let-else: use hir::Let in clippy

fix clippy format using `cargo fmt -p clippy_{lints,utils}`
manually revert rustfmt line truncations
rename to hir::Let in clippy
Undo the shadowing of various `expr` variables after renaming `scrutinee`
reduce destructuring of hir::Let to avoid `expr` collisions
cargo fmt -p clippy_{lints,utils}
bless new clippy::author output

3 files changed, 23 insertions, 8 deletions

diff --git a/src/tools/clippy/clippy_utils/src/higher.rs b/src/tools/clippy/clippy_utils/src/higher.rs
index 7297265d08c..3f11dd801f9 100644
--- a/src/tools/clippy/clippy_utils/src/higher.rs
+++ b/src/tools/clippy/clippy_utils/src/higher.rs
@@ -101,7 +101,12 @@ impl<'hir> IfLet<'hir> {
     pub fn hir(cx: &LateContext<'_>, expr: &Expr<'hir>) -> Option<Self> {
         if let ExprKind::If(
             Expr {
-                kind: ExprKind::Let(let_pat, let_expr, _),
+                kind:
+                    ExprKind::Let(hir::Let {
+                        pat: let_pat,
+                        init: let_expr,
+                        ..
+                    }),
                 ..
             },
             if_then,
@@ -368,7 +373,12 @@ impl<'hir> WhileLet<'hir> {
                         kind:
                             ExprKind::If(
                                 Expr {
-                                    kind: ExprKind::Let(let_pat, let_expr, _),
+                                    kind:
+                                        ExprKind::Let(hir::Let {
+                                            pat: let_pat,
+                                            init: let_expr,
+                                            ..
+                                        }),
                                     ..
                                 },
                                 if_then,
diff --git a/src/tools/clippy/clippy_utils/src/hir_utils.rs b/src/tools/clippy/clippy_utils/src/hir_utils.rs
index 7438b6eabf9..5f5d878597e 100644
--- a/src/tools/clippy/clippy_utils/src/hir_utils.rs
+++ b/src/tools/clippy/clippy_utils/src/hir_utils.rs
@@ -7,7 +7,7 @@ use rustc_hir::def::Res;
 use rustc_hir::HirIdMap;
 use rustc_hir::{
     BinOpKind, Block, BodyId, Expr, ExprField, ExprKind, FnRetTy, GenericArg, GenericArgs, Guard, HirId,
-    InlineAsmOperand, Lifetime, LifetimeName, ParamName, Pat, PatField, PatKind, Path, PathSegment, QPath, Stmt,
+    InlineAsmOperand, Let, Lifetime, LifetimeName, ParamName, Pat, PatField, PatKind, Path, PathSegment, QPath, Stmt,
     StmtKind, Ty, TyKind, TypeBinding,
 };
 use rustc_lexer::{tokenize, TokenKind};
@@ -232,7 +232,9 @@ impl HirEqInterExpr<'_, '_, '_> {
             (&ExprKind::If(lc, lt, ref le), &ExprKind::If(rc, rt, ref re)) => {
                 self.eq_expr(lc, rc) && self.eq_expr(&**lt, &**rt) && both(le, re, |l, r| self.eq_expr(l, r))
             },
-            (&ExprKind::Let(lp, le, _), &ExprKind::Let(rp, re, _)) => self.eq_pat(lp, rp) && self.eq_expr(le, re),
+            (&ExprKind::Let(l), &ExprKind::Let(r)) => {
+                self.eq_pat(l.pat, r.pat) && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r)) && self.eq_expr(l.init, r.init)
+            },
             (&ExprKind::Lit(ref l), &ExprKind::Lit(ref r)) => l.node == r.node,
             (&ExprKind::Loop(lb, ref ll, ref lls, _), &ExprKind::Loop(rb, ref rl, ref rls, _)) => {
                 lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.name == r.ident.name)
@@ -666,8 +668,11 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
                     }
                 }
             },
-            ExprKind::Let(pat, expr, _) => {
-                self.hash_expr(expr);
+            ExprKind::Let(Let { pat, init, ty, .. }) => {
+                self.hash_expr(init);
+                if let Some(ty) = ty {
+                    self.hash_ty(ty);
+                }
                 self.hash_pat(pat);
             },
             ExprKind::LlvmInlineAsm(..) | ExprKind::Err => {},
diff --git a/src/tools/clippy/clippy_utils/src/lib.rs b/src/tools/clippy/clippy_utils/src/lib.rs
index f011380c127..32d9a9a42ed 100644
--- a/src/tools/clippy/clippy_utils/src/lib.rs
+++ b/src/tools/clippy/clippy_utils/src/lib.rs
@@ -871,8 +871,8 @@ pub fn capture_local_usage(cx: &LateContext<'tcx>, e: &Expr<'_>) -> CaptureKind
                         capture_expr_ty = e;
                     }
                 },
-                ExprKind::Let(pat, ..) => {
-                    let mutability = match pat_capture_kind(cx, pat) {
+                ExprKind::Let(let_expr) => {
+                    let mutability = match pat_capture_kind(cx, let_expr.pat) {
                         CaptureKind::Value => Mutability::Not,
                         CaptureKind::Ref(m) => m,
                     };