Re: Missing RUST_EXAMPLE option in linux-next-20210331

Re: Missing RUST_EXAMPLE option in linux-next-20210331

[Manas]

I am working on a device driver in rust in linux-next as an academic
project. I used the following command to create .config:

$ make LLVM=1 menuconfig

But, sometimes the RUST_EXAMPLE option is not visible in menuconfig
(under /Device Drivers/Character devices/). It seemingly happens at
random that this option disappears, despite having a working rust 
nightly environment (and other dependencies).

My rust nightly version is 2021-02-20-x86_64-unknown-linux-gnu, with 
rustc 1.52.0-nightly.

Can someone point me to why is this happening?

Thank you
-- 
Manas
CSAM Undergraduate | 2022
IIIT-Delhi, India

Re: Missing RUST_EXAMPLE option in linux-next-20210331

[Geert Stappers]

On Thu, Apr 01, 2021 at 11:48:40AM +0530, Manas wrote:
> I am working on a device driver in rust in linux-next as an academic
> project. I used the following command to create .config:
> 
> $ make LLVM=1 menuconfig
> 
> But, sometimes the RUST_EXAMPLE option is not visible in menuconfig
> (under /Device Drivers/Character devices/). It seemingly happens at
> random that this option disappears, despite having a working rust 
> nightly environment (and other dependencies).
> 
> My rust nightly version is 2021-02-20-x86_64-unknown-linux-gnu, with 
> rustc 1.52.0-nightly.
> 
> Can someone point me to why is this happening?

Time will answer that question.


Thing I would like to known if this "randomness" happens
in the very same git branch. Does it? [Yes/No]


Groeten
Geert Stappers
-- 
Silence is hard to parse

Re: Missing RUST_EXAMPLE option in linux-next-20210331

[Manas]

On Thu, Apr 01, 2021 at 01:31:10PM +0200, Geert Stappers wrote:
> On Thu, Apr 01, 2021 at 11:48:40AM +0530, Manas wrote:
> > I am working on a device driver in rust in linux-next as an academic
> > project. I used the following command to create .config:
> > 
> > $ make LLVM=1 menuconfig
> > 
> > But, sometimes the RUST_EXAMPLE option is not visible in menuconfig
> > (under /Device Drivers/Character devices/). It seemingly happens at
> > random that this option disappears, despite having a working rust 
> > nightly environment (and other dependencies).
> > 
> > My rust nightly version is 2021-02-20-x86_64-unknown-linux-gnu, with 
> > rustc 1.52.0-nightly.
> > 
> > Can someone point me to why is this happening?
> 
> Time will answer that question.
> 
> 
> Thing I would like to known if this "randomness" happens
> in the very same git branch. Does it? [Yes/No]
> 
I am not sure. I haven't checked with other branches.

-- 
Manas
CSAM Undergraduate | 2022
IIIT-Delhi, India

Re: Missing RUST_EXAMPLE option in linux-next-20210331

[Miguel Ojeda]

Hi Manas,

On Thu, Apr 1, 2021 at 8:19 AM Manas <manas18244@iiitd.ac.in> wrote:
>
> I am working on a device driver in rust in linux-next as an academic
> project. I used the following command to create .config:
>
> $ make LLVM=1 menuconfig
>
> But, sometimes the RUST_EXAMPLE option is not visible in menuconfig
> (under /Device Drivers/Character devices/). It seemingly happens at
> random that this option disappears, despite having a working rust
> nightly environment (and other dependencies).
>
> My rust nightly version is 2021-02-20-x86_64-unknown-linux-gnu, with
> rustc 1.52.0-nightly.
>
> Can someone point me to why is this happening?

Rust support in the kernel (`RUST`) defaults to off at the moment, so
if created a new configuration from scratch, it is likely that it
ended up disabled, which in turn makes everything that depends on Rust
disappear, including `RUST_EXAMPLE`.

Please check in `General setup` --> `Rust support` if it is enabled.

HTH,

Cheers,
Miguel

Re: Missing RUST_EXAMPLE option in linux-next-20210331

[Geert Stappers]

On Thu, Apr 01, 2021 at 05:29:05PM +0530, Manas wrote:
> On Thu, Apr 01, 2021 at 01:31:10PM +0200, Geert Stappers wrote:
> > On Thu, Apr 01, 2021 at 11:48:40AM +0530, Manas wrote:
> > > I am working on a device driver in rust in linux-next as an academic
> > > project. I used the following command to create .config:
> > > 
> > > $ make LLVM=1 menuconfig
> > > 
> > > But, sometimes the RUST_EXAMPLE option is not visible in menuconfig
> > > (under /Device Drivers/Character devices/). It seemingly happens at
> > > random that this option disappears, despite having a working rust 
> > > nightly environment (and other dependencies).
> > > 
> > > My rust nightly version is 2021-02-20-x86_64-unknown-linux-gnu, with 
> > > rustc 1.52.0-nightly.
> > > 
> > > Can someone point me to why is this happening?
> > 
> > Time will answer that question.

https://lore.kernel.org/rust-for-linux/CANiq72kjwKuRCzeB54JPpCfBO7hfzZKAoAHBtbSBAzfvZY8d0A@mail.gmail.com/T/#mcd107c4fc625cadd6d812ae3d2d191c498f5943b
and hopefully will the archive known how good that answer was.
(in other words: Do a reply to all on the Miguel Ojeda posting.)

> > Thing I would like to known if this "randomness" happens
> > in the very same git branch. Does it? [Yes/No]
> > 
> I am not sure. I haven't checked with other branches.

No need to check that, consider it done.  The
} } Does it happen in the same git branch?
is being answered with something like
} Yes, all work was done in same git branch,
} there was no switching between branches.

OK


Groeten
Geert Stappers
-- 
Silence is hard to parse

Re: Missing RUST_EXAMPLE option in linux-next-20210331

[Manas]

On Thu, Apr 01, 2021 at 05:07:06PM +0200, Miguel Ojeda wrote:
> Hi Manas,
> 
> On Thu, Apr 1, 2021 at 8:19 AM Manas <manas18244@iiitd.ac.in> wrote:
> >
> > I am working on a device driver in rust in linux-next as an academic
> > project. I used the following command to create .config:
> >
> > $ make LLVM=1 menuconfig
> >
> > But, sometimes the RUST_EXAMPLE option is not visible in menuconfig
> > (under /Device Drivers/Character devices/). It seemingly happens at
> > random that this option disappears, despite having a working rust
> > nightly environment (and other dependencies).
> >
> > My rust nightly version is 2021-02-20-x86_64-unknown-linux-gnu, with
> > rustc 1.52.0-nightly.
> >
> > Can someone point me to why is this happening?
> 
> Rust support in the kernel (`RUST`) defaults to off at the moment, so
> if created a new configuration from scratch, it is likely that it
> ended up disabled, which in turn makes everything that depends on Rust
> disappear, including `RUST_EXAMPLE`.
> 
> Please check in `General setup` --> `Rust support` if it is enabled.
It was also not present.

Nevertheless, I tweaked around a little bit and found that when I enabled
CONFIG_COMPILE_TEST, then it removed CONFIG_RUST and RUST_EXAMPLE,
(while HAS_RUST=y).

But CONFIG_COMPILE_TEST's documentation mentions to enable it to build
everything. This confused me at that moment.

-- 
Manas
CSAM Undergraduate | 2022
IIIT-Delhi, India

Re: Missing RUST_EXAMPLE option in linux-next-20210331

[Miguel Ojeda]

On Fri, Apr 2, 2021 at 2:35 AM Manas <manas18244@iiitd.ac.in> wrote:
>
> It was also not present.
>
> Nevertheless, I tweaked around a little bit and found that when I enabled
> CONFIG_COMPILE_TEST, then it removed CONFIG_RUST and RUST_EXAMPLE,
> (while HAS_RUST=y).
>
> But CONFIG_COMPILE_TEST's documentation mentions to enable it to build
> everything. This confused me at that moment.

If "Rust support" (CONFIG_RUST) was not there either, it is because
`HAS_RUST` was off, or, as you found out, if `COMPILE_TEST` is
enabled.

The reason we depend on `!COMPILE_TEST` at the moment is to prevent
Rust support from being built in `allmodconfig` builds in linux-next
as a precaution until we are given the go ahead, but this will change
in the future.

Cheers,
Miguel

Re: Missing RUST_EXAMPLE option in linux-next-20210331

[Manas]

On Fri, Apr 02, 2021 at 03:19:30AM +0200, Miguel Ojeda wrote:
> If "Rust support" (CONFIG_RUST) was not there either, it is because
> `HAS_RUST` was off, or, as you found out, if `COMPILE_TEST` is
> enabled.
> 
> The reason we depend on `!COMPILE_TEST` at the moment is to prevent
> Rust support from being built in `allmodconfig` builds in linux-next
> as a precaution until we are given the go ahead, but this will change
> in the future.
> 
Understood.

Thanks a lot!
-- 
Manas
CSAM Undergraduate | 2022
IIIT-Delhi, India