# allow extension writers to ignore E_NOTICE warnings about unset variables - Thread: https://externals.io/message/23285 - Original archive: https://news-web.php.net/php.internals/23285 - Started by D. Dante Lorenso on 2006-05-11T22:49:45+00:00 - Messages: 8 - Reply by email to internals@lists.php.net - More for agents: search with https://externals.io/search.md?q={query} · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt --- ## #23285 — D. Dante Lorenso — 2006-05-11T22:49:45+00:00 URL: https://externals.io/message/23285#23285 All, Is there a way to define a function in an extension which would not require a passed in variable to exist? In other words, can ZE be modified to allow extensions to not trigger `E_NOTICE` warnings if an unset variable is passed to a function which does not care if the var is set? I can specify preferences about whether variables are passed by reference or not using macros like: * PHP_FE(..., first_arg_force_ref) * PHP_FE(..., third_arg_force_by_ref_rest) * PHP_FE(..., first_through_third_args_force_ref) Which probably boil down somewhere into: * #define ZEND_SEND_BY_VAL 0 * #define ZEND_SEND_BY_REF 1 * #define ZEND_SEND_PREFER_REF 2 And I notice that if a variable is passed by reference to an extension function, no `E_NOTICE` is thrown. Well, can we extend this concept further to say something like: * #define ZEND_SEND_WHO_CARES_IF_IT_EXISTS_OR_NOT 4 *but with a better name, of course* Then, extension developers can write 'ifsetor', 'coalesce', and 'filled' as extensions (by themselves) and not need those specific functions added to the 'PHP core language' per-se. Dante --- ## #23286 — Antony Dovgal — 2006-05-11T22:56:05+00:00 URL: https://externals.io/message/23285#23286 · In reply to: #23285 > All, > > Is there a way to define a function in an extension which would not > require a passed in variable to exist? In other words, can ZE be > modified to allow extensions to not trigger `E_NOTICE` warnings if an > unset variable is passed to a function which does not care if the var is > set? > > I can specify preferences about whether variables are passed by > reference or not using macros like: > > * PHP_FE(..., first_arg_force_ref) > * PHP_FE(..., third_arg_force_by_ref_rest) > * PHP_FE(..., first_through_third_args_force_ref) > > Which probably boil down somewhere into: > > * #define ZEND_SEND_BY_VAL 0 > * #define ZEND_SEND_BY_REF 1 This one is what you need. -- Wbr, Antony Dovgal --- ## #23287 — Marcus Boerger — 2006-05-11T22:56:34+00:00 URL: https://externals.io/message/23285#23287 · In reply to: #23285 Hello D., no, the compiler generates code that makes the executor generate the variable and complain prior to performing the call. In a zend extension you could try to hook into that process. marcus Friday, May 12, 2006, 12:49:45 AM, you wrote: > All, > Is there a way to define a function in an extension which would not > require a passed in variable to exist? In other words, can ZE be > modified to allow extensions to not trigger `E_NOTICE` warnings if an > unset variable is passed to a function which does not care if the var is > set? > I can specify preferences about whether variables are passed by > reference or not using macros like: > * PHP_FE(..., first_arg_force_ref) > * PHP_FE(..., third_arg_force_by_ref_rest) > * PHP_FE(..., first_through_third_args_force_ref) > Which probably boil down somewhere into: > * #define ZEND_SEND_BY_VAL 0 > * #define ZEND_SEND_BY_REF 1 > * #define ZEND_SEND_PREFER_REF 2 > And I notice that if a variable is passed by reference to an extension > function, no `E_NOTICE` is thrown. Well, can we extend this concept > further to say something like: > * #define ZEND_SEND_WHO_CARES_IF_IT_EXISTS_OR_NOT 4 > *but with a better name, of course* > Then, extension developers can write 'ifsetor', 'coalesce', and 'filled' > as extensions (by themselves) and not need those specific functions > added to the 'PHP core language' per-se. > Dante Best regards, Marcus --- ## #23288 — D. Dante Lorenso — 2006-05-11T23:05:30+00:00 URL: https://externals.io/message/23285#23288 · In reply to: #23286 Antony Dovgal wrote: > > > […] > This one is what you need. I don't think it is. The variable did not exist before the function was called and should STILL not exist afterwards. I believe when you pass by reference, the variable will exist after the call. This is bad since future calls to 'isset' will suddenly start returning `TRUE` when they shouldn't. Dante --- ## #23292 — D. Dante Lorenso — 2006-05-11T23:10:41+00:00 URL: https://externals.io/message/23285#23292 · In reply to: #23287 Marcus Boerger wrote: > no, the compiler generates code that makes the executor generate the > variable and complain prior to performing the call. > The executor doesn't complain about unset variables prior to calling functions by reference, so I was thinking it could be modified to also not complain when calling functions that don't care about set variables. Naturally, the unset variable would evaluate as `NULL` and be passed as such, just there would be no E_NOTICE. > In a zend extension you could try to hook into that process. > How do you mean? Got any pointers? Dante --- ## #23289 — Marcus Boerger — 2006-05-11T23:21:08+00:00 URL: https://externals.io/message/23285#23289 · In reply to: #23292 Hello D., Friday, May 12, 2006, 1:10:41 AM, you wrote: > Marcus Boerger wrote: > > […] > The executor doesn't complain about unset variables prior to calling > functions by reference, so I was thinking it could be modified to also > not complain when calling functions that don't care about set > variables. Naturally, the unset variable would evaluate as `NULL` and be > passed as such, just there would be no E_NOTICE. > > […] > How do you mean? Got any pointers? Sorry no. Maybe Sara captures that in her book. Only places i could imagine to touch what you need is Saras pecl/run-kit. Best regards, Marcus --- ## #23290 — Antony Dovgal — 2006-05-11T23:23:47+00:00 URL: https://externals.io/message/23285#23290 · In reply to: #23288 > Antony Dovgal wrote: > > […] > I don't think it is. The variable did not exist before the function was > called and should STILL not exist afterwards. I believe when you pass > by reference, the variable will exist after the call. Only if you created it during the call. bool(false) > This is bad since > future calls to 'isset' will suddenly start returning `TRUE` when they > shouldn't. -- Wbr, Antony Dovgal --- ## #23303 — Stefan Walk — 2006-05-12T12:38:19+00:00 URL: https://externals.io/message/23285#23303 · In reply to: #23290 Antony Dovgal wrote: > Only if you created it during the call. > > function foo(&$arg) { > } > > foo($nonex); > var_dump(isset($nonex)); > ?> > > bool(false) > $ php -r 'function foo(&$foo){} function bar(){ foo($var); var_dump(get_defined_vars());} bar();' array(1) { ["var"]=> `NULL` }