-
Show log
Commit
-
Hash : 3bf7994f
Author :
Date : 2021-09-27T14:38:12
Add and use `SDL_FALLTHROUGH` for fallthroughs Case fallthrough warnings can be suppressed using the __fallthrough__ compiler attribute. Unfortunately, not all compilers have this attribute, or even have __has_attribute to check if they have the __fallthrough__ attribute. [[fallthrough]] is also available in C++17 and the next C2x, but not everyone uses C++17 or C2x. So define the SDL_FALLTHROUGH macro to deal with those problems - if we are using C++17 or C2x, it expands to [[fallthrough]]; else if the compiler has __has_attribute and has the __fallthrough__ attribute, then it expands to __attribute__((__fallthrough__)); else it expands to an empty statement, with a /* fallthrough */ comment (it's a do {} while (0) statement, because users of this macro need to use a semicolon, because [[fallthrough]] and __attribute__((__fallthrough__)) require a semicolon). Clang before Clang 10 and GCC before GCC 7 have problems with using __attribute__ as a sole statement and warn about a "declaration not declaring anything", so fall back to using the /* fallthrough */ comment if we are using those older compiler versions. Applications using SDL are also free to use this macro (because it is defined in begin_code.h). All existing /* fallthrough */ comments have been replaced with this macro. Some of them were unnecessary because they were the last case in a switch; using SDL_FALLTHROUGH in those cases would result in a compile error on compilers that support __fallthrough__, for having a __attribute__((__fallthrough__)) statement that didn't immediately precede a case label.
-
Properties
-
Git HTTP https://git.kmx.io/kc3-lang/SDL.git Git SSH git@git.kmx.io:kc3-lang/SDL.git Public access ? public Description Users
Tags
