From afbdb0cc4138be4f1d8970caf6c97a9a13eb8e7e Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Sun, 19 Apr 2015 10:07:11 -0700
Subject: [PATCH] Add Rust to C example

---
 .gitignore             |  2 ++
 rust-to-c/Cargo.toml   | 11 +++++++++++
 rust-to-c/build.rs     |  5 +++++
 rust-to-c/src/double.c |  3 +++
 rust-to-c/src/main.rs  | 11 +++++++++++
 5 files changed, 32 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 rust-to-c/Cargo.toml
 create mode 100644 rust-to-c/build.rs
 create mode 100644 rust-to-c/src/double.c
 create mode 100644 rust-to-c/src/main.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..fa8d85a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+Cargo.lock
+target
diff --git a/rust-to-c/Cargo.toml b/rust-to-c/Cargo.toml
new file mode 100644
index 0000000..aedebe0
--- /dev/null
+++ b/rust-to-c/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "rust-to-c"
+version = "0.1.0"
+authors = ["Alex Crichton <alex@alexcrichton.com>"]
+build = "build.rs"
+
+[dependencies]
+libc = "0.1"
+
+[build-dependencies]
+gcc = "0.3"
diff --git a/rust-to-c/build.rs b/rust-to-c/build.rs
new file mode 100644
index 0000000..ec8cc94
--- /dev/null
+++ b/rust-to-c/build.rs
@@ -0,0 +1,5 @@
+extern crate gcc;
+
+fn main() {
+    gcc::Config::new().file("src/double.c").compile("libdouble.a");
+}
diff --git a/rust-to-c/src/double.c b/rust-to-c/src/double.c
new file mode 100644
index 0000000..9fd3c60
--- /dev/null
+++ b/rust-to-c/src/double.c
@@ -0,0 +1,3 @@
+int double_input(int input) {
+    return input * 2;
+}
diff --git a/rust-to-c/src/main.rs b/rust-to-c/src/main.rs
new file mode 100644
index 0000000..2104230
--- /dev/null
+++ b/rust-to-c/src/main.rs
@@ -0,0 +1,11 @@
+extern crate libc;
+
+extern {
+    fn double_input(input: libc::c_int) -> libc::c_int;
+}
+
+fn main() {
+    let input = 4;
+    let output = unsafe { double_input(input) };
+    println!("{} * 2 = {}", input, output);
+}