RE: [PHP-DEV] Re: Labeled Breaks (not the G-word)

One more thing. The patch has problems with "interactve mode" (php -a). Thanks. Dmitry. > -----Original Message----- > From: Dmitry Stogov [mailto:dmitry@zend.com] > Sent: Thursday, November 24, 2005 12:54 PM > To: 'Sara Golemon'; internals@lists.php.net > Cc: Andi Gutmans; Zeev Suraski; Stanislav Malyshev; Marcus > Boerger; Wez Furlong; Derick Rethans; Andrei Zmievski; Jani > Taskinen; Rasmus Lerdorf > Subject: RE: [PHP-DEV] Re: Labeled Breaks (not the G-word) > > > Hi Sara, > > I didn't like "goto" in PHP, but after looking in this patch > I see that limited "goto" can work. > > 1) The new syntax makes mess for me. > "break" is a statement that exits from loop or switch, now we > make a "goto" statement but name it "break". I belive that if > we really implement goto (even with some limitations) we > shuld name it "goto", but not "break". (changed in attached patch). > > 2) After (1) I don't see any reason in limitation to jump > only down, if we can jump up as well. (the limitation is > removed in attached patch). > > 2) Your patch doesn't care about freeing loop variables and > we got a memory leaks in the following example (this is fixed > in attahed patch). > > <?php > foreach (array(1,2,3) as $v) { > break LABEL; > } > LABEL: > ?> > > 3) You can declare one LABEL twich. This should emit > comilation error. (this is fixed in attached patch). > > 4) Keeping "labels" field in op_array after compilation make > not sense as it used only during compilation and not during > execution. (this is fixed in attached patch) May be we should > place this HashTable somewere outside of op_array. > > Now I don't see inconsistencies. > But I still not sure that PHP needs "goto". > > Thanks. Dmitry. > > > -----Original Message----- > > From: Sara Golemon [mailto:pollita@php.net] > > Sent: Thursday, November 24, 2005 8:03 AM > > To: internals@lists.php.net > > Subject: [PHP-DEV] Re: Labeled Breaks (not the G-word) > > > > > > Set of tests available too now: > > http://libssh2.org/patches/labeled_break_tests.tgz > > > > It can be untarred from the root of a PHP dist and it'll unfold into > > Zend/tests/break/ > > > > > http://libssh2.org/patches/labeled_break.diff > > > > > > A few notes about the implementation: > > > > > > * The parser is modified slightly to catch T_BREAK > T_LNUMBER ';' and > > > T_BREAK T_STRING ';' specifically. This is in-line with the > > decision to remove > > > the > > > ability to jump to variable targets. e.g. break > > > $foo; > > will result in an > > > E_PARSE. > > > > > > * current break container is moved from op1.u.opline_num to > > > extended_value (This means updating continue; as well) > > > > > > * op1 is used to store the label's name until pass_two(), at that > > > point > > > it's > > > converted to a jmp_addr. Non-labeled breaks leave op1 > > unused and jmp_addr > > > explicitly set to NULL > > > > > > * zend_brk opcode handler updated to use op1->u.jmp_addr if > > available > > > (labeled breaks), or el->brk (numbered breaks) if not. > > zend_brk and > > > zend_cont both updated per current break container change above. > > > > > > * Labeled breaks must target the same break container or > > higher within > > > the same op_array, and must only jump "forward" in > > execution. These > > > checks are handled in pass_two() which is the earliest > > point at which > > > all labeled are declared. > > > > > > * Label hash is only allocated/initialized if labels are declared. > > > > > > Known Issues: > > > > > > * When an error is thrown from pass_two(), the error > message states > > > it's > > > in > > > Unknown on line 0. Gotta find a better way to handle that.... > > > > > > * This adds an element to zend_op_array so be sure to either `make > > > clean` > > > or > > > at least touch Zend/*.c after applying it otherwise > you'll be in > > > segfault > > > country. > > > > > > -Sara > > > > -- > > PHP Internals - PHP Runtime Development Mailing List > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > >