Stdlib: strcmp()/strncmp() null operands — TypeError not empty-string coercion (ext/standard/string.c)

[PurHur]

Category

stdlib

Problem

Zend coerces null string operands to "" for internal string-compare builtins (strcmp, strncmp, etc.) and returns an integer compare result. This compiler’s VM raises TypeError on null, changing observable behavior for legacy code and php-src-strict parity.

Distinct from #4346 (array/object operands must TypeError) and #8825 (enum case operands must TypeError).

php-src reference

• php/php-src ext/standard/string.c — PHP_FUNCTION(strcmp), PHP_FUNCTION(strncmp) (ZPP coerces null to empty string)

Repro

<?php
echo strcmp(null, 'a'), "\n";
echo strncmp(null, 'a', 1), "\n";
echo strcmp('a', null), "\n";

Committed: test/repro/maintainer_gap_strcmp_null_coerce.php

./script/docker-exec.sh -- bash -lc '
  source script/php-env.sh
  php test/repro/maintainer_gap_strcmp_null_coerce.php
  php bin/vm.php test/repro/maintainer_gap_strcmp_null_coerce.php
'

Call	Zend PHP 8.2	This compiler VM
strcmp(null, 'a')	-1	TypeError
strncmp(null, 'a', 1)	-1	TypeError
strcmp('a', null)	1	(fatal on first null arg in script)

Scope (PHP-in-PHP)

Layer	Path
VM	ext/standard/strcmp.php, strncmp.php, shared VmString::coerceStringBuiltinArg guards
JIT/AOT	matching lib/JIT/Builtin/ handlers
Tests	test/compliance/cases/stdlib/strcmp_null_coerce.phpt

Done when (php-src-strict)

• null operands coerce to "" and return Zend compare integers (no TypeError).
• Enum/array/object rejection behavior from Stdlib: str_contains()/str_starts_with()/str_ends_with()/strcmp()/strcoll() — enum case operands must TypeError (ext/standard/string.c) #8825 / Stdlib: strcmp family — TypeError for array/object operands (ext/standard/string.c parity) #4346 unchanged.
• VM/JIT/AOT agree on repro.

[PurHur]

claim: PHP Compiler STD Lib — batch (issues #11260, #11261, #11263)

[PurHur]

Merged #11270 — null coerce without strict_types; #10908 strict_types test still green; AOT compile.php -l green.