x/sys/unix: expose signal and errno names as strings

[AlekSi]

Currently, signal and errno names are represented by the following generated Go code (abbreviated):

const (
  SIGINT = syscall.Signal(0x2)
)

const (
  EAGAIN = syscall.Errno(0xb)
)

var signals = [...]string{
  2: "interrupt",
}

var errors = [...]string{
  11: "resource temporarily unavailable",
}

There is no way to get back signal or errno name (SIGINT and EAGAIN) from the number for, for example, nice logging messages.

I propose to expose them via two functions:

func SignalName(s syscall.Signal) string { }
func ErrnoName(e syscall.Errno) string { }

That's something that annoyed me for years, but I finally decided to create an issue.

[gopherbot]

Change https://golang.org/cl/110156 mentions this issue: zerros: Expose functions to get back names from the number

[tklauser]

Sounds fine to me. It would be nice if we had unix.Errno and unix.Signal types (not sure why these were not converted in the initial x/sys package split). We could then even have

func (s Signal) Name() string { ... }
func (e Errno) Name() string {... }

@ianlancetaylor @bradfitz what do you think?

[ianlancetaylor]

I think we would still want SignalName and ErrnoName, for use with the standard library. It seems a little confusing to require people to convert to unix.Signal or unix.Errno.

[gopherbot]

Change https://golang.org/cl/110875 mentions this issue: unix: add ErrnoName and SignalName

[kolyshkin]

@tklauser it seems that zerrors_linux_sparc64.go is not converted to the new format.

[gopherbot]

Change https://golang.org/cl/139977 mentions this issue: unix: convert errorList and signalList to new format for linux/sparc64

[tklauser]

@kolyshkin uh, I forgot to change it there because linux/sparc64is not integrated with the Docker-based build system. I sent https://golang.org/cl/139977 to fix it. Thanks.