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", issue = "27812")]
  19 #![crate_type = "dylib"]
  20 #![crate_type = "rlib"]
  21 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
  22       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
  23       html_root_url = "https://doc.rust-lang.org/nightly/")]
  24 #![cfg_attr(not(stage0), deny(warnings))]
  25
  26 #![feature(box_syntax)]
  27 #![feature(libc)]
  28 #![feature(quote)]
  29 #![feature(rustc_diagnostic_macros)]
  30 #![feature(rustc_private)]
  31 #![feature(set_stdio)]
  32 #![feature(staged_api)]
  33 #![feature(question_mark)]
  34
  35 extern crate arena;
  36 extern crate flate;
  37 extern crate getopts;
  38 extern crate graphviz;
  39 extern crate libc;
  40 extern crate rustc;
  41 extern crate rustc_back;
  42 extern crate rustc_borrowck;
  43 extern crate rustc_const_eval;
  44 extern crate rustc_errors as errors;
  45 extern crate rustc_passes;
  46 extern crate rustc_lint;
  47 extern crate rustc_plugin;
  48 extern crate rustc_privacy;
  49 extern crate rustc_incremental;
  50 extern crate rustc_metadata;
  51 extern crate rustc_mir;
  52 extern crate rustc_resolve;
  53 extern crate rustc_save_analysis;
  54 extern crate rustc_trans;
  55 extern crate rustc_typeck;
  56 extern crate serialize;
  57 extern crate rustc_llvm as llvm;
  58 #[macro_use]
  59 extern crate log;
  60 #[macro_use]
  61 extern crate syntax;
  62 extern crate syntax_ext;
  63 extern crate syntax_pos;
  64
  65 use driver::CompileController;
  66 use pretty::{PpMode, UserIdentifiedItem};
  67
  68 use rustc_resolve as resolve;
  69 use rustc_save_analysis as save;
  70 use rustc_trans::back::link;
  71 use rustc_trans::back::write::{create_target_machine, RELOC_MODEL_ARGS, CODE_GEN_MODEL_ARGS};
  72 use rustc::dep_graph::DepGraph;
  73 use rustc::session::{self, config, Session, build_session, CompileResult};
  74 use rustc::session::config::{Input, PrintRequest, OutputType, ErrorOutputType};
  75 use rustc::session::config::{get_unstable_features_setting, nightly_options};
  76 use rustc::lint::Lint;
  77 use rustc::lint;
  78 use rustc_metadata::loader;
  79 use rustc_metadata::cstore::CStore;
  80 use rustc::util::common::time;
  81
  82 use std::cmp::max;
  83 use std::cmp::Ordering::Equal;
  84 use std::default::Default;
  85 use std::env;
  86 use std::io::{self, Read, Write};
  87 use std::iter::repeat;
  88 use std::path::PathBuf;
  89 use std::process;
  90 use std::rc::Rc;
  91 use std::str;
  92 use std::sync::{Arc, Mutex};
  93 use std::thread;
  94
  95 use rustc::session::early_error;
  96
  97 use syntax::{ast, json};
  98 use syntax::codemap::{CodeMap, FileLoader, RealFileLoader};
  99 use syntax::feature_gate::{GatedCfg, UnstableFeatures};
 100 use syntax::parse::{self, PResult};
 101 use syntax_pos::MultiSpan;
 102 use errors::emitter::Emitter;
 103
 104 #[cfg(test)]
 105 pub mod test;
 106
 107 pub mod driver;
 108 pub mod pretty;
 109 pub mod target_features;
 110
 111
 112 const BUG_REPORT_URL: &'static str = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.\
 113                                       md#bug-reports";
 114
 115 #[inline]
 116 fn abort_msg(err_count: usize) -> String {
 117     match err_count {
 118         0 => "aborting with no errors (maybe a bug?)".to_owned(),
 119         1 => "aborting due to previous error".to_owned(),
 120         e => format!("aborting due to {} previous errors", e),
 121     }
 122 }
 123
 124 pub fn abort_on_err<T>(result: Result<T, usize>, sess: &Session) -> T {
 125     match result {
 126         Err(err_count) => {
 127             sess.fatal(&abort_msg(err_count));
 128         }
 129         Ok(x) => x,
 130     }
 131 }
 132
 133 pub fn run(args: Vec<String>) -> isize {
 134     monitor(move || {
 135         let (result, session) = run_compiler(&args, &mut RustcDefaultCalls);
 136         if let Err(err_count) = result {
 137             if err_count > 0 {
 138                 match session {
 139                     Some(sess) => sess.fatal(&abort_msg(err_count)),
 140                     None => {
 141                         let emitter =
 142                             errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto,
 143                                                                    None);
 144                         let handler = errors::Handler::with_emitter(true, false, Box::new(emitter));
 145                         handler.emit(&MultiSpan::new(),
 146                                      &abort_msg(err_count),
 147                                      errors::Level::Fatal);
 148                         exit_on_err();
 149                     }
 150                 }
 151             }
 152         }
 153     });
 154     0
 155 }
 156
 157 pub fn run_compiler<'a>(args: &[String],
 158                         callbacks: &mut CompilerCalls<'a>)
 159                         -> (CompileResult, Option<Session>) {
 160     run_compiler_with_file_loader(args, callbacks, box RealFileLoader)
 161 }
 162
 163 // Parse args and run the compiler. This is the primary entry point for rustc.
 164 // See comments on CompilerCalls below for details about the callbacks argument.
 165 // The FileLoader provides a way to load files from sources other than the file system.
 166 pub fn run_compiler_with_file_loader<'a, L>(args: &[String],
 167                                             callbacks: &mut CompilerCalls<'a>,
 168                                             loader: Box<L>)
 169                                             -> (CompileResult, Option<Session>)
 170     where L: FileLoader + 'static {
 171     macro_rules! do_or_return {($expr: expr, $sess: expr) => {
 172         match $expr {
 173             Compilation::Stop => return (Ok(()), $sess),
 174             Compilation::Continue => {}
 175         }
 176     }}
 177
 178     let matches = match handle_options(args) {
 179         Some(matches) => matches,
 180         None => return (Ok(()), None),
 181     };
 182
 183     let (sopts, cfg) = config::build_session_options_and_crate_config(&matches);
 184
 185     if sopts.debugging_opts.debug_llvm {
 186         unsafe { llvm::LLVMRustSetDebug(1); }
 187     }
 188
 189     let descriptions = diagnostics_registry();
 190
 191     do_or_return!(callbacks.early_callback(&matches,
 192                                            &sopts,
 193                                            &cfg,
 194                                            &descriptions,
 195                                            sopts.error_format),
 196                                            None);
 197
 198     let (odir, ofile) = make_output(&matches);
 199     let (input, input_file_path) = match make_input(&matches.free) {
 200         Some((input, input_file_path)) => callbacks.some_input(input, input_file_path),
 201         None => match callbacks.no_input(&matches, &sopts, &cfg, &odir, &ofile, &descriptions) {
 202             Some((input, input_file_path)) => (input, input_file_path),
 203             None => return (Ok(()), None),
 204         },
 205     };
 206
 207     let dep_graph = DepGraph::new(sopts.build_dep_graph());
 208     let cstore = Rc::new(CStore::new(&dep_graph));
 209     let codemap = Rc::new(CodeMap::with_file_loader(loader));
 210     let sess = session::build_session_with_codemap(sopts,
 211                                                    &dep_graph,
 212                                                    input_file_path,
 213                                                    descriptions,
 214                                                    cstore.clone(),
 215                                                    codemap);
 216     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 217     let mut cfg = config::build_configuration(&sess, cfg);
 218     target_features::add_configuration(&mut cfg, &sess);
 219
 220     do_or_return!(callbacks.late_callback(&matches, &sess, &cfg, &input, &odir, &ofile),
 221                   Some(sess));
 222
 223     let plugins = sess.opts.debugging_opts.extra_plugins.clone();
 224     let control = callbacks.build_controller(&sess, &matches);
 225     (driver::compile_input(&sess, &cstore, cfg, &input, &odir, &ofile,
 226                            Some(plugins), &control),
 227      Some(sess))
 228 }
 229
 230 // Extract output directory and file from matches.
 231 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
 232     let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
 233     let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
 234     (odir, ofile)
 235 }
 236
 237 // Extract input (string or file and optional path) from matches.
 238 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>)> {
 239     if free_matches.len() == 1 {
 240         let ifile = &free_matches[0][..];
 241         if ifile == "-" {
 242             let mut src = String::new();
 243             io::stdin().read_to_string(&mut src).unwrap();
 244             Some((Input::Str { name: driver::anon_src(), input: src },
 245                   None))
 246         } else {
 247             Some((Input::File(PathBuf::from(ifile)),
 248                   Some(PathBuf::from(ifile))))
 249         }
 250     } else {
 251         None
 252     }
 253 }
 254
 255 fn parse_pretty(sess: &Session,
 256                 matches: &getopts::Matches)
 257                 -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 258     let pretty = if sess.opts.debugging_opts.unstable_options {
 259         matches.opt_default("pretty", "normal").map(|a| {
 260             // stable pretty-print variants only
 261             pretty::parse_pretty(sess, &a, false)
 262         })
 263     } else {
 264         None
 265     };
 266     if pretty.is_none() && sess.unstable_options() {
 267         matches.opt_str("unpretty").map(|a| {
 268             // extended with unstable pretty-print variants
 269             pretty::parse_pretty(sess, &a, true)
 270         })
 271     } else {
 272         pretty
 273     }
 274 }
 275
 276 // Whether to stop or continue compilation.
 277 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 278 pub enum Compilation {
 279     Stop,
 280     Continue,
 281 }
 282
 283 impl Compilation {
 284     pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
 285         match self {
 286             Compilation::Stop => Compilation::Stop,
 287             Compilation::Continue => next(),
 288         }
 289     }
 290 }
 291
 292 // A trait for customising the compilation process. Offers a number of hooks for
 293 // executing custom code or customising input.
 294 pub trait CompilerCalls<'a> {
 295     // Hook for a callback early in the process of handling arguments. This will
 296     // be called straight after options have been parsed but before anything
 297     // else (e.g., selecting input and output).
 298     fn early_callback(&mut self,
 299                       _: &getopts::Matches,
 300                       _: &config::Options,
 301                       _: &ast::CrateConfig,
 302                       _: &errors::registry::Registry,
 303                       _: ErrorOutputType)
 304                       -> Compilation {
 305         Compilation::Continue
 306     }
 307
 308     // Hook for a callback late in the process of handling arguments. This will
 309     // be called just before actual compilation starts (and before build_controller
 310     // is called), after all arguments etc. have been completely handled.
 311     fn late_callback(&mut self,
 312                      _: &getopts::Matches,
 313                      _: &Session,
 314                      _: &ast::CrateConfig,
 315                      _: &Input,
 316                      _: &Option<PathBuf>,
 317                      _: &Option<PathBuf>)
 318                      -> Compilation {
 319         Compilation::Continue
 320     }
 321
 322     // Called after we extract the input from the arguments. Gives the implementer
 323     // an opportunity to change the inputs or to add some custom input handling.
 324     // The default behaviour is to simply pass through the inputs.
 325     fn some_input(&mut self,
 326                   input: Input,
 327                   input_path: Option<PathBuf>)
 328                   -> (Input, Option<PathBuf>) {
 329         (input, input_path)
 330     }
 331
 332     // Called after we extract the input from the arguments if there is no valid
 333     // input. Gives the implementer an opportunity to supply alternate input (by
 334     // returning a Some value) or to add custom behaviour for this error such as
 335     // emitting error messages. Returning None will cause compilation to stop
 336     // at this point.
 337     fn no_input(&mut self,
 338                 _: &getopts::Matches,
 339                 _: &config::Options,
 340                 _: &ast::CrateConfig,
 341                 _: &Option<PathBuf>,
 342                 _: &Option<PathBuf>,
 343                 _: &errors::registry::Registry)
 344                 -> Option<(Input, Option<PathBuf>)> {
 345         None
 346     }
 347
 348     // Create a CompilController struct for controlling the behaviour of
 349     // compilation.
 350     fn build_controller(&mut self, &Session, &getopts::Matches) -> CompileController<'a>;
 351 }
 352
 353 // CompilerCalls instance for a regular rustc build.
 354 #[derive(Copy, Clone)]
 355 pub struct RustcDefaultCalls;
 356
 357 fn handle_explain(code: &str,
 358                   descriptions: &errors::registry::Registry,
 359                   output: ErrorOutputType) {
 360     let normalised = if code.starts_with("E") {
 361         code.to_string()
 362     } else {
 363         format!("E{0:0>4}", code)
 364     };
 365     match descriptions.find_description(&normalised) {
 366         Some(ref description) => {
 367             // Slice off the leading newline and print.
 368             print!("{}", &(&description[1..]).split("\n").map(|x| {
 369                 format!("{}\n", if x.starts_with("```") {
 370                     "```"
 371                 } else {
 372                     x
 373                 })
 374             }).collect::<String>());
 375         }
 376         None => {
 377             early_error(output, &format!("no extended information for {}", code));
 378         }
 379     }
 380 }
 381
 382 fn check_cfg(cfg: &ast::CrateConfig,
 383              output: ErrorOutputType) {
 384     let emitter: Box<Emitter> = match output {
 385         config::ErrorOutputType::HumanReadable(color_config) => {
 386             Box::new(errors::emitter::EmitterWriter::stderr(color_config, None))
 387         }
 388         config::ErrorOutputType::Json => Box::new(json::JsonEmitter::basic()),
 389     };
 390     let handler = errors::Handler::with_emitter(true, false, emitter);
 391
 392     let mut saw_invalid_predicate = false;
 393     for item in cfg.iter() {
 394         if item.is_meta_item_list() {
 395             saw_invalid_predicate = true;
 396             handler.emit(&MultiSpan::new(),
 397                          &format!("invalid predicate in --cfg command line argument: `{}`",
 398                                   item.name()),
 399                             errors::Level::Fatal);
 400         }
 401     }
 402
 403     if saw_invalid_predicate {
 404         panic!(errors::FatalError);
 405     }
 406 }
 407
 408 impl<'a> CompilerCalls<'a> for RustcDefaultCalls {
 409     fn early_callback(&mut self,
 410                       matches: &getopts::Matches,
 411                       _: &config::Options,
 412                       cfg: &ast::CrateConfig,
 413                       descriptions: &errors::registry::Registry,
 414                       output: ErrorOutputType)
 415                       -> Compilation {
 416         if let Some(ref code) = matches.opt_str("explain") {
 417             handle_explain(code, descriptions, output);
 418             return Compilation::Stop;
 419         }
 420
 421         check_cfg(cfg, output);
 422         Compilation::Continue
 423     }
 424
 425     fn no_input(&mut self,
 426                 matches: &getopts::Matches,
 427                 sopts: &config::Options,
 428                 cfg: &ast::CrateConfig,
 429                 odir: &Option<PathBuf>,
 430                 ofile: &Option<PathBuf>,
 431                 descriptions: &errors::registry::Registry)
 432                 -> Option<(Input, Option<PathBuf>)> {
 433         match matches.free.len() {
 434             0 => {
 435                 if sopts.describe_lints {
 436                     let mut ls = lint::LintStore::new();
 437                     rustc_lint::register_builtins(&mut ls, None);
 438                     describe_lints(&ls, false);
 439                     return None;
 440                 }
 441                 let dep_graph = DepGraph::new(sopts.build_dep_graph());
 442                 let cstore = Rc::new(CStore::new(&dep_graph));
 443                 let sess = build_session(sopts.clone(),
 444                     &dep_graph,
 445                     None,
 446                     descriptions.clone(),
 447                     cstore.clone());
 448                 rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 449                 let mut cfg = config::build_configuration(&sess, cfg.clone());
 450                 target_features::add_configuration(&mut cfg, &sess);
 451                 let should_stop = RustcDefaultCalls::print_crate_info(&sess,
 452                                                                       &cfg,
 453                                                                       None,
 454                                                                       odir,
 455                                                                       ofile);
 456                 if should_stop == Compilation::Stop {
 457                     return None;
 458                 }
 459                 early_error(sopts.error_format, "no input filename given");
 460             }
 461             1 => panic!("make_input should have provided valid inputs"),
 462             _ => early_error(sopts.error_format, "multiple input filenames provided"),
 463         }
 464
 465         None
 466     }
 467
 468     fn late_callback(&mut self,
 469                      matches: &getopts::Matches,
 470                      sess: &Session,
 471                      cfg: &ast::CrateConfig,
 472                      input: &Input,
 473                      odir: &Option<PathBuf>,
 474                      ofile: &Option<PathBuf>)
 475                      -> Compilation {
 476         RustcDefaultCalls::print_crate_info(sess, cfg, Some(input), odir, ofile)
 477             .and_then(|| RustcDefaultCalls::list_metadata(sess, matches, input))
 478     }
 479
 480     fn build_controller(&mut self,
 481                         sess: &Session,
 482                         matches: &getopts::Matches)
 483                         -> CompileController<'a> {
 484         let mut control = CompileController::basic();
 485
 486         if let Some((ppm, opt_uii)) = parse_pretty(sess, matches) {
 487             if ppm.needs_ast_map(&opt_uii) {
 488                 control.after_hir_lowering.stop = Compilation::Stop;
 489
 490                 control.after_parse.callback = box move |state| {
 491                     state.krate = Some(pretty::fold_crate(state.krate.take().unwrap(), ppm));
 492                 };
 493                 control.after_hir_lowering.callback = box move |state| {
 494                     pretty::print_after_hir_lowering(state.session,
 495                                                      state.ast_map.unwrap(),
 496                                                      state.analysis.unwrap(),
 497                                                      state.resolutions.unwrap(),
 498                                                      state.input,
 499                                                      &state.expanded_crate.take().unwrap(),
 500                                                      state.crate_name.unwrap(),
 501                                                      ppm,
 502                                                      state.arenas.unwrap(),
 503                                                      opt_uii.clone(),
 504                                                      state.out_file);
 505                 };
 506             } else {
 507                 control.after_parse.stop = Compilation::Stop;
 508
 509                 control.after_parse.callback = box move |state| {
 510                     let krate = pretty::fold_crate(state.krate.take().unwrap(), ppm);
 511                     pretty::print_after_parsing(state.session,
 512                                                 state.input,
 513                                                 &krate,
 514                                                 ppm,
 515                                                 state.out_file);
 516                 };
 517             }
 518
 519             return control;
 520         }
 521
 522         if sess.opts.debugging_opts.parse_only ||
 523            sess.opts.debugging_opts.show_span.is_some() ||
 524            sess.opts.debugging_opts.ast_json_noexpand {
 525             control.after_parse.stop = Compilation::Stop;
 526         }
 527
 528         if sess.opts.debugging_opts.no_analysis ||
 529            sess.opts.debugging_opts.ast_json {
 530             control.after_hir_lowering.stop = Compilation::Stop;
 531         }
 532
 533         if !sess.opts.output_types.keys().any(|&i| i == OutputType::Exe) {
 534             control.after_llvm.stop = Compilation::Stop;
 535         }
 536
 537         if save_analysis(sess) {
 538             control.after_analysis.callback = box |state| {
 539                 time(state.session.time_passes(), "save analysis", || {
 540                     save::process_crate(state.tcx.unwrap(),
 541                                         state.expanded_crate.unwrap(),
 542                                         state.analysis.unwrap(),
 543                                         state.crate_name.unwrap(),
 544                                         state.out_dir,
 545                                         save_analysis_format(state.session))
 546                 });
 547             };
 548             control.after_analysis.run_callback_on_error = true;
 549             control.make_glob_map = resolve::MakeGlobMap::Yes;
 550         }
 551
 552         control
 553     }
 554 }
 555
 556 fn save_analysis(sess: &Session) -> bool {
 557     sess.opts.debugging_opts.save_analysis ||
 558     sess.opts.debugging_opts.save_analysis_csv
 559 }
 560
 561 fn save_analysis_format(sess: &Session) -> save::Format {
 562     if sess.opts.debugging_opts.save_analysis {
 563         save::Format::Json
 564     } else if sess.opts.debugging_opts.save_analysis_csv {
 565         save::Format::Csv
 566     } else {
 567         unreachable!();
 568     }
 569 }
 570
 571 impl RustcDefaultCalls {
 572     pub fn list_metadata(sess: &Session, matches: &getopts::Matches, input: &Input) -> Compilation {
 573         let r = matches.opt_strs("Z");
 574         if r.contains(&("ls".to_string())) {
 575             match input {
 576                 &Input::File(ref ifile) => {
 577                     let path = &(*ifile);
 578                     let mut v = Vec::new();
 579                     loader::list_file_metadata(&sess.target.target, path, &mut v)
 580                         .unwrap();
 581                     println!("{}", String::from_utf8(v).unwrap());
 582                 }
 583                 &Input::Str { .. } => {
 584                     early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
 585                 }
 586             }
 587             return Compilation::Stop;
 588         }
 589
 590         return Compilation::Continue;
 591     }
 592
 593
 594     fn print_crate_info(sess: &Session,
 595                         cfg: &ast::CrateConfig,
 596                         input: Option<&Input>,
 597                         odir: &Option<PathBuf>,
 598                         ofile: &Option<PathBuf>)
 599                         -> Compilation {
 600         if sess.opts.prints.is_empty() {
 601             return Compilation::Continue;
 602         }
 603
 604         let attrs = match input {
 605             None => None,
 606             Some(input) => {
 607                 let result = parse_crate_attrs(sess, input);
 608                 match result {
 609                     Ok(attrs) => Some(attrs),
 610                     Err(mut parse_error) => {
 611                         parse_error.emit();
 612                         return Compilation::Stop;
 613                     }
 614                 }
 615             }
 616         };
 617         for req in &sess.opts.prints {
 618             match *req {
 619                 PrintRequest::TargetList => {
 620                     let mut targets = rustc_back::target::get_targets().collect::<Vec<String>>();
 621                     targets.sort();
 622                     println!("{}", targets.join("\n"));
 623                 },
 624                 PrintRequest::Sysroot => println!("{}", sess.sysroot().display()),
 625                 PrintRequest::FileNames |
 626                 PrintRequest::CrateName => {
 627                     let input = match input {
 628                         Some(input) => input,
 629                         None => early_error(ErrorOutputType::default(), "no input file provided"),
 630                     };
 631                     let attrs = attrs.as_ref().unwrap();
 632                     let t_outputs = driver::build_output_filenames(input, odir, ofile, attrs, sess);
 633                     let id = link::find_crate_name(Some(sess), attrs, input);
 634                     if *req == PrintRequest::CrateName {
 635                         println!("{}", id);
 636                         continue;
 637                     }
 638                     let crate_types = driver::collect_crate_types(sess, attrs);
 639                     for &style in &crate_types {
 640                         let fname = link::filename_for_input(sess, style, &id, &t_outputs);
 641                         println!("{}",
 642                                  fname.file_name()
 643                                       .unwrap()
 644                                       .to_string_lossy());
 645                     }
 646                 }
 647                 PrintRequest::Cfg => {
 648                     let allow_unstable_cfg = match get_unstable_features_setting() {
 649                         UnstableFeatures::Disallow => false,
 650                         _ => true,
 651                     };
 652
 653                     for cfg in cfg {
 654                         if !allow_unstable_cfg && GatedCfg::gate(&*cfg).is_some() {
 655                             continue;
 656                         }
 657
 658                         if cfg.is_word() {
 659                             println!("{}", cfg.name());
 660                         } else if let Some(s) = cfg.value_str() {
 661                             println!("{}=\"{}\"", cfg.name(), s);
 662                         } else if cfg.is_meta_item_list() {
 663                             // Right now there are not and should not be any
 664                             // MetaItemKind::List items in the configuration returned by
 665                             // `build_configuration`.
 666                             panic!("Found an unexpected list in cfg attribute '{}'!", cfg.name())
 667                         } else {
 668                             // There also shouldn't be literals.
 669                             panic!("Found an unexpected literal in cfg attribute '{}'!", cfg.name())
 670                         }
 671                     }
 672                 }
 673                 PrintRequest::TargetCPUs => {
 674                     let tm = create_target_machine(sess);
 675                     unsafe { llvm::LLVMRustPrintTargetCPUs(tm); }
 676                 }
 677                 PrintRequest::TargetFeatures => {
 678                     let tm = create_target_machine(sess);
 679                     unsafe { llvm::LLVMRustPrintTargetFeatures(tm); }
 680                 }
 681                 PrintRequest::RelocationModels => {
 682                     println!("Available relocation models:");
 683                     for &(name, _) in RELOC_MODEL_ARGS.iter() {
 684                         println!("    {}", name);
 685                     }
 686                     println!("");
 687                 }
 688                 PrintRequest::CodeModels => {
 689                     println!("Available code models:");
 690                     for &(name, _) in CODE_GEN_MODEL_ARGS.iter(){
 691                         println!("    {}", name);
 692                     }
 693                     println!("");
 694                 }
 695             }
 696         }
 697         return Compilation::Stop;
 698     }
 699 }
 700
 701 /// Returns a version string such as "0.12.0-dev".
 702 pub fn release_str() -> Option<&'static str> {
 703     option_env!("CFG_RELEASE")
 704 }
 705
 706 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 707 pub fn commit_hash_str() -> Option<&'static str> {
 708     option_env!("CFG_VER_HASH")
 709 }
 710
 711 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 712 pub fn commit_date_str() -> Option<&'static str> {
 713     option_env!("CFG_VER_DATE")
 714 }
 715
 716 /// Prints version information
 717 pub fn version(binary: &str, matches: &getopts::Matches) {
 718     let verbose = matches.opt_present("verbose");
 719
 720     println!("{} {}",
 721              binary,
 722              option_env!("CFG_VERSION").unwrap_or("unknown version"));
 723     if verbose {
 724         fn unw(x: Option<&str>) -> &str {
 725             x.unwrap_or("unknown")
 726         }
 727         println!("binary: {}", binary);
 728         println!("commit-hash: {}", unw(commit_hash_str()));
 729         println!("commit-date: {}", unw(commit_date_str()));
 730         println!("host: {}", config::host_triple());
 731         println!("release: {}", unw(release_str()));
 732     }
 733 }
 734
 735 fn usage(verbose: bool, include_unstable_options: bool) {
 736     let groups = if verbose {
 737         config::rustc_optgroups()
 738     } else {
 739         config::rustc_short_optgroups()
 740     };
 741     let groups: Vec<_> = groups.into_iter()
 742                                .filter(|x| include_unstable_options || x.is_stable())
 743                                .map(|x| x.opt_group)
 744                                .collect();
 745     let message = format!("Usage: rustc [OPTIONS] INPUT");
 746     let extra_help = if verbose {
 747         ""
 748     } else {
 749         "\n    --help -v           Print the full set of options rustc accepts"
 750     };
 751     println!("{}\nAdditional help:
 752     -C help             Print codegen options
 753     -W help             \
 754               Print 'lint' options and default settings
 755     -Z help             Print internal \
 756               options for debugging rustc{}\n",
 757              getopts::usage(&message, &groups),
 758              extra_help);
 759 }
 760
 761 fn describe_lints(lint_store: &lint::LintStore, loaded_plugins: bool) {
 762     println!("
 763 Available lint options:
 764     -W <foo>           Warn about <foo>
 765     -A <foo>           \
 766               Allow <foo>
 767     -D <foo>           Deny <foo>
 768     -F <foo>           Forbid <foo> \
 769               (deny, and deny all overrides)
 770
 771 ");
 772
 773     fn sort_lints(lints: Vec<(&'static Lint, bool)>) -> Vec<&'static Lint> {
 774         let mut lints: Vec<_> = lints.into_iter().map(|(x, _)| x).collect();
 775         lints.sort_by(|x: &&Lint, y: &&Lint| {
 776             match x.default_level.cmp(&y.default_level) {
 777                 // The sort doesn't case-fold but it's doubtful we care.
 778                 Equal => x.name.cmp(y.name),
 779                 r => r,
 780             }
 781         });
 782         lints
 783     }
 784
 785     fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
 786                         -> Vec<(&'static str, Vec<lint::LintId>)> {
 787         let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
 788         lints.sort_by(|&(x, _): &(&'static str, Vec<lint::LintId>),
 789                        &(y, _): &(&'static str, Vec<lint::LintId>)| {
 790             x.cmp(y)
 791         });
 792         lints
 793     }
 794
 795     let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints()
 796                                                    .iter()
 797                                                    .cloned()
 798                                                    .partition(|&(_, p)| p);
 799     let plugin = sort_lints(plugin);
 800     let builtin = sort_lints(builtin);
 801
 802     let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups()
 803                                                                  .iter()
 804                                                                  .cloned()
 805                                                                  .partition(|&(_, _, p)| p);
 806     let plugin_groups = sort_lint_groups(plugin_groups);
 807     let builtin_groups = sort_lint_groups(builtin_groups);
 808
 809     let max_name_len = plugin.iter()
 810                              .chain(&builtin)
 811                              .map(|&s| s.name.chars().count())
 812                              .max()
 813                              .unwrap_or(0);
 814     let padded = |x: &str| {
 815         let mut s = repeat(" ")
 816                         .take(max_name_len - x.chars().count())
 817                         .collect::<String>();
 818         s.push_str(x);
 819         s
 820     };
 821
 822     println!("Lint checks provided by rustc:\n");
 823     println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
 824     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
 825
 826     let print_lints = |lints: Vec<&Lint>| {
 827         for lint in lints {
 828             let name = lint.name_lower().replace("_", "-");
 829             println!("    {}  {:7.7}  {}",
 830                      padded(&name[..]),
 831                      lint.default_level.as_str(),
 832                      lint.desc);
 833         }
 834         println!("\n");
 835     };
 836
 837     print_lints(builtin);
 838
 839
 840
 841     let max_name_len = max("warnings".len(),
 842                            plugin_groups.iter()
 843                                         .chain(&builtin_groups)
 844                                         .map(|&(s, _)| s.chars().count())
 845                                         .max()
 846                                         .unwrap_or(0));
 847
 848     let padded = |x: &str| {
 849         let mut s = repeat(" ")
 850                         .take(max_name_len - x.chars().count())
 851                         .collect::<String>();
 852         s.push_str(x);
 853         s
 854     };
 855
 856     println!("Lint groups provided by rustc:\n");
 857     println!("    {}  {}", padded("name"), "sub-lints");
 858     println!("    {}  {}", padded("----"), "---------");
 859     println!("    {}  {}", padded("warnings"), "all built-in lints");
 860
 861     let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
 862         for (name, to) in lints {
 863             let name = name.to_lowercase().replace("_", "-");
 864             let desc = to.into_iter()
 865                          .map(|x| x.to_string().replace("_", "-"))
 866                          .collect::<Vec<String>>()
 867                          .join(", ");
 868             println!("    {}  {}", padded(&name[..]), desc);
 869         }
 870         println!("\n");
 871     };
 872
 873     print_lint_groups(builtin_groups);
 874
 875     match (loaded_plugins, plugin.len(), plugin_groups.len()) {
 876         (false, 0, _) | (false, _, 0) => {
 877             println!("Compiler plugins can provide additional lints and lint groups. To see a \
 878                       listing of these, re-run `rustc -W help` with a crate filename.");
 879         }
 880         (false, _, _) => panic!("didn't load lint plugins but got them anyway!"),
 881         (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
 882         (true, l, g) => {
 883             if l > 0 {
 884                 println!("Lint checks provided by plugins loaded by this crate:\n");
 885                 print_lints(plugin);
 886             }
 887             if g > 0 {
 888                 println!("Lint groups provided by plugins loaded by this crate:\n");
 889                 print_lint_groups(plugin_groups);
 890             }
 891         }
 892     }
 893 }
 894
 895 fn describe_debug_flags() {
 896     println!("\nAvailable debug options:\n");
 897     print_flag_list("-Z", config::DB_OPTIONS);
 898 }
 899
 900 fn describe_codegen_flags() {
 901     println!("\nAvailable codegen options:\n");
 902     print_flag_list("-C", config::CG_OPTIONS);
 903 }
 904
 905 fn print_flag_list<T>(cmdline_opt: &str,
 906                       flag_list: &[(&'static str, T, Option<&'static str>, &'static str)]) {
 907     let max_len = flag_list.iter()
 908                            .map(|&(name, _, opt_type_desc, _)| {
 909                                let extra_len = match opt_type_desc {
 910                                    Some(..) => 4,
 911                                    None => 0,
 912                                };
 913                                name.chars().count() + extra_len
 914                            })
 915                            .max()
 916                            .unwrap_or(0);
 917
 918     for &(name, _, opt_type_desc, desc) in flag_list {
 919         let (width, extra) = match opt_type_desc {
 920             Some(..) => (max_len - 4, "=val"),
 921             None => (max_len, ""),
 922         };
 923         println!("    {} {:>width$}{} -- {}",
 924                  cmdline_opt,
 925                  name.replace("_", "-"),
 926                  extra,
 927                  desc,
 928                  width = width);
 929     }
 930 }
 931
 932 /// Process command line options. Emits messages as appropriate. If compilation
 933 /// should continue, returns a getopts::Matches object parsed from args,
 934 /// otherwise returns None.
 935 ///
 936 /// The compiler's handling of options is a little complication as it ties into
 937 /// our stability story, and it's even *more* complicated by historical
 938 /// accidents. The current intention of each compiler option is to have one of
 939 /// three modes:
 940 ///
 941 /// 1. An option is stable and can be used everywhere.
 942 /// 2. An option is unstable, but was historically allowed on the stable
 943 ///    channel.
 944 /// 3. An option is unstable, and can only be used on nightly.
 945 ///
 946 /// Like unstable library and language features, however, unstable options have
 947 /// always required a form of "opt in" to indicate that you're using them. This
 948 /// provides the easy ability to scan a code base to check to see if anything
 949 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
 950 ///
 951 /// All options behind `-Z` are considered unstable by default. Other top-level
 952 /// options can also be considered unstable, and they were unlocked through the
 953 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
 954 /// instability in both cases, though.
 955 ///
 956 /// So with all that in mind, the comments below have some more detail about the
 957 /// contortions done here to get things to work out correctly.
 958 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
 959     // Throw away the first argument, the name of the binary
 960     let args = &args[1..];
 961
 962     if args.is_empty() {
 963         // user did not write `-v` nor `-Z unstable-options`, so do not
 964         // include that extra information.
 965         usage(false, false);
 966         return None;
 967     }
 968
 969     // Parse with *all* options defined in the compiler, we don't worry about
 970     // option stability here we just want to parse as much as possible.
 971     let all_groups: Vec<getopts::OptGroup> = config::rustc_optgroups()
 972                                                  .into_iter()
 973                                                  .map(|x| x.opt_group)
 974                                                  .collect();
 975     let matches = match getopts::getopts(&args[..], &all_groups) {
 976         Ok(m) => m,
 977         Err(f) => early_error(ErrorOutputType::default(), &f.to_string()),
 978     };
 979
 980     // For all options we just parsed, we check a few aspects:
 981     //
 982     // * If the option is stable, we're all good
 983     // * If the option wasn't passed, we're all good
 984     // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
 985     //   ourselves), then we require the `-Z unstable-options` flag to unlock
 986     //   this option that was passed.
 987     // * If we're a nightly compiler, then unstable options are now unlocked, so
 988     //   we're good to go.
 989     // * Otherwise, if we're a truly unstable option then we generate an error
 990     //   (unstable option being used on stable)
 991     // * If we're a historically stable-but-should-be-unstable option then we
 992     //   emit a warning that we're going to turn this into an error soon.
 993     nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
 994
 995     if matches.opt_present("h") || matches.opt_present("help") {
 996         // Only show unstable options in --help if we *really* accept unstable
 997         // options, which catches the case where we got `-Z unstable-options` on
 998         // the stable channel of Rust which was accidentally allowed
 999         // historically.
1000         usage(matches.opt_present("verbose"),
1001               nightly_options::is_unstable_enabled(&matches));
1002         return None;
1003     }
1004
1005     // Don't handle -W help here, because we might first load plugins.
1006     let r = matches.opt_strs("Z");
1007     if r.iter().any(|x| *x == "help") {
1008         describe_debug_flags();
1009         return None;
1010     }
1011
1012     let cg_flags = matches.opt_strs("C");
1013     if cg_flags.iter().any(|x| *x == "help") {
1014         describe_codegen_flags();
1015         return None;
1016     }
1017
1018     if cg_flags.contains(&"passes=list".to_string()) {
1019         unsafe {
1020             ::llvm::LLVMRustPrintPasses();
1021         }
1022         return None;
1023     }
1024
1025     if matches.opt_present("version") {
1026         version("rustc", &matches);
1027         return None;
1028     }
1029
1030     Some(matches)
1031 }
1032
1033 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1034     match *input {
1035         Input::File(ref ifile) => {
1036             parse::parse_crate_attrs_from_file(ifile, Vec::new(), &sess.parse_sess)
1037         }
1038         Input::Str { ref name, ref input } => {
1039             parse::parse_crate_attrs_from_source_str(name.clone(),
1040                                                      input.clone(),
1041                                                      Vec::new(),
1042                                                      &sess.parse_sess)
1043         }
1044     }
1045 }
1046
1047 /// Run a procedure which will detect panics in the compiler and print nicer
1048 /// error messages rather than just failing the test.
1049 ///
1050 /// The diagnostic emitter yielded to the procedure should be used for reporting
1051 /// errors of the compiler.
1052 pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
1053     const STACK_SIZE: usize = 8 * 1024 * 1024; // 8MB
1054
1055     struct Sink(Arc<Mutex<Vec<u8>>>);
1056     impl Write for Sink {
1057         fn write(&mut self, data: &[u8]) -> io::Result<usize> {
1058             Write::write(&mut *self.0.lock().unwrap(), data)
1059         }
1060         fn flush(&mut self) -> io::Result<()> {
1061             Ok(())
1062         }
1063     }
1064
1065     let data = Arc::new(Mutex::new(Vec::new()));
1066     let err = Sink(data.clone());
1067
1068     let mut cfg = thread::Builder::new().name("rustc".to_string());
1069
1070     // FIXME: Hacks on hacks. If the env is trying to override the stack size
1071     // then *don't* set it explicitly.
1072     if env::var_os("RUST_MIN_STACK").is_none() {
1073         cfg = cfg.stack_size(STACK_SIZE);
1074     }
1075
1076     let thread = cfg.spawn(move || {
1077          io::set_panic(box err);
1078          f()
1079      });
1080
1081      if let Err(value) = thread.unwrap().join() {
1082         // Thread panicked without emitting a fatal diagnostic
1083         if !value.is::<errors::FatalError>() {
1084             let emitter =
1085                 Box::new(errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None));
1086             let handler = errors::Handler::with_emitter(true, false, emitter);
1087
1088             // a .span_bug or .bug call has already printed what
1089             // it wants to print.
1090             if !value.is::<errors::ExplicitBug>() {
1091                 handler.emit(&MultiSpan::new(),
1092                              "unexpected panic",
1093                              errors::Level::Bug);
1094             }
1095
1096             let xs = ["the compiler unexpectedly panicked. this is a bug.".to_string(),
1097                       format!("we would appreciate a bug report: {}", BUG_REPORT_URL)];
1098             for note in &xs {
1099                 handler.emit(&MultiSpan::new(),
1100                              &note[..],
1101                              errors::Level::Note);
1102             }
1103             if match env::var_os("RUST_BACKTRACE") {
1104                 Some(val) => &val != "0",
1105                 None => false,
1106             } {
1107                 handler.emit(&MultiSpan::new(),
1108                              "run with `RUST_BACKTRACE=1` for a backtrace",
1109                              errors::Level::Note);
1110             }
1111
1112             println!("{}", str::from_utf8(&data.lock().unwrap()).unwrap());
1113         }
1114
1115         exit_on_err();
1116     }
1117 }
1118
1119 fn exit_on_err() -> ! {
1120     // Panic so the process returns a failure code, but don't pollute the
1121     // output with some unnecessary panic messages, we've already
1122     // printed everything that we needed to.
1123     io::set_panic(box io::sink());
1124     panic!();
1125 }
1126
1127 pub fn diagnostics_registry() -> errors::registry::Registry {
1128     use errors::registry::Registry;
1129
1130     let mut all_errors = Vec::new();
1131     all_errors.extend_from_slice(&rustc::DIAGNOSTICS);
1132     all_errors.extend_from_slice(&rustc_typeck::DIAGNOSTICS);
1133     all_errors.extend_from_slice(&rustc_borrowck::DIAGNOSTICS);
1134     all_errors.extend_from_slice(&rustc_resolve::DIAGNOSTICS);
1135     all_errors.extend_from_slice(&rustc_privacy::DIAGNOSTICS);
1136     all_errors.extend_from_slice(&rustc_trans::DIAGNOSTICS);
1137     all_errors.extend_from_slice(&rustc_const_eval::DIAGNOSTICS);
1138
1139     Registry::new(&all_errors)
1140 }
1141
1142 pub fn main() {
1143     let result = run(env::args().collect());
1144     process::exit(result as i32);
1145 }