mep_vm/
ext.rs

1// Copyright 2015-2020 Parity Technologies (UK) Ltd.
2// This file is part of Parity Ethereum.
3
4// Parity Ethereum is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8
9// Parity Ethereum is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12// GNU General Public License for more details.
13
14// You should have received a copy of the GNU General Public License
15// along with Parity Ethereum.  If not, see <http://www.gnu.org/licenses/>.
16
17//! Interface for Evm externalities.
18
19use std::sync::Arc;
20use ethereum_types::{U256, H256, Address};
21use bytes::Bytes;
22use action_type::ActionType;
23use env_info::EnvInfo;
24use schedule::Schedule;
25use return_data::ReturnData;
26use error::{Result, TrapKind};
27
28#[derive(Debug)]
29/// Result of externalities create function.
30pub enum ContractCreateResult {
31	/// Returned when creation was successfull.
32	/// Contains an address of newly created contract and gas left.
33	Created(Address, U256),
34	/// Returned when contract creation failed.
35	/// VM doesn't have to know the reason.
36	Failed,
37	/// Reverted with REVERT.
38	Reverted(U256, ReturnData),
39}
40
41#[derive(Debug)]
42/// Result of externalities call function.
43pub enum MessageCallResult {
44	/// Returned when message call was successfull.
45	/// Contains gas left and output data.
46	Success(U256, ReturnData),
47	/// Returned when message call failed.
48	/// VM doesn't have to know the reason.
49	Failed,
50	/// Returned when message call was reverted.
51	/// Contains gas left and output data.
52	Reverted(U256, ReturnData),
53}
54
55/// Specifies how an address is calculated for a new contract.
56#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
57pub enum CreateContractAddress {
58	/// Address is calculated from sender and nonce. pWASM `create` scheme.
59	FromSenderAndNonce,
60	/// Address is calculated from sender, salt and code hash. pWASM `create2` scheme and EIP-1014 CREATE2 scheme.
61	FromSenderSaltAndCodeHash(H256),
62	/// Address is calculated from code hash and sender. Used by pwasm create ext.
63	FromSenderAndCodeHash,
64}
65
66/// Externalities interface for EVMs
67pub trait Ext {
68	/// Returns the storage value for a given key if reversion happens on the current transaction.
69	fn initial_storage_at(&self, key: &H256) -> Result<H256>;
70
71	/// Returns a value for given key.
72	fn storage_at(&self, key: &H256) -> Result<H256>;
73
74	/// Stores a value for given key.
75	fn set_storage(&mut self, key: H256, value: H256) -> Result<()>;
76
77	/// Determine whether an account exists.
78	fn exists(&self, address: &Address) -> Result<bool>;
79
80	/// Determine whether an account exists and is not null (zero balance/nonce, no code).
81	fn exists_and_not_null(&self, address: &Address) -> Result<bool>;
82
83	/// Balance of the origin account.
84	fn origin_balance(&self) -> Result<U256>;
85
86	/// Returns address balance.
87	fn balance(&self, address: &Address) -> Result<U256>;
88
89	/// Returns the hash of one of the 256 most recent complete blocks.
90	fn blockhash(&mut self, number: &U256) -> H256;
91
92	/// Creates new contract.
93	///
94	/// Returns gas_left and contract address if contract creation was successful.
95	fn create(
96		&mut self,
97		gas: &U256,
98		value: &U256,
99		code: &[u8],
100		parent_version: &U256,
101		address: CreateContractAddress,
102		trap: bool,
103	) -> ::std::result::Result<ContractCreateResult, TrapKind>;
104
105	/// Message call.
106	///
107	/// Returns Err, if we run out of gas.
108	/// Otherwise returns call_result which contains gas left
109	/// and true if subcall was successfull.
110	fn call(
111		&mut self,
112		gas: &U256,
113		sender_address: &Address,
114		receive_address: &Address,
115		value: Option<U256>,
116		data: &[u8],
117		code_address: &Address,
118		call_type: ActionType,
119		trap: bool
120	) -> ::std::result::Result<MessageCallResult, TrapKind>;
121
122	/// Returns code at given address
123	fn extcode(&self, address: &Address) -> Result<Option<Arc<Bytes>>>;
124
125	/// Returns code hash at given address
126	fn extcodehash(&self, address: &Address) -> Result<Option<H256>>;
127
128	/// Returns code size at given address
129	fn extcodesize(&self, address: &Address) -> Result<Option<usize>>;
130
131	/// Creates log entry with given topics and data
132	fn log(&mut self, topics: Vec<H256>, data: &[u8]) -> Result<()>;
133
134	/// Should be called when transaction calls `RETURN` opcode.
135	/// Returns gas_left if cost of returning the data is not too high.
136	fn ret(self, gas: &U256, data: &ReturnData, apply_state: bool) -> Result<U256>;
137
138	/// Should be called when contract commits suicide.
139	/// Address to which funds should be refunded.
140	fn suicide(&mut self, refund_address: &Address) -> Result<()> ;
141
142	/// Returns schedule.
143	fn schedule(&self) -> &Schedule;
144
145	/// Returns environment info.
146	fn env_info(&self) -> &EnvInfo;
147
148	/// Returns the chain ID of the blockchain
149	fn chain_id(&self) -> u64;
150
151	/// Returns current depth of execution.
152	///
153	/// If contract A calls contract B, and contract B calls C,
154	/// then A depth is 0, B is 1, C is 2 and so on.
155	fn depth(&self) -> usize;
156
157	/// Increments sstore refunds counter.
158	fn add_sstore_refund(&mut self, value: usize);
159
160	/// Decrements sstore refunds counter.
161	fn sub_sstore_refund(&mut self, value: usize);
162
163	/// Decide if any more operations should be traced. Passthrough for the VM trace.
164	fn trace_next_instruction(&mut self, _pc: usize, _instruction: u8, _current_gas: U256) -> bool { false }
165
166	/// Prepare to trace an operation. Passthrough for the VM trace.
167	/// For each call of `trace_prepare_execute` either `trace_failed` or `trace_executed` MUST be called.
168	fn trace_prepare_execute(&mut self, _pc: usize, _instruction: u8, _gas_cost: U256, _mem_written: Option<(usize, usize)>, _store_written: Option<(U256, U256)>) {}
169
170	/// Trace the execution failure of a single instruction.
171	fn trace_failed(&mut self) {}
172
173	/// Trace the finalised execution of a single instruction.
174	fn trace_executed(&mut self, _gas_used: U256, _stack_push: &[U256], _mem: &[u8]) {}
175
176	/// Check if running in static context.
177	fn is_static(&self) -> bool;
178}
mep_vm/ext.rs

mep_vm/
ext.rs
