fn build_from_src()

in tensorflow-sys/build.rs [297:412]

• 110 lines of code
• 11 McCabe index (conditional complexity)

fn build_from_src() {
    let dll_suffix = dll_suffix();
    let framework_target = FRAMEWORK_TARGET.to_string() + dll_suffix;
    let target = TARGET.to_string() + dll_suffix;

    let output = PathBuf::from(&get!("OUT_DIR"));
    log_var!(output);
    let source = PathBuf::from(&get!("CARGO_MANIFEST_DIR")).join(format!("target/source-{}", TAG));
    log_var!(source);
    let lib_dir = output.join(format!("lib-{}", TAG));
    log_var!(lib_dir);
    if lib_dir.exists() {
        log!("Directory {:?} already exists", lib_dir);
    } else {
        log!("Creating directory {:?}", lib_dir);
        fs::create_dir(lib_dir.clone()).unwrap();
    }
    let framework_unversioned_library_path = lib_dir.join(format!("lib{}.so", FRAMEWORK_LIBRARY));
    let framework_library_path = lib_dir.join(format!("lib{}.so.2", FRAMEWORK_LIBRARY));
    log_var!(framework_library_path);
    let unversioned_library_path = lib_dir.join(format!("lib{}.so", LIBRARY));
    let library_path = lib_dir.join(format!("lib{}.so.2", LIBRARY));
    log_var!(library_path);
    if library_path.exists() && framework_library_path.exists() {
        log!(
            "{:?} and {:?} already exist, not building",
            library_path,
            framework_library_path
        );
    } else {
        if let Err(e) = check_bazel() {
            println!(
                "cargo:error=Bazel must be installed at version {} or greater. (Error: {})",
                MIN_BAZEL, e
            );
            process::exit(1);
        }
        let framework_target_path = &format!("{}.2", framework_target.replace(":", "/"));
        log_var!(framework_target_path);
        let target_path = &format!("{}.so", TARGET.replace(":", "/"));
        log_var!(target_path);
        if !Path::new(&source.join(".git")).exists() {
            run("git", |command| {
                command
                    .arg("clone")
                    .arg(format!("--branch={}", TAG))
                    .arg("--recursive")
                    .arg(REPOSITORY)
                    .arg(&source)
            });
        }
        // Only configure if not previously configured.  Configuring runs a
        // `bazel clean`, which we don't want, because we want to be able to
        // continue from a cancelled build.
        let configure_hint_file_pb = source.join(".rust-configured");
        let configure_hint_file = Path::new(&configure_hint_file_pb);
        if !configure_hint_file.exists() {
            run("bash", |command| {
                command
                    .current_dir(&source)
                    .env(
                        "TF_NEED_CUDA",
                        if cfg!(feature = "tensorflow_gpu") {
                            "1"
                        } else {
                            "0"
                        },
                    )
                    .arg("-c")
                    .arg("yes ''|./configure")
            });
            File::create(configure_hint_file).unwrap();
        }
        // Allows us to pass in --incompatible_load_argument_is_label=false
        // to work around https://github.com/tensorflow/tensorflow/issues/15492
        let bazel_args_string = if let Ok(args) = env::var("TF_RUST_BAZEL_OPTS") {
            args
        } else {
            "".to_string()
        };
        run("bazel", |command| {
            command
                .current_dir(&source)
                .arg("build")
                .arg(format!("--jobs={}", get!("NUM_JOBS")))
                .arg("--compilation_mode=opt")
                .arg("--copt=-march=native")
                .args(bazel_args_string.split_whitespace())
                .arg(&target)
        });
        let framework_target_bazel_bin = source.join("bazel-bin").join(framework_target_path);
        log!(
            "Copying {:?} to {:?}",
            framework_target_bazel_bin,
            framework_library_path
        );
        if framework_library_path.exists() {
            fs::remove_file(&framework_library_path).unwrap();
        }
        fs::copy(framework_target_bazel_bin, &framework_library_path).unwrap();
        let target_bazel_bin = source.join("bazel-bin").join(target_path);
        log!("Copying {:?} to {:?}", target_bazel_bin, library_path);
        if library_path.exists() {
            fs::remove_file(&library_path).unwrap();
        }
        fs::copy(target_bazel_bin, &library_path).unwrap();
    }
    symlink(
        framework_library_path.file_name().unwrap(),
        framework_unversioned_library_path,
    );
    symlink(library_path.file_name().unwrap(), unversioned_library_path);
    println!("cargo:rustc-link-lib=dylib={}", FRAMEWORK_LIBRARY);
    println!("cargo:rustc-link-lib=dylib={}", LIBRARY);
    println!("cargo:rustc-link-search={}", lib_dir.display());
}