Function gc_refs_in_frame

crates/wasmtime/src/runtime/debug.rs:833–862

(ft: FrameTable<'a>, pc: u32, fp: *mut usize)

// structured result) within the closure borrowed by a nested closure.
#[cfg(feature = "gc")]
pub(crate) fn gc_refs_in_frame<'a>(ft: FrameTable<'a>, pc: u32, fp: *mut usize) -> Vec<*mut u32> {
    let fp = fp.cast::<u8>();
    let mut ret = vec![];
    if let Some(frames) = ft.find_program_point(pc, FrameInstPos::Post) {
        for (_wasm_pc, frame_desc, stack_shape) in frames {
            let (frame_desc_data, slot_to_fp_offset) = ft.frame_descriptor(frame_desc).unwrap();
            let frame_base = unsafe { fp.offset(-isize::try_from(slot_to_fp_offset).unwrap()) };
            let frame_desc = FrameStateSlot::parse(frame_desc_data).unwrap();
            for (offset, ty) in frame_desc.stack_and_locals(stack_shape) {
                match ty {
                    FrameValType::AnyRef | FrameValType::ExnRef | FrameValType::ExternRef => {
                        let slot = unsafe {
                            frame_base
                                .offset(isize::try_from(offset.offset()).unwrap())
                                .cast::<u32>()
                        };
                        ret.push(slot);
                    }
                    FrameValType::ContRef | FrameValType::FuncRef => {}
                    FrameValType::I32
                    | FrameValType::I64
                    | FrameValType::F32
                    | FrameValType::F64
                    | FrameValType::V128 => {}
                }
            }
        }
    }
    ret
}

/// One debug event that occurs when running Wasm code on a store with
/// a debug handler attached.