Make const_eval_raw query return just an AllocId

5 files changed, 22 insertions, 8 deletions

diff --git a/src/librustc/ich/impls_ty.rs b/src/librustc/ich/impls_ty.rs
index 64685446e8f..679107160a6 100644
--- a/src/librustc/ich/impls_ty.rs
+++ b/src/librustc/ich/impls_ty.rs
@@ -317,6 +317,10 @@ impl_stable_hash_for!(
         ByRef(id, alloc, offset),
     }
 );
+impl_stable_hash_for!(struct ::mir::interpret::RawConst<'tcx> {
+    alloc_id,
+    ty,
+});
 
 impl_stable_hash_for! {
     impl<Tag> for struct mir::interpret::Pointer<Tag> {
diff --git a/src/librustc/mir/interpret/error.rs b/src/librustc/mir/interpret/error.rs
index f1c95e0f000..f1ac4b21058 100644
--- a/src/librustc/mir/interpret/error.rs
+++ b/src/librustc/mir/interpret/error.rs
@@ -16,7 +16,7 @@ use ty::{self, Ty, layout};
 use ty::layout::{Size, Align, LayoutError};
 use rustc_target::spec::abi::Abi;
 
-use super::{Pointer, InboundsCheck, ScalarMaybeUndef};
+use super::{RawConst, Pointer, InboundsCheck, ScalarMaybeUndef};
 
 use backtrace::Backtrace;
 
@@ -46,6 +46,7 @@ impl ErrorHandled {
     }
 }
 
+pub type ConstEvalRawResult<'tcx> = Result<RawConst<'tcx>, ErrorHandled>;
 pub type ConstEvalResult<'tcx> = Result<&'tcx ty::Const<'tcx>, ErrorHandled>;
 
 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
diff --git a/src/librustc/mir/interpret/mod.rs b/src/librustc/mir/interpret/mod.rs
index ec25431bd1f..9369b6e56f1 100644
--- a/src/librustc/mir/interpret/mod.rs
+++ b/src/librustc/mir/interpret/mod.rs
@@ -22,10 +22,10 @@ mod pointer;
 
 pub use self::error::{
     EvalError, EvalResult, EvalErrorKind, AssertMessage, ConstEvalErr, struct_error,
-    FrameInfo, ConstEvalResult, ErrorHandled,
+    FrameInfo, ConstEvalRawResult, ConstEvalResult, ErrorHandled,
 };
 
-pub use self::value::{Scalar, ConstValue, ScalarMaybeUndef};
+pub use self::value::{Scalar, ScalarMaybeUndef, RawConst, ConstValue};
 
 pub use self::allocation::{
     InboundsCheck, Allocation, AllocationExtra,
diff --git a/src/librustc/mir/interpret/value.rs b/src/librustc/mir/interpret/value.rs
index 47c42c9431a..4bcba9d5467 100644
--- a/src/librustc/mir/interpret/value.rs
+++ b/src/librustc/mir/interpret/value.rs
@@ -10,12 +10,20 @@
 
 use std::fmt;
 
-use ty::layout::{HasDataLayout, Size};
-use ty::subst::Substs;
-use hir::def_id::DefId;
+use crate::ty::{Ty, subst::Substs, layout::{HasDataLayout, Size}};
+use crate::hir::def_id::DefId;
 
 use super::{EvalResult, Pointer, PointerArithmetic, Allocation, AllocId, sign_extend, truncate};
 
+/// Represents the result of a raw const operation, pre-validation.
+#[derive(Copy, Clone, Debug, Eq, PartialEq, RustcEncodable, RustcDecodable, Hash)]
+pub struct RawConst<'tcx> {
+    // the value lives here, at offset 0, and that allocation definitely is a `AllocType::Memory`
+    // (so you can use `AllocMap::unwrap_memory`).
+    pub alloc_id: AllocId,
+    pub ty: Ty<'tcx>,
+}
+
 /// Represents a constant value in Rust. Scalar and ScalarPair are optimizations which
 /// matches the LocalValue optimizations for easy conversions between Value and ConstValue.
 #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord, RustcEncodable, RustcDecodable, Hash)]
@@ -23,6 +31,7 @@ pub enum ConstValue<'tcx> {
     /// Never returned from the `const_eval` query, but the HIR contains these frequently in order
     /// to allow HIR creation to happen for everything before needing to be able to run constant
     /// evaluation
+    /// FIXME: The query should then return a type that does not even have this variant.
     Unevaluated(DefId, &'tcx Substs<'tcx>),
 
     /// Used only for types with layout::abi::Scalar ABI and ZSTs
diff --git a/src/librustc/ty/query/mod.rs b/src/librustc/ty/query/mod.rs
index 89e7f4db502..22bd1e26ba3 100644
--- a/src/librustc/ty/query/mod.rs
+++ b/src/librustc/ty/query/mod.rs
@@ -27,7 +27,7 @@ use middle::stability::{self, DeprecationEntry};
 use middle::lib_features::LibFeatures;
 use middle::lang_items::{LanguageItems, LangItem};
 use middle::exported_symbols::{SymbolExportLevel, ExportedSymbol};
-use mir::interpret::ConstEvalResult;
+use mir::interpret::{ConstEvalRawResult, ConstEvalResult};
 use mir::mono::CodegenUnit;
 use mir;
 use mir::interpret::GlobalId;
@@ -309,7 +309,7 @@ define_queries! { <'tcx>
         /// validation. Please add a comment to every use site explaining why using `const_eval`
         /// isn't sufficient
         [] fn const_eval_raw: const_eval_raw_dep_node(ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>)
-            -> ConstEvalResult<'tcx>,
+            -> ConstEvalRawResult<'tcx>,
 
         /// Results of evaluating const items or constants embedded in
         /// other items (such as enum variant explicit discriminants).