Cargo C-ABI helpers

cargo applet to build and install C-ABI compatibile dynamic and static libraries.

It produces and installs a correct pkg-config file, a static library and a dynamic library, and a C header to be used by any C (and C-compatible) software.

Usage

``` sh

build the library, create the .h header, create the .pc file

$ cargo cbuild --destdir=${D} --prefix=/usr --libdir=/usr/lib64 sh

build the library, create the .h header, create the .pc file and install all of it

$ cargo cinstall --destdir=${D} --prefix=/usr --libdir=/usr/lib64 ```

For a more in-depth explanation of how cargo-c works and how to use it for your crates, read Building Crates so they Look Like C ABI Libraries.

The TL;DR:

• Create a capi.rs with the C-API you want to expose and use #[cfg(cargo_c)] to hide it when you build a normal rust library.
• Make sure you have a lib target and if you are using a workspace the first member is the crate you want to export, that means that you might have to add a "." member at the start of the list.
• Remember to add a [cbindgen.toml][cbinden-toml] and fill it with at least the include guard and probably you want to set the language to C (it defaults to C++)
• Once you are happy with the result update your documentation to tell the user to install cargo-c and do cargo cinstall --prefix=/usr --destdir=/tmp/some-place or something along those lines.

Users

• gcode-rs
• lewton
• rav1e

Status

• [x] cli
  • [x] build command
  • [x] install command
  • [x] cargo applet support
• [x] build targets
  • [x] pkg-config generation
  • [x] header generation (cbindgen integration)
• [x] staticlib support
• [x] cdylib support
• [ ] Extra Cargo.toml keys
• [ ] Better status reporting