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(dotdot_in_tuple_patterns)]
  28 #![feature(libc)]
  29 #![feature(quote)]
  30 #![feature(rustc_diagnostic_macros)]
  31 #![feature(rustc_private)]
  32 #![feature(set_stdio)]
  33 #![feature(staged_api)]
  34 #![cfg_attr(stage0, feature(question_mark))]
  35
  36 extern crate arena;
  37 extern crate flate;
  38 extern crate getopts;
  39 extern crate graphviz;
  40 extern crate libc;
  41 extern crate rustc;
  42 extern crate rustc_back;
  43 extern crate rustc_borrowck;
  44 extern crate rustc_const_eval;
  45 extern crate rustc_data_structures;
  46 extern crate rustc_errors as errors;
  47 extern crate rustc_passes;
  48 extern crate rustc_lint;
  49 extern crate rustc_plugin;
  50 extern crate rustc_privacy;
  51 extern crate rustc_incremental;
  52 extern crate rustc_metadata;
  53 extern crate rustc_mir;
  54 extern crate rustc_resolve;
  55 extern crate rustc_save_analysis;
  56 extern crate rustc_trans;
  57 extern crate rustc_typeck;
  58 extern crate serialize;
  59 extern crate rustc_llvm as llvm;
  60 #[macro_use]
  61 extern crate log;
  62 #[macro_use]
  63 extern crate syntax;
  64 extern crate syntax_ext;
  65 extern crate syntax_pos;
  66
  67 use driver::CompileController;
  68 use pretty::{PpMode, UserIdentifiedItem};
  69
  70 use rustc_resolve as resolve;
  71 use rustc_save_analysis as save;
  72 use rustc_trans::back::link;
  73 use rustc_trans::back::write::{create_target_machine, RELOC_MODEL_ARGS, CODE_GEN_MODEL_ARGS};
  74 use rustc::dep_graph::DepGraph;
  75 use rustc::session::{self, config, Session, build_session, CompileResult};
  76 use rustc::session::config::{Input, PrintRequest, OutputType, ErrorOutputType};
  77 use rustc::session::config::nightly_options;
  78 use rustc::session::early_error;
  79 use rustc::lint::Lint;
  80 use rustc::lint;
  81 use rustc_metadata::locator;
  82 use rustc_metadata::cstore::CStore;
  83 use rustc::util::common::time;
  84
  85 use std::cmp::max;
  86 use std::cmp::Ordering::Equal;
  87 use std::default::Default;
  88 use std::env;
  89 use std::io::{self, Read, Write};
  90 use std::iter::repeat;
  91 use std::path::PathBuf;
  92 use std::process;
  93 use std::rc::Rc;
  94 use std::str;
  95 use std::sync::{Arc, Mutex};
  96 use std::thread;
  97
  98 use syntax::{ast, json};
  99 use syntax::codemap::{CodeMap, FileLoader, RealFileLoader};
 100 use syntax::feature_gate::{GatedCfg, UnstableFeatures};
 101 use syntax::parse::{self, PResult};
 102 use syntax_pos::MultiSpan;
 103 use errors::emitter::Emitter;
 104
 105 #[cfg(test)]
 106 pub mod test;
 107
 108 pub mod driver;
 109 pub mod pretty;
 110 pub mod target_features;
 111 mod derive_registrar;
 112
 113 const BUG_REPORT_URL: &'static str = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.\
 114                                       md#bug-reports";
 115
 116 #[inline]
 117 fn abort_msg(err_count: usize) -> String {
 118     match err_count {
 119         0 => "aborting with no errors (maybe a bug?)".to_owned(),
 120         1 => "aborting due to previous error".to_owned(),
 121         e => format!("aborting due to {} previous errors", e),
 122     }
 123 }
 124
 125 pub fn abort_on_err<T>(result: Result<T, usize>, sess: &Session) -> T {
 126     match result {
 127         Err(err_count) => {
 128             sess.fatal(&abort_msg(err_count));
 129         }
 130         Ok(x) => x,
 131     }
 132 }
 133
 134 pub fn run<F>(run_compiler: F) -> isize
 135     where F: FnOnce() -> (CompileResult, Option<Session>) + Send + 'static
 136 {
 137     monitor(move || {
 138         let (result, session) = run_compiler();
 139         if let Err(err_count) = result {
 140             if err_count > 0 {
 141                 match session {
 142                     Some(sess) => sess.fatal(&abort_msg(err_count)),
 143                     None => {
 144                         let emitter =
 145                             errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None);
 146                         let handler = errors::Handler::with_emitter(true, false, Box::new(emitter));
 147                         handler.emit(&MultiSpan::new(),
 148                                      &abort_msg(err_count),
 149                                      errors::Level::Fatal);
 150                         exit_on_err();
 151                     }
 152                 }
 153             }
 154         }
 155     });
 156     0
 157 }
 158
 159 // Parse args and run the compiler. This is the primary entry point for rustc.
 160 // See comments on CompilerCalls below for details about the callbacks argument.
 161 // The FileLoader provides a way to load files from sources other than the file system.
 162 pub fn run_compiler<'a>(args: &[String],
 163                         callbacks: &mut CompilerCalls<'a>,
 164                         file_loader: Option<Box<FileLoader + 'static>>,
 165                         emitter_dest: Option<Box<Write + Send>>)
 166                         -> (CompileResult, Option<Session>)
 167 {
 168     macro_rules! do_or_return {($expr: expr, $sess: expr) => {
 169         match $expr {
 170             Compilation::Stop => return (Ok(()), $sess),
 171             Compilation::Continue => {}
 172         }
 173     }}
 174
 175     let matches = match handle_options(args) {
 176         Some(matches) => matches,
 177         None => return (Ok(()), None),
 178     };
 179
 180     let (sopts, cfg) = config::build_session_options_and_crate_config(&matches);
 181
 182     if sopts.debugging_opts.debug_llvm {
 183         unsafe { llvm::LLVMRustSetDebug(1); }
 184     }
 185
 186     let descriptions = diagnostics_registry();
 187
 188     do_or_return!(callbacks.early_callback(&matches,
 189                                            &sopts,
 190                                            &cfg,
 191                                            &descriptions,
 192                                            sopts.error_format),
 193                                            None);
 194
 195     let (odir, ofile) = make_output(&matches);
 196     let (input, input_file_path) = match make_input(&matches.free) {
 197         Some((input, input_file_path)) => callbacks.some_input(input, input_file_path),
 198         None => match callbacks.no_input(&matches, &sopts, &cfg, &odir, &ofile, &descriptions) {
 199             Some((input, input_file_path)) => (input, input_file_path),
 200             None => return (Ok(()), None),
 201         },
 202     };
 203
 204     let dep_graph = DepGraph::new(sopts.build_dep_graph());
 205     let cstore = Rc::new(CStore::new(&dep_graph));
 206
 207     let loader = file_loader.unwrap_or(box RealFileLoader);
 208     let codemap = Rc::new(CodeMap::with_file_loader(loader));
 209     let mut sess = session::build_session_with_codemap(
 210         sopts, &dep_graph, input_file_path, descriptions, cstore.clone(), codemap, emitter_dest,
 211     );
 212     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 213
 214     let mut cfg = config::build_configuration(&sess, cfg);
 215     target_features::add_configuration(&mut cfg, &sess);
 216     sess.parse_sess.config = cfg;
 217
 218     do_or_return!(callbacks.late_callback(&matches, &sess, &input, &odir, &ofile), Some(sess));
 219
 220     let plugins = sess.opts.debugging_opts.extra_plugins.clone();
 221     let control = callbacks.build_controller(&sess, &matches);
 222     (driver::compile_input(&sess, &cstore, &input, &odir, &ofile, Some(plugins), &control),
 223      Some(sess))
 224 }
 225
 226 // Extract output directory and file from matches.
 227 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
 228     let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
 229     let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
 230     (odir, ofile)
 231 }
 232
 233 // Extract input (string or file and optional path) from matches.
 234 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>)> {
 235     if free_matches.len() == 1 {
 236         let ifile = &free_matches[0][..];
 237         if ifile == "-" {
 238             let mut src = String::new();
 239             io::stdin().read_to_string(&mut src).unwrap();
 240             Some((Input::Str { name: driver::anon_src(), input: src },
 241                   None))
 242         } else {
 243             Some((Input::File(PathBuf::from(ifile)),
 244                   Some(PathBuf::from(ifile))))
 245         }
 246     } else {
 247         None
 248     }
 249 }
 250
 251 fn parse_pretty(sess: &Session,
 252                 matches: &getopts::Matches)
 253                 -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 254     let pretty = if sess.opts.debugging_opts.unstable_options {
 255         matches.opt_default("pretty", "normal").map(|a| {
 256             // stable pretty-print variants only
 257             pretty::parse_pretty(sess, &a, false)
 258         })
 259     } else {
 260         None
 261     };
 262     if pretty.is_none() && sess.unstable_options() {
 263         matches.opt_str("unpretty").map(|a| {
 264             // extended with unstable pretty-print variants
 265             pretty::parse_pretty(sess, &a, true)
 266         })
 267     } else {
 268         pretty
 269     }
 270 }
 271
 272 // Whether to stop or continue compilation.
 273 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 274 pub enum Compilation {
 275     Stop,
 276     Continue,
 277 }
 278
 279 impl Compilation {
 280     pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
 281         match self {
 282             Compilation::Stop => Compilation::Stop,
 283             Compilation::Continue => next(),
 284         }
 285     }
 286 }
 287
 288 // A trait for customising the compilation process. Offers a number of hooks for
 289 // executing custom code or customising input.
 290 pub trait CompilerCalls<'a> {
 291     // Hook for a callback early in the process of handling arguments. This will
 292     // be called straight after options have been parsed but before anything
 293     // else (e.g., selecting input and output).
 294     fn early_callback(&mut self,
 295                       _: &getopts::Matches,
 296                       _: &config::Options,
 297                       _: &ast::CrateConfig,
 298                       _: &errors::registry::Registry,
 299                       _: ErrorOutputType)
 300                       -> Compilation {
 301         Compilation::Continue
 302     }
 303
 304     // Hook for a callback late in the process of handling arguments. This will
 305     // be called just before actual compilation starts (and before build_controller
 306     // is called), after all arguments etc. have been completely handled.
 307     fn late_callback(&mut self,
 308                      _: &getopts::Matches,
 309                      _: &Session,
 310                      _: &Input,
 311                      _: &Option<PathBuf>,
 312                      _: &Option<PathBuf>)
 313                      -> Compilation {
 314         Compilation::Continue
 315     }
 316
 317     // Called after we extract the input from the arguments. Gives the implementer
 318     // an opportunity to change the inputs or to add some custom input handling.
 319     // The default behaviour is to simply pass through the inputs.
 320     fn some_input(&mut self,
 321                   input: Input,
 322                   input_path: Option<PathBuf>)
 323                   -> (Input, Option<PathBuf>) {
 324         (input, input_path)
 325     }
 326
 327     // Called after we extract the input from the arguments if there is no valid
 328     // input. Gives the implementer an opportunity to supply alternate input (by
 329     // returning a Some value) or to add custom behaviour for this error such as
 330     // emitting error messages. Returning None will cause compilation to stop
 331     // at this point.
 332     fn no_input(&mut self,
 333                 _: &getopts::Matches,
 334                 _: &config::Options,
 335                 _: &ast::CrateConfig,
 336                 _: &Option<PathBuf>,
 337                 _: &Option<PathBuf>,
 338                 _: &errors::registry::Registry)
 339                 -> Option<(Input, Option<PathBuf>)> {
 340         None
 341     }
 342
 343     // Create a CompilController struct for controlling the behaviour of
 344     // compilation.
 345     fn build_controller(&mut self, &Session, &getopts::Matches) -> CompileController<'a>;
 346 }
 347
 348 // CompilerCalls instance for a regular rustc build.
 349 #[derive(Copy, Clone)]
 350 pub struct RustcDefaultCalls;
 351
 352 fn handle_explain(code: &str,
 353                   descriptions: &errors::registry::Registry,
 354                   output: ErrorOutputType) {
 355     let normalised = if code.starts_with("E") {
 356         code.to_string()
 357     } else {
 358         format!("E{0:0>4}", code)
 359     };
 360     match descriptions.find_description(&normalised) {
 361         Some(ref description) => {
 362             // Slice off the leading newline and print.
 363             print!("{}", &(&description[1..]).split("\n").map(|x| {
 364                 format!("{}\n", if x.starts_with("```") {
 365                     "```"
 366                 } else {
 367                     x
 368                 })
 369             }).collect::<String>());
 370         }
 371         None => {
 372             early_error(output, &format!("no extended information for {}", code));
 373         }
 374     }
 375 }
 376
 377 fn check_cfg(cfg: &ast::CrateConfig,
 378              output: ErrorOutputType) {
 379     let emitter: Box<Emitter> = match output {
 380         config::ErrorOutputType::HumanReadable(color_config) => {
 381             Box::new(errors::emitter::EmitterWriter::stderr(color_config, None))
 382         }
 383         config::ErrorOutputType::Json => Box::new(json::JsonEmitter::basic()),
 384     };
 385     let handler = errors::Handler::with_emitter(true, false, emitter);
 386
 387     let mut saw_invalid_predicate = false;
 388     for item in cfg.iter() {
 389         if item.is_meta_item_list() {
 390             saw_invalid_predicate = true;
 391             handler.emit(&MultiSpan::new(),
 392                          &format!("invalid predicate in --cfg command line argument: `{}`",
 393                                   item.name()),
 394                             errors::Level::Fatal);
 395         }
 396     }
 397
 398     if saw_invalid_predicate {
 399         panic!(errors::FatalError);
 400     }
 401 }
 402
 403 impl<'a> CompilerCalls<'a> for RustcDefaultCalls {
 404     fn early_callback(&mut self,
 405                       matches: &getopts::Matches,
 406                       _: &config::Options,
 407                       cfg: &ast::CrateConfig,
 408                       descriptions: &errors::registry::Registry,
 409                       output: ErrorOutputType)
 410                       -> Compilation {
 411         if let Some(ref code) = matches.opt_str("explain") {
 412             handle_explain(code, descriptions, output);
 413             return Compilation::Stop;
 414         }
 415
 416         check_cfg(cfg, output);
 417         Compilation::Continue
 418     }
 419
 420     fn no_input(&mut self,
 421                 matches: &getopts::Matches,
 422                 sopts: &config::Options,
 423                 cfg: &ast::CrateConfig,
 424                 odir: &Option<PathBuf>,
 425                 ofile: &Option<PathBuf>,
 426                 descriptions: &errors::registry::Registry)
 427                 -> Option<(Input, Option<PathBuf>)> {
 428         match matches.free.len() {
 429             0 => {
 430                 if sopts.describe_lints {
 431                     let mut ls = lint::LintStore::new();
 432                     rustc_lint::register_builtins(&mut ls, None);
 433                     describe_lints(&ls, false);
 434                     return None;
 435                 }
 436                 let dep_graph = DepGraph::new(sopts.build_dep_graph());
 437                 let cstore = Rc::new(CStore::new(&dep_graph));
 438                 let mut sess = build_session(sopts.clone(),
 439                     &dep_graph,
 440                     None,
 441                     descriptions.clone(),
 442                     cstore.clone());
 443                 rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 444                 let mut cfg = config::build_configuration(&sess, cfg.clone());
 445                 target_features::add_configuration(&mut cfg, &sess);
 446                 sess.parse_sess.config = cfg;
 447                 let should_stop =
 448                     RustcDefaultCalls::print_crate_info(&sess, None, odir, ofile);
 449
 450                 if should_stop == Compilation::Stop {
 451                     return None;
 452                 }
 453                 early_error(sopts.error_format, "no input filename given");
 454             }
 455             1 => panic!("make_input should have provided valid inputs"),
 456             _ => early_error(sopts.error_format, "multiple input filenames provided"),
 457         }
 458
 459         None
 460     }
 461
 462     fn late_callback(&mut self,
 463                      matches: &getopts::Matches,
 464                      sess: &Session,
 465                      input: &Input,
 466                      odir: &Option<PathBuf>,
 467                      ofile: &Option<PathBuf>)
 468                      -> Compilation {
 469         RustcDefaultCalls::print_crate_info(sess, Some(input), odir, ofile)
 470             .and_then(|| RustcDefaultCalls::list_metadata(sess, matches, input))
 471     }
 472
 473     fn build_controller(&mut self,
 474                         sess: &Session,
 475                         matches: &getopts::Matches)
 476                         -> CompileController<'a> {
 477         let mut control = CompileController::basic();
 478
 479         if let Some((ppm, opt_uii)) = parse_pretty(sess, matches) {
 480             if ppm.needs_ast_map(&opt_uii) {
 481                 control.after_hir_lowering.stop = Compilation::Stop;
 482
 483                 control.after_parse.callback = box move |state| {
 484                     state.krate = Some(pretty::fold_crate(state.krate.take().unwrap(), ppm));
 485                 };
 486                 control.after_hir_lowering.callback = box move |state| {
 487                     pretty::print_after_hir_lowering(state.session,
 488                                                      state.ast_map.unwrap(),
 489                                                      state.analysis.unwrap(),
 490                                                      state.resolutions.unwrap(),
 491                                                      state.input,
 492                                                      &state.expanded_crate.take().unwrap(),
 493                                                      state.crate_name.unwrap(),
 494                                                      ppm,
 495                                                      state.arenas.unwrap(),
 496                                                      opt_uii.clone(),
 497                                                      state.out_file);
 498                 };
 499             } else {
 500                 control.after_parse.stop = Compilation::Stop;
 501
 502                 control.after_parse.callback = box move |state| {
 503                     let krate = pretty::fold_crate(state.krate.take().unwrap(), ppm);
 504                     pretty::print_after_parsing(state.session,
 505                                                 state.input,
 506                                                 &krate,
 507                                                 ppm,
 508                                                 state.out_file);
 509                 };
 510             }
 511
 512             return control;
 513         }
 514
 515         if sess.opts.debugging_opts.parse_only ||
 516            sess.opts.debugging_opts.show_span.is_some() ||
 517            sess.opts.debugging_opts.ast_json_noexpand {
 518             control.after_parse.stop = Compilation::Stop;
 519         }
 520
 521         if sess.opts.debugging_opts.no_analysis ||
 522            sess.opts.debugging_opts.ast_json {
 523             control.after_hir_lowering.stop = Compilation::Stop;
 524         }
 525
 526         if !sess.opts.output_types.keys().any(|&i| i == OutputType::Exe) {
 527             control.after_llvm.stop = Compilation::Stop;
 528         }
 529
 530         if save_analysis(sess) {
 531             control.after_analysis.callback = box |state| {
 532                 time(state.session.time_passes(), "save analysis", || {
 533                     save::process_crate(state.tcx.unwrap(),
 534                                         state.expanded_crate.unwrap(),
 535                                         state.analysis.unwrap(),
 536                                         state.crate_name.unwrap(),
 537                                         state.out_dir,
 538                                         save_analysis_format(state.session))
 539                 });
 540             };
 541             control.after_analysis.run_callback_on_error = true;
 542             control.make_glob_map = resolve::MakeGlobMap::Yes;
 543         }
 544
 545         control
 546     }
 547 }
 548
 549 fn save_analysis(sess: &Session) -> bool {
 550     sess.opts.debugging_opts.save_analysis ||
 551     sess.opts.debugging_opts.save_analysis_csv ||
 552     sess.opts.debugging_opts.save_analysis_api
 553 }
 554
 555 fn save_analysis_format(sess: &Session) -> save::Format {
 556     if sess.opts.debugging_opts.save_analysis {
 557         save::Format::Json
 558     } else if sess.opts.debugging_opts.save_analysis_csv {
 559         save::Format::Csv
 560     } else if sess.opts.debugging_opts.save_analysis_api {
 561         save::Format::JsonApi
 562     } else {
 563         unreachable!();
 564     }
 565 }
 566
 567 impl RustcDefaultCalls {
 568     pub fn list_metadata(sess: &Session, matches: &getopts::Matches, input: &Input) -> Compilation {
 569         let r = matches.opt_strs("Z");
 570         if r.contains(&("ls".to_string())) {
 571             match input {
 572                 &Input::File(ref ifile) => {
 573                     let path = &(*ifile);
 574                     let mut v = Vec::new();
 575                     locator::list_file_metadata(&sess.target.target, path, &mut v).unwrap();
 576                     println!("{}", String::from_utf8(v).unwrap());
 577                 }
 578                 &Input::Str { .. } => {
 579                     early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
 580                 }
 581             }
 582             return Compilation::Stop;
 583         }
 584
 585         return Compilation::Continue;
 586     }
 587
 588
 589     fn print_crate_info(sess: &Session,
 590                         input: Option<&Input>,
 591                         odir: &Option<PathBuf>,
 592                         ofile: &Option<PathBuf>)
 593                         -> Compilation {
 594         if sess.opts.prints.is_empty() {
 595             return Compilation::Continue;
 596         }
 597
 598         let attrs = match input {
 599             None => None,
 600             Some(input) => {
 601                 let result = parse_crate_attrs(sess, input);
 602                 match result {
 603                     Ok(attrs) => Some(attrs),
 604                     Err(mut parse_error) => {
 605                         parse_error.emit();
 606                         return Compilation::Stop;
 607                     }
 608                 }
 609             }
 610         };
 611         for req in &sess.opts.prints {
 612             match *req {
 613                 PrintRequest::TargetList => {
 614                     let mut targets = rustc_back::target::get_targets().collect::<Vec<String>>();
 615                     targets.sort();
 616                     println!("{}", targets.join("\n"));
 617                 },
 618                 PrintRequest::Sysroot => println!("{}", sess.sysroot().display()),
 619                 PrintRequest::FileNames |
 620                 PrintRequest::CrateName => {
 621                     let input = match input {
 622                         Some(input) => input,
 623                         None => early_error(ErrorOutputType::default(), "no input file provided"),
 624                     };
 625                     let attrs = attrs.as_ref().unwrap();
 626                     let t_outputs = driver::build_output_filenames(input, odir, ofile, attrs, sess);
 627                     let id = link::find_crate_name(Some(sess), attrs, input);
 628                     if *req == PrintRequest::CrateName {
 629                         println!("{}", id);
 630                         continue;
 631                     }
 632                     let crate_types = driver::collect_crate_types(sess, attrs);
 633                     for &style in &crate_types {
 634                         let fname = link::filename_for_input(sess, style, &id, &t_outputs);
 635                         println!("{}",
 636                                  fname.file_name()
 637                                       .unwrap()
 638                                       .to_string_lossy());
 639                     }
 640                 }
 641                 PrintRequest::Cfg => {
 642                     let allow_unstable_cfg = UnstableFeatures::from_environment()
 643                         .is_nightly_build();
 644
 645                     for cfg in &sess.parse_sess.config {
 646                         if !allow_unstable_cfg && GatedCfg::gate(cfg).is_some() {
 647                             continue;
 648                         }
 649
 650                         if cfg.is_word() {
 651                             println!("{}", cfg.name());
 652                         } else if let Some(s) = cfg.value_str() {
 653                             println!("{}=\"{}\"", cfg.name(), s);
 654                         } else if cfg.is_meta_item_list() {
 655                             // Right now there are not and should not be any
 656                             // MetaItemKind::List items in the configuration returned by
 657                             // `build_configuration`.
 658                             panic!("Found an unexpected list in cfg attribute '{}'!", cfg.name())
 659                         } else {
 660                             // There also shouldn't be literals.
 661                             panic!("Found an unexpected literal in cfg attribute '{}'!", cfg.name())
 662                         }
 663                     }
 664                 }
 665                 PrintRequest::TargetCPUs => {
 666                     let tm = create_target_machine(sess);
 667                     unsafe { llvm::LLVMRustPrintTargetCPUs(tm); }
 668                 }
 669                 PrintRequest::TargetFeatures => {
 670                     let tm = create_target_machine(sess);
 671                     unsafe { llvm::LLVMRustPrintTargetFeatures(tm); }
 672                 }
 673                 PrintRequest::RelocationModels => {
 674                     println!("Available relocation models:");
 675                     for &(name, _) in RELOC_MODEL_ARGS.iter() {
 676                         println!("    {}", name);
 677                     }
 678                     println!("");
 679                 }
 680                 PrintRequest::CodeModels => {
 681                     println!("Available code models:");
 682                     for &(name, _) in CODE_GEN_MODEL_ARGS.iter(){
 683                         println!("    {}", name);
 684                     }
 685                     println!("");
 686                 }
 687             }
 688         }
 689         return Compilation::Stop;
 690     }
 691 }
 692
 693 /// Returns a version string such as "0.12.0-dev".
 694 pub fn release_str() -> Option<&'static str> {
 695     option_env!("CFG_RELEASE")
 696 }
 697
 698 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 699 pub fn commit_hash_str() -> Option<&'static str> {
 700     option_env!("CFG_VER_HASH")
 701 }
 702
 703 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 704 pub fn commit_date_str() -> Option<&'static str> {
 705     option_env!("CFG_VER_DATE")
 706 }
 707
 708 /// Prints version information
 709 pub fn version(binary: &str, matches: &getopts::Matches) {
 710     let verbose = matches.opt_present("verbose");
 711
 712     println!("{} {}",
 713              binary,
 714              option_env!("CFG_VERSION").unwrap_or("unknown version"));
 715     if verbose {
 716         fn unw(x: Option<&str>) -> &str {
 717             x.unwrap_or("unknown")
 718         }
 719         println!("binary: {}", binary);
 720         println!("commit-hash: {}", unw(commit_hash_str()));
 721         println!("commit-date: {}", unw(commit_date_str()));
 722         println!("host: {}", config::host_triple());
 723         println!("release: {}", unw(release_str()));
 724         unsafe {
 725             println!("LLVM version: {}.{}",
 726                      llvm::LLVMRustVersionMajor(), llvm::LLVMRustVersionMinor());
 727         }
 728     }
 729 }
 730
 731 fn usage(verbose: bool, include_unstable_options: bool) {
 732     let groups = if verbose {
 733         config::rustc_optgroups()
 734     } else {
 735         config::rustc_short_optgroups()
 736     };
 737     let groups: Vec<_> = groups.into_iter()
 738                                .filter(|x| include_unstable_options || x.is_stable())
 739                                .map(|x| x.opt_group)
 740                                .collect();
 741     let message = format!("Usage: rustc [OPTIONS] INPUT");
 742     let extra_help = if verbose {
 743         ""
 744     } else {
 745         "\n    --help -v           Print the full set of options rustc accepts"
 746     };
 747     println!("{}\nAdditional help:
 748     -C help             Print codegen options
 749     -W help             \
 750               Print 'lint' options and default settings
 751     -Z help             Print internal \
 752               options for debugging rustc{}\n",
 753              getopts::usage(&message, &groups),
 754              extra_help);
 755 }
 756
 757 fn describe_lints(lint_store: &lint::LintStore, loaded_plugins: bool) {
 758     println!("
 759 Available lint options:
 760     -W <foo>           Warn about <foo>
 761     -A <foo>           \
 762               Allow <foo>
 763     -D <foo>           Deny <foo>
 764     -F <foo>           Forbid <foo> \
 765               (deny, and deny all overrides)
 766
 767 ");
 768
 769     fn sort_lints(lints: Vec<(&'static Lint, bool)>) -> Vec<&'static Lint> {
 770         let mut lints: Vec<_> = lints.into_iter().map(|(x, _)| x).collect();
 771         lints.sort_by(|x: &&Lint, y: &&Lint| {
 772             match x.default_level.cmp(&y.default_level) {
 773                 // The sort doesn't case-fold but it's doubtful we care.
 774                 Equal => x.name.cmp(y.name),
 775                 r => r,
 776             }
 777         });
 778         lints
 779     }
 780
 781     fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
 782                         -> Vec<(&'static str, Vec<lint::LintId>)> {
 783         let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
 784         lints.sort_by(|&(x, _): &(&'static str, Vec<lint::LintId>),
 785                        &(y, _): &(&'static str, Vec<lint::LintId>)| {
 786             x.cmp(y)
 787         });
 788         lints
 789     }
 790
 791     let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints()
 792                                                    .iter()
 793                                                    .cloned()
 794                                                    .partition(|&(_, p)| p);
 795     let plugin = sort_lints(plugin);
 796     let builtin = sort_lints(builtin);
 797
 798     let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups()
 799                                                                  .iter()
 800                                                                  .cloned()
 801                                                                  .partition(|&(.., p)| p);
 802     let plugin_groups = sort_lint_groups(plugin_groups);
 803     let builtin_groups = sort_lint_groups(builtin_groups);
 804
 805     let max_name_len = plugin.iter()
 806                              .chain(&builtin)
 807                              .map(|&s| s.name.chars().count())
 808                              .max()
 809                              .unwrap_or(0);
 810     let padded = |x: &str| {
 811         let mut s = repeat(" ")
 812                         .take(max_name_len - x.chars().count())
 813                         .collect::<String>();
 814         s.push_str(x);
 815         s
 816     };
 817
 818     println!("Lint checks provided by rustc:\n");
 819     println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
 820     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
 821
 822     let print_lints = |lints: Vec<&Lint>| {
 823         for lint in lints {
 824             let name = lint.name_lower().replace("_", "-");
 825             println!("    {}  {:7.7}  {}",
 826                      padded(&name[..]),
 827                      lint.default_level.as_str(),
 828                      lint.desc);
 829         }
 830         println!("\n");
 831     };
 832
 833     print_lints(builtin);
 834
 835
 836
 837     let max_name_len = max("warnings".len(),
 838                            plugin_groups.iter()
 839                                         .chain(&builtin_groups)
 840                                         .map(|&(s, _)| s.chars().count())
 841                                         .max()
 842                                         .unwrap_or(0));
 843
 844     let padded = |x: &str| {
 845         let mut s = repeat(" ")
 846                         .take(max_name_len - x.chars().count())
 847                         .collect::<String>();
 848         s.push_str(x);
 849         s
 850     };
 851
 852     println!("Lint groups provided by rustc:\n");
 853     println!("    {}  {}", padded("name"), "sub-lints");
 854     println!("    {}  {}", padded("----"), "---------");
 855     println!("    {}  {}", padded("warnings"), "all built-in lints");
 856
 857     let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
 858         for (name, to) in lints {
 859             let name = name.to_lowercase().replace("_", "-");
 860             let desc = to.into_iter()
 861                          .map(|x| x.to_string().replace("_", "-"))
 862                          .collect::<Vec<String>>()
 863                          .join(", ");
 864             println!("    {}  {}", padded(&name[..]), desc);
 865         }
 866         println!("\n");
 867     };
 868
 869     print_lint_groups(builtin_groups);
 870
 871     match (loaded_plugins, plugin.len(), plugin_groups.len()) {
 872         (false, 0, _) | (false, _, 0) => {
 873             println!("Compiler plugins can provide additional lints and lint groups. To see a \
 874                       listing of these, re-run `rustc -W help` with a crate filename.");
 875         }
 876         (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
 877         (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
 878         (true, l, g) => {
 879             if l > 0 {
 880                 println!("Lint checks provided by plugins loaded by this crate:\n");
 881                 print_lints(plugin);
 882             }
 883             if g > 0 {
 884                 println!("Lint groups provided by plugins loaded by this crate:\n");
 885                 print_lint_groups(plugin_groups);
 886             }
 887         }
 888     }
 889 }
 890
 891 fn describe_debug_flags() {
 892     println!("\nAvailable debug options:\n");
 893     print_flag_list("-Z", config::DB_OPTIONS);
 894 }
 895
 896 fn describe_codegen_flags() {
 897     println!("\nAvailable codegen options:\n");
 898     print_flag_list("-C", config::CG_OPTIONS);
 899 }
 900
 901 fn print_flag_list<T>(cmdline_opt: &str,
 902                       flag_list: &[(&'static str, T, Option<&'static str>, &'static str)]) {
 903     let max_len = flag_list.iter()
 904                            .map(|&(name, _, opt_type_desc, _)| {
 905                                let extra_len = match opt_type_desc {
 906                                    Some(..) => 4,
 907                                    None => 0,
 908                                };
 909                                name.chars().count() + extra_len
 910                            })
 911                            .max()
 912                            .unwrap_or(0);
 913
 914     for &(name, _, opt_type_desc, desc) in flag_list {
 915         let (width, extra) = match opt_type_desc {
 916             Some(..) => (max_len - 4, "=val"),
 917             None => (max_len, ""),
 918         };
 919         println!("    {} {:>width$}{} -- {}",
 920                  cmdline_opt,
 921                  name.replace("_", "-"),
 922                  extra,
 923                  desc,
 924                  width = width);
 925     }
 926 }
 927
 928 /// Process command line options. Emits messages as appropriate. If compilation
 929 /// should continue, returns a getopts::Matches object parsed from args,
 930 /// otherwise returns None.
 931 ///
 932 /// The compiler's handling of options is a little complication as it ties into
 933 /// our stability story, and it's even *more* complicated by historical
 934 /// accidents. The current intention of each compiler option is to have one of
 935 /// three modes:
 936 ///
 937 /// 1. An option is stable and can be used everywhere.
 938 /// 2. An option is unstable, but was historically allowed on the stable
 939 ///    channel.
 940 /// 3. An option is unstable, and can only be used on nightly.
 941 ///
 942 /// Like unstable library and language features, however, unstable options have
 943 /// always required a form of "opt in" to indicate that you're using them. This
 944 /// provides the easy ability to scan a code base to check to see if anything
 945 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
 946 ///
 947 /// All options behind `-Z` are considered unstable by default. Other top-level
 948 /// options can also be considered unstable, and they were unlocked through the
 949 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
 950 /// instability in both cases, though.
 951 ///
 952 /// So with all that in mind, the comments below have some more detail about the
 953 /// contortions done here to get things to work out correctly.
 954 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
 955     // Throw away the first argument, the name of the binary
 956     let args = &args[1..];
 957
 958     if args.is_empty() {
 959         // user did not write `-v` nor `-Z unstable-options`, so do not
 960         // include that extra information.
 961         usage(false, false);
 962         return None;
 963     }
 964
 965     // Parse with *all* options defined in the compiler, we don't worry about
 966     // option stability here we just want to parse as much as possible.
 967     let all_groups: Vec<getopts::OptGroup> = config::rustc_optgroups()
 968                                                  .into_iter()
 969                                                  .map(|x| x.opt_group)
 970                                                  .collect();
 971     let matches = match getopts::getopts(&args[..], &all_groups) {
 972         Ok(m) => m,
 973         Err(f) => early_error(ErrorOutputType::default(), &f.to_string()),
 974     };
 975
 976     // For all options we just parsed, we check a few aspects:
 977     //
 978     // * If the option is stable, we're all good
 979     // * If the option wasn't passed, we're all good
 980     // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
 981     //   ourselves), then we require the `-Z unstable-options` flag to unlock
 982     //   this option that was passed.
 983     // * If we're a nightly compiler, then unstable options are now unlocked, so
 984     //   we're good to go.
 985     // * Otherwise, if we're a truly unstable option then we generate an error
 986     //   (unstable option being used on stable)
 987     // * If we're a historically stable-but-should-be-unstable option then we
 988     //   emit a warning that we're going to turn this into an error soon.
 989     nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
 990
 991     if matches.opt_present("h") || matches.opt_present("help") {
 992         // Only show unstable options in --help if we *really* accept unstable
 993         // options, which catches the case where we got `-Z unstable-options` on
 994         // the stable channel of Rust which was accidentally allowed
 995         // historically.
 996         usage(matches.opt_present("verbose"),
 997               nightly_options::is_unstable_enabled(&matches));
 998         return None;
 999     }
1000
1001     // Don't handle -W help here, because we might first load plugins.
1002     let r = matches.opt_strs("Z");
1003     if r.iter().any(|x| *x == "help") {
1004         describe_debug_flags();
1005         return None;
1006     }
1007
1008     let cg_flags = matches.opt_strs("C");
1009     if cg_flags.iter().any(|x| *x == "help") {
1010         describe_codegen_flags();
1011         return None;
1012     }
1013
1014     if cg_flags.contains(&"passes=list".to_string()) {
1015         unsafe {
1016             ::llvm::LLVMRustPrintPasses();
1017         }
1018         return None;
1019     }
1020
1021     if matches.opt_present("version") {
1022         version("rustc", &matches);
1023         return None;
1024     }
1025
1026     Some(matches)
1027 }
1028
1029 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1030     match *input {
1031         Input::File(ref ifile) => {
1032             parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess)
1033         }
1034         Input::Str { ref name, ref input } => {
1035             parse::parse_crate_attrs_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
1036         }
1037     }
1038 }
1039
1040 /// Run a procedure which will detect panics in the compiler and print nicer
1041 /// error messages rather than just failing the test.
1042 ///
1043 /// The diagnostic emitter yielded to the procedure should be used for reporting
1044 /// errors of the compiler.
1045 pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
1046     // Temporarily have stack size set to 16MB to deal with nom-using crates failing
1047     const STACK_SIZE: usize = 16 * 1024 * 1024; // 16MB
1048
1049     struct Sink(Arc<Mutex<Vec<u8>>>);
1050     impl Write for Sink {
1051         fn write(&mut self, data: &[u8]) -> io::Result<usize> {
1052             Write::write(&mut *self.0.lock().unwrap(), data)
1053         }
1054         fn flush(&mut self) -> io::Result<()> {
1055             Ok(())
1056         }
1057     }
1058
1059     let data = Arc::new(Mutex::new(Vec::new()));
1060     let err = Sink(data.clone());
1061
1062     let mut cfg = thread::Builder::new().name("rustc".to_string());
1063
1064     // FIXME: Hacks on hacks. If the env is trying to override the stack size
1065     // then *don't* set it explicitly.
1066     if env::var_os("RUST_MIN_STACK").is_none() {
1067         cfg = cfg.stack_size(STACK_SIZE);
1068     }
1069
1070     let thread = cfg.spawn(move || {
1071          io::set_panic(Some(box err));
1072          f()
1073      });
1074
1075      if let Err(value) = thread.unwrap().join() {
1076         // Thread panicked without emitting a fatal diagnostic
1077         if !value.is::<errors::FatalError>() {
1078             let emitter =
1079                 Box::new(errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None));
1080             let handler = errors::Handler::with_emitter(true, false, emitter);
1081
1082             // a .span_bug or .bug call has already printed what
1083             // it wants to print.
1084             if !value.is::<errors::ExplicitBug>() {
1085                 handler.emit(&MultiSpan::new(),
1086                              "unexpected panic",
1087                              errors::Level::Bug);
1088             }
1089
1090             let xs = ["the compiler unexpectedly panicked. this is a bug.".to_string(),
1091                       format!("we would appreciate a bug report: {}", BUG_REPORT_URL)];
1092             for note in &xs {
1093                 handler.emit(&MultiSpan::new(),
1094                              &note[..],
1095                              errors::Level::Note);
1096             }
1097             if match env::var_os("RUST_BACKTRACE") {
1098                 Some(val) => &val != "0",
1099                 None => false,
1100             } {
1101                 handler.emit(&MultiSpan::new(),
1102                              "run with `RUST_BACKTRACE=1` for a backtrace",
1103                              errors::Level::Note);
1104             }
1105
1106             writeln!(io::stderr(), "{}", str::from_utf8(&data.lock().unwrap()).unwrap()).unwrap();
1107         }
1108
1109         exit_on_err();
1110     }
1111 }
1112
1113 fn exit_on_err() -> ! {
1114     // Panic so the process returns a failure code, but don't pollute the
1115     // output with some unnecessary panic messages, we've already
1116     // printed everything that we needed to.
1117     io::set_panic(Some(box io::sink()));
1118     panic!();
1119 }
1120
1121 pub fn diagnostics_registry() -> errors::registry::Registry {
1122     use errors::registry::Registry;
1123
1124     let mut all_errors = Vec::new();
1125     all_errors.extend_from_slice(&rustc::DIAGNOSTICS);
1126     all_errors.extend_from_slice(&rustc_typeck::DIAGNOSTICS);
1127     all_errors.extend_from_slice(&rustc_borrowck::DIAGNOSTICS);
1128     all_errors.extend_from_slice(&rustc_resolve::DIAGNOSTICS);
1129     all_errors.extend_from_slice(&rustc_privacy::DIAGNOSTICS);
1130     all_errors.extend_from_slice(&rustc_trans::DIAGNOSTICS);
1131     all_errors.extend_from_slice(&rustc_const_eval::DIAGNOSTICS);
1132     all_errors.extend_from_slice(&rustc_metadata::DIAGNOSTICS);
1133
1134     Registry::new(&all_errors)
1135 }
1136
1137 pub fn main() {
1138     let result = run(|| run_compiler(&env::args().collect::<Vec<_>>(),
1139                                      &mut RustcDefaultCalls,
1140                                      None,
1141                                      None));
1142     process::exit(result as i32);
1143 }