From 2adc6da7aa4f3f8cb646b8f7b7759e73c98ade12 Mon Sep 17 00:00:00 2001
From: Oliver Scherer <github35764891676564198441@oli-obk.de>
Date: Tue, 14 May 2019 14:19:46 +0200
Subject: [PATCH] Fix incremental compilation of cdylib emitting spurious
 unused_attributes lint

---
 src/libsyntax/feature_gate.rs     |  2 +-
 src/test/incremental/no_mangle.rs | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 src/test/incremental/no_mangle.rs

diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 8a066f3f4a0..5b1a9bb739f 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -998,7 +998,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     (sym::repr, Normal, template!(List: "C, packed, ..."), Ungated),
     (sym::path, Normal, template!(NameValueStr: "file"), Ungated),
     (sym::automatically_derived, Normal, template!(Word), Ungated),
-    (sym::no_mangle, Normal, template!(Word), Ungated),
+    (sym::no_mangle, Whitelisted, template!(Word), Ungated),
     (sym::no_link, Normal, template!(Word), Ungated),
     (sym::derive, Normal, template!(List: "Trait1, Trait2, ..."), Ungated),
     (
diff --git a/src/test/incremental/no_mangle.rs b/src/test/incremental/no_mangle.rs
new file mode 100644
index 00000000000..1b17886a4f9
--- /dev/null
+++ b/src/test/incremental/no_mangle.rs
@@ -0,0 +1,10 @@
+// revisions:rpass1 rpass2
+// compile-flags: --crate-type cdylib
+// skip-codegen
+
+#![deny(unused_attributes)]
+
+#[no_mangle]
+pub extern "C" fn rust_no_mangle() -> i32 {
+    42
+}