[codemod] comment unused parameters to turn on -Wunused-parameter flag

db/db_sst_test.cc

@@ -685,7 +685,7 @@ TEST_F(DBSSTTest, CancellingManualCompactionsWorks) {
   sfm->SetMaxAllowedSpaceUsage(0);
   int completed_compactions = 0;
   rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "CompactFilesImpl:End", [&](void* arg) { completed_compactions++; });
+      "CompactFilesImpl:End", [&](void* /*arg*/) { completed_compactions++; });
 
   rocksdb::SyncPoint::GetInstance()->EnableProcessing();
   dbfull()->CompactFiles(rocksdb::CompactionOptions(), l0_files, 0);

env/env_posix.cc

@@ -876,6 +876,7 @@ class PosixEnv : public Env {
         return false;
     }
 #else
+    (void)path;
     return false;
 #endif
   }

env/io_posix.cc

@@ -48,6 +48,10 @@ int Fadvise(int fd, off_t offset, size_t len, int advice) {
 #ifdef OS_LINUX
   return posix_fadvise(fd, offset, len, advice);
 #else
+  (void)fd;
+  (void)offset;
+  (void)len;
+  (void)advice;
   return 0;  // simply do nothing.
 #endif
 }
@@ -227,6 +231,8 @@ Status PosixSequentialFile::Skip(uint64_t n) {
 
 Status PosixSequentialFile::InvalidateCache(size_t offset, size_t length) {
 #ifndef OS_LINUX
+  (void)offset;
+  (void)length;
   return Status::OK();
 #else
   if (!use_direct_io()) {
@@ -410,6 +416,8 @@ Status PosixRandomAccessFile::InvalidateCache(size_t offset, size_t length) {
     return Status::OK();
   }
 #ifndef OS_LINUX
+  (void)offset;
+  (void)length;
   return Status::OK();
 #else
   // free OS pages
@@ -464,6 +472,8 @@ Status PosixMmapReadableFile::Read(uint64_t offset, size_t n, Slice* result,
 
 Status PosixMmapReadableFile::InvalidateCache(size_t offset, size_t length) {
 #ifndef OS_LINUX
+  (void)offset;
+  (void)length;
   return Status::OK();
 #else
   // free OS pages
@@ -672,6 +682,8 @@ uint64_t PosixMmapFile::GetFileSize() {
 
 Status PosixMmapFile::InvalidateCache(size_t offset, size_t length) {
 #ifndef OS_LINUX
+  (void)offset;
+  (void)length;
   return Status::OK();
 #else
   // free OS pages
@@ -874,6 +886,8 @@ void PosixWritableFile::SetWriteLifeTimeHint(Env::WriteLifeTimeHint hint) {
     write_hint_ = hint;
   }
 #endif
+#else
+  (void)hint;
 #endif
 }
 
@@ -882,6 +896,8 @@ Status PosixWritableFile::InvalidateCache(size_t offset, size_t length) {
     return Status::OK();
   }
 #ifndef OS_LINUX
+  (void)offset;
+  (void)length;
   return Status::OK();
 #else
   // free OS pages

util/arena.cc

@@ -62,6 +62,8 @@ Arena::Arena(size_t block_size, AllocTracker* tracker, size_t huge_page_size)
   if (hugetlb_size_ && kBlockSize > hugetlb_size_) {
     hugetlb_size_ = ((kBlockSize - 1U) / hugetlb_size_ + 1U) * hugetlb_size_;
   }
+#else
+  (void)huge_page_size;
 #endif
   if (tracker_ != nullptr) {
     tracker_->Allocate(kInlineSize);
@@ -152,6 +154,7 @@ char* Arena::AllocateFromHugePage(size_t bytes) {
   }
   return reinterpret_cast<char*>(addr);
 #else
+  (void)bytes;
   return nullptr;
 #endif
 }
@@ -179,6 +182,9 @@ char* Arena::AllocateAligned(size_t bytes, size_t huge_page_size,
       return addr;
     }
   }
+#else
+  (void)huge_page_size;
+  (void)logger;
 #endif
 
   size_t current_mod =