What GNU extensions does Snow actually depend on?

[Qqwy]

The README currently only state that Snow depends on 'some' GNU extensions. It might be worthwhile to write down an explicit list of the extensions, because that allows developers to see more easily if they'd be able to use the library in combination with their existing tooling/stack (like when doing work for embedded devices) or not.

[mortie]

Hi, sorry for a way too late response.

The GNU extensions Snow currently depends on is local labels, label pointers, the "GCC diagnostic ignored" pragmas, and __attribute__((constructor)). However, the set of GNU extensions isn't set in stone; I'm working on a new version which will probably use the standard setjmp/longjmp functions instead of label pointers, but might depend on nested functions or the typeof operator. Also, just because a compiler supports a particular GNU extension doesn't necessarily mean it works in the same way; I had to do some extra work to make Snow work in Clang because its label pointers worked slightly differently from GCC's.

It might still be a good idea though to document what GNU extensions are used, and consider any new GNU extension dependencies a breaking change.