From b79edf008f3191e28d96ed98c77fa25533c650d7 Mon Sep 17 00:00:00 2001
From: iancormac84 <wilnathan@gmail.com>
Date: Tue, 8 May 2018 19:57:45 -0400
Subject: [PATCH] Added extra hashing step.

---
 src/librustc_codegen_utils/symbol_names.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/librustc_codegen_utils/symbol_names.rs b/src/librustc_codegen_utils/symbol_names.rs
index 8ddefdf474fb..2063db6dc533 100644
--- a/src/librustc_codegen_utils/symbol_names.rs
+++ b/src/librustc_codegen_utils/symbol_names.rs
@@ -168,6 +168,13 @@ fn get_symbol_hash<'a, 'tcx>(
             });
         });
 
+        // If this is a function, we hash the signature as well.
+        // This is not *strictly* needed, but it may help in some
+        // situations, see the `run-make/a-b-a-linker-guard` test.
+        if let ty::TyFnDef(..) = item_type.sty {
+            item_type.fn_sig(tcx).hash_stable(&mut hcx, &mut hasher);
+        }
+
         // also include any type parameters (for generic items)
         assert!(!substs.has_erasable_regions());
         assert!(!substs.needs_subst());