Fix exception description in lldb-vscode

[yinghuitan]

Summary

There is a bug in lldb-vscode that only shows stop reason ("exception") in
stopped event without showing the stop description of thrown exception. This
causes VSCode UI to only show "Paused on Exception" general message in
callstack window UI.

This patch fixes the bug so that VSCode callstack will show the detailed
exceptioni description, like "signal SIGABRT" or "EXC_BAD_ACCESS..." which
aligns with command line lldb experience.

I use C++ exception in testcase because the hardware exception description is
platform dependent and hard to verify.

[labath]

If you're explicitly checking for SIGABRT, then you might as well raise that signal directly (raise(SIGABRT)) instead of relying on the runtime to do it (in response to an unhandled exception). Or, if you want this to work on windows, then you'll need to adjust the expectation for the fact that this will be reported differently there (I don't know how, but it will definitely not be SIGABRT).

[yinghuitan]

Directly raise signal.

[yinghuitan]

Fix comment

lldb/packages/Python/lldbsuite/test/tools/lldb-vscode/lldbvscode_testcase.py

def verify_breakpoint_hit(self, breakpoint_ids):
                 # location.
                 description = body['description']
                 for breakpoint_id in breakpoint_ids:
                     match_desc = 'breakpoint %s.' % (breakpoint_id)
                     if match_desc in description:
                         return
         self.assertTrue(False, "breakpoint not hit")
 
-    def verify_exception_breakpoint_hit(self, filter_label):
+    def verify_stop_exception_info(self, expected_description):
         '''Wait for the process we are debugging to stop, and verify the stop
            reason is 'exception' and that the description matches
-           'filter_label'
+           'expected_description'
         '''
         stopped_events = self.vscode.wait_for_stopped()
         for stopped_event in stopped_events:
             if 'body' in stopped_event:
                 body = stopped_event['body']
                 if 'reason' not in body:
                     continue
                 if body['reason'] != 'exception':
                     continue
                 if 'description' not in body:
                     continue
                 description = body['description']
-                if filter_label == description:
+                if expected_description == description:
                     return True
         return False
 
     def verify_commands(self, flavor, output, commands):
         self.assertTrue(output and len(output) > 0, "expect console output")
         lines = output.splitlines()
         prefix = '(lldb) '
         for cmd in commands:
def continue_to_next_stop(self):
         return self.vscode.wait_for_stopped()
 
     def continue_to_breakpoints(self, breakpoint_ids):
         self.vscode.request_continue()
         self.verify_breakpoint_hit(breakpoint_ids)
 
     def continue_to_exception_breakpoint(self, filter_label):
         self.vscode.request_continue()
-        self.assertTrue(self.verify_exception_breakpoint_hit(filter_label),
+        self.assertTrue(self.verify_stop_exception_info(filter_label),
                         'verify we got "%s"' % (filter_label))
 
     def continue_to_exit(self, exitCode=0):
         self.vscode.request_continue()
         stopped_events = self.vscode.wait_for_stopped()
         self.assertEquals(len(stopped_events), 1,
                         "stopped_events = {}".format(stopped_events))
         self.assertEquals(stopped_events[0]['event'], 'exited',

lldb/test/API/tools/lldb-vscode/exception/Makefile

+CXX_SOURCES := main.cpp
+
+include Makefile.rules

lldb/test/API/tools/lldb-vscode/exception/TestVSCode_exception.py

+"""
+Test exception behavior in VSCode
+"""
+
+
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+import lldbvscode_testcase
+
+
+class TestVSCode_exception(lldbvscode_testcase.VSCodeTestCaseBase):
+
+    @skipIfWindows
+    def test_stopped_description(self):
+        '''
+            Test that exception description is shown correctly in stopped
+            event.
+        '''
+        program = self.getBuildArtifact("a.out")
+        print("test_stopped_description called", flush=True)
+        self.build_and_launch(program)
+
+        self.vscode.request_continue()
+        self.assertTrue(self.verify_stop_exception_info("signal SIGABRT"))

lldb/test/API/tools/lldb-vscode/exception/main.cpp

+#include <signal.h>
+
+int main() {
+  raise(SIGABRT);
+  return 0;
+}

lldb/tools/lldb-vscode/JSONUtils.cpp

llvm::json::Value CreateThreadStopped(lldb::SBThread &thread,
   }
   if (stop_id == 0)
     body.try_emplace("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
   // description. If we have breakpoints that get hit and shouldn't be reported
   // as breakpoints, then they will set the description above.
-  if (ObjectContainsKey(body, "description")) {
+  if (!ObjectContainsKey(body, "description")) {
     char description[1024];
     if (thread.GetStopDescription(description, sizeof(description))) {
       EmplaceSafeString(body, "description", std::string(description));
     }
   }
   if (tid == g_vsc.focus_tid) {
     body.try_emplace("threadCausedFocus", true);
   }