diff options
Diffstat (limited to 'compiler/rustc_mir_build/src/thir/pattern/check_match.rs')
| -rw-r--r-- | compiler/rustc_mir_build/src/thir/pattern/check_match.rs | 727 |
1 files changed, 339 insertions, 388 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 2640ca56b..8f58db504 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs @@ -2,45 +2,48 @@ use super::deconstruct_pat::{Constructor, DeconstructedPat}; use super::usefulness::{ compute_match_usefulness, MatchArm, MatchCheckCtxt, Reachability, UsefulnessReport, }; -use super::{PatCtxt, PatternError}; use crate::errors::*; -use hir::{ExprKind, PatKind}; use rustc_arena::TypedArena; -use rustc_ast::{LitKind, Mutability}; +use rustc_ast::Mutability; +use rustc_data_structures::stack::ensure_sufficient_stack; use rustc_errors::{ struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, MultiSpan, }; use rustc_hir as hir; use rustc_hir::def::*; -use rustc_hir::def_id::DefId; -use rustc_hir::intravisit::{self, Visitor}; -use rustc_hir::{HirId, Pat}; +use rustc_hir::def_id::LocalDefId; +use rustc_hir::HirId; +use rustc_middle::thir::visit::{self, Visitor}; +use rustc_middle::thir::*; use rustc_middle::ty::print::with_no_trimmed_paths; use rustc_middle::ty::{self, AdtDef, Ty, TyCtxt}; - use rustc_session::lint::builtin::{ BINDINGS_WITH_VARIANT_NAME, IRREFUTABLE_LET_PATTERNS, UNREACHABLE_PATTERNS, }; use rustc_session::Session; -use rustc_span::source_map::Spanned; -use rustc_span::{BytePos, Span}; - -pub(crate) fn check_match(tcx: TyCtxt<'_>, def_id: DefId) { - let body_id = match def_id.as_local() { - None => return, - Some(def_id) => tcx.hir().body_owned_by(def_id), - }; +use rustc_span::hygiene::DesugaringKind; +use rustc_span::Span; +pub(crate) fn check_match(tcx: TyCtxt<'_>, def_id: LocalDefId) { + let Ok((thir, expr)) = tcx.thir_body(ty::WithOptConstParam::unknown(def_id)) else { return }; + let thir = thir.borrow(); let pattern_arena = TypedArena::default(); let mut visitor = MatchVisitor { tcx, - typeck_results: tcx.typeck_body(body_id), + thir: &*thir, param_env: tcx.param_env(def_id), + lint_level: tcx.hir().local_def_id_to_hir_id(def_id), + let_source: LetSource::None, pattern_arena: &pattern_arena, }; - visitor.visit_body(tcx.hir().body(body_id)); + visitor.visit_expr(&thir[expr]); + for param in thir.params.iter() { + if let Some(box ref pattern) = param.pat { + visitor.check_irrefutable(pattern, "function argument", None); + } + } } fn create_e0004( @@ -58,77 +61,132 @@ enum RefutableFlag { } use RefutableFlag::*; +#[derive(Clone, Copy, Debug, PartialEq, Eq)] +enum LetSource { + None, + IfLet, + IfLetGuard, + LetElse, + WhileLet, +} + struct MatchVisitor<'a, 'p, 'tcx> { tcx: TyCtxt<'tcx>, - typeck_results: &'a ty::TypeckResults<'tcx>, param_env: ty::ParamEnv<'tcx>, + thir: &'a Thir<'tcx>, + lint_level: HirId, + let_source: LetSource, pattern_arena: &'p TypedArena<DeconstructedPat<'p, 'tcx>>, } -impl<'tcx> Visitor<'tcx> for MatchVisitor<'_, '_, 'tcx> { - fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) { - intravisit::walk_expr(self, ex); - match &ex.kind { - hir::ExprKind::Match(scrut, arms, source) => { - self.check_match(scrut, arms, *source, ex.span) +impl<'a, 'tcx> Visitor<'a, 'tcx> for MatchVisitor<'a, '_, 'tcx> { + fn thir(&self) -> &'a Thir<'tcx> { + self.thir + } + + #[instrument(level = "trace", skip(self))] + fn visit_arm(&mut self, arm: &Arm<'tcx>) { + match arm.guard { + Some(Guard::If(expr)) => { + self.with_let_source(LetSource::IfLetGuard, |this| { + this.visit_expr(&this.thir[expr]) + }); } - hir::ExprKind::Let(hir::Let { pat, init, span, .. }) => { - self.check_let(pat, init, *span) + Some(Guard::IfLet(ref pat, expr)) => { + self.with_let_source(LetSource::IfLetGuard, |this| { + this.check_let(pat, expr, LetSource::IfLetGuard, pat.span); + this.visit_pat(pat); + this.visit_expr(&this.thir[expr]); + }); } - _ => {} + None => {} } + self.visit_pat(&arm.pattern); + self.visit_expr(&self.thir[arm.body]); } - fn visit_local(&mut self, loc: &'tcx hir::Local<'tcx>) { - intravisit::walk_local(self, loc); - let els = loc.els; - if let Some(init) = loc.init && els.is_some() { - // Build a span without the else { ... } as we don't want to underline - // the entire else block in the IDE setting. - let span = loc.span.with_hi(init.span.hi()); - self.check_let(&loc.pat, init, span); - } - - let (msg, sp) = match loc.source { - hir::LocalSource::Normal => ("local binding", Some(loc.span)), - hir::LocalSource::AsyncFn => ("async fn binding", None), - hir::LocalSource::AwaitDesugar => ("`await` future binding", None), - hir::LocalSource::AssignDesugar(_) => ("destructuring assignment binding", None), + #[instrument(level = "trace", skip(self))] + fn visit_expr(&mut self, ex: &Expr<'tcx>) { + match ex.kind { + ExprKind::Scope { value, lint_level, .. } => { + let old_lint_level = self.lint_level; + if let LintLevel::Explicit(hir_id) = lint_level { + self.lint_level = hir_id; + } + self.visit_expr(&self.thir[value]); + self.lint_level = old_lint_level; + return; + } + ExprKind::If { cond, then, else_opt, if_then_scope: _ } => { + // Give a specific `let_source` for the condition. + let let_source = match ex.span.desugaring_kind() { + Some(DesugaringKind::WhileLoop) => LetSource::WhileLet, + _ => LetSource::IfLet, + }; + self.with_let_source(let_source, |this| this.visit_expr(&self.thir[cond])); + self.with_let_source(LetSource::None, |this| { + this.visit_expr(&this.thir[then]); + if let Some(else_) = else_opt { + this.visit_expr(&this.thir[else_]); + } + }); + return; + } + ExprKind::Match { scrutinee, box ref arms } => { + let source = match ex.span.desugaring_kind() { + Some(DesugaringKind::ForLoop) => hir::MatchSource::ForLoopDesugar, + Some(DesugaringKind::QuestionMark) => hir::MatchSource::TryDesugar, + Some(DesugaringKind::Await) => hir::MatchSource::AwaitDesugar, + _ => hir::MatchSource::Normal, + }; + self.check_match(scrutinee, arms, source, ex.span); + } + ExprKind::Let { box ref pat, expr } => { + self.check_let(pat, expr, self.let_source, ex.span); + } + ExprKind::LogicalOp { op: LogicalOp::And, lhs, rhs } => { + self.check_let_chain(self.let_source, ex.span, lhs, rhs); + } + _ => {} }; - if els.is_none() { - self.check_irrefutable(&loc.pat, msg, sp); - } + self.with_let_source(LetSource::None, |this| visit::walk_expr(this, ex)); } - fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) { - intravisit::walk_param(self, param); - self.check_irrefutable(¶m.pat, "function argument", None); - } -} - -impl PatCtxt<'_, '_> { - fn report_inlining_errors(&self) { - for error in &self.errors { - match *error { - PatternError::StaticInPattern(span) => { - self.tcx.sess.emit_err(StaticInPattern { span }); + fn visit_stmt(&mut self, stmt: &Stmt<'tcx>) { + let old_lint_level = self.lint_level; + match stmt.kind { + StmtKind::Let { + box ref pattern, initializer, else_block, lint_level, span, .. + } => { + if let LintLevel::Explicit(lint_level) = lint_level { + self.lint_level = lint_level; } - PatternError::AssocConstInPattern(span) => { - self.tcx.sess.emit_err(AssocConstInPattern { span }); - } - PatternError::ConstParamInPattern(span) => { - self.tcx.sess.emit_err(ConstParamInPattern { span }); + + if let Some(initializer) = initializer && else_block.is_some() { + self.check_let(pattern, initializer, LetSource::LetElse, span); } - PatternError::NonConstPath(span) => { - self.tcx.sess.emit_err(NonConstPath { span }); + + if else_block.is_none() { + self.check_irrefutable(pattern, "local binding", Some(span)); } } + _ => {} } + visit::walk_stmt(self, stmt); + self.lint_level = old_lint_level; } } impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { - fn check_patterns(&self, pat: &Pat<'_>, rf: RefutableFlag) { + #[instrument(level = "trace", skip(self, f))] + fn with_let_source(&mut self, let_source: LetSource, f: impl FnOnce(&mut Self)) { + let old_let_source = self.let_source; + self.let_source = let_source; + ensure_sufficient_stack(|| f(self)); + self.let_source = old_let_source; + } + + fn check_patterns(&self, pat: &Pat<'tcx>, rf: RefutableFlag) { pat.walk_always(|pat| check_borrow_conflicts_in_at_patterns(self, pat)); check_for_bindings_named_same_as_variants(self, pat, rf); } @@ -136,73 +194,63 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { fn lower_pattern( &self, cx: &mut MatchCheckCtxt<'p, 'tcx>, - pat: &'tcx hir::Pat<'tcx>, - have_errors: &mut bool, + pattern: &Pat<'tcx>, ) -> &'p DeconstructedPat<'p, 'tcx> { - let mut patcx = PatCtxt::new(self.tcx, self.param_env, self.typeck_results); - patcx.include_lint_checks(); - let pattern = patcx.lower_pattern(pat); - let pattern: &_ = cx.pattern_arena.alloc(DeconstructedPat::from_pat(cx, &pattern)); - if !patcx.errors.is_empty() { - *have_errors = true; - patcx.report_inlining_errors(); - } - pattern + cx.pattern_arena.alloc(DeconstructedPat::from_pat(cx, &pattern)) } - fn new_cx(&self, hir_id: HirId) -> MatchCheckCtxt<'p, 'tcx> { + fn new_cx(&self, hir_id: HirId, refutable: bool) -> MatchCheckCtxt<'p, 'tcx> { MatchCheckCtxt { tcx: self.tcx, param_env: self.param_env, module: self.tcx.parent_module(hir_id).to_def_id(), pattern_arena: &self.pattern_arena, + refutable, } } - fn check_let(&mut self, pat: &'tcx hir::Pat<'tcx>, scrutinee: &hir::Expr<'_>, span: Span) { + #[instrument(level = "trace", skip(self))] + fn check_let(&mut self, pat: &Pat<'tcx>, scrutinee: ExprId, source: LetSource, span: Span) { + if let LetSource::None = source { + return; + } self.check_patterns(pat, Refutable); - let mut cx = self.new_cx(scrutinee.hir_id); - let tpat = self.lower_pattern(&mut cx, pat, &mut false); - self.check_let_reachability(&mut cx, pat.hir_id, tpat, span); + let mut cx = self.new_cx(self.lint_level, true); + let tpat = self.lower_pattern(&mut cx, pat); + self.check_let_reachability(&mut cx, self.lint_level, source, tpat, span); } fn check_match( &mut self, - scrut: &hir::Expr<'_>, - hir_arms: &'tcx [hir::Arm<'tcx>], + scrut: ExprId, + arms: &[ArmId], source: hir::MatchSource, expr_span: Span, ) { - let mut cx = self.new_cx(scrut.hir_id); + let mut cx = self.new_cx(self.lint_level, true); - for arm in hir_arms { + for &arm in arms { // Check the arm for some things unrelated to exhaustiveness. - self.check_patterns(&arm.pat, Refutable); - if let Some(hir::Guard::IfLet(ref let_expr)) = arm.guard { - self.check_patterns(let_expr.pat, Refutable); - let tpat = self.lower_pattern(&mut cx, let_expr.pat, &mut false); - self.check_let_reachability(&mut cx, let_expr.pat.hir_id, tpat, tpat.span()); - } + let arm = &self.thir.arms[arm]; + self.check_patterns(&arm.pattern, Refutable); } - let mut have_errors = false; - - let arms: Vec<_> = hir_arms + let tarms: Vec<_> = arms .iter() - .map(|hir::Arm { pat, guard, .. }| MatchArm { - pat: self.lower_pattern(&mut cx, pat, &mut have_errors), - hir_id: pat.hir_id, - has_guard: guard.is_some(), + .map(|&arm| { + let arm = &self.thir.arms[arm]; + let hir_id = match arm.lint_level { + LintLevel::Explicit(hir_id) => hir_id, + LintLevel::Inherited => self.lint_level, + }; + let pat = self.lower_pattern(&mut cx, &arm.pattern); + MatchArm { pat, hir_id, has_guard: arm.guard.is_some() } }) .collect(); - // Bail out early if lowering failed. - if have_errors { - return; - } - - let scrut_ty = self.typeck_results.expr_ty_adjusted(scrut); - let report = compute_match_usefulness(&cx, &arms, scrut.hir_id, scrut_ty); + let scrut = &self.thir[scrut]; + let scrut_ty = scrut.ty; + let report = compute_match_usefulness(&cx, &tarms, self.lint_level, scrut_ty); match source { // Don't report arm reachability of desugared `match $iter.into_iter() { iter => .. }` @@ -219,12 +267,18 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { // Check if the match is exhaustive. let witnesses = report.non_exhaustiveness_witnesses; if !witnesses.is_empty() { - if source == hir::MatchSource::ForLoopDesugar && hir_arms.len() == 2 { + if source == hir::MatchSource::ForLoopDesugar && arms.len() == 2 { // the for loop pattern is not irrefutable - let pat = hir_arms[1].pat.for_loop_some().unwrap(); - self.check_irrefutable(pat, "`for` loop binding", None); + let pat = &self.thir[arms[1]].pattern; + // `pat` should be `Some(<pat_field>)` from a desugared for loop. + debug_assert_eq!(pat.span.desugaring_kind(), Some(DesugaringKind::ForLoop)); + let PatKind::Variant { ref subpatterns, .. } = pat.kind else { bug!() }; + let [pat_field] = &subpatterns[..] else { bug!() }; + self.check_irrefutable(&pat_field.pattern, "`for` loop binding", None); } else { - non_exhaustive_match(&cx, scrut_ty, scrut.span, witnesses, hir_arms, expr_span); + non_exhaustive_match( + &cx, self.thir, scrut_ty, scrut.span, witnesses, arms, expr_span, + ); } } } @@ -233,114 +287,93 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { &mut self, cx: &mut MatchCheckCtxt<'p, 'tcx>, pat_id: HirId, + source: LetSource, pat: &'p DeconstructedPat<'p, 'tcx>, span: Span, ) { - if self.check_let_chain(cx, pat_id) { - return; - } - if is_let_irrefutable(cx, pat_id, pat) { - irrefutable_let_pattern(cx.tcx, pat_id, span); + irrefutable_let_patterns(cx.tcx, pat_id, source, 1, span); } } - fn check_let_chain(&mut self, cx: &mut MatchCheckCtxt<'p, 'tcx>, pat_id: HirId) -> bool { - let hir = self.tcx.hir(); - let parent = hir.parent_id(pat_id); + #[instrument(level = "trace", skip(self))] + fn check_let_chain( + &mut self, + let_source: LetSource, + top_expr_span: Span, + mut lhs: ExprId, + rhs: ExprId, + ) { + if let LetSource::None = let_source { + return; + } - // First, figure out if the given pattern is part of a let chain, - // and if so, obtain the top node of the chain. - let mut top = parent; - let mut part_of_chain = false; - loop { - let new_top = hir.parent_id(top); - if let hir::Node::Expr( - hir::Expr { - kind: hir::ExprKind::Binary(Spanned { node: hir::BinOpKind::And, .. }, lhs, rhs), - .. - }, - .., - ) = hir.get(new_top) - { - // If this isn't the first iteration, we need to check - // if there is a let expr before us in the chain, so - // that we avoid doubly checking the let chain. - - // The way a chain of &&s is encoded is ((let ... && let ...) && let ...) && let ... - // as && is left-to-right associative. Thus, we need to check rhs. - if part_of_chain && matches!(rhs.kind, hir::ExprKind::Let(..)) { - return true; + // Lint level enclosing the next `lhs`. + let mut cur_lint_level = self.lint_level; + + // Obtain the refutabilities of all exprs in the chain, + // and record chain members that aren't let exprs. + let mut chain_refutabilities = Vec::new(); + + let add = |expr: ExprId, mut local_lint_level| { + // `local_lint_level` is the lint level enclosing the pattern inside `expr`. + let mut expr = &self.thir[expr]; + debug!(?expr, ?local_lint_level, "add"); + // Fast-forward through scopes. + while let ExprKind::Scope { value, lint_level, .. } = expr.kind { + if let LintLevel::Explicit(hir_id) = lint_level { + local_lint_level = hir_id } - // If there is a let at the lhs, and we provide the rhs, we don't do any checking either. - if !part_of_chain && matches!(lhs.kind, hir::ExprKind::Let(..)) && rhs.hir_id == top - { - return true; + expr = &self.thir[value]; + } + debug!(?expr, ?local_lint_level, "after scopes"); + match expr.kind { + ExprKind::Let { box ref pat, expr: _ } => { + let mut ncx = self.new_cx(local_lint_level, true); + let tpat = self.lower_pattern(&mut ncx, pat); + let refutable = !is_let_irrefutable(&mut ncx, local_lint_level, tpat); + Some((expr.span, refutable)) } - } else { - // We've reached the top. - break; + _ => None, } + }; - // Since this function is called within a let context, it is reasonable to assume that any parent - // `&&` infers a let chain - part_of_chain = true; - top = new_top; - } - if !part_of_chain { - return false; - } + // Let chains recurse on the left, so we start by adding the rightmost. + chain_refutabilities.push(add(rhs, cur_lint_level)); - // Second, obtain the refutabilities of all exprs in the chain, - // and record chain members that aren't let exprs. - let mut chain_refutabilities = Vec::new(); - let hir::Node::Expr(top_expr) = hir.get(top) else { - // We ensure right above that it's an Expr - unreachable!() - }; - let mut cur_expr = top_expr; loop { - let mut add = |expr: &hir::Expr<'tcx>| { - let refutability = match expr.kind { - hir::ExprKind::Let(hir::Let { pat, init, span, .. }) => { - let mut ncx = self.new_cx(init.hir_id); - let tpat = self.lower_pattern(&mut ncx, pat, &mut false); - - let refutable = !is_let_irrefutable(&mut ncx, pat.hir_id, tpat); - Some((*span, refutable)) - } - _ => None, - }; - chain_refutabilities.push(refutability); - }; - if let hir::Expr { - kind: hir::ExprKind::Binary(Spanned { node: hir::BinOpKind::And, .. }, lhs, rhs), - .. - } = cur_expr + while let ExprKind::Scope { value, lint_level, .. } = self.thir[lhs].kind { + if let LintLevel::Explicit(hir_id) = lint_level { + cur_lint_level = hir_id + } + lhs = value; + } + if let ExprKind::LogicalOp { op: LogicalOp::And, lhs: new_lhs, rhs: expr } = + self.thir[lhs].kind { - add(rhs); - cur_expr = lhs; + chain_refutabilities.push(add(expr, cur_lint_level)); + lhs = new_lhs; } else { - add(cur_expr); + chain_refutabilities.push(add(lhs, cur_lint_level)); break; } } + debug!(?chain_refutabilities); chain_refutabilities.reverse(); // Third, emit the actual warnings. - if chain_refutabilities.iter().all(|r| matches!(*r, Some((_, false)))) { // The entire chain is made up of irrefutable `let` statements - let let_source = let_source_parent(self.tcx, top, None); irrefutable_let_patterns( - cx.tcx, - top, + self.tcx, + self.lint_level, let_source, chain_refutabilities.len(), - top_expr.span, + top_expr_span, ); - return true; + return; } + if let Some(until) = chain_refutabilities.iter().position(|r| !matches!(*r, Some((_, false)))) && until > 0 { // The chain has a non-zero prefix of irrefutable `let` statements. @@ -350,7 +383,6 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { // so can't always be moved out. // FIXME: Add checking whether the bindings are actually used in the prefix, // and lint if they are not. - let let_source = let_source_parent(self.tcx, top, None); if !matches!(let_source, LetSource::WhileLet | LetSource::IfLetGuard) { // Emit the lint let prefix = &chain_refutabilities[..until]; @@ -358,9 +390,10 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { let span_end = prefix.last().unwrap().unwrap().0; let span = span_start.to(span_end); let count = prefix.len(); - cx.tcx.emit_spanned_lint(IRREFUTABLE_LET_PATTERNS, top, span, LeadingIrrefutableLetPatterns { count }); + self.tcx.emit_spanned_lint(IRREFUTABLE_LET_PATTERNS, self.lint_level, span, LeadingIrrefutableLetPatterns { count }); } } + if let Some(from) = chain_refutabilities.iter().rposition(|r| !matches!(*r, Some((_, false)))) && from != (chain_refutabilities.len() - 1) { // The chain has a non-empty suffix of irrefutable `let` statements let suffix = &chain_refutabilities[from + 1..]; @@ -368,18 +401,18 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { let span_end = suffix.last().unwrap().unwrap().0; let span = span_start.to(span_end); let count = suffix.len(); - cx.tcx.emit_spanned_lint(IRREFUTABLE_LET_PATTERNS, top, span, TrailingIrrefutableLetPatterns { count }); + self.tcx.emit_spanned_lint(IRREFUTABLE_LET_PATTERNS, self.lint_level, span, TrailingIrrefutableLetPatterns { count }); } - true } - fn check_irrefutable(&self, pat: &'tcx Pat<'tcx>, origin: &str, sp: Option<Span>) { - let mut cx = self.new_cx(pat.hir_id); + #[instrument(level = "trace", skip(self))] + fn check_irrefutable(&self, pat: &Pat<'tcx>, origin: &str, sp: Option<Span>) { + let mut cx = self.new_cx(self.lint_level, false); - let pattern = self.lower_pattern(&mut cx, pat, &mut false); + let pattern = self.lower_pattern(&mut cx, pat); let pattern_ty = 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); + let arm = MatchArm { pat: pattern, hir_id: self.lint_level, has_guard: false }; + let report = compute_match_usefulness(&cx, &[arm], self.lint_level, pattern_ty); // Note: we ignore whether the pattern is unreachable (i.e. whether the type is empty). We // only care about exhaustiveness here. @@ -390,58 +423,45 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { return; } - let (inform, interpreted_as_const, res_defined_here,let_suggestion, misc_suggestion) = - if let hir::PatKind::Path(hir::QPath::Resolved( - None, - hir::Path { - segments: &[hir::PathSegment { args: None, res, ident, .. }], - .. - }, - )) = &pat.kind - { - ( - 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); - } + let inform = sp.is_some().then_some(Inform); + let mut let_suggestion = None; + let mut misc_suggestion = None; + let mut interpreted_as_const = None; + if let PatKind::Constant { .. } = pat.kind + && let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(pat.span) + { + // If the pattern to match is an integer literal: + if snippet.chars().all(|c| c.is_digit(10)) { + // Then give a suggestion, the user might've meant to create a binding instead. + misc_suggestion = Some(MiscPatternSuggestion::AttemptedIntegerLiteral { + start_span: pat.span.shrink_to_lo() }); - 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(); - let count = witnesses.len(); - - // If the pattern to match is an integer literal: - let int_suggestion = if - let PatKind::Lit(expr) = &pat.kind - && bindings.is_empty() - && let ExprKind::Lit(Spanned { node: LitKind::Int(_, _), span }) = expr.kind { - // Then give a suggestion, the user might've meant to create a binding instead. - Some(MiscPatternSuggestion::AttemptedIntegerLiteral { start_span: span.shrink_to_lo() }) - } else { None }; - - let let_suggestion = if bindings.is_empty() {SuggestLet::If{start_span, semi_span, count}} else{ SuggestLet::Else{end_span, count }}; - (sp.map(|_|Inform), None, None, Some(let_suggestion), int_suggestion) - } else{ - (sp.map(|_|Inform), None, None, None, None) - }; + } else if snippet.chars().all(|c| c.is_alphanumeric() || c == '_') { + interpreted_as_const = Some(InterpretedAsConst { + span: pat.span, + variable: snippet, + }); + } + } + + if let Some(span) = sp + && self.tcx.sess.source_map().is_span_accessible(span) + && interpreted_as_const.is_none() + { + let mut bindings = vec![]; + pat.each_binding(|name, _, _, _| bindings.push(name)); + + let semi_span = span.shrink_to_hi(); + let start_span = span.shrink_to_lo(); + let end_span = semi_span.shrink_to_lo(); + let count = witnesses.len(); + + let_suggestion = Some(if bindings.is_empty() { + SuggestLet::If { start_span, semi_span, count } + } else { + SuggestLet::Else { end_span, count } + }); + }; let adt_defined_here = try { let ty = pattern_ty.peel_refs(); @@ -465,7 +485,6 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { pattern_ty, let_suggestion, misc_suggestion, - res_defined_here, adt_defined_here, }); } @@ -477,14 +496,18 @@ fn check_for_bindings_named_same_as_variants( rf: RefutableFlag, ) { pat.walk_always(|p| { - if let hir::PatKind::Binding(_, _, ident, None) = p.kind - && let Some(ty::BindByValue(hir::Mutability::Not)) = - cx.typeck_results.extract_binding_mode(cx.tcx.sess, p.hir_id, p.span) - && let pat_ty = cx.typeck_results.pat_ty(p).peel_refs() - && let ty::Adt(edef, _) = pat_ty.kind() + if let PatKind::Binding { + name, + mode: BindingMode::ByValue, + mutability: Mutability::Not, + subpattern: None, + ty, + .. + } = p.kind + && let ty::Adt(edef, _) = ty.peel_refs().kind() && edef.is_enum() && edef.variants().iter().any(|variant| { - variant.ident(cx.tcx) == ident && variant.ctor_kind() == Some(CtorKind::Const) + variant.name == name && variant.ctor_kind() == Some(CtorKind::Const) }) { let variant_count = edef.variants().len(); @@ -493,7 +516,7 @@ fn check_for_bindings_named_same_as_variants( }); cx.tcx.emit_spanned_lint( BINDINGS_WITH_VARIANT_NAME, - p.hir_id, + cx.lint_level, p.span, BindingsWithVariantName { // If this is an irrefutable pattern, and there's > 1 variant, @@ -503,7 +526,7 @@ fn check_for_bindings_named_same_as_variants( Some(p.span) } else { None }, ty_path, - ident, + name, }, ) } @@ -529,11 +552,6 @@ fn unreachable_pattern(tcx: TyCtxt<'_>, span: Span, id: HirId, catchall: Option< ); } -fn irrefutable_let_pattern(tcx: TyCtxt<'_>, id: HirId, span: Span) { - let source = let_source(tcx, id); - irrefutable_let_patterns(tcx, id, source, 1, span); -} - fn irrefutable_let_patterns( tcx: TyCtxt<'_>, id: HirId, @@ -548,7 +566,7 @@ fn irrefutable_let_patterns( } match source { - LetSource::GenericLet => emit_diag!(IrrefutableLetPatternsGenericLet), + LetSource::None => bug!(), LetSource::IfLet => emit_diag!(IrrefutableLetPatternsIfLet), LetSource::IfLetGuard => emit_diag!(IrrefutableLetPatternsIfLetGuard), LetSource::LetElse => emit_diag!(IrrefutableLetPatternsLetElse), @@ -604,10 +622,11 @@ fn report_arm_reachability<'p, 'tcx>( /// Report that a match is not exhaustive. fn non_exhaustive_match<'p, 'tcx>( cx: &MatchCheckCtxt<'p, 'tcx>, + thir: &Thir<'tcx>, scrut_ty: Ty<'tcx>, sp: Span, witnesses: Vec<DeconstructedPat<'p, 'tcx>>, - arms: &[hir::Arm<'tcx>], + arms: &[ArmId], expr_span: Span, ) { let is_empty_match = arms.is_empty(); @@ -705,6 +724,7 @@ fn non_exhaustive_match<'p, 'tcx>( )); } [only] => { + let only = &thir[*only]; let (pre_indentation, is_multiline) = if let Some(snippet) = sm.indentation_before(only.span) && let Ok(with_trailing) = sm.span_extend_while(only.span, |c| c.is_whitespace() || c == ',') && sm.is_multiline(with_trailing) @@ -713,8 +733,9 @@ fn non_exhaustive_match<'p, 'tcx>( } else { (" ".to_string(), false) }; - let comma = if matches!(only.body.kind, hir::ExprKind::Block(..)) - && only.span.eq_ctxt(only.body.span) + let only_body = &thir[only.body]; + let comma = if matches!(only_body.kind, ExprKind::Block { .. }) + && only.span.eq_ctxt(only_body.span) && is_multiline { "" @@ -726,24 +747,29 @@ fn non_exhaustive_match<'p, 'tcx>( format!("{}{}{} => todo!()", comma, pre_indentation, pattern), )); } - [.., prev, last] if prev.span.eq_ctxt(last.span) => { - let comma = if matches!(last.body.kind, hir::ExprKind::Block(..)) - && last.span.eq_ctxt(last.body.span) - { - "" - } else { - "," - }; - let spacing = if sm.is_multiline(prev.span.between(last.span)) { - sm.indentation_before(last.span).map(|indent| format!("\n{indent}")) - } else { - Some(" ".to_string()) - }; - if let Some(spacing) = spacing { - suggestion = Some(( - last.span.shrink_to_hi(), - format!("{}{}{} => todo!()", comma, spacing, pattern), - )); + [.., prev, last] => { + let prev = &thir[*prev]; + let last = &thir[*last]; + if prev.span.eq_ctxt(last.span) { + let last_body = &thir[last.body]; + let comma = if matches!(last_body.kind, ExprKind::Block { .. }) + && last.span.eq_ctxt(last_body.span) + { + "" + } else { + "," + }; + let spacing = if sm.is_multiline(prev.span.between(last.span)) { + sm.indentation_before(last.span).map(|indent| format!("\n{indent}")) + } else { + Some(" ".to_string()) + }; + if let Some(spacing) = spacing { + suggestion = Some(( + last.span.shrink_to_hi(), + format!("{}{}{} => todo!()", comma, spacing, pattern), + )); + } } } _ => {} @@ -863,10 +889,6 @@ fn maybe_point_at_variant<'a, 'p: 'a, 'tcx: 'a>( } /// Check if a by-value binding is by-value. That is, check if the binding's type is not `Copy`. -fn is_binding_by_move(cx: &MatchVisitor<'_, '_, '_>, hir_id: HirId) -> bool { - !cx.typeck_results.node_type(hir_id).is_copy_modulo_regions(cx.tcx, cx.param_env) -} - /// Check that there are no borrow or move conflicts in `binding @ subpat` patterns. /// /// For example, this would reject: @@ -877,45 +899,36 @@ fn is_binding_by_move(cx: &MatchVisitor<'_, '_, '_>, hir_id: HirId) -> bool { /// - `x @ Some(ref mut? y)`. /// /// This analysis is *not* subsumed by NLL. -fn check_borrow_conflicts_in_at_patterns(cx: &MatchVisitor<'_, '_, '_>, pat: &Pat<'_>) { +fn check_borrow_conflicts_in_at_patterns<'tcx>(cx: &MatchVisitor<'_, '_, 'tcx>, pat: &Pat<'tcx>) { // Extract `sub` in `binding @ sub`. - let (name, sub) = match &pat.kind { - hir::PatKind::Binding(.., name, Some(sub)) => (*name, sub), - _ => return, - }; - let binding_span = pat.span.with_hi(name.span.hi()); + let PatKind::Binding { name, mode, ty, subpattern: Some(box ref sub), .. } = pat.kind else { return }; + + let is_binding_by_move = |ty: Ty<'tcx>| !ty.is_copy_modulo_regions(cx.tcx, cx.param_env); - let typeck_results = cx.typeck_results; let sess = cx.tcx.sess; // Get the binding move, extract the mutability if by-ref. - let mut_outer = match typeck_results.extract_binding_mode(sess, pat.hir_id, pat.span) { - Some(ty::BindByValue(_)) if is_binding_by_move(cx, pat.hir_id) => { + let mut_outer = match mode { + BindingMode::ByValue if is_binding_by_move(ty) => { // We have `x @ pat` where `x` is by-move. Reject all borrows in `pat`. let mut conflicts_ref = Vec::new(); - sub.each_binding(|_, hir_id, span, _| { - match typeck_results.extract_binding_mode(sess, hir_id, span) { - Some(ty::BindByValue(_)) | None => {} - Some(ty::BindByReference(_)) => conflicts_ref.push(span), - } + sub.each_binding(|_, mode, _, span| match mode { + BindingMode::ByValue => {} + BindingMode::ByRef(_) => conflicts_ref.push(span), }); if !conflicts_ref.is_empty() { sess.emit_err(BorrowOfMovedValue { - span: pat.span, - binding_span, + binding_span: pat.span, conflicts_ref, name, - ty: typeck_results.node_type(pat.hir_id), - suggest_borrowing: pat - .span - .contains(binding_span) - .then(|| binding_span.shrink_to_lo()), + ty, + suggest_borrowing: Some(pat.span.shrink_to_lo()), }); } return; } - Some(ty::BindByValue(_)) | None => return, - Some(ty::BindByReference(m)) => m, + BindingMode::ByValue => return, + BindingMode::ByRef(m) => m.mutability(), }; // We now have `ref $mut_outer binding @ sub` (semantically). @@ -923,9 +936,9 @@ fn check_borrow_conflicts_in_at_patterns(cx: &MatchVisitor<'_, '_, '_>, pat: &Pa let mut conflicts_move = Vec::new(); let mut conflicts_mut_mut = Vec::new(); let mut conflicts_mut_ref = Vec::new(); - sub.each_binding(|_, hir_id, span, name| { - match typeck_results.extract_binding_mode(sess, hir_id, span) { - Some(ty::BindByReference(mut_inner)) => match (mut_outer, mut_inner) { + sub.each_binding(|name, mode, ty, span| { + match mode { + BindingMode::ByRef(mut_inner) => match (mut_outer, mut_inner.mutability()) { // Both sides are `ref`. (Mutability::Not, Mutability::Not) => {} // 2x `ref mut`. @@ -939,10 +952,10 @@ fn check_borrow_conflicts_in_at_patterns(cx: &MatchVisitor<'_, '_, '_>, pat: &Pa conflicts_mut_ref.push(Conflict::Ref { span, name }) } }, - Some(ty::BindByValue(_)) if is_binding_by_move(cx, hir_id) => { + BindingMode::ByValue if is_binding_by_move(ty) => { conflicts_move.push(Conflict::Moved { span, name }) // `ref mut?` + by-move conflict. } - Some(ty::BindByValue(_)) | None => {} // `ref mut?` + by-copy is fine. + BindingMode::ByValue => {} // `ref mut?` + by-copy is fine. } }); @@ -950,92 +963,30 @@ fn check_borrow_conflicts_in_at_patterns(cx: &MatchVisitor<'_, '_, '_>, pat: &Pa let report_mut_ref = !conflicts_mut_ref.is_empty(); let report_move_conflict = !conflicts_move.is_empty(); - let mut occurences = match mut_outer { - Mutability::Mut => vec![Conflict::Mut { span: binding_span, name }], - Mutability::Not => vec![Conflict::Ref { span: binding_span, name }], + let mut occurrences = match mut_outer { + Mutability::Mut => vec![Conflict::Mut { span: pat.span, name }], + Mutability::Not => vec![Conflict::Ref { span: pat.span, name }], }; - occurences.extend(conflicts_mut_mut); - occurences.extend(conflicts_mut_ref); - occurences.extend(conflicts_move); + occurrences.extend(conflicts_mut_mut); + occurrences.extend(conflicts_mut_ref); + occurrences.extend(conflicts_move); // Report errors if any. if report_mut_mut { // Report mutability conflicts for e.g. `ref mut x @ Some(ref mut y)`. - sess.emit_err(MultipleMutBorrows { span: pat.span, occurences }); + sess.emit_err(MultipleMutBorrows { span: pat.span, occurrences }); } else if report_mut_ref { // Report mutability conflicts for e.g. `ref x @ Some(ref mut y)` or the converse. match mut_outer { Mutability::Mut => { - sess.emit_err(AlreadyMutBorrowed { span: pat.span, occurences }); + sess.emit_err(AlreadyMutBorrowed { span: pat.span, occurrences }); } Mutability::Not => { - sess.emit_err(AlreadyBorrowed { span: pat.span, occurences }); + sess.emit_err(AlreadyBorrowed { span: pat.span, occurrences }); } }; } else if report_move_conflict { // Report by-ref and by-move conflicts, e.g. `ref x @ y`. - sess.emit_err(MovedWhileBorrowed { span: pat.span, occurences }); - } -} - -#[derive(Clone, Copy, Debug)] -pub enum LetSource { - GenericLet, - IfLet, - IfLetGuard, - LetElse, - WhileLet, -} - -fn let_source(tcx: TyCtxt<'_>, pat_id: HirId) -> LetSource { - let hir = tcx.hir(); - - let parent = hir.parent_id(pat_id); - let_source_parent(tcx, parent, Some(pat_id)) -} - -fn let_source_parent(tcx: TyCtxt<'_>, parent: HirId, pat_id: Option<HirId>) -> LetSource { - let hir = tcx.hir(); - - let parent_node = hir.get(parent); - - match parent_node { - hir::Node::Arm(hir::Arm { - guard: Some(hir::Guard::IfLet(&hir::Let { pat: hir::Pat { hir_id, .. }, .. })), - .. - }) if Some(*hir_id) == pat_id => { - return LetSource::IfLetGuard; - } - _ => {} - } - - let parent_parent = hir.parent_id(parent); - let parent_parent_node = hir.get(parent_parent); - match parent_parent_node { - hir::Node::Stmt(hir::Stmt { kind: hir::StmtKind::Local(_), .. }) => { - return LetSource::LetElse; - } - hir::Node::Arm(hir::Arm { guard: Some(hir::Guard::If(_)), .. }) => { - return LetSource::IfLetGuard; - } - _ => {} + sess.emit_err(MovedWhileBorrowed { span: pat.span, occurrences }); } - - let parent_parent_parent = hir.parent_id(parent_parent); - let parent_parent_parent_parent = hir.parent_id(parent_parent_parent); - let parent_parent_parent_parent_node = hir.get(parent_parent_parent_parent); - - if let hir::Node::Expr(hir::Expr { - kind: hir::ExprKind::Loop(_, _, hir::LoopSource::While, _), - .. - }) = parent_parent_parent_parent_node - { - return LetSource::WhileLet; - } - - if let hir::Node::Expr(hir::Expr { kind: hir::ExprKind::If(..), .. }) = parent_parent_node { - return LetSource::IfLet; - } - - LetSource::GenericLet } |