Merge lp:~dave-cheney/goetveld/003-fix-syscall-constants-for-gccgo into lp:goetveld

[Dave Cheney]

Define local syscall constants so gccgo+ppc works

The gccgo syscall package is missing two constants that goetveld needs.

After discussion with niemeyer on IRC we decided to define
them locally and be done with it.

[Dave Cheney (dave-cheney)]

Please take a look.

[Gustavo Niemeyer (niemeyer)]

*** Submitted:

Define local syscall constants so gccgo+ppc works

The gccgo syscall package is missing two constants that goetveld needs.

After discussion with niemeyer on IRC we decided to define
them locally and be done with it.

=== modified file 'terminal_linux.go'
--- terminal_linux.go	2012-09-25 02:04:48 +0000
+++ terminal_linux.go	2014-03-26 23:38:13 +0000
@@ -12,23 +12,31 @@
 
 // This was copied from package exp/terminal
 
+// The gccgo version of the syscall package lacks these constants.
+// Declare them here to work around gccgo.
+// TODO(dfc) revert this if/when the gccgo syscall package is fixed.
+const (
+	ioctlTCGETS = 0x5401 // syscall.TCGETS
+	ioctlTCSETS = 0x5402 // syscall.TCSETS
+)
+
 // readPassword reads a line of input from a terminal without local echo.  This
 // is commonly used for inputting passwords and other sensitive data. The slice
 // returned does not include the \n.
 func readPassword(fd uintptr) ([]byte, error) {
 	var oldState syscall.Termios
-	if _, _, e := syscall.Syscall6(syscall.SYS_IOCTL, fd, uintptr(syscall.TCGETS), uintptr(unsafe.Pointer(&oldState)), 0, 0, 0); e != 0 {
+	if _, _, e := syscall.Syscall6(syscall.SYS_IOCTL, fd, ioctlTCGETS, uintptr(unsafe.Pointer(&oldState)), 0, 0, 0); e != 0 {
 		return nil, syscall.Errno(e)
 	}
 
 	newState := oldState
 	newState.Lflag &^= syscall.ECHO
-	if _, _, e := syscall.Syscall6(syscall.SYS_IOCTL, fd, uintptr(syscall.TCSETS), uintptr(unsafe.Pointer(&newState)), 0, 0, 0); e != 0 {
+	if _, _, e := syscall.Syscall6(syscall.SYS_IOCTL, fd, ioctlTCSETS, uintptr(unsafe.Pointer(&newState)), 0, 0, 0); e != 0 {
 		return nil, syscall.Errno(e)
 	}
 
 	defer func() {
-		syscall.Syscall6(syscall.SYS_IOCTL, fd, uintptr(syscall.TCSETS), uintptr(unsafe.Pointer(&oldState)), 0, 0, 0)
+		syscall.Syscall6(syscall.SYS_IOCTL, fd, ioctlTCSETS, uintptr(unsafe.Pointer(&oldState)), 0, 0, 0)
 	}()
 
 	var buf [16]byte