Add unstable C APIs for allocation-free raw-frame stack inspection

Feature or enhancement

Proposal:

https://github.com/python/cpython/issues/145559 proposes a signal-safe mechanism to print backtraces. This is useful for human debugging, but not ideal for tools because it requires parsing human-readable text. For example, a crash-tracker may wish to export and analyze structured backtraces. Similarly, a profiler can benefit from the ability to generate structure stack-traces in pure C, without needing to reason about the safety of reentering the python interpreter.

Has this already been discussed elsewhere?

I have already discussed this feature proposal on Discourse

Links to previous discussion of this feature:

https://discuss.python.org/t/pure-c-structured-traceback/106872/8

Linked PRs

• gh-148930