Struct VStack 

pub(super) struct VStack<T> {
    base_offset: i32,
    top_offset: i32,
    slots: Vec<Option<VSlot<T>>>,
}

A section-local virtual stack indexed by section-relative offsets.

Offsets are relative to section_start_sp:

• Negative offsets (-inputs .. 0) represent values that existed on the stack before the section started (the section’s inputs).
• Non-negative offsets represent values pushed within the section.

Fields

base_offset: i32

Lowest tracked offset (inclusive), relative to section_start_sp.

top_offset: i32

One-past-top offset, relative to section_start_sp. Equivalent to section_len_offset + len_offset in FunctionCx.

slots: Vec<Option<VSlot<T>>>

Slot states, indexed by (offset - base_offset).

Implementations

impl<T: Copy> VStack<T>

pub(super) fn reset(&mut self, inputs: usize, max_growth: usize)

Resets the virtual stack for a new section.

inputs is the number of stack values consumed by the section (the section’s minimum required stack depth). max_growth is the maximum number of slots the section pushes beyond the entry height.

All input slots start as VSlot::Materialized because they were written by the previous section (or the function entry) and are already in memory.

pub(super) fn top_offset(&self) -> i32

Returns the current top offset (one-past-top, relative to section start).

pub(super) fn offset_at_depth(&self, depth: usize) -> i32

Returns the section-relative offset for a given operand depth (0 = TOS, 1 = second from top, etc.).

fn idx(&self, offset: i32) -> usize

pub(super) fn get(&self, depth: usize) -> VSlot<T>

Returns the slot state at the given operand depth.

pub(super) fn get_at_offset(&self, offset: i32) -> VSlot<T>

Returns the slot state at the given section-relative offset. Returns VSlot::Materialized if the offset is outside the tracked range.

pub(super) fn set(&mut self, depth: usize, value: T)

Sets a slot to virtual at the given operand depth.

pub(super) fn set_at_offset(&mut self, offset: i32, value: T)

Sets a slot to virtual at a section-relative offset.

pub(super) fn push(&mut self, value: T)

Pushes a virtual value onto the top of the stack.

pub(super) fn push_mem(&mut self)

Pushes a materialized marker onto the top of the stack. Used when a builtin writes directly to the physical stack slot.

pub(super) fn drop_top(&mut self, n: usize)

Drops n elements from the top of the stack.

pub(super) fn live_range(&self) -> Range<i32>

Returns the live range of offsets (base_offset..top_offset).

pub(super) fn virtual_count(&self) -> usize

Returns the number of virtual (non-materialized) slots in the live range.

pub(super) fn pending_stores( &self, range: Range<i32>, ) -> impl Iterator<Item = (i32, T)> + '_

Returns pending virtual slots that need physical stores in the given range, yielding (offset, value) pairs.

Offsets outside the tracked range are silently skipped (they are already materialized by the previous section or not yet live).

pub(super) fn mark_materialized_range(&mut self, range: Range<i32>)

Marks all slots in the given range as materialized.

Offsets outside the tracked range are silently skipped.

Trait Implementations

impl<T: Clone> Clone for VStack<T>

fn clone(&self) -> VStack<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for VStack<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Default for VStack<T>

fn default() -> Self

Returns the “default value” for a type.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 32 bytes