Fix preloaded constant erroneously propagated to file-cached script

Since GH-15021 preloaded constants are propagated to compiled scripts. This is
problematic for file cache, which assumes all referenced zvals are either
persistently allocated or local to the current script. However, preloaded
constants live in shm as immutable, but not persistent.

To solve this, we'd need to duplicate propagated constants in the optimizer when
file cache is used. This is error prone given it needs to happen in many places.
It's debatable whether constant propagation is even correct in this case, as
running the preloaded script on a restart isn't guaranteed to produce the same
result.

Hence, avoid the issue for now by just not relying on preloaded symbols when
file cache is used.

Fixes GH-21052
Closes GH-21281

NEWS

@@ -39,6 +39,8 @@ PHP                                                                        NEWS
     (Petr Sumbera)
   . Fixed bug GH-21227 (Borked SCCP of array containing partial object).
     (ilutov)
+  . Fixed bug GH-21052 (Preloaded constant erroneously propagated to file-cached
+    script). (ilutov)
 
 - OpenSSL:
   . Fix a bunch of leaks and error propagation. (ndossche)

Zend/Optimizer/zend_optimizer.c

@@ -799,6 +799,9 @@ static bool zend_optimizer_ignore_class(zval *ce_zv, zend_string *filename)
 	zend_class_entry *ce = Z_PTR_P(ce_zv);
 
 	if (ce->ce_flags & ZEND_ACC_PRELOADED) {
+		if (CG(compiler_options) & ZEND_COMPILE_WITH_FILE_CACHE) {
+			return true;
+		}
 		Bucket *ce_bucket = (Bucket*)((uintptr_t)ce_zv - XtOffsetOf(Bucket, val));
 		size_t offset = ce_bucket - EG(class_table)->arData;
 		if (offset < EG(persistent_classes_count)) {
@@ -817,6 +820,9 @@ static bool zend_optimizer_ignore_function(zval *fbc_zv, zend_string *filename)
 		return false;
 	} else if (fbc->type == ZEND_USER_FUNCTION) {
 		if (fbc->op_array.fn_flags & ZEND_ACC_PRELOADED) {
+			if (CG(compiler_options) & ZEND_COMPILE_WITH_FILE_CACHE) {
+				return true;
+			}
 			Bucket *fbc_bucket = (Bucket*)((uintptr_t)fbc_zv - XtOffsetOf(Bucket, val));
 			size_t offset = fbc_bucket - EG(function_table)->arData;
 			if (offset < EG(persistent_functions_count)) {

ext/opcache/tests/gh21052.phpt

@@ -0,0 +1,32 @@
+--TEST--
+GH-21052: Preloaded constant erroneously propagated to file-cached script
+--CREDITS--
+Grummfy
+--EXTENSIONS--
+opcache
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.file_cache="{TMP}"
+opcache.preload={PWD}/gh21052_a.inc
+--SKIPIF--
+<?php
+if (PHP_OS_FAMILY == 'Windows') die('skip Preloading is not supported on Windows');
+?>
+--FILE--
+<?php
+require __DIR__ . '/gh21052_b.inc';
+?>
+--EXPECT--
+array(1) {
+  [0]=>
+  string(3) "foo"
+}
+array(1) {
+  [0]=>
+  string(3) "foo"
+}
+array(1) {
+  [0]=>
+  string(3) "foo"
+}

ext/opcache/tests/gh21052_a.inc

@@ -0,0 +1,13 @@
+<?php
+
+class A {
+    const C = ['foo'];
+
+    public static function test() {
+        return ['foo'];
+    }
+}
+
+function test() {
+    return ['foo'];
+}

ext/opcache/tests/gh21052_b.inc

@@ -0,0 +1,5 @@
+<?php
+
+var_dump(A::C);
+var_dump(A::test());
+var_dump(test());