bjoernager/rust
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avoid pairing up AllocId and PointerTag, which is redundant

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This commit is contained in:
Ralf Jung 2022-04-18 10:00:42 -04:00
parent 54ab357a5b
commit c9e568f72e
3 changed files with 43 additions and 23 deletions
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26
compiler/rustc_const_eval/src/interpret/machine.rs
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@ -88,6 +88,10 @@ pub trait Machine<'mir, 'tcx>: Sized {
/// Pointers are "tagged" with provenance information; typically the `AllocId` they belong to.
type PointerTag: Provenance + Eq + Hash + 'static;
/// When getting the AllocId of a pointer, some extra data is also obtained from the tag
/// that is passed to memory access hooks so they can do things with it.
type TagExtra: Copy + 'static;
/// Machines can define extra (non-instance) things that represent values of function pointers.
/// For example, Miri uses this to return a function pointer from `dlsym`
/// that can later be called to execute the right thing.
@ -285,11 +289,14 @@ pub trait Machine<'mir, 'tcx>: Sized {
addr: u64,
) -> Pointer<Option<Self::PointerTag>>;
/// Convert a pointer with provenance into an allocation-offset pair.
/// Convert a pointer with provenance into an allocation-offset pair
/// and extra provenance info.
///
/// The returned `AllocId` must be the same as `ptr.provenance.get_alloc_id()`.
fn ptr_get_alloc(
ecx: &InterpCx<'mir, 'tcx, Self>,
ptr: Pointer<Self::PointerTag>,
) -> (AllocId, Size);
) -> (AllocId, Size, Self::TagExtra);
/// Called to initialize the "extra" state of an allocation and make the pointers
/// it contains (in relocations) tagged. The way we construct allocations is
@ -321,7 +328,7 @@ pub trait Machine<'mir, 'tcx>: Sized {
_tcx: TyCtxt<'tcx>,
_machine: &Self,
_alloc_extra: &Self::AllocExtra,
_tag: Self::PointerTag,
_tag: (AllocId, Self::TagExtra),
_range: AllocRange,
) -> InterpResult<'tcx> {
Ok(())
@ -333,7 +340,7 @@ pub trait Machine<'mir, 'tcx>: Sized {
_tcx: TyCtxt<'tcx>,
_machine: &mut Self,
_alloc_extra: &mut Self::AllocExtra,
_tag: Self::PointerTag,
_tag: (AllocId, Self::TagExtra),
_range: AllocRange,
) -> InterpResult<'tcx> {
Ok(())
@ -345,7 +352,7 @@ pub trait Machine<'mir, 'tcx>: Sized {
_tcx: TyCtxt<'tcx>,
_machine: &mut Self,
_alloc_extra: &mut Self::AllocExtra,
_tag: Self::PointerTag,
_tag: (AllocId, Self::TagExtra),
_range: AllocRange,
) -> InterpResult<'tcx> {
Ok(())
@ -397,6 +404,8 @@ pub trait Machine<'mir, 'tcx>: Sized {
// (CTFE and ConstProp) use the same instance. Here, we share that code.
pub macro compile_time_machine(<$mir: lifetime, $tcx: lifetime>) {
type PointerTag = AllocId;
type TagExtra = ();
type ExtraFnVal = !;
type MemoryMap =
@ -474,9 +483,12 @@ pub macro compile_time_machine(<$mir: lifetime, $tcx: lifetime>) {
}
#[inline(always)]
fn ptr_get_alloc(_ecx: &InterpCx<$mir, $tcx, Self>, ptr: Pointer<AllocId>) -> (AllocId, Size) {
fn ptr_get_alloc(
_ecx: &InterpCx<$mir, $tcx, Self>,
ptr: Pointer<AllocId>,
) -> (AllocId, Size, Self::TagExtra) {
// We know `offset` is relative to the allocation, so we can use `into_parts`.
let (alloc_id, offset) = ptr.into_parts();
(alloc_id, offset)
(alloc_id, offset, ())
}
}