1 files changed, 203 insertions, 0 deletions
diff --git a/lldb/source/Core/TTYState.cpp b/lldb/source/Core/TTYState.cpp
new file mode 100644
index 00000000000..6ba415832d4
--- /dev/null
+++ b/lldb/source/Core/TTYState.cpp
@@ -0,0 +1,203 @@
+//===-- TTYState.cpp --------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Core/TTYState.h"
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/signal.h>
+
+using namespace lldb_private;
+
+//----------------------------------------------------------------------
+// Default constructor
+//----------------------------------------------------------------------
+TTYState::TTYState() :
+    m_fd(-1),
+    m_tflags(-1),
+    m_ttystate_err(-1),
+    m_ttystate(),
+    m_process_group(-1)
+{
+}
+
+//----------------------------------------------------------------------
+// Destructor
+//----------------------------------------------------------------------
+TTYState::~TTYState()
+{
+}
+
+//----------------------------------------------------------------------
+// Save the current state of the TTY for the file descriptor "fd"
+// and if "save_process_group" is true, attempt to save the process
+// group info for the TTY.
+//----------------------------------------------------------------------
+bool
+TTYState::Save (int fd, bool save_process_group)
+{
+    if (fd >= 0 && ::isatty (fd))
+    {
+        m_fd = fd;
+        m_tflags = ::fcntl (fd, F_GETFL, 0);
+        m_ttystate_err = ::tcgetattr (fd, &m_ttystate);
+        if (save_process_group)
+            m_process_group = ::tcgetpgrp (0);
+        else
+            m_process_group = -1;
+    }
+    else
+    {
+        m_fd = -1;
+        m_tflags = -1;
+        m_ttystate_err = -1;
+        m_process_group = -1;
+    }
+    return m_ttystate_err == 0;
+}
+
+//----------------------------------------------------------------------
+// Restore the state of the TTY using the cached values from a
+// previous call to Save().
+//----------------------------------------------------------------------
+bool
+TTYState::Restore () const
+{
+    int result = 0;
+    if (IsValid())
+    {
+        if (TFlagsIsValid())
+            result = fcntl (m_fd, F_SETFL, m_tflags);
+
+        if (TTYStateIsValid())
+            result = tcsetattr (m_fd, TCSANOW, &m_ttystate);
+
+        if (ProcessGroupIsValid())
+        {
+            // Save the original signal handler.
+            void (*saved_sigttou_callback) (int) = NULL;
+            saved_sigttou_callback = (void (*)(int)) signal (SIGTTOU, SIG_IGN);
+            // Set the process group
+            result = tcsetpgrp (m_fd, m_process_group);
+            // Restore the original signal handler.
+            signal (SIGTTOU, saved_sigttou_callback);
+        }
+        return true;
+    }
+    return false;
+}
+
+
+
+
+//----------------------------------------------------------------------
+// Returns true if this object has valid saved TTY state settings
+// that can be used to restore a previous state.
+//----------------------------------------------------------------------
+bool
+TTYState::IsValid() const
+{
+    return (m_fd >= 0) && (TFlagsIsValid() || TTYStateIsValid());
+}
+
+//----------------------------------------------------------------------
+// Returns true if m_tflags is valid
+//----------------------------------------------------------------------
+bool
+TTYState::TFlagsIsValid() const
+{
+    return m_tflags != -1;
+}
+
+//----------------------------------------------------------------------
+// Returns true if m_ttystate is valid
+//----------------------------------------------------------------------
+bool
+TTYState::TTYStateIsValid() const
+{
+    return m_ttystate_err == 0;
+}
+
+//----------------------------------------------------------------------
+// Returns true if m_process_group is valid
+//----------------------------------------------------------------------
+bool
+TTYState::ProcessGroupIsValid() const
+{
+    return m_process_group != -1;
+}
+
+//------------------------------------------------------------------
+// Constructor
+//------------------------------------------------------------------
+TTYStateSwitcher::TTYStateSwitcher () :
+    m_currentState(UINT32_MAX)
+{
+}
+
+//------------------------------------------------------------------
+// Destructor
+//------------------------------------------------------------------
+TTYStateSwitcher::~TTYStateSwitcher ()
+{
+}
+
+//------------------------------------------------------------------
+// Returns the number of states that this switcher contains
+//------------------------------------------------------------------
+uint32_t
+TTYStateSwitcher::GetNumberOfStates() const
+{
+    return sizeof(m_ttystates)/sizeof(TTYState);
+}
+
+//------------------------------------------------------------------
+// Restore the state at index "idx".
+//
+// Returns true if the restore was successful, false otherwise.
+//------------------------------------------------------------------
+bool
+TTYStateSwitcher::Restore (uint32_t idx) const
+{
+    const uint32_t num_states = GetNumberOfStates();
+    if (idx >= num_states)
+        return false;
+
+    // See if we already are in this state?
+    if (m_currentState < num_states && (idx == m_currentState) && m_ttystates[idx].IsValid())
+        return true;
+
+    // Set the state to match the index passed in and only update the
+    // current state if there are no errors.
+    if (m_ttystates[idx].Restore())
+    {
+        m_currentState = idx;
+        return true;
+    }
+
+    // We failed to set the state. The tty state was invalid or not
+    // initialized.
+    return false;
+}
+
+//------------------------------------------------------------------
+// Save the state at index "idx" for file descriptor "fd" and
+// save the process group if requested.
+//
+// Returns true if the restore was successful, false otherwise.
+//------------------------------------------------------------------
+bool
+TTYStateSwitcher::Save (uint32_t idx, int fd, bool save_process_group)
+{
+    const uint32_t num_states = GetNumberOfStates();
+    if (idx < num_states)
+        return m_ttystates[idx].Save(fd, save_process_group);
+    return false;
+}
+
+