Port clippy lint redundant_field_names to compiler

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -1751,7 +1751,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             .map(|&(category, span)| BlameConstraint {
                 category,
                 from_closure: true,
-                span: span,
+                span,
                 variance_info: constraint.variance_info,
             })
             .unwrap_or(BlameConstraint {

compiler/rustc_codegen_llvm/src/type_of.rs

@@ -268,10 +268,9 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
         };
         debug!("--> mapped {:#?} to llty={:?}", self, llty);
 
-        cx.type_lowering.borrow_mut().insert(
-            (self.ty, variant_index),
-            TypeLowering { lltype: llty, field_remapping: field_remapping },
-        );
+        cx.type_lowering
+            .borrow_mut()
+            .insert((self.ty, variant_index), TypeLowering { lltype: llty, field_remapping });
 
         if let Some((llty, layout)) = defer {
             let (llfields, packed, new_field_remapping) = struct_llfields(cx, layout);

compiler/rustc_const_eval/src/interpret/place.rs

@@ -447,7 +447,7 @@ where
         let actual_to = if from_end {
             if from.checked_add(to).map_or(true, |to| to > len) {
                 // This can only be reached in ConstProp and non-rustc-MIR.
-                throw_ub!(BoundsCheckFailed { len: len, index: from.saturating_add(to) });
+                throw_ub!(BoundsCheckFailed { len, index: from.saturating_add(to) });
             }
             len.checked_sub(to).unwrap()
         } else {

compiler/rustc_graphviz/src/lib.rs

@@ -154,7 +154,7 @@
 //! pub fn render_to<W: Write>(output: &mut W) {
 //!     let nodes = vec!["{x,y}","{x}","{y}","{}"];
 //!     let edges = vec![(0,1), (0,2), (1,3), (2,3)];
-//!     let graph = Graph { nodes: nodes, edges: edges };
+//!     let graph = Graph { nodes, edges };
 //!
 //!     dot::render(&graph, output).unwrap()
 //! }
@@ -216,7 +216,7 @@
 //! pub fn render_to<W: Write>(output: &mut W) {
 //!     let nodes = vec!["{x,y}","{x}","{y}","{}"];
 //!     let edges = vec![(0,1), (0,2), (1,3), (2,3)];
-//!     let graph = Graph { nodes: nodes, edges: edges };
+//!     let graph = Graph { nodes, edges };
 //!
 //!     dot::render(&graph, output).unwrap()
 //! }

compiler/rustc_lint/src/lib.rs

@@ -57,6 +57,7 @@ mod non_fmt_panic;
 mod nonstandard_style;
 mod noop_method_call;
 mod passes;
+mod redundant_field_initializers;
 mod redundant_semicolon;
 mod traits;
 mod types;
@@ -83,6 +84,7 @@ use non_ascii_idents::*;
 use non_fmt_panic::NonPanicFmt;
 use nonstandard_style::*;
 use noop_method_call::*;
+use redundant_field_initializers::*;
 use redundant_semicolon::*;
 use traits::*;
 use types::*;
@@ -129,6 +131,7 @@ macro_rules! early_lint_passes {
                 WhileTrue: WhileTrue,
                 NonAsciiIdents: NonAsciiIdents,
                 IncompleteFeatures: IncompleteFeatures,
+                RedundantFieldInitializers: RedundantFieldInitializers,
                 RedundantSemicolons: RedundantSemicolons,
                 UnusedDocComment: UnusedDocComment,
             ]

compiler/rustc_lint/src/passes.rs

@@ -127,6 +127,7 @@ macro_rules! declare_combined_late_lint_pass {
         }
 
         impl $name {
+            #[allow(redundant_field_initializers)]
             $v fn new() -> Self {
                 Self {
                     $($passes: $constructor,)*
@@ -254,6 +255,7 @@ macro_rules! declare_combined_early_lint_pass {
         }
 
         impl $name {
+            #[allow(redundant_field_initializers)]
             $v fn new() -> Self {
                 Self {
                     $($passes: $constructor,)*

compiler/rustc_lint/src/redundant_field_initializers.rs

@@ -0,0 +1,65 @@
+use crate::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_ast as ast;
+use rustc_errors::Applicability;
+use rustc_middle::lint::in_external_macro;
+
+declare_lint! {
+    /// The `redundant_field_initializers` lint checks for fields in struct literals
+    /// where shorthands could be used.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// let bar: u8 = 123;
+    ///
+    /// struct Foo {
+    ///     bar: u8,
+    /// }
+    ///
+    /// let foo = Foo { bar: bar };
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// If the field and variable names are the same,
+    /// the field name is redundant.
+    pub REDUNDANT_FIELD_INITIALIZERS,
+    Warn,
+    "checks for fields in struct literals where shorthands could be used"
+}
+
+declare_lint_pass!(RedundantFieldInitializers => [REDUNDANT_FIELD_INITIALIZERS]);
+
+impl EarlyLintPass for RedundantFieldInitializers {
+    fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
+        if in_external_macro(cx.sess(), expr.span) {
+            return;
+        }
+        if let ast::ExprKind::Struct(ref se) = expr.kind {
+            for field in &se.fields {
+                if field.is_shorthand {
+                    continue;
+                }
+                if let ast::ExprKind::Path(None, path) = &field.expr.kind {
+                    if path.segments.len() == 1
+                        && path.segments[0].ident == field.ident
+                        && path.segments[0].args.is_none()
+                    {
+                        cx.struct_span_lint(REDUNDANT_FIELD_INITIALIZERS, field.span, |lint| {
+                            lint.build("redundant field names in struct initialization")
+                                .span_suggestion(
+                                    field.span,
+                                    "replace it with",
+                                    field.ident.to_string(),
+                                    Applicability::MachineApplicable,
+                                )
+                                .emit();
+                        });
+                    }
+                }
+            }
+        }
+    }
+}

compiler/rustc_middle/src/hir/map/collector.rs

@@ -141,7 +141,7 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
         insert_vec_map(
             &mut nodes.nodes,
             hir_id.local_id,
-            ParentedNode { parent: self.parent_node.local_id, node: node },
+            ParentedNode { parent: self.parent_node.local_id, node },
         );
     }
 

compiler/rustc_mir_build/src/build/expr/as_constant.rs

@@ -30,7 +30,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 Constant { span, user_ty: None, literal: literal.into() }
             }
             ExprKind::ConstBlock { value } => {
-                Constant { span: span, user_ty: None, literal: value.into() }
+                Constant { span, user_ty: None, literal: value.into() }
             }
             _ => span_bug!(span, "expression is not a valid constant {:?}", kind),
         }

compiler/rustc_mir_build/src/thir/cx/expr.rs

@@ -704,8 +704,7 @@ impl<'tcx> Cx<'tcx> {
                                     ty: var_ty,
                                 };
                                 let lhs = self.thir.exprs.push(mk_const(self.tcx().mk_const(lhs)));
-                                let bin =
-                                    ExprKind::Binary { op: BinOp::Add, lhs: lhs, rhs: offset };
+                                let bin = ExprKind::Binary { op: BinOp::Add, lhs, rhs: offset };
                                 self.thir.exprs.push(Expr {
                                     temp_lifetime,
                                     ty: var_ty,
@@ -719,7 +718,7 @@ impl<'tcx> Cx<'tcx> {
                         self.mirror_expr(source)
                     };
 
-                    ExprKind::Cast { source: source }
+                    ExprKind::Cast { source }
                 };
 
                 if let Some(user_ty) = user_ty {

compiler/rustc_target/src/spec/aarch64_apple_ios_sim.rs

@@ -12,7 +12,7 @@ pub fn target() -> Target {
     let llvm_target = super::apple_base::ios_sim_llvm_target(arch);
 
     Target {
-        llvm_target: llvm_target,
+        llvm_target,
         pointer_width: 64,
         data_layout: "e-m:o-i64:64-i128:128-n32:64-S128".to_string(),
         arch: "aarch64".to_string(),

compiler/rustc_typeck/src/check/upvar.rs

@@ -1548,8 +1548,9 @@ fn apply_capture_kind_on_capture_ty(
 ) -> Ty<'tcx> {
     match capture_kind {
         ty::UpvarCapture::ByValue(_) => ty,
-        ty::UpvarCapture::ByRef(borrow) => tcx
-            .mk_ref(borrow.region, ty::TypeAndMut { ty: ty, mutbl: borrow.kind.to_mutbl_lossy() }),
+        ty::UpvarCapture::ByRef(borrow) => {
+            tcx.mk_ref(borrow.region, ty::TypeAndMut { ty, mutbl: borrow.kind.to_mutbl_lossy() })
+        }
     }
 }
 

library/alloc/tests/slice.rs

@@ -1802,7 +1802,7 @@ fn panic_safe() {
                 let mut input = (0..len)
                     .map(|id| DropCounter {
                         x: rng.next_u32() % modulus,
-                        id: id,
+                        id,
                         version: Cell::new(0),
                     })
                     .collect::<Vec<_>>();

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -296,7 +296,7 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
     ) -> Result<(Res, Option<String>), ErrorKind<'path>> {
         let tcx = self.cx.tcx;
         let no_res = || ResolutionFailure::NotResolved {
-            module_id: module_id,
+            module_id,
             partial_res: None,
             unresolved: path_str.into(),
         };

src/test/ui-fulldeps/regions-mock-tcx.rs

@@ -55,11 +55,11 @@ struct TypeContext<'tcx, 'ast> {
 impl<'tcx,'ast> TypeContext<'tcx, 'ast> {
     fn new(ty_arena: &'tcx TyArena<'tcx>, ast_arena: &'ast AstArena<'ast>)
            -> TypeContext<'tcx, 'ast> {
-        TypeContext { ty_arena: ty_arena,
+        TypeContext { ty_arena,
                       types: Vec::new(),
                       type_table: HashMap::new(),
 
-                      ast_arena: ast_arena,
+                      ast_arena,
                       ast_counter: 0 }
     }
 
@@ -83,7 +83,7 @@ impl<'tcx,'ast> TypeContext<'tcx, 'ast> {
     fn ast(&mut self, a: AstKind<'ast>) -> Ast<'ast> {
         let id = self.ast_counter;
         self.ast_counter += 1;
-        self.ast_arena.alloc(AstStructure { id: NodeId {id:id}, kind: a })
+        self.ast_arena.alloc(AstStructure { id: NodeId {id}, kind: a })
     }
 }
 

src/test/ui/alias-uninit-value.rs

@@ -14,7 +14,7 @@ enum sty { ty_nil, }
 struct RawT {struct_: sty, cname: Option<String>, hash: usize}
 
 fn mk_raw_ty(st: sty, cname: Option<String>) -> RawT {
-    return RawT {struct_: st, cname: cname, hash: 0};
+    return RawT {struct_: st, cname, hash: 0};
 }
 
 pub fn main() { mk_raw_ty(sty::ty_nil, None::<String>); }

src/test/ui/alignment-gep-tup-like-1.rs

@@ -26,8 +26,8 @@ impl<A:Clone> Invokable<A> for Invoker<A> {
 
 fn f<A:Clone + 'static>(a: A, b: u16) -> Box<dyn Invokable<A>+'static> {
     box Invoker {
-        a: a,
-        b: b,
+        a,
+        b,
     } as Box<dyn Invokable<A>+'static>
 }
 

src/test/ui/array-slice-vec/destructure-array-1.rs

@@ -8,7 +8,7 @@ struct D { x: u8 }
 impl Drop for D { fn drop(&mut self) { } }
 
 fn main() {
-    fn d(x: u8) -> D { D { x: x } }
+    fn d(x: u8) -> D { D { x } }
 
     let d1 = foo([d(1), d(2), d(3), d(4)], 1);
     let d3 = foo([d(5), d(6), d(7), d(8)], 3);

src/test/ui/array-slice-vec/vec-res-add.rs

@@ -3,7 +3,7 @@ struct R {
   i:isize
 }
 
-fn r(i:isize) -> R { R { i: i } }
+fn r(i:isize) -> R { R { i } }
 
 impl Drop for R {
     fn drop(&mut self) {}

src/test/ui/associated-types/associated-types-normalize-unifield-struct.rs

@@ -17,7 +17,7 @@ impl OffsetState for Y {}
 pub fn now() -> DateTime<X> { from_utc(Y) }
 
 pub struct DateTime<Off: Offset> { pub offset: Off::State }
-pub fn from_utc<Off: Offset>(offset: Off::State) -> DateTime<Off> { DateTime { offset: offset } }
+pub fn from_utc<Off: Offset>(offset: Off::State) -> DateTime<Off> { DateTime { offset } }
 
 pub fn main() {
     let _x = now();

src/test/ui/associated-types/associated-types-ref-from-struct.rs

@@ -16,7 +16,7 @@ struct TesterPair<T:Test> {
 
 impl<T:Test> TesterPair<T> {
     fn new(tester: T, value: T::V) -> TesterPair<T> {
-        TesterPair { tester: tester, value: value }
+        TesterPair { tester, value }
     }
 
     fn test(&self) -> bool {

src/test/ui/attributes/class-attributes-1.rs

@@ -14,6 +14,6 @@ impl Drop for Cat {
 
 
 #[rustc_dummy]
-fn cat(name: String) -> Cat { Cat{name: name,} }
+fn cat(name: String) -> Cat { Cat{name,} }
 
 fn main() { let _kitty = cat("Spotty".to_string()); }

src/test/ui/attributes/class-attributes-2.rs

@@ -22,7 +22,7 @@ Maybe it should technically be a kitten_maker.
 */
 fn cat(name: String) -> Cat {
     Cat {
-        name: name
+        name
     }
 }
 

src/test/ui/binop/binops.rs

@@ -60,8 +60,8 @@ struct p {
 
 fn p(x: isize, y: isize) -> p {
     p {
-        x: x,
-        y: y
+        x,
+        y
     }
 }
 

src/test/ui/borrowck/borrowck-borrowed-uniq-rvalue-2.rs

@@ -12,7 +12,7 @@ impl<'a> Drop for Defer<'a> {
 
 fn defer<'r>(x: &'r [&'r str]) -> Defer<'r> {
     Defer {
-        x: x
+        x
     }
 }
 

src/test/ui/borrowck/fsu-moves-and-copies.rs

@@ -8,7 +8,7 @@
 #![feature(box_syntax, core)]
 
 struct ncint { v: isize }
-fn ncint(v: isize) -> ncint { ncint { v: v } }
+fn ncint(v: isize) -> ncint { ncint { v } }
 
 struct NoFoo { copied: isize, nocopy: ncint, }
 impl NoFoo {

src/test/ui/cfg/conditional-compile.rs

@@ -46,15 +46,15 @@ struct r {
 
 #[cfg(bogus)]
 fn r(i: isize) -> r {
-    r { i: i }
+    r { i }
 }
 
 struct r {
     i: isize,
 }
 
 fn r(i: isize) -> r {
-    r { i: i }
+    r { i }
 }
 
 #[cfg(bogus)]

src/test/ui/cleanup-rvalue-for-scope.rs

@@ -14,7 +14,7 @@ struct Box<T> { f: T }
 struct AddFlags { bits: u64 }
 
 fn AddFlags(bits: u64) -> AddFlags {
-    AddFlags { bits: bits }
+    AddFlags { bits }
 }
 
 fn arg(exp: u64, _x: &AddFlags) {

src/test/ui/cleanup-rvalue-scopes-cf.rs

@@ -9,7 +9,7 @@ struct StackBox<T> { f: T }
 struct AddFlags { bits: u64 }
 
 fn AddFlags(bits: u64) -> AddFlags {
-    AddFlags { bits: bits }
+    AddFlags { bits }
 }
 
 fn arg(x: &AddFlags) -> &AddFlags {