Regression: strlen()/strtolower()/strtoupper()/strrev(null) — coerce on 8.4 forward profile not TypeError (re-#18599/#18190, ext/standard/string.c)

[PurHur]

Category

stdlib · php-src-strict · PHP_COMPILER_PROFILE=8.4 forward null guards

Problem

Closed #18599 / #18780 / #18190 required null→TypeError for core case/length builtins. Under PHP_COMPILER_PROFILE=8.4, master again coerces null → "" / 0 (2026-07-15). Sibling phonetic pair is green after #19251; this batch still coerces.

Repro	Zend 8.4 forward	VM PROFILE=8.4 (2026-07-15)
strlen(null)	TypeError	0
strtolower(null) / strtoupper(null)	TypeError	''
strrev(null)	TypeError	''

php-src reference

• php/php-src ext/standard/string.c — PHP_FUNCTION(strlen) / strtolower / strtoupper / strrev Z_PARAM_STR

PHP implementation target

• ext/standard/VmString.php — shared forward-profile null guard for case/length/rev batch
• lib/JIT/Builtin/String* — VM/JIT/AOT agree

Repro

./script/docker-exec.sh -- bash -lc 'export PHP_COMPILER_PROFILE=8.4
php -r '"'"'file_put_contents("/tmp/sl.php", "<?php
foreach ([\"strlen\",\"strtolower\",\"strtoupper\",\"strrev\"] as \$f) {
  try { var_export(\$f(null)); echo \" \$f:OK\\n\"; }
  catch (Throwable \$e) { echo \"\$f: \".get_class(\$e).\"\\n\"; }
}
");'"'"'
php bin/vm.php /tmp/sl.php'
# expect: *: TypeError · actual: *:OK coerced

Done when

• All four builtins throw TypeError on null under PHP_COMPILER_PROFILE=8.4 (VM/JIT/AOT)
• Compliance .phpt under test/compliance/cases/string/
• php-src-strict; no php-compiler-strict coerce shortcut

[PurHur]

claim: PHP Compiler STD Lib — starting this run

Pre-work gate snapshot (master):

• inventory: OK 4931/4931 (after regen)
• user_release_ready: no — first fail: spine-coverage (StringVarExportUserScriptLlvm.php missing from spine) then north-star5-fast (php-cfg-lazy-property: Parser getVisibility anchor missing)
• vm-driver-probe: OK

In-flight #17316/#5965: urlencoded putenv+request_parse_body multi-field echo AOT green; var_export/print_r user-script AOT still SIGABRT on master — holding that WIP; taking this strlen/case/rev null TypeError batch (#19276) for a mergeable php-src-strict fix.

[PurHur]

Merged via #19288.

Fix: strlen/strtolower/strtoupper/strrev now use shared Z_PARAM_STR guards (coerceZparamStrBuiltinArg / lowerZparamStr) under PHP_COMPILER_PROFILE=8.4; JitStrlen TypeError uses ExceptionBridge for AOT-safe fatals.

Verification: VM/JIT repro green; AOT per-builtin null probes exit 255 with TypeError; compliance + AOT phpunit filters green in Docker.