Struct Patch 

pub struct Patch {
    pub at: usize,
    pub before: usize,
}

Where the room a patcher was promised at the top of a function ended up.

What -fpatchable-function-entry= asks for, once it is bytes rather than instructions. Two numbers because the writer has two questions: where the address it records points, and how much of the function is in front of the symbol.

They are not the same number. The room can be split by the landing pad a function opens with, since the pad has to be the first instruction after the label and the room does not, so the part in front of the label and the part after it are not always next to each other. What is recorded is the front of the whole thing, which is the part in front of the label when there is one.

Fields

at: usize

Where the room begins, as an offset into the same bytes Extent::start is one into.

before: usize

How many bytes of the function are in front of Extent::start, which is where its symbol is and where an unwinder is told the function begins.

Trait Implementations

impl Clone for Patch

fn clone(&self) -> Patch

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Patch

impl Debug for Patch

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

Formats the value using the given formatter.

impl Eq for Patch

impl PartialEq for Patch

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Patch