preparation for London hard fork

This preparation is needed for subsequent
EIPs included in London.

- Add London to Fork enum
- Block number to fork
- Parsing London fork in chain config
- Prepare gas costs table for London
- Prepare EVM opcode dispatcher for London
- Block rewards for London
- Prepare hive script for London

hive_integration/nimbus/mapper.jq

@@ -64,5 +64,6 @@ def to_bool:
     "istanbulBlock": env.HIVE_FORK_ISTANBUL|to_int,
     "muirGlacierBlock": env.HIVE_FORK_MUIR_GLACIER|to_int,
     "berlinBlock": env.HIVE_FORK_BERLIN|to_int
+    "londonBlock": env.HIVE_FORK_LONDON|to_int
   }|remove_empty
 }

hive_integration/nimbus/nimbus.sh

@@ -30,6 +30,7 @@
 #  - [x] HIVE_FORK_ISTANBUL           block number for Istanbul transition
 #  - [x] HIVE_FORK_MUIRGLACIER        block number for Muir Glacier transition
 #  - [x] HIVE_FORK_BERLIN             block number for Berlin transition
+#  - [x] HIVE_FORK_LONDON             block number for London transition
 #
 # Clique PoA:
 #

nimbus/chain_config.nim

@@ -32,6 +32,7 @@ type
     istanbulBlock      : Option[BlockNumber]
     muirGlacierBlock   : Option[BlockNumber]
     berlinBlock        : Option[BlockNumber]
+    londonBlock        : Option[BlockNumber]
 
   ChainConfig* = object
     chainId*            : ChainId
@@ -52,6 +53,7 @@ type
     istanbulBlock*      : BlockNumber
     muirGlacierBlock*   : BlockNumber
     berlinBlock*        : BlockNumber
+    londonBlock*        : BlockNumber
 
     # TODO: this need to be fixed somehow
     # using `real` engine configuration
@@ -174,7 +176,8 @@ proc loadCustomGenesis*(fileName: string, cg: var CustomGenesis): bool =
       error "Forks can't be assigned out of order", fork=fork
       return false
 
-  validateFork(berlinBlock,         high(BlockNumber).toBlockNumber)
+  validateFork(londonBlock,         high(BlockNumber).toBlockNumber)
+  validateFork(berlinBlock,         cg.config.londonBlock)
   validateFork(muirGlacierBlock,    cg.config.berlinBlock)
   validateFork(istanbulBlock,       cg.config.muirGlacierBlock)
   validateFork(petersburgBlock,     cg.config.istanbulBlock)

nimbus/config.nim

@@ -159,7 +159,8 @@ proc `$`*(c: ChainId): string =
   $(c.int)
 
 proc toFork*(c: ChainConfig, number: BlockNumber): Fork =
-  if number >= c.berlinBlock: FkBerlin
+  if number >= c.londonBlock: FkLondon
+  elif number >= c.berlinBlock: FkBerlin
   elif number >= c.istanbulBlock: FkIstanbul
   elif number >= c.petersburgBlock: FkPetersburg
   elif number >= c.constantinopleBlock: FkConstantinople
@@ -190,7 +191,8 @@ proc chainConfig*(id: NetworkId): ChainConfig =
       petersburgBlock:7_280_000.toBlockNumber, # 28/02/2019 07:52:04
       istanbulBlock:  9_069_000.toBlockNumber, # 08/12/2019 12:25:09
       muirGlacierBlock: 9_200_000.toBlockNumber, # 02/01/2020 08:30:49
-      berlinBlock:      12_244_000.toBlockNumber # 15/04/2021 10:07:03
+      berlinBlock:    12_244_000.toBlockNumber, # 15/04/2021 10:07:03
+      londonBlock:    high(BlockNumber)
     )
   of RopstenNet:
     ChainConfig(
@@ -207,7 +209,8 @@ proc chainConfig*(id: NetworkId): ChainConfig =
       petersburgBlock:4_939_394.toBlockNumber,
       istanbulBlock:  6_485_846.toBlockNumber,
       muirGlacierBlock: 7_117_117.toBlockNumber,
-      berlinBlock:      9_812_189.toBlockNumber
+      berlinBlock:      9_812_189.toBlockNumber,
+      londonBlock:    high(BlockNumber)
     )
   of RinkebyNet:
     ChainConfig(
@@ -224,7 +227,8 @@ proc chainConfig*(id: NetworkId): ChainConfig =
       petersburgBlock:4_321_234.toBlockNumber,
       istanbulBlock:  5_435_345.toBlockNumber,
       muirGlacierBlock: 8_290_928.toBlockNumber, # never occured in rinkeby network
-      berlinBlock:      8_290_928.toBlockNumber
+      berlinBlock:      8_290_928.toBlockNumber,
+      londonBlock:    high(BlockNumber)
     )
   of GoerliNet:
     ChainConfig(
@@ -241,7 +245,8 @@ proc chainConfig*(id: NetworkId): ChainConfig =
       petersburgBlock: 0.toBlockNumber,
       istanbulBlock:  1_561_651.toBlockNumber,
       muirGlacierBlock: 4_460_644.toBlockNumber, # never occured in goerli network
-      berlinBlock:      4_460_644.toBlockNumber
+      berlinBlock:    4_460_644.toBlockNumber,
+      londonBlock:    high(BlockNumber)
     )
   else:
     # everything else will use CustomNet config

nimbus/forks.nim

@@ -17,3 +17,4 @@ type
     FkPetersburg     = "Petersburg"
     FkIstanbul       = "Istanbul"
     FkBerlin         = "Berlin"
+    FkLondon         = "London"

nimbus/p2p/chain.nim

@@ -30,7 +30,8 @@ type
     Petersburg,
     Istanbul,
     MuirGlacier,
-    Berlin
+    Berlin,
+    London
 
   Chain* = ref object of AbstractChainDB
     db: BaseChainDB
@@ -40,7 +41,8 @@ type
     extraValidation: bool
 
 func toChainFork(c: ChainConfig, number: BlockNumber): ChainFork =
-  if number >= c.berlinBlock: Berlin
+  if number >= c.londonBlock: London
+  elif number >= c.berlinBlock: Berlin
   elif number >= c.muirGlacierBlock: MuirGlacier
   elif number >= c.istanbulBlock: Istanbul
   elif number >= c.petersburgBlock: Petersburg
@@ -71,6 +73,7 @@ func getNextFork(c: ChainConfig, fork: ChainFork): uint64 =
     toNextFork(c.istanbulBlock),
     toNextFork(c.muirGlacierBlock),
     toNextFork(c.berlinBlock),
+    toNextFork(c.londonBlock)
   ]
 
   if fork == high(ChainFork):

nimbus/p2p/clique/clique_utils.nim

@@ -151,8 +151,7 @@ proc validateGasLimit*(c: var BaseChainDB; header: BlockHeader): CliqueResult {.
 
 # params/config.go(450): func (c *ChainConfig) IsLondon(num [..]
 proc isLondonOrLater*(c: var ChainConfig; number: BlockNumber): bool =
-  ## FIXME: London is not defined yet, will come after Berlin
-  FkBerlin < c.toFork(number)
+  c.toFork(number) >= FkLondon
 
 # consensus/misc/eip1559.go(55): func CalcBaseFee(config [..]
 proc calc1599BaseFee*(c: var ChainConfig; parent: BlockHeader): UInt256 =

nimbus/p2p/executor.nim

@@ -90,7 +90,8 @@ const
     eth2, # FkConstantinople
     eth2, # FkPetersburg
     eth2, # FkIstanbul
-    eth2  # FkBerlin
+    eth2, # FkBerlin
+    eth2  # FkLondon
   ]
 
 proc calculateReward(fork: Fork, header: BlockHeader, body: BlockBody, vmState: BaseVMState) =

nimbus/vm/evmc_api.nim

@@ -25,6 +25,7 @@ type
     block_gas_limit* : int64          # The block gas limit.
     block_difficulty*: evmc_uint256be # The block difficulty.
     chain_id*        : evmc_uint256be # The blockchain's ChainID.
+    block_base_fee*  : evmc_uint256be # The block base fee.
 
   nimbus_message* = object
     kind*: evmc_call_kind

nimbus/vm/evmc_host.nim

@@ -33,7 +33,7 @@ proc hostGetStorageImpl(ctx: Computation, address: EthAddress, key: var evmc_byt
   ctx.vmState.accountDB.getStorage(address, Uint256.fromEvmc(key)).toEvmc()
 
 proc sstoreNetGasMetering(ctx: Computation): bool {.inline.} =
-  ctx.fork in {FkConstantinople, FkIstanbul, FkBerlin}
+  ctx.fork in {FkConstantinople, FkIstanbul, FkBerlin, FkLondon}
 
 proc hostSetStorageImpl(ctx: Computation, address: EthAddress,
                         key, value: var evmc_bytes32): evmc_storage_status {.cdecl.} =

nimbus/vm/interpreter/gas_costs.nim

@@ -738,7 +738,8 @@ const
     FkConstantinople: SpuriousGasFees,
     FkPetersburg: SpuriousGasFees,
     FkIstanbul: IstanbulGasFees,
-    FkBerlin: BerlinGasFees
+    FkBerlin: BerlinGasFees,
+    FkLondon: BerlinGasFees
   ]
 
 
@@ -749,6 +750,7 @@ gasCosts(FkSpurious, spurious, SpuriousGasCosts)
 gasCosts(FkConstantinople, constantinople, ConstantinopleGasCosts)
 gasCosts(FkIstanbul, istanbul, IstanbulGasCosts)
 gasCosts(FkBerlin, berlin, BerlinGasCosts)
+gasCosts(FkLondon, london, LondonGasCosts)
 
 proc forkToSchedule*(fork: Fork): GasCosts =
   if fork < FkHomestead:
@@ -763,8 +765,10 @@ proc forkToSchedule*(fork: Fork): GasCosts =
     SpuriousGasCosts
   elif fork < FkBerlin:
     IstanbulGasCosts
-  else:
+  elif fork < FkLondon:
     BerlinGasCosts
+  else:
+    LondonGasCosts
 
 const
   ## Precompile costs

nimbus/vm/interpreter_dispatch.nim

@@ -248,6 +248,12 @@ proc genBerlinJumpTable(ops: array[Op, NimNode]): array[Op, NimNode] {.compileTi
 
 let BerlinOpDispatch {.compileTime.}: array[Op, NimNode] = genBerlinJumpTable(IstanbulOpDispatch)
 
+proc genLondonJumpTable(ops: array[Op, NimNode]): array[Op, NimNode] {.compileTime.} =
+  result = ops
+  # incoming EIP-3198 and EIP-3529
+
+let LondonOpDispatch {.compileTime.}: array[Op, NimNode] = genLondonJumpTable(BerlinOpDispatch)
+
 proc opTableToCaseStmt(opTable: array[Op, NimNode], c: NimNode): NimNode =
 
   let instr = quote do: `c`.instr
@@ -336,6 +342,9 @@ macro genIstanbulDispatch(c: Computation): untyped =
 macro genBerlinDispatch(c: Computation): untyped =
   result = opTableToCaseStmt(BerlinOpDispatch, c)
 
+macro genLondonDispatch(c: Computation): untyped =
+  result = opTableToCaseStmt(LondonOpDispatch, c)
+
 proc frontierVM(c: Computation) =
   genFrontierDispatch(c)
 
@@ -363,6 +372,9 @@ proc istanbulVM(c: Computation) {.gcsafe.} =
 proc berlinVM(c: Computation) {.gcsafe.} =
   genBerlinDispatch(c)
 
+proc londonVM(c: Computation) {.gcsafe.} =
+  genLondonDispatch(c)
+
 proc selectVM(c: Computation, fork: Fork) {.gcsafe.} =
   # TODO: Optimise getting fork and updating opCodeExec only when necessary
   case fork
@@ -382,8 +394,10 @@ proc selectVM(c: Computation, fork: Fork) {.gcsafe.} =
     c.petersburgVM()
   of FkIstanbul:
     c.istanbulVM()
-  else:
+  of FkBerlin:
     c.berlinVM()
+  else:
+    c.londonVM()
 
 proc executeOpcodes(c: Computation) =
   let fork = c.fork

nimbus/vm2/interpreter/gas_costs.nim

@@ -708,7 +708,8 @@ const
     FkConstantinople: SpuriousGasFees,
     FkPetersburg: SpuriousGasFees,
     FkIstanbul: IstanbulGasFees,
-    FkBerlin: BerlinGasFees
+    FkBerlin: BerlinGasFees,
+    FkLondon: BerlinGasFees
   ]
 
 
@@ -719,6 +720,7 @@ gasCosts(FkSpurious, spurious, SpuriousGasCosts)
 gasCosts(FkConstantinople, constantinople, ConstantinopleGasCosts)
 gasCosts(FkIstanbul, istanbul, IstanbulGasCosts)
 gasCosts(FkBerlin, berlin, BerlinGasCosts)
+gasCosts(FkLondon, london, LondonGasCosts)
 
 proc forkToSchedule*(fork: Fork): GasCosts =
   if fork < FkHomestead:
@@ -733,8 +735,10 @@ proc forkToSchedule*(fork: Fork): GasCosts =
     SpuriousGasCosts
   elif fork < FkBerlin:
     IstanbulGasCosts
-  else:
+  elif fork < FkLondon:
     BerlinGasCosts
+  else:
+    LondonGasCosts
 
 const
   ## Precompile costs

nimbus/vm2/interpreter/op_handlers/oph_defs.nim

@@ -78,6 +78,9 @@ const
   Vm2OpBerlinAndLater* =
     Vm2OpIstanbulAndLater - {FkIstanbul}
 
+  Vm2OpLondonAndLater* =
+    Vm2OpBerlinAndLater - {FkBerlin}
+
 # ------------------------------------------------------------------------------
 # End
 # ------------------------------------------------------------------------------