[lldb] Fix exception breakpoint not being resolved when set on dummy target

[poya]

Summary

Ensure that breakpoint ivar is properly set in exception breakpoint resolver so that exception breakpoints set on dummy targets are resolved once real targets are created and run.

[poya]

@jingham I think this might have slipped through the cracks, do you think you'll have time to help me review and commit this one, or advice on a suitable alternate reviewer?

[jingham]

Ack, sorry about that! This looks fine, thanks for chasing it down.

[poya]

Thanks, currently no commit access, so would like to ask you for that favor as well

[teemperor]

I can land this right now, thanks for the patch!

lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/cpp_exception/TestCPPExceptionBreakpoint.py

class TestCPPExceptionBreakpoint (TestBase):
     @add_test_categories(['pyapi'])
     @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr24538")
     @expectedFailureNetBSD
     def test_cpp_exception_breakpoint(self):
         """Test setting and hitting the C++ exception breakpoint."""
         self.build()
         self.do_cpp_exception_bkpt()
 
+    @add_test_categories(['pyapi'])
+    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr24538")
+    @expectedFailureNetBSD
+    def test_dummy_target_cpp_exception_breakpoint(self):
+        """Test setting and hitting the C++ exception breakpoint from dummy target."""
+        self.build()
+        self.do_dummy_target_cpp_exception_bkpt()
+
     def setUp(self):
         TestBase.setUp(self)
         self.main_source = "main.c"
         self.main_source_spec = lldb.SBFileSpec(self.main_source)
 
     def do_cpp_exception_bkpt(self):
         exe = self.getBuildArtifact("a.out")
         error = lldb.SBError()
def do_cpp_exception_bkpt(self):
         process = self.target.LaunchSimple(
             None, None, self.get_process_working_directory())
         self.assertTrue(process, PROCESS_IS_VALID)
 
         thread_list = lldbutil.get_threads_stopped_at_breakpoint(
             process, exception_bkpt)
         self.assertTrue(len(thread_list) == 1,
                         "One thread stopped at the exception breakpoint.")
+
+    def do_dummy_target_cpp_exception_bkpt(self):
+        exe = self.getBuildArtifact("a.out")
+        error = lldb.SBError()
+
+        dummy_exception_bkpt = self.dbg.GetDummyTarget().BreakpointCreateForException(
+            lldb.eLanguageTypeC_plus_plus, False, True)
+        self.assertTrue(
+            dummy_exception_bkpt.IsValid(),
+            "Created exception breakpoint in dummy target.")
+
+        self.target = self.dbg.CreateTarget(exe)
+        self.assertTrue(self.target, VALID_TARGET)
+
+        exception_bkpt = self.target.GetBreakpointAtIndex(0)
+        self.assertTrue(
+            exception_bkpt.IsValid(),
+            "Target primed with exception breakpoint from dummy target.")
+
+        process = self.target.LaunchSimple(
+            None, None, self.get_process_working_directory())
+        self.assertTrue(process, PROCESS_IS_VALID)
+
+        thread_list = lldbutil.get_threads_stopped_at_breakpoint(
+           process, exception_bkpt)
+        self.assertTrue(len(thread_list) == 1,
+                       "One thread stopped at the exception breakpoint.")

lldb/source/Target/LanguageRuntime.cpp

public:
   /// Methods for support type inquiry through isa, cast, and dyn_cast:
   static inline bool classof(const BreakpointResolverName *) { return true; }
   static inline bool classof(const BreakpointResolver *V) {
     return V->getResolverID() == BreakpointResolver::ExceptionResolver;
   }
 
 protected:
   BreakpointResolverSP CopyForBreakpoint(Breakpoint &breakpoint) override {
-    return BreakpointResolverSP(
+    BreakpointResolverSP ret_sp(
         new ExceptionBreakpointResolver(m_language, m_catch_bp, m_throw_bp));
+    ret_sp->SetBreakpoint(&breakpoint);
+    return ret_sp;
   }
 
   bool SetActualResolver() {
     ProcessSP process_sp;
     if (m_breakpoint) {
       process_sp = m_breakpoint->GetTarget().GetProcessSP();
       if (process_sp) {
         bool refreash_resolver = !m_actual_resolver_sp;