hw_dcmi_wrapper_sys 0.1.2

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

fn init_bindgen_builder(header: impl Into<String>) -> bindgen::Builder {
    bindgen::Builder::default()
        // The input header we would like to generate bindings for.
        .header(header)
        // Tell cargo to invalidate the built crate whenever any of the
        // included header files changed.
        .parse_callbacks(Box::new(bindgen::CargoCallbacks::new()))
        .layout_tests(false)
        .raw_line("#![allow(non_upper_case_globals)]")
        .raw_line("#![allow(non_camel_case_types)]")
        .raw_line("#![allow(non_snake_case)]")
        .raw_line("#![allow(dead_code)]")
}

fn main() {
    // 读取环境变量HW_DCMI_PATH作为库搜索路径
    let hw_dcmi_path = env::var("HW_DCMI_PATH").unwrap_or_else(|_| "/usr/local/dcmi".to_string());
    println!("cargo:rustc-link-search=native={}", hw_dcmi_path);

    #[cfg(not(feature = "load_dynamic"))]
    println!("cargo:rustc-link-lib=dylib=dcmi");

    // 当且仅当HW_DCMI_BINDING_BUILD为true时才生成绑定
    println!("cargo:rerun-if-env-changed=HW_DCMI_BINDING_BUILD");
    if env::var("HW_DCMI_BINDING_BUILD").is_err() {
        return;
    }
    if env::var("HW_DCMI_BINDING_BUILD").unwrap() != "true" {
        return;
    }

    let interface_path = format!("{}/dcmi_interface_api.h", hw_dcmi_path);

    // The bindgen::Builder is the main entry point to bindgen,
    // and lets you build up options for the resulting bindings.

    let builder = init_bindgen_builder(interface_path);

    #[cfg(feature = "load_dynamic")]
    let builder = builder
        .dynamic_library_name("dcmi")
        .dynamic_link_require_all(true);

    let bindings = builder
        // Finish the builder and generate the bindings.
        .generate()
        // Unwrap the Result and panic on failure.
        .expect("Unable to generate bindings");

    // 指定输出文件的路径为 src/hw_dcmi_wrapper_sys.rs
    #[cfg(feature = "load_dynamic")]
    let out_path =
        PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap()).join("src/bindings_dyn.rs");
    #[cfg(not(feature = "load_dynamic"))]
    let out_path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap()).join("src/bindings.rs");

    // Write the bindings to the specified file.
    bindings
        .write_to_file(out_path)
        .expect("Couldn't write bindings!");
}