On Fri, 2008-08-15 at 18:34 -0500, Shawn McKenzie wrote: > Herman Gomez wrote: > > Hi, > > > > Here is something I used to do in C/C++ to include/exclude automaticaly > > all debugging code at compiling time: > > > > #define debug TRUE > > #ifdef(debug) > > //debugging code > > #endif > > > > That way I can include/exclude easily all debugging code in the final > > compiled code. In PHP I have not been able to find anything like that. > > The only solution I've found is having this kind of code in every debug > > code block: > > > > if ($debug) { > > //debugging code > > } > > > > But this means that the debugging code is in the final compiled > > (interpreted) code, wasting cpu cycles even if there won't be any > > debugging in production. > > > > Does somebody know if there is something like conditional compilation in > > PHP that I can use? > > > > Regards, > > Herman Gomez > > Madrid, Spain. > > Well PHP isn't compiled it's interpreted. Still I don't see much diff > and no overhead between the following: > > #ifdef(debug) > //debugging code > #endif > > ---and--- > > if (defined('DEBUG')) { > //debugging code > } > > I don't think checking a define is cpu intensive or even measurable. > You could "assume" that it's defined as true or false and: > > if (DEBUG === true)) { > //debugging code > } > > Still, I don't think that even checking $debug is measurable. That depends on where the conditional exists. In C you can place it anywhere, including wihtin a tight loop. In PHP you end up having to either take an overhead penalty or duplicate code to force the conditional outside of a tight loop. Contrast the following: <?php if( DEBUG === true ) { for( $i = 0; $i < 1000000; $i++ ) { // Do something common between DEBUG and !DEBUG modes. // Do something dependent on debug mode. } } else { for( $i = 0; $i < 1000000; $i++ ) { // Do something common between DEBUG and !DEBUG modes. } } ?> Versus: <?php for( $i = 0; $i < 1000000; $i++ ) { // Do something common between DEBUG and !DEBUG modes. if( DEBUG === true ) { // Do something dependent on debug mode. } } ?> Now depending on what "Do something common between DEBUG and !DEBUG modes" does, it can be a real PITA to do code duplication to optimize debug mode handling, but on the other hand, you really don't want to check if DEBUG is enabled 1 million times. If I recall though... a few years ago the answer to this question was that there's no reason why you can't use the C pre-processor to accomplish the same thing with PHP. The down side though is that then you lose debugging information such as the real line number on which an error occurs. Cheers, Rob. -- http://www.interjinn.com Application and Templating Framework for PHP -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php