Improve type declarations for Zend APIs

Voidification of Zend API which always succeeded
Use bool argument types instead of int for boolean arguments
Use bool return type for functions which return true/false (1/0)
Use zend_result return type for functions which return SUCCESS/FAILURE as they don't follow normal boolean semantics

Closes GH-6002

UPGRADING.INTERNALS

@@ -158,6 +158,28 @@ PHP 8.0 INTERNALS UPGRADE NOTES
         - zend_fcall_info_argp()
         - zend_fcall_info_argv()
         - zend_fcall_info_argn()
+        - zend_startup()
+        - zend_set_memory_limit()
+        - pass_two()
+        - zend_startup_constants()
+        - zend_shutdown_constants()
+        - zend_startup_extensions_mechanism()
+        - zend_startup_extensions()
+        - zend_register_extension()
+        - highlight_string()
+        - zend_ini_startup()
+        - zend_ini_shutdown()
+        - zend_ini_global_shutdown()
+        - zend_ini_deactivate()
+        - zend_copy_ini_directives()
+        - zend_prepare_string_for_scanning()
+        - zend_init_rsrc_list()
+        - zend_list_close()
+        - zend_signal()
+        - zend_sigaction()
+        - zend_stack_init()
+        - zend_stack_del_top()
+        - zend_stack_destroy()
      2. Argument int to uint32_t in Zend Engine 4.0:
         - _zend_get_parameters_array_ex()
         - zend_copy_parameters_array()
@@ -169,8 +191,39 @@ PHP 8.0 INTERNALS UPGRADE NOTES
         - zend_wrong_parameter*()
         - zend_wrong_callback_error()
         - zend_parse_arg_class()
-     3. Argument int to zend_bool in Zend Engine 4.0:
+     3. Argument int to bool in Zend Engine 4.0:
         - add_next_index_bool()
+        - zend_register_class_alias_ex()
+        - add_assoc_bool_ex()
+        - add_index_bool()
+        - zend_fcall_info_args_clear()
+        - zend_set_local_var()
+        - zend_set_local_var_str()
+        - zend_parse_arg_*()
+        - shutdown_memory_manager()
+        - zend_memory_usage()
+        - zend_memory_peak_usage()
+        - zend_mm_shutdown()
+        - zend_eval_string*()
+        - zend_set_timeout()
+        - _zend_hash_append_ex()
+        - _zend_hash_append_ptr_ex()
+        - zend_alter_ini_entry_ex()
+        - (*zend_encoding_list_parser) typedef
+        - zend_multibyte_parse_encoding_list()
+        - zend_safe_address()
+        - zend_string_tolower_ex()
+        - zend_string_alloc()
+        - zend_string_safe_alloc()
+        - zend_string_init()
+        - zend_string_dup()
+        - zend_string_realloc()
+        - zend_string_extend()
+        - zend_string_truncate()
+        - zend_string_safe_realloc()
+        - zend_string_release_ex()
+        - zend_ts_hash_merge()
+        - zend_ts_hash_sort()
      4. Argument int to size_t in Zend Engine 4.0:
         - zend_set_hash_symbol()
      5. Argument zval* to zend_object* in Zend Engine 4.0:
@@ -185,6 +238,135 @@ PHP 8.0 INTERNALS UPGRADE NOTES
         - zend_get_exception_base()
      6. Argument zval* to zend_long in Zend Engine 4.0:
         - _php_math_longtobase()
+     7. Return type from int to zend_result in Zend Engine 4.0:
+        - (*stream_open_function) in _zend_utility_functions
+        - (*zend_post_startup_cb)
+        - (*zend_preload_autoload)
+        - zend_execute_scripts()
+        - zend_post_startup()
+        - _zend_get_parameters_array_ex()
+        - zend_copy_parameters_array()
+        - zend_parse_parameters()
+        - zend_parse_parameters_ex()
+        - zend_parse_method_parameters()
+        - zend_parse_method_parameters_ex()
+        - zend_parse_method_parameters()
+        - zend_register_functions()
+        - zend_startup_module()
+        - zend_startup_module_ex()
+        - zend_register_class_alias_ex()
+        - zend_disable_function()
+        - zend_disable_class()
+        - zend_update_class_constants()
+        - zend_update_static_property*()
+        - object_init_ex()
+        - object_and_properties_init()
+        - add_index_zval()
+        - add_next_index_long_*()
+        - array_set_zval_key()
+        - _call_user_function_impl()
+        - zend_fcall_info_*()
+        - zend_call_function()
+        - zend_set_hash_symbol()
+        - zend_delete_global_variable()
+        - zend_set_local_var()
+        - zend_set_local_var_str()
+        - zend_forbid_dynamic_call()
+        - zend_get_default_from_internal_arg_info()
+        - zend_try_assign_typed_ref*()
+        - zend_ast_evaluate()
+        - zend_startup_builtin_functions()
+        - do_bind_function()
+        - do_bind_class()
+        - zend_unmangle_property_name_ex()
+        - zend_register_auto_global()
+        - zend_register_constant()
+        - zend_exception_error()
+        - zend_eval_string*()
+        - zend_undefined_offset_write()
+        - zend_undefined_index_write()
+        - zval_update_constant(_ex)()
+        - zend_load_extension()
+        - zend_load_extension_handle()
+        - zend_hash_del(_ind)()
+        - zend_hash_str_del(_ind)()
+        - zend_hash_index_del()
+        - zend_hash_move_forward_ex()
+        - zend_hash_move_backward_ex()
+        - zend_hash_get_current_key_ex()
+        - zend_hash_get_current_key_type_ex()
+        - zend_symtable_del(_ind)()
+        - zend_symtable_str_del(_ind)()
+        - highlight_file()
+        - zend_do_link_class()
+        - zend_alter_ini_entry*()
+        - zend_restore_ini_entry()
+        - zend_ini_register_displayer()
+        - zend_ini_open_file_for_scanning()
+        - zend_ini_prepare_string_for_scanning()
+        - zend_user_it_valid()
+        - zend_create_internal_iterator_zval()
+        - zend_multibyte_set_filter()
+        - zend_lex_tstring()
+        - _zend_module_entry module_startup_func, module_shutdown_func,
+          request_startup_func, and request_shutdown_func function pointers
+        - (*zend_encoding_list_parser) typedef
+        - (*zend_encoding_internal_encoding_setter) typedef
+        - zend_multibyte_set_functions()
+        - zend_multibyte_set_script_encoding_by_string()
+        - add_function()
+        - sub_function()
+        - mul_function()
+        - pow_function()
+        - div_function()
+        - mod_function()
+        - boolean_xor_function()
+        - boolean_not_function()
+        - bitwise_not_function()
+        - bitwise_or_function()
+        - bitwise_and_function()
+        - bitwise_xor_function()
+        - shift_left_function()
+        - shift_right_function()
+        - concat_function()
+        - is_equal_function(
+        - is_identical_function()
+        - is_not_identical_function()
+        - is_not_equal_function()
+        - is_smaller_function()
+        - is_smaller_or_equal_function(zv
+        - increment_function()
+        - decrement_function()
+        - zend_stream_open()
+        - zend_stream_fixup()
+        - zend_ts_hash_del()
+        - zend_ts_hash_index_del()
+     8. Return type from int to bool in Zend Engine 4.0:
+        - zend_make_printable_zval()
+        - zend_parse_arg_*()
+        - is_zend_mm()
+        - is_zend_ptr()
+        - zend_mm_is_custom_heap()
+        - (*zend_mm_chunk_truncate_t)
+        - (*zend_mm_chunk_extend_t)
+        - zend_bitset_empty()
+        - zend_is_smart_branch()
+        - zend_check_arg_send_type()
+        - zend_verify_const_access()
+        - zend_gdb_register_code()
+        - zend_gdb_present()
+        - _zend_handle_numeric_str(_ex)()
+        - zend_hash_exists_ind()
+        - zend_hash_str_exists_ind()
+        - zend_symtable_exists(_ind)()
+        - zend_symtable_str_exists()
+        - (*zend_encoding_lexer_compatibility_checker)
+        - zend_object_is_true()
+        - i_zend_is_true()
+        - zendi_smart_streq()
+        - zend_stack_is_empty()
+        - zend_ts_hash_exists()
+        - zend_ts_hash_index_exists()
 
   u. Instead of overwriting zend_error_cb extensions with debugging, monitoring
      use-cases catching Errors/Exceptions are strongly encouraged to use

Zend/zend.c

@@ -74,17 +74,17 @@ ZEND_API zend_class_entry *zend_standard_class_def = NULL;
 ZEND_API size_t (*zend_printf)(const char *format, ...);
 ZEND_API zend_write_func_t zend_write;
 ZEND_API FILE *(*zend_fopen)(const char *filename, zend_string **opened_path);
-ZEND_API int (*zend_stream_open_function)(const char *filename, zend_file_handle *handle);
+ZEND_API zend_result (*zend_stream_open_function)(const char *filename, zend_file_handle *handle);
 ZEND_API void (*zend_ticks_function)(int ticks);
 ZEND_API void (*zend_interrupt_function)(zend_execute_data *execute_data);
 ZEND_API void (*zend_error_cb)(int type, const char *error_filename, const uint32_t error_lineno, zend_string *message);
 void (*zend_printf_to_smart_string)(smart_string *buf, const char *format, va_list ap);
 void (*zend_printf_to_smart_str)(smart_str *buf, const char *format, va_list ap);
 ZEND_API char *(*zend_getenv)(const char *name, size_t name_len);
 ZEND_API zend_string *(*zend_resolve_path)(const char *filename, size_t filename_len);
-ZEND_API int (*zend_post_startup_cb)(void) = NULL;
+ZEND_API zend_result (*zend_post_startup_cb)(void) = NULL;
 ZEND_API void (*zend_post_shutdown_cb)(void) = NULL;
-ZEND_API int (*zend_preload_autoload)(zend_string *filename) = NULL;
+ZEND_API zend_result (*zend_preload_autoload)(zend_string *filename) = NULL;
 
 /* This callback must be signal handler safe! */
 void (*zend_on_timeout)(int seconds);
@@ -365,7 +365,7 @@ static void print_flat_hash(HashTable *ht) /* {{{ */
 }
 /* }}} */
 
-ZEND_API int zend_make_printable_zval(zval *expr, zval *expr_copy) /* {{{ */
+ZEND_API bool zend_make_printable_zval(zval *expr, zval *expr_copy) /* {{{ */
 {
 	if (Z_TYPE_P(expr) == IS_STRING) {
 		return 0;
@@ -757,9 +757,8 @@ static void executor_globals_dtor(zend_executor_globals *executor_globals) /* {{
 
 static void zend_new_thread_end_handler(THREAD_T thread_id) /* {{{ */
 {
-	if (zend_copy_ini_directives() == SUCCESS) {
-		zend_ini_refresh_caches(ZEND_INI_STAGE_STARTUP);
-	}
+	zend_copy_ini_directives();
+	zend_ini_refresh_caches(ZEND_INI_STAGE_STARTUP);
 }
 /* }}} */
 #endif
@@ -803,7 +802,7 @@ static zend_bool php_auto_globals_create_globals(zend_string *name) /* {{{ */
 }
 /* }}} */
 
-int zend_startup(zend_utility_functions *utility_functions) /* {{{ */
+void zend_startup(zend_utility_functions *utility_functions) /* {{{ */
 {
 #ifdef ZTS
 	zend_compiler_globals *compiler_globals;
@@ -969,8 +968,6 @@ int zend_startup(zend_utility_functions *utility_functions) /* {{{ */
 	tsrm_set_new_thread_end_handler(zend_new_thread_end_handler);
 	tsrm_set_shutdown_handler(zend_interned_strings_dtor);
 #endif
-
-	return SUCCESS;
 }
 /* }}} */
 
@@ -1021,7 +1018,7 @@ static void zend_resolve_property_types(void) /* {{{ */
 /* Unlink the global (r/o) copies of the class, function and constant tables,
  * and use a fresh r/w copy for the startup thread
  */
-int zend_post_startup(void) /* {{{ */
+zend_result zend_post_startup(void) /* {{{ */
 {
 #ifdef ZTS
 	zend_encoding **script_encoding_list;
@@ -1033,7 +1030,7 @@ int zend_post_startup(void) /* {{{ */
 	zend_resolve_property_types();
 
 	if (zend_post_startup_cb) {
-		int (*cb)(void) = zend_post_startup_cb;
+		zend_result (*cb)(void) = zend_post_startup_cb;
 
 		zend_post_startup_cb = NULL;
 		if (cb() != SUCCESS) {
@@ -1665,13 +1662,13 @@ ZEND_API ZEND_COLD void zend_user_exception_handler(void) /* {{{ */
 	}
 } /* }}} */
 
-ZEND_API int zend_execute_scripts(int type, zval *retval, int file_count, ...) /* {{{ */
+ZEND_API zend_result zend_execute_scripts(int type, zval *retval, int file_count, ...) /* {{{ */
 {
 	va_list files;
 	int i;
 	zend_file_handle *file_handle;
 	zend_op_array *op_array;
-	int ret = SUCCESS;
+	zend_result ret = SUCCESS;
 
 	va_start(files, file_count);
 	for (i = 0; i < file_count; i++) {

Zend/zend.h

@@ -195,7 +195,7 @@ typedef struct _zend_utility_functions {
 	zval *(*get_configuration_directive)(zend_string *name);
 	void (*ticks_function)(int ticks);
 	void (*on_timeout)(int seconds);
-	int (*stream_open_function)(const char *filename, zend_file_handle *handle);
+	zend_result (*stream_open_function)(const char *filename, zend_file_handle *handle);
 	void (*printf_to_smart_string_function)(smart_string *buf, const char *format, va_list ap);
 	void (*printf_to_smart_str_function)(smart_str *buf, const char *format, va_list ap);
 	char *(*getenv_function)(const char *name, size_t name_len);
@@ -227,10 +227,10 @@ typedef size_t (*zend_write_func_t)(const char *str, size_t str_length);
 #define zend_first_try		EG(bailout)=NULL;	zend_try
 
 BEGIN_EXTERN_C()
-int zend_startup(zend_utility_functions *utility_functions);
+void zend_startup(zend_utility_functions *utility_functions);
 void zend_shutdown(void);
 void zend_register_standard_ini_entries(void);
-int zend_post_startup(void);
+zend_result zend_post_startup(void);
 void zend_set_utility_values(zend_utility_values *utility_values);
 
 ZEND_API ZEND_COLD ZEND_NORETURN void _zend_bailout(const char *filename, uint32_t lineno);
@@ -246,7 +246,7 @@ ZEND_API size_t zend_spprintf_unchecked(char **message, size_t max_len, const ch
 ZEND_API zend_string *zend_strpprintf_unchecked(size_t max_len, const char *format, ...);
 
 ZEND_API const char *get_zend_version(void);
-ZEND_API int zend_make_printable_zval(zval *expr, zval *expr_copy);
+ZEND_API bool zend_make_printable_zval(zval *expr, zval *expr_copy);
 ZEND_API size_t zend_print_zval(zval *expr, int indent);
 ZEND_API void zend_print_zval_r(zval *expr, int indent);
 ZEND_API zend_string *zend_print_zval_r_to_str(zval *expr, int indent);
@@ -283,18 +283,18 @@ extern ZEND_API void (*zend_ticks_function)(int ticks);
 extern ZEND_API void (*zend_interrupt_function)(zend_execute_data *execute_data);
 extern ZEND_API void (*zend_error_cb)(int type, const char *error_filename, const uint32_t error_lineno, zend_string *message);
 extern ZEND_API void (*zend_on_timeout)(int seconds);
-extern ZEND_API int (*zend_stream_open_function)(const char *filename, zend_file_handle *handle);
+extern ZEND_API zend_result (*zend_stream_open_function)(const char *filename, zend_file_handle *handle);
 extern void (*zend_printf_to_smart_string)(smart_string *buf, const char *format, va_list ap);
 extern void (*zend_printf_to_smart_str)(smart_str *buf, const char *format, va_list ap);
 extern ZEND_API char *(*zend_getenv)(const char *name, size_t name_len);
 extern ZEND_API zend_string *(*zend_resolve_path)(const char *filename, size_t filename_len);
 
 /* These two callbacks are especially for opcache */
-extern ZEND_API int (*zend_post_startup_cb)(void);
+extern ZEND_API zend_result (*zend_post_startup_cb)(void);
 extern ZEND_API void (*zend_post_shutdown_cb)(void);
 
 /* Callback for loading of not preloaded part of the script */
-extern ZEND_API int (*zend_preload_autoload)(zend_string *filename);
+extern ZEND_API zend_result (*zend_preload_autoload)(zend_string *filename);
 
 ZEND_API ZEND_COLD void zend_error(int type, const char *format, ...) ZEND_ATTRIBUTE_FORMAT(printf, 2, 3);
 ZEND_API ZEND_COLD ZEND_NORETURN void zend_error_noreturn(int type, const char *format, ...) ZEND_ATTRIBUTE_FORMAT(printf, 2, 3);