1 files changed, 69 insertions, 0 deletions
diff --git a/book/src/code-formatting.md b/book/src/code-formatting.md
new file mode 100644
index 00000000..9039984a
--- /dev/null
+++ b/book/src/code-formatting.md
@@ -0,0 +1,69 @@
+# Code Formatting
+
+`bindgen` uses `rustfmt` to format the emitted bindings. This section describes
+how to adjust the `rustfmt` behavior when being used from `bindgen`.
+
+## Passing a `rustfmt.toml` configuration file
+
+`rustfmt` should automatically use any `rustfmt.toml` file that is present in
+the directory from where `bindgen` will be run. If you want to use a
+configuration file that has a different name or that is in a different
+directory you can use the `--rustfmt-configuration-file` flag or the
+[`Builder::rustfmt_configuration_file`](https://docs.rs/bindgen/latest/bindgen/struct.Builder.html#method.rustfmt_configuration_file)
+method.
+
+## Using a nightly release of `rustfmt`
+
+If the `rustfmt` command does not correspond to a nightly release of `rustfmt`
+but you have `rustup` available, you can use `nightly` by following these
+steps:
+
+### When using `bindgen` as a CLI application
+
+Use `rustup run` to run `bindgen`:
+
+```bash
+$ rustup run nightly bindgen [ARGS]
+```
+
+### When using `bindgen` as a library
+
+Take the output of the following command:
+```bash
+$ rustup which rustfmt --toolchain=nightly
+```
+and pass it to
+[`Builder::with_rustfmt`](https://docs.rs/bindgen/latest/bindgen/struct.Builder.html#method.with_rustfmt):
+
+```rust,ignore
+use bindgen::Builder;
+use std::process::Command;
+
+fn main() {
+    let output = Command::new("rustup")
+        .args(["which", "rustfmt", "--toolchain", "nightly"])
+        .output()
+        .expect("Could not spawn `rustup` command");
+
+    assert!(
+        output.status.success(),
+        "Unsuccessful status code when running `rustup`: {:?}",
+        output
+    );
+
+    let rustfmt_path =
+        String::from_utf8(output.stdout).expect("The `rustfmt` path is not valid `utf-8`");
+
+    let bindings = Builder::default()
+        .header("path/to/input.h")
+        .with_rustfmt(rustfmt_path)
+        .generate()
+        .expect("Could not generate bindings");
+
+    bindings
+        .write_to_file("path/to/output.rs")
+        .expect("Could not write bindings");
+}
+```
+
+These two methods also apply to any other toolchain available in your system.