From c6046515d5a4da8bdabec638f01dabccd254c0fc Mon Sep 17 00:00:00 2001
From: Manish Goregaokar <manishsmail@gmail.com>
Date: Tue, 9 Oct 2018 16:46:51 -0700
Subject: [PATCH] Mention tool lint attributes

---
 src/attributes.md | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/src/attributes.md b/src/attributes.md
index 7294de6e2..f4d44e420 100644
--- a/src/attributes.md
+++ b/src/attributes.md
@@ -357,6 +357,35 @@ pub mod m3 {
 }
 ```
 
+#### Tool lint attributes (`#[allow(clippy::foo)]`)
+
+Tool lints let you use scoped lints, to `allow`, `warn`, `deny` or `forbid` lints of
+certain tools.
+
+Currently `clippy` is the only available lint tool.
+
+They only get checked when the associated tool is active, so if you try to use an `allow` attribute for a nonexistant tool lint, the compiler will not warn about the nonexistant lint until you use the tool.
+
+Otherwise, they work just like regular lint attributes:
+
+
+```rust,ignore
+// set the entire `pedantic` clippy lint group to warn
+#![warn(clippy::pedantic)]
+// silence warnings from the `filter_map` clippy lint
+#![allow(clippy::filter_map)]
+
+fn main() {
+    // ...
+}
+
+// silence the `cmp_nan` clippy lint just for this function
+#[allow(clippy::cmp_nan)]
+fn foo() {
+    // ...
+}
+```
+
 #### `must_use`
 
 The `must_use` attribute can be used on user-defined composite types