Auto merge of #4628 - flip1995:rustup, r=phansch

Rustup to rust-lang/rust#64874

TODO:
- [x] replace `rvalue_promotable_map` in [1]
- [ ] ~~fix [2] according to this comment rust-lang/rust#64874 (comment) this should be merged with `consume`, but I didn't figure out how to merge them, yet.~~
- [ ] ~~fix [3]; What to do with `LoanCause`?~~

[2]+[3] probably have to be resolved by a rewrite of the lint. #4628 (comment)

[1]
https://github.com/rust-lang/rust-clippy/blob/54bf4ffd626970e831bb80c037f804a3b3450835/clippy_lints/src/methods/mod.rs#L1292-L1299

[2]
https://github.com/rust-lang/rust-clippy/blob/54bf4ffd626970e831bb80c037f804a3b3450835/clippy_lints/src/escape.rs#L126

[3]
https://github.com/rust-lang/rust-clippy/blob/54bf4ffd626970e831bb80c037f804a3b3450835/clippy_lints/src/escape.rs#L166-L176

I could need some help with [1]. The purpose of this is to "don't lint for constant values". cc @matthewjasper

For now I see what I can do with [2].

changelog: Temporary break `boxed_local` lint.

Author: bors

clippy_lints/src/escape.rs

@@ -78,16 +78,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BoxedLocal {
 
         let fn_def_id = cx.tcx.hir().local_def_id(hir_id);
         let region_scope_tree = &cx.tcx.region_scope_tree(fn_def_id);
-        ExprUseVisitor::new(
-            &mut v,
-            cx.tcx,
-            fn_def_id,
-            cx.param_env,
-            region_scope_tree,
-            cx.tables,
-            None,
-        )
-        .consume_body(body);
+        ExprUseVisitor::new(&mut v, cx.tcx, fn_def_id, cx.param_env, region_scope_tree, cx.tables).consume_body(body);
 
         for node in v.set {
             span_lint(
@@ -114,86 +105,47 @@ fn is_argument(map: &hir::map::Map<'_>, id: HirId) -> bool {
 }
 
 impl<'a, 'tcx> Delegate<'tcx> for EscapeDelegate<'a, 'tcx> {
-    fn consume(&mut self, _: HirId, _: Span, cmt: &cmt_<'tcx>, mode: ConsumeMode) {
+    fn consume(&mut self, cmt: &cmt_<'tcx>, mode: ConsumeMode) {
         if let Categorization::Local(lid) = cmt.cat {
-            if let Move(DirectRefMove) | Move(CaptureMove) = mode {
+            if let ConsumeMode::Move = mode {
                 // moved out or in. clearly can't be localized
                 self.set.remove(&lid);
             }
         }
-    }
-    fn matched_pat(&mut self, _: &Pat, _: &cmt_<'tcx>, _: MatchMode) {}
-    fn consume_pat(&mut self, consume_pat: &Pat, cmt: &cmt_<'tcx>, _: ConsumeMode) {
         let map = &self.cx.tcx.hir();
-        if is_argument(map, consume_pat.hir_id) {
-            // Skip closure arguments
-            let parent_id = map.get_parent_node(consume_pat.hir_id);
-            if let Some(Node::Expr(..)) = map.find(map.get_parent_node(parent_id)) {
-                return;
-            }
-
-            if is_non_trait_box(cmt.ty) && !self.is_large_box(cmt.ty) {
-                self.set.insert(consume_pat.hir_id);
-            }
-            return;
-        }
-        if let Categorization::Rvalue(..) = cmt.cat {
-            if let Some(Node::Stmt(st)) = map.find(map.get_parent_node(cmt.hir_id)) {
-                if let StmtKind::Local(ref loc) = st.kind {
-                    if let Some(ref ex) = loc.init {
-                        if let ExprKind::Box(..) = ex.kind {
-                            if is_non_trait_box(cmt.ty) && !self.is_large_box(cmt.ty) {
-                                // let x = box (...)
-                                self.set.insert(consume_pat.hir_id);
-                            }
-                            // TODO Box::new
-                            // TODO vec![]
-                            // TODO "foo".to_owned() and friends
-                        }
-                    }
+        if let Categorization::Local(lid) = cmt.cat {
+            if let Some(Node::Binding(_)) = map.find(cmt.hir_id) {
+                if self.set.contains(&lid) {
+                    // let y = x where x is known
+                    // remove x, insert y
+                    self.set.insert(cmt.hir_id);
+                    self.set.remove(&lid);
                 }
             }
         }
+    }
+
+    fn borrow(&mut self, cmt: &cmt_<'tcx>, _: ty::BorrowKind) {
         if let Categorization::Local(lid) = cmt.cat {
-            if self.set.contains(&lid) {
-                // let y = x where x is known
-                // remove x, insert y
-                self.set.insert(consume_pat.hir_id);
-                self.set.remove(&lid);
-            }
+            self.set.remove(&lid);
         }
     }
-    fn borrow(
-        &mut self,
-        _: HirId,
-        _: Span,
-        cmt: &cmt_<'tcx>,
-        _: ty::Region<'_>,
-        _: ty::BorrowKind,
-        loan_cause: LoanCause,
-    ) {
-        if let Categorization::Local(lid) = cmt.cat {
-            match loan_cause {
-                // `x.foo()`
-                // Used without autoderef-ing (i.e., `x.clone()`).
-                LoanCause::AutoRef |
-
-                // `&x`
-                // `foo(&x)` where no extra autoref-ing is happening.
-                LoanCause::AddrOf |
 
-                // `match x` can move.
-                LoanCause::MatchDiscriminant => {
-                    self.set.remove(&lid);
-                }
+    fn mutate(&mut self, cmt: &cmt_<'tcx>) {
+        let map = &self.cx.tcx.hir();
+        if is_argument(map, cmt.hir_id) {
+            // Skip closure arguments
+            let parent_id = map.get_parent_node(cmt.hir_id);
+            if let Some(Node::Expr(..)) = map.find(map.get_parent_node(parent_id)) {
+                return;
+            }
 
-                // Do nothing for matches, etc. These can't escape.
-                _ => {}
+            if is_non_trait_box(cmt.ty) && !self.is_large_box(cmt.ty) {
+                self.set.insert(cmt.hir_id);
             }
+            return;
         }
     }
-    fn decl_without_init(&mut self, _: HirId, _: Span) {}
-    fn mutate(&mut self, _: HirId, _: Span, _: &cmt_<'tcx>, _: MutateMode) {}
 }
 
 impl<'a, 'tcx> EscapeDelegate<'a, 'tcx> {

clippy_lints/src/loops.rs

@@ -1547,37 +1547,31 @@ struct MutatePairDelegate {
 }
 
 impl<'tcx> Delegate<'tcx> for MutatePairDelegate {
-    fn consume(&mut self, _: HirId, _: Span, _: &cmt_<'tcx>, _: ConsumeMode) {}
+    fn consume(&mut self, _: &cmt_<'tcx>, _: ConsumeMode) {}
 
-    fn matched_pat(&mut self, _: &Pat, _: &cmt_<'tcx>, _: MatchMode) {}
-
-    fn consume_pat(&mut self, _: &Pat, _: &cmt_<'tcx>, _: ConsumeMode) {}
-
-    fn borrow(&mut self, _: HirId, sp: Span, cmt: &cmt_<'tcx>, _: ty::Region<'_>, bk: ty::BorrowKind, _: LoanCause) {
+    fn borrow(&mut self, cmt: &cmt_<'tcx>, bk: ty::BorrowKind) {
         if let ty::BorrowKind::MutBorrow = bk {
             if let Categorization::Local(id) = cmt.cat {
                 if Some(id) == self.hir_id_low {
-                    self.span_low = Some(sp)
+                    self.span_low = Some(cmt.span)
                 }
                 if Some(id) == self.hir_id_high {
-                    self.span_high = Some(sp)
+                    self.span_high = Some(cmt.span)
                 }
             }
         }
     }
 
-    fn mutate(&mut self, _: HirId, sp: Span, cmt: &cmt_<'tcx>, _: MutateMode) {
+    fn mutate(&mut self, cmt: &cmt_<'tcx>) {
         if let Categorization::Local(id) = cmt.cat {
             if Some(id) == self.hir_id_low {
-                self.span_low = Some(sp)
+                self.span_low = Some(cmt.span)
             }
             if Some(id) == self.hir_id_high {
-                self.span_high = Some(sp)
+                self.span_high = Some(cmt.span)
             }
         }
     }
-
-    fn decl_without_init(&mut self, _: HirId, _: Span) {}
 }
 
 impl<'tcx> MutatePairDelegate {
@@ -1655,7 +1649,6 @@ fn check_for_mutation(
         cx.param_env,
         region_scope_tree,
         cx.tables,
-        None,
     )
     .walk_expr(body);
     delegate.mutation_span()

clippy_lints/src/methods/mod.rs

@@ -21,11 +21,11 @@ use syntax::symbol::{sym, LocalInternedString, Symbol};
 use crate::utils::usage::mutated_variables;
 use crate::utils::{
     get_arg_name, get_parent_expr, get_trait_def_id, has_iter_method, implements_trait, in_macro, is_copy,
-    is_ctor_function, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path,
-    match_qpath, match_trait_method, match_type, match_var, method_calls, method_chain_args, paths, remove_blocks,
-    return_ty, same_tys, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite,
-    span_help_and_lint, span_lint, span_lint_and_sugg, span_lint_and_then, span_note_and_lint, sugg, walk_ptrs_ty,
-    walk_ptrs_ty_depth, SpanlessEq,
+    is_ctor_or_promotable_const_function, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment,
+    match_def_path, match_qpath, match_trait_method, match_type, match_var, method_calls, method_chain_args, paths,
+    remove_blocks, return_ty, same_tys, single_segment_path, snippet, snippet_with_applicability,
+    snippet_with_macro_callsite, span_help_and_lint, span_lint, span_lint_and_sugg, span_lint_and_then,
+    span_note_and_lint, sugg, walk_ptrs_ty, walk_ptrs_ty_depth, SpanlessEq,
 };
 
 declare_clippy_lint! {
@@ -1281,22 +1281,13 @@ fn lint_or_fun_call<'a, 'tcx>(
         fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
             let call_found = match &expr.kind {
                 // ignore enum and struct constructors
-                hir::ExprKind::Call(..) => !is_ctor_function(self.cx, expr),
+                hir::ExprKind::Call(..) => !is_ctor_or_promotable_const_function(self.cx, expr),
                 hir::ExprKind::MethodCall(..) => true,
                 _ => false,
             };
 
             if call_found {
-                // don't lint for constant values
-                let owner_def = self.cx.tcx.hir().get_parent_did(expr.hir_id);
-                let promotable = self
-                    .cx
-                    .tcx
-                    .rvalue_promotable_map(owner_def)
-                    .contains(&expr.hir_id.local_id);
-                if !promotable {
-                    self.found |= true;
-                }
+                self.found |= true;
             }
 
             if !self.found {

clippy_lints/src/needless_pass_by_value.rs

@@ -134,18 +134,10 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NeedlessPassByValue {
             spans_need_deref,
             ..
         } = {
-            let mut ctx = MovedVariablesCtxt::new(cx);
+            let mut ctx = MovedVariablesCtxt::default();
             let region_scope_tree = &cx.tcx.region_scope_tree(fn_def_id);
-            euv::ExprUseVisitor::new(
-                &mut ctx,
-                cx.tcx,
-                fn_def_id,
-                cx.param_env,
-                region_scope_tree,
-                cx.tables,
-                None,
-            )
-            .consume_body(body);
+            euv::ExprUseVisitor::new(&mut ctx, cx.tcx, fn_def_id, cx.param_env, region_scope_tree, cx.tables)
+                .consume_body(body);
             ctx
         };
 
@@ -325,115 +317,34 @@ fn requires_exact_signature(attrs: &[Attribute]) -> bool {
     })
 }
 
-struct MovedVariablesCtxt<'a, 'tcx> {
-    cx: &'a LateContext<'a, 'tcx>,
+#[derive(Default)]
+struct MovedVariablesCtxt {
     moved_vars: FxHashSet<HirId>,
     /// Spans which need to be prefixed with `*` for dereferencing the
     /// suggested additional reference.
     spans_need_deref: FxHashMap<HirId, FxHashSet<Span>>,
 }
 
-impl<'a, 'tcx> MovedVariablesCtxt<'a, 'tcx> {
-    fn new(cx: &'a LateContext<'a, 'tcx>) -> Self {
-        Self {
-            cx,
-            moved_vars: FxHashSet::default(),
-            spans_need_deref: FxHashMap::default(),
-        }
-    }
-
-    fn move_common(&mut self, _consume_id: HirId, _span: Span, cmt: &mc::cmt_<'tcx>) {
+impl MovedVariablesCtxt {
+    fn move_common(&mut self, cmt: &mc::cmt_<'_>) {
         let cmt = unwrap_downcast_or_interior(cmt);
 
         if let mc::Categorization::Local(vid) = cmt.cat {
             self.moved_vars.insert(vid);
         }
     }
-
-    fn non_moving_pat(&mut self, matched_pat: &Pat, cmt: &mc::cmt_<'tcx>) {
-        let cmt = unwrap_downcast_or_interior(cmt);
-
-        if let mc::Categorization::Local(vid) = cmt.cat {
-            let mut id = matched_pat.hir_id;
-            loop {
-                let parent = self.cx.tcx.hir().get_parent_node(id);
-                if id == parent {
-                    // no parent
-                    return;
-                }
-                id = parent;
-
-                if let Some(node) = self.cx.tcx.hir().find(id) {
-                    match node {
-                        Node::Expr(e) => {
-                            // `match` and `if let`
-                            if let ExprKind::Match(ref c, ..) = e.kind {
-                                self.spans_need_deref
-                                    .entry(vid)
-                                    .or_insert_with(FxHashSet::default)
-                                    .insert(c.span);
-                            }
-                        },
-
-                        Node::Stmt(s) => {
-                            // `let <pat> = x;`
-                            if_chain! {
-                                if let StmtKind::Local(ref local) = s.kind;
-                                then {
-                                    self.spans_need_deref
-                                        .entry(vid)
-                                        .or_insert_with(FxHashSet::default)
-                                        .insert(local.init
-                                            .as_ref()
-                                            .map(|e| e.span)
-                                            .expect("`let` stmt without init aren't caught by match_pat"));
-                                }
-                            }
-                        },
-
-                        _ => {},
-                    }
-                }
-            }
-        }
-    }
 }
 
-impl<'a, 'tcx> euv::Delegate<'tcx> for MovedVariablesCtxt<'a, 'tcx> {
-    fn consume(&mut self, consume_id: HirId, consume_span: Span, cmt: &mc::cmt_<'tcx>, mode: euv::ConsumeMode) {
-        if let euv::ConsumeMode::Move(_) = mode {
-            self.move_common(consume_id, consume_span, cmt);
-        }
-    }
-
-    fn matched_pat(&mut self, matched_pat: &Pat, cmt: &mc::cmt_<'tcx>, mode: euv::MatchMode) {
-        if let euv::MatchMode::MovingMatch = mode {
-            self.move_common(matched_pat.hir_id, matched_pat.span, cmt);
-        } else {
-            self.non_moving_pat(matched_pat, cmt);
-        }
-    }
-
-    fn consume_pat(&mut self, consume_pat: &Pat, cmt: &mc::cmt_<'tcx>, mode: euv::ConsumeMode) {
-        if let euv::ConsumeMode::Move(_) = mode {
-            self.move_common(consume_pat.hir_id, consume_pat.span, cmt);
+impl<'tcx> euv::Delegate<'tcx> for MovedVariablesCtxt {
+    fn consume(&mut self, cmt: &mc::cmt_<'tcx>, mode: euv::ConsumeMode) {
+        if let euv::ConsumeMode::Move = mode {
+            self.move_common(cmt);
         }
     }
 
-    fn borrow(
-        &mut self,
-        _: HirId,
-        _: Span,
-        _: &mc::cmt_<'tcx>,
-        _: ty::Region<'_>,
-        _: ty::BorrowKind,
-        _: euv::LoanCause,
-    ) {
-    }
-
-    fn mutate(&mut self, _: HirId, _: Span, _: &mc::cmt_<'tcx>, _: euv::MutateMode) {}
+    fn borrow(&mut self, _: &mc::cmt_<'tcx>, _: ty::BorrowKind) {}
 
-    fn decl_without_init(&mut self, _: HirId, _: Span) {}
+    fn mutate(&mut self, _: &mc::cmt_<'tcx>) {}
 }
 
 fn unwrap_downcast_or_interior<'a, 'tcx>(mut cmt: &'a mc::cmt_<'tcx>) -> mc::cmt_<'tcx> {

clippy_lints/src/utils/mod.rs

@@ -803,13 +803,15 @@ pub fn is_copy<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool {
 }
 
 /// Checks if an expression is constructing a tuple-like enum variant or struct
-pub fn is_ctor_function(cx: &LateContext<'_, '_>, expr: &Expr) -> bool {
+pub fn is_ctor_or_promotable_const_function(cx: &LateContext<'_, '_>, expr: &Expr) -> bool {
     if let ExprKind::Call(ref fun, _) = expr.kind {
         if let ExprKind::Path(ref qp) = fun.kind {
-            return matches!(
-                cx.tables.qpath_res(qp, fun.hir_id),
-                def::Res::Def(DefKind::Variant, ..) | Res::Def(DefKind::Ctor(..), _)
-            );
+            let res = cx.tables.qpath_res(qp, fun.hir_id);
+            return match res {
+                def::Res::Def(DefKind::Variant, ..) | Res::Def(DefKind::Ctor(..), _) => true,
+                def::Res::Def(_, def_id) => cx.tcx.is_promotable_const_fn(def_id),
+                _ => false,
+            };
         }
     }
     false