Follow chdir() and include_path changes made earlier in the file when resolving an include

src/Parser/IncludeResolutionChangedVisitor.php

@@ -0,0 +1,100 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Parser;
+
+use Override;
+use PhpParser\Node;
+use PhpParser\NodeVisitorAbstract;
+use PHPStan\DependencyInjection\AutowiredService;
+use function in_array;
+use function strtolower;
+
+/**
+ * Where an `include`/`require` path ends up depends on the working directory, on the `include_path`
+ * setting and on the registered stream wrappers, all of which the analysed file can change at
+ * runtime. This marks every `Include_` node that such a call appears before in the same file, so
+ * that RequireFileExistsRule can treat its path as one that does not resolve to a known place
+ * instead of assuming the state of PHPStan's own process.
+ */
+#[AutowiredService]
+final class IncludeResolutionChangedVisitor extends NodeVisitorAbstract
+{
+
+	/** Holds `true` when a call earlier in the file changed where a path resolves. */
+	public const ATTRIBUTE_NAME = 'includeResolutionChanged';
+
+	private const FUNCTION_NAMES = [
+		'chdir',
+		'set_include_path',
+		'stream_wrapper_register',
+		'ini_set',
+		'ini_alter',
+	];
+
+	private bool $changed = false;
+
+	#[Override]
+	public function beforeTraverse(array $nodes): ?array
+	{
+		$this->changed = false;
+
+		return null;
+	}
+
+	#[Override]
+	public function enterNode(Node $node): ?Node
+	{
+		if ($node instanceof Node\Expr\Include_) {
+			if ($this->changed) {
+				$node->setAttribute(self::ATTRIBUTE_NAME, true);
+			}
+
+			return null;
+		}
+
+		if (
+			!$node instanceof Node\Expr\FuncCall
+			|| !$node->name instanceof Node\Name
+			|| $node->isFirstClassCallable()
+		) {
+			return null;
+		}
+
+		$functionName = $node->name->toLowerString();
+		if (!in_array($functionName, self::FUNCTION_NAMES, true)) {
+			return null;
+		}
+
+		if (
+			($functionName === 'ini_set' || $functionName === 'ini_alter')
+			&& !$this->couldSetIncludePath($node)
+		) {
+			return null;
+		}
+
+		$this->changed = true;
+
+		return null;
+	}
+
+	/**
+	 * An `ini_set()` of an unrelated option such as `memory_limit` leaves include resolution alone.
+	 * An option name that is not a literal string could be `include_path` just as well as anything
+	 * else.
+	 */
+	private function couldSetIncludePath(Node\Expr\FuncCall $node): bool
+	{
+		$args = $node->getArgs();
+		if ($args === []) {
+			return false;
+		}
+
+		$optionName = $args[0]->value;
+		if (!$optionName instanceof Node\Scalar\String_) {
+			return true;
+		}
+
+		return strtolower($optionName->value) === 'include_path';
+	}
+
+}

src/Rules/Keywords/RequireFileExistsRule.php

@@ -14,6 +14,7 @@
 use PHPStan\File\FileHelper;
 use PHPStan\File\IncludedFilePathResolver;
 use PHPStan\Node\Printer\ExprPrinter;
+use PHPStan\Parser\IncludeResolutionChangedVisitor;
 use PHPStan\Rules\IdentifierRuleError;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
@@ -64,6 +65,12 @@ public function processNode(Node $node, Scope $scope): array
 			return [];
 		}
 
+		if ($node->getAttribute(IncludeResolutionChangedVisitor::ATTRIBUTE_NAME) === true) {
+			// A call earlier in the file moved the working directory, changed the include path or
+			// registered a stream wrapper, so the path no longer names a place PHPStan can look at.
+			return [];
+		}
+
 		$errors = [];
 		$usedMagicDirFallback = false;
 		$paths = $this->resolveFilePaths($node->expr, $scope, $usedMagicDirFallback);

tests/PHPStan/Rules/Keywords/RequireFileExistsRuleTest.php

@@ -57,6 +57,18 @@ public function testPathWithAnUnregisteredStreamWrapper(): void
 		]);
 	}
 
+	public function testStreamWrapperRegisteredByTheFileItself(): void
+	{
+		// Only the include before the stream_wrapper_register() call is reported: after it, the
+		// file resolves paths through wrappers PHPStan does not have.
+		$this->analyse([__DIR__ . '/data/require-file-stream-wrapper-registered.php'], [
+			[
+				'Path in require_once() "modulea://sites/default/modulea.php" is not a file or it does not exist.',
+				5,
+			],
+		]);
+	}
+
 	public function testBasicCase(): void
 	{
 		$this->analyse([__DIR__ . '/data/require-file-simple-case.php'], [
@@ -204,6 +216,58 @@ public function testBug15015(): void
 		]);
 	}
 
+	public function testChdir(): void
+	{
+		// The include after the chdir() is not reported: the path is relative to a working
+		// directory the file moved, so it no longer names a place PHPStan can look at. Neither is
+		// the absolute one - the whole file is given up on, which is the point of keeping this
+		// simple.
+		$this->analyse([__DIR__ . '/data/require-file-chdir.php'], [
+			[
+				'Path in require_once() "a-file-that-does-not-exist.php" is not a file or it does not exist.',
+				5,
+			],
+		]);
+	}
+
+	public function testSetIncludePath(): void
+	{
+		$this->analyse([__DIR__ . '/data/require-file-set-include-path.php'], [
+			[
+				'Path in require_once() "a-file-that-does-not-exist.php" is not a file or it does not exist.',
+				5,
+			],
+		]);
+	}
+
+	public function testIniSetIncludePath(): void
+	{
+		// ini_set('memory_limit', ...) and ini_alter('precision', ...) leave include resolution
+		// alone, ini_set('INCLUDE_PATH', ...) does not - the option name is case-insensitive.
+		$this->analyse([__DIR__ . '/data/require-file-include-path.php'], [
+			[
+				'Path in require_once() "a-file-that-does-not-exist.php" is not a file or it does not exist.',
+				8,
+			],
+		]);
+	}
+
+	public function testIniSetWithUnknownOption(): void
+	{
+		// The option could be include_path just as well as anything else.
+		$this->analyse([__DIR__ . '/data/require-file-ini-set-unknown.php'], [
+			[
+				'Path in require_once() "a-file-that-does-not-exist.php" is not a file or it does not exist.',
+				5,
+			],
+		]);
+	}
+
+	public function testBug15260(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-15260/sub/bug-15260.php'], []);
+	}
+
 	public function testInFileExists(): void
 	{
 		$this->analyse([__DIR__ . '/data/include-in-file-exists.php'], []);

tests/PHPStan/Rules/Keywords/data/bug-15260/config.php

@@ -0,0 +1,3 @@
+<?php declare(strict_types = 1);
+
+// Included by bug-15260/sub/bug-15260.php after it chdir()s into this directory.

tests/PHPStan/Rules/Keywords/data/bug-15260/sub/bug-15260.php

@@ -0,0 +1,6 @@
+<?php declare(strict_types = 1);
+
+namespace Bug15260;
+
+chdir('..');
+require_once('config.php');

tests/PHPStan/Rules/Keywords/data/require-file-chdir.php

@@ -0,0 +1,10 @@
+<?php declare(strict_types = 1);
+
+namespace RequireFileChdir;
+
+require_once 'a-file-that-does-not-exist.php';
+
+chdir('..');
+
+require_once 'a-file-that-does-not-exist.php';
+require_once __DIR__ . '/a-file-that-does-not-exist.php';

tests/PHPStan/Rules/Keywords/data/require-file-include-path.php

@@ -0,0 +1,12 @@
+<?php declare(strict_types = 1);
+
+namespace RequireFileIncludePath;
+
+ini_set('memory_limit', '1G');
+ini_alter('precision', '10');
+
+require_once 'a-file-that-does-not-exist.php';
+
+ini_set('INCLUDE_PATH', __DIR__);
+
+require_once 'a-file-that-does-not-exist.php';

tests/PHPStan/Rules/Keywords/data/require-file-ini-set-unknown.php

@@ -0,0 +1,9 @@
+<?php declare(strict_types = 1);
+
+namespace RequireFileIniSetUnknown;
+
+require_once 'a-file-that-does-not-exist.php';
+
+ini_set($_SERVER['OPTION'], $_SERVER['VALUE']);
+
+require_once 'a-file-that-does-not-exist.php';

tests/PHPStan/Rules/Keywords/data/require-file-set-include-path.php

@@ -0,0 +1,9 @@
+<?php declare(strict_types = 1);
+
+namespace RequireFileSetIncludePath;
+
+require_once 'a-file-that-does-not-exist.php';
+
+\set_include_path(__DIR__);
+
+require_once 'a-file-that-does-not-exist.php';

tests/PHPStan/Rules/Keywords/data/require-file-stream-wrapper-registered.php

@@ -0,0 +1,10 @@
+<?php declare(strict_types = 1);
+
+namespace RequireFileStreamWrapperRegistered;
+
+require_once 'modulea://sites/default/modulea.php';
+
+\stream_wrapper_register('modulea', \stdClass::class);
+
+require_once 'modulea://sites/default/modulea.php';
+require_once 'moduleb://sites/default/moduleb.php';