fix(compiler): preserve trait parent scope

phpunit/code/trait-method-override-final.php

@@ -0,0 +1,24 @@
+<?php
+
+trait FinalOverrideTrait
+{
+    public function execute(): void
+    {
+    }
+}
+
+class FinalMethodParent
+{
+    final public function execute(): void
+    {
+    }
+}
+
+class FinalMethodChild extends FinalMethodParent
+{
+    use FinalOverrideTrait;
+}
+
+function main(): void
+{
+}

phpunit/code/trait-method-shadows-private.php

@@ -0,0 +1,27 @@
+<?php
+
+trait PrivateShadowTrait
+{
+    public function execute(string $value): string
+    {
+        return $value;
+    }
+}
+
+class PrivateMethodParent
+{
+    private function execute(int $value, bool $flag): int
+    {
+        return $value;
+    }
+}
+
+class PrivateMethodChild extends PrivateMethodParent
+{
+    use PrivateShadowTrait;
+}
+
+function main(): void
+{
+    var_dump((new PrivateMethodChild())->execute('ok'));
+}

phpunit/code/trait-parent-without-parent.php

@@ -0,0 +1,18 @@
+<?php
+
+trait MissingParentTrait
+{
+    public function execute(): void
+    {
+        parent::execute();
+    }
+}
+
+class NoParentClass
+{
+    use MissingParentTrait;
+}
+
+function main(): void
+{
+}

phpunit/src/ClassTest.php

@@ -54,6 +54,11 @@ class ClassTest extends \BaseTest
         $this->exec('Cannot access private method `BaseSecret::secret()`', 'trait-parent-method-private.php');
     }
 
+    public function testTraitMethodMayShadowPrivateParentMethod()
+    {
+        $this->compile('trait-method-shadows-private.php');
+    }
+
     public function testSelfCanBePartOfUnionType()
     {
         global $translator;

phpunit/src/InheritanceErrorTest.php

@@ -325,4 +325,14 @@ class InheritanceErrorTest extends TestCase
         // runtime fatal error that the compiled binary would otherwise ignore.
         $this->exec('must be compatible', 'trait-method-override-incompatible.php');
     }
+
+    public function testTraitMethodCannotOverrideFinalParentMethod()
+    {
+        $this->exec('Cannot override final method', 'trait-method-override-final.php');
+    }
+
+    public function testTraitParentCallRequiresParentClass()
+    {
+        $this->exec('has no parent', 'trait-parent-without-parent.php');
+    }
 }

src/Generator/CallArgumentGenerator.php

@@ -348,7 +348,8 @@ trait CallArgumentGenerator
         string $funcName = '',
         string $className = '',
         bool $separateNamedArgs = true,
-        bool $forceArrayArgs = false
+        bool $forceArrayArgs = false,
+        bool $preserveExistingReferences = false
     ): string
     {
         $list_args = [];
@@ -390,7 +391,8 @@ trait CallArgumentGenerator
                     $this->fatalError($arg, "Duplicate named argument `{$arg->name->name}`");
                 }
                 $namedArgs[$arg->name->name] = true;
-                $byRef = $funcName && $this->isReferenceNamedArgument($funcName, $className, $arg->name->name);
+                $byRef = ($funcName && $this->isReferenceNamedArgument($funcName, $className, $arg->name->name))
+                    || ($preserveExistingReferences && $this->isExistingReferenceCallArg($arg));
                 $value = ($byRef || $this->isRefvalCall($arg->value) || $this->isToRefCall($arg->value))
                     ? $this->parseReferenceCallArgValue($arg)
                     : $this->parseCallArgValue($arg);
@@ -409,7 +411,8 @@ trait CallArgumentGenerator
             if ($hasUnpack) {
                 $this->fatalError($arg, 'Cannot use positional argument after argument unpacking');
             }
-            $byRef = $funcName && $this->isReferenceArgument($funcName, $className, $i);
+            $byRef = ($funcName && $this->isReferenceArgument($funcName, $className, $i))
+                || ($preserveExistingReferences && $this->isExistingReferenceCallArg($arg));
             if (($funcName === 'call_user_func' || $funcName === 'call_user_func_array') && $i === 0) {
                 $callback = $this->parseScopedCallbackArg($arg);
                 if ($callback !== null) {
@@ -499,6 +502,15 @@ trait CallArgumentGenerator
         return $namedArgsVar !== null ? $callArgs . ', ' . $namedArgsVar . '.array()' : $callArgs;
     }
 
+    private function isExistingReferenceCallArg(Node\Arg $arg): bool
+    {
+        if (!$this->isVarExpr($arg->value)) {
+            return $this->isReferenceWrapperCall($arg->value);
+        }
+        $name = $this->parseIdentifier($arg->value);
+        return $this->hasVar($name) && $this->getVarType($name) === Type::REF;
+    }
+
     protected function parseScopedCallbackArg(Node\Arg $arg): ?string
     {
         $value = $arg->value;
@@ -716,6 +728,8 @@ trait CallArgumentGenerator
         if (!$this->hasVar($name)) {
             // 若参数是引用类型，可以传入未定义变量，将立即创建变量作为引用
             $this->addLocalVar($name, Type::REF);
+        } elseif ($this->getVarType($name) === Type::REF) {
+            return '&' . $name;
         } else {
             // 本地变量，且是原生类型，则转为普通变量
             if ($this->hasLocalVar($name) and $this->isNativeType($this->getVarType($name))) {
@@ -788,4 +802,3 @@ trait CallArgumentGenerator
     }
 
 }
-

src/Parser/MethodCallTrait.php

@@ -243,11 +243,10 @@ trait MethodCallTrait
 
     protected function parseParentMethodCall(Expr\StaticCall $expr): string
     {
-        // Inside a trait, `parent::` refers to the parent of the class that
-        // *uses* the trait. That parent class is only known at runtime (a single
-        // trait may be composed into classes with different parents), so resolve
-        // it dynamically from the current object's class entry instead of the
-        // trait's own (non-existent) parent.
+        // A trait's parent scope is supplied by the wrapper generated for the
+        // class that composes it. It must not be derived from the runtime
+        // object's class: an inherited trait method is still lexically bound to
+        // the parent of the composing class, not to the runtime object's parent.
         if ($this->classDef !== null && $this->classDef->trait !== null) {
             $method = $this->isIdExpr($expr->name) ? $this->parseIdentifier($expr->name) : '';
             // Record the parent:: call so it can be validated against the parent
@@ -256,12 +255,19 @@ trait MethodCallTrait
             if ($method !== '' && isset($this->methodDef)) {
                 $this->methodDef->parentMethodCalls[] = ['method' => $method, 'node' => $expr];
             }
-            $methodPtr = 'php::getMethod(this_.parent_ce(), ' . $this->identifierToStr($expr->name) . ')';
+            $methodPtr = 'php::getMethod(trait_parent_ce, ' . $this->identifierToStr($expr->name) . ')';
             if (empty($expr->args)) {
                 return 'this_.call(' . $methodPtr . ')';
             }
-            // Parent class is unknown statically, so by-ref argument detection is skipped.
-            return 'this_.call(' . $methodPtr . ', ' . $this->parseCallArgs($expr->args, $method, '') . ')';
+            // The concrete parent signature is only known at each trait use
+            // site. Preserve arguments that are already references so forwarding
+            // a by-reference trait parameter does not silently drop its alias.
+            return 'this_.call(' . $methodPtr . ', ' . $this->parseCallArgs(
+                $expr->args,
+                $method,
+                '',
+                preserveExistingReferences: true
+            ) . ')';
         }
 
         if (!$this->classDef->extends) {

src/Translator.php

@@ -2506,8 +2506,7 @@ CODE;
 
         if ($fn->returnTypeKeyword !== '' && $methodStmt->returnType instanceof Node\Name) {
             if ($fn->returnTypeKeyword === 'static') {
-                // `static` is late-static-bound: keep the keyword so ZendVM
-                // resolves it to the concrete class at call time.
+                // `static` remains late-bound in the composed method signature.
                 $methodStmt->returnType = new Node\Name('static');
             } else {
                 $resolved = $this->resolveLateBoundClass($usingClassDef, $fn->returnTypeKeyword);
@@ -2734,7 +2733,12 @@ CODE;
         return $code;
     }
 
-    protected function genWrapperFunctionArgs(string $fn, FunctionDef $functionDef, string $displayName): string
+    protected function genWrapperFunctionArgs(
+        string $fn,
+        FunctionDef $functionDef,
+        string $displayName,
+        array $implicitMethodArgs = []
+    ): string
     {
         $cppCode = '';
         $callParams = '';
@@ -2783,7 +2787,8 @@ CODE;
         }
 
         if ($functionDef->method) {
-            $callParams = $functionDef->argInfoList ? 'this_, ' . rtrim($callParams, ',') : 'this_';
+            $methodArgs = implode(', ', array_merge(['this_'], $implicitMethodArgs));
+            $callParams = $functionDef->argInfoList ? $methodArgs . ', ' . rtrim($callParams, ',') : $methodArgs;
         } else {
             $callParams = $functionDef->argInfoList ? rtrim($callParams, ',') : '';
         }
@@ -2844,7 +2849,18 @@ CODE;
         $cppCode = 'ZEND_METHOD(' . $name . ', ' . $methodDef->name . '){' . PHP_EOL;
         $cppCode .= $this->getIndent() . Type::OBJECT . ' this_(&execute_data->This);' . PHP_EOL;
         $fn = self::PREFIX . $this->getNativeMethodName($classDef, $methodDef);
-        $cppCode .= $this->genWrapperFunctionArgs($fn, $methodDef->functionDef, $classDef->getNamespacedName(false) . '::' . $methodDef->name);
+        $implicitMethodArgs = [];
+        if ($classDef->trait !== null && $methodDef->parentMethodCalls) {
+            // Trait methods are not directly callable without a composing class,
+            // but keep the generated Zend wrapper well-formed.
+            $implicitMethodArgs[] = 'this_.parent_ce()';
+        }
+        $cppCode .= $this->genWrapperFunctionArgs(
+            $fn,
+            $methodDef->functionDef,
+            $classDef->getNamespacedName(false) . '::' . $methodDef->name,
+            $implicitMethodArgs
+        );
 
         return $cppCode;
     }
@@ -3041,6 +3057,9 @@ CODE;
         $functionDeclCode = $cppReturnType . ' ' . ($multiReturn ? $this->getMultiReturnImplName($name) : $nativeName) . '(';
         if ($this->class) {
             $functionDeclCode .= Type::OBJECT . ' &this_';
+            if ($this->classDef?->trait !== null && $this->methodDef?->parentMethodCalls) {
+                $functionDeclCode .= ', zend_class_entry *trait_parent_ce';
+            }
             if ($this->functionDef->params) {
                 $functionDeclCode .= ', ';
             }
@@ -3733,6 +3752,11 @@ CODE;
         $traitMethodNativeName = $this->getNativeName($traitMethodName, $traitDef->namespace, $traitDef->name);
         $classMethodNativeName = $this->getNativeName($classMethodName, $classDef->namespace, $classDef->name);
         $argList = ['this_'];
+        if ($methodDef->parentMethodCalls) {
+            // Bind parent:: to the class that actually composes the trait. This
+            // remains correct when the generated wrapper is inherited further.
+            $argList[] = $this->getClassEntryPtr($classDef->extends);
+        }
         foreach ($methodDef->functionDef->argInfoList as $argInfo) {
             $argList[] = $argInfo->name;
         }
@@ -3853,8 +3877,10 @@ CODE;
     private function validateTraitParentCall(ClassDef $traitDef, ClassDef $usingClassDef, string $method, NodeAbstract $node): void
     {
         if (!$usingClassDef->extends) {
-            // No parent class: cannot validate; PHP would report at runtime.
-            return;
+            $this->fatalError(
+                $node,
+                "Cannot access parent when class `{$usingClassDef->getNamespacedName(false)}` has no parent"
+            );
         }
         $parentClass = $usingClassDef->extends;
         // Internal / not-compiled parents are opaque to the compiler; let the
@@ -3895,18 +3921,33 @@ CODE;
             if (!$extends) {
                 break;
             }
-            // Internal / not-compiled parents are opaque to the compiler; let the
-            // runtime enforce compatibility for those.
-            if ($classDef->inheritedFromInternalClass || !$this->hasClass($extends)) {
+            if ($classDef->inheritedFromInternalClass) {
+                $modifiers = Reflection::getClassMethodModifiers($extends, $methodName);
+                if ($modifiers !== null && ($modifiers & \ReflectionMethod::IS_FINAL)) {
+                    $this->fatalError($methodDef->node, "Cannot override final method `{$extends}::{$methodName}()`");
+                }
+                break;
+            }
+            // Dynamically supplied parents are opaque to the compiler.
+            if (!$this->hasClass($extends)) {
                 break;
             }
             $classDef = $this->getClass($extends);
             if ($classDef->hasMethod($methodName)) {
+                $parentMethodDef = $classDef->getMethod($methodName);
+                // A private method is a separate slot and may be shadowed by the
+                // method imported from the trait.
+                if ($parentMethodDef->flags & Modifiers::PRIVATE) {
+                    break;
+                }
+                if ($parentMethodDef->flags & Modifiers::FINAL) {
+                    $this->fatalError($methodDef->node, "Cannot override final method `{$extends}::{$methodName}()`");
+                }
                 $this->validateMethodOverrideSignature(
                     $methodDef->node,
                     $methodName,
                     $methodDef,
-                    $classDef->getMethod($methodName),
+                    $parentMethodDef,
                     $extends
                 );
                 break;

tests/compiler/trait/trait-parent-method-inherited.phpt

@@ -0,0 +1,52 @@
+--TEST--
+Trait parent:: call remains bound to the composing class when inherited
+--FILE--
+<?php
+
+trait ParentCallTrait
+{
+    public function source(): string
+    {
+        return parent::source();
+    }
+}
+
+class RootClass
+{
+    public function source(): string
+    {
+        return 'root';
+    }
+}
+
+class TraitUser extends RootClass
+{
+    use ParentCallTrait;
+}
+
+class ChildClass extends TraitUser
+{
+}
+
+class OtherRootClass
+{
+    public function source(): string
+    {
+        return 'other';
+    }
+}
+
+class OtherTraitUser extends OtherRootClass
+{
+    use ParentCallTrait;
+}
+
+function main(): void
+{
+    var_dump((new ChildClass())->source());
+    var_dump((new OtherTraitUser())->source());
+}
+?>
+--EXPECT--
+string(4) "root"
+string(5) "other"

tests/compiler/trait/trait-parent-method-reference.phpt

@@ -0,0 +1,36 @@
+--TEST--
+Trait parent:: call forwards an existing reference parameter
+--FILE--
+<?php
+
+trait ParentReferenceTrait
+{
+    public function update(string &$value): void
+    {
+        parent::update($value);
+    }
+}
+
+class ReferenceParent
+{
+    public function update(string &$value): void
+    {
+        $value = 'updated';
+    }
+}
+
+class ReferenceChild extends ReferenceParent
+{
+    use ParentReferenceTrait;
+}
+
+function main(): void
+{
+    $value = 'initial';
+    $child = new ReferenceChild();
+    $child->update($value);
+    var_dump($value);
+}
+?>
+--EXPECT--
+string(7) "updated"