core/vm: BLOBHASH opcode 0x49 (ethereum#27356)

Author: gzliudan

core/vm/eips.go

@@ -256,13 +256,38 @@ func opMcopy(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]by
 	return nil, nil
 }
 
+// opBlobHash implements the BLOBHASH opcode
+func opBlobHash(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
+	index := scope.Stack.peek()
+	// xdc chain have no blob hash, so len(interpreter.evm.TxContext.BlobHashes) is always 0
+	// and index.LtUint64(uint64(len(interpreter.evm.TxContext.BlobHashes))) is always false
+	// if index.LtUint64(uint64(len(interpreter.evm.TxContext.BlobHashes))) {
+	// 	blobHash := interpreter.evm.TxContext.BlobHashes[index.Uint64()]
+	// 	index.SetBytes32(blobHash[:])
+	// } else {
+	// 	index.Clear()
+	// }
+	index.Clear()
+	return nil, nil
+}
+
 // opBlobBaseFee implements BLOBBASEFEE opcode
 func opBlobBaseFee(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
 	blobBaseFee := new(uint256.Int)
 	scope.Stack.push(blobBaseFee)
 	return nil, nil
 }
 
+// enable4844 applies EIP-4844 (BLOBHASH opcode)
+func enable4844(jt *JumpTable) {
+	jt[BLOBHASH] = &operation{
+		execute:     opBlobHash,
+		constantGas: GasFastestStep,
+		minStack:    minStack(1, 1),
+		maxStack:    maxStack(1, 1),
+	}
+}
+
 // enable7516 applies EIP-7516 (BLOBBASEFEE opcode)
 func enable7516(jt *JumpTable) {
 	jt[BLOBBASEFEE] = &operation{

core/vm/instructions_test.go

@@ -755,6 +755,48 @@ func TestRandom(t *testing.T) {
 	}
 }
 
+func TestBlobHash(t *testing.T) {
+	type testcase struct {
+		name   string
+		idx    uint64
+		expect common.Hash
+		hashes []common.Hash
+	}
+	var (
+		zero  = common.Hash{0}
+		one   = common.Hash{1}
+		two   = common.Hash{2}
+		three = common.Hash{3}
+	)
+	for _, tt := range []testcase{
+		{name: "[{1}]", idx: 0, expect: zero, hashes: []common.Hash{one}},
+		{name: "[1,{2},3]", idx: 2, expect: zero, hashes: []common.Hash{one, two, three}},
+		{name: "out-of-bounds (empty)", idx: 10, expect: zero, hashes: []common.Hash{}},
+		{name: "out-of-bounds", idx: 25, expect: zero, hashes: []common.Hash{one, two, three}},
+		{name: "out-of-bounds (nil)", idx: 25, expect: zero, hashes: nil},
+	} {
+		var (
+			evm   = NewEVM(BlockContext{}, TxContext{}, nil, nil, params.TestChainConfig, Config{})
+			stack = newstack()
+			pc    = uint64(0)
+		)
+		// evm.SetTxContext(TxContext{BlobHashes: tt.hashes})
+		stack.push(uint256.NewInt(tt.idx))
+		opBlobHash(&pc, evm.interpreter, &ScopeContext{nil, stack, nil})
+		if len(stack.data) != 1 {
+			t.Errorf("Expected one item on stack after %v, got %d: ", tt.name, len(stack.data))
+		}
+		actual := stack.pop()
+		expected, overflow := uint256.FromBig(new(big.Int).SetBytes(tt.expect.Bytes()))
+		if overflow {
+			t.Errorf("Testcase %v: invalid overflow", tt.name)
+		}
+		if actual.Cmp(expected) != 0 {
+			t.Errorf("Testcase %v: expected  %x, got %x", tt.name, expected, actual)
+		}
+	}
+}
+
 func TestOpMCopy(t *testing.T) {
 	// Test cases from https://eips.ethereum.org/EIPS/eip-5656#test-cases
 	for i, tc := range []struct {

core/vm/jump_table.go

@@ -82,6 +82,7 @@ func validate(jt JumpTable) JumpTable {
 
 func newCancunInstructionSet() JumpTable {
 	instructionSet := newEip1559InstructionSet()
+	enable4844(&instructionSet) // EIP-4844 (BLOBHASH opcode)
 	enable7516(&instructionSet) // EIP-7516 (BLOBBASEFEE opcode)
 	enable1153(&instructionSet) // EIP-1153 "Transient Storage"
 	enable5656(&instructionSet) // EIP-5656 (MCOPY opcode)

core/vm/opcodes.go

@@ -100,6 +100,7 @@ const (
 	CHAINID     OpCode = 0x46
 	SELFBALANCE OpCode = 0x47
 	BASEFEE     OpCode = 0x48
+	BLOBHASH    OpCode = 0x49
 	BLOBBASEFEE OpCode = 0x4a
 )
 
@@ -285,6 +286,7 @@ var opCodeToString = [256]string{
 	CHAINID:     "CHAINID",
 	SELFBALANCE: "SELFBALANCE",
 	BASEFEE:     "BASEFEE",
+	BLOBHASH:    "BLOBHASH",
 	BLOBBASEFEE: "BLOBBASEFEE",
 
 	// 0x50 range - 'storage' and execution.
@@ -460,6 +462,7 @@ var stringToOp = map[string]OpCode{
 	"GASLIMIT":       GASLIMIT,
 	"SELFBALANCE":    SELFBALANCE,
 	"BASEFEE":        BASEFEE,
+	"BLOBHASH":       BLOBHASH,
 	"BLOBBASEFEE":    BLOBBASEFEE,
 	"POP":            POP,
 	"MLOAD":          MLOAD,