gdb: unix: allow to use custom baud rate

gdb/config.in

@@ -93,6 +93,9 @@
 /* Define if amd-dbgapi is being linked in. */
 #undef HAVE_AMD_DBGAPI
 
+/* Define to 1 if you have the <asm/termios.h> header file. */
+#undef HAVE_ASM_TERMIOS_H
+
 /* Define to 1 if you have the `btowc' function. */
 #undef HAVE_BTOWC
 
@@ -241,6 +244,9 @@
 /* Define to 1 if you have the <inttypes.h> header file. */
 #undef HAVE_INTTYPES_H
 
+/* Define to 1 if you have the <IOKit/serial/ioss.h> header file. */
+#undef HAVE_IOKIT_SERIAL_IOSS_H
+
 /* Define to 1 if you have the `kinfo_getfile' function. */
 #undef HAVE_KINFO_GETFILE
 

gdb/configure

@@ -11504,7 +11504,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11503 "configure"
+#line 11507 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11610,7 +11610,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11609 "configure"
+#line 11613 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -29228,6 +29228,8 @@ $as_echo "#define STDC_HEADERS 1" >>confdefs.h
 fi
 
 for ac_header in  \
+  asm/termios.h \
+  IOKit/serial/ioss.h \
   machine/reg.h \
   nlist.h \
   ptrace.h \

gdb/configure.ac

@@ -1332,6 +1332,8 @@ AC_SUBST(SRCHIGH_CFLAGS)
 
 AC_HEADER_STDC
 AC_CHECK_HEADERS([ \
+  asm/termios.h \
+  IOKit/serial/ioss.h \
   machine/reg.h \
   nlist.h \
   ptrace.h \

gdb/ser-unix.c

@@ -30,9 +30,30 @@
 #include "gdbsupport/gdb_select.h"
 #include "cli/cli-cmds.h"
 #include "gdbsupport/filestuff.h"
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+#if HAVE_IOKIT_SERIAL_IOSS_H
+#include <IOKit/serial/ioss.h>
+#endif
+#if HAVE_ASM_TERMIOS_H
+/* Workaround to resolve conflicting declarations of termios
+ * in <asm/termbits.h> and <termios.h>.  */
+#define termios asmtermios
+#include <asm/termbits.h>
+#undef termios
+#endif
+#ifdef HAVE_TERMIOS_H
 #include <termios.h>
+#else
+#error "termios.h must be present to control serial port"
+#endif
 #include "gdbsupport/scoped_ignore_sigttou.h"
 
+#if defined(HAVE_SYS_IOCTL_H) && (defined(BOTHER) || defined(IOSSIOSPEED))
+#define HAVE_CUSTOM_BAUDRATE_SUPPORT 1
+#endif
+
 struct hardwire_ttystate
   {
     struct termios termios;
@@ -289,10 +310,28 @@ baudtab[] =
     4800, B4800
   }
   ,
+#ifdef B7200
+  {
+    7200, B7200
+  }
+  ,
+#endif
   {
     9600, B9600
   }
   ,
+#ifdef B14400
+  {
+    14400, B14400
+  }
+  ,
+#endif
+#ifdef B28800
+  {
+    28800, B28800
+  }
+  ,
+#endif
   {
     19200, B19200
   }
@@ -307,6 +346,12 @@ baudtab[] =
   }
   ,
 #endif
+#ifdef B76800
+  {
+    76800, B76800
+  }
+  ,
+#endif
 #ifdef B115200
   {
     115200, B115200
@@ -412,6 +457,7 @@ rate_to_code (int rate)
 	  /* check if it is in between valid values.  */
 	  if (rate < baudtab[i].rate)
 	    {
+#if !HAVE_CUSTOM_BAUDRATE_SUPPORT
 	      if (i)
 		{
 		  error (_("Invalid baud rate %d.  "
@@ -423,21 +469,29 @@ rate_to_code (int rate)
 		  error (_("Invalid baud rate %d.  Minimum value is %d."),
 			 rate, baudtab[0].rate);
 		}
+#else
+	      return -1;
+#endif
 	    }
 	}
     }
- 
+
+#if !HAVE_CUSTOM_BAUDRATE_SUPPORT
   /* The requested speed was too large.  */
   error (_("Invalid baud rate %d.  Maximum value is %d."),
 	 rate, baudtab[i - 1].rate);
+#else
+  return -1;
+#endif
 }
 
+/* Set baud rate using B_code from termios.h.  */
+
 static void
-hardwire_setbaudrate (struct serial *scb, int rate)
+set_baudcode_baudrate (struct serial *scb, int baud_code)
 {
   struct hardwire_ttystate state;
-  int baud_code = rate_to_code (rate);
+
-  
   if (get_tty_state (scb, &state))
     perror_with_name ("could not get tty state");
 
@@ -448,6 +502,101 @@ hardwire_setbaudrate (struct serial *scb, int rate)
     perror_with_name ("could not set tty state");
 }
 
+#if HAVE_CUSTOM_BAUDRATE_SUPPORT && defined(BOTHER)
+
+/* Set a custom baud rate using the termios BOTHER.  */
+
+static void
+set_custom_baudrate_linux (int fd, int rate)
+{
+#ifdef TCGETS2
+  struct termios2 tio;
+  const unsigned long req_get = TCGETS2;
+  const unsigned long req_set = TCSETS2;
+#else
+  struct termios tio;
+  const unsigned long req_get = TCGETS;
+  const unsigned long req_set = TCSETS;
+#endif
+
+  if (ioctl (fd, req_get, &tio) < 0)
+    {
+      perror_with_name ("Can not get current baud rate");
+    }
+
+  /* Clear the current output baud rate and fill a new value */
+  tio.c_cflag &= ~CBAUD;
+  tio.c_cflag |= BOTHER;
+  tio.c_ospeed = rate;
+
+  /* Clear the current input baud rate and fill a new value */
+  tio.c_cflag &= ~(CBAUD << IBSHIFT);
+  tio.c_cflag |= BOTHER << IBSHIFT;
+  tio.c_ispeed = rate;
+
+  if (ioctl (fd, req_set, &tio) < 0)
+    {
+      perror_with_name ("Can not set custom baud rate");
+    }
+}
+
+#elif HAVE_CUSTOM_BAUDRATE_SUPPORT && defined(IOSSIOSPEED)
+
+/* Set a custom baud rate using the IOSSIOSPEED ioctl call.  */
+
+static void
+set_custom_baudrate_darwin (int fd, int rate)
+{
+
+  if (ioctl (fd, IOSSIOSPEED, &rate) < 0)
+    {
+      error ("Can not set custom baud rate");
+    }
+}
+
+#endif /* HAVE_CUSTOM_BAUDRATE_SUPPORT
+	  && (defined(BOTHER) || defined(IOSSIOSPEED)) */
+
+#if HAVE_CUSTOM_BAUDRATE_SUPPORT
+
+/* Set a baud rate that differs from the OS B_codes.
+ * This is possible if one of the following macros is available:
+ * - BOTHER (Linux).
+ * - IOSSIOSPEED (Darwin).  */
+
+static void
+set_custom_baudrate (int fd, int rate)
+{
+#if defined(BOTHER)
+  set_custom_baudrate_linux (fd, rate);
+#elif defined(IOSSIOSPEED)
+  set_custom_baudrate_darwin (fd, rate);
+#endif
+}
+
+#endif /* HAVE_CUSTOM_BAUDRATE_SUPPORT */
+
+/* Set the baud rate for the serial communication.  */
+
+static void
+hardwire_setbaudrate (struct serial *scb, int rate)
+{
+  int baud_code = rate_to_code (rate);
+
+  if (baud_code < 0)
+    {
+#if HAVE_CUSTOM_BAUDRATE_SUPPORT
+      set_custom_baudrate (scb->fd, rate);
+#else
+      /* An error should already have been thrown by rate_to_code().
+       * Add an additional error in case execution somehow reaches this line.  */
+      perror_with_name ("Serial baud rate was not found in B_codes");
+#endif
+    }
+  else
+    set_baudcode_baudrate (scb, baud_code);
+}
+
 static int
 hardwire_setstopbits (struct serial *scb, int num)
 {