Refactor vtable format.

Author: crlf0710

compiler/rustc_infer/src/traits/util.rs

@@ -14,17 +14,17 @@ pub fn anonymize_predicate<'tcx>(
     tcx.reuse_or_mk_predicate(pred, new)
 }
 
-struct PredicateSet<'tcx> {
+pub struct PredicateSet<'tcx> {
     tcx: TyCtxt<'tcx>,
     set: FxHashSet<ty::Predicate<'tcx>>,
 }
 
 impl PredicateSet<'tcx> {
-    fn new(tcx: TyCtxt<'tcx>) -> Self {
+    pub fn new(tcx: TyCtxt<'tcx>) -> Self {
         Self { tcx, set: Default::default() }
     }
 
-    fn insert(&mut self, pred: ty::Predicate<'tcx>) -> bool {
+    pub fn insert(&mut self, pred: ty::Predicate<'tcx>) -> bool {
         // We have to be careful here because we want
         //
         //    for<'a> Foo<&'a i32>

compiler/rustc_middle/src/ty/vtable.rs

@@ -2,7 +2,7 @@ use std::convert::TryFrom;
 
 use crate::mir::interpret::{alloc_range, AllocId, Allocation, Pointer, Scalar, ScalarMaybeUninit};
 use crate::ty::fold::TypeFoldable;
-use crate::ty::{self, DefId, SubstsRef, Ty, TyCtxt};
+use crate::ty::{self, DefId, PolyExistentialTraitRef, SubstsRef, Ty, TyCtxt};
 use rustc_ast::Mutability;
 
 #[derive(Clone, Copy, Debug, PartialEq, HashStable)]
@@ -12,6 +12,7 @@ pub enum VtblEntry<'tcx> {
     MetadataAlign,
     Vacant,
     Method(DefId, SubstsRef<'tcx>),
+    TraitVPtr(PolyExistentialTraitRef<'tcx>),
 }
 
 pub const COMMON_VTABLE_ENTRIES: &[VtblEntry<'_>] =
@@ -92,6 +93,11 @@ impl<'tcx> TyCtxt<'tcx> {
                     let fn_ptr = Pointer::from(fn_alloc_id);
                     ScalarMaybeUninit::from_pointer(fn_ptr, &tcx)
                 }
+                VtblEntry::TraitVPtr(trait_ref) => {
+                    let supertrait_alloc_id = self.vtable_allocation(ty, Some(*trait_ref));
+                    let vptr = Pointer::from(supertrait_alloc_id);
+                    ScalarMaybeUninit::from_pointer(vptr, &tcx)
+                }
             };
             vtable
                 .write_scalar(&tcx, alloc_range(ptr_size * idx, ptr_size), scalar)

compiler/rustc_mir/src/monomorphize/collector.rs

@@ -1116,6 +1116,10 @@ fn create_mono_items_for_vtable_methods<'tcx>(
                     | VtblEntry::MetadataSize
                     | VtblEntry::MetadataAlign
                     | VtblEntry::Vacant => None,
+                    VtblEntry::TraitVPtr(_) => {
+                        // all super trait items already covered, so skip them.
+                        None
+                    }
                     VtblEntry::Method(def_id, substs) => ty::Instance::resolve_for_vtable(
                         tcx,
                         ty::ParamEnv::reveal_all(),

compiler/rustc_trait_selection/src/lib.rs

@@ -31,6 +31,8 @@ extern crate rustc_data_structures;
 extern crate tracing;
 #[macro_use]
 extern crate rustc_middle;
+#[macro_use]
+extern crate smallvec;
 
 pub mod autoderef;
 pub mod infer;