From 01ea7c40be973ea35de2f34b22964e8c29ae7ccc Mon Sep 17 00:00:00 2001
From: tianfenghan <rango@swoole.com>
Date: Tue, 11 Aug 2026 18:14:38 +0800
Subject: [PATCH] feat(parser): support dynamic class constant name fetch
 expressions

- Extended BinaryOpTrait to handle temporary variable cleanup for STR, ARRAY, and OBJECT types
- Added parseDynamicClassConstNameFetch method to handle dynamic constant name resolution
- Implemented proper evaluation order for class target and dynamic constant name
- Added support for static, self, parent, and regular class references in dynamic context
- Created materializeDynamicClassConstOperand helper for operand processing
- Updated temporary variable management to clear zval-owning PHPX wrappers
- Added comprehensive tests for dynamic class constant name evaluation semantics
- Implemented proper object lifetime management for temporary arguments
- Added tests for reference-returning function alias preservation
- Fixed temporary call argument lifetime handling in object constructors
---
 src/Parser/BinaryOpTrait.php                  |  8 +-
 src/Parser/ClassConstantFetchTrait.php        | 45 ++++++++++-
 .../class/dynamic-class-constant-name.phpt    | 75 +++++++++++++++++++
 .../temporary-call-argument-lifetime.phpt     | 36 +++++++++
 .../compiler/ref/nested-reference-return.phpt | 50 +++++++++++++
 5 files changed, 210 insertions(+), 4 deletions(-)
 create mode 100644 tests/compiler/class/dynamic-class-constant-name.phpt
 create mode 100644 tests/compiler/object_ctor/temporary-call-argument-lifetime.phpt
 create mode 100644 tests/compiler/ref/nested-reference-return.phpt

diff --git a/src/Parser/BinaryOpTrait.php b/src/Parser/BinaryOpTrait.php
index a6722e0f..7f365f5a 100644
--- a/src/Parser/BinaryOpTrait.php
+++ b/src/Parser/BinaryOpTrait.php
@@ -535,11 +535,13 @@ trait BinaryOpTrait
         $tmpVar = $this->addTmpVar($type);
         $this->context->beforeStmtLines[] = $tmpVar . ' = ' . $value . ';';
         $this->appendCapturedStmtLinesToContext($afterStmts);
-        if ($type === Type::VAR) {
+        if (in_array($type, [Type::VAR, Type::STR, Type::ARRAY, Type::OBJECT], true)) {
             // The declaration is function-scoped, but PHP releases an owned
             // expression temporary after the statement that consumes it.
-            // Keeping the value here would extend object lifetimes (notably
-            // WeakReference targets) until the native function returns.
+            // All zval-owning PHPX wrappers must be cleared here: an Object is
+            // directly observable through __destruct(), while an Array may own
+            // objects whose destruction would otherwise also be delayed until
+            // the native function returns.
             $this->context->afterStmtLines[] = $tmpVar . '.unset();';
         }
         return $tmpVar;
diff --git a/src/Parser/ClassConstantFetchTrait.php b/src/Parser/ClassConstantFetchTrait.php
index 850cff42..f1ea7c38 100644
--- a/src/Parser/ClassConstantFetchTrait.php
+++ b/src/Parser/ClassConstantFetchTrait.php
@@ -19,6 +19,10 @@ trait ClassConstantFetchTrait
     {
         $this->rejectPythonModuleClassConstantFetch($expr);
 
+        if (!$this->isIdExpr($expr->name)) {
+            return $this->parseDynamicClassConstNameFetch($expr);
+        }
+
         if (!$this->isNameExpr($expr->class)) {
             return $this->parseDynamicClassConstFetch($expr);
         }
@@ -97,9 +101,48 @@ trait ClassConstantFetchTrait
         return Symbol::constant() . '(php::concat({' . $className . ', "::", ' . $this->getLiteralString($const) . '}))';
     }
 
+    protected function parseDynamicClassConstNameFetch(Expr\ClassConstFetch $expr): string
+    {
+        $scope = $this->methodDef && $this->classDef
+            ? $this->getClassEntryPtr($this->getFullClassName())
+            : 'nullptr';
+
+        if (!$this->isNameExpr($expr->class)) {
+            // PHP evaluates the class target before the dynamic constant name.
+            $target = $this->materializeDynamicClassConstOperand($expr->class, 'class constant target');
+            $name = $this->materializeDynamicClassConstOperand($expr->name, 'class constant name');
+            return 'php::classConstant(' . $target . ', ' . $name . ', ' . $scope . ')';
+        }
+
+        $class = $this->parseIdentifier($expr->class);
+        if ($class === 'static') {
+            if (!$this->methodDef) {
+                $this->fatalError($expr, "The 'static' keyword can only be used as the class name in class methods");
+            }
+            $ce = Symbol::getCalledCe();
+        } elseif ($class === 'self' or $class === 'this_') {
+            $ce = $this->getClassEntryPtr($this->getFullClassName());
+        } elseif ($class === 'parent') {
+            if (!$this->classDef || !$this->classDef->extends) {
+                $this->fatalError($expr, 'Cannot use "parent" outside a class or class does not extend any class');
+            }
+            $ce = $this->getClassEntryPtr($this->classDef->extends);
+        } else {
+            $ce = $this->getClassEntryPtr($this->getNamespacedClassName($class));
+        }
+
+        $name = $this->materializeDynamicClassConstOperand($expr->name, 'class constant name');
+        return 'php::classConstant(' . $ce . ', ' . $name . ', ' . $scope . ')';
+    }
+
     protected function materializeDynamicClassConstTarget(NodeAbstract $expr): string
     {
-        $this->assertExprCanBeUsedAsValue($expr, 'class constant target');
+        return $this->materializeDynamicClassConstOperand($expr, 'class constant target');
+    }
+
+    protected function materializeDynamicClassConstOperand(NodeAbstract $expr, string $description): string
+    {
+        $this->assertExprCanBeUsedAsValue($expr, $description);
         [$value, $beforeStmts, $afterStmts] = $this->parseExprWithCapturedStmts($expr);
         $tmpVar = $this->addTmpVar(Type::VAR);
         $this->appendCapturedStmtLinesToContext($beforeStmts);
diff --git a/tests/compiler/class/dynamic-class-constant-name.phpt b/tests/compiler/class/dynamic-class-constant-name.phpt
new file mode 100644
index 00000000..91fe8b3f
--- /dev/null
+++ b/tests/compiler/class/dynamic-class-constant-name.phpt
@@ -0,0 +1,75 @@
+--TEST--
+dynamic class constant names preserve PHP lookup and evaluation semantics
+--FILE--
+<?php
+
+class DynamicConstantName
+{
+    public const ANSWER = 42;
+    private const SECRET = 'secret';
+
+    public static function secret(string $name): string
+    {
+        return self::{$name};
+    }
+}
+
+enum DynamicConstantCase
+{
+    case READY;
+}
+
+function dynamic_constant_target(): string
+{
+    echo "target\n";
+    return DynamicConstantName::class;
+}
+
+function dynamic_constant_name(): string
+{
+    echo "name\n";
+    return 'ANSWER';
+}
+
+function main(): void
+{
+    $name = 'ANSWER';
+    var_dump(DynamicConstantName::{$name});
+
+    var_dump(dynamic_constant_target()::{dynamic_constant_name()});
+
+    $className = 'class';
+    var_dump(DynamicConstantName::{$className});
+    $className = 'CLASS';
+    var_dump(DynamicConstantName::{$className});
+
+    $case = 'READY';
+    var_dump(DynamicConstantCase::{$case} === DynamicConstantCase::READY);
+
+    $secret = 'SECRET';
+    var_dump(DynamicConstantName::secret($secret));
+    try {
+        DynamicConstantName::{$secret};
+    } catch (Error $error) {
+        echo $error->getMessage(), "\n";
+    }
+
+    $invalid = 1;
+    try {
+        DynamicConstantName::{$invalid};
+    } catch (TypeError $error) {
+        echo $error->getMessage(), "\n";
+    }
+}
+?>
+--EXPECT--
+int(42)
+target
+name
+int(42)
+string(19) "DynamicConstantName"
+string(19) "DynamicConstantName"
+bool(true)
+string(6) "secret"
+Cannot access private constant DynamicConstantName::SECRET
+Cannot use value of type int as class constant name
diff --git a/tests/compiler/object_ctor/temporary-call-argument-lifetime.phpt b/tests/compiler/object_ctor/temporary-call-argument-lifetime.phpt
new file mode 100644
index 00000000..fee87233
--- /dev/null
+++ b/tests/compiler/object_ctor/temporary-call-argument-lifetime.phpt
@@ -0,0 +1,36 @@
+--TEST--
+Owned call argument temporaries are released at the end of the call statement
+--FILE--
+<?php
+
+final class TemporaryArgumentLifetimeProbe
+{
+    public static int $destroyed = 0;
+
+    public function __destruct()
+    {
+        self::$destroyed++;
+    }
+}
+
+function consume_temporary_object(TemporaryArgumentLifetimeProbe $value): void
+{
+}
+
+function consume_temporary_array(array $values): void
+{
+}
+
+function main(): void
+{
+    TemporaryArgumentLifetimeProbe::$destroyed = 0;
+    consume_temporary_object(new TemporaryArgumentLifetimeProbe());
+    echo 'object=', TemporaryArgumentLifetimeProbe::$destroyed, "\n";
+
+    consume_temporary_array([new TemporaryArgumentLifetimeProbe()]);
+    echo 'array=', TemporaryArgumentLifetimeProbe::$destroyed, "\n";
+}
+?>
+--EXPECT--
+object=1
+array=2
diff --git a/tests/compiler/ref/nested-reference-return.phpt b/tests/compiler/ref/nested-reference-return.phpt
new file mode 100644
index 00000000..f9985fd2
--- /dev/null
+++ b/tests/compiler/ref/nested-reference-return.phpt
@@ -0,0 +1,50 @@
+--TEST--
+Reference-returning functions preserve aliases to nested array elements and object properties
+--FILE--
+<?php
+
+final class NestedReferenceBox
+{
+    public string $value = 'object-before';
+}
+
+function &array_element_ref(array &$values): mixed
+{
+    return $values['item'];
+}
+
+function &nested_array_element_ref(array &$values): mixed
+{
+    return $values['outer']['inner'];
+}
+
+function &object_property_ref(NestedReferenceBox $box): mixed
+{
+    return $box->value;
+}
+
+function main(): void
+{
+    $values = [
+        'item' => 'before',
+        'outer' => ['inner' => 'nested-before'],
+    ];
+
+    $item =& array_element_ref($values);
+    $item = 'after';
+    var_dump($values['item']);
+
+    $inner =& nested_array_element_ref($values);
+    $inner = 'nested-after';
+    var_dump($values['outer']['inner']);
+
+    $box = new NestedReferenceBox();
+    $property =& object_property_ref($box);
+    $property = 'object-after';
+    var_dump($box->value);
+}
+?>
+--EXPECT--
+string(5) "after"
+string(12) "nested-after"
+string(12) "object-after"