Merge pull request #1040 from crytic/issue-929

fix issue-929, FP in dead-code detector

slither/detectors/functions/dead_code.py

@@ -68,6 +68,9 @@ contract Contract{
                 function.contract_declarer.is_from_dependency()
             ):
                 continue
+            # Continue if the functon is not implemented because it means the contract is abstract
+            if not function.is_implemented:
+                continue
             info = [function, " is never used and should be removed\n"]
             res = self.generate_result(info)
             results.append(res)

tests/detectors/dead-code/0.8.0/dead-code.sol

@@ -27,3 +27,7 @@ contract Test4 is Test2{
 
     }
 }
+
+abstract contract Test5 {
+    function unused_but_abstract() internal virtual;
+}