src/tools/clippy/clippy_lints/src/missing_doc.rs

   1 // This file incorporates work covered by the following copyright and
   2 // permission notice:
   3 //   Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
   4 //   file at the top-level directory of this distribution and at
   5 //   http://rust-lang.org/COPYRIGHT.
   6 //
   7 //   Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   8 //   http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   9 //   <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
  10 //   option. This file may not be copied, modified, or distributed
  11 //   except according to those terms.
  12 //
  13
  14 // Note: More specifically this lint is largely inspired (aka copied) from
  15 // *rustc*'s
  16 // [`missing_doc`].
  17 //
  18 // [`missing_doc`]: https://github.com/rust-lang/rust/blob/d6d05904697d89099b55da3331155392f1db9c00/src/librustc_lint/builtin.rs#L246
  19 //
  20
  21 use rustc::hir;
  22 use rustc::lint::*;
  23 use rustc::ty;
  24 use syntax::ast;
  25 use syntax::attr;
  26 use syntax::codemap::Span;
  27 use utils::in_macro;
  28
  29 /// **What it does:** Warns if there is missing doc for any documentable item
  30 /// (public or private).
  31 ///
  32 /// **Why is this bad?** Doc is good. *rustc* has a `MISSING_DOCS`
  33 /// allowed-by-default lint for
  34 /// public members, but has no way to enforce documentation of private items.
  35 /// This lint fixes that.
  36 ///
  37 /// **Known problems:** None.
  38 declare_lint! {
  39     pub MISSING_DOCS_IN_PRIVATE_ITEMS,
  40     Allow,
  41     "detects missing documentation for public and private members"
  42 }
  43
  44 pub struct MissingDoc {
  45     /// Stack of whether #[doc(hidden)] is set
  46     /// at each level which has lint attributes.
  47     doc_hidden_stack: Vec<bool>,
  48 }
  49
  50 impl ::std::default::Default for MissingDoc {
  51     fn default() -> Self {
  52         Self::new()
  53     }
  54 }
  55
  56 impl MissingDoc {
  57     pub fn new() -> Self {
  58         Self {
  59             doc_hidden_stack: vec![false],
  60         }
  61     }
  62
  63     fn doc_hidden(&self) -> bool {
  64         *self.doc_hidden_stack
  65             .last()
  66             .expect("empty doc_hidden_stack")
  67     }
  68
  69     fn check_missing_docs_attrs(&self, cx: &LateContext, attrs: &[ast::Attribute], sp: Span, desc: &'static str) {
  70         // If we're building a test harness, then warning about
  71         // documentation is probably not really relevant right now.
  72         if cx.sess().opts.test {
  73             return;
  74         }
  75
  76         // `#[doc(hidden)]` disables missing_docs check.
  77         if self.doc_hidden() {
  78             return;
  79         }
  80
  81         if in_macro(sp) {
  82             return;
  83         }
  84
  85         let has_doc = attrs
  86             .iter()
  87             .any(|a| a.is_value_str() && a.name().map_or(false, |n| n == "doc"));
  88         if !has_doc {
  89             cx.span_lint(
  90                 MISSING_DOCS_IN_PRIVATE_ITEMS,
  91                 sp,
  92                 &format!("missing documentation for {}", desc),
  93             );
  94         }
  95     }
  96 }
  97
  98 impl LintPass for MissingDoc {
  99     fn get_lints(&self) -> LintArray {
 100         lint_array![MISSING_DOCS_IN_PRIVATE_ITEMS]
 101     }
 102 }
 103
 104 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDoc {
 105     fn enter_lint_attrs(&mut self, _: &LateContext<'a, 'tcx>, attrs: &'tcx [ast::Attribute]) {
 106         let doc_hidden = self.doc_hidden() || attrs.iter().any(|attr| {
 107             attr.check_name("doc") && match attr.meta_item_list() {
 108                 None => false,
 109                 Some(l) => attr::list_contains_name(&l[..], "hidden"),
 110             }
 111         });
 112         self.doc_hidden_stack.push(doc_hidden);
 113     }
 114
 115     fn exit_lint_attrs(&mut self, _: &LateContext<'a, 'tcx>, _: &'tcx [ast::Attribute]) {
 116         self.doc_hidden_stack.pop().expect("empty doc_hidden_stack");
 117     }
 118
 119     fn check_crate(&mut self, cx: &LateContext<'a, 'tcx>, krate: &'tcx hir::Crate) {
 120         self.check_missing_docs_attrs(cx, &krate.attrs, krate.span, "crate");
 121     }
 122
 123     fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, it: &'tcx hir::Item) {
 124         let desc = match it.node {
 125             hir::ItemConst(..) => "a constant",
 126             hir::ItemEnum(..) => "an enum",
 127             hir::ItemFn(..) => "a function",
 128             hir::ItemMod(..) => "a module",
 129             hir::ItemStatic(..) => "a static",
 130             hir::ItemStruct(..) => "a struct",
 131             hir::ItemTrait(..) => "a trait",
 132             hir::ItemGlobalAsm(..) => "an assembly blob",
 133             hir::ItemTy(..) => "a type alias",
 134             hir::ItemUnion(..) => "a union",
 135             hir::ItemAutoImpl(..) |
 136             hir::ItemExternCrate(..) |
 137             hir::ItemForeignMod(..) |
 138             hir::ItemImpl(..) |
 139             hir::ItemUse(..) => return,
 140         };
 141
 142         self.check_missing_docs_attrs(cx, &it.attrs, it.span, desc);
 143     }
 144
 145     fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, trait_item: &'tcx hir::TraitItem) {
 146         let desc = match trait_item.node {
 147             hir::TraitItemKind::Const(..) => "an associated constant",
 148             hir::TraitItemKind::Method(..) => "a trait method",
 149             hir::TraitItemKind::Type(..) => "an associated type",
 150         };
 151
 152         self.check_missing_docs_attrs(cx, &trait_item.attrs, trait_item.span, desc);
 153     }
 154
 155     fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, impl_item: &'tcx hir::ImplItem) {
 156         // If the method is an impl for a trait, don't doc.
 157         let def_id = cx.tcx.hir.local_def_id(impl_item.id);
 158         match cx.tcx.associated_item(def_id).container {
 159             ty::TraitContainer(_) => return,
 160             ty::ImplContainer(cid) => if cx.tcx.impl_trait_ref(cid).is_some() {
 161                 return;
 162             },
 163         }
 164
 165         let desc = match impl_item.node {
 166             hir::ImplItemKind::Const(..) => "an associated constant",
 167             hir::ImplItemKind::Method(..) => "a method",
 168             hir::ImplItemKind::Type(_) => "an associated type",
 169         };
 170         self.check_missing_docs_attrs(cx, &impl_item.attrs, impl_item.span, desc);
 171     }
 172
 173     fn check_struct_field(&mut self, cx: &LateContext<'a, 'tcx>, sf: &'tcx hir::StructField) {
 174         if !sf.is_positional() {
 175             self.check_missing_docs_attrs(cx, &sf.attrs, sf.span, "a struct field");
 176         }
 177     }
 178
 179     fn check_variant(&mut self, cx: &LateContext<'a, 'tcx>, v: &'tcx hir::Variant, _: &hir::Generics) {
 180         self.check_missing_docs_attrs(cx, &v.node.attrs, v.span, "a variant");
 181     }
 182 }