How hard should PHP try to finish a script? View as Markdown

Hi,

I think the example of the abstract method not containing a body is a bad example, as it is fatal and would normally be caught at compilation in a compiled language. I think these sorts of errors shouldn't be catchable, although, I can see instances where it could be a useful interface but it is only for some edge cases such as loading some concrete implementation that your script has no prior knowledge about, if it's incorrect your application can't recover, but this can be avoided anyway I think.

Sam
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-----Original Message-----
From: Karoly Negyesi karoly@negyesi.net
Date: Sun, 17 Jun 2012 12:06:03
To: internals@lists.php.net
Subject: [PHP-DEV] How hard should PHP try to finish a script?
Hi,

PHP often throws fatal errors when it could throw an exception.

Take PHP Fatal error: Non-abstract method foo::bar() must contain
body this error for example. It would be possible to mark this class
as 'invalid' instead and when doing a new foo , throw an exception. Or
if you try really hard then only the method call should throw an
exception.

Or, I was extending ReflectionClass and got Fatal error:
ReflectionClass::getFileName(): Internal error: Failed to retrieve the
reflection object (same happens if you try serialzie / unserialzie on
ReflectionClass as a comment in the manual points out). I could argue
this is an exception and not a fatal.

Let me quote documentation:

Fatal run-time errors. These indicate errors that can not be recovered
from, such as a memory allocation problem. Execution of the script is
halted.

I do not see the above or , indeed , most of fatals I see this sort of
error. Sure, if a malloc call fails, the world has ended and it's time
to die. Otherwise, could we just get an exception so that it can be
handled ?

Thanks

Karoly "chx" Negyesi

Hi,

PHP often throws fatal errors when it could throw an exception.

Take PHP Fatal error: Non-abstract method foo::bar() must contain
body this error for example. It would be possible to mark this class
as 'invalid' instead and when doing a new foo , throw an exception. Or
if you try really hard then only the method call should throw an
exception.

Or, I was extending ReflectionClass and got Fatal error:
ReflectionClass::getFileName(): Internal error: Failed to retrieve the
reflection object (same happens if you try serialzie / unserialzie on
ReflectionClass as a comment in the manual points out). I could argue
this is an exception and not a fatal.

Let me quote documentation:

Fatal run-time errors. These indicate errors that can not be recovered
from, such as a memory allocation problem. Execution of the script is
halted.

I do not see the above or , indeed , most of fatals I see this sort of
error. Sure, if a malloc call fails, the world has ended and it's time
to die. Otherwise, could we just get an exception so that it can be
handled ?

Thanks

Karoly "chx" Negyesi

--

This kind of thing has come up before, without resolution. There are two
separate issues in your proposal:

1. Fatal errors that mean the script should stop executing, but don't
   actually reflect instability in the engine.
2. Throwing exceptions from PHP core.

It seems to me that #2 is strongly opposed by a lot of people.

I think most people here sympathize with #1, but it hasn't been important
enough for anyone to actually do the work, and there hasn't been a proposal
about how it should be done. In general, it requires an audit of every
E_FATAL error thrown. Some can be changed to E_RECOVERABLE_ERROR. Some
however, really should kill the script, but don't need to skip error
handlers. These would need some new E_ constant, and a rule that when
thrown, an error handler can be called, but the script will die after the
error handler has finished. There's probably more to it than that, which is
why there would need to be a RFC. I'm guessing that if someone wrote an
RFC, and had a patch, it would be received well.

Thanks,
John LeSueur