Function parse_iovs

src/iov.rs:92–131

(ctx: &VmCtx, iovs: u32, iovcnt: u32)

)]
#[external_methods(push)]
pub fn parse_iovs(ctx: &VmCtx, iovs: u32, iovcnt: u32) -> RuntimeResult<WasmIoVecs> {
    let mut i = 0;
    let mut wasm_iovs = WasmIoVecs::new();
    while i < iovcnt {
        body_invariant!(ctx_safe(ctx));
        body_invariant!(trace_safe(trace, ctx));
        body_invariant!(wasm_iovs.len() >= 0);
        body_invariant!(
            forall(|idx: usize|  (idx < wasm_iovs.len() && idx >= 0) ==> {
                let iov = wasm_iovs.lookup(idx);
                let buf = iov.iov_base;
                let cnt = iov.iov_len;
                // ctx.fits_in_lin_mem(buf, cnt, trace)
                (buf >= 0) && (cnt >= 0) &&
                (buf as usize) + (cnt as usize) < LINEAR_MEM_SIZE &&
                (buf <= buf + cnt)
            })

        );

        let start = (iovs + i * 8) as usize;
        //TODO: Once we fix ? operatior - fix this
        //let (ptr, len) = ctx.read_u32_pair(start)?;
        let v = ctx.read_u32_pair(start);
        unwrap_result!(v);
        let (ptr, len) = v;

        if !ctx.fits_in_lin_mem(ptr, len) {
            return Err(Efault);
        }

        wasm_iovs.push(WasmIoVec {
            iov_base: ptr,
            iov_len: len,
        });
        i += 1;
    }
    assert!(wasm_iovs.len() >= 0);
    Ok(wasm_iovs)
}