From 078375061b4171e802b506af5f193c7fc5e448f6 Mon Sep 17 00:00:00 2001
From: andri lim <jangko128@gmail.com>
Date: Mon, 11 Nov 2019 12:12:58 +0700
Subject: [PATCH] implement EIP 1884 stub

---
 nimbus/vm/interpreter/gas_costs.nim     | 9 ++++++++-
 nimbus/vm/interpreter/opcode_values.nim | 1 +
 nimbus/vm/interpreter/opcodes_impl.nim  | 5 +++++
 nimbus/vm/interpreter_dispatch.nim      | 1 +
 4 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/nimbus/vm/interpreter/gas_costs.nim b/nimbus/vm/interpreter/gas_costs.nim
index 8193b1e46..d84820ae0 100644
--- a/nimbus/vm/interpreter/gas_costs.nim
+++ b/nimbus/vm/interpreter/gas_costs.nim
@@ -604,10 +604,17 @@ func spuriousGasFees(previous_fees: GasFeeSchedule): GasFeeSchedule =
   result = previous_fees
   result[GasExpByte]      = 50
 
+func istanbulGasFees(previous_fees: GasFeeSchedule): GasFeeSchedule =
+  # https://eips.ethereum.org/EIPS/eip-1884
+  result[GasSload]        = 800
+  result[GasExtCodeHash]  = 700
+  result[GasBalance]      = 700
+
 const
   HomesteadGasFees = BaseGasFees.homesteadGasFees
   TangerineGasFees = HomesteadGasFees.tangerineGasFees
   SpuriousGasFees = TangerineGasFees.spuriousGasFees
+  IstanbulGasFees = SpuriousGasFees.istanbulGasFees
 
   gasFees*: array[Fork, GasFeeSchedule] = [
     FkFrontier: BaseGasFees,
@@ -618,7 +625,7 @@ const
     FkSpurious: SpuriousGasFees,
     FkByzantium: SpuriousGasFees,
     FkConstantinople: SpuriousGasFees,
-    FkIstanbul: SpuriousGasFees
+    FkIstanbul: IstanbulGasFees
   ]
 
 
diff --git a/nimbus/vm/interpreter/opcode_values.nim b/nimbus/vm/interpreter/opcode_values.nim
index 3bc7b8ebe..0de3b2bc4 100644
--- a/nimbus/vm/interpreter/opcode_values.nim
+++ b/nimbus/vm/interpreter/opcode_values.nim
@@ -80,6 +80,7 @@ fill_enum_holes:
       GasLimit =       0x45, # Get the block's gas limit.
 
       ChainID =        0x46, # Get current chain’s EIP-155 unique identifier.
+      SelfBalance =    0x47, # Get current contract's balance.
 
       # 50s: Stack, Memory, Storage and Flow Operations
       Pop =            0x50, # Remove item from stack.
diff --git a/nimbus/vm/interpreter/opcodes_impl.nim b/nimbus/vm/interpreter/opcodes_impl.nim
index 8ed57fd1e..a7dfddb12 100644
--- a/nimbus/vm/interpreter/opcodes_impl.nim
+++ b/nimbus/vm/interpreter/opcodes_impl.nim
@@ -377,6 +377,11 @@ op chainID, inline = true:
   # TODO: this is a stub
   push: 0
 
+op selfBalance, inline = true:
+  ## 0x47, Get current contract's balance.
+  # TODO: this is a stub
+  push: 0
+
 # ##########################################
 # 50s: Stack, Memory, Storage and Flow Operations
 
diff --git a/nimbus/vm/interpreter_dispatch.nim b/nimbus/vm/interpreter_dispatch.nim
index 82fcd2622..c3832b5e0 100644
--- a/nimbus/vm/interpreter_dispatch.nim
+++ b/nimbus/vm/interpreter_dispatch.nim
@@ -218,6 +218,7 @@ let ConstantinopleOpDispatch {.compileTime.}: array[Op, NimNode] = genConstantin
 proc genIstanbulJumpTable(ops: array[Op, NimNode]): array[Op, NimNode] {.compileTime.} =
   result = ops
   result[ChainID] = newIdentNode "chainID"
+  result[SelfBalance] = newIdentNode "selfBalance"
 
 let IstanbulOpDispatch {.compileTime.}: array[Op, NimNode] = genIstanbulJumpTable(ConstantinopleOpDispatch)