fix issue #367 and remove too-small range type usage for ValidatorIndex

beacon_chain/beacon_node.nim

@@ -299,7 +299,7 @@ proc addLocalValidators(node: BeaconNode, state: BeaconState) =
   info "Local validators attached ", count = node.attachedValidators.count
 
 proc getAttachedValidator(
-    node: BeaconNode, state: BeaconState, idx: int): AttachedValidator =
+    node: BeaconNode, state: BeaconState, idx: ValidatorIndex): AttachedValidator =
   let validatorKey = state.validators[idx].pubkey
   node.attachedValidators.getValidator(validatorKey)
 

beacon_chain/spec/beaconstate.nim

@@ -621,7 +621,7 @@ proc process_attestation*(
         data: attestation.data,
         aggregation_bits: attestation.aggregation_bits,
         inclusion_delay: state.slot - attestation_slot,
-        proposer_index: get_beacon_proposer_index(state, stateCache),
+        proposer_index: get_beacon_proposer_index(state, stateCache).uint64,
       )
 
     if attestation.data.target.epoch == get_current_epoch(state):

beacon_chain/spec/datatypes.nim

@@ -73,7 +73,14 @@ template maxSize*(n: int) {.pragma.}
 type
   Bytes = seq[byte]
 
-  ValidatorIndex* = range[0'u32 .. 0xFFFFFF'u32] # TODO: wrap-around
+  # https://github.com/nim-lang/Nim/issues/574 and be consistent across
+  # 32-bit and 64-bit word platforms.
+  # TODO VALIDATOR_REGISTRY_LIMIT is 1 shl 40 in 0.8.3, and
+  # proc newSeq(typ: PNimType, len: int): pointer {.compilerRtl.}
+  # in Nim/lib/system/gc.nim quite tightly ties seq addressibility
+  # to the system wordsize. This lifts smaller, and now incorrect,
+  # range-limit.
+  ValidatorIndex* = distinct uint32
   Shard* = uint64
   Gwei* = uint64
 
@@ -517,6 +524,24 @@ template ethTimeUnit(typ: type) {.dirty.} =
 proc `%`*(i: uint64): JsonNode =
   % int(i)
 
+# `ValidatorIndex` seq handling.
+proc max*(a: ValidatorIndex, b: int) : auto =
+  max(a.int, b)
+
+proc `[]`*[T](a: var seq[T], b: ValidatorIndex): var T =
+  a[b.int]
+
+proc `[]`*[T](a: seq[T], b: ValidatorIndex): auto =
+  a[b.int]
+
+proc `[]=`*[T](a: var seq[T], b: ValidatorIndex, c: T) =
+  a[b.int] = c
+
+# `ValidatorIndex` Nim integration
+proc `==`*(x, y: ValidatorIndex) : bool {.borrow.}
+proc hash*(x: ValidatorIndex): Hash {.borrow.}
+proc `$`*(x: ValidatorIndex): auto = $(x.int64)
+
 ethTimeUnit Slot
 ethTimeUnit Epoch
 

beacon_chain/ssz.nim

@@ -39,7 +39,7 @@ type
   SszWriter* = object
     stream: OutputStreamVar
 
-  BasicType = char|bool|SomeUnsignedInt|StUint
+  BasicType = char|bool|SomeUnsignedInt|StUint|ValidatorIndex
 
   SszChunksMerkelizer = ref object of RootObj
     combinedChunks: array[maxChunkTreeDepth, Eth2Digest]

tests/official/test_fixture_shuffling.nim

@@ -7,7 +7,7 @@
 
 import
   # Standard library
-  os, unittest,
+  os, unittest, sequtils,
   # Beacon chain internals
   ../../beacon_chain/spec/[datatypes, validator, digest],
   # Test utilities
@@ -18,7 +18,7 @@ type
   Shuffling* = object
     seed*: Eth2Digest
     count*: uint64
-    mapping*: seq[ValidatorIndex]
+    mapping*: seq[uint64]
 
 const ShufflingDir = JsonTestsDir/const_preset/"phase0"/"shuffling"/"core"/"shuffle"
 
@@ -27,4 +27,4 @@ suite "Official - Shuffling tests [Preset: " & preset():
     for file in walkDirRec(ShufflingDir):
       let t = parseTest(file, Json, Shuffling)
       let implResult = get_shuffled_seq(t.seed, t.count)
-      check: implResult == t.mapping
+      check: implResult == mapIt(t.mapping, it.ValidatorIndex)