Cleanup post_mortem implementation and interface a bit. Add as_uncaught flag which says whether to apply uncaught exception breakpoint filters, defaulting to True.

Author: nshepperd

src/debugpy/__init__.py

@@ -19,7 +19,7 @@
     "is_client_connected",
     "listen",
     "log_to",
-    "postmortem",
+    "post_mortem",
     "trace_this_thread",
     "wait_for_client",
 ]

src/debugpy/_vendored/pydevd/_pydevd_sys_monitoring/_pydevd_sys_monitoring.py

@@ -1837,7 +1837,7 @@ def suspend_current_thread_tracing():
     Returns the previous tracing state (True if tracing was enabled, False otherwise).
     This is useful for temporarily disabling tracing to prevent recursive debugging.
 
-    Use resume_current_thread_tracing() or set_current_thread_tracing_state() to restore.
+    Use resume_current_thread_tracing() to restore.
     """
     try:
         thread_info = _thread_local_info.thread_info
@@ -1860,9 +1860,6 @@ def resume_current_thread_tracing():
 # fmt: on
     """
     Resumes tracing for the current thread.
-
-    This unconditionally enables tracing. For conditional restoration,
-    use set_current_thread_tracing_state().
     """
     try:
         thread_info = _thread_local_info.thread_info
@@ -1873,31 +1870,6 @@ def resume_current_thread_tracing():
     thread_info.trace = True
 
 
-# fmt: off
-# IFDEF CYTHON
-# cpdef set_current_thread_tracing_state(bint trace):
-#     cdef ThreadInfo thread_info
-# ELSE
-def set_current_thread_tracing_state(trace):
-# ENDIF
-# fmt: on
-    """
-    Sets the tracing state for the current thread.
-
-    :param trace: True to enable tracing, False to disable.
-
-    This is typically used to restore a previously saved state from
-    suspend_current_thread_tracing().
-    """
-    try:
-        thread_info = _thread_local_info.thread_info
-    except:
-        thread_info = _get_thread_info(False, 1)
-        if thread_info is None:
-            return
-    thread_info.trace = trace
-
-
 def update_monitor_events(suspend_requested: Optional[bool]=None) -> None:
     """
     This should be called when breakpoints change.

src/debugpy/_vendored/pydevd/pydevd.py

@@ -2392,6 +2392,51 @@ def do_stop_on_unhandled_exception(self, thread, frame, frames_byid, arg):
             remove_exception_from_frame(frame)
             frame = None
 
+    def post_mortem(self, excinfo, as_uncaught=True):
+        """
+        Triggers post-mortem debugging as if handling an uncaught exception.
+
+        If as_uncaught is True (default), respects exception breakpoint configuration and applies breakpoint filters.
+
+        :param excinfo: A tuple of (exc_type, exc_value, exc_traceback).
+        """
+        if not as_uncaught:
+            exctype, value, tb = excinfo
+
+            # Walk traceback to build frames list and find user frame
+            frames = []
+            user_frame = None
+            while tb is not None:
+                frame = tb.tb_frame
+                # Skip debugger-internal frames, use last user frame
+                if self.get_file_type(frame) is None:
+                    user_frame = frame
+                frames.append(frame)
+                tb = tb.tb_next
+
+            if user_frame is None:
+                pydev_log.debug("post_mortem: no user frame found in traceback")
+                return
+
+            frames_byid = dict([(id(frame), frame) for frame in frames])
+
+        if PYDEVD_USE_SYS_MONITORING:
+            saved_sys_monitoring_trace = pydevd_sys_monitoring.suspend_current_thread_tracing()
+        thread = threading.current_thread()
+        additional_info = self.set_additional_thread_info(thread)
+        additional_info.is_tracing += 1
+
+        try:
+            if as_uncaught:
+                self.stop_on_unhandled_exception(self, thread, additional_info, excinfo)
+            else:
+                self.do_stop_on_unhandled_exception(thread, user_frame, frames_byid, excinfo)
+        finally:
+            if PYDEVD_USE_SYS_MONITORING:
+                if saved_sys_monitoring_trace:
+                    pydevd_sys_monitoring.resume_current_thread_tracing()
+            additional_info.is_tracing -= 1
+
     def set_trace_for_frame_and_parents(self, thread_ident: Optional[int], frame, **kwargs):
         disable = kwargs.pop("disable", False)
         assert not kwargs

src/debugpy/public_api.py

@@ -213,8 +213,9 @@ def trace_this_thread(__should_trace: bool):
 
 
 @_api()
-def postmortem(
-    __excinfo: typing.Tuple[type, BaseException, typing.Any] | None = None
+def post_mortem(
+    __excinfo: typing.Tuple[type, BaseException, typing.Any] | None = None,
+    as_uncaught: bool = True,
 ) -> None:
     """Stops the debugger on an unhandled exception.
 

src/debugpy/server/api.py

@@ -366,7 +366,7 @@ def trace_this_thread(should_trace):
         pydb.disable_tracing()
 
 
-def postmortem(excinfo=None):
+def post_mortem(excinfo=None, as_uncaught=True):
     ensure_logging()
 
     if excinfo is None:
@@ -388,27 +388,5 @@ def postmortem(excinfo=None):
         log.warning("postmortem() ignored - no global debugger")
         return
 
-    thread = threading.current_thread()
-    additional_info = pydb.set_additional_thread_info(thread)
+    pydb.post_mortem(excinfo, as_uncaught=as_uncaught)
 
-    # Save states for restoration
-    saved_is_tracing = additional_info.is_tracing
-    saved_sys_monitoring_trace = None
-
-    try:
-        # Prevent recursive tracing (settrace protection)
-        additional_info.is_tracing += 1
-
-        # For Python 3.12+, suspend sys.monitoring tracing
-        if hasattr(sys, 'monitoring'):
-            from _pydevd_sys_monitoring import pydevd_sys_monitoring
-            saved_sys_monitoring_trace = pydevd_sys_monitoring.suspend_current_thread_tracing()
-
-        from _pydevd_bundle.pydevd_breakpoints import stop_on_unhandled_exception
-        stop_on_unhandled_exception(pydb, thread, additional_info, excinfo)
-
-    finally:
-        additional_info.is_tracing = saved_is_tracing
-        if saved_sys_monitoring_trace is not None:
-            from _pydevd_sys_monitoring import pydevd_sys_monitoring
-            pydevd_sys_monitoring.set_current_thread_tracing_state(saved_sys_monitoring_trace)