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use rustc::mir::{Local, Location};
use rustc::mir::Mir;
use rustc::mir::visit::PlaceContext;
use rustc::mir::visit::Visitor;
crate trait FindAssignments {
fn find_assignments(&self, local: Local) -> Vec<Location>;
}
impl<'tcx> FindAssignments for Mir<'tcx>{
fn find_assignments(&self, local: Local) -> Vec<Location>{
let mut visitor = FindLocalAssignmentVisitor{ needle: local, locations: vec![]};
visitor.visit_mir(self);
visitor.locations
}
}
struct FindLocalAssignmentVisitor {
needle: Local,
locations: Vec<Location>,
}
impl<'tcx> Visitor<'tcx> for FindLocalAssignmentVisitor {
fn visit_local(&mut self,
local: &Local,
place_context: PlaceContext<'tcx>,
location: Location) {
if self.needle != *local {
return;
}
if is_place_assignment(&place_context) {
self.locations.push(location);
}
}
}
crate fn is_place_assignment(place_context: &PlaceContext) -> bool {
match *place_context {
PlaceContext::Store | PlaceContext::Call | PlaceContext::AsmOutput => true,
PlaceContext::Drop
| PlaceContext::Inspect
| PlaceContext::Borrow { .. }
| PlaceContext::Projection(..)
| PlaceContext::Copy
| PlaceContext::Move
| PlaceContext::StorageLive
| PlaceContext::StorageDead
| PlaceContext::Validate => false,
}
}