Auto merge of rust-lang#120550 - oli-obk:track_errors8, r=estebank

Continue to borrowck even if there were previous errors

but only from the perspective of the whole compiler. Individual items should not get borrowcked if their MIR is tainted by errors.

r? `@estebank` `@nnethercote`

Author: bors

compiler/rustc_borrowck/src/lib.rs

@@ -111,14 +111,16 @@ fn mir_borrowck(tcx: TyCtxt<'_>, def: LocalDefId) -> &BorrowCheckResult<'_> {
     let (input_body, promoted) = tcx.mir_promoted(def);
     debug!("run query mir_borrowck: {}", tcx.def_path_str(def));
 
-    if input_body.borrow().should_skip() {
-        debug!("Skipping borrowck because of injected body");
+    let input_body: &Body<'_> = &input_body.borrow();
+
+    if input_body.should_skip() || input_body.tainted_by_errors.is_some() {
+        debug!("Skipping borrowck because of injected body or tainted body");
         // Let's make up a borrowck result! Fun times!
         let result = BorrowCheckResult {
             concrete_opaque_types: FxIndexMap::default(),
             closure_requirements: None,
             used_mut_upvars: SmallVec::new(),
-            tainted_by_errors: None,
+            tainted_by_errors: input_body.tainted_by_errors,
         };
         return tcx.arena.alloc(result);
     }
@@ -127,7 +129,6 @@ fn mir_borrowck(tcx: TyCtxt<'_>, def: LocalDefId) -> &BorrowCheckResult<'_> {
 
     let infcx =
         tcx.infer_ctxt().with_opaque_type_inference(DefiningAnchor::Bind(hir_owner.def_id)).build();
-    let input_body: &Body<'_> = &input_body.borrow();
     let promoted: &IndexSlice<_, _> = &promoted.borrow();
     let opt_closure_req = do_mir_borrowck(&infcx, input_body, promoted, None).0;
     debug!("mir_borrowck done");

compiler/rustc_hir/src/hir.rs

@@ -163,10 +163,6 @@ impl Lifetime {
             (LifetimeSuggestionPosition::Normal, self.ident.span)
         }
     }
-
-    pub fn is_static(&self) -> bool {
-        self.res == LifetimeName::Static
-    }
 }
 
 /// A `Path` is essentially Rust's notion of a name; for instance,

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -12,7 +12,7 @@ use crate::astconv::errors::prohibit_assoc_ty_binding;
 use crate::astconv::generics::{check_generic_arg_count, create_args_for_parent_generic_args};
 use crate::bounds::Bounds;
 use crate::collect::HirPlaceholderCollector;
-use crate::errors::{AmbiguousLifetimeBound, TypeofReservedKeywordUsed};
+use crate::errors::AmbiguousLifetimeBound;
 use crate::middle::resolve_bound_vars as rbv;
 use crate::require_c_abi_if_c_variadic;
 use rustc_ast::TraitObjectSyntax;
@@ -30,8 +30,8 @@ use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
 use rustc_infer::traits::ObligationCause;
 use rustc_middle::middle::stability::AllowUnstable;
 use rustc_middle::ty::{
-    self, Const, GenericArgKind, GenericArgsRef, GenericParamDefKind, IsSuggestable, ParamEnv, Ty,
-    TyCtxt, TypeVisitableExt,
+    self, Const, GenericArgKind, GenericArgsRef, GenericParamDefKind, ParamEnv, Ty, TyCtxt,
+    TypeVisitableExt,
 };
 use rustc_session::lint::builtin::AMBIGUOUS_ASSOCIATED_ITEMS;
 use rustc_span::edit_distance::find_best_match_for_name;
@@ -2539,21 +2539,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
 
                 Ty::new_array_with_const_len(tcx, self.ast_ty_to_ty(ty), length)
             }
-            hir::TyKind::Typeof(e) => {
-                let ty_erased = tcx.type_of(e.def_id).instantiate_identity();
-                let ty = tcx.fold_regions(ty_erased, |r, _| {
-                    if r.is_erased() { tcx.lifetimes.re_static } else { r }
-                });
-                let span = ast_ty.span;
-                let (ty, opt_sugg) = if let Some(ty) = ty.make_suggestable(tcx, false) {
-                    (ty, Some((span, Applicability::MachineApplicable)))
-                } else {
-                    (ty, None)
-                };
-                tcx.dcx().emit_err(TypeofReservedKeywordUsed { span, ty, opt_sugg });
-
-                ty
-            }
+            hir::TyKind::Typeof(e) => tcx.type_of(e.def_id).instantiate_identity(),
             hir::TyKind::Infer => {
                 // Infer also appears as the type of arguments or return
                 // values in an ExprKind::Closure, or as

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -9,6 +9,8 @@ use rustc_middle::ty::{self, ImplTraitInTraitData, IsSuggestable, Ty, TyCtxt, Ty
 use rustc_span::symbol::Ident;
 use rustc_span::{Span, DUMMY_SP};
 
+use crate::errors::TypeofReservedKeywordUsed;
+
 use super::bad_placeholder;
 use super::ItemCtxt;
 pub use opaque::test_opaque_hidden_types;
@@ -39,8 +41,18 @@ fn anon_const_type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Ty<'tcx> {
         {
             return tcx.types.usize;
         }
-        Node::Ty(&hir::Ty { kind: TyKind::Typeof(ref e), .. }) if e.hir_id == hir_id => {
-            return tcx.typeck(def_id).node_type(e.hir_id);
+        Node::Ty(&hir::Ty { kind: TyKind::Typeof(ref e), span, .. }) if e.hir_id == hir_id => {
+            let ty = tcx.typeck(def_id).node_type(e.hir_id);
+            let ty = tcx.fold_regions(ty, |r, _| {
+                if r.is_erased() { ty::Region::new_error_misc(tcx) } else { r }
+            });
+            let (ty, opt_sugg) = if let Some(ty) = ty.make_suggestable(tcx, false) {
+                (ty, Some((span, Applicability::MachineApplicable)))
+            } else {
+                (ty, None)
+            };
+            tcx.dcx().emit_err(TypeofReservedKeywordUsed { span, ty, opt_sugg });
+            return ty;
         }
         Node::Expr(&Expr { kind: ExprKind::InlineAsm(asm), .. })
         | Node::Item(&Item { kind: ItemKind::GlobalAsm(asm), .. })

compiler/rustc_hir_analysis/src/lib.rs

@@ -209,7 +209,7 @@ pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
 
     tcx.ensure().check_unused_traits(());
 
-    if let Some(reported) = tcx.dcx().has_errors() { Err(reported) } else { Ok(()) }
+    Ok(())
 }
 
 /// A quasi-deprecated helper used in rustdoc and clippy to get

compiler/rustc_mir_build/src/build/mod.rs

@@ -666,7 +666,7 @@ fn construct_error(tcx: TyCtxt<'_>, def_id: LocalDefId, guar: ErrorGuaranteed) -
                     let yield_ty = args.yield_ty();
                     let return_ty = args.return_ty();
                     (
-                        vec![closure_ty, args.resume_ty()],
+                        vec![closure_ty, resume_ty],
                         return_ty,
                         Some(Box::new(CoroutineInfo::initial(
                             tcx.coroutine_kind(def_id).unwrap(),
@@ -675,8 +675,23 @@ fn construct_error(tcx: TyCtxt<'_>, def_id: LocalDefId, guar: ErrorGuaranteed) -
                         ))),
                     )
                 }
-                _ => {
-                    span_bug!(span, "expected type of closure body to be a closure or coroutine");
+                ty::CoroutineClosure(did, _args) => {
+                    // FIXME(async_closures): Recover the proper error signature
+                    let inputs = tcx
+                        .closure_user_provided_sig(did.expect_local())
+                        .value
+                        .skip_binder()
+                        .inputs();
+
+                    let err = Ty::new_error(tcx, guar);
+                    (inputs.iter().map(|_| err).collect(), err, None)
+                }
+                ty::Error(_) => (vec![closure_ty, closure_ty], closure_ty, None),
+                kind => {
+                    span_bug!(
+                        span,
+                        "expected type of closure body to be a closure or coroutine, got {kind:?}"
+                    );
                 }
             }
         }

compiler/rustc_mir_build/src/build/scope.rs

@@ -655,7 +655,17 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         let drops = if destination.is_some() {
             &mut self.scopes.breakable_scopes[break_index].break_drops
         } else {
-            self.scopes.breakable_scopes[break_index].continue_drops.as_mut().unwrap()
+            let Some(drops) = self.scopes.breakable_scopes[break_index].continue_drops.as_mut()
+            else {
+                self.tcx.dcx().span_delayed_bug(
+                    source_info.span,
+                    "unlabelled `continue` within labelled block",
+                );
+                self.cfg.terminate(block, source_info, TerminatorKind::Unreachable);
+
+                return self.cfg.start_new_block().unit();
+            };
+            drops
         };
 
         let drop_idx = self.scopes.scopes[scope_index + 1..]

compiler/rustc_mir_transform/src/ffi_unwind_calls.rs

@@ -59,6 +59,7 @@ fn has_ffi_unwind_calls(tcx: TyCtxt<'_>, local_def_id: LocalDefId) -> bool {
         ty::Closure(..) => Abi::RustCall,
         ty::CoroutineClosure(..) => Abi::RustCall,
         ty::Coroutine(..) => Abi::Rust,
+        ty::Error(_) => return false,
         _ => span_bug!(body.span, "unexpected body ty: {:?}", body_ty),
     };
     let body_can_unwind = layout::fn_can_unwind(tcx, Some(def_id), body_abi);

compiler/rustc_parse/src/parser/expr.rs

@@ -2911,12 +2911,22 @@ impl<'a> Parser<'a> {
                 Ok(arm) => arms.push(arm),
                 Err(e) => {
                     // Recover by skipping to the end of the block.
-                    e.emit();
+                    let guar = e.emit();
                     self.recover_stmt();
                     let span = lo.to(self.token.span);
                     if self.token == token::CloseDelim(Delimiter::Brace) {
                         self.bump();
                     }
+                    // Always push at least one arm to make the match non-empty
+                    arms.push(Arm {
+                        attrs: Default::default(),
+                        pat: self.mk_pat(span, ast::PatKind::Err(guar)),
+                        guard: None,
+                        body: Some(self.mk_expr_err(span)),
+                        span,
+                        id: DUMMY_NODE_ID,
+                        is_placeholder: false,
+                    });
                     return Ok(self.mk_expr_with_attrs(
                         span,
                         ExprKind::Match(scrutinee, arms),

compiler/rustc_passes/src/liveness.rs

@@ -123,6 +123,7 @@ enum LiveNodeKind {
     VarDefNode(Span, HirId),
     ClosureNode,
     ExitNode,
+    ErrNode,
 }
 
 fn live_node_kind_to_string(lnk: LiveNodeKind, tcx: TyCtxt<'_>) -> String {
@@ -133,6 +134,7 @@ fn live_node_kind_to_string(lnk: LiveNodeKind, tcx: TyCtxt<'_>) -> String {
         VarDefNode(s, _) => format!("Var def node [{}]", sm.span_to_diagnostic_string(s)),
         ClosureNode => "Closure node".to_owned(),
         ExitNode => "Exit node".to_owned(),
+        ErrNode => "Error node".to_owned(),
     }
 }
 
@@ -967,10 +969,10 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
 
                 // Now that we know the label we're going to,
                 // look it up in the continue loop nodes table
-                self.cont_ln
-                    .get(&sc)
-                    .cloned()
-                    .unwrap_or_else(|| span_bug!(expr.span, "continue to unknown label"))
+                self.cont_ln.get(&sc).cloned().unwrap_or_else(|| {
+                    self.ir.tcx.dcx().span_delayed_bug(expr.span, "continue to unknown label");
+                    self.ir.add_live_node(ErrNode)
+                })
             }
 
             hir::ExprKind::Assign(ref l, ref r, _) => {