diff options
Diffstat (limited to 'compiler/rustc_middle/src/mir/interpret/pointer.rs')
| -rw-r--r-- | compiler/rustc_middle/src/mir/interpret/pointer.rs | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/compiler/rustc_middle/src/mir/interpret/pointer.rs b/compiler/rustc_middle/src/mir/interpret/pointer.rs index 23c2ce647..9c270ba1e 100644 --- a/compiler/rustc_middle/src/mir/interpret/pointer.rs +++ b/compiler/rustc_middle/src/mir/interpret/pointer.rs @@ -103,8 +103,7 @@ impl<T: HasDataLayout> PointerArithmetic for T {} /// This trait abstracts over the kind of provenance that is associated with a `Pointer`. It is /// mostly opaque; the `Machine` trait extends it with some more operations that also have access to /// some global state. -/// We don't actually care about this `Debug` bound (we use `Provenance::fmt` to format the entire -/// pointer), but `derive` adds some unnecessary bounds. +/// The `Debug` rendering is used to distplay bare provenance, and for the default impl of `fmt`. pub trait Provenance: Copy + fmt::Debug { /// Says whether the `offset` field of `Pointer`s with this provenance is the actual physical address. /// - If `false`, the offset *must* be relative. This means the bytes representing a pointer are @@ -115,14 +114,23 @@ pub trait Provenance: Copy + fmt::Debug { /// pointer, and implement ptr-to-int transmutation by stripping provenance. const OFFSET_IS_ADDR: bool; - /// We also use this trait to control whether to abort execution when a pointer is being partially overwritten - /// (this avoids a separate trait in `allocation.rs` just for this purpose). - const ERR_ON_PARTIAL_PTR_OVERWRITE: bool; - /// Determines how a pointer should be printed. + /// + /// Default impl is only good for when `OFFSET_IS_ADDR == true`. fn fmt(ptr: &Pointer<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result where - Self: Sized; + Self: Sized, + { + assert!(Self::OFFSET_IS_ADDR); + let (prov, addr) = ptr.into_parts(); // address is absolute + write!(f, "{:#x}", addr.bytes())?; + if f.alternate() { + write!(f, "{prov:#?}")?; + } else { + write!(f, "{prov:?}")?; + } + Ok(()) + } /// If `OFFSET_IS_ADDR == false`, provenance must always be able to /// identify the allocation this ptr points to (i.e., this must return `Some`). @@ -139,9 +147,6 @@ impl Provenance for AllocId { // so ptr-to-int casts are not possible (since we do not know the global physical offset). const OFFSET_IS_ADDR: bool = false; - // For now, do not allow this, so that we keep our options open. - const ERR_ON_PARTIAL_PTR_OVERWRITE: bool = true; - fn fmt(ptr: &Pointer<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result { // Forward `alternate` flag to `alloc_id` printing. if f.alternate() { @@ -168,7 +173,7 @@ impl Provenance for AllocId { /// Represents a pointer in the Miri engine. /// /// Pointers are "tagged" with provenance information; typically the `AllocId` they belong to. -#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, TyEncodable, TyDecodable, Hash)] +#[derive(Copy, Clone, Eq, PartialEq, TyEncodable, TyDecodable, Hash)] #[derive(HashStable)] pub struct Pointer<Prov = AllocId> { pub(super) offset: Size, // kept private to avoid accidental misinterpretation (meaning depends on `Prov` type) |