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 extern crate arena;
  32 extern crate getopts;
  33 extern crate graphviz;
  34 extern crate env_logger;
  35 extern crate libc;
  36 extern crate rustc;
  37 extern crate rustc_back;
  38 extern crate rustc_borrowck;
  39 extern crate rustc_const_eval;
  40 extern crate rustc_data_structures;
  41 extern crate rustc_errors as errors;
  42 extern crate rustc_passes;
  43 extern crate rustc_lint;
  44 extern crate rustc_plugin;
  45 extern crate rustc_privacy;
  46 extern crate rustc_incremental;
  47 extern crate rustc_metadata;
  48 extern crate rustc_mir;
  49 extern crate rustc_resolve;
  50 extern crate rustc_save_analysis;
  51 extern crate rustc_trans;
  52 extern crate rustc_typeck;
  53 extern crate serialize;
  54 #[macro_use]
  55 extern crate log;
  56 extern crate syntax;
  57 extern crate syntax_ext;
  58 extern crate syntax_pos;
  59
  60 use driver::CompileController;
  61 use pretty::{PpMode, UserIdentifiedItem};
  62
  63 use rustc_resolve as resolve;
  64 use rustc_save_analysis as save;
  65 use rustc_save_analysis::DumpHandler;
  66 use rustc_trans::back::link;
  67 use rustc_trans::back::write::{RELOC_MODEL_ARGS, CODE_GEN_MODEL_ARGS};
  68 use rustc::dep_graph::DepGraph;
  69 use rustc::session::{self, config, Session, build_session, CompileResult};
  70 use rustc::session::config::{Input, PrintRequest, OutputType, ErrorOutputType};
  71 use rustc::session::config::nightly_options;
  72 use rustc::session::{early_error, early_warn};
  73 use rustc::lint::Lint;
  74 use rustc::lint;
  75 use rustc_metadata::locator;
  76 use rustc_metadata::cstore::CStore;
  77 use rustc::util::common::time;
  78
  79 use serialize::json::ToJson;
  80
  81 use std::any::Any;
  82 use std::cmp::max;
  83 use std::cmp::Ordering::Equal;
  84 use std::default::Default;
  85 use std::env;
  86 use std::io::{self, Read, Write};
  87 use std::iter::repeat;
  88 use std::path::PathBuf;
  89 use std::process;
  90 use std::rc::Rc;
  91 use std::str;
  92 use std::sync::{Arc, Mutex};
  93 use std::thread;
  94
  95 use syntax::ast;
  96 use syntax::codemap::{CodeMap, FileLoader, RealFileLoader};
  97 use syntax::feature_gate::{GatedCfg, UnstableFeatures};
  98 use syntax::parse::{self, PResult};
  99 use syntax_pos::{DUMMY_SP, MultiSpan};
 100
 101 #[cfg(test)]
 102 pub mod test;
 103
 104 pub mod driver;
 105 pub mod pretty;
 106 pub mod target_features;
 107 mod derive_registrar;
 108
 109 const BUG_REPORT_URL: &'static str = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.\
 110                                       md#bug-reports";
 111
 112 #[inline]
 113 fn abort_msg(err_count: usize) -> String {
 114     match err_count {
 115         0 => "aborting with no errors (maybe a bug?)".to_owned(),
 116         _ => "aborting due to previous error(s)".to_owned(),
 117     }
 118 }
 119
 120 pub fn abort_on_err<T>(result: Result<T, usize>, sess: &Session) -> T {
 121     match result {
 122         Err(err_count) => {
 123             sess.fatal(&abort_msg(err_count));
 124         }
 125         Ok(x) => x,
 126     }
 127 }
 128
 129 pub fn run<F>(run_compiler: F) -> isize
 130     where F: FnOnce() -> (CompileResult, Option<Session>) + Send + 'static
 131 {
 132     monitor(move || {
 133         let (result, session) = run_compiler();
 134         if let Err(err_count) = result {
 135             if err_count > 0 {
 136                 match session {
 137                     Some(sess) => sess.fatal(&abort_msg(err_count)),
 138                     None => {
 139                         let emitter =
 140                             errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None);
 141                         let handler = errors::Handler::with_emitter(true, false, Box::new(emitter));
 142                         handler.emit(&MultiSpan::new(),
 143                                      &abort_msg(err_count),
 144                                      errors::Level::Fatal);
 145                         exit_on_err();
 146                     }
 147                 }
 148             }
 149         }
 150     });
 151     0
 152 }
 153
 154 // Parse args and run the compiler. This is the primary entry point for rustc.
 155 // See comments on CompilerCalls below for details about the callbacks argument.
 156 // The FileLoader provides a way to load files from sources other than the file system.
 157 pub fn run_compiler<'a>(args: &[String],
 158                         callbacks: &mut CompilerCalls<'a>,
 159                         file_loader: Option<Box<FileLoader + 'static>>,
 160                         emitter_dest: Option<Box<Write + Send>>)
 161                         -> (CompileResult, Option<Session>)
 162 {
 163     macro_rules! do_or_return {($expr: expr, $sess: expr) => {
 164         match $expr {
 165             Compilation::Stop => return (Ok(()), $sess),
 166             Compilation::Continue => {}
 167         }
 168     }}
 169
 170     let matches = match handle_options(args) {
 171         Some(matches) => matches,
 172         None => return (Ok(()), None),
 173     };
 174
 175     let (sopts, cfg) = config::build_session_options_and_crate_config(&matches);
 176
 177     if sopts.debugging_opts.debug_llvm {
 178         rustc_trans::enable_llvm_debug();
 179     }
 180
 181     let descriptions = diagnostics_registry();
 182
 183     do_or_return!(callbacks.early_callback(&matches,
 184                                            &sopts,
 185                                            &cfg,
 186                                            &descriptions,
 187                                            sopts.error_format),
 188                                            None);
 189
 190     let (odir, ofile) = make_output(&matches);
 191     let (input, input_file_path) = match make_input(&matches.free) {
 192         Some((input, input_file_path)) => callbacks.some_input(input, input_file_path),
 193         None => match callbacks.no_input(&matches, &sopts, &cfg, &odir, &ofile, &descriptions) {
 194             Some((input, input_file_path)) => (input, input_file_path),
 195             None => return (Ok(()), None),
 196         },
 197     };
 198
 199     let dep_graph = DepGraph::new(sopts.build_dep_graph());
 200     let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
 201
 202     let loader = file_loader.unwrap_or(box RealFileLoader);
 203     let codemap = Rc::new(CodeMap::with_file_loader(loader, sopts.file_path_mapping()));
 204     let mut sess = session::build_session_with_codemap(
 205         sopts, &dep_graph, input_file_path, descriptions, cstore.clone(), codemap, emitter_dest,
 206     );
 207     rustc_trans::init(&sess);
 208     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 209
 210     let mut cfg = config::build_configuration(&sess, cfg);
 211     target_features::add_configuration(&mut cfg, &sess);
 212     sess.parse_sess.config = cfg;
 213
 214     do_or_return!(callbacks.late_callback(&matches, &sess, &input, &odir, &ofile), Some(sess));
 215
 216     let plugins = sess.opts.debugging_opts.extra_plugins.clone();
 217     let control = callbacks.build_controller(&sess, &matches);
 218     (driver::compile_input(&sess, &cstore, &input, &odir, &ofile, Some(plugins), &control),
 219      Some(sess))
 220 }
 221
 222 // Extract output directory and file from matches.
 223 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
 224     let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
 225     let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
 226     (odir, ofile)
 227 }
 228
 229 // Extract input (string or file and optional path) from matches.
 230 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>)> {
 231     if free_matches.len() == 1 {
 232         let ifile = &free_matches[0];
 233         if ifile == "-" {
 234             let mut src = String::new();
 235             io::stdin().read_to_string(&mut src).unwrap();
 236             Some((Input::Str { name: driver::anon_src(), input: src },
 237                   None))
 238         } else {
 239             Some((Input::File(PathBuf::from(ifile)),
 240                   Some(PathBuf::from(ifile))))
 241         }
 242     } else {
 243         None
 244     }
 245 }
 246
 247 fn parse_pretty(sess: &Session,
 248                 matches: &getopts::Matches)
 249                 -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 250     let pretty = if sess.opts.debugging_opts.unstable_options {
 251         matches.opt_default("pretty", "normal").map(|a| {
 252             // stable pretty-print variants only
 253             pretty::parse_pretty(sess, &a, false)
 254         })
 255     } else {
 256         None
 257     };
 258     if pretty.is_none() && sess.unstable_options() {
 259         matches.opt_str("unpretty").map(|a| {
 260             // extended with unstable pretty-print variants
 261             pretty::parse_pretty(sess, &a, true)
 262         })
 263     } else {
 264         pretty
 265     }
 266 }
 267
 268 // Whether to stop or continue compilation.
 269 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 270 pub enum Compilation {
 271     Stop,
 272     Continue,
 273 }
 274
 275 impl Compilation {
 276     pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
 277         match self {
 278             Compilation::Stop => Compilation::Stop,
 279             Compilation::Continue => next(),
 280         }
 281     }
 282 }
 283
 284 // A trait for customising the compilation process. Offers a number of hooks for
 285 // executing custom code or customising input.
 286 pub trait CompilerCalls<'a> {
 287     // Hook for a callback early in the process of handling arguments. This will
 288     // be called straight after options have been parsed but before anything
 289     // else (e.g., selecting input and output).
 290     fn early_callback(&mut self,
 291                       _: &getopts::Matches,
 292                       _: &config::Options,
 293                       _: &ast::CrateConfig,
 294                       _: &errors::registry::Registry,
 295                       _: ErrorOutputType)
 296                       -> Compilation {
 297         Compilation::Continue
 298     }
 299
 300     // Hook for a callback late in the process of handling arguments. This will
 301     // be called just before actual compilation starts (and before build_controller
 302     // is called), after all arguments etc. have been completely handled.
 303     fn late_callback(&mut self,
 304                      _: &getopts::Matches,
 305                      _: &Session,
 306                      _: &Input,
 307                      _: &Option<PathBuf>,
 308                      _: &Option<PathBuf>)
 309                      -> Compilation {
 310         Compilation::Continue
 311     }
 312
 313     // Called after we extract the input from the arguments. Gives the implementer
 314     // an opportunity to change the inputs or to add some custom input handling.
 315     // The default behaviour is to simply pass through the inputs.
 316     fn some_input(&mut self,
 317                   input: Input,
 318                   input_path: Option<PathBuf>)
 319                   -> (Input, Option<PathBuf>) {
 320         (input, input_path)
 321     }
 322
 323     // Called after we extract the input from the arguments if there is no valid
 324     // input. Gives the implementer an opportunity to supply alternate input (by
 325     // returning a Some value) or to add custom behaviour for this error such as
 326     // emitting error messages. Returning None will cause compilation to stop
 327     // at this point.
 328     fn no_input(&mut self,
 329                 _: &getopts::Matches,
 330                 _: &config::Options,
 331                 _: &ast::CrateConfig,
 332                 _: &Option<PathBuf>,
 333                 _: &Option<PathBuf>,
 334                 _: &errors::registry::Registry)
 335                 -> Option<(Input, Option<PathBuf>)> {
 336         None
 337     }
 338
 339     // Create a CompilController struct for controlling the behaviour of
 340     // compilation.
 341     fn build_controller(&mut self, _: &Session, _: &getopts::Matches) -> CompileController<'a>;
 342 }
 343
 344 // CompilerCalls instance for a regular rustc build.
 345 #[derive(Copy, Clone)]
 346 pub struct RustcDefaultCalls;
 347
 348 fn handle_explain(code: &str,
 349                   descriptions: &errors::registry::Registry,
 350                   output: ErrorOutputType) {
 351     let normalised = if code.starts_with("E") {
 352         code.to_string()
 353     } else {
 354         format!("E{0:0>4}", code)
 355     };
 356     match descriptions.find_description(&normalised) {
 357         Some(ref description) => {
 358             let mut is_in_code_block = false;
 359             // Slice off the leading newline and print.
 360             for line in description[1..].lines() {
 361                 let indent_level = line.find(|c: char| !c.is_whitespace())
 362                     .unwrap_or_else(|| line.len());
 363                 let dedented_line = &line[indent_level..];
 364                 if dedented_line.starts_with("```") {
 365                     is_in_code_block = !is_in_code_block;
 366                     println!("{}", &line[..(indent_level+3)]);
 367                 } else if is_in_code_block && dedented_line.starts_with("# ") {
 368                     continue;
 369                 } else {
 370                     println!("{}", line);
 371                 }
 372             }
 373         }
 374         None => {
 375             early_error(output, &format!("no extended information for {}", code));
 376         }
 377     }
 378 }
 379
 380 impl<'a> CompilerCalls<'a> for RustcDefaultCalls {
 381     fn early_callback(&mut self,
 382                       matches: &getopts::Matches,
 383                       _: &config::Options,
 384                       _: &ast::CrateConfig,
 385                       descriptions: &errors::registry::Registry,
 386                       output: ErrorOutputType)
 387                       -> Compilation {
 388         if let Some(ref code) = matches.opt_str("explain") {
 389             handle_explain(code, descriptions, output);
 390             return Compilation::Stop;
 391         }
 392
 393         Compilation::Continue
 394     }
 395
 396     fn no_input(&mut self,
 397                 matches: &getopts::Matches,
 398                 sopts: &config::Options,
 399                 cfg: &ast::CrateConfig,
 400                 odir: &Option<PathBuf>,
 401                 ofile: &Option<PathBuf>,
 402                 descriptions: &errors::registry::Registry)
 403                 -> Option<(Input, Option<PathBuf>)> {
 404         match matches.free.len() {
 405             0 => {
 406                 if sopts.describe_lints {
 407                     let mut ls = lint::LintStore::new();
 408                     rustc_lint::register_builtins(&mut ls, None);
 409                     describe_lints(&ls, false);
 410                     return None;
 411                 }
 412                 let dep_graph = DepGraph::new(sopts.build_dep_graph());
 413                 let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
 414                 let mut sess = build_session(sopts.clone(),
 415                     &dep_graph,
 416                     None,
 417                     descriptions.clone(),
 418                     cstore.clone());
 419                 rustc_trans::init(&sess);
 420                 rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 421                 let mut cfg = config::build_configuration(&sess, cfg.clone());
 422                 target_features::add_configuration(&mut cfg, &sess);
 423                 sess.parse_sess.config = cfg;
 424                 let should_stop =
 425                     RustcDefaultCalls::print_crate_info(&sess, None, odir, ofile);
 426
 427                 if should_stop == Compilation::Stop {
 428                     return None;
 429                 }
 430                 early_error(sopts.error_format, "no input filename given");
 431             }
 432             1 => panic!("make_input should have provided valid inputs"),
 433             _ => early_error(sopts.error_format, "multiple input filenames provided"),
 434         }
 435     }
 436
 437     fn late_callback(&mut self,
 438                      matches: &getopts::Matches,
 439                      sess: &Session,
 440                      input: &Input,
 441                      odir: &Option<PathBuf>,
 442                      ofile: &Option<PathBuf>)
 443                      -> Compilation {
 444         RustcDefaultCalls::print_crate_info(sess, Some(input), odir, ofile)
 445             .and_then(|| RustcDefaultCalls::list_metadata(sess, matches, input))
 446     }
 447
 448     fn build_controller(&mut self,
 449                         sess: &Session,
 450                         matches: &getopts::Matches)
 451                         -> CompileController<'a> {
 452         let mut control = CompileController::basic();
 453
 454         if let Some((ppm, opt_uii)) = parse_pretty(sess, matches) {
 455             if ppm.needs_ast_map(&opt_uii) {
 456                 control.after_hir_lowering.stop = Compilation::Stop;
 457
 458                 control.after_parse.callback = box move |state| {
 459                     state.krate = Some(pretty::fold_crate(state.krate.take().unwrap(), ppm));
 460                 };
 461                 control.after_hir_lowering.callback = box move |state| {
 462                     pretty::print_after_hir_lowering(state.session,
 463                                                      state.hir_map.unwrap(),
 464                                                      state.analysis.unwrap(),
 465                                                      state.resolutions.unwrap(),
 466                                                      state.input,
 467                                                      &state.expanded_crate.take().unwrap(),
 468                                                      state.crate_name.unwrap(),
 469                                                      ppm,
 470                                                      state.arena.unwrap(),
 471                                                      state.arenas.unwrap(),
 472                                                      opt_uii.clone(),
 473                                                      state.out_file);
 474                 };
 475             } else {
 476                 control.after_parse.stop = Compilation::Stop;
 477
 478                 control.after_parse.callback = box move |state| {
 479                     let krate = pretty::fold_crate(state.krate.take().unwrap(), ppm);
 480                     pretty::print_after_parsing(state.session,
 481                                                 state.input,
 482                                                 &krate,
 483                                                 ppm,
 484                                                 state.out_file);
 485                 };
 486             }
 487
 488             return control;
 489         }
 490
 491         if sess.opts.debugging_opts.parse_only ||
 492            sess.opts.debugging_opts.show_span.is_some() ||
 493            sess.opts.debugging_opts.ast_json_noexpand {
 494             control.after_parse.stop = Compilation::Stop;
 495         }
 496
 497         if sess.opts.debugging_opts.no_analysis ||
 498            sess.opts.debugging_opts.ast_json {
 499             control.after_hir_lowering.stop = Compilation::Stop;
 500         }
 501
 502         if !sess.opts.output_types.keys().any(|&i| i == OutputType::Exe ||
 503                                                    i == OutputType::Metadata) {
 504             control.after_llvm.stop = Compilation::Stop;
 505         }
 506
 507         if save_analysis(sess) {
 508             control.after_analysis.callback = box |state| {
 509                 time(state.session.time_passes(), "save analysis", || {
 510                     save::process_crate(state.tcx.unwrap(),
 511                                         state.expanded_crate.unwrap(),
 512                                         state.analysis.unwrap(),
 513                                         state.crate_name.unwrap(),
 514                                         DumpHandler::new(save_analysis_format(state.session),
 515                                                          state.out_dir,
 516                                                          state.crate_name.unwrap()))
 517                 });
 518             };
 519             control.after_analysis.run_callback_on_error = true;
 520             control.make_glob_map = resolve::MakeGlobMap::Yes;
 521         }
 522
 523         if sess.print_fuel_crate.is_some() {
 524             let old_callback = control.compilation_done.callback;
 525             control.compilation_done.callback = box move |state| {
 526                 old_callback(state);
 527                 let sess = state.session;
 528                 println!("Fuel used by {}: {}",
 529                     sess.print_fuel_crate.as_ref().unwrap(),
 530                     sess.print_fuel.get());
 531             }
 532         }
 533         control
 534     }
 535 }
 536
 537 fn save_analysis(sess: &Session) -> bool {
 538     sess.opts.debugging_opts.save_analysis ||
 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_api {
 546         save::Format::JsonApi
 547     } else {
 548         unreachable!();
 549     }
 550 }
 551
 552 impl RustcDefaultCalls {
 553     pub fn list_metadata(sess: &Session, matches: &getopts::Matches, input: &Input) -> Compilation {
 554         let r = matches.opt_strs("Z");
 555         if r.contains(&("ls".to_string())) {
 556             match input {
 557                 &Input::File(ref ifile) => {
 558                     let path = &(*ifile);
 559                     let mut v = Vec::new();
 560                     locator::list_file_metadata(&sess.target.target,
 561                                                 path,
 562                                                 sess.cstore.metadata_loader(),
 563                                                 &mut v)
 564                             .unwrap();
 565                     println!("{}", String::from_utf8(v).unwrap());
 566                 }
 567                 &Input::Str { .. } => {
 568                     early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
 569                 }
 570             }
 571             return Compilation::Stop;
 572         }
 573
 574         return Compilation::Continue;
 575     }
 576
 577
 578     fn print_crate_info(sess: &Session,
 579                         input: Option<&Input>,
 580                         odir: &Option<PathBuf>,
 581                         ofile: &Option<PathBuf>)
 582                         -> Compilation {
 583         if sess.opts.prints.is_empty() {
 584             return Compilation::Continue;
 585         }
 586
 587         let attrs = match input {
 588             None => None,
 589             Some(input) => {
 590                 let result = parse_crate_attrs(sess, input);
 591                 match result {
 592                     Ok(attrs) => Some(attrs),
 593                     Err(mut parse_error) => {
 594                         parse_error.emit();
 595                         return Compilation::Stop;
 596                     }
 597                 }
 598             }
 599         };
 600         for req in &sess.opts.prints {
 601             match *req {
 602                 PrintRequest::TargetList => {
 603                     let mut targets = rustc_back::target::get_targets().collect::<Vec<String>>();
 604                     targets.sort();
 605                     println!("{}", targets.join("\n"));
 606                 },
 607                 PrintRequest::Sysroot => println!("{}", sess.sysroot().display()),
 608                 PrintRequest::TargetSpec => println!("{}", sess.target.target.to_json().pretty()),
 609                 PrintRequest::FileNames |
 610                 PrintRequest::CrateName => {
 611                     let input = match input {
 612                         Some(input) => input,
 613                         None => early_error(ErrorOutputType::default(), "no input file provided"),
 614                     };
 615                     let attrs = attrs.as_ref().unwrap();
 616                     let t_outputs = driver::build_output_filenames(input, odir, ofile, attrs, sess);
 617                     let id = link::find_crate_name(Some(sess), attrs, input);
 618                     if *req == PrintRequest::CrateName {
 619                         println!("{}", id);
 620                         continue;
 621                     }
 622                     let crate_types = driver::collect_crate_types(sess, attrs);
 623                     for &style in &crate_types {
 624                         let fname = link::filename_for_input(sess, style, &id, &t_outputs);
 625                         println!("{}",
 626                                  fname.file_name()
 627                                       .unwrap()
 628                                       .to_string_lossy());
 629                     }
 630                 }
 631                 PrintRequest::Cfg => {
 632                     let allow_unstable_cfg = UnstableFeatures::from_environment()
 633                         .is_nightly_build();
 634
 635                     let mut cfgs = Vec::new();
 636                     for &(name, ref value) in sess.parse_sess.config.iter() {
 637                         let gated_cfg = GatedCfg::gate(&ast::MetaItem {
 638                             name: name,
 639                             node: ast::MetaItemKind::Word,
 640                             span: DUMMY_SP,
 641                         });
 642
 643                         // Note that crt-static is a specially recognized cfg
 644                         // directive that's printed out here as part of
 645                         // rust-lang/rust#37406, but in general the
 646                         // `target_feature` cfg is gated under
 647                         // rust-lang/rust#29717. For now this is just
 648                         // specifically allowing the crt-static cfg and that's
 649                         // it, this is intended to get into Cargo and then go
 650                         // through to build scripts.
 651                         let value = value.as_ref().map(|s| s.as_str());
 652                         let value = value.as_ref().map(|s| s.as_ref());
 653                         if name != "target_feature" || value != Some("crt-static") {
 654                             if !allow_unstable_cfg && gated_cfg.is_some() {
 655                                 continue;
 656                             }
 657                         }
 658
 659                         cfgs.push(if let Some(value) = value {
 660                             format!("{}=\"{}\"", name, value)
 661                         } else {
 662                             format!("{}", name)
 663                         });
 664                     }
 665
 666                     cfgs.sort();
 667                     for cfg in cfgs {
 668                         println!("{}", cfg);
 669                     }
 670                 }
 671                 PrintRequest::RelocationModels => {
 672                     println!("Available relocation models:");
 673                     for &(name, _) in RELOC_MODEL_ARGS.iter() {
 674                         println!("    {}", name);
 675                     }
 676                     println!("");
 677                 }
 678                 PrintRequest::CodeModels => {
 679                     println!("Available code models:");
 680                     for &(name, _) in CODE_GEN_MODEL_ARGS.iter(){
 681                         println!("    {}", name);
 682                     }
 683                     println!("");
 684                 }
 685                 PrintRequest::TargetCPUs | PrintRequest::TargetFeatures => {
 686                     rustc_trans::print(*req, sess);
 687                 }
 688             }
 689         }
 690         return Compilation::Stop;
 691     }
 692 }
 693
 694 /// Returns a version string such as "0.12.0-dev".
 695 pub fn release_str() -> Option<&'static str> {
 696     option_env!("CFG_RELEASE")
 697 }
 698
 699 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 700 pub fn commit_hash_str() -> Option<&'static str> {
 701     option_env!("CFG_VER_HASH")
 702 }
 703
 704 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 705 pub fn commit_date_str() -> Option<&'static str> {
 706     option_env!("CFG_VER_DATE")
 707 }
 708
 709 /// Prints version information
 710 pub fn version(binary: &str, matches: &getopts::Matches) {
 711     let verbose = matches.opt_present("verbose");
 712
 713     println!("{} {}",
 714              binary,
 715              option_env!("CFG_VERSION").unwrap_or("unknown version"));
 716     if verbose {
 717         fn unw(x: Option<&str>) -> &str {
 718             x.unwrap_or("unknown")
 719         }
 720         println!("binary: {}", binary);
 721         println!("commit-hash: {}", unw(commit_hash_str()));
 722         println!("commit-date: {}", unw(commit_date_str()));
 723         println!("host: {}", config::host_triple());
 724         println!("release: {}", unw(release_str()));
 725         rustc_trans::print_version();
 726     }
 727 }
 728
 729 fn usage(verbose: bool, include_unstable_options: bool) {
 730     let groups = if verbose {
 731         config::rustc_optgroups()
 732     } else {
 733         config::rustc_short_optgroups()
 734     };
 735     let mut options = getopts::Options::new();
 736     for option in groups.iter().filter(|x| include_unstable_options || x.is_stable()) {
 737         (option.apply)(&mut options);
 738     }
 739     let message = format!("Usage: rustc [OPTIONS] INPUT");
 740     let extra_help = if verbose {
 741         ""
 742     } else {
 743         "\n    --help -v           Print the full set of options rustc accepts"
 744     };
 745     println!("{}\nAdditional help:
 746     -C help             Print codegen options
 747     -W help             \
 748               Print 'lint' options and default settings
 749     -Z help             Print internal \
 750               options for debugging rustc{}\n",
 751              options.usage(&message),
 752              extra_help);
 753 }
 754
 755 fn describe_lints(lint_store: &lint::LintStore, loaded_plugins: bool) {
 756     println!("
 757 Available lint options:
 758     -W <foo>           Warn about <foo>
 759     -A <foo>           \
 760               Allow <foo>
 761     -D <foo>           Deny <foo>
 762     -F <foo>           Forbid <foo> \
 763               (deny <foo> and all attempts to override)
 764
 765 ");
 766
 767     fn sort_lints(lints: Vec<(&'static Lint, bool)>) -> Vec<&'static Lint> {
 768         let mut lints: Vec<_> = lints.into_iter().map(|(x, _)| x).collect();
 769         lints.sort_by(|x: &&Lint, y: &&Lint| {
 770             match x.default_level.cmp(&y.default_level) {
 771                 // The sort doesn't case-fold but it's doubtful we care.
 772                 Equal => x.name.cmp(y.name),
 773                 r => r,
 774             }
 775         });
 776         lints
 777     }
 778
 779     fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
 780                         -> Vec<(&'static str, Vec<lint::LintId>)> {
 781         let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
 782         lints.sort_by(|&(x, _): &(&'static str, Vec<lint::LintId>),
 783                        &(y, _): &(&'static str, Vec<lint::LintId>)| {
 784             x.cmp(y)
 785         });
 786         lints
 787     }
 788
 789     let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints()
 790                                                    .iter()
 791                                                    .cloned()
 792                                                    .partition(|&(_, p)| p);
 793     let plugin = sort_lints(plugin);
 794     let builtin = sort_lints(builtin);
 795
 796     let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups()
 797                                                                  .iter()
 798                                                                  .cloned()
 799                                                                  .partition(|&(.., p)| p);
 800     let plugin_groups = sort_lint_groups(plugin_groups);
 801     let builtin_groups = sort_lint_groups(builtin_groups);
 802
 803     let max_name_len = plugin.iter()
 804                              .chain(&builtin)
 805                              .map(|&s| s.name.chars().count())
 806                              .max()
 807                              .unwrap_or(0);
 808     let padded = |x: &str| {
 809         let mut s = repeat(" ")
 810                         .take(max_name_len - x.chars().count())
 811                         .collect::<String>();
 812         s.push_str(x);
 813         s
 814     };
 815
 816     println!("Lint checks provided by rustc:\n");
 817     println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
 818     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
 819
 820     let print_lints = |lints: Vec<&Lint>| {
 821         for lint in lints {
 822             let name = lint.name_lower().replace("_", "-");
 823             println!("    {}  {:7.7}  {}",
 824                      padded(&name),
 825                      lint.default_level.as_str(),
 826                      lint.desc);
 827         }
 828         println!("\n");
 829     };
 830
 831     print_lints(builtin);
 832
 833
 834
 835     let max_name_len = max("warnings".len(),
 836                            plugin_groups.iter()
 837                                         .chain(&builtin_groups)
 838                                         .map(|&(s, _)| s.chars().count())
 839                                         .max()
 840                                         .unwrap_or(0));
 841
 842     let padded = |x: &str| {
 843         let mut s = repeat(" ")
 844                         .take(max_name_len - x.chars().count())
 845                         .collect::<String>();
 846         s.push_str(x);
 847         s
 848     };
 849
 850     println!("Lint groups provided by rustc:\n");
 851     println!("    {}  {}", padded("name"), "sub-lints");
 852     println!("    {}  {}", padded("----"), "---------");
 853     println!("    {}  {}", padded("warnings"), "all built-in lints");
 854
 855     let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
 856         for (name, to) in lints {
 857             let name = name.to_lowercase().replace("_", "-");
 858             let desc = to.into_iter()
 859                          .map(|x| x.to_string().replace("_", "-"))
 860                          .collect::<Vec<String>>()
 861                          .join(", ");
 862             println!("    {}  {}", padded(&name), desc);
 863         }
 864         println!("\n");
 865     };
 866
 867     print_lint_groups(builtin_groups);
 868
 869     match (loaded_plugins, plugin.len(), plugin_groups.len()) {
 870         (false, 0, _) | (false, _, 0) => {
 871             println!("Compiler plugins can provide additional lints and lint groups. To see a \
 872                       listing of these, re-run `rustc -W help` with a crate filename.");
 873         }
 874         (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
 875         (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
 876         (true, l, g) => {
 877             if l > 0 {
 878                 println!("Lint checks provided by plugins loaded by this crate:\n");
 879                 print_lints(plugin);
 880             }
 881             if g > 0 {
 882                 println!("Lint groups provided by plugins loaded by this crate:\n");
 883                 print_lint_groups(plugin_groups);
 884             }
 885         }
 886     }
 887 }
 888
 889 fn describe_debug_flags() {
 890     println!("\nAvailable debug options:\n");
 891     print_flag_list("-Z", config::DB_OPTIONS);
 892 }
 893
 894 fn describe_codegen_flags() {
 895     println!("\nAvailable codegen options:\n");
 896     print_flag_list("-C", config::CG_OPTIONS);
 897 }
 898
 899 fn print_flag_list<T>(cmdline_opt: &str,
 900                       flag_list: &[(&'static str, T, Option<&'static str>, &'static str)]) {
 901     let max_len = flag_list.iter()
 902                            .map(|&(name, _, opt_type_desc, _)| {
 903                                let extra_len = match opt_type_desc {
 904                                    Some(..) => 4,
 905                                    None => 0,
 906                                };
 907                                name.chars().count() + extra_len
 908                            })
 909                            .max()
 910                            .unwrap_or(0);
 911
 912     for &(name, _, opt_type_desc, desc) in flag_list {
 913         let (width, extra) = match opt_type_desc {
 914             Some(..) => (max_len - 4, "=val"),
 915             None => (max_len, ""),
 916         };
 917         println!("    {} {:>width$}{} -- {}",
 918                  cmdline_opt,
 919                  name.replace("_", "-"),
 920                  extra,
 921                  desc,
 922                  width = width);
 923     }
 924 }
 925
 926 /// Process command line options. Emits messages as appropriate. If compilation
 927 /// should continue, returns a getopts::Matches object parsed from args,
 928 /// otherwise returns None.
 929 ///
 930 /// The compiler's handling of options is a little complicated as it ties into
 931 /// our stability story, and it's even *more* complicated by historical
 932 /// accidents. The current intention of each compiler option is to have one of
 933 /// three modes:
 934 ///
 935 /// 1. An option is stable and can be used everywhere.
 936 /// 2. An option is unstable, but was historically allowed on the stable
 937 ///    channel.
 938 /// 3. An option is unstable, and can only be used on nightly.
 939 ///
 940 /// Like unstable library and language features, however, unstable options have
 941 /// always required a form of "opt in" to indicate that you're using them. This
 942 /// provides the easy ability to scan a code base to check to see if anything
 943 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
 944 ///
 945 /// All options behind `-Z` are considered unstable by default. Other top-level
 946 /// options can also be considered unstable, and they were unlocked through the
 947 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
 948 /// instability in both cases, though.
 949 ///
 950 /// So with all that in mind, the comments below have some more detail about the
 951 /// contortions done here to get things to work out correctly.
 952 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
 953     // Throw away the first argument, the name of the binary
 954     let args = &args[1..];
 955
 956     if args.is_empty() {
 957         // user did not write `-v` nor `-Z unstable-options`, so do not
 958         // include that extra information.
 959         usage(false, false);
 960         return None;
 961     }
 962
 963     // Parse with *all* options defined in the compiler, we don't worry about
 964     // option stability here we just want to parse as much as possible.
 965     let mut options = getopts::Options::new();
 966     for option in config::rustc_optgroups() {
 967         (option.apply)(&mut options);
 968     }
 969     let matches = match options.parse(args) {
 970         Ok(m) => m,
 971         Err(f) => early_error(ErrorOutputType::default(), &f.to_string()),
 972     };
 973
 974     // For all options we just parsed, we check a few aspects:
 975     //
 976     // * If the option is stable, we're all good
 977     // * If the option wasn't passed, we're all good
 978     // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
 979     //   ourselves), then we require the `-Z unstable-options` flag to unlock
 980     //   this option that was passed.
 981     // * If we're a nightly compiler, then unstable options are now unlocked, so
 982     //   we're good to go.
 983     // * Otherwise, if we're a truly unstable option then we generate an error
 984     //   (unstable option being used on stable)
 985     // * If we're a historically stable-but-should-be-unstable option then we
 986     //   emit a warning that we're going to turn this into an error soon.
 987     nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
 988
 989     if matches.opt_present("h") || matches.opt_present("help") {
 990         // Only show unstable options in --help if we *really* accept unstable
 991         // options, which catches the case where we got `-Z unstable-options` on
 992         // the stable channel of Rust which was accidentally allowed
 993         // historically.
 994         usage(matches.opt_present("verbose"),
 995               nightly_options::is_unstable_enabled(&matches));
 996         return None;
 997     }
 998
 999     // Don't handle -W help here, because we might first load plugins.
1000     let r = matches.opt_strs("Z");
1001     if r.iter().any(|x| *x == "help") {
1002         describe_debug_flags();
1003         return None;
1004     }
1005
1006     let cg_flags = matches.opt_strs("C");
1007     if cg_flags.iter().any(|x| *x == "help") {
1008         describe_codegen_flags();
1009         return None;
1010     }
1011
1012     if cg_flags.iter().any(|x| *x == "no-stack-check") {
1013         early_warn(ErrorOutputType::default(),
1014                    "the --no-stack-check flag is deprecated and does nothing");
1015     }
1016
1017     if cg_flags.contains(&"passes=list".to_string()) {
1018         rustc_trans::print_passes();
1019         return None;
1020     }
1021
1022     if matches.opt_present("version") {
1023         version("rustc", &matches);
1024         return None;
1025     }
1026
1027     Some(matches)
1028 }
1029
1030 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1031     match *input {
1032         Input::File(ref ifile) => {
1033             parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess)
1034         }
1035         Input::Str { ref name, ref input } => {
1036             parse::parse_crate_attrs_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
1037         }
1038     }
1039 }
1040
1041 /// Runs `f` in a suitable thread for running `rustc`; returns a
1042 /// `Result` with either the return value of `f` or -- if a panic
1043 /// occurs -- the panic value.
1044 pub fn in_rustc_thread<F, R>(f: F) -> Result<R, Box<Any + Send>>
1045     where F: FnOnce() -> R + Send + 'static,
1046           R: Send + 'static,
1047 {
1048     // Temporarily have stack size set to 16MB to deal with nom-using crates failing
1049     const STACK_SIZE: usize = 16 * 1024 * 1024; // 16MB
1050
1051     let mut cfg = thread::Builder::new().name("rustc".to_string());
1052
1053     // FIXME: Hacks on hacks. If the env is trying to override the stack size
1054     // then *don't* set it explicitly.
1055     if env::var_os("RUST_MIN_STACK").is_none() {
1056         cfg = cfg.stack_size(STACK_SIZE);
1057     }
1058
1059     let thread = cfg.spawn(f);
1060     thread.unwrap().join()
1061 }
1062
1063 /// Run a procedure which will detect panics in the compiler and print nicer
1064 /// error messages rather than just failing the test.
1065 ///
1066 /// The diagnostic emitter yielded to the procedure should be used for reporting
1067 /// errors of the compiler.
1068 pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
1069     struct Sink(Arc<Mutex<Vec<u8>>>);
1070     impl Write for Sink {
1071         fn write(&mut self, data: &[u8]) -> io::Result<usize> {
1072             Write::write(&mut *self.0.lock().unwrap(), data)
1073         }
1074         fn flush(&mut self) -> io::Result<()> {
1075             Ok(())
1076         }
1077     }
1078
1079     let data = Arc::new(Mutex::new(Vec::new()));
1080     let err = Sink(data.clone());
1081
1082     let result = in_rustc_thread(move || {
1083         io::set_panic(Some(box err));
1084         f()
1085     });
1086
1087     if let Err(value) = result {
1088         // Thread panicked without emitting a fatal diagnostic
1089         if !value.is::<errors::FatalError>() {
1090             let emitter =
1091                 Box::new(errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None));
1092             let handler = errors::Handler::with_emitter(true, false, emitter);
1093
1094             // a .span_bug or .bug call has already printed what
1095             // it wants to print.
1096             if !value.is::<errors::ExplicitBug>() {
1097                 handler.emit(&MultiSpan::new(),
1098                              "unexpected panic",
1099                              errors::Level::Bug);
1100             }
1101
1102             let xs = ["the compiler unexpectedly panicked. this is a bug.".to_string(),
1103                       format!("we would appreciate a bug report: {}", BUG_REPORT_URL),
1104                       format!("rustc {} running on {}",
1105                               option_env!("CFG_VERSION").unwrap_or("unknown_version"),
1106                               config::host_triple())];
1107             for note in &xs {
1108                 handler.emit(&MultiSpan::new(),
1109                              &note,
1110                              errors::Level::Note);
1111             }
1112             if match env::var_os("RUST_BACKTRACE") {
1113                 Some(val) => &val != "0",
1114                 None => false,
1115             } {
1116                 handler.emit(&MultiSpan::new(),
1117                              "run with `RUST_BACKTRACE=1` for a backtrace",
1118                              errors::Level::Note);
1119             }
1120
1121             writeln!(io::stderr(), "{}", str::from_utf8(&data.lock().unwrap()).unwrap()).unwrap();
1122         }
1123
1124         exit_on_err();
1125     }
1126 }
1127
1128 fn exit_on_err() -> ! {
1129     // Panic so the process returns a failure code, but don't pollute the
1130     // output with some unnecessary panic messages, we've already
1131     // printed everything that we needed to.
1132     io::set_panic(Some(box io::sink()));
1133     panic!();
1134 }
1135
1136 pub fn diagnostics_registry() -> errors::registry::Registry {
1137     use errors::registry::Registry;
1138
1139     let mut all_errors = Vec::new();
1140     all_errors.extend_from_slice(&rustc::DIAGNOSTICS);
1141     all_errors.extend_from_slice(&rustc_typeck::DIAGNOSTICS);
1142     all_errors.extend_from_slice(&rustc_borrowck::DIAGNOSTICS);
1143     all_errors.extend_from_slice(&rustc_resolve::DIAGNOSTICS);
1144     all_errors.extend_from_slice(&rustc_privacy::DIAGNOSTICS);
1145     all_errors.extend_from_slice(&rustc_trans::DIAGNOSTICS);
1146     all_errors.extend_from_slice(&rustc_const_eval::DIAGNOSTICS);
1147     all_errors.extend_from_slice(&rustc_metadata::DIAGNOSTICS);
1148
1149     Registry::new(&all_errors)
1150 }
1151
1152 fn get_args() -> Vec<String> {
1153     env::args_os().enumerate()
1154         .map(|(i, arg)| arg.into_string().unwrap_or_else(|arg| {
1155              early_error(ErrorOutputType::default(),
1156                          &format!("Argument {} is not valid Unicode: {:?}", i, arg))
1157          }))
1158         .collect()
1159 }
1160
1161 pub fn main() {
1162     env_logger::init().unwrap();
1163     let result = run(|| run_compiler(&get_args(),
1164                                      &mut RustcDefaultCalls,
1165                                      None,
1166                                      None));
1167     process::exit(result as i32);
1168 }