Rework LLDB system initialization.

In an effort to reduce binary size for components not wishing to
link against all of LLDB, as well as a parallel effort to reduce
link dependencies on Python, this patch splits out the notion of
LLDB initialization into "full" and "common" initialization.

All code related to initializing the full LLDB suite lives directly
in API now.  Previously it was only referenced from API, but because
it was defined in lldbCore, it would get implicitly linked against
by everything including lldb-server, causing a considerable
increase in binary size.

By moving this to the API layer, it also creates a better layering
for the ongoing effort to make the embedded interpreter replacable
with one from a different language (or even be completely removeable).

One semantic change necessary to get this all working was to remove
the notion of a shared debugger refcount.  The debugger is either
initialized or uninitialized now, and calling Initialize() multiple
times will simply have no effect, while the first Terminate() will
now shut it down no matter how many times Initialize() was called.
This behaves nicely with all of our supported usage patterns though,
and allows us to fix a number of nasty hacks from before.

Differential Revision: http://reviews.llvm.org/D8462

llvm-svn: 233758

1 files changed, 30 insertions, 62 deletions

diff --git a/lldb/source/Interpreter/ScriptInterpreterPython.cpp b/lldb/source/Interpreter/ScriptInterpreterPython.cpp
index eec7c9134b8..f8532e7e8c0 100644
--- a/lldb/source/Interpreter/ScriptInterpreterPython.cpp
+++ b/lldb/source/Interpreter/ScriptInterpreterPython.cpp
@@ -48,33 +48,34 @@
 using namespace lldb;
 using namespace lldb_private;
 
-
-static ScriptInterpreter::SWIGInitCallback g_swig_init_callback = nullptr;
-static ScriptInterpreter::SWIGBreakpointCallbackFunction g_swig_breakpoint_callback = nullptr;
-static ScriptInterpreter::SWIGWatchpointCallbackFunction g_swig_watchpoint_callback = nullptr;
-static ScriptInterpreter::SWIGPythonTypeScriptCallbackFunction g_swig_typescript_callback = nullptr;
-static ScriptInterpreter::SWIGPythonCreateSyntheticProvider g_swig_synthetic_script = nullptr;
-static ScriptInterpreter::SWIGPythonCreateCommandObject g_swig_create_cmd = nullptr;
-static ScriptInterpreter::SWIGPythonCalculateNumChildren g_swig_calc_children = nullptr;
-static ScriptInterpreter::SWIGPythonGetChildAtIndex g_swig_get_child_index = nullptr;
-static ScriptInterpreter::SWIGPythonGetIndexOfChildWithName g_swig_get_index_child = nullptr;
-static ScriptInterpreter::SWIGPythonCastPyObjectToSBValue g_swig_cast_to_sbvalue  = nullptr;
-static ScriptInterpreter::SWIGPythonGetValueObjectSPFromSBValue g_swig_get_valobj_sp_from_sbvalue = nullptr;
-static ScriptInterpreter::SWIGPythonUpdateSynthProviderInstance g_swig_update_provider = nullptr;
-static ScriptInterpreter::SWIGPythonMightHaveChildrenSynthProviderInstance g_swig_mighthavechildren_provider = nullptr;
-static ScriptInterpreter::SWIGPythonGetValueSynthProviderInstance g_swig_getvalue_provider = nullptr;
-static ScriptInterpreter::SWIGPythonCallCommand g_swig_call_command = nullptr;
-static ScriptInterpreter::SWIGPythonCallCommandObject g_swig_call_command_object = nullptr;
-static ScriptInterpreter::SWIGPythonCallModuleInit g_swig_call_module_init = nullptr;
-static ScriptInterpreter::SWIGPythonCreateOSPlugin g_swig_create_os_plugin = nullptr;
-static ScriptInterpreter::SWIGPythonScriptKeyword_Process g_swig_run_script_keyword_process = nullptr;
-static ScriptInterpreter::SWIGPythonScriptKeyword_Thread g_swig_run_script_keyword_thread = nullptr;
-static ScriptInterpreter::SWIGPythonScriptKeyword_Target g_swig_run_script_keyword_target = nullptr;
-static ScriptInterpreter::SWIGPythonScriptKeyword_Frame g_swig_run_script_keyword_frame = nullptr;
-static ScriptInterpreter::SWIGPythonScriptKeyword_Value g_swig_run_script_keyword_value = nullptr;
-static ScriptInterpreter::SWIGPython_GetDynamicSetting g_swig_plugin_get = nullptr;
-static ScriptInterpreter::SWIGPythonCreateScriptedThreadPlan g_swig_thread_plan_script = nullptr;
-static ScriptInterpreter::SWIGPythonCallThreadPlan g_swig_call_thread_plan = nullptr;
+static ScriptInterpreterPython::SWIGInitCallback g_swig_init_callback = nullptr;
+static ScriptInterpreterPython::SWIGBreakpointCallbackFunction g_swig_breakpoint_callback = nullptr;
+static ScriptInterpreterPython::SWIGWatchpointCallbackFunction g_swig_watchpoint_callback = nullptr;
+static ScriptInterpreterPython::SWIGPythonTypeScriptCallbackFunction g_swig_typescript_callback = nullptr;
+static ScriptInterpreterPython::SWIGPythonCreateSyntheticProvider g_swig_synthetic_script = nullptr;
+static ScriptInterpreterPython::SWIGPythonCreateCommandObject g_swig_create_cmd = nullptr;
+static ScriptInterpreterPython::SWIGPythonCalculateNumChildren g_swig_calc_children = nullptr;
+static ScriptInterpreterPython::SWIGPythonGetChildAtIndex g_swig_get_child_index = nullptr;
+static ScriptInterpreterPython::SWIGPythonGetIndexOfChildWithName g_swig_get_index_child = nullptr;
+static ScriptInterpreterPython::SWIGPythonCastPyObjectToSBValue g_swig_cast_to_sbvalue  = nullptr;
+static ScriptInterpreterPython::SWIGPythonGetValueObjectSPFromSBValue g_swig_get_valobj_sp_from_sbvalue = nullptr;
+static ScriptInterpreterPython::SWIGPythonUpdateSynthProviderInstance g_swig_update_provider = nullptr;
+static ScriptInterpreterPython::SWIGPythonMightHaveChildrenSynthProviderInstance g_swig_mighthavechildren_provider = nullptr;
+static ScriptInterpreterPython::SWIGPythonGetValueSynthProviderInstance g_swig_getvalue_provider = nullptr;
+static ScriptInterpreterPython::SWIGPythonCallCommand g_swig_call_command = nullptr;
+static ScriptInterpreterPython::SWIGPythonCallCommandObject g_swig_call_command_object = nullptr;
+static ScriptInterpreterPython::SWIGPythonCallModuleInit g_swig_call_module_init = nullptr;
+static ScriptInterpreterPython::SWIGPythonCreateOSPlugin g_swig_create_os_plugin = nullptr;
+static ScriptInterpreterPython::SWIGPythonScriptKeyword_Process g_swig_run_script_keyword_process = nullptr;
+static ScriptInterpreterPython::SWIGPythonScriptKeyword_Thread g_swig_run_script_keyword_thread = nullptr;
+static ScriptInterpreterPython::SWIGPythonScriptKeyword_Target g_swig_run_script_keyword_target = nullptr;
+static ScriptInterpreterPython::SWIGPythonScriptKeyword_Frame g_swig_run_script_keyword_frame = nullptr;
+static ScriptInterpreterPython::SWIGPythonScriptKeyword_Value g_swig_run_script_keyword_value = nullptr;
+static ScriptInterpreterPython::SWIGPython_GetDynamicSetting g_swig_plugin_get = nullptr;
+static ScriptInterpreterPython::SWIGPythonCreateScriptedThreadPlan g_swig_thread_plan_script = nullptr;
+static ScriptInterpreterPython::SWIGPythonCallThreadPlan g_swig_call_thread_plan = nullptr;
+
+static bool g_initialized = false;
 
 static std::string
 ReadPythonBacktrace (PyObject* py_backtrace);
@@ -175,8 +176,7 @@ ScriptInterpreterPython::ScriptInterpreterPython (CommandInterpreter &interprete
     m_lock_count (0),
     m_command_thread_state (nullptr)
 {
-
-    ScriptInterpreterPython::InitializePrivate ();
+    assert(g_initialized && "ScriptInterpreterPython created but initialize has not been called!");
 
     m_dictionary_name.append("_dict");
     StreamString run_string;
@@ -189,16 +189,6 @@ ScriptInterpreterPython::ScriptInterpreterPython (CommandInterpreter &interprete
 
     run_string.Clear();
 
-    // Importing 'lldb' module calls SBDebugger::Initialize, which calls Debugger::Initialize, which increments a
-    // global debugger ref-count; therefore we need to check the ref-count before and after importing lldb, and if the
-    // ref-count increased we need to call Debugger::Terminate here to decrement the ref-count so that when the final 
-    // call to Debugger::Terminate is made, the ref-count has the correct value. 
-    //
-    // Bonus question:  Why doesn't the ref-count always increase?  Because sometimes lldb has already been imported, in
-    // which case the code inside it, including the call to SBDebugger::Initialize(), does not get executed.
-    
-    int old_count = Debugger::TestDebuggerRefCount();
-    
     run_string.Printf ("run_one_line (%s, 'import copy, keyword, os, re, sys, uuid, lldb')", m_dictionary_name.c_str());
     PyRun_SimpleString (run_string.GetData());
 
@@ -209,11 +199,6 @@ ScriptInterpreterPython::ScriptInterpreterPython (CommandInterpreter &interprete
     PyRun_SimpleString (run_string.GetData());
     run_string.Clear();
 
-    int new_count = Debugger::TestDebuggerRefCount();
-    
-    if (new_count > old_count)
-        Debugger::Terminate();
-
     run_string.Printf ("run_one_line (%s, 'import lldb.embedded_interpreter; from lldb.embedded_interpreter import run_python_interpreter; from lldb.embedded_interpreter import run_one_line')", m_dictionary_name.c_str());
     PyRun_SimpleString (run_string.GetData());
     run_string.Clear();
@@ -3029,11 +3014,7 @@ ScriptInterpreterPython::InitializeInterpreter (SWIGInitCallback swig_init_callb
 void
 ScriptInterpreterPython::InitializePrivate ()
 {
-    static int g_initialized = false;
-    
-    if (g_initialized)
-        return;
-    
+    assert(!g_initialized && "ScriptInterpreterPython::InitializePrivate() called more than once!");
     g_initialized = true;
 
     Timer scoped_timer (__PRETTY_FUNCTION__, __PRETTY_FUNCTION__);
@@ -3057,7 +3038,6 @@ ScriptInterpreterPython::InitializePrivate ()
     }
     Py_InitializeEx (0);
 
-    // Initialize SWIG after setting up python
     if (g_swig_init_callback)
         g_swig_init_callback ();
 
@@ -3095,20 +3075,8 @@ ScriptInterpreterPython::InitializePrivate ()
         }
     }
 
-    // Importing 'lldb' module calls SBDebugger::Initialize, which calls Debugger::Initialize, which increments a
-    // global debugger ref-count; therefore we need to check the ref-count before and after importing lldb, and if the
-    // ref-count increased we need to call Debugger::Terminate here to decrement the ref-count so that when the final 
-    // call to Debugger::Terminate is made, the ref-count has the correct value. 
-    
-    int old_count = Debugger::TestDebuggerRefCount ();
-
     PyRun_SimpleString ("sys.dont_write_bytecode = 1; import lldb.embedded_interpreter; from lldb.embedded_interpreter import run_python_interpreter; from lldb.embedded_interpreter import run_one_line");
 
-    int new_count = Debugger::TestDebuggerRefCount ();
-    
-    if (new_count > old_count)
-        Debugger::Terminate ();
-
     if (threads_already_initialized) {
         if (log)
             log->Printf("Releasing PyGILState. Returning to state = %slocked\n", gstate == PyGILState_UNLOCKED ? "un" : "");