Index: lldb/trunk/include/lldb/API/SBDebugger.h
===================================================================
--- lldb/trunk/include/lldb/API/SBDebugger.h
+++ lldb/trunk/include/lldb/API/SBDebugger.h
@@ -78,6 +78,8 @@
   void SetOutputFileHandle(FILE *f, bool transfer_ownership);
 
   void SetErrorFileHandle(FILE *f, bool transfer_ownership);
+  
+  void Flush();
 
   FILE *GetInputFileHandle();
 
Index: lldb/trunk/include/lldb/Core/Debugger.h
===================================================================
--- lldb/trunk/include/lldb/Core/Debugger.h
+++ lldb/trunk/include/lldb/Core/Debugger.h
@@ -139,6 +139,8 @@
   void SetOutputFileHandle(FILE *fh, bool tranfer_ownership);
 
   void SetErrorFileHandle(FILE *fh, bool tranfer_ownership);
+                     
+  void Flush();
 
   void SaveInputTerminalState();
 
Index: lldb/trunk/include/lldb/Host/File.h
===================================================================
--- lldb/trunk/include/lldb/Host/File.h
+++ lldb/trunk/include/lldb/Host/File.h
@@ -62,6 +62,17 @@
         m_is_interactive(eLazyBoolCalculate),
         m_is_real_terminal(eLazyBoolCalculate) {}
 
+  File(File &&rhs);
+
+  File& operator= (File &&rhs);
+
+  void Swap(File &other);
+
+  File(void *cookie,
+       int (*readfn)(void *, char *, int),
+       int (*writefn)(void *, const char *, int),
+       int (*closefn)(void *));
+
   //------------------------------------------------------------------
   /// Constructor with path.
   ///
@@ -479,9 +490,6 @@
   LazyBool m_is_interactive;
   LazyBool m_is_real_terminal;
   LazyBool m_supports_colors;
-
-private:
-  DISALLOW_COPY_AND_ASSIGN(File);
 };
 
 } // namespace lldb_private
Index: lldb/trunk/scripts/interface/SBDebugger.i
===================================================================
--- lldb/trunk/scripts/interface/SBDebugger.i
+++ lldb/trunk/scripts/interface/SBDebugger.i
@@ -171,6 +171,9 @@
     void
     SetErrorFileHandle (FILE *f, bool transfer_ownership);
 
+    void
+    Flush ();
+
     FILE *
     GetInputFileHandle ();
 
Index: lldb/trunk/source/API/SBDebugger.cpp
===================================================================
--- lldb/trunk/source/API/SBDebugger.cpp
+++ lldb/trunk/source/API/SBDebugger.cpp
@@ -270,6 +270,18 @@
     m_opaque_sp->SetInputFileHandle(fh, transfer_ownership);
 }
 
+void SBDebugger::Flush() {
+  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
+  
+  if (log)
+    log->Printf(
+                "SBDebugger(%p)::Flush ()",
+                static_cast<void *>(m_opaque_sp.get()));
+
+  if (m_opaque_sp)
+    m_opaque_sp->Flush();
+}
+
 void SBDebugger::SetOutputFileHandle(FILE *fh, bool transfer_ownership) {
   Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
 
Index: lldb/trunk/source/Core/Debugger.cpp
===================================================================
--- lldb/trunk/source/Core/Debugger.cpp
+++ lldb/trunk/source/Core/Debugger.cpp
@@ -680,6 +680,15 @@
   if (!debugger_sp)
     return;
 
+  /*
+   * FILE* get flushed on process exit.  If those FILEs need to call into python
+   * to flush, we can't have them flushing after python is already torn down.
+   * That would result in a segfault.  We are still relying on the python script
+   * to tear down the debugger before it exits.
+   */
+  debugger_sp->m_output_file_sp->Flush();
+  debugger_sp->m_error_file_sp->Flush();
+
   debugger_sp->Clear();
 
   if (g_debugger_list_ptr && g_debugger_list_mutex_ptr) {
@@ -896,6 +905,11 @@
     err_file.SetStream(stderr, false);
 }
 
+void Debugger::Flush() {
+  m_output_file_sp->Flush();
+  m_error_file_sp->Flush();
+}
+
 void Debugger::SaveInputTerminalState() {
   if (m_input_file_sp) {
     File &in_file = m_input_file_sp->GetFile();
Index: lldb/trunk/source/Host/common/File.cpp
===================================================================
--- lldb/trunk/source/Host/common/File.cpp
+++ lldb/trunk/source/Host/common/File.cpp
@@ -14,6 +14,7 @@
 #include <limits.h>
 #include <stdarg.h>
 #include <stdio.h>
+#include <assert.h>
 
 #ifdef _WIN32
 #include "lldb/Host/windows/windows.h"
@@ -71,6 +72,129 @@
 int File::kInvalidDescriptor = -1;
 FILE *File::kInvalidStream = NULL;
 
+File::File(File &&rhs)
+  : IOObject(eFDTypeFile, false), m_descriptor(kInvalidDescriptor),
+  m_stream(kInvalidStream), m_options(), m_own_stream(false),
+  m_is_interactive(eLazyBoolCalculate),
+  m_is_real_terminal(eLazyBoolCalculate),
+  m_supports_colors(eLazyBoolCalculate)
+{
+  Swap(rhs);
+}
+
+File& File::operator= (File &&rhs)
+{
+  Close();
+  Swap(rhs);
+  return *this;
+}
+
+void File::Swap(File &rhs)
+{
+    std::swap(m_descriptor, rhs.m_descriptor);
+    std::swap(m_stream, rhs.m_stream);
+    std::swap(m_own_stream, rhs.m_own_stream);
+    std::swap(m_options, rhs.m_options);
+    std::swap(m_is_interactive, rhs.m_is_interactive);
+    std::swap(m_is_real_terminal, rhs.m_is_real_terminal);
+    std::swap(m_supports_colors, rhs.m_supports_colors);
+}
+
+#if defined(__linux__)
+
+struct context {
+  void *cookie;
+  int (*readfn)(void *, char *, int);
+  int (*writefn)(void *, const char *, int);
+  int (*closefn)(void *);
+};
+
+static ssize_t
+write_wrapper(void *c, const char *buf, size_t size)
+{
+  auto ctx = (struct context *)c;
+  if (size > INT_MAX) {
+    size = INT_MAX;
+  }
+  ssize_t wrote = ctx->writefn(ctx->cookie, buf, (int)size);
+  assert(wrote < 0 || (size_t)wrote <= size);
+  if (wrote < 0) {
+    return -1;
+  } else {
+    return (int)wrote;
+  }
+}
+
+static ssize_t
+read_wrapper(void *c, char *buf, size_t size)
+{
+  auto ctx = (struct context *)c;
+  if (size > INT_MAX) {
+    size = INT_MAX;
+  }
+  ssize_t read = ctx->writefn(ctx->cookie, buf, (int)size);
+  assert(read < 0 || (size_t)read <= size);
+  if (read < 0) {
+    return -1;
+  } else {
+    return (int)read;
+  }
+}
+
+static int
+close_wrapper(void *c)
+{
+  auto ctx = (struct context *)c;
+  int ret = ctx->closefn(ctx->cookie);
+  delete ctx;
+  return ret;
+}
+
+#endif
+
+File::File(void *cookie,
+           int (*readfn)(void *, char *, int),
+           int (*writefn)(void *, const char *, int),
+           int (*closefn)(void *))
+    : IOObject(eFDTypeFile, false), m_descriptor(kInvalidDescriptor),
+    m_stream(kInvalidStream), m_options(), m_own_stream(false),
+    m_is_interactive(eLazyBoolCalculate),
+    m_is_real_terminal(eLazyBoolCalculate),
+    m_supports_colors(eLazyBoolCalculate)
+{
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__)
+    m_stream = funopen(cookie, readfn, writefn, NULL, closefn);
+#elif defined(__linux__)
+    cookie_io_functions_t io_funcs = {};
+    io_funcs.read = read_wrapper;
+    io_funcs.write = write_wrapper;
+    io_funcs.close = close_wrapper;
+    const char *mode = NULL;
+    if (readfn && writefn) {
+      mode = "r+";
+    } else if (readfn) {
+      mode = "r";
+    } else if (writefn) {
+      mode = "w";
+    }
+    if (mode) {
+      struct context *ctx = new context;
+      ctx->readfn = readfn;
+      ctx->writefn = writefn;
+      ctx->closefn = closefn;
+      ctx->cookie = cookie;
+      m_stream = fopencookie(ctx, mode, io_funcs);
+      if (!m_stream) {
+        delete ctx;
+      }
+    }
+#endif
+    if (m_stream) {
+        m_own_stream = true;
+    }
+}
+
+
 File::File(const char *path, uint32_t options, uint32_t permissions)
     : IOObject(eFDTypeFile, false), m_descriptor(kInvalidDescriptor),
       m_stream(kInvalidStream), m_options(), m_own_stream(false),
Index: lldb/trunk/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp
===================================================================
--- lldb/trunk/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp
+++ lldb/trunk/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp
@@ -17,6 +17,7 @@
 #include "PythonDataObjects.h"
 #include "ScriptInterpreterPython.h"
 
+#include "lldb/Utility/Log.h"
 #include "lldb/Host/File.h"
 #include "lldb/Host/FileSystem.h"
 #include "lldb/Interpreter/ScriptInterpreter.h"
@@ -959,8 +960,11 @@
 
 bool PythonFile::Check(PyObject *py_obj) {
 #if PY_MAJOR_VERSION < 3
-  return PyFile_Check(py_obj);
-#else
+  bool is_ordinary_file = PyFile_Check(py_obj);
+  if (is_ordinary_file) {
+    return true;
+  }
+#endif
   // In Python 3, there is no `PyFile_Check`, and in fact PyFile is not even a
   // first-class object type anymore.  `PyFile_FromFd` is just a thin wrapper
   // over `io.open()`, which returns some object derived from `io.IOBase`.
@@ -981,7 +985,6 @@
     return false;
 
   return true;
-#endif
 }
 
 void PythonFile::Reset(PyRefType type, PyObject *py_obj) {
@@ -989,7 +992,7 @@
   // `py_obj` it still gets decremented if necessary.
   PythonObject result(type, py_obj);
 
-  if (!PythonFile::Check(py_obj)) {
+  if (py_obj == NULL || !PythonFile::Check(py_obj)) {
     PythonObject::Reset();
     return;
   }
@@ -1034,17 +1037,131 @@
       .Default(0);
 }
 
+static void
+log_exception(const char *fmt, PyObject *obj)
+{
+  Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_SCRIPT);
+  if (!log) {
+    return;
+  }
+  const char *classname = "unknown class";
+  PyObject *pyclass = PyObject_Type(obj);
+  if (pyclass) {
+    PyObject *s = PyObject_GetAttrString(pyclass, "__name__");
+    if (s) {
+      classname = PyString_AsString(s);
+      Py_XDECREF(s);
+    }
+    Py_XDECREF(pyclass);
+  }
+  const char *error = "unknown error";
+  PyObject *exception, *v, *tb;
+  PyErr_Fetch(&exception, &v, &tb);
+  if (exception) {
+    PyErr_NormalizeException(&exception, &v, &tb);
+  }
+  PyObject *string = NULL;
+  if (v) {
+    string = PyObject_Str(v);
+  }
+  error = PyString_AsString(string);
+  log->Printf(fmt, classname, error);
+  Py_XDECREF(exception);
+  Py_XDECREF(v);
+  Py_XDECREF(tb);
+  Py_XDECREF(string);
+}
+
+static int readfn(void *ctx, char *buffer, int n)
+{
+  auto state = PyGILState_Ensure();
+  auto *file = (PyObject *) ctx;
+  int result = -1;
+  auto pybuffer = PyBuffer_FromMemory(buffer, n);
+  PyObject *pyresult = NULL;
+  if (!pybuffer) {
+    goto fail;
+  }
+  pyresult = PyEval_CallMethod(file, "read", "(i)", n);
+  if (pyresult == NULL || !PyInt_Check(pyresult)) {
+    log_exception("read from python %s failed: %s", file);
+    goto fail;
+  }
+  result =  _PyInt_AsInt(pyresult);
+fail:
+  Py_XDECREF(pybuffer);
+  Py_XDECREF(pyresult);
+  PyGILState_Release(state);
+  return result;
+}
+
+static int writefn(void *ctx, const char *buffer, int n)
+{
+  auto state = PyGILState_Ensure();
+  auto *file = (PyObject *) ctx;
+  int result = -1;
+  auto pyresult = PyEval_CallMethod(file, "write", "(s#)", buffer, n);
+  if (pyresult == NULL || !PyInt_Check(pyresult)) {
+    log_exception("write to python %s failed: %s", file);
+    goto fail;
+  }
+  result =  _PyInt_AsInt(pyresult);
+fail:
+  Py_XDECREF(pyresult);
+  PyGILState_Release(state);
+  return result;
+}
+
+
+static int closefn(void *ctx) {
+  auto *file = (PyObject *) ctx;
+  auto state = PyGILState_Ensure();
+  Py_XDECREF(file);
+  PyGILState_Release(state);
+  return 0;
+}
+
+
 bool PythonFile::GetUnderlyingFile(File &file) const {
   if (!IsValid())
     return false;
-
+  
   file.Close();
-  // We don't own the file descriptor returned by this function, make sure the
-  // File object knows about that.
-  file.SetDescriptor(PyObject_AsFileDescriptor(m_py_obj), false);
-  PythonString py_mode = GetAttributeValue("mode").AsType<PythonString>();
-  file.SetOptions(PythonFile::GetOptionsFromMode(py_mode.GetString()));
-  return file.IsValid();
+  
+  int fd = PyObject_AsFileDescriptor(m_py_obj);
+  if (fd >= 0) {
+    // We don't own the file descriptor returned by this function, make sure the
+    // File object knows about that.
+    file.SetDescriptor(PyObject_AsFileDescriptor(m_py_obj), false);
+    PythonString py_mode = GetAttributeValue("mode").AsType<PythonString>();
+    file.SetOptions(PythonFile::GetOptionsFromMode(py_mode.GetString()));
+    return file.IsValid();
+  }
+  
+  PythonObject io_module(PyRefType::Owned, PyImport_ImportModule("io"));
+  PythonDictionary io_dict(PyRefType::Borrowed,
+                           PyModule_GetDict(io_module.get()));
+  PythonObject io_base_class = io_dict.GetItemForKey(PythonString("IOBase"));
+  
+  PythonObject object_type(PyRefType::Owned, PyObject_Type(m_py_obj));
+  
+  if (1 != PyObject_IsSubclass(object_type.get(), io_base_class.get()))
+    return false;
+  
+  PyObject *r = PyEval_CallMethod(m_py_obj, "readable", "()");
+  bool readable = PyObject_IsTrue(r);
+
+  r = PyEval_CallMethod(m_py_obj, "writable", "()");
+  bool writable = PyObject_IsTrue(r);
+
+  Py_XINCREF(m_py_obj);
+  file = File(m_py_obj, readable ? readfn : NULL, writable ? writefn : NULL, closefn);
+  if (!file.IsValid()) {
+    closefn(m_py_obj);
+    return false;
+  } else {
+    return true;
+  }
 }
 
 #endif
Index: lldb/trunk/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h
===================================================================
--- lldb/trunk/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h
+++ lldb/trunk/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h
@@ -541,12 +541,12 @@
 
   bool GetEmbeddedInterpreterModuleObjects();
 
-  bool SetStdHandle(File &file, const char *py_name, PythonFile &save_file,
+  bool SetStdHandle(File &file, const char *py_name, PythonObject &save_file,
                     const char *mode);
 
-  PythonFile m_saved_stdin;
-  PythonFile m_saved_stdout;
-  PythonFile m_saved_stderr;
+  PythonObject m_saved_stdin;
+  PythonObject m_saved_stdout;
+  PythonObject m_saved_stderr;
   PythonObject m_main_module;
   PythonObject m_lldb_module;
   PythonDictionary m_session_dict;
Index: lldb/trunk/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
===================================================================
--- lldb/trunk/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
+++ lldb/trunk/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
@@ -504,7 +504,7 @@
 }
 
 bool ScriptInterpreterPython::SetStdHandle(File &file, const char *py_name,
-                                           PythonFile &save_file,
+                                           PythonObject &save_file,
                                            const char *mode) {
   if (file.IsValid()) {
     // Flush the file before giving it to python to avoid interleaved output.
@@ -512,8 +512,7 @@
 
     PythonDictionary &sys_module_dict = GetSysModuleDictionary();
 
-    save_file = sys_module_dict.GetItemForKey(PythonString(py_name))
-                    .AsType<PythonFile>();
+    save_file = sys_module_dict.GetItemForKey(PythonString(py_name));
 
     PythonFile new_file(file, mode);
     sys_module_dict.SetItemForKey(PythonString(py_name), new_file);