use clippy_utils::diagnostics::span_lint_hir_and_then;
-use clippy_utils::paths;
+use clippy_utils::return_ty;
use clippy_utils::source::snippet;
use clippy_utils::sugg::DiagnosticBuilderExt;
-use clippy_utils::{get_trait_def_id, return_ty};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_hir::HirIdSet;
use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::{Ty, TyS};
+use rustc_middle::ty::TyS;
use rustc_session::{declare_tool_lint, impl_lint_pass};
use rustc_span::sym;
declare_clippy_lint! {
- /// **What it does:** Checks for types with a `fn new() -> Self` method and no
+ /// ### What it does
+ /// Checks for types with a `fn new() -> Self` method and no
/// implementation of
/// [`Default`](https://doc.rust-lang.org/std/default/trait.Default.html).
///
- /// **Why is this bad?** The user might expect to be able to use
+ /// ### Why is this bad?
+ /// The user might expect to be able to use
/// [`Default`](https://doc.rust-lang.org/std/default/trait.Default.html) as the
/// type can be constructed without arguments.
///
- /// **Known problems:** Hopefully none.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```ignore
/// struct Foo(Bar);
///
if let hir::ItemKind::Impl(hir::Impl {
of_trait: None,
ref generics,
+ self_ty: impl_self_ty,
items,
..
}) = item.kind
// impl of `Default`
return;
}
- if sig.decl.inputs.is_empty() && name == sym::new && cx.access_levels.is_reachable(id) {
+ if_chain! {
+ if sig.decl.inputs.is_empty();
+ if name == sym::new;
+ if cx.access_levels.is_reachable(impl_item.def_id);
let self_def_id = cx.tcx.hir().local_def_id(cx.tcx.hir().get_parent_item(id));
let self_ty = cx.tcx.type_of(self_def_id);
- if_chain! {
- if TyS::same_type(self_ty, return_ty(cx, id));
- if let Some(default_trait_id) = get_trait_def_id(cx, &paths::DEFAULT_TRAIT);
- then {
- if self.impling_types.is_none() {
- let mut impls = HirIdSet::default();
- cx.tcx.for_each_impl(default_trait_id, |d| {
- if let Some(ty_def) = cx.tcx.type_of(d).ty_adt_def() {
- if let Some(local_def_id) = ty_def.did.as_local() {
- impls.insert(cx.tcx.hir().local_def_id_to_hir_id(local_def_id));
- }
- }
- });
- self.impling_types = Some(impls);
- }
-
- // Check if a Default implementation exists for the Self type, regardless of
- // generics
- if_chain! {
- if let Some(ref impling_types) = self.impling_types;
- if let Some(self_def) = cx.tcx.type_of(self_def_id).ty_adt_def();
- if let Some(self_local_did) = self_def.did.as_local();
- then {
- let self_id = cx.tcx.hir().local_def_id_to_hir_id(self_local_did);
- if impling_types.contains(&self_id) {
- return;
+ if TyS::same_type(self_ty, return_ty(cx, id));
+ if let Some(default_trait_id) = cx.tcx.get_diagnostic_item(sym::Default);
+ then {
+ if self.impling_types.is_none() {
+ let mut impls = HirIdSet::default();
+ cx.tcx.for_each_impl(default_trait_id, |d| {
+ if let Some(ty_def) = cx.tcx.type_of(d).ty_adt_def() {
+ if let Some(local_def_id) = ty_def.did.as_local() {
+ impls.insert(cx.tcx.hir().local_def_id_to_hir_id(local_def_id));
}
}
- }
+ });
+ self.impling_types = Some(impls);
+ }
- let generics_sugg = snippet(cx, generics.span, "");
- span_lint_hir_and_then(
- cx,
- NEW_WITHOUT_DEFAULT,
- id,
- impl_item.span,
- &format!(
- "you should consider adding a `Default` implementation for `{}`",
- self_ty
- ),
- |diag| {
- diag.suggest_prepend_item(
- cx,
- item.span,
- "try this",
- &create_new_without_default_suggest_msg(self_ty, &generics_sugg),
- Applicability::MaybeIncorrect,
- );
- },
- );
+ // Check if a Default implementation exists for the Self type, regardless of
+ // generics
+ if_chain! {
+ if let Some(ref impling_types) = self.impling_types;
+ if let Some(self_def) = cx.tcx.type_of(self_def_id).ty_adt_def();
+ if let Some(self_local_did) = self_def.did.as_local();
+ let self_id = cx.tcx.hir().local_def_id_to_hir_id(self_local_did);
+ if impling_types.contains(&self_id);
+ then {
+ return;
+ }
}
+
+ let generics_sugg = snippet(cx, generics.span, "");
+ let self_ty_fmt = self_ty.to_string();
+ let self_type_snip = snippet(cx, impl_self_ty.span, &self_ty_fmt);
+ span_lint_hir_and_then(
+ cx,
+ NEW_WITHOUT_DEFAULT,
+ id,
+ impl_item.span,
+ &format!(
+ "you should consider adding a `Default` implementation for `{}`",
+ self_type_snip
+ ),
+ |diag| {
+ diag.suggest_prepend_item(
+ cx,
+ item.span,
+ "try adding this",
+ &create_new_without_default_suggest_msg(&self_type_snip, &generics_sugg),
+ Applicability::MaybeIncorrect,
+ );
+ },
+ );
}
}
}
}
}
-fn create_new_without_default_suggest_msg(ty: Ty<'_>, generics_sugg: &str) -> String {
+fn create_new_without_default_suggest_msg(self_type_snip: &str, generics_sugg: &str) -> String {
#[rustfmt::skip]
format!(
"impl{} Default for {} {{
fn default() -> Self {{
Self::new()
}}
-}}", generics_sugg, ty)
+}}", generics_sugg, self_type_snip)
}
projects / rust.git / blobdiff