core, core/vm: added gas price variance table

This implements 1b & 1c of EIP150 by adding a new GasTable which must be
returned from the RuleSet config method. This table is used to determine
the gas prices for the current epoch.

Please note that when the CreateBySuicide gas price is set it is assumed
that we're in the new epoch phase.

In addition this PR will serve as temporary basis while refactorisation
in being done in the EVM64 PR, which will substentially overhaul the gas
price code.

Author: obscuren

.zshrc

@@ -0,0 +1 @@
+/Users/jeffrey/dotfiles/zsh/zshrc

cmd/ethtest/main.go

@@ -74,7 +74,7 @@ func runTestWithReader(test string, r io.Reader) error {
 	var err error
 	switch strings.ToLower(test) {
 	case "bk", "block", "blocktest", "blockchaintest", "blocktests", "blockchaintests":
-		err = tests.RunBlockTestWithReader(params.MainNetHomesteadBlock, params.MainNetDAOForkBlock, r, skipTests)
+		err = tests.RunBlockTestWithReader(params.MainNetHomesteadBlock, params.MainNetDAOForkBlock, params.MainNetHomesteadGasRepriceBlock, r, skipTests)
 	case "st", "state", "statetest", "statetests":
 		rs := tests.RuleSet{HomesteadBlock: params.MainNetHomesteadBlock, DAOForkBlock: params.MainNetDAOForkBlock, DAOForkSupport: true}
 		err = tests.RunStateTestWithReader(rs, r, skipTests)

cmd/evm/main.go

@@ -33,6 +33,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/params"
 	"gopkg.in/urfave/cli.v1"
 )
 
@@ -226,6 +227,9 @@ func NewEnv(state *state.StateDB, transactor common.Address, value *big.Int, cfg
 type ruleSet struct{}
 
 func (ruleSet) IsHomestead(*big.Int) bool { return true }
+func (ruleSet) GasTable(*big.Int) params.GasTable {
+	return params.GasTableHomesteadGasRepriceFork
+}
 
 func (self *VMEnv) RuleSet() vm.RuleSet       { return ruleSet{} }
 func (self *VMEnv) Vm() vm.Vm                 { return self.evm }

cmd/utils/flags.go

@@ -792,6 +792,13 @@ func MakeChainConfigFromDb(ctx *cli.Context, db ethdb.Database) *core.ChainConfi
 		}
 		config.DAOForkSupport = true
 	}
+	if config.HomesteadGasRepriceBlock == nil {
+		if ctx.GlobalBool(TestNetFlag.Name) {
+			config.HomesteadGasRepriceBlock = params.TestNetHomesteadGasRepriceBlock
+		} else {
+			config.HomesteadGasRepriceBlock = params.MainNetHomesteadGasRepriceBlock
+		}
+	}
 	// Force override any existing configs if explicitly requested
 	switch {
 	case ctx.GlobalBool(SupportDAOFork.Name):

core/config.go

@@ -21,6 +21,7 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/params"
 )
 
 var ChainConfigNotFoundErr = errors.New("ChainConfig not found") // general config not found error
@@ -35,6 +36,8 @@ type ChainConfig struct {
 	DAOForkBlock   *big.Int `json:"daoForkBlock"`   // TheDAO hard-fork switch block (nil = no fork)
 	DAOForkSupport bool     `json:"daoForkSupport"` // Whether the nodes supports or opposes the DAO hard-fork
 
+	HomesteadGasRepriceBlock *big.Int `json:"homesteadGasRepriceBlock"` // Homestead gas reprice switch block (nil = no fork)
+
 	VmConfig vm.Config `json:"-"`
 }
 
@@ -45,3 +48,14 @@ func (c *ChainConfig) IsHomestead(num *big.Int) bool {
 	}
 	return num.Cmp(c.HomesteadBlock) >= 0
 }
+
+// GasTable returns the gas table corresponding to the current phase (homestead or homestead reprice).
+//
+// The returned GasTable's fields shouldn't, under any circumstances, be changed.
+func (c *ChainConfig) GasTable(num *big.Int) params.GasTable {
+	if c.HomesteadGasRepriceBlock == nil || num == nil || num.Cmp(c.HomesteadGasRepriceBlock) < 0 {
+		return params.GasTableHomestead
+	}
+
+	return params.GasTableHomesteadGasRepriceFork
+}

core/vm/environment.go

@@ -20,12 +20,16 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/params"
 )
 
 // RuleSet is an interface that defines the current rule set during the
 // execution of the EVM instructions (e.g. whether it's homestead)
 type RuleSet interface {
 	IsHomestead(*big.Int) bool
+	// GasTable returns the gas prices for this phase, which is based on
+	// block number passed in.
+	GasTable(*big.Int) params.GasTable
 }
 
 // Environment is an EVM requirement and helper which allows access to outside

core/vm/gas.go

@@ -35,8 +35,27 @@ var (
 	GasStop   = big.NewInt(0)
 
 	GasContractByte = big.NewInt(200)
+
+	n64 = big.NewInt(64)
 )
 
+// calcGas returns the actual gas cost of the call.
+//
+// The cost of gas was changed during the homestead price change HF. To allow for EIP150
+// to be implemented. The returned gas is gas - base * 63 / 64.
+func callGas(gasTable params.GasTable, availableGas, base, callCost *big.Int) *big.Int {
+	if gasTable.CreateBySuicide != nil {
+		availableGas = new(big.Int).Sub(availableGas, base)
+		g := new(big.Int).Div(availableGas, n64)
+		g.Sub(availableGas, g)
+
+		if g.Cmp(callCost) < 0 {
+			return g
+		}
+	}
+	return callCost
+}
+
 // baseCheck checks for any stack error underflows
 func baseCheck(op OpCode, stack *Stack, gas *big.Int) error {
 	// PUSH and DUP are a bit special. They all cost the same but we do want to have checking on stack push limit
@@ -127,18 +146,19 @@ var _baseCheck = map[OpCode]req{
 	MSIZE:        {0, GasQuickStep, 1},
 	GAS:          {0, GasQuickStep, 1},
 	BLOCKHASH:    {1, GasExtStep, 1},
-	BALANCE:      {1, GasExtStep, 1},
-	EXTCODESIZE:  {1, GasExtStep, 1},
-	EXTCODECOPY:  {4, GasExtStep, 0},
+	BALANCE:      {1, Zero, 1},
+	EXTCODESIZE:  {1, Zero, 1},
+	EXTCODECOPY:  {4, Zero, 0},
 	SLOAD:        {1, params.SloadGas, 1},
 	SSTORE:       {2, Zero, 0},
 	SHA3:         {2, params.Sha3Gas, 1},
 	CREATE:       {3, params.CreateGas, 1},
-	CALL:         {7, params.CallGas, 1},
-	CALLCODE:     {7, params.CallGas, 1},
-	DELEGATECALL: {6, params.CallGas, 1},
-	JUMPDEST:     {0, params.JumpdestGas, 0},
+	// Zero is calculated in the gasSwitch
+	CALL:         {7, Zero, 1},
+	CALLCODE:     {7, Zero, 1},
+	DELEGATECALL: {6, Zero, 1},
 	SUICIDE:      {1, Zero, 0},
+	JUMPDEST:     {0, params.JumpdestGas, 0},
 	RETURN:       {2, Zero, 0},
 	PUSH1:        {0, GasFastestStep, 1},
 	DUP1:         {0, Zero, 1},

core/vm/instructions.go

@@ -514,7 +514,12 @@ func opCreate(instr instruction, pc *uint64, env Environment, contract *Contract
 		input        = memory.Get(offset.Int64(), size.Int64())
 		gas          = new(big.Int).Set(contract.Gas)
 	)
-	contract.UseGas(contract.Gas)
+	if env.RuleSet().GasTable(env.BlockNumber()).CreateBySuicide != nil {
+		gas.Div(gas, n64)
+		gas = gas.Sub(contract.Gas, gas)
+	}
+
+	contract.UseGas(gas)
 	_, addr, suberr := env.Create(contract, input, gas, contract.Price, value)
 	// Push item on the stack based on the returned error. If the ruleset is
 	// homestead we must check for CodeStoreOutOfGasError (homestead only

core/vm/runtime/runtime.go

@@ -25,12 +25,16 @@ import (
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/params"
 )
 
 // The default, always homestead, rule set for the vm env
 type ruleSet struct{}
 
 func (ruleSet) IsHomestead(*big.Int) bool { return true }
+func (ruleSet) GasTable(*big.Int) params.GasTable {
+	return params.GasTableHomesteadGasRepriceFork
+}
 
 // Config is a basic type specifying certain configuration flags for running
 // the EVM.

core/vm/util_test.go

@@ -16,10 +16,17 @@
 
 package vm
 
-import "math/big"
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/params"
+)
 
 type ruleSet struct {
 	hs *big.Int
 }
 
 func (r ruleSet) IsHomestead(n *big.Int) bool { return n.Cmp(r.hs) >= 0 }
+func (r ruleSet) GasTable(*big.Int) params.GasTable {
+	return params.GasTableHomestead
+}