Resolve some small issues related to #63580

src/librustc/mir/mod.rs

@@ -1733,13 +1733,20 @@ pub enum PlaceBase<'tcx> {
 pub struct Static<'tcx> {
  pub ty: Ty<'tcx>,
  pub kind: StaticKind<'tcx>,
+ /// The `DefId` of the item this static was declared in. For promoted values, usually, this is
+ /// the same as the `DefId` of the `mir::Body` containing the `Place` this promoted appears in.
+ /// However, after inlining, that might no longer be the case as inlined `Place`s are copied
+ /// into the calling frame.
  pub def_id: DefId,
 }
 
 #[derive(
  Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, HashStable, RustcEncodable, RustcDecodable,
 )]
 pub enum StaticKind<'tcx> {
+ /// Promoted references consist of an id (`Promoted`) and the substs necessary to monomorphize
+ /// it. Usually, these substs are just the identity substs for the item. However, the inliner
+ /// will adjust these substs when it inlines a function based on the substs at the callsite.
  Promoted(Promoted, SubstsRef<'tcx>),
  Static,
 }

src/librustc_metadata/cstore_impl.rs

@@ -127,24 +127,8 @@ provide! { <'tcx> tcx, def_id, other, cdata,
  bug!("coerce_unsized_info: `{:?}` is missing its info", def_id);
  })
  }
- optimized_mir => {
- let mir = cdata.maybe_get_optimized_mir(tcx, def_id.index).unwrap_or_else(|| {
- bug!("get_optimized_mir: missing MIR for `{:?}`", def_id)
- });
-
- let mir = tcx.arena.alloc(mir);
-
- mir
- }
- promoted_mir => {
- let promoted = cdata.maybe_get_promoted_mir(tcx, def_id.index).unwrap_or_else(|| {
- bug!("get_promoted_mir: missing promoted MIR for `{:?}`", def_id)
- });
-
- let promoted = tcx.arena.alloc(promoted);
-
- promoted
- }
+ optimized_mir => { tcx.arena.alloc(cdata.get_optimized_mir(tcx, def_id.index)) }
+ promoted_mir => { tcx.arena.alloc(cdata.get_promoted_mir(tcx, def_id.index)) }
  mir_const_qualif => {
  (cdata.mir_const_qualif(def_id.index), tcx.arena.alloc(BitSet::new_empty(0)))
  }

src/librustc_metadata/decoder.rs

@@ -450,11 +450,19 @@ impl<'a, 'tcx> CrateMetadata {
  pub fn is_proc_macro_crate(&self) -> bool {
  self.root.proc_macro_decls_static.is_some()
  }
+
  fn is_proc_macro(&self, id: DefIndex) -> bool {
  self.is_proc_macro_crate() &&
  self.root.proc_macro_data.unwrap().decode(self).find(|x| *x == id).is_some()
  }
 
+ fn entry_unless_proc_macro(&self, id: DefIndex) -> Option<Entry<'tcx>> {
+ match self.is_proc_macro(id) {
+ true => None,
+ false => Some(self.entry(id)),
+ }
+ }
+
  fn maybe_entry(&self, item_id: DefIndex) -> Option<Lazy<Entry<'tcx>>> {
  self.root.entries_index.lookup(self.blob.raw_bytes(), item_id)
  }
@@ -704,10 +712,8 @@ impl<'a, 'tcx> CrateMetadata {
  }
 
  pub fn get_deprecation(&self, id: DefIndex) -> Option<attr::Deprecation> {
- match self.is_proc_macro(id) {
- true => None,
- false => self.entry(id).deprecation.map(|depr| depr.decode(self)),
- }
+ self.entry_unless_proc_macro(id)
+ .and_then(|entry| entry.deprecation.map(|depr| depr.decode(self)))
  }
 
  pub fn get_visibility(&self, id: DefIndex) -> ty::Visibility {
@@ -917,22 +923,24 @@ impl<'a, 'tcx> CrateMetadata {
  self.maybe_entry(id).and_then(|item| item.decode(self).mir).is_some()
  }
 
- pub fn maybe_get_optimized_mir(&self, tcx: TyCtxt<'tcx>, id: DefIndex) -> Option<Body<'tcx>> {
- match self.is_proc_macro(id) {
- true => None,
- false => self.entry(id).mir.map(|mir| mir.decode((self, tcx))),
- }
+ pub fn get_optimized_mir(&self, tcx: TyCtxt<'tcx>, id: DefIndex) -> Body<'tcx> {
+ self.entry_unless_proc_macro(id)
+ .and_then(|entry| entry.mir.map(|mir| mir.decode((self, tcx))))
+ .unwrap_or_else(|| {
+ bug!("get_optimized_mir: missing MIR for `{:?}", self.local_def_id(id))
+ })
  }
 
- pub fn maybe_get_promoted_mir(
+ pub fn get_promoted_mir(
  &self,
  tcx: TyCtxt<'tcx>,
  id: DefIndex,
- ) -> Option<IndexVec<Promoted, Body<'tcx>>> {
- match self.is_proc_macro(id) {
- true => None,
- false => self.entry(id).promoted_mir.map(|promoted| promoted.decode((self, tcx)),)
- }
+ ) -> IndexVec<Promoted, Body<'tcx>> {
+ self.entry_unless_proc_macro(id)
+ .and_then(|entry| entry.promoted_mir.map(|promoted| promoted.decode((self, tcx))))
+ .unwrap_or_else(|| {
+ bug!("get_promoted_mir: missing MIR for `{:?}`", self.local_def_id(id))
+ })
  }
 
  pub fn mir_const_qualif(&self, id: DefIndex) -> u8 {