Auto merge of #5334 - flip1995:backport_remerge, r=flip1995

[rust.git] / clippy_lints / src / needless_pass_by_value.rs

diff --git a/clippy_lints/src/needless_pass_by_value.rs b/clippy_lints/src/needless_pass_by_value.rs
index bb5fc655755828d79c4af57edee2c1327271ee31..dc18a745c265127d57b82cddd715f16f6e778d2a 100644 (file)
--- a/clippy_lints/src/needless_pass_by_value.rs
+++ b/clippy_lints/src/needless_pass_by_value.rs
@@ -4,22 +4,21 @@
     snippet, snippet_opt, span_lint_and_then,
 };
 use if_chain::if_chain;
-use matches::matches;
-use rustc::hir::intravisit::FnKind;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::middle::expr_use_visitor as euv;
-use rustc::middle::mem_categorization as mc;
-use rustc::traits;
-use rustc::ty::{self, RegionKind, TypeFoldable};
-use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc::ty::{self, TypeFoldable};
+use rustc_ast::ast::Attribute;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_errors::Applicability;
+use rustc_errors::{Applicability, DiagnosticBuilder};
+use rustc_hir::intravisit::FnKind;
+use rustc_hir::{BindingAnnotation, Body, FnDecl, GenericArg, HirId, ItemKind, Node, PatKind, QPath, TyKind};
+use rustc_infer::infer::TyCtxtInferExt;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{Span, Symbol};
 use rustc_target::spec::abi::Abi;
+use rustc_trait_selection::traits;
+use rustc_trait_selection::traits::misc::can_type_implement_copy;
+use rustc_typeck::expr_use_visitor as euv;
 use std::borrow::Cow;
-use syntax::ast::Attribute;
-use syntax::errors::DiagnosticBuilder;
-use syntax_pos::{Span, Symbol};
 
 declare_clippy_lint! {
     /// **What it does:** Checks for functions taking arguments by value, but not
@@ -71,8 +70,8 @@ fn check_fn(
         &mut self,
         cx: &LateContext<'a, 'tcx>,
         kind: FnKind<'tcx>,
-        decl: &'tcx FnDecl,
-        body: &'tcx Body,
+        decl: &'tcx FnDecl<'_>,
+        body: &'tcx Body<'_>,
         span: Span,
         hir_id: HirId,
     ) {
@@ -92,7 +91,7 @@ fn check_fn(
 
         // Exclude non-inherent impls
         if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) {
-            if matches!(item.kind, ItemKind::Impl(_, _, _, _, Some(_), _, _) |
+            if matches!(item.kind, ItemKind::Impl{ of_trait: Some(_), .. } |
                 ItemKind::Trait(..))
             {
                 return;
@@ -115,7 +114,7 @@ fn check_fn(
         let preds = traits::elaborate_predicates(cx.tcx, cx.param_env.caller_bounds.to_vec())
             .filter(|p| !p.is_global())
             .filter_map(|pred| {
-                if let ty::Predicate::Trait(poly_trait_ref) = pred {
+                if let ty::Predicate::Trait(poly_trait_ref, _) = pred {
                     if poly_trait_ref.def_id() == sized_trait || poly_trait_ref.skip_binder().has_escaping_bound_vars()
                     {
                         return None;
@@ -135,16 +134,16 @@ fn check_fn(
             ..
         } = {
             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)
-                .consume_body(body);
+            cx.tcx.infer_ctxt().enter(|infcx| {
+                euv::ExprUseVisitor::new(&mut ctx, &infcx, fn_def_id, cx.param_env, cx.tables).consume_body(body);
+            });
             ctx
         };
 
         let fn_sig = cx.tcx.fn_sig(fn_def_id);
         let fn_sig = cx.tcx.erase_late_bound_regions(&fn_sig);
 
-        for (idx, ((input, &ty), arg)) in decl.inputs.iter().zip(fn_sig.inputs()).zip(&body.params).enumerate() {
+        for (idx, ((input, &ty), arg)) in decl.inputs.iter().zip(fn_sig.inputs()).zip(body.params).enumerate() {
             // All spans generated from a proc-macro invocation are the same...
             if span == input.span {
                 return;
@@ -171,8 +170,9 @@ fn check_fn(
 
                 (
                     preds.iter().any(|t| t.def_id() == borrow_trait),
-                    !preds.is_empty()
-                        && preds.iter().all(|t| {
+                    !preds.is_empty() && {
+                        let ty_empty_region = cx.tcx.mk_imm_ref(cx.tcx.lifetimes.re_root_empty, ty);
+                        preds.iter().all(|t| {
                             let ty_params = &t
                                 .skip_binder()
                                 .trait_ref
@@ -181,8 +181,9 @@ fn check_fn(
                                 .skip(1)
                                 .cloned()
                                 .collect::<Vec<_>>();
-                            implements_trait(cx, cx.tcx.mk_imm_ref(&RegionKind::ReEmpty, ty), t.def_id(), ty_params)
-                        }),
+                            implements_trait(cx, ty_empty_region, t.def_id(), ty_params)
+                        })
+                    },
                 )
             };
 
@@ -205,8 +206,8 @@ fn check_fn(
                     let sugg = |db: &mut DiagnosticBuilder<'_>| {
                         if let ty::Adt(def, ..) = ty.kind {
                             if let Some(span) = cx.tcx.hir().span_if_local(def.did) {
-                                if cx.param_env.can_type_implement_copy(cx.tcx, ty).is_ok() {
-                                    db.span_help(span, "consider marking this type as Copy");
+                                if can_type_implement_copy(cx.tcx, cx.param_env, ty).is_ok() {
+                                    db.span_help(span, "consider marking this type as `Copy`");
                                 }
                             }
                         }
@@ -326,34 +327,21 @@ struct MovedVariablesCtxt {
 }
 
 impl MovedVariablesCtxt {
-    fn move_common(&mut self, cmt: &mc::Place<'_>) {
-        let cmt = unwrap_downcast_or_interior(cmt);
-
-        if let mc::Categorization::Local(vid) = cmt.cat {
+    fn move_common(&mut self, cmt: &euv::Place<'_>) {
+        if let euv::PlaceBase::Local(vid) = cmt.base {
             self.moved_vars.insert(vid);
         }
     }
 }
 
 impl<'tcx> euv::Delegate<'tcx> for MovedVariablesCtxt {
-    fn consume(&mut self, cmt: &mc::Place<'tcx>, mode: euv::ConsumeMode) {
+    fn consume(&mut self, cmt: &euv::Place<'tcx>, mode: euv::ConsumeMode) {
         if let euv::ConsumeMode::Move = mode {
             self.move_common(cmt);
         }
     }
 
-    fn borrow(&mut self, _: &mc::Place<'tcx>, _: ty::BorrowKind) {}
-
-    fn mutate(&mut self, _: &mc::Place<'tcx>) {}
-}
+    fn borrow(&mut self, _: &euv::Place<'tcx>, _: ty::BorrowKind) {}
 
-fn unwrap_downcast_or_interior<'a, 'tcx>(mut cmt: &'a mc::Place<'tcx>) -> mc::Place<'tcx> {
-    loop {
-        match cmt.cat {
-            mc::Categorization::Downcast(ref c, _) | mc::Categorization::Interior(ref c, _) => {
-                cmt = c;
-            },
-            _ => return (*cmt).clone(),
-        }
-    }
+    fn mutate(&mut self, _: &euv::Place<'tcx>) {}
 }