fixes #236

nimbus/vm/computation.nim

@@ -333,11 +333,11 @@ proc getGasRemaining*(c: BaseComputation): GasInt =
 proc tracingEnabled*(c: BaseComputation): bool =
  c.vmState.tracingEnabled
 
-proc traceOpCodeStarted*(c: BaseComputation, op: Op) =
+proc traceOpCodeStarted*(c: BaseComputation, op: Op): int =
  c.vmState.tracer.traceOpCodeStarted(c, op)
 
-proc traceOpCodeEnded*(c: BaseComputation, op: Op) =
- c.vmState.tracer.traceOpCodeEnded(c, op)
+proc traceOpCodeEnded*(c: BaseComputation, op: Op, lastIndex: int) =
+ c.vmState.tracer.traceOpCodeEnded(c, op, lastIndex)
 
 proc traceError*(c: BaseComputation) =
  c.vmState.tracer.traceError(c)

nimbus/vm/interpreter_dispatch.nim

@@ -196,20 +196,22 @@ proc opTableToCaseStmt(opTable: array[Op, NimNode], computation: NimNode): NimNo
  let asOp = quote do: Op(`op`) # TODO: unfortunately when passing to runtime, ops are transformed into int
  if BaseGasCosts[op].kind == GckFixed:
  quote do:
+ var lastOpIndex: int
  if `computation`.tracingEnabled:
- `computation`.traceOpCodeStarted(`asOp`)
+ lastOpIndex = `computation`.traceOpCodeStarted(`asOp`)
  `computation`.gasMeter.consumeGas(`computation`.gasCosts[`asOp`].cost, reason = $`asOp`)
  `opImpl`(`computation`)
  if `computation`.tracingEnabled:
- `computation`.traceOpCodeEnded(`asOp`)
+ `computation`.traceOpCodeEnded(`asOp`, lastOpIndex)
  `instr` = `computation`.code.next()
  else:
  quote do:
+ var lastOpIndex: int
  if `computation`.tracingEnabled:
- `computation`.traceOpCodeStarted(`asOp`)
+ lastOpIndex = `computation`.traceOpCodeStarted(`asOp`)
  `opImpl`(`computation`)
  if `computation`.tracingEnabled:
- `computation`.traceOpCodeEnded(`asOp`)
+ `computation`.traceOpCodeEnded(`asOp`, lastOpIndex)
  when `asOp` in {Return, Revert, SelfDestruct}:
  break
  else:

nimbus/vm/transaction_tracer.nim

@@ -38,7 +38,7 @@ iterator storage(tracer: TransactionTracer, compDepth: int): Uint256 =
  for key in tracer.storageKeys[compDepth]:
  yield key
 
-proc traceOpCodeStarted*(tracer: var TransactionTracer, c: BaseComputation, op: Op) =
+proc traceOpCodeStarted*(tracer: var TransactionTracer, c: BaseComputation, op: Op): int =
  if unlikely tracer.trace.isNil:
  tracer.initTracer()
 
@@ -49,7 +49,6 @@ proc traceOpCodeStarted*(tracer: var TransactionTracer, c: BaseComputation, op:
  j["pc"] = %(c.code.pc - 1)
  j["depth"] = %(c.msg.depth + 1)
  j["gas"] = %c.gasMeter.gasRemaining
- tracer.gasRemaining = c.gasMeter.gasRemaining
 
  # log stack
  if TracerFlags.DisableStack notin tracer.flags:
@@ -83,8 +82,10 @@ proc traceOpCodeStarted*(tracer: var TransactionTracer, c: BaseComputation, op:
  assert(c.stack.values.len > 1)
  tracer.rememberStorageKey(c.msg.depth, c.stack[^1, Uint256])
 
-proc traceOpCodeEnded*(tracer: var TransactionTracer, c: BaseComputation, op: Op) =
- let j = tracer.trace["structLogs"].elems[^1]
+ result = tracer.trace["structLogs"].len - 1
+
+proc traceOpCodeEnded*(tracer: var TransactionTracer, c: BaseComputation, op: Op, lastIndex: int) =
+ let j = tracer.trace["structLogs"].elems[lastIndex]
 
  # TODO: figure out how to get storage
  # when contract execution interrupted by exception
@@ -97,7 +98,8 @@ proc traceOpCodeEnded*(tracer: var TransactionTracer, c: BaseComputation, op: Op
  storage[key.dumpHex] = %(value.dumpHex)
  j["storage"] = storage
 
- j["gasCost"] = %(tracer.gasRemaining - c.gasMeter.gasRemaining)
+ let gasRemaining = j["gas"].getInt()
+ j["gasCost"] = %(gasRemaining - c.gasMeter.gasRemaining)
 
  if op in {Return, Revert}:
  let returnValue = %("0x" & toHex(c.rawOutput, true))

nimbus/vm_types.nim

@@ -40,7 +40,6 @@ type
 
  TransactionTracer* = object
  trace*: JsonNode
- gasRemaining*: GasInt
  flags*: set[TracerFlags]
  accounts*: HashSet[EthAddress]
  storageKeys*: seq[HashSet[Uint256]]

premix/premixcore.nim

@@ -13,8 +13,10 @@ proc fakeAlloc(n: JsonNode) =
  let
  prevMem = n[i-1]["memory"]
  currMem = n[i]["memory"]
-
- if currMem.len > prevMem.len:
+ prevPc = n[i-1]["pc"].getInt()
+ currPc = n[i]["pc"].getInt()
+
+ if currMem.len > prevMem.len and prevPc == currPc - 1:
  let diff = currMem.len - prevMem.len
  for _ in 0 ..< diff:
  prevMem.add %chunk