Re: [libgpiod][PATCH V9 0/8] libgpiod: Add Rust bindings

[Bartosz Golaszewski <brgl@xxxxxxxx>]

On Mon, Nov 7, 2022 at 10:57 AM Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
>
> Hello,
>
> Here is another version of the rust bindings, based of the master branch.
>
> Pushed here:
>
> https://github.com/vireshk/libgpiod v9
>
> V8->V9:
> - Merged the last patch (supporting Events) with the other patches.
> - Events implementation is simplified and made efficient. nth() is also
>   implemented for the iterator.
> - Unnecessary comment removed from Cargo.toml files.
> - Updated categories in libgpiod's Cargo.toml.
> - Updated gpio_events example to show cloned events live past another
>   read_edge_events().
> - Implement AsRawFd for Chip.
> - Other minor changes.
>
> V7->V8:
> - Several updates to cargo.toml files, like license, version, etc.
> - Removed Sync support for chip and gpiosim.
> - Implemented, in a separate patch, iterator support for Events.
> - Fixed missing SAFETY comments.
> - Fixed build for 32 bit systems.
> - Use errno::Errno.
> - Removed Clone derive for many structures, that store raw pointers.
> - line setting helpers return the object back, so another helper can be called
>   directly on them. Also made all helpers public and used the same in tests and
>   example for single configurations.
> - Enums for gpiosim constants.
> - New examples to demonstrate parallelism and event handling.
> - Separated out HTE tests and marked as #[ignore] now.
> - Updated commit subjects.
> - Other minor changes.
>
> V6->V7:
> - Don't let buffer read new events if the earlier events are still referenced.
> - BufferIntenal is gone now, to make the above work.
> - Update example and tests too for the same.
>
> V5->V6:
> - Updates according to the new line-settings interface.
> - New file, line_settings.rs.
> - Renamed 'enum Setting' as 'SettingVal' to avoid conflicting names, as we also
>   have 'struct Settings' now.
> - Support for HTE clock type.
> - Implement 'Eq' for public structure/enums (reported by build).
> - Remove 'SettingKindMap' and 'SettingMap' as they aren't required anymore.
> - Updated tests based on new interface.
>
> V4->V5:
> - Arrange as workspace with crates for libgpiod-sys, libgpiod, gpiosim.
> - Use static libgpiod and libgpiosim libraries instead of rebuilding again.
> - Arrange in modules instead of flattened approach.
> - New enums like Setting and SettingKind and new types based on them SettingMap
>   and SettingKindMap.
> - New property independent helpers for line_config, like set_prop_default().
> - Improved tests/examples, new example for gpiowatch.
> - Add pre-built bindings for gpiosim too.
> - Many other changes.
>
> V3->V4:
> - Rebased on top of new changes, and made changes accordingly.
> - Added rust integration tests with gpiosim.
> - Found a kernel bug with tests, sent a patch for that to LKML.
>
> V2->V3:
> - Remove naming redundancy, users just need to do this now
>   use libgpiod:{Chip, Direction, LineConfig} now (Bartosz);
> - Fix lifetime issues between event-buffer and edge-event modules, the event
>   buffer is released after the last edge-event reference is dropped (Bartosz).
> - Allow edge-event to be copied, and freed later (Bartosz).
> - Add two separate rust crates, sys and wrapper (Gerard).
> - Null-terminate the strings passed to libgpiod (Wedson).
> - Drop unnecessary checks to validate string returned from chip:name/label/path.
> - Fix SAFETY comments (Wedson).
> - Drop unnecessary clone() instances (Bartosz).
>
> V1->V2:
> - Added examples (I tested everything except gpiomon.rs, didn't have right
>   hardware/mock device to test).
> - Build rust bindings as part of Make, update documentation.
>
> Thanks.
>
> --
> Viresh
>
> Viresh Kumar (8):
>   bindings: rust: Add libgpiod-sys rust crate
>   bindings: rust: Add pre generated bindings for libgpiod-sys
>   bindings: rust: Add gpiosim crate
>   bindings: rust: Add pre generated bindings for gpiosim
>   bindings: rust: Add libgpiod crate
>   bindings: rust: Add examples to libgpiod crate
>   bindings: rust: Add tests for libgpiod crate
>   bindings: rust: Integrate building of bindings with make
>
>  .gitignore                                    |    5 +
>  README                                        |    8 +-
>  TODO                                          |    8 -
>  bindings/Makefile.am                          |    6 +
>  bindings/rust/Cargo.toml                      |    7 +
>  bindings/rust/Makefile.am                     |   18 +
>  bindings/rust/gpiosim/Cargo.toml              |   22 +
>  bindings/rust/gpiosim/README.md               |   11 +
>  bindings/rust/gpiosim/build.rs                |   43 +
>  bindings/rust/gpiosim/src/bindings.rs         |  180 +++
>  bindings/rust/gpiosim/src/lib.rs              |   79 ++
>  bindings/rust/gpiosim/src/sim.rs              |  331 +++++
>  bindings/rust/libgpiod-sys/Cargo.toml         |   20 +
>  bindings/rust/libgpiod-sys/README.md          |   11 +
>  bindings/rust/libgpiod-sys/build.rs           |   41 +
>  bindings/rust/libgpiod-sys/src/bindings.rs    | 1173 +++++++++++++++++
>  bindings/rust/libgpiod-sys/src/lib.rs         |   13 +
>  bindings/rust/libgpiod/Cargo.toml             |   21 +
>  .../rust/libgpiod/examples/gpio_events.rs     |   89 ++
>  .../examples/gpio_threaded_info_events.rs     |  133 ++
>  bindings/rust/libgpiod/examples/gpiodetect.rs |   31 +
>  bindings/rust/libgpiod/examples/gpiofind.rs   |   37 +
>  bindings/rust/libgpiod/examples/gpioget.rs    |   46 +
>  bindings/rust/libgpiod/examples/gpioinfo.rs   |   98 ++
>  bindings/rust/libgpiod/examples/gpiomon.rs    |   75 ++
>  bindings/rust/libgpiod/examples/gpioset.rs    |   64 +
>  bindings/rust/libgpiod/examples/gpiowatch.rs  |   54 +
>  bindings/rust/libgpiod/src/chip.rs            |  310 +++++
>  bindings/rust/libgpiod/src/edge_event.rs      |   93 ++
>  bindings/rust/libgpiod/src/event_buffer.rs    |  167 +++
>  bindings/rust/libgpiod/src/info_event.rs      |   69 +
>  bindings/rust/libgpiod/src/lib.rs             |  479 +++++++
>  bindings/rust/libgpiod/src/line_config.rs     |  135 ++
>  bindings/rust/libgpiod/src/line_info.rs       |  162 +++
>  bindings/rust/libgpiod/src/line_request.rs    |  227 ++++
>  bindings/rust/libgpiod/src/line_settings.rs   |  297 +++++
>  bindings/rust/libgpiod/src/request_config.rs  |   95 ++
>  bindings/rust/libgpiod/tests/chip.rs          |   98 ++
>  bindings/rust/libgpiod/tests/common/config.rs |  143 ++
>  bindings/rust/libgpiod/tests/common/mod.rs    |   10 +
>  bindings/rust/libgpiod/tests/edge_event.rs    |  298 +++++
>  bindings/rust/libgpiod/tests/info_event.rs    |  167 +++
>  bindings/rust/libgpiod/tests/line_config.rs   |   96 ++
>  bindings/rust/libgpiod/tests/line_info.rs     |  276 ++++
>  bindings/rust/libgpiod/tests/line_request.rs  |  510 +++++++
>  bindings/rust/libgpiod/tests/line_settings.rs |  204 +++
>  .../rust/libgpiod/tests/request_config.rs     |   39 +
>  configure.ac                                  |   16 +
>  48 files changed, 6504 insertions(+), 11 deletions(-)
>  create mode 100644 bindings/rust/Cargo.toml
>  create mode 100644 bindings/rust/Makefile.am
>  create mode 100644 bindings/rust/gpiosim/Cargo.toml
>  create mode 100644 bindings/rust/gpiosim/README.md
>  create mode 100644 bindings/rust/gpiosim/build.rs
>  create mode 100644 bindings/rust/gpiosim/src/bindings.rs
>  create mode 100644 bindings/rust/gpiosim/src/lib.rs
>  create mode 100644 bindings/rust/gpiosim/src/sim.rs
>  create mode 100644 bindings/rust/libgpiod-sys/Cargo.toml
>  create mode 100644 bindings/rust/libgpiod-sys/README.md
>  create mode 100644 bindings/rust/libgpiod-sys/build.rs
>  create mode 100644 bindings/rust/libgpiod-sys/src/bindings.rs
>  create mode 100644 bindings/rust/libgpiod-sys/src/lib.rs
>  create mode 100644 bindings/rust/libgpiod/Cargo.toml
>  create mode 100644 bindings/rust/libgpiod/examples/gpio_events.rs
>  create mode 100644 bindings/rust/libgpiod/examples/gpio_threaded_info_events.rs
>  create mode 100644 bindings/rust/libgpiod/examples/gpiodetect.rs
>  create mode 100644 bindings/rust/libgpiod/examples/gpiofind.rs
>  create mode 100644 bindings/rust/libgpiod/examples/gpioget.rs
>  create mode 100644 bindings/rust/libgpiod/examples/gpioinfo.rs
>  create mode 100644 bindings/rust/libgpiod/examples/gpiomon.rs
>  create mode 100644 bindings/rust/libgpiod/examples/gpioset.rs
>  create mode 100644 bindings/rust/libgpiod/examples/gpiowatch.rs
>  create mode 100644 bindings/rust/libgpiod/src/chip.rs
>  create mode 100644 bindings/rust/libgpiod/src/edge_event.rs
>  create mode 100644 bindings/rust/libgpiod/src/event_buffer.rs
>  create mode 100644 bindings/rust/libgpiod/src/info_event.rs
>  create mode 100644 bindings/rust/libgpiod/src/lib.rs
>  create mode 100644 bindings/rust/libgpiod/src/line_config.rs
>  create mode 100644 bindings/rust/libgpiod/src/line_info.rs
>  create mode 100644 bindings/rust/libgpiod/src/line_request.rs
>  create mode 100644 bindings/rust/libgpiod/src/line_settings.rs
>  create mode 100644 bindings/rust/libgpiod/src/request_config.rs
>  create mode 100644 bindings/rust/libgpiod/tests/chip.rs
>  create mode 100644 bindings/rust/libgpiod/tests/common/config.rs
>  create mode 100644 bindings/rust/libgpiod/tests/common/mod.rs
>  create mode 100644 bindings/rust/libgpiod/tests/edge_event.rs
>  create mode 100644 bindings/rust/libgpiod/tests/info_event.rs
>  create mode 100644 bindings/rust/libgpiod/tests/line_config.rs
>  create mode 100644 bindings/rust/libgpiod/tests/line_info.rs
>  create mode 100644 bindings/rust/libgpiod/tests/line_request.rs
>  create mode 100644 bindings/rust/libgpiod/tests/line_settings.rs
>  create mode 100644 bindings/rust/libgpiod/tests/request_config.rs
>
> --
> 2.31.1.272.g89b43f80a514
>

Hi Viresh,

There are some licensing issues I noticed now: can you make sure
`reuse lint` doesn't return errors for rust bindings?

One other thing is the license of the rust bindings themselves - I'm
not a lawyer but it seems to me that if you link against LGPL code
statically, your code must be licensed under an LGPL-compatible
license. It seems that BSD-3-Clause and Apache-2.0 are compatible but
it would be great to have someone knowledgeable comment on that. Is
there anyone at linaro we could contact?

Bart