Save code section bounds in Contract instead of EOF header

Author: gumb0

core/vm/analysis.go

@@ -65,16 +65,16 @@ func codeBitmap(c *Contract) bitvec {
 	// The bitmap is 4 bytes longer than necessary, in case the code
 	// ends with a PUSH32, the algorithm will push zeroes onto the
 	// bitvector outside the bounds of the actual code.
-	bits := make(bitvec, c.CodeSize()/8+1+4)
+	bits := make(bitvec, c.CodeSize/8+1+4)
 	return codeBitmapInternal(c, bits)
 }
 
 // codeBitmapInternal is the internal implementation of codeBitmap.
 // It exists for the purpose of being able to run benchmark tests
 // without dynamic allocations affecting the results.
 func codeBitmapInternal(c *Contract, bits bitvec) bitvec {
-	codeBegin := c.CodeBeginOffset()
-	for pc := uint64(0); pc < c.CodeSize(); {
+	codeBegin := c.CodeBeginOffset
+	for pc := uint64(0); pc < c.CodeSize; {
 		op := OpCode(c.Code[codeBegin+pc])
 		pc++
 		if int8(op) < int8(PUSH1) { // If not PUSH (the int8(op) > int(PUSH32) is always false).

core/vm/contract.go

@@ -50,7 +50,8 @@ type Contract struct {
 	caller        ContractRef
 	self          ContractRef
 
-	header EOF1Header
+	CodeBeginOffset uint64 // starting offset of the code section if EOF or 0 if legacy
+	CodeSize        uint64 // size of the code section if EOF or bytecode size if legacy
 
 	jumpdests map[common.Hash]bitvec // Aggregated result of JUMPDEST analysis.
 	analysis  bitvec                 // Locally cached result of JUMPDEST analysis
@@ -90,7 +91,7 @@ func (c *Contract) validJumpdest(dest *uint256.Int) bool {
 	udest, overflow := dest.Uint64WithOverflow()
 	// PC cannot go beyond len(code) and certainly can't be bigger than 63bits.
 	// Don't bother checking for JUMPDEST in that case.
-	if overflow || udest >= c.CodeSize() {
+	if overflow || udest >= c.CodeSize {
 		return false
 	}
 	// Only JUMPDESTs allowed for destinations
@@ -148,8 +149,8 @@ func (c *Contract) AsDelegate() *Contract {
 // GetOp returns the n'th element in the contract's byte array
 // n is offset inside code section in case of EOF contract
 func (c *Contract) GetOp(n uint64) OpCode {
-	if n < c.CodeSize() {
-		return OpCode(c.Code[c.CodeBeginOffset()+n])
+	if n < c.CodeSize {
+		return OpCode(c.Code[c.CodeBeginOffset+n])
 	}
 
 	return STOP
@@ -182,34 +183,19 @@ func (c *Contract) Value() *big.Int {
 	return c.value
 }
 
-// IsLegacy returns true if contract is not EOF
-func (c *Contract) IsLegacy() bool {
+// getCodeBounds returns beginning offset and size of the code section if EOF
+// or 0 and bytecode length if legacy
+func getCodeBounds(container []byte, header *EOF1Header) (begin uint64, size uint64) {
 	// EOF1 doesn't allow contracts without code section
-	return c.header.codeSize == 0
-}
-
-// CodeBeginOffset returns starting offset of the code section
-func (c *Contract) CodeBeginOffset() uint64 {
-	if c.IsLegacy() {
-		return 0
-	}
-	return c.header.CodeBeginOffset()
-}
-
-// CodeEndOffset returns offset of the code section end
-func (c *Contract) CodeEndOffset() uint64 {
-	if c.IsLegacy() {
-		return uint64(len(c.Code))
-	}
-	return c.header.CodeEndOffset()
-}
-
-// CodeSize returns the size of the code (if legacy) or code section (if EOF)
-func (c *Contract) CodeSize() uint64 {
-	if c.IsLegacy() {
-		return uint64(len(c.Code))
+	isLegacy := (header.codeSize == 0)
+	if isLegacy {
+		begin = 0
+		size = uint64(len(container))
+	} else {
+		begin = header.CodeBeginOffset()
+		size = uint64(header.codeSize)
 	}
-	return uint64(c.header.codeSize)
+	return
 }
 
 // SetCallCode sets the code of the contract and address of the backing data
@@ -219,8 +205,7 @@ func (c *Contract) SetCallCode(addr *common.Address, hash common.Hash, code []by
 	c.CodeHash = hash
 	c.CodeAddr = addr
 
-	c.header.codeSize = header.codeSize
-	c.header.dataSize = header.dataSize
+	c.CodeBeginOffset, c.CodeSize = getCodeBounds(code, header)
 }
 
 // SetCodeOptionalHash can be used to provide code, but it's optional to provide hash.
@@ -230,6 +215,5 @@ func (c *Contract) SetCodeOptionalHash(addr *common.Address, codeAndHash *codeAn
 	c.CodeHash = codeAndHash.hash
 	c.CodeAddr = addr
 
-	c.header.codeSize = header.codeSize
-	c.header.dataSize = header.dataSize
+	c.CodeBeginOffset, c.CodeSize = getCodeBounds(codeAndHash.code, header)
 }

core/vm/instructions.go

@@ -867,11 +867,11 @@ func makeLog(size int) executionFunc {
 // opPush1 is a specialized version of pushN
 func opPush1(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
 	var (
-		codeEnd = scope.Contract.CodeEndOffset()
+		codeEnd = scope.Contract.CodeBeginOffset + scope.Contract.CodeSize
 		integer = new(uint256.Int)
 	)
 	*pc += 1
-	dataPos := scope.Contract.CodeBeginOffset() + *pc
+	dataPos := scope.Contract.CodeBeginOffset + *pc
 	if dataPos < codeEnd {
 		scope.Stack.push(integer.SetUint64(uint64(scope.Contract.Code[dataPos])))
 	} else {
@@ -883,10 +883,10 @@ func opPush1(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]by
 // make push instruction function
 func makePush(size uint64, pushByteSize int) executionFunc {
 	return func(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
-		codeEnd := int(scope.Contract.CodeEndOffset())
+		codeEnd := int(scope.Contract.CodeBeginOffset + scope.Contract.CodeSize)
 
 		startMin := codeEnd
-		pcAbsolute := scope.Contract.CodeBeginOffset() + *pc
+		pcAbsolute := scope.Contract.CodeBeginOffset + *pc
 		if int(pcAbsolute+1) < startMin {
 			startMin = int(pcAbsolute + 1)
 		}

eth/tracers/js/tracer_test.go

@@ -72,6 +72,7 @@ func runTrace(tracer tracers.Tracer, vmctx *vmContext, chaincfg *params.ChainCon
 	if contractCode != nil {
 		contract.Code = contractCode
 	}
+	contract.CodeSize = uint64(len(contract.Code))
 
 	tracer.CaptureTxStart(gasLimit)
 	tracer.CaptureStart(env, contract.Caller(), contract.Address(), false, []byte{}, startGas, value)

eth/tracers/logger/logger_test.go

@@ -59,6 +59,7 @@ func TestStoreCapture(t *testing.T) {
 		contract = vm.NewContract(&dummyContractRef{}, &dummyContractRef{}, new(big.Int), 100000)
 	)
 	contract.Code = []byte{byte(vm.PUSH1), 0x1, byte(vm.PUSH1), 0x0, byte(vm.SSTORE)}
+	contract.CodeSize = uint64(len(contract.Code))
 	var index common.Hash
 	logger.CaptureStart(env, common.Address{}, contract.Address(), false, nil, 0, nil)
 	_, err := env.Interpreter().Run(contract, []byte{}, false)