Add exec_c and eval_c

[kailando]

Feature or enhancement

Proposal:

I want to add two functions to the CPython programming language. They interact with the CPython backend itself. Here they are:

exec_c()
eval_c()

It would make Python way more customizable.
They would have full access to the global variables of the backend, so it could be used as an extender for the project,
or you could use it to test a driver, say:
You have a driver that nullifies BugKeCheck2 (the function that raises BSODs) and want to test it, but don't have gcc, etc...
You are familiar with Python, but you know you have to raise it from low(er)-level C, so you do:

exec_c("BugKeCheck.BugKeCheck1.BugKeCheck2();", accept_errors=True)

Example:

# P.S.: I don't know how to code in C, so im using what I do know
exec_c('"Hello" >> stdout;') # None
eval_c('"Hello" >> stdout;') # "Hello"

[EDIT: I am not a big fan of this anymore.]

Has this already been discussed elsewhere?

This is a minor feature [EDIT: This is proven otherwise, as it "needs a PEP" (-@sobolevn. Nov 10, 2024)], which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

[gaogaotiantian]

Interesting idea, but how could Python execute C code without a C compiler? It's a very big project to be able to run arbitrary C code in a script language. I don't believe this is something CPython currently intends to do.

Also, for big features like this, you should discuss it in discuss.python.org first :)

[ericvsmith]

Feature requests should be discussed on discuss.python.org. I'm going to close this, it can be reopened if it's accepted after that discussion.

[ZeroIntensity]

Well, this wouldn't be possible to implement, unless we decided it would be a good idea to spend a few years developing our own C compiler. With that being said, this is probably my favorite feature idea ever 😄

[vasily-v-ryabov]

There is a 3rd-party package cppyy which can do exactly the same. It is a Python wrapped C/C++ JIT compiler cling.

Also Python standard library has module ctypes which load DLL or SO binary library and call any function that may be written originally in pure C programming language. For other languages there are some bindings like PyO3 for Rust which do the same interoperability with already compiled code.

New proposals should be clearly compared with such existing solutions.

[sobolevn]

Bun JS runtime allows something similar: https://bun.sh/blog/compile-and-run-c-in-js
It uses tinycc inside and compiles C code on the fly.

It might be a fun idea for a side project.

[kailando]

Ok, I will talk about this on the CPython forum, but this is a minor feature so I wouldn't expect it to go there.

[kailando]

Interesting idea, but how could Python execute C code without a C compiler? It's a very big project to be able to run arbitrary C code in a script language. I don't believe this is something CPython currently intends to do.

Also, for big features like this, you should discuss it in discuss.python.org first :)

I don't think this would be classified as a big feature.

[sobolevn]

@kailando it is. It will also require a PEP.

[kailando]

@sobolevn Why would it need a PEP?
Also, I'm gonna cancel this idea, because I'm not a big fan of it anymore.

[ZeroIntensity]

Because additions to builtins require PEPs, and the maintenance cost would be huge.

Also, I'm gonna cancel this idea, because I'm not a big fan of it anymore.

I still think this is a super fun idea, but I also think that there's a better chance of Python 4 being released tomorrow than this ever getting accepted.