fix: needless_continue wrongly unmangled macros

Author: profetia

clippy_lints/src/needless_continue.rs

@@ -1,5 +1,5 @@
 use clippy_utils::diagnostics::span_lint_and_help;
-use clippy_utils::source::{indent_of, snippet, snippet_block, snippet_with_context};
+use clippy_utils::source::{indent_of, snippet_block, snippet_with_context};
 use clippy_utils::{higher, is_from_proc_macro};
 use rustc_ast::Label;
 use rustc_errors::Applicability;
@@ -193,15 +193,15 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessContinue {
 /// - The expression node is a block with the first statement being a `continue`.
 fn needless_continue_in_else(else_expr: &Expr<'_>, label: Option<&Label>) -> bool {
     match else_expr.kind {
-        ExprKind::Block(ref else_block, _) => is_first_block_stmt_continue(else_block, label),
+        ExprKind::Block(else_block, _) => is_first_block_stmt_continue(else_block, label),
         ExprKind::Continue(l) => compare_labels(label, l.label.as_ref()),
         _ => false,
     }
 }
 
 fn is_first_block_stmt_continue(block: &Block<'_>, label: Option<&Label>) -> bool {
     block.stmts.first().is_some_and(|stmt| match stmt.kind {
-        StmtKind::Semi(ref e) | StmtKind::Expr(ref e) => {
+        StmtKind::Semi(e) | StmtKind::Expr(e) => {
             if let ExprKind::Continue(ref l) = e.kind {
                 compare_labels(label, l.label.as_ref())
             } else {
@@ -366,7 +366,14 @@ fn suggestion_snippet_for_continue_inside_if(cx: &LateContext<'_>, data: &LintDa
 }
 
 fn suggestion_snippet_for_continue_inside_else(cx: &LateContext<'_>, data: &LintData<'_>) -> String {
-    let cond_code = snippet(cx, data.if_cond.span, "..");
+    let mut applicability = Applicability::MachineApplicable;
+    let (cond_code, _) = snippet_with_context(
+        cx,
+        data.if_cond.span,
+        data.if_expr.span.ctxt(),
+        "..",
+        &mut applicability,
+    );
 
     // Region B
     let block_code = erode_from_back(&snippet_block(cx, data.if_block.span, "..", Some(data.if_expr.span)));
@@ -402,7 +409,7 @@ fn suggestion_snippet_for_continue_inside_else(cx: &LateContext<'_>, data: &Lint
         }
         lines.join("\n")
     } else {
-        "".to_string()
+        String::new()
     };
 
     let indent_if = indent_of(cx, data.if_expr.span).unwrap_or(0);
@@ -417,7 +424,7 @@ fn check_last_stmt_in_expr<F>(cx: &LateContext<'_>, inner_expr: &Expr<'_>, func:
 where
     F: Fn(Option<&Label>, Span),
 {
-    match &inner_expr.kind {
+    match inner_expr.kind {
         ExprKind::Continue(continue_label) => {
             func(continue_label.label.as_ref(), inner_expr.span);
         },
@@ -432,7 +439,7 @@ where
             if !match_ty.is_unit() && !match_ty.is_never() {
                 return;
             }
-            for arm in arms.iter() {
+            for arm in arms {
                 check_last_stmt_in_expr(cx, arm.body, func);
             }
         },

tests/ui/needless_continue.rs

@@ -259,3 +259,13 @@ fn issue14550(mut producer: impl Iterator<Item = Result<i32, u32>>) -> Result<u3
         };
     }
 }
+
+fn issue15548() {
+    loop {
+        if todo!() {
+        } else {
+            //~^ needless_continue
+            continue;
+        }
+    }
+}

tests/ui/needless_continue.stderr

@@ -220,5 +220,21 @@ LL | |             }
                            do_something();
                        }
 
-error: aborting due to 15 previous errors
+error: this `else` block is redundant
+  --> tests/ui/needless_continue.rs:266:16
+   |
+LL |           } else {
+   |  ________________^
+LL | |
+LL | |             continue;
+LL | |         }
+   | |_________^
+   |
+   = help: consider dropping the `else` clause and merging the code that follows (in the loop) with the `if` block
+                   if todo!() {
+           // merged code follows:
+           
+                   }
+
+error: aborting due to 16 previous errors