core/vm: opcode-test for mcopy

core/vm/instructions_test.go

@@ -22,9 +22,11 @@ import (
 	"fmt"
 	"math/big"
 	"os"
+	"strings"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
@@ -788,3 +790,142 @@ func TestBlobHash(t *testing.T) {
 		}
 	}
 }
+
+func TestOpMCopy(t *testing.T) {
+
+	// Test cases from https://eips.ethereum.org/EIPS/eip-5656#test-cases
+	for i, tc := range []struct {
+		dst, src, len string
+		pre           string
+		want          string
+		wantGas       uint64
+	}{
+		{ // MCOPY 0 32 32 - copy 32 bytes from offset 32 to offset 0.
+			dst: "0x0", src: "0x20", len: "0x20",
+			pre:     "0000000000000000000000000000000000000000000000000000000000000000 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f",
+			want:    "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f",
+			wantGas: 6,
+		},
+
+		{ // MCOPY 0 0 32 - copy 32 bytes from offset 0 to offset 0.
+			dst: "0x0", src: "0x0", len: "0x20",
+			pre:     "0101010101010101010101010101010101010101010101010101010101010101",
+			want:    "0101010101010101010101010101010101010101010101010101010101010101",
+			wantGas: 6,
+		},
+		{ // MCOPY 0 1 8 - copy 8 bytes from offset 1 to offset 0 (overlapping).
+			dst: "0x0", src: "0x1", len: "0x8",
+			pre:     "000102030405060708 000000000000000000000000000000000000000000000000",
+			want:    "010203040506070808 000000000000000000000000000000000000000000000000",
+			wantGas: 6,
+		},
+		{ // MCOPY 1 0 8 - copy 8 bytes from offset 0 to offset 1 (overlapping).
+			dst: "0x1", src: "0x0", len: "0x8",
+			pre:     "000102030405060708 000000000000000000000000000000000000000000000000",
+			want:    "000001020304050607 000000000000000000000000000000000000000000000000",
+			wantGas: 6,
+		},
+		// Tests below are not in the EIP, but maybe should be added
+		{ // MCOPY 0xFFFFFFFFFFFF 0xFFFFFFFFFFFF 0 - copy zero bytes from out-of-bounds index(overlapping).
+			dst: "0xFFFFFFFFFFFF", src: "0xFFFFFFFFFFFF", len: "0x0",
+			pre:     "11",
+			want:    "11",
+			wantGas: 3,
+		},
+		{ // MCOPY 0xFFFFFFFFFFFF 0 0 - copy zero bytes from start of mem to out-of-bounds.
+			dst: "0xFFFFFFFFFFFF", src: "0x0", len: "0x0",
+			pre:     "11",
+			want:    "11",
+			wantGas: 3,
+		},
+		{ // MCOPY 0 0xFFFFFFFFFFFF 0 - copy zero bytes from out-of-bounds to start of mem
+			dst: "0x0", src: "0xFFFFFFFFFFFF", len: "0x0",
+			pre:     "11",
+			want:    "11",
+			wantGas: 3,
+		},
+		{ // MCOPY - copy 1 from space outside of uint64  space
+			dst: "0x0", src: "0x10000000000000000", len: "0x1",
+			pre: "0",
+		},
+		{ // MCOPY - copy 1 from 0 to space outside of uint64
+			dst: "0x10000000000000000", src: "0x0", len: "0x1",
+			pre: "0",
+		},
+		{ // MCOPY - copy nothing from 0 to space outside of uint64
+			dst: "0x10000000000000000", src: "0x0", len: "0x0",
+			pre:     "",
+			want:    "",
+			wantGas: 3,
+		},
+		{ // MCOPY - copy 1 from 0x20 to 0x10, with no prior allocated mem
+			dst: "0x10", src: "0x20", len: "0x1",
+			pre: "",
+			// 64 bytes
+			want:    "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+			wantGas: 12,
+		},
+		{ // MCOPY - copy 1 from 0x19 to 0x10, with no prior allocated mem
+			dst: "0x10", src: "0x19", len: "0x1",
+			pre: "",
+			// 32 bytes
+			want:    "0x0000000000000000000000000000000000000000000000000000000000000000",
+			wantGas: 9,
+		},
+	} {
+		var (
+			env            = NewEVM(BlockContext{}, TxContext{}, nil, params.TestChainConfig, Config{})
+			stack          = newstack()
+			pc             = uint64(0)
+			evmInterpreter = env.interpreter
+		)
+		data := common.FromHex(strings.ReplaceAll(tc.pre, " ", ""))
+		// Set pre
+		mem := NewMemory()
+		mem.Resize(uint64(len(data)))
+		mem.Set(0, uint64(len(data)), data)
+		// Push stack args
+		len, _ := uint256.FromHex(tc.len)
+		src, _ := uint256.FromHex(tc.src)
+		dst, _ := uint256.FromHex(tc.dst)
+
+		stack.push(len)
+		stack.push(src)
+		stack.push(dst)
+		wantErr := (tc.wantGas == 0)
+		// Calc mem expansion
+		var memorySize uint64
+		if memSize, overflow := memoryMcopy(stack); overflow {
+			if wantErr {
+				continue
+			}
+			t.Errorf("overflow")
+		} else {
+			var overflow bool
+			if memorySize, overflow = math.SafeMul(toWordSize(memSize), 32); overflow {
+				t.Error(ErrGasUintOverflow)
+			}
+		}
+		// and the dynamic cost
+		var haveGas uint64
+		if dynamicCost, err := gasMcopy(env, nil, stack, mem, memorySize); err != nil {
+			t.Error(err)
+		} else {
+			haveGas = GasFastestStep + dynamicCost
+		}
+		// Expand mem
+		if memorySize > 0 {
+			mem.Resize(memorySize)
+		}
+		// Do the copy
+		opMcopy(&pc, evmInterpreter, &ScopeContext{mem, stack, nil})
+		want := common.FromHex(strings.ReplaceAll(tc.want, " ", ""))
+		if have := mem.store; !bytes.Equal(want, have) {
+			t.Errorf("case %d: \nwant: %#x\nhave: %#x\n", i, want, have)
+		}
+		wantGas := tc.wantGas
+		if haveGas != wantGas {
+			t.Errorf("case %d: gas wrong, want %d have %d\n", i, wantGas, haveGas)
+		}
+	}
+}