use crate::path_to_local_id;
use rustc_hir as hir;
-use rustc_hir::intravisit::{self, walk_expr, ErasedMap, NestedVisitorMap, Visitor};
-use rustc_hir::{def::Res, Arm, Block, Body, BodyId, Destination, Expr, ExprKind, HirId, Stmt};
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::intravisit::{self, walk_expr, NestedVisitorMap, Visitor};
+use rustc_hir::{Arm, Block, Body, BodyId, Expr, ExprKind, HirId, Stmt, UnOp};
use rustc_lint::LateContext;
use rustc_middle::hir::map::Map;
-use std::ops::ControlFlow;
+use rustc_middle::ty;
-/// returns `true` if expr contains match expr desugared from try
-fn contains_try(expr: &hir::Expr<'_>) -> bool {
- struct TryFinder {
- found: bool,
+/// 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)
+ }
- impl<'hir> intravisit::Visitor<'hir> for TryFinder {
- type Map = Map<'hir>;
+ fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
+ if (self.f)(expr) {
+ walk_expr(self, expr);
+ }
+ }
+ }
+ V { hir: cx.tcx.hir(), f }
+}
- fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
- intravisit::NestedVisitorMap::None
+/// 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, expr: &'hir hir::Expr<'hir>) {
- if self.found {
- return;
- }
- match expr.kind {
- hir::ExprKind::Match(_, _, hir::MatchSource::TryDesugar) => self.found = true,
- _ => intravisit::walk_expr(self, expr),
+ fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
+ if (self.0)(e) {
+ walk_expr(self, e);
}
}
}
+ V(f)
+}
- let mut visitor = TryFinder { found: false };
- visitor.visit_expr(expr);
- visitor.found
+/// 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));
+ }
+ !found
+ })
+ .visit_expr(expr);
+ found
}
pub fn find_all_ret_expressions<'hir, F>(_cx: &LateContext<'_>, expr: &'hir hir::Expr<'hir>, callback: F) -> bool
// }
// }
-/// Calls the given function for each break expression.
-pub fn visit_break_exprs<'tcx>(
- node: impl Visitable<'tcx>,
- f: impl FnMut(&'tcx Expr<'tcx>, Destination, Option<&'tcx Expr<'tcx>>),
-) {
- struct V<F>(F);
- impl<'tcx, F: FnMut(&'tcx Expr<'tcx>, Destination, Option<&'tcx Expr<'tcx>>)> Visitor<'tcx> for V<F> {
- type Map = ErasedMap<'tcx>;
- fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
- NestedVisitorMap::None
+/// 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;
}
- fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
- if let ExprKind::Break(dest, sub_expr) = e.kind {
- self.0(e, dest, sub_expr);
+ if let ExprKind::Path(p) = &e.kind {
+ if cx.qpath_res(p, e.hir_id) == res {
+ found = true;
}
- walk_expr(self, e);
}
- }
+ !found
+ })
+ .visit_expr(&cx.tcx.hir().body(body).value);
+ found
+}
- node.visit(&mut V(f));
+/// Checks if the given local is used.
+pub fn is_local_used(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);
+ }
+ !is_used
+ });
+ visitable.visit(&mut visitor);
+ drop(visitor);
+ is_used
}
-/// Checks if the given resolved path is used in the given body.
-pub fn is_res_used(cx: &LateContext<'_>, res: Res, body: BodyId) -> bool {
+/// Checks if the given expression is a constant.
+pub fn is_const_evaluatable(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> bool {
struct V<'a, 'tcx> {
cx: &'a LateContext<'tcx>,
- res: Res,
- found: bool,
+ is_const: bool,
}
- impl Visitor<'tcx> for V<'_, 'tcx> {
+ impl<'tcx> Visitor<'tcx> for V<'_, 'tcx> {
type Map = Map<'tcx>;
fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
NestedVisitorMap::OnlyBodies(self.cx.tcx.hir())
}
fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
- if self.found {
+ if !self.is_const {
return;
}
+ match e.kind {
+ ExprKind::ConstBlock(_) => return,
+ ExprKind::Call(
+ &Expr {
+ kind: ExprKind::Path(ref p),
+ hir_id,
+ ..
+ },
+ _,
+ ) if self
+ .cx
+ .qpath_res(p, hir_id)
+ .opt_def_id()
+ .map_or(false, |id| self.cx.tcx.is_const_fn_raw(id)) => {},
+ ExprKind::MethodCall(..)
+ if self
+ .cx
+ .typeck_results()
+ .type_dependent_def_id(e.hir_id)
+ .map_or(false, |id| self.cx.tcx.is_const_fn_raw(id)) => {},
+ ExprKind::Binary(_, lhs, rhs)
+ if self.cx.typeck_results().expr_ty(lhs).peel_refs().is_primitive_ty()
+ && self.cx.typeck_results().expr_ty(rhs).peel_refs().is_primitive_ty() => {},
+ ExprKind::Unary(UnOp::Deref, e) if self.cx.typeck_results().expr_ty(e).is_ref() => (),
+ ExprKind::Unary(_, e) if self.cx.typeck_results().expr_ty(e).peel_refs().is_primitive_ty() => (),
+ ExprKind::Index(base, _)
+ if matches!(
+ self.cx.typeck_results().expr_ty(base).peel_refs().kind(),
+ ty::Slice(_) | ty::Array(..)
+ ) => {},
+ ExprKind::Path(ref p)
+ if matches!(
+ self.cx.qpath_res(p, e.hir_id),
+ Res::Def(
+ DefKind::Const
+ | DefKind::AssocConst
+ | DefKind::AnonConst
+ | DefKind::ConstParam
+ | DefKind::Ctor(..)
+ | DefKind::Fn
+ | DefKind::AssocFn,
+ _
+ ) | Res::SelfCtor(_)
+ ) => {},
- if let ExprKind::Path(p) = &e.kind {
- if self.cx.qpath_res(p, e.hir_id) == self.res {
- self.found = true;
- }
- } else {
- walk_expr(self, e);
- }
- }
- }
-
- let mut v = V { cx, res, found: false };
- v.visit_expr(&cx.tcx.hir().body(body).value);
- v.found
-}
-
-/// Calls the given function for each usage of the given local.
-pub fn for_each_local_usage<'tcx, B>(
- cx: &LateContext<'tcx>,
- visitable: impl Visitable<'tcx>,
- id: HirId,
- f: impl FnMut(&'tcx Expr<'tcx>) -> ControlFlow<B>,
-) -> ControlFlow<B> {
- struct V<'tcx, B, F> {
- map: Map<'tcx>,
- id: HirId,
- f: F,
- res: ControlFlow<B>,
- }
- impl<'tcx, B, F: FnMut(&'tcx Expr<'tcx>) -> ControlFlow<B>> Visitor<'tcx> for V<'tcx, B, F> {
- type Map = Map<'tcx>;
- fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
- NestedVisitorMap::OnlyBodies(self.map)
- }
+ ExprKind::AddrOf(..)
+ | ExprKind::Array(_)
+ | ExprKind::Block(..)
+ | ExprKind::Cast(..)
+ | ExprKind::DropTemps(_)
+ | ExprKind::Field(..)
+ | ExprKind::If(..)
+ | ExprKind::Let(..)
+ | ExprKind::Lit(_)
+ | ExprKind::Match(..)
+ | ExprKind::Repeat(..)
+ | ExprKind::Struct(..)
+ | ExprKind::Tup(_)
+ | ExprKind::Type(..) => (),
- fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
- if self.res.is_continue() {
- if path_to_local_id(e, self.id) {
- self.res = (self.f)(e);
- } else {
- walk_expr(self, e);
- }
+ _ => {
+ self.is_const = false;
+ return;
+ },
}
+ walk_expr(self, e);
}
}
- let mut v = V {
- map: cx.tcx.hir(),
- id,
- f,
- res: ControlFlow::CONTINUE,
- };
- visitable.visit(&mut v);
- v.res
-}
-
-/// Checks if the given local is used.
-pub fn is_local_used(cx: &LateContext<'tcx>, visitable: impl Visitable<'tcx>, id: HirId) -> bool {
- for_each_local_usage(cx, visitable, id, |_| ControlFlow::BREAK).is_break()
+ let mut v = V { cx, is_const: true };
+ v.visit_expr(e);
+ v.is_const
}
projects / rust.git / blobdiff