Rollup merge of #51636 - oli-obk:const_diagnostics, r=eddyb

Refactor error reporting of constants

cc @eddyb

This PR should not change any behaviour. It solely simplifies the internal handling of the errors

Author: Mark-Simulacrum

src/librustc/dep_graph/dep_node.rs

@@ -60,7 +60,7 @@
 //! user of the `DepNode` API of having to know how to compute the expected
 //! fingerprint for a given set of node parameters.
 
-use mir::interpret::{GlobalId, ConstValue};
+use mir::interpret::GlobalId;
 use hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX};
 use hir::map::DefPathHash;
 use hir::{HirId, ItemLocalId};
@@ -75,7 +75,7 @@ use traits::query::{
     CanonicalPredicateGoal, CanonicalTypeOpProvePredicateGoal, CanonicalTypeOpNormalizeGoal,
 };
 use ty::{TyCtxt, FnSig, Instance, InstanceDef,
-         ParamEnv, ParamEnvAnd, Predicate, PolyFnSig, PolyTraitRef, Ty};
+         ParamEnv, ParamEnvAnd, Predicate, PolyFnSig, PolyTraitRef, Ty, self};
 use ty::subst::Substs;
 
 // erase!() just makes tokens go away. It's used to specify which macro argument
@@ -632,7 +632,7 @@ define_dep_nodes!( <'tcx>
     // queries). Making them anonymous avoids hashing the result, which
     // may save a bit of time.
     [anon] EraseRegionsTy { ty: Ty<'tcx> },
-    [anon] ConstValueToAllocation { val: ConstValue<'tcx>, ty: Ty<'tcx> },
+    [anon] ConstValueToAllocation { val: &'tcx ty::Const<'tcx> },
 
     [input] Freevars(DefId),
     [input] MaybeUnusedTraitImport(DefId),

src/librustc/ich/impls_ty.rs

@@ -364,11 +364,11 @@ impl_stable_hash_for!(struct ty::FieldDef {
 });
 
 impl<'a, 'gcx> HashStable<StableHashingContext<'a>>
-for ::middle::const_val::ConstVal<'gcx> {
+for ::mir::interpret::ConstValue<'gcx> {
     fn hash_stable<W: StableHasherResult>(&self,
                                           hcx: &mut StableHashingContext<'a>,
                                           hasher: &mut StableHasher<W>) {
-        use middle::const_val::ConstVal::*;
+        use mir::interpret::ConstValue::*;
 
         mem::discriminant(self).hash_stable(hcx, hasher);
 
@@ -377,23 +377,6 @@ for ::middle::const_val::ConstVal<'gcx> {
                 def_id.hash_stable(hcx, hasher);
                 substs.hash_stable(hcx, hasher);
             }
-            Value(ref value) => {
-                value.hash_stable(hcx, hasher);
-            }
-        }
-    }
-}
-
-impl<'a, 'gcx> HashStable<StableHashingContext<'a>>
-for ::mir::interpret::ConstValue<'gcx> {
-    fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a>,
-                                          hasher: &mut StableHasher<W>) {
-        use mir::interpret::ConstValue::*;
-
-        mem::discriminant(self).hash_stable(hcx, hasher);
-
-        match *self {
             Scalar(val) => {
                 val.hash_stable(hcx, hasher);
             }
@@ -497,40 +480,18 @@ impl_stable_hash_for!(struct ty::Const<'tcx> {
     val
 });
 
-impl_stable_hash_for!(struct ::middle::const_val::ConstEvalErr<'tcx> {
+impl_stable_hash_for!(struct ::mir::interpret::ConstEvalErr<'tcx> {
     span,
-    kind
+    stacktrace,
+    error
 });
 
-impl_stable_hash_for!(struct ::middle::const_val::FrameInfo {
+impl_stable_hash_for!(struct ::mir::interpret::FrameInfo {
     span,
     lint_root,
     location
 });
 
-impl<'a, 'gcx> HashStable<StableHashingContext<'a>>
-for ::middle::const_val::ErrKind<'gcx> {
-    fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a>,
-                                          hasher: &mut StableHasher<W>) {
-        use middle::const_val::ErrKind::*;
-
-        mem::discriminant(self).hash_stable(hcx, hasher);
-
-        match *self {
-            TypeckError |
-            CouldNotResolve |
-            CheckMatchError => {
-                // nothing to do
-            }
-            Miri(ref err, ref trace) => {
-                err.hash_stable(hcx, hasher);
-                trace.hash_stable(hcx, hasher);
-            },
-        }
-    }
-}
-
 impl_stable_hash_for!(struct ty::ClosureSubsts<'tcx> { substs });
 impl_stable_hash_for!(struct ty::GeneratorSubsts<'tcx> { substs });
 
@@ -579,6 +540,8 @@ for ::mir::interpret::EvalErrorKind<'gcx, O> {
             ReadFromReturnPointer |
             UnimplementedTraitSelection |
             TypeckError |
+            TooGeneric |
+            CheckMatchError |
             DerefFunctionPointer |
             ExecuteMemory |
             OverflowNeg |

src/librustc/lib.rs

@@ -132,7 +132,6 @@ pub mod middle {
     pub mod allocator;
     pub mod borrowck;
     pub mod expr_use_visitor;
-    pub mod const_val;
     pub mod cstore;
     pub mod dataflow;
     pub mod dead;