remove a lot of XDeclaredButNotUsed spam from SSZ

beacon_chain/ssz.nim

@@ -46,8 +46,6 @@ type
     totalChunks: uint64
     limit: uint64
 
-  Chunk = array[bytesPerChunk, byte]
-
   TypeWithMaxLen*[T; maxLen: static int64] = distinct T
 
   SizePrefixed*[T] = distinct T
@@ -130,7 +128,7 @@ func writeFixedSized(c: var WriteCursor, x: auto) =
       else: unsupported x.type
       c.append bytes
     else:
-      let valueAddr = unsafeAddr x
+      let valueAddr {.used.} = unsafeAddr x
       trs "APPENDING INT ", x, " = ", makeOpenArray(cast[ptr byte](valueAddr), sizeof(x))
       c.appendMemCopy x
   elif x is StUint:
@@ -266,10 +264,6 @@ func writeValue*[T](w: var SszWriter, x: SizePrefixed[T]) =
     buf.appendVarint length
     cursor.writeAndFinalize buf.writtenBytes
 
-template checkEof(n: int) =
-  if not r.stream[].ensureBytes(n):
-    raise newException(UnexpectedEofError, "SSZ has insufficient number of bytes")
-
 template fromSszBytes*(T: type BlsValue, bytes: openarray[byte]): auto =
   fromBytes(T, bytes)
 
@@ -456,7 +450,7 @@ template merkelizeFields(body: untyped): Eth2Digest {.dirty.} =
     addChunk(merkelizer, hash.data)
     trs "CHUNK ADDED"
 
-  template addField2(field) =
+  template addField2(field) {.used.}=
     const maxLen = fieldMaxLen(field)
     when maxLen > 0:
       type FieldType = type field
@@ -492,7 +486,6 @@ func bitlistHashTreeRoot(merkelizer: SszChunksMerkelizer, x: BitSeq): Eth2Digest
 
   var
     bytesInLastChunk = totalBytes mod bytesPerChunk
-    paddingBytes = bytesPerChunk - bytesInLastChunk
     fullChunks = totalBytes div bytesPerChunk
 
   if bytesInLastChunk == 0:

beacon_chain/ssz/bytes_reader.nim

@@ -61,9 +61,9 @@ proc fromSszBytes*[N](T: type BitList[N], bytes: openarray[byte]): auto =
 proc readSszValue*(input: openarray[byte], T: type): T =
   mixin fromSszBytes, toSszType
 
-  type T = type(result)
+  type T {.used.}= type(result)
 
-  template readOffset(n: int): int =
+  template readOffset(n: int): int {.used.}=
     int fromSszBytes(uint32, input[n ..< n + offsetSize])
 
   when useListType and result is List:
@@ -158,4 +158,3 @@ proc readSszValue*(input: openarray[byte], T: type): T =
 
   else:
     unsupported T
-