Remove check_mod_loops query and run the checks per-body instead

1 files changed, 0 insertions, 402 deletions

diff --git a/compiler/rustc_passes/src/loops.rs b/compiler/rustc_passes/src/loops.rs
deleted file mode 100644
index b06f16cc7bd..00000000000
--- a/compiler/rustc_passes/src/loops.rs
+++ /dev/null
@@ -1,402 +0,0 @@
-use std::collections::BTreeMap;
-use std::fmt;
-
-use Context::*;
-use rustc_hir as hir;
-use rustc_hir::def_id::{LocalDefId, LocalModDefId};
-use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::{Destination, Node};
-use rustc_middle::hir::nested_filter;
-use rustc_middle::query::Providers;
-use rustc_middle::span_bug;
-use rustc_middle::ty::TyCtxt;
-use rustc_span::hygiene::DesugaringKind;
-use rustc_span::{BytePos, Span};
-
-use crate::errors::{
-    BreakInsideClosure, BreakInsideCoroutine, BreakNonLoop, ContinueLabeledBlock, OutsideLoop,
-    OutsideLoopSuggestion, UnlabeledCfInWhileCondition, UnlabeledInLabeledBlock,
-};
-
-/// The context in which a block is encountered.
-#[derive(Clone, Copy, Debug, PartialEq)]
-enum Context {
-    Normal,
-    Fn,
-    Loop(hir::LoopSource),
-    Closure(Span),
-    Coroutine {
-        coroutine_span: Span,
-        kind: hir::CoroutineDesugaring,
-        source: hir::CoroutineSource,
-    },
-    UnlabeledBlock(Span),
-    UnlabeledIfBlock(Span),
-    LabeledBlock,
-    /// E.g. The labeled block inside `['_'; 'block: { break 'block 1 + 2; }]`.
-    AnonConst,
-    /// E.g. `const { ... }`.
-    ConstBlock,
-}
-
-#[derive(Clone)]
-struct BlockInfo {
-    name: String,
-    spans: Vec<Span>,
-    suggs: Vec<Span>,
-}
-
-#[derive(PartialEq)]
-enum BreakContextKind {
-    Break,
-    Continue,
-}
-
-impl fmt::Display for BreakContextKind {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            BreakContextKind::Break => "break",
-            BreakContextKind::Continue => "continue",
-        }
-        .fmt(f)
-    }
-}
-
-#[derive(Clone)]
-struct CheckLoopVisitor<'tcx> {
-    tcx: TyCtxt<'tcx>,
-    // Keep track of a stack of contexts, so that suggestions
-    // are not made for contexts where it would be incorrect,
-    // such as adding a label for an `if`.
-    // e.g. `if 'foo: {}` would be incorrect.
-    cx_stack: Vec<Context>,
-    block_breaks: BTreeMap<Span, BlockInfo>,
-}
-
-fn check_mod_loops(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
-    let mut check =
-        CheckLoopVisitor { tcx, cx_stack: vec![Normal], block_breaks: Default::default() };
-    tcx.hir_visit_item_likes_in_module(module_def_id, &mut check);
-    check.report_outside_loop_error();
-}
-
-pub(crate) fn provide(providers: &mut Providers) {
-    *providers = Providers { check_mod_loops, ..*providers };
-}
-
-impl<'hir> Visitor<'hir> for CheckLoopVisitor<'hir> {
-    type NestedFilter = nested_filter::OnlyBodies;
-
-    fn maybe_tcx(&mut self) -> Self::MaybeTyCtxt {
-        self.tcx
-    }
-
-    fn visit_anon_const(&mut self, c: &'hir hir::AnonConst) {
-        self.with_context(AnonConst, |v| intravisit::walk_anon_const(v, c));
-    }
-
-    fn visit_inline_const(&mut self, c: &'hir hir::ConstBlock) {
-        self.with_context(ConstBlock, |v| intravisit::walk_inline_const(v, c));
-    }
-
-    fn visit_fn(
-        &mut self,
-        fk: hir::intravisit::FnKind<'hir>,
-        fd: &'hir hir::FnDecl<'hir>,
-        b: hir::BodyId,
-        _: Span,
-        id: LocalDefId,
-    ) {
-        self.with_context(Fn, |v| intravisit::walk_fn(v, fk, fd, b, id));
-    }
-
-    fn visit_trait_item(&mut self, trait_item: &'hir hir::TraitItem<'hir>) {
-        self.with_context(Fn, |v| intravisit::walk_trait_item(v, trait_item));
-    }
-
-    fn visit_impl_item(&mut self, impl_item: &'hir hir::ImplItem<'hir>) {
-        self.with_context(Fn, |v| intravisit::walk_impl_item(v, impl_item));
-    }
-
-    fn visit_expr(&mut self, e: &'hir hir::Expr<'hir>) {
-        match e.kind {
-            hir::ExprKind::If(cond, then, else_opt) => {
-                self.visit_expr(cond);
-
-                let get_block = |ck_loop: &CheckLoopVisitor<'hir>,
-                                 expr: &hir::Expr<'hir>|
-                 -> Option<&hir::Block<'hir>> {
-                    if let hir::ExprKind::Block(b, None) = expr.kind
-                        && matches!(
-                            ck_loop.cx_stack.last(),
-                            Some(&Normal)
-                                | Some(&AnonConst)
-                                | Some(&UnlabeledBlock(_))
-                                | Some(&UnlabeledIfBlock(_))
-                        )
-                    {
-                        Some(b)
-                    } else {
-                        None
-                    }
-                };
-
-                if let Some(b) = get_block(self, then) {
-                    self.with_context(UnlabeledIfBlock(b.span.shrink_to_lo()), |v| {
-                        v.visit_block(b)
-                    });
-                } else {
-                    self.visit_expr(then);
-                }
-
-                if let Some(else_expr) = else_opt {
-                    if let Some(b) = get_block(self, else_expr) {
-                        self.with_context(UnlabeledIfBlock(b.span.shrink_to_lo()), |v| {
-                            v.visit_block(b)
-                        });
-                    } else {
-                        self.visit_expr(else_expr);
-                    }
-                }
-            }
-            hir::ExprKind::Loop(ref b, _, source, _) => {
-                self.with_context(Loop(source), |v| v.visit_block(b));
-            }
-            hir::ExprKind::Closure(&hir::Closure {
-                ref fn_decl, body, fn_decl_span, kind, ..
-            }) => {
-                let cx = match kind {
-                    hir::ClosureKind::Coroutine(hir::CoroutineKind::Desugared(kind, source)) => {
-                        Coroutine { coroutine_span: fn_decl_span, kind, source }
-                    }
-                    _ => Closure(fn_decl_span),
-                };
-                self.visit_fn_decl(fn_decl);
-                self.with_context(cx, |v| v.visit_nested_body(body));
-            }
-            hir::ExprKind::Block(ref b, Some(_label)) => {
-                self.with_context(LabeledBlock, |v| v.visit_block(b));
-            }
-            hir::ExprKind::Block(ref b, None)
-                if matches!(self.cx_stack.last(), Some(&Fn) | Some(&ConstBlock)) =>
-            {
-                self.with_context(Normal, |v| v.visit_block(b));
-            }
-            hir::ExprKind::Block(
-                ref b @ hir::Block { rules: hir::BlockCheckMode::DefaultBlock, .. },
-                None,
-            ) if matches!(
-                self.cx_stack.last(),
-                Some(&Normal) | Some(&AnonConst) | Some(&UnlabeledBlock(_))
-            ) =>
-            {
-                self.with_context(UnlabeledBlock(b.span.shrink_to_lo()), |v| v.visit_block(b));
-            }
-            hir::ExprKind::Break(break_label, ref opt_expr) => {
-                if let Some(e) = opt_expr {
-                    self.visit_expr(e);
-                }
-
-                if self.require_label_in_labeled_block(e.span, &break_label, "break") {
-                    // If we emitted an error about an unlabeled break in a labeled
-                    // block, we don't need any further checking for this break any more
-                    return;
-                }
-
-                let loop_id = match break_label.target_id {
-                    Ok(loop_id) => Some(loop_id),
-                    Err(hir::LoopIdError::OutsideLoopScope) => None,
-                    Err(hir::LoopIdError::UnlabeledCfInWhileCondition) => {
-                        self.tcx.dcx().emit_err(UnlabeledCfInWhileCondition {
-                            span: e.span,
-                            cf_type: "break",
-                        });
-                        None
-                    }
-                    Err(hir::LoopIdError::UnresolvedLabel) => None,
-                };
-
-                if let Some(Node::Block(_)) = loop_id.map(|id| self.tcx.hir_node(id)) {
-                    return;
-                }
-
-                if let Some(break_expr) = opt_expr {
-                    let (head, loop_label, loop_kind) = if let Some(loop_id) = loop_id {
-                        match self.tcx.hir_expect_expr(loop_id).kind {
-                            hir::ExprKind::Loop(_, label, source, sp) => {
-                                (Some(sp), label, Some(source))
-                            }
-                            ref r => {
-                                span_bug!(e.span, "break label resolved to a non-loop: {:?}", r)
-                            }
-                        }
-                    } else {
-                        (None, None, None)
-                    };
-                    match loop_kind {
-                        None | Some(hir::LoopSource::Loop) => (),
-                        Some(kind) => {
-                            let suggestion = format!(
-                                "break{}",
-                                break_label
-                                    .label
-                                    .map_or_else(String::new, |l| format!(" {}", l.ident))
-                            );
-                            self.tcx.dcx().emit_err(BreakNonLoop {
-                                span: e.span,
-                                head,
-                                kind: kind.name(),
-                                suggestion,
-                                loop_label,
-                                break_label: break_label.label,
-                                break_expr_kind: &break_expr.kind,
-                                break_expr_span: break_expr.span,
-                            });
-                        }
-                    }
-                }
-
-                let sp_lo = e.span.with_lo(e.span.lo() + BytePos("break".len() as u32));
-                let label_sp = match break_label.label {
-                    Some(label) => sp_lo.with_hi(label.ident.span.hi()),
-                    None => sp_lo.shrink_to_lo(),
-                };
-                self.require_break_cx(
-                    BreakContextKind::Break,
-                    e.span,
-                    label_sp,
-                    self.cx_stack.len() - 1,
-                );
-            }
-            hir::ExprKind::Continue(destination) => {
-                self.require_label_in_labeled_block(e.span, &destination, "continue");
-
-                match destination.target_id {
-                    Ok(loop_id) => {
-                        if let Node::Block(block) = self.tcx.hir_node(loop_id) {
-                            self.tcx.dcx().emit_err(ContinueLabeledBlock {
-                                span: e.span,
-                                block_span: block.span,
-                            });
-                        }
-                    }
-                    Err(hir::LoopIdError::UnlabeledCfInWhileCondition) => {
-                        self.tcx.dcx().emit_err(UnlabeledCfInWhileCondition {
-                            span: e.span,
-                            cf_type: "continue",
-                        });
-                    }
-                    Err(_) => {}
-                }
-                self.require_break_cx(
-                    BreakContextKind::Continue,
-                    e.span,
-                    e.span,
-                    self.cx_stack.len() - 1,
-                )
-            }
-            _ => intravisit::walk_expr(self, e),
-        }
-    }
-}
-
-impl<'hir> CheckLoopVisitor<'hir> {
-    fn with_context<F>(&mut self, cx: Context, f: F)
-    where
-        F: FnOnce(&mut CheckLoopVisitor<'hir>),
-    {
-        self.cx_stack.push(cx);
-        f(self);
-        self.cx_stack.pop();
-    }
-
-    fn require_break_cx(
-        &mut self,
-        br_cx_kind: BreakContextKind,
-        span: Span,
-        break_span: Span,
-        cx_pos: usize,
-    ) {
-        match self.cx_stack[cx_pos] {
-            LabeledBlock | Loop(_) => {}
-            Closure(closure_span) => {
-                self.tcx.dcx().emit_err(BreakInsideClosure {
-                    span,
-                    closure_span,
-                    name: &br_cx_kind.to_string(),
-                });
-            }
-            Coroutine { coroutine_span, kind, source } => {
-                let kind = match kind {
-                    hir::CoroutineDesugaring::Async => "async",
-                    hir::CoroutineDesugaring::Gen => "gen",
-                    hir::CoroutineDesugaring::AsyncGen => "async gen",
-                };
-                let source = match source {
-                    hir::CoroutineSource::Block => "block",
-                    hir::CoroutineSource::Closure => "closure",
-                    hir::CoroutineSource::Fn => "function",
-                };
-                self.tcx.dcx().emit_err(BreakInsideCoroutine {
-                    span,
-                    coroutine_span,
-                    name: &br_cx_kind.to_string(),
-                    kind,
-                    source,
-                });
-            }
-            UnlabeledBlock(block_span)
-                if br_cx_kind == BreakContextKind::Break && block_span.eq_ctxt(break_span) =>
-            {
-                let block = self.block_breaks.entry(block_span).or_insert_with(|| BlockInfo {
-                    name: br_cx_kind.to_string(),
-                    spans: vec![],
-                    suggs: vec![],
-                });
-                block.spans.push(span);
-                block.suggs.push(break_span);
-            }
-            UnlabeledIfBlock(_) if br_cx_kind == BreakContextKind::Break => {
-                self.require_break_cx(br_cx_kind, span, break_span, cx_pos - 1);
-            }
-            Normal | AnonConst | Fn | UnlabeledBlock(_) | UnlabeledIfBlock(_) | ConstBlock => {
-                self.tcx.dcx().emit_err(OutsideLoop {
-                    spans: vec![span],
-                    name: &br_cx_kind.to_string(),
-                    is_break: br_cx_kind == BreakContextKind::Break,
-                    suggestion: None,
-                });
-            }
-        }
-    }
-
-    fn require_label_in_labeled_block(
-        &self,
-        span: Span,
-        label: &Destination,
-        cf_type: &str,
-    ) -> bool {
-        if !span.is_desugaring(DesugaringKind::QuestionMark)
-            && self.cx_stack.last() == Some(&LabeledBlock)
-            && label.label.is_none()
-        {
-            self.tcx.dcx().emit_err(UnlabeledInLabeledBlock { span, cf_type });
-            return true;
-        }
-        false
-    }
-
-    fn report_outside_loop_error(&self) {
-        for (s, block) in &self.block_breaks {
-            self.tcx.dcx().emit_err(OutsideLoop {
-                spans: block.spans.clone(),
-                name: &block.name,
-                is_break: true,
-                suggestion: Some(OutsideLoopSuggestion {
-                    block_span: *s,
-                    break_spans: block.suggs.clone(),
-                }),
-            });
-        }
-    }
-}