vendor/llvm-project/llvmorg-10-init-17466-ge26a78e7085

8 files changed, 365 insertions, 147 deletions

diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp
index 70d93424fdec..e5a67653e334 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp
@@ -6,11 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifdef LLDB_DISABLE_PYTHON
+#include "lldb/Host/Config.h"
 
-// Python is disabled in this build
-
-#else
+#if LLDB_ENABLE_PYTHON
 
 #include "PythonDataObjects.h"
 #include "ScriptInterpreterPython.h"
@@ -802,29 +800,11 @@ bool PythonCallable::Check(PyObject *py_obj) {
   return PyCallable_Check(py_obj);
 }
 
-PythonCallable::ArgInfo PythonCallable::GetNumInitArguments() const {
-  auto arginfo = GetInitArgInfo();
-  if (!arginfo) {
-    llvm::consumeError(arginfo.takeError());
-    return ArgInfo{};
-  }
-  return arginfo.get();
-}
-
-Expected<PythonCallable::ArgInfo> PythonCallable::GetInitArgInfo() const {
-  if (!IsValid())
-    return nullDeref();
-  auto init = As<PythonCallable>(GetAttribute("__init__"));
-  if (!init)
-    return init.takeError();
-  return init.get().GetArgInfo();
-}
-
 #if PY_MAJOR_VERSION >= 3 && PY_MINOR_VERSION >= 3
 static const char get_arg_info_script[] = R"(
 from inspect import signature, Parameter, ismethod
 from collections import namedtuple
-ArgInfo = namedtuple('ArgInfo', ['count', 'has_varargs', 'is_bound_method'])
+ArgInfo = namedtuple('ArgInfo', ['count', 'has_varargs'])
 def main(f):
     count = 0
     varargs = False
@@ -840,7 +820,7 @@ def main(f):
             pass
         else:
             raise Exception(f'unknown parameter kind: {kind}')
-    return ArgInfo(count, varargs, ismethod(f))
+    return ArgInfo(count, varargs)
 )";
 #endif
 
@@ -856,21 +836,27 @@ Expected<PythonCallable::ArgInfo> PythonCallable::GetArgInfo() const {
   Expected<PythonObject> pyarginfo = get_arg_info(*this);
   if (!pyarginfo)
     return pyarginfo.takeError();
-  result.count = cantFail(As<long long>(pyarginfo.get().GetAttribute("count")));
-  result.has_varargs =
+  long long count =
+      cantFail(As<long long>(pyarginfo.get().GetAttribute("count")));
+  bool has_varargs =
       cantFail(As<bool>(pyarginfo.get().GetAttribute("has_varargs")));
-  bool is_method =
-      cantFail(As<bool>(pyarginfo.get().GetAttribute("is_bound_method")));
-  result.max_positional_args =
-      result.has_varargs ? ArgInfo::UNBOUNDED : result.count;
-
-  // FIXME emulate old broken behavior
-  if (is_method)
-    result.count++;
+  result.max_positional_args = has_varargs ? ArgInfo::UNBOUNDED : count;
 
 #else
+  PyObject *py_func_obj;
   bool is_bound_method = false;
-  PyObject *py_func_obj = m_py_obj;
+  bool is_class = false;
+
+  if (PyType_Check(m_py_obj) || PyClass_Check(m_py_obj)) {
+    auto init = GetAttribute("__init__");
+    if (!init)
+      return init.takeError();
+    py_func_obj = init.get().get();
+    is_class = true;
+  } else {
+    py_func_obj = m_py_obj;
+  }
+
   if (PyMethod_Check(py_func_obj)) {
     py_func_obj = PyMethod_GET_FUNCTION(py_func_obj);
     PythonObject im_self = GetAttributeValue("im_self");
@@ -899,11 +885,11 @@ Expected<PythonCallable::ArgInfo> PythonCallable::GetArgInfo() const {
   if (!code)
     return result;
 
-  result.count = code->co_argcount;
-  result.has_varargs = !!(code->co_flags & CO_VARARGS);
-  result.max_positional_args = result.has_varargs
-                                   ? ArgInfo::UNBOUNDED
-                                   : (result.count - (int)is_bound_method);
+  auto count = code->co_argcount;
+  bool has_varargs = !!(code->co_flags & CO_VARARGS);
+  result.max_positional_args =
+      has_varargs ? ArgInfo::UNBOUNDED
+                  : (count - (int)is_bound_method) - (int)is_class;
 
 #endif
 
@@ -913,15 +899,6 @@ Expected<PythonCallable::ArgInfo> PythonCallable::GetArgInfo() const {
 constexpr unsigned
     PythonCallable::ArgInfo::UNBOUNDED; // FIXME delete after c++17
 
-PythonCallable::ArgInfo PythonCallable::GetNumArguments() const {
-  auto arginfo = GetArgInfo();
-  if (!arginfo) {
-    llvm::consumeError(arginfo.takeError());
-    return ArgInfo{};
-  }
-  return arginfo.get();
-}
-
 PythonObject PythonCallable::operator()() {
   return PythonObject(PyRefType::Owned, PyObject_CallObject(m_py_obj, nullptr));
 }
@@ -1385,11 +1362,13 @@ llvm::Expected<FileSP> PythonFile::ConvertToFile(bool borrowed) {
   if (!options)
     return options.takeError();
 
-  // LLDB and python will not share I/O buffers.  We should probably
-  // flush the python buffers now.
-  auto r = CallMethod("flush");
-  if (!r)
-    return r.takeError();
+  if (options.get() & File::eOpenOptionWrite) {
+    // LLDB and python will not share I/O buffers.  We should probably
+    // flush the python buffers now.
+    auto r = CallMethod("flush");
+    if (!r)
+      return r.takeError();
+  }
 
   FileSP file_sp;
   if (borrowed) {
@@ -1498,14 +1477,23 @@ Expected<PythonFile> PythonFile::FromFile(File &file, const char *mode) {
   PyObject *file_obj;
 #if PY_MAJOR_VERSION >= 3
   file_obj = PyFile_FromFd(file.GetDescriptor(), nullptr, mode, -1, nullptr,
-                           "ignore", nullptr, 0);
+                           "ignore", nullptr, /*closefd=*/0);
 #else
-  // Read through the Python source, doesn't seem to modify these strings
-  char *cmode = const_cast<char *>(mode);
-  // We pass ::flush instead of ::fclose here so we borrow the FILE* --
-  // the lldb_private::File still owns it.
-  file_obj =
-      PyFile_FromFile(file.GetStream(), const_cast<char *>(""), cmode, ::fflush);
+  // I'd like to pass ::fflush here if the file is writable,  so that
+  // when the python side destructs the file object it will be flushed.
+  // However, this would be dangerous.    It can cause fflush to be called
+  // after fclose if the python program keeps a reference to the file after
+  // the original lldb_private::File has been destructed.
+  //
+  // It's all well and good to ask a python program not to use a closed file
+  // but asking a python program to make sure objects get released in a
+  // particular order is not safe.
+  //
+  // The tradeoff here is that if a python 2 program wants to make sure this
+  // file gets flushed, they'll have to do it explicitly or wait untill the
+  // original lldb File itself gets flushed.
+  file_obj = PyFile_FromFile(file.GetStream(), py2_const_cast(""),
+                             py2_const_cast(mode), [](FILE *) { return 0; });
 #endif
 
   if (!file_obj)
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h
index 373d3212697d..b75045b239a8 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.h
@@ -48,7 +48,9 @@
 #ifndef LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_PYTHONDATAOBJECTS_H
 #define LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_PYTHONDATAOBJECTS_H
 
-#ifndef LLDB_DISABLE_PYTHON
+#include "lldb/Host/Config.h"
+
+#if LLDB_ENABLE_PYTHON
 
 // LLDB Python header must be included first
 #include "lldb-python.h"
@@ -130,7 +132,7 @@ template <typename T> T Take(PyObject *obj) {
   assert(!PyErr_Occurred());
   T thing(PyRefType::Owned, obj);
   assert(thing.IsValid());
-  return std::move(thing);
+  return thing;
 }
 
 // Retain a reference you have borrowed, and turn it into
@@ -148,7 +150,7 @@ template <typename T> T Retain(PyObject *obj) {
   assert(!PyErr_Occurred());
   T thing(PyRefType::Borrowed, obj);
   assert(thing.IsValid());
-  return std::move(thing);
+  return thing;
 }
 
 // This class can be used like a utility function to convert from
@@ -189,6 +191,14 @@ inline llvm::Error keyError() {
                                  "key not in dict");
 }
 
+#if PY_MAJOR_VERSION < 3
+// The python 2 API declares some arguments as char* that should
+// be const char *, but it doesn't actually modify them.
+inline char *py2_const_cast(const char *s) { return const_cast<char *>(s); }
+#else
+inline const char *py2_const_cast(const char *s) { return s; }
+#endif
+
 enum class PyInitialValue { Invalid, Empty };
 
 template <typename T, typename Enable = void> struct PythonFormat;
@@ -309,16 +319,6 @@ public:
 
   StructuredData::ObjectSP CreateStructuredObject() const;
 
-protected:
-
-#if PY_MAJOR_VERSION < 3
-  // The python 2 API declares some arguments as char* that should
-  // be const char *, but it doesn't actually modify them.
-  static char *py2_const_cast(const char *s) { return const_cast<char *>(s); }
-#else
-  static const char *py2_const_cast(const char *s) { return s; }
-#endif
-
 public:
   template <typename... T>
   llvm::Expected<PythonObject> CallMethod(const char *name,
@@ -621,30 +621,12 @@ public:
      * function and can accept an arbitrary number */
     unsigned max_positional_args;
     static constexpr unsigned UNBOUNDED = UINT_MAX; // FIXME c++17 inline
-    /* the number of positional arguments, including optional ones,
-     * and excluding varargs.  If this is a bound method, then the
-     * count will still include a +1 for self.
-     *
-     * FIXME. That's crazy.  This should be replaced with
-     * an accurate min and max for positional args.
-     */
-    int count;
-    /* does the callable have positional varargs? */
-    bool has_varargs : 1; // FIXME delete this
   };
 
   static bool Check(PyObject *py_obj);
 
   llvm::Expected<ArgInfo> GetArgInfo() const;
 
-  llvm::Expected<ArgInfo> GetInitArgInfo() const;
-
-  ArgInfo GetNumArguments() const; // DEPRECATED
-
-  // If the callable is a Py_Class, then find the number of arguments
-  // of the __init__ method.
-  ArgInfo GetNumInitArguments() const; // DEPRECATED
-
   PythonObject operator()();
 
   PythonObject operator()(std::initializer_list<PyObject *> args);
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.cpp
new file mode 100644
index 000000000000..5f6429f5cd0e
--- /dev/null
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.cpp
@@ -0,0 +1,88 @@
+#include "PythonReadline.h"
+
+#ifdef LLDB_USE_LIBEDIT_READLINE_COMPAT_MODULE
+
+#include <stdio.h>
+
+#include <editline/readline.h>
+
+// Simple implementation of the Python readline module using libedit.
+// In the event that libedit is excluded from the build, this turns
+// back into a null implementation that blocks the module from pulling
+// in the GNU readline shared lib, which causes linkage confusion when
+// both readline and libedit's readline compatibility symbols collide.
+//
+// Currently it only installs a PyOS_ReadlineFunctionPointer, without
+// implementing any of the readline module methods. This is meant to
+// work around LLVM pr18841 to avoid seg faults in the stock Python
+// readline.so linked against GNU readline.
+//
+// Bug on the cpython side: https://bugs.python.org/issue38634
+
+PyDoc_STRVAR(moduleDocumentation,
+             "Simple readline module implementation based on libedit.");
+
+#if PY_MAJOR_VERSION >= 3
+static struct PyModuleDef readline_module = {
+    PyModuleDef_HEAD_INIT, // m_base
+    "lldb_editline",       // m_name
+    moduleDocumentation,   // m_doc
+    -1,                    // m_size
+    nullptr,               // m_methods
+    nullptr,               // m_reload
+    nullptr,               // m_traverse
+    nullptr,               // m_clear
+    nullptr,               // m_free
+};
+#else
+static struct PyMethodDef moduleMethods[] = {{nullptr, nullptr, 0, nullptr}};
+#endif
+
+static char *
+#if PY_MAJOR_VERSION >= 3
+simple_readline(FILE *stdin, FILE *stdout, const char *prompt)
+#else
+simple_readline(FILE *stdin, FILE *stdout, char *prompt)
+#endif
+{
+  rl_instream = stdin;
+  rl_outstream = stdout;
+  char *line = readline(prompt);
+  if (!line) {
+#if PY_MAJOR_VERSION >= 3
+    char *ret = (char *)PyMem_RawMalloc(1);
+#else
+    char *ret = (char *)PyMem_Malloc(1);
+#endif
+    if (ret != NULL)
+      *ret = '\0';
+    return ret;
+  }
+  if (*line)
+    add_history(line);
+  int n = strlen(line);
+#if PY_MAJOR_VERSION >= 3
+  char *ret = (char *)PyMem_RawMalloc(n + 2);
+#else
+  char *ret = (char *)PyMem_Malloc(n + 2);
+#endif
+  if (ret) {
+    memcpy(ret, line, n);
+    free(line);
+    ret[n] = '\n';
+    ret[n + 1] = '\0';
+  }
+  return ret;
+}
+
+PyMODINIT_FUNC initlldb_readline(void) {
+  PyOS_ReadlineFunctionPointer = simple_readline;
+
+#if PY_MAJOR_VERSION >= 3
+  return PyModule_Create(&readline_module);
+#else
+  Py_InitModule4("readline", moduleMethods, moduleDocumentation,
+                 static_cast<PyObject *>(NULL), PYTHON_API_VERSION);
+#endif
+}
+#endif
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.h b/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.h
new file mode 100644
index 000000000000..c75219eb1a4f
--- /dev/null
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.h
@@ -0,0 +1,28 @@
+//===-- PythonReadline.h ----------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_PYTHONREADLINE_H
+#define LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_PYTHONREADLINE_H
+
+#include "lldb/Host/Config.h"
+
+#if LLDB_ENABLE_LIBEDIT && defined(__linux__)
+// NOTE: Since Python may define some pre-processor definitions which affect the
+// standard headers on some systems, you must include Python.h before any
+// standard headers are included.
+#include "Python.h"
+
+// no need to hack into Python's readline module if libedit isn't used.
+//
+#define LLDB_USE_LIBEDIT_READLINE_COMPAT_MODULE 1
+
+PyMODINIT_FUNC initlldb_readline(void);
+
+#endif
+
+#endif // LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_PYTHONREADLINE_H
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
index 3eee52184142..06e0d5bfa63f 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
@@ -6,16 +6,15 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifdef LLDB_DISABLE_PYTHON
+#include "lldb/Host/Config.h"
 
-// Python is disabled in this build
-
-#else
+#if LLDB_ENABLE_PYTHON
 
 // LLDB Python header must be included first
 #include "lldb-python.h"
 
 #include "PythonDataObjects.h"
+#include "PythonReadline.h"
 #include "ScriptInterpreterPythonImpl.h"
 
 #include "lldb/API/SBFrame.h"
@@ -72,10 +71,28 @@ extern "C" void init_lldb(void);
 // These prototypes are the Pythonic implementations of the required callbacks.
 // Although these are scripting-language specific, their definition depends on
 // the public API.
-extern "C" bool LLDBSwigPythonBreakpointCallbackFunction(
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wreturn-type-c-linkage"
+
+// Disable warning C4190: 'LLDBSwigPythonBreakpointCallbackFunction' has
+// C-linkage specified, but returns UDT 'llvm::Expected<bool>' which is
+// incompatible with C
+#if _MSC_VER
+#pragma warning (push)
+#pragma warning (disable : 4190)
+#endif
+
+extern "C" llvm::Expected<bool> LLDBSwigPythonBreakpointCallbackFunction(
     const char *python_function_name, const char *session_dictionary_name,
     const lldb::StackFrameSP &sb_frame,
-    const lldb::BreakpointLocationSP &sb_bp_loc);
+    const lldb::BreakpointLocationSP &sb_bp_loc, StructuredDataImpl *args_impl);
+
+#if _MSC_VER
+#pragma warning (pop)
+#endif
+
+#pragma clang diagnostic pop
 
 extern "C" bool LLDBSwigPythonWatchpointCallbackFunction(
     const char *python_function_name, const char *session_dictionary_name,
@@ -211,6 +228,22 @@ public:
 
     InitializePythonHome();
 
+#ifdef LLDB_USE_LIBEDIT_READLINE_COMPAT_MODULE
+    // Python's readline is incompatible with libedit being linked into lldb.
+    // Provide a patched version local to the embedded interpreter.
+    bool ReadlinePatched = false;
+    for (auto *p = PyImport_Inittab; p->name != NULL; p++) {
+      if (strcmp(p->name, "readline") == 0) {
+        p->initfunc = initlldb_readline;
+        break;
+      }
+    }
+    if (!ReadlinePatched) {
+      PyImport_AppendInittab("readline", initlldb_readline);
+      ReadlinePatched = true;
+    }
+#endif
+
     // Register _lldb as a built-in module.
     PyImport_AppendInittab("_lldb", LLDBSwigPyInit);
 
@@ -552,8 +585,10 @@ void ScriptInterpreterPythonImpl::IOHandlerInputComplete(IOHandler &io_handler,
         break;
       data_up->user_source.SplitIntoLines(data);
 
+      StructuredData::ObjectSP empty_args_sp;
       if (GenerateBreakpointCommandCallbackData(data_up->user_source,
-                                                data_up->script_source)
+                                                data_up->script_source,
+                                                false)
               .Success()) {
         auto baton_sp = std::make_shared<BreakpointOptions::CommandBaton>(
             std::move(data_up));
@@ -779,6 +814,32 @@ PythonDictionary &ScriptInterpreterPythonImpl::GetSysModuleDictionary() {
   return m_sys_module_dict;
 }
 
+llvm::Expected<unsigned>
+ScriptInterpreterPythonImpl::GetMaxPositionalArgumentsForCallable(
+    const llvm::StringRef &callable_name) {
+  if (callable_name.empty()) {
+    return llvm::createStringError(
+        llvm::inconvertibleErrorCode(),
+        "called with empty callable name.");
+  }
+  Locker py_lock(this, Locker::AcquireLock |
+                 Locker::InitSession |
+                 Locker::NoSTDIN);
+  auto dict = PythonModule::MainModule()
+      .ResolveName<PythonDictionary>(m_dictionary_name);
+  auto pfunc = PythonObject::ResolveNameWithDictionary<PythonCallable>(
+      callable_name, dict);
+  if (!pfunc.IsAllocated()) {
+    return llvm::createStringError(
+        llvm::inconvertibleErrorCode(),
+        "can't find callable: %s", callable_name.str().c_str());
+  }
+  llvm::Expected<PythonCallable::ArgInfo> arg_info = pfunc.GetArgInfo();
+  if (!arg_info)
+    return arg_info.takeError();
+  return arg_info.get().max_positional_args;
+}
+
 static std::string GenerateUniqueName(const char *base_name_wanted,
                                       uint32_t &functions_counter,
                                       const void *name_token = nullptr) {
@@ -1139,6 +1200,7 @@ bool ScriptInterpreterPythonImpl::ExecuteOneLineWithReturn(
     return true;
   }
   }
+  llvm_unreachable("Fully covered switch!");
 }
 
 Status ScriptInterpreterPythonImpl::ExecuteMultipleLines(
@@ -1186,24 +1248,56 @@ void ScriptInterpreterPythonImpl::CollectDataForBreakpointCommandCallback(
     CommandReturnObject &result) {
   m_active_io_handler = eIOHandlerBreakpoint;
   m_debugger.GetCommandInterpreter().GetPythonCommandsFromIOHandler(
-      "    ", *this, true, &bp_options_vec);
+      "    ", *this, &bp_options_vec);
 }
 
 void ScriptInterpreterPythonImpl::CollectDataForWatchpointCommandCallback(
     WatchpointOptions *wp_options, CommandReturnObject &result) {
   m_active_io_handler = eIOHandlerWatchpoint;
   m_debugger.GetCommandInterpreter().GetPythonCommandsFromIOHandler(
-      "    ", *this, true, wp_options);
+      "    ", *this, wp_options);
 }
 
-void ScriptInterpreterPythonImpl::SetBreakpointCommandCallbackFunction(
-    BreakpointOptions *bp_options, const char *function_name) {
+Status ScriptInterpreterPythonImpl::SetBreakpointCommandCallbackFunction(
+    BreakpointOptions *bp_options, const char *function_name,
+    StructuredData::ObjectSP extra_args_sp) {
+  Status error;
   // For now just cons up a oneliner that calls the provided function.
   std::string oneliner("return ");
   oneliner += function_name;
-  oneliner += "(frame, bp_loc, internal_dict)";
-  m_debugger.GetScriptInterpreter()->SetBreakpointCommandCallback(
-      bp_options, oneliner.c_str());
+
+  llvm::Expected<unsigned> maybe_args =
+      GetMaxPositionalArgumentsForCallable(function_name);
+  if (!maybe_args) {
+    error.SetErrorStringWithFormat(
+        "could not get num args: %s",
+        llvm::toString(maybe_args.takeError()).c_str());
+    return error;
+  }
+  size_t max_args = *maybe_args;
+
+  bool uses_extra_args = false;
+  if (max_args >= 4) {
+    uses_extra_args = true;
+    oneliner += "(frame, bp_loc, extra_args, internal_dict)";
+  } else if (max_args >= 3) {
+    if (extra_args_sp) {
+      error.SetErrorString("cannot pass extra_args to a three argument callback"
+                          );
+      return error;
+    }
+    uses_extra_args = false;
+    oneliner += "(frame, bp_loc, internal_dict)";
+  } else {
+    error.SetErrorStringWithFormat("expected 3 or 4 argument "
+                                   "function, %s can only take %zu",
+                                   function_name, max_args);
+    return error;
+  }
+
+  SetBreakpointCommandCallback(bp_options, oneliner.c_str(), extra_args_sp,
+                               uses_extra_args);
+  return error;
 }
 
 Status ScriptInterpreterPythonImpl::SetBreakpointCommandCallback(
@@ -1211,7 +1305,8 @@ Status ScriptInterpreterPythonImpl::SetBreakpointCommandCallback(
     std::unique_ptr<BreakpointOptions::CommandData> &cmd_data_up) {
   Status error;
   error = GenerateBreakpointCommandCallbackData(cmd_data_up->user_source,
-                                                cmd_data_up->script_source);
+                                                cmd_data_up->script_source,
+                                                false);
   if (error.Fail()) {
     return error;
   }
@@ -1222,11 +1317,17 @@ Status ScriptInterpreterPythonImpl::SetBreakpointCommandCallback(
   return error;
 }
 
-// Set a Python one-liner as the callback for the breakpoint.
 Status ScriptInterpreterPythonImpl::SetBreakpointCommandCallback(
     BreakpointOptions *bp_options, const char *command_body_text) {
-  auto data_up = std::make_unique<CommandDataPython>();
+  return SetBreakpointCommandCallback(bp_options, command_body_text, {},false);
+}
 
+// Set a Python one-liner as the callback for the breakpoint.
+Status ScriptInterpreterPythonImpl::SetBreakpointCommandCallback(
+    BreakpointOptions *bp_options, const char *command_body_text,
+    StructuredData::ObjectSP extra_args_sp,
+    bool uses_extra_args) {
+  auto data_up = std::make_unique<CommandDataPython>(extra_args_sp);
   // Split the command_body_text into lines, and pass that to
   // GenerateBreakpointCommandCallbackData.  That will wrap the body in an
   // auto-generated function, and return the function name in script_source.
@@ -1234,7 +1335,8 @@ Status ScriptInterpreterPythonImpl::SetBreakpointCommandCallback(
 
   data_up->user_source.SplitIntoLines(command_body_text);
   Status error = GenerateBreakpointCommandCallbackData(data_up->user_source,
-                                                       data_up->script_source);
+                                                       data_up->script_source,
+                                                       uses_extra_args);
   if (error.Success()) {
     auto baton_sp =
         std::make_shared<BreakpointOptions::CommandBaton>(std::move(data_up));
@@ -1771,8 +1873,7 @@ StructuredData::DictionarySP ScriptInterpreterPythonImpl::OSPlugin_CreateThread(
 
 StructuredData::ObjectSP ScriptInterpreterPythonImpl::CreateScriptedThreadPlan(
     const char *class_name, StructuredDataImpl *args_data,
-    std::string &error_str, 
-    lldb::ThreadPlanSP thread_plan_sp) {
+    std::string &error_str, lldb::ThreadPlanSP thread_plan_sp) {
   if (class_name == nullptr || class_name[0] == '\0')
     return StructuredData::ObjectSP();
 
@@ -1956,8 +2057,7 @@ ScriptInterpreterPythonImpl::LoadPluginModule(const FileSpec &file_spec,
 
   StructuredData::ObjectSP module_sp;
 
-  if (LoadScriptingModule(file_spec.GetPath().c_str(), true, true, error,
-                          &module_sp))
+  if (LoadScriptingModule(file_spec.GetPath().c_str(), true, error, &module_sp))
     return module_sp;
 
   return StructuredData::ObjectSP();
@@ -2063,7 +2163,8 @@ bool ScriptInterpreterPythonImpl::GenerateTypeSynthClass(
 }
 
 Status ScriptInterpreterPythonImpl::GenerateBreakpointCommandCallbackData(
-    StringList &user_input, std::string &output) {
+    StringList &user_input, std::string &output,
+    bool has_extra_args) {
   static uint32_t num_created_functions = 0;
   user_input.RemoveBlankLines();
   StreamString sstr;
@@ -2075,8 +2176,12 @@ Status ScriptInterpreterPythonImpl::GenerateBreakpointCommandCallbackData(
 
   std::string auto_generated_function_name(GenerateUniqueName(
       "lldb_autogen_python_bp_callback_func_", num_created_functions));
-  sstr.Printf("def %s (frame, bp_loc, internal_dict):",
-              auto_generated_function_name.c_str());
+  if (has_extra_args)
+    sstr.Printf("def %s (frame, bp_loc, extra_args, internal_dict):",
+                auto_generated_function_name.c_str());
+  else
+    sstr.Printf("def %s (frame, bp_loc, internal_dict):",
+                auto_generated_function_name.c_str());
 
   error = GenerateFunction(sstr.GetData(), user_input);
   if (!error.Success())
@@ -2193,10 +2298,26 @@ bool ScriptInterpreterPythonImpl::BreakpointCallbackFunction(
           Locker py_lock(python_interpreter, Locker::AcquireLock |
                                                  Locker::InitSession |
                                                  Locker::NoSTDIN);
-          ret_val = LLDBSwigPythonBreakpointCallbackFunction(
-              python_function_name,
-              python_interpreter->m_dictionary_name.c_str(), stop_frame_sp,
-              bp_loc_sp);
+          Expected<bool> maybe_ret_val =
+              LLDBSwigPythonBreakpointCallbackFunction(
+                  python_function_name,
+                  python_interpreter->m_dictionary_name.c_str(), stop_frame_sp,
+                  bp_loc_sp, bp_option_data->m_extra_args_up.get());
+
+          if (!maybe_ret_val) {
+
+            llvm::handleAllErrors(
+                maybe_ret_val.takeError(),
+                [&](PythonException &E) {
+                  debugger.GetErrorStream() << E.ReadBacktrace();
+                },
+                [&](const llvm::ErrorInfoBase &E) {
+                  debugger.GetErrorStream() << E.message();
+                });
+
+          } else {
+            ret_val = maybe_ret_val.get();
+          }
         }
         return ret_val;
       }
@@ -2615,8 +2736,8 @@ uint64_t replace_all(std::string &str, const std::string &oldStr,
 }
 
 bool ScriptInterpreterPythonImpl::LoadScriptingModule(
-    const char *pathname, bool can_reload, bool init_session,
-    lldb_private::Status &error, StructuredData::ObjectSP *module_sp) {
+    const char *pathname, bool init_session, lldb_private::Status &error,
+    StructuredData::ObjectSP *module_sp) {
   if (!pathname || !pathname[0]) {
     error.SetErrorString("invalid pathname");
     return false;
@@ -2716,11 +2837,6 @@ bool ScriptInterpreterPythonImpl::LoadScriptingModule(
 
     bool was_imported = (was_imported_globally || was_imported_locally);
 
-    if (was_imported && !can_reload) {
-      error.SetErrorString("module already imported");
-      return false;
-    }
-
     // now actually do the import
     command_stream.Clear();
 
@@ -3171,4 +3287,4 @@ void ScriptInterpreterPythonImpl::AddToSysPath(AddLocation location,
 //
 // void ScriptInterpreterPythonImpl::Terminate() { Py_Finalize (); }
 
-#endif // LLDB_DISABLE_PYTHON
+#endif
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h
index 33ae308041b2..e59fedbd0971 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h
@@ -9,14 +9,13 @@
 #ifndef LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_SCRIPTINTERPRETERPYTHON_H
 #define LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_SCRIPTINTERPRETERPYTHON_H
 
-#ifdef LLDB_DISABLE_PYTHON
+#include "lldb/Host/Config.h"
 
-// Python is disabled in this build
-
-#else
+#if LLDB_ENABLE_PYTHON
 
 #include "lldb/Breakpoint/BreakpointOptions.h"
 #include "lldb/Core/IOHandler.h"
+#include "lldb/Core/StructuredDataImpl.h"
 #include "lldb/Interpreter/ScriptInterpreter.h"
 #include "lldb/lldb-private.h"
 
@@ -34,6 +33,13 @@ public:
     CommandDataPython() : BreakpointOptions::CommandData() {
       interpreter = lldb::eScriptLanguagePython;
     }
+    CommandDataPython(StructuredData::ObjectSP extra_args_sp) :
+        BreakpointOptions::CommandData(),
+        m_extra_args_up(new StructuredDataImpl()) {
+        interpreter = lldb::eScriptLanguagePython;
+        m_extra_args_up->SetObjectSP(extra_args_sp);
+    }
+    lldb::StructuredDataImplUP m_extra_args_up;
   };
 
   ScriptInterpreterPython(Debugger &debugger)
@@ -52,5 +58,5 @@ protected:
 };
 } // namespace lldb_private
 
-#endif // LLDB_DISABLE_PYTHON
+#endif // LLDB_ENABLE_PYTHON
 #endif // LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_SCRIPTINTERPRETERPYTHON_H
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h
index 929567e579d8..1fa198b07e54 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h
@@ -6,11 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifdef LLDB_DISABLE_PYTHON
+#include "lldb/Host/Config.h"
 
-// Python is disabled in this build
-
-#else
+#if LLDB_ENABLE_PYTHON
 
 #include "lldb-python.h"
 
@@ -179,8 +177,10 @@ public:
   Status GenerateFunction(const char *signature,
                           const StringList &input) override;
 
-  Status GenerateBreakpointCommandCallbackData(StringList &input,
-                                               std::string &output) override;
+  Status GenerateBreakpointCommandCallbackData(
+      StringList &input,
+      std::string &output,
+      bool has_extra_args) override;
 
   bool GenerateWatchpointCommandCallbackData(StringList &input,
                                              std::string &output) override;
@@ -224,7 +224,7 @@ public:
                               std::string &output, Status &error) override;
 
   bool
-  LoadScriptingModule(const char *filename, bool can_reload, bool init_session,
+  LoadScriptingModule(const char *filename, bool init_session,
                       lldb_private::Status &error,
                       StructuredData::ObjectSP *module_sp = nullptr) override;
 
@@ -244,14 +244,21 @@ public:
   Status SetBreakpointCommandCallback(BreakpointOptions *bp_options,
                                       const char *callback_body) override;
 
-  void SetBreakpointCommandCallbackFunction(BreakpointOptions *bp_options,
-                                            const char *function_name) override;
+  Status SetBreakpointCommandCallbackFunction(
+      BreakpointOptions *bp_options,
+      const char *function_name,
+      StructuredData::ObjectSP extra_args_sp) override;
 
   /// This one is for deserialization:
   Status SetBreakpointCommandCallback(
       BreakpointOptions *bp_options,
       std::unique_ptr<BreakpointOptions::CommandData> &data_up) override;
 
+  Status SetBreakpointCommandCallback(BreakpointOptions *bp_options,
+                                      const char *command_body_text,
+                                      StructuredData::ObjectSP extra_args_sp,
+                                      bool uses_extra_args);
+
   /// Set a one-liner as the callback for the watchpoint.
   void SetWatchpointCommandCallback(WatchpointOptions *wp_options,
                                     const char *oneliner) override;
@@ -369,6 +376,9 @@ public:
 
   python::PythonDictionary &GetSysModuleDictionary();
 
+  llvm::Expected<unsigned> GetMaxPositionalArgumentsForCallable(
+      const llvm::StringRef &callable_name) override;
+
   bool GetEmbeddedInterpreterModuleObjects();
 
   bool SetStdHandle(lldb::FileSP file, const char *py_name,
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/lldb-python.h b/lldb/source/Plugins/ScriptInterpreter/Python/lldb-python.h
index 884514da9924..48f27b09b95c 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/lldb-python.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/lldb-python.h
@@ -9,12 +9,12 @@
 #ifndef LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_LLDB_PYTHON_H
 #define LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_LLDB_PYTHON_H
 
+#include "lldb/Host/Config.h"
+
 // Python.h needs to be included before any system headers in order to avoid
 // redefinition of macros
 
-#ifdef LLDB_DISABLE_PYTHON
-// Python is disabled in this build
-#else
+#if LLDB_ENABLE_PYTHON
 #include "llvm/Support/Compiler.h"
 #if defined(_WIN32)
 // If anyone #includes Host/PosixApi.h later, it will try to typedef pid_t.  We
@@ -40,6 +40,6 @@
 
 // Include python for non windows machines
 #include <Python.h>
-#endif // LLDB_DISABLE_PYTHON
+#endif
 
 #endif // LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_LLDB_PYTHON_H