[ErrorHandler] Make assert() silent when assert.quiet_eval=1

[nicolas-grekas]

Q	A
Branch?	master
Bug fix?	no
New feature?	yes
Deprecations?	no
Tickets	-
License	MIT
Doc PR	-

Working around https://bugs.php.net/75769
/cc @nikic FYI :)

[nikic]

Please don't. assert.quiet_eval is meaningless for non-string asserts and removed in PHP 8.

[nicolas-grekas]

It would be really useful to make it work in PHP8! The use case is the following: turn assert() "on" in prod, but in a silenced mode only. Instead of disrupting execution, this would trigger warnings with error_reporting() set to zero. Then, userland error handlers would catch those and log them, allowing to debug issues with assert() on prod systems. I don't know the plan for PHP8, but please don't make assert() always throw!

[nikic]

@nicolas-grekas I think you are mixing up assert.exception/assert.warning with assert.quiet_eval. quiet_eval only affects errors generated during evaluation of the assert itself, it does not affect how an assertion failure is reported.

You may also want to look into ASSERT_CALLBACK, which is probably a more convenient way to add custom assert handling than to listen for warnings in an error handler.

[nicolas-grekas]

OK, I'll give it a 2nd look, thanks for the feedback. By any chance, do you have any hints about the plans for PHP 8 on this topic?

[nikic]

@nicolas-grekas Don't think there are any plans in that area (yet...) There was only some talk of making assert.exception=1 the default (instead of assert.warning=1).

[nicolas-grekas]

Alternative proposal in #35645