Function extcodecopy

gevm/instructions.go:397–414

This is a mocked version and doesn't behave exactly as it would in a real EVM. extcodecopy copies a zero-length mocked byte slice to memory.

(evm *EVM)

//
// extcodecopy copies a zero-length mocked byte slice to memory.
func extcodecopy(evm *EVM) {
	_ = evm.Stack.Pop() // Pop external address off the stack
	destMemOffsetU256 := evm.Stack.Pop()
	_ = evm.Stack.Pop() // Pop offset of the external code to copy. This isn't used.
	sizeU256 := evm.Stack.Pop()

	destMemOffset, size := destMemOffsetU256.Uint64(), sizeU256.Uint64()

	extCodeCopy := []byte{}                                          // mocked (no external code)
	memExpansionCost := evm.Memory.Store(destMemOffset, extCodeCopy) // extCode has zero length

	wordSize := toWordSize(size)
	dynamicGas := 3*wordSize + memExpansionCost + 2600 // '2600' here represents "address access cost" and can be 100 for warm access, but we are assuming cold access since this is a mocked version.

	evm.PC++
	evm.deductGas(dynamicGas)
	dgMap[EXTCODECOPY] = dynamicGas
}

// returndatasize pushes a mocked (zero-value) length of the return data onto the stack.
func returndatasize(evm *EVM) {