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 #![crate_type = "dylib"]
  19 #![crate_type = "rlib"]
  20 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
  21       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
  22       html_root_url = "https://doc.rust-lang.org/nightly/")]
  23 #![deny(warnings)]
  24
  25 #![feature(box_syntax)]
  26 #![feature(loop_break_value)]
  27 #![feature(libc)]
  28 #![feature(quote)]
  29 #![feature(rustc_diagnostic_macros)]
  30 #![feature(set_stdio)]
  31
  32 #![cfg_attr(stage0, unstable(feature = "rustc_private", issue = "27812"))]
  33 #![cfg_attr(stage0, feature(rustc_private))]
  34 #![cfg_attr(stage0, feature(staged_api))]
  35
  36 extern crate arena;
  37 extern crate getopts;
  38 extern crate graphviz;
  39 extern crate env_logger;
  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 extern crate syntax;
  63 extern crate syntax_ext;
  64 extern crate syntax_pos;
  65
  66 use driver::CompileController;
  67 use pretty::{PpMode, UserIdentifiedItem};
  68
  69 use rustc_resolve as resolve;
  70 use rustc_save_analysis as save;
  71 use rustc_save_analysis::DumpHandler;
  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, early_warn};
  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 serialize::json::ToJson;
  86
  87 use std::any::Any;
  88 use std::cmp::max;
  89 use std::cmp::Ordering::Equal;
  90 use std::default::Default;
  91 use std::env;
  92 use std::io::{self, Read, Write};
  93 use std::iter::repeat;
  94 use std::path::PathBuf;
  95 use std::process;
  96 use std::rc::Rc;
  97 use std::str;
  98 use std::sync::{Arc, Mutex};
  99 use std::thread;
 100
 101 use syntax::ast;
 102 use syntax::codemap::{CodeMap, FileLoader, RealFileLoader};
 103 use syntax::feature_gate::{GatedCfg, UnstableFeatures};
 104 use syntax::parse::{self, PResult};
 105 use syntax_pos::{DUMMY_SP, MultiSpan};
 106
 107 #[cfg(test)]
 108 pub mod test;
 109
 110 pub mod driver;
 111 pub mod pretty;
 112 pub mod target_features;
 113 mod derive_registrar;
 114
 115 const BUG_REPORT_URL: &'static str = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.\
 116                                       md#bug-reports";
 117
 118 #[inline]
 119 fn abort_msg(err_count: usize) -> String {
 120     match err_count {
 121         0 => "aborting with no errors (maybe a bug?)".to_owned(),
 122         1 => "aborting due to previous error".to_owned(),
 123         e => format!("aborting due to {} previous errors", e),
 124     }
 125 }
 126
 127 pub fn abort_on_err<T>(result: Result<T, usize>, sess: &Session) -> T {
 128     match result {
 129         Err(err_count) => {
 130             sess.fatal(&abort_msg(err_count));
 131         }
 132         Ok(x) => x,
 133     }
 134 }
 135
 136 pub fn run<F>(run_compiler: F) -> isize
 137     where F: FnOnce() -> (CompileResult, Option<Session>) + Send + 'static
 138 {
 139     monitor(move || {
 140         let (result, session) = run_compiler();
 141         if let Err(err_count) = result {
 142             if err_count > 0 {
 143                 match session {
 144                     Some(sess) => sess.fatal(&abort_msg(err_count)),
 145                     None => {
 146                         let emitter =
 147                             errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None);
 148                         let handler = errors::Handler::with_emitter(true, false, Box::new(emitter));
 149                         handler.emit(&MultiSpan::new(),
 150                                      &abort_msg(err_count),
 151                                      errors::Level::Fatal);
 152                         exit_on_err();
 153                     }
 154                 }
 155             }
 156         }
 157     });
 158     0
 159 }
 160
 161 // Parse args and run the compiler. This is the primary entry point for rustc.
 162 // See comments on CompilerCalls below for details about the callbacks argument.
 163 // The FileLoader provides a way to load files from sources other than the file system.
 164 pub fn run_compiler<'a>(args: &[String],
 165                         callbacks: &mut CompilerCalls<'a>,
 166                         file_loader: Option<Box<FileLoader + 'static>>,
 167                         emitter_dest: Option<Box<Write + Send>>)
 168                         -> (CompileResult, Option<Session>)
 169 {
 170     macro_rules! do_or_return {($expr: expr, $sess: expr) => {
 171         match $expr {
 172             Compilation::Stop => return (Ok(()), $sess),
 173             Compilation::Continue => {}
 174         }
 175     }}
 176
 177     let matches = match handle_options(args) {
 178         Some(matches) => matches,
 179         None => return (Ok(()), None),
 180     };
 181
 182     let (sopts, cfg) = config::build_session_options_and_crate_config(&matches);
 183
 184     if sopts.debugging_opts.debug_llvm {
 185         unsafe { llvm::LLVMRustSetDebug(1); }
 186     }
 187
 188     let descriptions = diagnostics_registry();
 189
 190     do_or_return!(callbacks.early_callback(&matches,
 191                                            &sopts,
 192                                            &cfg,
 193                                            &descriptions,
 194                                            sopts.error_format),
 195                                            None);
 196
 197     let (odir, ofile) = make_output(&matches);
 198     let (input, input_file_path) = match make_input(&matches.free) {
 199         Some((input, input_file_path)) => callbacks.some_input(input, input_file_path),
 200         None => match callbacks.no_input(&matches, &sopts, &cfg, &odir, &ofile, &descriptions) {
 201             Some((input, input_file_path)) => (input, input_file_path),
 202             None => return (Ok(()), None),
 203         },
 204     };
 205
 206     let dep_graph = DepGraph::new(sopts.build_dep_graph());
 207     let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
 208
 209     let loader = file_loader.unwrap_or(box RealFileLoader);
 210     let codemap = Rc::new(CodeMap::with_file_loader(loader, sopts.file_path_mapping()));
 211     let mut sess = session::build_session_with_codemap(
 212         sopts, &dep_graph, input_file_path, descriptions, cstore.clone(), codemap, emitter_dest,
 213     );
 214     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 215
 216     let mut cfg = config::build_configuration(&sess, cfg);
 217     target_features::add_configuration(&mut cfg, &sess);
 218     sess.parse_sess.config = cfg;
 219
 220     do_or_return!(callbacks.late_callback(&matches, &sess, &input, &odir, &ofile), Some(sess));
 221
 222     let plugins = sess.opts.debugging_opts.extra_plugins.clone();
 223     let control = callbacks.build_controller(&sess, &matches);
 224     (driver::compile_input(&sess, &cstore, &input, &odir, &ofile, Some(plugins), &control),
 225      Some(sess))
 226 }
 227
 228 // Extract output directory and file from matches.
 229 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
 230     let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
 231     let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
 232     (odir, ofile)
 233 }
 234
 235 // Extract input (string or file and optional path) from matches.
 236 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>)> {
 237     if free_matches.len() == 1 {
 238         let ifile = &free_matches[0];
 239         if ifile == "-" {
 240             let mut src = String::new();
 241             io::stdin().read_to_string(&mut src).unwrap();
 242             Some((Input::Str { name: driver::anon_src(), input: src },
 243                   None))
 244         } else {
 245             Some((Input::File(PathBuf::from(ifile)),
 246                   Some(PathBuf::from(ifile))))
 247         }
 248     } else {
 249         None
 250     }
 251 }
 252
 253 fn parse_pretty(sess: &Session,
 254                 matches: &getopts::Matches)
 255                 -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 256     let pretty = if sess.opts.debugging_opts.unstable_options {
 257         matches.opt_default("pretty", "normal").map(|a| {
 258             // stable pretty-print variants only
 259             pretty::parse_pretty(sess, &a, false)
 260         })
 261     } else {
 262         None
 263     };
 264     if pretty.is_none() && sess.unstable_options() {
 265         matches.opt_str("unpretty").map(|a| {
 266             // extended with unstable pretty-print variants
 267             pretty::parse_pretty(sess, &a, true)
 268         })
 269     } else {
 270         pretty
 271     }
 272 }
 273
 274 // Whether to stop or continue compilation.
 275 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 276 pub enum Compilation {
 277     Stop,
 278     Continue,
 279 }
 280
 281 impl Compilation {
 282     pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
 283         match self {
 284             Compilation::Stop => Compilation::Stop,
 285             Compilation::Continue => next(),
 286         }
 287     }
 288 }
 289
 290 // A trait for customising the compilation process. Offers a number of hooks for
 291 // executing custom code or customising input.
 292 pub trait CompilerCalls<'a> {
 293     // Hook for a callback early in the process of handling arguments. This will
 294     // be called straight after options have been parsed but before anything
 295     // else (e.g., selecting input and output).
 296     fn early_callback(&mut self,
 297                       _: &getopts::Matches,
 298                       _: &config::Options,
 299                       _: &ast::CrateConfig,
 300                       _: &errors::registry::Registry,
 301                       _: ErrorOutputType)
 302                       -> Compilation {
 303         Compilation::Continue
 304     }
 305
 306     // Hook for a callback late in the process of handling arguments. This will
 307     // be called just before actual compilation starts (and before build_controller
 308     // is called), after all arguments etc. have been completely handled.
 309     fn late_callback(&mut self,
 310                      _: &getopts::Matches,
 311                      _: &Session,
 312                      _: &Input,
 313                      _: &Option<PathBuf>,
 314                      _: &Option<PathBuf>)
 315                      -> Compilation {
 316         Compilation::Continue
 317     }
 318
 319     // Called after we extract the input from the arguments. Gives the implementer
 320     // an opportunity to change the inputs or to add some custom input handling.
 321     // The default behaviour is to simply pass through the inputs.
 322     fn some_input(&mut self,
 323                   input: Input,
 324                   input_path: Option<PathBuf>)
 325                   -> (Input, Option<PathBuf>) {
 326         (input, input_path)
 327     }
 328
 329     // Called after we extract the input from the arguments if there is no valid
 330     // input. Gives the implementer an opportunity to supply alternate input (by
 331     // returning a Some value) or to add custom behaviour for this error such as
 332     // emitting error messages. Returning None will cause compilation to stop
 333     // at this point.
 334     fn no_input(&mut self,
 335                 _: &getopts::Matches,
 336                 _: &config::Options,
 337                 _: &ast::CrateConfig,
 338                 _: &Option<PathBuf>,
 339                 _: &Option<PathBuf>,
 340                 _: &errors::registry::Registry)
 341                 -> Option<(Input, Option<PathBuf>)> {
 342         None
 343     }
 344
 345     // Create a CompilController struct for controlling the behaviour of
 346     // compilation.
 347     fn build_controller(&mut self, _: &Session, _: &getopts::Matches) -> CompileController<'a>;
 348 }
 349
 350 // CompilerCalls instance for a regular rustc build.
 351 #[derive(Copy, Clone)]
 352 pub struct RustcDefaultCalls;
 353
 354 fn handle_explain(code: &str,
 355                   descriptions: &errors::registry::Registry,
 356                   output: ErrorOutputType) {
 357     let normalised = if code.starts_with("E") {
 358         code.to_string()
 359     } else {
 360         format!("E{0:0>4}", code)
 361     };
 362     match descriptions.find_description(&normalised) {
 363         Some(ref description) => {
 364             // Slice off the leading newline and print.
 365             print!("{}", &(&description[1..]).split("\n").map(|x| {
 366                 format!("{}\n", if x.starts_with("```") {
 367                     "```"
 368                 } else {
 369                     x
 370                 })
 371             }).collect::<String>());
 372         }
 373         None => {
 374             early_error(output, &format!("no extended information for {}", code));
 375         }
 376     }
 377 }
 378
 379 impl<'a> CompilerCalls<'a> for RustcDefaultCalls {
 380     fn early_callback(&mut self,
 381                       matches: &getopts::Matches,
 382                       _: &config::Options,
 383                       _: &ast::CrateConfig,
 384                       descriptions: &errors::registry::Registry,
 385                       output: ErrorOutputType)
 386                       -> Compilation {
 387         if let Some(ref code) = matches.opt_str("explain") {
 388             handle_explain(code, descriptions, output);
 389             return Compilation::Stop;
 390         }
 391
 392         Compilation::Continue
 393     }
 394
 395     fn no_input(&mut self,
 396                 matches: &getopts::Matches,
 397                 sopts: &config::Options,
 398                 cfg: &ast::CrateConfig,
 399                 odir: &Option<PathBuf>,
 400                 ofile: &Option<PathBuf>,
 401                 descriptions: &errors::registry::Registry)
 402                 -> Option<(Input, Option<PathBuf>)> {
 403         match matches.free.len() {
 404             0 => {
 405                 if sopts.describe_lints {
 406                     let mut ls = lint::LintStore::new();
 407                     rustc_lint::register_builtins(&mut ls, None);
 408                     describe_lints(&ls, false);
 409                     return None;
 410                 }
 411                 let dep_graph = DepGraph::new(sopts.build_dep_graph());
 412                 let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
 413                 let mut sess = build_session(sopts.clone(),
 414                     &dep_graph,
 415                     None,
 416                     descriptions.clone(),
 417                     cstore.clone());
 418                 rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 419                 let mut cfg = config::build_configuration(&sess, cfg.clone());
 420                 target_features::add_configuration(&mut cfg, &sess);
 421                 sess.parse_sess.config = cfg;
 422                 let should_stop =
 423                     RustcDefaultCalls::print_crate_info(&sess, None, odir, ofile);
 424
 425                 if should_stop == Compilation::Stop {
 426                     return None;
 427                 }
 428                 early_error(sopts.error_format, "no input filename given");
 429             }
 430             1 => panic!("make_input should have provided valid inputs"),
 431             _ => early_error(sopts.error_format, "multiple input filenames provided"),
 432         }
 433     }
 434
 435     fn late_callback(&mut self,
 436                      matches: &getopts::Matches,
 437                      sess: &Session,
 438                      input: &Input,
 439                      odir: &Option<PathBuf>,
 440                      ofile: &Option<PathBuf>)
 441                      -> Compilation {
 442         RustcDefaultCalls::print_crate_info(sess, Some(input), odir, ofile)
 443             .and_then(|| RustcDefaultCalls::list_metadata(sess, matches, input))
 444     }
 445
 446     fn build_controller(&mut self,
 447                         sess: &Session,
 448                         matches: &getopts::Matches)
 449                         -> CompileController<'a> {
 450         let mut control = CompileController::basic();
 451
 452         if let Some((ppm, opt_uii)) = parse_pretty(sess, matches) {
 453             if ppm.needs_ast_map(&opt_uii) {
 454                 control.after_hir_lowering.stop = Compilation::Stop;
 455
 456                 control.after_parse.callback = box move |state| {
 457                     state.krate = Some(pretty::fold_crate(state.krate.take().unwrap(), ppm));
 458                 };
 459                 control.after_hir_lowering.callback = box move |state| {
 460                     pretty::print_after_hir_lowering(state.session,
 461                                                      state.hir_map.unwrap(),
 462                                                      state.analysis.unwrap(),
 463                                                      state.resolutions.unwrap(),
 464                                                      state.input,
 465                                                      &state.expanded_crate.take().unwrap(),
 466                                                      state.crate_name.unwrap(),
 467                                                      ppm,
 468                                                      state.arena.unwrap(),
 469                                                      state.arenas.unwrap(),
 470                                                      opt_uii.clone(),
 471                                                      state.out_file);
 472                 };
 473             } else {
 474                 control.after_parse.stop = Compilation::Stop;
 475
 476                 control.after_parse.callback = box move |state| {
 477                     let krate = pretty::fold_crate(state.krate.take().unwrap(), ppm);
 478                     pretty::print_after_parsing(state.session,
 479                                                 state.input,
 480                                                 &krate,
 481                                                 ppm,
 482                                                 state.out_file);
 483                 };
 484             }
 485
 486             return control;
 487         }
 488
 489         if sess.opts.debugging_opts.parse_only ||
 490            sess.opts.debugging_opts.show_span.is_some() ||
 491            sess.opts.debugging_opts.ast_json_noexpand {
 492             control.after_parse.stop = Compilation::Stop;
 493         }
 494
 495         if sess.opts.debugging_opts.no_analysis ||
 496            sess.opts.debugging_opts.ast_json {
 497             control.after_hir_lowering.stop = Compilation::Stop;
 498         }
 499
 500         if !sess.opts.output_types.keys().any(|&i| i == OutputType::Exe ||
 501                                                    i == OutputType::Metadata) {
 502             control.after_llvm.stop = Compilation::Stop;
 503         }
 504
 505         if save_analysis(sess) {
 506             control.after_analysis.callback = box |state| {
 507                 time(state.session.time_passes(), "save analysis", || {
 508                     save::process_crate(state.tcx.unwrap(),
 509                                         state.expanded_crate.unwrap(),
 510                                         state.analysis.unwrap(),
 511                                         state.crate_name.unwrap(),
 512                                         DumpHandler::new(save_analysis_format(state.session),
 513                                                          state.out_dir,
 514                                                          state.crate_name.unwrap()))
 515                 });
 516             };
 517             control.after_analysis.run_callback_on_error = true;
 518             control.make_glob_map = resolve::MakeGlobMap::Yes;
 519         }
 520
 521         if sess.print_fuel_crate.is_some() {
 522             let old_callback = control.compilation_done.callback;
 523             control.compilation_done.callback = box move |state| {
 524                 old_callback(state);
 525                 let sess = state.session;
 526                 println!("Fuel used by {}: {}",
 527                     sess.print_fuel_crate.as_ref().unwrap(),
 528                     sess.print_fuel.get());
 529             }
 530         }
 531         control
 532     }
 533 }
 534
 535 fn save_analysis(sess: &Session) -> bool {
 536     sess.opts.debugging_opts.save_analysis ||
 537     sess.opts.debugging_opts.save_analysis_csv ||
 538     sess.opts.debugging_opts.save_analysis_api
 539 }
 540
 541 fn save_analysis_format(sess: &Session) -> save::Format {
 542     if sess.opts.debugging_opts.save_analysis {
 543         save::Format::Json
 544     } else if sess.opts.debugging_opts.save_analysis_csv {
 545         save::Format::Csv
 546     } else if sess.opts.debugging_opts.save_analysis_api {
 547         save::Format::JsonApi
 548     } else {
 549         unreachable!();
 550     }
 551 }
 552
 553 impl RustcDefaultCalls {
 554     pub fn list_metadata(sess: &Session, matches: &getopts::Matches, input: &Input) -> Compilation {
 555         let r = matches.opt_strs("Z");
 556         if r.contains(&("ls".to_string())) {
 557             match input {
 558                 &Input::File(ref ifile) => {
 559                     let path = &(*ifile);
 560                     let mut v = Vec::new();
 561                     locator::list_file_metadata(&sess.target.target,
 562                                                 path,
 563                                                 sess.cstore.metadata_loader(),
 564                                                 &mut v)
 565                             .unwrap();
 566                     println!("{}", String::from_utf8(v).unwrap());
 567                 }
 568                 &Input::Str { .. } => {
 569                     early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
 570                 }
 571             }
 572             return Compilation::Stop;
 573         }
 574
 575         return Compilation::Continue;
 576     }
 577
 578
 579     fn print_crate_info(sess: &Session,
 580                         input: Option<&Input>,
 581                         odir: &Option<PathBuf>,
 582                         ofile: &Option<PathBuf>)
 583                         -> Compilation {
 584         if sess.opts.prints.is_empty() {
 585             return Compilation::Continue;
 586         }
 587
 588         let attrs = match input {
 589             None => None,
 590             Some(input) => {
 591                 let result = parse_crate_attrs(sess, input);
 592                 match result {
 593                     Ok(attrs) => Some(attrs),
 594                     Err(mut parse_error) => {
 595                         parse_error.emit();
 596                         return Compilation::Stop;
 597                     }
 598                 }
 599             }
 600         };
 601         for req in &sess.opts.prints {
 602             match *req {
 603                 PrintRequest::TargetList => {
 604                     let mut targets = rustc_back::target::get_targets().collect::<Vec<String>>();
 605                     targets.sort();
 606                     println!("{}", targets.join("\n"));
 607                 },
 608                 PrintRequest::Sysroot => println!("{}", sess.sysroot().display()),
 609                 PrintRequest::TargetSpec => println!("{}", sess.target.target.to_json().pretty()),
 610                 PrintRequest::FileNames |
 611                 PrintRequest::CrateName => {
 612                     let input = match input {
 613                         Some(input) => input,
 614                         None => early_error(ErrorOutputType::default(), "no input file provided"),
 615                     };
 616                     let attrs = attrs.as_ref().unwrap();
 617                     let t_outputs = driver::build_output_filenames(input, odir, ofile, attrs, sess);
 618                     let id = link::find_crate_name(Some(sess), attrs, input);
 619                     if *req == PrintRequest::CrateName {
 620                         println!("{}", id);
 621                         continue;
 622                     }
 623                     let crate_types = driver::collect_crate_types(sess, attrs);
 624                     for &style in &crate_types {
 625                         let fname = link::filename_for_input(sess, style, &id, &t_outputs);
 626                         println!("{}",
 627                                  fname.file_name()
 628                                       .unwrap()
 629                                       .to_string_lossy());
 630                     }
 631                 }
 632                 PrintRequest::Cfg => {
 633                     let allow_unstable_cfg = UnstableFeatures::from_environment()
 634                         .is_nightly_build();
 635
 636                     let mut cfgs = Vec::new();
 637                     for &(name, ref value) in sess.parse_sess.config.iter() {
 638                         let gated_cfg = GatedCfg::gate(&ast::MetaItem {
 639                             name: name,
 640                             node: ast::MetaItemKind::Word,
 641                             span: DUMMY_SP,
 642                         });
 643
 644                         // Note that crt-static is a specially recognized cfg
 645                         // directive that's printed out here as part of
 646                         // rust-lang/rust#37406, but in general the
 647                         // `target_feature` cfg is gated under
 648                         // rust-lang/rust#29717. For now this is just
 649                         // specifically allowing the crt-static cfg and that's
 650                         // it, this is intended to get into Cargo and then go
 651                         // through to build scripts.
 652                         let value = value.as_ref().map(|s| s.as_str());
 653                         let value = value.as_ref().map(|s| s.as_ref());
 654                         if name != "target_feature" || value != Some("crt-static") {
 655                             if !allow_unstable_cfg && gated_cfg.is_some() {
 656                                 continue;
 657                             }
 658                         }
 659
 660                         cfgs.push(if let Some(value) = value {
 661                             format!("{}=\"{}\"", name, value)
 662                         } else {
 663                             format!("{}", name)
 664                         });
 665                     }
 666
 667                     cfgs.sort();
 668                     for cfg in cfgs {
 669                         println!("{}", cfg);
 670                     }
 671                 }
 672                 PrintRequest::TargetCPUs => {
 673                     let tm = create_target_machine(sess);
 674                     unsafe { llvm::LLVMRustPrintTargetCPUs(tm); }
 675                 }
 676                 PrintRequest::TargetFeatures => {
 677                     let tm = create_target_machine(sess);
 678                     unsafe { llvm::LLVMRustPrintTargetFeatures(tm); }
 679                 }
 680                 PrintRequest::RelocationModels => {
 681                     println!("Available relocation models:");
 682                     for &(name, _) in RELOC_MODEL_ARGS.iter() {
 683                         println!("    {}", name);
 684                     }
 685                     println!("");
 686                 }
 687                 PrintRequest::CodeModels => {
 688                     println!("Available code models:");
 689                     for &(name, _) in CODE_GEN_MODEL_ARGS.iter(){
 690                         println!("    {}", name);
 691                     }
 692                     println!("");
 693                 }
 694             }
 695         }
 696         return Compilation::Stop;
 697     }
 698 }
 699
 700 /// Returns a version string such as "0.12.0-dev".
 701 pub fn release_str() -> Option<&'static str> {
 702     option_env!("CFG_RELEASE")
 703 }
 704
 705 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 706 pub fn commit_hash_str() -> Option<&'static str> {
 707     option_env!("CFG_VER_HASH")
 708 }
 709
 710 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 711 pub fn commit_date_str() -> Option<&'static str> {
 712     option_env!("CFG_VER_DATE")
 713 }
 714
 715 /// Prints version information
 716 pub fn version(binary: &str, matches: &getopts::Matches) {
 717     let verbose = matches.opt_present("verbose");
 718
 719     println!("{} {}",
 720              binary,
 721              option_env!("CFG_VERSION").unwrap_or("unknown version"));
 722     if verbose {
 723         fn unw(x: Option<&str>) -> &str {
 724             x.unwrap_or("unknown")
 725         }
 726         println!("binary: {}", binary);
 727         println!("commit-hash: {}", unw(commit_hash_str()));
 728         println!("commit-date: {}", unw(commit_date_str()));
 729         println!("host: {}", config::host_triple());
 730         println!("release: {}", unw(release_str()));
 731         unsafe {
 732             println!("LLVM version: {}.{}",
 733                      llvm::LLVMRustVersionMajor(), llvm::LLVMRustVersionMinor());
 734         }
 735     }
 736 }
 737
 738 fn usage(verbose: bool, include_unstable_options: bool) {
 739     let groups = if verbose {
 740         config::rustc_optgroups()
 741     } else {
 742         config::rustc_short_optgroups()
 743     };
 744     let groups: Vec<_> = groups.into_iter()
 745                                .filter(|x| include_unstable_options || x.is_stable())
 746                                .map(|x| x.opt_group)
 747                                .collect();
 748     let message = format!("Usage: rustc [OPTIONS] INPUT");
 749     let extra_help = if verbose {
 750         ""
 751     } else {
 752         "\n    --help -v           Print the full set of options rustc accepts"
 753     };
 754     println!("{}\nAdditional help:
 755     -C help             Print codegen options
 756     -W help             \
 757               Print 'lint' options and default settings
 758     -Z help             Print internal \
 759               options for debugging rustc{}\n",
 760              getopts::usage(&message, &groups),
 761              extra_help);
 762 }
 763
 764 fn describe_lints(lint_store: &lint::LintStore, loaded_plugins: bool) {
 765     println!("
 766 Available lint options:
 767     -W <foo>           Warn about <foo>
 768     -A <foo>           \
 769               Allow <foo>
 770     -D <foo>           Deny <foo>
 771     -F <foo>           Forbid <foo> \
 772               (deny <foo> and all attempts to override)
 773
 774 ");
 775
 776     fn sort_lints(lints: Vec<(&'static Lint, bool)>) -> Vec<&'static Lint> {
 777         let mut lints: Vec<_> = lints.into_iter().map(|(x, _)| x).collect();
 778         lints.sort_by(|x: &&Lint, y: &&Lint| {
 779             match x.default_level.cmp(&y.default_level) {
 780                 // The sort doesn't case-fold but it's doubtful we care.
 781                 Equal => x.name.cmp(y.name),
 782                 r => r,
 783             }
 784         });
 785         lints
 786     }
 787
 788     fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
 789                         -> Vec<(&'static str, Vec<lint::LintId>)> {
 790         let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
 791         lints.sort_by(|&(x, _): &(&'static str, Vec<lint::LintId>),
 792                        &(y, _): &(&'static str, Vec<lint::LintId>)| {
 793             x.cmp(y)
 794         });
 795         lints
 796     }
 797
 798     let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints()
 799                                                    .iter()
 800                                                    .cloned()
 801                                                    .partition(|&(_, p)| p);
 802     let plugin = sort_lints(plugin);
 803     let builtin = sort_lints(builtin);
 804
 805     let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups()
 806                                                                  .iter()
 807                                                                  .cloned()
 808                                                                  .partition(|&(.., p)| p);
 809     let plugin_groups = sort_lint_groups(plugin_groups);
 810     let builtin_groups = sort_lint_groups(builtin_groups);
 811
 812     let max_name_len = plugin.iter()
 813                              .chain(&builtin)
 814                              .map(|&s| s.name.chars().count())
 815                              .max()
 816                              .unwrap_or(0);
 817     let padded = |x: &str| {
 818         let mut s = repeat(" ")
 819                         .take(max_name_len - x.chars().count())
 820                         .collect::<String>();
 821         s.push_str(x);
 822         s
 823     };
 824
 825     println!("Lint checks provided by rustc:\n");
 826     println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
 827     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
 828
 829     let print_lints = |lints: Vec<&Lint>| {
 830         for lint in lints {
 831             let name = lint.name_lower().replace("_", "-");
 832             println!("    {}  {:7.7}  {}",
 833                      padded(&name),
 834                      lint.default_level.as_str(),
 835                      lint.desc);
 836         }
 837         println!("\n");
 838     };
 839
 840     print_lints(builtin);
 841
 842
 843
 844     let max_name_len = max("warnings".len(),
 845                            plugin_groups.iter()
 846                                         .chain(&builtin_groups)
 847                                         .map(|&(s, _)| s.chars().count())
 848                                         .max()
 849                                         .unwrap_or(0));
 850
 851     let padded = |x: &str| {
 852         let mut s = repeat(" ")
 853                         .take(max_name_len - x.chars().count())
 854                         .collect::<String>();
 855         s.push_str(x);
 856         s
 857     };
 858
 859     println!("Lint groups provided by rustc:\n");
 860     println!("    {}  {}", padded("name"), "sub-lints");
 861     println!("    {}  {}", padded("----"), "---------");
 862     println!("    {}  {}", padded("warnings"), "all built-in lints");
 863
 864     let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
 865         for (name, to) in lints {
 866             let name = name.to_lowercase().replace("_", "-");
 867             let desc = to.into_iter()
 868                          .map(|x| x.to_string().replace("_", "-"))
 869                          .collect::<Vec<String>>()
 870                          .join(", ");
 871             println!("    {}  {}", padded(&name), desc);
 872         }
 873         println!("\n");
 874     };
 875
 876     print_lint_groups(builtin_groups);
 877
 878     match (loaded_plugins, plugin.len(), plugin_groups.len()) {
 879         (false, 0, _) | (false, _, 0) => {
 880             println!("Compiler plugins can provide additional lints and lint groups. To see a \
 881                       listing of these, re-run `rustc -W help` with a crate filename.");
 882         }
 883         (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
 884         (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
 885         (true, l, g) => {
 886             if l > 0 {
 887                 println!("Lint checks provided by plugins loaded by this crate:\n");
 888                 print_lints(plugin);
 889             }
 890             if g > 0 {
 891                 println!("Lint groups provided by plugins loaded by this crate:\n");
 892                 print_lint_groups(plugin_groups);
 893             }
 894         }
 895     }
 896 }
 897
 898 fn describe_debug_flags() {
 899     println!("\nAvailable debug options:\n");
 900     print_flag_list("-Z", config::DB_OPTIONS);
 901 }
 902
 903 fn describe_codegen_flags() {
 904     println!("\nAvailable codegen options:\n");
 905     print_flag_list("-C", config::CG_OPTIONS);
 906 }
 907
 908 fn print_flag_list<T>(cmdline_opt: &str,
 909                       flag_list: &[(&'static str, T, Option<&'static str>, &'static str)]) {
 910     let max_len = flag_list.iter()
 911                            .map(|&(name, _, opt_type_desc, _)| {
 912                                let extra_len = match opt_type_desc {
 913                                    Some(..) => 4,
 914                                    None => 0,
 915                                };
 916                                name.chars().count() + extra_len
 917                            })
 918                            .max()
 919                            .unwrap_or(0);
 920
 921     for &(name, _, opt_type_desc, desc) in flag_list {
 922         let (width, extra) = match opt_type_desc {
 923             Some(..) => (max_len - 4, "=val"),
 924             None => (max_len, ""),
 925         };
 926         println!("    {} {:>width$}{} -- {}",
 927                  cmdline_opt,
 928                  name.replace("_", "-"),
 929                  extra,
 930                  desc,
 931                  width = width);
 932     }
 933 }
 934
 935 /// Process command line options. Emits messages as appropriate. If compilation
 936 /// should continue, returns a getopts::Matches object parsed from args,
 937 /// otherwise returns None.
 938 ///
 939 /// The compiler's handling of options is a little complicated as it ties into
 940 /// our stability story, and it's even *more* complicated by historical
 941 /// accidents. The current intention of each compiler option is to have one of
 942 /// three modes:
 943 ///
 944 /// 1. An option is stable and can be used everywhere.
 945 /// 2. An option is unstable, but was historically allowed on the stable
 946 ///    channel.
 947 /// 3. An option is unstable, and can only be used on nightly.
 948 ///
 949 /// Like unstable library and language features, however, unstable options have
 950 /// always required a form of "opt in" to indicate that you're using them. This
 951 /// provides the easy ability to scan a code base to check to see if anything
 952 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
 953 ///
 954 /// All options behind `-Z` are considered unstable by default. Other top-level
 955 /// options can also be considered unstable, and they were unlocked through the
 956 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
 957 /// instability in both cases, though.
 958 ///
 959 /// So with all that in mind, the comments below have some more detail about the
 960 /// contortions done here to get things to work out correctly.
 961 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
 962     // Throw away the first argument, the name of the binary
 963     let args = &args[1..];
 964
 965     if args.is_empty() {
 966         // user did not write `-v` nor `-Z unstable-options`, so do not
 967         // include that extra information.
 968         usage(false, false);
 969         return None;
 970     }
 971
 972     // Parse with *all* options defined in the compiler, we don't worry about
 973     // option stability here we just want to parse as much as possible.
 974     let all_groups: Vec<getopts::OptGroup> = config::rustc_optgroups()
 975                                                  .into_iter()
 976                                                  .map(|x| x.opt_group)
 977                                                  .collect();
 978     let matches = match getopts::getopts(&args, &all_groups) {
 979         Ok(m) => m,
 980         Err(f) => early_error(ErrorOutputType::default(), &f.to_string()),
 981     };
 982
 983     // For all options we just parsed, we check a few aspects:
 984     //
 985     // * If the option is stable, we're all good
 986     // * If the option wasn't passed, we're all good
 987     // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
 988     //   ourselves), then we require the `-Z unstable-options` flag to unlock
 989     //   this option that was passed.
 990     // * If we're a nightly compiler, then unstable options are now unlocked, so
 991     //   we're good to go.
 992     // * Otherwise, if we're a truly unstable option then we generate an error
 993     //   (unstable option being used on stable)
 994     // * If we're a historically stable-but-should-be-unstable option then we
 995     //   emit a warning that we're going to turn this into an error soon.
 996     nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
 997
 998     if matches.opt_present("h") || matches.opt_present("help") {
 999         // Only show unstable options in --help if we *really* accept unstable
1000         // options, which catches the case where we got `-Z unstable-options` on
1001         // the stable channel of Rust which was accidentally allowed
1002         // historically.
1003         usage(matches.opt_present("verbose"),
1004               nightly_options::is_unstable_enabled(&matches));
1005         return None;
1006     }
1007
1008     // Don't handle -W help here, because we might first load plugins.
1009     let r = matches.opt_strs("Z");
1010     if r.iter().any(|x| *x == "help") {
1011         describe_debug_flags();
1012         return None;
1013     }
1014
1015     let cg_flags = matches.opt_strs("C");
1016     if cg_flags.iter().any(|x| *x == "help") {
1017         describe_codegen_flags();
1018         return None;
1019     }
1020
1021     if cg_flags.iter().any(|x| *x == "no-stack-check") {
1022         early_warn(ErrorOutputType::default(),
1023                    "the --no-stack-check flag is deprecated and does nothing");
1024     }
1025
1026     if cg_flags.contains(&"passes=list".to_string()) {
1027         unsafe {
1028             ::llvm::LLVMRustPrintPasses();
1029         }
1030         return None;
1031     }
1032
1033     if matches.opt_present("version") {
1034         version("rustc", &matches);
1035         return None;
1036     }
1037
1038     Some(matches)
1039 }
1040
1041 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1042     match *input {
1043         Input::File(ref ifile) => {
1044             parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess)
1045         }
1046         Input::Str { ref name, ref input } => {
1047             parse::parse_crate_attrs_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
1048         }
1049     }
1050 }
1051
1052 /// Runs `f` in a suitable thread for running `rustc`; returns a
1053 /// `Result` with either the return value of `f` or -- if a panic
1054 /// occurs -- the panic value.
1055 pub fn in_rustc_thread<F, R>(f: F) -> Result<R, Box<Any + Send>>
1056     where F: FnOnce() -> R + Send + 'static,
1057           R: Send + 'static,
1058 {
1059     // Temporarily have stack size set to 16MB to deal with nom-using crates failing
1060     const STACK_SIZE: usize = 16 * 1024 * 1024; // 16MB
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(f);
1071     thread.unwrap().join()
1072 }
1073
1074 /// Run a procedure which will detect panics in the compiler and print nicer
1075 /// error messages rather than just failing the test.
1076 ///
1077 /// The diagnostic emitter yielded to the procedure should be used for reporting
1078 /// errors of the compiler.
1079 pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
1080     struct Sink(Arc<Mutex<Vec<u8>>>);
1081     impl Write for Sink {
1082         fn write(&mut self, data: &[u8]) -> io::Result<usize> {
1083             Write::write(&mut *self.0.lock().unwrap(), data)
1084         }
1085         fn flush(&mut self) -> io::Result<()> {
1086             Ok(())
1087         }
1088     }
1089
1090     let data = Arc::new(Mutex::new(Vec::new()));
1091     let err = Sink(data.clone());
1092
1093     let result = in_rustc_thread(move || {
1094         io::set_panic(Some(box err));
1095         f()
1096     });
1097
1098     if let Err(value) = result {
1099         // Thread panicked without emitting a fatal diagnostic
1100         if !value.is::<errors::FatalError>() {
1101             let emitter =
1102                 Box::new(errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None));
1103             let handler = errors::Handler::with_emitter(true, false, emitter);
1104
1105             // a .span_bug or .bug call has already printed what
1106             // it wants to print.
1107             if !value.is::<errors::ExplicitBug>() {
1108                 handler.emit(&MultiSpan::new(),
1109                              "unexpected panic",
1110                              errors::Level::Bug);
1111             }
1112
1113             let xs = ["the compiler unexpectedly panicked. this is a bug.".to_string(),
1114                       format!("we would appreciate a bug report: {}", BUG_REPORT_URL)];
1115             for note in &xs {
1116                 handler.emit(&MultiSpan::new(),
1117                              &note,
1118                              errors::Level::Note);
1119             }
1120             if match env::var_os("RUST_BACKTRACE") {
1121                 Some(val) => &val != "0",
1122                 None => false,
1123             } {
1124                 handler.emit(&MultiSpan::new(),
1125                              "run with `RUST_BACKTRACE=1` for a backtrace",
1126                              errors::Level::Note);
1127             }
1128
1129             writeln!(io::stderr(), "{}", str::from_utf8(&data.lock().unwrap()).unwrap()).unwrap();
1130         }
1131
1132         exit_on_err();
1133     }
1134 }
1135
1136 fn exit_on_err() -> ! {
1137     // Panic so the process returns a failure code, but don't pollute the
1138     // output with some unnecessary panic messages, we've already
1139     // printed everything that we needed to.
1140     io::set_panic(Some(box io::sink()));
1141     panic!();
1142 }
1143
1144 pub fn diagnostics_registry() -> errors::registry::Registry {
1145     use errors::registry::Registry;
1146
1147     let mut all_errors = Vec::new();
1148     all_errors.extend_from_slice(&rustc::DIAGNOSTICS);
1149     all_errors.extend_from_slice(&rustc_typeck::DIAGNOSTICS);
1150     all_errors.extend_from_slice(&rustc_borrowck::DIAGNOSTICS);
1151     all_errors.extend_from_slice(&rustc_resolve::DIAGNOSTICS);
1152     all_errors.extend_from_slice(&rustc_privacy::DIAGNOSTICS);
1153     all_errors.extend_from_slice(&rustc_trans::DIAGNOSTICS);
1154     all_errors.extend_from_slice(&rustc_const_eval::DIAGNOSTICS);
1155     all_errors.extend_from_slice(&rustc_metadata::DIAGNOSTICS);
1156
1157     Registry::new(&all_errors)
1158 }
1159
1160 pub fn main() {
1161     env_logger::init().unwrap();
1162     let result = run(|| run_compiler(&env::args().collect::<Vec<_>>(),
1163                                      &mut RustcDefaultCalls,
1164                                      None,
1165                                      None));
1166     process::exit(result as i32);
1167 }