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))]


extern crate log;
extern crate rustfmt;
extern crate toml;
extern crate env_logger;
extern crate getopts;

use rustfmt::{run, Input, Summary};
use rustfmt::file_lines::FileLines;
use rustfmt::config::{Config, WriteMode};

use std::{env, error};
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};

type FmtError = Box<error::Error + Send + Sync>;
type FmtResult<T> = std::result::Result<T, FmtError>;

/// Rustfmt operations.
enum Operation {
    /// Format files and their child modules.
    Format {
        files: Vec<PathBuf>,
        config_path: Option<PathBuf>,
        minimal_config_path: Option<String>,
    },
    /// Print the help message.
    Help,
    // Print version information
    Version,
    /// Print detailed configuration help.
    ConfigHelp,
    /// Output default config to a file
    ConfigOutputDefault { path: String },
    /// No file specified, read from stdin
    Stdin {
        input: String,
        config_path: Option<PathBuf>,
    },
}

/// Parsed command line options.
#[derive(Clone, Debug, Default)]
struct CliOptions {
    skip_children: bool,
    verbose: bool,
    write_mode: Option<WriteMode>,
    file_lines: FileLines, // Default is all lines in all files.
}

impl CliOptions {
    fn from_matches(matches: &Matches) -> FmtResult<CliOptions> {
        let mut options = CliOptions::default();
        options.skip_children = matches.opt_present("skip-children");
        options.verbose = matches.opt_present("verbose");

        if let Some(ref write_mode) = matches.opt_str("write-mode") {
            if let Ok(write_mode) = WriteMode::from_str(write_mode) {
                options.write_mode = Some(write_mode);
            } else {
                return Err(FmtError::from(format!("Invalid write-mode: {}", write_mode)));
            }
        }

        if let Some(ref file_lines) = matches.opt_str("file-lines") {
            options.file_lines = file_lines.parse()?;
        }

        Ok(options)
    }

    fn apply_to(self, config: &mut Config) {
        config.set().skip_children(self.skip_children);
        config.set().verbose(self.verbose);
        config.set().file_lines(self.file_lines);
        if let Some(write_mode) = self.write_mode {
            config.set().write_mode(write_mode);
        }
    }
}

const CONFIG_FILE_NAMES: [&'static str; 2] = [".rustfmt.toml", "rustfmt.toml"];

/// 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) -> FmtResult<Option<PathBuf>> {
    let mut current = if dir.is_relative() {
        env::current_dir()?.join(dir)
    } else {
        dir.to_path_buf()
    };

    current = fs::canonicalize(current)?;

    loop {
        for config_file_name in &CONFIG_FILE_NAMES {
            let config_file = current.join(config_file_name);
            match fs::metadata(&config_file) {
                // Only return if it's a file to handle the unlikely situation of a directory named
                // `rustfmt.toml`.
                Ok(ref md) if md.is_file() => return Ok(Some(config_file)),
                // Return the error if it's something other than `NotFound`; otherwise we didn't
                // find the project file yet, and continue searching.
                Err(e) => {
                    if e.kind() != ErrorKind::NotFound {
                        return Err(FmtError::from(e));
                    }
                }
                _ => {}
            }
        }

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

fn open_config_file(file_path: &Path) -> FmtResult<(Config, Option<PathBuf>)> {
    let mut file = File::open(&file_path)?;
    let mut toml = String::new();
    file.read_to_string(&mut toml)?;
    match Config::from_toml(&toml) {
        Ok(cfg) => Ok((cfg, Some(file_path.to_path_buf()))),
        Err(err) => Err(FmtError::from(err)),
    }
}

/// 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) -> FmtResult<(Config, Option<PathBuf>)> {
    let path = lookup_project_file(dir)?;
    if path.is_none() {
        return Ok((Config::default(), None));
    }
    open_config_file(&path.unwrap())
}

/// 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)
                          -> FmtResult<(Config, Option<PathBuf>)> {

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

fn make_opts() -> Options {
    let mut opts = Options::new();
    opts.optflag("h", "help", "show this message");
    opts.optflag("V", "version", "show version information");
    opts.optflag("v", "verbose", "print verbose output");
    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("",
                "dump-default-config",
                "Dumps the default configuration to a file and exits.",
                "PATH");
    opts.optopt("",
                "dump-minimal-config",
                "Dumps configuration options that were checked during formatting to a file.",
                "PATH");
    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]");
    opts.optopt("",
                "file-lines",
                "Format specified line ranges. See README for more detail on the JSON format.",
                "JSON");

    opts
}

fn execute(opts: &Options) -> FmtResult<Summary> {
    let matches = opts.parse(env::args().skip(1))?;

    match determine_operation(&matches)? {
        Operation::Help => {
            print_usage(opts, "");
            Summary::print_exit_codes();
            Ok(Summary::new())
        }
        Operation::Version => {
            print_version();
            Ok(Summary::new())
        }
        Operation::ConfigHelp => {
            Config::print_docs();
            Ok(Summary::new())
        }
        Operation::ConfigOutputDefault { path } => {
            let mut file = File::create(path)?;
            let toml = Config::default().all_options().to_toml()?;
            file.write_all(toml.as_bytes())?;
            Ok(Summary::new())
        }
        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())?;

            // write_mode is always Plain for Stdin.
            config.set().write_mode(WriteMode::Plain);

            // parse file_lines
            if let Some(ref file_lines) = matches.opt_str("file-lines") {
                config.set().file_lines(file_lines.parse()?);
                for f in config.file_lines().files() {
                    if f != "stdin" {
                        println!("Warning: Extra file listed in file_lines option '{}'", f);
                    }
                }
            }

            Ok(run(Input::Text(input), &config))
        }
        Operation::Format {
            files,
            config_path,
            minimal_config_path,
        } => {
            let options = CliOptions::from_matches(&matches)?;

            for f in options.file_lines.files() {
                if !files.contains(&PathBuf::from(f)) {
                    println!("Warning: Extra file listed in file_lines option '{}'", f);
                }
            }

            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) = open_config_file(config_file.as_ref())?;
                config = cfg_tmp;
                path = path_tmp;
            };

            if options.verbose {
                if let Some(path) = path.as_ref() {
                    println!("Using rustfmt config file {}", path.display());
                }
            }

            let mut error_summary = Summary::new();
            for file in files {
                if !file.exists() {
                    println!("Error: file `{}` does not exist", file.to_str().unwrap());
                    error_summary.add_operational_error();
                } else if file.is_dir() {
                    println!("Error: `{}` is a directory", file.to_str().unwrap());
                    error_summary.add_operational_error();
                } else {
                    // 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())?;
                        if options.verbose {
                            if let Some(path) = path_tmp.as_ref() {
                                println!("Using rustfmt config file {} for {}",
                                         path.display(),
                                         file.display());
                            }
                        }
                        config = config_tmp;
                    }

                    options.clone().apply_to(&mut config);
                    error_summary.add(run(Input::File(file), &config));
                }
            }

            // If we were given a path via dump-minimal-config, output any options
            // that were used during formatting as TOML.
            if let Some(path) = minimal_config_path {
                let mut file = File::create(path)?;
                let toml = config.used_options().to_toml()?;
                file.write_all(toml.as_bytes())?;
            }

            Ok(error_summary)
        }
    }
}

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

    let opts = make_opts();

    let exit_code = match execute(&opts) {
        Ok(summary) => {
            if summary.has_operational_errors() {
                1
            } else if summary.has_parsing_errors() {
                2
            } else if summary.has_formatting_errors() {
                3
            } else if summary.has_diff {
                // should only happen in diff mode
                4
            } else {
                assert!(summary.has_no_errors());
                0
            }
        }
        Err(e) => {
            print_usage(&opts, &e.to_string());
            1
        }
    };
    // 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!("{}\n\nusage: {} [options] <file>...",
                         reason,
                         env::args_os().next().unwrap().to_string_lossy());
    println!("{}", opts.usage(&reason));
}

fn print_version() {
    println!("{}-nightly{}",
             env!("CARGO_PKG_VERSION"),
             include_str!(concat!(env!("OUT_DIR"), "/commit-info.txt")))
}

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

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

    if let Some(path) = matches.opt_str("dump-default-config") {
        return Ok(Operation::ConfigOutputDefault { path });
    }

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

    let config_path_not_found = |path: &str| -> FmtResult<Operation> {
        Err(FmtError::from(format!("Error: unable to find a config file for the given path: `{}`",
                                   path)))
    };

    // Read the config_path and convert to parent dir if a file is provided.
    // If a config file cannot be found from the given path, return error.
    let config_path: Option<PathBuf> = match matches.opt_str("config-path").map(PathBuf::from) {
        Some(ref path) if !path.exists() => return config_path_not_found(path.to_str().unwrap()),
        Some(ref path) if path.is_dir() => {
            let mut config_file_path = None;
            for config_file_name in &CONFIG_FILE_NAMES {
                let temp_path = path.join(config_file_name);
                if temp_path.is_file() {
                    config_file_path = Some(temp_path);
                }
            }
            if config_file_path.is_some() {
                config_file_path
            } else {
                return config_path_not_found(path.to_str().unwrap());
            }
        }
        path @ _ => path,
    };

    // If no path is given, we won't output a minimal config.
    let minimal_config_path = matches.opt_str("dump-minimal-config");

    // if no file argument is supplied, read from stdin
    if matches.free.is_empty() {
        let mut buffer = String::new();
        io::stdin().read_to_string(&mut buffer)?;

        return Ok(Operation::Stdin {
                      input: buffer,
                      config_path: config_path,
                  });
    }

    let files: Vec<_> = matches
        .free
        .iter()
        .map(|s| {
                 let p = PathBuf::from(s);
                 // we will do comparison later, so here tries to canonicalize first
                 // to get the expected behavior.
                 p.canonicalize().unwrap_or(p)
             })
        .collect();

    Ok(Operation::Format {
           files: files,
           config_path: config_path,
           minimal_config_path: minimal_config_path,
       })
}