Auto merge of #61590 - matthewjasper:remove-borrowck-mir-dependency, …

…r=pnkfelix

Remove rustc_mir dependency from rustc_borrowck

Also renames `rustc_borrowck` to `rustc_ast_borrowck` and removes all error reporting from it.

cc #59193

Cargo.lock

@@ -2946,15 +2946,14 @@ dependencies = [
 ]
 
 [[package]]
-name = "rustc_borrowck"
+name = "rustc_ast_borrowck"
 version = "0.0.0"
 dependencies = [
  "graphviz 0.0.0",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc 0.0.0",
  "rustc_data_structures 0.0.0",
  "rustc_errors 0.0.0",
- "rustc_mir 0.0.0",
  "syntax 0.0.0",
  "syntax_pos 0.0.0",
 ]
@@ -3045,7 +3044,7 @@ dependencies = [
  "rustc 0.0.0",
  "rustc-rayon 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_allocator 0.0.0",
- "rustc_borrowck 0.0.0",
+ "rustc_ast_borrowck 0.0.0",
  "rustc_codegen_utils 0.0.0",
  "rustc_data_structures 0.0.0",
  "rustc_errors 0.0.0",
@@ -3110,7 +3109,7 @@ dependencies = [
  "rustc 0.0.0",
  "rustc-rayon 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_allocator 0.0.0",
- "rustc_borrowck 0.0.0",
+ "rustc_ast_borrowck 0.0.0",
  "rustc_codegen_ssa 0.0.0",
  "rustc_codegen_utils 0.0.0",
  "rustc_data_structures 0.0.0",

src/librustc/middle/borrowck.rs

@@ -1,6 +1,4 @@
 use crate::ich::StableHashingContext;
-use crate::hir::HirId;
-use crate::util::nodemap::FxHashSet;
 
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher,
                                            StableHasherResult};
@@ -18,7 +16,6 @@ impl_stable_hash_for!(enum self::SignalledError { SawSomeError, NoErrorsSeen });
 
 #[derive(Debug, Default, RustcEncodable, RustcDecodable)]
 pub struct BorrowCheckResult {
-    pub used_mut_nodes: FxHashSet<HirId>,
     pub signalled_any_error: SignalledError,
 }
 
@@ -27,10 +24,8 @@ impl<'a> HashStable<StableHashingContext<'a>> for BorrowCheckResult {
                                           hcx: &mut StableHashingContext<'a>,
                                           hasher: &mut StableHasher<W>) {
         let BorrowCheckResult {
-            ref used_mut_nodes,
             ref signalled_any_error,
         } = *self;
-        used_mut_nodes.hash_stable(hcx, hasher);
         signalled_any_error.hash_stable(hcx, hasher);
     }
 }

src/librustc/middle/mem_categorization.rs

@@ -66,7 +66,6 @@ use crate::hir::def::{CtorOf, Res, DefKind, CtorKind};
 use crate::ty::adjustment;
 use crate::ty::{self, DefIdTree, Ty, TyCtxt};
 use crate::ty::fold::TypeFoldable;
-use crate::ty::layout::VariantIdx;
 
 use crate::hir::{MutImmutable, MutMutable, PatKind};
 use crate::hir::pat_util::EnumerateAndAdjustIterator;
@@ -79,7 +78,6 @@ use std::borrow::Cow;
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use rustc_data_structures::fx::FxIndexMap;
-use rustc_data_structures::indexed_vec::Idx;
 use std::rc::Rc;
 use crate::util::nodemap::ItemLocalSet;
 
@@ -198,79 +196,6 @@ pub struct cmt_<'tcx> {
 
 pub type cmt<'tcx> = Rc<cmt_<'tcx>>;
 
-pub enum ImmutabilityBlame<'tcx> {
-    ImmLocal(hir::HirId),
-    ClosureEnv(LocalDefId),
-    LocalDeref(hir::HirId),
-    AdtFieldDeref(&'tcx ty::AdtDef, &'tcx ty::FieldDef)
-}
-
-impl<'tcx> cmt_<'tcx> {
-    fn resolve_field(&self, field_index: usize) -> Option<(&'tcx ty::AdtDef, &'tcx ty::FieldDef)>
-    {
-        let adt_def = match self.ty.sty {
-            ty::Adt(def, _) => def,
-            ty::Tuple(..) => return None,
-            // closures get `Categorization::Upvar` rather than `Categorization::Interior`
-            _ =>  bug!("interior cmt {:?} is not an ADT", self)
-        };
-        let variant_def = match self.cat {
-            Categorization::Downcast(_, variant_did) => {
-                adt_def.variant_with_id(variant_did)
-            }
-            _ => {
-                assert_eq!(adt_def.variants.len(), 1);
-                &adt_def.variants[VariantIdx::new(0)]
-            }
-        };
-        Some((adt_def, &variant_def.fields[field_index]))
-    }
-
-    pub fn immutability_blame(&self) -> Option<ImmutabilityBlame<'tcx>> {
-        match self.cat {
-            Categorization::Deref(ref base_cmt, BorrowedPtr(ty::ImmBorrow, _)) => {
-                // try to figure out where the immutable reference came from
-                match base_cmt.cat {
-                    Categorization::Local(hir_id) =>
-                        Some(ImmutabilityBlame::LocalDeref(hir_id)),
-                    Categorization::Interior(ref base_cmt, InteriorField(field_index)) => {
-                        base_cmt.resolve_field(field_index.0).map(|(adt_def, field_def)| {
-                            ImmutabilityBlame::AdtFieldDeref(adt_def, field_def)
-                        })
-                    }
-                    Categorization::Upvar(Upvar { id, .. }) => {
-                        if let NoteClosureEnv(..) = self.note {
-                            Some(ImmutabilityBlame::ClosureEnv(id.closure_expr_id))
-                        } else {
-                            None
-                        }
-                    }
-                    _ => None
-                }
-            }
-            Categorization::Local(hir_id) => {
-                Some(ImmutabilityBlame::ImmLocal(hir_id))
-            }
-            Categorization::Rvalue(..) |
-            Categorization::Upvar(..) |
-            Categorization::Deref(_, UnsafePtr(..)) => {
-                // This should not be reachable up to inference limitations.
-                None
-            }
-            Categorization::Interior(ref base_cmt, _) |
-            Categorization::Downcast(ref base_cmt, _) |
-            Categorization::Deref(ref base_cmt, _) => {
-                base_cmt.immutability_blame()
-            }
-            Categorization::ThreadLocal(..) |
-            Categorization::StaticItem => {
-                // Do we want to do something here?
-                None
-            }
-        }
-    }
-}
-
 pub trait HirNode {
     fn hir_id(&self) -> hir::HirId;
     fn span(&self) -> Span;

src/librustc_borrowck/Cargo.toml → src/librustc_ast_borrowck/Cargo.toml

@@ -1,11 +1,11 @@
 [package]
 authors = ["The Rust Project Developers"]
-name = "rustc_borrowck"
+name = "rustc_ast_borrowck"
 version = "0.0.0"
 edition = "2018"
 
 [lib]
-name = "rustc_borrowck"
+name = "rustc_ast_borrowck"
 path = "lib.rs"
 test = false
 doctest = false
@@ -18,6 +18,5 @@ syntax_pos = { path = "../libsyntax_pos" }
 # refers to the borrowck-specific graphviz adapter traits.
 dot = { path = "../libgraphviz", package = "graphviz" }
 rustc = { path = "../librustc" }
-rustc_mir = { path = "../librustc_mir" }
 errors = { path = "../librustc_errors", package = "rustc_errors" }
 rustc_data_structures = { path = "../librustc_data_structures" }