assert that we are (de)seiralizing ProvenanceMap correctly

Author: RalfJung

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -112,15 +112,15 @@ pub struct Memory<'mir, 'tcx, M: Machine<'mir, 'tcx>> {
 /// A reference to some allocation that was already bounds-checked for the given region
 /// and had the on-access machine hooks run.
 #[derive(Copy, Clone)]
-pub struct AllocRef<'a, 'tcx, Prov, Extra> {
+pub struct AllocRef<'a, 'tcx, Prov: Provenance, Extra> {
     alloc: &'a Allocation<Prov, Extra>,
     range: AllocRange,
     tcx: TyCtxt<'tcx>,
     alloc_id: AllocId,
 }
 /// A reference to some allocation that was already bounds-checked for the given region
 /// and had the on-access machine hooks run.
-pub struct AllocRefMut<'a, 'tcx, Prov, Extra> {
+pub struct AllocRefMut<'a, 'tcx, Prov: Provenance, Extra> {
     alloc: &'a mut Allocation<Prov, Extra>,
     range: AllocRange,
     tcx: TyCtxt<'tcx>,

compiler/rustc_middle/src/mir/interpret/allocation.rs

@@ -36,7 +36,7 @@ pub use init_mask::{InitChunk, InitChunkIter};
 // hashed. (see the `Hash` impl below for more details), so the impl is not derived.
 #[derive(Clone, Eq, PartialEq, PartialOrd, Ord, TyEncodable, TyDecodable)]
 #[derive(HashStable)]
-pub struct Allocation<Prov = AllocId, Extra = ()> {
+pub struct Allocation<Prov: Provenance = AllocId, Extra = ()> {
     /// The actual bytes of the allocation.
     /// Note that the bytes of a pointer represent the offset of the pointer.
     bytes: Box<[u8]>,
@@ -108,9 +108,7 @@ impl hash::Hash for Allocation {
 /// (`ConstAllocation`) are used quite a bit.
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, HashStable)]
 #[rustc_pass_by_value]
-pub struct ConstAllocation<'tcx, Prov = AllocId, Extra = ()>(
-    pub Interned<'tcx, Allocation<Prov, Extra>>,
-);
+pub struct ConstAllocation<'tcx>(pub Interned<'tcx, Allocation>);
 
 impl<'tcx> fmt::Debug for ConstAllocation<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -120,8 +118,8 @@ impl<'tcx> fmt::Debug for ConstAllocation<'tcx> {
     }
 }
 
-impl<'tcx, Prov, Extra> ConstAllocation<'tcx, Prov, Extra> {
-    pub fn inner(self) -> &'tcx Allocation<Prov, Extra> {
+impl<'tcx> ConstAllocation<'tcx> {
+    pub fn inner(self) -> &'tcx Allocation {
         self.0.0
     }
 }
@@ -220,7 +218,7 @@ impl AllocRange {
 }
 
 // The constructors are all without extra; the extra gets added by a machine hook later.
-impl<Prov> Allocation<Prov> {
+impl<Prov: Provenance> Allocation<Prov> {
     /// Creates an allocation initialized by the given bytes
     pub fn from_bytes<'a>(
         slice: impl Into<Cow<'a, [u8]>>,
@@ -278,7 +276,7 @@ impl<Prov> Allocation<Prov> {
 impl Allocation {
     /// Adjust allocation from the ones in tcx to a custom Machine instance
     /// with a different Provenance and Extra type.
-    pub fn adjust_from_tcx<Prov, Extra, Err>(
+    pub fn adjust_from_tcx<Prov: Provenance, Extra, Err>(
         self,
         cx: &impl HasDataLayout,
         extra: Extra,
@@ -311,7 +309,7 @@ impl Allocation {
 }
 
 /// Raw accessors. Provide access to otherwise private bytes.
-impl<Prov, Extra> Allocation<Prov, Extra> {
+impl<Prov: Provenance, Extra> Allocation<Prov, Extra> {
     pub fn len(&self) -> usize {
         self.bytes.len()
     }

compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs

@@ -22,15 +22,17 @@ pub struct ProvenanceMap<Prov = AllocId> {
     bytes: Option<Box<SortedMap<Size, Prov>>>,
 }
 
-impl<D: Decoder, Prov: Decodable<D>> Decodable<D> for ProvenanceMap<Prov> {
+impl<D: Decoder, Prov: Provenance + Decodable<D>> Decodable<D> for ProvenanceMap<Prov> {
     fn decode(d: &mut D) -> Self {
+        assert!(!Prov::OFFSET_IS_ADDR); // only `AllocId` is ever serialized
         Self { ptrs: Decodable::decode(d), bytes: None }
     }
 }
 
-impl<S: Encoder, Prov: Encodable<S>> Encodable<S> for ProvenanceMap<Prov> {
+impl<S: Encoder, Prov: Provenance + Encodable<S>> Encodable<S> for ProvenanceMap<Prov> {
     fn encode(&self, s: &mut S) {
         let Self { ptrs, bytes } = self;
+        assert!(!Prov::OFFSET_IS_ADDR); // only `AllocId` is ever serialized
         debug_assert!(bytes.is_none());
         ptrs.encode(s)
     }

compiler/rustc_middle/src/mir/pretty.rs

@@ -788,15 +788,15 @@ pub fn write_allocations<'tcx>(
 /// After the hex dump, an ascii dump follows, replacing all unprintable characters (control
 /// characters or characters whose value is larger than 127) with a `.`
 /// This also prints provenance adequately.
-pub fn display_allocation<'a, 'tcx, Prov, Extra>(
+pub fn display_allocation<'a, 'tcx, Prov: Provenance, Extra>(
     tcx: TyCtxt<'tcx>,
     alloc: &'a Allocation<Prov, Extra>,
 ) -> RenderAllocation<'a, 'tcx, Prov, Extra> {
     RenderAllocation { tcx, alloc }
 }
 
 #[doc(hidden)]
-pub struct RenderAllocation<'a, 'tcx, Prov, Extra> {
+pub struct RenderAllocation<'a, 'tcx, Prov: Provenance, Extra> {
     tcx: TyCtxt<'tcx>,
     alloc: &'a Allocation<Prov, Extra>,
 }

compiler/rustc_mir_transform/src/const_prop.rs

@@ -266,7 +266,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for ConstPropMachine<'mir, 'tcx>
         _tcx: TyCtxt<'tcx>,
         _machine: &Self,
         _alloc_id: AllocId,
-        alloc: ConstAllocation<'tcx, Self::Provenance, Self::AllocExtra>,
+        alloc: ConstAllocation<'tcx>,
         _static_def_id: Option<DefId>,
         is_write: bool,
     ) -> InterpResult<'tcx> {