Auto merge of #6325 - flip1995:rustup, r=flip1995

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

diff --git a/clippy_lints/src/loops.rs b/clippy_lints/src/loops.rs
index c7d3f4e9b083bcad06c326d62d975d70eb8fe867..0d31e9cfc3decb073691ca18766184563141b25f 100644 (file)
--- a/clippy_lints/src/loops.rs
+++ b/clippy_lints/src/loops.rs
@@ -4,10 +4,10 @@
 use crate::utils::usage::{is_unused, mutated_variables};
 use crate::utils::{
     contains_name, get_enclosing_block, get_parent_expr, get_trait_def_id, has_iter_method, higher, implements_trait,
-    indent_of, is_integer_const, is_no_std_crate, is_refutable, is_type_diagnostic_item, last_path_segment,
-    match_trait_method, match_type, match_var, multispan_sugg, qpath_res, single_segment_path, snippet,
-    snippet_with_applicability, snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg,
-    span_lint_and_then, sugg, SpanlessEq,
+    indent_of, is_in_panic_handler, is_integer_const, is_no_std_crate, is_refutable, is_type_diagnostic_item,
+    last_path_segment, match_trait_method, match_type, match_var, multispan_sugg, qpath_res, single_segment_path,
+    snippet, snippet_with_applicability, snippet_with_macro_callsite, span_lint, span_lint_and_help,
+    span_lint_and_sugg, span_lint_and_then, sugg, SpanlessEq,
 };
 use if_chain::if_chain;
 use rustc_ast::ast;
@@ -543,17 +543,15 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         // (also matches an explicit "match" instead of "if let")
         // (even if the "match" or "if let" is used for declaration)
         if let ExprKind::Loop(ref block, _, LoopSource::Loop) = expr.kind {
-            // also check for empty `loop {}` statements
-            // TODO(issue #6161): Enable for no_std crates (outside of #[panic_handler])
-            if block.stmts.is_empty() && block.expr.is_none() && !is_no_std_crate(cx.tcx.hir().krate()) {
-                span_lint_and_help(
-                    cx,
-                    EMPTY_LOOP,
-                    expr.span,
-                    "empty `loop {}` wastes CPU cycles",
-                    None,
-                    "You should either use `panic!()` or add `std::thread::sleep(..);` to the loop body.",
-                );
+            // also check for empty `loop {}` statements, skipping those in #[panic_handler]
+            if block.stmts.is_empty() && block.expr.is_none() && !is_in_panic_handler(cx, expr) {
+                let msg = "empty `loop {}` wastes CPU cycles";
+                let help = if is_no_std_crate(cx.tcx.hir().krate()) {
+                    "you should either use `panic!()` or add a call pausing or sleeping the thread to the loop body"
+                } else {
+                    "you should either use `panic!()` or add `std::thread::sleep(..);` to the loop body"
+                };
+                span_lint_and_help(cx, EMPTY_LOOP, expr.span, msg, None, help);
             }
 
             // extract the expression from the first statement (if any) in a block
@@ -1957,28 +1955,28 @@ struct MutatePairDelegate<'a, 'tcx> {
 }
 
 impl<'tcx> Delegate<'tcx> for MutatePairDelegate<'_, 'tcx> {
-    fn consume(&mut self, _: &PlaceWithHirId<'tcx>, _: ConsumeMode) {}
+    fn consume(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId, _: ConsumeMode) {}
 
-    fn borrow(&mut self, cmt: &PlaceWithHirId<'tcx>, bk: ty::BorrowKind) {
+    fn borrow(&mut self, cmt: &PlaceWithHirId<'tcx>, diag_expr_id: HirId, bk: ty::BorrowKind) {
         if let ty::BorrowKind::MutBorrow = bk {
             if let PlaceBase::Local(id) = cmt.place.base {
                 if Some(id) == self.hir_id_low {
-                    self.span_low = Some(self.cx.tcx.hir().span(cmt.hir_id))
+                    self.span_low = Some(self.cx.tcx.hir().span(diag_expr_id))
                 }
                 if Some(id) == self.hir_id_high {
-                    self.span_high = Some(self.cx.tcx.hir().span(cmt.hir_id))
+                    self.span_high = Some(self.cx.tcx.hir().span(diag_expr_id))
                 }
             }
         }
     }
 
-    fn mutate(&mut self, cmt: &PlaceWithHirId<'tcx>) {
+    fn mutate(&mut self, cmt: &PlaceWithHirId<'tcx>, diag_expr_id: HirId) {
         if let PlaceBase::Local(id) = cmt.place.base {
             if Some(id) == self.hir_id_low {
-                self.span_low = Some(self.cx.tcx.hir().span(cmt.hir_id))
+                self.span_low = Some(self.cx.tcx.hir().span(diag_expr_id))
             }
             if Some(id) == self.hir_id_high {
-                self.span_high = Some(self.cx.tcx.hir().span(cmt.hir_id))
+                self.span_high = Some(self.cx.tcx.hir().span(diag_expr_id))
             }
         }
     }
@@ -3089,7 +3087,7 @@ fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
     }
 }
 
-/// Detect the occurences of calls to `iter` or `into_iter` for the
+/// Detect the occurrences of calls to `iter` or `into_iter` for the
 /// given identifier
 fn detect_iter_and_into_iters<'tcx>(block: &'tcx Block<'tcx>, identifier: Ident) -> Option<Vec<IterFunction>> {
     let mut visitor = IterFunctionVisitor {