Namespaced function is not honored when already called

[mvorisek]

Description

The following code:

online repro: https://3v4l.org/A5kUZ

bugs.php.net issue: https://bugs.php.net/bug.php?id=64346

<?php

namespace X;

eval('function c() { var_dump("global"); }');

function foo() {
    c();
}

function foo2() {
    c();
}

foo();

eval('namespace X; function c() { var_dump("namespaced"); }');

foo();
foo2();

Resulted in this output:

string(6) "global"
string(6) "global"
string(10) "namespaced"

But I expected this output instead:

string(6) "global"
string(10) "namespaced"
string(10) "namespaced"

PHP Version

since PHP 5.4

Operating System

any probably

[iluuu1994]

This is known and not a bug. It's a performance tradeoff. The cache slot is filled for the given lexical function call when called for the first time. Afterwards, the function lookup is assumed not to change. This cannot reasonably be fixed without tanking performance.

[mvorisek]

The current behaviour is quite dangerous and hard to debug, especially as there is no function autoloading.

Excluding impossible optimization, as the real X\c cannot be known until seen, how fast would be to have one more internal function pointer indirection?

The pointer address can be then linked via a map, and the pointer can be updated when the X\c is defined. No name lookup needed on runtime.

[iluuu1994]

The current behaviour is quite dangerous and hard to debug, especially as there is no function autoloading.

What is actually hard to debug is conditionally and time-dependently declaring functions that collide with global functions. 😉 I do not think it's worth investing significant amount of time here. But let's see what others think. /cc @bwoebi

[Girgias]

Seems like a duplicate of https://bugs.php.net/bug.php?id=64346 from a quick glance. Oh it literally is.

We don't open issues for corresponding bugsnet ones. But I suppose we now have one....

[bwoebi]

@iluuu1994 Yep, that's not going to change anytime soon.

[iluuu1994]

Thank you, let's close this then.