1 use rustc_data_structures::undo_log::UndoLogs;
2 use rustc_hir::OpaqueTyOrigin;
3 use rustc_middle::ty::{self, OpaqueTypeKey, Ty};
4 use rustc_span::DUMMY_SP;
6 use crate::infer::{InferCtxtUndoLogs, UndoLog};
8 use super::{OpaqueHiddenType, OpaqueTypeDecl, OpaqueTypeMap};
10 #[derive(Default, Debug)]
11 pub struct OpaqueTypeStorage<'tcx> {
12 // Opaque types found in explicit return types and their
13 // associated fresh inference variable. Writeback resolves these
14 // variables to get the concrete type, which can be used to
15 // 'de-opaque' OpaqueTypeDecl, after typeck is done with all functions.
16 pub opaque_types: OpaqueTypeMap<'tcx>,
19 impl<'tcx> OpaqueTypeStorage<'tcx> {
20 #[instrument(level = "debug")]
21 pub(crate) fn remove(&mut self, key: OpaqueTypeKey<'tcx>, idx: Option<OpaqueHiddenType<'tcx>>) {
22 if let Some(idx) = idx {
23 self.opaque_types.get_mut(&key).unwrap().hidden_type = idx;
25 match self.opaque_types.remove(&key) {
26 None => bug!("reverted opaque type inference that was never registered: {:?}", key),
32 pub fn get_decl(&self, key: &OpaqueTypeKey<'tcx>) -> Option<&OpaqueTypeDecl<'tcx>> {
33 self.opaque_types.get(key)
36 pub fn opaque_types(&self) -> OpaqueTypeMap<'tcx> {
37 self.opaque_types.clone()
40 #[instrument(level = "debug")]
41 pub fn take_opaque_types(&mut self) -> OpaqueTypeMap<'tcx> {
42 std::mem::take(&mut self.opaque_types)
46 pub(crate) fn with_log<'a>(
48 undo_log: &'a mut InferCtxtUndoLogs<'tcx>,
49 ) -> OpaqueTypeTable<'a, 'tcx> {
50 OpaqueTypeTable { storage: self, undo_log }
54 impl<'tcx> Drop for OpaqueTypeStorage<'tcx> {
56 if !self.opaque_types.is_empty() {
58 tcx.sess.delay_span_bug(DUMMY_SP, &format!("{:?}", self.opaque_types))
64 pub struct OpaqueTypeTable<'a, 'tcx> {
65 storage: &'a mut OpaqueTypeStorage<'tcx>,
67 undo_log: &'a mut InferCtxtUndoLogs<'tcx>,
70 impl<'a, 'tcx> OpaqueTypeTable<'a, 'tcx> {
71 #[instrument(skip(self), level = "debug")]
74 key: OpaqueTypeKey<'tcx>,
75 hidden_type: OpaqueHiddenType<'tcx>,
76 origin: OpaqueTyOrigin,
77 ) -> Option<Ty<'tcx>> {
78 if let Some(decl) = self.storage.opaque_types.get_mut(&key) {
79 let prev = std::mem::replace(&mut decl.hidden_type, hidden_type);
80 self.undo_log.push(UndoLog::OpaqueTypes(key, Some(prev)));
83 let decl = OpaqueTypeDecl { hidden_type, origin };
84 self.storage.opaque_types.insert(key, decl);
85 self.undo_log.push(UndoLog::OpaqueTypes(key, None));