Language: reject closure use($this) as Zend lexical fatal (#32152)

[PurHur]

Summary

• Reject function () use ($this) at compile time with Zend's Cannot use $this as lexical variable (Zend/zend_compile.c zend_compile_closure_binding()).
• Covers file-scope, method-scope, by-ref, and mixed use lists. Legal use ($a) and auto-bound $this without use are unchanged.
• PHP compile path only (lib/Compiler.php). No new runtime/*.c. php-src-strict.

Closes #32152

PHP implementation

• lib/Compiler.php — assertNoThisInClosureUseVars() on closure use lists
• php-src reference: php/php-src Zend/zend_compile.c zend_compile_closure_binding()

Test plan

• Issue VM repro
• Issue JIT repro
• ./script/phpunit.sh --filter ClosureUseThis
• Existing ClosureCompileTest|ClosureUseOperandAliasTest

Verification

./script/docker-exec.sh -- bash -lc 'php bin/vm.php test/repro/maintainer_gap_use_this.php > /tmp/vm32152.out 2>&1; echo EXIT:$?; cat /tmp/vm32152.out'
EXIT:255
PHP Fatal error:  Cannot use $this as lexical variable in /compiler/test/repro/maintainer_gap_use_this.php on line 7

./script/docker-exec.sh -- bash -lc 'php bin/jit.php test/repro/maintainer_gap_use_this.php > /tmp/jit32152.out 2>&1; echo EXIT:$?; cat /tmp/jit32152.out'
EXIT:255
PHP Fatal error:  Cannot use $this as lexical variable in /compiler/test/repro/maintainer_gap_use_this.php on line 7

./script/phpunit.sh --filter ClosureUseThis
OK (10 tests, 20 assertions)

./script/phpunit.sh --filter 'ClosureCompileTest|ClosureUseOperandAliasTest'
OK (12 tests, 19 assertions)

JIT stderr may also include a pre-existing php-cfg Optional parameter $extends deprecation; the fatal substring and rc=255 match Zend. Full VMTest/JITTest suites were not run (not green on master; compare by case name). No differential sweep (compile-time reject, no lowering/CFG shape change for valid programs).

Made with Cursor