build.rs - mozsearch

// Copyright 2015 Brendan Zabarauskas and the gl-rs developers

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

// This build script is used to discover all of the accepted extensions

// described in the Khronos WebGL repository, and construct a static slice

// containing the XML specifications for all of them.

use std::env;

use std::fs::File;

use std::io::Write;

use std::path::*;

fn main() {

    // Create and open a file in the output directory to contain our generated rust code

    let dest = env::var("OUT_DIR").unwrap();

    let mut file = File::create(&Path::new(&dest).join("webgl_exts.rs")).unwrap();

    // Find the absolute path to the folder containing the WebGL extensions.

    // The absolute path is needed, because we don't know where the output

    // directory will be, and `include_bytes!(..)` resolves paths relative to the

    // containing file.

    let root = env::current_dir().unwrap().join("api_webgl/extensions");

    // Generate a slice literal, looking like this:

    // `&[&*include_bytes!(..), &*include_bytes!(..), ..]`

    writeln!(file, "&[").unwrap();

    // The slice will have one entry for each WebGL extension. To find the

    // extensions we mirror the behaviour of the `api_webgl/extensions/find-exts`

    // shell script.

    for entry in root.read_dir().unwrap() {

        let entry = entry.unwrap();

        let path = entry.path();

        let ext_name = path.file_name().unwrap().to_str().unwrap();

        // Each item which is a directory, and is not named `template`, may be

        // an extension.

        if path.is_dir() && ext_name != "template" {

            // If the directory contains a file named `extension.xml`, then this

            // really is an extension.

            let ext_path = path.join("extension.xml");

            if ext_path.is_file() {

                // Include the XML file, making sure to use an absolute path.

                writeln!(file, "&*include_bytes!({:?}),", ext_path.to_str().unwrap()).unwrap();

    // Close the slice

    writeln!(file, "]").unwrap();