src/librustc_driver/lib.rs

   1 // Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! The Rust compiler.
  12 //!
  13 //! # Note
  14 //!
  15 //! This API is completely unstable and subject to change.
  16
  17 #![crate_name = "rustc_driver"]
  18 #![unstable(feature = "rustc_private")]
  19 #![staged_api]
  20 #![crate_type = "dylib"]
  21 #![crate_type = "rlib"]
  22 #![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
  23       html_favicon_url = "http://www.rust-lang.org/favicon.ico",
  24       html_root_url = "http://doc.rust-lang.org/nightly/")]
  25
  26 #![feature(box_syntax)]
  27 #![feature(collections)]
  28 #![feature(core)]
  29 #![feature(env)]
  30 #![feature(int_uint)]
  31 #![feature(old_io)]
  32 #![feature(libc)]
  33 #![feature(os)]
  34 #![feature(old_path)]
  35 #![feature(quote)]
  36 #![feature(rustc_diagnostic_macros)]
  37 #![feature(rustc_private)]
  38 #![feature(unsafe_destructor)]
  39 #![feature(staged_api)]
  40 #![feature(unicode)]
  41
  42 extern crate arena;
  43 extern crate flate;
  44 extern crate getopts;
  45 extern crate graphviz;
  46 extern crate libc;
  47 extern crate rustc;
  48 extern crate rustc_back;
  49 extern crate rustc_borrowck;
  50 extern crate rustc_privacy;
  51 extern crate rustc_resolve;
  52 extern crate rustc_trans;
  53 extern crate rustc_typeck;
  54 extern crate serialize;
  55 extern crate "rustc_llvm" as llvm;
  56 #[macro_use] extern crate log;
  57 #[macro_use] extern crate syntax;
  58
  59 pub use syntax::diagnostic;
  60
  61 use driver::CompileController;
  62 use pretty::{PpMode, UserIdentifiedItem};
  63
  64 use rustc_resolve as resolve;
  65 use rustc_trans::back::link;
  66 use rustc_trans::save;
  67 use rustc::session::{config, Session, build_session};
  68 use rustc::session::config::{Input, PrintRequest};
  69 use rustc::lint::Lint;
  70 use rustc::lint;
  71 use rustc::metadata;
  72 use rustc::util::common::time;
  73
  74 use std::cmp::Ordering::Equal;
  75 use std::old_io::{self, stdio};
  76 use std::iter::repeat;
  77 use std::env;
  78 use std::sync::mpsc::channel;
  79 use std::thread;
  80
  81 use rustc::session::early_error;
  82
  83 use syntax::ast;
  84 use syntax::parse;
  85 use syntax::diagnostic::Emitter;
  86 use syntax::diagnostics;
  87
  88 #[cfg(test)]
  89 pub mod test;
  90
  91 pub mod driver;
  92 pub mod pretty;
  93
  94
  95 static BUG_REPORT_URL: &'static str =
  96     "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports";
  97
  98
  99 pub fn run(args: Vec<String>) -> int {
 100     monitor(move || run_compiler(&args, &mut RustcDefaultCalls));
 101     0
 102 }
 103
 104 // Parse args and run the compiler. This is the primary entry point for rustc.
 105 // See comments on CompilerCalls below for details about the callbacks argument.
 106 pub fn run_compiler<'a>(args: &[String],
 107                         callbacks: &mut CompilerCalls<'a>) {
 108     macro_rules! do_or_return {($expr: expr) => {
 109         match $expr {
 110             Compilation::Stop => return,
 111             Compilation::Continue => {}
 112         }
 113     }}
 114
 115     let matches = match handle_options(args.to_vec()) {
 116         Some(matches) => matches,
 117         None => return
 118     };
 119
 120     let descriptions = diagnostics_registry();
 121
 122     do_or_return!(callbacks.early_callback(&matches, &descriptions));
 123
 124     let sopts = config::build_session_options(&matches);
 125
 126     let (odir, ofile) = make_output(&matches);
 127     let (input, input_file_path) = match make_input(&matches.free[]) {
 128         Some((input, input_file_path)) => callbacks.some_input(input, input_file_path),
 129         None => match callbacks.no_input(&matches, &sopts, &odir, &ofile, &descriptions) {
 130             Some((input, input_file_path)) => (input, input_file_path),
 131             None => return
 132         }
 133     };
 134
 135     let mut sess = build_session(sopts, input_file_path, descriptions);
 136     if sess.unstable_options() {
 137         sess.opts.show_span = matches.opt_str("show-span");
 138     }
 139     let cfg = config::build_configuration(&sess);
 140
 141     do_or_return!(callbacks.late_callback(&matches, &sess, &input, &odir, &ofile));
 142
 143     // It is somewhat unfortunate that this is hardwired in - this is forced by
 144     // the fact that pretty_print_input requires the session by value.
 145     let pretty = callbacks.parse_pretty(&sess, &matches);
 146     match pretty {
 147         Some((ppm, opt_uii)) => {
 148             pretty::pretty_print_input(sess, cfg, &input, ppm, opt_uii, ofile);
 149             return;
 150         }
 151         None => {/* continue */ }
 152     }
 153
 154     let plugins = sess.opts.debugging_opts.extra_plugins.clone();
 155     let control = callbacks.build_controller(&sess);
 156     driver::compile_input(sess, cfg, &input, &odir, &ofile, Some(plugins), control);
 157 }
 158
 159 // Extract output directory and file from matches.
 160 fn make_output(matches: &getopts::Matches) -> (Option<Path>, Option<Path>) {
 161     let odir = matches.opt_str("out-dir").map(|o| Path::new(o));
 162     let ofile = matches.opt_str("o").map(|o| Path::new(o));
 163     (odir, ofile)
 164 }
 165
 166 // Extract input (string or file and optional path) from matches.
 167 fn make_input(free_matches: &[String]) -> Option<(Input, Option<Path>)> {
 168     if free_matches.len() == 1 {
 169         let ifile = &free_matches[0][];
 170         if ifile == "-" {
 171             let contents = old_io::stdin().read_to_end().unwrap();
 172             let src = String::from_utf8(contents).unwrap();
 173             Some((Input::Str(src), None))
 174         } else {
 175             Some((Input::File(Path::new(ifile)), Some(Path::new(ifile))))
 176         }
 177     } else {
 178         None
 179     }
 180 }
 181
 182 // Whether to stop or continue compilation.
 183 #[derive(Copy, Debug, Eq, PartialEq)]
 184 pub enum Compilation {
 185     Stop,
 186     Continue,
 187 }
 188
 189 impl Compilation {
 190     pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
 191         match self {
 192             Compilation::Stop => Compilation::Stop,
 193             Compilation::Continue => next()
 194         }
 195     }
 196 }
 197
 198 // A trait for customising the compilation process. Offers a number of hooks for
 199 // executing custom code or customising input.
 200 pub trait CompilerCalls<'a> {
 201     // Hook for a callback early in the process of handling arguments. This will
 202     // be called straight after options have been parsed but before anything
 203     // else (e.g., selecting input and output).
 204     fn early_callback(&mut self,
 205                       &getopts::Matches,
 206                       &diagnostics::registry::Registry)
 207                       -> Compilation;
 208
 209     // Hook for a callback late in the process of handling arguments. This will
 210     // be called just before actual compilation starts (and before build_controller
 211     // is called), after all arguments etc. have been completely handled.
 212     fn late_callback(&mut self,
 213                      &getopts::Matches,
 214                      &Session,
 215                      &Input,
 216                      &Option<Path>,
 217                      &Option<Path>)
 218                      -> Compilation;
 219
 220     // Called after we extract the input from the arguments. Gives the implementer
 221     // an opportunity to change the inputs or to add some custom input handling.
 222     // The default behaviour is to simply pass through the inputs.
 223     fn some_input(&mut self, input: Input, input_path: Option<Path>) -> (Input, Option<Path>) {
 224         (input, input_path)
 225     }
 226
 227     // Called after we extract the input from the arguments if there is no valid
 228     // input. Gives the implementer an opportunity to supply alternate input (by
 229     // returning a Some value) or to add custom behaviour for this error such as
 230     // emitting error messages. Returning None will cause compilation to stop
 231     // at this point.
 232     fn no_input(&mut self,
 233                 &getopts::Matches,
 234                 &config::Options,
 235                 &Option<Path>,
 236                 &Option<Path>,
 237                 &diagnostics::registry::Registry)
 238                 -> Option<(Input, Option<Path>)>;
 239
 240     // Parse pretty printing information from the arguments. The implementer can
 241     // choose to ignore this (the default will return None) which will skip pretty
 242     // printing. If you do want to pretty print, it is recommended to use the
 243     // implementation of this method from RustcDefaultCalls.
 244     // FIXME, this is a terrible bit of API. Parsing of pretty printing stuff
 245     // should be done as part of the framework and the implementor should customise
 246     // handling of it. However, that is not possible atm because pretty printing
 247     // essentially goes off and takes another path through the compiler which
 248     // means the session is either moved or not depending on what parse_pretty
 249     // returns (we could fix this by cloning, but it's another hack). The proper
 250     // solution is to handle pretty printing as if it were a compiler extension,
 251     // extending CompileController to make this work (see for example the treatment
 252     // of save-analysis in RustcDefaultCalls::build_controller).
 253     fn parse_pretty(&mut self,
 254                     _sess: &Session,
 255                     _matches: &getopts::Matches)
 256                     -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 257         None
 258     }
 259
 260     // Create a CompilController struct for controlling the behaviour of compilation.
 261     fn build_controller(&mut self, &Session) -> CompileController<'a>;
 262 }
 263
 264 // CompilerCalls instance for a regular rustc build.
 265 #[derive(Copy)]
 266 pub struct RustcDefaultCalls;
 267
 268 impl<'a> CompilerCalls<'a> for RustcDefaultCalls {
 269     fn early_callback(&mut self,
 270                       matches: &getopts::Matches,
 271                       descriptions: &diagnostics::registry::Registry)
 272                       -> Compilation {
 273         match matches.opt_str("explain") {
 274             Some(ref code) => {
 275                 match descriptions.find_description(&code[..]) {
 276                     Some(ref description) => {
 277                         println!("{}", description);
 278                     }
 279                     None => {
 280                         early_error(&format!("no extended information for {}", code)[]);
 281                     }
 282                 }
 283                 return Compilation::Stop;
 284             },
 285             None => ()
 286         }
 287
 288         return Compilation::Continue;
 289     }
 290
 291     fn no_input(&mut self,
 292                 matches: &getopts::Matches,
 293                 sopts: &config::Options,
 294                 odir: &Option<Path>,
 295                 ofile: &Option<Path>,
 296                 descriptions: &diagnostics::registry::Registry)
 297                 -> Option<(Input, Option<Path>)> {
 298         match matches.free.len() {
 299             0 => {
 300                 if sopts.describe_lints {
 301                     let mut ls = lint::LintStore::new();
 302                     ls.register_builtin(None);
 303                     describe_lints(&ls, false);
 304                     return None;
 305                 }
 306                 let sess = build_session(sopts.clone(), None, descriptions.clone());
 307                 let should_stop = RustcDefaultCalls::print_crate_info(&sess, None, odir, ofile);
 308                 if should_stop == Compilation::Stop {
 309                     return None;
 310                 }
 311                 early_error("no input filename given");
 312             }
 313             1 => panic!("make_input should have provided valid inputs"),
 314             _ => early_error("multiple input filenames provided")
 315         }
 316
 317         None
 318     }
 319
 320     fn parse_pretty(&mut self,
 321                     sess: &Session,
 322                     matches: &getopts::Matches)
 323                     -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 324         let pretty = if sess.opts.debugging_opts.unstable_options {
 325             matches.opt_default("pretty", "normal").map(|a| {
 326                 // stable pretty-print variants only
 327                 pretty::parse_pretty(sess, &a, false)
 328             })
 329         } else {
 330             None
 331         };
 332         if pretty.is_none() && sess.unstable_options() {
 333             matches.opt_str("xpretty").map(|a| {
 334                 // extended with unstable pretty-print variants
 335                 pretty::parse_pretty(sess, &a, true)
 336             })
 337         } else {
 338             pretty
 339         }
 340     }
 341
 342     fn late_callback(&mut self,
 343                      matches: &getopts::Matches,
 344                      sess: &Session,
 345                      input: &Input,
 346                      odir: &Option<Path>,
 347                      ofile: &Option<Path>)
 348                      -> Compilation {
 349         RustcDefaultCalls::print_crate_info(sess, Some(input), odir, ofile).and_then(
 350             || RustcDefaultCalls::list_metadata(sess, matches, input))
 351     }
 352
 353     fn build_controller(&mut self, sess: &Session) -> CompileController<'a> {
 354         let mut control = CompileController::basic();
 355
 356         if sess.opts.parse_only ||
 357            sess.opts.show_span.is_some() ||
 358            sess.opts.debugging_opts.ast_json_noexpand {
 359             control.after_parse.stop = Compilation::Stop;
 360         }
 361
 362         if sess.opts.no_analysis || sess.opts.debugging_opts.ast_json {
 363             control.after_write_deps.stop = Compilation::Stop;
 364         }
 365
 366         if sess.opts.no_trans {
 367             control.after_analysis.stop = Compilation::Stop;
 368         }
 369
 370         if !sess.opts.output_types.iter().any(|&i| i == config::OutputTypeExe) {
 371             control.after_llvm.stop = Compilation::Stop;
 372         }
 373
 374         if sess.opts.debugging_opts.save_analysis {
 375             control.after_analysis.callback = box |state| {
 376                 time(state.session.time_passes(), "save analysis", state.krate.unwrap(), |krate|
 377                      save::process_crate(state.session,
 378                                          krate,
 379                                          state.analysis.unwrap(),
 380                                          state.out_dir));
 381             };
 382             control.make_glob_map = resolve::MakeGlobMap::Yes;
 383         }
 384
 385         control
 386     }
 387 }
 388
 389 impl RustcDefaultCalls {
 390     pub fn list_metadata(sess: &Session,
 391                          matches: &getopts::Matches,
 392                          input: &Input)
 393                          -> Compilation {
 394         let r = matches.opt_strs("Z");
 395         if r.contains(&("ls".to_string())) {
 396             match input {
 397                 &Input::File(ref ifile) => {
 398                     let mut stdout = old_io::stdout();
 399                     let path = &(*ifile);
 400                     metadata::loader::list_file_metadata(sess.target.target.options.is_like_osx,
 401                                                          path,
 402                                                          &mut stdout).unwrap();
 403                 }
 404                 &Input::Str(_) => {
 405                     early_error("cannot list metadata for stdin");
 406                 }
 407             }
 408             return Compilation::Stop;
 409         }
 410
 411         return Compilation::Continue;
 412     }
 413
 414
 415     fn print_crate_info(sess: &Session,
 416                         input: Option<&Input>,
 417                         odir: &Option<Path>,
 418                         ofile: &Option<Path>)
 419                         -> Compilation {
 420         if sess.opts.prints.len() == 0 {
 421             return Compilation::Continue;
 422         }
 423
 424         let attrs = input.map(|input| parse_crate_attrs(sess, input));
 425         for req in &sess.opts.prints {
 426             match *req {
 427                 PrintRequest::Sysroot => println!("{}", sess.sysroot().display()),
 428                 PrintRequest::FileNames |
 429                 PrintRequest::CrateName => {
 430                     let input = match input {
 431                         Some(input) => input,
 432                         None => early_error("no input file provided"),
 433                     };
 434                     let attrs = attrs.as_ref().unwrap();
 435                     let t_outputs = driver::build_output_filenames(input,
 436                                                                    odir,
 437                                                                    ofile,
 438                                                                    attrs,
 439                                                                    sess);
 440                     let id = link::find_crate_name(Some(sess),
 441                                                    attrs,
 442                                                    input);
 443                     if *req == PrintRequest::CrateName {
 444                         println!("{}", id);
 445                         continue
 446                     }
 447                     let crate_types = driver::collect_crate_types(sess, attrs);
 448                     let metadata = driver::collect_crate_metadata(sess, attrs);
 449                     *sess.crate_metadata.borrow_mut() = metadata;
 450                     for &style in &crate_types {
 451                         let fname = link::filename_for_input(sess,
 452                                                              style,
 453                                                              &id,
 454                                                              &t_outputs.with_extension(""));
 455                         println!("{}", fname.filename_display());
 456                     }
 457                 }
 458             }
 459         }
 460         return Compilation::Stop;
 461     }
 462 }
 463
 464 /// Returns a version string such as "0.12.0-dev".
 465 pub fn release_str() -> Option<&'static str> {
 466     option_env!("CFG_RELEASE")
 467 }
 468
 469 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 470 pub fn commit_hash_str() -> Option<&'static str> {
 471     option_env!("CFG_VER_HASH")
 472 }
 473
 474 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 475 pub fn commit_date_str() -> Option<&'static str> {
 476     option_env!("CFG_VER_DATE")
 477 }
 478
 479 pub fn build_date_str() -> Option<&'static str> {
 480     option_env!("CFG_BUILD_DATE")
 481 }
 482
 483 /// Prints version information and returns None on success or an error
 484 /// message on panic.
 485 pub fn version(binary: &str, matches: &getopts::Matches) {
 486     let verbose = matches.opt_present("verbose");
 487
 488     println!("{} {}", binary, option_env!("CFG_VERSION").unwrap_or("unknown version"));
 489     if verbose {
 490         fn unw(x: Option<&str>) -> &str { x.unwrap_or("unknown") }
 491         println!("binary: {}", binary);
 492         println!("commit-hash: {}", unw(commit_hash_str()));
 493         println!("commit-date: {}", unw(commit_date_str()));
 494         println!("build-date: {}", unw(build_date_str()));
 495         println!("host: {}", config::host_triple());
 496         println!("release: {}", unw(release_str()));
 497     }
 498 }
 499
 500 fn usage(verbose: bool, include_unstable_options: bool) {
 501     let groups = if verbose {
 502         config::rustc_optgroups()
 503     } else {
 504         config::rustc_short_optgroups()
 505     };
 506     let groups : Vec<_> = groups.into_iter()
 507         .filter(|x| include_unstable_options || x.is_stable())
 508         .map(|x|x.opt_group)
 509         .collect();
 510     let message = format!("Usage: rustc [OPTIONS] INPUT");
 511     let extra_help = if verbose {
 512         ""
 513     } else {
 514         "\n    --help -v           Print the full set of options rustc accepts"
 515     };
 516     println!("{}\n\
 517 Additional help:
 518     -C help             Print codegen options
 519     -W help             Print 'lint' options and default settings
 520     -Z help             Print internal options for debugging rustc{}\n",
 521               getopts::usage(&message, &groups),
 522               extra_help);
 523 }
 524
 525 fn describe_lints(lint_store: &lint::LintStore, loaded_plugins: bool) {
 526     println!("
 527 Available lint options:
 528     -W <foo>           Warn about <foo>
 529     -A <foo>           Allow <foo>
 530     -D <foo>           Deny <foo>
 531     -F <foo>           Forbid <foo> (deny, and deny all overrides)
 532
 533 ");
 534
 535     fn sort_lints(lints: Vec<(&'static Lint, bool)>) -> Vec<&'static Lint> {
 536         let mut lints: Vec<_> = lints.into_iter().map(|(x, _)| x).collect();
 537         lints.sort_by(|x: &&Lint, y: &&Lint| {
 538             match x.default_level.cmp(&y.default_level) {
 539                 // The sort doesn't case-fold but it's doubtful we care.
 540                 Equal => x.name.cmp(y.name),
 541                 r => r,
 542             }
 543         });
 544         lints
 545     }
 546
 547     fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
 548                      -> Vec<(&'static str, Vec<lint::LintId>)> {
 549         let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
 550         lints.sort_by(|&(x, _): &(&'static str, Vec<lint::LintId>),
 551                        &(y, _): &(&'static str, Vec<lint::LintId>)| {
 552             x.cmp(y)
 553         });
 554         lints
 555     }
 556
 557     let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints()
 558         .iter().cloned().partition(|&(_, p)| p);
 559     let plugin = sort_lints(plugin);
 560     let builtin = sort_lints(builtin);
 561
 562     let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups()
 563         .iter().cloned().partition(|&(_, _, p)| p);
 564     let plugin_groups = sort_lint_groups(plugin_groups);
 565     let builtin_groups = sort_lint_groups(builtin_groups);
 566
 567     let max_name_len = plugin.iter().chain(builtin.iter())
 568         .map(|&s| s.name.width(true))
 569         .max().unwrap_or(0);
 570     let padded = |x: &str| {
 571         let mut s = repeat(" ").take(max_name_len - x.chars().count())
 572                                .collect::<String>();
 573         s.push_str(x);
 574         s
 575     };
 576
 577     println!("Lint checks provided by rustc:\n");
 578     println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
 579     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
 580
 581     let print_lints = |lints: Vec<&Lint>| {
 582         for lint in lints {
 583             let name = lint.name_lower().replace("_", "-");
 584             println!("    {}  {:7.7}  {}",
 585                      padded(&name[..]), lint.default_level.as_str(), lint.desc);
 586         }
 587         println!("\n");
 588     };
 589
 590     print_lints(builtin);
 591
 592
 593
 594     let max_name_len = plugin_groups.iter().chain(builtin_groups.iter())
 595         .map(|&(s, _)| s.width(true))
 596         .max().unwrap_or(0);
 597     let padded = |x: &str| {
 598         let mut s = repeat(" ").take(max_name_len - x.chars().count())
 599                                .collect::<String>();
 600         s.push_str(x);
 601         s
 602     };
 603
 604     println!("Lint groups provided by rustc:\n");
 605     println!("    {}  {}", padded("name"), "sub-lints");
 606     println!("    {}  {}", padded("----"), "---------");
 607
 608     let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
 609         for (name, to) in lints {
 610             let name = name.chars().map(|x| x.to_lowercase())
 611                            .collect::<String>().replace("_", "-");
 612             let desc = to.into_iter().map(|x| x.as_str().replace("_", "-"))
 613                          .collect::<Vec<String>>().connect(", ");
 614             println!("    {}  {}",
 615                      padded(&name[..]), desc);
 616         }
 617         println!("\n");
 618     };
 619
 620     print_lint_groups(builtin_groups);
 621
 622     match (loaded_plugins, plugin.len(), plugin_groups.len()) {
 623         (false, 0, _) | (false, _, 0) => {
 624             println!("Compiler plugins can provide additional lints and lint groups. To see a \
 625                       listing of these, re-run `rustc -W help` with a crate filename.");
 626         }
 627         (false, _, _) => panic!("didn't load lint plugins but got them anyway!"),
 628         (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
 629         (true, l, g) => {
 630             if l > 0 {
 631                 println!("Lint checks provided by plugins loaded by this crate:\n");
 632                 print_lints(plugin);
 633             }
 634             if g > 0 {
 635                 println!("Lint groups provided by plugins loaded by this crate:\n");
 636                 print_lint_groups(plugin_groups);
 637             }
 638         }
 639     }
 640 }
 641
 642 fn describe_debug_flags() {
 643     println!("\nAvailable debug options:\n");
 644     for &(name, _, opt_type_desc, desc) in config::DB_OPTIONS {
 645         let (width, extra) = match opt_type_desc {
 646             Some(..) => (21, "=val"),
 647             None => (25, "")
 648         };
 649         println!("    -Z {:>width$}{} -- {}", name.replace("_", "-"),
 650                  extra, desc, width=width);
 651     }
 652 }
 653
 654 fn describe_codegen_flags() {
 655     println!("\nAvailable codegen options:\n");
 656     for &(name, _, opt_type_desc, desc) in config::CG_OPTIONS {
 657         let (width, extra) = match opt_type_desc {
 658             Some(..) => (21, "=val"),
 659             None => (25, "")
 660         };
 661         println!("    -C {:>width$}{} -- {}", name.replace("_", "-"),
 662                  extra, desc, width=width);
 663     }
 664 }
 665
 666 /// Process command line options. Emits messages as appropriate. If compilation
 667 /// should continue, returns a getopts::Matches object parsed from args, otherwise
 668 /// returns None.
 669 pub fn handle_options(mut args: Vec<String>) -> Option<getopts::Matches> {
 670     // Throw away the first argument, the name of the binary
 671     let _binary = args.remove(0);
 672
 673     if args.is_empty() {
 674         // user did not write `-v` nor `-Z unstable-options`, so do not
 675         // include that extra information.
 676         usage(false, false);
 677         return None;
 678     }
 679
 680     let matches =
 681         match getopts::getopts(&args[..], &config::optgroups()[]) {
 682             Ok(m) => m,
 683             Err(f_stable_attempt) => {
 684                 // redo option parsing, including unstable options this time,
 685                 // in anticipation that the mishandled option was one of the
 686                 // unstable ones.
 687                 let all_groups : Vec<getopts::OptGroup>
 688                     = config::rustc_optgroups().into_iter().map(|x|x.opt_group).collect();
 689                 match getopts::getopts(&args, &all_groups) {
 690                     Ok(m_unstable) => {
 691                         let r = m_unstable.opt_strs("Z");
 692                         let include_unstable_options = r.iter().any(|x| *x == "unstable-options");
 693                         if include_unstable_options {
 694                             m_unstable
 695                         } else {
 696                             early_error(&f_stable_attempt.to_string());
 697                         }
 698                     }
 699                     Err(_) => {
 700                         // ignore the error from the unstable attempt; just
 701                         // pass the error we got from the first try.
 702                         early_error(&f_stable_attempt.to_string());
 703                     }
 704                 }
 705             }
 706         };
 707
 708     let r = matches.opt_strs("Z");
 709     let include_unstable_options = r.iter().any(|x| *x == "unstable-options");
 710
 711     if matches.opt_present("h") || matches.opt_present("help") {
 712         usage(matches.opt_present("verbose"), include_unstable_options);
 713         return None;
 714     }
 715
 716     // Don't handle -W help here, because we might first load plugins.
 717
 718     let r = matches.opt_strs("Z");
 719     if r.iter().any(|x| *x == "help") {
 720         describe_debug_flags();
 721         return None;
 722     }
 723
 724     let cg_flags = matches.opt_strs("C");
 725     if cg_flags.iter().any(|x| *x == "help") {
 726         describe_codegen_flags();
 727         return None;
 728     }
 729
 730     if cg_flags.contains(&"passes=list".to_string()) {
 731         unsafe { ::llvm::LLVMRustPrintPasses(); }
 732         return None;
 733     }
 734
 735     if matches.opt_present("version") {
 736         version("rustc", &matches);
 737         return None;
 738     }
 739
 740     Some(matches)
 741 }
 742
 743 fn parse_crate_attrs(sess: &Session, input: &Input) ->
 744                      Vec<ast::Attribute> {
 745     let result = match *input {
 746         Input::File(ref ifile) => {
 747             parse::parse_crate_attrs_from_file(ifile,
 748                                                Vec::new(),
 749                                                &sess.parse_sess)
 750         }
 751         Input::Str(ref src) => {
 752             parse::parse_crate_attrs_from_source_str(
 753                 driver::anon_src().to_string(),
 754                 src.to_string(),
 755                 Vec::new(),
 756                 &sess.parse_sess)
 757         }
 758     };
 759     result.into_iter().collect()
 760 }
 761
 762 /// Run a procedure which will detect panics in the compiler and print nicer
 763 /// error messages rather than just failing the test.
 764 ///
 765 /// The diagnostic emitter yielded to the procedure should be used for reporting
 766 /// errors of the compiler.
 767 pub fn monitor<F:FnOnce()+Send+'static>(f: F) {
 768     static STACK_SIZE: uint = 8 * 1024 * 1024; // 8MB
 769
 770     let (tx, rx) = channel();
 771     let w = old_io::ChanWriter::new(tx);
 772     let mut r = old_io::ChanReader::new(rx);
 773
 774     let mut cfg = thread::Builder::new().name("rustc".to_string());
 775
 776     // FIXME: Hacks on hacks. If the env is trying to override the stack size
 777     // then *don't* set it explicitly.
 778     if env::var_os("RUST_MIN_STACK").is_none() {
 779         cfg = cfg.stack_size(STACK_SIZE);
 780     }
 781
 782     match cfg.spawn(move || { stdio::set_stderr(box w); f() }).unwrap().join() {
 783         Ok(()) => { /* fallthrough */ }
 784         Err(value) => {
 785             // Thread panicked without emitting a fatal diagnostic
 786             if !value.is::<diagnostic::FatalError>() {
 787                 let mut emitter = diagnostic::EmitterWriter::stderr(diagnostic::Auto, None);
 788
 789                 // a .span_bug or .bug call has already printed what
 790                 // it wants to print.
 791                 if !value.is::<diagnostic::ExplicitBug>() {
 792                     emitter.emit(
 793                         None,
 794                         "unexpected panic",
 795                         None,
 796                         diagnostic::Bug);
 797                 }
 798
 799                 let xs = [
 800                     "the compiler unexpectedly panicked. this is a bug.".to_string(),
 801                     format!("we would appreciate a bug report: {}",
 802                             BUG_REPORT_URL),
 803                     "run with `RUST_BACKTRACE=1` for a backtrace".to_string(),
 804                 ];
 805                 for note in &xs {
 806                     emitter.emit(None, &note[..], None, diagnostic::Note)
 807                 }
 808
 809                 match r.read_to_string() {
 810                     Ok(s) => println!("{}", s),
 811                     Err(e) => {
 812                         emitter.emit(None,
 813                                      &format!("failed to read internal \
 814                                               stderr: {}", e)[],
 815                                      None,
 816                                      diagnostic::Error)
 817                     }
 818                 }
 819             }
 820
 821             // Panic so the process returns a failure code, but don't pollute the
 822             // output with some unnecessary panic messages, we've already
 823             // printed everything that we needed to.
 824             old_io::stdio::set_stderr(box old_io::util::NullWriter);
 825             panic!();
 826         }
 827     }
 828 }
 829
 830 pub fn diagnostics_registry() -> diagnostics::registry::Registry {
 831     use syntax::diagnostics::registry::Registry;
 832
 833     let all_errors = Vec::new() +
 834         rustc::diagnostics::DIAGNOSTICS.as_slice() +
 835         rustc_typeck::diagnostics::DIAGNOSTICS.as_slice() +
 836         rustc_resolve::diagnostics::DIAGNOSTICS.as_slice();
 837
 838     Registry::new(&*all_errors)
 839 }
 840
 841 pub fn main() {
 842     let result = run(env::args().collect());
 843     std::env::set_exit_status(result as i32);
 844 }
 845