Regression: file_exists()/is_dir()/is_file() with inline __DIR__/__FILE__ return false (magic constant lowering)

[PurHur]

Category

stdlib + compiler · php-src-strict

Problem

Passing magic constants __DIR__ / __FILE__ directly as the first argument to path stat builtins returns false on VM, while assigning the same constant to a variable first works. Zend treats both forms identically (true).

This cascades into realpath(), filetype(), and any code using file_exists(__DIR__) without a temp variable.

Verified maintainer run 2026-06-16.

php-src reference

• php/php-src ext/standard/filestat.c — php_stat() argument coercion
• php/php-src Zend/zend_compile.c — magic constant folding at compile time

Repro

<?php
declare(strict_types=1);

echo json_encode(file_exists(__DIR__)), "\n";
$p = __DIR__;
echo json_encode(file_exists($p)), "\n";

echo json_encode(is_dir(__DIR__)), "\n";
$d = __DIR__;
echo json_encode(is_dir($d)), "\n";

Commands

source script/php-env.sh
php repro.php
# true / true / true / true

php bin/vm.php repro.php
# false / true / false / true   ← wrong inline form

Scope (this repo)

Layer	Path
Compiler	magic constant operand lowering for builtin calls (lib/Compiler.php)
VM	ext/standard/file_exists.php, is_dir.php, VmStatNative.php — ensure path string reaches stat layer
Tests	test/compliance/cases/stdlib/magic_const_filestat.phpt

Done when

• Inline __DIR__ / __FILE__ matches variable form on file_exists, is_dir, is_file, is_link, is_readable, is_writable
• realpath(__DIR__) and filetype(__DIR__) work when inline magic constants are used
• JIT/AOT agree when stat builtins are lowered

Ref: #1492, #8948 (enum path operands — separate)

[PurHur]

Maintainer audit 2026-06-17: inline __DIR__/__FILE__ currently fails at compile with Unknown variable op found: Expr_MagicScriptConst (not runtime false). Root-cause issue filed as #9136 — fix compiler/type-reconstructor lowering first, then verify stat builtin runtime path from this issue's checklist.

[PurHur]

claim: cursor-agent-lane-b — verifying post-#9139 checklist and closing if green

[PurHur]

Merged via #9146.

Status: Runtime checklist green on master after compile fix #9139 (#9136). Inline __DIR__/`FILE now match variable form on VM and JIT for stat builtins.

Verification:

php bin/vm.php test/repro/maintainer_magic_const_filestat.php  # true / true
./script/docker-exec.sh -- bash -lc './vendor/bin/phpunit --filter magic_const_filestat'  # OK (VM + JIT)

Expanded magic_const_filestat.phpt to guard is_dir/is_file/is_link/is_readable/is_writable/realpath/filetype inline magic constants.