3350: Don't emit `new_without_default_derive` if an impl of Default exists regardless of generics r=oli-obk a=pengowen123

Fixes #2226

Co-authored-by: Owen Sanchez <pengowen816@gmail.com>
This commit is contained in:
bors[bot] 2018-10-24 07:59:06 +00:00
commit 03f8899fa5
3 changed files with 43 additions and 5 deletions

View file

@ -391,7 +391,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
reg.register_early_lint_pass(box int_plus_one::IntPlusOne);
reg.register_late_lint_pass(box overflow_check_conditional::OverflowCheckConditional);
reg.register_late_lint_pass(box unused_label::UnusedLabel);
reg.register_late_lint_pass(box new_without_default::NewWithoutDefault);
reg.register_late_lint_pass(box new_without_default::NewWithoutDefault::default());
reg.register_late_lint_pass(box blacklisted_name::BlackListedName::new(conf.blacklisted_names.clone()));
reg.register_late_lint_pass(box functions::Functions::new(conf.too_many_arguments_threshold));
reg.register_early_lint_pass(box doc::Doc::new(conf.doc_valid_idents.clone()));

View file

@ -11,6 +11,7 @@
use crate::rustc::hir::def_id::DefId;
use crate::rustc::hir;
use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass, in_external_macro, LintContext};
use crate::rustc::util::nodemap::NodeSet;
use crate::rustc::{declare_tool_lint, lint_array};
use if_chain::if_chain;
use crate::rustc::ty::{self, Ty};
@ -91,8 +92,10 @@ declare_clippy_lint! {
"`fn new() -> Self` without `#[derive]`able `Default` implementation"
}
#[derive(Copy, Clone)]
pub struct NewWithoutDefault;
#[derive(Clone, Default)]
pub struct NewWithoutDefault {
impling_types: Option<NodeSet>,
}
impl LintPass for NewWithoutDefault {
fn get_lints(&self) -> LintArray {
@ -130,13 +133,39 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NewWithoutDefault {
return;
}
if sig.decl.inputs.is_empty() && name == "new" && cx.access_levels.is_reachable(id) {
let self_did = cx.tcx.hir.local_def_id(cx.tcx.hir.get_parent(id));
let self_ty = cx.tcx
.type_of(cx.tcx.hir.local_def_id(cx.tcx.hir.get_parent(id)));
.type_of(self_did);
if_chain! {
if same_tys(cx, self_ty, return_ty(cx, id));
if let Some(default_trait_id) = get_trait_def_id(cx, &paths::DEFAULT_TRAIT);
if !implements_trait(cx, self_ty, default_trait_id, &[]);
then {
if self.impling_types.is_none() {
let mut impls = NodeSet();
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(node_id) = cx.tcx.hir.as_local_node_id(ty_def.did) {
impls.insert(node_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_did).ty_adt_def();
if self_def.did.is_local();
then {
let self_id = cx.tcx.hir.local_def_id_to_node_id(self_def.did.to_local());
if impling_types.contains(&self_id) {
return;
}
}
}
if let Some(sp) = can_derive_default(self_ty, cx, default_trait_id) {
span_lint_and_then(
cx,

View file

@ -107,4 +107,13 @@ impl IgnoreUnsafeNew {
pub unsafe fn new() -> Self { IgnoreUnsafeNew }
}
#[derive(Default)]
pub struct OptionRefWrapper<'a, T: 'a>(Option<&'a T>);
impl<'a, T: 'a> OptionRefWrapper<'a, T> {
pub fn new() -> Self {
OptionRefWrapper(None)
}
}
fn main() {}