diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_error_messages/locales/en-US/mir_build.ftl | 36 | ||||
| -rw-r--r-- | compiler/rustc_mir_build/src/errors.rs | 164 | ||||
| -rw-r--r-- | compiler/rustc_mir_build/src/lib.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_mir_build/src/thir/pattern/check_match.rs | 207 | ||||
| -rw-r--r-- | compiler/rustc_mir_build/src/thir/pattern/usefulness.rs | 59 |
5 files changed, 278 insertions, 189 deletions
diff --git a/compiler/rustc_error_messages/locales/en-US/mir_build.ftl b/compiler/rustc_error_messages/locales/en-US/mir_build.ftl index 9f10dc4b634..b277942cdcc 100644 --- a/compiler/rustc_error_messages/locales/en-US/mir_build.ftl +++ b/compiler/rustc_error_messages/locales/en-US/mir_build.ftl @@ -326,11 +326,39 @@ mir_build_overlapping_range_endpoints = multiple patterns overlap on their endpo mir_build_overlapping_range = this range overlaps on `{$range}`... mir_build_non_exhaustive_omitted_pattern = some variants are not matched explicitly - .label = {$count -> + .help = ensure that all variants are matched explicitly by adding the suggested match arms + .note = the matched value is of type `{$scrut_ty}` and the `non_exhaustive_omitted_patterns` attribute was found + +mir_build_uncovered = {$count -> [1] pattern `{$witness_1}` [2] patterns `{$witness_1}` and `{$witness_2}` [3] patterns `{$witness_1}`, `{$witness_2}` and `{$witness_3}` - *[other] patterns `{$witness_1}`, `{$witness_2}`, `{$witness_3}` and more + *[other] patterns `{$witness_1}`, `{$witness_2}`, `{$witness_3}` and {$remainder} more } not covered - .help = ensure that all variants are matched explicitly by adding the suggested match arms - .note = the matched value is of type `{$scrut_ty}` and the `non_exhaustive_omitted_patterns` attribute was found + +mir_build_pattern_not_covered = refutable pattern in {$origin} + .pattern_ty = the matched value is of type `{$pattern_ty}` + +mir_build_inform_irrefutable = `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + +mir_build_more_information = for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html + +mir_build_res_defined_here = {$res} defined here + +mir_build_adt_defined_here = `{$ty}` defined here + +mir_build_variant_defined_here = not covered + +mir_build_interpreted_as_const = introduce a variable instead + +mir_build_confused = missing patterns are not covered because `{$variable}` is interpreted as {$article} {$res} pattern, not a new variable + +mir_build_suggest_if_let = you might want to use `if let` to ignore the {$count -> + [one] variant that isn't + *[other] variants that aren't + } matched + +mir_build_suggest_let_else = alternatively, you might want to use `let else` to handle the {$count -> + [one] variant that isn't + *[other] variants that aren't + } matched diff --git a/compiler/rustc_mir_build/src/errors.rs b/compiler/rustc_mir_build/src/errors.rs index e15da5bb9ce..a3c58c31654 100644 --- a/compiler/rustc_mir_build/src/errors.rs +++ b/compiler/rustc_mir_build/src/errors.rs @@ -1,8 +1,11 @@ +use crate::thir::pattern::deconstruct_pat::DeconstructedPat; use crate::thir::pattern::MatchCheckCtxt; use rustc_errors::Handler; use rustc_errors::{ - error_code, Applicability, DiagnosticBuilder, ErrorGuaranteed, IntoDiagnostic, MultiSpan, + error_code, AddToDiagnostic, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, + IntoDiagnostic, MultiSpan, SubdiagnosticMessage, }; +use rustc_hir::def::Res; use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic}; use rustc_middle::thir::Pat; use rustc_middle::ty::{self, Ty}; @@ -677,7 +680,6 @@ pub struct OverlappingRangeEndpoints<'tcx> { pub overlap: Overlap<'tcx>, } -#[derive(Debug)] #[derive(Subdiagnostic)] #[label(mir_build_overlapping_range)] pub struct Overlap<'tcx> { @@ -692,10 +694,158 @@ pub struct Overlap<'tcx> { #[note] pub(crate) struct NonExhaustiveOmittedPattern<'tcx> { pub scrut_ty: Ty<'tcx>, - #[label] - pub uncovered: Span, + #[subdiagnostic] + pub uncovered: Uncovered<'tcx>, +} + +#[derive(Subdiagnostic)] +#[label(mir_build_uncovered)] +pub(crate) struct Uncovered<'tcx> { + #[primary_span] + span: Span, + count: usize, + witness_1: Pat<'tcx>, + witness_2: Pat<'tcx>, + witness_3: Pat<'tcx>, + remainder: usize, +} + +impl<'tcx> Uncovered<'tcx> { + pub fn new<'p>( + span: Span, + cx: &MatchCheckCtxt<'p, 'tcx>, + witnesses: Vec<DeconstructedPat<'p, 'tcx>>, + ) -> Self { + let witness_1 = witnesses.get(0).unwrap().to_pat(cx); + Self { + span, + count: witnesses.len(), + // Substitute dummy values if witnesses is smaller than 3. These will never be read. + witness_2: witnesses.get(1).map(|w| w.to_pat(cx)).unwrap_or_else(|| witness_1.clone()), + witness_3: witnesses.get(2).map(|w| w.to_pat(cx)).unwrap_or_else(|| witness_1.clone()), + witness_1, + remainder: witnesses.len().saturating_sub(3), + } + } +} + +#[derive(Diagnostic)] +#[diag(mir_build_pattern_not_covered, code = "E0005")] +pub(crate) struct PatternNotCovered<'s, 'tcx> { + #[primary_span] + pub span: Span, + pub origin: &'s str, + #[subdiagnostic] + pub uncovered: Uncovered<'tcx>, + #[subdiagnostic] + pub inform: Option<Inform>, + #[subdiagnostic] + pub interpreted_as_const: Option<InterpretedAsConst>, + #[subdiagnostic] + pub adt_defined_here: Option<AdtDefinedHere<'tcx>>, + #[note(pattern_ty)] + pub _p: (), + pub pattern_ty: Ty<'tcx>, + #[subdiagnostic] + pub if_let_suggestion: Option<SuggestIfLet>, + #[subdiagnostic] + pub let_else_suggestion: Option<SuggestLetElse>, + #[subdiagnostic] + pub res_defined_here: Option<ResDefinedHere>, +} + +#[derive(Subdiagnostic)] +#[note(mir_build_inform_irrefutable)] +#[note(mir_build_more_information)] +pub struct Inform; + +pub struct AdtDefinedHere<'tcx> { + pub adt_def_span: Span, + pub ty: Ty<'tcx>, + pub variants: Vec<Variant>, +} + +pub struct Variant { + pub span: Span, +} + +impl<'tcx> AddToDiagnostic for AdtDefinedHere<'tcx> { + fn add_to_diagnostic_with<F>(self, diag: &mut Diagnostic, _: F) + where + F: Fn(&mut Diagnostic, SubdiagnosticMessage) -> SubdiagnosticMessage, + { + diag.set_arg("ty", self.ty); + let mut spans = MultiSpan::from(self.adt_def_span); + + for Variant { span } in self.variants { + spans.push_span_label(span, rustc_errors::fluent::mir_build_variant_defined_here); + } + + diag.span_note(spans, rustc_errors::fluent::mir_build_adt_defined_here); + } +} + +#[derive(Subdiagnostic)] +#[label(mir_build_res_defined_here)] +pub struct ResDefinedHere { + #[primary_span] + pub def_span: Span, + pub res: Res, +} + +#[derive(Subdiagnostic)] +#[suggestion( + mir_build_interpreted_as_const, + code = "{variable}_var", + applicability = "maybe-incorrect" +)] +#[label(mir_build_confused)] +pub struct InterpretedAsConst { + #[primary_span] + pub span: Span, + pub article: &'static str, + pub variable: String, + pub res: Res, +} + +#[derive(Subdiagnostic)] +pub enum SuggestIfLet { + #[multipart_suggestion(mir_build_suggest_if_let, applicability = "has-placeholders")] + None { + #[suggestion_part(code = "if ")] + start_span: Span, + #[suggestion_part(code = " {{ todo!() }}")] + semi_span: Span, + count: usize, + }, + #[multipart_suggestion(mir_build_suggest_if_let, applicability = "has-placeholders")] + One { + #[suggestion_part(code = "let {binding} = if ")] + start_span: Span, + #[suggestion_part(code = " {{ {binding} }} else {{ todo!() }}")] + end_span: Span, + binding: Ident, + count: usize, + }, + #[multipart_suggestion(mir_build_suggest_if_let, applicability = "has-placeholders")] + More { + #[suggestion_part(code = "let ({bindings}) = if ")] + start_span: Span, + #[suggestion_part(code = " {{ ({bindings}) }} else {{ todo!() }}")] + end_span: Span, + bindings: String, + count: usize, + }, +} + +#[derive(Subdiagnostic)] +#[suggestion( + mir_build_suggest_let_else, + code = " else {{ todo!() }}", + applicability = "has-placeholders" +)] +pub struct SuggestLetElse { + #[primary_span] + pub end_span: Span, pub count: usize, - pub witness_1: Pat<'tcx>, - pub witness_2: Pat<'tcx>, - pub witness_3: Pat<'tcx>, } diff --git a/compiler/rustc_mir_build/src/lib.rs b/compiler/rustc_mir_build/src/lib.rs index 2b05e92fdcf..fb7ae6f1d24 100644 --- a/compiler/rustc_mir_build/src/lib.rs +++ b/compiler/rustc_mir_build/src/lib.rs @@ -10,6 +10,7 @@ #![feature(let_chains)] #![feature(min_specialization)] #![feature(once_cell)] +#![feature(try_blocks)] #![recursion_limit = "256"] #[macro_use] 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 e7ee0d9e908..422c2ff3ede 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs @@ -1,3 +1,8 @@ +//#![allow(unused_imports, unused_variables)] + +//#![warn(rustc::untranslatable_diagnostic)] +//#![warn(rustc::diagnostic_outside_of_impl)] + use super::deconstruct_pat::{Constructor, DeconstructedPat}; use super::usefulness::{ compute_match_usefulness, MatchArm, MatchCheckCtxt, Reachability, UsefulnessReport, @@ -9,8 +14,7 @@ use crate::errors::*; use rustc_arena::TypedArena; use rustc_ast::Mutability; use rustc_errors::{ - pluralize, struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, - MultiSpan, + struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, MultiSpan, }; use rustc_hir as hir; use rustc_hir::def::*; @@ -378,8 +382,8 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { let pattern = self.lower_pattern(&mut cx, pat, &mut false); let pattern_ty = pattern.ty(); - let arms = vec![MatchArm { pat: pattern, hir_id: pat.hir_id, has_guard: false }]; - let report = compute_match_usefulness(&cx, &arms, pat.hir_id, pattern_ty); + let arm = MatchArm { pat: pattern, hir_id: pat.hir_id, has_guard: false }; + let report = compute_match_usefulness(&cx, &[arm], pat.hir_id, pattern_ty); // Note: we ignore whether the pattern is unreachable (i.e. whether the type is empty). We // only care about exhaustiveness here. @@ -390,145 +394,82 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { return; } - let joined_patterns = joined_uncovered_patterns(&cx, &witnesses); - - let mut bindings = vec![]; - - let mut err = struct_span_err!( - self.tcx.sess, - pat.span, - E0005, - "refutable pattern in {}: {} not covered", - origin, - joined_patterns - ); - let suggest_if_let = match &pat.kind { - hir::PatKind::Path(hir::QPath::Resolved(None, path)) - if path.segments.len() == 1 && path.segments[0].args.is_none() => + let (inform, interpreted_as_const, res_defined_here, if_let_suggestion, let_else_suggestion) = + if let hir::PatKind::Path(hir::QPath::Resolved( + None, + hir::Path { + segments: &[hir::PathSegment { args: None, res, ident, .. }], + .. + }, + )) = &pat.kind { - const_not_var(&mut err, cx.tcx, pat, path); - false - } - _ => { - pat.walk(&mut |pat: &hir::Pat<'_>| { - match pat.kind { - hir::PatKind::Binding(_, _, ident, _) => { - bindings.push(ident); + ( + None, + Some(InterpretedAsConst { + span: pat.span, + article: res.article(), + variable: ident.to_string().to_lowercase(), + res, + }), + try { + ResDefinedHere { + def_span: cx.tcx.hir().res_span(res)?, + res, } - _ => {} + }, + None, None, + ) + } else if let Some(span) = sp && self.tcx.sess.source_map().is_span_accessible(span) { + let mut bindings = vec![]; + pat.walk_always(&mut |pat: &hir::Pat<'_>| { + if let hir::PatKind::Binding(_, _, ident, _) = pat.kind { + bindings.push(ident); } - true }); - - err.span_label(pat.span, pattern_not_covered_label(&witnesses, &joined_patterns)); - true - } - }; - - if let (Some(span), true) = (sp, suggest_if_let) { - err.note( - "`let` bindings require an \"irrefutable pattern\", like a `struct` or \ - an `enum` with only one variant", - ); - if self.tcx.sess.source_map().is_span_accessible(span) { let semi_span = span.shrink_to_hi().with_lo(span.hi() - BytePos(1)); let start_span = span.shrink_to_lo(); let end_span = semi_span.shrink_to_lo(); - err.multipart_suggestion( - &format!( - "you might want to use `if let` to ignore the variant{} that {} matched", - pluralize!(witnesses.len()), - match witnesses.len() { - 1 => "isn't", - _ => "aren't", - }, - ), - vec![ - match &bindings[..] { - [] => (start_span, "if ".to_string()), - [binding] => (start_span, format!("let {} = if ", binding)), - bindings => ( - start_span, - format!( - "let ({}) = if ", - bindings - .iter() - .map(|ident| ident.to_string()) - .collect::<Vec<_>>() - .join(", ") - ), - ), - }, - match &bindings[..] { - [] => (semi_span, " { todo!() }".to_string()), - [binding] => { - (end_span, format!(" {{ {} }} else {{ todo!() }}", binding)) - } - bindings => ( - end_span, - format!( - " {{ ({}) }} else {{ todo!() }}", - bindings - .iter() - .map(|ident| ident.to_string()) - .collect::<Vec<_>>() - .join(", ") - ), - ), - }, - ], - Applicability::HasPlaceholders, - ); - if !bindings.is_empty() { - err.span_suggestion_verbose( - semi_span.shrink_to_lo(), - &format!( - "alternatively, you might want to use \ - let else to handle the variant{} that {} matched", - pluralize!(witnesses.len()), - match witnesses.len() { - 1 => "isn't", - _ => "aren't", - }, - ), - " else { todo!() }", - Applicability::HasPlaceholders, - ); - } - } - err.note( - "for more information, visit \ - https://doc.rust-lang.org/book/ch18-02-refutability.html", - ); - } - - adt_defined_here(&cx, &mut err, pattern_ty, &witnesses); - err.note(&format!("the matched value is of type `{}`", pattern_ty)); - err.emit(); - } -} + let count = witnesses.len(); + let if_let = match *bindings { + [] => SuggestIfLet::None{start_span, semi_span, count}, + [binding] => SuggestIfLet::One{start_span, end_span, count, binding }, + _ => SuggestIfLet::More{start_span, end_span, count, bindings: bindings + .iter() + .map(|ident| ident.to_string()) + .collect::<Vec<_>>() + .join(", ")}, + }; + let let_else = if bindings.is_empty() {None} else{Some( SuggestLetElse{end_span, count })}; + (sp.map(|_|Inform), None, None, Some(if_let), let_else) + } else{ + (sp.map(|_|Inform), None, None, None, None) + }; -/// A path pattern was interpreted as a constant, not a new variable. -/// This caused an irrefutable match failure in e.g. `let`. -fn const_not_var(err: &mut Diagnostic, tcx: TyCtxt<'_>, pat: &Pat<'_>, path: &hir::Path<'_>) { - let descr = path.res.descr(); - err.span_label( - pat.span, - format!("interpreted as {} {} pattern, not a new variable", path.res.article(), descr,), - ); + let adt_defined_here = try { + let ty = pattern_ty.peel_refs(); + let ty::Adt(def, _) = ty.kind() else { None? }; + let adt_def_span = cx.tcx.hir().get_if_local(def.did())?.ident()?.span; + let mut variants = vec![]; - err.span_suggestion( - pat.span, - "introduce a variable instead", - format!("{}_var", path.segments[0].ident).to_lowercase(), - // Cannot use `MachineApplicable` as it's not really *always* correct - // because there may be such an identifier in scope or the user maybe - // really wanted to match against the constant. This is quite unlikely however. - Applicability::MaybeIncorrect, - ); + for span in maybe_point_at_variant(&cx, *def, witnesses.iter().take(5)) { + variants.push(Variant { span }); + } + AdtDefinedHere { adt_def_span, ty, variants } + }; - if let Some(span) = tcx.hir().res_span(path.res) { - err.span_label(span, format!("{} defined here", descr)); + self.tcx.sess.emit_err(PatternNotCovered { + span: pat.span, + origin, + uncovered: Uncovered::new(pat.span, &cx, witnesses), + inform, + interpreted_as_const, + _p: (), + pattern_ty, + if_let_suggestion, + let_else_suggestion, + res_defined_here, + adt_defined_here, + }); } } diff --git a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs index 37aed5bd14d..be66d0d4765 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs @@ -292,7 +292,7 @@ use self::ArmType::*; use self::Usefulness::*; use super::deconstruct_pat::{Constructor, DeconstructedPat, Fields, SplitWildcard}; -use crate::errors::NonExhaustiveOmittedPattern; +use crate::errors::{NonExhaustiveOmittedPattern, Uncovered}; use rustc_data_structures::captures::Captures; @@ -742,49 +742,6 @@ impl<'p, 'tcx> Witness<'p, 'tcx> { } } -/// Report that a match of a `non_exhaustive` enum marked with `non_exhaustive_omitted_patterns` -/// is not exhaustive enough. -/// -/// NB: The partner lint for structs lives in `compiler/rustc_hir_analysis/src/check/pat.rs`. -fn lint_non_exhaustive_omitted_patterns<'p, 'tcx>( - cx: &MatchCheckCtxt<'p, 'tcx>, - scrut_ty: Ty<'tcx>, - sp: Span, - hir_id: HirId, - witnesses: Vec<DeconstructedPat<'p, 'tcx>>, -) { - let witness_1 = witnesses.get(0).unwrap().to_pat(cx); - - cx.tcx.emit_spanned_lint( - NON_EXHAUSTIVE_OMITTED_PATTERNS, - hir_id, - sp, - NonExhaustiveOmittedPattern { - scrut_ty, - uncovered: sp, - count: witnesses.len(), - // Substitute dummy values if witnesses is smaller than 3. - witness_2: witnesses.get(1).map(|w| w.to_pat(cx)).unwrap_or_else(|| witness_1.clone()), - witness_3: witnesses.get(2).map(|w| w.to_pat(cx)).unwrap_or_else(|| witness_1.clone()), - witness_1, - }, - ); - /* - cx.tcx.struct_span_lint_hir(NON_EXHAUSTIVE_OMITTED_PATTERNS, hir_id, sp, "some variants are not matched explicitly", |lint| { - let joined_patterns = joined_uncovered_patterns(cx, &witnesses); - lint.span_label(sp, pattern_not_covered_label(&witnesses, &joined_patterns)); - lint.help( - "ensure that all variants are matched explicitly by adding the suggested match arms", - ); - lint.note(&format!( - "the matched value is of type `{}` and the `non_exhaustive_omitted_patterns` attribute was found", - scrut_ty, - )); - lint - }); - */ -} - /// Algorithm from <http://moscova.inria.fr/~maranget/papers/warn/index.html>. /// The algorithm from the paper has been modified to correctly handle empty /// types. The changes are: @@ -930,7 +887,19 @@ fn is_useful<'p, 'tcx>( .collect::<Vec<_>>() }; - lint_non_exhaustive_omitted_patterns(pcx.cx, pcx.ty, pcx.span, hir_id, patterns); + // Report that a match of a `non_exhaustive` enum marked with `non_exhaustive_omitted_patterns` + // is not exhaustive enough. + // + // NB: The partner lint for structs lives in `compiler/rustc_hir_analysis/src/check/pat.rs`. + cx.tcx.emit_spanned_lint( + NON_EXHAUSTIVE_OMITTED_PATTERNS, + hir_id, + pcx.span, + NonExhaustiveOmittedPattern { + scrut_ty: pcx.ty, + uncovered: Uncovered::new(pcx.span, pcx.cx, patterns), + }, + ); } ret.extend(usefulness); |