Re: Const-correctness

Hello Marcus, Em Dom, 2008-08-03 às 18:46 +0200, Marcus Boerger escreveu: > Index: Zend/zend.c > =================================================================== > -static void print_hash(HashTable *ht, int indent, zend_bool is_object TSRMLS_DC) /* {{{ */ > +static void print_hash(HashTable * const ht, int indent, zend_bool is_object TSRMLS_DC) /* {{{ > */ > -static void print_flat_hash(HashTable *ht TSRMLS_DC) /* {{{ */ > +static void print_flat_hash(HashTable * const ht TSRMLS_DC) /* {{{ */ > > Why not 'const HashTable * const ht', print doesn't sound like it should modify > the table itself. That because the zend_hash_internal_pointer_reset_ex() called in print_hash() and print_flat_hash() makes: ht->pInternalPointer = ht->pListHead; > -ZEND_API int zend_print_zval_ex(zend_write_func_t write_func, zval *expr, int indent) /* {{{ > */ > +ZEND_API int zend_print_zval_ex(const zend_write_func_t write_func, zval *expr, int indent) /* > {{{ */ > -ZEND_API void zend_print_flat_zval_r(zval *expr TSRMLS_DC) /* {{{ */ > +ZEND_API void zend_print_flat_zval_r(zval * const expr TSRMLS_DC) /* > {{{ */ > -ZEND_API void zend_print_zval_r(zval *expr, int indent TSRMLS_DC) /* > {{{ */ > +ZEND_API void zend_print_zval_r(zval * const expr, int indent > TSRMLS_DC) /* {{{ */ > -ZEND_API void zend_print_zval_r_ex(zend_write_func_t write_func, zval > *expr, int indent TSRMLS_DC) /* {{{ */ > +ZEND_API void zend_print_zval_r_ex(const zend_write_func_t > write_func, zval *expr, int indent TSRMLS_DC) /* {{{ */ > > In the same way these should be 'const zval * const expr'. The reason is that zend_print_zval_ex() uses: zval_dtor(expr); > Also note that not all of them use const for expr. Oh right, I added in zend_print_zval_r_ex() now. > Index: Zend/zend_API.c > =================================================================== > -ZEND_API int zend_copy_parameters_array(int param_count, zval *argument_array TSRMLS_DC) /* > {{{ */ > +ZEND_API int zend_copy_parameters_array(int param_count, zval * const argument_array > TSRMLS_DC) /* {{{ */ > > 'const zval * const' Fixed! > -ZEND_API int zend_get_object_classname(zval *object, char **class_name, zend_uint > *class_name_len TSRMLS_DC) /* {{{ */ > +ZEND_API int zend_get_object_classname(zval * const object, char **class_name, zend_uint > *class_name_len TSRMLS_DC) /* {{{ */ > > Does not modify the zval container, so use 'const zval * const object'. Fixed. > -static char *zend_parse_arg_impl(int arg_num, zval **arg, va_list *va, char **spec, char > **error, int *severity TSRMLS_DC) /* {{{ */ > +static char *zend_parse_arg_impl(int arg_num, zval **arg, va_list * const va, char ** const > spec, char **error, int *severity TSRMLS_DC) /* {{{ */ > -static int zend_parse_arg(int arg_num, zval **arg, va_list *va, char **spec, int quiet > TSRMLS_DC) /* {{{ */ > +static int zend_parse_arg(int arg_num, zval **arg, va_list * const va, char ** const spec, int > quiet TSRMLS_DC) /* {{{ */ > > Shouldn't this be 'const char ** const spec'. After all we don't modify the > actual string. > -static int zend_parse_va_args(int num_args, char *type_spec, va_list *va, int flags TSRMLS_DC) > /* {{{ */ > +static int zend_parse_va_args(int num_args, char *type_spec, va_list * const va, int flags > TSRMLS_DC) /* {{{ */ > > Shouldn't this be 'const char *type_spec' for the same reason as above? Fixed! > -ZEND_API int zend_parse_parameters_ex(int flags, int num_args TSRMLS_DC, char *type_spec, ...) > /* {{{ */ > +ZEND_API int zend_parse_parameters_ex(int flags, int num_args TSRMLS_DC, char * const > type_spec, ...) /* {{{ */ > -ZEND_API int zend_parse_parameters(int num_args TSRMLS_DC, char *type_spec, ...) /* {{{ */ > +ZEND_API int zend_parse_parameters(int num_args TSRMLS_DC, char * const type_spec, ...) /* {{{ > */ > -ZEND_API int zend_parse_method_parameters(int num_args TSRMLS_DC, zval *this_ptr, char > *type_spec, ...) /* {{{ */ > +ZEND_API int zend_parse_method_parameters(int num_args TSRMLS_DC, zval * const this_ptr, char > * const type_spec, ...) /* {{{ */ > -ZEND_API int zend_parse_method_parameters_ex(int flags, int num_args TSRMLS_DC, zval > *this_ptr, char *type_spec, ...) /* {{{ */ > +ZEND_API int zend_parse_method_parameters_ex(int flags, int num_args TSRMLS_DC, zval * const > this_ptr, char * const type_spec, ...) /* {{{ */ > > Shouldn't this be 'const char * const type_spec'. > For the method versions it should also be 'const zval * const this_ptr'. Fixed! > -ZEND_API int zend_startup_module_ex(zend_module_entry *module TSRMLS_DC) /* {{{ */ > +ZEND_API int zend_startup_module_ex(zend_module_entry * const module TSRMLS_DC) /* {{{ */ > > Why not 'const zend_module_entry * const module'? Because module->module_started had your value changed in the function. > > -ZEND_API zend_module_entry* zend_register_internal_module(zend_module_entry *module TSRMLS_DC) > /* {{{ */ > +ZEND_API zend_module_entry* zend_register_internal_module(zend_module_entry * const module > TSRMLS_DC) /* {{{ */ > > If only we had mutable... > > > Overall you do a ton of 'struct * const var' which only means that you are > going to copy the pointer explicitly. Now functions that use a pointer in a > loop and increment it cannot optimize the code anymore and are forced to use > an additional real variable on the stack. So unless you have a very smart > compiler, the result is an increased stack size. Generally speaking I prefer > const on the reight and mid (between *'s) only. But others prefer it to denote > that not even the passed in pointer gets modifed and this sometimes even makes > debugging easier. > Hmmm, ok. I'll remove all the 'struct * const var', and to find other cases where 'const struct * const var' and 'const var' can be suitable too. const thanks! :D -- Regards, Felipe Pena.