Language: resource as array subject matches Zend dim semantics (#30028)

lib/VM.php

@@ -5483,6 +5483,32 @@ static function () use ($arg3, $writeTarget, $dnfCtx, $strict): void {
                         }
                     } else {
                         $scriptFile = '' !== $frame->scriptPath ? $frame->scriptPath : null;
+                        // Resource as array subject — Zend Warning/null on read, scalar Error on write (#30028).
+                        if (
+                            Variable::TYPE_OBJECT === $container->type
+                            && VM\ResourceSupport::isResourceObject($container->toObject())
+                        ) {
+                            if ($forWrite) {
+                                $catchFrame = $this->dispatchVmError(
+                                    TypeCheck::SCALAR_USED_AS_ARRAY_MESSAGE,
+                                    $frame
+                                );
+                                if (null !== $catchFrame) {
+                                    $frame = $catchFrame;
+                                    goto restart;
+                                }
+                                break;
+                            }
+                            if (!$fetchIs) {
+                                $this->context->errors->arrayOffsetOnResource(
+                                    $this->context,
+                                    $frame,
+                                    $scriptFile
+                                );
+                            }
+                            $arg1->null();
+                            break;
+                        }
                         if (!$forWrite && TypeCheck::isScalarNonContainerDimRead($container)) {
                             if (!$fetchIs) {
                                 $resolved = $container->resolveIndirect();
@@ -9389,6 +9415,11 @@ function () use ($frame, $op, $arg1, $strict, $arraySpec, $vmContext): void {
                                 break;
                             }
                             if (!$op->issetOnProperty) {
+                                // Resource as array subject — isset soft-false like scalars (zend_execute.c, #30028).
+                                if (VM\ResourceSupport::isResourceObject($object)) {
+                                    $dst->bool(false);
+                                    break;
+                                }
                                 // isset($obj[$k]) without has_dimension / ArrayAccess — Zend Error
                                 // (ResourceBundle has read_dimension only; #25145).
                                 $catchFrame = $this->dispatchVmError(

lib/VM/ErrorReporter.php

@@ -325,6 +325,20 @@ public static function arrayOffsetOnNonContainerMessage(string $typeName): strin
         return "Trying to access array offset on value of type {$typeName}";
     }
 
+    /**
+     * Zend E_WARNING for dim-read on a resource container (zend_execute.c, #30028).
+     *
+     * PHP 8.3+ shortens "on value of type resource" → "on resource"; PROFILE≥8.3 matches.
+     */
+    public static function arrayOffsetOnResourceMessage(): string
+    {
+        if (version_compare(\PHPCompiler\CompilerVersion::languageProfileVersion(), '8.3.0', '>=')) {
+            return 'Trying to access array offset on resource';
+        }
+
+        return self::arrayOffsetOnNonContainerMessage('resource');
+    }
+
     /**
      * Zend E_WARNING for ZEND_FETCH_DIM_R on scalars (zend_execute.c, #4867).
      */
@@ -342,6 +356,22 @@ public function arrayOffsetOnNonContainer(
         );
     }
 
+    /**
+     * Zend E_WARNING for ZEND_FETCH_DIM_R when the container is a resource (#30028).
+     */
+    public function arrayOffsetOnResource(
+        ?Context $context = null,
+        ?Frame $frame = null,
+        ?string $file = null
+    ): void {
+        $this->emitWarning(
+            self::arrayOffsetOnResourceMessage(),
+            $context,
+            $frame,
+            $file
+        );
+    }
+
     /**
      * Zend E_WARNING for undefined instance property read (zend_object_handlers.c, #14938).
      */

lib/VM/VmEmptyDimension.php

@@ -93,6 +93,12 @@ public static function evaluate(
 
                 return null;
             }
+            // Resource as array subject — empty soft-true like scalars (zend_execute.c, #30028).
+            if (ResourceSupport::isResourceObject($object)) {
+                $dst->bool(true);
+
+                return null;
+            }
             if (!$vm->objectImplementsArrayAccess($object)) {
                 $className = $object->class->name;
                 $catchFrame = $vm->propagateEmptyDimensionError(

test/compliance/ResourceDimFetch30028JITTest.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPCompiler;
+
+/**
+ * JIT: resource as array subject — Warning/null read, scalar Error write, soft isset/empty (#30028).
+ */
+require_once __DIR__.'/../BaseTest.php';
+
+final class ResourceDimFetch30028JITTest extends BaseTest
+{
+    protected static string $DIR = __DIR__;
+
+    public static function providePHPTests(): \Generator
+    {
+        yield 'resource_dim_fetch.phpt' => self::parsePHPT(
+            __DIR__.'/cases/language/resource_dim_fetch.phpt',
+            'resource_dim_fetch.phpt'
+        );
+    }
+
+    public function setUp(): void
+    {
+        $this->BIN = realpath(__DIR__.'/../../bin/jit.php');
+        putenv('PHP_COMPILER_PROFILE=8.4');
+        $_ENV['PHP_COMPILER_PROFILE'] = '8.4';
+    }
+
+    public function tearDown(): void
+    {
+        putenv('PHP_COMPILER_PROFILE');
+        unset($_ENV['PHP_COMPILER_PROFILE']);
+    }
+}

test/compliance/ResourceDimFetch30028VMTest.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPCompiler;
+
+/**
+ * VM: resource as array subject — Warning/null read, scalar Error write, soft isset/empty (#30028).
+ */
+require_once __DIR__.'/../BaseTest.php';
+
+final class ResourceDimFetch30028VMTest extends BaseTest
+{
+    protected static string $DIR = __DIR__;
+
+    public static function providePHPTests(): \Generator
+    {
+        yield 'resource_dim_fetch.phpt' => self::parsePHPT(
+            __DIR__.'/cases/language/resource_dim_fetch.phpt',
+            'resource_dim_fetch.phpt'
+        );
+    }
+
+    public function setUp(): void
+    {
+        $this->BIN = realpath(__DIR__.'/../../bin/vm.php');
+        putenv('PHP_COMPILER_PROFILE=8.4');
+        $_ENV['PHP_COMPILER_PROFILE'] = '8.4';
+    }
+
+    public function tearDown(): void
+    {
+        putenv('PHP_COMPILER_PROFILE');
+        unset($_ENV['PHP_COMPILER_PROFILE']);
+    }
+}

test/compliance/cases/language/resource_dim_fetch.phpt

@@ -0,0 +1,36 @@
+--TEST--
+Language: resource as array subject — Warning on read, scalar Error on write, soft isset/empty (#30028)
+--FILE--
+<?php
+function warn_capture(int $errno, string $message): bool
+{
+    echo 'W:', $message, "\n";
+
+    return true;
+}
+set_error_handler('warn_capture');
+
+$f = fopen('php://memory', 'r');
+try {
+    var_export($f[0]);
+    echo "\n";
+} catch (Throwable $e) {
+    echo get_class($e), ':', $e->getMessage(), "\n";
+}
+try {
+    $f[0] = 1;
+    echo "write ok\n";
+} catch (Throwable $e) {
+    echo get_class($e), ':', $e->getMessage(), "\n";
+}
+var_export(isset($f[0]));
+echo "\n";
+var_export(empty($f[0]));
+echo "\n";
+fclose($f);
+--EXPECTF--
+W:Trying to access array offset on %Sresource
+NULL
+Error:Cannot use a scalar value as an array
+false
+true

test/unit/ResourceDimFetchTest.php

@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPCompiler\Test\Unit;
+
+use PHPCompiler\VM\ErrorReporter;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Resource used as array container — Zend dim semantics (#30028).
+ */
+final class ResourceDimFetchTest extends TestCase
+{
+    public function testResourceOffsetWarningMessageUnderProfile84(): void
+    {
+        $prev = getenv('PHP_COMPILER_PROFILE');
+        putenv('PHP_COMPILER_PROFILE=8.4');
+        try {
+            $this->assertSame(
+                'Trying to access array offset on resource',
+                ErrorReporter::arrayOffsetOnResourceMessage()
+            );
+        } finally {
+            if (false === $prev) {
+                putenv('PHP_COMPILER_PROFILE');
+            } else {
+                putenv('PHP_COMPILER_PROFILE='.$prev);
+            }
+        }
+    }
+
+    public function testVmResourceDimMatchesZendShape(): void
+    {
+        $code = <<<'PHP'
+<?php
+set_error_handler(static function (int $errno, string $message): bool {
+    echo 'W:', $message, "\n";
+    return true;
+});
+$f = fopen('php://memory', 'r');
+try {
+    var_export($f[0]);
+    echo "\n";
+} catch (Throwable $e) {
+    echo get_class($e), ':', $e->getMessage(), "\n";
+}
+try {
+    $f[0] = 1;
+} catch (Throwable $e) {
+    echo get_class($e), ':', $e->getMessage(), "\n";
+}
+var_export(isset($f[0]));
+echo "\n";
+var_export(empty($f[0]));
+echo "\n";
+fclose($f);
+PHP;
+        $path = sys_get_temp_dir().'/phpc_resource_dim_30028.php';
+        file_put_contents($path, $code);
+        $cmd = 'PHP_COMPILER_PROFILE=8.4 '
+            .escapeshellarg(PHP_BINARY).' -d error_reporting=E_ALL -d display_errors=1 '
+            .escapeshellarg(dirname(__DIR__, 2).'/bin/vm.php').' '
+            .escapeshellarg($path).' 2>&1';
+        $output = shell_exec($cmd) ?? '';
+        @unlink($path);
+
+        $this->assertStringContainsString('W:Trying to access array offset on resource', $output);
+        $this->assertStringContainsString("NULL\n", $output);
+        $this->assertStringContainsString('Error:Cannot use a scalar value as an array', $output);
+        $this->assertStringContainsString("false\ntrue\n", $output);
+        $this->assertStringNotContainsString('Cannot use object of type Resource as array', $output);
+    }
+}