Language: implements clause — compile-time missing method fatal (Zend zend_inheritance.c parity) #3536

Category

language

Problem

class C implements I { } parses and runs when interface methods are missing. Zend fails at compile time with a fatal error listing unimplemented interface methods.

This is called out as a gap on #144; split here for a single claimable fix.

php-src reference

• Zend/zend_inheritance.c — zend_do_implement_interface(), zend_class_implements_interface()
• Zend/zend_compile.c — interface method table vs class method table at declare time

Repro (today)

<?php
interface I {
    public function required(): int;
}
class C implements I {
}
new C();

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php repro.php'
# Zend: Fatal error: Class C contains 1 abstract method...
# This compiler: succeeds (no error)

Scope (this repo)

Done when

• Repro fails at compile time with message shape similar to Zend (class name + missing method list)
• Valid implements classes still compile (test/compliance/cases/language/implements_ok.phpt)
• Language: Traits, abstract classes, and interfaces #144 checklist updated — do not duplicate trait adaptation work (Language: TraitUseAdaptation — insteadof / as alias (Zend compile parity) #3238)

Related

• Language: Traits, abstract classes, and interfaces #144 — traits / abstract / interfaces umbrella
• Compiler: Class inheritance (extends) and interfaces #101 — extends inheritance

Links

• North star: Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492