X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=src%2Ftools%2Fclippy%2Fclippy_utils%2Fsrc%2Fvisitors.rs;h=d4294f18fd5019c0eed128e9321f8caca80b0109;hb=1e926f06528ecb2503f026e2fd53cb735d487b10;hp=232d571902b6c20a8f84684e7ca1ca5e88206f47;hpb=24aab524cbafec7ff8c7cd54ba4f6fb18216c623;p=rust.git diff --git a/src/tools/clippy/clippy_utils/src/visitors.rs b/src/tools/clippy/clippy_utils/src/visitors.rs index 232d571902b..d4294f18fd5 100644 --- a/src/tools/clippy/clippy_utils/src/visitors.rs +++ b/src/tools/clippy/clippy_utils/src/visitors.rs @@ -5,14 +5,13 @@ use rustc_hir::def::{CtorKind, DefKind, Res}; use rustc_hir::intravisit::{self, walk_block, walk_expr, Visitor}; use rustc_hir::{ - Arm, Block, BlockCheckMode, Body, BodyId, Expr, ExprKind, HirId, ItemId, ItemKind, Let, Pat, QPath, Stmt, UnOp, - UnsafeSource, Unsafety, + AnonConst, Arm, Block, BlockCheckMode, Body, BodyId, Expr, ExprKind, HirId, ItemId, ItemKind, Let, Pat, QPath, + Stmt, UnOp, UnsafeSource, Unsafety, }; use rustc_lint::LateContext; -use rustc_middle::hir::map::Map; use rustc_middle::hir::nested_filter; use rustc_middle::ty::adjustment::Adjust; -use rustc_middle::ty::{self, Ty, TypeckResults}; +use rustc_middle::ty::{self, Ty, TyCtxt, TypeckResults}; use rustc_span::Span; mod internal { @@ -48,6 +47,26 @@ fn descend(&self) -> bool { } } +/// A type which can be visited. +pub trait Visitable<'tcx> { + /// Calls the corresponding `visit_*` function on the visitor. + fn visit>(self, visitor: &mut V); +} +macro_rules! visitable_ref { + ($t:ident, $f:ident) => { + impl<'tcx> Visitable<'tcx> for &'tcx $t<'tcx> { + fn visit>(self, visitor: &mut V) { + visitor.$f(self); + } + } + }; +} +visitable_ref!(Arm, visit_arm); +visitable_ref!(Block, visit_block); +visitable_ref!(Body, visit_body); +visitable_ref!(Expr, visit_expr); +visitable_ref!(Stmt, visit_stmt); + /// Calls the given function once for each expression contained. This does not enter any bodies or /// nested items. pub fn for_each_expr<'tcx, B, C: Continue>( @@ -82,57 +101,63 @@ fn visit_nested_item(&mut self, _: ItemId) {} v.res } -/// Convenience method for creating a `Visitor` with just `visit_expr` overridden and nested -/// bodies (i.e. closures) are visited. -/// If the callback returns `true`, the expr just provided to the callback is walked. -#[must_use] -pub fn expr_visitor<'tcx>(cx: &LateContext<'tcx>, f: impl FnMut(&'tcx Expr<'tcx>) -> bool) -> impl Visitor<'tcx> { - struct V<'tcx, F> { - hir: Map<'tcx>, +/// Calls the given function once for each expression contained. This will enter bodies, but not +/// nested items. +pub fn for_each_expr_with_closures<'tcx, B, C: Continue>( + cx: &LateContext<'tcx>, + node: impl Visitable<'tcx>, + f: impl FnMut(&'tcx Expr<'tcx>) -> ControlFlow, +) -> Option { + struct V<'tcx, B, F> { + tcx: TyCtxt<'tcx>, f: F, + res: Option, } - impl<'tcx, F: FnMut(&'tcx Expr<'tcx>) -> bool> Visitor<'tcx> for V<'tcx, F> { + impl<'tcx, B, C: Continue, F: FnMut(&'tcx Expr<'tcx>) -> ControlFlow> Visitor<'tcx> for V<'tcx, B, F> { type NestedFilter = nested_filter::OnlyBodies; fn nested_visit_map(&mut self) -> Self::Map { - self.hir + self.tcx.hir() } - fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) { - if (self.f)(expr) { - walk_expr(self, expr); + fn visit_expr(&mut self, e: &'tcx Expr<'tcx>) { + if self.res.is_some() { + return; } - } - } - V { hir: cx.tcx.hir(), f } -} - -/// Convenience method for creating a `Visitor` with just `visit_expr` overridden and nested -/// bodies (i.e. closures) are not visited. -/// If the callback returns `true`, the expr just provided to the callback is walked. -#[must_use] -pub fn expr_visitor_no_bodies<'tcx>(f: impl FnMut(&'tcx Expr<'tcx>) -> bool) -> impl Visitor<'tcx> { - struct V(F); - impl<'tcx, F: FnMut(&'tcx Expr<'tcx>) -> bool> Visitor<'tcx> for V { - fn visit_expr(&mut self, e: &'tcx Expr<'_>) { - if (self.0)(e) { - walk_expr(self, e); + match (self.f)(e) { + ControlFlow::Continue(c) if c.descend() => walk_expr(self, e), + ControlFlow::Break(b) => self.res = Some(b), + ControlFlow::Continue(_) => (), } } + + // Only walk closures + fn visit_anon_const(&mut self, _: &'tcx AnonConst) {} + // Avoid unnecessary `walk_*` calls. + fn visit_ty(&mut self, _: &'tcx hir::Ty<'tcx>) {} + fn visit_pat(&mut self, _: &'tcx Pat<'tcx>) {} + fn visit_qpath(&mut self, _: &'tcx QPath<'tcx>, _: HirId, _: Span) {} + // Avoid monomorphising all `visit_*` functions. + fn visit_nested_item(&mut self, _: ItemId) {} } - V(f) + let mut v = V { + tcx: cx.tcx, + f, + res: None, + }; + node.visit(&mut v); + v.res } /// returns `true` if expr contains match expr desugared from try fn contains_try(expr: &hir::Expr<'_>) -> bool { - let mut found = false; - expr_visitor_no_bodies(|e| { - if !found { - found = matches!(e.kind, hir::ExprKind::Match(_, _, hir::MatchSource::TryDesugar)); + for_each_expr(expr, |e| { + if matches!(e.kind, hir::ExprKind::Match(_, _, hir::MatchSource::TryDesugar)) { + ControlFlow::Break(()) + } else { + ControlFlow::Continue(()) } - !found }) - .visit_expr(expr); - found + .is_some() } pub fn find_all_ret_expressions<'hir, F>(_cx: &LateContext<'_>, expr: &'hir hir::Expr<'hir>, callback: F) -> bool @@ -228,68 +253,29 @@ fn visit_expr(&mut self, expr: &'hir hir::Expr<'_>) { } } -/// A type which can be visited. -pub trait Visitable<'tcx> { - /// Calls the corresponding `visit_*` function on the visitor. - fn visit>(self, visitor: &mut V); -} -macro_rules! visitable_ref { - ($t:ident, $f:ident) => { - impl<'tcx> Visitable<'tcx> for &'tcx $t<'tcx> { - fn visit>(self, visitor: &mut V) { - visitor.$f(self); - } - } - }; -} -visitable_ref!(Arm, visit_arm); -visitable_ref!(Block, visit_block); -visitable_ref!(Body, visit_body); -visitable_ref!(Expr, visit_expr); -visitable_ref!(Stmt, visit_stmt); - -// impl<'tcx, I: IntoIterator> Visitable<'tcx> for I -// where -// I::Item: Visitable<'tcx>, -// { -// fn visit>(self, visitor: &mut V) { -// for x in self { -// x.visit(visitor); -// } -// } -// } - /// Checks if the given resolved path is used in the given body. pub fn is_res_used(cx: &LateContext<'_>, res: Res, body: BodyId) -> bool { - let mut found = false; - expr_visitor(cx, |e| { - if found { - return false; - } - + for_each_expr_with_closures(cx, cx.tcx.hir().body(body).value, |e| { if let ExprKind::Path(p) = &e.kind { if cx.qpath_res(p, e.hir_id) == res { - found = true; + return ControlFlow::Break(()); } } - !found + ControlFlow::Continue(()) }) - .visit_expr(cx.tcx.hir().body(body).value); - found + .is_some() } /// Checks if the given local is used. pub fn is_local_used<'tcx>(cx: &LateContext<'tcx>, visitable: impl Visitable<'tcx>, id: HirId) -> bool { - let mut is_used = false; - let mut visitor = expr_visitor(cx, |expr| { - if !is_used { - is_used = path_to_local_id(expr, id); + for_each_expr_with_closures(cx, visitable, |e| { + if path_to_local_id(e, id) { + ControlFlow::Break(()) + } else { + ControlFlow::Continue(()) } - !is_used - }); - visitable.visit(&mut visitor); - drop(visitor); - is_used + }) + .is_some() } /// Checks if the given expression is a constant.