Struct CallSite 

pub struct CallSite<'a> { /* private fields */ }

What a call instruction records besides its operands: the stack slots that hold its GC roots while it runs (its stack map), and the landing pad control reaches if the callee unwinds.

Examples

use backend_lang::mir::{Function, SlotKind};
use backend_lang::x86_64::{op, SYSV};

let mut f = Function::new("f", &SYSV);
let b = f.block()?;
let root = f.stack_slot(SlotKind::Local { size: 8, align: 8 })?;
let g = f.symbol("g")?;
let call = f.push(b, op::CALL, &[g.into()])?;
f.push(b, op::RET, &[])?;
f.set_call_site(call, &[root], None)?;
let site = f.call_site(call).unwrap();
assert_eq!(site.gc_slots(), [root]);
assert_eq!(site.landing_pad(), None);

Implementations

impl<'a> CallSite<'a>

pub const fn inst(&self) -> Inst

The call instruction.

Examples

use backend_lang::mir::Function;
use backend_lang::x86_64::{op, SYSV};

let mut f = Function::new("f", &SYSV);
let b = f.block()?;
let g = f.symbol("g")?;
let call = f.push(b, op::CALL, &[g.into()])?;
f.set_call_site(call, &[], None)?;
assert_eq!(f.call_site(call).unwrap().inst(), call);

pub const fn gc_slots(&self) -> &'a [StackSlot]

The slots holding the GC references live across the call, which a collector reads and may rewrite while the callee runs.

Examples

use backend_lang::mir::{Function, SlotKind};
use backend_lang::x86_64::{op, SYSV};

let mut f = Function::new("f", &SYSV);
let b = f.block()?;
let s = f.stack_slot(SlotKind::Local { size: 8, align: 8 })?;
let g = f.symbol("g")?;
let call = f.push(b, op::CALL, &[g.into()])?;
f.set_call_site(call, &[s], None)?;
assert_eq!(f.call_site(call).unwrap().gc_slots().len(), 1);

pub const fn landing_pad(&self) -> Option<Block>

The block control reaches when the callee unwinds, if any.

Examples

use backend_lang::mir::Function;
use backend_lang::x86_64::{op, SYSV};

let mut f = Function::new("f", &SYSV);
let b = f.block()?;
let pad = f.block()?;
let g = f.symbol("g")?;
let call = f.push(b, op::CALL, &[g.into()])?;
f.set_call_site(call, &[], Some(pad))?;
assert_eq!(f.call_site(call).unwrap().landing_pad(), Some(pad));

Trait Implementations

impl<'a> Clone for CallSite<'a>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for CallSite<'a>

impl<'a> Debug for CallSite<'a>

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

Formats the value using the given formatter.

impl<'a> Eq for CallSite<'a>

impl<'a> PartialEq for CallSite<'a>

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

Equality operator ==.

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

Inequality operator !=.

impl<'a> StructuralPartialEq for CallSite<'a>