EIP-1884 Implement SELFBALANCE opcode in LegacyVM

Author: gumb0

libethcore/EVMSchedule.h

@@ -41,6 +41,7 @@ struct EVMSchedule
     bool haveStaticCall = false;
     bool haveCreate2 = false;
     bool haveExtcodehash = false;
+    bool haveSelfbalance = false;
     std::array<unsigned, 8> tierStepGas;
     unsigned expGas = 10;
     unsigned expByteGas = 10;
@@ -153,6 +154,7 @@ static const EVMSchedule IstanbulSchedule = [] {
     schedule.sloadGas = 800;
     schedule.balanceGas = 700;
     schedule.extcodehashGas = 700;
+    schedule.haveSelfbalance = true;
     return schedule;
 }();
 

libevm/Instruction.cpp

@@ -22,7 +22,7 @@ namespace dev
 {
 namespace eth
 {
-
+// clang-format off
 static const std::map<Instruction,  InstructionInfo> c_instructionInfo =
 { //                                                   Args,  Ret,  GasPriceTier
     { Instruction::STOP,         { "STOP",                0,    0,  Tier::Zero } },
@@ -74,6 +74,7 @@ static const std::map<Instruction,  InstructionInfo> c_instructionInfo =
     { Instruction::NUMBER,       { "NUMBER",              0,    1,  Tier::Base } },
     { Instruction::DIFFICULTY,   { "DIFFICULTY",          0,    1,  Tier::Base } },
     { Instruction::GASLIMIT,     { "GASLIMIT",            0,    1,  Tier::Base } },
+    { Instruction::SELFBALANCE,  { "SELFBALANCE",         0,    1,  Tier::Low } },
     { Instruction::POP,          { "POP",                 1,    0,  Tier::Base } },
     { Instruction::MLOAD,        { "MLOAD",               1,    1,  Tier::VeryLow } },
     { Instruction::MSTORE,       { "MSTORE",              2,    0,  Tier::VeryLow } },
@@ -215,8 +216,9 @@ static const std::map<Instruction,  InstructionInfo> c_instructionInfo =
     { Instruction::PUSHC,        { "PUSHC",               0,    1, Tier::VeryLow } },
     { Instruction::JUMPC,        { "JUMPC",               1,    0, Tier::Mid } },
     { Instruction::JUMPCI,       { "JUMPCI",              2,    0, Tier::High } },
-}; 
- 
+};
+// clang-format on
+
 InstructionInfo instructionInfo(Instruction _inst)
 {
     auto it = c_instructionInfo.find(_inst);

libevm/Instruction.h

@@ -75,12 +75,13 @@ enum class Instruction : uint8_t
     RETURNDATACOPY = 0x3e,  ///< copy data returned from previous call to memory
     EXTCODEHASH = 0x3f,     ///< get external code hash
 
-    BLOCKHASH = 0x40,  ///< get hash of most recent complete block
-    COINBASE,          ///< get the block's coinbase address
-    TIMESTAMP,         ///< get the block's timestamp
-    NUMBER,            ///< get the block's number
-    DIFFICULTY,        ///< get the block's difficulty
-    GASLIMIT,          ///< get the block's gas limit
+    BLOCKHASH = 0x40,    ///< get hash of most recent complete block
+    COINBASE,            ///< get the block's coinbase address
+    TIMESTAMP,           ///< get the block's timestamp
+    NUMBER,              ///< get the block's number
+    DIFFICULTY,          ///< get the block's difficulty
+    GASLIMIT,            ///< get the block's gas limit
+    SELFBALANCE = 0x47,  ///< get balance of the current address
 
     POP = 0x50,  ///< remove item from stack
     MLOAD,       ///< load word from memory

libevm/LegacyVM.cpp

@@ -1439,6 +1439,19 @@ void LegacyVM::interpretCases()
         }
         NEXT
 
+        CASE(SELFBALANCE)
+        {
+            ON_OP();
+
+            if (!m_schedule->haveSelfbalance)
+                throwBadInstruction();
+
+            updateIOGas();
+
+            m_SPP[0] = m_ext->balance(m_ext->myAddress);
+        }
+        NEXT
+
         CASE(POP)
         {
             ON_OP();

libevm/LegacyVMConfig.h

@@ -226,15 +226,15 @@ namespace dev
         &&EXTCODECOPY,                          \
         &&RETURNDATASIZE,                       \
         &&RETURNDATACOPY,                       \
-        &&EXTCODEHASH,                         \
+        &&EXTCODEHASH,                          \
         &&BLOCKHASH, /* 40, */                  \
         &&COINBASE,                             \
         &&TIMESTAMP,                            \
         &&NUMBER,                               \
         &&DIFFICULTY,                           \
         &&GASLIMIT,                             \
         &&INVALID,                              \
-        &&INVALID,                              \
+        &&SELFBALANCE,                          \
         &&INVALID,                              \
         &&INVALID,                              \
         &&INVALID,                              \