Merge remote-tracking branch 'upstream/master' into rustup

clippy_utils/src/consts.rs

@@ -412,8 +412,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
     /// Simple constant folding: Insert an expression, get a constant or none.
     pub fn expr(&mut self, e: &Expr<'_>) -> Option<Constant<'tcx>> {
         match e.kind {
-            ExprKind::ConstBlock(e) |
-            ExprKind::DropTemps(e) => self.expr(e),
+            ExprKind::ConstBlock(e) | ExprKind::DropTemps(e) => self.expr(e),
             ExprKind::Path(ref qpath) => {
                 self.fetch_path_and_apply(qpath, e.hir_id, self.typeck_results.expr_ty(e), |this, result| {
                     let result = mir_to_const(this.lcx, result)?;
@@ -491,8 +490,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
     /// leaves the local crate.
     pub fn expr_is_empty(&mut self, e: &Expr<'_>) -> Option<bool> {
         match e.kind {
-            ExprKind::ConstBlock(e) |
-            ExprKind::DropTemps(e) => self.expr_is_empty(e),
+            ExprKind::ConstBlock(e) | ExprKind::DropTemps(e) => self.expr_is_empty(e),
             ExprKind::Path(ref qpath) => {
                 if !self
                     .typeck_results

clippy_utils/src/hir_utils.rs

@@ -769,7 +769,7 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
                 // closures inherit TypeckResults
                 self.hash_expr(self.cx.tcx.hir().body(body).value);
             },
-            ExprKind::ConstBlock(ref l_id) => {
+            ExprKind::ConstBlock(l_id) => {
                 self.hash_expr(l_id);
             },
             ExprKind::DropTemps(e) | ExprKind::Yield(e, _) => {

clippy_utils/src/lib.rs

@@ -3370,3 +3370,25 @@ pub fn is_parent_stmt(cx: &LateContext<'_>, id: HirId) -> bool {
         Node::Stmt(..) | Node::Block(Block { stmts: &[], .. })
     )
 }
+
+/// Returns true if the given `expr` is a block or resembled as a block,
+/// such as `if`, `loop`, `match` expressions etc.
+pub fn is_block_like(expr: &Expr<'_>) -> bool {
+    matches!(
+        expr.kind,
+        ExprKind::Block(..) | ExprKind::ConstBlock(..) | ExprKind::If(..) | ExprKind::Loop(..) | ExprKind::Match(..)
+    )
+}
+
+/// Returns true if the given `expr` is binary expression that needs to be wrapped in parentheses.
+pub fn binary_expr_needs_parentheses(expr: &Expr<'_>) -> bool {
+    fn contains_block(expr: &Expr<'_>, is_operand: bool) -> bool {
+        match expr.kind {
+            ExprKind::Binary(_, lhs, _) => contains_block(lhs, true),
+            _ if is_block_like(expr) => is_operand,
+            _ => false,
+        }
+    }
+
+    contains_block(expr, false)
+}

clippy_utils/src/source.rs

@@ -8,7 +8,7 @@ use rustc_hir::{BlockCheckMode, Expr, ExprKind, UnsafeSource};
 use rustc_lint::{LateContext, LintContext};
 use rustc_session::Session;
 use rustc_span::source_map::{original_sp, SourceMap};
-use rustc_span::{hygiene, BytePos, SourceFileAndLine, Pos, SourceFile, Span, SpanData, SyntaxContext, DUMMY_SP};
+use rustc_span::{hygiene, BytePos, Pos, SourceFile, SourceFileAndLine, Span, SpanData, SyntaxContext, DUMMY_SP};
 use std::borrow::Cow;
 use std::ops::Range;
 

clippy_utils/src/ty.rs

@@ -9,7 +9,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_hir::def_id::DefId;
-use rustc_hir::{Expr, FnDecl, Safety, LangItem, TyKind};
+use rustc_hir::{Expr, FnDecl, LangItem, Safety, TyKind};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::LateContext;
 use rustc_middle::mir::interpret::Scalar;
@@ -18,8 +18,8 @@ use rustc_middle::traits::EvaluationResult;
 use rustc_middle::ty::layout::ValidityRequirement;
 use rustc_middle::ty::{
     self, AdtDef, AliasTy, AssocKind, Binder, BoundRegion, FnSig, GenericArg, GenericArgKind, GenericArgsRef,
-    GenericParamDefKind, IntTy, ParamEnv, Region, RegionKind, Upcast, TraitRef, Ty, TyCtxt,
-    TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor, UintTy, VariantDef, VariantDiscr,
+    GenericParamDefKind, IntTy, ParamEnv, Region, RegionKind, TraitRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable,
+    TypeVisitableExt, TypeVisitor, UintTy, Upcast, VariantDef, VariantDiscr,
 };
 use rustc_span::symbol::Ident;
 use rustc_span::{sym, Span, Symbol, DUMMY_SP};