96 lines
4.5 KiB
Markdown
96 lines
4.5 KiB
Markdown
libcsp-rust
|
|
=========
|
|
|
|
This project aims to provide libraries and tools to build and use
|
|
the [`libcsp`](https://github.com/libcsp/libcsp) C library in your Rust project.
|
|
|
|
It provides 3 crates for this:
|
|
|
|
- [`libcsp`](https://egit.irs.uni-stuttgart.de/rust/libcsp-rust/src/branch/main)
|
|
provides a safe and ergonomic Rust interface on top of the `libcsp-sys` crate.
|
|
- [`libcsp-sys`](https://egit.irs.uni-stuttgart.de/rust/libcsp-rust/src/branch/main/libcsp-sys)
|
|
provides the Rust bindings to [`libcsp`](https://github.com/libcsp/libcsp).
|
|
- [`libcsp-cargo-build`](https://egit.irs.uni-stuttgart.de/rust/libcsp-rust/src/branch/main/libcsp-cargo-build)
|
|
provides an API to build the `libcsp` using `cargo` with the [`cc`](https://docs.rs/cc/latest/cc/) crate.
|
|
|
|
In addition, it provides a workspace to allow updating the `libcsp` C sources and the corresponding
|
|
bindings more easily inside the `clib` directory. Some of the examples `libcsp` provides were ported
|
|
to Rust and are showcased in the `examples` directory.
|
|
|
|
Please note that this is early-stage/experimental software. Important features might be missing.
|
|
PRs and improvement suggestions are welcome! This project was primarily tested on a Linux/POSIX
|
|
system so far.
|
|
|
|
## How it works
|
|
|
|
We assume that cargo should also take care of building the library.
|
|
|
|
1. Add the `libcsp-cargo-build` as a build dependency inside your `Cargo.toml`.
|
|
2. Add the `libcsp` as a regular dependency inside your `Cargo.toml`.
|
|
3. Create a custom `build.rs` script which takes care of building the `libcsp` C library using the
|
|
API provided by `libcsp-cargo-build`. You have to provide the source code for `libcsp` inside
|
|
some directory and pass the directory path to the builder API.
|
|
4. You can now write regular Rust code and use the Rust API provided by the `libcsp` crate to use
|
|
the `libcsp` C library.
|
|
|
|
It is recommended to have a look at the [example build script](https://egit.irs.uni-stuttgart.de/rust/libcsp-rust/src/branch/main/examples/build.rs)
|
|
which should give you a general idea of how a build script which does the 4 steps above might look
|
|
like.
|
|
|
|
## Running the example
|
|
|
|
The example uses both the builder crate and the bindings and API crate and implements the
|
|
[server/client example](https://github.com/libcsp/libcsp/blob/develop/examples/csp_server_client.c)
|
|
in Rust. You can run the example using the following steps:
|
|
|
|
1. Clone/Copy `libcsp` into the `lib` folder, for example by using the provided `lib/clone-csp.sh`
|
|
script or adding `libcsp` as a git submodule.
|
|
2. You can now use `cargo run -p libcsp-rust-examples` to run the server/client example.
|
|
|
|
## Compile-time configuration of the `libcsp-sys` library
|
|
|
|
The `libcsp-sys` requires some compile-time configuration file to be included to work
|
|
properly. You can see an example version of the file for the workspace
|
|
[here](https://egit.irs.uni-stuttgart.de/rust/libcsp-rust/src/branch/main/examples/autoconfig.rs).
|
|
The user has to provide the path to a directory containing this `autoconfig.rs` file using the
|
|
`CSP_CONFIG_DIR` environmental variable.
|
|
|
|
You can automatically generate this file when using `libcsp-cargo-build` by using the
|
|
[`generate_autoconf_rust_file`](here be link soon) method of the Builder object as done in the
|
|
example build script.
|
|
|
|
In this workspace, the `CSP_CONFIG_DIR` variable is hardcoded using the following `.cargo/config.toml`
|
|
configuration:
|
|
|
|
```toml
|
|
[env]
|
|
CSP_CONFIG_DIR = { value = "examples", relative = true }
|
|
```
|
|
|
|
## Generating and update the bindings using the `clib` folder
|
|
|
|
The `lib` folder in this repository serves as the staging directory for the `libcsp` library to
|
|
build. However, it can also be used to update the bindings provided in `libcsp-sys` by providing
|
|
some tools and helpers to auto-generate and update the bindings file `bindings.rs`.
|
|
|
|
If you want to do this, you should install `bindgen-cli` first:
|
|
|
|
```sh
|
|
cargo install bindgen-cli --locked
|
|
```
|
|
|
|
`bindgen` needs some additional information provided by the user to generate the bindings:
|
|
An `autoconfig.h` file which is used to configure `libcsp`. Normally, this file is generated
|
|
by the C build system. This file is located at `clib/cfg/csp` and is also updated automatically
|
|
when running the example application.
|
|
|
|
After cloning the repository, you can now run the following command to re-generate the bindings
|
|
file:
|
|
|
|
```sh
|
|
bindgen --use-core wrapper.h -- "-I./libcsp/include" "-I./cfg" "-I./libcsp/src" > bindings.rs
|
|
```
|
|
|
|
With the bindings file, you can now manually update the FFI bindings provided in
|
|
`libcsp-sys/src/lib.rs` or in your own CSP library.
|