Merge branch 'master' into fix-4727

[rust.git] / clippy_lints / src / utils / usage.rs

diff --git a/clippy_lints/src/utils/usage.rs b/clippy_lints/src/utils/usage.rs
index 2661bc945f36ba175d70b9b76386a51210fcc609..41662099fd3d785ec64bb97d170e1ad71d3d580b 100644 (file)
--- a/clippy_lints/src/utils/usage.rs
+++ b/clippy_lints/src/utils/usage.rs
@@ -1,24 +1,29 @@
-use rustc::lint::LateContext;
-
-use rustc::hir::def::Def;
+use rustc::hir::def::Res;
 use rustc::hir::*;
+use rustc::lint::LateContext;
 use rustc::middle::expr_use_visitor::*;
 use rustc::middle::mem_categorization::cmt_;
 use rustc::middle::mem_categorization::Categorization;
 use rustc::ty;
-use std::collections::HashSet;
-use syntax::ast::NodeId;
-use syntax::source_map::Span;
+use rustc_data_structures::fx::FxHashSet;
 
-/// Returns a set of mutated local variable ids or None if mutations could not be determined.
-pub fn mutated_variables<'a, 'tcx: 'a>(expr: &'tcx Expr, cx: &'a LateContext<'a, 'tcx>) -> Option<HashSet<NodeId>> {
+/// Returns a set of mutated local variable IDs, or `None` if mutations could not be determined.
+pub fn mutated_variables<'a, 'tcx>(expr: &'tcx Expr, cx: &'a LateContext<'a, 'tcx>) -> Option<FxHashSet<HirId>> {
     let mut delegate = MutVarsDelegate {
-        used_mutably: HashSet::new(),
+        used_mutably: FxHashSet::default(),
         skip: false,
     };
     let def_id = def_id::DefId::local(expr.hir_id.owner);
     let region_scope_tree = &cx.tcx.region_scope_tree(def_id);
-    ExprUseVisitor::new(&mut delegate, cx.tcx, cx.param_env, region_scope_tree, cx.tables, None).walk_expr(expr);
+    ExprUseVisitor::new(
+        &mut delegate,
+        cx.tcx,
+        def_id,
+        cx.param_env,
+        region_scope_tree,
+        cx.tables,
+    )
+    .walk_expr(expr);
 
     if delegate.skip {
         return None;
@@ -26,24 +31,21 @@ pub fn mutated_variables<'a, 'tcx: 'a>(expr: &'tcx Expr, cx: &'a LateContext<'a,
     Some(delegate.used_mutably)
 }
 
-pub fn is_potentially_mutated<'a, 'tcx: 'a>(
-    variable: &'tcx Path,
-    expr: &'tcx Expr,
-    cx: &'a LateContext<'a, 'tcx>,
-) -> bool {
-    let id = match variable.def {
-        Def::Local(id) | Def::Upvar(id, ..) => id,
-        _ => return true,
-    };
-    mutated_variables(expr, cx).map_or(true, |mutated| mutated.contains(&id))
+pub fn is_potentially_mutated<'a, 'tcx>(variable: &'tcx Path, expr: &'tcx Expr, cx: &'a LateContext<'a, 'tcx>) -> bool {
+    if let Res::Local(id) = variable.res {
+        mutated_variables(expr, cx).map_or(true, |mutated| mutated.contains(&id))
+    } else {
+        true
+    }
 }
 
 struct MutVarsDelegate {
-    used_mutably: HashSet<NodeId>,
+    used_mutably: FxHashSet<HirId>,
     skip: bool,
 }
 
 impl<'tcx> MutVarsDelegate {
+    #[allow(clippy::similar_names)]
     fn update(&mut self, cat: &'tcx Categorization<'_>) {
         match *cat {
             Categorization::Local(id) => {
@@ -62,21 +64,15 @@ fn update(&mut self, cat: &'tcx Categorization<'_>) {
 }
 
 impl<'tcx> Delegate<'tcx> for MutVarsDelegate {
-    fn consume(&mut self, _: NodeId, _: Span, _: &cmt_<'tcx>, _: ConsumeMode) {}
-
-    fn matched_pat(&mut self, _: &Pat, _: &cmt_<'tcx>, _: MatchMode) {}
+    fn consume(&mut self, _: &cmt_<'tcx>, _: ConsumeMode) {}
 
-    fn consume_pat(&mut self, _: &Pat, _: &cmt_<'tcx>, _: ConsumeMode) {}
-
-    fn borrow(&mut self, _: NodeId, _: 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 {
             self.update(&cmt.cat)
         }
     }
 
-    fn mutate(&mut self, _: NodeId, _: Span, cmt: &cmt_<'tcx>, _: MutateMode) {
+    fn mutate(&mut self, cmt: &cmt_<'tcx>) {
         self.update(&cmt.cat)
     }
-
-    fn decl_without_init(&mut self, _: NodeId, _: Span) {}
 }