This crate supports generating a C header for a library crate, directly in the library itself.

Typically the crate would be annotated with ffizz_header macros to define the header content. Then, the header is generated by calling [generate].

Generating Headers

What follows is a simple, effective way to generate the header file, using the excellent cargo-xtask. With this in place, simply run cargo xtask codegen to generate the header file. The file can either be checked in (in which case CI should verify that it is up-to-date), or generated as part of the release / packaging process.

Setup

In your library's top level, add a call to

```ignore

[cfg(debug_assertions)] // only include this in debug builds

/// Generate the header pub fn generateheader() -> String { ffizzheader::generate() } ```

Set up an xtask project as described in the project's documentation. Add your library as a dependency of the xtask crate. In xtask/src/main.rs, for a mysupercool-lib crate:

```ignore use std::env; use std::fs::File; use std::io::Write; use std::path::PathBuf;

fn main() { let manifestdir = PathBuf::from(env::var("CARGOMANIFESTDIR").unwrap()); let workspacedir = manifest_dir.parent().unwrap();

// assume the mysupercool-lib crate is in `lib/`..
let lib_crate_dir = workspace_dir.join("tests").join("lib");
let mut file = File::create(lib_crate_dir.join("mysupercoollib.h")).unwrap();
write!(&mut file, "{}", ::mysupercool_lib::generate_header()).unwrap();

} ```

You may wish to improve on this impementation, with proper command-line parsing and error handling.

Caveats

This method does not support producing multiple header files for a single workspace. Rust refuses to link them, due to duplicate symbols. If your workspace contains multiple libraries, another option is to build a binary for each one, that generates the header file for only that library.