lldb: Set environment variable to detect when running lldb from Creator

Instead of relying on __name__ being 'lldbbridge', which can also
be the case if the lldbbridge.py script is imported into a plain
LLDB process, we can now look at the environment variable.

This also lets us break out early from __lldb_init_module
if the user has a `command script import llbdbridge.py`
in their .lldbinit, or is automatically loading the bridge
via the Qt Core debug script.

Change-Id: Id8168c692ef66ce50119b7426ca85c7bc99d9503
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

share/qtcreator/debugger/lldbbridge.py

@@ -2068,6 +2068,13 @@ class Tester(Dumper):
 
         lldb.SBDebugger.Destroy(self.debugger)
 
+if 'QT_CREATOR_LLDB_PROCESS' in os.environ:
+    # Initialize Qt Creator dumper
+    try:
+        theDumper = Dumper()
+    except Exception as error:
+        print('@\nstate="enginesetupfailed",error="{}"@\n'.format(error))
+
 # ------------------------------ For use in LLDB ------------------------------
 
 
@@ -2437,6 +2444,9 @@ class SyntheticChildrenProvider(SummaryProvider):
 
 def __lldb_init_module(debugger, internal_dict):
     # Module is being imported in an LLDB session
+    if 'QT_CREATOR_LLDB_PROCESS' in os.environ:
+        # Let Qt Creator take care of its own dumper
+        return
 
     if not __name__ == 'qt':
         # Make available under global 'qt' name for consistency,
@@ -2471,10 +2481,3 @@ def __lldb_init_module(debugger, internal_dict):
                            % ("qt.SyntheticChildrenProvider", type_category))
 
     debugger.HandleCommand('type category enable %s' % type_category)
-
-
-if __name__ == "lldbbridge":
-    try:
-        theDumper = Dumper()
-    except Exception as error:
-        print('@\nstate="enginesetupfailed",error="{}"@\n'.format(error))

src/plugins/debugger/lldb/lldbengine.cpp

@@ -179,6 +179,7 @@ void LldbEngine::setupEngine()
 
     showMessage("STARTING LLDB: " + lldbCmd.toUserOutput());
     Environment environment = runParameters().debugger.environment;
+    environment.appendOrSet("QT_CREATOR_LLDB_PROCESS", "1");
     environment.appendOrSet("PYTHONUNBUFFERED", "1");  // avoid flushing problem on macOS
     DebuggerItem::addAndroidLldbPythonEnv(lldbCmd, environment);