[lldb-dap] Correctly trigger 'entry' stop reasons. (#165901)

Noticed this while looking into test stability that the 'entry' stop
reason is not triggering correctly. This should ensure we correctly
trigger the 'entry' stop reason when launching a process with
`"stopOnEntry": true`. I've also updated the tests to ensure we receive
the 'entry' stop reason to catch this regression.

Author: ashgti

lldb/packages/Python/lldbsuite/test/tools/lldb-dap/lldbdap_testcase.py

@@ -223,6 +223,16 @@ def verify_stop_exception_info(self, expected_description):
                     return True
         return False
 
+    def verify_stop_on_entry(self) -> None:
+        """Waits for the process to be stopped and then verifies at least one
+        thread has the stop reason 'entry'."""
+        self.dap_server.wait_for_stopped()
+        self.assertIn(
+            "entry",
+            (t["reason"] for t in self.dap_server.thread_stop_reasons.values()),
+            "Expected at least one thread to report stop reason 'entry' in {self.dap_server.thread_stop_reasons}",
+        )
+
     def verify_commands(self, flavor: str, output: str, commands: list[str]):
         self.assertTrue(output and len(output) > 0, "expect console output")
         lines = output.splitlines()

lldb/test/API/tools/lldb-dap/restart/TestDAP_restart.py

@@ -51,20 +51,8 @@ def test_stopOnEntry(self):
         self.build_and_launch(program, stopOnEntry=True)
         [bp_main] = self.set_function_breakpoints(["main"])
 
-        self.dap_server.request_configurationDone()
-        self.dap_server.wait_for_stopped()
-        # Once the "configuration done" event is sent, we should get a stopped
-        # event immediately because of stopOnEntry.
-        self.assertTrue(
-            len(self.dap_server.thread_stop_reasons) > 0,
-            "expected stopped event during launch",
-        )
-        for _, body in self.dap_server.thread_stop_reasons.items():
-            if "reason" in body:
-                reason = body["reason"]
-                self.assertNotEqual(
-                    reason, "breakpoint", 'verify stop isn\'t "main" breakpoint'
-                )
+        self.continue_to_next_stop()
+        self.verify_stop_on_entry()
 
         # Then, if we continue, we should hit the breakpoint at main.
         self.continue_to_breakpoints([bp_main])
@@ -73,17 +61,7 @@ def test_stopOnEntry(self):
         # main.
         resp = self.dap_server.request_restart()
         self.assertTrue(resp["success"])
-        stopped_events = self.dap_server.wait_for_stopped()
-        for stopped_event in stopped_events:
-            if "body" in stopped_event:
-                body = stopped_event["body"]
-                if "reason" in body:
-                    reason = body["reason"]
-                    self.assertNotEqual(
-                        reason,
-                        "breakpoint",
-                        'verify stop after restart isn\'t "main" breakpoint',
-                    )
+        self.verify_stop_on_entry()
 
     @skipIfWindows
     def test_arguments(self):

lldb/test/API/tools/lldb-dap/restart/TestDAP_restart_console.py

@@ -11,27 +11,6 @@
 
 @skipIfBuildType(["debug"])
 class TestDAP_restart_console(lldbdap_testcase.DAPTestCaseBase):
-    def verify_stopped_on_entry(self, stopped_events: List[Dict[str, Any]]):
-        seen_stopped_event = 0
-        for stopped_event in stopped_events:
-            body = stopped_event.get("body")
-            if body is None:
-                continue
-
-            reason = body.get("reason")
-            if reason is None:
-                continue
-
-            self.assertNotEqual(
-                reason,
-                "breakpoint",
-                'verify stop after restart isn\'t "main" breakpoint',
-            )
-            if reason == "entry":
-                seen_stopped_event += 1
-
-        self.assertEqual(seen_stopped_event, 1, "expect only one stopped entry event.")
-
     @skipIfAsan
     @skipIfWindows
     @skipIf(oslist=["linux"], archs=["arm$"])  # Always times out on buildbot
@@ -92,11 +71,8 @@ def test_stopOnEntry(self):
         self.build_and_launch(program, console="integratedTerminal", stopOnEntry=True)
         [bp_main] = self.set_function_breakpoints(["main"])
 
-        self.dap_server.request_continue()  # sends configuration done
-        stopped_events = self.dap_server.wait_for_stopped()
-        # We should be stopped at the entry point.
-        self.assertGreaterEqual(len(stopped_events), 0, "expect stopped events")
-        self.verify_stopped_on_entry(stopped_events)
+        self.dap_server.request_configurationDone()
+        self.verify_stop_on_entry()
 
         # Then, if we continue, we should hit the breakpoint at main.
         self.dap_server.request_continue()
@@ -105,8 +81,7 @@ def test_stopOnEntry(self):
         # Restart and check that we still get a stopped event before reaching
         # main.
         self.dap_server.request_restart()
-        stopped_events = self.dap_server.wait_for_stopped()
-        self.verify_stopped_on_entry(stopped_events)
+        self.verify_stop_on_entry()
 
         # continue to main
         self.dap_server.request_continue()

lldb/tools/lldb-dap/EventHelper.cpp

@@ -176,7 +176,7 @@ llvm::Error SendThreadStoppedEvent(DAP &dap, bool on_entry) {
 
   llvm::DenseSet<lldb::tid_t> old_thread_ids;
   old_thread_ids.swap(dap.thread_ids);
-  uint32_t stop_id = process.GetStopID();
+  uint32_t stop_id = on_entry ? 0 : process.GetStopID();
   const uint32_t num_threads = process.GetNumThreads();
 
   // First make a pass through the threads to see if the focused thread

lldb/tools/lldb-dap/JSONUtils.cpp

@@ -711,7 +711,7 @@ llvm::json::Value CreateThreadStopped(DAP &dap, lldb::SBThread &thread,
     break;
   }
   if (stop_id == 0)
-    body.try_emplace("reason", "entry");
+    body["reason"] = "entry";
   const lldb::tid_t tid = thread.GetThreadID();
   body.try_emplace("threadId", (int64_t)tid);
   // If no description has been set, then set it to the default thread stopped