Move some utils out of rustc_const_eval

This allows us to get rid of the `rustc_const_eval->rustc_borrowck`
dependency edge which was delaying the compilation of borrowck.

The added utils in `rustc_middle` are small and should not affect
compile times there.

Cargo.lock

@@ -4421,7 +4421,6 @@ dependencies = [
  "either",
  "itertools",
  "polonius-engine",
- "rustc_const_eval",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_graphviz",

compiler/rustc_borrowck/Cargo.toml

@@ -20,7 +20,6 @@ rustc_infer = { path = "../rustc_infer" }
 rustc_lexer = { path = "../rustc_lexer" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_middle = { path = "../rustc_middle" }
-rustc_const_eval = { path = "../rustc_const_eval" }
 rustc_mir_dataflow = { path = "../rustc_mir_dataflow" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -1,5 +1,4 @@
 use either::Either;
-use rustc_const_eval::util::CallKind;
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::{
@@ -18,6 +17,7 @@
     ProjectionElem, Rvalue, Statement, StatementKind, Terminator, TerminatorKind, VarBindingForm,
 };
 use rustc_middle::ty::{self, suggest_constraining_type_params, PredicateKind, Ty};
+use rustc_middle::util::CallKind;
 use rustc_mir_dataflow::move_paths::{InitKind, MoveOutIndex, MovePathIndex};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::hygiene::DesugaringKind;
@@ -2424,7 +2424,7 @@ fn explain_deref_coercion(&mut self, loan: &BorrowData<'tcx>, err: &mut Diagnost
             Some((method_did, method_substs)),
         ) = (
             &self.body[loan.reserve_location.block].terminator,
-            rustc_const_eval::util::find_self_call(
+            rustc_middle::util::find_self_call(
                 tcx,
                 self.body,
                 loan.assigned_place.local,

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -1,7 +1,6 @@
 //! Borrow checker diagnostics.
 
 use itertools::Itertools;
-use rustc_const_eval::util::{call_kind, CallDesugaringKind};
 use rustc_errors::{Applicability, Diagnostic};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, Namespace};
@@ -15,6 +14,7 @@
 };
 use rustc_middle::ty::print::Print;
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
+use rustc_middle::util::{call_kind, CallDesugaringKind};
 use rustc_mir_dataflow::move_paths::{InitLocation, LookupResult};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::{symbol::sym, Span, Symbol, DUMMY_SP};
@@ -45,7 +45,7 @@
 pub(crate) use outlives_suggestion::OutlivesSuggestionBuilder;
 pub(crate) use region_errors::{ErrorConstraintInfo, RegionErrorKind, RegionErrors};
 pub(crate) use region_name::{RegionName, RegionNameSource};
-pub(crate) use rustc_const_eval::util::CallKind;
+pub(crate) use rustc_middle::util::CallKind;
 
 pub(super) struct DescribePlaceOpt {
     pub including_downcast: bool,
@@ -874,7 +874,7 @@ pub(super) fn move_spans(
         }) = &self.body[location.block].terminator
         {
             let Some((method_did, method_substs)) =
-                rustc_const_eval::util::find_self_call(
+            rustc_middle::util::find_self_call(
                     self.infcx.tcx,
                     &self.body,
                     target_temp,

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -15,8 +15,8 @@
 use rustc_target::abi::FieldIdx;
 
 use crate::diagnostics::BorrowedContentSource;
+use crate::util::FindAssignments;
 use crate::MirBorrowckCtxt;
-use rustc_const_eval::util::collect_writes::FindAssignments;
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub(crate) enum AccessKind {

compiler/rustc_borrowck/src/lib.rs

@@ -88,6 +88,7 @@
 mod type_check;
 mod universal_regions;
 mod used_muts;
+mod util;
 
 /// A public API provided for the Rust compiler consumers.
 pub mod consumers;

compiler/rustc_borrowck/src/util/mod.rs

@@ -0,0 +1,3 @@
+mod collect_writes;
+
+pub use collect_writes::FindAssignments;

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

@@ -14,6 +14,7 @@
 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
 use rustc_middle::ty::{suggest_constraining_type_param, Adt, Closure, FnDef, FnPtr, Param, Ty};
 use rustc_middle::ty::{Binder, TraitRef};
+use rustc_middle::util::{call_kind, CallDesugaringKind, CallKind};
 use rustc_session::parse::feature_err;
 use rustc_span::symbol::sym;
 use rustc_span::{BytePos, Pos, Span, Symbol};
@@ -21,7 +22,6 @@
 
 use super::ConstCx;
 use crate::errors;
-use crate::util::{call_kind, CallDesugaringKind, CallKind};
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum Status {

compiler/rustc_const_eval/src/util/mod.rs

@@ -1,14 +1,9 @@
 mod alignment;
-mod call_kind;
 mod check_validity_requirement;
-pub mod collect_writes;
 mod compare_types;
-mod find_self_call;
 mod type_name;
 
 pub use self::alignment::is_disaligned;
-pub use self::call_kind::{call_kind, CallDesugaringKind, CallKind};
 pub use self::check_validity_requirement::check_validity_requirement;
 pub use self::compare_types::{is_equal_up_to_subtyping, is_subtype};
-pub use self::find_self_call::find_self_call;
 pub use self::type_name::type_name;

compiler/rustc_middle/src/lib.rs

@@ -99,13 +99,9 @@
 pub mod thir;
 pub mod traits;
 pub mod ty;
+pub mod util;
 mod values;
 
-pub mod util {
-    pub mod bug;
-    pub mod common;
-}
-
 // Allows macros to refer to this crate as `::rustc_middle`
 extern crate self as rustc_middle;
 

compiler/rustc_middle/src/util/call_kind.rs

@@ -2,10 +2,10 @@
 //! as well as errors when attempting to call a non-const function in a const
 //! context.
 
+use crate::ty::subst::SubstsRef;
+use crate::ty::{AssocItemContainer, Instance, ParamEnv, Ty, TyCtxt};
 use rustc_hir::def_id::DefId;
 use rustc_hir::{lang_items, LangItem};
-use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{AssocItemContainer, Instance, ParamEnv, Ty, TyCtxt};
 use rustc_span::symbol::Ident;
 use rustc_span::{sym, DesugaringKind, Span};
 

compiler/rustc_middle/src/util/find_self_call.rs

@@ -1,6 +1,6 @@
-use rustc_middle::mir::*;
-use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{self, TyCtxt};
+use crate::mir::*;
+use crate::ty::subst::SubstsRef;
+use crate::ty::{self, TyCtxt};
 use rustc_span::def_id::DefId;
 
 /// Checks if the specified `local` is used as the `self` parameter of a method call

compiler/rustc_middle/src/util/mod.rs

@@ -0,0 +1,7 @@
+pub mod bug;
+pub mod call_kind;
+pub mod common;
+pub mod find_self_call;
+
+pub use call_kind::{call_kind, CallDesugaringKind, CallKind};
+pub use find_self_call::find_self_call;

compiler/rustc_mir_transform/src/check_const_item_mutation.rs

@@ -134,7 +134,12 @@ fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, loc: Location) {
                 // the `self` parameter of a method call (as the terminator of our current
                 // BasicBlock). If so, we emit a more specific lint.
                 let method_did = self.target_local.and_then(|target_local| {
-                    crate::util::find_self_call(self.tcx, &self.body, target_local, loc.block)
+                    rustc_middle::util::find_self_call(
+                        self.tcx,
+                        &self.body,
+                        target_local,
+                        loc.block,
+                    )
                 });
                 let lint_loc =
                     if method_did.is_some() { self.body.terminator_loc(loc.block) } else { loc };