Cleanup SPL autoload implementation

Replace EG(autoload_func) with a C level zend_autoload hook.
This avoids having to do one indirection through PHP function
calls. The need for EG(autoload_func) was a leftover from the
__autoload() implementation.

Additionally, drop special-casing of spl_autoload(), and instead
register it just like any other autoloading function. This fixes
bug #71236 as a side-effect.

Finally, change spl_autoload_functions() to always return an array.
The distinction between false and an empty array no longer makes
sense here.

Closes GH-5696.

Author: nikic

NEWS

@@ -160,6 +160,10 @@ PHP                                                                        NEWS
 - SQLite3:
   . Added SQLite3::setAuthorizer() and respective class constants. (bohwaz)
 
+- SPL:
+  . Fixed bug #71236 (Second call of spl_autoload_register() does nothing if it
+    has no arguments). (Nikita)
+
 - Standard:
   . Implemented FR #78638 (__PHP_Incomplete_Class should be final). (Laruence)
   . Fixed bug #77204 (getimagesize(): Read error! should mention file path).

Zend/tests/bug49908.phpt

@@ -29,9 +29,7 @@ string(3) "Bar"
 
 Fatal error: Uncaught Exception: Bar in %s:%d
 Stack trace:
-#0 [internal function]: {closure}('Bar')
-#1 %s(%d): spl_autoload_call('Bar')
-#2 [internal function]: {closure}('Foo')
-#3 %s(%d): spl_autoload_call('Foo')
-#4 {main}
+#0 %s(%d): {closure}('Bar')
+#1 %s(%d): {closure}('Foo')
+#2 {main}
   thrown in %s on line %d

Zend/tests/generators/bug65161.phpt

@@ -19,8 +19,7 @@ foreach (testGenerator() as $i);
 --EXPECTF--
 Fatal error: Uncaught Error: Call to undefined function foo() in %s:%d
 Stack trace:
-#0 [internal function]: autoload('SyntaxError')
-#1 %s(%d): spl_autoload_call('SyntaxError')
-#2 %s(%d): testGenerator()
-#3 {main}
+#0 %s(%d): autoload('SyntaxError')
+#1 %s(%d): testGenerator()
+#2 {main}
   thrown in %s on line %d

Zend/tests/type_declarations/variance/loading_exception1.phpt

@@ -44,6 +44,5 @@ Class A does not exist
 
 Fatal error: During inheritance of B with variance dependencies: Uncaught Exception: Class A does not exist in %s:%d
 Stack trace:
-#0 [internal function]: {closure}('A')
-#1 %s(%d): spl_autoload_call('A')
-#2 {main} in %s on line %d
+#0 %s(%d): {closure}('A')
+#1 {main} in %s on line %d

Zend/tests/type_declarations/variance/loading_exception2.phpt

@@ -46,6 +46,5 @@ Class I does not exist
 
 Fatal error: During inheritance of B with variance dependencies: Uncaught Exception: Class I does not exist in %s:%d
 Stack trace:
-#0 [internal function]: {closure}('I')
-#1 %s(%d): spl_autoload_call('I')
-#2 {main} in %s on line %d
+#0 %s(%d): {closure}('I')
+#1 {main} in %s on line %d

Zend/tests/use_unlinked_class.phpt

@@ -15,7 +15,6 @@ class A implements I {
 Fatal error: Uncaught ReflectionException: Class A does not exist in %s:%d
 Stack trace:
 #0 %s(%d): ReflectionClass->__construct('A')
-#1 [internal function]: {closure}('I')
-#2 %s(%d): spl_autoload_call('I')
-#3 {main}
+#1 %s(%d): {closure}('I')
+#2 {main}
   thrown in %s on line %d

Zend/zend_execute.h

@@ -31,6 +31,9 @@ struct _zend_fcall_info;
 ZEND_API extern void (*zend_execute_ex)(zend_execute_data *execute_data);
 ZEND_API extern void (*zend_execute_internal)(zend_execute_data *execute_data, zval *return_value);
 
+/* The lc_name may be stack allocated! */
+ZEND_API extern zend_class_entry *(*zend_autoload)(zend_string *name, zend_string *lc_name);
+
 void init_executor(void);
 void shutdown_executor(void);
 void shutdown_destructors(void);

Zend/zend_execute_API.c

@@ -44,6 +44,7 @@
 
 ZEND_API void (*zend_execute_ex)(zend_execute_data *execute_data);
 ZEND_API void (*zend_execute_internal)(zend_execute_data *execute_data, zval *return_value);
+ZEND_API zend_class_entry *(*zend_autoload)(zend_string *name, zend_string *lc_name);
 
 /* true globals */
 ZEND_API const zend_fcall_info empty_fcall_info = {0};
@@ -140,7 +141,6 @@ void init_executor(void) /* {{{ */
 	EG(class_table) = CG(class_table);
 
 	EG(in_autoload) = NULL;
-	EG(autoload_func) = NULL;
 	EG(error_handling) = EH_NORMAL;
 	EG(flags) = EG_FLAGS_INITIAL;
 
@@ -913,11 +913,9 @@ ZEND_API void zend_call_known_instance_method_with_2_params(
 ZEND_API zend_class_entry *zend_lookup_class_ex(zend_string *name, zend_string *key, uint32_t flags) /* {{{ */
 {
 	zend_class_entry *ce = NULL;
-	zval args[1], *zv;
-	zval local_retval;
+	zval *zv;
 	zend_string *lc_name;
-	zend_fcall_info fcall_info;
-	zend_fcall_info_cache fcall_cache;
+	zend_string *autoload_name;
 
 	if (key) {
 		lc_name = key;
@@ -952,25 +950,22 @@ ZEND_API zend_class_entry *zend_lookup_class_ex(zend_string *name, zend_string *
 		return ce;
 	}
 
-	/* The compiler is not-reentrant. Make sure we __autoload() only during run-time
-	 * (doesn't impact functionality of __autoload()
-	*/
+	/* The compiler is not-reentrant. Make sure we autoload only during run-time. */
 	if ((flags & ZEND_FETCH_CLASS_NO_AUTOLOAD) || zend_is_compiling()) {
 		if (!key) {
 			zend_string_release_ex(lc_name, 0);
 		}
 		return NULL;
 	}
 
-	if (!EG(autoload_func)) {
+	if (!zend_autoload) {
 		if (!key) {
 			zend_string_release_ex(lc_name, 0);
 		}
 		return NULL;
-
 	}
 
-	/* Verify class name before passing it to __autoload() */
+	/* Verify class name before passing it to the autoloader. */
 	if (!key && strspn(ZSTR_VAL(name), "0123456789_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ\200\201\202\203\204\205\206\207\210\211\212\213\214\215\216\217\220\221\222\223\224\225\226\227\230\231\232\233\234\235\236\237\240\241\242\243\244\245\246\247\250\251\252\253\254\255\256\257\260\261\262\263\264\265\266\267\270\271\272\273\274\275\276\277\300\301\302\303\304\305\306\307\310\311\312\313\314\315\316\317\320\321\322\323\324\325\326\327\330\331\332\333\334\335\336\337\340\341\342\343\344\345\346\347\350\351\352\353\354\355\356\357\360\361\362\363\364\365\366\367\370\371\372\373\374\375\376\377\\") != ZSTR_LEN(name)) {
 		zend_string_release_ex(lc_name, 0);
 		return NULL;
@@ -988,39 +983,19 @@ ZEND_API zend_class_entry *zend_lookup_class_ex(zend_string *name, zend_string *
 		return NULL;
 	}
 
-	ZVAL_UNDEF(&local_retval);
-
 	if (ZSTR_VAL(name)[0] == '\\') {
-		ZVAL_STRINGL(&args[0], ZSTR_VAL(name) + 1, ZSTR_LEN(name) - 1);
+		autoload_name = zend_string_init(ZSTR_VAL(name) + 1, ZSTR_LEN(name) - 1, 0);
 	} else {
-		ZVAL_STR_COPY(&args[0], name);
+		autoload_name = zend_string_copy(name);
 	}
 
-	fcall_info.size = sizeof(fcall_info);
-	ZVAL_STR_COPY(&fcall_info.function_name, EG(autoload_func)->common.function_name);
-	fcall_info.retval = &local_retval;
-	fcall_info.param_count = 1;
-	fcall_info.params = args;
-	fcall_info.object = NULL;
-	fcall_info.no_separation = 1;
-
-	fcall_cache.function_handler = EG(autoload_func);
-	fcall_cache.called_scope = NULL;
-	fcall_cache.object = NULL;
-
 	zend_exception_save();
-	if ((zend_call_function(&fcall_info, &fcall_cache) == SUCCESS) && !EG(exception)) {
-		ce = zend_hash_find_ptr(EG(class_table), lc_name);
-	}
+	ce = zend_autoload(autoload_name, lc_name);
 	zend_exception_restore();
 
-	zval_ptr_dtor(&args[0]);
-	zval_ptr_dtor_str(&fcall_info.function_name);
-
+	zend_string_release_ex(autoload_name, 0);
 	zend_hash_del(EG(in_autoload), lc_name);
 
-	zval_ptr_dtor(&local_retval);
-
 	if (!key) {
 		zend_string_release_ex(lc_name, 0);
 	}

Zend/zend_globals.h

@@ -176,7 +176,6 @@ struct _zend_executor_globals {
 	uint32_t persistent_classes_count;
 
 	HashTable *in_autoload;
-	zend_function *autoload_func;
 	zend_bool full_tables_cleanup;
 
 	/* for extended information support */