Merge branch 'master' of https://github.com/rust-lang/rust-clippy

Author: suyashb95

CHANGELOG.md

@@ -1632,6 +1632,7 @@ Released 2018-09-13
 [`assign_ops`]: https://rust-lang.github.io/rust-clippy/master/index.html#assign_ops
 [`async_yields_async`]: https://rust-lang.github.io/rust-clippy/master/index.html#async_yields_async
 [`await_holding_lock`]: https://rust-lang.github.io/rust-clippy/master/index.html#await_holding_lock
+[`await_holding_refcell_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#await_holding_refcell_ref
 [`bad_bit_mask`]: https://rust-lang.github.io/rust-clippy/master/index.html#bad_bit_mask
 [`bind_instead_of_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#bind_instead_of_map
 [`blacklisted_name`]: https://rust-lang.github.io/rust-clippy/master/index.html#blacklisted_name
@@ -1779,6 +1780,7 @@ Released 2018-09-13
 [`large_digit_groups`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_digit_groups
 [`large_enum_variant`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_enum_variant
 [`large_stack_arrays`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_stack_arrays
+[`large_types_passed_by_value`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_types_passed_by_value
 [`len_without_is_empty`]: https://rust-lang.github.io/rust-clippy/master/index.html#len_without_is_empty
 [`len_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
 [`let_and_return`]: https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return
@@ -1793,6 +1795,7 @@ Released 2018-09-13
 [`manual_async_fn`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_async_fn
 [`manual_memcpy`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_memcpy
 [`manual_non_exhaustive`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_non_exhaustive
+[`manual_range_contains`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_contains
 [`manual_saturating_arithmetic`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_saturating_arithmetic
 [`manual_strip`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_strip
 [`manual_swap`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_swap
@@ -1841,6 +1844,7 @@ Released 2018-09-13
 [`must_use_unit`]: https://rust-lang.github.io/rust-clippy/master/index.html#must_use_unit
 [`mut_from_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#mut_from_ref
 [`mut_mut`]: https://rust-lang.github.io/rust-clippy/master/index.html#mut_mut
+[`mut_mutex_lock`]: https://rust-lang.github.io/rust-clippy/master/index.html#mut_mutex_lock
 [`mut_range_bound`]: https://rust-lang.github.io/rust-clippy/master/index.html#mut_range_bound
 [`mutable_key_type`]: https://rust-lang.github.io/rust-clippy/master/index.html#mutable_key_type
 [`mutex_atomic`]: https://rust-lang.github.io/rust-clippy/master/index.html#mutex_atomic
@@ -1936,6 +1940,7 @@ Released 2018-09-13
 [`single_char_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_char_pattern
 [`single_char_push_str`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_char_push_str
 [`single_component_path_imports`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_component_path_imports
+[`single_element_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
 [`single_match`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_match
 [`single_match_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_match_else
 [`skip_while_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#skip_while_next
@@ -1979,6 +1984,7 @@ Released 2018-09-13
 [`try_err`]: https://rust-lang.github.io/rust-clippy/master/index.html#try_err
 [`type_complexity`]: https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity
 [`type_repetition_in_bounds`]: https://rust-lang.github.io/rust-clippy/master/index.html#type_repetition_in_bounds
+[`undropped_manually_drops`]: https://rust-lang.github.io/rust-clippy/master/index.html#undropped_manually_drops
 [`unicode_not_nfc`]: https://rust-lang.github.io/rust-clippy/master/index.html#unicode_not_nfc
 [`unimplemented`]: https://rust-lang.github.io/rust-clippy/master/index.html#unimplemented
 [`uninit_assumed_init`]: https://rust-lang.github.io/rust-clippy/master/index.html#uninit_assumed_init
@@ -2011,6 +2017,7 @@ Released 2018-09-13
 [`unused_label`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_label
 [`unused_self`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_self
 [`unused_unit`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_unit
+[`unusual_byte_groupings`]: https://rust-lang.github.io/rust-clippy/master/index.html#unusual_byte_groupings
 [`unwrap_in_result`]: https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_in_result
 [`unwrap_used`]: https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_used
 [`use_debug`]: https://rust-lang.github.io/rust-clippy/master/index.html#use_debug

CONTRIBUTING.md

@@ -316,8 +316,8 @@ If you have @bors permissions, you can find an overview of the available
 commands [here][homu_instructions].
 
 [triage]: https://forge.rust-lang.org/release/triage-procedure.html
-[l-crash]: https://github.com/rust-lang/rust-clippy/labels/L-crash%20%3Aboom%3A
-[l-bug]: https://github.com/rust-lang/rust-clippy/labels/L-bug%20%3Abeetle%3A
+[l-crash]: https://github.com/rust-lang/rust-clippy/labels/L-crash
+[l-bug]: https://github.com/rust-lang/rust-clippy/labels/L-bug
 [homu]: https://github.com/rust-lang/homu
 [homu_instructions]: https://buildbot2.rust-lang.org/homu/
 [homu_queue]: https://buildbot2.rust-lang.org/homu/queue/clippy

clippy_lints/src/await_holding_lock.rs renamed to clippy_lints/src/await_holding_invalid.rs

@@ -45,13 +45,52 @@ declare_clippy_lint! {
     /// }
     /// ```
     pub AWAIT_HOLDING_LOCK,
-    pedantic,
+    correctness,
     "Inside an async function, holding a MutexGuard while calling await"
 }
 
-declare_lint_pass!(AwaitHoldingLock => [AWAIT_HOLDING_LOCK]);
+declare_clippy_lint! {
+    /// **What it does:** Checks for calls to await while holding a
+    /// `RefCell` `Ref` or `RefMut`.
+    ///
+    /// **Why is this bad?** `RefCell` refs only check for exclusive mutable access
+    /// at runtime. Holding onto a `RefCell` ref across an `await` suspension point
+    /// risks panics from a mutable ref shared while other refs are outstanding.
+    ///
+    /// **Known problems:** None.
+    ///
+    /// **Example:**
+    ///
+    /// ```rust,ignore
+    /// use std::cell::RefCell;
+    ///
+    /// async fn foo(x: &RefCell<u32>) {
+    ///   let b = x.borrow_mut()();
+    ///   *ref += 1;
+    ///   bar.await;
+    /// }
+    /// ```
+    ///
+    /// Use instead:
+    /// ```rust,ignore
+    /// use std::cell::RefCell;
+    ///
+    /// async fn foo(x: &RefCell<u32>) {
+    ///   {
+    ///     let b = x.borrow_mut();
+    ///     *ref += 1;
+    ///   }
+    ///   bar.await;
+    /// }
+    /// ```
+    pub AWAIT_HOLDING_REFCELL_REF,
+    correctness,
+    "Inside an async function, holding a RefCell ref while calling await"
+}
 
-impl LateLintPass<'_> for AwaitHoldingLock {
+declare_lint_pass!(AwaitHolding => [AWAIT_HOLDING_LOCK, AWAIT_HOLDING_REFCELL_REF]);
+
+impl LateLintPass<'_> for AwaitHolding {
     fn check_body(&mut self, cx: &LateContext<'_>, body: &'_ Body<'_>) {
         use AsyncGeneratorKind::{Block, Closure, Fn};
         if let Some(GeneratorKind::Async(Block | Closure | Fn)) = body.generator_kind {
@@ -78,6 +117,16 @@ fn check_interior_types(cx: &LateContext<'_>, ty_causes: &[GeneratorInteriorType
                     "these are all the await points this lock is held through",
                 );
             }
+            if is_refcell_ref(cx, adt.did) {
+                span_lint_and_note(
+                        cx,
+                        AWAIT_HOLDING_REFCELL_REF,
+                        ty_cause.span,
+                        "this RefCell Ref is held across an 'await' point. Consider ensuring the Ref is dropped before calling await.",
+                        ty_cause.scope_span.or(Some(span)),
+                        "these are all the await points this ref is held through",
+                    );
+            }
         }
     }
 }
@@ -90,3 +139,7 @@ fn is_mutex_guard(cx: &LateContext<'_>, def_id: DefId) -> bool {
         || match_def_path(cx, def_id, &paths::PARKING_LOT_RWLOCK_READ_GUARD)
         || match_def_path(cx, def_id, &paths::PARKING_LOT_RWLOCK_WRITE_GUARD)
 }
+
+fn is_refcell_ref(cx: &LateContext<'_>, def_id: DefId) -> bool {
+    match_def_path(cx, def_id, &paths::REFCELL_REF) || match_def_path(cx, def_id, &paths::REFCELL_REFMUT)
+}

clippy_lints/src/blocks_in_if_conditions.rs

@@ -28,7 +28,6 @@ declare_clippy_lint! {
     ///
     /// ```rust
     /// # fn somefunc() -> bool { true };
-    ///
     /// // Bad
     /// if { let x = somefunc(); x } { /* ... */ }
     ///