The light at the end of the SSZ typed tunnel

status-im · Dec 23, 2020 · ce0f7af · ce0f7af
1 parent 6df6931
commit ce0f7af
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Showing 3 changed files with 9 additions and 9 deletions.
diff --git a/beacon_chain/ssz/bytes_reader.nim b/beacon_chain/ssz/bytes_reader.nim
@@ -216,7 +216,8 @@ func readSszValue*[T](input: openArray[byte],
       raise newException(MalformedSszError, "SSZ input of insufficient size")
 
     enumInstanceSerializedFields(val, fieldName, field):
-      const boundingOffsets = getFieldBoundingOffsets(T, fieldName)
+      type RecordType = T # Upstream: Workaround type resolution
+      const boundingOffsets = getFieldBoundingOffsets(RecordType, fieldName)
 
       # type FieldType = type field # buggy
       # For some reason, Nim gets confused about the alias here. This could be a

diff --git a/beacon_chain/ssz/ssz_serialization.nim b/beacon_chain/ssz/ssz_serialization.nim
@@ -110,17 +110,15 @@ template writeField*(w: var SszWriter,
   mixin toSszType
   when ctx is FixedSizedWriterCtx:
     writeFixedSized(w.stream, toSszType(field))
-  else:
-    type FieldType = type toSszType(field)
-
-    when isFixedSize(FieldType):
+  else: # Upstream: type RecordType = type toSszType(field) will crash
+    when isFixedSize(type toSszType(field)):
       writeFixedSized(ctx.fixedParts, toSszType(field))
     else:
       trs "WRITING OFFSET ", ctx.offset, " FOR ", fieldName
       writeOffset(ctx.fixedParts, ctx.offset)
       let initPos = w.stream.pos
-      trs "WRITING VAR SIZE VALUE OF TYPE ", name(FieldType)
-      when FieldType is BitList:
+      trs "WRITING VAR SIZE VALUE OF TYPE ", name(type toSszType(field))
+      when (type toSszType(field)) is BitList:
         trs "BIT SEQ ", bytes(field)
       writeVarSizeType(w, toSszType(field))
       ctx.offset += w.stream.pos - initPos
@@ -164,7 +162,8 @@ proc writeVarSizeType(w: var SszWriter, value: auto) {.raises: [Defect, IOError]
     writeSeq(w, bytes value)
   elif value is object|tuple|array:
     trs "WRITING OBJECT OR ARRAY"
-    var ctx = beginRecord(w, type value)
+    type RecordType = type value # Upstream, alias needed or crash
+    var ctx = beginRecord(w, RecordType)
     enumerateSubFields(value, field):
       writeField w, ctx, astToStr(field), field
     endRecord w, ctx

diff --git a/docs/block_validation_flow.md b/docs/block_validation_flow.md
@@ -21,7 +21,7 @@ The related base types are:
   - metadata (slot, blockchain state before/after, proposer)
   - merkle hash of the BeaconBlockBody
 - SignedBeaconBlock
-  - BeaconBLock
+  - BeaconBlock
   - + BLS signature
 
 The base types are defined in the Eth2 specs.