Add a MISSING_DOCS_IN_PRIVATE_ITEMS lint

CHANGELOG.md

@@ -2,7 +2,7 @@
 All notable changes to this project will be documented in this file.
 
 ## 0.0.86 — ?
-* New lint: [`zero_prefixed_literal`]
+* New lints: [`missing_docs_in_private_items`], [`zero_prefixed_literal`]
 
 ## 0.0.85 — 2016-08-19
 * Fix ICE with [`useless_attribute`]
@@ -241,6 +241,7 @@ All notable changes to this project will be documented in this file.
 [`mem_forget`]: https://github.com/Manishearth/rust-clippy/wiki#mem_forget
 [`min_max`]: https://github.com/Manishearth/rust-clippy/wiki#min_max
 [`misrefactored_assign_op`]: https://github.com/Manishearth/rust-clippy/wiki#misrefactored_assign_op
+[`missing_docs_in_private_items`]: https://github.com/Manishearth/rust-clippy/wiki#missing_docs_in_private_items
 [`mixed_case_hex_literals`]: https://github.com/Manishearth/rust-clippy/wiki#mixed_case_hex_literals
 [`module_inception`]: https://github.com/Manishearth/rust-clippy/wiki#module_inception
 [`modulo_one`]: https://github.com/Manishearth/rust-clippy/wiki#modulo_one

README.md

@@ -17,7 +17,7 @@ Table of contents:
 
 ## Lints
 
-There are 167 lints included in this crate:
+There are 168 lints included in this crate:
 
 name                                                                                                                 | default | triggers on
 ---------------------------------------------------------------------------------------------------------------------|---------|----------------------------------------------------------------------------------------------------------------------------------
@@ -100,6 +100,7 @@ name
 [mem_forget](https://github.com/Manishearth/rust-clippy/wiki#mem_forget)                                             | allow   | `mem::forget` usage on `Drop` types, likely to cause memory leaks
 [min_max](https://github.com/Manishearth/rust-clippy/wiki#min_max)                                                   | warn    | `min(_, max(_, _))` (or vice versa) with bounds clamping the result to a constant
 [misrefactored_assign_op](https://github.com/Manishearth/rust-clippy/wiki#misrefactored_assign_op)                   | warn    | having a variable on both sides of an assign op
+[missing_docs_in_private_items](https://github.com/Manishearth/rust-clippy/wiki#missing_docs_in_private_items)       | allow   | detects missing documentation for public and private members
 [mixed_case_hex_literals](https://github.com/Manishearth/rust-clippy/wiki#mixed_case_hex_literals)                   | warn    | hex literals whose letter digits are not consistently upper- or lowercased
 [module_inception](https://github.com/Manishearth/rust-clippy/wiki#module_inception)                                 | warn    | modules that have the same name as their parent module
 [modulo_one](https://github.com/Manishearth/rust-clippy/wiki#modulo_one)                                             | warn    | taking a number modulo 1, which always returns 0

clippy_lints/src/lib.rs

@@ -10,7 +10,7 @@
 #![feature(stmt_expr_attributes)]
 #![feature(type_macros)]
 
-#![allow(indexing_slicing, shadow_reuse, unknown_lints)]
+#![allow(indexing_slicing, shadow_reuse, unknown_lints, missing_docs_in_private_items)]
 
 #[macro_use]
 extern crate syntax;
@@ -96,6 +96,7 @@ pub mod methods;
 pub mod minmax;
 pub mod misc;
 pub mod misc_early;
+pub mod missing_doc;
 pub mod module_inception;
 pub mod mut_mut;
 pub mod mut_reference;
@@ -260,6 +261,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
     reg.register_late_lint_pass(box assign_ops::AssignOps);
     reg.register_late_lint_pass(box let_if_seq::LetIfSeq);
     reg.register_late_lint_pass(box eval_order_dependence::EvalOrderDependence);
+    reg.register_late_lint_pass(box missing_doc::MissingDoc::new());
 
     reg.register_lint_group("clippy_restrictions", vec![
         arithmetic::FLOAT_ARITHMETIC,
@@ -282,6 +284,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
         methods::WRONG_PUB_SELF_CONVENTION,
         misc::USED_UNDERSCORE_BINDING,
         misc_early::UNSEPARATED_LITERAL_SUFFIX,
+        missing_doc::MISSING_DOCS_IN_PRIVATE_ITEMS,
         mut_mut::MUT_MUT,
         mutex_atomic::MUTEX_INTEGER,
         non_expressive_names::SIMILAR_NAMES,

clippy_lints/src/missing_doc.rs

@@ -0,0 +1,172 @@
+/* This file incorporates work covered by the following copyright and
+ * permission notice:
+ *   Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
+ *   file at the top-level directory of this distribution and at
+ *   http://rust-lang.org/COPYRIGHT.
+ *
+ *   Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+ *   http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+ *   <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+ *   option. This file may not be copied, modified, or distributed
+ *   except according to those terms.
+ */
+
+/* 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 rustc::hir;
+use rustc::lint::*;
+use rustc::ty;
+use syntax::ast;
+use syntax::attr::{self, AttrMetaMethods};
+use syntax::codemap::Span;
+
+/// **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.
+declare_lint! {
+    pub MISSING_DOCS_IN_PRIVATE_ITEMS,
+    Allow,
+    "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 ::std::default::Default for MissingDoc {
+    fn default() -> MissingDoc {
+        MissingDoc::new()
+    }
+}
+
+impl MissingDoc {
+    pub fn new() -> MissingDoc {
+        MissingDoc {
+            doc_hidden_stack: vec![false],
+        }
+    }
+
+    fn doc_hidden(&self) -> bool {
+        *self.doc_hidden_stack.last().expect("empty doc_hidden_stack")
+    }
+
+    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;
+        }
+
+        let has_doc = attrs.iter().any(|a| a.is_value_str() && a.name() == "doc");
+        if !has_doc {
+            cx.span_lint(MISSING_DOCS_IN_PRIVATE_ITEMS, sp,
+                         &format!("missing documentation for {}", desc));
+        }
+    }
+}
+
+impl LintPass for MissingDoc {
+    fn get_lints(&self) -> LintArray {
+        lint_array![MISSING_DOCS_IN_PRIVATE_ITEMS]
+    }
+}
+
+impl LateLintPass for MissingDoc {
+    fn enter_lint_attrs(&mut self, _: &LateContext, attrs: &[ast::Attribute]) {
+        let doc_hidden = self.doc_hidden() || attrs.iter().any(|attr| {
+            attr.check_name("doc") && match attr.meta_item_list() {
+                None => false,
+                Some(l) => attr::contains_name(&l[..], "hidden"),
+            }
+        });
+        self.doc_hidden_stack.push(doc_hidden);
+    }
+
+    fn exit_lint_attrs(&mut self, _: &LateContext, _: &[ast::Attribute]) {
+        self.doc_hidden_stack.pop().expect("empty doc_hidden_stack");
+    }
+
+    fn check_crate(&mut self, cx: &LateContext, krate: &hir::Crate) {
+        self.check_missing_docs_attrs(cx, &krate.attrs, krate.span, "crate");
+    }
+
+    fn check_item(&mut self, cx: &LateContext, it: &hir::Item) {
+        let desc = match it.node {
+            hir::ItemConst(..) => "a constant",
+            hir::ItemEnum(..) => "an enum",
+            hir::ItemFn(..) => "a function",
+            hir::ItemMod(..) => "a module",
+            hir::ItemStatic(..) => "a static",
+            hir::ItemStruct(..) => "a struct",
+            hir::ItemTrait(..) => "a trait",
+            hir::ItemTy(..) => "a type alias",
+            hir::ItemDefaultImpl(..) |
+            hir::ItemExternCrate(..) |
+            hir::ItemForeignMod(..) |
+            hir::ItemImpl(..) |
+            hir::ItemUse(..) => return,
+        };
+
+        self.check_missing_docs_attrs(cx, &it.attrs, it.span, desc);
+    }
+
+    fn check_trait_item(&mut self, cx: &LateContext, trait_item: &hir::TraitItem) {
+        let desc = match trait_item.node {
+            hir::ConstTraitItem(..) => "an associated constant",
+            hir::MethodTraitItem(..) => "a trait method",
+            hir::TypeTraitItem(..) => "an associated type",
+        };
+
+        self.check_missing_docs_attrs(cx, &trait_item.attrs, trait_item.span, desc);
+    }
+
+    fn check_impl_item(&mut self, cx: &LateContext, impl_item: &hir::ImplItem) {
+        // If the method is an impl for a trait, don't doc.
+        let def_id = cx.tcx.map.local_def_id(impl_item.id);
+        match cx.tcx.impl_or_trait_items.borrow()
+                                         .get(&def_id)
+                                         .expect("missing method descriptor?!")
+                                         .container() {
+            ty::TraitContainer(_) => return,
+            ty::ImplContainer(cid) => {
+                if cx.tcx.impl_trait_ref(cid).is_some() {
+                    return
+                }
+            }
+        }
+
+        let desc = match impl_item.node {
+            hir::ImplItemKind::Const(..) => "an associated constant",
+            hir::ImplItemKind::Method(..) => "a method",
+            hir::ImplItemKind::Type(_) => "an associated type",
+        };
+        self.check_missing_docs_attrs(cx, &impl_item.attrs, impl_item.span, desc);
+    }
+
+    fn check_struct_field(&mut self, cx: &LateContext, sf: &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, v: &hir::Variant, _: &hir::Generics) {
+        self.check_missing_docs_attrs(cx, &v.node.attrs, v.span, "a variant");
+    }
+}

src/lib.rs

@@ -2,6 +2,7 @@
 #![feature(plugin_registrar)]
 #![feature(rustc_private)]
 #![allow(unknown_lints)]
+#![allow(missing_docs_in_private_items)]
 
 extern crate rustc_plugin;
 use rustc_plugin::Registry;

src/main.rs

@@ -2,6 +2,8 @@
 #![feature(box_syntax)]
 #![feature(rustc_private)]
 
+#![allow(unknown_lints, missing_docs_in_private_items)]
+
 extern crate clippy_lints;
 extern crate getopts;
 extern crate rustc;

tests/compile-fail/enum_glob_use.rs

@@ -1,7 +1,7 @@
 #![feature(plugin)]
 #![plugin(clippy)]
 #![deny(clippy, clippy_pedantic)]
-#![allow(unused_imports, dead_code)]
+#![allow(unused_imports, dead_code, missing_docs_in_private_items)]
 
 use std::cmp::Ordering::*; //~ ERROR: don't use glob imports for enum variants
 

tests/compile-fail/filter_methods.rs

@@ -2,6 +2,8 @@
 #![plugin(clippy)]
 
 #![deny(clippy, clippy_pedantic)]
+#![allow(missing_docs_in_private_items)]
+
 fn main() {
     let _: Vec<_> = vec![5; 6].into_iter() //~ERROR called `filter(p).map(q)` on an `Iterator`
                               .filter(|&x| x == 0)

tests/compile-fail/methods.rs

@@ -3,7 +3,7 @@
 #![plugin(clippy)]
 
 #![deny(clippy, clippy_pedantic)]
-#![allow(blacklisted_name, unused, print_stdout, non_ascii_literal, new_without_default, new_without_default_derive)]
+#![allow(blacklisted_name, unused, print_stdout, non_ascii_literal, new_without_default, new_without_default_derive, missing_docs_in_private_items)]
 
 use std::collections::BTreeMap;
 use std::collections::HashMap;

tests/compile-fail/missing-doc.rs

@@ -0,0 +1,202 @@
+/* This file incorporates work covered by the following copyright and
+ * permission notice:
+ *   Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+ *   file at the top-level directory of this distribution and at
+ *   http://rust-lang.org/COPYRIGHT.
+ *
+ *   Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+ *   http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+ *   <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+ *   option. This file may not be copied, modified, or distributed
+ *   except according to those terms.
+ */
+
+#![feature(plugin)]
+#![plugin(clippy)]
+#![deny(missing_docs_in_private_items)]
+
+// When denying at the crate level, be sure to not get random warnings from the
+// injected intrinsics by the compiler.
+#![allow(dead_code)]
+#![feature(associated_type_defaults)]
+
+//! Some garbage docs for the crate here
+#![doc="More garbage"]
+
+type Typedef = String; //~ ERROR: missing documentation for a type alias
+pub type PubTypedef = String; //~ ERROR: missing documentation for a type alias
+
+struct Foo { //~ ERROR: missing documentation for a struct
+    a: isize, //~ ERROR: missing documentation for a struct field
+    b: isize, //~ ERROR: missing documentation for a struct field
+}
+
+pub struct PubFoo { //~ ERROR: missing documentation for a struct
+    pub a: isize,      //~ ERROR: missing documentation for a struct field
+    b: isize, //~ ERROR: missing documentation for a struct field
+}
+
+#[allow(missing_docs_in_private_items)]
+pub struct PubFoo2 {
+    pub a: isize,
+    pub c: isize,
+}
+
+mod module_no_dox {} //~ ERROR: missing documentation for a module
+pub mod pub_module_no_dox {} //~ ERROR: missing documentation for a module
+
+/// dox
+pub fn foo() {}
+pub fn foo2() {} //~ ERROR: missing documentation for a function
+fn foo3() {} //~ ERROR: missing documentation for a function
+#[allow(missing_docs_in_private_items)] pub fn foo4() {}
+
+/// dox
+pub trait A {
+    /// dox
+    fn foo(&self);
+    /// dox
+    fn foo_with_impl(&self) {}
+}
+
+#[allow(missing_docs_in_private_items)]
+trait B {
+    fn foo(&self);
+    fn foo_with_impl(&self) {}
+}
+
+pub trait C { //~ ERROR: missing documentation for a trait
+    fn foo(&self); //~ ERROR: missing documentation for a trait method
+    fn foo_with_impl(&self) {} //~ ERROR: missing documentation for a trait method
+}
+
+#[allow(missing_docs_in_private_items)]
+pub trait D {
+    fn dummy(&self) { }
+}
+
+/// dox
+pub trait E {
+    type AssociatedType; //~ ERROR: missing documentation for an associated type
+    type AssociatedTypeDef = Self; //~ ERROR: missing documentation for an associated type
+
+    /// dox
+    type DocumentedType;
+    /// dox
+    type DocumentedTypeDef = Self;
+    /// dox
+    fn dummy(&self) {}
+}
+
+impl Foo {
+    pub fn foo() {} //~ ERROR: missing documentation for a method
+    fn bar() {} //~ ERROR: missing documentation for a method
+}
+
+impl PubFoo {
+    pub fn foo() {} //~ ERROR: missing documentation for a method
+    /// dox
+    pub fn foo1() {}
+    fn foo2() {} //~ ERROR: missing documentation for a method
+    #[allow(missing_docs_in_private_items)] pub fn foo3() {}
+}
+
+#[allow(missing_docs_in_private_items)]
+trait F {
+    fn a();
+    fn b(&self);
+}
+
+// should need to redefine documentation for implementations of traits
+impl F for Foo {
+    fn a() {}
+    fn b(&self) {}
+}
+
+// It sure is nice if doc(hidden) implies allow(missing_docs), and that it
+// applies recursively
+#[doc(hidden)]
+mod a {
+    pub fn baz() {}
+    pub mod b {
+        pub fn baz() {}
+    }
+}
+
+enum Baz { //~ ERROR: missing documentation for an enum
+    BazA { //~ ERROR: missing documentation for a variant
+        a: isize, //~ ERROR: missing documentation for a struct field
+        b: isize //~ ERROR: missing documentation for a struct field
+    },
+    BarB //~ ERROR: missing documentation for a variant
+}
+
+pub enum PubBaz { //~ ERROR: missing documentation for an enum
+    PubBazA { //~ ERROR: missing documentation for a variant
+        a: isize, //~ ERROR: missing documentation for a struct field
+    },
+}
+
+/// dox
+pub enum PubBaz2 {
+    /// dox
+    PubBaz2A {
+        /// dox
+        a: isize,
+    },
+}
+
+#[allow(missing_docs_in_private_items)]
+pub enum PubBaz3 {
+    PubBaz3A {
+        b: isize
+    },
+}
+
+#[doc(hidden)]
+pub fn baz() {}
+
+
+const FOO: u32 = 0; //~ ERROR: missing documentation for a const
+/// dox
+pub const FOO1: u32 = 0;
+#[allow(missing_docs_in_private_items)]
+pub const FOO2: u32 = 0;
+#[doc(hidden)]
+pub const FOO3: u32 = 0;
+pub const FOO4: u32 = 0; //~ ERROR: missing documentation for a const
+
+
+static BAR: u32 = 0; //~ ERROR: missing documentation for a static
+/// dox
+pub static BAR1: u32 = 0;
+#[allow(missing_docs_in_private_items)]
+pub static BAR2: u32 = 0;
+#[doc(hidden)]
+pub static BAR3: u32 = 0;
+pub static BAR4: u32 = 0; //~ ERROR: missing documentation for a static
+
+
+mod internal_impl { //~ ERROR: missing documentation for a module
+    /// dox
+    pub fn documented() {}
+    pub fn undocumented1() {} //~ ERROR: missing documentation for a function
+    pub fn undocumented2() {} //~ ERROR: missing documentation for a function
+    fn undocumented3() {} //~ ERROR: missing documentation for a function
+    /// dox
+    pub mod globbed {
+        /// dox
+        pub fn also_documented() {}
+        pub fn also_undocumented1() {} //~ ERROR: missing documentation for a function
+        fn also_undocumented2() {} //~ ERROR: missing documentation for a function
+    }
+}
+/// dox
+pub mod public_interface {
+    pub use internal_impl::documented as foo;
+    pub use internal_impl::undocumented1 as bar;
+    pub use internal_impl::{documented, undocumented2};
+    pub use internal_impl::globbed::*;
+}
+
+fn main() {} //~ ERROR: missing documentation for a function

tests/compile-fail/shadow.rs

@@ -1,8 +1,8 @@
 #![feature(plugin)]
 #![plugin(clippy)]
 
-#![allow(unused_parens, unused_variables)]
 #![deny(clippy, clippy_pedantic)]
+#![allow(unused_parens, unused_variables, missing_docs_in_private_items)]
 
 fn id<T>(x: T) -> T { x }