rust/clippy_lints/src/missing_doc.rs
2020-11-02 11:46:37 -06:00

199 lines
6.8 KiB
Rust

// Note: More specifically this lint is largely inspired (aka copied) from
// *rustc*'s
// [`missing_doc`].
//
// [`missing_doc`]: https://github.com/rust-lang/rust/blob/d6d05904697d89099b55da3331155392f1db9c00/src/librustc_lint/builtin.rs#L246
//
use crate::utils::span_lint;
use if_chain::if_chain;
use rustc_ast::ast::{self, MetaItem, MetaItemKind};
use rustc_ast::attr;
use rustc_hir as hir;
use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_middle::ty;
use rustc_session::{declare_tool_lint, impl_lint_pass};
use rustc_span::source_map::Span;
use rustc_span::sym;
declare_clippy_lint! {
/// **What it does:** Warns if there is missing doc for any documentable item
/// (public or private).
///
/// **Why is this bad?** Doc is good. *rustc* has a `MISSING_DOCS`
/// allowed-by-default lint for
/// public members, but has no way to enforce documentation of private items.
/// This lint fixes that.
///
/// **Known problems:** None.
pub MISSING_DOCS_IN_PRIVATE_ITEMS,
restriction,
"detects missing documentation for public and private members"
}
pub struct MissingDoc {
/// Stack of whether #[doc(hidden)] is set
/// at each level which has lint attributes.
doc_hidden_stack: Vec<bool>,
}
impl Default for MissingDoc {
#[must_use]
fn default() -> Self {
Self::new()
}
}
impl MissingDoc {
#[must_use]
pub fn new() -> Self {
Self {
doc_hidden_stack: vec![false],
}
}
fn doc_hidden(&self) -> bool {
*self.doc_hidden_stack.last().expect("empty doc_hidden_stack")
}
fn has_include(meta: Option<MetaItem>) -> bool {
if_chain! {
if let Some(meta) = meta;
if let MetaItemKind::List(list) = meta.kind;
if let Some(meta) = list.get(0);
if let Some(name) = meta.ident();
then {
name.as_str() == "include"
} else {
false
}
}
}
fn check_missing_docs_attrs(&self, cx: &LateContext<'_>, attrs: &[ast::Attribute], sp: Span, desc: &'static str) {
// If we're building a test harness, then warning about
// documentation is probably not really relevant right now.
if cx.sess().opts.test {
return;
}
// `#[doc(hidden)]` disables missing_docs check.
if self.doc_hidden() {
return;
}
if sp.from_expansion() {
return;
}
let has_doc = attrs
.iter()
.any(|a| a.is_doc_comment() || a.doc_str().is_some() || a.is_value_str() || Self::has_include(a.meta()));
if !has_doc {
span_lint(
cx,
MISSING_DOCS_IN_PRIVATE_ITEMS,
sp,
&format!("missing documentation for {}", desc),
);
}
}
}
impl_lint_pass!(MissingDoc => [MISSING_DOCS_IN_PRIVATE_ITEMS]);
impl<'tcx> LateLintPass<'tcx> for MissingDoc {
fn enter_lint_attrs(&mut self, _: &LateContext<'tcx>, attrs: &'tcx [ast::Attribute]) {
let doc_hidden = self.doc_hidden()
|| attrs.iter().any(|attr| {
attr.has_name(sym::doc)
&& match attr.meta_item_list() {
None => false,
Some(l) => attr::list_contains_name(&l[..], sym::hidden),
}
});
self.doc_hidden_stack.push(doc_hidden);
}
fn exit_lint_attrs(&mut self, _: &LateContext<'tcx>, _: &'tcx [ast::Attribute]) {
self.doc_hidden_stack.pop().expect("empty doc_hidden_stack");
}
fn check_crate(&mut self, cx: &LateContext<'tcx>, krate: &'tcx hir::Crate<'_>) {
self.check_missing_docs_attrs(cx, &krate.item.attrs, krate.item.span, "crate");
}
fn check_item(&mut self, cx: &LateContext<'tcx>, it: &'tcx hir::Item<'_>) {
let desc = match it.kind {
hir::ItemKind::Const(..) => "a constant",
hir::ItemKind::Enum(..) => "an enum",
hir::ItemKind::Fn(..) => {
// ignore main()
if it.ident.name == sym::main {
let def_id = it.hir_id.owner;
let def_key = cx.tcx.hir().def_key(def_id);
if def_key.parent == Some(hir::def_id::CRATE_DEF_INDEX) {
return;
}
}
"a function"
},
hir::ItemKind::Mod(..) => "a module",
hir::ItemKind::Static(..) => "a static",
hir::ItemKind::Struct(..) => "a struct",
hir::ItemKind::Trait(..) => "a trait",
hir::ItemKind::TraitAlias(..) => "a trait alias",
hir::ItemKind::TyAlias(..) => "a type alias",
hir::ItemKind::Union(..) => "a union",
hir::ItemKind::OpaqueTy(..) => "an existential type",
hir::ItemKind::ExternCrate(..)
| hir::ItemKind::ForeignMod(..)
| hir::ItemKind::GlobalAsm(..)
| hir::ItemKind::Impl { .. }
| hir::ItemKind::Use(..) => return,
};
self.check_missing_docs_attrs(cx, &it.attrs, it.span, desc);
}
fn check_trait_item(&mut self, cx: &LateContext<'tcx>, trait_item: &'tcx hir::TraitItem<'_>) {
let desc = match trait_item.kind {
hir::TraitItemKind::Const(..) => "an associated constant",
hir::TraitItemKind::Fn(..) => "a trait method",
hir::TraitItemKind::Type(..) => "an associated type",
};
self.check_missing_docs_attrs(cx, &trait_item.attrs, trait_item.span, desc);
}
fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx hir::ImplItem<'_>) {
// If the method is an impl for a trait, don't doc.
let def_id = cx.tcx.hir().local_def_id(impl_item.hir_id);
match cx.tcx.associated_item(def_id).container {
ty::TraitContainer(_) => return,
ty::ImplContainer(cid) => {
if cx.tcx.impl_trait_ref(cid).is_some() {
return;
}
},
}
let desc = match impl_item.kind {
hir::ImplItemKind::Const(..) => "an associated constant",
hir::ImplItemKind::Fn(..) => "a method",
hir::ImplItemKind::TyAlias(_) => "an associated type",
};
self.check_missing_docs_attrs(cx, &impl_item.attrs, impl_item.span, desc);
}
fn check_struct_field(&mut self, cx: &LateContext<'tcx>, sf: &'tcx hir::StructField<'_>) {
if !sf.is_positional() {
self.check_missing_docs_attrs(cx, &sf.attrs, sf.span, "a struct field");
}
}
fn check_variant(&mut self, cx: &LateContext<'tcx>, v: &'tcx hir::Variant<'_>) {
self.check_missing_docs_attrs(cx, &v.attrs, v.span, "a variant");
}
}