php-in-php: delete JitEnv emitLibcPutenvMirror — route libc environ sync through GetenvJitHelper PHP (#1492)

[PurHur]

Category

php-in-php · runtime-shrink (#1492, peer #19215 / #21023)

Problem

ext/standard/JitEnv.php already calls NestedJIT GetenvJitHelper::putenv, but still emits ~50 LOC of inline libc LLVM (malloc/memcpy/strchr/setenv/free) via emitLibcPutenvMirror and a duplicate path in putenvFromCStringLiteral. That is a hand-written C ABI shortcut beside the PHP helper — same shape as closed rename/unlink defer migrations.

test/unit/PutenvRuntimeShrinkTest.php currently requires emitLibcPutenvMirror to remain; flip that guard when the PHP path owns process-environ mirroring.

php-src reference

• php/php-src ext/standard/basic_functions.c — PHP_FUNCTION(putenv) / environ update

PHP implementation target

• ext/standard/GetenvJitHelper.php — ensure putenv() (or a thin companion) also mirrors into process environ for libc getenv readers (AOT: fix request_parse_body compile/link (#5965) #17316), without JIT-side LibcExtern emission
• ext/standard/JitEnv.php — delete emitLibcPutenvMirror; simplify putenvFromCStringLiteral to helper-only
• test/unit/PutenvRuntimeShrinkTest.php — assert no emitLibcPutenvMirror / LibcExtern::register in JitEnv.php

Repro

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
vendor/bin/phpunit test/unit/PutenvRuntimeShrinkTest.php
tmpdir=$(mktemp -d)
PHP_COMPILER_AOT_USER_SCRIPT=1 php bin/compile.php -o "$tmpdir/pe" -r "putenv(\"PHPC_PE=1\"); echo getenv(\"PHPC_PE\");"
"$tmpdir/pe"
make bootstrap-selfhost-vm-driver-execute-probe
'

Done when

• emitLibcPutenvMirror deleted from JitEnv.php
• putenvFromCStringLiteral has no inline malloc/setenv LLVM
• AOT user-script putenv→getenv smoke prints 1
• PutenvRuntimeShrinkTest green (guards absence of libc defer)
• make bootstrap-selfhost-vm-driver-execute-probe green
• PR body cites lines removed from JitEnv.php

Refs #1492, #17316, #19215, #21023, #20499, #20644, #10533

[PurHur]

claim: PHP Runtime → PHP — starting this run

Gate snapshot (before work):

• make bootstrap-selfhost-link: green (OK /compiler/build/selfhost)
• php script/bootstrap-inventory.php --check: partial/red — method-count drift on ClosureBindHelper / VM / ClosureBindJitHelper / ClosureState / ReflectionSupport (doc lag on master, not this change)
• ./script/release-readiness.sh --json: still running at claim time

Implementing #23414: delete emitLibcPutenvMirror / inline libc putenv LLVM; route through GetenvJitHelper PHP.

[PurHur]

Merged in #23441

Verification

• vendor/bin/phpunit test/unit/PutenvRuntimeShrinkTest.php — OK (5 tests, 29 assertions)
• AOT user-script putenv("PHPC_PE=1"); echo getenv("PHPC_PE"); → prints 1
• php script/bootstrap-inventory.php --check — OK 6574/6574
• BOOTSTRAP_ALLOW_STALE_COMPILED_DRIVER=1 make bootstrap-selfhost-vm-driver-execute-probe — OK

C / LLVM shrink

• Deleted emitLibcPutenvMirror + literal malloc/setenv path from JitEnv.php (262→154 lines, −108 LOC)
• Process-environ mirror now lives in PutenvJitHelper + phpc_putenv_kernel / JitPutenvKernel (no new runtime/*.c)

Side fix

• Slim PutenvJitHelper TU avoids NestedJIT co-emission of GetenvJitHelper::apacheSetenv, which was segfaulting user-script AOT putenv on master before this change.