https://github.com/python/cpython/commit/8bcf118dcb2cab88acc8a6dffb7968b1854802b4 commit: 8bcf118dcb2cab88acc8a6dffb7968b1854802b4 branch: main author: Irit Katriel <[email protected]> committer: iritkatriel <[email protected]> date: 2024-10-05T00:48:12+01:00 summary:
gh-119786: move a few more details on exception handling from devguide to InternalDocs (#124989) files: M InternalDocs/exception_handling.md diff --git a/InternalDocs/exception_handling.md b/InternalDocs/exception_handling.md index ec09e0769929fa..2e306c7046e237 100644 --- a/InternalDocs/exception_handling.md +++ b/InternalDocs/exception_handling.md @@ -75,7 +75,8 @@ table. If it finds a handler, control flow transfers to it. Otherwise, the exception bubbles up to the caller, and the caller's frame is checked for a handler covering the `CALL` instruction. This repeats until a handler is found or the topmost frame is reached. -If no handler is found, the program terminates. During unwinding, +If no handler is found, then the interpreter function +(``_PyEval_EvalFrameDefault()``) returns NULL. During unwinding, the traceback is constructed as each frame is added to it by ``PyTraceBack_Here()``, which is in [Python/traceback.c](https://github.com/python/cpython/blob/main/Python/traceback.c). @@ -182,3 +183,12 @@ The interpreter's function to lookup the table by instruction offset is The Python function ``_parse_exception_table()`` in [Lib/dis.py](https://github.com/python/cpython/blob/main/Lib/dis.py) returns the exception table content as a list of namedtuple instances. + +Exception Chaining Implementation +--------------------------------- + +[Exception chaining](https://docs.python.org/dev/tutorial/errors.html#exception-chaining) +refers to setting the ``__context__`` and ``__cause__`` fields of an exception as it is +being raised. The ``__context__`` field is set by ``_PyErr_SetObject()`` in +:cpy-file:`Python/errors.c` (which is ultimately called by all ``PyErr_Set*()`` functions). +The ``__cause__`` field (explicit chaining) is set by the ``RAISE_VARARGS`` bytecode. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
