Method drop_last

winch/codegen/src/codegen/context.rs:631–649

Drops the last `n` elements of the stack, calling the provided function for each `n` stack value. The values are dropped in top-to-bottom order.

(&mut self, last: usize, mut f: F)

    /// function for each `n` stack value.
    /// The values are dropped in top-to-bottom order.
    pub fn drop_last<F>(&mut self, last: usize, mut f: F) -> Result<()>
    where
        F: FnMut(&mut RegAlloc, &Val) -> Result<()>,
    {
        if last > 0 {
            let len = self.stack.len();
            ensure!(last <= len, CodeGenError::unexpected_value_stack_index(),);
            let truncate = self.stack.len() - last;
            let stack_mut = self.stack.inner_mut();

            // Invoke the callback in top-to-bottom order.
            for v in stack_mut[truncate..].into_iter().rev() {
                f(&mut self.regalloc, v)?
            }
            stack_mut.truncate(truncate);
        }

        Ok(())
    }

    /// Convenience wrapper around [`Self::spill_callback`].
    ///