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authorDeterminant <[email protected]>2020-07-30 14:18:44 -0400
committerDeterminant <[email protected]>2020-07-30 14:18:44 -0400
commit0444e66f640999c15496066637841efcc0433934 (patch)
treec19aec2dced2e9129c880c19c52ca0f87b3d62f6 /core/vm/gas_table.go
parentcffa0954bbdb43821d1b71d00f99fb705cecd25b (diff)
parent1f49826de2bb8bb4f5f99f69fd2beb039b1172d9 (diff)
Merge branch 'multi-coin'
Diffstat (limited to 'core/vm/gas_table.go')
-rw-r--r--core/vm/gas_table.go441
1 files changed, 441 insertions, 0 deletions
diff --git a/core/vm/gas_table.go b/core/vm/gas_table.go
new file mode 100644
index 0000000..2adaf85
--- /dev/null
+++ b/core/vm/gas_table.go
@@ -0,0 +1,441 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package vm
+
+import (
+ "errors"
+
+ "github.com/ava-labs/coreth/params"
+ "github.com/ava-labs/go-ethereum/common"
+ "github.com/ava-labs/go-ethereum/common/math"
+)
+
+// memoryGasCost calculates the quadratic gas for memory expansion. It does so
+// only for the memory region that is expanded, not the total memory.
+func memoryGasCost(mem *Memory, newMemSize uint64) (uint64, error) {
+ if newMemSize == 0 {
+ return 0, nil
+ }
+ // The maximum that will fit in a uint64 is max_word_count - 1. Anything above
+ // that will result in an overflow. Additionally, a newMemSize which results in
+ // a newMemSizeWords larger than 0xFFFFFFFF will cause the square operation to
+ // overflow. The constant 0x1FFFFFFFE0 is the highest number that can be used
+ // without overflowing the gas calculation.
+ if newMemSize > 0x1FFFFFFFE0 {
+ return 0, errGasUintOverflow
+ }
+ newMemSizeWords := toWordSize(newMemSize)
+ newMemSize = newMemSizeWords * 32
+
+ if newMemSize > uint64(mem.Len()) {
+ square := newMemSizeWords * newMemSizeWords
+ linCoef := newMemSizeWords * params.MemoryGas
+ quadCoef := square / params.QuadCoeffDiv
+ newTotalFee := linCoef + quadCoef
+
+ fee := newTotalFee - mem.lastGasCost
+ mem.lastGasCost = newTotalFee
+
+ return fee, nil
+ }
+ return 0, nil
+}
+
+// memoryCopierGas creates the gas functions for the following opcodes, and takes
+// the stack position of the operand which determines the size of the data to copy
+// as argument:
+// CALLDATACOPY (stack position 2)
+// CODECOPY (stack position 2)
+// EXTCODECOPY (stack poition 3)
+// RETURNDATACOPY (stack position 2)
+func memoryCopierGas(stackpos int) gasFunc {
+ return func(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ // Gas for expanding the memory
+ gas, err := memoryGasCost(mem, memorySize)
+ if err != nil {
+ return 0, err
+ }
+ // And gas for copying data, charged per word at param.CopyGas
+ words, overflow := bigUint64(stack.Back(stackpos))
+ if overflow {
+ return 0, errGasUintOverflow
+ }
+
+ if words, overflow = math.SafeMul(toWordSize(words), params.CopyGas); overflow {
+ return 0, errGasUintOverflow
+ }
+
+ if gas, overflow = math.SafeAdd(gas, words); overflow {
+ return 0, errGasUintOverflow
+ }
+ return gas, nil
+ }
+}
+
+var (
+ gasCallDataCopy = memoryCopierGas(2)
+ gasCodeCopy = memoryCopierGas(2)
+ gasExtCodeCopy = memoryCopierGas(3)
+ gasReturnDataCopy = memoryCopierGas(2)
+)
+
+func gasSStore(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ var (
+ y, x = stack.Back(1), stack.Back(0)
+ current = evm.StateDB.GetState(contract.Address(), common.BigToHash(x))
+ )
+ // The legacy gas metering only takes into consideration the current state
+ // Legacy rules should be applied if we are in Petersburg (removal of EIP-1283)
+ // OR Constantinople is not active
+ if evm.chainRules.IsPetersburg || !evm.chainRules.IsConstantinople {
+ // This checks for 3 scenario's and calculates gas accordingly:
+ //
+ // 1. From a zero-value address to a non-zero value (NEW VALUE)
+ // 2. From a non-zero value address to a zero-value address (DELETE)
+ // 3. From a non-zero to a non-zero (CHANGE)
+ switch {
+ case current == (common.Hash{}) && y.Sign() != 0: // 0 => non 0
+ return params.SstoreSetGas, nil
+ case current != (common.Hash{}) && y.Sign() == 0: // non 0 => 0
+ evm.StateDB.AddRefund(params.SstoreRefundGas)
+ return params.SstoreClearGas, nil
+ default: // non 0 => non 0 (or 0 => 0)
+ return params.SstoreResetGas, nil
+ }
+ }
+ // The new gas metering is based on net gas costs (EIP-1283):
+ //
+ // 1. If current value equals new value (this is a no-op), 200 gas is deducted.
+ // 2. If current value does not equal new value
+ // 2.1. If original value equals current value (this storage slot has not been changed by the current execution context)
+ // 2.1.1. If original value is 0, 20000 gas is deducted.
+ // 2.1.2. Otherwise, 5000 gas is deducted. If new value is 0, add 15000 gas to refund counter.
+ // 2.2. If original value does not equal current value (this storage slot is dirty), 200 gas is deducted. Apply both of the following clauses.
+ // 2.2.1. If original value is not 0
+ // 2.2.1.1. If current value is 0 (also means that new value is not 0), remove 15000 gas from refund counter. We can prove that refund counter will never go below 0.
+ // 2.2.1.2. If new value is 0 (also means that current value is not 0), add 15000 gas to refund counter.
+ // 2.2.2. If original value equals new value (this storage slot is reset)
+ // 2.2.2.1. If original value is 0, add 19800 gas to refund counter.
+ // 2.2.2.2. Otherwise, add 4800 gas to refund counter.
+ value := common.BigToHash(y)
+ if current == value { // noop (1)
+ return params.NetSstoreNoopGas, nil
+ }
+ original := evm.StateDB.GetCommittedState(contract.Address(), common.BigToHash(x))
+ if original == current {
+ if original == (common.Hash{}) { // create slot (2.1.1)
+ return params.NetSstoreInitGas, nil
+ }
+ if value == (common.Hash{}) { // delete slot (2.1.2b)
+ evm.StateDB.AddRefund(params.NetSstoreClearRefund)
+ }
+ return params.NetSstoreCleanGas, nil // write existing slot (2.1.2)
+ }
+ if original != (common.Hash{}) {
+ if current == (common.Hash{}) { // recreate slot (2.2.1.1)
+ evm.StateDB.SubRefund(params.NetSstoreClearRefund)
+ } else if value == (common.Hash{}) { // delete slot (2.2.1.2)
+ evm.StateDB.AddRefund(params.NetSstoreClearRefund)
+ }
+ }
+ if original == value {
+ if original == (common.Hash{}) { // reset to original inexistent slot (2.2.2.1)
+ evm.StateDB.AddRefund(params.NetSstoreResetClearRefund)
+ } else { // reset to original existing slot (2.2.2.2)
+ evm.StateDB.AddRefund(params.NetSstoreResetRefund)
+ }
+ }
+ return params.NetSstoreDirtyGas, nil
+}
+
+// 0. If *gasleft* is less than or equal to 2300, fail the current call.
+// 1. If current value equals new value (this is a no-op), SSTORE_NOOP_GAS gas is deducted.
+// 2. If current value does not equal new value:
+// 2.1. If original value equals current value (this storage slot has not been changed by the current execution context):
+// 2.1.1. If original value is 0, SSTORE_INIT_GAS gas is deducted.
+// 2.1.2. Otherwise, SSTORE_CLEAN_GAS gas is deducted. If new value is 0, add SSTORE_CLEAR_REFUND to refund counter.
+// 2.2. If original value does not equal current value (this storage slot is dirty), SSTORE_DIRTY_GAS gas is deducted. Apply both of the following clauses:
+// 2.2.1. If original value is not 0:
+// 2.2.1.1. If current value is 0 (also means that new value is not 0), subtract SSTORE_CLEAR_REFUND gas from refund counter. We can prove that refund counter will never go below 0.
+// 2.2.1.2. If new value is 0 (also means that current value is not 0), add SSTORE_CLEAR_REFUND gas to refund counter.
+// 2.2.2. If original value equals new value (this storage slot is reset):
+// 2.2.2.1. If original value is 0, add SSTORE_INIT_REFUND to refund counter.
+// 2.2.2.2. Otherwise, add SSTORE_CLEAN_REFUND gas to refund counter.
+func gasSStoreEIP2200(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ // If we fail the minimum gas availability invariant, fail (0)
+ if contract.Gas <= params.SstoreSentryGasEIP2200 {
+ return 0, errors.New("not enough gas for reentrancy sentry")
+ }
+ // Gas sentry honoured, do the actual gas calculation based on the stored value
+ var (
+ y, x = stack.Back(1), stack.Back(0)
+ current = evm.StateDB.GetState(contract.Address(), common.BigToHash(x))
+ )
+ value := common.BigToHash(y)
+
+ if current == value { // noop (1)
+ return params.SstoreNoopGasEIP2200, nil
+ }
+ original := evm.StateDB.GetCommittedState(contract.Address(), common.BigToHash(x))
+ if original == current {
+ if original == (common.Hash{}) { // create slot (2.1.1)
+ return params.SstoreInitGasEIP2200, nil
+ }
+ if value == (common.Hash{}) { // delete slot (2.1.2b)
+ evm.StateDB.AddRefund(params.SstoreClearRefundEIP2200)
+ }
+ return params.SstoreCleanGasEIP2200, nil // write existing slot (2.1.2)
+ }
+ if original != (common.Hash{}) {
+ if current == (common.Hash{}) { // recreate slot (2.2.1.1)
+ evm.StateDB.SubRefund(params.SstoreClearRefundEIP2200)
+ } else if value == (common.Hash{}) { // delete slot (2.2.1.2)
+ evm.StateDB.AddRefund(params.SstoreClearRefundEIP2200)
+ }
+ }
+ if original == value {
+ if original == (common.Hash{}) { // reset to original inexistent slot (2.2.2.1)
+ evm.StateDB.AddRefund(params.SstoreInitRefundEIP2200)
+ } else { // reset to original existing slot (2.2.2.2)
+ evm.StateDB.AddRefund(params.SstoreCleanRefundEIP2200)
+ }
+ }
+ return params.SstoreDirtyGasEIP2200, nil // dirty update (2.2)
+}
+
+func makeGasLog(n uint64) gasFunc {
+ return func(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ requestedSize, overflow := bigUint64(stack.Back(1))
+ if overflow {
+ return 0, errGasUintOverflow
+ }
+
+ gas, err := memoryGasCost(mem, memorySize)
+ if err != nil {
+ return 0, err
+ }
+
+ if gas, overflow = math.SafeAdd(gas, params.LogGas); overflow {
+ return 0, errGasUintOverflow
+ }
+ if gas, overflow = math.SafeAdd(gas, n*params.LogTopicGas); overflow {
+ return 0, errGasUintOverflow
+ }
+
+ var memorySizeGas uint64
+ if memorySizeGas, overflow = math.SafeMul(requestedSize, params.LogDataGas); overflow {
+ return 0, errGasUintOverflow
+ }
+ if gas, overflow = math.SafeAdd(gas, memorySizeGas); overflow {
+ return 0, errGasUintOverflow
+ }
+ return gas, nil
+ }
+}
+
+func gasSha3(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ gas, err := memoryGasCost(mem, memorySize)
+ if err != nil {
+ return 0, err
+ }
+ wordGas, overflow := bigUint64(stack.Back(1))
+ if overflow {
+ return 0, errGasUintOverflow
+ }
+ if wordGas, overflow = math.SafeMul(toWordSize(wordGas), params.Sha3WordGas); overflow {
+ return 0, errGasUintOverflow
+ }
+ if gas, overflow = math.SafeAdd(gas, wordGas); overflow {
+ return 0, errGasUintOverflow
+ }
+ return gas, nil
+}
+
+// pureMemoryGascost is used by several operations, which aside from their
+// static cost have a dynamic cost which is solely based on the memory
+// expansion
+func pureMemoryGascost(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ return memoryGasCost(mem, memorySize)
+}
+
+var (
+ gasReturn = pureMemoryGascost
+ gasRevert = pureMemoryGascost
+ gasMLoad = pureMemoryGascost
+ gasMStore8 = pureMemoryGascost
+ gasMStore = pureMemoryGascost
+ gasCreate = pureMemoryGascost
+)
+
+func gasCreate2(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ gas, err := memoryGasCost(mem, memorySize)
+ if err != nil {
+ return 0, err
+ }
+ wordGas, overflow := bigUint64(stack.Back(2))
+ if overflow {
+ return 0, errGasUintOverflow
+ }
+ if wordGas, overflow = math.SafeMul(toWordSize(wordGas), params.Sha3WordGas); overflow {
+ return 0, errGasUintOverflow
+ }
+ if gas, overflow = math.SafeAdd(gas, wordGas); overflow {
+ return 0, errGasUintOverflow
+ }
+ return gas, nil
+}
+
+func gasExpFrontier(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ expByteLen := uint64((stack.data[stack.len()-2].BitLen() + 7) / 8)
+
+ var (
+ gas = expByteLen * params.ExpByteFrontier // no overflow check required. Max is 256 * ExpByte gas
+ overflow bool
+ )
+ if gas, overflow = math.SafeAdd(gas, params.ExpGas); overflow {
+ return 0, errGasUintOverflow
+ }
+ return gas, nil
+}
+
+func gasExpEIP158(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ expByteLen := uint64((stack.data[stack.len()-2].BitLen() + 7) / 8)
+
+ var (
+ gas = expByteLen * params.ExpByteEIP158 // no overflow check required. Max is 256 * ExpByte gas
+ overflow bool
+ )
+ if gas, overflow = math.SafeAdd(gas, params.ExpGas); overflow {
+ return 0, errGasUintOverflow
+ }
+ return gas, nil
+}
+
+func gasCall(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ var (
+ gas uint64
+ transfersValue = stack.Back(2).Sign() != 0
+ address = common.BigToAddress(stack.Back(1))
+ )
+ if evm.chainRules.IsEIP158 {
+ if transfersValue && evm.StateDB.Empty(address) {
+ gas += params.CallNewAccountGas
+ }
+ } else if !evm.StateDB.Exist(address) {
+ gas += params.CallNewAccountGas
+ }
+ if transfersValue {
+ gas += params.CallValueTransferGas
+ }
+ memoryGas, err := memoryGasCost(mem, memorySize)
+ if err != nil {
+ return 0, err
+ }
+ var overflow bool
+ if gas, overflow = math.SafeAdd(gas, memoryGas); overflow {
+ return 0, errGasUintOverflow
+ }
+
+ evm.callGasTemp, err = callGas(evm.chainRules.IsEIP150, contract.Gas, gas, stack.Back(0))
+ if err != nil {
+ return 0, err
+ }
+ if gas, overflow = math.SafeAdd(gas, evm.callGasTemp); overflow {
+ return 0, errGasUintOverflow
+ }
+ return gas, nil
+}
+
+func gasCallCode(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ memoryGas, err := memoryGasCost(mem, memorySize)
+ if err != nil {
+ return 0, err
+ }
+ var (
+ gas uint64
+ overflow bool
+ )
+ if stack.Back(2).Sign() != 0 {
+ gas += params.CallValueTransferGas
+ }
+ if gas, overflow = math.SafeAdd(gas, memoryGas); overflow {
+ return 0, errGasUintOverflow
+ }
+ evm.callGasTemp, err = callGas(evm.chainRules.IsEIP150, contract.Gas, gas, stack.Back(0))
+ if err != nil {
+ return 0, err
+ }
+ if gas, overflow = math.SafeAdd(gas, evm.callGasTemp); overflow {
+ return 0, errGasUintOverflow
+ }
+ return gas, nil
+}
+
+func gasDelegateCall(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ gas, err := memoryGasCost(mem, memorySize)
+ if err != nil {
+ return 0, err
+ }
+ evm.callGasTemp, err = callGas(evm.chainRules.IsEIP150, contract.Gas, gas, stack.Back(0))
+ if err != nil {
+ return 0, err
+ }
+ var overflow bool
+ if gas, overflow = math.SafeAdd(gas, evm.callGasTemp); overflow {
+ return 0, errGasUintOverflow
+ }
+ return gas, nil
+}
+
+func gasStaticCall(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ gas, err := memoryGasCost(mem, memorySize)
+ if err != nil {
+ return 0, err
+ }
+ evm.callGasTemp, err = callGas(evm.chainRules.IsEIP150, contract.Gas, gas, stack.Back(0))
+ if err != nil {
+ return 0, err
+ }
+ var overflow bool
+ if gas, overflow = math.SafeAdd(gas, evm.callGasTemp); overflow {
+ return 0, errGasUintOverflow
+ }
+ return gas, nil
+}
+
+func gasSelfdestruct(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+ var gas uint64
+ // EIP150 homestead gas reprice fork:
+ if evm.chainRules.IsEIP150 {
+ gas = params.SelfdestructGasEIP150
+ var address = common.BigToAddress(stack.Back(0))
+
+ if evm.chainRules.IsEIP158 {
+ // if empty and transfers value
+ if evm.StateDB.Empty(address) && evm.StateDB.GetBalance(contract.Address()).Sign() != 0 {
+ gas += params.CreateBySelfdestructGas
+ }
+ } else if !evm.StateDB.Exist(address) {
+ gas += params.CreateBySelfdestructGas
+ }
+ }
+
+ if !evm.StateDB.HasSuicided(contract.Address()) {
+ evm.StateDB.AddRefund(params.SelfdestructRefundGas)
+ }
+ return gas, nil
+}