rust/src/bin/rustfmt.rs

// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#![cfg(not(test))]

#[macro_use]
extern crate log;
extern crate rustfmt;
extern crate toml;
extern crate env_logger;
extern crate getopts;

use rustfmt::{run, run_from_stdin};
use rustfmt::config::{Config, WriteMode};

use std::env;
use std::fs::{self, File};
use std::io::{self, ErrorKind, Read, Write};
use std::path::{Path, PathBuf};
use std::str::FromStr;

use getopts::{Matches, Options};

/// Rustfmt operations.
enum Operation {
    /// Format files and their child modules.
    Format(Vec<PathBuf>, Option<PathBuf>),
    /// Print the help message.
    Help,
    // Print version information
    Version,
    /// Print detailed configuration help.
    ConfigHelp,
    /// Invalid program input, including reason.
    InvalidInput(String),
    /// No file specified, read from stdin
    Stdin(String, Option<PathBuf>),
}

/// Try to find a project file in the given directory and its parents. Returns the path of a the
/// nearest project file if one exists, or `None` if no project file was found.
fn lookup_project_file(dir: &Path) -> io::Result<Option<PathBuf>> {
    let mut current = if dir.is_relative() {
        try!(env::current_dir()).join(dir)
    } else {
        dir.to_path_buf()
    };

    current = try!(fs::canonicalize(current));

    loop {
        let config_file = current.join("rustfmt.toml");
        match fs::metadata(&config_file) {
            Ok(md) => {
                // Properly handle unlikely situation of a directory named `rustfmt.toml`.
                if md.is_file() {
                    return Ok(Some(config_file));
                }
            }
            // If it's not found, we continue searching; otherwise something went wrong and we
            // return the error.
            Err(e) => {
                if e.kind() != ErrorKind::NotFound {
                    return Err(e);
                }
            }
        }

        // If the current directory has no parent, we're done searching.
        if !current.pop() {
            return Ok(None);
        }
    }
}

/// Resolve the config for input in `dir`.
///
/// Returns the `Config` to use, and the path of the project file if there was
/// one.
fn resolve_config(dir: &Path) -> io::Result<(Config, Option<PathBuf>)> {
    let path = try!(lookup_project_file(dir));
    if path.is_none() {
        return Ok((Config::default(), None));
    }
    let path = path.unwrap();
    let mut file = try!(File::open(&path));
    let mut toml = String::new();
    try!(file.read_to_string(&mut toml));
    Ok((Config::from_toml(&toml), Some(path)))
}

/// read the given config file path recursively if present else read the project file path
fn match_cli_path_or_file(config_path: Option<PathBuf>,
                          input_file: &Path)
                          -> io::Result<(Config, Option<PathBuf>)> {

    if let Some(config_file) = config_path {
        let (toml, path) = try!(resolve_config(config_file.as_ref()));
        if path.is_some() {
            return Ok((toml, path));
        }
    }
    resolve_config(input_file)
}

fn update_config(config: &mut Config, matches: &Matches) -> Result<(), String> {
    config.verbose = matches.opt_present("verbose");
    config.skip_children = matches.opt_present("skip-children");

    let write_mode = matches.opt_str("write-mode");
    match matches.opt_str("write-mode").map(|wm| WriteMode::from_str(&wm)) {
        None => Ok(()),
        Some(Ok(write_mode)) => {
            config.write_mode = write_mode;
            Ok(())
        }
        Some(Err(_)) => Err(format!("Invalid write-mode: {}", write_mode.expect("cannot happen"))),
    }
}

fn execute() -> i32 {
    let mut opts = Options::new();
    opts.optflag("h", "help", "show this message");
    opts.optflag("V", "version", "show version information");
    opts.optflag("v", "verbose", "show progress");
    opts.optopt("",
                "write-mode",
                "mode to write in (not usable when piping from stdin)",
                "[replace|overwrite|display|diff|coverage|checkstyle]");
    opts.optflag("", "skip-children", "don't reformat child modules");

    opts.optflag("",
                 "config-help",
                 "show details of rustfmt configuration options");
    opts.optopt("",
                "config-path",
                "Recursively searches the given path for the rustfmt.toml config file. If not \
                 found reverts to the input file path",
                "[Path for the configuration file]");

    let matches = match opts.parse(env::args().skip(1)) {
        Ok(m) => m,
        Err(e) => {
            print_usage(&opts, &e.to_string());
            return 1;
        }
    };

    let operation = determine_operation(&matches);

    match operation {
        Operation::InvalidInput(reason) => {
            print_usage(&opts, &reason);
            1
        }
        Operation::Help => {
            print_usage(&opts, "");
            0
        }
        Operation::Version => {
            print_version();
            0
        }
        Operation::ConfigHelp => {
            Config::print_docs();
            0
        }
        Operation::Stdin(input, config_path) => {
            // try to read config from local directory
            let (mut config, _) = match_cli_path_or_file(config_path, &env::current_dir().unwrap())
                                      .expect("Error resolving config");

            // write_mode is always Plain for Stdin.
            config.write_mode = WriteMode::Plain;

            run_from_stdin(input, &config);
            0
        }
        Operation::Format(files, config_path) => {
            let mut config = Config::default();
            let mut path = None;
            // Load the config path file if provided
            if let Some(config_file) = config_path {
                let (cfg_tmp, path_tmp) = resolve_config(config_file.as_ref())
                                              .expect(&format!("Error resolving config for {:?}",
                                                               config_file));
                config = cfg_tmp;
                path = path_tmp;
            };
            if let Some(path) = path.as_ref() {
                println!("Using rustfmt config file {}", path.display());
            }
            for file in files {
                // Check the file directory if the config-path could not be read or not provided
                if path.is_none() {
                    let (config_tmp, path_tmp) = resolve_config(file.parent().unwrap())
                                                     .expect(&format!("Error resolving config \
                                                                       for {}",
                                                                      file.display()));
                    if let Some(path) = path_tmp.as_ref() {
                        println!("Using rustfmt config file {} for {}",
                                 path.display(),
                                 file.display());
                    }
                    config = config_tmp;
                }

                if let Err(e) = update_config(&mut config, &matches) {
                    print_usage(&opts, &e);
                    return 1;
                }
                run(&file, &config);
            }
            0
        }
    }
}

fn main() {
    let _ = env_logger::init();
    let exit_code = execute();

    // Make sure standard output is flushed before we exit.
    std::io::stdout().flush().unwrap();

    // Exit with given exit code.
    //
    // NOTE: This immediately terminates the process without doing any cleanup,
    // so make sure to finish all necessary cleanup before this is called.
    std::process::exit(exit_code);
}

fn print_usage(opts: &Options, reason: &str) {
    let reason = format!("{}\nusage: {} [options] <file>...",
                         reason,
                         env::args_os().next().unwrap().to_string_lossy());
    println!("{}", opts.usage(&reason));
}

fn print_version() {
    println!("{}.{}.{}{}",
             option_env!("CARGO_PKG_VERSION_MAJOR").unwrap_or("X"),
             option_env!("CARGO_PKG_VERSION_MINOR").unwrap_or("X"),
             option_env!("CARGO_PKG_VERSION_PATCH").unwrap_or("X"),
             option_env!("CARGO_PKG_VERSION_PRE").unwrap_or(""));
}

fn determine_operation(matches: &Matches) -> Operation {
    if matches.opt_present("h") {
        return Operation::Help;
    }

    if matches.opt_present("config-help") {
        return Operation::ConfigHelp;
    }

    if matches.opt_present("version") {
        return Operation::Version;
    }

    // Read the config_path and convert to parent dir if a file is provided.
    let config_path: Option<PathBuf> = matches.opt_str("config-path")
                                              .map(PathBuf::from)
                                              .and_then(|dir| {
                                                  if dir.is_file() {
                                                      return dir.parent().map(|v| v.into());
                                                  }
                                                  Some(dir)
                                              });

    // if no file argument is supplied, read from stdin
    if matches.free.is_empty() {

        let mut buffer = String::new();
        match io::stdin().read_to_string(&mut buffer) {
            Ok(..) => (),
            Err(e) => return Operation::InvalidInput(e.to_string()),
        }

        return Operation::Stdin(buffer, config_path);
    }

    let files: Vec<_> = matches.free.iter().map(PathBuf::from).collect();

    Operation::Format(files, config_path)
}