update clippy to the rustc-pr-67224 branch

Actually to commit <69f99e74ac2266dff4b5adc7c59b35236f0abef1>.

Author: nikomatsakis

CHANGELOG.md

@@ -1092,6 +1092,7 @@ Released 2018-09-13
 [`misrefactored_assign_op`]: https://rust-lang.github.io/rust-clippy/master/index.html#misrefactored_assign_op
 [`missing_const_for_fn`]: https://rust-lang.github.io/rust-clippy/master/index.html#missing_const_for_fn
 [`missing_docs_in_private_items`]: https://rust-lang.github.io/rust-clippy/master/index.html#missing_docs_in_private_items
+[`missing_errors_doc`]: https://rust-lang.github.io/rust-clippy/master/index.html#missing_errors_doc
 [`missing_inline_in_public_items`]: https://rust-lang.github.io/rust-clippy/master/index.html#missing_inline_in_public_items
 [`missing_safety_doc`]: https://rust-lang.github.io/rust-clippy/master/index.html#missing_safety_doc
 [`mistyped_literal_suffixes`]: https://rust-lang.github.io/rust-clippy/master/index.html#mistyped_literal_suffixes
@@ -1213,6 +1214,7 @@ Released 2018-09-13
 [`too_many_lines`]: https://rust-lang.github.io/rust-clippy/master/index.html#too_many_lines
 [`toplevel_ref_arg`]: https://rust-lang.github.io/rust-clippy/master/index.html#toplevel_ref_arg
 [`transmute_bytes_to_str`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_bytes_to_str
+[`transmute_float_to_int`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_float_to_int
 [`transmute_int_to_bool`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_int_to_bool
 [`transmute_int_to_char`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_int_to_char
 [`transmute_int_to_float`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_int_to_float

README.md

@@ -6,7 +6,7 @@
 
 A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.
 
-[There are 338 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
+[There are 340 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
 
 We have a bunch of lint categories to allow you to choose how much Clippy is supposed to ~~annoy~~ help you:
 

clippy_lints/src/doc.rs

@@ -1,4 +1,4 @@
-use crate::utils::span_lint;
+use crate::utils::{match_type, paths, return_ty, span_lint};
 use itertools::Itertools;
 use pulldown_cmark;
 use rustc::hir;
@@ -8,7 +8,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_session::declare_tool_lint;
 use std::ops::Range;
 use syntax::ast::{AttrKind, Attribute};
-use syntax::source_map::{BytePos, Span};
+use syntax::source_map::{BytePos, MultiSpan, Span};
 use syntax_pos::Pos;
 use url::Url;
 
@@ -45,7 +45,7 @@ declare_clippy_lint! {
     ///
     /// **Known problems:** None.
     ///
-    /// **Examples**:
+    /// **Examples:**
     /// ```rust
     ///# type Universe = ();
     /// /// This function should really be documented
@@ -70,6 +70,35 @@ declare_clippy_lint! {
     "`pub unsafe fn` without `# Safety` docs"
 }
 
+declare_clippy_lint! {
+    /// **What it does:** Checks the doc comments of publicly visible functions that
+    /// return a `Result` type and warns if there is no `# Errors` section.
+    ///
+    /// **Why is this bad?** Documenting the type of errors that can be returned from a
+    /// function can help callers write code to handle the errors appropriately.
+    ///
+    /// **Known problems:** None.
+    ///
+    /// **Examples:**
+    ///
+    /// Since the following function returns a `Result` it has an `# Errors` section in
+    /// its doc comment:
+    ///
+    /// ```rust
+    ///# use std::io;
+    /// /// # Errors
+    /// ///
+    /// /// Will return `Err` if `filename` does not exist or the user does not have
+    /// /// permission to read it.
+    /// pub fn read(filename: String) -> io::Result<String> {
+    ///     unimplemented!();
+    /// }
+    /// ```
+    pub MISSING_ERRORS_DOC,
+    pedantic,
+    "`pub fn` returns `Result` without `# Errors` in doc comment"
+}
+
 declare_clippy_lint! {
     /// **What it does:** Checks for `fn main() { .. }` in doctests
     ///
@@ -114,28 +143,18 @@ impl DocMarkdown {
     }
 }
 
-impl_lint_pass!(DocMarkdown => [DOC_MARKDOWN, MISSING_SAFETY_DOC, NEEDLESS_DOCTEST_MAIN]);
+impl_lint_pass!(DocMarkdown => [DOC_MARKDOWN, MISSING_SAFETY_DOC, MISSING_ERRORS_DOC, NEEDLESS_DOCTEST_MAIN]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DocMarkdown {
     fn check_crate(&mut self, cx: &LateContext<'a, 'tcx>, krate: &'tcx hir::Crate) {
         check_attrs(cx, &self.valid_idents, &krate.attrs);
     }
 
     fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item) {
-        if check_attrs(cx, &self.valid_idents, &item.attrs) {
-            return;
-        }
-        // no safety header
+        let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
         match item.kind {
             hir::ItemKind::Fn(ref sig, ..) => {
-                if cx.access_levels.is_exported(item.hir_id) && sig.header.unsafety == hir::Unsafety::Unsafe {
-                    span_lint(
-                        cx,
-                        MISSING_SAFETY_DOC,
-                        item.span,
-                        "unsafe function's docs miss `# Safety` section",
-                    );
-                }
+                lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers);
             },
             hir::ItemKind::Impl(_, _, _, _, ref trait_ref, ..) => {
                 self.in_trait_impl = trait_ref.is_some();
@@ -151,40 +170,51 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DocMarkdown {
     }
 
     fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::TraitItem) {
-        if check_attrs(cx, &self.valid_idents, &item.attrs) {
-            return;
-        }
-        // no safety header
+        let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
         if let hir::TraitItemKind::Method(ref sig, ..) = item.kind {
-            if cx.access_levels.is_exported(item.hir_id) && sig.header.unsafety == hir::Unsafety::Unsafe {
-                span_lint(
-                    cx,
-                    MISSING_SAFETY_DOC,
-                    item.span,
-                    "unsafe function's docs miss `# Safety` section",
-                );
-            }
+            lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers);
         }
     }
 
     fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::ImplItem) {
-        if check_attrs(cx, &self.valid_idents, &item.attrs) || self.in_trait_impl {
+        let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
+        if self.in_trait_impl {
             return;
         }
-        // no safety header
         if let hir::ImplItemKind::Method(ref sig, ..) = item.kind {
-            if cx.access_levels.is_exported(item.hir_id) && sig.header.unsafety == hir::Unsafety::Unsafe {
-                span_lint(
-                    cx,
-                    MISSING_SAFETY_DOC,
-                    item.span,
-                    "unsafe function's docs miss `# Safety` section",
-                );
-            }
+            lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers);
         }
     }
 }
 
+fn lint_for_missing_headers<'a, 'tcx>(
+    cx: &LateContext<'a, 'tcx>,
+    hir_id: hir::HirId,
+    span: impl Into<MultiSpan> + Copy,
+    sig: &hir::FnSig,
+    headers: DocHeaders,
+) {
+    if !cx.access_levels.is_exported(hir_id) {
+        return; // Private functions do not require doc comments
+    }
+    if !headers.safety && sig.header.unsafety == hir::Unsafety::Unsafe {
+        span_lint(
+            cx,
+            MISSING_SAFETY_DOC,
+            span,
+            "unsafe function's docs miss `# Safety` section",
+        );
+    }
+    if !headers.errors && match_type(cx, return_ty(cx, hir_id), &paths::RESULT) {
+        span_lint(
+            cx,
+            MISSING_ERRORS_DOC,
+            span,
+            "docs for function returning `Result` missing `# Errors` section",
+        );
+    }
+}
+
 /// Cleanup documentation decoration (`///` and such).
 ///
 /// We can't use `syntax::attr::AttributeMethods::with_desugared_doc` or
@@ -243,7 +273,13 @@ pub fn strip_doc_comment_decoration(comment: &str, span: Span) -> (String, Vec<(
     panic!("not a doc-comment: {}", comment);
 }
 
-pub fn check_attrs<'a>(cx: &LateContext<'_, '_>, valid_idents: &FxHashSet<String>, attrs: &'a [Attribute]) -> bool {
+#[derive(Copy, Clone)]
+struct DocHeaders {
+    safety: bool,
+    errors: bool,
+}
+
+fn check_attrs<'a>(cx: &LateContext<'_, '_>, valid_idents: &FxHashSet<String>, attrs: &'a [Attribute]) -> DocHeaders {
     let mut doc = String::new();
     let mut spans = vec![];
 
@@ -255,7 +291,11 @@ pub fn check_attrs<'a>(cx: &LateContext<'_, '_>, valid_idents: &FxHashSet<String
             doc.push_str(&comment);
         } else if attr.check_name(sym!(doc)) {
             // ignore mix of sugared and non-sugared doc
-            return true; // don't trigger the safety check
+            // don't trigger the safety or errors check
+            return DocHeaders {
+                safety: true,
+                errors: true,
+            };
         }
     }
 
@@ -267,7 +307,10 @@ pub fn check_attrs<'a>(cx: &LateContext<'_, '_>, valid_idents: &FxHashSet<String
     }
 
     if doc.is_empty() {
-        return false;
+        return DocHeaders {
+            safety: false,
+            errors: false,
+        };
     }
 
     let parser = pulldown_cmark::Parser::new(&doc).into_offset_iter();
@@ -295,12 +338,15 @@ fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize
     valid_idents: &FxHashSet<String>,
     events: Events,
     spans: &[(usize, Span)],
-) -> bool {
+) -> DocHeaders {
     // true if a safety header was found
     use pulldown_cmark::Event::*;
     use pulldown_cmark::Tag::*;
 
-    let mut safety_header = false;
+    let mut headers = DocHeaders {
+        safety: false,
+        errors: false,
+    };
     let mut in_code = false;
     let mut in_link = None;
     let mut in_heading = false;
@@ -323,7 +369,8 @@ fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize
                     // text "http://example.com" by pulldown-cmark
                     continue;
                 }
-                safety_header |= in_heading && text.trim() == "Safety";
+                headers.safety |= in_heading && text.trim() == "Safety";
+                headers.errors |= in_heading && text.trim() == "Errors";
                 let index = match spans.binary_search_by(|c| c.0.cmp(&range.start)) {
                     Ok(o) => o,
                     Err(e) => e - 1,
@@ -340,7 +387,7 @@ fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize
             },
         }
     }
-    safety_header
+    headers
 }
 
 fn check_code(cx: &LateContext<'_, '_>, text: &str, span: Span) {

clippy_lints/src/functions.rs

@@ -449,6 +449,7 @@ fn check_must_use_candidate<'a, 'tcx>(
         || mutates_static(cx, body)
         || in_external_macro(cx.sess(), item_span)
         || returns_unit(decl)
+        || !cx.access_levels.is_exported(item_id)
         || is_must_use_ty(cx, return_ty(cx, item_id))
     {
         return;

clippy_lints/src/lib.rs

@@ -488,6 +488,7 @@ pub fn register_plugins(store: &mut lint::LintStore, sess: &Session, conf: &Conf
         &derive::DERIVE_HASH_XOR_EQ,
         &derive::EXPL_IMPL_CLONE_ON_COPY,
         &doc::DOC_MARKDOWN,
+        &doc::MISSING_ERRORS_DOC,
         &doc::MISSING_SAFETY_DOC,
         &doc::NEEDLESS_DOCTEST_MAIN,
         &double_comparison::DOUBLE_COMPARISONS,
@@ -734,6 +735,7 @@ pub fn register_plugins(store: &mut lint::LintStore, sess: &Session, conf: &Conf
         &trait_bounds::TYPE_REPETITION_IN_BOUNDS,
         &transmute::CROSSPOINTER_TRANSMUTE,
         &transmute::TRANSMUTE_BYTES_TO_STR,
+        &transmute::TRANSMUTE_FLOAT_TO_INT,
         &transmute::TRANSMUTE_INT_TO_BOOL,
         &transmute::TRANSMUTE_INT_TO_CHAR,
         &transmute::TRANSMUTE_INT_TO_FLOAT,
@@ -1013,6 +1015,7 @@ pub fn register_plugins(store: &mut lint::LintStore, sess: &Session, conf: &Conf
         LintId::of(&default_trait_access::DEFAULT_TRAIT_ACCESS),
         LintId::of(&derive::EXPL_IMPL_CLONE_ON_COPY),
         LintId::of(&doc::DOC_MARKDOWN),
+        LintId::of(&doc::MISSING_ERRORS_DOC),
         LintId::of(&empty_enum::EMPTY_ENUM),
         LintId::of(&enum_glob_use::ENUM_GLOB_USE),
         LintId::of(&enum_variants::MODULE_NAME_REPETITIONS),
@@ -1584,6 +1587,7 @@ pub fn register_plugins(store: &mut lint::LintStore, sess: &Session, conf: &Conf
         LintId::of(&mutex_atomic::MUTEX_INTEGER),
         LintId::of(&needless_borrow::NEEDLESS_BORROW),
         LintId::of(&path_buf_push_overwrite::PATH_BUF_PUSH_OVERWRITE),
+        LintId::of(&transmute::TRANSMUTE_FLOAT_TO_INT),
         LintId::of(&use_self::USE_SELF),
     ]);
 }

clippy_lints/src/strings.rs

@@ -1,6 +1,6 @@
 use rustc::declare_lint_pass;
 use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintContext, LintPass};
 use rustc_errors::Applicability;
 use rustc_session::declare_tool_lint;
 use syntax::source_map::Spanned;
@@ -80,6 +80,10 @@ declare_lint_pass!(StringAdd => [STRING_ADD, STRING_ADD_ASSIGN]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for StringAdd {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
+        if in_external_macro(cx.sess(), e.span) {
+            return;
+        }
+
         if let ExprKind::Binary(
             Spanned {
                 node: BinOpKind::Add, ..