feat: first-class hybrid zend_extension/zend_module_entry

Zend/zend_API.h

@@ -238,9 +238,11 @@ typedef struct _zend_fcall_info_cache {
 #define ZEND_MODULE_GLOBALS_CTOR_D(module)  void ZEND_MODULE_GLOBALS_CTOR_N(module)(zend_##module##_globals *module##_globals)
 #define ZEND_MODULE_GLOBALS_DTOR_D(module)  void ZEND_MODULE_GLOBALS_DTOR_N(module)(zend_##module##_globals *module##_globals)
 
+#define ZEND_MODULE_ENTRY(name) (&name##_module_entry)
+
 #define ZEND_GET_MODULE(name) \
     BEGIN_EXTERN_C()\
-	ZEND_DLEXPORT zend_module_entry *get_module(void) { return &name##_module_entry; }\
+	ZEND_DLEXPORT zend_module_entry *get_module(void) { return ZEND_MODULE_ENTRY(name); }\
     END_EXTERN_C()
 
 #define ZEND_BEGIN_MODULE_GLOBALS(module_name)		\

Zend/zend_extensions.c

@@ -19,13 +19,50 @@
 
 #include "zend_extensions.h"
 #include "zend_system_id.h"
+#include "zend_API.h"
+#include "zend_modules.h"
 
 ZEND_API zend_llist zend_extensions;
 ZEND_API uint32_t zend_extension_flags = 0;
 ZEND_API int zend_op_array_extension_handles = 0;
 ZEND_API int zend_internal_function_extension_handles = 0;
 static int last_resource_number;
 
+// TODO: revisit this name if we want to make it ZEND_API.
+static zend_result zend_try_register_hybrid_module(zend_extension *extension)
+{
+	zend_module_entry *module = extension->module_entry;
+
+	if (!module) {
+		return SUCCESS;
+	}
+
+	if (module->zend_api != ZEND_MODULE_API_NO) {
+		zend_error(E_CORE_WARNING,
+			"Hybrid module \"%s\" from Zend extension \"%s\" cannot be initialized: "
+			"Module API=%d, PHP API=%d",
+			module->name ? module->name : "<unknown>",
+			extension->name ? extension->name : "<unknown>",
+			module->zend_api, ZEND_MODULE_API_NO);
+		return FAILURE;
+	}
+
+	if (!module->build_id || strcmp(module->build_id, ZEND_MODULE_BUILD_ID)) {
+		zend_error(E_CORE_WARNING,
+			"Hybrid module \"%s\" from Zend extension \"%s\" cannot be initialized: "
+			"Module build ID=%s, PHP build ID=%s",
+			module->name ? module->name : "<unknown>",
+			extension->name ? extension->name : "<unknown>",
+			module->build_id ? module->build_id : "<unknown>",
+			ZEND_MODULE_BUILD_ID);
+		return FAILURE;
+	}
+
+	// The handle is owned by the zend_extension for hybrid extensions.
+	module->handle = NULL;
+	return zend_register_module_ex(module, MODULE_PERSISTENT) ? SUCCESS : FAILURE;
+}
+
 zend_result zend_load_extension(const char *path)
 {
 #if ZEND_EXTENSIONS_SUPPORT
@@ -134,6 +171,14 @@ zend_result zend_load_extension_handle(DL_HANDLE handle, const char *path)
 		return FAILURE;
 	}
 
+	// The module_entry is registered before the extension is registered
+	// because zend_register_extension() returns void and is ZEND_API, so
+	// operations which can fail need to be performed before it.
+	if (zend_try_register_hybrid_module(new_extension) != SUCCESS) {
+		DL_UNLOAD(handle);
+		return FAILURE;
+	}
+
 	zend_register_extension(new_extension, handle);
 	return SUCCESS;
 #else

Zend/zend_extensions.h

@@ -54,6 +54,7 @@ typedef struct _zend_extension_version_info {
 #define ZEND_EXTENSION_BUILD_ID "API" ZEND_TOSTR(ZEND_EXTENSION_API_NO) ZEND_BUILD_TS ZEND_BUILD_DEBUG ZEND_BUILD_SYSTEM ZEND_BUILD_EXTRA
 
 typedef struct _zend_extension zend_extension;
+typedef struct _zend_module_entry zend_module_entry;
 
 /* Typedef's for zend_extension function pointers */
 typedef int (*startup_func_t)(zend_extension *extension);
@@ -101,7 +102,19 @@ struct _zend_extension {
 	int (*build_id_check)(const char* build_id);
 	op_array_persist_calc_func_t op_array_persist_calc;
 	op_array_persist_func_t op_array_persist;
-	void *reserved5;
+
+	/* Setting a module_entry indicates a hybrid extension, meaning an
+	 * extension which is also a module. Such extensions can be loaded with
+	 * either "zend_extension=<name>" or "extension=<name>" by INI.
+	 *
+	 * The symbol "get_module" must _not_ be exported, i.e. don't call
+	 * ZEND_GET_MODULE(), and instead use ZEND_MODULE_ENTRY() to assign a value
+	 * to `.module_entry`.
+	 *
+	 * The DL_HANDLE is owned by the zend_extension for hybrid extensions, so
+	 * the handle should be null for the module entry.
+	 */
+	zend_module_entry *module_entry;
 	void *reserved6;
 	void *reserved7;
 	void *reserved8;

ext/standard/dl.c

@@ -21,6 +21,8 @@
 #include "php_globals.h"
 #include "php_ini.h"
 #include "ext/standard/info.h"
+#include "Zend/zend_API.h"
+#include "Zend/zend_extensions.h"
 
 #include "SAPI.h"
 
@@ -106,6 +108,28 @@ PHPAPI void *php_load_shlib(const char *path, char **errp)
 }
 /* }}} */
 
+/* This helper handles the hybrid zend_{extension,module_entry} fallback path.
+ * It unloads the handle on failure but it does not free libpath. */
+static zend_result php_try_load_hybrid_zend_extension(
+	DL_HANDLE handle, const char *filename, char *libpath, int error_type)
+{
+	zend_extension *zend_extension_entry = (zend_extension *) DL_FETCH_SYMBOL(handle, "zend_extension_entry");
+	if (!zend_extension_entry) {
+		zend_extension_entry = (zend_extension *) DL_FETCH_SYMBOL(handle, "_zend_extension_entry");
+	}
+	if (zend_extension_entry && zend_extension_entry->module_entry) {
+		return zend_load_extension_handle(handle, libpath);
+	}
+	if (zend_extension_entry) {
+		php_error_docref(NULL, error_type, "Invalid library (appears to be a Zend Extension, try loading using zend_extension=%s from php.ini)", filename);
+		DL_UNLOAD(handle);
+		return FAILURE;
+	}
+	php_error_docref(NULL, error_type, "Invalid library (maybe not a PHP library) '%s'", filename);
+	DL_UNLOAD(handle);
+	return FAILURE;
+}
+
 /* {{{ php_load_extension */
 PHPAPI int php_load_extension(const char *filename, int type, int start_now)
 {
@@ -173,13 +197,12 @@ PHPAPI int php_load_extension(const char *filename, int type, int start_now)
 		efree(orig_libpath);
 		efree(err1);
 	}
-	efree(libpath);
-
 #ifdef PHP_WIN32
 	if (!php_win32_image_compatible(handle, &err1)) {
 			php_error_docref(NULL, error_type, "%s", err1);
 			efree(err1);
 			DL_UNLOAD(handle);
+			efree(libpath);
 			return FAILURE;
 	}
 #endif
@@ -195,15 +218,13 @@ PHPAPI int php_load_extension(const char *filename, int type, int start_now)
 	}
 
 	if (!get_module) {
-		if (DL_FETCH_SYMBOL(handle, "zend_extension_entry") || DL_FETCH_SYMBOL(handle, "_zend_extension_entry")) {
-			DL_UNLOAD(handle);
-			php_error_docref(NULL, error_type, "Invalid library (appears to be a Zend Extension, try loading using zend_extension=%s from php.ini)", filename);
-			return FAILURE;
-		}
-		DL_UNLOAD(handle);
-		php_error_docref(NULL, error_type, "Invalid library (maybe not a PHP library) '%s'", filename);
-		return FAILURE;
+		// If get_module still isn't found, maybe it's a zend_extension with a module entry.
+		zend_result result = php_try_load_hybrid_zend_extension(handle, filename, libpath, error_type);
+		efree(libpath);
+		return result;
 	}
+	efree(libpath);
+
 	module_entry = get_module();
 	if (zend_hash_str_exists(&module_registry, module_entry->name, strlen(module_entry->name))) {
 		zend_error(E_CORE_WARNING, "Module \"%s\" is already loaded", module_entry->name);