Integrate ARM plan9asm support in llgo

go.mod

@@ -17,7 +17,7 @@ require (
 )
 
 require (
-	github.com/goplus/plan9asm v0.0.0-20260307134905-822503d6bf44
+	github.com/goplus/plan9asm v0.1.1-0.20260314085947-7f506d4eb357
 	github.com/marcinbor85/gohex v0.0.0-20210308104911-55fb1c624d84
 	github.com/mattn/go-tty v0.0.7
 	github.com/sigurn/crc16 v0.0.0-20240131213347-83fcde1e29d1

go.sum

@@ -14,14 +14,8 @@ github.com/goplus/llvm v0.8.7 h1:FUpjuZ4Y+F9wNw2ztN5dCGnZnAQgH1YHaYEiX2QpfkQ=
 github.com/goplus/llvm v0.8.7/go.mod h1:PeVK8GgzxwAYCiMiUAJb5wJR6xbhj989tu9oulKLLT4=
 github.com/goplus/mod v0.19.5 h1:36sbRxKie2Or9aSfWT06X6WV37sBwARXYfKfGfHzEQs=
 github.com/goplus/mod v0.19.5/go.mod h1:T6Ta3xPXx8NQaRb8h632P5iBgIB77zXfh9vLNRFqMqk=
-github.com/goplus/plan9asm v0.0.0-20260212064924-71ea5584065b h1:DFZ0n92lGC3ogziCvtAHK8TKJf7oqiT4U576TIENiyk=
-github.com/goplus/plan9asm v0.0.0-20260212064924-71ea5584065b/go.mod h1:nnr49+IlbnOI5c0yb1fkbilBRcr50RPX0JAreDdYTUI=
-github.com/goplus/plan9asm v0.0.0-20260306151730-9203c54dfd4c h1:1S6F8dDxAnRiZAhqKjzLhAdx71jOaB5YdlHzfwCkdH8=
-github.com/goplus/plan9asm v0.0.0-20260306151730-9203c54dfd4c/go.mod h1:nnr49+IlbnOI5c0yb1fkbilBRcr50RPX0JAreDdYTUI=
-github.com/goplus/plan9asm v0.0.0-20260307044640-a5f1e3b27fc1 h1:hlVAtc3x34x6CQoOPnkOtz9p4juJ+cEZzgDyJpWnit4=
-github.com/goplus/plan9asm v0.0.0-20260307044640-a5f1e3b27fc1/go.mod h1:nnr49+IlbnOI5c0yb1fkbilBRcr50RPX0JAreDdYTUI=
-github.com/goplus/plan9asm v0.0.0-20260307134905-822503d6bf44 h1:zZXTz5CBO1uZIJGZSGWov5gE1CbulJ1QH6ruTMv3UdY=
-github.com/goplus/plan9asm v0.0.0-20260307134905-822503d6bf44/go.mod h1:gpS4VVNoRykYTtc8kPFBowraN5SrBj8lIjW8/lNjaG4=
+github.com/goplus/plan9asm v0.1.1-0.20260314085947-7f506d4eb357 h1:4typFkJN/D0YbNeNi5UIMoQdlWC+E4dn8goD4ddjMFs=
+github.com/goplus/plan9asm v0.1.1-0.20260314085947-7f506d4eb357/go.mod h1:gpS4VVNoRykYTtc8kPFBowraN5SrBj8lIjW8/lNjaG4=
 github.com/marcinbor85/gohex v0.0.0-20210308104911-55fb1c624d84 h1:hyAgCuG5nqTMDeUD8KZs7HSPs6KprPgPP8QmGV8nyvk=
 github.com/marcinbor85/gohex v0.0.0-20210308104911-55fb1c624d84/go.mod h1:Pb6XcsXyropB9LNHhnqaknG/vEwYztLkQzVCHv8sQ3M=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=

internal/build/build.go

@@ -1253,10 +1253,12 @@ func buildPkg(ctx *context, aPkg *aPackage, verbose bool) error {
 	}
 	aPkg.ObjFiles = append(aPkg.ObjFiles, cgoLLFiles...)
 	aPkg.ObjFiles = append(aPkg.ObjFiles, concatPkgLinkFiles(ctx, pkg, printCmds)...)
-	if asmObjFiles, err := compilePkgSFiles(ctx, aPkg, pkg, printCmds); err != nil {
-		return err
-	} else {
-		aPkg.ObjFiles = append(aPkg.ObjFiles, asmObjFiles...)
+	if aPkg.AltPkg == nil || llruntime.HasAdditiveAltPkg(pkgPath) {
+		if asmObjFiles, err := compilePkgSFiles(ctx, aPkg, pkg, printCmds); err != nil {
+			return err
+		} else {
+			aPkg.ObjFiles = append(aPkg.ObjFiles, asmObjFiles...)
+		}
 	}
 	if aliasObjs, err := buildGoCgoAliasObjects(ctx, pkgPath, aPkg.Package.Syntax, printCmds); err != nil {
 		return err

internal/build/plan9asm.go

@@ -201,6 +201,10 @@ func plan9asmSigsForPkg(ctx *context, pkgPath string) (map[string]struct{}, erro
 		plan9AsmSigCache.Store(key, sigs)
 		return sigs, nil
 	}
+	if hasAltPkgForTarget(ctx.buildConf, pkgPath) && !llruntime.HasAdditiveAltPkgForGOARCH(pkgPath, ctx.buildConf.Goarch) {
+		plan9AsmSigCache.Store(key, sigs)
+		return sigs, nil
+	}
 
 	var pkg *packages.Package
 	for p := range ctx.pkgs {
@@ -297,10 +301,10 @@ func (ctx *context) plan9asmEnabled(pkgPath string) bool {
 }
 
 func hasAltPkgForTarget(conf *Config, pkgPath string) bool {
-	if !llruntime.HasAltPkg(pkgPath) {
+	if conf == nil || !llruntime.HasAltPkgForGOARCH(pkgPath, conf.Goarch) {
 		return false
 	}
-	if llruntime.HasAdditiveAltPkg(pkgPath) {
+	if llruntime.HasAdditiveAltPkgForGOARCH(pkgPath, conf.Goarch) {
 		return true
 	}
 	// When Plan9 asm translation is enabled, avoid also pulling in alt packages
@@ -334,7 +338,7 @@ func plan9asmEnabledByDefault(conf *Config, pkgPath string) bool {
 	if !archSupportsPlan9AsmDefaults(conf.Goarch) {
 		return false
 	}
-	return !llruntime.HasAltPkg(pkgPath) || llruntime.HasAdditiveAltPkg(pkgPath)
+	return !llruntime.HasAltPkgForGOARCH(pkgPath, conf.Goarch) || llruntime.HasAdditiveAltPkgForGOARCH(pkgPath, conf.Goarch)
 }
 
 func pkgSFiles(ctx *context, pkg *packages.Package) ([]string, error) {
@@ -403,14 +407,33 @@ func pkgSFiles(ctx *context, pkg *packages.Package) ([]string, error) {
 			return paths, nil
 		}
 	}
+	// Embedded ARM targets currently reuse GOOS=linux metadata, but they do not
+	// have a Linux syscall surface. Skip syscall asm in that mode so embedded
+	// builds do not inherit Linux/ARM-specific frame layouts.
+	if shouldSkipPlan9AsmSFilesForTarget(ctx.buildConf, pkg.PkgPath) {
+		ctx.sfilesCache[pkg.ID] = nil
+		return nil, nil
+	}
 
-	paths := make([]string, 0, len(lp.SFiles))
-	for _, f := range lp.SFiles {
-		if lp.Dir == "" {
+	paths := selectedSFiles(lp.Dir, lp.SFiles)
+	ctx.sfilesCache[pkg.ID] = paths
+	return paths, nil
+}
+
+func selectedSFiles(dir string, files []string) []string {
+	if dir == "" || len(files) == 0 {
+		return nil
+	}
+	paths := make([]string, 0, len(files))
+	for _, f := range files {
+		if strings.HasSuffix(f, "_test.s") || strings.HasSuffix(f, "_test.S") {
 			continue
 		}
-		paths = append(paths, filepath.Join(lp.Dir, f))
+		paths = append(paths, filepath.Join(dir, f))
 	}
-	ctx.sfilesCache[pkg.ID] = paths
-	return paths, nil
+	return paths
+}
+
+func shouldSkipPlan9AsmSFilesForTarget(conf *Config, pkgPath string) bool {
+	return conf != nil && conf.Target != "" && conf.Goarch == "arm" && pkgPath == "syscall"
 }

internal/build/plan9asm_altpkg_test.go

@@ -18,3 +18,15 @@ func TestHasAltPkgForTarget_AllowsAdditivePatchWithPlan9Asm(t *testing.T) {
 		t.Fatal("internal/runtime/sys should keep its additive alt package even when plan9asm is enabled")
 	}
 }
+
+func TestHasAltPkgForTarget_UsesAtomicFallbackOnArm(t *testing.T) {
+	conf := &Config{Goarch: "arm", AbiMode: cabi.ModeAllFunc}
+	if !hasAltPkgForTarget(conf, "internal/runtime/atomic") {
+		t.Fatal("internal/runtime/atomic should use alt package on arm")
+	}
+
+	conf = &Config{Goarch: "arm64", AbiMode: cabi.ModeAllFunc}
+	if hasAltPkgForTarget(conf, "internal/runtime/atomic") {
+		t.Fatal("internal/runtime/atomic should keep plan9asm/std paths on arm64")
+	}
+}

internal/build/plan9asm_sfiles_test.go

@@ -0,0 +1,51 @@
+//go:build !llgo
+// +build !llgo
+
+package build
+
+import (
+	"path/filepath"
+	"reflect"
+	"testing"
+)
+
+func TestSelectedSFilesSkipsTestAsm(t *testing.T) {
+	dir := "/tmp/pkg"
+	got := selectedSFiles(dir, []string{
+		"abi_test.s",
+		"stub.s",
+		"helper.S",
+		"compare_test.S",
+	})
+	want := []string{
+		filepath.Join(dir, "stub.s"),
+		filepath.Join(dir, "helper.S"),
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("selectedSFiles() = %#v, want %#v", got, want)
+	}
+}
+
+func TestSelectedSFilesHandlesEmptyInput(t *testing.T) {
+	if got := selectedSFiles("", []string{"stub.s"}); got != nil {
+		t.Fatalf("selectedSFiles(empty dir) = %#v, want nil", got)
+	}
+	if got := selectedSFiles("/tmp/pkg", nil); got != nil {
+		t.Fatalf("selectedSFiles(nil files) = %#v, want nil", got)
+	}
+}
+
+func TestShouldSkipPlan9AsmSFilesForTarget(t *testing.T) {
+	if !shouldSkipPlan9AsmSFilesForTarget(&Config{Target: "cortex-m-qemu", Goarch: "arm"}, "syscall") {
+		t.Fatal("embedded arm syscall asm should be skipped")
+	}
+	if shouldSkipPlan9AsmSFilesForTarget(&Config{Target: "", Goarch: "arm"}, "syscall") {
+		t.Fatal("host arm syscall asm should not be skipped")
+	}
+	if shouldSkipPlan9AsmSFilesForTarget(&Config{Target: "cortex-m-qemu", Goarch: "arm64"}, "syscall") {
+		t.Fatal("arm64 syscall asm should not be skipped by arm-only rule")
+	}
+	if shouldSkipPlan9AsmSFilesForTarget(&Config{Target: "cortex-m-qemu", Goarch: "arm"}, "internal/bytealg") {
+		t.Fatal("only syscall asm should be skipped by embedded arm rule")
+	}
+}

internal/plan9asm/bytealg_arm_sigs_test.go

@@ -0,0 +1,85 @@
+//go:build !llgo
+// +build !llgo
+
+package plan9asm
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/goplus/llgo/internal/packages"
+	extplan9asm "github.com/goplus/plan9asm"
+)
+
+func loadStdlibInternalBytealgForTarget(t *testing.T, goos, goarch string) *packages.Package {
+	t.Helper()
+	cfg := &packages.Config{
+		Mode: packages.NeedName | packages.NeedFiles | packages.NeedSyntax | packages.NeedTypes | packages.NeedTypesSizes | packages.NeedTypesInfo | packages.NeedImports,
+		Env:  append(os.Environ(), "GOOS="+goos, "GOARCH="+goarch),
+	}
+	pkgs, err := packages.LoadEx(nil, nil, cfg, "internal/bytealg")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(pkgs) != 1 || pkgs[0].Types == nil {
+		t.Fatalf("load internal/bytealg: got %d pkgs, types=%v", len(pkgs), pkgs[0].Types)
+	}
+	return pkgs[0]
+}
+
+func TestSigsForStdlibInternalBytealgArmHelpers(t *testing.T) {
+	goroot := runtime.GOROOT()
+	if goroot == "" {
+		t.Skip("GOROOT not available")
+	}
+	pkg := loadStdlibInternalBytealgForTarget(t, "linux", "arm")
+
+	tests := map[string]map[string]extplan9asm.FuncSig{
+		filepath.Join(goroot, "src", "internal", "bytealg", "compare_arm.s"): {
+			"internal/bytealg.cmpbody": {
+				Args:    []extplan9asm.LLVMType{extplan9asm.Ptr, "i32", extplan9asm.Ptr, "i32", extplan9asm.Ptr},
+				Ret:     extplan9asm.Void,
+				ArgRegs: []extplan9asm.Reg{"R2", "R0", "R3", "R1", "R7"},
+			},
+		},
+		filepath.Join(goroot, "src", "internal", "bytealg", "count_arm.s"): {
+			"internal/bytealg.countbytebody": {
+				Args:    []extplan9asm.LLVMType{extplan9asm.Ptr, "i32", "i8", extplan9asm.Ptr},
+				Ret:     extplan9asm.Void,
+				ArgRegs: []extplan9asm.Reg{"R0", "R1", "R2", "R7"},
+			},
+		},
+		filepath.Join(goroot, "src", "internal", "bytealg", "equal_arm.s"): {
+			"internal/bytealg.memeqbody": {
+				Args:    []extplan9asm.LLVMType{extplan9asm.Ptr, extplan9asm.Ptr, "i32", extplan9asm.Ptr},
+				Ret:     extplan9asm.Void,
+				ArgRegs: []extplan9asm.Reg{"R0", "R2", "R1", "R7"},
+			},
+		},
+		filepath.Join(goroot, "src", "internal", "bytealg", "indexbyte_arm.s"): {
+			"internal/bytealg.indexbytebody": {
+				Args:    []extplan9asm.LLVMType{extplan9asm.Ptr, "i32", "i8", extplan9asm.Ptr},
+				Ret:     extplan9asm.Void,
+				ArgRegs: []extplan9asm.Reg{"R0", "R1", "R2", "R5"},
+			},
+		},
+	}
+
+	for path, wantSigs := range tests {
+		tr, err := TranslateFileForPkg(pkg, path, "linux", "arm", nil)
+		if err != nil {
+			t.Fatalf("translate %s: %v", path, err)
+		}
+		for name, want := range wantSigs {
+			got, ok := tr.Signatures[name]
+			if !ok {
+				t.Fatalf("missing symbol %s in %s", name, path)
+			}
+			if err := checkSig(got, want); err != nil {
+				t.Fatalf("%s (%s): %v", name, path, err)
+			}
+		}
+	}
+}

internal/plan9asm/translate.go

@@ -195,6 +195,27 @@ func extraAsmSigsAndDeclMap(pkgPath string, goarch string) map[string]extplan9as
 	manual := map[string]extplan9asm.FuncSig{}
 	if pkgPath == "internal/bytealg" {
 		switch goarch {
+		case "arm":
+			manual["internal/bytealg.cmpbody"] = extplan9asm.FuncSig{
+				Args:    []extplan9asm.LLVMType{extplan9asm.Ptr, "i32", extplan9asm.Ptr, "i32", extplan9asm.Ptr},
+				Ret:     extplan9asm.Void,
+				ArgRegs: []extplan9asm.Reg{"R2", "R0", "R3", "R1", "R7"},
+			}
+			manual["internal/bytealg.memeqbody"] = extplan9asm.FuncSig{
+				Args:    []extplan9asm.LLVMType{extplan9asm.Ptr, extplan9asm.Ptr, "i32", extplan9asm.Ptr},
+				Ret:     extplan9asm.Void,
+				ArgRegs: []extplan9asm.Reg{"R0", "R2", "R1", "R7"},
+			}
+			manual["internal/bytealg.countbytebody"] = extplan9asm.FuncSig{
+				Args:    []extplan9asm.LLVMType{extplan9asm.Ptr, "i32", "i8", extplan9asm.Ptr},
+				Ret:     extplan9asm.Void,
+				ArgRegs: []extplan9asm.Reg{"R0", "R1", "R2", "R7"},
+			}
+			manual["internal/bytealg.indexbytebody"] = extplan9asm.FuncSig{
+				Args:    []extplan9asm.LLVMType{extplan9asm.Ptr, "i32", "i8", extplan9asm.Ptr},
+				Ret:     extplan9asm.Void,
+				ArgRegs: []extplan9asm.Reg{"R0", "R1", "R2", "R5"},
+			}
 		case "arm64":
 			manual["internal/bytealg.cmpbody"] = extplan9asm.FuncSig{Args: []extplan9asm.LLVMType{extplan9asm.Ptr, extplan9asm.I64, extplan9asm.Ptr, extplan9asm.I64}, Ret: extplan9asm.I64}
 			manual["internal/bytealg.memeqbody"] = extplan9asm.FuncSig{Args: []extplan9asm.LLVMType{extplan9asm.Ptr, extplan9asm.Ptr, extplan9asm.I64}, Ret: extplan9asm.I1}

internal/plan9asm/translate_helpers_test.go

@@ -193,6 +193,18 @@ func TestExtraAsmSigsAndDeclMap(t *testing.T) {
 		t.Fatalf("unexpected manual sigs for other/pkg: %#v", got)
 	}
 
+	arm := extraAsmSigsAndDeclMap("internal/bytealg", "arm")
+	for _, name := range []string{
+		"internal/bytealg.cmpbody",
+		"internal/bytealg.memeqbody",
+		"internal/bytealg.countbytebody",
+		"internal/bytealg.indexbytebody",
+	} {
+		if _, ok := arm[name]; !ok {
+			t.Fatalf("missing arm manual sig %s", name)
+		}
+	}
+
 	arm64 := extraAsmSigsAndDeclMap("internal/bytealg", "arm64")
 	for _, name := range []string{
 		"internal/bytealg.cmpbody",

runtime/build.go

@@ -7,6 +7,23 @@ const (
 	altPkgAdditive
 )
 
+type altPkgSpec struct {
+	mode    altPkgMode
+	goarchs map[string]struct{}
+}
+
+func (s altPkgSpec) enabledFor(goarch string) bool {
+	return len(s.goarchs) == 0 || hasGoarch(s.goarchs, goarch)
+}
+
+func hasGoarch(goarchs map[string]struct{}, goarch string) bool {
+	if goarchs == nil {
+		return false
+	}
+	_, ok := goarchs[goarch]
+	return ok
+}
+
 func SkipToBuild(pkgPath string) bool {
 	if _, ok := altPkgs[pkgPath]; ok {
 		return false
@@ -19,19 +36,30 @@ func HasAltPkg(path string) (b bool) {
 	return
 }
 
+func HasAltPkgForGOARCH(path, goarch string) bool {
+	spec, ok := altPkgs[path]
+	return ok && spec.enabledFor(goarch)
+}
+
 func HasAdditiveAltPkg(path string) bool {
-	return altPkgs[path] == altPkgAdditive
-}
-
-var altPkgs = map[string]altPkgMode{
-	"internal/abi":          altPkgReplace,
-	"internal/reflectlite":  altPkgReplace,
-	"internal/runtime/maps": altPkgReplace,
-	"internal/runtime/sys":  altPkgAdditive,
-	"iter":                  altPkgReplace,
-	"reflect":               altPkgReplace,
-	"runtime":               altPkgReplace,
-	"unique":                altPkgReplace,
-	"syscall/js":            altPkgReplace,
-	"sync/atomic":           altPkgReplace,
+	return altPkgs[path].mode == altPkgAdditive
+}
+
+func HasAdditiveAltPkgForGOARCH(path, goarch string) bool {
+	spec, ok := altPkgs[path]
+	return ok && spec.mode == altPkgAdditive && spec.enabledFor(goarch)
+}
+
+var altPkgs = map[string]altPkgSpec{
+	"internal/abi":            {mode: altPkgReplace},
+	"internal/runtime/atomic": {mode: altPkgReplace, goarchs: map[string]struct{}{"arm": {}}},
+	"internal/reflectlite":    {mode: altPkgReplace},
+	"internal/runtime/maps":   {mode: altPkgReplace},
+	"internal/runtime/sys":    {mode: altPkgAdditive},
+	"iter":                    {mode: altPkgReplace},
+	"reflect":                 {mode: altPkgReplace},
+	"runtime":                 {mode: altPkgReplace},
+	"sync/atomic":             {mode: altPkgReplace},
+	"unique":                  {mode: altPkgReplace},
+	"syscall/js":              {mode: altPkgReplace},
 }