cleanup dead ast-borrowck / migrate-mode code.

src/librustc/arena.rs

@@ -86,7 +86,6 @@ macro_rules! arena_types {
                     rustc::infer::canonical::QueryResponse<'tcx, rustc::ty::Ty<'tcx>>
                 >,
             [few] crate_inherent_impls: rustc::ty::CrateInherentImpls,
-            [decode] borrowck: rustc::middle::borrowck::BorrowCheckResult,
             [few] upstream_monomorphizations:
                 rustc::util::nodemap::DefIdMap<
                     rustc_data_structures::fx::FxHashMap<

src/librustc/infer/mod.rs

@@ -93,6 +93,8 @@ impl SuppressRegionErrors {
     /// checks, so we should ignore errors if NLL is (unconditionally)
     /// enabled.
     pub fn when_nll_is_enabled(tcx: TyCtxt<'_>) -> Self {
+        // FIXME(Centril): Once we actually remove `::Migrate` also make
+        // this always `true` and then proceed to eliminate the dead code.
         match tcx.borrowck_mode() {
             // If we're on Migrate mode, report AST region errors
             BorrowckMode::Migrate => SuppressRegionErrors { suppressed: false },

src/librustc/lib.rs

@@ -100,7 +100,6 @@ pub mod infer;
 pub mod lint;
 
 pub mod middle {
-    pub mod borrowck;
     pub mod expr_use_visitor;
     pub mod cstore;
     pub mod dead;

src/librustc/middle/borrowck.rs

@@ -1,31 +0,0 @@
-use crate::ich::StableHashingContext;
-
-use rustc_data_structures::stable_hasher::{HashStable, StableHasher,
-                                           StableHasherResult};
-
-#[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable)]
-pub enum SignalledError { SawSomeError, NoErrorsSeen }
-
-impl Default for SignalledError {
-    fn default() -> SignalledError {
-        SignalledError::NoErrorsSeen
-    }
-}
-
-impl_stable_hash_for!(enum self::SignalledError { SawSomeError, NoErrorsSeen });
-
-#[derive(Debug, Default, RustcEncodable, RustcDecodable)]
-pub struct BorrowCheckResult {
-    pub signalled_any_error: SignalledError,
-}
-
-impl<'a> HashStable<StableHashingContext<'a>> for BorrowCheckResult {
-    fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a>,
-                                          hasher: &mut StableHasher<W>) {
-        let BorrowCheckResult {
-            ref signalled_any_error,
-        } = *self;
-        signalled_any_error.hash_stable(hcx, hasher);
-    }
-}

src/librustc/query/mod.rs

@@ -397,10 +397,6 @@ rustc_queries! {
     }
 
     BorrowChecking {
-        query borrowck(key: DefId) -> &'tcx BorrowCheckResult {
-            cache_on_disk_if { key.is_local() }
-        }
-
         /// Borrow-checks the function body. If this is a closure, returns
         /// additional requirements that the closure's creator must verify.
         query mir_borrowck(key: DefId) -> mir::BorrowCheckResult<'tcx> {

src/librustc/session/config.rs

@@ -478,14 +478,6 @@ impl BorrowckMode {
             BorrowckMode::Migrate => true,
         }
     }
-
-    /// Returns whether we should emit the AST-based borrow checker errors.
-    pub fn use_ast(self) -> bool {
-        match self {
-            BorrowckMode::Mir => false,
-            BorrowckMode::Migrate => false,
-        }
-    }
 }
 
 pub enum Input {

src/librustc/ty/context.rs

@@ -1435,12 +1435,6 @@ impl<'tcx> TyCtxt<'tcx> {
         self.queries.on_disk_cache.serialize(self.global_tcx(), encoder)
     }
 
-    /// If `true`, we should use the AST-based borrowck (we may *also* use
-    /// the MIR-based borrowck).
-    pub fn use_ast_borrowck(self) -> bool {
-        self.borrowck_mode().use_ast()
-    }
-
     /// If `true`, we should use the MIR-based borrowck, but also
     /// fall back on the AST borrowck if the MIR-based one errors.
     pub fn migrate_borrowck(self) -> bool {

src/librustc/ty/query/mod.rs

@@ -4,7 +4,6 @@ use crate::hir::def::{DefKind, Export};
 use crate::hir::{self, TraitCandidate, ItemLocalId, CodegenFnAttrs};
 use crate::infer::canonical::{self, Canonical};
 use crate::lint;
-use crate::middle::borrowck::BorrowCheckResult;
 use crate::middle::cstore::{ExternCrate, LinkagePreference, NativeLibrary, ForeignModule};
 use crate::middle::cstore::{NativeLibraryKind, DepKind, CrateSource};
 use crate::middle::privacy::AccessLevels;