Language: Magic constants __CLASS__, __METHOD__, __NAMESPACE__, __FUNCTION__

[PurHur]

Problem

#85 covers __DIR__, __FILE__, __LINE__. OOP web code also needs __CLASS__, __METHOD__, __NAMESPACE__, and __FUNCTION__ in templates, logging, and error pages.

MiniWebApp does not use these today, but production apps and #445 deployment docs will.

Goal

Resolve magic constants per PHP rules at compile time (when statically known) or from the active frame at runtime.

class C {
    public function id(): string {
        return __CLASS__ . '::' . __FUNCTION__;
    }
}
echo (new C)->id(); // C::id

VM + JIT + AOT parity for methods inside namespaced classes (#84).

Implementation hints

Constant	When known	Compiler / VM
__CLASS__	Inside class method	Current class name from compileClassBody context
__METHOD__	Inside method	ClassName::methodName
__FUNCTION__	Inside function	Function name from block
__NAMESPACE__	File with namespace	Prefix from lib/Compiler.php namespace stack
__TRAIT__	Inside trait method	Defer v2 (#144)

Area	Files	Notes
Compiler	lib/Compiler.php — compileMagicConst() or Expr\ClassConstFetch path	Mirror __DIR__ lowering from #85
VM	lib/VM.php	Read from call frame / class metadata
JIT	lib/JIT.php	Embed string literals when monomorphic
Lint	lib/Lint/UnsupportedRegistry.php	Until done, map to #199
Tests	test/compliance/cases/magic_const_class_method.phpt	VM + JIT when #98 runs
Matrix	script/capability-matrix.php	Row per constant (#611 OOP rows)

Namespaced example

namespace App\\Web;
class Home {
    public function label(): string { return __NAMESPACE__ . '\\\\' . __CLASS__; }
}
// App\\Web\\Home

Acceptance criteria

./script/ci-fast.sh --filter magic_const
docker run --rm -v "$(pwd):/compiler" -w /compiler php-compiler:22.04-dev \
  ./script/ci-fast.sh --filter magic_const

New PHPT passes VM; JIT when LLVM present (#98).

Dependencies

• Language: PHP namespaces (namespace, use, qualified names) #84 — namespaces in compiler
• Language: Class methods and property access in JIT #58 / Language: Visibility, constructors, and destructors #145 — class methods (call frame context)
• Language: Magic constants __DIR__, __FILE__, __LINE__ for multi-file apps #85 — __DIR__ / __FILE__ pattern to reuse

Related

• DevEx: Builtin capability matrix (VM / JIT / AOT per function) #176 / Docs: OOP syntax rows in capabilities matrix (match #569) #611 — capabilities matrix
• ROADMAP 🗺️ ROADMAP: Self-host + web-capable PHP subset (living) #78 Phase 1 Language

[PurHur]

Fixed in #629 (merged): __FUNCTION__ in methods and file-level __NAMESPACE__ via patches/php-cfg-magic-constants.patch. VM compliance PHPTs + MagicConstantsTest.