Fixed the python interpreter so that it correctly inherits the top IOHandler's files instead of always using stdin/out/err.

Removed lldb_private::File::Duplicate() and the copy constructor and the assignment operator that used to duplicate the file handles and made them private so no one uses them. Previously the lldb_private::File::Duplicate() function duplicated files that used file descriptors, (int) but not file streams (FILE *), so the lldb_private::File::Duplicate() function only worked some of the time. No one else excep thee ScriptInterpreterPython was using these functions, so that aren't needed nor desired. Previously every time you would drop into the python interpreter we would duplicate files, and now we avoid this file churn.

<rdar://problem/24877720>

llvm-svn: 263161

2 files changed, 38 insertions, 37 deletions

diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
index 99e1d099788..4ca7cd01177 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
@@ -547,6 +547,27 @@ ScriptInterpreterPython::LeaveSession ()
 }
 
 bool
+ScriptInterpreterPython::SetStdHandle(File &file, const char *py_name, PythonFile &save_file, const char *mode)
+{
+    if (file.IsValid())
+    {
+        // Flush the file before giving it to python to avoid interleaved output.
+        file.Flush();
+
+        PythonDictionary &sys_module_dict = GetSysModuleDictionary();
+
+        save_file = sys_module_dict.GetItemForKey(PythonString(py_name)).AsType<PythonFile>();
+
+        PythonFile new_file(file, mode);
+        sys_module_dict.SetItemForKey(PythonString(py_name), new_file);
+        return true;
+    }
+    else
+        save_file.Reset();
+    return false;
+}
+
+bool
 ScriptInterpreterPython::EnterSession (uint16_t on_entry_flags,
                                        FILE *in,
                                        FILE *out,
@@ -604,54 +625,31 @@ ScriptInterpreterPython::EnterSession (uint16_t on_entry_flags,
         if (!in_file.IsValid() || !out_file.IsValid() || !err_file.IsValid())
             m_interpreter.GetDebugger().AdoptTopIOHandlerFilesIfInvalid (in_sp, out_sp, err_sp);
 
-        m_saved_stdin.Reset();
 
-        if ((on_entry_flags & Locker::NoSTDIN) == 0)
+        if (on_entry_flags & Locker::NoSTDIN)
+        {
+            m_saved_stdin.Reset();
+        }
+        else
         {
-            // STDIN is enabled
-            if (!in_file.IsValid() && in_sp)
-                in_file = in_sp->GetFile();
-            if (in_file.IsValid())
+            if (!SetStdHandle(in_file, "stdin", m_saved_stdin, "r"))
             {
-                // Flush the file before giving it to python to avoid interleaved output.
-                in_file.Flush();
-
-                m_saved_stdin = sys_module_dict.GetItemForKey(PythonString("stdin")).AsType<PythonFile>();
-                // This call can deadlock your process if the file is locked
-                PythonFile new_file(in_file, "r");
-                sys_module_dict.SetItemForKey (PythonString("stdin"), new_file);
+                if (in_sp)
+                    SetStdHandle(in_sp->GetFile(), "stdin", m_saved_stdin, "r");
             }
         }
 
-        if (!out_file.IsValid() && out_sp)
-            out_file = out_sp->GetFile();
-        if (out_file.IsValid())
+        if (!SetStdHandle(out_file, "stdout", m_saved_stdout, "w"))
         {
-            // Flush the file before giving it to python to avoid interleaved output.
-            out_file.Flush();
-
-            m_saved_stdout = sys_module_dict.GetItemForKey(PythonString("stdout")).AsType<PythonFile>();
-
-            PythonFile new_file(out_file, "w");
-            sys_module_dict.SetItemForKey (PythonString("stdout"), new_file);
+            if (out_sp)
+                SetStdHandle(out_sp->GetFile(), "stdout", m_saved_stdout, "w");
         }
-        else
-            m_saved_stdout.Reset();
 
-        if (!err_file.IsValid() && err_sp)
-            err_file = err_sp->GetFile();
-        if (err_file.IsValid())
+        if (!SetStdHandle(err_file, "stderr", m_saved_stderr, "w"))
         {
-            // Flush the file before giving it to python to avoid interleaved output.
-            err_file.Flush();
-
-            m_saved_stderr = sys_module_dict.GetItemForKey(PythonString("stderr")).AsType<PythonFile>();
-
-            PythonFile new_file(err_file, "w");
-            sys_module_dict.SetItemForKey (PythonString("stderr"), new_file);
+            if (err_sp)
+                SetStdHandle(err_sp->GetFile(), "stderr", m_saved_stderr, "w");
         }
-        else
-            m_saved_stderr.Reset();
     }
 
     if (PyErr_Occurred())
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h
index 4c6eb394989..83702a02554 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h
@@ -581,6 +581,9 @@ protected:
     bool
     GetEmbeddedInterpreterModuleObjects ();
 
+    bool
+    SetStdHandle(File &file, const char *py_name, PythonFile &save_file, const char *mode);
+
     PythonFile m_saved_stdin;
     PythonFile m_saved_stdout;
     PythonFile m_saved_stderr;