[lldb/Interpreter] Add ScriptInterpreter Wrapper for ScriptedProcess

This patch adds a ScriptedProcess interface to the ScriptInterpreter and
more specifically, to the ScriptInterpreterPython.

This interface will be used in the C++ `ScriptProcess` Process Plugin to
call the script methods.

At the moment, not all methods are implemented, they will upstreamed in
upcoming patches.

This patch also adds helper methods to the ScriptInterpreter to
convert `SBAPI` Types (SBData & SBError) to `lldb_private` types
(DataExtractor & Status).

rdar://65508855

Differential Revision: https://reviews.llvm.org/D95711

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>

1 files changed, 287 insertions, 0 deletions

diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptedProcessPythonInterface.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptedProcessPythonInterface.cpp
new file mode 100644
index 0000000..03f745e
--- /dev/null
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptedProcessPythonInterface.cpp
@@ -0,0 +1,287 @@
+//===-- ScriptedProcessPythonInterface.cpp --------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/Config.h"
+#include "lldb/lldb-enumerations.h"
+
+#if LLDB_ENABLE_PYTHON
+
+// LLDB Python header must be included first
+#include "lldb-python.h"
+
+#include "SWIGPythonBridge.h"
+#include "ScriptInterpreterPythonImpl.h"
+#include "ScriptedProcessPythonInterface.h"
+
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::python;
+using Locker = ScriptInterpreterPythonImpl::Locker;
+
+StructuredData::GenericSP ScriptedProcessPythonInterface::CreatePluginObject(
+    const llvm::StringRef class_name, lldb::TargetSP target_sp,
+    StructuredData::DictionarySP args_sp) {
+  if (class_name.empty())
+    return {};
+
+  std::string error_string;
+  StructuredDataImpl *args_impl = nullptr;
+  if (args_sp) {
+    args_impl = new StructuredDataImpl();
+    args_impl->SetObjectSP(args_sp);
+  }
+
+  void *ret_val;
+
+  {
+
+    Locker py_lock(&m_interpreter, Locker::AcquireLock | Locker::NoSTDIN,
+                   Locker::FreeLock);
+
+    ret_val = LLDBSwigPythonCreateScriptedProcess(
+        class_name.str().c_str(), m_interpreter.GetDictionaryName(), target_sp,
+        args_impl, error_string);
+  }
+
+  m_object_instance_sp =
+      StructuredData::GenericSP(new StructuredPythonObject(ret_val));
+
+  return m_object_instance_sp;
+}
+
+Status ScriptedProcessPythonInterface::Launch() {
+  return LaunchOrResume("launch");
+}
+
+Status ScriptedProcessPythonInterface::Resume() {
+  return LaunchOrResume("resume");
+}
+
+Status
+ScriptedProcessPythonInterface::LaunchOrResume(llvm::StringRef method_name) {
+  Locker py_lock(&m_interpreter, Locker::AcquireLock | Locker::NoSTDIN,
+                 Locker::FreeLock);
+
+  if (!m_object_instance_sp)
+    return Status("Python object ill-formed.");
+
+  if (!m_object_instance_sp)
+    return Status("Cannot convert Python object to StructuredData::Generic.");
+  PythonObject implementor(PyRefType::Borrowed,
+                           (PyObject *)m_object_instance_sp->GetValue());
+
+  if (!implementor.IsAllocated())
+    return Status("Python implementor not allocated.");
+
+  PythonObject pmeth(
+      PyRefType::Owned,
+      PyObject_GetAttrString(implementor.get(), method_name.str().c_str()));
+
+  if (PyErr_Occurred())
+    PyErr_Clear();
+
+  if (!pmeth.IsAllocated())
+    return Status("Python method not allocated.");
+
+  if (PyCallable_Check(pmeth.get()) == 0) {
+    if (PyErr_Occurred())
+      PyErr_Clear();
+    return Status("Python method not callable.");
+  }
+
+  if (PyErr_Occurred())
+    PyErr_Clear();
+
+  PythonObject py_return(PyRefType::Owned,
+                         PyObject_CallMethod(implementor.get(),
+                                             method_name.str().c_str(),
+                                             nullptr));
+
+  if (PyErr_Occurred()) {
+    PyErr_Print();
+    PyErr_Clear();
+    return Status("Python method could not be called.");
+  }
+
+  if (PyObject *py_ret_ptr = py_return.get()) {
+    lldb::SBError *sb_error =
+        (lldb::SBError *)LLDBSWIGPython_CastPyObjectToSBError(py_ret_ptr);
+
+    if (!sb_error)
+      return Status("Couldn't cast lldb::SBError to lldb::Status.");
+
+    Status status = m_interpreter.GetStatusFromSBError(*sb_error);
+
+    if (status.Fail())
+      return Status("error: %s", status.AsCString());
+
+    return status;
+  }
+
+  return Status("Returned object is null.");
+}
+
+size_t
+ScriptedProcessPythonInterface::GetGenericInteger(llvm::StringRef method_name) {
+  Locker py_lock(&m_interpreter, Locker::AcquireLock | Locker::NoSTDIN,
+                 Locker::FreeLock);
+
+  if (!m_object_instance_sp)
+    return LLDB_INVALID_ADDRESS;
+
+  if (!m_object_instance_sp)
+    return LLDB_INVALID_ADDRESS;
+  PythonObject implementor(PyRefType::Borrowed,
+                           (PyObject *)m_object_instance_sp->GetValue());
+
+  if (!implementor.IsAllocated())
+    return LLDB_INVALID_ADDRESS;
+
+  PythonObject pmeth(
+      PyRefType::Owned,
+      PyObject_GetAttrString(implementor.get(), method_name.str().c_str()));
+
+  if (PyErr_Occurred())
+    PyErr_Clear();
+
+  if (!pmeth.IsAllocated())
+    return LLDB_INVALID_ADDRESS;
+
+  if (PyCallable_Check(pmeth.get()) == 0) {
+    if (PyErr_Occurred())
+      PyErr_Clear();
+    return LLDB_INVALID_ADDRESS;
+  }
+
+  if (PyErr_Occurred())
+    PyErr_Clear();
+
+  PythonObject py_return(PyRefType::Owned,
+                         PyObject_CallMethod(implementor.get(),
+                                             method_name.str().c_str(),
+                                             nullptr));
+
+  if (PyErr_Occurred()) {
+    PyErr_Print();
+    PyErr_Clear();
+  }
+
+  if (py_return.get()) {
+    auto size = py_return.AsUnsignedLongLong();
+    return (size) ? *size : LLDB_INVALID_ADDRESS;
+  }
+  return LLDB_INVALID_ADDRESS;
+}
+
+lldb::MemoryRegionInfoSP
+ScriptedProcessPythonInterface::GetMemoryRegionContainingAddress(
+    lldb::addr_t address) {
+  // TODO: Implement
+  return nullptr;
+}
+
+StructuredData::DictionarySP
+ScriptedProcessPythonInterface::GetThreadWithID(lldb::tid_t tid) {
+  // TODO: Implement
+  return nullptr;
+}
+
+StructuredData::DictionarySP
+ScriptedProcessPythonInterface::GetRegistersForThread(lldb::tid_t tid) {
+  // TODO: Implement
+  return nullptr;
+}
+
+lldb::DataExtractorSP ScriptedProcessPythonInterface::ReadMemoryAtAddress(
+    lldb::addr_t address, size_t size, Status &error) {
+  Locker py_lock(&m_interpreter, Locker::AcquireLock | Locker::NoSTDIN,
+                 Locker::FreeLock);
+
+  auto error_with_message = [&error](llvm::StringRef message) {
+    error.SetErrorString(message);
+    return nullptr;
+  };
+
+  static char callee_name[] = "read_memory_at_address";
+  std::string param_format = GetPythonValueFormatString(address);
+  param_format += GetPythonValueFormatString(size);
+
+  if (!m_object_instance_sp)
+    return error_with_message("Python object ill-formed.");
+
+  if (!m_object_instance_sp)
+    return error_with_message("Python method not callable.");
+
+  PythonObject implementor(PyRefType::Borrowed,
+                           (PyObject *)m_object_instance_sp->GetValue());
+
+  if (!implementor.IsAllocated())
+    return error_with_message("Python implementor not allocated.");
+
+  PythonObject pmeth(PyRefType::Owned,
+                     PyObject_GetAttrString(implementor.get(), callee_name));
+
+  if (PyErr_Occurred())
+    PyErr_Clear();
+
+  if (!pmeth.IsAllocated())
+    return error_with_message("Python method not allocated.");
+
+  if (PyCallable_Check(pmeth.get()) == 0) {
+    if (PyErr_Occurred())
+      PyErr_Clear();
+    return error_with_message("Python method not callable.");
+  }
+
+  if (PyErr_Occurred())
+    PyErr_Clear();
+
+  PythonObject py_return(PyRefType::Owned,
+                         PyObject_CallMethod(implementor.get(), callee_name,
+                                             param_format.c_str(), address,
+                                             size));
+
+  if (PyErr_Occurred()) {
+    PyErr_Print();
+    PyErr_Clear();
+    return error_with_message("Python method could not be called.");
+  }
+
+  if (PyObject *py_ret_ptr = py_return.get()) {
+    lldb::SBData *sb_data =
+        (lldb::SBData *)LLDBSWIGPython_CastPyObjectToSBData(py_ret_ptr);
+
+    if (!sb_data)
+      return error_with_message(
+          "Couldn't cast lldb::SBData to lldb::DataExtractor.");
+
+    return m_interpreter.GetDataExtractorFromSBData(*sb_data);
+  }
+
+  return error_with_message("Returned object is null.");
+}
+
+StructuredData::DictionarySP ScriptedProcessPythonInterface::GetLoadedImages() {
+  // TODO: Implement
+  return nullptr;
+}
+
+lldb::pid_t ScriptedProcessPythonInterface::GetProcessID() {
+  size_t pid = GetGenericInteger("get_process_id");
+
+  return (pid >= std::numeric_limits<lldb::pid_t>::max())
+             ? LLDB_INVALID_PROCESS_ID
+             : pid;
+}
+
+bool ScriptedProcessPythonInterface::IsAlive() {
+  return GetGenericInteger("is_alive");
+  ;
+}
+
+#endif