cmd/internal/objfile: add arm64 disassembler support

Fixes #19157

Change-Id: Ieea286e8dc03929c3645f3113c33df569f8e26f3
Reviewed-on: https://go-review.googlesource.com/58930Reviewed-by: Cherry Zhang <cherryyz@google.com>

src/cmd/internal/objfile/disasm.go

@@ -22,6 +22,7 @@ import (
 	"text/tabwriter"
 
 	"golang.org/x/arch/arm/armasm"
+	"golang.org/x/arch/arm64/arm64asm"
 	"golang.org/x/arch/ppc64/ppc64asm"
 	"golang.org/x/arch/x86/x86asm"
 )
@@ -348,6 +349,17 @@ func disasm_arm(code []byte, pc uint64, lookup lookupFunc, _ binary.ByteOrder) (
 	return text, size
 }
 
+func disasm_arm64(code []byte, pc uint64, lookup lookupFunc, byteOrder binary.ByteOrder) (string, int) {
+	inst, err := arm64asm.Decode(code)
+	var text string
+	if err != nil || inst.Op == 0 {
+		text = "?"
+	} else {
+		text = arm64asm.GoSyntax(inst, pc, lookup, textReader{code, pc})
+	}
+	return text, 4
+}
+
 func disasm_ppc64(code []byte, pc uint64, lookup lookupFunc, byteOrder binary.ByteOrder) (string, int) {
 	inst, err := ppc64asm.Decode(code, byteOrder)
 	var text string
@@ -365,6 +377,7 @@ var disasms = map[string]disasmFunc{
 	"386":     disasm_386,
 	"amd64":   disasm_amd64,
 	"arm":     disasm_arm,
+	"arm64":   disasm_arm64,
 	"ppc64":   disasm_ppc64,
 	"ppc64le": disasm_ppc64,
 }
@@ -373,6 +386,7 @@ var byteOrders = map[string]binary.ByteOrder{
 	"386":     binary.LittleEndian,
 	"amd64":   binary.LittleEndian,
 	"arm":     binary.LittleEndian,
+	"arm64":   binary.LittleEndian,
 	"ppc64":   binary.BigEndian,
 	"ppc64le": binary.LittleEndian,
 	"s390x":   binary.BigEndian,

src/cmd/internal/objfile/elf.go

@@ -99,6 +99,8 @@ func (f *elfFile) goarch() string {
 		return "amd64"
 	case elf.EM_ARM:
 		return "arm"
+	case elf.EM_AARCH64:
+		return "arm64"
 	case elf.EM_PPC64:
 		if f.elf.ByteOrder == binary.LittleEndian {
 			return "ppc64le"

src/cmd/objdump/objdump_test.go

@@ -155,8 +155,6 @@ func testDisasm(t *testing.T, printCode bool, flags ...string) {
 
 func TestDisasm(t *testing.T) {
 	switch runtime.GOARCH {
-	case "arm64":
-		t.Skipf("skipping on %s, issue 10106", runtime.GOARCH)
 	case "mips", "mipsle", "mips64", "mips64le":
 		t.Skipf("skipping on %s, issue 12559", runtime.GOARCH)
 	case "s390x":
@@ -167,8 +165,6 @@ func TestDisasm(t *testing.T) {
 
 func TestDisasmCode(t *testing.T) {
 	switch runtime.GOARCH {
-	case "arm64":
-		t.Skipf("skipping on %s, issue 10106", runtime.GOARCH)
 	case "mips", "mipsle", "mips64", "mips64le":
 		t.Skipf("skipping on %s, issue 12559", runtime.GOARCH)
 	case "s390x":
@@ -185,8 +181,6 @@ func TestDisasmExtld(t *testing.T) {
 	switch runtime.GOARCH {
 	case "ppc64":
 		t.Skipf("skipping on %s, no support for external linking, issue 9038", runtime.GOARCH)
-	case "arm64":
-		t.Skipf("skipping on %s, issue 10106", runtime.GOARCH)
 	case "mips64", "mips64le", "mips", "mipsle":
 		t.Skipf("skipping on %s, issue 12559 and 12560", runtime.GOARCH)
 	case "s390x":
@@ -206,8 +200,6 @@ func TestDisasmGoobj(t *testing.T) {
 	switch runtime.GOARCH {
 	case "arm":
 		t.Skipf("skipping on %s, issue 19811", runtime.GOARCH)
-	case "arm64":
-		t.Skipf("skipping on %s, issue 10106", runtime.GOARCH)
 	case "mips", "mipsle", "mips64", "mips64le":
 		t.Skipf("skipping on %s, issue 12559", runtime.GOARCH)
 	case "s390x":