diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_typeck/src/check/coercion.rs | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/compiler/rustc_typeck/src/check/coercion.rs b/compiler/rustc_typeck/src/check/coercion.rs index 6c6bbfa22e3..da575cb1367 100644 --- a/compiler/rustc_typeck/src/check/coercion.rs +++ b/compiler/rustc_typeck/src/check/coercion.rs @@ -1594,7 +1594,9 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> { let hir::ExprKind::Loop(_, _, _, loop_span) = expr.kind else { return;}; let mut span: MultiSpan = vec![loop_span].into(); span.push_span_label(loop_span, "this might have zero elements to iterate on"); - for ret_expr in ret_exprs { + const MAXITER: usize = 3; + let iter = ret_exprs.iter().take(MAXITER); + for ret_expr in iter { span.push_span_label( ret_expr.span, "if the loop doesn't execute, this value would never get returned", @@ -1604,6 +1606,12 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> { span, "the function expects a value to always be returned, but loops might run zero times", ); + if MAXITER < ret_exprs.len() { + err.note(&format!( + "if the loop doesn't execute, {} other values would never get returned", + ret_exprs.len() - MAXITER + )); + } err.help( "return a value for the case when the loop has zero elements to iterate on, or \ consider changing the return type to account for that possibility", |