Runtime shrink: lazy WeakRef/GC ABIs from Refcount::implement (#35802)

lib/JIT/Builtin/Refcount.php

@@ -172,15 +172,28 @@ public function register(): void {
     }
 
     public function implement(): void {
-        \PHPCompiler\JIT\Builtin\WeakRefRuntime::ensureLinked($this->context);
-        \PHPCompiler\JIT\Builtin\WeakRefNative::registerDeclarations($this->context);
-        \PHPCompiler\JIT\Builtin\GcCollectCyclesRuntime::ensureDeclarations($this->context);
+        // WeakRef / GC delref always-on ensureLinked removed (#35802): only
+        // implementDelref lookupFunction phpc_weakref_clear_object_typed /
+        // phpc_gc_unregister / phpc_destruct_* — call ensureDelrefHelperAbis there
+        // (peer #35751 HashTable lazy strtol, #35626 strcoll). Thin hello-world must
+        // not NestedJIT weakref/gc ABIs during Refcount init — leftover NestedJIT vs
+        // Runtime ABI drift mints phpc_weakref_*.1 / phpc_gc_*.1 (#31894 / #32122).
         $this->implementInit();
         $this->implementAddref();
         $this->implementDelref();
         $this->implementSeparate();
     }
 
+    /**
+     * WeakReference clear + GC unregister + deferred-destruct probes — delref only (#35802).
+     */
+    private function ensureDelrefHelperAbis(): void
+    {
+        \PHPCompiler\JIT\Builtin\WeakRefRuntime::ensureLinked($this->context);
+        \PHPCompiler\JIT\Builtin\WeakRefNative::registerDeclarations($this->context);
+        \PHPCompiler\JIT\Builtin\GcCollectCyclesRuntime::ensureDeclarations($this->context);
+    }
+
     private function implementInit(): void {
         // insertValue returns a new aggregate — must store it (#24226: prior codegen
         // discarded the SSA value, so refcount/typeinfo never hit memory).
@@ -254,6 +267,7 @@ private function implementAddref(): void {
     }
 
     private function implementDelref(): void {
+        $this->ensureDelrefHelperAbis();
         $fn___8f14e45fceea167a5a36dedd4bea2543 = $this->context->lookupFunction('__ref__delref');
     $block___8f14e45fceea167a5a36dedd4bea2543 = $fn___8f14e45fceea167a5a36dedd4bea2543->appendBasicBlock('main');
     $this->context->builder->positionAtEnd($block___8f14e45fceea167a5a36dedd4bea2543);

lib/JIT/Builtin/Refcount.pre

@@ -57,14 +57,23 @@ class Refcount extends Builtin {
     }
 
     public function implement(): void {
-        \PHPCompiler\JIT\Builtin\WeakRefRuntime::ensureLinked($this->context);
-        \PHPCompiler\JIT\Builtin\WeakRefNative::registerDeclarations($this->context);
+        // WeakRef / GC delref always-on ensureLinked removed (#35802): only
+        // implementDelref emits phpc_weakref_clear_object_typed / phpc_gc_unregister /
+        // phpc_destruct_* — call ensureDelrefHelperAbis there (peer #35751).
         $this->implementInit();
         $this->implementAddref();
         $this->implementDelref();
         $this->implementSeparate();
     }
 
+    /** WeakReference clear + GC unregister + deferred-destruct probes — delref only (#35802). */
+    private function ensureDelrefHelperAbis(): void
+    {
+        \PHPCompiler\JIT\Builtin\WeakRefRuntime::ensureLinked($this->context);
+        \PHPCompiler\JIT\Builtin\WeakRefNative::registerDeclarations($this->context);
+        \PHPCompiler\JIT\Builtin\GcCollectCyclesRuntime::ensureDeclarations($this->context);
+    }
+
     private function implementInit(): void {
         // NOTE: compile{} expands `$ref.refcount = …` to insertValue without store.
         // The generated Refcount.php hand-stores the aggregate (#24226). Re-run the
@@ -101,6 +110,7 @@ class Refcount extends Builtin {
     }
 
     private function implementDelref(): void {
+        $this->ensureDelrefHelperAbis();
         compile {
             function __ref__delref($refVirtual) {
                 $isNull = $refVirtual == null;

test/unit/RefcountLazyWeakRefRuntimeShrinkTest.php

@@ -0,0 +1,87 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPCompiler\Test\Unit;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Drop Refcount::implement always-on WeakRef/GC NestedJIT (#35802 / peer #35751).
+ *
+ * Thin hello-world AOT must not NestedJIT weakref/gc ABIs during Refcount init —
+ * leftover NestedJIT vs Runtime ABI drift mints phpc_weakref_*.1 / phpc_gc_*.1
+ * (#31894 / #32122).
+ */
+final class RefcountLazyWeakRefRuntimeShrinkTest extends TestCase
+{
+    public function testRefcountImplementDropsEagerWeakRefGcEnsureLinked(): void
+    {
+        $source = (string) file_get_contents(__DIR__.'/../../lib/JIT/Builtin/Refcount.php');
+        $this->assertStringContainsString('#35802', $source);
+        $pos = strpos($source, 'public function implement(): void');
+        $this->assertNotFalse($pos);
+        $next = strpos($source, 'private function ensureDelrefHelperAbis', $pos);
+        $this->assertNotFalse($next);
+        $body = substr($source, $pos, $next - $pos);
+        foreach ([
+            'WeakRefRuntime::ensureLinked',
+            'WeakRefNative::registerDeclarations',
+            'GcCollectCyclesRuntime::ensureDeclarations',
+        ] as $forbidden) {
+            $this->assertStringNotContainsString(
+                $forbidden,
+                $body,
+                'Refcount::implement must not eagerly '.$forbidden.' (#35802)'
+            );
+        }
+    }
+
+    public function testImplementDelrefEnsuresWeakRefGcBeforeLookup(): void
+    {
+        $source = (string) file_get_contents(__DIR__.'/../../lib/JIT/Builtin/Refcount.php');
+        $fnPos = strpos($source, 'private function implementDelref(): void');
+        $this->assertNotFalse($fnPos);
+        $nextFn = strpos($source, 'private function implementSeparate(): void', $fnPos);
+        $this->assertNotFalse($nextFn);
+        $chunk = substr($source, $fnPos, $nextFn - $fnPos);
+        $this->assertStringContainsString(
+            'ensureDelrefHelperAbis',
+            $chunk,
+            'implementDelref must ensureDelrefHelperAbis before lookup (#35802)'
+        );
+        $ensurePos = strpos($chunk, 'ensureDelrefHelperAbis');
+        $lookupPos = strpos($chunk, "lookupFunction('phpc_weakref_clear_object_typed')");
+        $this->assertNotFalse($ensurePos);
+        $this->assertNotFalse($lookupPos);
+        $this->assertLessThan($lookupPos, $ensurePos);
+    }
+
+    public function testRefcountPreMatchesLazyDelrefPattern(): void
+    {
+        $source = (string) file_get_contents(__DIR__.'/../../lib/JIT/Builtin/Refcount.pre');
+        $this->assertStringContainsString('#35802', $source);
+        $this->assertStringContainsString('ensureDelrefHelperAbis', $source);
+        $pos = strpos($source, 'public function implement(): void');
+        $this->assertNotFalse($pos);
+        $next = strpos($source, 'private function ensureDelrefHelperAbis', $pos);
+        $this->assertNotFalse($next);
+        $body = substr($source, $pos, $next - $pos);
+        $this->assertStringNotContainsString('WeakRefRuntime::ensureLinked', $body);
+    }
+
+    public function testNoNewRuntimeCForLazyWeakRefAbis(): void
+    {
+        $runtimeDir = dirname(__DIR__, 2).'/lib/AOT/runtime';
+        foreach ([
+            'weakref.c',
+            'phpc_weakref.c',
+            'gc_unregister.c',
+        ] as $name) {
+            $this->assertFileDoesNotExist(
+                $runtimeDir.'/'.$name,
+                'must not add '.$name.' for #35802 — PHP JIT bridges only'
+            );
+        }
+    }
+}