func processOptions()

in cpu/cpu.go [219:287]

• 61 lines of code
• 19 McCabe index (conditional complexity)

func processOptions() {
	env := os.Getenv("GODEBUG")
field:
	for env != "" {
		field := ""
		i := strings.IndexByte(env, ',')
		if i < 0 {
			field, env = env, ""
		} else {
			field, env = env[:i], env[i+1:]
		}
		if len(field) < 4 || field[:4] != "cpu." {
			continue
		}
		i = strings.IndexByte(field, '=')
		if i < 0 {
			print("GODEBUG sys/cpu: no value specified for \"", field, "\"\n")
			continue
		}
		key, value := field[4:i], field[i+1:] // e.g. "SSE2", "on"

		var enable bool
		switch value {
		case "on":
			enable = true
		case "off":
			enable = false
		default:
			print("GODEBUG sys/cpu: value \"", value, "\" not supported for cpu option \"", key, "\"\n")
			continue field
		}

		if key == "all" {
			for i := range options {
				options[i].Specified = true
				options[i].Enable = enable || options[i].Required
			}
			continue field
		}

		for i := range options {
			if options[i].Name == key {
				options[i].Specified = true
				options[i].Enable = enable
				continue field
			}
		}

		print("GODEBUG sys/cpu: unknown cpu feature \"", key, "\"\n")
	}

	for _, o := range options {
		if !o.Specified {
			continue
		}

		if o.Enable && !*o.Feature {
			print("GODEBUG sys/cpu: can not enable \"", o.Name, "\", missing CPU support\n")
			continue
		}

		if !o.Enable && o.Required {
			print("GODEBUG sys/cpu: can not disable \"", o.Name, "\", required CPU feature\n")
			continue
		}

		*o.Feature = o.Enable
	}
}