Auto merge of #9148 - arieluy:then_some_unwrap_or, r=Jarcho

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

diff --git a/clippy_lints/src/let_if_seq.rs b/clippy_lints/src/let_if_seq.rs
index 13f0d43cf8dd1343774ab28d0edd0df2cb82f76b..56bbbbbc819e5aa58020185a6ddee98dc0be15d0 100644 (file)
--- a/clippy_lints/src/let_if_seq.rs
+++ b/clippy_lints/src/let_if_seq.rs
@@ -1,6 +1,6 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet;
-use clippy_utils::{path_to_local_id, visitors::LocalUsedVisitor};
+use clippy_utils::{path_to_local_id, visitors::is_local_used};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
@@ -48,6 +48,7 @@
     ///     None
     /// };
     /// ```
+    #[clippy::version = "pre 1.29.0"]
     pub USELESS_LET_IF_SEQ,
     nursery,
     "unidiomatic `let mut` declaration followed by initialization in `if`"
@@ -64,12 +65,11 @@ fn check_block(&mut self, cx: &LateContext<'tcx>, block: &'tcx hir::Block<'_>) {
                 if let hir::StmtKind::Local(local) = stmt.kind;
                 if let hir::PatKind::Binding(mode, canonical_id, ident, None) = local.pat.kind;
                 if let hir::StmtKind::Expr(if_) = expr.kind;
-                if let hir::ExprKind::If(cond, then, ref else_) = if_.kind;
-                let mut used_visitor = LocalUsedVisitor::new(cx, canonical_id);
-                if !used_visitor.check_expr(cond);
+                if let hir::ExprKind::If(hir::Expr { kind: hir::ExprKind::DropTemps(cond), ..}, then, else_) = if_.kind;
+                if !is_local_used(cx, *cond, canonical_id);
                 if let hir::ExprKind::Block(then, _) = then.kind;
-                if let Some(value) = check_assign(cx, canonical_id, &*then);
-                if !used_visitor.check_expr(value);
+                if let Some(value) = check_assign(cx, canonical_id, then);
+                if !is_local_used(cx, value, canonical_id);
                 then {
                     let span = stmt.span.to(if_.span);
 
@@ -79,7 +79,7 @@ fn check_block(&mut self, cx: &LateContext<'tcx>, block: &'tcx hir::Block<'_>) {
                     );
                     if has_interior_mutability { return; }
 
-                    let (default_multi_stmts, default) = if let Some(else_) = *else_ {
+                    let (default_multi_stmts, default) = if let Some(else_) = else_ {
                         if let hir::ExprKind::Block(else_, _) = else_.kind {
                             if let Some(default) = check_assign(cx, canonical_id, else_) {
                                 (else_.stmts.len() > 1, default)
@@ -148,15 +148,13 @@ fn check_assign<'tcx>(
         if let hir::ExprKind::Assign(var, value, _) = expr.kind;
         if path_to_local_id(var, decl);
         then {
-            let mut v = LocalUsedVisitor::new(cx, decl);
-
-            if block.stmts.iter().take(block.stmts.len()-1).any(|stmt| v.check_stmt(stmt)) {
-                return None;
+            if block.stmts.iter().take(block.stmts.len()-1).any(|stmt| is_local_used(cx, stmt, decl)) {
+                None
+            } else {
+                Some(value)
             }
-
-            return Some(value);
+        } else {
+            None
         }
     }
-
-    None
 }