re-integrated 0x5# op handlers

nimbus/vm2/interpreter/op_handlers.nim

@@ -21,59 +21,37 @@ import
   ./op_codes,
   ./op_handlers/[oph_defs,
                  oph_arithmetic, oph_hash, oph_envinfo, oph_blockdata,
+                 oph_memory,
                  oph_sysops]
 
 # ------------------------------------------------------------------------------
 # Helper
 # ------------------------------------------------------------------------------
 
-const
+proc importList(rc: var array[Op,Vm2OpExec];
-  allForksTable = block:
+                sel: Fork; list: seq[Vm2OpExec]; s: string) {.compileTime.} =
-      var rc: array[Op, Vm2OpExec]
+  for w in list:
-
+    if sel notin w.forks:
-      proc complain(rec: Vm2OpExec; s: string): bool =
+      continue
-        var
+    var oInf = rc[w.opCode].info
-          op = rec.opCode
+    if oInf != "" or 0 < rc[w.opCode].forks.card:
-          oInfo = rc[op].info
+      echo &"*** {s}: duplicate <{w.opCode}> entry: \"{oInf}\" vs. \"{w.info}\""
-          nInfo = rec.info
-        if oInfo != "":
-          echo &"*** {s}: duplicate <{op}> entry: \"{oInfo}\" vs. \"{nInfo}\""
-          return true
-
-      for w in vm2OpExecArithmetic:
-        if w.complain("Arithmetic"):
       doAssert rc[w.opCode].info == ""
+      doAssert rc[w.opCode].forks.card == 0
     rc[w.opCode] = w
 
-      for w in vm2OpExecHash:
-        if w.complain("Hash"):
-          doAssert rc[w.opCode].info == ""
-        rc[w.opCode] = w
-
-      for w in vm2OpExecEnvInfo:
-        if w.complain("EnvInfo"):
-          doAssert rc[w.opCode].info == ""
-        rc[w.opCode] = w
-
-      for w in vm2OpExecBlockData:
-        if w.complain("BlockData"):
-          doAssert rc[w.opCode].info == ""
-        rc[w.opCode] = w
-
-      for w in vm2OpExecSysOP:
-        if w.complain("SysOp"):
-          doAssert rc[w.opCode].info == ""
-        rc[w.opCode] = w
-
-      rc
 
 proc mkOpTable(select: Fork): array[Op,Vm2OpExec] {.compileTime.} =
+  result.importList(select, vm2OpExecArithmetic, "Arithmetic")
+  result.importList(select, vm2OpExecHash,       "Hash")
+  result.importList(select, vm2OpExecEnvInfo,    "EnvInfo")
+  result.importList(select, vm2OpExecBlockData,  "BlockData")
+  result.importList(select, vm2OpExecMemory,     "Memory")
+  result.importList(select, vm2OpExecSysOP,      "SysOp")
+
   for op in Op:
-    var w = allForksTable[op]
+    if select notin result[op].forks:
-    if select in w.forks:
+      result[op] = result[Invalid]
-      result[op] = w
-    else:
-      result[op] = allForksTable[Invalid]
       result[op].opCode = op
 
 # ------------------------------------------------------------------------------
@@ -87,15 +65,15 @@ const
       rc[w] = w.mkOpTable
     rc
 
-  vm2OpTabFrontier*       = vm2OpHandlers[FkFrontier]
+  # vm2OpTabFrontier*       = vm2OpHandlers[FkFrontier]
-  vm2OpTabHomestead*      = vm2OpHandlers[FkHomestead]
+  # vm2OpTabHomestead*      = vm2OpHandlers[FkHomestead]
-  vm2OpTabTangerine*      = vm2OpHandlers[FkTangerine]
+  # vm2OpTabTangerine*      = vm2OpHandlers[FkTangerine]
-  vm2OpTabSpurious*       = vm2OpHandlers[FkSpurious]
+  # vm2OpTabSpurious*       = vm2OpHandlers[FkSpurious]
-  vm2OpTabByzantium*      = vm2OpHandlers[FkByzantium]
+  # vm2OpTabByzantium*      = vm2OpHandlers[FkByzantium]
-  vm2OpTabConstantinople* = vm2OpHandlers[FkConstantinople]
+  # vm2OpTabConstantinople* = vm2OpHandlers[FkConstantinople]
-  vm2OpTabPetersburg*     = vm2OpHandlers[FkPetersburg]
+  # vm2OpTabPetersburg*     = vm2OpHandlers[FkPetersburg]
-  vm2OpTabIstanbul*       = vm2OpHandlers[FkIstanbul]
+  # vm2OpTabIstanbul*       = vm2OpHandlers[FkIstanbul]
-  vm2OpTabBerlin*         = vm2OpHandlers[FkBerlin]
+  # vm2OpTabBerlin*         = vm2OpHandlers[FkBerlin]
 
 # ------------------------------------------------------------------------------
 # Debugging ...
@@ -106,12 +84,18 @@ when isMainModule and isNoisy:
   proc gdbBPSink() =
     dummy.inc
 
-  const
-    a = vm2OpTabBerlin
-    b = a[Shl].info
-
   gdbBPSink()
-  echo ">>> ", b
+  echo ">>> berlin[shl]:            ",
+        vm2OpHandlers[FkBerlin][Shl].info
+
+  echo ">>> frontier[sstore]:       ",
+        vm2OpHandlers[FkFrontier][Sstore].info
+
+  echo ">>> constantinople[sstore]: ",
+        vm2OpHandlers[FkConstantinople][Sstore].info
+
+  echo ">>> berlin[sstore]:         ",
+        vm2OpHandlers[FkBerlin][Sstore].info
 
 # ------------------------------------------------------------------------------
 # End

nimbus/vm2/interpreter/op_handlers/oph_defs.nim

@@ -36,19 +36,29 @@ else:
     {.fatal: "Flag \"vm2_enabled\" must be unset "&
              "while circular dependency breaker kludge is activated".}
   type
+    ReadOnlyStateDB* =
+      seq[byte]
+
     GasMeter* = object
-      whatever: int
+      gasRemaining*: int
 
     CodeStream* = ref object
       bytes*: seq[byte]
+      pc*: int
+
+    BaseVMState* = ref object
+      accountDb*: ReadOnlyStateDB
 
     Message* = ref object
       contractAddress*: UInt256
       sender*: UInt256
       value*: UInt256
       data*: seq[byte]
+      flags*: int
 
     Computation* = ref object
+      returnStack*: seq[int]
+      vmState*: BaseVMState
       gasMeter*: GasMeter
       stack*: Stack
       memory*: Memory

nimbus/vm2/interpreter/op_handlers/oph_memory.nim

@@ -0,0 +1,466 @@
+# Nimbus
+# Copyright (c) 2018 Status Research & Development GmbH
+# Licensed under either of
+#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
+#    http://www.apache.org/licenses/LICENSE-2.0)
+#  * MIT license ([LICENSE-MIT](LICENSE-MIT) or
+#    http://opensource.org/licenses/MIT)
+# at your option. This file may not be copied, modified, or distributed except
+# according to those terms.
+
+## EVM Opcode Handlers: Stack, Memory, Storage And Flow Operations
+## ===============================================================
+##
+
+const
+  kludge {.intdefine.}: int = 0
+  breakCircularDependency {.used.} = kludge > 0
+
+import
+  ../../../errors,
+  ./oph_defs,
+  strformat,
+  stint
+
+# ------------------------------------------------------------------------------
+# Kludge BEGIN
+# ------------------------------------------------------------------------------
+
+when not breakCircularDependency:
+  import
+    ../../../db/accounts_cache,
+    ../../code_stream,
+    ../../stack,
+    ../../v2computation,
+    ../../v2memory,
+    ../../v2state,
+    ../../v2types,
+    ../gas_meter,
+    ../utils/v2utils_numeric,
+    ../v2gas_costs,
+    eth/common,
+    times
+
+else:
+  import macros
+
+  const emvcStatic = 1
+  var blindGasCosts: array[Op,int]
+
+  # copied from stack.nim
+  macro genTupleType(len: static[int], elemType: untyped): untyped =
+    result = nnkTupleConstr.newNimNode()
+    for i in 0 ..< len: result.add(elemType)
+
+  # function stubs from stack.nim (to satisfy compiler logic)
+  proc push[T](x: Stack; n: T) = discard
+  proc popInt(x: var Stack): UInt256 = discard
+  proc popInt(x: var Stack, n: static[int]): auto =
+    var rc: genTupleType(n, UInt256)
+    return rc
+
+  # function stubs from v2computation.nim (to satisfy compiler logic)
+  proc getStorage(c: Computation, slot: Uint256): Uint256 = 0.u256
+  proc gasCosts(c: Computation): array[Op,int] = blindGasCosts
+
+  # function stubs from v2utils_numeric.nim
+  func cleanMemRef(x: UInt256): int = 0
+
+  # function stubs from v2memory.nim
+  proc len(mem: Memory): int = 0
+  proc extend(mem: var Memory; startPos: Natural; size: Natural) = discard
+  proc write(mem: var Memory, startPos: Natural, val: openarray[byte]) = discard
+  proc read(mem: var Memory, startPos: Natural, size: Natural): seq[byte] = @[]
+
+  # function stubs from code_stream.nim
+  proc len(c: CodeStream): int = len(c.bytes)
+  proc peek(c: var CodeStream): Op = Stop
+  proc isValidOpcode(c: CodeStream, position: int): bool = false
+
+  # function stubs from v2state.nim
+  proc readOnlyStateDB(x: BaseVMState): ReadOnlyStateDB = x.accountDb
+  template mutateStateDB(vmState: BaseVMState, body: untyped) = discard
+
+  # function stubs from gas_meter.nim
+  proc refundGas(gasMeter: var GasMeter; amount: int) = discard
+  proc consumeGas(gasMeter: var GasMeter; amount: int; reason: string) = discard
+
+  # stubs from v2gas_costs.nim
+  type GasParams = object
+    case kind*: Op
+    of Sstore:
+      s_currentValue: Uint256
+      s_originalValue: Uint256
+    else:
+      discard
+  proc c_handler(x: int; y: Uint256, z: GasParams): (int,int) = (0,0)
+  proc m_handler(x: int; curMemSize, memOffset, memLen: int64): int = 0
+
+  # function stubs from state_db.nim
+  proc getCommittedStorage(x: ReadOnlyStateDB; y,z: Uint256): Uint256 = 0.u256
+
+# ------------------------------------------------------------------------------
+# Kludge END
+# ------------------------------------------------------------------------------
+
+# ------------------------------------------------------------------------------
+# Private helpers
+# ------------------------------------------------------------------------------
+
+template checkInStaticContext(c: Computation) =
+  # TODO: if possible, this check only appear
+  # when fork >= FkByzantium
+  if emvcStatic == c.msg.flags:
+    raise newException(
+      StaticContextError,
+      "Cannot modify state while inside of STATICCALL context")
+
+proc sstoreNetGasMeteringImpl(c: Computation; slot, newValue: Uint256) =
+  let
+    stateDB = c.vmState.readOnlyStateDB
+    currentValue = c.getStorage(slot)
+
+    gasParam = GasParams(
+      kind: Op.Sstore,
+      s_currentValue: currentValue,
+      s_originalValue: stateDB.getCommittedStorage(c.msg.contractAddress, slot))
+
+    (gasCost, gasRefund) = c.gasCosts[Sstore].c_handler(newValue, gasParam)
+
+  c.gasMeter.consumeGas(
+    gasCost, &"SSTORE EIP2200: {c.msg.contractAddress}[{slot}]" &
+             &" -> {newValue} ({currentValue})")
+
+  if gasRefund != 0:
+    c.gasMeter.refundGas(gasRefund)
+
+  c.vmState.mutateStateDB:
+    db.setStorage(c.msg.contractAddress, slot, newValue)
+
+
+proc jumpImpl(c: Computation; jumpTarget: UInt256) =
+  if jumpTarget >= c.code.len.u256:
+    raise newException(
+      InvalidJumpDestination, "Invalid Jump Destination")
+
+  let jt = jumpTarget.truncate(int)
+  c.code.pc = jt
+
+  let nextOpcode = c.code.peek
+  if nextOpcode != JUMPDEST:
+    raise newException(InvalidJumpDestination, "Invalid Jump Destination")
+
+  # TODO: next check seems redundant
+  if not c.code.isValidOpcode(jt):
+    raise newException(
+      InvalidInstruction, "Jump resulted in invalid instruction")
+
+# ------------------------------------------------------------------------------
+# Private, op handlers implementation
+# ------------------------------------------------------------------------------
+
+const
+  popOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x50, Remove item from stack.
+    discard k.cpt.stack.popInt
+
+  mloadOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x51, Load word from memory
+    let (memStartPos) = k.cpt.stack.popInt(1)
+
+    let memPos = memStartPos.cleanMemRef
+    k.cpt.gasMeter.consumeGas(
+      k.cpt.gasCosts[MLoad].m_handler(k.cpt.memory.len, memPos, 32),
+      reason = "MLOAD: GasVeryLow + memory expansion")
+
+    k.cpt.memory.extend(memPos, 32)
+    k.cpt.stack.push:
+      k.cpt.memory.read(memPos, 32)
+
+
+  mstoreOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x52, Save word to memory
+    let (memStartPos, value) = k.cpt.stack.popInt(2)
+
+    let memPos = memStartPos.cleanMemRef
+    k.cpt.gasMeter.consumeGas(
+      k.cpt.gasCosts[MStore].m_handler(k.cpt.memory.len, memPos, 32),
+      reason = "MSTORE: GasVeryLow + memory expansion")
+
+    k.cpt.memory.extend(memPos, 32)
+    k.cpt.memory.write(memPos, value.toByteArrayBE)
+
+
+  mstore8Op: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x53, Save byte to memory
+    let (memStartPos, value) = k.cpt.stack.popInt(2)
+
+    let memPos = memStartPos.cleanMemRef
+    k.cpt.gasMeter.consumeGas(
+      k.cpt.gasCosts[MStore].m_handler(k.cpt.memory.len, memPos, 1),
+      reason = "MSTORE8: GasVeryLow + memory expansion")
+
+    k.cpt.memory.extend(memPos, 1)
+    k.cpt.memory.write(memPos, [value.toByteArrayBE[31]])
+
+
+  sloadOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x54, Load word from storage.
+    let (slot) = k.cpt.stack.popInt(1)
+    k.cpt.stack.push:
+      k.cpt.getStorage(slot)
+
+  sstoreOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x55, Save word to storage.
+    let (slot, newValue) = k.cpt.stack.popInt(2)
+
+    checkInStaticContext(k.cpt)
+    # sstoreImpl(k.cpt, slot, newValue)
+    # template sstoreImpl(c: Computation, slot, newValue: Uint256) =
+    let
+      currentValue = k.cpt.getStorage(slot)
+      gasParam = GasParams(
+        kind: Op.Sstore,
+        s_currentValue: currentValue)
+
+      (gasCost, gasRefund) =
+        k.cpt.gasCosts[Sstore].c_handler(newValue, gasParam)
+
+    k.cpt.gasMeter.consumeGas(
+      gasCost, &"SSTORE: {k.cpt.msg.contractAddress}[{slot}] " &
+               &"-> {newValue} ({currentValue})")
+    if gasRefund > 0:
+      k.cpt.gasMeter.refundGas(gasRefund)
+
+    k.cpt.vmState.mutateStateDB:
+      db.setStorage(k.cpt.msg.contractAddress, slot, newValue)
+
+
+  sstoreEIP1283Op: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x55, EIP1283: sstore for Constantinople and later
+    let (slot, newValue) = k.cpt.stack.popInt(2)
+
+    checkInStaticContext(k.cpt)
+    sstoreNetGasMeteringImpl(k.cpt, slot, newValue)
+
+
+  sstoreEIP2200Op: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x55, EIP2200: sstore for Istanbul and later
+    let (slot, newValue) = k.cpt.stack.popInt(2)
+
+    checkInStaticContext(k.cpt)
+    const SentryGasEIP2200 = 2300
+
+    if k.cpt.gasMeter.gasRemaining <= SentryGasEIP2200:
+      raise newException(
+        OutOfGas,
+        "Gas not enough to perform EIP2200 SSTORE")
+
+    sstoreNetGasMeteringImpl(k.cpt, slot, newValue)
+
+
+  jumpOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x56, Alter the program counter
+    let (jumpTarget) = k.cpt.stack.popInt(1)
+    jumpImpl(k.cpt, jumpTarget)
+
+  jumpIOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x57, Conditionally alter the program counter.
+    let (jumpTarget, testedValue) = k.cpt.stack.popInt(2)
+    if testedValue != 0:
+      jumpImpl(k.cpt, jumpTarget)
+
+  pcOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x58, Get the value of the program counter prior to the increment
+    ##       corresponding to this instruction.
+    k.cpt.stack.push:
+      max(k.cpt.code.pc - 1, 0)
+
+  msizeOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x59, Get the size of active memory in bytes.
+    k.cpt.stack.push:
+      k.cpt.memory.len
+
+  gasOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x5a, Get the amount of available gas, including the corresponding
+    ##       reduction for the cost of this instruction.
+    k.cpt.stack.push:
+      k.cpt.gasMeter.gasRemaining
+
+  jumpDestOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x5b, Mark a valid destination for jumps. This operation has no effect
+    ##       on machine state during execution.
+    discard
+
+  beginSubOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x5c, Marks the entry point to a subroutine
+    raise newException(
+      OutOfGas,
+      "Abort: Attempt to execute BeginSub opcode")
+
+
+  returnSubOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x5d, Returns control to the caller of a subroutine.
+    if k.cpt.returnStack.len == 0:
+      raise newException(
+        OutOfGas,
+        "Abort: invalid returnStack during ReturnSub")
+    k.cpt.code.pc = k.cpt.returnStack.pop()
+
+
+  jumpSubOp: Vm2OpFn = proc (k: Vm2Ctx) =
+    ## 0x5e, Transfers control to a subroutine.
+    let (jumpTarget) = k.cpt.stack.popInt(1)
+
+    if jumpTarget >= k.cpt.code.len.u256:
+      raise newException(
+        InvalidJumpDestination, "JumpSub destination exceeds code len")
+
+    let returnPC = k.cpt.code.pc
+    let jt = jumpTarget.truncate(int)
+    k.cpt.code.pc = jt
+
+    let nextOpcode = k.cpt.code.peek
+    if nextOpcode != BeginSub:
+      raise newException(
+        InvalidJumpDestination, "Invalid JumpSub destination")
+
+    if k.cpt.returnStack.len == 1023:
+      raise newException(
+        FullStack, "Out of returnStack")
+
+    k.cpt.returnStack.add returnPC
+    inc k.cpt.code.pc
+
+# ------------------------------------------------------------------------------
+# Public, op exec table entries
+# ------------------------------------------------------------------------------
+
+const
+  vm2OpExecMemory*: seq[Vm2OpExec] = @[
+
+    (opCode: Pop,       ## x50, Remove item from stack
+     forks: Vm2OpAllForks,
+     info: "Remove item from stack",
+     exec: (prep: vm2OpIgnore,
+            run:  popOp,
+            post: vm2OpIgnore)),
+
+    (opCode: Mload,     ## 0x51, Load word from memory
+     forks: Vm2OpAllForks,
+     info: "Load word from memory",
+     exec: (prep: vm2OpIgnore,
+            run:  mloadOp,
+            post: vm2OpIgnore)),
+
+    (opCode: Mstore,    ## 0x52, Save word to memory
+     forks: Vm2OpAllForks,
+     info: "Save word to memory",
+     exec: (prep: vm2OpIgnore,
+            run:  mstoreOp,
+            post: vm2OpIgnore)),
+
+    (opCode: Mstore8,   ## 0x53, Save byte to memory
+     forks: Vm2OpAllForks,
+     info: "Save byte to memory",
+     exec: (prep: vm2OpIgnore,
+            run:  mstore8Op,
+            post: vm2OpIgnore)),
+
+    (opCode: Sload,     ## 0x54, Load word from storage
+     forks: Vm2OpAllForks,
+     info: "Load word from storage",
+     exec: (prep: vm2OpIgnore,
+            run:  sloadOp,
+            post: vm2OpIgnore)),
+
+    (opCode: Sstore,    ## 0x55, Save word
+     forks: Vm2OpAllForks - Vm2OpConstantinopleAndLater,
+     info: "Save word to storage",
+     exec: (prep: vm2OpIgnore,
+            run:  sstoreOp,
+            post: vm2OpIgnore)),
+
+    (opCode: Sstore,    ## 0x55, sstore for Constantinople and later
+     forks: Vm2OpConstantinopleAndLater - Vm2OpIstanbulAndLater,
+     info: "EIP1283: sstore for Constantinople and later",
+     exec: (prep: vm2OpIgnore,
+            run:  sstoreEIP1283Op,
+            post: vm2OpIgnore)),
+
+    (opCode: Sstore,    ##  0x55, sstore for Istanbul and later
+     forks: Vm2OpIstanbulAndLater,
+     info: "EIP2200: sstore for Istanbul and later",
+     exec: (prep: vm2OpIgnore,
+            run:  sstoreEIP2200Op,
+            post: vm2OpIgnore)),
+
+    (opCode: Jump,      ## 0x56, Jump
+     forks: Vm2OpIstanbulAndLater,
+     info: "Alter the program counter",
+     exec: (prep: vm2OpIgnore,
+            run:  jumpOp,
+            post: vm2OpIgnore)),
+
+    (opCode: JumpI,     ## 0x57, Conditional jump
+     forks: Vm2OpAllForks,
+     info: "Conditionally alter the program counter",
+     exec: (prep: vm2OpIgnore,
+            run:  jumpIOp,
+            post: vm2OpIgnore)),
+
+    (opCode: Pc,        ## 0x58, Program counter prior to instruction
+     forks: Vm2OpAllForks,
+     info: "Get the value of the program counter prior to the increment "&
+           "corresponding to this instruction",
+     exec: (prep: vm2OpIgnore,
+            run:  pcOp,
+            post: vm2OpIgnore)),
+
+    (opCode: Msize,     ## 0x59, Memory size
+     forks: Vm2OpAllForks,
+     info: "Get the size of active memory in bytes",
+     exec: (prep: vm2OpIgnore,
+            run:  msizeOp,
+            post: vm2OpIgnore)),
+
+    (opCode: Gas,       ##  0x5a, Get available gas
+     forks: Vm2OpAllForks,
+     info: "Get the amount of available gas, including the corresponding "&
+           "reduction for the cost of this instruction",
+     exec: (prep: vm2OpIgnore,
+            run:  gasOp,
+            post: vm2OpIgnore)),
+
+    (opCode: JumpDest,  ## 0x5b, Mark jump target. This operation has no effect
+                        ##       on machine state during execution
+     forks: Vm2OpAllForks,
+     info: "Mark a valid destination for jumps",
+     exec: (prep: vm2OpIgnore,
+            run:  jumpDestOp,
+            post: vm2OpIgnore)),
+
+    (opCode: BeginSub,  ## 0x5c, Begin subroutine
+     forks: Vm2OpAllForks,
+     info: " Marks the entry point to a subroutine",
+     exec: (prep: vm2OpIgnore,
+            run:  beginSubOp,
+            post: vm2OpIgnore)),
+
+    (opCode: ReturnSub, ## 0x5d, Return
+     forks: Vm2OpAllForks,
+     info: "Returns control to the caller of a subroutine",
+     exec: (prep: vm2OpIgnore,
+            run:  returnSubOp,
+            post: vm2OpIgnore)),
+
+    (opCode: JumpSub,   ## 0x5e, Call subroutine
+     forks: Vm2OpAllForks,
+     info: "Transfers control to a subroutine",
+     exec: (prep: vm2OpIgnore,
+            run:  jumpSubOp,
+            post: vm2OpIgnore))]
+
+# ------------------------------------------------------------------------------
+# End
+# ------------------------------------------------------------------------------

nimbus/vm2/interpreter/opcodes_impl.nim

@@ -55,6 +55,25 @@ proc writePaddedResult(mem: var Memory,
     # TODO: avoid unnecessary memory allocation
     mem.write(paddingOffset, repeat(paddingValue, numPaddingBytes))
 
+template sstoreNetGasMeteringImpl(c: Computation, slot, newValue: Uint256) =
+  let stateDB = c.vmState.readOnlyStateDB
+  let currentValue {.inject.} = c.getStorage(slot)
+
+  let
+    gasParam = GasParams(
+      kind: Op.Sstore,
+      s_currentValue: currentValue,
+      s_originalValue: stateDB.getCommittedStorage(c.msg.contractAddress, slot))
+    (gasCost, gasRefund) = c.gasCosts[Sstore].c_handler(newValue, gasParam)
+
+  c.gasMeter.consumeGas(gasCost, &"SSTORE EIP2200: {c.msg.contractAddress}[{slot}] -> {newValue} ({currentValue})")
+
+  if gasRefund != 0:
+    c.gasMeter.refundGas(gasRefund)
+
+  c.vmState.mutateStateDB:
+    db.setStorage(c.msg.contractAddress, slot, newValue)
+
 # ##################################
 # re-implemented OP handlers
 
@@ -64,18 +83,18 @@ proc gdbBPHook*() =
   stderr.write &"*** Hello {gdbBPHook_counter}\n"
   stderr.flushFile
 
-template opHandlerX(callName: untyped; opCode: Op) =
+template opHandlerX(callName: untyped; opCode: Op; fork = FkBerlin) =
   proc callName*(c: Computation) =
     gdbBPHook()
     var desc: Vm2Ctx
     desc.cpt = c
-    vm2OpTabBerlin[opCode].exec.run(desc)
+    vm2OpHandlers[fork][opCode].exec.run(desc)
 
-template opHandler(callName: untyped; opCode: Op) =
+template opHandler(callName: untyped; opCode: Op; fork = FkBerlin) =
   proc callName*(c: Computation) =
     var desc: Vm2Ctx
     desc.cpt = c
-    vm2OpTabBerlin[opCode].exec.run(desc)
+    vm2OpHandlers[fork][opCode].exec.run(desc)
 
 opHandler            add, Op.Add
 opHandler            mul, Op.Mul
@@ -123,178 +142,23 @@ opHandler     difficulty, Op.Difficulty
 opHandler       gasLimit, Op.GasLimit
 opHandler        chainId, Op.ChainId
 opHandler    selfBalance, Op.SelfBalance
-
+opHandler            pop, Op.Pop
-# ##########################################
+opHandler          mload, Op.Mload
-# 50s: Stack, Memory, Storage and Flow Operations
+opHandler         mstore, Op.Mstore
-
+opHandler        mstore8, Op.Mstore8
-op pop, inline = true:
+opHandler          sload, Op.Sload
-  ## 0x50, Remove item from stack.
+opHandler         sstore, Op.Sstore, FkFrontier
-  discard c.stack.popInt()
+opHandler  sstoreEIP1283, Op.Sstore, FkConstantinople
-
+opHandler  sstoreEIP2200, Op.Sstore
-op mload, inline = true, memStartPos:
+opHandler           jump, Op.Jump
-  ## 0x51, Load word from memory
+opHandler          jumpI, Op.JumpI
-  let memPos = memStartPos.cleanMemRef
+opHandler             pc, Op.Pc
-
+opHandler          msize, Op.Msize
-  c.gasMeter.consumeGas(
+opHandler            gas, Op.Gas
-    c.gasCosts[MLoad].m_handler(c.memory.len, memPos, 32),
+opHandler       jumpDest, Op.JumpDest
-    reason="MLOAD: GasVeryLow + memory expansion"
+opHandler       beginSub, Op.BeginSub
-    )
+opHandler      returnSub, Op.ReturnSub
-  c.memory.extend(memPos, 32)
+opHandler        jumpSub, Op.JumpSub
-
-  push: c.memory.read(memPos, 32) # TODO, should we convert to native endianness?
-
-op mstore, inline = true, memStartPos, value:
-  ## 0x52, Save word to memory
-  let memPos = memStartPos.cleanMemRef
-
-  c.gasMeter.consumeGas(
-    c.gasCosts[MStore].m_handler(c.memory.len, memPos, 32),
-    reason="MSTORE: GasVeryLow + memory expansion"
-    )
-
-  c.memory.extend(memPos, 32)
-  c.memory.write(memPos, value.toByteArrayBE) # is big-endian correct? Parity/Geth do convert
-
-op mstore8, inline = true, memStartPos, value:
-  ## 0x53, Save byte to memory
-  let memPos = memStartPos.cleanMemRef
-
-  c.gasMeter.consumeGas(
-    c.gasCosts[MStore].m_handler(c.memory.len, memPos, 1),
-    reason="MSTORE8: GasVeryLow + memory expansion"
-    )
-
-  c.memory.extend(memPos, 1)
-  c.memory.write(memPos, [value.toByteArrayBE[31]])
-
-op sload, inline = true, slot:
-  ## 0x54, Load word from storage.
-  push: c.getStorage(slot)
-
-template sstoreImpl(c: Computation, slot, newValue: Uint256) =
-    let currentValue {.inject.} = c.getStorage(slot)
-
-    let
-      gasParam = GasParams(kind: Op.Sstore, s_currentValue: currentValue)
-      (gasCost, gasRefund) = c.gasCosts[Sstore].c_handler(newValue, gasParam)
-
-    c.gasMeter.consumeGas(gasCost, &"SSTORE: {c.msg.contractAddress}[{slot}] -> {newValue} ({currentValue})")
-
-    if gasRefund > 0:
-      c.gasMeter.refundGas(gasRefund)
-
-    c.vmState.mutateStateDB:
-      db.setStorage(c.msg.contractAddress, slot, newValue)
-
-op sstore, inline = false, slot, newValue:
-  ## 0x55, Save word to storage.
-  checkInStaticContext(c)
-  block:
-    sstoreImpl(c, slot, newValue)
-
-template sstoreNetGasMeteringImpl(c: Computation, slot, newValue: Uint256) =
-    let stateDB = c.vmState.readOnlyStateDB
-    let currentValue {.inject.} = c.getStorage(slot)
-
-    let
-      gasParam = GasParams(kind: Op.Sstore,
-        s_currentValue: currentValue,
-        s_originalValue: stateDB.getCommittedStorage(c.msg.contractAddress, slot)
-      )
-      (gasCost, gasRefund) = c.gasCosts[Sstore].c_handler(newValue, gasParam)
-
-    c.gasMeter.consumeGas(gasCost, &"SSTORE EIP2200: {c.msg.contractAddress}[{slot}] -> {newValue} ({currentValue})")
-
-    if gasRefund != 0:
-      c.gasMeter.refundGas(gasRefund)
-
-    c.vmState.mutateStateDB:
-      db.setStorage(c.msg.contractAddress, slot, newValue)
-
-op sstoreEIP2200, inline = false, slot, newValue:
-  checkInStaticContext(c)
-  const SentryGasEIP2200 = 2300  # Minimum gas required to be present for an SSTORE call, not consumed
-
-  if c.gasMeter.gasRemaining <= SentryGasEIP2200:
-    raise newException(OutOfGas, "Gas not enough to perform EIP2200 SSTORE")
-  block:
-    sstoreNetGasMeteringImpl(c, slot, newValue)
-
-op sstoreEIP1283, inline = false, slot, newValue:
-  checkInStaticContext(c)
-  block:
-    sstoreNetGasMeteringImpl(c, slot, newValue)
-
-proc jumpImpl(c: Computation, jumpTarget: UInt256) =
-  if jumpTarget >= c.code.len.u256:
-    raise newException(InvalidJumpDestination, "Invalid Jump Destination")
-
-  let jt = jumpTarget.truncate(int)
-  c.code.pc = jt
-
-  let nextOpcode = c.code.peek
-  if nextOpcode != JUMPDEST:
-    raise newException(InvalidJumpDestination, "Invalid Jump Destination")
-  # TODO: next check seems redundant
-  if not c.code.isValidOpcode(jt):
-    raise newException(InvalidInstruction, "Jump resulted in invalid instruction")
-
-op jump, inline = true, jumpTarget:
-  ## 0x56, Alter the program counter
-  jumpImpl(c, jumpTarget)
-
-op jumpI, inline = true, jumpTarget, testedValue:
-  ## 0x57, Conditionally alter the program counter.
-  if testedValue != 0:
-    jumpImpl(c, jumpTarget)
-
-op pc, inline = true:
-  ## 0x58, Get the value of the program counter prior to the increment corresponding to this instruction.
-  push: max(c.code.pc - 1, 0)
-
-op msize, inline = true:
-  ## 0x59, Get the size of active memory in bytes.
-  push: c.memory.len
-
-op gas, inline = true:
-  ## 0x5a, Get the amount of available gas, including the corresponding reduction for the cost of this instruction.
-  push: c.gasMeter.gasRemaining
-
-op jumpDest, inline = true:
-  ## 0x5b, Mark a valid destination for jumps. This operation has no effect on machine state during execution.
-  discard
-
-op beginSub, inline = true:
-  ## 0x5c, Marks the entry point to a subroutine
-  raise newException(OutOfGas, "Abort: Attempt to execute BeginSub opcode")
-
-op returnSub, inline = true:
-  ## 0x5d, Returns control to the caller of a subroutine.
-  if c.returnStack.len == 0:
-    raise newException(OutOfGas, "Abort: invalid returnStack during ReturnSub")
-  # Other than the check that the return stack is not empty, there is no
-  # need to validate the pc from 'returns', since we only ever push valid
-  # values onto it via jumpsub.
-  c.code.pc = c.returnStack.pop()
-
-op jumpSub, inline = true, jumpTarget:
-  ## 0x5e, Transfers control to a subroutine.
-  if jumpTarget >= c.code.len.u256:
-    raise newException(InvalidJumpDestination, "JumpSub destination exceeds code len")
-
-  let returnPC = c.code.pc
-  let jt = jumpTarget.truncate(int)
-  c.code.pc = jt
-
-  let nextOpcode = c.code.peek
-  if nextOpcode != BeginSub:
-    raise newException(InvalidJumpDestination, "Invalid JumpSub destination")
-
-  if c.returnStack.len == 1023:
-    raise newException(FullStack, "Out of returnStack")
-
-  c.returnStack.add returnPC
-  inc c.code.pc
 
 # ##########################################
 # 60s & 70s: Push Operations.