find function path references early in the lint pass

This commit is contained in:
y21 2024-01-14 06:12:15 +01:00
parent a71211d0b5
commit 0774489086

View file

@ -5,16 +5,15 @@ use clippy_utils::visitors::for_each_expr_with_closures;
use clippy_utils::{get_parent_node, inherits_cfg, is_from_proc_macro, is_self};
use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
use rustc_errors::Applicability;
use rustc_hir::intravisit::{walk_qpath, FnKind, Visitor};
use rustc_hir::intravisit::FnKind;
use rustc_hir::{
BlockCheckMode, Body, Closure, Expr, ExprKind, FnDecl, HirId, HirIdMap, HirIdSet, Impl, ItemKind, Mutability, Node,
PatKind, QPath,
PatKind,
};
use rustc_hir_typeck::expr_use_visitor as euv;
use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::hir::map::associated_body;
use rustc_middle::hir::nested_filter::OnlyBodies;
use rustc_middle::mir::FakeReadCause;
use rustc_middle::ty::{self, Ty, TyCtxt, UpvarId, UpvarPath};
use rustc_session::impl_lint_pass;
@ -234,12 +233,29 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByRefMut<'tcx> {
}
}
fn check_crate_post(&mut self, cx: &LateContext<'tcx>) {
cx.tcx.hir().visit_all_item_likes_in_crate(&mut FnNeedsMutVisitor {
cx,
used_fn_def_ids: &mut self.used_fn_def_ids,
});
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
// #11182; do not lint if mutability is required elsewhere
if let ExprKind::Path(..) = expr.kind
&& let Some(parent) = get_parent_node(cx.tcx, expr.hir_id)
&& let ty::FnDef(def_id, _) = cx.typeck_results().expr_ty(expr).kind()
&& let Some(def_id) = def_id.as_local()
{
if let Node::Expr(e) = parent
&& let ExprKind::Call(call, _) = e.kind
&& call.hir_id == expr.hir_id
{
return;
}
// We don't need to check each argument individually as you cannot coerce a function
// taking `&mut` -> `&`, for some reason, so if we've gotten this far we know it's
// passed as a `fn`-like argument (or is unified) and should ignore every "unused"
// argument entirely
self.used_fn_def_ids.insert(def_id);
}
}
fn check_crate_post(&mut self, cx: &LateContext<'tcx>) {
for (fn_def_id, unused) in self
.fn_def_ids_to_maybe_unused_mut
.iter()
@ -501,48 +517,3 @@ impl<'tcx> euv::Delegate<'tcx> for MutablyUsedVariablesCtxt<'tcx> {
}
}
}
/// A final pass to check for paths referencing this function that require the argument to be
/// `&mut`, basically if the function is ever used as a `fn`-like argument.
struct FnNeedsMutVisitor<'a, 'tcx> {
cx: &'a LateContext<'tcx>,
used_fn_def_ids: &'a mut FxHashSet<LocalDefId>,
}
impl<'tcx> Visitor<'tcx> for FnNeedsMutVisitor<'_, 'tcx> {
type NestedFilter = OnlyBodies;
fn nested_visit_map(&mut self) -> Self::Map {
self.cx.tcx.hir()
}
fn visit_qpath(&mut self, qpath: &'tcx QPath<'tcx>, hir_id: HirId, _: Span) {
walk_qpath(self, qpath, hir_id);
let Self { cx, used_fn_def_ids } = self;
// #11182; do not lint if mutability is required elsewhere
if let Node::Expr(expr) = cx.tcx.hir_node(hir_id)
&& let Some(parent) = get_parent_node(cx.tcx, expr.hir_id)
&& let ty::FnDef(def_id, _) = cx
.tcx
.typeck(cx.tcx.hir().enclosing_body_owner(hir_id))
.expr_ty(expr)
.kind()
&& let Some(def_id) = def_id.as_local()
{
if let Node::Expr(e) = parent
&& let ExprKind::Call(call, _) = e.kind
&& call.hir_id == expr.hir_id
{
return;
}
// We don't need to check each argument individually as you cannot coerce a function
// taking `&mut` -> `&`, for some reason, so if we've gotten this far we know it's
// passed as a `fn`-like argument (or is unified) and should ignore every "unused"
// argument entirely
used_fn_def_ids.insert(def_id);
}
}
}