Go back to just passing MemoryExtra to the machine-level allocation hooks

This is needed to avoid doing unnecessary global alloc_map lookups

Author: RalfJung

src/librustc_mir/const_eval.rs

@@ -23,7 +23,7 @@ use crate::interpret::{self,
     PlaceTy, MPlaceTy, OpTy, ImmTy, Immediate, Scalar,
     RawConst, ConstValue,
     InterpResult, InterpErrorInfo, InterpError, GlobalId, InterpCx, StackPopCleanup,
-    Allocation, AllocId, MemoryKind, Memory,
+    Allocation, AllocId, MemoryKind,
     snapshot, RefTracking, intern_const_alloc_recursive,
 };
 
@@ -406,7 +406,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
 
     #[inline(always)]
     fn tag_allocation<'b>(
-        _memory: &Memory<'mir, 'tcx, Self>,
+        _memory_extra: &(),
         _id: AllocId,
         alloc: Cow<'b, Allocation>,
         _kind: Option<MemoryKind<!>>,
@@ -417,7 +417,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
 
     #[inline(always)]
     fn tag_static_base_pointer(
-        _memory: &Memory<'mir, 'tcx, Self>,
+        _memory_extra: &(),
         _id: AllocId,
     ) -> Self::PointerTag {
         ()

src/librustc_mir/interpret/machine.rs

@@ -174,7 +174,7 @@ pub trait Machine<'mir, 'tcx>: Sized {
     /// For static allocations, the tag returned must be the same as the one returned by
     /// `tag_static_base_pointer`.
     fn tag_allocation<'b>(
-        memory: &Memory<'mir, 'tcx, Self>,
+        memory_extra: &Self::MemoryExtra,
         id: AllocId,
         alloc: Cow<'b, Allocation>,
         kind: Option<MemoryKind<Self::MemoryKinds>>,
@@ -186,7 +186,7 @@ pub trait Machine<'mir, 'tcx>: Sized {
     /// Be aware that requesting the `Allocation` for that `id` will lead to cycles
     /// for cyclic statics!
     fn tag_static_base_pointer(
-        memory: &Memory<'mir, 'tcx, Self>,
+        memory_extra: &Self::MemoryExtra,
         id: AllocId,
     ) -> Self::PointerTag;
 

src/librustc_mir/interpret/memory.rs

@@ -117,7 +117,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
 
     #[inline]
     pub fn tag_static_base_pointer(&self, ptr: Pointer) -> Pointer<M::PointerTag> {
-        ptr.with_tag(M::tag_static_base_pointer(&self, ptr.alloc_id))
+        ptr.with_tag(M::tag_static_base_pointer(&self.extra, ptr.alloc_id))
     }
 
     pub fn create_fn_alloc(&mut self, instance: Instance<'tcx>) -> Pointer<M::PointerTag> {
@@ -150,7 +150,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
         kind: MemoryKind<M::MemoryKinds>,
     ) -> Pointer<M::PointerTag> {
         let id = self.tcx.alloc_map.lock().reserve();
-        let (alloc, tag) = M::tag_allocation(&self, id, Cow::Owned(alloc), Some(kind));
+        let (alloc, tag) = M::tag_allocation(&self.extra, id, Cow::Owned(alloc), Some(kind));
         self.alloc_map.insert(id, (kind, alloc.into_owned()));
         Pointer::from(id).with_tag(tag)
     }
@@ -368,9 +368,9 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
     /// contains a reference to memory that was created during its evaluation (i.e., not to
     /// another static), those inner references only exist in "resolved" form.
     fn get_static_alloc(
-        id: AllocId,
+        memory_extra: &M::MemoryExtra,
         tcx: TyCtxtAt<'tcx>,
-        memory: &Memory<'mir, 'tcx, M>,
+        id: AllocId,
     ) -> InterpResult<'tcx, Cow<'tcx, Allocation<M::PointerTag, M::AllocExtra>>> {
         let alloc = tcx.alloc_map.lock().get(id);
         let alloc = match alloc {
@@ -414,7 +414,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
         // We got tcx memory. Let the machine figure out whether and how to
         // turn that into memory with the right pointer tag.
         Ok(M::tag_allocation(
-            memory,
+            memory_extra,
             id, // always use the ID we got as input, not the "hidden" one.
             alloc,
             M::STATIC_KIND.map(MemoryKind::Machine),
@@ -430,7 +430,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
         // `get_static_alloc` that we can actually use directly without inserting anything anywhere.
         // So the error type is `InterpResult<'tcx, &Allocation<M::PointerTag>>`.
         let a = self.alloc_map.get_or(id, || {
-            let alloc = Self::get_static_alloc(id, self.tcx, &self).map_err(Err)?;
+            let alloc = Self::get_static_alloc(&self.extra, self.tcx, id).map_err(Err)?;
             match alloc {
                 Cow::Borrowed(alloc) => {
                     // We got a ref, cheaply return that as an "error" so that the
@@ -459,11 +459,11 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
         id: AllocId,
     ) -> InterpResult<'tcx, &mut Allocation<M::PointerTag, M::AllocExtra>> {
         let tcx = self.tcx;
-        let alloc = Self::get_static_alloc(id, tcx, &self);
+        let memory_extra = &self.extra;
         let a = self.alloc_map.get_mut_or(id, || {
             // Need to make a copy, even if `get_static_alloc` is able
             // to give us a cheap reference.
-            let alloc = alloc?;
+            let alloc = Self::get_static_alloc(memory_extra, tcx, id)?;
             if alloc.mutability == Mutability::Immutable {
                 return err!(ModifiedConstantMemory);
             }