clippy: conditions are no longer wrapped in DropTemps

Author: dianne

src/tools/clippy/clippy_lints/src/booleans.rs

@@ -1,5 +1,6 @@
 use clippy_config::Conf;
 use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_hir_and_then};
+use clippy_utils::higher::has_let_expr;
 use clippy_utils::msrvs::{self, Msrv};
 use clippy_utils::source::SpanRangeExt;
 use clippy_utils::sugg::Sugg;
@@ -646,7 +647,9 @@ impl<'tcx> Visitor<'tcx> for NonminimalBoolVisitor<'_, 'tcx> {
     fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
         if !e.span.from_expansion() {
             match &e.kind {
-                ExprKind::Binary(binop, _, _) if binop.node == BinOpKind::Or || binop.node == BinOpKind::And => {
+                ExprKind::Binary(binop, _, _)
+                    if binop.node == BinOpKind::Or || binop.node == BinOpKind::And && !has_let_expr(e) =>
+                {
                     self.bool_expr(e);
                 },
                 ExprKind::Unary(UnOp::Not, inner) => {

src/tools/clippy/clippy_lints/src/if_not_else.rs

@@ -51,7 +51,6 @@ declare_lint_pass!(IfNotElse => [IF_NOT_ELSE]);
 impl LateLintPass<'_> for IfNotElse {
     fn check_expr(&mut self, cx: &LateContext<'_>, e: &Expr<'_>) {
         if let ExprKind::If(cond, cond_inner, Some(els)) = e.kind
-            && let ExprKind::DropTemps(cond) = cond.kind
             && let ExprKind::Block(..) = els.kind
         {
             let (msg, help) = match cond.kind {

src/tools/clippy/clippy_lints/src/implicit_saturating_add.rs

@@ -41,8 +41,7 @@ declare_lint_pass!(ImplicitSaturatingAdd => [IMPLICIT_SATURATING_ADD]);
 impl<'tcx> LateLintPass<'tcx> for ImplicitSaturatingAdd {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
         if let ExprKind::If(cond, then, None) = expr.kind
-            && let ExprKind::DropTemps(expr1) = cond.kind
-            && let Some((c, op_node, l)) = get_const(cx, expr1)
+            && let Some((c, op_node, l)) = get_const(cx, cond)
             && let BinOpKind::Ne | BinOpKind::Lt = op_node
             && let ExprKind::Block(block, None) = then.kind
             && let Block {
@@ -66,7 +65,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitSaturatingAdd {
             && Some(c) == get_int_max(ty)
             && let ctxt = expr.span.ctxt()
             && ex.span.ctxt() == ctxt
-            && expr1.span.ctxt() == ctxt
+            && cond.span.ctxt() == ctxt
             && clippy_utils::SpanlessEq::new(cx).eq_expr(l, target)
             && AssignOpKind::AddAssign == op1.node
             && let ExprKind::Lit(lit) = value.kind

src/tools/clippy/clippy_lints/src/let_if_seq.rs

@@ -62,15 +62,8 @@ impl<'tcx> LateLintPass<'tcx> for LetIfSeq {
             if let hir::StmtKind::Let(local) = stmt.kind
                 && let hir::PatKind::Binding(mode, canonical_id, ident, None) = local.pat.kind
                 && let hir::StmtKind::Expr(if_) = next.kind
-                && let hir::ExprKind::If(
-                    hir::Expr {
-                        kind: hir::ExprKind::DropTemps(cond),
-                        ..
-                    },
-                    then,
-                    else_,
-                ) = if_.kind
-                && !is_local_used(cx, *cond, canonical_id)
+                && let hir::ExprKind::If(cond, then, else_) = if_.kind
+                && !is_local_used(cx, cond, canonical_id)
                 && let hir::ExprKind::Block(then, _) = then.kind
                 && let Some(value) = check_assign(cx, canonical_id, then)
                 && !is_local_used(cx, value, canonical_id)

src/tools/clippy/clippy_utils/src/higher.rs

@@ -54,7 +54,7 @@ impl<'tcx> ForLoop<'tcx> {
     }
 }
 
-/// An `if` expression without `DropTemps`
+/// An `if` expression without `let`
 pub struct If<'hir> {
     /// `if` condition
     pub cond: &'hir Expr<'hir>,
@@ -66,16 +66,10 @@ pub struct If<'hir> {
 
 impl<'hir> If<'hir> {
     #[inline]
-    /// Parses an `if` expression
+    /// Parses an `if` expression without `let`
     pub const fn hir(expr: &Expr<'hir>) -> Option<Self> {
-        if let ExprKind::If(
-            Expr {
-                kind: ExprKind::DropTemps(cond),
-                ..
-            },
-            then,
-            r#else,
-        ) = expr.kind
+        if let ExprKind::If(cond, then, r#else) = expr.kind
+            && !has_let_expr(cond)
         {
             Some(Self { cond, then, r#else })
         } else {
@@ -198,18 +192,10 @@ impl<'hir> IfOrIfLet<'hir> {
     /// Parses an `if` or `if let` expression
     pub const fn hir(expr: &Expr<'hir>) -> Option<Self> {
         if let ExprKind::If(cond, then, r#else) = expr.kind {
-            if let ExprKind::DropTemps(new_cond) = cond.kind {
-                return Some(Self {
-                    cond: new_cond,
-                    then,
-                    r#else,
-                });
-            }
-            if let ExprKind::Let(..) = cond.kind {
-                return Some(Self { cond, then, r#else });
-            }
+            Some(Self { cond, then, r#else })
+        } else {
+            None
         }
-        None
     }
 }
 
@@ -343,15 +329,7 @@ impl<'hir> While<'hir> {
             Block {
                 expr:
                     Some(Expr {
-                        kind:
-                            ExprKind::If(
-                                Expr {
-                                    kind: ExprKind::DropTemps(condition),
-                                    ..
-                                },
-                                body,
-                                _,
-                            ),
+                        kind: ExprKind::If(condition, body, _),
                         ..
                     }),
                 ..
@@ -360,6 +338,7 @@ impl<'hir> While<'hir> {
             LoopSource::While,
             span,
         ) = expr.kind
+            && !has_let_expr(condition)
         {
             return Some(Self { condition, body, span });
         }
@@ -493,3 +472,13 @@ pub fn get_vec_init_kind<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -
     }
     None
 }
+
+/// Checks that a condition doesn't have a `let` expression, to keep `If` and `While` from accepting
+/// `if let` and `while let`.
+pub const fn has_let_expr<'tcx>(cond: &'tcx Expr<'tcx>) -> bool {
+    match &cond.kind {
+        ExprKind::Let(_) => true,
+        ExprKind::Binary(_, lhs, rhs) => has_let_expr(lhs) || has_let_expr(rhs),
+        _ => false,
+    }
+}

src/tools/clippy/tests/ui/author/if.stdout

@@ -1,8 +1,7 @@
 if let StmtKind::Let(local) = stmt.kind
     && let Some(init) = local.init
     && let ExprKind::If(cond, then, Some(else_expr)) = init.kind
-    && let ExprKind::DropTemps(expr) = cond.kind
-    && let ExprKind::Lit(ref lit) = expr.kind
+    && let ExprKind::Lit(ref lit) = cond.kind
     && let LitKind::Bool(true) = lit.node
     && let ExprKind::Block(block, None) = then.kind
     && block.stmts.len() == 1

src/tools/clippy/tests/ui/author/struct.stdout

@@ -2,8 +2,7 @@ if let ExprKind::Struct(qpath, fields, None) = expr.kind
     && fields.len() == 1
     && fields[0].ident.as_str() == "field"
     && let ExprKind::If(cond, then, Some(else_expr)) = fields[0].expr.kind
-    && let ExprKind::DropTemps(expr1) = cond.kind
-    && let ExprKind::Lit(ref lit) = expr1.kind
+    && let ExprKind::Lit(ref lit) = cond.kind
     && let LitKind::Bool(true) = lit.node
     && let ExprKind::Block(block, None) = then.kind
     && block.stmts.is_empty()