Remove support for preloading on Windows

Due to ASLR restrictions, preloading on Windows does not work with
any code that has preloading dependencies on internal classes.
This effectively makes it unusable for any non-trivial codebase.

Instead of pretending like preloading is going to work, only to
make people realize that it really doesn't once they get beyond
a dummy example, we disable support for preloading on Windows
entirely.

Closes GH-4999.

Author: nikic

NEWS

@@ -4,6 +4,7 @@ PHP                                                                        NEWS
 ?? ??? ????, PHP 7.4.2
 
 - Core:
+  . Preloading support on Windows has been disabled. (Nikita)
   . Fixed bug #79022 (class_exists returns True for classes that are not ready
     to be used). (Laruence)
   . Fixed bug #78929 (plus signs in cookie values are converted to spaces).

ext/ffi/tests/300-win32.phpt

@@ -1,7 +1,10 @@
 --TEST--
 Bug #78761 (Zend memory heap corruption with preload and casting)
 --SKIPIF--
-<?php require_once('skipif.inc'); ?>
+<?php
+require_once('skipif.inc');
+if (PHP_OS_FAMILY == 'Windows') die('skip Preloading is not supported on Windows');
+?>
 --INI--
 opcache.enable_cli=1
 opcache.preload={PWD}/bug78761_preload.php

ext/ffi/tests/bug78761.phpt

@@ -3397,13 +3397,6 @@ static void get_unlinked_dependency(zend_class_entry *ce, const char **kind, con
 			*name = ZSTR_VAL(ce->parent_name);
 			return;
 		}
-#ifdef ZEND_WIN32
-		if (p->type == ZEND_INTERNAL_CLASS) {
-			*kind = "Windows can't link to internal parent ";
-			*name = ZSTR_VAL(ce->parent_name);
-			return;
-		}
-#endif
 		if (!(p->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
 			*kind = "Parent with unresolved initializers ";
 			*name = ZSTR_VAL(ce->parent_name);
@@ -3523,13 +3516,6 @@ static zend_bool preload_try_resolve_property_types(zend_class_entry *ce)
 				continue;
 			}
 			if (p != ce) {
-#ifdef ZEND_WIN32
-				/* On Windows we can't link with internal class, because of ASLR */
-				if (p->type == ZEND_INTERNAL_CLASS) {
-					ok = 0;
-					continue;
-				}
-#endif
 				if (!(p->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
 					ok = 0;
 					continue;
@@ -3666,10 +3652,6 @@ static void preload_link(void)
 					parent = zend_hash_find_ptr(EG(class_table), key);
 					zend_string_release(key);
 					if (!parent) continue;
-#ifdef ZEND_WIN32
-					/* On Windows we can't link with internal class, because of ASLR */
-					if (parent->type == ZEND_INTERNAL_CLASS) continue;
-#endif
 					if (!(parent->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
 						continue;
 					}
@@ -3686,13 +3668,6 @@ static void preload_link(void)
 							found = 0;
 							break;
 						}
-#ifdef ZEND_WIN32
-						/* On Windows we can't link with internal class, because of ASLR */
-						if (p->type == ZEND_INTERNAL_CLASS) {
-							found = 0;
-							break;
-						}
-#endif
 						if (!(p->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
 							found = 0;
 							break;
@@ -3709,13 +3684,6 @@ static void preload_link(void)
 							found = 0;
 							break;
 						}
-#ifdef ZEND_WIN32
-						/* On Windows we can't link with internal class, because of ASLR */
-						if (p->type == ZEND_INTERNAL_CLASS) {
-							found = 0;
-							break;
-						}
-#endif
 					}
 					if (!found) continue;
 				}
@@ -3859,26 +3827,6 @@ static void preload_link(void)
 	} ZEND_HASH_FOREACH_END();
 }
 
-#ifdef ZEND_WIN32
-static void preload_check_windows_restriction(zend_class_entry *scope, zend_class_entry *ce) {
-	if (ce && ce->type == ZEND_INTERNAL_CLASS) {
-		zend_error_noreturn(E_ERROR,
-			"Class %s uses internal class %s during preloading, which is not supported on Windows",
-			ZSTR_VAL(scope->name), ZSTR_VAL(ce->name));
-	}
-}
-
-static void preload_check_windows_restrictions(zend_class_entry *scope) {
-	uint32_t i;
-
-	preload_check_windows_restriction(scope, scope->parent);
-
-	for (i = 0; i < scope->num_interfaces; i++) {
-		preload_check_windows_restriction(scope, scope->interfaces[i]);
-	}
-}
-#endif
-
 static inline int preload_update_class_constants(zend_class_entry *ce) {
 	/* This is a separate function to work around what appears to be a bug in GCC
 	 * maybe-uninitialized analysis. */
@@ -3931,10 +3879,6 @@ static void preload_ensure_classes_loadable() {
 				continue;
 			}
 
-#ifdef ZEND_WIN32
-			preload_check_windows_restrictions(ce);
-#endif
-
 			if (!(ce->ce_flags & ZEND_ACC_CONSTANTS_UPDATED)) {
 				if (preload_update_class_constants(ce) == FAILURE) {
 					zend_error_noreturn(E_ERROR,
@@ -4601,9 +4545,11 @@ static int accel_finish_startup(void)
 	}
 
 	if (ZCG(accel_directives).preload && *ZCG(accel_directives).preload) {
-#ifndef ZEND_WIN32
+#ifdef ZEND_WIN32
+		zend_accel_error(ACCEL_LOG_ERROR, "Preloading is not supported on Windows");
+		return FAILURE;
+#else
 		int in_child = 0;
-#endif
 		int ret = SUCCESS;
 		int rc;
 		int orig_error_reporting;
@@ -4637,7 +4583,6 @@ static int accel_finish_startup(void)
 			return SUCCESS;
 		}
 
-#ifndef ZEND_WIN32
 		if (geteuid() == 0) {
 			pid_t pid;
 			struct passwd *pw;
@@ -4701,7 +4646,6 @@ static int accel_finish_startup(void)
 				zend_accel_error(ACCEL_LOG_WARNING, "\"opcache.preload_user\" is ignored");
 			}
 		}
-#endif
 
 		sapi_module.activate = NULL;
 		sapi_module.deactivate = NULL;
@@ -4713,11 +4657,9 @@ static int accel_finish_startup(void)
 		sapi_module.ub_write = preload_ub_write;
 		sapi_module.flush = preload_flush;
 
-#ifndef ZEND_WIN32
 		if (in_child) {
 			CG(compiler_options) |= ZEND_COMPILE_PRELOAD_IN_CHILD;
 		}
-#endif
 		CG(compiler_options) |= ZEND_COMPILE_PRELOAD;
 		CG(compiler_options) |= ZEND_COMPILE_HANDLE_OP_ARRAY;
 		CG(compiler_options) |= ZEND_COMPILE_IGNORE_INTERNAL_CLASSES;
@@ -4792,17 +4734,16 @@ static int accel_finish_startup(void)
 
 		sapi_activate();
 
-#ifndef ZEND_WIN32
 		if (in_child) {
 			if (ret == SUCCESS) {
 				exit(0);
 			} else {
 				exit(2);
 			}
 		}
-#endif
 
 		return ret;
+#endif
 	}
 
 	return SUCCESS;

ext/opcache/ZendAccelerator.c

@@ -6,7 +6,10 @@ opcache.enable_cli=1
 opcache.optimization_level=-1
 opcache.preload={PWD}/preload_bug78014.inc
 --SKIPIF--
-<?php require_once('skipif.inc'); ?>
+<?php
+require_once('skipif.inc');
+if (PHP_OS_FAMILY == 'Windows') die('skip Preloading is not supported on Windows');
+?>
 --FILE--
 <?php
 class B extends A {

ext/opcache/tests/bug78014.phpt

@@ -6,7 +6,10 @@ opcache.enable_cli=1
 opcache.optimization_level=-1
 opcache.preload={PWD}/preload_bug78175.inc
 --SKIPIF--
-<?php require_once('skipif.inc'); ?>
+<?php
+require_once('skipif.inc');
+if (PHP_OS_FAMILY == 'Windows') die('skip Preloading is not supported on Windows');
+?>
 --FILE--
 OK
 --EXPECT--

ext/opcache/tests/bug78175.phpt

@@ -6,7 +6,10 @@ opcache.enable_cli=1
 opcache.optimization_level=-1
 opcache.preload={PWD}/preload_bug78175_2.inc
 --SKIPIF--
-<?php require_once('skipif.inc'); ?>
+<?php
+require_once('skipif.inc');
+if (PHP_OS_FAMILY == 'Windows') die('skip Preloading is not supported on Windows');
+?>
 --FILE--
 <?php
 var_dump(get_class(Loader::getLoader()));

ext/opcache/tests/bug78175_2.phpt

@@ -6,10 +6,13 @@ opcache.enable_cli=1
 opcache.optimization_level=-1
 opcache.preload={PWD}/preload_bug78376.inc
 --SKIPIF--
-<?php require_once('skipif.inc'); ?>
+<?php
+require_once('skipif.inc');
+if (PHP_OS_FAMILY == 'Windows') die('skip Preloading is not supported on Windows');
+?>
 --FILE--
 <?php
 var_dump(\A::$a);
 ?>
 --EXPECT--
-string(4) "aaaa"
+string(4) "aaaa"

ext/opcache/tests/bug78376.phpt

@@ -6,7 +6,10 @@ opcache.enable_cli=1
 opcache.optimization_level=-1
 opcache.preload={PWD}/preload_bug78937.inc
 --SKIPIF--
-<?php require_once('skipif.inc'); ?>
+<?php
+require_once('skipif.inc');
+if (PHP_OS_FAMILY == 'Windows') die('skip Preloading is not supported on Windows');
+?>
 --FILE--
 <?php
 class Bar {

ext/opcache/tests/bug78937_1.phpt

@@ -6,7 +6,10 @@ opcache.enable_cli=1
 opcache.optimization_level=-1
 opcache.preload={PWD}/preload_bug78937.inc
 --SKIPIF--
-<?php require_once('skipif.inc'); ?>
+<?php
+require_once('skipif.inc');
+if (PHP_OS_FAMILY == 'Windows') die('skip Preloading is not supported on Windows');
+?>
 --FILE--
 <?php
 include(__DIR__ . "/preload_bug78937.inc");
@@ -19,4 +22,4 @@ Warning: Can't preload unlinked class Foo: Unknown parent Bar in %spreload_bug78
 
 Warning: Can't preload unlinked class class@anonymous: Unknown parent Bar in %spreload_bug78937.inc on line 3
 object(class@anonymous)#%d (0) {
-}
+}