]> git.lizzy.rs Git - rust.git/blobdiff - src/bin/main.rs
Use edition in rustfmt.toml when no command line argument is passed
[rust.git] / src / bin / main.rs
index 330bec55588ff22e7bda300be0c21df25022d9ba..b3c61b3df428fe3e6dc2177829bf87cd0b0dcb19 100644 (file)
@@ -8,44 +8,59 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![cfg(not(test))]
-
 extern crate env_logger;
+#[macro_use]
+extern crate failure;
 extern crate getopts;
 extern crate rustfmt_nightly as rustfmt;
 
+use std::env;
 use std::fs::File;
 use std::io::{self, stdout, Read, Write};
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
-use std::{env, error};
+
+use failure::err_msg;
 
 use getopts::{Matches, Options};
 
-use rustfmt::checkstyle;
-use rustfmt::config::file_lines::FileLines;
-use rustfmt::config::{get_toml_path, Color, Config, WriteMode};
-use rustfmt::{run, FileName, Input, Summary};
+use rustfmt::{
+    load_config, CliOptions, Color, Config, Edition, EmitMode, ErrorKind, FileLines, FileName,
+    Input, Session, Verbosity,
+};
 
-type FmtError = Box<error::Error + Send + Sync>;
-type FmtResult<T> = std::result::Result<T, FmtError>;
+fn main() {
+    env_logger::init();
+    let opts = make_opts();
 
-const WRITE_MODE_LIST: &str = "[replace|overwrite|display|plain|diff|coverage|checkstyle]";
+    let exit_code = match execute(&opts) {
+        Ok(code) => code,
+        Err(e) => {
+            eprintln!("{}", 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);
+}
 
 /// 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,
+    Help(HelpOp),
     // Print version information
     Version,
-    /// Print detailed configuration help.
-    ConfigHelp,
     /// Output default config to a file, or stdout if None
     ConfigOutputDefault {
         path: Option<String>,
@@ -53,116 +68,33 @@ enum Operation {
     /// 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: Option<bool>,
-    verbose: bool,
-    write_mode: Option<WriteMode>,
-    color: Option<Color>,
-    file_lines: FileLines, // Default is all lines in all files.
-    unstable_features: bool,
-    error_on_unformatted: Option<bool>,
-}
-
-impl CliOptions {
-    fn from_matches(matches: &Matches) -> FmtResult<CliOptions> {
-        let mut options = CliOptions::default();
-        options.verbose = matches.opt_present("verbose");
-        let unstable_features = matches.opt_present("unstable-features");
-        let rust_nightly = option_env!("CFG_RELEASE_CHANNEL")
-            .map(|c| c == "nightly")
-            .unwrap_or(false);
-        if unstable_features && !rust_nightly {
-            return Err(FmtError::from(
-                "Unstable features are only available on Nightly channel",
-            ));
-        } else {
-            options.unstable_features = unstable_features;
-        }
-
-        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: {}, expected one of {}",
-                    write_mode, WRITE_MODE_LIST
-                )));
-            }
-        }
-
-        if let Some(ref color) = matches.opt_str("color") {
-            match Color::from_str(color) {
-                Ok(color) => options.color = Some(color),
-                _ => return Err(FmtError::from(format!("Invalid color: {}", color))),
-            }
-        }
-
-        if let Some(ref file_lines) = matches.opt_str("file-lines") {
-            options.file_lines = file_lines.parse()?;
-        }
-
-        if matches.opt_present("skip-children") {
-            options.skip_children = Some(true);
-        }
-        if matches.opt_present("error-on-unformatted") {
-            options.error_on_unformatted = Some(true);
-        }
-
-        Ok(options)
-    }
-
-    fn apply_to(self, config: &mut Config) {
-        config.set().verbose(self.verbose);
-        config.set().file_lines(self.file_lines);
-        config.set().unstable_features(self.unstable_features);
-        if let Some(skip_children) = self.skip_children {
-            config.set().skip_children(skip_children);
-        }
-        if let Some(error_on_unformatted) = self.error_on_unformatted {
-            config.set().error_on_unformatted(error_on_unformatted);
-        }
-        if let Some(write_mode) = self.write_mode {
-            config.set().write_mode(write_mode);
-        }
-        if let Some(color) = self.color {
-            config.set().color(color);
-        }
-    }
-}
-
-/// 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 = Config::from_toml_path(config_file.as_ref())?;
-        return Ok((toml, Some(config_file)));
-    }
-    Config::from_resolved_toml_path(input_file).map_err(FmtError::from)
+/// Arguments to `--help`
+enum HelpOp {
+    None,
+    Config,
+    FileLines,
 }
 
 fn make_opts() -> Options {
     let mut opts = Options::new();
 
-    // Sorted in alphabetical order.
-    opts.optopt(
-        "",
-        "color",
-        "Use colored output (if supported)",
-        "[always|never|auto]",
-    );
     opts.optflag(
         "",
-        "config-help",
-        "Show details of rustfmt configuration options",
+        "check",
+        "Run in 'check' mode. Exits with 0 if input is formatted correctly. Exits \
+         with 1 and prints a diff if formatting is required.",
     );
+    let is_nightly = is_nightly();
+    let emit_opts = if is_nightly {
+        "[files|stdout|coverage|checkstyle]"
+    } else {
+        "[files|stdout]"
+    };
+    opts.optopt("", "emit", "What data to emit and how", emit_opts);
+    opts.optflag("", "backup", "Backup any modified files.");
     opts.optopt(
         "",
         "config-path",
@@ -170,220 +102,224 @@ fn make_opts() -> Options {
          found reverts to the input file path",
         "[Path for the configuration file]",
     );
-    opts.opt(
-        "",
-        "dump-default-config",
-        "Dumps default configuration to PATH. PATH defaults to stdout, if omitted.",
-        "PATH",
-        getopts::HasArg::Maybe,
-        getopts::Occur::Optional,
-    );
+    opts.optopt("", "edition", "Rust edition to use", "[2015|2018]");
     opts.optopt(
         "",
-        "dump-minimal-config",
-        "Dumps configuration options that were checked during formatting to a file.",
-        "PATH",
-    );
-    opts.optflag(
-        "",
-        "error-on-unformatted",
-        "Error if unable to get comments or string literals within max_width, \
-         or they are left with trailing whitespaces",
+        "color",
+        "Use colored output (if supported)",
+        "[always|never|auto]",
     );
     opts.optopt(
         "",
-        "file-lines",
-        "Format specified line ranges. See README for more detail on the JSON format.",
-        "JSON",
-    );
-    opts.optflag("h", "help", "Show this message");
-    opts.optflag("", "skip-children", "Don't reformat child modules");
-    opts.optflag(
-        "",
-        "unstable-features",
-        "Enables unstable features. Only available on nightly channel",
+        "print-config",
+        "Dumps a default or minimal config to PATH. A minimal config is the \
+         subset of the current config file used for formatting the current program.",
+        "[minimal|default] PATH",
     );
+
+    if is_nightly {
+        opts.optflag(
+            "",
+            "unstable-features",
+            "Enables unstable features. Only available on nightly channel.",
+        );
+        opts.optopt(
+            "",
+            "file-lines",
+            "Format specified line ranges. Run with `--help=file-lines` for \
+             more detail (unstable).",
+            "JSON",
+        );
+        opts.optflag(
+            "",
+            "error-on-unformatted",
+            "Error if unable to get comments or string literals within max_width, \
+             or they are left with trailing whitespaces (unstable).",
+        );
+        opts.optflag(
+            "",
+            "skip-children",
+            "Don't reformat child modules (unstable).",
+        );
+    }
+
     opts.optflag("v", "verbose", "Print verbose output");
+    opts.optflag("q", "quiet", "Print less output");
     opts.optflag("V", "version", "Show version information");
-    opts.optopt(
-        "",
-        "write-mode",
-        "How to write output (not usable when piping from stdin)",
-        WRITE_MODE_LIST,
+    opts.optflagopt(
+        "h",
+        "help",
+        "Show this message or help about a specific topic: `config` or `file-lines`",
+        "=TOPIC",
     );
 
     opts
 }
 
-fn execute(opts: &Options) -> FmtResult<Summary> {
+fn is_nightly() -> bool {
+    option_env!("CFG_RELEASE_CHANNEL").map_or(false, |c| c == "nightly" || c == "dev")
+}
+
+// Returned i32 is an exit code
+fn execute(opts: &Options) -> Result<i32, failure::Error> {
     let matches = opts.parse(env::args().skip(1))?;
+    let options = GetOptsOptions::from_matches(&matches)?;
 
     match determine_operation(&matches)? {
-        Operation::Help => {
+        Operation::Help(HelpOp::None) => {
             print_usage_to_stdout(opts, "");
-            Summary::print_exit_codes();
-            Ok(Summary::default())
+            Ok(0)
+        }
+        Operation::Help(HelpOp::Config) => {
+            Config::print_docs(&mut stdout(), options.unstable_features);
+            Ok(0)
+        }
+        Operation::Help(HelpOp::FileLines) => {
+            print_help_file_lines();
+            Ok(0)
         }
         Operation::Version => {
             print_version();
-            Ok(Summary::default())
-        }
-        Operation::ConfigHelp => {
-            Config::print_docs(&mut stdout(), matches.opt_present("unstable-features"));
-            Ok(Summary::default())
+            Ok(0)
         }
         Operation::ConfigOutputDefault { path } => {
-            let toml = Config::default().all_options().to_toml()?;
+            let toml = Config::default().all_options().to_toml().map_err(err_msg)?;
             if let Some(path) = path {
                 let mut file = File::create(path)?;
                 file.write_all(toml.as_bytes())?;
             } else {
                 io::stdout().write_all(toml.as_bytes())?;
             }
-            Ok(Summary::default())
-        }
-        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() {
-                    match *f {
-                        FileName::Custom(ref f) if f == "stdin" => {}
-                        _ => eprintln!("Warning: Extra file listed in file_lines option '{}'", f),
-                    }
-                }
-            }
-
-            let mut error_summary = Summary::default();
-            if config.version_meets_requirement(&mut error_summary) {
-                let mut out = &mut stdout();
-                checkstyle::output_header(&mut out, config.write_mode())?;
-                error_summary.add(run(Input::Text(input), &config));
-                checkstyle::output_footer(&mut out, config.write_mode())?;
-            }
-
-            Ok(error_summary)
+            Ok(0)
         }
+        Operation::Stdin { input } => format_string(input, options),
         Operation::Format {
             files,
-            config_path,
             minimal_config_path,
-        } => {
-            let options = CliOptions::from_matches(&matches)?;
-
-            for f in options.file_lines.files() {
-                match *f {
-                    FileName::Real(ref f) if files.contains(f) => {}
-                    FileName::Real(_) => {
-                        eprintln!("Warning: Extra file listed in file_lines option '{}'", f)
-                    }
-                    _ => eprintln!("Warning: Not a file '{}'", f),
-                }
-            }
-
-            let mut config = Config::default();
-            // Load the config path file if provided
-            if let Some(config_file) = config_path.as_ref() {
-                config = Config::from_toml_path(config_file.as_ref())?;
-            };
+        } => format(files, minimal_config_path, &options),
+    }
+}
 
-            if options.verbose {
-                if let Some(path) = config_path.as_ref() {
-                    println!("Using rustfmt config file {}", path.display());
-                }
-            }
+fn format_string(input: String, options: GetOptsOptions) -> Result<i32, failure::Error> {
+    // try to read config from local directory
+    let (mut config, _) = load_config(Some(Path::new(".")), Some(options.clone()))?;
 
-            let mut out = &mut stdout();
-            checkstyle::output_header(&mut out, config.write_mode())?;
-            let mut error_summary = Summary::default();
-            for file in files {
-                if !file.exists() {
-                    eprintln!("Error: file `{}` does not exist", file.to_str().unwrap());
-                    error_summary.add_operational_error();
-                } else if file.is_dir() {
-                    eprintln!("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 config_path.is_none() {
-                        let (config_tmp, path_tmp) =
-                            Config::from_resolved_toml_path(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;
-                    }
+    // emit mode is always Stdout for Stdin.
+    config.set().emit_mode(EmitMode::Stdout);
+    config.set().verbose(Verbosity::Quiet);
 
-                    if !config.version_meets_requirement(&mut error_summary) {
-                        break;
-                    }
+    // parse file_lines
+    config.set().file_lines(options.file_lines);
+    for f in config.file_lines().files() {
+        match *f {
+            FileName::Stdin => {}
+            _ => eprintln!("Warning: Extra file listed in file_lines option '{}'", f),
+        }
+    }
 
-                    options.clone().apply_to(&mut config);
-                    error_summary.add(run(Input::File(file), &config));
-                }
-            }
-            checkstyle::output_footer(&mut out, config.write_mode())?;
+    let out = &mut stdout();
+    let mut session = Session::new(config, Some(out));
+    format_and_emit_report(&mut session, Input::Text(input));
 
-            // 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())?;
-            }
+    let exit_code = if session.has_operational_errors() || session.has_parsing_errors() {
+        1
+    } else {
+        0
+    };
+    Ok(exit_code)
+}
 
-            Ok(error_summary)
+fn format(
+    files: Vec<PathBuf>,
+    minimal_config_path: Option<String>,
+    options: &GetOptsOptions,
+) -> Result<i32, failure::Error> {
+    options.verify_file_lines(&files);
+    let (config, config_path) = load_config(None, Some(options.clone()))?;
+
+    if config.verbose() == Verbosity::Verbose {
+        if let Some(path) = config_path.as_ref() {
+            println!("Using rustfmt config file {}", path.display());
         }
     }
-}
 
-fn main() {
-    env_logger::init();
+    let out = &mut stdout();
+    let mut session = Session::new(config, Some(out));
 
-    let opts = make_opts();
+    for file in files {
+        if !file.exists() {
+            eprintln!("Error: file `{}` does not exist", file.to_str().unwrap());
+            session.add_operational_error();
+        } else if file.is_dir() {
+            eprintln!("Error: `{}` is a directory", file.to_str().unwrap());
+            session.add_operational_error();
+        } else {
+            // Check the file directory if the config-path could not be read or not provided
+            if config_path.is_none() {
+                let (local_config, config_path) =
+                    load_config(Some(file.parent().unwrap()), Some(options.clone()))?;
+                if local_config.verbose() == Verbosity::Verbose {
+                    if let Some(path) = config_path {
+                        println!(
+                            "Using rustfmt config file {} for {}",
+                            path.display(),
+                            file.display()
+                        );
+                    }
+                }
 
-    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
+                session.override_config(local_config, |sess| {
+                    format_and_emit_report(sess, Input::File(file))
+                });
             } else {
-                assert!(summary.has_no_errors());
-                0
+                format_and_emit_report(&mut session, Input::File(file));
             }
         }
-        Err(e) => {
-            eprintln!("{}", e.to_string());
-            1
-        }
+    }
+
+    // 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 = session.config.used_options().to_toml().map_err(err_msg)?;
+        file.write_all(toml.as_bytes())?;
+    }
+
+    let exit_code = if session.has_operational_errors()
+        || session.has_parsing_errors()
+        || ((session.has_diff() || session.has_check_errors()) && options.check)
+    {
+        1
+    } else {
+        0
     };
-    // Make sure standard output is flushed before we exit.
-    std::io::stdout().flush().unwrap();
+    Ok(exit_code)
+}
 
-    // 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 format_and_emit_report<T: Write>(session: &mut Session<T>, input: Input) {
+    match session.format(input) {
+        Ok(report) => {
+            if report.has_warnings() {
+                match term::stderr() {
+                    Some(ref t)
+                        if session.config.color().use_colored_tty()
+                            && t.supports_color()
+                            && t.supports_attr(term::Attr::Bold) =>
+                    {
+                        match report.fancy_print(term::stderr().unwrap()) {
+                            Ok(..) => (),
+                            Err(..) => panic!("Unable to write to stderr: {}", report),
+                        }
+                    }
+                    _ => eprintln!("{}", report),
+                }
+            }
+        }
+        Err(msg) => {
+            eprintln!("Error writing files: {}", msg);
+            session.add_operational_error();
+        }
+    }
 }
 
 fn print_usage_to_stdout(opts: &Options, reason: &str) {
@@ -400,6 +336,29 @@ fn print_usage_to_stdout(opts: &Options, reason: &str) {
     println!("{}", opts.usage(&msg));
 }
 
+fn print_help_file_lines() {
+    println!(
+        "If you want to restrict reformatting to specific sets of lines, you can
+use the `--file-lines` option. Its argument is a JSON array of objects
+with `file` and `range` properties, where `file` is a file name, and
+`range` is an array representing a range of lines like `[7,13]`. Ranges
+are 1-based and inclusive of both end points. Specifying an empty array
+will result in no files being formatted. For example,
+
+```
+rustfmt --file-lines '[
+    {{\"file\":\"src/lib.rs\",\"range\":[7,13]}},
+    {{\"file\":\"src/lib.rs\",\"range\":[21,29]}},
+    {{\"file\":\"src/foo.rs\",\"range\":[10,11]}},
+    {{\"file\":\"src/foo.rs\",\"range\":[15,15]}}]'
+```
+
+would format lines `7-13` and `21-29` of `src/lib.rs`, and lines `10-11`,
+and `15` of `src/foo.rs`. No other files would be formatted, even if they
+are included as out of line modules from `src/lib.rs`."
+    );
+}
+
 fn print_version() {
     let version_info = format!(
         "{}-{}",
@@ -410,28 +369,31 @@ fn print_version() {
     println!("rustfmt {}", version_info);
 }
 
-fn determine_operation(matches: &Matches) -> FmtResult<Operation> {
+fn determine_operation(matches: &Matches) -> Result<Operation, ErrorKind> {
     if matches.opt_present("h") {
-        return Ok(Operation::Help);
-    }
-
-    if matches.opt_present("config-help") {
-        return Ok(Operation::ConfigHelp);
+        let topic = matches.opt_str("h");
+        if topic == None {
+            return Ok(Operation::Help(HelpOp::None));
+        } else if topic == Some("config".to_owned()) {
+            return Ok(Operation::Help(HelpOp::Config));
+        } else if topic == Some("file-lines".to_owned()) {
+            return Ok(Operation::Help(HelpOp::FileLines));
+        } else {
+            println!("Unknown help topic: `{}`\n", topic.unwrap());
+            return Ok(Operation::Help(HelpOp::None));
+        }
     }
 
-    if matches.opt_present("dump-default-config") {
-        // NOTE for some reason when configured with HasArg::Maybe + Occur::Optional opt_default
-        // doesn't recognize `--foo bar` as a long flag with an argument but as a long flag with no
-        // argument *plus* a free argument. Thus we check for that case in this branch -- this is
-        // required for backward compatibility.
-        if let Some(path) = matches.free.get(0) {
-            return Ok(Operation::ConfigOutputDefault {
-                path: Some(path.clone()),
-            });
-        } else {
-            return Ok(Operation::ConfigOutputDefault {
-                path: matches.opt_str("dump-default-config"),
-            });
+    let mut minimal_config_path = None;
+    if let Some(ref kind) = matches.opt_str("print-config") {
+        let path = matches.free.get(0).cloned();
+        if kind == "default" {
+            return Ok(Operation::ConfigOutputDefault { path });
+        } else if kind == "minimal" {
+            minimal_config_path = path;
+            if minimal_config_path.is_none() {
+                println!("WARNING: PATH required for `--print-config minimal`");
+            }
         }
     }
 
@@ -439,40 +401,12 @@ fn determine_operation(matches: &Matches) -> FmtResult<Operation> {
         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 config_file_path = get_toml_path(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,
-        });
+        return Ok(Operation::Stdin { input: buffer });
     }
 
     let files: Vec<_> = matches
@@ -488,7 +422,178 @@ fn determine_operation(matches: &Matches) -> FmtResult<Operation> {
 
     Ok(Operation::Format {
         files,
-        config_path,
         minimal_config_path,
     })
 }
+
+const STABLE_EMIT_MODES: [EmitMode; 3] = [EmitMode::Files, EmitMode::Stdout, EmitMode::Diff];
+
+/// Parsed command line options.
+#[derive(Clone, Debug, Default)]
+struct GetOptsOptions {
+    skip_children: Option<bool>,
+    quiet: bool,
+    verbose: bool,
+    config_path: Option<PathBuf>,
+    emit_mode: EmitMode,
+    backup: bool,
+    check: bool,
+    edition: Option<Edition>,
+    color: Option<Color>,
+    file_lines: FileLines, // Default is all lines in all files.
+    unstable_features: bool,
+    error_on_unformatted: Option<bool>,
+}
+
+impl GetOptsOptions {
+    pub fn from_matches(matches: &Matches) -> Result<GetOptsOptions, failure::Error> {
+        let mut options = GetOptsOptions::default();
+        options.verbose = matches.opt_present("verbose");
+        options.quiet = matches.opt_present("quiet");
+        if options.verbose && options.quiet {
+            return Err(format_err!("Can't use both `--verbose` and `--quiet`"));
+        }
+
+        let rust_nightly = is_nightly();
+
+        if rust_nightly {
+            options.unstable_features = matches.opt_present("unstable-features");
+
+            if options.unstable_features {
+                if matches.opt_present("skip-children") {
+                    options.skip_children = Some(true);
+                }
+                if matches.opt_present("error-on-unformatted") {
+                    options.error_on_unformatted = Some(true);
+                }
+                if let Some(ref file_lines) = matches.opt_str("file-lines") {
+                    options.file_lines = file_lines.parse().map_err(err_msg)?;
+                }
+            } else {
+                let mut unstable_options = vec![];
+                if matches.opt_present("skip-children") {
+                    unstable_options.push("`--skip-children`");
+                }
+                if matches.opt_present("error-on-unformatted") {
+                    unstable_options.push("`--error-on-unformatted`");
+                }
+                if matches.opt_present("file-lines") {
+                    unstable_options.push("`--file-lines`");
+                }
+                if !unstable_options.is_empty() {
+                    let s = if unstable_options.len() == 1 { "" } else { "s" };
+                    return Err(format_err!(
+                        "Unstable option{} ({}) used without `--unstable-features`",
+                        s,
+                        unstable_options.join(", "),
+                    ));
+                }
+            }
+        }
+
+        options.config_path = matches.opt_str("config-path").map(PathBuf::from);
+
+        options.check = matches.opt_present("check");
+        if let Some(ref emit_str) = matches.opt_str("emit") {
+            if options.check {
+                return Err(format_err!("Invalid to use `--emit` and `--check`"));
+            }
+
+            options.emit_mode = emit_mode_from_emit_str(emit_str)?;
+        }
+
+        if let Some(ref edition_str) = matches.opt_str("edition") {
+            options.edition = Some(edition_from_edition_str(edition_str)?);
+        }
+
+        if matches.opt_present("backup") {
+            options.backup = true;
+        }
+
+        if !rust_nightly {
+            if !STABLE_EMIT_MODES.contains(&options.emit_mode) {
+                return Err(format_err!(
+                    "Invalid value for `--emit` - using an unstable \
+                     value without `--unstable-features`",
+                ));
+            }
+        }
+
+        if let Some(ref color) = matches.opt_str("color") {
+            match Color::from_str(color) {
+                Ok(color) => options.color = Some(color),
+                _ => return Err(format_err!("Invalid color: {}", color)),
+            }
+        }
+
+        Ok(options)
+    }
+
+    fn verify_file_lines(&self, files: &[PathBuf]) {
+        for f in self.file_lines.files() {
+            match *f {
+                FileName::Real(ref f) if files.contains(f) => {}
+                FileName::Real(_) => {
+                    eprintln!("Warning: Extra file listed in file_lines option '{}'", f)
+                }
+                FileName::Stdin => eprintln!("Warning: Not a file '{}'", f),
+            }
+        }
+    }
+}
+
+impl CliOptions for GetOptsOptions {
+    fn apply_to(self, config: &mut Config) {
+        if self.verbose {
+            config.set().verbose(Verbosity::Verbose);
+        } else if self.quiet {
+            config.set().verbose(Verbosity::Quiet);
+        } else {
+            config.set().verbose(Verbosity::Normal);
+        }
+        config.set().file_lines(self.file_lines);
+        config.set().unstable_features(self.unstable_features);
+        if let Some(skip_children) = self.skip_children {
+            config.set().skip_children(skip_children);
+        }
+        if let Some(error_on_unformatted) = self.error_on_unformatted {
+            config.set().error_on_unformatted(error_on_unformatted);
+        }
+        if let Some(edition) = self.edition {
+            config.set().edition(edition);
+        }
+        if self.check {
+            config.set().emit_mode(EmitMode::Diff);
+        } else {
+            config.set().emit_mode(self.emit_mode);
+        }
+        if self.backup {
+            config.set().make_backup(true);
+        }
+        if let Some(color) = self.color {
+            config.set().color(color);
+        }
+    }
+
+    fn config_path(&self) -> Option<&Path> {
+        self.config_path.as_ref().map(|p| &**p)
+    }
+}
+
+fn edition_from_edition_str(edition_str: &str) -> Result<Edition, failure::Error> {
+    match edition_str {
+        "2015" => Ok(Edition::Edition2015),
+        "2018" => Ok(Edition::Edition2018),
+        _ => Err(format_err!("Invalid value for `--edition`")),
+    }
+}
+
+fn emit_mode_from_emit_str(emit_str: &str) -> Result<EmitMode, failure::Error> {
+    match emit_str {
+        "files" => Ok(EmitMode::Files),
+        "stdout" => Ok(EmitMode::Stdout),
+        "coverage" => Ok(EmitMode::Coverage),
+        "checkstyle" => Ok(EmitMode::Checkstyle),
+        _ => Err(format_err!("Invalid value for `--emit`")),
+    }
+}