github.com/0xPolygon/supernets2-node@v0.0.0-20230711153321-2fe574524eaa/state/runtime/fakevm/interpreter.go (about)

     1  // Copyright 2014 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser 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  // The go-ethereum library 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 Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package fakevm
    18  
    19  import (
    20  	"github.com/ethereum/go-ethereum/common"
    21  	"github.com/ethereum/go-ethereum/common/math"
    22  	"github.com/ethereum/go-ethereum/crypto"
    23  	"github.com/ethereum/go-ethereum/log"
    24  )
    25  
    26  // Config are the configuration options for the Interpreter
    27  type Config struct {
    28  	Debug                   bool      // Enables debugging
    29  	Tracer                  EVMLogger // Opcode logger
    30  	NoBaseFee               bool      // Forces the EIP-1559 baseFee to 0 (needed for 0 price calls)
    31  	EnablePreimageRecording bool      // Enables recording of SHA3/keccak preimages
    32  	ExtraEips               []int     // Additional EIPS that are to be enabled
    33  }
    34  
    35  // ScopeContext contains the things that are per-call, such as stack and memory,
    36  // but not transients like pc and gas
    37  type ScopeContext struct {
    38  	Memory   *Memory
    39  	Stack    *Stack
    40  	Contract *Contract
    41  }
    42  
    43  // EVMInterpreter represents an EVM interpreter
    44  type EVMInterpreter struct {
    45  	evm   *FakeEVM
    46  	table *JumpTable
    47  
    48  	hasher    crypto.KeccakState // Keccak256 hasher instance shared across opcodes
    49  	hasherBuf common.Hash        // Keccak256 hasher result array shared aross opcodes
    50  
    51  	readOnly   bool   // Whether to throw on stateful modifications
    52  	returnData []byte // Last CALL's return data for subsequent reuse
    53  }
    54  
    55  // NewEVMInterpreter returns a new instance of the Interpreter.
    56  func NewEVMInterpreter(evm *FakeEVM) *EVMInterpreter {
    57  	// If jump table was not initialised we set the default one.
    58  	var table *JumpTable
    59  	switch {
    60  	case evm.chainRules.IsShanghai:
    61  		table = &shanghaiInstructionSet
    62  	case evm.chainRules.IsMerge:
    63  		table = &mergeInstructionSet
    64  	case evm.chainRules.IsLondon:
    65  		table = &londonInstructionSet
    66  	case evm.chainRules.IsBerlin:
    67  		table = &berlinInstructionSet
    68  	case evm.chainRules.IsIstanbul:
    69  		table = &istanbulInstructionSet
    70  	case evm.chainRules.IsConstantinople:
    71  		table = &constantinopleInstructionSet
    72  	case evm.chainRules.IsByzantium:
    73  		table = &byzantiumInstructionSet
    74  	case evm.chainRules.IsEIP158:
    75  		table = &spuriousDragonInstructionSet
    76  	case evm.chainRules.IsEIP150:
    77  		table = &tangerineWhistleInstructionSet
    78  	case evm.chainRules.IsHomestead:
    79  		table = &homesteadInstructionSet
    80  	default:
    81  		table = &frontierInstructionSet
    82  	}
    83  	var extraEips []int
    84  	if len(evm.Config.ExtraEips) > 0 {
    85  		// Deep-copy jumptable to prevent modification of opcodes in other tables
    86  		table = copyJumpTable(table)
    87  	}
    88  	for _, eip := range evm.Config.ExtraEips {
    89  		if err := EnableEIP(eip, table); err != nil {
    90  			// Disable it, so caller can check if it's activated or not
    91  			log.Error("EIP activation failed", "eip", eip, "error", err)
    92  		} else {
    93  			extraEips = append(extraEips, eip)
    94  		}
    95  	}
    96  	evm.Config.ExtraEips = extraEips
    97  	return &EVMInterpreter{evm: evm, table: table}
    98  }
    99  
   100  // Run loops and evaluates the contract's code with the given input data and returns
   101  // the return byte-slice and an error if one occurred.
   102  //
   103  // It's important to note that any errors returned by the interpreter should be
   104  // considered a revert-and-consume-all-gas operation except for
   105  // ErrExecutionReverted which means revert-and-keep-gas-left.
   106  func (in *EVMInterpreter) Run(contract *Contract, input []byte, readOnly bool) (ret []byte, err error) {
   107  	// Increment the call depth which is restricted to 1024
   108  	in.evm.depth++
   109  	defer func() { in.evm.depth-- }()
   110  
   111  	// Make sure the readOnly is only set if we aren't in readOnly yet.
   112  	// This also makes sure that the readOnly flag isn't removed for child calls.
   113  	if readOnly && !in.readOnly {
   114  		in.readOnly = true
   115  		defer func() { in.readOnly = false }()
   116  	}
   117  
   118  	// Reset the previous call's return data. It's unimportant to preserve the old buffer
   119  	// as every returning call will return new data anyway.
   120  	in.returnData = nil
   121  
   122  	// Don't bother with the execution if there's no code.
   123  	if len(contract.Code) == 0 {
   124  		return nil, nil
   125  	}
   126  
   127  	var (
   128  		op          OpCode        // current opcode
   129  		mem         = NewMemory() // bound memory
   130  		stack       = NewStack()  // local stack
   131  		callContext = &ScopeContext{
   132  			Memory:   mem,
   133  			Stack:    stack,
   134  			Contract: contract,
   135  		}
   136  		// For optimisation reason we're using uint64 as the program counter.
   137  		// It's theoretically possible to go above 2^64. The YP defines the PC
   138  		// to be uint256. Practically much less so feasible.
   139  		pc   = uint64(0) // program counter
   140  		cost uint64
   141  		// copies used by tracer
   142  		pcCopy  uint64 // needed for the deferred EVMLogger
   143  		gasCopy uint64 // for EVMLogger to log gas remaining before execution
   144  		logged  bool   // deferred EVMLogger should ignore already logged steps
   145  		res     []byte // result of the opcode execution function
   146  	)
   147  	// Don't move this deferred function, it's placed before the capturestate-deferred method,
   148  	// so that it get's executed _after_: the capturestate needs the stacks before
   149  	// they are returned to the pools
   150  	defer func() {
   151  		returnStack(stack)
   152  	}()
   153  	contract.Input = input
   154  
   155  	if in.evm.Config.Debug {
   156  		defer func() {
   157  			if err != nil {
   158  				if !logged {
   159  					in.evm.Config.Tracer.CaptureState(pcCopy, op, gasCopy, cost, callContext, in.returnData, in.evm.depth, err)
   160  				} else {
   161  					in.evm.Config.Tracer.CaptureFault(pcCopy, op, gasCopy, cost, callContext, in.evm.depth, err)
   162  				}
   163  			}
   164  		}()
   165  	}
   166  	// The Interpreter main run loop (contextual). This loop runs until either an
   167  	// explicit STOP, RETURN or SELFDESTRUCT is executed, an error occurred during
   168  	// the execution of one of the operations or until the done flag is set by the
   169  	// parent context.
   170  	for {
   171  		if in.evm.Config.Debug {
   172  			// Capture pre-execution values for tracing.
   173  			logged, pcCopy, gasCopy = false, pc, contract.Gas
   174  		}
   175  		// Get the operation from the jump table and validate the stack to ensure there are
   176  		// enough stack items available to perform the operation.
   177  		op = contract.GetOp(pc)
   178  		operation := in.table[op]
   179  		cost = operation.constantGas // For tracing
   180  		// Validate stack
   181  		if sLen := stack.len(); sLen < operation.minStack {
   182  			return nil, &ErrStackUnderflow{stackLen: sLen, required: operation.minStack}
   183  		} else if sLen > operation.maxStack {
   184  			return nil, &ErrStackOverflow{stackLen: sLen, limit: operation.maxStack}
   185  		}
   186  		if !contract.UseGas(cost) {
   187  			return nil, ErrOutOfGas
   188  		}
   189  		if operation.dynamicGas != nil {
   190  			// All ops with a dynamic memory usage also has a dynamic gas cost.
   191  			var memorySize uint64
   192  			// calculate the new memory size and expand the memory to fit
   193  			// the operation
   194  			// Memory check needs to be done prior to evaluating the dynamic gas portion,
   195  			// to detect calculation overflows
   196  			if operation.memorySize != nil {
   197  				memSize, overflow := operation.memorySize(stack)
   198  				if overflow {
   199  					return nil, ErrGasUintOverflow
   200  				}
   201  				// memory is expanded in words of 32 bytes. Gas
   202  				// is also calculated in words.
   203  				if memorySize, overflow = math.SafeMul(toWordSize(memSize), 32); overflow {
   204  					return nil, ErrGasUintOverflow
   205  				}
   206  			}
   207  			// Consume the gas and return an error if not enough gas is available.
   208  			// cost is explicitly set so that the capture state defer method can get the proper cost
   209  			var dynamicCost uint64
   210  			dynamicCost, err = operation.dynamicGas(in.evm, contract, stack, mem, memorySize)
   211  			cost += dynamicCost // for tracing
   212  			if err != nil || !contract.UseGas(dynamicCost) {
   213  				return nil, ErrOutOfGas
   214  			}
   215  			// Do tracing before memory expansion
   216  			if in.evm.Config.Debug {
   217  				in.evm.Config.Tracer.CaptureState(pc, op, gasCopy, cost, callContext, in.returnData, in.evm.depth, err)
   218  				logged = true
   219  			}
   220  			if memorySize > 0 {
   221  				mem.Resize(memorySize)
   222  			}
   223  		} else if in.evm.Config.Debug {
   224  			in.evm.Config.Tracer.CaptureState(pc, op, gasCopy, cost, callContext, in.returnData, in.evm.depth, err)
   225  			logged = true
   226  		}
   227  		// execute the operation
   228  		res, err = operation.execute(&pc, in, callContext)
   229  		if err != nil {
   230  			break
   231  		}
   232  		pc++
   233  	}
   234  
   235  	if err == errStopToken {
   236  		err = nil // clear stop token error
   237  	}
   238  
   239  	return res, err
   240  }