build.rs

//! Regenerates `include/sqlrite.h` from the `extern "C"` surface in
//! `src/lib.rs` whenever a dependency changes. `cbindgen` walks the
//! crate root and emits a C header with the function signatures,
//! type definitions, and doc comments preserved.
//!
//! Output lives in `sqlrite-ffi/include/sqlrite.h` so downstream
//! consumers (the C examples, future Python/Node/Go SDKs) can grab
//! the header from a stable path even without running `cargo build`
//! themselves — we commit it alongside the code.

use std::env;
use std::path::PathBuf;

fn main() {
    let crate_dir = env::var("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR set by cargo");
    let crate_dir = PathBuf::from(crate_dir);

    let out_dir = crate_dir.join("include");
    if let Err(e) = std::fs::create_dir_all(&out_dir) {
        panic!("failed to create include/ dir: {e}");
    }
    let out_path = out_dir.join("sqlrite.h");

    let config = cbindgen::Config {
        language: cbindgen::Language::C,
        header: Some(
            "// Auto-generated by cbindgen from sqlrite-ffi/src/lib.rs.\n\
             // Do not edit by hand — changes will be overwritten on the next build.\n\
             //\n\
             // This is the C ABI for the SQLRite embedded database engine. Every\n\
             // non-Rust SDK (Python / Node.js / Go / raw C) binds against the same\n\
             // functions declared here. See sqlrite-ffi/src/lib.rs for the full\n\
             // memory-ownership and error-handling rules."
                .to_string(),
        ),
        include_guard: Some("SQLRITE_H".to_string()),
        cpp_compat: true,
        pragma_once: true,
        documentation: true,
        documentation_style: cbindgen::DocumentationStyle::C99,
        documentation_length: cbindgen::DocumentationLength::Full,
        ..Default::default()
    };

    match cbindgen::generate_with_config(&crate_dir, config) {
        Ok(bindings) => {
            bindings.write_to_file(&out_path);
            println!("cargo:rerun-if-changed=src/lib.rs");
        }
        // Don't fail the build on a cbindgen error — just warn. This
        // keeps `cargo build` working on systems where cbindgen's
        // toolchain dependencies aren't present, while still
        // regenerating the header on dev machines.
        Err(e) => {
            println!("cargo:warning=cbindgen header generation failed: {e}");
        }
    }
}