Struct Escapes 

pub struct Escapes { /* private fields */ }

Which of a function’s locals had their address leave it.

Section 8.4 calls this the most valuable interprocedural-flavoured fact available without interprocedural analysis, because it covers every local a C programmer takes the address of only to pass one field of, and because a local whose address never escaped cannot be touched by any call at all.

Section 8.6 says how it goes wrong, which is by missing an escape, and what to do about it. keeps_address is a whitelist: an opcode it does not name lets the address out, and so does an opcode added to the IR after this was written. A blacklist would mean the next person to add an opcode introduces a miscompilation without touching this file.

Implementations

impl Escapes

pub fn of(func: &Func) -> Self

Works out which locals of this function escaped it.

pub fn escaped(&self, local: Inst) -> bool

Whether the address of this alloca left the function.

pub fn count(&self) -> usize

How many locals escaped.

Trait Implementations

impl Clone for Escapes

fn clone(&self) -> Escapes

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Escapes

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

Formats the value using the given formatter.

impl Default for Escapes

fn default() -> Escapes

Returns the “default value” for a type.