fix build failures on platforms that use -Wunused-private-variable for builds

llvm-svn: 188983

lld/include/lld/Driver/CoreInputGraph.h

@@ -38,7 +38,10 @@ public:
   createLinkerInput(const lld::LinkingContext &);
 
   /// \brief validates the Input Element
-  virtual bool validate() { return true; }
+  virtual bool validate() {
+    (void)_ctx;
+    return true;
+  }
 
   /// \brief Dump the Input Element
   virtual bool dump(raw_ostream &) { return true; }

lld/include/lld/Driver/DarwinInputGraph.h

@@ -39,7 +39,10 @@ public:
   createLinkerInput(const lld::LinkingContext &);
 
   /// \brief validates the Input Element
-  virtual bool validate() { return true; }
+  virtual bool validate() {
+    (void)_ctx;
+    return true;
+  }
 
   /// \brief Dump the Input Element
   virtual bool dump(raw_ostream &) { return true; }

lld/include/lld/Driver/GnuLDInputGraph.h

@@ -89,12 +89,15 @@ public:
   }
 
   /// \brief Validate the options
-  virtual bool validate() { return true; }
+  virtual bool validate() {
+    (void)_elfLinkingContext;
+    return true;
+  }
 
   /// \brief Dump the ELFGroup
   virtual bool dump(llvm::raw_ostream &) { return true; }
 
-protected:
+private:
   ELFLinkingContext &_elfLinkingContext;
 };