feat(asm): symbol-valued DATA, division slash in symbols and plain semicolons

Assisted-by: GLM 5.3 Flash
2026-09-20 19:15:05 +02:00
parent 289cabe993
commit 6556b85abf
14 changed files with 1027 additions and 18 deletions
@@ -245,3 +245,104 @@ func main() {
 		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")
+	}
+}