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Date: Thu, 17 Jul 2008 11:50:02 +0200
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Subject: autoload somewhat broken? or do the docs need more info?
From: jochem@iamjochem.com (Jochem Maas)

hello people,

I believe there is something wrong (or inconsitent) with the way __autoload()
behaves. at the least the current docs don't reflect what I'm seeing.

1. the docs state:

	"Exceptions thrown in __autoload function cannot be caught in the catch block and results in a fatal error."

this is not exactly true, I can catch exception throw from __autoload() IF
__autoload() was triggered via call_user_func*(), class_exists() & is_callable()


2. if a user error handler is set with set_error_handler() any errors (at least upto and
including E_WARNING) that occur in a function that triggers (e.g. call_user_func()) __autoload()
will not be given to the error handler function (it never recieves a call) if the
__autoload() it triggered throws an exception (that is not caught inside __autoload().


3. I suspect that point 2. is the reason that in some real-world situations even
Fatal Errors are not logged at (to screen or file, regardless of error_reporting/display_error
settings), resulting in a blank screen and no idea as to the cause ... I have seen this
happen repeatedly on different versions/machines/etc since php5 was in beta ... I have
still not be able to reproduce the vanishing Fatal Errors in a simple test script ...
that said on all occasions where nothing was logged for such Fatal Errors (which in
my case are always the result of a class that cannot be found) I could run the same
script via a debugger which then always did show the Fatal Error message ... why would
running the script via a debugger show [Fatal Error] output in the browser window where as
running the script normally [in the browser] results in no output whatsoever?


Anyway I don't really know if anything is wrong, whether the docs need updating, or
whether someone should really look at the situation.

I have written a little 'test suite'[1] with which one can observe __autoload()
behaviour in various configurations ... it comes with little shell script called
'runtests.sh':



$ ./runtests.sh
usage: ./runtests.sh <testset> [--set-err-handler] [--display-errors] [--gen-class] [--no-autoload|--no-throw [--spl-autoload]]

   <testset> must be one of: new new2 static class_exists call_user_func call_user_func_array is_callable OR all

       --set-err-handler       = define a user function to trap php errors.
       --display-errors        = sets php ini setting display_errors on.
       --no-autoload           = skip autoloader function definition.
       --no-throw              = tell the autoloader not to throw the exception.
       --spl-autoload          = use spl_autoload_register() instead of __autoload()
       --recurse-autoload      = trigger __autoload from within __autoload
       --gen-class             = to have autoload auto-generate the class (exception will still be thrown)
                                 classes will have __construct(), __call() and __callstatic() methods

   1. you may export an environment variable $PHP_TEST_BIN to control which php binary used to run the tests
   2. errors logs are recreated on each run for each <testset> in ./logs/<testset>.log




rgds,
Jochem

[1] http://iamjochem.com/autoload_behaviour_tests.zip