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 #[macro_use]
  60 extern crate log;
  61 extern crate syntax;
  62 extern crate syntax_ext;
  63 extern crate syntax_pos;
  64
  65 use driver::CompileController;
  66 use pretty::{PpMode, UserIdentifiedItem};
  67
  68 use rustc_resolve as resolve;
  69 use rustc_save_analysis as save;
  70 use rustc_save_analysis::DumpHandler;
  71 use rustc_trans::back::link;
  72 use rustc_trans::back::write::{RELOC_MODEL_ARGS, CODE_GEN_MODEL_ARGS};
  73 use rustc::dep_graph::DepGraph;
  74 use rustc::session::{self, config, Session, build_session, CompileResult};
  75 use rustc::session::config::{Input, PrintRequest, OutputType, ErrorOutputType};
  76 use rustc::session::config::nightly_options;
  77 use rustc::session::{early_error, early_warn};
  78 use rustc::lint::Lint;
  79 use rustc::lint;
  80 use rustc_metadata::locator;
  81 use rustc_metadata::cstore::CStore;
  82 use rustc::util::common::time;
  83
  84 use serialize::json::ToJson;
  85
  86 use std::any::Any;
  87 use std::cmp::max;
  88 use std::cmp::Ordering::Equal;
  89 use std::default::Default;
  90 use std::env;
  91 use std::io::{self, Read, Write};
  92 use std::iter::repeat;
  93 use std::path::PathBuf;
  94 use std::process;
  95 use std::rc::Rc;
  96 use std::str;
  97 use std::sync::{Arc, Mutex};
  98 use std::thread;
  99
 100 use syntax::ast;
 101 use syntax::codemap::{CodeMap, FileLoader, RealFileLoader};
 102 use syntax::feature_gate::{GatedCfg, UnstableFeatures};
 103 use syntax::parse::{self, PResult};
 104 use syntax_pos::{DUMMY_SP, MultiSpan};
 105
 106 #[cfg(test)]
 107 pub mod test;
 108
 109 pub mod driver;
 110 pub mod pretty;
 111 pub mod target_features;
 112 mod derive_registrar;
 113
 114 const BUG_REPORT_URL: &'static str = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.\
 115                                       md#bug-reports";
 116
 117 #[inline]
 118 fn abort_msg(err_count: usize) -> String {
 119     match err_count {
 120         0 => "aborting with no errors (maybe a bug?)".to_owned(),
 121         1 => "aborting due to previous error".to_owned(),
 122         e => format!("aborting due to {} previous errors", e),
 123     }
 124 }
 125
 126 pub fn abort_on_err<T>(result: Result<T, usize>, sess: &Session) -> T {
 127     match result {
 128         Err(err_count) => {
 129             sess.fatal(&abort_msg(err_count));
 130         }
 131         Ok(x) => x,
 132     }
 133 }
 134
 135 pub fn run<F>(run_compiler: F) -> isize
 136     where F: FnOnce() -> (CompileResult, Option<Session>) + Send + 'static
 137 {
 138     monitor(move || {
 139         let (result, session) = run_compiler();
 140         if let Err(err_count) = result {
 141             if err_count > 0 {
 142                 match session {
 143                     Some(sess) => sess.fatal(&abort_msg(err_count)),
 144                     None => {
 145                         let emitter =
 146                             errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None);
 147                         let handler = errors::Handler::with_emitter(true, false, Box::new(emitter));
 148                         handler.emit(&MultiSpan::new(),
 149                                      &abort_msg(err_count),
 150                                      errors::Level::Fatal);
 151                         exit_on_err();
 152                     }
 153                 }
 154             }
 155         }
 156     });
 157     0
 158 }
 159
 160 // Parse args and run the compiler. This is the primary entry point for rustc.
 161 // See comments on CompilerCalls below for details about the callbacks argument.
 162 // The FileLoader provides a way to load files from sources other than the file system.
 163 pub fn run_compiler<'a>(args: &[String],
 164                         callbacks: &mut CompilerCalls<'a>,
 165                         file_loader: Option<Box<FileLoader + 'static>>,
 166                         emitter_dest: Option<Box<Write + Send>>)
 167                         -> (CompileResult, Option<Session>)
 168 {
 169     macro_rules! do_or_return {($expr: expr, $sess: expr) => {
 170         match $expr {
 171             Compilation::Stop => return (Ok(()), $sess),
 172             Compilation::Continue => {}
 173         }
 174     }}
 175
 176     let matches = match handle_options(args) {
 177         Some(matches) => matches,
 178         None => return (Ok(()), None),
 179     };
 180
 181     let (sopts, cfg) = config::build_session_options_and_crate_config(&matches);
 182
 183     if sopts.debugging_opts.debug_llvm {
 184         rustc_trans::enable_llvm_debug();
 185     }
 186
 187     let descriptions = diagnostics_registry();
 188
 189     do_or_return!(callbacks.early_callback(&matches,
 190                                            &sopts,
 191                                            &cfg,
 192                                            &descriptions,
 193                                            sopts.error_format),
 194                                            None);
 195
 196     let (odir, ofile) = make_output(&matches);
 197     let (input, input_file_path) = match make_input(&matches.free) {
 198         Some((input, input_file_path)) => callbacks.some_input(input, input_file_path),
 199         None => match callbacks.no_input(&matches, &sopts, &cfg, &odir, &ofile, &descriptions) {
 200             Some((input, input_file_path)) => (input, input_file_path),
 201             None => return (Ok(()), None),
 202         },
 203     };
 204
 205     let dep_graph = DepGraph::new(sopts.build_dep_graph());
 206     let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
 207
 208     let loader = file_loader.unwrap_or(box RealFileLoader);
 209     let codemap = Rc::new(CodeMap::with_file_loader(loader, sopts.file_path_mapping()));
 210     let mut sess = session::build_session_with_codemap(
 211         sopts, &dep_graph, input_file_path, descriptions, cstore.clone(), codemap, emitter_dest,
 212     );
 213     rustc_trans::init(&sess);
 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_trans::init(&sess);
 419                 rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 420                 let mut cfg = config::build_configuration(&sess, cfg.clone());
 421                 target_features::add_configuration(&mut cfg, &sess);
 422                 sess.parse_sess.config = cfg;
 423                 let should_stop =
 424                     RustcDefaultCalls::print_crate_info(&sess, None, odir, ofile);
 425
 426                 if should_stop == Compilation::Stop {
 427                     return None;
 428                 }
 429                 early_error(sopts.error_format, "no input filename given");
 430             }
 431             1 => panic!("make_input should have provided valid inputs"),
 432             _ => early_error(sopts.error_format, "multiple input filenames provided"),
 433         }
 434     }
 435
 436     fn late_callback(&mut self,
 437                      matches: &getopts::Matches,
 438                      sess: &Session,
 439                      input: &Input,
 440                      odir: &Option<PathBuf>,
 441                      ofile: &Option<PathBuf>)
 442                      -> Compilation {
 443         RustcDefaultCalls::print_crate_info(sess, Some(input), odir, ofile)
 444             .and_then(|| RustcDefaultCalls::list_metadata(sess, matches, input))
 445     }
 446
 447     fn build_controller(&mut self,
 448                         sess: &Session,
 449                         matches: &getopts::Matches)
 450                         -> CompileController<'a> {
 451         let mut control = CompileController::basic();
 452
 453         if let Some((ppm, opt_uii)) = parse_pretty(sess, matches) {
 454             if ppm.needs_ast_map(&opt_uii) {
 455                 control.after_hir_lowering.stop = Compilation::Stop;
 456
 457                 control.after_parse.callback = box move |state| {
 458                     state.krate = Some(pretty::fold_crate(state.krate.take().unwrap(), ppm));
 459                 };
 460                 control.after_hir_lowering.callback = box move |state| {
 461                     pretty::print_after_hir_lowering(state.session,
 462                                                      state.hir_map.unwrap(),
 463                                                      state.analysis.unwrap(),
 464                                                      state.resolutions.unwrap(),
 465                                                      state.input,
 466                                                      &state.expanded_crate.take().unwrap(),
 467                                                      state.crate_name.unwrap(),
 468                                                      ppm,
 469                                                      state.arena.unwrap(),
 470                                                      state.arenas.unwrap(),
 471                                                      opt_uii.clone(),
 472                                                      state.out_file);
 473                 };
 474             } else {
 475                 control.after_parse.stop = Compilation::Stop;
 476
 477                 control.after_parse.callback = box move |state| {
 478                     let krate = pretty::fold_crate(state.krate.take().unwrap(), ppm);
 479                     pretty::print_after_parsing(state.session,
 480                                                 state.input,
 481                                                 &krate,
 482                                                 ppm,
 483                                                 state.out_file);
 484                 };
 485             }
 486
 487             return control;
 488         }
 489
 490         if sess.opts.debugging_opts.parse_only ||
 491            sess.opts.debugging_opts.show_span.is_some() ||
 492            sess.opts.debugging_opts.ast_json_noexpand {
 493             control.after_parse.stop = Compilation::Stop;
 494         }
 495
 496         if sess.opts.debugging_opts.no_analysis ||
 497            sess.opts.debugging_opts.ast_json {
 498             control.after_hir_lowering.stop = Compilation::Stop;
 499         }
 500
 501         if !sess.opts.output_types.keys().any(|&i| i == OutputType::Exe ||
 502                                                    i == OutputType::Metadata) {
 503             control.after_llvm.stop = Compilation::Stop;
 504         }
 505
 506         if save_analysis(sess) {
 507             control.after_analysis.callback = box |state| {
 508                 time(state.session.time_passes(), "save analysis", || {
 509                     save::process_crate(state.tcx.unwrap(),
 510                                         state.expanded_crate.unwrap(),
 511                                         state.analysis.unwrap(),
 512                                         state.crate_name.unwrap(),
 513                                         DumpHandler::new(save_analysis_format(state.session),
 514                                                          state.out_dir,
 515                                                          state.crate_name.unwrap()))
 516                 });
 517             };
 518             control.after_analysis.run_callback_on_error = true;
 519             control.make_glob_map = resolve::MakeGlobMap::Yes;
 520         }
 521
 522         if sess.print_fuel_crate.is_some() {
 523             let old_callback = control.compilation_done.callback;
 524             control.compilation_done.callback = box move |state| {
 525                 old_callback(state);
 526                 let sess = state.session;
 527                 println!("Fuel used by {}: {}",
 528                     sess.print_fuel_crate.as_ref().unwrap(),
 529                     sess.print_fuel.get());
 530             }
 531         }
 532         control
 533     }
 534 }
 535
 536 fn save_analysis(sess: &Session) -> bool {
 537     sess.opts.debugging_opts.save_analysis ||
 538     sess.opts.debugging_opts.save_analysis_csv ||
 539     sess.opts.debugging_opts.save_analysis_api
 540 }
 541
 542 fn save_analysis_format(sess: &Session) -> save::Format {
 543     if sess.opts.debugging_opts.save_analysis {
 544         save::Format::Json
 545     } else if sess.opts.debugging_opts.save_analysis_csv {
 546         save::Format::Csv
 547     } else if sess.opts.debugging_opts.save_analysis_api {
 548         save::Format::JsonApi
 549     } else {
 550         unreachable!();
 551     }
 552 }
 553
 554 impl RustcDefaultCalls {
 555     pub fn list_metadata(sess: &Session, matches: &getopts::Matches, input: &Input) -> Compilation {
 556         let r = matches.opt_strs("Z");
 557         if r.contains(&("ls".to_string())) {
 558             match input {
 559                 &Input::File(ref ifile) => {
 560                     let path = &(*ifile);
 561                     let mut v = Vec::new();
 562                     locator::list_file_metadata(&sess.target.target,
 563                                                 path,
 564                                                 sess.cstore.metadata_loader(),
 565                                                 &mut v)
 566                             .unwrap();
 567                     println!("{}", String::from_utf8(v).unwrap());
 568                 }
 569                 &Input::Str { .. } => {
 570                     early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
 571                 }
 572             }
 573             return Compilation::Stop;
 574         }
 575
 576         return Compilation::Continue;
 577     }
 578
 579
 580     fn print_crate_info(sess: &Session,
 581                         input: Option<&Input>,
 582                         odir: &Option<PathBuf>,
 583                         ofile: &Option<PathBuf>)
 584                         -> Compilation {
 585         if sess.opts.prints.is_empty() {
 586             return Compilation::Continue;
 587         }
 588
 589         let attrs = match input {
 590             None => None,
 591             Some(input) => {
 592                 let result = parse_crate_attrs(sess, input);
 593                 match result {
 594                     Ok(attrs) => Some(attrs),
 595                     Err(mut parse_error) => {
 596                         parse_error.emit();
 597                         return Compilation::Stop;
 598                     }
 599                 }
 600             }
 601         };
 602         for req in &sess.opts.prints {
 603             match *req {
 604                 PrintRequest::TargetList => {
 605                     let mut targets = rustc_back::target::get_targets().collect::<Vec<String>>();
 606                     targets.sort();
 607                     println!("{}", targets.join("\n"));
 608                 },
 609                 PrintRequest::Sysroot => println!("{}", sess.sysroot().display()),
 610                 PrintRequest::TargetSpec => println!("{}", sess.target.target.to_json().pretty()),
 611                 PrintRequest::FileNames |
 612                 PrintRequest::CrateName => {
 613                     let input = match input {
 614                         Some(input) => input,
 615                         None => early_error(ErrorOutputType::default(), "no input file provided"),
 616                     };
 617                     let attrs = attrs.as_ref().unwrap();
 618                     let t_outputs = driver::build_output_filenames(input, odir, ofile, attrs, sess);
 619                     let id = link::find_crate_name(Some(sess), attrs, input);
 620                     if *req == PrintRequest::CrateName {
 621                         println!("{}", id);
 622                         continue;
 623                     }
 624                     let crate_types = driver::collect_crate_types(sess, attrs);
 625                     for &style in &crate_types {
 626                         let fname = link::filename_for_input(sess, style, &id, &t_outputs);
 627                         println!("{}",
 628                                  fname.file_name()
 629                                       .unwrap()
 630                                       .to_string_lossy());
 631                     }
 632                 }
 633                 PrintRequest::Cfg => {
 634                     let allow_unstable_cfg = UnstableFeatures::from_environment()
 635                         .is_nightly_build();
 636
 637                     let mut cfgs = Vec::new();
 638                     for &(name, ref value) in sess.parse_sess.config.iter() {
 639                         let gated_cfg = GatedCfg::gate(&ast::MetaItem {
 640                             name: name,
 641                             node: ast::MetaItemKind::Word,
 642                             span: DUMMY_SP,
 643                         });
 644
 645                         // Note that crt-static is a specially recognized cfg
 646                         // directive that's printed out here as part of
 647                         // rust-lang/rust#37406, but in general the
 648                         // `target_feature` cfg is gated under
 649                         // rust-lang/rust#29717. For now this is just
 650                         // specifically allowing the crt-static cfg and that's
 651                         // it, this is intended to get into Cargo and then go
 652                         // through to build scripts.
 653                         let value = value.as_ref().map(|s| s.as_str());
 654                         let value = value.as_ref().map(|s| s.as_ref());
 655                         if name != "target_feature" || value != Some("crt-static") {
 656                             if !allow_unstable_cfg && gated_cfg.is_some() {
 657                                 continue;
 658                             }
 659                         }
 660
 661                         cfgs.push(if let Some(value) = value {
 662                             format!("{}=\"{}\"", name, value)
 663                         } else {
 664                             format!("{}", name)
 665                         });
 666                     }
 667
 668                     cfgs.sort();
 669                     for cfg in cfgs {
 670                         println!("{}", cfg);
 671                     }
 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                 PrintRequest::TargetCPUs | PrintRequest::TargetFeatures => {
 688                     rustc_trans::print(*req, sess);
 689                 }
 690             }
 691         }
 692         return Compilation::Stop;
 693     }
 694 }
 695
 696 /// Returns a version string such as "0.12.0-dev".
 697 pub fn release_str() -> Option<&'static str> {
 698     option_env!("CFG_RELEASE")
 699 }
 700
 701 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 702 pub fn commit_hash_str() -> Option<&'static str> {
 703     option_env!("CFG_VER_HASH")
 704 }
 705
 706 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 707 pub fn commit_date_str() -> Option<&'static str> {
 708     option_env!("CFG_VER_DATE")
 709 }
 710
 711 /// Prints version information
 712 pub fn version(binary: &str, matches: &getopts::Matches) {
 713     let verbose = matches.opt_present("verbose");
 714
 715     println!("{} {}",
 716              binary,
 717              option_env!("CFG_VERSION").unwrap_or("unknown version"));
 718     if verbose {
 719         fn unw(x: Option<&str>) -> &str {
 720             x.unwrap_or("unknown")
 721         }
 722         println!("binary: {}", binary);
 723         println!("commit-hash: {}", unw(commit_hash_str()));
 724         println!("commit-date: {}", unw(commit_date_str()));
 725         println!("host: {}", config::host_triple());
 726         println!("release: {}", unw(release_str()));
 727         rustc_trans::print_version();
 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 <foo> and all attempts to override)
 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 complicated 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.iter().any(|x| *x == "no-stack-check") {
1015         early_warn(ErrorOutputType::default(),
1016                    "the --no-stack-check flag is deprecated and does nothing");
1017     }
1018
1019     if cg_flags.contains(&"passes=list".to_string()) {
1020         rustc_trans::print_passes();
1021         return None;
1022     }
1023
1024     if matches.opt_present("version") {
1025         version("rustc", &matches);
1026         return None;
1027     }
1028
1029     Some(matches)
1030 }
1031
1032 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1033     match *input {
1034         Input::File(ref ifile) => {
1035             parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess)
1036         }
1037         Input::Str { ref name, ref input } => {
1038             parse::parse_crate_attrs_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
1039         }
1040     }
1041 }
1042
1043 /// Runs `f` in a suitable thread for running `rustc`; returns a
1044 /// `Result` with either the return value of `f` or -- if a panic
1045 /// occurs -- the panic value.
1046 pub fn in_rustc_thread<F, R>(f: F) -> Result<R, Box<Any + Send>>
1047     where F: FnOnce() -> R + Send + 'static,
1048           R: Send + 'static,
1049 {
1050     // Temporarily have stack size set to 16MB to deal with nom-using crates failing
1051     const STACK_SIZE: usize = 16 * 1024 * 1024; // 16MB
1052
1053     let mut cfg = thread::Builder::new().name("rustc".to_string());
1054
1055     // FIXME: Hacks on hacks. If the env is trying to override the stack size
1056     // then *don't* set it explicitly.
1057     if env::var_os("RUST_MIN_STACK").is_none() {
1058         cfg = cfg.stack_size(STACK_SIZE);
1059     }
1060
1061     let thread = cfg.spawn(f);
1062     thread.unwrap().join()
1063 }
1064
1065 /// Run a procedure which will detect panics in the compiler and print nicer
1066 /// error messages rather than just failing the test.
1067 ///
1068 /// The diagnostic emitter yielded to the procedure should be used for reporting
1069 /// errors of the compiler.
1070 pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
1071     struct Sink(Arc<Mutex<Vec<u8>>>);
1072     impl Write for Sink {
1073         fn write(&mut self, data: &[u8]) -> io::Result<usize> {
1074             Write::write(&mut *self.0.lock().unwrap(), data)
1075         }
1076         fn flush(&mut self) -> io::Result<()> {
1077             Ok(())
1078         }
1079     }
1080
1081     let data = Arc::new(Mutex::new(Vec::new()));
1082     let err = Sink(data.clone());
1083
1084     let result = in_rustc_thread(move || {
1085         io::set_panic(Some(box err));
1086         f()
1087     });
1088
1089     if let Err(value) = result {
1090         // Thread panicked without emitting a fatal diagnostic
1091         if !value.is::<errors::FatalError>() {
1092             let emitter =
1093                 Box::new(errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None));
1094             let handler = errors::Handler::with_emitter(true, false, emitter);
1095
1096             // a .span_bug or .bug call has already printed what
1097             // it wants to print.
1098             if !value.is::<errors::ExplicitBug>() {
1099                 handler.emit(&MultiSpan::new(),
1100                              "unexpected panic",
1101                              errors::Level::Bug);
1102             }
1103
1104             let xs = ["the compiler unexpectedly panicked. this is a bug.".to_string(),
1105                       format!("we would appreciate a bug report: {}", BUG_REPORT_URL)];
1106             for note in &xs {
1107                 handler.emit(&MultiSpan::new(),
1108                              &note,
1109                              errors::Level::Note);
1110             }
1111             if match env::var_os("RUST_BACKTRACE") {
1112                 Some(val) => &val != "0",
1113                 None => false,
1114             } {
1115                 handler.emit(&MultiSpan::new(),
1116                              "run with `RUST_BACKTRACE=1` for a backtrace",
1117                              errors::Level::Note);
1118             }
1119
1120             writeln!(io::stderr(), "{}", str::from_utf8(&data.lock().unwrap()).unwrap()).unwrap();
1121         }
1122
1123         exit_on_err();
1124     }
1125 }
1126
1127 fn exit_on_err() -> ! {
1128     // Panic so the process returns a failure code, but don't pollute the
1129     // output with some unnecessary panic messages, we've already
1130     // printed everything that we needed to.
1131     io::set_panic(Some(box io::sink()));
1132     panic!();
1133 }
1134
1135 pub fn diagnostics_registry() -> errors::registry::Registry {
1136     use errors::registry::Registry;
1137
1138     let mut all_errors = Vec::new();
1139     all_errors.extend_from_slice(&rustc::DIAGNOSTICS);
1140     all_errors.extend_from_slice(&rustc_typeck::DIAGNOSTICS);
1141     all_errors.extend_from_slice(&rustc_borrowck::DIAGNOSTICS);
1142     all_errors.extend_from_slice(&rustc_resolve::DIAGNOSTICS);
1143     all_errors.extend_from_slice(&rustc_privacy::DIAGNOSTICS);
1144     all_errors.extend_from_slice(&rustc_trans::DIAGNOSTICS);
1145     all_errors.extend_from_slice(&rustc_const_eval::DIAGNOSTICS);
1146     all_errors.extend_from_slice(&rustc_metadata::DIAGNOSTICS);
1147
1148     Registry::new(&all_errors)
1149 }
1150
1151 pub fn main() {
1152     env_logger::init().unwrap();
1153     let result = run(|| run_compiler(&env::args().collect::<Vec<_>>(),
1154                                      &mut RustcDefaultCalls,
1155                                      None,
1156                                      None));
1157     process::exit(result as i32);
1158 }