Function frame_iterator

crates/unwinder/src/stackwalk.rs:285–307

Wrap `FrameCursor` in a true iterator. This captures the `unwind` borrow for the duration of the iterator's lifetime. # Safety Safety conditions for this function are the same as for the [`FrameCursor::new`] function, plus the condition on `unwind` from the [`FrameCursor::advance`] method.

(
    unwind: &dyn Unwind,
    pc: usize,
    fp: usize,
    trampoline_fp: usize,
)

/// [`FrameCursor::new`] function, plus the condition on `unwind` from
/// the [`FrameCursor::advance`] method.
pub unsafe fn frame_iterator(
    unwind: &dyn Unwind,
    pc: usize,
    fp: usize,
    trampoline_fp: usize,
) -> impl Iterator<Item = Frame> {
    // SAFETY: our safety conditions include those of
    // `FrameCursor::new`.
    let mut cursor = unsafe { FrameCursor::new(pc, fp, trampoline_fp) };
    core::iter::from_fn(move || {
        if cursor.done() {
            None
        } else {
            let frame = cursor.frame();
            // SAFETY: `unwind` is associated with the stack as per
            // our safety conditions.
            unsafe {
                cursor.advance(unwind);
            }
            Some(frame)
        }
    })
}

/// Walk through a contiguous sequence of Wasm frames starting with
/// the frame at the given PC and FP and ending at