Change serial_setbaudrate to throw exception

remote.c has this code:

      if (serial_setbaudrate (rs->remote_desc, baud_rate))
	{
	  /* The requested speed could not be set.  Error out to
	     top level after closing remote_desc.  Take care to
	     set remote_desc to NULL to avoid closing remote_desc
	     more than once.  */
	  serial_close (rs->remote_desc);
	  rs->remote_desc = NULL;
	  perror_with_name (name);

The perror here cannot be correct, because if serial_setbaudrate did
set errno, it may be obscured by serial_close.

This patch changes serial_setbaudrate to throw an exception instead.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30770

7 files changed, 31 insertions, 35 deletions

diff --git a/gdb/remote.c b/gdb/remote.c
index 1bc5992..00c84f1 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -6082,7 +6082,11 @@ remote_target::open_1 (const char *name, int from_tty, int extended_p)
 
   if (baud_rate != -1)
     {
-      if (serial_setbaudrate (rs->remote_desc, baud_rate))
+      try
+	{
+	  serial_setbaudrate (rs->remote_desc, baud_rate);
+	}
+      catch (const gdb_exception_error &)
 	{
 	  /* The requested speed could not be set.  Error out to
 	     top level after closing remote_desc.  Take care to
@@ -6090,7 +6094,7 @@ remote_target::open_1 (const char *name, int from_tty, int extended_p)
 	     more than once.  */
 	  serial_close (rs->remote_desc);
 	  rs->remote_desc = NULL;
-	  perror_with_name (name);
+	  throw;
 	}
     }
 
diff --git a/gdb/ser-base.c b/gdb/ser-base.c
index 0883305..072211d 100644
--- a/gdb/ser-base.c
+++ b/gdb/ser-base.c
@@ -561,10 +561,10 @@ ser_base_print_tty_state (struct serial *scb,
   return;
 }
 
-int
+void
 ser_base_setbaudrate (struct serial *scb, int rate)
 {
-  return 0;			/* Never fails!  */
+  /* Never fails!  */
 }
 
 int
diff --git a/gdb/ser-base.h b/gdb/ser-base.h
index 27f9f34..aeb7a4d 100644
--- a/gdb/ser-base.h
+++ b/gdb/ser-base.h
@@ -40,7 +40,7 @@ extern int ser_base_set_tty_state (struct serial *scb,
 extern void ser_base_print_tty_state (struct serial *scb,
 				      serial_ttystate ttystate,
 				      struct ui_file *stream);
-extern int ser_base_setbaudrate (struct serial *scb, int rate);
+extern void ser_base_setbaudrate (struct serial *scb, int rate);
 extern int ser_base_setstopbits (struct serial *scb, int num);
 extern int ser_base_setparity (struct serial *scb, int parity);
 extern int ser_base_drain_output (struct serial *scb);
diff --git a/gdb/ser-mingw.c b/gdb/ser-mingw.c
index 806f399..65ee169 100644
--- a/gdb/ser-mingw.c
+++ b/gdb/ser-mingw.c
@@ -226,18 +226,19 @@ ser_windows_setparity (struct serial *scb, int parity)
   return (SetCommState (h, &state) != 0) ? 0 : -1;
 }
 
-static int
+static void
 ser_windows_setbaudrate (struct serial *scb, int rate)
 {
   HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
   DCB state;
 
   if (GetCommState (h, &state) == 0)
-    return -1;
+    throw_winerror_with_name ("call to GetCommState failed", GetLastError ());
 
   state.BaudRate = rate;
 
-  return (SetCommState (h, &state) != 0) ? 0 : -1;
+  if (SetCommState (h, &state) == 0)
+    throw_winerror_with_name ("call to SetCommState failed", GetLastError ());
 }
 
 static void
diff --git a/gdb/ser-unix.c b/gdb/ser-unix.c
index cdc0cf9..5bd1598 100644
--- a/gdb/ser-unix.c
+++ b/gdb/ser-unix.c
@@ -53,7 +53,7 @@ show_serial_hwflow (struct ui_file *file, int from_tty,
 static int hardwire_open (struct serial *scb, const char *name);
 static void hardwire_raw (struct serial *scb);
 static int rate_to_code (int rate);
-static int hardwire_setbaudrate (struct serial *scb, int rate);
+static void hardwire_setbaudrate (struct serial *scb, int rate);
 static int hardwire_setparity (struct serial *scb, int parity);
 static void hardwire_close (struct serial *scb);
 static int get_tty_state (struct serial *scb,
@@ -417,47 +417,38 @@ rate_to_code (int rate)
 	    {
 	      if (i)
 		{
-		  warning (_("Invalid baud rate %d.  "
-			     "Closest values are %d and %d."),
-			   rate, baudtab[i - 1].rate, baudtab[i].rate);
+		  error (_("Invalid baud rate %d.  "
+			   "Closest values are %d and %d."),
+			 rate, baudtab[i - 1].rate, baudtab[i].rate);
 		}
 	      else
 		{
-		  warning (_("Invalid baud rate %d.  Minimum value is %d."),
-			   rate, baudtab[0].rate);
+		  error (_("Invalid baud rate %d.  Minimum value is %d."),
+			 rate, baudtab[0].rate);
 		}
-	      return -1;
 	    }
 	}
     }
  
   /* The requested speed was too large.  */
-  warning (_("Invalid baud rate %d.  Maximum value is %d."),
-	    rate, baudtab[i - 1].rate);
-  return -1;
+  error (_("Invalid baud rate %d.  Maximum value is %d."),
+	 rate, baudtab[i - 1].rate);
 }
 
-static int
+static void
 hardwire_setbaudrate (struct serial *scb, int rate)
 {
   struct hardwire_ttystate state;
   int baud_code = rate_to_code (rate);
   
-  if (baud_code < 0)
-    {
-      /* The baud rate was not valid.
-	 A warning has already been issued.  */
-      errno = EINVAL;
-      return -1;
-    }
-
   if (get_tty_state (scb, &state))
-    return -1;
+    perror_with_name ("could not get tty state");
 
   cfsetospeed (&state.termios, baud_code);
   cfsetispeed (&state.termios, baud_code);
 
-  return set_tty_state (scb, &state);
+  if (set_tty_state (scb, &state))
+    perror_with_name ("could not set tty state");
 }
 
 static int
diff --git a/gdb/serial.c b/gdb/serial.c
index 8a8bab4..122ab0b 100644
--- a/gdb/serial.c
+++ b/gdb/serial.c
@@ -512,10 +512,10 @@ serial_print_tty_state (struct serial *scb,
   scb->ops->print_tty_state (scb, ttystate, stream);
 }
 
-int
+void
 serial_setbaudrate (struct serial *scb, int rate)
 {
-  return scb->ops->setbaudrate (scb, rate);
+  scb->ops->setbaudrate (scb, rate);
 }
 
 int
diff --git a/gdb/serial.h b/gdb/serial.h
index 3b86120..9a51fdf 100644
--- a/gdb/serial.h
+++ b/gdb/serial.h
@@ -177,10 +177,10 @@ extern void serial_print_tty_state (struct serial *scb,
 				    serial_ttystate ttystate,
 				    struct ui_file *);
 
-/* Set the baudrate to the decimal value supplied.  Returns 0 for
-   success, -1 for failure.  */
+/* Set the baudrate to the decimal value supplied.  Throws exception
+   on error.  */
 
-extern int serial_setbaudrate (struct serial *scb, int rate);
+extern void serial_setbaudrate (struct serial *scb, int rate);
 
 /* Set the number of stop bits to the value specified.  Returns 0 for
    success, -1 for failure.  */
@@ -275,7 +275,7 @@ struct serial_ops
     int (*set_tty_state) (struct serial *, serial_ttystate);
     void (*print_tty_state) (struct serial *, serial_ttystate,
 			     struct ui_file *);
-    int (*setbaudrate) (struct serial *, int rate);
+    void (*setbaudrate) (struct serial *, int rate);
     int (*setstopbits) (struct serial *, int num);
     /* Set the value PARITY as parity setting for serial object.
        Return 0 in the case of success.  */