[lldb] Add a way to get a scripted process implementation from the SBAPI

This patch introduces a new `GetScriptedImplementation` method to the
SBProcess class in the SBAPI. It will allow users of Scripted Processes to
fetch the scripted implementation object from to script interpreter to be
able to interact with it directly (without having to go through lldb).

This allows to user to perform action that are not specified in the
scripted process interface, like calling un-specified methods, but also
to enrich the implementation, by passing it complex objects.

Differential Revision: https://reviews.llvm.org/D143236

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

lldb/test/API/functionalities/scripted_process/TestScriptedProcess.py

@@ -10,6 +10,8 @@ from lldbsuite.test.lldbtest import *
 from lldbsuite.test import lldbutil
 from lldbsuite.test import lldbtest
 
+import dummy_scripted_process
+
 class ScriptedProcesTestCase(TestBase):
 
     NO_DEBUG_INFO_TESTCASE = True
@@ -118,6 +120,14 @@ class ScriptedProcesTestCase(TestBase):
         self.assertEqual(process.GetProcessID(), 42)
         self.assertEqual(process.GetNumThreads(), 1)
 
+        py_impl = process.GetScriptedImplementation()
+        self.assertTrue(py_impl)
+        self.assertTrue(isinstance(py_impl, dummy_scripted_process.DummyScriptedProcess))
+        self.assertFalse(hasattr(py_impl, 'my_super_secret_member'))
+        py_impl.my_super_secret_member = 42
+        self.assertTrue(hasattr(py_impl, 'my_super_secret_member'))
+        self.assertEqual(py_impl.my_super_secret_method(), 42)
+
         addr = 0x500000000
         message = "Hello, world!"
         buff = process.ReadCStringFromMemory(addr, len(message) + 1, error)

lldb/test/API/functionalities/scripted_process/dummy_scripted_process.py

@@ -43,6 +43,12 @@ class DummyScriptedProcess(ScriptedProcess):
     def get_scripted_thread_plugin(self):
         return DummyScriptedThread.__module__ + "." + DummyScriptedThread.__name__
 
+    def my_super_secret_method(self):
+        if hasattr(self, 'my_super_secret_member'):
+            return self.my_super_secret_member
+        else:
+            return None
+
 
 class DummyScriptedThread(ScriptedThread):
     def __init__(self, process, args):