cbindgen 0.6.0

A tool for generating C bindings to Rust code.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

use std::env;
use std::io;
use std::path::Path;
use std::process::Command;
use std::str::{Utf8Error, from_utf8};

extern crate tempdir;
use self::tempdir::TempDir;

#[derive(Debug)]
/// Possible errors that can occur during `rustc --pretty=expanded`.
pub enum Error {
    /// Error during creation of temporary directory
    Io(io::Error),
    /// Output of `cargo metadata` was not valid utf8
    Utf8(Utf8Error),
    /// Error during execution of `cargo rustc --pretty=expanded`
    Compile(String),
}

impl From<io::Error> for Error {
    fn from(err: io::Error) -> Self {
        Error::Io(err)
    }
}
impl From<Utf8Error> for Error {
    fn from(err: Utf8Error) -> Self {
        Error::Utf8(err)
    }
}

/// Use rustc to expand and pretty print the crate into a single file,
/// removing any macros in the process.
pub fn expand(manifest_path: &Path, crate_name: &str, version: &str, use_tempdir: bool) -> Result<String, Error> {
    let cargo = env::var("CARGO").unwrap_or_else(|_| String::from("cargo"));
    let mut cmd = Command::new(cargo);

    let mut _temp_dir = None; // drop guard
    if use_tempdir {
        _temp_dir = Some(TempDir::new("cbindgen-expand")?);
        cmd.env("CARGO_TARGET_DIR", _temp_dir.unwrap().path());
    } else if let Ok(ref path) = env::var("CARGO_EXPAND_TARGET_DIR") {
        cmd.env("CARGO_TARGET_DIR", path);
    }

    cmd.arg("rustc");
    cmd.arg("--lib");
    cmd.arg("--manifest-path");
    cmd.arg(manifest_path);
    cmd.arg("--all-features");
    cmd.arg("-p");
    cmd.arg(&format!("{}:{}", crate_name, version));
    cmd.arg("--");
    cmd.arg("-Z");
    cmd.arg("unstable-options");
    cmd.arg("--pretty=expanded");
    let output = cmd.output()?;

    let src = from_utf8(&output.stdout)?.to_owned();
    let error = from_utf8(&output.stderr)?.to_owned();

    if src.len() == 0 {
        Err(Error::Compile(error))
    } else {
        Ok(src)
    }
}