Update serialport to be compatible to newer ruby versions

Gemfile

@@ -1,3 +1,3 @@
 source "https://rubygems.org"
-source "http://gems.github.com"
+
 gemspec

ext/native/extconf.rb

@@ -10,4 +10,7 @@
   exit(1) if not have_header("termios.h") or not have_header("unistd.h")
 end
 
+have_func("rb_io_descriptor") # ruby-3.1+
+have_func("rb_io_open_descriptor") # ruby-3.3+
+
 create_makefile('serialport')

ext/native/posix_serialport_impl.c

@@ -61,35 +61,23 @@ static char sTcsetattr[] = "tcsetattr";
 static char sIoctl[] = "ioctl";
 
 
-int get_fd_helper(obj)
-   VALUE obj;
+int get_fd_helper(VALUE io)
 {
-#ifdef HAVE_RUBY_IO_H
-   rb_io_t *fptr;
+#ifdef HAVE_RB_IO_DESCRIPTOR
+  return rb_io_descriptor(io);
 #else
-   OpenFile *fptr;
-#endif
-   GetOpenFile(obj, fptr);
-#ifdef HAVE_RUBY_IO_H
-   return (fptr->fd);
-#else
-   return (fileno(fptr->f));
+  rb_io_t* fp;
+  GetOpenFile(io, fp);
+  return fp->fd;
 #endif
 }
 
-VALUE sp_create_impl(class, _port)
-   VALUE class, _port;
+VALUE sp_create_impl(VALUE class, VALUE _port)
 {
-#ifdef HAVE_RUBY_IO_H
-   rb_io_t *fp;
-#else
-   OpenFile *fp;
-#endif
-
    int fd;
-   int num_port;
-   char *port;
-   char *ports[] = {
+   long num_port;
+   const char *port;
+   const char *ports[] = {
 #if defined(OS_LINUX) || defined(OS_CYGWIN)
       "/dev/ttyS0", "/dev/ttyS1", "/dev/ttyS2", "/dev/ttyS3",
       "/dev/ttyS4", "/dev/ttyS5", "/dev/ttyS6", "/dev/ttyS7"
@@ -108,16 +96,13 @@ VALUE sp_create_impl(class, _port)
 #endif
    };
    struct termios params;
-
-   NEWOBJ(sp, struct RFile);
-   OBJSETUP(sp, class, T_FILE);
-   MakeOpenFile((VALUE) sp, fp);
+   VALUE sp;
 
    switch(TYPE(_port))
    {
       case T_FIXNUM:
-         num_port = FIX2INT(_port);
-         if (num_port < 0 || num_port > sizeof(ports) / sizeof(ports[0]))
+         num_port = FIX2LONG(_port);
+         if (num_port < 0 || num_port > (long)(sizeof(ports) / sizeof(ports[0])))
          {
             rb_raise(rb_eArgError, "illegal port number");
          }
@@ -166,19 +151,12 @@ VALUE sp_create_impl(class, _port)
       rb_sys_fail(sTcsetattr);
    }
 
-#ifdef HAVE_RUBY_IO_H
-   fp->fd = fd;
-#else
-   fp->f = rb_fdopen(fd, "r+");
-#endif
-   fp->mode = FMODE_READWRITE | FMODE_SYNC;
+   sp = rb_io_open_descriptor(class, fd, FMODE_READWRITE | FMODE_SYNC, Qnil, Qnil, NULL);
 
-   return (VALUE) sp;
+   return sp;
 }
 
-VALUE sp_set_modem_params_impl(argc, argv, self)
-   int argc;
-   VALUE *argv, self;
+VALUE sp_set_modem_params_impl(int argc, VALUE *argv, VALUE self)
 {
    int fd;
    struct termios params;
@@ -399,9 +377,7 @@ VALUE sp_set_modem_params_impl(argc, argv, self)
    return argv[0];
 }
 
-void get_modem_params_impl(self, mp)
-   VALUE self;
-   struct modem_params *mp;
+void get_modem_params_impl(VALUE self, struct modem_params *mp)
 {
    int fd;
    struct termios params;
@@ -493,8 +469,7 @@ void get_modem_params_impl(self, mp)
    }
 }
 
-VALUE sp_set_flow_control_impl(self, val)
-   VALUE self, val;
+VALUE sp_set_flow_control_impl(VALUE self, VALUE val)
 {
    int fd;
    int flowc;
@@ -540,8 +515,7 @@ VALUE sp_set_flow_control_impl(self, val)
    return val;
 }
 
-VALUE sp_get_flow_control_impl(self)
-   VALUE self;
+VALUE sp_get_flow_control_impl(VALUE self)
 {
    int ret;
    int fd;
@@ -570,8 +544,7 @@ VALUE sp_get_flow_control_impl(self)
    return INT2FIX(ret);
 }
 
-VALUE sp_set_read_timeout_impl(self, val)
-   VALUE self, val;
+VALUE sp_set_read_timeout_impl(VALUE self, VALUE val)
 {
    int timeout;
    int fd;
@@ -610,8 +583,7 @@ VALUE sp_set_read_timeout_impl(self, val)
    return val;
 }
 
-VALUE sp_get_read_timeout_impl(self)
-   VALUE self;
+VALUE sp_get_read_timeout_impl(VALUE self)
 {
    int fd;
    struct termios params;
@@ -630,22 +602,17 @@ VALUE sp_get_read_timeout_impl(self)
    return INT2FIX(params.c_cc[VTIME] * 100);
 }
 
-VALUE sp_set_write_timeout_impl(self, val)
-   VALUE self, val;
+NORETURN(VALUE sp_set_write_timeout_impl(VALUE self, VALUE val))
 {
    rb_notimplement();
-   return self;
 }
 
-VALUE sp_get_write_timeout_impl(self)
-   VALUE self;
+NORETURN(VALUE sp_get_write_timeout_impl(VALUE self))
 {
    rb_notimplement();
-   return self;
 }
 
-VALUE sp_break_impl(self, time)
-   VALUE self, time;
+VALUE sp_break_impl(VALUE self, VALUE time)
 {
    int fd;
 
@@ -661,9 +628,7 @@ VALUE sp_break_impl(self, time)
    return Qnil;
 }
 
-void get_line_signals_helper_impl(obj, ls)
-   VALUE obj;
-   struct line_signals *ls;
+void get_line_signals_helper_impl(VALUE obj, struct line_signals *ls)
 {
    int fd, status;
 
@@ -682,9 +647,7 @@ void get_line_signals_helper_impl(obj, ls)
    ls->ri  = (status & TIOCM_RI ? 1 : 0);
 }
 
-VALUE set_signal_impl(obj, val, sig)
-   VALUE obj,val;
-   int sig;
+VALUE set_signal_impl(VALUE obj, VALUE val, int sig)
 {
    int status;
    int fd;
@@ -721,29 +684,25 @@ VALUE set_signal_impl(obj, val, sig)
    return val;
 }
 
-VALUE sp_set_rts_impl(self, val)
-   VALUE self, val;
+VALUE sp_set_rts_impl(VALUE self, VALUE val)
 {
    return set_signal_impl(self, val, TIOCM_RTS);
 }
 
-VALUE sp_set_dtr_impl(self, val)
-   VALUE self, val;
+VALUE sp_set_dtr_impl(VALUE self, VALUE val)
 {
    return set_signal_impl(self, val, TIOCM_DTR);
 }
 
-VALUE sp_get_rts_impl(self)
-   VALUE self;
+VALUE sp_get_rts_impl(VALUE self)
 {
    struct line_signals ls;
 
    get_line_signals_helper_impl(self, &ls);
    return INT2FIX(ls.rts);
 }
 
-VALUE sp_get_dtr_impl(self)
-   VALUE self;
+VALUE sp_get_dtr_impl(VALUE self)
 {
    struct line_signals ls;
 
@@ -752,8 +711,7 @@ VALUE sp_get_dtr_impl(self)
    return INT2FIX(ls.dtr);
 }
 
-VALUE sp_flush_input_data_impl(self)
-VALUE self;
+VALUE sp_flush_input_data_impl(VALUE self)
 {
 	int fd;
 	int ret;
@@ -768,8 +726,7 @@ VALUE self;
 	return Qtrue;
 }
 
-VALUE sp_flush_output_data_impl(self)
-VALUE self;
+VALUE sp_flush_output_data_impl(VALUE self)
 {
 	int fd;
 	int ret;