Rollup of 9 pull requests

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -1,4 +1,5 @@
 use either::Either;
+use rustc_const_eval::util::{CallDesugaringKind, CallKind};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_hir as hir;
@@ -26,7 +27,7 @@ use crate::{
 
 use super::{
     explain_borrow::{BorrowExplanation, LaterUseKind},
-    FnSelfUseKind, IncludingDowncast, RegionName, RegionNameSource, UseSpans,
+    IncludingDowncast, RegionName, RegionNameSource, UseSpans,
 };
 
 #[derive(Debug)]
@@ -195,7 +196,9 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         .map(|n| format!("`{}`", n))
                         .unwrap_or_else(|| "value".to_owned());
                     match kind {
-                        FnSelfUseKind::FnOnceCall => {
+                        CallKind::FnCall { fn_trait_id, .. }
+                            if Some(fn_trait_id) == self.infcx.tcx.lang_items().fn_once_trait() =>
+                        {
                             err.span_label(
                                 fn_call_span,
                                 &format!(
@@ -208,7 +211,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                                 "this value implements `FnOnce`, which causes it to be moved when called",
                             );
                         }
-                        FnSelfUseKind::Operator { self_arg } => {
+                        CallKind::Operator { self_arg, .. } => {
+                            let self_arg = self_arg.unwrap();
                             err.span_label(
                                 fn_call_span,
                                 &format!(
@@ -235,12 +239,9 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                                 );
                             }
                         }
-                        FnSelfUseKind::Normal {
-                            self_arg,
-                            implicit_into_iter,
-                            is_option_or_result,
-                        } => {
-                            if implicit_into_iter {
+                        CallKind::Normal { self_arg, desugaring, is_option_or_result } => {
+                            let self_arg = self_arg.unwrap();
+                            if let Some((CallDesugaringKind::ForLoopIntoIter, _)) = desugaring {
                                 err.span_label(
                                     fn_call_span,
                                     &format!(
@@ -305,8 +306,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                                     );
                             }
                         }
-                        // Deref::deref takes &self, which cannot cause a move
-                        FnSelfUseKind::DerefCoercion { .. } => unreachable!(),
+                        // Other desugarings takes &self, which cannot cause a move
+                        _ => unreachable!(),
                     }
                 } else {
                     err.span_label(
@@ -433,7 +434,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             }
 
             if let UseSpans::FnSelfUse {
-                kind: FnSelfUseKind::DerefCoercion { deref_target, deref_target_ty },
+                kind: CallKind::DerefCoercion { deref_target, deref_target_ty, .. },
                 ..
             } = use_spans
             {

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -1,10 +1,10 @@
 //! Borrow checker diagnostics.
 
+use rustc_const_eval::util::call_kind;
 use rustc_errors::DiagnosticBuilder;
 use rustc_hir as hir;
 use rustc_hir::def::Namespace;
 use rustc_hir::def_id::DefId;
-use rustc_hir::lang_items::LangItemGroup;
 use rustc_hir::GeneratorKind;
 use rustc_middle::mir::{
     AggregateKind, Constant, FakeReadCause, Field, Local, LocalInfo, LocalKind, Location, Operand,
@@ -13,7 +13,7 @@ use rustc_middle::mir::{
 use rustc_middle::ty::print::Print;
 use rustc_middle::ty::{self, DefIdTree, Instance, Ty, TyCtxt};
 use rustc_mir_dataflow::move_paths::{InitLocation, LookupResult};
-use rustc_span::{hygiene::DesugaringKind, symbol::sym, Span};
+use rustc_span::{symbol::sym, Span};
 use rustc_target::abi::VariantIdx;
 
 use super::borrow_set::BorrowData;
@@ -37,7 +37,7 @@ crate use mutability_errors::AccessKind;
 crate use outlives_suggestion::OutlivesSuggestionBuilder;
 crate use region_errors::{ErrorConstraintInfo, RegionErrorKind, RegionErrors};
 crate use region_name::{RegionName, RegionNameSource};
-use rustc_span::symbol::Ident;
+crate use rustc_const_eval::util::CallKind;
 
 pub(super) struct IncludingDowncast(pub(super) bool);
 
@@ -563,46 +563,23 @@ pub(super) enum UseSpans<'tcx> {
         fn_call_span: Span,
         /// The definition span of the method being called
         fn_span: Span,
-        kind: FnSelfUseKind<'tcx>,
+        kind: CallKind<'tcx>,
     },
     /// This access is caused by a `match` or `if let` pattern.
     PatUse(Span),
     /// This access has a single span associated to it: common case.
     OtherUse(Span),
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, Debug)]
-pub(super) enum FnSelfUseKind<'tcx> {
-    /// A normal method call of the form `receiver.foo(a, b, c)`
-    Normal {
-        self_arg: Ident,
-        implicit_into_iter: bool,
-        /// Whether the self type of the method call has an `.as_ref()` method.
-        /// Used for better diagnostics.
-        is_option_or_result: bool,
-    },
-    /// A call to `FnOnce::call_once`, desugared from `my_closure(a, b, c)`
-    FnOnceCall,
-    /// A call to an operator trait, desuraged from operator syntax (e.g. `a << b`)
-    Operator { self_arg: Ident },
-    DerefCoercion {
-        /// The `Span` of the `Target` associated type
-        /// in the `Deref` impl we are using.
-        deref_target: Span,
-        /// The type `T::Deref` we are dereferencing to
-        deref_target_ty: Ty<'tcx>,
-    },
-}
-
 impl UseSpans<'_> {
     pub(super) fn args_or_use(self) -> Span {
         match self {
             UseSpans::ClosureUse { args_span: span, .. }
             | UseSpans::PatUse(span)
             | UseSpans::OtherUse(span) => span,
-            UseSpans::FnSelfUse {
-                fn_call_span, kind: FnSelfUseKind::DerefCoercion { .. }, ..
-            } => fn_call_span,
+            UseSpans::FnSelfUse { fn_call_span, kind: CallKind::DerefCoercion { .. }, .. } => {
+                fn_call_span
+            }
             UseSpans::FnSelfUse { var_span, .. } => var_span,
         }
     }
@@ -613,9 +590,9 @@ impl UseSpans<'_> {
             UseSpans::ClosureUse { path_span: span, .. }
             | UseSpans::PatUse(span)
             | UseSpans::OtherUse(span) => span,
-            UseSpans::FnSelfUse {
-                fn_call_span, kind: FnSelfUseKind::DerefCoercion { .. }, ..
-            } => fn_call_span,
+            UseSpans::FnSelfUse { fn_call_span, kind: CallKind::DerefCoercion { .. }, .. } => {
+                fn_call_span
+            }
             UseSpans::FnSelfUse { var_span, .. } => var_span,
         }
     }
@@ -626,9 +603,9 @@ impl UseSpans<'_> {
             UseSpans::ClosureUse { capture_kind_span: span, .. }
             | UseSpans::PatUse(span)
             | UseSpans::OtherUse(span) => span,
-            UseSpans::FnSelfUse {
-                fn_call_span, kind: FnSelfUseKind::DerefCoercion { .. }, ..
-            } => fn_call_span,
+            UseSpans::FnSelfUse { fn_call_span, kind: CallKind::DerefCoercion { .. }, .. } => {
+                fn_call_span
+            }
             UseSpans::FnSelfUse { var_span, .. } => var_span,
         }
     }
@@ -904,67 +881,19 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 return normal_ret;
             };
 
-            let tcx = self.infcx.tcx;
-            let parent = tcx.parent(method_did);
-            let is_fn_once = parent == tcx.lang_items().fn_once_trait();
-            let is_operator = !from_hir_call
-                && parent.map_or(false, |p| tcx.lang_items().group(LangItemGroup::Op).contains(&p));
-            let is_deref = !from_hir_call && tcx.is_diagnostic_item(sym::deref_method, method_did);
-            let fn_call_span = *fn_span;
-
-            let self_arg = tcx.fn_arg_names(method_did)[0];
-
-            debug!(
-                "terminator = {:?} from_hir_call={:?}",
-                self.body[location.block].terminator, from_hir_call
+            let kind = call_kind(
+                self.infcx.tcx,
+                self.param_env,
+                method_did,
+                method_substs,
+                *fn_span,
+                *from_hir_call,
+                Some(self.infcx.tcx.fn_arg_names(method_did)[0]),
             );
 
-            // Check for a 'special' use of 'self' -
-            // an FnOnce call, an operator (e.g. `<<`), or a
-            // deref coercion.
-            let kind = if is_fn_once {
-                Some(FnSelfUseKind::FnOnceCall)
-            } else if is_operator {
-                Some(FnSelfUseKind::Operator { self_arg })
-            } else if is_deref {
-                let deref_target =
-                    tcx.get_diagnostic_item(sym::deref_target).and_then(|deref_target| {
-                        Instance::resolve(tcx, self.param_env, deref_target, method_substs)
-                            .transpose()
-                    });
-                if let Some(Ok(instance)) = deref_target {
-                    let deref_target_ty = instance.ty(tcx, self.param_env);
-                    Some(FnSelfUseKind::DerefCoercion {
-                        deref_target: tcx.def_span(instance.def_id()),
-                        deref_target_ty,
-                    })
-                } else {
-                    None
-                }
-            } else {
-                None
-            };
-
-            let kind = kind.unwrap_or_else(|| {
-                // This isn't a 'special' use of `self`
-                debug!("move_spans: method_did={:?}, fn_call_span={:?}", method_did, fn_call_span);
-                let implicit_into_iter = Some(method_did) == tcx.lang_items().into_iter_fn()
-                    && fn_call_span.desugaring_kind() == Some(DesugaringKind::ForLoop);
-                let parent_self_ty = parent
-                    .filter(|did| tcx.def_kind(*did) == rustc_hir::def::DefKind::Impl)
-                    .and_then(|did| match tcx.type_of(did).kind() {
-                        ty::Adt(def, ..) => Some(def.did),
-                        _ => None,
-                    });
-                let is_option_or_result = parent_self_ty.map_or(false, |def_id| {
-                    matches!(tcx.get_diagnostic_name(def_id), Some(sym::Option | sym::Result))
-                });
-                FnSelfUseKind::Normal { self_arg, implicit_into_iter, is_option_or_result }
-            });
-
             return FnSelfUse {
                 var_span: stmt.source_info.span,
-                fn_call_span,
+                fn_call_span: *fn_span,
                 fn_span: self
                     .infcx
                     .tcx

compiler/rustc_borrowck/src/diagnostics/move_errors.rs

@@ -1,3 +1,4 @@
+use rustc_const_eval::util::CallDesugaringKind;
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::mir::*;
@@ -8,7 +9,7 @@ use rustc_mir_dataflow::move_paths::{
 use rustc_span::{sym, Span, DUMMY_SP};
 use rustc_trait_selection::traits::type_known_to_meet_bound_modulo_regions;
 
-use crate::diagnostics::{FnSelfUseKind, UseSpans};
+use crate::diagnostics::{CallKind, UseSpans};
 use crate::prefixes::PrefixSet;
 use crate::MirBorrowckCtxt;
 
@@ -410,7 +411,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 Applicability::MaybeIncorrect,
             );
         } else if let Some(UseSpans::FnSelfUse {
-            kind: FnSelfUseKind::Normal { implicit_into_iter: true, .. },
+            kind:
+                CallKind::Normal { desugaring: Some((CallDesugaringKind::ForLoopIntoIter, _)), .. },
             ..
         }) = use_spans
         {