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Date: Sun, 8 Dec 2013 16:12:21 -0200
Message-ID: <CA+5g0SKUUbgRZKsFD7=XZ1s+YLqFBTMKzeW60gRX0QKjrcr96g@mail.gmail.com>
To: Terry Ellison <ellison.terry@gmail.com>
Cc: Alexey Zakhlestin <indeyets@gmail.com>, PHP Internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] Introducing pragmas into PHP?
From: felipensp@gmail.com (Felipe Pena)

Hello,

On Sun, Dec 8, 2013 at 4:07 PM, Terry Ellison <ellison.terry@gmail.com> wrote:
> On 08/12/13 17:14, Alexey Zakhlestin wrote:
>>>
>>> I am suggestion the overload of constants of the form PHP_PRAGMA_XXX to
>>> define PHP / Zend compiler / executor behaviours. This approach would be
>>> BC to 5.3 unless, of course, the application already used PHP_PRAGMA_*
>>> constants, in which case we might also need an allow_php_pragmas INI
>>> parameter to globally enable/disable their interpretation.
>>
>> we already have declare() for this purpose exactly.
>> http://docs.php.net/declare
>>
>> it might make sense to use it for more things
>
> Alexey, perhaps you missed the subtlety of my example:
>
>
>    namespace fred;
>    const PHP_PRAGMA_ALLOW_OVERRIDE_BUILTINS=false;
>    echo strlen("DDDD");
>
> define() is a runtime function implemented by
> Zend/zend_builtin_functions.c:ZEND_FUNCTION(define).  The constant which is
> defines is not available until the DO_FCALL_BY_NAME opcode is itself
> executed sometime *after* the compile of the current source completes.
>
> const is a syntactic construct that can be intercepted in zend_compile.c,
> etc.,  and therefore can condition the remainder of the compile of that
> source.  That's what pragmas do.
>
> However, you are quite correct that:
>
>    define('fred\PHP_PRAGMA_ALLOW_OVERRIDE_BUILTINS', false);
>    include "some_other_php_file_in_namespace_fred.php";
>    ...
>
> would set the pragma for subsequent source scripts in the "fred" namespace,
> if we adopted this convention.
>
> Hope this helps.  Terry

Looks like you misread Alexey's post. He was talking about declare
construct, not define() function.

-- 
Regards,
Felipe Pena