// FprintStack prints the stack trace of a machine from its exception
// and registers.
func FprintStack(w io.Writer, m *Machine, excep *CoreExcep) error {
sec := debugSection(m.Sections)
if sec == nil {
return errors.New("debug section not found")
}
t, err := debug8.UnmarshalTable(sec.Bytes)
if err != nil {
return err
}
funcs := sortTable(t)
core := byte(excep.Core)
regs := m.DumpRegs(core)
pc := regs[PC]
sp := regs[SP]
ret := regs[RET]
level := 0
for {
level++
name, f := findFunc(funcs, pc, t)
if f == nil {
if level == 1 {
_, err := fmt.Fprintf(w, "? pc=%08x\n", pc)
return err
}
return nil
}
_, err := fmt.Fprintln(w, f.String(name))
if err != nil {
return err
}
if f.Size <= 4 || f.Frame == 0 { // cannot be a normal function
if level != 1 {
// calling in a non-normal function
return nil
}
// use ret as pc
pc = ret
continue
}
retAddr, err := m.ReadWord(core, sp+f.Frame-4)
if err != nil {
_, err := fmt.Fprintf(w, "! unable to recover: %s\n", err)
return err
}
pc = retAddr
sp = sp + f.Frame
}
}
func main() {
flag.Parse()
args := flag.Args()
if len(args) != 1 {
log.Fatal("need exactly one input file\n")
}
fname := args[0]
if *doDasm {
f, err := os.Open(fname)
defer f.Close()
err = dasm8.DumpImage(f, os.Stdout)
if err != nil {
log.Fatal(err)
}
} else if *printDebug {
f, err := os.Open(fname)
defer f.Close()
secs, err := e8.Read(f)
if err != nil {
log.Fatal(err)
}
for _, sec := range secs {
if sec.Type != e8.Debug {
continue
}
tab, err := debug8.UnmarshalTable(sec.Bytes)
if err != nil {
log.Fatal(err)
}
tab.PrintTo(os.Stdout)
}
} else {
bs, err := ioutil.ReadFile(fname)
if err != nil {
log.Fatal(err)
}
n, e := run(bs)
fmt.Printf("(%d cycles)\n", n)
if e != nil {
if !arch8.IsHalt(e) {
fmt.Println(e)
}
} else {
fmt.Println("(end of time)")
}
}
}
func printStackTrace(m *arch8.Machine, exp error, sec *e8.Section) {
if sec == nil {
return
}
coreExp, ok := exp.(*arch8.CoreExcep)
if !ok {
return
}
tab, err := debug8.UnmarshalTable(sec.Bytes)
if err != nil {
log.Println(err)
return
}
debug8.FprintStack(os.Stdout, m, byte(coreExp.Core), tab)
}