linux.git/scripts/rust_is_available.sh, branch v6.6.131

rust: work around `bindgen` 0.69.0 issue

2024-08-29T15:33:29+00:00

[ Upstream commit 9e98db17837093cb0f4dcfcc3524739d93249c45 ]

`bindgen` 0.69.0 contains a bug: `--version` does not work without
providing a header [1]:

    error: the following required arguments were not provided:
      

    Usage: bindgen    -- ...

Thus, in preparation for supporting several `bindgen` versions, work
around the issue by passing a dummy argument.

Include a comment so that we can remove the workaround in the future.

Link: https://github.com/rust-lang/rust-bindgen/pull/2678 [1]
Reviewed-by: Finn Behrens 
Tested-by: Benno Lossin 
Tested-by: Andreas Hindborg 
Link: https://lore.kernel.org/r/20240709160615.998336-9-ojeda@kernel.org
Signed-off-by: Miguel Ojeda 
Stable-dep-of: 5ce86c6c8613 ("rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT")
Signed-off-by: Sasha Levin

kbuild: rust_is_available: check that output looks as expected

2023-08-09T23:18:34+00:00

The script already checks for `$RUSTC` and `$BINDGEN` existing
and exiting without failure. However, one may still pass an
unexpected binary that does not output what the later parsing
expects. The script still successfully reports a failure as
expected, but the error is confusing. For instance:

    $ RUSTC=true BINDGEN=bindgen CC=clang scripts/rust_is_available.sh
    scripts/rust_is_available.sh: 19: arithmetic expression: expecting primary: "100000 *  + 100 *  + "
    ***
    *** Please see Documentation/rust/quick-start.rst for details
    *** on how to set up the Rust support.
    ***

Thus add an explicit check and a proper message for unexpected
output from the called command.

Similarly, do so for the `libclang` version parsing, too.

Link: https://lore.kernel.org/rust-for-linux/CAK7LNAQYk6s11MASRHW6oxtkqF00EJVqhHOP=5rynWt-QDUsXw@mail.gmail.com/
Reviewed-by: Nathan Chancellor 
Reviewed-by: Martin Rodriguez Reboredo 
Link: https://lore.kernel.org/r/20230616001631.463536-11-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: handle failures calling `$RUSTC`/`$BINDGEN`

2023-08-09T23:18:34+00:00

The script already checks if `$RUSTC` and `$BINDGEN` exists via
`command`, but the environment variables may point to a
non-executable file, or the programs may fail for some other reason.
While the script successfully exits with a failure as it should,
the error given can be quite confusing depending on the shell and
the behavior of its `command`. For instance, with `dash`:

    $ RUSTC=./mm BINDGEN=bindgen CC=clang scripts/rust_is_available.sh
    scripts/rust_is_available.sh: 19: arithmetic expression: expecting primary: "100000 *  + 100 *  + "

Thus detect failure exit codes when calling `$RUSTC` and `$BINDGEN` and
print a better message, in a similar way to what we do when extracting
the `libclang` version found by `bindgen`.

Link: https://lore.kernel.org/rust-for-linux/CAK7LNAQYk6s11MASRHW6oxtkqF00EJVqhHOP=5rynWt-QDUsXw@mail.gmail.com/
Reviewed-by: Nathan Chancellor 
Reviewed-by: Martin Rodriguez Reboredo 
Link: https://lore.kernel.org/r/20230616001631.463536-10-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: normalize version matching

2023-08-09T23:18:34+00:00

In order to match the version string, `sed` is used in a couple
cases, and `grep` and `head` in a couple others.

Make the script more consistent and easier to understand by
using the same method, `sed`, for all of them.

This makes the version matching also a bit more strict for
the changed cases, since the strings `rustc ` and `bindgen `
will now be required, which should be fine since `rustc`
complains if one attempts to call it with another program
name, and `bindgen` uses a hardcoded string.

In addition, clarify why one of the existing `sed` commands
does not provide an address like the others.

Reviewed-by: Nathan Chancellor 
Reviewed-by: Masahiro Yamada 
Reviewed-by: Martin Rodriguez Reboredo 
Link: https://lore.kernel.org/r/20230616001631.463536-9-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: fix confusion when a version appears in the path

2023-08-09T23:18:22+00:00

`bindgen`'s output for `libclang`'s version check contains paths, which
in turn may contain strings that look like version numbers [1][2]:

    .../6.1.0-dev/.../rust_is_available_bindgen_libclang.h:2:9: warning: clang version 11.1.0  [-W#pragma-messages], err: false

which the script will pick up as the version instead of the latter.

It is also the case that versions may appear after the actual version
(e.g. distribution's version text), which was the reason behind `head` [3]:

    .../rust-is-available-bindgen-libclang.h:2:9: warning: clang version 13.0.0 (Fedora 13.0.0-3.fc35) [-W#pragma-messages], err: false

Thus instead ask for a match after the `clang version` string.

Reported-by: Jordan Isaacs 
Closes: https://github.com/Rust-for-Linux/linux/issues/942 [1]
Reported-by: "Ethan D. Twardy" 
Closes: https://lore.kernel.org/rust-for-linux/20230528131802.6390-2-ethan.twardy@gmail.com/ [2]
Reported-by: Tiago Lam 
Closes: https://github.com/Rust-for-Linux/linux/pull/789 [3]
Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`")
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Ethan Twardy 
Tested-by: Ethan Twardy 
Reviewed-by: Nathan Chancellor 
Link: https://lore.kernel.org/r/20230616001631.463536-8-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: check that environment variables are set

2023-08-09T17:33:31+00:00

Sometimes [1] users may attempt to setup the Rust support by
checking what Kbuild does and they end up finding out about
`scripts/rust_is_available.sh`. Inevitably, they run the script
directly, but unless they setup the required variables,
the result of the script is not meaningful.

We could add some defaults to the variables, but that could be
confusing for those that may override the defaults (compared
to their kernel builds), and `$CC` would not be a simple default
in any case.

Therefore, instead, explicitly check whether the expected variables
are set (`$RUSTC`, `$BINDGEN` and `$CC`). If not, print an explanation
about the fact that the script is meant to be called from Kbuild,
since that is the most likely cause for the variables not being set.

Link: https://lore.kernel.org/oe-kbuild-all/Y6r4mXz5NS0+HVXo@zn.tnic/ [1]
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Nathan Chancellor 
Link: https://lore.kernel.org/r/20230616001631.463536-7-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: add check for `bindgen` invocation

2023-08-09T17:33:31+00:00

`scripts/rust_is_available.sh` calls `bindgen` with a special
header in order to check whether the `libclang` version in use
is suitable.

However, the invocation itself may fail if, for instance, `bindgen`
cannot locate `libclang`. This is fine for Kconfig (since the
script will still fail and therefore disable Rust as it should),
but it is pretty confusing for users of the `rustavailable` target
given the error will be unrelated:

    ./scripts/rust_is_available.sh: 21: arithmetic expression: expecting primary: "100000 *  + 100 *  + "
    make: *** [Makefile:1816: rustavailable] Error 2

Instead, run the `bindgen` invocation independently in a previous
step, saving its output and return code. If it fails, then show
the user a proper error message. Otherwise, continue as usual
with the saved output.

Since the previous patch we show a reference to the docs, and
the docs now explain how `bindgen` looks for `libclang`,
thus the error message can leverage the documentation, avoiding
duplication here (and making users aware of the setup guide in
the documentation).

Reported-by: Nick Desaulniers 
Link: https://lore.kernel.org/rust-for-linux/CAKwvOdm5JT4wbdQQYuW+RT07rCi6whGBM2iUAyg8A1CmLXG6Nw@mail.gmail.com/
Reported-by: François Valenduc 
Closes: https://github.com/Rust-for-Linux/linux/issues/934
Reported-by: Alexandru Radovici 
Closes: https://github.com/Rust-for-Linux/linux/pull/921
Reported-by: Matthew Leach 
Closes: https://lore.kernel.org/rust-for-linux/20230507084116.1099067-1-dev@mattleach.net/
Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`")
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Masahiro Yamada 
Reviewed-by: Nathan Chancellor 
Link: https://lore.kernel.org/r/20230616001631.463536-6-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: print docs reference

2023-08-09T17:33:31+00:00

People trying out the Rust support in the kernel may get
warnings and errors from `scripts/rust_is_available.sh`
from the `rustavailable` target or the build step.

Some of those users may be following the Quick Start guide,
but others may not (likely those getting warnings from
the build step instead of the target).

While the messages are fairly clear on what the problem is,
it may not be clear how to solve the particular issue,
especially for those not aware of the documentation.

We could add all sorts of details on the script for each one,
but it is better to point users to the documentation instead,
where it is easily readable in different formats. It also
avoids duplication.

Thus add a reference to the documentation whenever the script
fails or there is at least a warning.

Reviewed-by: Finn Behrens 
Reviewed-by: Masahiro Yamada 
Reviewed-by: Nathan Chancellor 
Reviewed-by: Martin Rodriguez Reboredo 
Link: https://lore.kernel.org/r/20230616001631.463536-5-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: fix version check when CC has multiple arguments

2023-08-09T17:33:31+00:00

rust_is_available.sh uses cc-version.sh to identify which C compiler is
in use, as scripts/Kconfig.include does.  cc-version.sh isn't designed to
be able to handle multiple arguments in one variable, i.e. "ccache clang".
Its invocation in rust_is_available.sh quotes "$CC", which makes
$1 == "ccache clang" instead of the intended $1 == ccache & $2 == clang.

cc-version.sh could also be changed to handle having "ccache clang" as one
argument, but it only has the one consumer upstream, making it simpler to
fix the caller here.

Signed-off-by: Russell Currey 
Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`")
Link: https://github.com/Rust-for-Linux/linux/pull/873
[ Reworded title prefix and reflow line to 75 columns. ]
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Nathan Chancellor 
Link: https://lore.kernel.org/r/20230616001631.463536-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

kbuild: rust_is_available: remove -v option

2023-08-09T17:33:30+00:00

The -v option is passed when this script is invoked from Makefile,
but not when invoked from Kconfig.

As you can see in scripts/Kconfig.include, the 'success' macro suppresses
stdout and stderr anyway, so this script does not need to be quiet.

Signed-off-by: Masahiro Yamada 
Reviewed-by: Miguel Ojeda 
Tested-by: Miguel Ojeda 
Reviewed-by: Nathan Chancellor 
Link: https://lore.kernel.org/r/20230109061436.3146442-1-masahiroy@kernel.org
[ Reworded prefix to match the others in the patch series. ]
Reviewed-by: Martin Rodriguez Reboredo 
Link: https://lore.kernel.org/r/20230616001631.463536-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda