    $y = 20;
+    $arr = [1, 2, 3];
+    $arr[0] = &$x;   // 覆盖已有元素为引用
+    $arr[5] = &$y;   // 新建元素为引用
+    $x = 100;
+    $y = 200;
+    var_dump($arr[0], $arr[5]); // 100, 200
+
+    // 通过元素引用写回
+    $arr[0] = 111;
+    $arr[5] = 222;
+    var_dump($x, $y); // 111, 222
+
+    // 嵌套：引用赋值到多维数组元素
+    $z = 7;
+    $m = [[1], [2]];
+    $m[0][0] = &$z;
+    $z = 77;
+    var_dump($m[0][0]); // 77
+
+    // 左侧数组追加/元素写入不可因右侧是属性引用而被重新按读取解析
+    $source = new RefSource();
+    $propertyRefs = [];
+    $propertyRefs[] = &$source->value;
+    $propertyRefs[2] = &RefSource::$staticValue;
+    $propertyRefs[0] = 333;
+    $propertyRefs[2] = 444;
+    var_dump($source->value, RefSource::$staticValue);
+}
+?>
+--EXPECT--
+int(100)
+int(200)
+int(111)
+int(222)
+int(77)
+int(333)
+int(444)

tests/compiler/ref/array-ref-assign-003.phpt

@@ -0,0 +1,37 @@
+--TEST--
+dynamically typed array element assignment preserves references and ArrayAccess writes
+--FILE--
+<?php
+function writeElement(mixed $container, mixed $key, mixed $value): void
+{
+    $container[$key] = $value;
+}
+
+function writeReferencedContainer(mixed &$container, mixed $value): void
+{
+    $container[0] = $value;
+}
+
+function main()
+{
+    $referenced = 10;
+    $array = [&$referenced];
+    writeElement($array, 0, 123);
+    var_dump($referenced, $array[0]);
+
+    $referencedAgain = 20;
+    $arrayByReference = [&$referencedAgain];
+    writeReferencedContainer($arrayByReference, 234);
+    var_dump($referencedAgain, $arrayByReference[0]);
+
+    $object = new ArrayObject();
+    writeElement($object, 'key', 456);
+    var_dump($object['key']);
+}
+?>
+--EXPECT--
+int(123)
+int(123)
+int(234)
+int(234)
+int(456)

tests/compiler/trait/trait-ctor-basic.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Trait __construct is used by the composing class
+--FILE--
+<?php
+
+declare(strict_types=1);
+
+trait TestTrait
+{
+    public function __construct()
+    {
+        echo "trait ctor\n";
+    }
+}
+
+class TestClass
+{
+    use TestTrait;
+}
+
+function main()
+{
+    new TestClass();
+}
+?>
+--EXPECT--
+trait ctor

tests/compiler/trait/trait-ctor-override.phpt

@@ -0,0 +1,32 @@
+--TEST--
+Class __construct overrides the one provided by a trait
+--FILE--
+<?php
+
+declare(strict_types=1);
+
+trait TestTrait
+{
+    public function __construct()
+    {
+        echo "trait ctor\n";
+    }
+}
+
+class TestClass
+{
+    use TestTrait;
+
+    public function __construct()
+    {
+        echo "class ctor\n";
+    }
+}
+
+function main()
+{
+    new TestClass();
+}
+?>
+--EXPECT--
+class ctor

tests/compiler/trait/trait-ctor-protected-subclass.phpt

@@ -0,0 +1,37 @@
+--TEST--
+Trait protected __construct is accessible from a subclass
+--FILE--
+<?php
+
+declare(strict_types=1);
+
+trait TestTrait
+{
+    protected function __construct()
+    {
+        echo "base ctor\n";
+    }
+}
+
+class BaseClass
+{
+    use TestTrait;
+}
+
+class SubClass extends BaseClass
+{
+    public function __construct()
+    {
+        new BaseClass();
+        echo "sub ctor\n";
+    }
+}
+
+function main()
+{
+    new SubClass();
+}
+?>
+--EXPECT--
+base ctor
+sub ctor

tests/compiler/trait/trait-ctor-with-args.phpt

@@ -0,0 +1,30 @@
+--TEST--
+Trait __construct with arguments and $this property access
+--FILE--
+<?php
+
+declare(strict_types=1);
+
+trait TestTrait
+{
+    private int $value = 0;
+
+    public function __construct(int $value)
+    {
+        $this->value = $value;
+        echo "value=" . $this->value . "\n";
+    }
+}
+
+class TestClass
+{
+    use TestTrait;
+}
+
+function main()
+{
+    new TestClass(42);
+}
+?>
+--EXPECT--
+value=42

tests/compiler/type_decl/return-type-covariance.phpt

@@ -0,0 +1,120 @@
+--TEST--
+Return type covariance: union narrowing and object subtype
+--FILE--
+<?php
+
+interface UnionReturnContract
+{
+    public function make(): int|string;
+}
+
+class UnionReturnImpl implements UnionReturnContract
+{
+    // Covariant: narrowing a union return type (int|string -> int) is allowed.
+    public function make(): int
+    {
+        return 42;
+    }
+}
+
+class BaseType {}
+class ChildType extends BaseType {}
+
+interface ObjectReturnContract
+{
+    public function build(): BaseType;
+}
+
+class ObjectReturnImpl implements ObjectReturnContract
+{
+    // Covariant: returning a subtype (ChildType) for a BaseType return is allowed.
+    public function build(): ChildType
+    {
+        return new ChildType();
+    }
+}
+
+class StaticBase
+{
+    public function copy(): ?self
+    {
+        return $this;
+    }
+}
+
+class StaticChild extends StaticBase
+{
+    public function copy(): ?static
+    {
+        return $this;
+    }
+}
+
+interface IterableContract
+{
+    public function values(): iterable;
+}
+
+class IterableImpl implements IterableContract
+{
+    public function values(): array
+    {
+        return [1, 2];
+    }
+}
+
+interface BoolContract
+{
+    public function enabled(): bool;
+}
+
+class LiteralBoolImpl implements BoolContract
+{
+    public function enabled(): true
+    {
+        return true;
+    }
+}
+
+abstract class VoidContract
+{
+    abstract public function stop(): void;
+}
+
+abstract class NeverImpl extends VoidContract
+{
+    public function stop(): never
+    {
+        throw new RuntimeException('stop');
+    }
+}
+
+function main()
+{
+    $impl = new UnionReturnImpl();
+    var_dump($impl->make());
+
+    $obj = new ObjectReturnImpl();
+    $built = $obj->build();
+    var_dump($built instanceof BaseType);
+    var_dump($built instanceof ChildType);
+
+    $static = new StaticChild();
+    var_dump($static->copy() instanceof StaticChild);
+
+    var_dump((new IterableImpl())->values());
+    var_dump((new LiteralBoolImpl())->enabled());
+}
+?>
+--EXPECT--
+int(42)
+bool(true)
+bool(true)
+bool(true)
+array(2) {
+  [0]=>
+  int(1)
+  [1]=>
+  int(2)
+}
+bool(true)