build.rs

extern crate winapi_tlb_bindgen;
use std::io::prelude::*;

// E45885BF-50CB-4F8F-9B19-95767EAF0F5C

fn main() {
    let out_dir: std::path::PathBuf = std::env::var_os("OUT_DIR")
        .expect("OUT_DIR must exist")
        .into();

    let idl_content = {
        let dir_iter = std::fs::read_dir(r"C:\Program Files (x86)\Windows Kits\10\Include\")
            .expect("Windows Kits\\10\\Include\\ must exist");
        let mut idl_file_path = dir_iter
            .filter(|dir| match dir {
                Ok(ref entry) => entry
                    .path()
                    .to_str()
                    .unwrap()
                    .starts_with(r"C:\Program Files (x86)\Windows Kits\10\Include\10."),
                _ => false,
            })
            .last()
            .unwrap()
            .unwrap()
            .path();
        idl_file_path.push(r"um\spellcheckprovider.idl");
        let mut idl_file =
            std::fs::File::open(idl_file_path).expect("spellcheckprovider.idl must exist");
        //let mut idl_file = std::fs::File::open(r"C:\Program Files (x86)\Windows Kits\10\Include\10.0.10586.0\um\spellcheckprovider.idl").unwrap();
        let mut idl_content = String::new();
        idl_file.read_to_string(&mut idl_content).unwrap();
        idl_content
    };

    let idl_out = {
        let idl_out = out_dir.join("spellcheckprovider.idl");
        let mut idl_out_file = std::fs::OpenOptions::new()
            .create(true)
            .write(true)
            .truncate(true)
            .open(idl_out.clone())
            .unwrap();

        // Don't care about the version and UUID, this is just needed to generate the tlb that tlb_bindgen needs
        idl_out_file
            .write_all(
                b"[
				uuid(00B573B4-E925-4413-9F57-FAC7FE382719),
				version(1.0),
		]
		library SpellCheckProvider {",
            )
            .unwrap();
        idl_out_file.write_all(idl_content.as_bytes()).unwrap();
        idl_out_file.write_all(b"};").unwrap();
        idl_out
    };

    let midl_paths = vec![
        r"C:\Program Files (x86)\Windows Kits\10\bin\x86\midl.exe",
        r"C:\Program Files (x86)\Windows Kits\10\bin\10.0.18362.0\x86\midl.exe",
    ];

    let midl_path = midl_paths
        .into_iter()
        .filter(|p| std::path::Path::new(p).exists())
        .next()
        .unwrap_or("midl.exe");
    let midl_command_status = std::process::Command::new(midl_path) // Expected to be running in "x64 Native Tools Command Prompt"
        .arg(idl_out)
        .arg("/tlb")
        .arg("SpellCheckProvider.tlb")
        .current_dir(&out_dir)
        .status()
        .expect("midl must exist, run in x86 command prompt");

    assert!(midl_command_status.success());

    let spellcheckprovider_rs = {
        let spellcheckprovider_rs = out_dir.join("spellcheckprovider.rs");
        let spellcheckprovider_rs = std::fs::OpenOptions::new()
            .create(true)
            .write(true)
            .truncate(true)
            .open(spellcheckprovider_rs)
            .unwrap();
        std::io::BufWriter::new(spellcheckprovider_rs)
    };

    winapi_tlb_bindgen::build(
        &out_dir.join(r"SpellCheckProvider.tlb"),
        false,
        spellcheckprovider_rs,
    )
    .unwrap();
}