Prepare mir::Constant for ty::Const only supporting valtrees

12 files changed, 91 insertions, 73 deletions

diff --git a/compiler/rustc_mir/src/transform/check_consts/qualifs.rs b/compiler/rustc_mir/src/transform/check_consts/qualifs.rs
index 13d7166b4b5..748f65cba22 100644
--- a/compiler/rustc_mir/src/transform/check_consts/qualifs.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/qualifs.rs
@@ -246,25 +246,27 @@ where
     };
 
     // Check the qualifs of the value of `const` items.
-    if let ty::ConstKind::Unevaluated(def, _, promoted) = constant.literal.val {
-        assert!(promoted.is_none());
-        // Don't peek inside trait associated constants.
-        if cx.tcx.trait_of_item(def.did).is_none() {
-            let qualifs = if let Some((did, param_did)) = def.as_const_arg() {
-                cx.tcx.at(constant.span).mir_const_qualif_const_arg((did, param_did))
-            } else {
-                cx.tcx.at(constant.span).mir_const_qualif(def.did)
-            };
-
-            if !Q::in_qualifs(&qualifs) {
-                return false;
-            }
+    if let Some(ct) = constant.literal.const_for_ty() {
+        if let ty::ConstKind::Unevaluated(def, _, promoted) = ct.val {
+            assert!(promoted.is_none());
+            // Don't peek inside trait associated constants.
+            if cx.tcx.trait_of_item(def.did).is_none() {
+                let qualifs = if let Some((did, param_did)) = def.as_const_arg() {
+                    cx.tcx.at(constant.span).mir_const_qualif_const_arg((did, param_did))
+                } else {
+                    cx.tcx.at(constant.span).mir_const_qualif(def.did)
+                };
+
+                if !Q::in_qualifs(&qualifs) {
+                    return false;
+                }
 
-            // Just in case the type is more specific than
-            // the definition, e.g., impl associated const
-            // with type parameters, take it into account.
+                // Just in case the type is more specific than
+                // the definition, e.g., impl associated const
+                // with type parameters, take it into account.
+            }
         }
     }
     // Otherwise use the qualifs of the type.
-    Q::in_any_value_of_ty(cx, constant.literal.ty)
+    Q::in_any_value_of_ty(cx, constant.literal.ty())
 }
diff --git a/compiler/rustc_mir/src/transform/const_prop.rs b/compiler/rustc_mir/src/transform/const_prop.rs
index 9d03b1b027e..0d5c8953bc6 100644
--- a/compiler/rustc_mir/src/transform/const_prop.rs
+++ b/compiler/rustc_mir/src/transform/const_prop.rs
@@ -13,9 +13,9 @@ use rustc_middle::mir::visit::{
     MutVisitor, MutatingUseContext, NonMutatingUseContext, PlaceContext, Visitor,
 };
 use rustc_middle::mir::{
-    AssertKind, BasicBlock, BinOp, Body, ClearCrossCrate, Constant, Local, LocalDecl, LocalKind,
-    Location, Operand, Place, Rvalue, SourceInfo, SourceScope, SourceScopeData, Statement,
-    StatementKind, Terminator, TerminatorKind, UnOp, RETURN_PLACE,
+    AssertKind, BasicBlock, BinOp, Body, ClearCrossCrate, Constant, ConstantSource, Local,
+    LocalDecl, LocalKind, Location, Operand, Place, Rvalue, SourceInfo, SourceScope,
+    SourceScopeData, Statement, StatementKind, Terminator, TerminatorKind, UnOp, RETURN_PLACE,
 };
 use rustc_middle::ty::layout::{HasTyCtxt, LayoutError, TyAndLayout};
 use rustc_middle::ty::subst::{InternalSubsts, Subst};
@@ -482,18 +482,21 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             return None;
         }
 
-        match self.ecx.const_to_op(c.literal, None) {
+        match self.ecx.mir_const_to_op(&c.literal, None) {
             Ok(op) => Some(op),
             Err(error) => {
                 let tcx = self.ecx.tcx.at(c.span);
                 let err = ConstEvalErr::new(&self.ecx, error, Some(c.span));
                 if let Some(lint_root) = self.lint_root(source_info) {
-                    let lint_only = match c.literal.val {
-                        // Promoteds must lint and not error as the user didn't ask for them
-                        ConstKind::Unevaluated(_, _, Some(_)) => true,
-                        // Out of backwards compatibility we cannot report hard errors in unused
-                        // generic functions using associated constants of the generic parameters.
-                        _ => c.literal.needs_subst(),
+                    let lint_only = match c.literal {
+                        ConstantSource::Ty(ct) => match ct.val {
+                            // Promoteds must lint and not error as the user didn't ask for them
+                            ConstKind::Unevaluated(_, _, Some(_)) => true,
+                            // Out of backwards compatibility we cannot report hard errors in unused
+                            // generic functions using associated constants of the generic parameters.
+                            _ => c.literal.needs_subst(),
+                        },
+                        ConstantSource::Val(_, ty) => ty.needs_subst(),
                     };
                     if lint_only {
                         // Out of backwards compatibility we cannot report hard errors in unused
@@ -803,7 +806,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
         Operand::Constant(Box::new(Constant {
             span,
             user_ty: None,
-            literal: ty::Const::from_scalar(self.tcx, scalar, ty),
+            literal: ty::Const::from_scalar(self.tcx, scalar, ty).into(),
         }))
     }
 
@@ -814,9 +817,12 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
         source_info: SourceInfo,
     ) {
         if let Rvalue::Use(Operand::Constant(c)) = rval {
-            if !matches!(c.literal.val, ConstKind::Unevaluated(..)) {
-                trace!("skipping replace of Rvalue::Use({:?} because it is already a const", c);
-                return;
+            match c.literal {
+                ConstantSource::Ty(c) if matches!(c.val, ConstKind::Unevaluated(..)) => {}
+                _ => {
+                    trace!("skipping replace of Rvalue::Use({:?} because it is already a const", c);
+                    return;
+                }
             }
         }
 
@@ -883,13 +889,17 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
                                 *rval = Rvalue::Use(Operand::Constant(Box::new(Constant {
                                     span: source_info.span,
                                     user_ty: None,
-                                    literal: self.ecx.tcx.mk_const(ty::Const {
-                                        ty,
-                                        val: ty::ConstKind::Value(ConstValue::ByRef {
-                                            alloc,
-                                            offset: Size::ZERO,
-                                        }),
-                                    }),
+                                    literal: self
+                                        .ecx
+                                        .tcx
+                                        .mk_const(ty::Const {
+                                            ty,
+                                            val: ty::ConstKind::Value(ConstValue::ByRef {
+                                                alloc,
+                                                offset: Size::ZERO,
+                                            }),
+                                        })
+                                        .into(),
                                 })));
                             }
                         }
diff --git a/compiler/rustc_mir/src/transform/elaborate_drops.rs b/compiler/rustc_mir/src/transform/elaborate_drops.rs
index 3d435f6d0e7..c0fcfb620ff 100644
--- a/compiler/rustc_mir/src/transform/elaborate_drops.rs
+++ b/compiler/rustc_mir/src/transform/elaborate_drops.rs
@@ -471,7 +471,7 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> {
         Rvalue::Use(Operand::Constant(Box::new(Constant {
             span,
             user_ty: None,
-            literal: ty::Const::from_bool(self.tcx, val),
+            literal: ty::Const::from_bool(self.tcx, val).into(),
         })))
     }
 
diff --git a/compiler/rustc_mir/src/transform/generator.rs b/compiler/rustc_mir/src/transform/generator.rs
index f299b6ecc28..c85e9b9b932 100644
--- a/compiler/rustc_mir/src/transform/generator.rs
+++ b/compiler/rustc_mir/src/transform/generator.rs
@@ -989,7 +989,7 @@ fn insert_panic_block<'tcx>(
         cond: Operand::Constant(box Constant {
             span: body.span,
             user_ty: None,
-            literal: ty::Const::from_bool(tcx, false),
+            literal: ty::Const::from_bool(tcx, false).into(),
         }),
         expected: true,
         msg: message,
diff --git a/compiler/rustc_mir/src/transform/inline.rs b/compiler/rustc_mir/src/transform/inline.rs
index cf85503b3d5..dd06daecd5d 100644
--- a/compiler/rustc_mir/src/transform/inline.rs
+++ b/compiler/rustc_mir/src/transform/inline.rs
@@ -416,7 +416,7 @@ impl Inliner<'tcx> {
 
                 TerminatorKind::Call { func: Operand::Constant(ref f), cleanup, .. } => {
                     if let ty::FnDef(def_id, substs) =
-                        *callsite.callee.subst_mir(self.tcx, &f.literal.ty).kind()
+                        *callsite.callee.subst_mir(self.tcx, &f.literal.ty()).kind()
                     {
                         let substs = self.tcx.normalize_erasing_regions(self.param_env, substs);
                         if let Ok(Some(instance)) =
@@ -637,8 +637,11 @@ impl Inliner<'tcx> {
                 // `required_consts`, here we may not only have `ConstKind::Unevaluated`
                 // because we are calling `subst_and_normalize_erasing_regions`.
                 caller_body.required_consts.extend(
-                    callee_body.required_consts.iter().copied().filter(|&constant| {
-                        matches!(constant.literal.val, ConstKind::Unevaluated(_, _, _))
+                    callee_body.required_consts.iter().copied().filter(|&ct| {
+                        match ct.literal.const_for_ty() {
+                            Some(ct) => matches!(ct.val, ConstKind::Unevaluated(_, _, _)),
+                            None => true,
+                        }
                     }),
                 );
             }
diff --git a/compiler/rustc_mir/src/transform/instcombine.rs b/compiler/rustc_mir/src/transform/instcombine.rs
index bad82fe893e..7aaf0224164 100644
--- a/compiler/rustc_mir/src/transform/instcombine.rs
+++ b/compiler/rustc_mir/src/transform/instcombine.rs
@@ -79,7 +79,7 @@ impl<'tcx, 'a> InstCombineContext<'tcx, 'a> {
 
     fn try_eval_bool(&self, a: &Operand<'_>) -> Option<bool> {
         let a = a.constant()?;
-        if a.literal.ty.is_bool() { a.literal.val.try_to_bool() } else { None }
+        if a.literal.ty().is_bool() { a.literal.try_to_bool() } else { None }
     }
 
     /// Transform "&(*a)" ==> "a".
@@ -110,12 +110,13 @@ impl<'tcx, 'a> InstCombineContext<'tcx, 'a> {
     fn combine_len(&self, source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
         if let Rvalue::Len(ref place) = *rvalue {
             let place_ty = place.ty(self.local_decls, self.tcx).ty;
-            if let ty::Array(_, len) = place_ty.kind() {
+            if let ty::Array(_, len) = *place_ty.kind() {
                 if !self.should_combine(source_info, rvalue) {
                     return;
                 }
 
-                let constant = Constant { span: source_info.span, literal: len, user_ty: None };
+                let constant =
+                    Constant { span: source_info.span, literal: len.into(), user_ty: None };
                 *rvalue = Rvalue::Use(Operand::Constant(box constant));
             }
         }
diff --git a/compiler/rustc_mir/src/transform/lower_intrinsics.rs b/compiler/rustc_mir/src/transform/lower_intrinsics.rs
index d6a73360616..e6ee474285e 100644
--- a/compiler/rustc_mir/src/transform/lower_intrinsics.rs
+++ b/compiler/rustc_mir/src/transform/lower_intrinsics.rs
@@ -33,7 +33,7 @@ impl<'tcx> MirPass<'tcx> for LowerIntrinsics {
                                     Rvalue::Use(Operand::Constant(box Constant {
                                         span: terminator.source_info.span,
                                         user_ty: None,
-                                        literal: ty::Const::zero_sized(tcx, tcx.types.unit),
+                                        literal: ty::Const::zero_sized(tcx, tcx.types.unit).into(),
                                     })),
                                 )),
                             });
diff --git a/compiler/rustc_mir/src/transform/match_branches.rs b/compiler/rustc_mir/src/transform/match_branches.rs
index 15c2c3a160f..d04a7011ab0 100644
--- a/compiler/rustc_mir/src/transform/match_branches.rs
+++ b/compiler/rustc_mir/src/transform/match_branches.rs
@@ -93,8 +93,8 @@ impl<'tcx> MirPass<'tcx> for MatchBranchSimplification {
                         StatementKind::Assign(box (lhs_f, Rvalue::Use(Operand::Constant(f_c)))),
                         StatementKind::Assign(box (lhs_s, Rvalue::Use(Operand::Constant(s_c)))),
                     ) if lhs_f == lhs_s
-                        && f_c.literal.ty.is_bool()
-                        && s_c.literal.ty.is_bool()
+                        && f_c.literal.ty().is_bool()
+                        && s_c.literal.ty().is_bool()
                         && f_c.literal.try_eval_bool(tcx, param_env).is_some()
                         && s_c.literal.try_eval_bool(tcx, param_env).is_some() => {}
 
diff --git a/compiler/rustc_mir/src/transform/promote_consts.rs b/compiler/rustc_mir/src/transform/promote_consts.rs
index f60570483ce..7db790cf32b 100644
--- a/compiler/rustc_mir/src/transform/promote_consts.rs
+++ b/compiler/rustc_mir/src/transform/promote_consts.rs
@@ -921,7 +921,7 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> {
                         let unit = Rvalue::Use(Operand::Constant(box Constant {
                             span: statement.source_info.span,
                             user_ty: None,
-                            literal: ty::Const::zero_sized(self.tcx, self.tcx.types.unit),
+                            literal: ty::Const::zero_sized(self.tcx, self.tcx.types.unit).into(),
                         }));
                         mem::replace(rhs, unit)
                     },
@@ -998,20 +998,22 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> {
                 Operand::Constant(Box::new(Constant {
                     span,
                     user_ty: None,
-                    literal: tcx.mk_const(ty::Const {
-                        ty,
-                        val: ty::ConstKind::Unevaluated(
-                            def,
-                            InternalSubsts::for_item(tcx, def.did, |param, _| {
-                                if let ty::GenericParamDefKind::Lifetime = param.kind {
-                                    tcx.lifetimes.re_erased.into()
-                                } else {
-                                    tcx.mk_param_from_def(param)
-                                }
-                            }),
-                            Some(promoted_id),
-                        ),
-                    }),
+                    literal: tcx
+                        .mk_const(ty::Const {
+                            ty,
+                            val: ty::ConstKind::Unevaluated(
+                                def,
+                                InternalSubsts::for_item(tcx, def.did, |param, _| {
+                                    if let ty::GenericParamDefKind::Lifetime = param.kind {
+                                        tcx.lifetimes.re_erased.into()
+                                    } else {
+                                        tcx.mk_param_from_def(param)
+                                    }
+                                }),
+                                Some(promoted_id),
+                            ),
+                        })
+                        .into(),
                 }))
             };
             let (blocks, local_decls) = self.source.basic_blocks_and_local_decls_mut();
@@ -1250,8 +1252,8 @@ crate fn is_const_fn_in_array_repeat_expression<'tcx>(
         if let Some(Terminator { kind: TerminatorKind::Call { func, destination, .. }, .. }) =
             &block.terminator
         {
-            if let Operand::Constant(box Constant { literal: ty::Const { ty, .. }, .. }) = func {
-                if let ty::FnDef(def_id, _) = *ty.kind() {
+            if let Operand::Constant(box Constant { literal, .. }) = func {
+                if let ty::FnDef(def_id, _) = *literal.ty().kind() {
                     if let Some((destination_place, _)) = destination {
                         if destination_place == place {
                             if is_const_fn(ccx.tcx, def_id) {
diff --git a/compiler/rustc_mir/src/transform/required_consts.rs b/compiler/rustc_mir/src/transform/required_consts.rs
index a63ab30a68f..2b518bd3a48 100644
--- a/compiler/rustc_mir/src/transform/required_consts.rs
+++ b/compiler/rustc_mir/src/transform/required_consts.rs
@@ -14,10 +14,10 @@ impl<'a, 'tcx> RequiredConstsVisitor<'a, 'tcx> {
 
 impl<'a, 'tcx> Visitor<'tcx> for RequiredConstsVisitor<'a, 'tcx> {
     fn visit_constant(&mut self, constant: &Constant<'tcx>, _: Location) {
-        let const_kind = constant.literal.val;
-
-        if let ConstKind::Unevaluated(_, _, _) = const_kind {
-            self.required_consts.push(*constant);
+        if let Some(ct) = constant.literal.const_for_ty() {
+            if let ConstKind::Unevaluated(_, _, _) = ct.val {
+                self.required_consts.push(*constant);
+            }
         }
     }
 }
diff --git a/compiler/rustc_mir/src/transform/rustc_peek.rs b/compiler/rustc_mir/src/transform/rustc_peek.rs
index 7598be4e4a1..a6b8f20f6d4 100644
--- a/compiler/rustc_mir/src/transform/rustc_peek.rs
+++ b/compiler/rustc_mir/src/transform/rustc_peek.rs
@@ -205,7 +205,7 @@ impl PeekCall {
         if let mir::TerminatorKind::Call { func: Operand::Constant(func), args, .. } =
             &terminator.kind
         {
-            if let ty::FnDef(def_id, substs) = *func.literal.ty.kind() {
+            if let ty::FnDef(def_id, substs) = *func.literal.ty().kind() {
                 let sig = tcx.fn_sig(def_id);
                 let name = tcx.item_name(def_id);
                 if sig.abi() != Abi::RustIntrinsic || name != sym::rustc_peek {
diff --git a/compiler/rustc_mir/src/transform/simplify_comparison_integral.rs b/compiler/rustc_mir/src/transform/simplify_comparison_integral.rs
index 32df40ebf9e..9f473f3bae5 100644
--- a/compiler/rustc_mir/src/transform/simplify_comparison_integral.rs
+++ b/compiler/rustc_mir/src/transform/simplify_comparison_integral.rs
@@ -205,12 +205,12 @@ fn find_branch_value_info<'tcx>(
     match (left, right) {
         (Constant(branch_value), Copy(to_switch_on) | Move(to_switch_on))
         | (Copy(to_switch_on) | Move(to_switch_on), Constant(branch_value)) => {
-            let branch_value_ty = branch_value.literal.ty;
+            let branch_value_ty = branch_value.literal.ty();
             // we only want to apply this optimization if we are matching on integrals (and chars), as it is not possible to switch on floats
             if !branch_value_ty.is_integral() && !branch_value_ty.is_char() {
                 return None;
             };
-            let branch_value_scalar = branch_value.literal.val.try_to_scalar()?;
+            let branch_value_scalar = branch_value.literal.try_to_scalar()?;
             Some((branch_value_scalar, branch_value_ty, *to_switch_on))
         }
         _ => None,