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Language: bare throw; rethrow — parse error in catch block (Zend/zend_compile.c) #17691
Description
Category
language · php-src-strict
Problem
Zend PHP 8.0+ allows a bare throw; inside a catch block to rethrow the active exception. This compiler rejects the construct at parse time (unexpected token ";"), so exception propagation chains cannot match php-src.
| Repro | Zend 8.2+ | VM (2026-07-10) |
|---|---|---|
catch (Ex $e) { throw; } |
rethrows to outer catch, prints inner |
Fatal error: syntax error, unexpected token ";" |
php-src reference
- php/php-src
Zend/zend_compile.c—ZEND_THROWwithout an expression for rethrow - php/php-src
Zend/zend_ast.c— bare throw AST node
PHP implementation target
lib/Parser// compile pipeline — acceptthrow;as rethrow when inside catch scopelib/VM.php/lib/JIT/— propagate active exception object without a new expr- VM/JIT/AOT must agree on rethrow semantics
Repro
./script/docker-exec.sh -- bash -lc 'php bin/vm.php test/repro/maintainer_gap_bare_throw_rethrow.php'Done when
-
test/repro/maintainer_gap_bare_throw_rethrow.phpprintsinnerand exits 0 on VM - JIT repro green for the same script
- Compliance
.phptguard undertest/compliance/cases/language/bare_throw_rethrow.phpt - php-src-strict; no php-compiler-strict shortcut
Activity
PurHur commentedon Jul 10, 2026
claim: cursor-agent-lane-a — starting this run
Add maintainer_gap repro and compliance guard for bare throw; rethrow (…
PurHur commentedon Jul 10, 2026
Merged via #17705.
Bare `throw;` catch rethrow was already implemented on the PHP 8.4 forward profile (`SourceBareThrowRewriter` → `TYPE_RETHROW`). This PR adds the missing maintainer-gap repro and compliance guard.
Verification (all green):
Reference profile (8.2) correctly rejects bare `throw;` per Zend; enable via `PHP_COMPILER_PROFILE=8.4` or source pragma `// php-compiler-language-profile=8.4`.