Struct Area 

pub struct Area {
    pub floats_at: u32,
    pub size: u32,
    /* private fields */
}

How big a callee’s register save area is and where its two halves are.

Worked out from the convention rather than written down, so that a convention with a different number of argument registers gets an area the right size for it without anything here changing.

Fields

floats_at: u32

How many bytes of it the general purpose registers take, which is also where the vector half begins, since the general purpose half is first and starts at nothing.

size: u32

How many bytes the whole of it is.

Implementations

impl Area

pub fn of(conv: &CallRegs) -> Self

The save area a variadic callee under that convention needs.

pub fn stride(self, float: bool) -> u32

How far apart two of a file’s slots are.

pub fn starts_at(self, float: bool) -> u32

Where a file’s first slot is, which is what va_start writes into that file’s field when the signature named no argument that file carried.

pub fn last(self, float: bool) -> Option<u32>

The offset of a file’s last slot, which is the threshold va_arg compares against.

The last slot’s own offset and not the end of the area, because an offset equal to the end is one slot past the last argument while an offset a slot below the end is the last argument itself. An empty file has no such offset and nothing here has one.

Trait Implementations

impl Clone for Area

fn clone(&self) -> Area

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Area

impl Debug for Area

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

Formats the value using the given formatter.

impl Eq for Area

impl PartialEq for Area

fn eq(&self, other: &Area) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Area