PurHur · PurHur · Jul 25, 2026 · Jul 25, 2026
diff --git a/ext/standard/VmReflection.php b/ext/standard/VmReflection.php
@@ -2981,9 +2981,12 @@ public static function propertyReflectionModifiers(
             $modifiers |= self::REFLECTION_IS_READONLY;
         }
         // php-src prop->flags & ZEND_ACC_FINAL → ReflectionProperty::IS_FINAL (#22341).
-        if (null !== $instance && $instance->propertyFinal) {
-            $modifiers |= self::REFLECTION_IS_FINAL;
-        } elseif (self::propertyIsFinalFromHookRegistry($entry, $property, $ctx)) {
+        // private(set) is implicitly final (zend_API.c, #23068).
+        if (
+            (null !== $instance && $instance->propertyFinal)
+            || self::propertyIsFinalFromHookRegistry($entry, $property, $ctx)
+            || \PHPCompiler\PropertyVisibility::isImplicitlyFinalFromPrivateSet($meta['setVisibility'])
+        ) {
             $modifiers |= self::REFLECTION_IS_FINAL;
         }
 

diff --git a/lib/Compiler.php b/lib/Compiler.php
@@ -7484,8 +7484,13 @@ protected function compileClassBody(CfgBlock $block, int $type, ?string $classNa
                             || $this->isReadonlyPropertyFlags($child->visibility);
                         $declare->propertyLazy = (property_exists($child, 'propertyLazy') && $child->propertyLazy)
                             || LazyPropertyRewriter::isLazyFromAttributes($child->getAttributes());
-                        $declare->propertyFinal = $this->isFinalPropertyDeclaration($child);
-                        if ($declare->propertyFinal && !CompilerVersion::supportsFinalProperties()) {
+                        // Explicit `final` vs implicit from private(set) (zend_API.c, #23068).
+                        $explicitFinal = $this->isFinalPropertyDeclaration($child);
+                        $declare->propertyFinal = $explicitFinal
+                            || PropertyVisibility::isImplicitlyFinalFromPrivateSet(
+                                (int) $declare->propertySetVisibility
+                            );
+                        if ($explicitFinal && !CompilerVersion::supportsFinalProperties()) {
                             // php-src Zend/zend_compile.c — pre-8.4 (#22308, re-#22241).
                             $classDisplay = $this->compilingClassDisplayName ?? '{unknown}';
                             $this->throwCompileError(sprintf(
@@ -8207,9 +8212,16 @@ protected function compilePromotedPropertyDeclaration(Op\Expr\Param $param, Bloc
             $typeSlot
         );
         $declare->propertyReadonly = $this->isPromotedParamReadonly($param);
-        $declare->propertyFinal = FinalPromotedPropertyRewriter::isFinalFromAttributes($param->getAttributes())
+        $declare->propertyFromConstructorPromotion = true;
+        $declare->propertyVisibility = MethodVisibility::mask($param->promotionFlags);
+        $declare->propertySetVisibility = $this->asymmetricSetVisibilityFromCfgOp($param);
+        $declare->propertyGetVisibility = $this->asymmetricGetVisibilityFromCfgOp($param);
+        $explicitFinal = FinalPromotedPropertyRewriter::isFinalFromAttributes($param->getAttributes())
             || (property_exists($param, 'promotionFinal') && $param->promotionFinal);
-        if ($declare->propertyFinal && !CompilerVersion::supportsFinalProperties()) {
+        // php-src zend_API.c — private(set) promoted props are implicitly final (#23068).
+        $declare->propertyFinal = $explicitFinal
+            || PropertyVisibility::isImplicitlyFinalFromPrivateSet((int) $declare->propertySetVisibility);
+        if ($explicitFinal && !CompilerVersion::supportsFinalProperties()) {
             // php-src Zend/zend_compile.c — pre-8.4 (#22451, re-#22308).
             $classDisplay = $this->compilingClassDisplayName ?? '{unknown}';
             $propName = $param->name instanceof Operand\Literal && is_string($param->name->value)
@@ -8221,10 +8233,6 @@ protected function compilePromotedPropertyDeclaration(Op\Expr\Param $param, Bloc
                 $propName
             ));
         }
-        $declare->propertyFromConstructorPromotion = true;
-        $declare->propertyVisibility = MethodVisibility::mask($param->promotionFlags);
-        $declare->propertySetVisibility = $this->asymmetricSetVisibilityFromCfgOp($param);
-        $declare->propertyGetVisibility = $this->asymmetricGetVisibilityFromCfgOp($param);
         $declare->propertyAsymmetricExplicitRead = Ast\AsymmetricVisibilityRewriter::hasExplicitReadModifierFromAttributes(
             $param->getAttributes()
         );

diff --git a/lib/Compiler/FinalPropertyOverrideCheck.php b/lib/Compiler/FinalPropertyOverrideCheck.php
@@ -80,9 +80,10 @@ private function collectInstanceProperties(Op\Stmt\Class_ $class, string $classL
                 $propDisplay = $this->propertyDisplayName($member->name);
                 $propLc = strtolower($propDisplay);
                 $fromFlags = $this->isFinalFromFlags($member);
+                $fromPrivateSet = $this->isImplicitlyFinalFromPrivateSet($member);
                 $fromRegistry = $this->isFinalFromHookRegistry($classLc, $propDisplay);
                 $properties[$propLc] = [
-                    'final' => $fromFlags || $fromRegistry,
+                    'final' => $fromFlags || $fromPrivateSet || $fromRegistry,
                     'fromFlags' => $fromFlags,
                     'display' => $propDisplay,
                 ];
@@ -107,12 +108,13 @@ private function collectInstanceProperties(Op\Stmt\Class_ $class, string $classL
                     $param->getAttributes()
                 );
                 $fromField = property_exists($param, 'promotionFinal') && $param->promotionFinal;
-                $isFinal = $fromMarker || $fromField;
+                $fromPrivateSet = $this->isImplicitlyFinalFromPrivateSetParam($param);
+                $isFinal = $fromMarker || $fromField || $fromPrivateSet;
                 // Always record promoted props so a non-final child redeclaration can
                 // trip "Cannot override final property" against a final parent (#22451).
                 $properties[$propLc] = [
                     'final' => $isFinal,
-                    'fromFlags' => $isFinal,
+                    'fromFlags' => $fromMarker || $fromField,
                     'display' => $propDisplay,
                 ];
             }
@@ -131,6 +133,41 @@ private function isFinalFromFlags(Op\Stmt\Property $member): bool
         return ClassFinal::fromClassFlags((int) $member->visibility);
     }
 
+    /** php-src zend_API.c — private(set) ⇒ ZEND_ACC_FINAL (#23068). */
+    private function isImplicitlyFinalFromPrivateSet(Op\Stmt\Property $member): bool
+    {
+        $setVis = 0;
+        if (property_exists($member, 'setVisibility')) {
+            $setVis = (int) $member->setVisibility;
+        }
+        if (0 === $setVis) {
+            $setVis = \PHPCompiler\Ast\AsymmetricVisibilityRewriter::extractSetVisibilityFromAttributes(
+                $member->getAttributes()
+            );
+        }
+
+        return \PHPCompiler\PropertyVisibility::isImplicitlyFinalFromPrivateSet($setVis);
+    }
+
+    /** @param Op\Expr\Param $param */
+    private function isImplicitlyFinalFromPrivateSetParam(Op\Expr\Param $param): bool
+    {
+        $setVis = 0;
+        if (property_exists($param, 'setVisibility')) {
+            $setVis = (int) $param->setVisibility;
+        }
+        if (0 === $setVis && property_exists($param, 'promotionSetVisibility')) {
+            $setVis = (int) $param->promotionSetVisibility;
+        }
+        if (0 === $setVis) {
+            $setVis = \PHPCompiler\Ast\AsymmetricVisibilityRewriter::extractSetVisibilityFromAttributes(
+                $param->getAttributes()
+            );
+        }
+
+        return \PHPCompiler\PropertyVisibility::isImplicitlyFinalFromPrivateSet($setVis);
+    }
+
     private function isFinalFromHookRegistry(string $classLc, string $propDisplay): bool
     {
         $hooks = $this->propertyHookRegistry[$classLc][$propDisplay]

diff --git a/lib/PropertyVisibility.php b/lib/PropertyVisibility.php
@@ -21,6 +21,15 @@ public static function effectiveGetVisibility(int $writeVisibility, int $getVisi
         return 0 !== $getVisibility ? $getVisibility : $writeVisibility;
     }
 
+    /**
+     * php-src zend_API.c — `private(set)` properties are implicitly final (#23068).
+     * Uses the asymmetric set-visibility flag (not effective write = private).
+     */
+    public static function isImplicitlyFinalFromPrivateSet(int $setVisibilityFlags): bool
+    {
+        return ($setVisibilityFlags & CfgFunc::FLAG_PRIVATE) !== 0;
+    }
+
     /**
      * Parent private slots are not visible by plain name from a child method scope (zend_fetch_property).
      */

diff --git a/lib/VM.php b/lib/VM.php
@@ -17230,7 +17230,11 @@ protected function defineClass(ClassEntry $entry, Block $block, ?Frame $warningF
                         (bool) ($op->propertyLazy ?? false)
                     );
                     $incoming->fromConstructorPromotion = $op->propertyFromConstructorPromotion;
-                    $incoming->propertyFinal = (bool) ($op->propertyFinal ?? false);
+                    // php-src zend_API.c — private(set) ⇒ ZEND_ACC_FINAL (#23068).
+                    $incoming->propertyFinal = (bool) ($op->propertyFinal ?? false)
+                        || PropertyVisibility::isImplicitlyFinalFromPrivateSet(
+                            (int) ($op->propertySetVisibility ?? 0)
+                        );
                     if ($entry->readonly) {
                         $incoming->readonly = true;
                     }
@@ -17893,7 +17897,11 @@ private function finalizePendingNewPropertyDefault(
         );
         $property->defaultInitBlock = $block->fragmentForOpcodes($pendingNewDefaultOps);
         $property->defaultInitResultSlot = $resultSlot;
-        $property->propertyFinal = (bool) ($declareOp->propertyFinal ?? false);
+        // php-src zend_API.c — private(set) ⇒ ZEND_ACC_FINAL (#23068).
+        $property->propertyFinal = (bool) ($declareOp->propertyFinal ?? false)
+            || PropertyVisibility::isImplicitlyFinalFromPrivateSet(
+                (int) ($declareOp->propertySetVisibility ?? 0)
+            );
         $entry->properties[] = $property;
     }
 

diff --git a/lib/VM/ReflectionPropertyHookSupport.php b/lib/VM/ReflectionPropertyHookSupport.php
@@ -59,11 +59,22 @@ public static function isVirtual(ClassEntry $entry, ?ClassProperty $meta, string
 
     /**
      * php-src ReflectionProperty::isFinal — prop->flags & ZEND_ACC_FINAL (#20511).
+     * private(set) is implicitly final (zend_API.c / manual, #23068).
      */
     public static function isFinal(ClassEntry $entry, ?ClassProperty $meta, string $property, Context $ctx): bool
     {
         if (null !== $meta) {
-            return $meta->propertyFinal;
+            if ($meta->propertyFinal
+                || \PHPCompiler\PropertyVisibility::isImplicitlyFinalFromPrivateSet($meta->setVisibility)
+            ) {
+                return true;
+            }
+        }
+        $vis = VmReflection::propertyVisibilityMeta($entry, $property, $ctx);
+        if (null !== $vis
+            && \PHPCompiler\PropertyVisibility::isImplicitlyFinalFromPrivateSet($vis['setVisibility'])
+        ) {
+            return true;
         }
         $lcClass = strtolower($entry->name);
         $propLc = strtolower($property);

diff --git a/...compliance/cases/reflection/reflection_property_private_set_is_final_forward_profile.phpt b/...compliance/cases/reflection/reflection_property_private_set_is_final_forward_profile.phpt
@@ -0,0 +1,31 @@
+--TEST--
+ReflectionProperty::isFinal() true for public private(set) (#23068, zend_API.c / ext/reflection)
+--ENV--
+PHP_COMPILER_PROFILE=8.4
+--FILE--
+<?php
+class Example
+{
+    public string $name = 'n';
+    final protected int $age = 1;
+    public private(set) string $job = 'x';
+}
+$rClass = new ReflectionClass(Example::class);
+$name = $rClass->getProperty('name')->isFinal();
+$age = $rClass->getProperty('age')->isFinal();
+$jobFinal = $rClass->getProperty('job')->isFinal();
+$flags = [$name, $age, $jobFinal];
+var_export($flags);
+echo "\n";
+$job = $rClass->getProperty('job');
+echo ($job->getModifiers() & ReflectionProperty::IS_FINAL) !== 0 ? "final-bit\n" : "no-final-bit\n";
+var_export($job->isPrivateSet());
+echo "\n";
+--EXPECT--
+array (
+  0 => false,
+  1 => true,
+  2 => true,
+)
+final-bit
+true
diff --git a/test/repro/reflection_property_private_set_is_final.php b/test/repro/reflection_property_private_set_is_final.php
@@ -0,0 +1,22 @@
+<?php
+// Issue #23068 — public private(set) is implicitly final (zend_API.c / ReflectionProperty::isFinal).
+class C
+{
+    public private(set) string $job = 'x';
+    public string $name = 'n';
+}
+$job = new ReflectionProperty(C::class, 'job');
+$name = new ReflectionProperty(C::class, 'name');
+if (!$job->isFinal()) {
+    fwrite(STDERR, "fail: private(set) isFinal false\n");
+    exit(1);
+}
+if ($name->isFinal()) {
+    fwrite(STDERR, "fail: plain public isFinal true\n");
+    exit(1);
+}
+if (($job->getModifiers() & ReflectionProperty::IS_FINAL) === 0) {
+    fwrite(STDERR, 'fail: getModifiers missing IS_FINAL bit mods=' . $job->getModifiers() . "\n");
+    exit(1);
+}
+echo "ok\n";