Files
gasm-sdk/asm/aarch64_goobj_test.go
2026-09-26 11:08:43 +02:00

349 lines
10 KiB
Go

// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: BSD-3-Clause
package asm
import (
"encoding/binary"
"os"
"os/exec"
"path/filepath"
"strings"
"testing"
"sourcedock.dev/petrbalvin/gasm-sdk/parser"
)
// TestGOObjectAARCH64Structure checks the basic structure of the emitted
// AArch64 GOOBJ: the preamble, the magic, the block offsets and the
// non-package symbol definitions.
func TestGOObjectAARCH64Structure(t *testing.T) {
f, errs := parser.Parse("k_arm64.s", `
#include "textflag.h"
TEXT ·add(SB), NOSPLIT, $0-24
MOVD a+0(FP), R4
MOVD b+8(FP), R5
ADD R5, R4, R4
MOVD R4, ret+16(FP)
RET
`)
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
img, err := AssembleFileARM64(f)
if err != nil {
t.Fatalf("AssembleFileARM64: %v", err)
}
obj, err := img.GOObjectAARCH64("testpkg", "k_arm64.s")
if err != nil {
t.Fatalf("GOObjectAARCH64: %v", err)
}
// Check preamble.
idx := strings.Index(string(obj), "\n!\n")
if idx < 0 {
t.Fatal("missing preamble separator")
}
preamble := string(obj[:idx])
if !strings.HasPrefix(preamble, "go object") {
t.Errorf("preamble = %q, want 'go object ...'", preamble)
}
// Check GOOBJ magic.
magicIdx := idx + 3
if magicIdx+8 > len(obj) || string(obj[magicIdx:magicIdx+8]) != "\x00go120ld" {
t.Error("missing GOOBJ magic")
}
// The object should contain the function's code.
if len(img.Code) == 0 {
t.Error("no code generated")
}
}
// TestGOObjectAARCH64PairReloc pins the ADRP-pair relocation shape against
// the toolchain's own object for the same source: exactly one R_ADDRARM64
// of Siz 8 at the ADRP word (cmd/internal/obj/arm64/asm7.go adds a single
// Siz-8 relocation per pair and the linker patches both instructions from
// it). gasm's assembler records the ADRP+ADD form as two word relocs; the
// emitter must coalesce them, not emit two Siz-4 records.
func TestGOObjectAARCH64PairReloc(t *testing.T) {
f, errs := parser.Parse("gv_arm64.s", `
#include "textflag.h"
TEXT ·getv(SB), NOSPLIT, $0-8
MOVD $v<>(SB), R4
MOVD R4, ret+0(FP)
RET
GLOBL v<>(SB), RODATA, $8
DATA v<>+0(SB)/8, $7
`)
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
img, err := AssembleFileARM64(f)
if err != nil {
t.Fatalf("AssembleFileARM64: %v", err)
}
obj, err := img.GOObjectAARCH64("main", "gv_arm64.s")
if err != nil {
t.Fatalf("GOObjectAARCH64: %v", err)
}
v := openGoobj(t, obj)
relocs := v.blk(blkReloc)
le := binary.LittleEndian
// Two DWARF relocs on the lines/DIE symbols, then the code's one pair
// relocation.
if len(relocs) != 3*23 {
t.Fatalf("relocs = %d bytes, want three entries", len(relocs))
}
cr := relocs[2*23:]
if off := int32(le.Uint32(cr[0:])); off != 0 {
t.Errorf("pair reloc off = %d, want 0 (the ADRP word)", off)
}
if siz := cr[4]; siz != 8 {
t.Errorf("pair reloc siz = %d, want 8", siz)
}
if typ := le.Uint16(cr[5:]); typ != relocArm64Addr {
t.Errorf("pair reloc type = %d, want %d (R_ADDRARM64)", typ, relocArm64Addr)
}
if pkg := le.Uint32(cr[15:]); pkg != pkgIdxSelf {
t.Errorf("pair reloc PkgIdx = %#x, want pkgIdxSelf", pkg)
}
// The GLOBL is the first package definition.
if sym := le.Uint32(cr[19:]); sym != 0 {
t.Errorf("pair reloc SymIdx = %d, want 0 (the GLOBL definition)", sym)
}
}
// TestGOObjectAARCH64Link does an end-to-end link test: it cross-compiles a
// Go program for arm64, substitutes the gasm-produced object into the package
// archive, re-links with cmd/link, and verifies the symbol appears in the
// resulting binary. The binary is not executed (no arm64 host or qemu).
// Skipped when no Go toolchain is available.
func TestGOObjectAARCH64Link(t *testing.T) {
goBin, err := exec.LookPath("go")
if err != nil {
t.Skip("no Go toolchain available")
}
dir := t.TempDir()
asmSrc := `#include "textflag.h"
TEXT ·add(SB), NOSPLIT, $0-24
MOVD a+0(FP), R4
MOVD b+8(FP), R5
ADD R5, R4, R4
MOVD R4, ret+16(FP)
RET
TEXT ·getv(SB), NOSPLIT, $0-8
MOVD $v<>(SB), R4
MOVD R4, ret+0(FP)
RET
GLOBL v<>(SB), RODATA, $8
DATA v<>+0(SB)/8, $7
`
if err := os.WriteFile(filepath.Join(dir, "main_arm64.s"), []byte(asmSrc), 0o644); err != nil {
t.Fatal(err)
}
mainSrc := `package main
func add(a, b int64) int64
func getv() *int64
func main() {
if add(20, 22) != 42 {
panic("bad add")
}
if getv() == nil {
panic("bad getv")
}
}
`
if err := os.WriteFile(filepath.Join(dir, "main.go"), []byte(mainSrc), 0o644); err != nil {
t.Fatal(err)
}
if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module a64link\n\ngo 1.21\n"), 0o644); err != nil {
t.Fatal(err)
}
// Capture the cross build (GOARCH=arm64): the package archive and the
// link line.
build := exec.Command(goBin, "build", "-x", "-work", "-o", filepath.Join(dir, "prog"), ".")
build.Dir = dir
build.Env = append(os.Environ(), "GOARCH=arm64")
buildLog, err := build.CombinedOutput()
if err != nil {
t.Fatalf("baseline build: %v\n%s", err, buildLog)
}
var work, linkLine, asmObj string
for line := range strings.SplitSeq(string(buildLog), "\n") {
switch {
case strings.HasPrefix(line, "WORK="):
work = strings.TrimPrefix(line, "WORK=")
case strings.Contains(line, "/asm ") && strings.Contains(line, "main_arm64.s") && !strings.Contains(line, "-gensymabis"):
asmObj = fieldAfter(line, "-o")
case strings.Contains(line, "/link ") && strings.Contains(line, "-importcfg"):
linkLine = line
}
}
if work == "" || asmObj == "" {
t.Skipf("could not parse build log (work=%q asmObj=%q)", work, asmObj)
}
defer os.RemoveAll(work)
// Expand $WORK in the object path.
asmObj = strings.ReplaceAll(asmObj, "$WORK", work)
// Read the toolchain-produced object and assemble the same source with gasm.
src, err := os.ReadFile(filepath.Join(dir, "main_arm64.s"))
if err != nil {
t.Fatal(err)
}
f, errs := parser.Parse("main_arm64.s", string(src))
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
img, err := AssembleFileARM64(f)
if err != nil {
t.Fatalf("AssembleFileARM64: %v", err)
}
gasmObj, err := img.GOObjectAARCH64("a64link", "main_arm64.s")
if err != nil {
t.Fatalf("GOObjectAARCH64: %v", err)
}
// Replace the toolchain-produced object with gasm's.
if err := os.WriteFile(asmObj, gasmObj, 0o644); err != nil {
t.Fatalf("write gasm object: %v", err)
}
// Re-link.
if linkLine == "" {
t.Skip("could not find link command in build log")
}
// Expand $WORK in the link command.
linkLine = strings.ReplaceAll(linkLine, "$WORK", work)
linkCmd := exec.Command("bash", "-c", "cd "+dir+" && "+linkLine)
linkCmd.Env = append(os.Environ(), "GOARCH=arm64")
if out, err := linkCmd.CombinedOutput(); err != nil {
t.Fatalf("re-link with gasm object: %v\n%s", err, out)
}
// Verify the binary exists and contains the symbol.
binPath := filepath.Join(dir, "prog")
if _, err := os.Stat(binPath); err != nil {
t.Fatalf("binary not found: %v", err)
}
binData, err := os.ReadFile(binPath)
if err != nil {
t.Fatalf("read binary: %v", err)
}
if !strings.Contains(string(binData), "add") && !strings.Contains(string(binData), "a64link") {
t.Error("binary does not contain expected symbol")
}
}
// TestGOObjectAARCH64DataSymbolLink does for symbol-valued DATA fields what
// the rt0 files do ("DATA _rt0…lib+0(SB)/8, $_rt0…lib(SB)"): the gasm object
// carries an R_ADDR against the file's own TEXT symbol, the toolchain links
// it, and the binary is checked for the symbol (no arm64 host to run it).
func TestGOObjectAARCH64DataSymbolLink(t *testing.T) {
goBin, err := exec.LookPath("go")
if err != nil {
t.Skip("no Go toolchain available")
}
dir := t.TempDir()
asmSrc := `#include "textflag.h"
GLOBL entry(SB), NOPTR, $8
DATA entry+0(SB)/8, $·keepme(SB)
TEXT ·keepme(SB), NOSPLIT, $0-0
RET
TEXT ·entryptr(SB), NOSPLIT, $0-8
MOVD entry+0(SB), R4
MOVD R4, ret+0(FP)
RET
`
if err := os.WriteFile(filepath.Join(dir, "main_arm64.s"), []byte(asmSrc), 0o644); err != nil {
t.Fatal(err)
}
mainSrc := `package main
func keepme()
func entryptr() uintptr
func main() {
if entryptr() == 0 {
panic("the entry word is empty")
}
}
`
if err := os.WriteFile(filepath.Join(dir, "main.go"), []byte(mainSrc), 0o644); err != nil {
t.Fatal(err)
}
if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module a64dlink\n\ngo 1.21\n"), 0o644); err != nil {
t.Fatal(err)
}
build := exec.Command(goBin, "build", "-x", "-work", "-o", filepath.Join(dir, "prog"), ".")
build.Dir = dir
build.Env = append(os.Environ(), "GOARCH=arm64")
buildLog, err := build.CombinedOutput()
if err != nil {
t.Fatalf("baseline build: %v\n%s", err, buildLog)
}
var work, linkLine, asmObj string
for line := range strings.SplitSeq(string(buildLog), "\n") {
switch {
case strings.HasPrefix(line, "WORK="):
work = strings.TrimPrefix(line, "WORK=")
case strings.Contains(line, "/asm ") && strings.Contains(line, "main_arm64.s") && !strings.Contains(line, "-gensymabis"):
asmObj = fieldAfter(line, "-o")
case strings.Contains(line, "/link ") && strings.Contains(line, "-importcfg"):
linkLine = line
}
}
if work == "" || asmObj == "" || linkLine == "" {
t.Skipf("could not parse build log (work=%q asmObj=%q link=%q)", work, asmObj, linkLine)
}
defer os.RemoveAll(work)
asmObj = strings.ReplaceAll(asmObj, "$WORK", work)
linkLine = strings.ReplaceAll(linkLine, "$WORK", work)
src, err := os.ReadFile(filepath.Join(dir, "main_arm64.s"))
if err != nil {
t.Fatal(err)
}
f, errs := parser.Parse("main_arm64.s", string(src))
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
img, err := AssembleFileARM64(f)
if err != nil {
t.Fatalf("AssembleFileARM64: %v", err)
}
gasmObj, err := img.GOObjectAARCH64("a64dlink", "main_arm64.s")
if err != nil {
t.Fatalf("GOObjectAARCH64: %v", err)
}
if err := os.WriteFile(asmObj, gasmObj, 0o644); err != nil {
t.Fatalf("write gasm object: %v", err)
}
linkCmd := exec.Command("bash", "-c", "cd "+dir+" && "+linkLine)
linkCmd.Env = append(os.Environ(), "GOARCH=arm64")
if out, err := linkCmd.CombinedOutput(); err != nil {
t.Fatalf("re-link with gasm object: %v\n%s", err, out)
}
binData, err := os.ReadFile(filepath.Join(dir, "prog"))
if err != nil {
t.Fatal(err)
}
if !strings.Contains(string(binData), "keepme") {
t.Error("binary does not contain the keepme symbol")
}
}