10 files changed, 40 insertions, 31 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 5b69e3cab..49022502d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -214,9 +214,9 @@ dependencies = [
 
 [[package]]
 name = "chrono"
-version = "0.4.18"
+version = "0.4.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d021fddb7bd3e734370acfa4a83f34095571d8570c039f1420d77540f68d5772"
+checksum = "670ad68c9088c2a963aaa298cb369688cf3f9465ce5e2d4ca10e6e0098a1ce73"
 dependencies = [
  "libc",
  "num-integer",
@@ -365,9 +365,9 @@ checksum = "37ab347416e802de484e4d03c7316c48f1ecb56574dfd4a46a80f173ce1de04d"
 
 [[package]]
 name = "flate2"
-version = "1.0.17"
+version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "766d0e77a2c1502169d4a93ff3b8c15a71fd946cd0126309752104e5f3c46d94"
+checksum = "da80be589a72651dcda34d8b35bcdc9b7254ad06325611074d9cc0fbb19f60ee"
 dependencies = [
  "cfg-if",
  "crc32fast",
@@ -725,9 +725,9 @@ checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.77"
+version = "0.2.78"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2f96b10ec2560088a8e76961b00d47107b3a625fecb76dedb29ee7ccbf98235"
+checksum = "aa7087f49d294270db4e1928fc110c976cd4b9e5a16348e0a1df09afa99e6c98"
 
 [[package]]
 name = "libloading"
@@ -1071,9 +1071,9 @@ checksum = "28b9b4df73455c861d7cbf8be42f01d3b373ed7f02e378d55fa84eafc6f638b1"
 
 [[package]]
 name = "pin-project-lite"
-version = "0.1.9"
+version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fe74897791e156a0cd8cce0db31b9b2198e67877316bf3086c3acd187f719f0"
+checksum = "e555d9e657502182ac97b539fb3dae8b79cda19e3e4f8ffb5e8de4f18df93c95"
 
 [[package]]
 name = "plain"
@@ -1083,9 +1083,9 @@ checksum = "b4596b6d070b27117e987119b4dac604f3c58cfb0b191112e24771b2faeac1a6"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.23"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "51ef7cd2518ead700af67bf9d1a658d90b6037d77110fd9c0445429d0ba1c6c9"
+checksum = "1e0704ee1a7e00d7bb417d0770ea303c1bccbabf0ef1667dae92b5967f5f8a71"
 dependencies = [
  "unicode-xid",
 ]
@@ -1300,9 +1300,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_lexer"
-version = "673.0.0"
+version = "681.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f6b71fa1285bdefe5fb61e59b63d6cc246abf337f4acafdd620d721bc488e671"
+checksum = "01e579a90506e9d9c9a098f380cad55b9ecf9e7be9fa96cb67b31f52045f41a8"
 dependencies = [
  "unicode-xid",
 ]
@@ -1433,9 +1433,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.57"
+version = "1.0.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "164eacbdb13512ec2745fb09d51fd5b22b0d65ed294a1dcf7285a360c80a675c"
+checksum = "a230ea9107ca2220eea9d46de97eddcb04cd00e92d13dda78e478dd33fa82bd4"
 dependencies = [
  "itoa",
  "ryu",
diff --git a/crates/assists/src/handlers/add_missing_impl_members.rs b/crates/assists/src/handlers/add_missing_impl_members.rs
index 1ac5fefd6..51b5a2eb0 100644
--- a/crates/assists/src/handlers/add_missing_impl_members.rs
+++ b/crates/assists/src/handlers/add_missing_impl_members.rs
@@ -146,7 +146,7 @@ fn add_missing_impl_members_inner(
 
     let target = impl_def.syntax().text_range();
     acc.add(AssistId(assist_id, AssistKind::QuickFix), label, target, |builder| {
-        let impl_item_list = impl_def.assoc_item_list().unwrap_or(make::assoc_item_list());
+        let impl_item_list = impl_def.assoc_item_list().unwrap_or_else(make::assoc_item_list);
 
         let n_existing_items = impl_item_list.assoc_items().count();
         let source_scope = ctx.sema.scope_for_def(trait_);
diff --git a/crates/assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
index d1eadaa99..f5f03ef36 100644
--- a/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
+++ b/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -91,7 +91,7 @@ fn existing_struct_def(db: &RootDatabase, variant_name: &str, variant: &EnumVari
         .module(db)
         .scope(db, None)
         .into_iter()
-        .any(|(name, _)| name.to_string() == variant_name.to_string())
+        .any(|(name, _)| name.to_string() == variant_name)
 }
 
 #[allow(dead_code)]
diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index 567fd91af..5721a66c4 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -145,7 +145,7 @@ impl Crate {
             }
         }).flat_map(|t| t).next();
 
-        doc_url.map(|s| s.trim_matches('"').trim_end_matches("/").to_owned() + "/")
+        doc_url.map(|s| s.trim_matches('"').trim_end_matches('/').to_owned() + "/")
     }
 }
 
diff --git a/crates/ide/src/link_rewrite.rs b/crates/ide/src/link_rewrite.rs
index 107787bb9..a16f90e17 100644
--- a/crates/ide/src/link_rewrite.rs
+++ b/crates/ide/src/link_rewrite.rs
@@ -120,7 +120,7 @@ fn rewrite_intra_doc_link(
 
 /// Try to resolve path to local documentation via path-based links (i.e. `../gateway/struct.Shard.html`).
 fn rewrite_url_link(db: &RootDatabase, def: ModuleDef, target: &str) -> Option<String> {
-    if !(target.contains("#") || target.contains(".html")) {
+    if !(target.contains('#') || target.contains(".html")) {
         return None;
     }
 
@@ -190,7 +190,7 @@ fn strip_prefixes_suffixes(mut s: &str) -> &str {
         prefixes.clone().for_each(|prefix| s = s.trim_start_matches(*prefix));
         suffixes.clone().for_each(|suffix| s = s.trim_end_matches(*suffix));
     });
-    s.trim_start_matches("@").trim()
+    s.trim_start_matches('@').trim()
 }
 
 static TYPES: ([&str; 7], [&str; 0]) =
diff --git a/crates/ssr/src/resolving.rs b/crates/ssr/src/resolving.rs
index 5d2cbec47..347cc4aad 100644
--- a/crates/ssr/src/resolving.rs
+++ b/crates/ssr/src/resolving.rs
@@ -205,7 +205,7 @@ impl<'db> ResolutionScope<'db> {
 
     /// Returns the function in which SSR was invoked, if any.
     pub(crate) fn current_function(&self) -> Option<SyntaxNode> {
-        self.node.ancestors().find(|node| node.kind() == SyntaxKind::FN).map(|node| node.clone())
+        self.node.ancestors().find(|node| node.kind() == SyntaxKind::FN)
     }
 
     fn resolve_path(&self, path: &ast::Path) -> Option<hir::PathResolution> {
diff --git a/crates/syntax/Cargo.toml b/crates/syntax/Cargo.toml
index af61bb658..0b15f10e9 100644
--- a/crates/syntax/Cargo.toml
+++ b/crates/syntax/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 [dependencies]
 itertools = "0.9.0"
 rowan = "0.10.0"
-rustc_lexer = { version = "673.0.0", package = "rustc-ap-rustc_lexer" }
+rustc_lexer = { version = "681.0.0", package = "rustc-ap-rustc_lexer" }
 rustc-hash = "1.1.0"
 arrayvec = "0.5.1"
 once_cell = "1.3.1"
diff --git a/crates/syntax/src/ast/edit.rs b/crates/syntax/src/ast/edit.rs
index dda0a0319..77233ab31 100644
--- a/crates/syntax/src/ast/edit.rs
+++ b/crates/syntax/src/ast/edit.rs
@@ -159,7 +159,7 @@ impl ast::AssocItemList {
         let whitespace =
             last_token_before_curly.clone().into_token().and_then(ast::Whitespace::cast)?;
         let text = whitespace.syntax().text();
-        let newline = text.rfind("\n")?;
+        let newline = text.rfind('\n')?;
         let keep = tokens::WsBuilder::new(&text[newline..]);
         Some(self.replace_children(
             first_token_after_items..=last_token_before_curly,
diff --git a/crates/syntax/src/parsing/lexer.rs b/crates/syntax/src/parsing/lexer.rs
index fa3be1016..f1202113b 100644
--- a/crates/syntax/src/parsing/lexer.rs
+++ b/crates/syntax/src/parsing/lexer.rs
@@ -120,10 +120,10 @@ fn rustc_token_kind_to_syntax_kind(
 
     let syntax_kind = {
         match rustc_token_kind {
-            rustc_lexer::TokenKind::LineComment => COMMENT,
+            rustc_lexer::TokenKind::LineComment { doc_style: _ } => COMMENT,
 
-            rustc_lexer::TokenKind::BlockComment { terminated: true } => COMMENT,
-            rustc_lexer::TokenKind::BlockComment { terminated: false } => {
+            rustc_lexer::TokenKind::BlockComment { doc_style: _, terminated: true } => COMMENT,
+            rustc_lexer::TokenKind::BlockComment { doc_style: _, terminated: false } => {
                 return (
                     COMMENT,
                     Some("Missing trailing `*/` symbols to terminate the block comment"),
@@ -164,7 +164,7 @@ fn rustc_token_kind_to_syntax_kind(
             rustc_lexer::TokenKind::Colon => T![:],
             rustc_lexer::TokenKind::Dollar => T![$],
             rustc_lexer::TokenKind::Eq => T![=],
-            rustc_lexer::TokenKind::Not => T![!],
+            rustc_lexer::TokenKind::Bang => T![!],
             rustc_lexer::TokenKind::Lt => T![<],
             rustc_lexer::TokenKind::Gt => T![>],
             rustc_lexer::TokenKind::Minus => T![-],
diff --git a/docs/dev/style.md b/docs/dev/style.md
index bcd86fd3f..fb407afcd 100644
--- a/docs/dev/style.md
+++ b/docs/dev/style.md
@@ -197,7 +197,7 @@ fn frobnicate(walrus: Option<Walrus>) {
 }
 ```
 
-Avoid preconditions that spawn function boundaries:
+Avoid preconditions that span across function boundaries:
 
 
 ```rust
@@ -218,9 +218,8 @@ fn foo() {
 }
 
 // Not as good
-fn is_string_literal(s: &str) -> Option<&str> {
+fn is_string_literal(s: &str) -> bool {
     s.starts_with('"') && s.ends_with('"')
-    Some()
 }
 
 fn foo() {
@@ -231,8 +230,8 @@ fn foo() {
 }
 ```
 
-In the "Not as good" version, the precondition that `1` is a valid char boundary is checked in `is_string_literal` and utilized in `foo`.
-In the "Good" version, precondition check and usage are checked in the same block, and then encoded in the types.
+In the "Not as good" version, the precondition that `1` is a valid char boundary is checked in `is_string_literal` and used in `foo`.
+In the "Good" version, the precondition check and usage are checked in the same block, and then encoded in the types.
 
 # Early Returns
 
@@ -372,3 +371,13 @@ After you are happy with the state of the code, please use [interactive rebase](
 
 Avoid @mentioning people in commit messages and pull request descriptions(they are added to commit message by bors).
 Such messages create a lot of duplicate notification traffic during rebases.
+
+# Clippy
+
+We don't enforce Clippy.
+A number of default lints have high false positive rate.
+Selectively patching false-positives with `allow(clippy)` is considered worse than not using Clippy at all.
+There's `cargo xtask lint` command which runs a subset of low-FPR lints.
+Careful tweaking of `xtask lint` is welcome.
+See also [rust-lang/clippy#5537](https://github.com/rust-lang/rust-clippy/issues/5537).
+Of course, applying Clippy suggestions is welcome as long as they indeed improve the code.