rust/src/analyze.rs

59 lines
1.6 KiB
Rust

use crate::prelude::*;
use rustc::mir::StatementKind::*;
bitflags::bitflags! {
pub struct Flags: u8 {
const NOT_SSA = 0b00000001;
}
}
pub fn analyze<'a, 'tcx: 'a>(fx: &FunctionCx<'a, 'tcx, impl Backend>) -> HashMap<Local, Flags> {
let mut flag_map = HashMap::new();
for local in fx.mir.local_decls.indices() {
flag_map.insert(local, Flags::empty());
}
not_ssa(&mut flag_map, RETURN_PLACE);
for (local, local_decl) in fx.mir.local_decls.iter_enumerated() {
if fx.clif_type(local_decl.ty).is_none() {
not_ssa(&mut flag_map, local);
}
}
for bb in fx.mir.basic_blocks().iter() {
for stmt in bb.statements.iter() {
match &stmt.kind {
Assign(_, rval) => match &**rval {
Rvalue::Ref(_, _, place) => analyze_non_ssa_place(&mut flag_map, place),
_ => {}
},
_ => {}
}
}
match &bb.terminator().kind {
TerminatorKind::Call {
destination: Some((place, _)),
..
} => analyze_non_ssa_place(&mut flag_map, place),
_ => {}
}
}
flag_map
}
fn analyze_non_ssa_place(flag_map: &mut HashMap<Local, Flags>, place: &Place) {
match place {
Place::Base(PlaceBase::Local(local)) => not_ssa(flag_map, local),
_ => {}
}
}
fn not_ssa<L: ::std::borrow::Borrow<Local>>(flag_map: &mut HashMap<Local, Flags>, local: L) {
*flag_map.get_mut(local.borrow()).unwrap() |= Flags::NOT_SSA;
}