cmd/objdump: add loong64 disassembler support

This CL provides vendor support for loong64 disassembler gnu and plan9 syntax.

cd $GOROOT/src/cmd
go get golang.org/x/arch@master
go mod tidy
go mod vendor

Change-Id: Ic8b888de0aa11cba58cbf559f8f69337d1d69309
Reviewed-on: https://go-review.googlesource.com/c/go/+/609015
Reviewed-by: Meidan Li <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: David Chase <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: sophie zhao <[email protected]>

src/cmd/go.mod

@@ -4,7 +4,7 @@ go 1.24
 
 require (
 	github.com/google/pprof v0.0.0-20240722153945-304e4f0156b8
-	golang.org/x/arch v0.9.1-0.20240807172201-9d90945922a7
+	golang.org/x/arch v0.10.1-0.20240910142527-7874f23b9c06
 	golang.org/x/build v0.0.0-20240722200705-b9910f320300
 	golang.org/x/mod v0.20.0
 	golang.org/x/sync v0.8.0

src/cmd/go.sum

@@ -6,8 +6,8 @@ github.com/ianlancetaylor/demangle v0.0.0-20240312041847-bd984b5ce465 h1:KwWnWVW
 github.com/ianlancetaylor/demangle v0.0.0-20240312041847-bd984b5ce465/go.mod h1:gx7rwoVhcfuVKG5uya9Hs3Sxj7EIvldVofAWIUtGouw=
 github.com/yuin/goldmark v1.6.0 h1:boZcn2GTjpsynOsC0iJHnBWa4Bi0qzfJjthwauItG68=
 github.com/yuin/goldmark v1.6.0/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
-golang.org/x/arch v0.9.1-0.20240807172201-9d90945922a7 h1:4+03DsxQb03qtr7e32FA8tiq18ytCUClXaXxQBDRGbs=
-golang.org/x/arch v0.9.1-0.20240807172201-9d90945922a7/go.mod h1:FEVrYAQjsQXMVJ1nsMoVVXPZg6p2JE2mx8psSWTDQys=
+golang.org/x/arch v0.10.1-0.20240910142527-7874f23b9c06 h1:UQRD9d43XiTfPsm0o04gmvWqcLLGkwqV+bOwtb7AP6c=
+golang.org/x/arch v0.10.1-0.20240910142527-7874f23b9c06/go.mod h1:FEVrYAQjsQXMVJ1nsMoVVXPZg6p2JE2mx8psSWTDQys=
 golang.org/x/build v0.0.0-20240722200705-b9910f320300 h1:2Cqg4LnvfD2ZpG8+6KbyYUkweWhNS3SgfcN/eeVseJ0=
 golang.org/x/build v0.0.0-20240722200705-b9910f320300/go.mod h1:YsGhg4JUVUWLzdqU2wCrtpRrOveOql6w56FLDHq/CJ4=
 golang.org/x/mod v0.20.0 h1:utOm6MM3R3dnawAiJgn0y+xvuYRsm1RKM/4giyfDgV0=

src/cmd/internal/objfile/disasm.go

@@ -23,6 +23,7 @@ import (
 
 	"golang.org/x/arch/arm/armasm"
 	"golang.org/x/arch/arm64/arm64asm"
+	"golang.org/x/arch/loong64/loong64asm"
 	"golang.org/x/arch/ppc64/ppc64asm"
 	"golang.org/x/arch/s390x/s390xasm"
 	"golang.org/x/arch/x86/x86asm"
@@ -367,6 +368,19 @@ func disasm_arm64(code []byte, pc uint64, lookup lookupFunc, byteOrder binary.By
 	return text, 4
 }
 
+func disasm_loong64(code []byte, pc uint64, lookup lookupFunc, byteOrder binary.ByteOrder, gnuAsm bool) (string, int) {
+	inst, err := loong64asm.Decode(code)
+	var text string
+	if err != nil || inst.Op == 0 {
+		text = "?"
+	} else if gnuAsm {
+		text = fmt.Sprintf("%-36s // %s", loong64asm.GoSyntax(inst, pc, lookup), loong64asm.GNUSyntax(inst))
+	} else {
+		text = loong64asm.GoSyntax(inst, pc, lookup)
+	}
+	return text, 4
+}
+
 func disasm_ppc64(code []byte, pc uint64, lookup lookupFunc, byteOrder binary.ByteOrder, gnuAsm bool) (string, int) {
 	inst, err := ppc64asm.Decode(code, byteOrder)
 	var text string
@@ -406,6 +420,7 @@ var disasms = map[string]disasmFunc{
 	"amd64":   disasm_amd64,
 	"arm":     disasm_arm,
 	"arm64":   disasm_arm64,
+	"loong64": disasm_loong64,
 	"ppc64":   disasm_ppc64,
 	"ppc64le": disasm_ppc64,
 	"s390x":   disasm_s390x,
@@ -416,6 +431,7 @@ var byteOrders = map[string]binary.ByteOrder{
 	"amd64":   binary.LittleEndian,
 	"arm":     binary.LittleEndian,
 	"arm64":   binary.LittleEndian,
+	"loong64": binary.LittleEndian,
 	"ppc64":   binary.BigEndian,
 	"ppc64le": binary.LittleEndian,
 	"s390x":   binary.BigEndian,

src/cmd/internal/objfile/elf.go

@@ -120,6 +120,8 @@ func (f *elfFile) goarch() string {
 		return "arm"
 	case elf.EM_AARCH64:
 		return "arm64"
+	case elf.EM_LOONGARCH:
+		return "loong64"
 	case elf.EM_PPC64:
 		if f.elf.ByteOrder == binary.LittleEndian {
 			return "ppc64le"

src/cmd/objdump/objdump_test.go

@@ -65,6 +65,18 @@ var armGnuNeed = []string{ // for both ARM and AMR64
 	"cmp",
 }
 
+var loong64Need = []string{
+	"JMP main.main(SB)",
+	"CALL main.Println(SB)",
+	"RET",
+}
+
+var loong64GnuNeed = []string{
+	"ld.b",
+	"bl",
+	"beq",
+}
+
 var ppcNeed = []string{
 	"BR main.main(SB)",
 	"CALL main.Println(SB)",
@@ -91,8 +103,6 @@ var s390xGnuNeed = []string{
 
 func mustHaveDisasm(t *testing.T) {
 	switch runtime.GOARCH {
-	case "loong64":
-		t.Skipf("skipping on %s", runtime.GOARCH)
 	case "mips", "mipsle", "mips64", "mips64le":
 		t.Skipf("skipping on %s, issue 12559", runtime.GOARCH)
 	case "riscv64":
@@ -157,6 +167,8 @@ func testDisasm(t *testing.T, srcfname string, printCode bool, printGnuAsm bool,
 		need = append(need, armNeed...)
 	case "arm64":
 		need = append(need, arm64Need...)
+	case "loong64":
+		need = append(need, loong64Need...)
 	case "ppc64", "ppc64le":
 		var pie bool
 		for _, flag := range flags {
@@ -183,6 +195,8 @@ func testDisasm(t *testing.T, srcfname string, printCode bool, printGnuAsm bool,
 			need = append(need, i386GnuNeed...)
 		case "arm", "arm64":
 			need = append(need, armGnuNeed...)
+		case "loong64":
+			need = append(need, loong64GnuNeed...)
 		case "ppc64", "ppc64le":
 			need = append(need, ppcGnuNeed...)
 		case "s390x":