From c8a677e3d979c6412772a499cfeae83a7dceeb1c Mon Sep 17 00:00:00 2001
From: Martin Lund <martin.lund@keep-it-simple.com>
Date: Sat, 28 May 2016 08:52:12 +0200
Subject: [PATCH] Generate baudrate switch cases based on detection

Support a single source of baud rate configuration as discussed in
https://github.com/tio/tio/issues/45 .

To do so, autogeneration of the switch cases which do the baud rate
option value check and configuration/conversion in tty_configure() is
introduced via a single macro.

Just to be safe, this change also enables configure detection of all
baud rates, including the ones previously assumed supported by most/all
systems (POSIX).
---
 configure.ac | 14 +++++-----
 src/tty.c    | 78 ++++++++++------------------------------------------
 2 files changed, 22 insertions(+), 70 deletions(-)

diff --git a/configure.ac b/configure.ac
index 1df5908..e674b0f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -30,14 +30,11 @@ AM_CONDITIONAL([ENABLE_BASH_COMPLETION],[test "x$with_bash_completion_dir" != "x
 AC_DEFUN(
     [TIO_CHECK_BAUDRATE],
     [
-        tio_have_decl=0
-        AS_IF([test $1 -le 38400],
-            # Baud rates up to 38400 are defined by POSIX,
-            # so we don't have to check for them.
-            [tio_have_decl=1],
-            [AC_CHECK_DECLS([B$1], [tio_have_decl=1], [], [[#include <termios.h>]])]
+        AC_CHECK_DECL([B$1], [tio_have_decl=1], [tio_have_decl=0], [[#include <termios.h>]])
+        AS_IF([test $tio_have_decl = 1], [
+            AC_SUBST([BAUDRATES], ["$BAUDRATES $1"])
+            AC_SUBST([BAUDRATE_CASES], ["$BAUDRATE_CASES case $1: baudrate = B$1; break;"])]
         )
-        AS_IF([test $tio_have_decl = 1], [AC_SUBST([BAUDRATES], ["$BAUDRATES $1"])])
     ]
 )
 
@@ -49,6 +46,7 @@ AC_DEFUN(
 
 # Check for available terminal I/O speeds
 BAUDRATES=
+BAUDRATE_CASES=
 TIO_CHECK_BAUDRATES(
     0,
     50,
@@ -83,6 +81,8 @@ TIO_CHECK_BAUDRATES(
     4000000
 )
 
+AC_DEFINE_UNQUOTED([AUTOCONF_BAUDRATE_CASES],[$BAUDRATE_CASES],[Switch cases for detected baud rates])
+
 AC_CONFIG_FILES([Makefile])
 AC_CONFIG_FILES([src/Makefile])
 AC_CONFIG_FILES([src/bash-completion/tio])
diff --git a/src/tty.c b/src/tty.c
index f70121a..f60d8da 100644
--- a/src/tty.c
+++ b/src/tty.c
@@ -163,70 +163,22 @@ void tty_configure(void)
     /* Set speed */
     switch (option.baudrate)
     {
-        case 0: baudrate = B0; break;
-        case 50: baudrate = B50; break;
-        case 75: baudrate = B75; break;
-        case 110: baudrate = B110; break;
-        case 134: baudrate = B134; break;
-        case 150: baudrate = B150; break;
-        case 200: baudrate = B200; break;
-        case 300: baudrate = B300; break;
-        case 600: baudrate = B600; break;
-        case 1200: baudrate = B1200; break;
-        case 1800: baudrate = B1800; break;
-        case 2400: baudrate = B2400; break;
-        case 4800: baudrate = B4800; break;
-        case 9600: baudrate = B9600; break;
-        case 19200: baudrate = B19200; break;
-        case 38400: baudrate = B38400; break;
-#if HAVE_DECL_B57600
-        case 57600: baudrate = B57600; break;
-#endif
-#if HAVE_DECL_B115200
-        case 115200: baudrate = B115200; break;
-#endif
-#if HAVE_DECL_B230400
-        case 230400: baudrate = B230400; break;
-#endif
-#if HAVE_DECL_B460800
-        case 460800: baudrate = B460800; break;
-#endif
-#if HAVE_DECL_B500000
-        case 500000: baudrate = B500000; break;
-#endif
-#if HAVE_DECL_B576000
-        case 576000: baudrate = B576000; break;
-#endif
-#if HAVE_DECL_B921600
-        case 921600: baudrate = B921600; break;
-#endif
-#if HAVE_DECL_B1000000
-        case 1000000: baudrate = B1000000; break;
-#endif
-#if HAVE_DECL_B1152000
-        case 1152000: baudrate = B1152000; break;
-#endif
-#if HAVE_DECL_B1500000
-        case 1500000: baudrate = B1500000; break;
-#endif
-#if HAVE_DECL_B2000000
-        case 2000000: baudrate = B2000000; break;
-#endif
-#if HAVE_DECL_B2500000
-        case 2500000: baudrate = B2500000; break;
-#endif
-#if HAVE_DECL_B3000000
-        case 3000000: baudrate = B3000000; break;
-#endif
-#if HAVE_DECL_B3500000
-        case 3500000: baudrate = B3500000; break;
-#endif
-#if HAVE_DECL_B4000000
-        case 4000000: baudrate = B4000000; break;
-#endif
+        /* The macro below expands into switch cases autogenerated by the
+         * configure script. Each switch case verifies and configures the baud
+         * rate and is of the form:
+         *
+         * case $baudrate: baudrate = B$baudrate; break;
+         *
+         * Only switch cases for baud rates detected supported by the host
+         * system are inserted.
+         *
+         * To see which baud rates are being probed see configure.ac
+         */
+        AUTOCONF_BAUDRATE_CASES
+
         default:
-                      error_printf("Invalid baud rate");
-                      exit(EXIT_FAILURE);
+            error_printf("Invalid baud rate");
+            exit(EXIT_FAILURE);
     }
 
     cfsetispeed(&tio, baudrate);