Auto merge of rust-lang#96863 - SparrowLii:let, r=michaelwoerister

use `hir::Let` in `hir::Guard::IfLet`

This PR fixes the FIXME about using `hir::Let` in `hir::Guard::IfLet`

Author: bors

clippy_lints/src/collapsible_match.rs

@@ -5,7 +5,7 @@ use clippy_utils::{is_lang_ctor, is_unit_expr, path_to_local, peel_blocks_with_s
 use if_chain::if_chain;
 use rustc_errors::MultiSpan;
 use rustc_hir::LangItem::OptionNone;
-use rustc_hir::{Arm, Expr, Guard, HirId, Pat, PatKind};
+use rustc_hir::{Arm, Expr, Guard, HirId, Let, Pat, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::Span;
@@ -109,7 +109,7 @@ fn check_arm<'tcx>(
             (Some(a), Some(b)) => SpanlessEq::new(cx).eq_expr(a, b),
         };
         // the binding must not be used in the if guard
-        if outer_guard.map_or(true, |(Guard::If(e) | Guard::IfLet(_, e))| !is_local_used(cx, *e, binding_id));
+        if outer_guard.map_or(true, |(Guard::If(e) | Guard::IfLet(Let { init: e, .. }))| !is_local_used(cx, *e, binding_id));
         // ...or anywhere in the inner expression
         if match inner {
             IfLetOrMatch::IfLet(_, _, body, els) => {

clippy_lints/src/entry.rs

@@ -11,7 +11,7 @@ use rustc_errors::Applicability;
 use rustc_hir::{
     hir_id::HirIdSet,
     intravisit::{walk_expr, Visitor},
-    Block, Expr, ExprKind, Guard, HirId, Pat, Stmt, StmtKind, UnOp,
+    Block, Expr, ExprKind, Guard, HirId, Let, Pat, Stmt, StmtKind, UnOp,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -478,7 +478,7 @@ impl<'tcx> Visitor<'tcx> for InsertSearcher<'_, 'tcx> {
                     let mut is_map_used = self.is_map_used;
                     for arm in arms {
                         self.visit_pat(arm.pat);
-                        if let Some(Guard::If(guard) | Guard::IfLet(_, guard)) = arm.guard {
+                        if let Some(Guard::If(guard) | Guard::IfLet(&Let { init: guard, .. })) = arm.guard {
                             self.visit_non_tail_expr(guard);
                         }
                         is_map_used |= self.visit_cond_arm(arm.body);

clippy_lints/src/only_used_in_recursion.rs

@@ -596,7 +596,7 @@ impl<'tcx> SideEffectVisit<'tcx> {
                 let mut vars = std::mem::take(&mut self.ret_vars);
                 let _ = arm.guard.as_ref().map(|guard| {
                     self.visit_expr(match guard {
-                        Guard::If(expr) | Guard::IfLet(_, expr) => expr,
+                        Guard::If(expr) | Guard::IfLet(Let { init: expr, .. }) => expr,
                     });
                     vars.append(&mut self.ret_vars);
                 });

clippy_lints/src/utils/author.rs

@@ -315,11 +315,11 @@ impl<'a, 'tcx> PrintVisitor<'a, 'tcx> {
                 out!("if let Some(Guard::If({expr})) = {arm}.guard;");
                 self.expr(expr);
             },
-            Some(hir::Guard::IfLet(pat, expr)) => {
-                bind!(self, pat, expr);
-                out!("if let Some(Guard::IfLet({pat}, {expr}) = {arm}.guard;");
-                self.pat(pat);
-                self.expr(expr);
+            Some(hir::Guard::IfLet(let_expr)) => {
+                bind!(self, let_expr);
+                out!("if let Some(Guard::IfLet({let_expr}) = {arm}.guard;");
+                self.pat(field!(let_expr.pat));
+                self.expr(field!(let_expr.init));
             },
         }
         self.expr(field!(arm.body));

clippy_utils/src/hir_utils.rs

@@ -301,7 +301,9 @@ impl HirEqInterExpr<'_, '_, '_> {
     fn eq_guard(&mut self, left: &Guard<'_>, right: &Guard<'_>) -> bool {
         match (left, right) {
             (Guard::If(l), Guard::If(r)) => self.eq_expr(l, r),
-            (Guard::IfLet(lp, le), Guard::IfLet(rp, re)) => self.eq_pat(lp, rp) && self.eq_expr(le, re),
+            (Guard::IfLet(l), Guard::IfLet(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)
+            },
             _ => false,
         }
     }
@@ -894,7 +896,7 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
 
     pub fn hash_guard(&mut self, g: &Guard<'_>) {
         match g {
-            Guard::If(expr) | Guard::IfLet(_, expr) => {
+            Guard::If(expr) | Guard::IfLet(Let { init: expr, .. }) => {
                 self.hash_expr(expr);
             },
         }