6 files changed, 780 insertions, 0 deletions
diff --git a/src/bindgen/cargo/cargo.rs b/src/bindgen/cargo/cargo.rs
new file mode 100644
index 0000000..69cf938
--- /dev/null
+++ b/src/bindgen/cargo/cargo.rs
@@ -0,0 +1,252 @@
+/* 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::path::{Path, PathBuf};
+
+use crate::bindgen::cargo::cargo_expand;
+use crate::bindgen::cargo::cargo_lock::{self, Lock};
+pub(crate) use crate::bindgen::cargo::cargo_metadata::PackageRef;
+use crate::bindgen::cargo::cargo_metadata::{self, Metadata};
+use crate::bindgen::cargo::cargo_toml;
+use crate::bindgen::config::Profile;
+use crate::bindgen::error::Error;
+use crate::bindgen::ir::Cfg;
+
+/// Parse a dependency string used in Cargo.lock
+fn parse_dep_string(dep_string: &str) -> (&str, Option<&str>) {
+    let split: Vec<&str> = dep_string.split_whitespace().collect();
+
+    (split[0], split.get(1).cloned())
+}
+
+/// A collection of metadata for a library from cargo.
+#[derive(Clone, Debug)]
+pub(crate) struct Cargo {
+    manifest_path: PathBuf,
+    binding_crate_name: String,
+    lock: Option<Lock>,
+    metadata: Metadata,
+    clean: bool,
+}
+
+impl Cargo {
+    /// Gather metadata from cargo for a specific library and binding crate
+    /// name. If dependency finding isn't needed then Cargo.lock files don't
+    /// need to be parsed.
+    pub(crate) fn load(
+        crate_dir: &Path,
+        lock_file: Option<&str>,
+        binding_crate_name: Option<&str>,
+        use_cargo_lock: bool,
+        clean: bool,
+        only_target_dependencies: bool,
+        existing_metadata_file: Option<&Path>,
+    ) -> Result<Cargo, Error> {
+        let toml_path = crate_dir.join("Cargo.toml");
+        let metadata =
+            cargo_metadata::metadata(&toml_path, existing_metadata_file, only_target_dependencies)
+                .map_err(|x| Error::CargoMetadata(toml_path.to_str().unwrap().to_owned(), x))?;
+        let lock_path = lock_file
+            .map(PathBuf::from)
+            .unwrap_or_else(|| Path::new(&metadata.workspace_root).join("Cargo.lock"));
+
+        let lock = if use_cargo_lock {
+            match cargo_lock::lock(&lock_path) {
+                Ok(lock) => Some(lock),
+                Err(x) => {
+                    warn!("Couldn't load lock file {:?}: {:?}", lock_path, x);
+                    None
+                }
+            }
+        } else {
+            None
+        };
+
+        // Use the specified binding crate name or infer it from the manifest
+        let binding_crate_name = match binding_crate_name {
+            Some(s) => s.to_owned(),
+            None => {
+                let manifest = cargo_toml::manifest(&toml_path)
+                    .map_err(|x| Error::CargoToml(toml_path.to_str().unwrap().to_owned(), x))?;
+                manifest.package.name
+            }
+        };
+
+        Ok(Cargo {
+            manifest_path: toml_path,
+            binding_crate_name,
+            lock,
+            metadata,
+            clean,
+        })
+    }
+
+    pub(crate) fn binding_crate_name(&self) -> &str {
+        &self.binding_crate_name
+    }
+
+    pub(crate) fn binding_crate_ref(&self) -> PackageRef {
+        match self.find_pkg_ref(&self.binding_crate_name) {
+            Some(pkg_ref) => pkg_ref,
+            None => panic!(
+                "Unable to find {} for {:?}",
+                self.binding_crate_name, self.manifest_path
+            ),
+        }
+    }
+
+    pub(crate) fn dependencies(&self, package: &PackageRef) -> Vec<(PackageRef, Option<Cfg>)> {
+        let lock = match self.lock {
+            Some(ref lock) => lock,
+            None => return vec![],
+        };
+
+        let mut dependencies = None;
+
+        // Find the dependencies listing in the lockfile
+        if let Some(ref root) = lock.root {
+            // If the version is not on the lockfile then it shouldn't be
+            // ambiguous.
+            if root.name == package.name
+                && package
+                    .version
+                    .as_ref()
+                    .map_or(true, |v| *v == root.version)
+            {
+                dependencies = root.dependencies.as_ref();
+            }
+        }
+        if dependencies.is_none() {
+            if let Some(ref lock_packages) = lock.package {
+                for lock_package in lock_packages {
+                    if lock_package.name == package.name
+                        && package
+                            .version
+                            .as_ref()
+                            .map_or(true, |v| *v == lock_package.version)
+                    {
+                        dependencies = lock_package.dependencies.as_ref();
+                        break;
+                    }
+                }
+            }
+        }
+        if dependencies.is_none() {
+            return vec![];
+        }
+
+        dependencies
+            .unwrap()
+            .iter()
+            .map(|dep| {
+                let (dep_name, dep_version) = parse_dep_string(dep);
+
+                // If a version was not specified find the only package with the name of the dependency
+                let dep_version = dep_version.or_else(|| {
+                    let mut versions = self.metadata.packages.iter().filter_map(|package| {
+                        if package.name_and_version.name != dep_name {
+                            return None;
+                        }
+                        package.name_and_version.version.as_deref()
+                    });
+
+                    // If the iterator contains more items, meaning multiple versions of the same
+                    // package are present, warn! amd abort.
+                    let version = versions.next();
+                    if versions.next().is_none() {
+                        version
+                    } else {
+                        warn!("when looking for a version for package {}, multiple versions where found", dep_name);
+                        None
+                    }
+                });
+
+                // Try to find the cfgs in the Cargo.toml
+                let cfg = self
+                    .metadata
+                    .packages
+                    .get(package)
+                    .and_then(|meta_package| meta_package.dependencies.get(dep_name))
+                    .and_then(Cfg::load_metadata);
+
+                let package_ref = PackageRef {
+                    name: dep_name.to_owned(),
+                    version: dep_version.map(|v| v.to_owned()),
+                };
+
+                (package_ref, cfg)
+            })
+            .collect()
+    }
+
+    /// Finds the package reference in `cargo metadata` that has `package_name`
+    /// ignoring the version.
+    fn find_pkg_ref(&self, package_name: &str) -> Option<PackageRef> {
+        for package in &self.metadata.packages {
+            if package.name_and_version.name == package_name {
+                return Some(package.name_and_version.clone());
+            }
+        }
+        None
+    }
+
+    /// Finds the directory for a specified package reference.
+    #[allow(unused)]
+    pub(crate) fn find_crate_dir(&self, package: &PackageRef) -> Option<PathBuf> {
+        self.metadata
+            .packages
+            .get(package)
+            .and_then(|meta_package| {
+                Path::new(&meta_package.manifest_path)
+                    .parent()
+                    .map(|x| x.to_owned())
+            })
+    }
+
+    /// Finds `src/lib.rs` for a specified package reference.
+    pub(crate) fn find_crate_src(&self, package: &PackageRef) -> Option<PathBuf> {
+        let kind_lib = String::from("lib");
+        let kind_staticlib = String::from("staticlib");
+        let kind_rlib = String::from("rlib");
+        let kind_cdylib = String::from("cdylib");
+        let kind_dylib = String::from("dylib");
+
+        self.metadata
+            .packages
+            .get(package)
+            .and_then(|meta_package| {
+                for target in &meta_package.targets {
+                    if target.kind.contains(&kind_lib)
+                        || target.kind.contains(&kind_staticlib)
+                        || target.kind.contains(&kind_rlib)
+                        || target.kind.contains(&kind_cdylib)
+                        || target.kind.contains(&kind_dylib)
+                    {
+                        return Some(PathBuf::from(&target.src_path));
+                    }
+                }
+                None
+            })
+    }
+
+    pub(crate) fn expand_crate(
+        &self,
+        package: &PackageRef,
+        expand_all_features: bool,
+        expand_default_features: bool,
+        expand_features: &Option<Vec<String>>,
+        profile: Profile,
+    ) -> Result<String, cargo_expand::Error> {
+        cargo_expand::expand(
+            &self.manifest_path,
+            &package.name,
+            package.version.as_deref(),
+            self.clean,
+            expand_all_features,
+            expand_default_features,
+            expand_features,
+            profile,
+        )
+    }
+}
diff --git a/src/bindgen/cargo/cargo_expand.rs b/src/bindgen/cargo/cargo_expand.rs
new file mode 100644
index 0000000..565a0d1
--- /dev/null
+++ b/src/bindgen/cargo/cargo_expand.rs
@@ -0,0 +1,145 @@
+/* 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 crate::bindgen::config::Profile;
+use std::env;
+use std::error;
+use std::fmt;
+use std::io;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+use std::str::{from_utf8, Utf8Error};
+
+extern crate tempfile;
+use self::tempfile::Builder;
+
+#[derive(Debug)]
+/// Possible errors that can occur during `rustc -Zunpretty=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 -Zunpretty=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)
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Error::Io(ref err) => err.fmt(f),
+            Error::Utf8(ref err) => err.fmt(f),
+            Error::Compile(ref err) => write!(f, "{}", err),
+        }
+    }
+}
+
+impl error::Error for Error {
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        match self {
+            Error::Io(ref err) => Some(err),
+            Error::Utf8(ref err) => Some(err),
+            Error::Compile(..) => None,
+        }
+    }
+}
+
+/// Use rustc to expand and pretty print the crate into a single file,
+/// removing any macros in the process.
+#[allow(clippy::too_many_arguments)]
+pub fn expand(
+    manifest_path: &Path,
+    crate_name: &str,
+    version: Option<&str>,
+    use_tempdir: bool,
+    expand_all_features: bool,
+    expand_default_features: bool,
+    expand_features: &Option<Vec<String>>,
+    profile: Profile,
+) -> 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(Builder::new().prefix("cbindgen-expand").tempdir()?);
+        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);
+    } else if let Ok(ref path) = env::var("OUT_DIR") {
+        // When cbindgen was started programatically from a build.rs file, Cargo is running and
+        // locking the default target directory. In this case we need to use another directory,
+        // else we would end up in a deadlock. If Cargo is running `OUT_DIR` will be set, so we
+        // can use a directory relative to that.
+        cmd.env("CARGO_TARGET_DIR", PathBuf::from(path).join("expanded"));
+    }
+
+    // Set this variable so that we don't call it recursively if we expand a crate that is using
+    // cbindgen
+    cmd.env("_CBINDGEN_IS_RUNNING", "1");
+
+    cmd.arg("rustc");
+    cmd.arg("--lib");
+    // When build with the release profile we can't choose the `check` profile.
+    if profile != Profile::Release {
+        cmd.arg("--profile=check");
+    }
+    cmd.arg("--manifest-path");
+    cmd.arg(manifest_path);
+    if let Some(features) = expand_features {
+        cmd.arg("--features");
+        let mut features_str = String::new();
+        for (index, feature) in features.iter().enumerate() {
+            if index != 0 {
+                features_str.push(' ');
+            }
+            features_str.push_str(feature);
+        }
+        cmd.arg(features_str);
+    }
+    if expand_all_features {
+        cmd.arg("--all-features");
+    }
+    if !expand_default_features {
+        cmd.arg("--no-default-features");
+    }
+    match profile {
+        Profile::Debug => {}
+        Profile::Release => {
+            cmd.arg("--release");
+        }
+    }
+    cmd.arg("-p");
+    let mut package = crate_name.to_owned();
+    if let Some(version) = version {
+        package.push(':');
+        package.push_str(version);
+    }
+    cmd.arg(&package);
+    cmd.arg("--verbose");
+    cmd.arg("--");
+    cmd.arg("-Zunpretty=expanded");
+    info!("Command: {:?}", cmd);
+    let output = cmd.output()?;
+
+    let src = from_utf8(&output.stdout)?.to_owned();
+    let error = from_utf8(&output.stderr)?.to_owned();
+
+    if src.is_empty() {
+        Err(Error::Compile(error))
+    } else {
+        Ok(src)
+    }
+}
diff --git a/src/bindgen/cargo/cargo_lock.rs b/src/bindgen/cargo/cargo_lock.rs
new file mode 100644
index 0000000..9302082
--- /dev/null
+++ b/src/bindgen/cargo/cargo_lock.rs
@@ -0,0 +1,51 @@
+/* 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::fs::File;
+use std::io;
+use std::io::Read;
+use std::path::Path;
+
+#[derive(Debug)]
+/// Possible errors that can occur during Cargo.toml parsing.
+pub enum Error {
+    /// Error during reading of Cargo.toml
+    Io(io::Error),
+    /// Deserialization error
+    Toml(toml::de::Error),
+}
+
+impl From<io::Error> for Error {
+    fn from(err: io::Error) -> Self {
+        Error::Io(err)
+    }
+}
+impl From<toml::de::Error> for Error {
+    fn from(err: toml::de::Error) -> Self {
+        Error::Toml(err)
+    }
+}
+
+#[derive(Clone, Deserialize, Debug)]
+pub struct Lock {
+    pub root: Option<Package>,
+    pub package: Option<Vec<Package>>,
+}
+
+#[derive(Clone, Deserialize, Debug)]
+pub struct Package {
+    pub name: String,
+    pub version: String,
+    /// A list of dependencies formatted like "NAME VERSION-OPT REGISTRY-OPT"
+    pub dependencies: Option<Vec<String>>,
+}
+
+/// Parse the Cargo.toml for a given path
+pub fn lock(manifest_path: &Path) -> Result<Lock, Error> {
+    let mut s = String::new();
+    let mut f = File::open(manifest_path)?;
+    f.read_to_string(&mut s)?;
+
+    toml::from_str::<Lock>(&s).map_err(|x| x.into())
+}
diff --git a/src/bindgen/cargo/cargo_metadata.rs b/src/bindgen/cargo/cargo_metadata.rs
new file mode 100644
index 0000000..01ab80f
--- /dev/null
+++ b/src/bindgen/cargo/cargo_metadata.rs
@@ -0,0 +1,253 @@
+#![deny(missing_docs)]
+#![allow(dead_code)]
+//! Structured access to the output of `cargo metadata`
+//! Usually used from within a `cargo-*` executable
+
+// Forked from `https://github.com/oli-obk/cargo_metadata`
+// Modifications:
+//   1. Remove `resolve` from Metadata because it was causing parse failures
+//   2. Fix the `manifest-path` argument
+//   3. Add `--all-features` argument
+//   4. Remove the `--no-deps` argument
+
+use std::borrow::{Borrow, Cow};
+use std::collections::{HashMap, HashSet};
+use std::env;
+use std::error;
+use std::fmt;
+use std::hash::{Hash, Hasher};
+use std::io;
+use std::path::Path;
+use std::process::{Command, Output};
+use std::str::Utf8Error;
+
+#[derive(Clone, Deserialize, Debug)]
+/// Starting point for metadata returned by `cargo metadata`
+pub struct Metadata {
+    /// A list of all crates referenced by this crate (and the crate itself)
+    pub packages: HashSet<Package>,
+    version: usize,
+    /// path to the workspace containing the `Cargo.lock`
+    pub workspace_root: String,
+}
+
+/// A reference to a package including it's name and the specific version.
+#[derive(Clone, Debug, Hash, Eq, PartialEq, Serialize, Deserialize)]
+pub struct PackageRef {
+    pub name: String,
+    pub version: Option<String>,
+}
+
+#[derive(Clone, Deserialize, Debug)]
+/// A crate
+pub struct Package {
+    #[serde(flatten)]
+    pub name_and_version: PackageRef,
+    id: String,
+    source: Option<String>,
+    /// List of dependencies of this particular package
+    pub dependencies: HashSet<Dependency>,
+    /// Targets provided by the crate (lib, bin, example, test, ...)
+    pub targets: Vec<Target>,
+    features: HashMap<String, Vec<String>>,
+    /// path containing the `Cargo.toml`
+    pub manifest_path: String,
+}
+
+#[derive(Clone, Deserialize, Debug)]
+/// A dependency of the main crate
+pub struct Dependency {
+    /// Name as given in the `Cargo.toml`
+    pub name: String,
+    source: Option<String>,
+    /// Whether this is required or optional
+    pub req: String,
+    kind: Option<String>,
+    optional: bool,
+    uses_default_features: bool,
+    features: Vec<String>,
+    pub target: Option<String>,
+}
+
+#[derive(Clone, Deserialize, Debug)]
+/// A single target (lib, bin, example, ...) provided by a crate
+pub struct Target {
+    /// Name as given in the `Cargo.toml` or generated from the file name
+    pub name: String,
+    /// Kind of target ("bin", "example", "test", "bench", "lib")
+    pub kind: Vec<String>,
+    /// Almost the same as `kind`, except when an example is a library instad of an executable.
+    /// In that case `crate_types` contains things like `rlib` and `dylib` while `kind` is `example`
+    #[serde(default)]
+    pub crate_types: Vec<String>,
+    /// Path to the main source file of the target
+    pub src_path: String,
+}
+
+#[derive(Debug)]
+/// Possible errors that can occur during metadata parsing.
+pub enum Error {
+    /// Error during execution of `cargo metadata`
+    Io(io::Error),
+    /// Metadata extraction failure
+    Metadata(Output),
+    /// Output of `cargo metadata` was not valid utf8
+    Utf8(Utf8Error),
+    /// Deserialization error (structure of json did not match expected structure)
+    Json(serde_json::Error),
+}
+
+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)
+    }
+}
+impl From<serde_json::Error> for Error {
+    fn from(err: serde_json::Error) -> Self {
+        Error::Json(err)
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Error::Io(ref err) => err.fmt(f),
+            Error::Metadata(_) => write!(f, "Metadata error"),
+            Error::Utf8(ref err) => err.fmt(f),
+            Error::Json(ref err) => err.fmt(f),
+        }
+    }
+}
+
+impl error::Error for Error {
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        match self {
+            Error::Io(ref err) => Some(err),
+            Error::Metadata(_) => None,
+            Error::Utf8(ref err) => Some(err),
+            Error::Json(ref err) => Some(err),
+        }
+    }
+}
+
+// Implementations that let us lookup Packages and Dependencies by name (string)
+
+impl Borrow<PackageRef> for Package {
+    fn borrow(&self) -> &PackageRef {
+        &self.name_and_version
+    }
+}
+
+impl Hash for Package {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.name_and_version.hash(state);
+    }
+}
+
+impl PartialEq for Package {
+    fn eq(&self, other: &Self) -> bool {
+        self.name_and_version == other.name_and_version
+    }
+}
+
+impl Eq for Package {}
+
+impl Borrow<str> for Dependency {
+    fn borrow(&self) -> &str {
+        &self.name
+    }
+}
+
+impl Hash for Dependency {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.name.hash(state);
+    }
+}
+
+impl PartialEq for Dependency {
+    fn eq(&self, other: &Self) -> bool {
+        self.name == other.name
+    }
+}
+
+impl Eq for Dependency {}
+
+fn discover_target(manifest_path: &Path) -> Option<String> {
+    if let Ok(target) = std::env::var("TARGET") {
+        return Some(target);
+    }
+
+    // We must be running as a standalone script, not under cargo.
+    // Let's use the host platform instead.
+    // We figure out the host platform through rustc and use that.
+    // We unfortunatelly cannot go through cargo, since cargo rustc _also_ builds.
+    // If `rustc` fails to run, we just fall back to not passing --filter-platforms.
+    //
+    // NOTE: We set the current directory in case of rustup shenanigans.
+    let rustc = env::var("RUSTC").unwrap_or_else(|_| String::from("rustc"));
+    debug!("Discovering host platform by {:?}", rustc);
+
+    let rustc_output = Command::new(rustc)
+        .current_dir(manifest_path.parent().unwrap())
+        .arg("-vV")
+        .output();
+    let rustc_output = match rustc_output {
+        Ok(ref out) => String::from_utf8_lossy(&out.stdout),
+        Err(..) => return None,
+    };
+
+    let field = "host: ";
+    rustc_output
+        .lines()
+        .find_map(|l| l.strip_prefix(field).map(|stripped| stripped.to_string()))
+}
+
+/// The main entry point to obtaining metadata
+pub fn metadata(
+    manifest_path: &Path,
+    existing_metadata_file: Option<&Path>,
+    only_target: bool,
+) -> Result<Metadata, Error> {
+    let output;
+    let metadata = match existing_metadata_file {
+        Some(path) => Cow::Owned(std::fs::read_to_string(path)?),
+        None => {
+            let target = if only_target {
+                let target = discover_target(manifest_path);
+                if target.is_none() {
+                    warn!(
+                        "Failed to discover host platform for cargo metadata; \
+                        will fetch dependencies for all platforms."
+                    );
+                }
+                target
+            } else {
+                None
+            };
+
+            let cargo = env::var("CARGO").unwrap_or_else(|_| String::from("cargo"));
+            let mut cmd = Command::new(cargo);
+            cmd.arg("metadata");
+            cmd.arg("--all-features");
+            cmd.arg("--format-version").arg("1");
+            if let Some(target) = target {
+                cmd.arg("--filter-platform").arg(target);
+            }
+            cmd.arg("--manifest-path");
+            cmd.arg(manifest_path);
+            output = cmd.output()?;
+            if !output.status.success() {
+                return Err(Error::Metadata(output));
+            }
+            Cow::Borrowed(std::str::from_utf8(&output.stdout)?)
+        }
+    };
+
+    let meta: Metadata = serde_json::from_str(&metadata)?;
+    Ok(meta)
+}
diff --git a/src/bindgen/cargo/cargo_toml.rs b/src/bindgen/cargo/cargo_toml.rs
new file mode 100644
index 0000000..998176e
--- /dev/null
+++ b/src/bindgen/cargo/cargo_toml.rs
@@ -0,0 +1,67 @@
+/* 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::error;
+use std::fmt;
+use std::fs::File;
+use std::io;
+use std::io::Read;
+use std::path::Path;
+
+#[derive(Debug)]
+/// Possible errors that can occur during Cargo.toml parsing.
+pub enum Error {
+    /// Error during reading of Cargo.toml
+    Io(io::Error),
+    /// Deserialization error
+    Toml(toml::de::Error),
+}
+
+impl From<io::Error> for Error {
+    fn from(err: io::Error) -> Self {
+        Error::Io(err)
+    }
+}
+impl From<toml::de::Error> for Error {
+    fn from(err: toml::de::Error) -> Self {
+        Error::Toml(err)
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Error::Io(ref err) => err.fmt(f),
+            Error::Toml(ref err) => err.fmt(f),
+        }
+    }
+}
+
+impl error::Error for Error {
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        match self {
+            Error::Io(ref err) => Some(err),
+            Error::Toml(ref err) => Some(err),
+        }
+    }
+}
+
+#[derive(Clone, Deserialize, Debug)]
+pub struct Manifest {
+    pub package: Package,
+}
+
+#[derive(Clone, Deserialize, Debug)]
+pub struct Package {
+    pub name: String,
+}
+
+/// Parse the Cargo.toml for a given path
+pub fn manifest(manifest_path: &Path) -> Result<Manifest, Error> {
+    let mut s = String::new();
+    let mut f = File::open(manifest_path)?;
+    f.read_to_string(&mut s)?;
+
+    toml::from_str::<Manifest>(&s).map_err(|x| x.into())
+}
diff --git a/src/bindgen/cargo/mod.rs b/src/bindgen/cargo/mod.rs
new file mode 100644
index 0000000..19fef54
--- /dev/null
+++ b/src/bindgen/cargo/mod.rs
@@ -0,0 +1,12 @@
+/* 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/. */
+
+#[allow(clippy::module_inception)]
+mod cargo;
+pub(crate) mod cargo_expand;
+pub(crate) mod cargo_lock;
+pub(crate) mod cargo_metadata;
+pub(crate) mod cargo_toml;
+
+pub(crate) use self::cargo::*;