From 83fb255e471e0bf738ed9053e547d65321947e18 Mon Sep 17 00:00:00 2001
From: smblucker <smblucker@outlook.com>
Date: Mon, 5 Mar 2018 16:32:22 -0500
Subject: [PATCH] WIP implementation of REVERT opcode
Signed-off-by: smblucker <smblucker@outlook.com>
Signed-off-by: Silas Davis <silas@monax.io>
---
execution/evm/asm/opcodes.go | 2 ++
execution/evm/vm.go | 20 ++++++++++++++++++++
execution/evm/vm_test.go | 22 ++++++++++++++++++++++
3 files changed, 44 insertions(+)
diff --git a/execution/evm/asm/opcodes.go b/execution/evm/asm/opcodes.go
index 0a4e3531..f85f3b4d 100644
--- a/execution/evm/asm/opcodes.go
+++ b/execution/evm/asm/opcodes.go
@@ -182,6 +182,7 @@ const (
DELEGATECALL
// 0x70 range - other
+ REVERT = 0xfd
SELFDESTRUCT = 0xff
)
@@ -334,6 +335,7 @@ var opCodeNames = map[OpCode]string{
DELEGATECALL: "DELEGATECALL",
// 0x70 range - other
+ REVERT: "REVERT",
SELFDESTRUCT: "SELFDESTRUCT",
}
diff --git a/execution/evm/vm.go b/execution/evm/vm.go
index ed760c17..03a7249e 100644
--- a/execution/evm/vm.go
+++ b/execution/evm/vm.go
@@ -48,6 +48,7 @@ var (
ErrDataStackUnderflow = errors.New("Data stack underflow")
ErrInvalidContract = errors.New("Invalid contract")
ErrNativeContractCodeCopy = errors.New("Tried to copy native contract code")
+ ErrExecutionReverted = errors.New("Execution reverted")
)
type ErrPermission struct {
@@ -773,6 +774,10 @@ func (vm *VM) call(caller, callee acm.MutableAccount, code, input []byte, value
stack.Push(newAccount.Address().Word256())
}
+ if err_ == ErrExecutionReverted {
+ return ret, nil
+ }
+
case CALL, CALLCODE, DELEGATECALL: // 0xF1, 0xF2, 0xF4
if !HasPermission(vm.state, callee, permission.Call) {
return nil, ErrPermission{"call"}
@@ -863,6 +868,10 @@ func (vm *VM) call(caller, callee acm.MutableAccount, code, input []byte, value
// TODO: we probably don't want to return the error - decide
//err = firstErr(err, callErr)
stack.Push(Zero256)
+
+ if callErr == ErrExecutionReverted {
+ memory.Write(retOffset, RightPadBytes(ret, int(retSize)))
+ }
} else {
stack.Push(One256)
@@ -891,6 +900,17 @@ func (vm *VM) call(caller, callee acm.MutableAccount, code, input []byte, value
vm.Debugf(" => [%v, %v] (%d) 0x%X\n", offset, size, len(output), output)
return output, nil
+ case REVERT: // 0xFD
+ offset, size := stack.PopBigInt(), stack.PopBigInt()
+ output, memErr := memory.Read(offset, size)
+ if memErr != nil {
+ vm.Debugf(" => Memory err: %s", memErr)
+ return nil, firstErr(err, ErrMemoryOutOfBounds)
+ }
+
+ vm.Debugf(" => [%v, %v] (%d) 0x%X\n", offset, size, len(output), output)
+ return output, ErrExecutionReverted
+
case SELFDESTRUCT: // 0xFF
addr := stack.Pop()
if useGasNegative(gas, GasGetAccount, &err) {
diff --git a/execution/evm/vm_test.go b/execution/evm/vm_test.go
index a6335dee..0d8ee817 100644
--- a/execution/evm/vm_test.go
+++ b/execution/evm/vm_test.go
@@ -158,6 +158,28 @@ func TestSubcurrency(t *testing.T) {
}
}
+//This test case is taken from EIP-140 (https://github.com/ethereum/EIPs/blob/master/EIPS/eip-140.md);
+//it is meant to test the implementation of the REVERT opcode
+func TestRevert(t *testing.T) {
+ ourVm := NewVM(newAppState(), DefaultDynamicMemoryProvider, newParams(), acm.ZeroAddress, nil, logger)
+
+ // Create accounts
+ account1 := newAccount(1)
+ account2 := newAccount(1, 0, 1)
+
+ var gas uint64 = 100000
+
+ bytecode := MustSplice(PUSH32, 0x72, 0x65, 0x76, 0x65, 0x72, 0x74, 0x20, 0x6D, 0x65, 0x73, 0x73, 0x61,
+ 0x67, 0x65, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, PUSH1, 0x00, MSTORE, PUSH1, 0x0E, PUSH1, 0x00, REVERT)
+
+ start := time.Now()
+ output, err := ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+ assert.Error(t, err, "Expected execution reverted error")
+ fmt.Printf("Output: %v Error: %v\n", output, err)
+ fmt.Println("Call took:", time.Since(start))
+}
+
// Test sending tokens from a contract to another account
func TestSendCall(t *testing.T) {
fakeAppState := newAppState()
--
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