diff options
Diffstat (limited to 'core/vm/interpreter.go')
| -rw-r--r-- | core/vm/interpreter.go | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/core/vm/interpreter.go b/core/vm/interpreter.go index 661ada691..954839f2e 100644 --- a/core/vm/interpreter.go +++ b/core/vm/interpreter.go @@ -59,7 +59,8 @@ type Interpreter struct { gasTable params.GasTable intPool *intPool - readonly bool + readOnly bool // Whether to throw on stateful modifications + returnData []byte // Last CALL's return data for subsequent reuse } // NewInterpreter returns a new instance of the Interpreter. @@ -88,7 +89,7 @@ func NewInterpreter(evm *EVM, cfg Config) *Interpreter { func (in *Interpreter) enforceRestrictions(op OpCode, operation operation, stack *Stack) error { if in.evm.chainRules.IsMetropolis { - if in.readonly { + if in.readOnly { // If the interpreter is operating in readonly mode, make sure no // state-modifying operation is performed. The 3rd stack item // for a call operation is the value. Transfering value from one @@ -113,6 +114,10 @@ func (in *Interpreter) Run(snapshot int, contract *Contract, input []byte) (ret in.evm.depth++ defer func() { in.evm.depth-- }() + // Reset the previous call's return data. It's unimportant to preserve the old buffer + // as every returning call will return new data anyway. + in.returnData = nil + // Don't bother with the execution if there's no code. if len(contract.Code) == 0 { return nil, nil @@ -213,10 +218,10 @@ func (in *Interpreter) Run(snapshot int, contract *Contract, input []byte) (ret case !operation.jumps: pc++ } - // if the operation returned a value make sure that is also set - // the last return data. - if res != nil { - mem.lastReturn = ret + // if the operation clears the return data (e.g. it has returning data) + // set the last return to the result of the operation. + if operation.returns { + in.returnData = res } } return nil, nil |