diff options
| -rw-r--r-- | compiler/rustc_mir_build/src/thir/pattern/check_match.rs | 76 |
1 files changed, 36 insertions, 40 deletions
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs index 6a75573dfa0..e3393c184c7 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs @@ -939,9 +939,6 @@ fn report_non_exhaustive_match<'p, 'tcx>( }; // In the case of an empty match, replace the '`_` not covered' diagnostic with something more // informative. - let mut err; - let pattern; - let patterns_len; if is_empty_match && !non_empty_enum { return cx.tcx.dcx().emit_err(NonExhaustivePatternsTypeNotEmpty { cx, @@ -949,33 +946,23 @@ fn report_non_exhaustive_match<'p, 'tcx>( span: sp, ty: scrut_ty, }); - } else { - // FIXME: migration of this diagnostic will require list support - let joined_patterns = joined_uncovered_patterns(cx, &witnesses); - err = create_e0004( - cx.tcx.sess, - sp, - format!("non-exhaustive patterns: {joined_patterns} not covered"), - ); - err.span_label( - sp, - format!( - "pattern{} {} not covered", - rustc_errors::pluralize!(witnesses.len()), - joined_patterns - ), - ); - patterns_len = witnesses.len(); - pattern = if witnesses.len() < 4 { - witnesses - .iter() - .map(|witness| cx.hoist_witness_pat(witness).to_string()) - .collect::<Vec<String>>() - .join(" | ") - } else { - "_".to_string() - }; - }; + } + + // FIXME: migration of this diagnostic will require list support + let joined_patterns = joined_uncovered_patterns(cx, &witnesses); + let mut err = create_e0004( + cx.tcx.sess, + sp, + format!("non-exhaustive patterns: {joined_patterns} not covered"), + ); + err.span_label( + sp, + format!( + "pattern{} {} not covered", + rustc_errors::pluralize!(witnesses.len()), + joined_patterns + ), + ); // Point at the definition of non-covered `enum` variants. if let Some(AdtDefinedHere { adt_def_span, ty, variants }) = @@ -1022,16 +1009,25 @@ fn report_non_exhaustive_match<'p, 'tcx>( } } - let mut suggestion = None; - let sm = cx.tcx.sess.source_map(); - let suggested_arm = if witnesses.len() < 4 - && witnesses.iter().all(|p| p.is_never_pattern()) - && cx.tcx.features().never_patterns - { - pattern + // Whether we suggest the actual missing patterns or `_`. + let suggest_the_witnesses = witnesses.len() < 4; + let suggested_arm = if suggest_the_witnesses { + let pattern = witnesses + .iter() + .map(|witness| cx.hoist_witness_pat(witness).to_string()) + .collect::<Vec<String>>() + .join(" | "); + if witnesses.iter().all(|p| p.is_never_pattern()) && cx.tcx.features().never_patterns { + // Arms with a never pattern don't take a body. + pattern + } else { + format!("{pattern} => todo!()") + } } else { - format!("{pattern} => todo!()") + format!("_ => todo!()") }; + let mut suggestion = None; + let sm = cx.tcx.sess.source_map(); match arms { [] if sp.eq_ctxt(expr_span) => { // Get the span for the empty match body `{}`. @@ -1102,13 +1098,13 @@ fn report_non_exhaustive_match<'p, 'tcx>( let msg = format!( "ensure that all possible cases are being handled by adding a match arm with a wildcard \ pattern{}{}", - if patterns_len > 1 && patterns_len < 4 && suggestion.is_some() { + if witnesses.len() > 1 && suggest_the_witnesses && suggestion.is_some() { ", a match arm with multiple or-patterns" } else { // we are either not suggesting anything, or suggesting `_` "" }, - match patterns_len { + match witnesses.len() { // non-exhaustive enum case 0 if suggestion.is_some() => " as shown", 0 => "", |