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Stdlib: sprintf()/printf()/vsprintf() object operands — LogicException not __toString coercion (ext/standard/spprintf.c) #13467
Description
Category
stdlib · php-src-strict
Problem
sprintf() / printf() / vsprintf() reject object operands for %s with LogicException: sprintf() %s requires a scalar value in this compiler build. Zend coerces via __toString() (or throws Error when conversion fails).
Concat ('x'.$obj.'y') and echo $obj already invoke __toString correctly.
php-src reference
ext/standard/spprintf.c—php_sprintfobject-to-stringext/standard/sprintf.c
Repro (verified 2026-06-29)
./script/docker-exec.sh -- bash -lc '
php test/repro/maintainer-parity-probes/probe_sprintf_object_tostring.php; echo ---;
php bin/vm.php test/repro/maintainer-parity-probes/probe_sprintf_object_tostring.php
php test/repro/maintainer-parity-probes/probe_printf_object_tostring.php; echo ---;
php bin/vm.php test/repro/maintainer-parity-probes/probe_printf_object_tostring.php
php test/repro/maintainer-parity-probes/probe_vsprintf_object.php; echo ---;
php bin/vm.php test/repro/maintainer-parity-probes/probe_vsprintf_object.php
'| Call | Zend | VM |
|---|---|---|
sprintf('%s', $obj) |
'obj' |
LogicException ❌ |
printf('%s', $obj) |
prints obj, returns 3 |
LogicException ❌ |
vsprintf('%s', [$obj]) |
'obj' |
LogicException ❌ |
Scope (PHP-in-PHP first)
| Layer | Path |
|---|---|
| Builtin | ext/standard/sprintf_.php, printf_.php, vsprintf_.php — use shared string-coercion helper (VmString::coerceStringBuiltinArg / JitStringBuiltinArg) before format dispatch |
| JIT | lib/JIT/Builtin/ sprintf family must match VM |
| Tests | test/compliance/cases/stdlib/sprintf_object_tostring.phpt |
Done when (php-src-strict)
- All three repro probes match Zend
- Object without
__toStringthrowsError(same as concat) - Enum case operands still follow enum string rules (Stdlib: str_pad()/str_pad_left() — enum case operands must TypeError (ext/standard/string.c, php-src-strict) #8850 family)
- No new C in
runtime/
Verification
./script/docker-exec.sh -- php bin/vm.php test/repro/maintainer-parity-probes/probe_sprintf_object_tostring.php
./script/docker-exec.sh -- php bin/vm.php test/repro/maintainer-parity-probes/probe_vsprintf_object.php
Activity
PurHur commentedon Jun 29, 2026
claim: PHP Runtime → PHP — batch (issues #13468 #13467)
Fix sprintf family %s coercion for Stringable objects (closes #13467). (
PurHur commentedon Jun 29, 2026
Merged via #13481 — sprintf/printf/vsprintf %s coerces Stringable via VmString::coerceOperand; VM+JIT compliance green.