make serial_ops const

I noticed that the serial_ops vtable is not const, but really it ought
to be.

This patch constifies it, removing the only mutable field in the
process.

Tested by rebuilding on x86-64 Fedora 18, both natively and using the
mingw cross tools.

2013-12-19  Tom Tromey  <tromey@redhat.com>

	* serial.c (serial_ops_p): New typedef.
	(serial_ops_list): Now a VEC.
	(serial_interface_lookup): Return const.  Use VEC_iterate.
	(serial_add_interface): Make parameter const.
	(serial_open): Update.
	(serial_fdopen_ops): Make 'ops' const.
	(serial_pipe): Update.
	* ser-tcp.c (_initialize_ser_tcp): Update.
	* ser-pipe.c (_initialize_ser_pipe): Update.
	* ser-unix.c (_initialize_ser_hardwire): Update.
	* ser-mingw.c (_initialize_ser_windows): Update.
	* ser-go32.c (dos_ops): Now const.  Update.
	* serial.h (struct serial) <ops>: Now const.
	(struct serial_ops) <next>: Remove.
	(serial_add_interface): Make parameter const.

1 files changed, 15 insertions, 12 deletions

diff --git a/gdb/serial.c b/gdb/serial.c
index 78e9085df2f..0e0c4f71833 100644
--- a/gdb/serial.c
+++ b/gdb/serial.c
@@ -30,9 +30,12 @@ extern void _initialize_serial (void);
 
 static unsigned int global_serial_debug_p;
 
-/* Linked list of serial I/O handlers.  */
+typedef const struct serial_ops *serial_ops_p;
+DEF_VEC_P (serial_ops_p);
 
-static struct serial_ops *serial_ops_list = NULL;
+/* Serial I/O handlers.  */
+
+VEC (serial_ops_p) *serial_ops_list = NULL;
 
 /* Pointer to list of scb's.  */
 
@@ -44,7 +47,7 @@ static struct serial *scb_base;
 static char *serial_logfile = NULL;
 static struct ui_file *serial_logfp = NULL;
 
-static struct serial_ops *serial_interface_lookup (const char *);
+static const struct serial_ops *serial_interface_lookup (const char *);
 static void serial_logchar (struct ui_file *stream,
 			    int ch_type, int ch, int timeout);
 static const char logbase_hex[] = "hex";
@@ -143,12 +146,13 @@ serial_log_command (const char *cmd)
 }
 
 
-static struct serial_ops *
+static const struct serial_ops *
 serial_interface_lookup (const char *name)
 {
-  struct serial_ops *ops;
+  const struct serial_ops *ops;
+  int i;
 
-  for (ops = serial_ops_list; ops; ops = ops->next)
+  for (i = 0; VEC_iterate (serial_ops_p, serial_ops_list, i, ops); ++i)
     if (strcmp (name, ops->name) == 0)
       return ops;
 
@@ -156,10 +160,9 @@ serial_interface_lookup (const char *name)
 }
 
 void
-serial_add_interface (struct serial_ops *optable)
+serial_add_interface (const struct serial_ops *optable)
 {
-  optable->next = serial_ops_list;
-  serial_ops_list = optable;
+  VEC_safe_push (serial_ops_p, serial_ops_list, optable);
 }
 
 /* Return the open serial device for FD, if found, or NULL if FD is
@@ -183,7 +186,7 @@ struct serial *
 serial_open (const char *name)
 {
   struct serial *scb;
-  struct serial_ops *ops;
+  const struct serial_ops *ops;
   const char *open_name = name;
 
   if (strcmp (name, "pc") == 0)
@@ -246,7 +249,7 @@ serial_open (const char *name)
    interface ops OPS.  */
 
 static struct serial *
-serial_fdopen_ops (const int fd, struct serial_ops *ops)
+serial_fdopen_ops (const int fd, const struct serial_ops *ops)
 {
   struct serial *scb;
 
@@ -584,7 +587,7 @@ serial_done_wait_handle (struct serial *scb)
 int
 serial_pipe (struct serial *scbs[2])
 {
-  struct serial_ops *ops;
+  const struct serial_ops *ops;
   int fildes[2];
 
   ops = serial_interface_lookup ("pipe");