Auto merge of rust-lang#13285 - alex-semenyuk:ignore_todo_for_diverging_sub_expression, r=xFrednet

Diverging subexpression lint should not fire on todo!()

As per rust-lang#10243  it is not that helpful to point out that a subexpression diverges, so do not fire on todo

changelog: [`diverging_sub_expression`]: do not trigger on todo

Author: bors

clippy_lints/src/mixed_read_write_in_expression.rs

@@ -1,4 +1,5 @@
 use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
+use clippy_utils::macros::root_macro_call_first_node;
 use clippy_utils::{get_parent_expr, path_to_local, path_to_local_id};
 use rustc_hir::intravisit::{walk_expr, Visitor};
 use rustc_hir::{BinOpKind, Block, Expr, ExprKind, HirId, LetStmt, Node, Stmt, StmtKind};
@@ -134,6 +135,11 @@ impl<'a, 'tcx> DivergenceVisitor<'a, 'tcx> {
     }
 
     fn report_diverging_sub_expr(&mut self, e: &Expr<'_>) {
+        if let Some(macro_call) = root_macro_call_first_node(self.cx, e) {
+            if self.cx.tcx.item_name(macro_call.def_id).as_str() == "todo" {
+                return;
+            }
+        }
         span_lint(self.cx, DIVERGING_SUB_EXPRESSION, e.span, "sub-expression diverges");
     }
 }

tests/ui/diverging_sub_expression.rs

@@ -67,3 +67,9 @@ fn foobar() {
         };
     }
 }
+
+#[allow(unused)]
+fn ignore_todo() {
+    let x: u32 = todo!();
+    println!("{x}");
+}