fix(enum): fold enum case property fetches in constant expressions

phpunit/src/EnumCaseValuePropertyDefaultTest.php

@@ -0,0 +1,116 @@
+<?php
+/**
+ * This file is part of TypePHP(AOT).
+ *
+ * @link     https://www.swoole.com/aot/
+ * @contact  service@swoole.com
+ */
+
+use TypePhp\CompilerTest;
+
+/**
+ * PHP 8.2+ constant expressions may fetch `->value` and `->name` from enum
+ * cases (php-src "Fetch properties of enums in constant expressions"). The
+ * stub generator must fold those fetches into scalar property defaults the
+ * same way the declaration evaluator does; every other property fetch in a
+ * constant expression stays rejected.
+ * @internal
+ * @coversNothing
+ */
+final class EnumCaseValuePropertyDefaultTest extends PHPUnit\Framework\TestCase
+{
+    private string $testRoot;
+
+    protected function setUp(): void
+    {
+        $this->testRoot = sys_get_temp_dir() . '/typephp-enum-case-propdefault-' . bin2hex(random_bytes(8));
+        mkdir($this->testRoot, 0777, true);
+    }
+
+    protected function tearDown(): void
+    {
+        if (!is_dir($this->testRoot)) {
+            return;
+        }
+        $iterator = new RecursiveIteratorIterator(
+            new RecursiveDirectoryIterator($this->testRoot, FilesystemIterator::SKIP_DOTS),
+            RecursiveIteratorIterator::CHILD_FIRST,
+        );
+        foreach ($iterator as $entry) {
+            $entry->isDir() ? rmdir($entry->getPathname()) : unlink($entry->getPathname());
+        }
+        rmdir($this->testRoot);
+    }
+
+    /** @dataProvider foldedDefaultProvider */
+    public function testEnumCaseFetchFoldsIntoPropertyDefault(string $source, string $expectedInitCode): void
+    {
+        $compiler = $this->compilerFor($source);
+        $file = $this->testRoot . '/program.php';
+        $compiler->prepareFile($file);
+        $compiler->convertFile($file);
+
+        $header = file_get_contents($compiler->getArgInfoHeaderFile($file));
+        self::assertIsString($header);
+        self::assertStringContainsString($expectedInitCode, $header);
+    }
+
+    public static function foldedDefaultProvider(): iterable
+    {
+        yield 'int-backed ->value folds to negative backing value' => [
+            <<<'PHP'
+<?php
+enum TextRole: int { case Unset = -1; case User = 1; }
+class RoleHolder { private int $role = TextRole::Unset->value; }
+function main(): void {}
+PHP,
+            'ZVAL_LONG(&property_role_default_value, -1);',
+        ];
+        yield 'string-backed ->value folds to backing string' => [
+            <<<'PHP'
+<?php
+enum Level: string { case Guest = 'guest'; }
+class LevelHolder { public string $level = Level::Guest->value; }
+function main(): void {}
+PHP,
+            'zend_string_init_interned("guest", sizeof("guest") - 1, 1);',
+        ];
+        yield '->name folds to the case name string' => [
+            <<<'PHP'
+<?php
+enum Suit { case Hearts; }
+class SuitHolder { public string $suit = Suit::Hearts->name; }
+function main(): void {}
+PHP,
+            'zend_string_init_interned("Hearts", sizeof("Hearts") - 1, 1);',
+        ];
+    }
+
+    public function testNonEnumPropertyFetchRemainsRejected(): void
+    {
+        $compiler = $this->compilerFor(<<<'PHP'
+<?php
+class Container { public const DATA = ['key' => 1]; }
+class Broken { public int $value = Container::DATA->key; }
+function main(): void {}
+PHP);
+        $file = $this->testRoot . '/program.php';
+        $compiler->prepareFile($file);
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('must be a global, non-magic constant, Expr_PropertyFetch given');
+        $compiler->convertFile($file);
+    }
+
+    private function compilerFor(string $source): CompilerTest
+    {
+        $file = $this->testRoot . '/program.php';
+        file_put_contents($file, $source);
+
+        global $translator;
+        $compiler = CompilerTest::create($this->testRoot);
+        $translator = $compiler;
+        $compiler->addFiles([$file]);
+        return $compiler;
+    }
+}

src/Resolver/ClassConstantValueTrait.php

@@ -595,7 +595,7 @@ private function resolveCompileTimeClassName(
         return '\\' . $this->getNamespacedClassName($raw, $scope->namespace);
     }
 
-    private function resolveCompileTimeEnumCaseBackingValue(NodeAbstract $origin, EnumCaseRef $case): int|string
+    public function resolveCompileTimeEnumCaseBackingValue(NodeAbstract $origin, EnumCaseRef $case): int|string
     {
         if ($this->isInternalClass($case->enumClass)) {
             $value = constant(ltrim($case->enumClass, '\\') . '::' . $case->caseName);

src/gen_stub.php

@@ -2680,6 +2680,31 @@ static function (Expr $expr) use (
                     };
                 }
 
+                // PHP 8.2+ constant expressions fetch `->value`/`->name` from
+                // enum cases. Mirror the declaration evaluator: fold the two
+                // backed properties; any other property fetch falls through
+                // to the shared diagnostic below.
+                if ($expr instanceof Expr\PropertyFetch || $expr instanceof Expr\NullsafePropertyFetch) {
+                    $object = $evaluator->instance->evaluateDirectly($expr->var);
+                    if ($object === null && $expr instanceof Expr\NullsafePropertyFetch) {
+                        return null;
+                    }
+                    if ($object instanceof \TypePhp\Entity\EnumCaseRef) {
+                        $property = $expr->name instanceof Node\Identifier
+                            ? $expr->name->toString()
+                            : $evaluator->instance->evaluateDirectly($expr->name);
+                        if ($property === 'name') {
+                            return $object->caseName;
+                        }
+                        if ($property === 'value') {
+                            return getTranslator()->resolveCompileTimeEnumCaseBackingValue($expr, $object);
+                        }
+                        throw new Exception(
+                            "Undefined enum case property `{$object->enumClass}::{$object->caseName}->{$property}`"
+                        );
+                    }
+                }
+
                 // $expr is a ConstFetch with a name of a C macro here
                 if (!($expr instanceof Expr\ConstFetch) and !($expr instanceof Expr\ClassConstFetch)) {
                     _error:

tests/compiler/object_property/enum-case-value-property-default.phpt

@@ -0,0 +1,43 @@
+--TEST--
+Enum case ->value and ->name fold into property defaults (PHP 8.2+)
+--FILE--
+<?php
+
+enum TextRole: int
+{
+    case Unset = -1;
+    case User = 1;
+}
+
+enum Level: string
+{
+    case Guest = 'guest';
+}
+
+enum Suit
+{
+    case Hearts;
+}
+
+class RoleCard
+{
+    public int $role = TextRole::Unset->value;
+    public string $level = Level::Guest->value;
+    public string $caseName = Suit::Hearts->name;
+    public TextRole $defaultRole = TextRole::User;
+}
+
+function main(): void
+{
+    $card = new RoleCard();
+    var_dump($card->role);
+    var_dump($card->level);
+    var_dump($card->caseName);
+    var_dump($card->defaultRole === TextRole::User);
+}
+?>
+--EXPECT--
+int(-1)
+string(5) "guest"
+string(6) "Hearts"
+bool(true)