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(libc)]
  27 #![feature(quote)]
  28 #![feature(rustc_diagnostic_macros)]
  29 #![feature(set_stdio)]
  30
  31 #![cfg_attr(stage0, unstable(feature = "rustc_private", issue = "27812"))]
  32 #![cfg_attr(stage0, feature(rustc_private))]
  33 #![cfg_attr(stage0, feature(staged_api))]
  34 #![cfg_attr(stage0, feature(loop_break_value))]
  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         _ => "aborting due to previous error(s)".to_owned(),
 122     }
 123 }
 124
 125 pub fn abort_on_err<T>(result: Result<T, usize>, sess: &Session) -> T {
 126     match result {
 127         Err(err_count) => {
 128             sess.fatal(&abort_msg(err_count));
 129         }
 130         Ok(x) => x,
 131     }
 132 }
 133
 134 pub fn run<F>(run_compiler: F) -> isize
 135     where F: FnOnce() -> (CompileResult, Option<Session>) + Send + 'static
 136 {
 137     monitor(move || {
 138         let (result, session) = run_compiler();
 139         if let Err(err_count) = result {
 140             if err_count > 0 {
 141                 match session {
 142                     Some(sess) => sess.fatal(&abort_msg(err_count)),
 143                     None => {
 144                         let emitter =
 145                             errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None);
 146                         let handler = errors::Handler::with_emitter(true, false, Box::new(emitter));
 147                         handler.emit(&MultiSpan::new(),
 148                                      &abort_msg(err_count),
 149                                      errors::Level::Fatal);
 150                         exit_on_err();
 151                     }
 152                 }
 153             }
 154         }
 155     });
 156     0
 157 }
 158
 159 // Parse args and run the compiler. This is the primary entry point for rustc.
 160 // See comments on CompilerCalls below for details about the callbacks argument.
 161 // The FileLoader provides a way to load files from sources other than the file system.
 162 pub fn run_compiler<'a>(args: &[String],
 163                         callbacks: &mut CompilerCalls<'a>,
 164                         file_loader: Option<Box<FileLoader + 'static>>,
 165                         emitter_dest: Option<Box<Write + Send>>)
 166                         -> (CompileResult, Option<Session>)
 167 {
 168     macro_rules! do_or_return {($expr: expr, $sess: expr) => {
 169         match $expr {
 170             Compilation::Stop => return (Ok(()), $sess),
 171             Compilation::Continue => {}
 172         }
 173     }}
 174
 175     let matches = match handle_options(args) {
 176         Some(matches) => matches,
 177         None => return (Ok(()), None),
 178     };
 179
 180     let (sopts, cfg) = config::build_session_options_and_crate_config(&matches);
 181
 182     if sopts.debugging_opts.debug_llvm {
 183         rustc_trans::enable_llvm_debug();
 184     }
 185
 186     let descriptions = diagnostics_registry();
 187
 188     do_or_return!(callbacks.early_callback(&matches,
 189                                            &sopts,
 190                                            &cfg,
 191                                            &descriptions,
 192                                            sopts.error_format),
 193                                            None);
 194
 195     let (odir, ofile) = make_output(&matches);
 196     let (input, input_file_path) = match make_input(&matches.free) {
 197         Some((input, input_file_path)) => callbacks.some_input(input, input_file_path),
 198         None => match callbacks.no_input(&matches, &sopts, &cfg, &odir, &ofile, &descriptions) {
 199             Some((input, input_file_path)) => (input, input_file_path),
 200             None => return (Ok(()), None),
 201         },
 202     };
 203
 204     let dep_graph = DepGraph::new(sopts.build_dep_graph());
 205     let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
 206
 207     let loader = file_loader.unwrap_or(box RealFileLoader);
 208     let codemap = Rc::new(CodeMap::with_file_loader(loader, sopts.file_path_mapping()));
 209     let mut sess = session::build_session_with_codemap(
 210         sopts, &dep_graph, input_file_path, descriptions, cstore.clone(), codemap, emitter_dest,
 211     );
 212     rustc_trans::init(&sess);
 213     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 214
 215     let mut cfg = config::build_configuration(&sess, cfg);
 216     target_features::add_configuration(&mut cfg, &sess);
 217     sess.parse_sess.config = cfg;
 218
 219     do_or_return!(callbacks.late_callback(&matches, &sess, &input, &odir, &ofile), Some(sess));
 220
 221     let plugins = sess.opts.debugging_opts.extra_plugins.clone();
 222     let control = callbacks.build_controller(&sess, &matches);
 223     (driver::compile_input(&sess, &cstore, &input, &odir, &ofile, Some(plugins), &control),
 224      Some(sess))
 225 }
 226
 227 // Extract output directory and file from matches.
 228 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
 229     let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
 230     let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
 231     (odir, ofile)
 232 }
 233
 234 // Extract input (string or file and optional path) from matches.
 235 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>)> {
 236     if free_matches.len() == 1 {
 237         let ifile = &free_matches[0];
 238         if ifile == "-" {
 239             let mut src = String::new();
 240             io::stdin().read_to_string(&mut src).unwrap();
 241             Some((Input::Str { name: driver::anon_src(), input: src },
 242                   None))
 243         } else {
 244             Some((Input::File(PathBuf::from(ifile)),
 245                   Some(PathBuf::from(ifile))))
 246         }
 247     } else {
 248         None
 249     }
 250 }
 251
 252 fn parse_pretty(sess: &Session,
 253                 matches: &getopts::Matches)
 254                 -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 255     let pretty = if sess.opts.debugging_opts.unstable_options {
 256         matches.opt_default("pretty", "normal").map(|a| {
 257             // stable pretty-print variants only
 258             pretty::parse_pretty(sess, &a, false)
 259         })
 260     } else {
 261         None
 262     };
 263     if pretty.is_none() && sess.unstable_options() {
 264         matches.opt_str("unpretty").map(|a| {
 265             // extended with unstable pretty-print variants
 266             pretty::parse_pretty(sess, &a, true)
 267         })
 268     } else {
 269         pretty
 270     }
 271 }
 272
 273 // Whether to stop or continue compilation.
 274 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 275 pub enum Compilation {
 276     Stop,
 277     Continue,
 278 }
 279
 280 impl Compilation {
 281     pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
 282         match self {
 283             Compilation::Stop => Compilation::Stop,
 284             Compilation::Continue => next(),
 285         }
 286     }
 287 }
 288
 289 // A trait for customising the compilation process. Offers a number of hooks for
 290 // executing custom code or customising input.
 291 pub trait CompilerCalls<'a> {
 292     // Hook for a callback early in the process of handling arguments. This will
 293     // be called straight after options have been parsed but before anything
 294     // else (e.g., selecting input and output).
 295     fn early_callback(&mut self,
 296                       _: &getopts::Matches,
 297                       _: &config::Options,
 298                       _: &ast::CrateConfig,
 299                       _: &errors::registry::Registry,
 300                       _: ErrorOutputType)
 301                       -> Compilation {
 302         Compilation::Continue
 303     }
 304
 305     // Hook for a callback late in the process of handling arguments. This will
 306     // be called just before actual compilation starts (and before build_controller
 307     // is called), after all arguments etc. have been completely handled.
 308     fn late_callback(&mut self,
 309                      _: &getopts::Matches,
 310                      _: &Session,
 311                      _: &Input,
 312                      _: &Option<PathBuf>,
 313                      _: &Option<PathBuf>)
 314                      -> Compilation {
 315         Compilation::Continue
 316     }
 317
 318     // Called after we extract the input from the arguments. Gives the implementer
 319     // an opportunity to change the inputs or to add some custom input handling.
 320     // The default behaviour is to simply pass through the inputs.
 321     fn some_input(&mut self,
 322                   input: Input,
 323                   input_path: Option<PathBuf>)
 324                   -> (Input, Option<PathBuf>) {
 325         (input, input_path)
 326     }
 327
 328     // Called after we extract the input from the arguments if there is no valid
 329     // input. Gives the implementer an opportunity to supply alternate input (by
 330     // returning a Some value) or to add custom behaviour for this error such as
 331     // emitting error messages. Returning None will cause compilation to stop
 332     // at this point.
 333     fn no_input(&mut self,
 334                 _: &getopts::Matches,
 335                 _: &config::Options,
 336                 _: &ast::CrateConfig,
 337                 _: &Option<PathBuf>,
 338                 _: &Option<PathBuf>,
 339                 _: &errors::registry::Registry)
 340                 -> Option<(Input, Option<PathBuf>)> {
 341         None
 342     }
 343
 344     // Create a CompilController struct for controlling the behaviour of
 345     // compilation.
 346     fn build_controller(&mut self, _: &Session, _: &getopts::Matches) -> CompileController<'a>;
 347 }
 348
 349 // CompilerCalls instance for a regular rustc build.
 350 #[derive(Copy, Clone)]
 351 pub struct RustcDefaultCalls;
 352
 353 fn handle_explain(code: &str,
 354                   descriptions: &errors::registry::Registry,
 355                   output: ErrorOutputType) {
 356     let normalised = if code.starts_with("E") {
 357         code.to_string()
 358     } else {
 359         format!("E{0:0>4}", code)
 360     };
 361     match descriptions.find_description(&normalised) {
 362         Some(ref description) => {
 363             // Slice off the leading newline and print.
 364             print!("{}", &(&description[1..]).split("\n").map(|x| {
 365                 format!("{}\n", if x.starts_with("```") {
 366                     "```"
 367                 } else {
 368                     x
 369                 })
 370             }).collect::<String>());
 371         }
 372         None => {
 373             early_error(output, &format!("no extended information for {}", code));
 374         }
 375     }
 376 }
 377
 378 impl<'a> CompilerCalls<'a> for RustcDefaultCalls {
 379     fn early_callback(&mut self,
 380                       matches: &getopts::Matches,
 381                       _: &config::Options,
 382                       _: &ast::CrateConfig,
 383                       descriptions: &errors::registry::Registry,
 384                       output: ErrorOutputType)
 385                       -> Compilation {
 386         if let Some(ref code) = matches.opt_str("explain") {
 387             handle_explain(code, descriptions, output);
 388             return Compilation::Stop;
 389         }
 390
 391         Compilation::Continue
 392     }
 393
 394     fn no_input(&mut self,
 395                 matches: &getopts::Matches,
 396                 sopts: &config::Options,
 397                 cfg: &ast::CrateConfig,
 398                 odir: &Option<PathBuf>,
 399                 ofile: &Option<PathBuf>,
 400                 descriptions: &errors::registry::Registry)
 401                 -> Option<(Input, Option<PathBuf>)> {
 402         match matches.free.len() {
 403             0 => {
 404                 if sopts.describe_lints {
 405                     let mut ls = lint::LintStore::new();
 406                     rustc_lint::register_builtins(&mut ls, None);
 407                     describe_lints(&ls, false);
 408                     return None;
 409                 }
 410                 let dep_graph = DepGraph::new(sopts.build_dep_graph());
 411                 let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
 412                 let mut sess = build_session(sopts.clone(),
 413                     &dep_graph,
 414                     None,
 415                     descriptions.clone(),
 416                     cstore.clone());
 417                 rustc_trans::init(&sess);
 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::RelocationModels => {
 673                     println!("Available relocation models:");
 674                     for &(name, _) in RELOC_MODEL_ARGS.iter() {
 675                         println!("    {}", name);
 676                     }
 677                     println!("");
 678                 }
 679                 PrintRequest::CodeModels => {
 680                     println!("Available code models:");
 681                     for &(name, _) in CODE_GEN_MODEL_ARGS.iter(){
 682                         println!("    {}", name);
 683                     }
 684                     println!("");
 685                 }
 686                 PrintRequest::TargetCPUs | PrintRequest::TargetFeatures => {
 687                     rustc_trans::print(*req, sess);
 688                 }
 689             }
 690         }
 691         return Compilation::Stop;
 692     }
 693 }
 694
 695 /// Returns a version string such as "0.12.0-dev".
 696 pub fn release_str() -> Option<&'static str> {
 697     option_env!("CFG_RELEASE")
 698 }
 699
 700 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 701 pub fn commit_hash_str() -> Option<&'static str> {
 702     option_env!("CFG_VER_HASH")
 703 }
 704
 705 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 706 pub fn commit_date_str() -> Option<&'static str> {
 707     option_env!("CFG_VER_DATE")
 708 }
 709
 710 /// Prints version information
 711 pub fn version(binary: &str, matches: &getopts::Matches) {
 712     let verbose = matches.opt_present("verbose");
 713
 714     println!("{} {}",
 715              binary,
 716              option_env!("CFG_VERSION").unwrap_or("unknown version"));
 717     if verbose {
 718         fn unw(x: Option<&str>) -> &str {
 719             x.unwrap_or("unknown")
 720         }
 721         println!("binary: {}", binary);
 722         println!("commit-hash: {}", unw(commit_hash_str()));
 723         println!("commit-date: {}", unw(commit_date_str()));
 724         println!("host: {}", config::host_triple());
 725         println!("release: {}", unw(release_str()));
 726         rustc_trans::print_version();
 727     }
 728 }
 729
 730 fn usage(verbose: bool, include_unstable_options: bool) {
 731     let groups = if verbose {
 732         config::rustc_optgroups()
 733     } else {
 734         config::rustc_short_optgroups()
 735     };
 736     let groups: Vec<_> = groups.into_iter()
 737                                .filter(|x| include_unstable_options || x.is_stable())
 738                                .map(|x| x.opt_group)
 739                                .collect();
 740     let message = format!("Usage: rustc [OPTIONS] INPUT");
 741     let extra_help = if verbose {
 742         ""
 743     } else {
 744         "\n    --help -v           Print the full set of options rustc accepts"
 745     };
 746     println!("{}\nAdditional help:
 747     -C help             Print codegen options
 748     -W help             \
 749               Print 'lint' options and default settings
 750     -Z help             Print internal \
 751               options for debugging rustc{}\n",
 752              getopts::usage(&message, &groups),
 753              extra_help);
 754 }
 755
 756 fn describe_lints(lint_store: &lint::LintStore, loaded_plugins: bool) {
 757     println!("
 758 Available lint options:
 759     -W <foo>           Warn about <foo>
 760     -A <foo>           \
 761               Allow <foo>
 762     -D <foo>           Deny <foo>
 763     -F <foo>           Forbid <foo> \
 764               (deny <foo> and all attempts to override)
 765
 766 ");
 767
 768     fn sort_lints(lints: Vec<(&'static Lint, bool)>) -> Vec<&'static Lint> {
 769         let mut lints: Vec<_> = lints.into_iter().map(|(x, _)| x).collect();
 770         lints.sort_by(|x: &&Lint, y: &&Lint| {
 771             match x.default_level.cmp(&y.default_level) {
 772                 // The sort doesn't case-fold but it's doubtful we care.
 773                 Equal => x.name.cmp(y.name),
 774                 r => r,
 775             }
 776         });
 777         lints
 778     }
 779
 780     fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
 781                         -> Vec<(&'static str, Vec<lint::LintId>)> {
 782         let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
 783         lints.sort_by(|&(x, _): &(&'static str, Vec<lint::LintId>),
 784                        &(y, _): &(&'static str, Vec<lint::LintId>)| {
 785             x.cmp(y)
 786         });
 787         lints
 788     }
 789
 790     let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints()
 791                                                    .iter()
 792                                                    .cloned()
 793                                                    .partition(|&(_, p)| p);
 794     let plugin = sort_lints(plugin);
 795     let builtin = sort_lints(builtin);
 796
 797     let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups()
 798                                                                  .iter()
 799                                                                  .cloned()
 800                                                                  .partition(|&(.., p)| p);
 801     let plugin_groups = sort_lint_groups(plugin_groups);
 802     let builtin_groups = sort_lint_groups(builtin_groups);
 803
 804     let max_name_len = plugin.iter()
 805                              .chain(&builtin)
 806                              .map(|&s| s.name.chars().count())
 807                              .max()
 808                              .unwrap_or(0);
 809     let padded = |x: &str| {
 810         let mut s = repeat(" ")
 811                         .take(max_name_len - x.chars().count())
 812                         .collect::<String>();
 813         s.push_str(x);
 814         s
 815     };
 816
 817     println!("Lint checks provided by rustc:\n");
 818     println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
 819     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
 820
 821     let print_lints = |lints: Vec<&Lint>| {
 822         for lint in lints {
 823             let name = lint.name_lower().replace("_", "-");
 824             println!("    {}  {:7.7}  {}",
 825                      padded(&name),
 826                      lint.default_level.as_str(),
 827                      lint.desc);
 828         }
 829         println!("\n");
 830     };
 831
 832     print_lints(builtin);
 833
 834
 835
 836     let max_name_len = max("warnings".len(),
 837                            plugin_groups.iter()
 838                                         .chain(&builtin_groups)
 839                                         .map(|&(s, _)| s.chars().count())
 840                                         .max()
 841                                         .unwrap_or(0));
 842
 843     let padded = |x: &str| {
 844         let mut s = repeat(" ")
 845                         .take(max_name_len - x.chars().count())
 846                         .collect::<String>();
 847         s.push_str(x);
 848         s
 849     };
 850
 851     println!("Lint groups provided by rustc:\n");
 852     println!("    {}  {}", padded("name"), "sub-lints");
 853     println!("    {}  {}", padded("----"), "---------");
 854     println!("    {}  {}", padded("warnings"), "all built-in lints");
 855
 856     let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
 857         for (name, to) in lints {
 858             let name = name.to_lowercase().replace("_", "-");
 859             let desc = to.into_iter()
 860                          .map(|x| x.to_string().replace("_", "-"))
 861                          .collect::<Vec<String>>()
 862                          .join(", ");
 863             println!("    {}  {}", padded(&name), desc);
 864         }
 865         println!("\n");
 866     };
 867
 868     print_lint_groups(builtin_groups);
 869
 870     match (loaded_plugins, plugin.len(), plugin_groups.len()) {
 871         (false, 0, _) | (false, _, 0) => {
 872             println!("Compiler plugins can provide additional lints and lint groups. To see a \
 873                       listing of these, re-run `rustc -W help` with a crate filename.");
 874         }
 875         (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
 876         (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
 877         (true, l, g) => {
 878             if l > 0 {
 879                 println!("Lint checks provided by plugins loaded by this crate:\n");
 880                 print_lints(plugin);
 881             }
 882             if g > 0 {
 883                 println!("Lint groups provided by plugins loaded by this crate:\n");
 884                 print_lint_groups(plugin_groups);
 885             }
 886         }
 887     }
 888 }
 889
 890 fn describe_debug_flags() {
 891     println!("\nAvailable debug options:\n");
 892     print_flag_list("-Z", config::DB_OPTIONS);
 893 }
 894
 895 fn describe_codegen_flags() {
 896     println!("\nAvailable codegen options:\n");
 897     print_flag_list("-C", config::CG_OPTIONS);
 898 }
 899
 900 fn print_flag_list<T>(cmdline_opt: &str,
 901                       flag_list: &[(&'static str, T, Option<&'static str>, &'static str)]) {
 902     let max_len = flag_list.iter()
 903                            .map(|&(name, _, opt_type_desc, _)| {
 904                                let extra_len = match opt_type_desc {
 905                                    Some(..) => 4,
 906                                    None => 0,
 907                                };
 908                                name.chars().count() + extra_len
 909                            })
 910                            .max()
 911                            .unwrap_or(0);
 912
 913     for &(name, _, opt_type_desc, desc) in flag_list {
 914         let (width, extra) = match opt_type_desc {
 915             Some(..) => (max_len - 4, "=val"),
 916             None => (max_len, ""),
 917         };
 918         println!("    {} {:>width$}{} -- {}",
 919                  cmdline_opt,
 920                  name.replace("_", "-"),
 921                  extra,
 922                  desc,
 923                  width = width);
 924     }
 925 }
 926
 927 /// Process command line options. Emits messages as appropriate. If compilation
 928 /// should continue, returns a getopts::Matches object parsed from args,
 929 /// otherwise returns None.
 930 ///
 931 /// The compiler's handling of options is a little complicated as it ties into
 932 /// our stability story, and it's even *more* complicated by historical
 933 /// accidents. The current intention of each compiler option is to have one of
 934 /// three modes:
 935 ///
 936 /// 1. An option is stable and can be used everywhere.
 937 /// 2. An option is unstable, but was historically allowed on the stable
 938 ///    channel.
 939 /// 3. An option is unstable, and can only be used on nightly.
 940 ///
 941 /// Like unstable library and language features, however, unstable options have
 942 /// always required a form of "opt in" to indicate that you're using them. This
 943 /// provides the easy ability to scan a code base to check to see if anything
 944 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
 945 ///
 946 /// All options behind `-Z` are considered unstable by default. Other top-level
 947 /// options can also be considered unstable, and they were unlocked through the
 948 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
 949 /// instability in both cases, though.
 950 ///
 951 /// So with all that in mind, the comments below have some more detail about the
 952 /// contortions done here to get things to work out correctly.
 953 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
 954     // Throw away the first argument, the name of the binary
 955     let args = &args[1..];
 956
 957     if args.is_empty() {
 958         // user did not write `-v` nor `-Z unstable-options`, so do not
 959         // include that extra information.
 960         usage(false, false);
 961         return None;
 962     }
 963
 964     // Parse with *all* options defined in the compiler, we don't worry about
 965     // option stability here we just want to parse as much as possible.
 966     let all_groups: Vec<getopts::OptGroup> = config::rustc_optgroups()
 967                                                  .into_iter()
 968                                                  .map(|x| x.opt_group)
 969                                                  .collect();
 970     let matches = match getopts::getopts(&args, &all_groups) {
 971         Ok(m) => m,
 972         Err(f) => early_error(ErrorOutputType::default(), &f.to_string()),
 973     };
 974
 975     // For all options we just parsed, we check a few aspects:
 976     //
 977     // * If the option is stable, we're all good
 978     // * If the option wasn't passed, we're all good
 979     // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
 980     //   ourselves), then we require the `-Z unstable-options` flag to unlock
 981     //   this option that was passed.
 982     // * If we're a nightly compiler, then unstable options are now unlocked, so
 983     //   we're good to go.
 984     // * Otherwise, if we're a truly unstable option then we generate an error
 985     //   (unstable option being used on stable)
 986     // * If we're a historically stable-but-should-be-unstable option then we
 987     //   emit a warning that we're going to turn this into an error soon.
 988     nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
 989
 990     if matches.opt_present("h") || matches.opt_present("help") {
 991         // Only show unstable options in --help if we *really* accept unstable
 992         // options, which catches the case where we got `-Z unstable-options` on
 993         // the stable channel of Rust which was accidentally allowed
 994         // historically.
 995         usage(matches.opt_present("verbose"),
 996               nightly_options::is_unstable_enabled(&matches));
 997         return None;
 998     }
 999
1000     // Don't handle -W help here, because we might first load plugins.
1001     let r = matches.opt_strs("Z");
1002     if r.iter().any(|x| *x == "help") {
1003         describe_debug_flags();
1004         return None;
1005     }
1006
1007     let cg_flags = matches.opt_strs("C");
1008     if cg_flags.iter().any(|x| *x == "help") {
1009         describe_codegen_flags();
1010         return None;
1011     }
1012
1013     if cg_flags.iter().any(|x| *x == "no-stack-check") {
1014         early_warn(ErrorOutputType::default(),
1015                    "the --no-stack-check flag is deprecated and does nothing");
1016     }
1017
1018     if cg_flags.contains(&"passes=list".to_string()) {
1019         rustc_trans::print_passes();
1020         return None;
1021     }
1022
1023     if matches.opt_present("version") {
1024         version("rustc", &matches);
1025         return None;
1026     }
1027
1028     Some(matches)
1029 }
1030
1031 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1032     match *input {
1033         Input::File(ref ifile) => {
1034             parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess)
1035         }
1036         Input::Str { ref name, ref input } => {
1037             parse::parse_crate_attrs_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
1038         }
1039     }
1040 }
1041
1042 /// Runs `f` in a suitable thread for running `rustc`; returns a
1043 /// `Result` with either the return value of `f` or -- if a panic
1044 /// occurs -- the panic value.
1045 pub fn in_rustc_thread<F, R>(f: F) -> Result<R, Box<Any + Send>>
1046     where F: FnOnce() -> R + Send + 'static,
1047           R: Send + 'static,
1048 {
1049     // Temporarily have stack size set to 16MB to deal with nom-using crates failing
1050     const STACK_SIZE: usize = 16 * 1024 * 1024; // 16MB
1051
1052     let mut cfg = thread::Builder::new().name("rustc".to_string());
1053
1054     // FIXME: Hacks on hacks. If the env is trying to override the stack size
1055     // then *don't* set it explicitly.
1056     if env::var_os("RUST_MIN_STACK").is_none() {
1057         cfg = cfg.stack_size(STACK_SIZE);
1058     }
1059
1060     let thread = cfg.spawn(f);
1061     thread.unwrap().join()
1062 }
1063
1064 /// Run a procedure which will detect panics in the compiler and print nicer
1065 /// error messages rather than just failing the test.
1066 ///
1067 /// The diagnostic emitter yielded to the procedure should be used for reporting
1068 /// errors of the compiler.
1069 pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
1070     struct Sink(Arc<Mutex<Vec<u8>>>);
1071     impl Write for Sink {
1072         fn write(&mut self, data: &[u8]) -> io::Result<usize> {
1073             Write::write(&mut *self.0.lock().unwrap(), data)
1074         }
1075         fn flush(&mut self) -> io::Result<()> {
1076             Ok(())
1077         }
1078     }
1079
1080     let data = Arc::new(Mutex::new(Vec::new()));
1081     let err = Sink(data.clone());
1082
1083     let result = in_rustc_thread(move || {
1084         io::set_panic(Some(box err));
1085         f()
1086     });
1087
1088     if let Err(value) = result {
1089         // Thread panicked without emitting a fatal diagnostic
1090         if !value.is::<errors::FatalError>() {
1091             let emitter =
1092                 Box::new(errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None));
1093             let handler = errors::Handler::with_emitter(true, false, emitter);
1094
1095             // a .span_bug or .bug call has already printed what
1096             // it wants to print.
1097             if !value.is::<errors::ExplicitBug>() {
1098                 handler.emit(&MultiSpan::new(),
1099                              "unexpected panic",
1100                              errors::Level::Bug);
1101             }
1102
1103             let xs = ["the compiler unexpectedly panicked. this is a bug.".to_string(),
1104                       format!("we would appreciate a bug report: {}", BUG_REPORT_URL)];
1105             for note in &xs {
1106                 handler.emit(&MultiSpan::new(),
1107                              &note,
1108                              errors::Level::Note);
1109             }
1110             if match env::var_os("RUST_BACKTRACE") {
1111                 Some(val) => &val != "0",
1112                 None => false,
1113             } {
1114                 handler.emit(&MultiSpan::new(),
1115                              "run with `RUST_BACKTRACE=1` for a backtrace",
1116                              errors::Level::Note);
1117             }
1118
1119             writeln!(io::stderr(), "{}", str::from_utf8(&data.lock().unwrap()).unwrap()).unwrap();
1120         }
1121
1122         exit_on_err();
1123     }
1124 }
1125
1126 fn exit_on_err() -> ! {
1127     // Panic so the process returns a failure code, but don't pollute the
1128     // output with some unnecessary panic messages, we've already
1129     // printed everything that we needed to.
1130     io::set_panic(Some(box io::sink()));
1131     panic!();
1132 }
1133
1134 pub fn diagnostics_registry() -> errors::registry::Registry {
1135     use errors::registry::Registry;
1136
1137     let mut all_errors = Vec::new();
1138     all_errors.extend_from_slice(&rustc::DIAGNOSTICS);
1139     all_errors.extend_from_slice(&rustc_typeck::DIAGNOSTICS);
1140     all_errors.extend_from_slice(&rustc_borrowck::DIAGNOSTICS);
1141     all_errors.extend_from_slice(&rustc_resolve::DIAGNOSTICS);
1142     all_errors.extend_from_slice(&rustc_privacy::DIAGNOSTICS);
1143     all_errors.extend_from_slice(&rustc_trans::DIAGNOSTICS);
1144     all_errors.extend_from_slice(&rustc_const_eval::DIAGNOSTICS);
1145     all_errors.extend_from_slice(&rustc_metadata::DIAGNOSTICS);
1146
1147     Registry::new(&all_errors)
1148 }
1149
1150 fn get_args() -> Vec<String> {
1151     env::args_os().enumerate()
1152         .map(|(i, arg)| arg.into_string().unwrap_or_else(|arg| {
1153              early_error(ErrorOutputType::default(),
1154                          &format!("Argument {} is not valid Unicode: {:?}", i, arg))
1155          }))
1156         .collect()
1157 }
1158
1159 pub fn main() {
1160     env_logger::init().unwrap();
1161     let result = run(|| run_compiler(&get_args(),
1162                                      &mut RustcDefaultCalls,
1163                                      None,
1164                                      None));
1165     process::exit(result as i32);
1166 }