Rollup merge of #97935 - nnethercote:rename-ConstS-val-as-kind, r=lcnr

Rename the `ConstS::val` field as `kind`.

And likewise for the `Const::val` method.

Because its type is called `ConstKind`. Also `val` is a confusing name
because `ConstKind` is an enum with seven variants, one of which is
called `Value`. Also, this gives consistency with `TyS` and `PredicateS`
which have `kind` fields.

The commit also renames a few `Const` variables from `val` to `c`, to
avoid confusion with the `ConstKind::Value` variant.

r? `@BoxyUwU`

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -378,7 +378,7 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
         } else {
             let tcx = self.tcx();
             let maybe_uneval = match constant.literal {
-                ConstantKind::Ty(ct) => match ct.val() {
+                ConstantKind::Ty(ct) => match ct.kind() {
                     ty::ConstKind::Unevaluated(uv) => Some(uv),
                     _ => None,
                 },
@@ -1841,7 +1841,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
     fn check_operand(&mut self, op: &Operand<'tcx>, location: Location) {
         if let Operand::Constant(constant) = op {
             let maybe_uneval = match constant.literal {
-                ConstantKind::Ty(ct) => match ct.val() {
+                ConstantKind::Ty(ct) => match ct.kind() {
                     ty::ConstKind::Unevaluated(uv) => Some(uv),
                     _ => None,
                 },

compiler/rustc_codegen_cranelift/src/base.rs

@@ -710,7 +710,7 @@ fn codegen_stmt<'tcx>(
                     let times = fx
                         .monomorphize(times)
                         .eval(fx.tcx, ParamEnv::reveal_all())
-                        .val()
+                        .kind()
                         .try_to_bits(fx.tcx.data_layout.pointer_size)
                         .unwrap();
                     if operand.layout().size.bytes() == 0 {

compiler/rustc_codegen_cranelift/src/constant.rs

@@ -45,7 +45,7 @@ pub(crate) fn check_constants(fx: &mut FunctionCx<'_, '_, '_>) -> bool {
             ConstantKind::Ty(ct) => ct,
             ConstantKind::Val(..) => continue,
         };
-        match const_.val() {
+        match const_.kind() {
             ConstKind::Value(_) => {}
             ConstKind::Unevaluated(unevaluated) => {
                 if let Err(err) =
@@ -126,7 +126,7 @@ pub(crate) fn codegen_constant<'tcx>(
         ConstantKind::Ty(ct) => ct,
         ConstantKind::Val(val, ty) => return codegen_const_value(fx, val, ty),
     };
-    let const_val = match const_.val() {
+    let const_val = match const_.kind() {
         ConstKind::Value(const_val) => const_val,
         ConstKind::Unevaluated(ty::Unevaluated { def, substs, promoted })
             if fx.tcx.is_static(def.did) =>
@@ -469,7 +469,7 @@ pub(crate) fn mir_operand_get_const_val<'tcx>(
     match operand {
         Operand::Constant(const_) => match const_.literal {
             ConstantKind::Ty(const_) => {
-                fx.monomorphize(const_).eval(fx.tcx, ParamEnv::reveal_all()).val().try_to_value()
+                fx.monomorphize(const_).eval(fx.tcx, ParamEnv::reveal_all()).kind().try_to_value()
             }
             ConstantKind::Val(val, _) => Some(val),
         },

compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs

@@ -180,15 +180,15 @@ fn push_debuginfo_type_name<'tcx>(
             if cpp_like_debuginfo {
                 output.push_str("array$<");
                 push_debuginfo_type_name(tcx, inner_type, true, output, visited);
-                match len.val() {
+                match len.kind() {
                     ty::ConstKind::Param(param) => write!(output, ",{}>", param.name).unwrap(),
                     _ => write!(output, ",{}>", len.eval_usize(tcx, ty::ParamEnv::reveal_all()))
                         .unwrap(),
                 }
             } else {
                 output.push('[');
                 push_debuginfo_type_name(tcx, inner_type, true, output, visited);
-                match len.val() {
+                match len.kind() {
                     ty::ConstKind::Param(param) => write!(output, "; {}]", param.name).unwrap(),
                     _ => write!(output, "; {}]", len.eval_usize(tcx, ty::ParamEnv::reveal_all()))
                         .unwrap(),
@@ -679,7 +679,7 @@ fn push_generic_params_internal<'tcx>(
 }
 
 fn push_const_param<'tcx>(tcx: TyCtxt<'tcx>, ct: ty::Const<'tcx>, output: &mut String) {
-    match ct.val() {
+    match ct.kind() {
         ty::ConstKind::Param(param) => {
             write!(output, "{}", param.name)
         }
@@ -703,7 +703,7 @@ fn push_const_param<'tcx>(tcx: TyCtxt<'tcx>, ct: ty::Const<'tcx>, output: &mut S
                 // but we get a deterministic, virtually unique value for the constant.
                 let hcx = &mut tcx.create_stable_hashing_context();
                 let mut hasher = StableHasher::new();
-                hcx.while_hashing_spans(false, |hcx| ct.val().hash_stable(hcx, &mut hasher));
+                hcx.while_hashing_spans(false, |hcx| ct.kind().hash_stable(hcx, &mut hasher));
                 // Let's only emit 64 bits of the hash value. That should be plenty for
                 // avoiding collisions and will make the emitted type names shorter.
                 let hash: u64 = hasher.finish();

compiler/rustc_codegen_ssa/src/mir/constant.rs

@@ -29,7 +29,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             mir::ConstantKind::Ty(ct) => ct,
             mir::ConstantKind::Val(val, _) => return Ok(val),
         };
-        match ct.val() {
+        match ct.kind() {
             ty::ConstKind::Unevaluated(ct) => self
                 .cx
                 .tcx()
@@ -65,7 +65,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     .fields
                     .iter()
                     .map(|field| {
-                        if let Some(prim) = field.val().try_to_scalar() {
+                        if let Some(prim) = field.kind().try_to_scalar() {
                             let layout = bx.layout_of(field_ty);
                             let Abi::Scalar(scalar) = layout.abi else {
                                 bug!("from_const: invalid ByVal layout: {:#?}", layout);

compiler/rustc_const_eval/src/const_eval/mod.rs

@@ -197,7 +197,7 @@ pub(crate) fn deref_const<'tcx>(
         },
     };
 
-    tcx.mk_const(ty::ConstS { val: ty::ConstKind::Value(op_to_const(&ecx, &mplace.into())), ty })
+    tcx.mk_const(ty::ConstS { kind: ty::ConstKind::Value(op_to_const(&ecx, &mplace.into())), ty })
 }
 
 #[instrument(skip(tcx), level = "debug")]

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -622,10 +622,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     /// "universe" (param_env).
     pub fn const_to_op(
         &self,
-        val: ty::Const<'tcx>,
+        c: ty::Const<'tcx>,
         layout: Option<TyAndLayout<'tcx>>,
     ) -> InterpResult<'tcx, OpTy<'tcx, M::PointerTag>> {
-        match val.val() {
+        match c.kind() {
             ty::ConstKind::Param(_) | ty::ConstKind::Bound(..) => throw_inval!(TooGeneric),
             ty::ConstKind::Error(DelaySpanBugEmitted { reported, .. }) => {
                 throw_inval!(AlreadyReported(reported))
@@ -635,9 +635,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 Ok(self.eval_to_allocation(GlobalId { instance, promoted: uv.promoted })?.into())
             }
             ty::ConstKind::Infer(..) | ty::ConstKind::Placeholder(..) => {
-                span_bug!(self.cur_span(), "const_to_op: Unexpected ConstKind {:?}", val)
+                span_bug!(self.cur_span(), "const_to_op: Unexpected ConstKind {:?}", c)
             }
-            ty::ConstKind::Value(val_val) => self.const_val_to_op(val_val, val.ty(), layout),
+            ty::ConstKind::Value(val) => self.const_val_to_op(val, c.ty(), layout),
         }
     }
 

compiler/rustc_const_eval/src/interpret/util.rs

@@ -55,7 +55,7 @@ where
                                     assert!(matches!(ty.kind(), ty::Param(_)))
                                 }
                                 ty::subst::GenericArgKind::Const(ct) => {
-                                    assert!(matches!(ct.val(), ty::ConstKind::Param(_)))
+                                    assert!(matches!(ct.kind(), ty::ConstKind::Param(_)))
                                 }
                                 ty::subst::GenericArgKind::Lifetime(..) => (),
                             },
@@ -69,7 +69,7 @@ where
         }
 
         fn visit_const(&mut self, c: ty::Const<'tcx>) -> ControlFlow<Self::BreakTy> {
-            match c.val() {
+            match c.kind() {
                 ty::ConstKind::Param(..) => ControlFlow::Break(FoundParam),
                 _ => c.super_visit_with(self),
             }

compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs

@@ -353,7 +353,8 @@ where
 
     // Check the qualifs of the value of `const` items.
     if let Some(ct) = constant.literal.const_for_ty() {
-        if let ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs: _, promoted }) = ct.val() {
+        if let ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs: _, promoted }) = ct.kind()
+        {
             // Use qualifs of the type for the promoted. Promoteds in MIR body should be possible
             // only for `NeedsNonConstDrop` with precise drop checking. This is the only const
             // check performed after the promotion. Verify that with an assertion.

compiler/rustc_const_eval/src/transform/promote_consts.rs

@@ -842,7 +842,7 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> {
                     literal: tcx
                         .mk_const(ty::ConstS {
                             ty,
-                            val: ty::ConstKind::Unevaluated(ty::Unevaluated {
+                            kind: ty::ConstKind::Unevaluated(ty::Unevaluated {
                                 def,
                                 substs: InternalSubsts::for_item(tcx, def.did, |param, _| {
                                     if let ty::GenericParamDefKind::Lifetime = param.kind {

compiler/rustc_infer/src/infer/canonical/canonicalizer.rs

@@ -476,7 +476,7 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for Canonicalizer<'cx, 'tcx> {
     }
 
     fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> {
-        match ct.val() {
+        match ct.kind() {
             ty::ConstKind::Infer(InferConst::Var(vid)) => {
                 debug!("canonical: const var found with vid {:?}", vid);
                 match self.infcx.probe_const_var(vid) {
@@ -778,7 +778,7 @@ impl<'cx, 'tcx> Canonicalizer<'cx, 'tcx> {
         } else {
             let var = self.canonical_var(info, const_var.into());
             self.tcx().mk_const(ty::ConstS {
-                val: ty::ConstKind::Bound(self.binder_index, var),
+                kind: ty::ConstKind::Bound(self.binder_index, var),
                 ty: self.fold_ty(const_var.ty()),
             })
         }

compiler/rustc_infer/src/infer/canonical/mod.rs

@@ -149,7 +149,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
                 let placeholder_mapped = ty::PlaceholderConst { universe: universe_mapped, name };
                 self.tcx
                     .mk_const(ty::ConstS {
-                        val: ty::ConstKind::Placeholder(placeholder_mapped),
+                        kind: ty::ConstKind::Placeholder(placeholder_mapped),
                         ty: name.ty,
                     })
                     .into()

compiler/rustc_infer/src/infer/canonical/query_response.rs

@@ -458,7 +458,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
                     }
                 }
                 GenericArgKind::Const(result_value) => {
-                    if let ty::ConstKind::Bound(debrujin, b) = result_value.val() {
+                    if let ty::ConstKind::Bound(debrujin, b) = result_value.kind() {
                         // ...in which case we would set `canonical_vars[0]` to `Some(const X)`.
 
                         // We only allow a `ty::INNERMOST` index in substitutions.

compiler/rustc_infer/src/infer/combine.rs

@@ -142,7 +142,7 @@ impl<'infcx, 'tcx> InferCtxt<'infcx, 'tcx> {
 
         let a_is_expected = relation.a_is_expected();
 
-        match (a.val(), b.val()) {
+        match (a.kind(), b.kind()) {
             (
                 ty::ConstKind::Infer(InferConst::Var(a_vid)),
                 ty::ConstKind::Infer(InferConst::Var(b_vid)),
@@ -726,7 +726,7 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
     ) -> RelateResult<'tcx, ty::Const<'tcx>> {
         assert_eq!(c, c2); // we are abusing TypeRelation here; both LHS and RHS ought to be ==
 
-        match c.val() {
+        match c.kind() {
             ty::ConstKind::Infer(InferConst::Var(vid)) => {
                 let mut inner = self.infcx.inner.borrow_mut();
                 let variable_table = &mut inner.const_unification_table();
@@ -761,7 +761,7 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
                 )?;
                 Ok(self.tcx().mk_const(ty::ConstS {
                     ty: c.ty(),
-                    val: ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs, promoted }),
+                    kind: ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs, promoted }),
                 }))
             }
             _ => relate::super_relate_consts(self, c, c),
@@ -941,7 +941,7 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
         debug_assert_eq!(c, _c);
         debug!("ConstInferUnifier: c={:?}", c);
 
-        match c.val() {
+        match c.kind() {
             ty::ConstKind::Infer(InferConst::Var(vid)) => {
                 // Check if the current unification would end up
                 // unifying `target_vid` with a const which contains
@@ -992,7 +992,7 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
                 )?;
                 Ok(self.tcx().mk_const(ty::ConstS {
                     ty: c.ty(),
-                    val: ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs, promoted }),
+                    kind: ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs, promoted }),
                 }))
             }
             _ => relate::super_relate_consts(self, c, c),

compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs

@@ -247,7 +247,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 }
             }
             GenericArgKind::Const(ct) => {
-                if let ty::ConstKind::Infer(InferConst::Var(vid)) = ct.val() {
+                if let ty::ConstKind::Infer(InferConst::Var(vid)) = ct.kind() {
                     let origin =
                         self.inner.borrow_mut().const_unification_table().probe_value(vid).origin;
                     if let ConstVariableOriginKind::ConstParameterDefinition(name, def_id) =
@@ -673,7 +673,7 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> {
             }
             (GenericArgKind::Const(inner_ct), GenericArgKind::Const(target_ct)) => {
                 use ty::InferConst::*;
-                match (inner_ct.val(), target_ct.val()) {
+                match (inner_ct.kind(), target_ct.kind()) {
                     (ty::ConstKind::Infer(Var(a_vid)), ty::ConstKind::Infer(Var(b_vid))) => self
                         .infcx
                         .inner
@@ -713,7 +713,7 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> {
                     }
                 }
                 GenericArgKind::Const(ct) => {
-                    if matches!(ct.val(), ty::ConstKind::Unevaluated(..)) {
+                    if matches!(ct.kind(), ty::ConstKind::Unevaluated(..)) {
                         // You can't write the generic arguments for
                         // unevaluated constants.
                         walker.skip_current_subtree();

compiler/rustc_infer/src/infer/freshen.rs

@@ -218,7 +218,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for TypeFreshener<'a, 'tcx> {
     }
 
     fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> {
-        match ct.val() {
+        match ct.kind() {
             ty::ConstKind::Infer(ty::InferConst::Var(v)) => {
                 let opt_ct = self
                     .infcx

compiler/rustc_infer/src/infer/fudge.rs

@@ -229,7 +229,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for InferenceFudger<'a, 'tcx> {
     }
 
     fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> {
-        if let ty::ConstKind::Infer(ty::InferConst::Var(vid)) = ct.val() {
+        if let ty::ConstKind::Infer(ty::InferConst::Var(vid)) = ct.kind() {
             if self.const_vars.0.contains(&vid) {
                 // This variable was created during the fudging.
                 // Recreate it with a fresh variable here.

compiler/rustc_infer/src/infer/higher_ranked/mod.rs

@@ -99,7 +99,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
 
         let fld_c = |bound_var: ty::BoundVar, ty| {
             self.tcx.mk_const(ty::ConstS {
-                val: ty::ConstKind::Placeholder(ty::PlaceholderConst {
+                kind: ty::ConstKind::Placeholder(ty::PlaceholderConst {
                     universe: next_universe,
                     name: ty::BoundConst { var: bound_var, ty },
                 }),

compiler/rustc_infer/src/infer/mod.rs

@@ -1754,7 +1754,7 @@ impl<'tcx> TyOrConstInferVar<'tcx> {
     /// Tries to extract an inference variable from a constant, returns `None`
     /// for constants other than `ty::ConstKind::Infer(_)` (or `InferConst::Fresh`).
     pub fn maybe_from_const(ct: ty::Const<'tcx>) -> Option<Self> {
-        match ct.val() {
+        match ct.kind() {
             ty::ConstKind::Infer(InferConst::Var(v)) => Some(TyOrConstInferVar::Const(v)),
             _ => None,
         }
@@ -1833,7 +1833,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for ShallowResolver<'a, 'tcx> {
     }
 
     fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> {
-        if let ty::ConstKind::Infer(InferConst::Var(vid)) = ct.val() {
+        if let ty::ConstKind::Infer(InferConst::Var(vid)) = ct.kind() {
             self.infcx
                 .inner
                 .borrow_mut()

compiler/rustc_infer/src/infer/nll_relate/mod.rs

@@ -659,7 +659,7 @@ where
             b = self.infcx.shallow_resolve(b);
         }
 
-        match b.val() {
+        match b.kind() {
             ty::ConstKind::Infer(InferConst::Var(_)) if D::forbid_inference_vars() => {
                 // Forbid inference variables in the RHS.
                 bug!("unexpected inference var {:?}", b)
@@ -1034,7 +1034,7 @@ where
         a: ty::Const<'tcx>,
         _: ty::Const<'tcx>,
     ) -> RelateResult<'tcx, ty::Const<'tcx>> {
-        match a.val() {
+        match a.kind() {
             ty::ConstKind::Infer(InferConst::Var(_)) if D::forbid_inference_vars() => {
                 bug!("unexpected inference variable encountered in NLL generalization: {:?}", a);
             }

compiler/rustc_infer/src/infer/resolve.rs

@@ -223,7 +223,7 @@ impl<'a, 'tcx> FallibleTypeFolder<'tcx> for FullTypeResolver<'a, 'tcx> {
             Ok(c) // micro-optimize -- if there is nothing in this const that this fold affects...
         } else {
             let c = self.infcx.shallow_resolve(c);
-            match c.val() {
+            match c.kind() {
                 ty::ConstKind::Infer(InferConst::Var(vid)) => {
                     return Err(FixupError::UnresolvedConst(vid));
                 }

compiler/rustc_lint/src/builtin.rs

@@ -2873,7 +2873,7 @@ impl ClashingExternDeclarations {
                         }
                         (Array(a_ty, a_const), Array(b_ty, b_const)) => {
                             // For arrays, we also check the constness of the type.
-                            a_const.val() == b_const.val()
+                            a_const.kind() == b_const.kind()
                                 && structurally_same_type_impl(seen_types, cx, *a_ty, *b_ty, ckind)
                         }
                         (Slice(a_ty), Slice(b_ty)) => {

compiler/rustc_middle/src/infer/canonical.rs

@@ -336,7 +336,7 @@ impl<'tcx> CanonicalVarValues<'tcx> {
                     GenericArgKind::Const(ct) => tcx
                         .mk_const(ty::ConstS {
                             ty: ct.ty(),
-                            val: ty::ConstKind::Bound(ty::INNERMOST, ty::BoundVar::from_u32(i)),
+                            kind: ty::ConstKind::Bound(ty::INNERMOST, ty::BoundVar::from_u32(i)),
                         })
                         .into(),
                 })