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::CompileIncomplete;
  71 use rustc::session::config::{Input, PrintRequest, OutputType, ErrorOutputType};
  72 use rustc::session::config::nightly_options;
  73 use rustc::session::{early_error, early_warn};
  74 use rustc::lint::Lint;
  75 use rustc::lint;
  76 use rustc_metadata::locator;
  77 use rustc_metadata::cstore::CStore;
  78 use rustc::util::common::{time, ErrorReported};
  79
  80 use serialize::json::ToJson;
  81
  82 use std::any::Any;
  83 use std::cmp::max;
  84 use std::cmp::Ordering::Equal;
  85 use std::default::Default;
  86 use std::env;
  87 use std::io::{self, Read, Write};
  88 use std::iter::repeat;
  89 use std::path::PathBuf;
  90 use std::process;
  91 use std::rc::Rc;
  92 use std::str;
  93 use std::sync::{Arc, Mutex};
  94 use std::thread;
  95
  96 use syntax::ast;
  97 use syntax::codemap::{CodeMap, FileLoader, RealFileLoader};
  98 use syntax::feature_gate::{GatedCfg, UnstableFeatures};
  99 use syntax::parse::{self, PResult};
 100 use syntax_pos::{DUMMY_SP, MultiSpan};
 101
 102 #[cfg(test)]
 103 pub mod test;
 104
 105 pub mod driver;
 106 pub mod pretty;
 107 pub mod target_features;
 108 mod derive_registrar;
 109
 110 const BUG_REPORT_URL: &'static str = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.\
 111                                       md#bug-reports";
 112
 113 pub fn abort_on_err<T>(result: Result<T, CompileIncomplete>, sess: &Session) -> T {
 114     match result {
 115         Err(CompileIncomplete::Errored(ErrorReported)) => {
 116             sess.abort_if_errors();
 117             panic!("error reported but abort_if_errors didn't abort???");
 118         }
 119         Err(CompileIncomplete::Stopped) => {
 120             sess.fatal("compilation terminated");
 121         }
 122         Ok(x) => x,
 123     }
 124 }
 125
 126 pub fn run<F>(run_compiler: F) -> isize
 127     where F: FnOnce() -> (CompileResult, Option<Session>) + Send + 'static
 128 {
 129     monitor(move || {
 130         let (result, session) = run_compiler();
 131         if let Err(CompileIncomplete::Errored(_)) = result {
 132             match session {
 133                 Some(sess) => {
 134                     sess.abort_if_errors();
 135                     panic!("error reported but abort_if_errors didn't abort???");
 136                 }
 137                 None => {
 138                     let emitter =
 139                         errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None);
 140                     let handler = errors::Handler::with_emitter(true, false, Box::new(emitter));
 141                     handler.emit(&MultiSpan::new(),
 142                                  "aborting due to previous error(s)",
 143                                  errors::Level::Fatal);
 144                     exit_on_err();
 145                 }
 146             }
 147         }
 148     });
 149     0
 150 }
 151
 152 // Parse args and run the compiler. This is the primary entry point for rustc.
 153 // See comments on CompilerCalls below for details about the callbacks argument.
 154 // The FileLoader provides a way to load files from sources other than the file system.
 155 pub fn run_compiler<'a>(args: &[String],
 156                         callbacks: &mut CompilerCalls<'a>,
 157                         file_loader: Option<Box<FileLoader + 'static>>,
 158                         emitter_dest: Option<Box<Write + Send>>)
 159                         -> (CompileResult, Option<Session>)
 160 {
 161     macro_rules! do_or_return {($expr: expr, $sess: expr) => {
 162         match $expr {
 163             Compilation::Stop => return (Ok(()), $sess),
 164             Compilation::Continue => {}
 165         }
 166     }}
 167
 168     let matches = match handle_options(args) {
 169         Some(matches) => matches,
 170         None => return (Ok(()), None),
 171     };
 172
 173     let (sopts, cfg) = config::build_session_options_and_crate_config(&matches);
 174
 175     if sopts.debugging_opts.debug_llvm {
 176         rustc_trans::enable_llvm_debug();
 177     }
 178
 179     let descriptions = diagnostics_registry();
 180
 181     do_or_return!(callbacks.early_callback(&matches,
 182                                            &sopts,
 183                                            &cfg,
 184                                            &descriptions,
 185                                            sopts.error_format),
 186                                            None);
 187
 188     let (odir, ofile) = make_output(&matches);
 189     let (input, input_file_path) = match make_input(&matches.free) {
 190         Some((input, input_file_path)) => callbacks.some_input(input, input_file_path),
 191         None => match callbacks.no_input(&matches, &sopts, &cfg, &odir, &ofile, &descriptions) {
 192             Some((input, input_file_path)) => (input, input_file_path),
 193             None => return (Ok(()), None),
 194         },
 195     };
 196
 197     let dep_graph = DepGraph::new(sopts.build_dep_graph());
 198     let cstore = Rc::new(CStore::new(&dep_graph, box rustc_trans::LlvmMetadataLoader));
 199
 200     let loader = file_loader.unwrap_or(box RealFileLoader);
 201     let codemap = Rc::new(CodeMap::with_file_loader(loader, sopts.file_path_mapping()));
 202     let mut sess = session::build_session_with_codemap(
 203         sopts, &dep_graph, input_file_path, descriptions, cstore.clone(), codemap, emitter_dest,
 204     );
 205     rustc_trans::init(&sess);
 206     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 207
 208     let mut cfg = config::build_configuration(&sess, cfg);
 209     target_features::add_configuration(&mut cfg, &sess);
 210     sess.parse_sess.config = cfg;
 211
 212     do_or_return!(callbacks.late_callback(&matches, &sess, &input, &odir, &ofile), Some(sess));
 213
 214     let plugins = sess.opts.debugging_opts.extra_plugins.clone();
 215     let control = callbacks.build_controller(&sess, &matches);
 216     (driver::compile_input(&sess, &cstore, &input, &odir, &ofile, Some(plugins), &control),
 217      Some(sess))
 218 }
 219
 220 // Extract output directory and file from matches.
 221 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
 222     let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
 223     let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
 224     (odir, ofile)
 225 }
 226
 227 // Extract input (string or file and optional path) from matches.
 228 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>)> {
 229     if free_matches.len() == 1 {
 230         let ifile = &free_matches[0];
 231         if ifile == "-" {
 232             let mut src = String::new();
 233             io::stdin().read_to_string(&mut src).unwrap();
 234             Some((Input::Str { name: driver::anon_src(), input: src },
 235                   None))
 236         } else {
 237             Some((Input::File(PathBuf::from(ifile)),
 238                   Some(PathBuf::from(ifile))))
 239         }
 240     } else {
 241         None
 242     }
 243 }
 244
 245 fn parse_pretty(sess: &Session,
 246                 matches: &getopts::Matches)
 247                 -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 248     let pretty = if sess.opts.debugging_opts.unstable_options {
 249         matches.opt_default("pretty", "normal").map(|a| {
 250             // stable pretty-print variants only
 251             pretty::parse_pretty(sess, &a, false)
 252         })
 253     } else {
 254         None
 255     };
 256     if pretty.is_none() && sess.unstable_options() {
 257         matches.opt_str("unpretty").map(|a| {
 258             // extended with unstable pretty-print variants
 259             pretty::parse_pretty(sess, &a, true)
 260         })
 261     } else {
 262         pretty
 263     }
 264 }
 265
 266 // Whether to stop or continue compilation.
 267 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 268 pub enum Compilation {
 269     Stop,
 270     Continue,
 271 }
 272
 273 impl Compilation {
 274     pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
 275         match self {
 276             Compilation::Stop => Compilation::Stop,
 277             Compilation::Continue => next(),
 278         }
 279     }
 280 }
 281
 282 // A trait for customising the compilation process. Offers a number of hooks for
 283 // executing custom code or customising input.
 284 pub trait CompilerCalls<'a> {
 285     // Hook for a callback early in the process of handling arguments. This will
 286     // be called straight after options have been parsed but before anything
 287     // else (e.g., selecting input and output).
 288     fn early_callback(&mut self,
 289                       _: &getopts::Matches,
 290                       _: &config::Options,
 291                       _: &ast::CrateConfig,
 292                       _: &errors::registry::Registry,
 293                       _: ErrorOutputType)
 294                       -> Compilation {
 295         Compilation::Continue
 296     }
 297
 298     // Hook for a callback late in the process of handling arguments. This will
 299     // be called just before actual compilation starts (and before build_controller
 300     // is called), after all arguments etc. have been completely handled.
 301     fn late_callback(&mut self,
 302                      _: &getopts::Matches,
 303                      _: &Session,
 304                      _: &Input,
 305                      _: &Option<PathBuf>,
 306                      _: &Option<PathBuf>)
 307                      -> Compilation {
 308         Compilation::Continue
 309     }
 310
 311     // Called after we extract the input from the arguments. Gives the implementer
 312     // an opportunity to change the inputs or to add some custom input handling.
 313     // The default behaviour is to simply pass through the inputs.
 314     fn some_input(&mut self,
 315                   input: Input,
 316                   input_path: Option<PathBuf>)
 317                   -> (Input, Option<PathBuf>) {
 318         (input, input_path)
 319     }
 320
 321     // Called after we extract the input from the arguments if there is no valid
 322     // input. Gives the implementer an opportunity to supply alternate input (by
 323     // returning a Some value) or to add custom behaviour for this error such as
 324     // emitting error messages. Returning None will cause compilation to stop
 325     // at this point.
 326     fn no_input(&mut self,
 327                 _: &getopts::Matches,
 328                 _: &config::Options,
 329                 _: &ast::CrateConfig,
 330                 _: &Option<PathBuf>,
 331                 _: &Option<PathBuf>,
 332                 _: &errors::registry::Registry)
 333                 -> Option<(Input, Option<PathBuf>)> {
 334         None
 335     }
 336
 337     // Create a CompilController struct for controlling the behaviour of
 338     // compilation.
 339     fn build_controller(&mut self, _: &Session, _: &getopts::Matches) -> CompileController<'a>;
 340 }
 341
 342 // CompilerCalls instance for a regular rustc build.
 343 #[derive(Copy, Clone)]
 344 pub struct RustcDefaultCalls;
 345
 346 fn handle_explain(code: &str,
 347                   descriptions: &errors::registry::Registry,
 348                   output: ErrorOutputType) {
 349     let normalised = if code.starts_with("E") {
 350         code.to_string()
 351     } else {
 352         format!("E{0:0>4}", code)
 353     };
 354     match descriptions.find_description(&normalised) {
 355         Some(ref description) => {
 356             let mut is_in_code_block = false;
 357             // Slice off the leading newline and print.
 358             for line in description[1..].lines() {
 359                 let indent_level = line.find(|c: char| !c.is_whitespace())
 360                     .unwrap_or_else(|| line.len());
 361                 let dedented_line = &line[indent_level..];
 362                 if dedented_line.starts_with("```") {
 363                     is_in_code_block = !is_in_code_block;
 364                     println!("{}", &line[..(indent_level+3)]);
 365                 } else if is_in_code_block && dedented_line.starts_with("# ") {
 366                     continue;
 367                 } else {
 368                     println!("{}", line);
 369                 }
 370             }
 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_api
 538 }
 539
 540 fn save_analysis_format(sess: &Session) -> save::Format {
 541     if sess.opts.debugging_opts.save_analysis {
 542         save::Format::Json
 543     } else if sess.opts.debugging_opts.save_analysis_api {
 544         save::Format::JsonApi
 545     } else {
 546         unreachable!();
 547     }
 548 }
 549
 550 impl RustcDefaultCalls {
 551     pub fn list_metadata(sess: &Session, matches: &getopts::Matches, input: &Input) -> Compilation {
 552         let r = matches.opt_strs("Z");
 553         if r.contains(&("ls".to_string())) {
 554             match input {
 555                 &Input::File(ref ifile) => {
 556                     let path = &(*ifile);
 557                     let mut v = Vec::new();
 558                     locator::list_file_metadata(&sess.target.target,
 559                                                 path,
 560                                                 sess.cstore.metadata_loader(),
 561                                                 &mut v)
 562                             .unwrap();
 563                     println!("{}", String::from_utf8(v).unwrap());
 564                 }
 565                 &Input::Str { .. } => {
 566                     early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
 567                 }
 568             }
 569             return Compilation::Stop;
 570         }
 571
 572         return Compilation::Continue;
 573     }
 574
 575
 576     fn print_crate_info(sess: &Session,
 577                         input: Option<&Input>,
 578                         odir: &Option<PathBuf>,
 579                         ofile: &Option<PathBuf>)
 580                         -> Compilation {
 581         if sess.opts.prints.is_empty() {
 582             return Compilation::Continue;
 583         }
 584
 585         let attrs = match input {
 586             None => None,
 587             Some(input) => {
 588                 let result = parse_crate_attrs(sess, input);
 589                 match result {
 590                     Ok(attrs) => Some(attrs),
 591                     Err(mut parse_error) => {
 592                         parse_error.emit();
 593                         return Compilation::Stop;
 594                     }
 595                 }
 596             }
 597         };
 598         for req in &sess.opts.prints {
 599             match *req {
 600                 PrintRequest::TargetList => {
 601                     let mut targets = rustc_back::target::get_targets().collect::<Vec<String>>();
 602                     targets.sort();
 603                     println!("{}", targets.join("\n"));
 604                 },
 605                 PrintRequest::Sysroot => println!("{}", sess.sysroot().display()),
 606                 PrintRequest::TargetSpec => println!("{}", sess.target.target.to_json().pretty()),
 607                 PrintRequest::FileNames |
 608                 PrintRequest::CrateName => {
 609                     let input = match input {
 610                         Some(input) => input,
 611                         None => early_error(ErrorOutputType::default(), "no input file provided"),
 612                     };
 613                     let attrs = attrs.as_ref().unwrap();
 614                     let t_outputs = driver::build_output_filenames(input, odir, ofile, attrs, sess);
 615                     let id = link::find_crate_name(Some(sess), attrs, input);
 616                     if *req == PrintRequest::CrateName {
 617                         println!("{}", id);
 618                         continue;
 619                     }
 620                     let crate_types = driver::collect_crate_types(sess, attrs);
 621                     for &style in &crate_types {
 622                         let fname = link::filename_for_input(sess, style, &id, &t_outputs);
 623                         println!("{}",
 624                                  fname.file_name()
 625                                       .unwrap()
 626                                       .to_string_lossy());
 627                     }
 628                 }
 629                 PrintRequest::Cfg => {
 630                     let allow_unstable_cfg = UnstableFeatures::from_environment()
 631                         .is_nightly_build();
 632
 633                     let mut cfgs = Vec::new();
 634                     for &(name, ref value) in sess.parse_sess.config.iter() {
 635                         let gated_cfg = GatedCfg::gate(&ast::MetaItem {
 636                             name: name,
 637                             node: ast::MetaItemKind::Word,
 638                             span: DUMMY_SP,
 639                         });
 640
 641                         // Note that crt-static is a specially recognized cfg
 642                         // directive that's printed out here as part of
 643                         // rust-lang/rust#37406, but in general the
 644                         // `target_feature` cfg is gated under
 645                         // rust-lang/rust#29717. For now this is just
 646                         // specifically allowing the crt-static cfg and that's
 647                         // it, this is intended to get into Cargo and then go
 648                         // through to build scripts.
 649                         let value = value.as_ref().map(|s| s.as_str());
 650                         let value = value.as_ref().map(|s| s.as_ref());
 651                         if name != "target_feature" || value != Some("crt-static") {
 652                             if !allow_unstable_cfg && gated_cfg.is_some() {
 653                                 continue;
 654                             }
 655                         }
 656
 657                         cfgs.push(if let Some(value) = value {
 658                             format!("{}=\"{}\"", name, value)
 659                         } else {
 660                             format!("{}", name)
 661                         });
 662                     }
 663
 664                     cfgs.sort();
 665                     for cfg in cfgs {
 666                         println!("{}", cfg);
 667                     }
 668                 }
 669                 PrintRequest::RelocationModels => {
 670                     println!("Available relocation models:");
 671                     for &(name, _) in RELOC_MODEL_ARGS.iter() {
 672                         println!("    {}", name);
 673                     }
 674                     println!("");
 675                 }
 676                 PrintRequest::CodeModels => {
 677                     println!("Available code models:");
 678                     for &(name, _) in CODE_GEN_MODEL_ARGS.iter(){
 679                         println!("    {}", name);
 680                     }
 681                     println!("");
 682                 }
 683                 PrintRequest::TargetCPUs | PrintRequest::TargetFeatures => {
 684                     rustc_trans::print(*req, sess);
 685                 }
 686             }
 687         }
 688         return Compilation::Stop;
 689     }
 690 }
 691
 692 /// Returns a version string such as "0.12.0-dev".
 693 pub fn release_str() -> Option<&'static str> {
 694     option_env!("CFG_RELEASE")
 695 }
 696
 697 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 698 pub fn commit_hash_str() -> Option<&'static str> {
 699     option_env!("CFG_VER_HASH")
 700 }
 701
 702 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 703 pub fn commit_date_str() -> Option<&'static str> {
 704     option_env!("CFG_VER_DATE")
 705 }
 706
 707 /// Prints version information
 708 pub fn version(binary: &str, matches: &getopts::Matches) {
 709     let verbose = matches.opt_present("verbose");
 710
 711     println!("{} {}",
 712              binary,
 713              option_env!("CFG_VERSION").unwrap_or("unknown version"));
 714     if verbose {
 715         fn unw(x: Option<&str>) -> &str {
 716             x.unwrap_or("unknown")
 717         }
 718         println!("binary: {}", binary);
 719         println!("commit-hash: {}", unw(commit_hash_str()));
 720         println!("commit-date: {}", unw(commit_date_str()));
 721         println!("host: {}", config::host_triple());
 722         println!("release: {}", unw(release_str()));
 723         rustc_trans::print_version();
 724     }
 725 }
 726
 727 fn usage(verbose: bool, include_unstable_options: bool) {
 728     let groups = if verbose {
 729         config::rustc_optgroups()
 730     } else {
 731         config::rustc_short_optgroups()
 732     };
 733     let mut options = getopts::Options::new();
 734     for option in groups.iter().filter(|x| include_unstable_options || x.is_stable()) {
 735         (option.apply)(&mut options);
 736     }
 737     let message = format!("Usage: rustc [OPTIONS] INPUT");
 738     let extra_help = if verbose {
 739         ""
 740     } else {
 741         "\n    --help -v           Print the full set of options rustc accepts"
 742     };
 743     println!("{}\nAdditional help:
 744     -C help             Print codegen options
 745     -W help             \
 746               Print 'lint' options and default settings
 747     -Z help             Print internal \
 748               options for debugging rustc{}\n",
 749              options.usage(&message),
 750              extra_help);
 751 }
 752
 753 fn describe_lints(lint_store: &lint::LintStore, loaded_plugins: bool) {
 754     println!("
 755 Available lint options:
 756     -W <foo>           Warn about <foo>
 757     -A <foo>           \
 758               Allow <foo>
 759     -D <foo>           Deny <foo>
 760     -F <foo>           Forbid <foo> \
 761               (deny <foo> and all attempts to override)
 762
 763 ");
 764
 765     fn sort_lints(lints: Vec<(&'static Lint, bool)>) -> Vec<&'static Lint> {
 766         let mut lints: Vec<_> = lints.into_iter().map(|(x, _)| x).collect();
 767         lints.sort_by(|x: &&Lint, y: &&Lint| {
 768             match x.default_level.cmp(&y.default_level) {
 769                 // The sort doesn't case-fold but it's doubtful we care.
 770                 Equal => x.name.cmp(y.name),
 771                 r => r,
 772             }
 773         });
 774         lints
 775     }
 776
 777     fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
 778                         -> Vec<(&'static str, Vec<lint::LintId>)> {
 779         let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
 780         lints.sort_by(|&(x, _): &(&'static str, Vec<lint::LintId>),
 781                        &(y, _): &(&'static str, Vec<lint::LintId>)| {
 782             x.cmp(y)
 783         });
 784         lints
 785     }
 786
 787     let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints()
 788                                                    .iter()
 789                                                    .cloned()
 790                                                    .partition(|&(_, p)| p);
 791     let plugin = sort_lints(plugin);
 792     let builtin = sort_lints(builtin);
 793
 794     let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups()
 795                                                                  .iter()
 796                                                                  .cloned()
 797                                                                  .partition(|&(.., p)| p);
 798     let plugin_groups = sort_lint_groups(plugin_groups);
 799     let builtin_groups = sort_lint_groups(builtin_groups);
 800
 801     let max_name_len = plugin.iter()
 802                              .chain(&builtin)
 803                              .map(|&s| s.name.chars().count())
 804                              .max()
 805                              .unwrap_or(0);
 806     let padded = |x: &str| {
 807         let mut s = repeat(" ")
 808                         .take(max_name_len - x.chars().count())
 809                         .collect::<String>();
 810         s.push_str(x);
 811         s
 812     };
 813
 814     println!("Lint checks provided by rustc:\n");
 815     println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
 816     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
 817
 818     let print_lints = |lints: Vec<&Lint>| {
 819         for lint in lints {
 820             let name = lint.name_lower().replace("_", "-");
 821             println!("    {}  {:7.7}  {}",
 822                      padded(&name),
 823                      lint.default_level.as_str(),
 824                      lint.desc);
 825         }
 826         println!("\n");
 827     };
 828
 829     print_lints(builtin);
 830
 831
 832
 833     let max_name_len = max("warnings".len(),
 834                            plugin_groups.iter()
 835                                         .chain(&builtin_groups)
 836                                         .map(|&(s, _)| s.chars().count())
 837                                         .max()
 838                                         .unwrap_or(0));
 839
 840     let padded = |x: &str| {
 841         let mut s = repeat(" ")
 842                         .take(max_name_len - x.chars().count())
 843                         .collect::<String>();
 844         s.push_str(x);
 845         s
 846     };
 847
 848     println!("Lint groups provided by rustc:\n");
 849     println!("    {}  {}", padded("name"), "sub-lints");
 850     println!("    {}  {}", padded("----"), "---------");
 851     println!("    {}  {}", padded("warnings"), "all built-in lints");
 852
 853     let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
 854         for (name, to) in lints {
 855             let name = name.to_lowercase().replace("_", "-");
 856             let desc = to.into_iter()
 857                          .map(|x| x.to_string().replace("_", "-"))
 858                          .collect::<Vec<String>>()
 859                          .join(", ");
 860             println!("    {}  {}", padded(&name), desc);
 861         }
 862         println!("\n");
 863     };
 864
 865     print_lint_groups(builtin_groups);
 866
 867     match (loaded_plugins, plugin.len(), plugin_groups.len()) {
 868         (false, 0, _) | (false, _, 0) => {
 869             println!("Compiler plugins can provide additional lints and lint groups. To see a \
 870                       listing of these, re-run `rustc -W help` with a crate filename.");
 871         }
 872         (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
 873         (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
 874         (true, l, g) => {
 875             if l > 0 {
 876                 println!("Lint checks provided by plugins loaded by this crate:\n");
 877                 print_lints(plugin);
 878             }
 879             if g > 0 {
 880                 println!("Lint groups provided by plugins loaded by this crate:\n");
 881                 print_lint_groups(plugin_groups);
 882             }
 883         }
 884     }
 885 }
 886
 887 fn describe_debug_flags() {
 888     println!("\nAvailable debug options:\n");
 889     print_flag_list("-Z", config::DB_OPTIONS);
 890 }
 891
 892 fn describe_codegen_flags() {
 893     println!("\nAvailable codegen options:\n");
 894     print_flag_list("-C", config::CG_OPTIONS);
 895 }
 896
 897 fn print_flag_list<T>(cmdline_opt: &str,
 898                       flag_list: &[(&'static str, T, Option<&'static str>, &'static str)]) {
 899     let max_len = flag_list.iter()
 900                            .map(|&(name, _, opt_type_desc, _)| {
 901                                let extra_len = match opt_type_desc {
 902                                    Some(..) => 4,
 903                                    None => 0,
 904                                };
 905                                name.chars().count() + extra_len
 906                            })
 907                            .max()
 908                            .unwrap_or(0);
 909
 910     for &(name, _, opt_type_desc, desc) in flag_list {
 911         let (width, extra) = match opt_type_desc {
 912             Some(..) => (max_len - 4, "=val"),
 913             None => (max_len, ""),
 914         };
 915         println!("    {} {:>width$}{} -- {}",
 916                  cmdline_opt,
 917                  name.replace("_", "-"),
 918                  extra,
 919                  desc,
 920                  width = width);
 921     }
 922 }
 923
 924 /// Process command line options. Emits messages as appropriate. If compilation
 925 /// should continue, returns a getopts::Matches object parsed from args,
 926 /// otherwise returns None.
 927 ///
 928 /// The compiler's handling of options is a little complicated as it ties into
 929 /// our stability story, and it's even *more* complicated by historical
 930 /// accidents. The current intention of each compiler option is to have one of
 931 /// three modes:
 932 ///
 933 /// 1. An option is stable and can be used everywhere.
 934 /// 2. An option is unstable, but was historically allowed on the stable
 935 ///    channel.
 936 /// 3. An option is unstable, and can only be used on nightly.
 937 ///
 938 /// Like unstable library and language features, however, unstable options have
 939 /// always required a form of "opt in" to indicate that you're using them. This
 940 /// provides the easy ability to scan a code base to check to see if anything
 941 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
 942 ///
 943 /// All options behind `-Z` are considered unstable by default. Other top-level
 944 /// options can also be considered unstable, and they were unlocked through the
 945 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
 946 /// instability in both cases, though.
 947 ///
 948 /// So with all that in mind, the comments below have some more detail about the
 949 /// contortions done here to get things to work out correctly.
 950 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
 951     // Throw away the first argument, the name of the binary
 952     let args = &args[1..];
 953
 954     if args.is_empty() {
 955         // user did not write `-v` nor `-Z unstable-options`, so do not
 956         // include that extra information.
 957         usage(false, false);
 958         return None;
 959     }
 960
 961     // Parse with *all* options defined in the compiler, we don't worry about
 962     // option stability here we just want to parse as much as possible.
 963     let mut options = getopts::Options::new();
 964     for option in config::rustc_optgroups() {
 965         (option.apply)(&mut options);
 966     }
 967     let matches = match options.parse(args) {
 968         Ok(m) => m,
 969         Err(f) => early_error(ErrorOutputType::default(), &f.to_string()),
 970     };
 971
 972     // For all options we just parsed, we check a few aspects:
 973     //
 974     // * If the option is stable, we're all good
 975     // * If the option wasn't passed, we're all good
 976     // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
 977     //   ourselves), then we require the `-Z unstable-options` flag to unlock
 978     //   this option that was passed.
 979     // * If we're a nightly compiler, then unstable options are now unlocked, so
 980     //   we're good to go.
 981     // * Otherwise, if we're a truly unstable option then we generate an error
 982     //   (unstable option being used on stable)
 983     // * If we're a historically stable-but-should-be-unstable option then we
 984     //   emit a warning that we're going to turn this into an error soon.
 985     nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
 986
 987     if matches.opt_present("h") || matches.opt_present("help") {
 988         // Only show unstable options in --help if we *really* accept unstable
 989         // options, which catches the case where we got `-Z unstable-options` on
 990         // the stable channel of Rust which was accidentally allowed
 991         // historically.
 992         usage(matches.opt_present("verbose"),
 993               nightly_options::is_unstable_enabled(&matches));
 994         return None;
 995     }
 996
 997     // Don't handle -W help here, because we might first load plugins.
 998     let r = matches.opt_strs("Z");
 999     if r.iter().any(|x| *x == "help") {
1000         describe_debug_flags();
1001         return None;
1002     }
1003
1004     let cg_flags = matches.opt_strs("C");
1005     if cg_flags.iter().any(|x| *x == "help") {
1006         describe_codegen_flags();
1007         return None;
1008     }
1009
1010     if cg_flags.iter().any(|x| *x == "no-stack-check") {
1011         early_warn(ErrorOutputType::default(),
1012                    "the --no-stack-check flag is deprecated and does nothing");
1013     }
1014
1015     if cg_flags.contains(&"passes=list".to_string()) {
1016         rustc_trans::print_passes();
1017         return None;
1018     }
1019
1020     if matches.opt_present("version") {
1021         version("rustc", &matches);
1022         return None;
1023     }
1024
1025     Some(matches)
1026 }
1027
1028 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1029     match *input {
1030         Input::File(ref ifile) => {
1031             parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess)
1032         }
1033         Input::Str { ref name, ref input } => {
1034             parse::parse_crate_attrs_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
1035         }
1036     }
1037 }
1038
1039 /// Runs `f` in a suitable thread for running `rustc`; returns a
1040 /// `Result` with either the return value of `f` or -- if a panic
1041 /// occurs -- the panic value.
1042 pub fn in_rustc_thread<F, R>(f: F) -> Result<R, Box<Any + Send>>
1043     where F: FnOnce() -> R + Send + 'static,
1044           R: Send + 'static,
1045 {
1046     // Temporarily have stack size set to 16MB to deal with nom-using crates failing
1047     const STACK_SIZE: usize = 16 * 1024 * 1024; // 16MB
1048
1049     let mut cfg = thread::Builder::new().name("rustc".to_string());
1050
1051     // FIXME: Hacks on hacks. If the env is trying to override the stack size
1052     // then *don't* set it explicitly.
1053     if env::var_os("RUST_MIN_STACK").is_none() {
1054         cfg = cfg.stack_size(STACK_SIZE);
1055     }
1056
1057     let thread = cfg.spawn(f);
1058     thread.unwrap().join()
1059 }
1060
1061 /// Run a procedure which will detect panics in the compiler and print nicer
1062 /// error messages rather than just failing the test.
1063 ///
1064 /// The diagnostic emitter yielded to the procedure should be used for reporting
1065 /// errors of the compiler.
1066 pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
1067     struct Sink(Arc<Mutex<Vec<u8>>>);
1068     impl Write for Sink {
1069         fn write(&mut self, data: &[u8]) -> io::Result<usize> {
1070             Write::write(&mut *self.0.lock().unwrap(), data)
1071         }
1072         fn flush(&mut self) -> io::Result<()> {
1073             Ok(())
1074         }
1075     }
1076
1077     let data = Arc::new(Mutex::new(Vec::new()));
1078     let err = Sink(data.clone());
1079
1080     let result = in_rustc_thread(move || {
1081         io::set_panic(Some(box err));
1082         f()
1083     });
1084
1085     if let Err(value) = result {
1086         // Thread panicked without emitting a fatal diagnostic
1087         if !value.is::<errors::FatalError>() {
1088             let emitter =
1089                 Box::new(errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None));
1090             let handler = errors::Handler::with_emitter(true, false, emitter);
1091
1092             // a .span_bug or .bug call has already printed what
1093             // it wants to print.
1094             if !value.is::<errors::ExplicitBug>() {
1095                 handler.emit(&MultiSpan::new(),
1096                              "unexpected panic",
1097                              errors::Level::Bug);
1098             }
1099
1100             let xs = ["the compiler unexpectedly panicked. this is a bug.".to_string(),
1101                       format!("we would appreciate a bug report: {}", BUG_REPORT_URL),
1102                       format!("rustc {} running on {}",
1103                               option_env!("CFG_VERSION").unwrap_or("unknown_version"),
1104                               config::host_triple())];
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 }