Compiler Controls

Compiler controls let you influence how Ferlium compiles your program without changing its source-level behavior or type. They are intended for cases where the compiler’s default choices need to be adjusted.

Preventing function inlining

The optimizer normally decides whether to copy a function body into each call site. You can keep a function as a separate call with the Rust-compatible #[inline(never)] attribute:

#[inline(never)]
fn add_one(x: int) -> int { x + 1 }

This does not change the function’s source-level behavior or type; it only prevents MIR inlining. Currently, never is the only accepted argument to inline.

Hiding values from optimization

The safe std::black_box(value) function returns value unchanged while preventing the compiler from reasoning about its contents across that call. It is mainly useful for benchmarks; it is not a security boundary and does not prevent optimization of unrelated code.