php-in-php: delete JitVarExportKernel — always JitVmHelperLink + VarExportJitHelper PHP (#1492)

[PurHur]

Category

php-in-php · runtime-shrink (#1492, peer Htmlspecialchars #20487 / HashEquals #20469 / Bin2hex #20452)

Problem

lib/JIT/Builtin/StringVarExport.php still forks thin standalone AOT (isThinStandaloneAotMain) through ext/standard/JitVarExportKernel.php (~91 LOC). Both thin and embed paths already NestedJIT VarExportJitHelper — the kernel is only a duplicate coerce bridge + VmActiveContext init. Peer string transforms (StringHtmlspecialchars, StringBin2hex, StringHashEquals) always route through JitVmHelperLink::ensureBridge.

Path	Today	Target
Embed / non-thin	VarExportJitHelper via bridge	unchanged (unified ensureBridge)
Thin standalone AOT	JitVarExportKernel (same helper)	VarExportJitHelper via ensureBridge

php-src reference

• php/php-src ext/standard/var.c — php_var_export_ex

PHP implementation target

• lib/JIT/Builtin/StringVarExport.php — always JitVmHelperLink::ensureBridge after VmActiveContext init (drop isThinStandaloneAotMain fork)
• Delete ext/standard/JitVarExportKernel.php
• Update VarExportRuntimeShrinkTest + spine require list
• Mark helper runtime_unsafe in emit-helper-runtime-object.php until prelinked unit is green under HELPER_RUNTIME_O (peer php-in-php: delete JitHtmlspecialcharsKernel — always JitVmHelperLink + HtmlspecialcharsJitHelper PHP (#1492) #20487)

Repro

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
vendor/bin/phpunit test/unit/VarExportRuntimeShrinkTest.php
printf "%s\n" "<?php echo var_export([1,\"a\"], true);" > /tmp/ve.php
PHP_COMPILER_HELPER_RUNTIME_O=0 php bin/compile.php -o /tmp/ve /tmp/ve.php && /tmp/ve
make bootstrap-selfhost-vm-driver-execute-probe
'

Done when

• JitVarExportKernel.php deleted
• isThinStandaloneAotMain / kernel entry gone from StringVarExport
• AOT var_export smoke green
• Shrink + spine sync green
• make bootstrap-selfhost-vm-driver-execute-probe green
• PR body cites lines removed

Refs #1492, #20077, #19430, #20487, #10533

[PurHur]

claim: PHP Runtime → PHP — starting this run

TRY_FIRST gates (this workspace):

Gate	Result
make bootstrap-selfhost-link	OK /compiler/build/selfhost
php script/bootstrap-inventory.php --check	OK 5709/5709
./script/release-readiness.sh --json	user_release_ready: yes
make bootstrap-selfhost-helloworld	OK Hello World
Open PRs / #19215	none / already closed

Implementing: delete JitVarExportKernel, always JitVmHelperLink::ensureBridge + VarExportJitHelper (peer #20487).

[PurHur]

Merged: #20595

Shrink: deleted ext/standard/JitVarExportKernel.php (91 LOC); net −84 lines. Always JitVmHelperLink::ensureBridge + VarExportJitHelper.

Verification: shrink test OK (4/4); VM+JIT var_export([1,\"a\"], true) OK; bootstrap-selfhost-vm-driver-execute-probe OK; inventory OK 5708/5708; spine sync OK.

Thin user-script AOT smoke segfaults on master with the old kernel too (pre-existing NestedJIT/VM-context caveat) — not regressed by this PR.

[PurHur]

Merged: #20595 → 94d2b9b38

Shrink: deleted ext/standard/JitVarExportKernel.php (91 LOC); net −84 lines on the kernel commit. Always JitVmHelperLink::ensureBridge + VarExportJitHelper.

Also: spine-covered 4 inventory files master had listed without requires (gmp_divexact/gmp_kronecker/SQLite3CreateAggregate/SQLite3LoadExtension) so Pillar 1 spine sync stays green (5715→5714).

Verification: shrink OK; VM+JIT OK; inventory OK 5714/5714; spine sync OK; bootstrap-selfhost-vm-driver-execute-probe OK.

Thin user-script AOT bin/compile.php segfault for this snippet remains pre-existing on master (NestedJIT/VM-context caveat) — not regressed.