compiler warnings

Summary: This is a cleaner version of D51550307.

Reviewed By: h-friederich

Differential Revision: D51698161

fbshipit-source-id: 471ead81e1669c74e33dbba7be7c4f1eba3fe2a5

vrs/FileDelegator.h

@@ -16,17 +16,11 @@
 
 #pragma once
 
-#include <cstdint>
-
-#include <functional>
-#include <map>
 #include <memory>
-#include <string>
-#include <utility>
-#include <vector>
 
 #include <vrs/ErrorCode.h>
 #include <vrs/FileSpec.h>
+#include <vrs/os/CompilerAttributes.h>
 
 namespace vrs {
 
@@ -57,8 +51,7 @@ class FileDelegator {
   /// @return A status code, 0 on success, which doesn't necessarily mean that the file/object
   /// exists or can be opened, merely, that parsing the URI did not fail.
   /// On success, any of the fields may have been set or changed, including fileHandlerName and URI.
-  virtual int parseUri(FileSpec& inOutFileSpec, size_t colonIndex) const {
-    (void)colonIndex;
+  virtual int parseUri(FileSpec& inOutFileSpec, MAYBE_UNUSED size_t colonIndex) const {
     return inOutFileSpec.parseUri();
   }
 };

vrs/FileHandler.h

@@ -20,14 +20,14 @@
 
 #include <functional>
 #include <map>
-#include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include <vrs/FileDelegator.h>
 #include <vrs/FileSpec.h>
 #include <vrs/helpers/EnumTemplates.hpp>
+#include <vrs/os/CompilerAttributes.h>
 
 namespace vrs {
 
@@ -135,8 +135,7 @@ class FileHandler : public FileDelegator {
   /// Check if a number of bytes are available for immediate return (e.g. on disk or in-cache)
   /// @param length: the number of bytes to check availability of.
   /// @return true if available, false if unavailable (e.g. requiring a network fetch)
-  virtual bool isAvailableOrPrefetch(size_t length) {
-    (void)length;
+  virtual bool isAvailableOrPrefetch(MAYBE_UNUSED size_t length) {
     return !isRemoteFileSystem();
   }
   /// Read a number of bytes, in a chunk aware way.
@@ -210,10 +209,8 @@ class FileHandler : public FileDelegator {
   /// caching starts.
   /// @return True if the file handler support custom read sequences.
   virtual bool prefetchReadSequence(
-      const vector<std::pair<size_t, size_t>>& sequence,
-      bool clearSequence = true) {
-    (void)sequence;
-    (void)clearSequence;
+      MAYBE_UNUSED const vector<std::pair<size_t, size_t>>& sequence,
+      MAYBE_UNUSED bool clearSequence = true) {
     return false;
   }