diff options
| -rw-r--r-- | clippy_utils/src/visitors.rs | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/clippy_utils/src/visitors.rs b/clippy_utils/src/visitors.rs index 503effbdad5..4a3181dd027 100644 --- a/clippy_utils/src/visitors.rs +++ b/clippy_utils/src/visitors.rs @@ -6,6 +6,51 @@ use rustc_lint::LateContext; use rustc_middle::hir::map::Map; use std::ops::ControlFlow; +/// 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>, + f: F, + } + impl<'tcx, F: FnMut(&'tcx Expr<'tcx>) -> bool> Visitor<'tcx> for V<'tcx, F> { + type Map = Map<'tcx>; + fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { + NestedVisitorMap::OnlyBodies(self.hir) + } + + fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) { + if (self.f)(expr) { + walk_expr(self, expr); + } + } + } + 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>(F); + impl<'tcx, F: FnMut(&'tcx Expr<'tcx>) -> bool> Visitor<'tcx> for V<F> { + type Map = intravisit::ErasedMap<'tcx>; + fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { + NestedVisitorMap::None + } + + fn visit_expr(&mut self, e: &'tcx Expr<'_>) { + if (self.0)(e) { + walk_expr(self, e); + } + } + } + V(f) +} + /// returns `true` if expr contains match expr desugared from try fn contains_try(expr: &hir::Expr<'_>) -> bool { struct TryFinder { |