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 // Do not remove on snapshot creation. Needed for bootstrap. (Issue #22364)
  18 #![cfg_attr(stage0, feature(custom_attribute))]
  19 #![crate_name = "rustc_driver"]
  20 #![unstable(feature = "rustc_private", issue = "27812")]
  21 #![cfg_attr(stage0, staged_api)]
  22 #![crate_type = "dylib"]
  23 #![crate_type = "rlib"]
  24 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
  25       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
  26       html_root_url = "https://doc.rust-lang.org/nightly/")]
  27
  28 #![feature(box_syntax)]
  29 #![feature(libc)]
  30 #![feature(quote)]
  31 #![feature(rustc_diagnostic_macros)]
  32 #![feature(rustc_private)]
  33 #![feature(set_stdio)]
  34 #![feature(staged_api)]
  35 #![feature(raw)] // remove after snapshot
  36
  37 extern crate arena;
  38 extern crate flate;
  39 extern crate getopts;
  40 extern crate graphviz;
  41 extern crate libc;
  42 extern crate rustc;
  43 extern crate rustc_back;
  44 extern crate rustc_borrowck;
  45 extern crate rustc_front;
  46 extern crate rustc_lint;
  47 extern crate rustc_plugin;
  48 extern crate rustc_privacy;
  49 extern crate rustc_metadata;
  50 extern crate rustc_mir;
  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]
  57 extern crate log;
  58 #[macro_use]
  59 extern crate syntax;
  60
  61 pub use syntax::diagnostic;
  62
  63 use driver::CompileController;
  64 use pretty::{PpMode, UserIdentifiedItem};
  65
  66 use rustc_resolve as resolve;
  67 use rustc_trans::back::link;
  68 use rustc_trans::save;
  69 use rustc::session::{config, Session, build_session};
  70 use rustc::session::config::{Input, PrintRequest, OutputType};
  71 use rustc::middle::cstore::CrateStore;
  72 use rustc::lint::Lint;
  73 use rustc::lint;
  74 use rustc_metadata::loader;
  75 use rustc_metadata::cstore::CStore;
  76 use rustc::util::common::time;
  77
  78 use std::cmp::Ordering::Equal;
  79 use std::env;
  80 use std::io::{self, Read, Write};
  81 use std::iter::repeat;
  82 use std::path::PathBuf;
  83 use std::process;
  84 use std::rc::Rc;
  85 use std::str;
  86 use std::sync::{Arc, Mutex};
  87 use std::thread;
  88
  89 use rustc::session::early_error;
  90
  91 use syntax::ast;
  92 use syntax::parse;
  93 use syntax::diagnostic::Emitter;
  94 use syntax::diagnostics;
  95 use syntax::parse::token;
  96
  97 #[cfg(test)]
  98 pub mod test;
  99
 100 pub mod driver;
 101 pub mod pretty;
 102 pub mod target_features;
 103
 104
 105 const BUG_REPORT_URL: &'static str = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.\
 106                                       md#bug-reports";
 107
 108 // SNAP 1af31d4
 109 // This is a terrible hack. Our stage0 is older than 1.4 and does not
 110 // support DST coercions, so this function performs the corecion
 111 // manually. This should go away.
 112 pub fn cstore_to_cratestore(a: Rc<CStore>) -> Rc<for<'s> CrateStore<'s>>
 113 {
 114     use std::mem;
 115     use std::raw::TraitObject;
 116     unsafe {
 117         let TraitObject { vtable, .. } =
 118             mem::transmute::<&for<'s> CrateStore<'s>, TraitObject>(&*a);
 119         mem::transmute(TraitObject {
 120             data: mem::transmute(a),
 121             vtable: vtable
 122         })
 123     }
 124 }
 125
 126 pub fn run(args: Vec<String>) -> isize {
 127     monitor(move || run_compiler(&args, &mut RustcDefaultCalls));
 128     0
 129 }
 130
 131 // Parse args and run the compiler. This is the primary entry point for rustc.
 132 // See comments on CompilerCalls below for details about the callbacks argument.
 133 pub fn run_compiler<'a>(args: &[String], callbacks: &mut CompilerCalls<'a>) {
 134     macro_rules! do_or_return {($expr: expr) => {
 135         match $expr {
 136             Compilation::Stop => return,
 137             Compilation::Continue => {}
 138         }
 139     }}
 140
 141     let matches = match handle_options(args.to_vec()) {
 142         Some(matches) => matches,
 143         None => return,
 144     };
 145
 146     let sopts = config::build_session_options(&matches);
 147
 148     let descriptions = diagnostics_registry();
 149
 150     do_or_return!(callbacks.early_callback(&matches, &descriptions, sopts.color));
 151
 152     let (odir, ofile) = make_output(&matches);
 153     let (input, input_file_path) = match make_input(&matches.free) {
 154         Some((input, input_file_path)) => callbacks.some_input(input, input_file_path),
 155         None => match callbacks.no_input(&matches, &sopts, &odir, &ofile, &descriptions) {
 156             Some((input, input_file_path)) => (input, input_file_path),
 157             None => return,
 158         },
 159     };
 160
 161     let cstore = Rc::new(CStore::new(token::get_ident_interner()));
 162     let cstore_ = cstore_to_cratestore(cstore.clone());
 163     let mut sess = build_session(sopts, input_file_path, descriptions, cstore_);
 164     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 165     if sess.unstable_options() {
 166         sess.opts.show_span = matches.opt_str("show-span");
 167     }
 168     let mut cfg = config::build_configuration(&sess);
 169     target_features::add_configuration(&mut cfg, &sess);
 170
 171     do_or_return!(callbacks.late_callback(&matches, &sess, &input, &odir, &ofile));
 172
 173     // It is somewhat unfortunate that this is hardwired in - this is forced by
 174     // the fact that pretty_print_input requires the session by value.
 175     let pretty = callbacks.parse_pretty(&sess, &matches);
 176     match pretty {
 177         Some((ppm, opt_uii)) => {
 178             pretty::pretty_print_input(sess, &cstore, cfg, &input, ppm, opt_uii, ofile);
 179             return;
 180         }
 181         None => {
 182             // continue
 183         }
 184     }
 185
 186     let plugins = sess.opts.debugging_opts.extra_plugins.clone();
 187     let control = callbacks.build_controller(&sess);
 188     driver::compile_input(sess, &cstore, cfg, &input, &odir, &ofile,
 189                           Some(plugins), control);
 190 }
 191
 192 // Extract output directory and file from matches.
 193 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
 194     let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
 195     let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
 196     (odir, ofile)
 197 }
 198
 199 // Extract input (string or file and optional path) from matches.
 200 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>)> {
 201     if free_matches.len() == 1 {
 202         let ifile = &free_matches[0][..];
 203         if ifile == "-" {
 204             let mut src = String::new();
 205             io::stdin().read_to_string(&mut src).unwrap();
 206             Some((Input::Str(src), None))
 207         } else {
 208             Some((Input::File(PathBuf::from(ifile)),
 209                   Some(PathBuf::from(ifile))))
 210         }
 211     } else {
 212         None
 213     }
 214 }
 215
 216 // Whether to stop or continue compilation.
 217 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 218 pub enum Compilation {
 219     Stop,
 220     Continue,
 221 }
 222
 223 impl Compilation {
 224     pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
 225         match self {
 226             Compilation::Stop => Compilation::Stop,
 227             Compilation::Continue => next(),
 228         }
 229     }
 230 }
 231
 232 // A trait for customising the compilation process. Offers a number of hooks for
 233 // executing custom code or customising input.
 234 pub trait CompilerCalls<'a> {
 235     // Hook for a callback early in the process of handling arguments. This will
 236     // be called straight after options have been parsed but before anything
 237     // else (e.g., selecting input and output).
 238     fn early_callback(&mut self,
 239                       _: &getopts::Matches,
 240                       _: &diagnostics::registry::Registry,
 241                       _: diagnostic::ColorConfig)
 242                       -> Compilation {
 243         Compilation::Continue
 244     }
 245
 246     // Hook for a callback late in the process of handling arguments. This will
 247     // be called just before actual compilation starts (and before build_controller
 248     // is called), after all arguments etc. have been completely handled.
 249     fn late_callback(&mut self,
 250                      _: &getopts::Matches,
 251                      _: &Session,
 252                      _: &Input,
 253                      _: &Option<PathBuf>,
 254                      _: &Option<PathBuf>)
 255                      -> Compilation {
 256         Compilation::Continue
 257     }
 258
 259     // Called after we extract the input from the arguments. Gives the implementer
 260     // an opportunity to change the inputs or to add some custom input handling.
 261     // The default behaviour is to simply pass through the inputs.
 262     fn some_input(&mut self,
 263                   input: Input,
 264                   input_path: Option<PathBuf>)
 265                   -> (Input, Option<PathBuf>) {
 266         (input, input_path)
 267     }
 268
 269     // Called after we extract the input from the arguments if there is no valid
 270     // input. Gives the implementer an opportunity to supply alternate input (by
 271     // returning a Some value) or to add custom behaviour for this error such as
 272     // emitting error messages. Returning None will cause compilation to stop
 273     // at this point.
 274     fn no_input(&mut self,
 275                 _: &getopts::Matches,
 276                 _: &config::Options,
 277                 _: &Option<PathBuf>,
 278                 _: &Option<PathBuf>,
 279                 _: &diagnostics::registry::Registry)
 280                 -> Option<(Input, Option<PathBuf>)> {
 281         None
 282     }
 283
 284     // Parse pretty printing information from the arguments. The implementer can
 285     // choose to ignore this (the default will return None) which will skip pretty
 286     // printing. If you do want to pretty print, it is recommended to use the
 287     // implementation of this method from RustcDefaultCalls.
 288     // FIXME, this is a terrible bit of API. Parsing of pretty printing stuff
 289     // should be done as part of the framework and the implementor should customise
 290     // handling of it. However, that is not possible atm because pretty printing
 291     // essentially goes off and takes another path through the compiler which
 292     // means the session is either moved or not depending on what parse_pretty
 293     // returns (we could fix this by cloning, but it's another hack). The proper
 294     // solution is to handle pretty printing as if it were a compiler extension,
 295     // extending CompileController to make this work (see for example the treatment
 296     // of save-analysis in RustcDefaultCalls::build_controller).
 297     fn parse_pretty(&mut self,
 298                     _sess: &Session,
 299                     _matches: &getopts::Matches)
 300                     -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 301         None
 302     }
 303
 304     // Create a CompilController struct for controlling the behaviour of
 305     // compilation.
 306     fn build_controller(&mut self, &Session) -> CompileController<'a>;
 307 }
 308
 309 // CompilerCalls instance for a regular rustc build.
 310 #[derive(Copy, Clone)]
 311 pub struct RustcDefaultCalls;
 312
 313 impl<'a> CompilerCalls<'a> for RustcDefaultCalls {
 314     fn early_callback(&mut self,
 315                       matches: &getopts::Matches,
 316                       descriptions: &diagnostics::registry::Registry,
 317                       color: diagnostic::ColorConfig)
 318                       -> Compilation {
 319         match matches.opt_str("explain") {
 320             Some(ref code) => {
 321                 let normalised = if !code.starts_with("E") {
 322                     format!("E{0:0>4}", code)
 323                 } else {
 324                     code.to_string()
 325                 };
 326                 match descriptions.find_description(&normalised) {
 327                     Some(ref description) => {
 328                         // Slice off the leading newline and print.
 329                         print!("{}", &description[1..]);
 330                     }
 331                     None => {
 332                         early_error(color, &format!("no extended information for {}", code));
 333                     }
 334                 }
 335                 return Compilation::Stop;
 336             }
 337             None => (),
 338         }
 339
 340         return Compilation::Continue;
 341     }
 342
 343     fn no_input(&mut self,
 344                 matches: &getopts::Matches,
 345                 sopts: &config::Options,
 346                 odir: &Option<PathBuf>,
 347                 ofile: &Option<PathBuf>,
 348                 descriptions: &diagnostics::registry::Registry)
 349                 -> Option<(Input, Option<PathBuf>)> {
 350         match matches.free.len() {
 351             0 => {
 352                 if sopts.describe_lints {
 353                     let mut ls = lint::LintStore::new();
 354                     rustc_lint::register_builtins(&mut ls, None);
 355                     describe_lints(&ls, false);
 356                     return None;
 357                 }
 358                 let cstore = Rc::new(CStore::new(token::get_ident_interner()));
 359                 let cstore_ = cstore_to_cratestore(cstore.clone());
 360                 let sess = build_session(sopts.clone(), None, descriptions.clone(), cstore_);
 361                 rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 362                 let should_stop = RustcDefaultCalls::print_crate_info(&sess, None, odir, ofile);
 363                 if should_stop == Compilation::Stop {
 364                     return None;
 365                 }
 366                 early_error(sopts.color, "no input filename given");
 367             }
 368             1 => panic!("make_input should have provided valid inputs"),
 369             _ => early_error(sopts.color, "multiple input filenames provided"),
 370         }
 371
 372         None
 373     }
 374
 375     fn parse_pretty(&mut self,
 376                     sess: &Session,
 377                     matches: &getopts::Matches)
 378                     -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 379         let pretty = if sess.opts.debugging_opts.unstable_options {
 380             matches.opt_default("pretty", "normal").map(|a| {
 381                 // stable pretty-print variants only
 382                 pretty::parse_pretty(sess, &a, false)
 383             })
 384         } else {
 385             None
 386         };
 387         if pretty.is_none() && sess.unstable_options() {
 388             matches.opt_str("unpretty").map(|a| {
 389                 // extended with unstable pretty-print variants
 390                 pretty::parse_pretty(sess, &a, true)
 391             })
 392         } else {
 393             pretty
 394         }
 395     }
 396
 397     fn late_callback(&mut self,
 398                      matches: &getopts::Matches,
 399                      sess: &Session,
 400                      input: &Input,
 401                      odir: &Option<PathBuf>,
 402                      ofile: &Option<PathBuf>)
 403                      -> Compilation {
 404         RustcDefaultCalls::print_crate_info(sess, Some(input), odir, ofile)
 405             .and_then(|| RustcDefaultCalls::list_metadata(sess, matches, input))
 406     }
 407
 408     fn build_controller(&mut self, sess: &Session) -> CompileController<'a> {
 409         let mut control = CompileController::basic();
 410
 411         if sess.opts.parse_only || sess.opts.show_span.is_some() ||
 412            sess.opts.debugging_opts.ast_json_noexpand {
 413             control.after_parse.stop = Compilation::Stop;
 414         }
 415
 416         if sess.opts.no_analysis || sess.opts.debugging_opts.ast_json {
 417             control.after_write_deps.stop = Compilation::Stop;
 418         }
 419
 420         if sess.opts.no_trans {
 421             control.after_analysis.stop = Compilation::Stop;
 422         }
 423
 424         if !sess.opts.output_types.keys().any(|&i| i == OutputType::Exe) {
 425             control.after_llvm.stop = Compilation::Stop;
 426         }
 427
 428         if sess.opts.debugging_opts.save_analysis {
 429             control.after_analysis.callback = box |state| {
 430                 time(state.session.time_passes(), "save analysis", || {
 431                     save::process_crate(state.tcx.unwrap(),
 432                                         state.lcx.unwrap(),
 433                                         state.krate.unwrap(),
 434                                         state.analysis.unwrap(),
 435                                         state.crate_name.unwrap(),
 436                                         state.out_dir)
 437                 });
 438             };
 439             control.make_glob_map = resolve::MakeGlobMap::Yes;
 440         }
 441
 442         control
 443     }
 444 }
 445
 446 impl RustcDefaultCalls {
 447     pub fn list_metadata(sess: &Session, matches: &getopts::Matches, input: &Input) -> Compilation {
 448         let r = matches.opt_strs("Z");
 449         if r.contains(&("ls".to_string())) {
 450             match input {
 451                 &Input::File(ref ifile) => {
 452                     let path = &(*ifile);
 453                     let mut v = Vec::new();
 454                     loader::list_file_metadata(&sess.target.target, path, &mut v)
 455                         .unwrap();
 456                     println!("{}", String::from_utf8(v).unwrap());
 457                 }
 458                 &Input::Str(_) => {
 459                     early_error(sess.opts.color, "cannot list metadata for stdin");
 460                 }
 461             }
 462             return Compilation::Stop;
 463         }
 464
 465         return Compilation::Continue;
 466     }
 467
 468
 469     fn print_crate_info(sess: &Session,
 470                         input: Option<&Input>,
 471                         odir: &Option<PathBuf>,
 472                         ofile: &Option<PathBuf>)
 473                         -> Compilation {
 474         if sess.opts.prints.is_empty() {
 475             return Compilation::Continue;
 476         }
 477
 478         let attrs = input.map(|input| parse_crate_attrs(sess, input));
 479         for req in &sess.opts.prints {
 480             match *req {
 481                 PrintRequest::Sysroot => println!("{}", sess.sysroot().display()),
 482                 PrintRequest::FileNames |
 483                 PrintRequest::CrateName => {
 484                     let input = match input {
 485                         Some(input) => input,
 486                         None => early_error(sess.opts.color, "no input file provided"),
 487                     };
 488                     let attrs = attrs.as_ref().unwrap();
 489                     let t_outputs = driver::build_output_filenames(input, odir, ofile, attrs, sess);
 490                     let id = link::find_crate_name(Some(sess), attrs, input);
 491                     if *req == PrintRequest::CrateName {
 492                         println!("{}", id);
 493                         continue;
 494                     }
 495                     let crate_types = driver::collect_crate_types(sess, attrs);
 496                     let metadata = driver::collect_crate_metadata(sess, attrs);
 497                     *sess.crate_metadata.borrow_mut() = metadata;
 498                     for &style in &crate_types {
 499                         let fname = link::filename_for_input(sess, style, &id, &t_outputs);
 500                         println!("{}",
 501                                  fname.file_name()
 502                                       .unwrap()
 503                                       .to_string_lossy());
 504                     }
 505                 }
 506             }
 507         }
 508         return Compilation::Stop;
 509     }
 510 }
 511
 512 /// Returns a version string such as "0.12.0-dev".
 513 pub fn release_str() -> Option<&'static str> {
 514     option_env!("CFG_RELEASE")
 515 }
 516
 517 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 518 pub fn commit_hash_str() -> Option<&'static str> {
 519     option_env!("CFG_VER_HASH")
 520 }
 521
 522 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 523 pub fn commit_date_str() -> Option<&'static str> {
 524     option_env!("CFG_VER_DATE")
 525 }
 526
 527 /// Prints version information
 528 pub fn version(binary: &str, matches: &getopts::Matches) {
 529     let verbose = matches.opt_present("verbose");
 530
 531     println!("{} {}",
 532              binary,
 533              option_env!("CFG_VERSION").unwrap_or("unknown version"));
 534     if verbose {
 535         fn unw(x: Option<&str>) -> &str {
 536             x.unwrap_or("unknown")
 537         }
 538         println!("binary: {}", binary);
 539         println!("commit-hash: {}", unw(commit_hash_str()));
 540         println!("commit-date: {}", unw(commit_date_str()));
 541         println!("host: {}", config::host_triple());
 542         println!("release: {}", unw(release_str()));
 543     }
 544 }
 545
 546 fn usage(verbose: bool, include_unstable_options: bool) {
 547     let groups = if verbose {
 548         config::rustc_optgroups()
 549     } else {
 550         config::rustc_short_optgroups()
 551     };
 552     let groups: Vec<_> = groups.into_iter()
 553                                .filter(|x| include_unstable_options || x.is_stable())
 554                                .map(|x| x.opt_group)
 555                                .collect();
 556     let message = format!("Usage: rustc [OPTIONS] INPUT");
 557     let extra_help = if verbose {
 558         ""
 559     } else {
 560         "\n    --help -v           Print the full set of options rustc accepts"
 561     };
 562     println!("{}\nAdditional help:
 563     -C help             Print codegen options
 564     -W help             \
 565               Print 'lint' options and default settings
 566     -Z help             Print internal \
 567               options for debugging rustc{}\n",
 568              getopts::usage(&message, &groups),
 569              extra_help);
 570 }
 571
 572 fn describe_lints(lint_store: &lint::LintStore, loaded_plugins: bool) {
 573     println!("
 574 Available lint options:
 575     -W <foo>           Warn about <foo>
 576     -A <foo>           \
 577               Allow <foo>
 578     -D <foo>           Deny <foo>
 579     -F <foo>           Forbid <foo> \
 580               (deny, and deny all overrides)
 581
 582 ");
 583
 584     fn sort_lints(lints: Vec<(&'static Lint, bool)>) -> Vec<&'static Lint> {
 585         let mut lints: Vec<_> = lints.into_iter().map(|(x, _)| x).collect();
 586         lints.sort_by(|x: &&Lint, y: &&Lint| {
 587             match x.default_level.cmp(&y.default_level) {
 588                 // The sort doesn't case-fold but it's doubtful we care.
 589                 Equal => x.name.cmp(y.name),
 590                 r => r,
 591             }
 592         });
 593         lints
 594     }
 595
 596     fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
 597                         -> Vec<(&'static str, Vec<lint::LintId>)> {
 598         let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
 599         lints.sort_by(|&(x, _): &(&'static str, Vec<lint::LintId>),
 600                        &(y, _): &(&'static str, Vec<lint::LintId>)| {
 601             x.cmp(y)
 602         });
 603         lints
 604     }
 605
 606     let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints()
 607                                                    .iter()
 608                                                    .cloned()
 609                                                    .partition(|&(_, p)| p);
 610     let plugin = sort_lints(plugin);
 611     let builtin = sort_lints(builtin);
 612
 613     let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups()
 614                                                                  .iter()
 615                                                                  .cloned()
 616                                                                  .partition(|&(_, _, p)| p);
 617     let plugin_groups = sort_lint_groups(plugin_groups);
 618     let builtin_groups = sort_lint_groups(builtin_groups);
 619
 620     let max_name_len = plugin.iter()
 621                              .chain(&builtin)
 622                              .map(|&s| s.name.chars().count())
 623                              .max()
 624                              .unwrap_or(0);
 625     let padded = |x: &str| {
 626         let mut s = repeat(" ")
 627                         .take(max_name_len - x.chars().count())
 628                         .collect::<String>();
 629         s.push_str(x);
 630         s
 631     };
 632
 633     println!("Lint checks provided by rustc:\n");
 634     println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
 635     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
 636
 637     let print_lints = |lints: Vec<&Lint>| {
 638         for lint in lints {
 639             let name = lint.name_lower().replace("_", "-");
 640             println!("    {}  {:7.7}  {}",
 641                      padded(&name[..]),
 642                      lint.default_level.as_str(),
 643                      lint.desc);
 644         }
 645         println!("\n");
 646     };
 647
 648     print_lints(builtin);
 649
 650
 651
 652     let max_name_len = plugin_groups.iter()
 653                                     .chain(&builtin_groups)
 654                                     .map(|&(s, _)| s.chars().count())
 655                                     .max()
 656                                     .unwrap_or(0);
 657     let padded = |x: &str| {
 658         let mut s = repeat(" ")
 659                         .take(max_name_len - x.chars().count())
 660                         .collect::<String>();
 661         s.push_str(x);
 662         s
 663     };
 664
 665     println!("Lint groups provided by rustc:\n");
 666     println!("    {}  {}", padded("name"), "sub-lints");
 667     println!("    {}  {}", padded("----"), "---------");
 668
 669     let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
 670         for (name, to) in lints {
 671             let name = name.to_lowercase().replace("_", "-");
 672             let desc = to.into_iter()
 673                          .map(|x| x.as_str().replace("_", "-"))
 674                          .collect::<Vec<String>>()
 675                          .join(", ");
 676             println!("    {}  {}", padded(&name[..]), desc);
 677         }
 678         println!("\n");
 679     };
 680
 681     print_lint_groups(builtin_groups);
 682
 683     match (loaded_plugins, plugin.len(), plugin_groups.len()) {
 684         (false, 0, _) | (false, _, 0) => {
 685             println!("Compiler plugins can provide additional lints and lint groups. To see a \
 686                       listing of these, re-run `rustc -W help` with a crate filename.");
 687         }
 688         (false, _, _) => panic!("didn't load lint plugins but got them anyway!"),
 689         (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
 690         (true, l, g) => {
 691             if l > 0 {
 692                 println!("Lint checks provided by plugins loaded by this crate:\n");
 693                 print_lints(plugin);
 694             }
 695             if g > 0 {
 696                 println!("Lint groups provided by plugins loaded by this crate:\n");
 697                 print_lint_groups(plugin_groups);
 698             }
 699         }
 700     }
 701 }
 702
 703 fn describe_debug_flags() {
 704     println!("\nAvailable debug options:\n");
 705     print_flag_list("-Z", config::DB_OPTIONS);
 706 }
 707
 708 fn describe_codegen_flags() {
 709     println!("\nAvailable codegen options:\n");
 710     print_flag_list("-C", config::CG_OPTIONS);
 711 }
 712
 713 fn print_flag_list<T>(cmdline_opt: &str,
 714                       flag_list: &[(&'static str, T, Option<&'static str>, &'static str)]) {
 715     let max_len = flag_list.iter()
 716                            .map(|&(name, _, opt_type_desc, _)| {
 717                                let extra_len = match opt_type_desc {
 718                                    Some(..) => 4,
 719                                    None => 0,
 720                                };
 721                                name.chars().count() + extra_len
 722                            })
 723                            .max()
 724                            .unwrap_or(0);
 725
 726     for &(name, _, opt_type_desc, desc) in flag_list {
 727         let (width, extra) = match opt_type_desc {
 728             Some(..) => (max_len - 4, "=val"),
 729             None => (max_len, ""),
 730         };
 731         println!("    {} {:>width$}{} -- {}",
 732                  cmdline_opt,
 733                  name.replace("_", "-"),
 734                  extra,
 735                  desc,
 736                  width = width);
 737     }
 738 }
 739
 740 /// Process command line options. Emits messages as appropriate. If compilation
 741 /// should continue, returns a getopts::Matches object parsed from args, otherwise
 742 /// returns None.
 743 pub fn handle_options(mut args: Vec<String>) -> Option<getopts::Matches> {
 744     // Throw away the first argument, the name of the binary
 745     let _binary = args.remove(0);
 746
 747     if args.is_empty() {
 748         // user did not write `-v` nor `-Z unstable-options`, so do not
 749         // include that extra information.
 750         usage(false, false);
 751         return None;
 752     }
 753
 754     fn allows_unstable_options(matches: &getopts::Matches) -> bool {
 755         let r = matches.opt_strs("Z");
 756         r.iter().any(|x| *x == "unstable-options")
 757     }
 758
 759     fn parse_all_options(args: &Vec<String>) -> getopts::Matches {
 760         let all_groups: Vec<getopts::OptGroup> = config::rustc_optgroups()
 761                                                      .into_iter()
 762                                                      .map(|x| x.opt_group)
 763                                                      .collect();
 764         match getopts::getopts(&args[..], &all_groups) {
 765             Ok(m) => {
 766                 if !allows_unstable_options(&m) {
 767                     // If -Z unstable-options was not specified, verify that
 768                     // no unstable options were present.
 769                     for opt in config::rustc_optgroups().into_iter().filter(|x| !x.is_stable()) {
 770                         let opt_name = if !opt.opt_group.long_name.is_empty() {
 771                             &opt.opt_group.long_name
 772                         } else {
 773                             &opt.opt_group.short_name
 774                         };
 775                         if m.opt_present(opt_name) {
 776                             early_error(diagnostic::Auto,
 777                                         &format!("use of unstable option '{}' requires -Z \
 778                                                   unstable-options",
 779                                                  opt_name));
 780                         }
 781                     }
 782                 }
 783                 m
 784             }
 785             Err(f) => early_error(diagnostic::Auto, &f.to_string()),
 786         }
 787     }
 788
 789     // As a speed optimization, first try to parse the command-line using just
 790     // the stable options.
 791     let matches = match getopts::getopts(&args[..], &config::optgroups()) {
 792         Ok(ref m) if allows_unstable_options(m) => {
 793             // If -Z unstable-options was specified, redo parsing with the
 794             // unstable options to ensure that unstable options are defined
 795             // in the returned getopts::Matches.
 796             parse_all_options(&args)
 797         }
 798         Ok(m) => m,
 799         Err(_) => {
 800             // redo option parsing, including unstable options this time,
 801             // in anticipation that the mishandled option was one of the
 802             // unstable ones.
 803             parse_all_options(&args)
 804         }
 805     };
 806
 807     if matches.opt_present("h") || matches.opt_present("help") {
 808         usage(matches.opt_present("verbose"),
 809               allows_unstable_options(&matches));
 810         return None;
 811     }
 812
 813     // Don't handle -W help here, because we might first load plugins.
 814
 815     let r = matches.opt_strs("Z");
 816     if r.iter().any(|x| *x == "help") {
 817         describe_debug_flags();
 818         return None;
 819     }
 820
 821     let cg_flags = matches.opt_strs("C");
 822     if cg_flags.iter().any(|x| *x == "help") {
 823         describe_codegen_flags();
 824         return None;
 825     }
 826
 827     if cg_flags.contains(&"passes=list".to_string()) {
 828         unsafe {
 829             ::llvm::LLVMRustPrintPasses();
 830         }
 831         return None;
 832     }
 833
 834     if matches.opt_present("version") {
 835         version("rustc", &matches);
 836         return None;
 837     }
 838
 839     Some(matches)
 840 }
 841
 842 fn parse_crate_attrs(sess: &Session, input: &Input) -> Vec<ast::Attribute> {
 843     let result = match *input {
 844         Input::File(ref ifile) => {
 845             parse::parse_crate_attrs_from_file(ifile, Vec::new(), &sess.parse_sess)
 846         }
 847         Input::Str(ref src) => {
 848             parse::parse_crate_attrs_from_source_str(driver::anon_src().to_string(),
 849                                                      src.to_string(),
 850                                                      Vec::new(),
 851                                                      &sess.parse_sess)
 852         }
 853     };
 854     result.into_iter().collect()
 855 }
 856
 857 /// Run a procedure which will detect panics in the compiler and print nicer
 858 /// error messages rather than just failing the test.
 859 ///
 860 /// The diagnostic emitter yielded to the procedure should be used for reporting
 861 /// errors of the compiler.
 862 pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
 863     const STACK_SIZE: usize = 8 * 1024 * 1024; // 8MB
 864
 865     struct Sink(Arc<Mutex<Vec<u8>>>);
 866     impl Write for Sink {
 867         fn write(&mut self, data: &[u8]) -> io::Result<usize> {
 868             Write::write(&mut *self.0.lock().unwrap(), data)
 869         }
 870         fn flush(&mut self) -> io::Result<()> {
 871             Ok(())
 872         }
 873     }
 874
 875     let data = Arc::new(Mutex::new(Vec::new()));
 876     let err = Sink(data.clone());
 877
 878     let mut cfg = thread::Builder::new().name("rustc".to_string());
 879
 880     // FIXME: Hacks on hacks. If the env is trying to override the stack size
 881     // then *don't* set it explicitly.
 882     if env::var_os("RUST_MIN_STACK").is_none() {
 883         cfg = cfg.stack_size(STACK_SIZE);
 884     }
 885
 886     match cfg.spawn(move || {
 887                  io::set_panic(box err);
 888                  f()
 889              })
 890              .unwrap()
 891              .join() {
 892         Ok(()) => {
 893             // fallthrough
 894         }
 895         Err(value) => {
 896             // Thread panicked without emitting a fatal diagnostic
 897             if !value.is::<diagnostic::FatalError>() {
 898                 let mut emitter = diagnostic::EmitterWriter::stderr(diagnostic::Auto, None);
 899
 900                 // a .span_bug or .bug call has already printed what
 901                 // it wants to print.
 902                 if !value.is::<diagnostic::ExplicitBug>() {
 903                     emitter.emit(None, "unexpected panic", None, diagnostic::Bug);
 904                 }
 905
 906                 let xs = ["the compiler unexpectedly panicked. this is a bug.".to_string(),
 907                           format!("we would appreciate a bug report: {}", BUG_REPORT_URL)];
 908                 for note in &xs {
 909                     emitter.emit(None, &note[..], None, diagnostic::Note)
 910                 }
 911                 if let None = env::var_os("RUST_BACKTRACE") {
 912                     emitter.emit(None,
 913                                  "run with `RUST_BACKTRACE=1` for a backtrace",
 914                                  None,
 915                                  diagnostic::Note);
 916                 }
 917
 918                 println!("{}", str::from_utf8(&data.lock().unwrap()).unwrap());
 919             }
 920
 921             // Panic so the process returns a failure code, but don't pollute the
 922             // output with some unnecessary panic messages, we've already
 923             // printed everything that we needed to.
 924             io::set_panic(box io::sink());
 925             panic!();
 926         }
 927     }
 928 }
 929
 930 pub fn diagnostics_registry() -> diagnostics::registry::Registry {
 931     use syntax::diagnostics::registry::Registry;
 932
 933     let mut all_errors = Vec::new();
 934     all_errors.extend_from_slice(&rustc::DIAGNOSTICS);
 935     all_errors.extend_from_slice(&rustc_typeck::DIAGNOSTICS);
 936     all_errors.extend_from_slice(&rustc_borrowck::DIAGNOSTICS);
 937     all_errors.extend_from_slice(&rustc_resolve::DIAGNOSTICS);
 938     all_errors.extend_from_slice(&rustc_privacy::DIAGNOSTICS);
 939     all_errors.extend_from_slice(&rustc_trans::DIAGNOSTICS);
 940
 941     Registry::new(&*all_errors)
 942 }
 943
 944 pub fn main() {
 945     let result = run(env::args().collect());
 946     process::exit(result as i32);
 947 }