bpo-43502: Convert PyExceptionClass_Check from macro to static inline function

[erlend-aasland]

https://bugs.python.org/issue43502

[erlend-aasland]

cc. @vstinner

Should the NEWS entry include more info? For example "the macro was problematic because it reused its arguments twice".

[vstinner]

If the function is not used in performance critical hot code, the macro can be converted to a regular function (not a static function).

[erlend-aasland]

If the function is not used in performance critical hot code, the macro can be converted to a regular function (not a static function).

My gut feeling is to convert PyExceptionClass_Check to a static inlined function, not a regular function. Let me know if you want it to be a regular C function.

[vstinner]

Include/ contains more than 450+ functions defined as macros. I don't want to have to review 450 PRs to change all macros.

Do you have an idea on how many macros have the double evaluation bug?

[erlend-aasland]

Include/ contains more than 450+ functions defined as macros. I don't want to have to review 450 PRs to change all macros.

Do you have an idea on how many macros have the double evaluation bug?

I doubt all of them are clearly problematic. I'll see if I can create a list of worst cases and put it on the issue.

UPDATE There are 88 macros that reuse arguments in Include (including subdirectories):
macros-that-reuse-args.txt

[erlend-aasland]

I'm closing this until there's some consensus regarding bpo-43502.