Hi all,
Following up this Stack Overflow question
https://stackoverflow.com/q/66854655/157957 and accompanying bug report
https://bugs.php.net/bug.php?id=80914 I have discovered the odd fact
that a function was accidentally added to PHP 8.0: getdir() is now an
alias for dir()
Well, actually, it's slightly weirder than that: dir() is the alias, and
getdir() is the real function. It's just that from PHP 4.0 until PHP
7.4, only the alias existed: https://3v4l.org/ZHJ9U
In PHP 8.0.x, getdir() is a callable function, and users can't define a
function with that name.
Here's what seems to have happened:
dir() is a function from PHP 3, which is why it creates a weird object
with no constructor. Its function entry originally looked like this:
{"dir", php3_getdir, NULL},
Because the PHP function didn't match the C function name, this got
translated to a function alias in PHP 4 [1]:
PHP_FALIAS(dir, getdir, NULL)
But it wasn't really an alias: there was no separate PHP_FE line for
"getdir", so "dir" remained the only name you could actually use in PHP
code.
This situation survived until the move to add arginfo in PHP 8. Maté,
quite reasonably, saw that getdir() was missing a stub, and added one.
[2] The stubs were then used to re-generate the function entries, and
after more than 20 years, getdir() finally got its own function entry:
ZEND_FE(getdir, arginfo_getdir)
ZEND_FALIAS(dir, getdir, arginfo_dir)
I've compared the list of PHP_FE / ZEND_FE macros in 7.4 and 8.0, and
can't see any others that are obviously wrong, although I noticed that
get_mangled_object_vars isn't documented.
The obvious question is: should this be considered a bug, and undone,
and if so, how?
The answer is probably to do what should have been done 20 years ago,
and rename the internal definition to match the function name exposed to
the user.
[1]
https://github.com/php/php-src/commit/7a167cd0c1f6ee7c0dce0196b5ca9209a54f534c#diff-a6738c9e7e606e49fc4e7225c281deca86191ada31a5dc077169418541541d1cL59
[2]
https://github.com/php/php-src/commit/736b22dc0b2fc36e9bd87f2ee5af8c4b2be9fd3d#diff-96c05a0551ccbeca3ff610c111f88b54a0d727888cf353f477ea8dc951a18637R723
--
Rowan Tommins
[IMSoP]
On Tue, Apr 6, 2021 at 5:04 PM Rowan Tommins rowan.collins@gmail.com
wrote:
Because the PHP function didn't match the C function name,
this got translated to a function alias in PHP 4 [1]:
Curious, since PHP_NAMED_FE did exist in this revision that Ze'ev didn't
choose to use that macro. Mid 1999 though, so I imagine the development
pace going into ZE1 was pretty heavy. Whoopsie!
The obvious question is: should this be considered a bug, and undone,
and if so, how?The answer is probably to do what should have been done 20 years ago,
and rename the internal definition to match the function name exposed to
the user.
With my 8.0 RM hat on, I say we do that. Call this a bug that the
undocumented function existed in 8.0.0 through 8.0.3 and remove it. The
window of code that will break will be vanishingly small, and if it does
impact anyone, the fix is to call dir() instead. Sorted.
As to whether or not we deprecate dir()/Directory in 8.x... eh... I'm
swiss on that. It's been there for ages and isn't hurting anyone, is it?
-Sara
With my 8.0 RM hat on, I say we do that. Call this a bug that the
undocumented function existed in 8.0.0 through 8.0.3 and remove it.
The window of code that will break will be vanishingly small, and if
it does impact anyone, the fix is to calldir()instead. Sorted.
Since nobody objected, but nobody seemed to have got round to it yet,
I've raised a PR to remove getdir() and rename the internal
implementation to dir() once and for all:
https://github.com/php/php-src/pull/6855
Regards,
--
Rowan Tommins
[IMSoP]