Known Limitations of Translation

This document is to track things that we know the translator can't handle, as well as things it probably won't ever handle.

Unimplemented

• bitfields
• variadic function definitions (blocked by Rust language)
• some static initializers (blocked by Rust language)
• preserving comments
• long double and _Complex types (partially blocked by Rust language, see https://github.com/GaloisInc/C2Rust/issues/17)

Unimplemented, might be implementable but very low priority

• GNU packed structs (Rust has #[repr(packed)] compatible with #[repr(C)])
• inline functions (Rust has #[inline])
• restrict pointers (Rust has references)
• inline assembly (see https://github.com/GaloisInc/C2Rust/issues/96)
• macros (see https://github.com/GaloisInc/C2Rust/issues/9)

Likely won't ever support

• longjmp/setjmp Although there are LLVM intrinsics for these, it is unclear how these interact with Rust (esp. idiomatic Rust).
• jumps into and out of statement expressions We support GNU C statement expressions, but we can not handle jumping into or out of these. Both entry and exit into the expression has to be through the usual fall-through evaluation of the expression.