diff --git a/execution/evm/vm.go b/execution/evm/vm.go
index 35a3ac63a96805f35e209ba74dfcbe484ca64b32..aca675675cf1feffb53603685e804f2c1d7a712f 100644
--- a/execution/evm/vm.go
+++ b/execution/evm/vm.go
@@ -42,6 +42,7 @@ var (
ErrMemoryOutOfBounds = errors.New("Memory out of bounds")
ErrCodeOutOfBounds = errors.New("Code out of bounds")
ErrInputOutOfBounds = errors.New("Input out of bounds")
+ ErrReturnDataOutOfBounds = errors.New("Return data out of bounds")
ErrCallStackOverflow = errors.New("Call stack overflow")
ErrCallStackUnderflow = errors.New("Call stack underflow")
ErrDataStackOverflow = errors.New("Data stack overflow")
@@ -113,6 +114,7 @@ type VM struct {
nestedCallErrors []ErrNestedCall
publisher event.Publisher
logger *logging.Logger
+ returnData []byte
debugOpcodes bool
dumpTokens bool
}
@@ -666,6 +668,28 @@ func (vm *VM) call(caller acm.Account, callee acm.MutableAccount, code, input []
}
vm.Debugf(" => [%v, %v, %v] %X\n", memOff, codeOff, length, data)
+ case RETURNDATASIZE: // 0x3D
+ stack.Push64(int64(len(vm.returnData)))
+ vm.Debugf(" => %d\n", len(vm.returnData))
+
+ case RETURNDATACOPY: // 0x3E
+ memOff, outputOff, length := stack.PopBigInt(), stack.PopBigInt(), stack.PopBigInt()
+
+ end := new(big.Int).Add(outputOff, length)
+
+ if end.BitLen() > 64 || uint64(len(vm.returnData)) < end.Uint64() {
+ return nil, ErrReturnDataOutOfBounds
+ }
+
+ data := vm.returnData
+
+ memErr := memory.Write(memOff, data)
+ if memErr != nil {
+ vm.Debugf(" => Memory err: %s", memErr)
+ return nil, firstErr(err, ErrMemoryOutOfBounds)
+ }
+ vm.Debugf(" => [%v, %v, %v] %X\n", memOff, outputOff, length, data)
+
case BLOCKHASH: // 0x40
stack.Push(Zero256)
vm.Debugf(" => 0x%X (NOT SUPPORTED)\n", stack.Peek().Bytes())
@@ -834,6 +858,8 @@ func (vm *VM) call(caller acm.Account, callee acm.MutableAccount, code, input []
vm.Debugf(" => T:%X D:%X\n", topics, data)
case CREATE: // 0xF0
+ vm.returnData = nil
+
if !HasPermission(vm.stateWriter, callee, permission.CreateContract) {
return nil, ErrPermission{"create_contract"}
}
@@ -868,6 +894,7 @@ func (vm *VM) call(caller acm.Account, callee acm.MutableAccount, code, input []
ret, err_ := vm.Call(callee, newAccount, input, input, contractValue, gas)
if err_ != nil {
stack.Push(Zero256)
+ vm.returnData = ret
} else {
newAccount.SetCode(ret) // Set the code (ret need not be copied as per Call contract)
stack.Push(newAccount.Address().Word256())
@@ -878,6 +905,8 @@ func (vm *VM) call(caller acm.Account, callee acm.MutableAccount, code, input []
}
case CALL, CALLCODE, DELEGATECALL: // 0xF1, 0xF2, 0xF4
+ vm.returnData = nil
+
if !HasPermission(vm.stateWriter, callee, permission.Call) {
return nil, ErrPermission{"call"}
}
@@ -973,6 +1002,8 @@ func (vm *VM) call(caller acm.Account, callee acm.MutableAccount, code, input []
ret, callErr = vm.Call(callee, acc, acc.Code(), args, value, &gasLimit)
}
}
+ vm.returnData = ret
+
// In case any calls deeper in the stack (particularly SNatives) has altered either of two accounts to which
// we hold a reference, we need to freshen our state for subsequent iterations of this call frame's EVM loop
var getErr error
@@ -1080,7 +1111,7 @@ func (vm *VM) call(caller acm.Account, callee acm.MutableAccount, code, input []
case STOP: // 0x00
return nil, nil
- case STATICCALL, SHL, SHR, SAR, RETURNDATASIZE, RETURNDATACOPY:
+ case STATICCALL, SHL, SHR, SAR:
return nil, fmt.Errorf("%s not yet implemented", op.Name())
default:
vm.Debugf("(pc) %-3v Unknown opcode %X\n", pc, op)
diff --git a/execution/evm/vm_test.go b/execution/evm/vm_test.go
index 23f942a8cb152c46fc0eed94ef2a9e7b77585665..ffa5454c83bf4931eaa34095c6c16ebaef029730 100644
--- a/execution/evm/vm_test.go
+++ b/execution/evm/vm_test.go
@@ -394,6 +394,83 @@ func TestInvalid(t *testing.T) {
}
+func TestReturnDataSize(t *testing.T) {
+ cache := state.NewCache(newAppState())
+ ourVm := NewVM(cache, newParams(), acm.ZeroAddress, nil, logger)
+
+ accountName := "account2addresstests"
+
+ callcode := 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, RETURN)
+
+ // Create accounts
+ account1 := newAccount(1)
+ account2, _ := makeAccountWithCode(cache, accountName, callcode)
+
+ var gas uint64 = 100000
+
+ gas1, gas2 := byte(0x1), byte(0x1)
+ value := byte(0x69)
+ inOff, inSize := byte(0x0), byte(0x0) // no call data
+ retOff, retSize := byte(0x0), byte(0x0E)
+
+ bytecode := MustSplice(PUSH1, retSize, PUSH1, retOff, PUSH1, inSize, PUSH1, inOff, PUSH1, value, PUSH20,
+ 0x61, 0x63, 0x63, 0x6F, 0x75, 0x6E, 0x74, 0x32, 0x61, 0x64, 0x64, 0x72, 0x65, 0x73, 0x73, 0x74, 0x65,
+ 0x73, 0x74, 0x73, PUSH2, gas1, gas2, CALL, RETURNDATASIZE, PUSH1, 0x00, MSTORE, PUSH1, 0x20, PUSH1, 0x00, RETURN)
+
+ expected := LeftPadBytes([]byte{0x0E}, 32)
+
+ output, err := ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+
+ assert.Equal(t, expected, output)
+
+ t.Logf("Output: %v Error: %v\n", output, err)
+
+ if err != nil {
+ t.Fatal(err)
+ }
+}
+
+func TestReturnDataCopy(t *testing.T) {
+ cache := state.NewCache(newAppState())
+ ourVm := NewVM(cache, newParams(), acm.ZeroAddress, nil, logger)
+
+ accountName := "account2addresstests"
+
+ callcode := 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, RETURN)
+
+ // Create accounts
+ account1 := newAccount(1)
+ account2, _ := makeAccountWithCode(cache, accountName, callcode)
+
+ var gas uint64 = 100000
+
+ gas1, gas2 := byte(0x1), byte(0x1)
+ value := byte(0x69)
+ inOff, inSize := byte(0x0), byte(0x0) // no call data
+ retOff, retSize := byte(0x0), byte(0x0E)
+
+ bytecode := MustSplice(PUSH1, retSize, PUSH1, retOff, PUSH1, inSize, PUSH1, inOff, PUSH1, value, PUSH20,
+ 0x61, 0x63, 0x63, 0x6F, 0x75, 0x6E, 0x74, 0x32, 0x61, 0x64, 0x64, 0x72, 0x65, 0x73, 0x73, 0x74, 0x65,
+ 0x73, 0x74, 0x73, PUSH2, gas1, gas2, CALL, RETURNDATASIZE, PUSH1, 0x00, PUSH1, 0x00, RETURNDATACOPY,
+ RETURNDATASIZE, PUSH1, 0x00, RETURN)
+
+ expected := []byte{0x72, 0x65, 0x76, 0x65, 0x72, 0x74, 0x20, 0x6D, 0x65, 0x73, 0x73, 0x61, 0x67, 0x65}
+
+ output, err := ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+
+ assert.Equal(t, expected, output)
+
+ t.Logf("Output: %v Error: %v\n", output, err)
+
+ if err != nil {
+ t.Fatal(err)
+ }
+}
+
// These code segment helpers exercise the MSTORE MLOAD MSTORE cycle to test
// both of the memory operations. Each MSTORE is done on the memory boundary
// (at MSIZE) which Solidity uses to find guaranteed unallocated memory.