Currently, disabling a function only replaces the internal
function handler with one that throws a warning, and a few
places in the engine special-case such functions, such as
function_exists. This leaves us with a Schrödinger's function,
which both does not exist (function_exists returns false) and
does exist (you cannot define a function with the same name).
In particular, this prevents the implementation of robust
polyfills, as reported in https://bugs.php.net/bug.php?id=79382:
if (!function_exists('getallheaders')) {
function getallheaders(...) { ... }
}
If getallheaders() is a disabled function, this code will break.
This patch changes disable_functions to remove the functions from
the function table completely. For all intents and purposes, it
will look like the function does not exist.
This also renders two bits of PHP functionality obsolete and thus
deprecated:
* ReflectionFunction::isDisabled(), as it will no longer be
possible to construct the ReflectionFunction of a disabled
function in the first place.
* get_defined_functions() with $exclude_disabled=false, as
get_defined_functions() now never returns disabled functions.
Fixed bug #79382.
Closes GH-5473.
This may produce different behavior if operator overloading is
involved, and may change the error message.
If there's strong interest, this could be done in the DFA pass
with available type information. It does not look particularly
practically useful to me though.
- all rules from pass2 moved to pass1
- all JMP unrelated rules from pass3 moved to pass1
- pass3 keeps only JMP optimization rules
- pass2.c is removed
- pass1_5.c remaned to pass1.c ("_5" was related to PHP 5)
Ilija Tovilo