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 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
  18       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
  19       html_root_url = "https://doc.rust-lang.org/nightly/")]
  20 #![deny(warnings)]
  21
  22 #![feature(box_syntax)]
  23 #![cfg_attr(unix, feature(libc))]
  24 #![feature(quote)]
  25 #![feature(rustc_diagnostic_macros)]
  26 #![feature(set_stdio)]
  27
  28 extern crate arena;
  29 extern crate getopts;
  30 extern crate graphviz;
  31 extern crate env_logger;
  32 #[cfg(unix)]
  33 extern crate libc;
  34 extern crate rustc;
  35 extern crate rustc_allocator;
  36 extern crate rustc_back;
  37 extern crate rustc_borrowck;
  38 extern crate rustc_const_eval;
  39 extern crate rustc_data_structures;
  40 extern crate rustc_errors as errors;
  41 extern crate rustc_passes;
  42 extern crate rustc_lint;
  43 extern crate rustc_plugin;
  44 extern crate rustc_privacy;
  45 extern crate rustc_incremental;
  46 extern crate rustc_metadata;
  47 extern crate rustc_mir;
  48 extern crate rustc_resolve;
  49 extern crate rustc_save_analysis;
  50 #[cfg(feature="llvm")]
  51 extern crate rustc_trans;
  52 extern crate rustc_trans_utils;
  53 extern crate rustc_typeck;
  54 extern crate serialize;
  55 #[macro_use]
  56 extern crate log;
  57 extern crate syntax;
  58 extern crate syntax_ext;
  59 extern crate syntax_pos;
  60
  61 use driver::CompileController;
  62 use pretty::{PpMode, UserIdentifiedItem};
  63
  64 use rustc_resolve as resolve;
  65 use rustc_save_analysis as save;
  66 use rustc_save_analysis::DumpHandler;
  67 use rustc::session::{self, config, Session, build_session, CompileResult};
  68 use rustc::session::CompileIncomplete;
  69 use rustc::session::config::{Input, PrintRequest, OutputType, ErrorOutputType};
  70 use rustc::session::config::nightly_options;
  71 use rustc::session::{early_error, early_warn};
  72 use rustc::lint::Lint;
  73 use rustc::lint;
  74 use rustc::middle::cstore::CrateStore;
  75 use rustc_metadata::locator;
  76 use rustc_metadata::cstore::CStore;
  77 use rustc::util::common::{time, ErrorReported};
  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::ffi::OsString;
  87 use std::io::{self, Read, Write};
  88 use std::iter::repeat;
  89 use std::path::PathBuf;
  90 use std::process::{self, Command, Stdio};
  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 mod test;
 104
 105 pub mod profile;
 106 pub mod driver;
 107 pub mod pretty;
 108 pub mod target_features;
 109 mod derive_registrar;
 110
 111 const BUG_REPORT_URL: &'static str = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.\
 112                                       md#bug-reports";
 113
 114 pub fn abort_on_err<T>(result: Result<T, CompileIncomplete>, sess: &Session) -> T {
 115     match result {
 116         Err(CompileIncomplete::Errored(ErrorReported)) => {
 117             sess.abort_if_errors();
 118             panic!("error reported but abort_if_errors didn't abort???");
 119         }
 120         Err(CompileIncomplete::Stopped) => {
 121             sess.fatal("compilation terminated");
 122         }
 123         Ok(x) => x,
 124     }
 125 }
 126
 127 pub fn run<F>(run_compiler: F) -> isize
 128     where F: FnOnce() -> (CompileResult, Option<Session>) + Send + 'static
 129 {
 130     monitor(move || {
 131         let (result, session) = run_compiler();
 132         if let Err(CompileIncomplete::Errored(_)) = result {
 133             match session {
 134                 Some(sess) => {
 135                     sess.abort_if_errors();
 136                     panic!("error reported but abort_if_errors didn't abort???");
 137                 }
 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                                  "aborting due to previous error(s)",
 144                                  errors::Level::Fatal);
 145                     exit_on_err();
 146                 }
 147             }
 148         }
 149     });
 150     0
 151 }
 152
 153 #[cfg(not(feature="llvm"))]
 154 pub use no_llvm_metadata_loader::NoLLvmMetadataLoader as MetadataLoader;
 155 #[cfg(feature="llvm")]
 156 pub use rustc_trans::LlvmMetadataLoader as MetadataLoader;
 157
 158 #[cfg(not(feature="llvm"))]
 159 mod no_llvm_metadata_loader {
 160     extern crate ar;
 161     extern crate owning_ref;
 162
 163     use rustc::middle::cstore::MetadataLoader as MetadataLoaderTrait;
 164     use rustc_back::target::Target;
 165     use std::io;
 166     use std::fs::File;
 167     use std::path::Path;
 168
 169     use self::ar::Archive;
 170     use self::owning_ref::{OwningRef, ErasedBoxRef};
 171
 172     pub struct NoLLvmMetadataLoader;
 173
 174     impl MetadataLoaderTrait for NoLLvmMetadataLoader {
 175         fn get_rlib_metadata(
 176             &self,
 177             _: &Target,
 178             filename: &Path
 179         ) -> Result<ErasedBoxRef<[u8]>, String> {
 180             let file = File::open(filename).map_err(|e| {
 181                 format!("metadata file open err: {:?}", e)
 182             })?;
 183             let mut archive = Archive::new(file);
 184
 185             while let Some(entry_result) = archive.next_entry() {
 186                 let mut entry = entry_result.map_err(|e| {
 187                     format!("metadata section read err: {:?}", e)
 188                 })?;
 189                 if entry.header().identifier() == "rust.metadata.bin" {
 190                     let mut buf = Vec::new();
 191                     io::copy(&mut entry, &mut buf).unwrap();
 192                     let buf: OwningRef<Vec<u8>, [u8]> = OwningRef::new(buf).into();
 193                     return Ok(buf.map_owner_box().erase_owner());
 194                 }
 195             }
 196
 197             Err("Couldnt find metadata section".to_string())
 198         }
 199
 200         fn get_dylib_metadata(&self,
 201                             _target: &Target,
 202                             _filename: &Path)
 203                             -> Result<ErasedBoxRef<[u8]>, String> {
 204             panic!("Dylib metadata loading not supported without LLVM")
 205         }
 206     }
 207 }
 208
 209 #[cfg(not(feature="llvm"))]
 210 mod rustc_trans {
 211     use syntax_pos::symbol::Symbol;
 212     use rustc::session::Session;
 213     use rustc::session::config::{PrintRequest, OutputFilenames};
 214     use rustc::ty::{TyCtxt, CrateAnalysis};
 215     use rustc::ty::maps::Providers;
 216     use rustc_incremental::IncrementalHashesMap;
 217
 218     use self::back::write::OngoingCrateTranslation;
 219
 220     pub fn init(_sess: &Session) {}
 221     pub fn enable_llvm_debug() {}
 222     pub fn provide(_providers: &mut Providers) {}
 223     pub fn print_version() {}
 224     pub fn print_passes() {}
 225     pub fn print(_req: PrintRequest, _sess: &Session) {}
 226     pub fn target_features(_sess: &Session) -> Vec<Symbol> { vec![] }
 227
 228     pub fn trans_crate<'a, 'tcx>(
 229         _tcx: TyCtxt<'a, 'tcx, 'tcx>,
 230         _analysis: CrateAnalysis,
 231         _incr_hashes_map: IncrementalHashesMap,
 232         _output_filenames: &OutputFilenames
 233     ) -> OngoingCrateTranslation {
 234         OngoingCrateTranslation(())
 235     }
 236
 237     pub struct CrateTranslation(());
 238
 239     pub mod back {
 240         pub mod write {
 241             pub struct OngoingCrateTranslation(pub (in ::rustc_trans) ());
 242
 243             pub const RELOC_MODEL_ARGS: [(&'static str, ()); 0] = [];
 244             pub const CODE_GEN_MODEL_ARGS: [(&'static str, ()); 0] = [];
 245         }
 246     }
 247
 248     __build_diagnostic_array! { librustc_trans, DIAGNOSTICS }
 249 }
 250
 251 // Parse args and run the compiler. This is the primary entry point for rustc.
 252 // See comments on CompilerCalls below for details about the callbacks argument.
 253 // The FileLoader provides a way to load files from sources other than the file system.
 254 pub fn run_compiler<'a>(args: &[String],
 255                         callbacks: &mut CompilerCalls<'a>,
 256                         file_loader: Option<Box<FileLoader + 'static>>,
 257                         emitter_dest: Option<Box<Write + Send>>)
 258                         -> (CompileResult, Option<Session>)
 259 {
 260     macro_rules! do_or_return {($expr: expr, $sess: expr) => {
 261         match $expr {
 262             Compilation::Stop => return (Ok(()), $sess),
 263             Compilation::Continue => {}
 264         }
 265     }}
 266
 267     let matches = match handle_options(args) {
 268         Some(matches) => matches,
 269         None => return (Ok(()), None),
 270     };
 271
 272     let (sopts, cfg) = config::build_session_options_and_crate_config(&matches);
 273
 274     if sopts.debugging_opts.debug_llvm {
 275         rustc_trans::enable_llvm_debug();
 276     }
 277
 278     let descriptions = diagnostics_registry();
 279
 280     do_or_return!(callbacks.early_callback(&matches,
 281                                            &sopts,
 282                                            &cfg,
 283                                            &descriptions,
 284                                            sopts.error_format),
 285                                            None);
 286
 287     let (odir, ofile) = make_output(&matches);
 288     let (input, input_file_path) = match make_input(&matches.free) {
 289         Some((input, input_file_path)) => callbacks.some_input(input, input_file_path),
 290         None => match callbacks.no_input(&matches, &sopts, &cfg, &odir, &ofile, &descriptions) {
 291             Some((input, input_file_path)) => (input, input_file_path),
 292             None => return (Ok(()), None),
 293         },
 294     };
 295
 296     let cstore = Rc::new(CStore::new(box ::MetadataLoader));
 297
 298     let loader = file_loader.unwrap_or(box RealFileLoader);
 299     let codemap = Rc::new(CodeMap::with_file_loader(loader, sopts.file_path_mapping()));
 300     let mut sess = session::build_session_with_codemap(
 301         sopts, input_file_path, descriptions, codemap, emitter_dest,
 302     );
 303     rustc_trans::init(&sess);
 304     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 305
 306     let mut cfg = config::build_configuration(&sess, cfg);
 307     target_features::add_configuration(&mut cfg, &sess);
 308     sess.parse_sess.config = cfg;
 309
 310     do_or_return!(callbacks.late_callback(&matches,
 311                                           &sess,
 312                                           &*cstore,
 313                                           &input,
 314                                           &odir,
 315                                           &ofile), Some(sess));
 316
 317     let plugins = sess.opts.debugging_opts.extra_plugins.clone();
 318     let control = callbacks.build_controller(&sess, &matches);
 319     (driver::compile_input(&sess,
 320                            &cstore,
 321                            &input,
 322                            &odir,
 323                            &ofile,
 324                            Some(plugins),
 325                            &control),
 326      Some(sess))
 327 }
 328
 329 // Extract output directory and file from matches.
 330 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
 331     let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
 332     let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
 333     (odir, ofile)
 334 }
 335
 336 // Extract input (string or file and optional path) from matches.
 337 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>)> {
 338     if free_matches.len() == 1 {
 339         let ifile = &free_matches[0];
 340         if ifile == "-" {
 341             let mut src = String::new();
 342             io::stdin().read_to_string(&mut src).unwrap();
 343             Some((Input::Str { name: driver::anon_src(), input: src },
 344                   None))
 345         } else {
 346             Some((Input::File(PathBuf::from(ifile)),
 347                   Some(PathBuf::from(ifile))))
 348         }
 349     } else {
 350         None
 351     }
 352 }
 353
 354 fn parse_pretty(sess: &Session,
 355                 matches: &getopts::Matches)
 356                 -> Option<(PpMode, Option<UserIdentifiedItem>)> {
 357     let pretty = if sess.opts.debugging_opts.unstable_options {
 358         matches.opt_default("pretty", "normal").map(|a| {
 359             // stable pretty-print variants only
 360             pretty::parse_pretty(sess, &a, false)
 361         })
 362     } else {
 363         None
 364     };
 365     if pretty.is_none() && sess.unstable_options() {
 366         matches.opt_str("unpretty").map(|a| {
 367             // extended with unstable pretty-print variants
 368             pretty::parse_pretty(sess, &a, true)
 369         })
 370     } else {
 371         pretty
 372     }
 373 }
 374
 375 // Whether to stop or continue compilation.
 376 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 377 pub enum Compilation {
 378     Stop,
 379     Continue,
 380 }
 381
 382 impl Compilation {
 383     pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
 384         match self {
 385             Compilation::Stop => Compilation::Stop,
 386             Compilation::Continue => next(),
 387         }
 388     }
 389 }
 390
 391 // A trait for customising the compilation process. Offers a number of hooks for
 392 // executing custom code or customising input.
 393 pub trait CompilerCalls<'a> {
 394     // Hook for a callback early in the process of handling arguments. This will
 395     // be called straight after options have been parsed but before anything
 396     // else (e.g., selecting input and output).
 397     fn early_callback(&mut self,
 398                       _: &getopts::Matches,
 399                       _: &config::Options,
 400                       _: &ast::CrateConfig,
 401                       _: &errors::registry::Registry,
 402                       _: ErrorOutputType)
 403                       -> Compilation {
 404         Compilation::Continue
 405     }
 406
 407     // Hook for a callback late in the process of handling arguments. This will
 408     // be called just before actual compilation starts (and before build_controller
 409     // is called), after all arguments etc. have been completely handled.
 410     fn late_callback(&mut self,
 411                      _: &getopts::Matches,
 412                      _: &Session,
 413                      _: &CrateStore,
 414                      _: &Input,
 415                      _: &Option<PathBuf>,
 416                      _: &Option<PathBuf>)
 417                      -> Compilation {
 418         Compilation::Continue
 419     }
 420
 421     // Called after we extract the input from the arguments. Gives the implementer
 422     // an opportunity to change the inputs or to add some custom input handling.
 423     // The default behaviour is to simply pass through the inputs.
 424     fn some_input(&mut self,
 425                   input: Input,
 426                   input_path: Option<PathBuf>)
 427                   -> (Input, Option<PathBuf>) {
 428         (input, input_path)
 429     }
 430
 431     // Called after we extract the input from the arguments if there is no valid
 432     // input. Gives the implementer an opportunity to supply alternate input (by
 433     // returning a Some value) or to add custom behaviour for this error such as
 434     // emitting error messages. Returning None will cause compilation to stop
 435     // at this point.
 436     fn no_input(&mut self,
 437                 _: &getopts::Matches,
 438                 _: &config::Options,
 439                 _: &ast::CrateConfig,
 440                 _: &Option<PathBuf>,
 441                 _: &Option<PathBuf>,
 442                 _: &errors::registry::Registry)
 443                 -> Option<(Input, Option<PathBuf>)> {
 444         None
 445     }
 446
 447     // Create a CompilController struct for controlling the behaviour of
 448     // compilation.
 449     fn build_controller(&mut self, _: &Session, _: &getopts::Matches) -> CompileController<'a>;
 450 }
 451
 452 // CompilerCalls instance for a regular rustc build.
 453 #[derive(Copy, Clone)]
 454 pub struct RustcDefaultCalls;
 455
 456 // FIXME remove these and use winapi 0.3 instead
 457 // Duplicates: bootstrap/compile.rs, librustc_errors/emitter.rs
 458 #[cfg(unix)]
 459 fn stdout_isatty() -> bool {
 460     unsafe { libc::isatty(libc::STDOUT_FILENO) != 0 }
 461 }
 462
 463 #[cfg(windows)]
 464 fn stdout_isatty() -> bool {
 465     type DWORD = u32;
 466     type BOOL = i32;
 467     type HANDLE = *mut u8;
 468     type LPDWORD = *mut u32;
 469     const STD_OUTPUT_HANDLE: DWORD = -11i32 as DWORD;
 470     extern "system" {
 471         fn GetStdHandle(which: DWORD) -> HANDLE;
 472         fn GetConsoleMode(hConsoleHandle: HANDLE, lpMode: LPDWORD) -> BOOL;
 473     }
 474     unsafe {
 475         let handle = GetStdHandle(STD_OUTPUT_HANDLE);
 476         let mut out = 0;
 477         GetConsoleMode(handle, &mut out) != 0
 478     }
 479 }
 480
 481 fn handle_explain(code: &str,
 482                   descriptions: &errors::registry::Registry,
 483                   output: ErrorOutputType) {
 484     let normalised = if code.starts_with("E") {
 485         code.to_string()
 486     } else {
 487         format!("E{0:0>4}", code)
 488     };
 489     match descriptions.find_description(&normalised) {
 490         Some(ref description) => {
 491             let mut is_in_code_block = false;
 492             let mut text = String::new();
 493
 494             // Slice off the leading newline and print.
 495             for line in description[1..].lines() {
 496                 let indent_level = line.find(|c: char| !c.is_whitespace())
 497                     .unwrap_or_else(|| line.len());
 498                 let dedented_line = &line[indent_level..];
 499                 if dedented_line.starts_with("```") {
 500                     is_in_code_block = !is_in_code_block;
 501                     text.push_str(&line[..(indent_level+3)]);
 502                 } else if is_in_code_block && dedented_line.starts_with("# ") {
 503                     continue;
 504                 } else {
 505                     text.push_str(line);
 506                 }
 507                 text.push('\n');
 508             }
 509
 510             if stdout_isatty() {
 511                 show_content_with_pager(&text);
 512             } else {
 513                 print!("{}", text);
 514             }
 515         }
 516         None => {
 517             early_error(output, &format!("no extended information for {}", code));
 518         }
 519     }
 520 }
 521
 522 fn show_content_with_pager(content: &String) {
 523     let pager_name = env::var_os("PAGER").unwrap_or_else(|| if cfg!(windows) {
 524         OsString::from("more.com")
 525     } else {
 526         OsString::from("less")
 527     });
 528
 529     let mut fallback_to_println = false;
 530
 531     match Command::new(pager_name).stdin(Stdio::piped()).spawn() {
 532         Ok(mut pager) => {
 533             if let Some(pipe) = pager.stdin.as_mut() {
 534                 if pipe.write_all(content.as_bytes()).is_err() {
 535                     fallback_to_println = true;
 536                 }
 537             }
 538
 539             if pager.wait().is_err() {
 540                 fallback_to_println = true;
 541             }
 542         }
 543         Err(_) => {
 544             fallback_to_println = true;
 545         }
 546     }
 547
 548     // If pager fails for whatever reason, we should still print the content
 549     // to standard output
 550     if fallback_to_println {
 551         print!("{}", content);
 552     }
 553 }
 554
 555 impl<'a> CompilerCalls<'a> for RustcDefaultCalls {
 556     fn early_callback(&mut self,
 557                       matches: &getopts::Matches,
 558                       _: &config::Options,
 559                       _: &ast::CrateConfig,
 560                       descriptions: &errors::registry::Registry,
 561                       output: ErrorOutputType)
 562                       -> Compilation {
 563         if let Some(ref code) = matches.opt_str("explain") {
 564             handle_explain(code, descriptions, output);
 565             return Compilation::Stop;
 566         }
 567
 568         Compilation::Continue
 569     }
 570
 571     fn no_input(&mut self,
 572                 matches: &getopts::Matches,
 573                 sopts: &config::Options,
 574                 cfg: &ast::CrateConfig,
 575                 odir: &Option<PathBuf>,
 576                 ofile: &Option<PathBuf>,
 577                 descriptions: &errors::registry::Registry)
 578                 -> Option<(Input, Option<PathBuf>)> {
 579         match matches.free.len() {
 580             0 => {
 581                 if sopts.describe_lints {
 582                     let mut ls = lint::LintStore::new();
 583                     rustc_lint::register_builtins(&mut ls, None);
 584                     describe_lints(&ls, false);
 585                     return None;
 586                 }
 587                 let mut sess = build_session(sopts.clone(),
 588                     None,
 589                     descriptions.clone());
 590                 rustc_trans::init(&sess);
 591                 rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 592                 let mut cfg = config::build_configuration(&sess, cfg.clone());
 593                 target_features::add_configuration(&mut cfg, &sess);
 594                 sess.parse_sess.config = cfg;
 595                 let should_stop =
 596                     RustcDefaultCalls::print_crate_info(&sess, None, odir, ofile);
 597
 598                 if should_stop == Compilation::Stop {
 599                     return None;
 600                 }
 601                 early_error(sopts.error_format, "no input filename given");
 602             }
 603             1 => panic!("make_input should have provided valid inputs"),
 604             _ => early_error(sopts.error_format, "multiple input filenames provided"),
 605         }
 606     }
 607
 608     fn late_callback(&mut self,
 609                      matches: &getopts::Matches,
 610                      sess: &Session,
 611                      cstore: &CrateStore,
 612                      input: &Input,
 613                      odir: &Option<PathBuf>,
 614                      ofile: &Option<PathBuf>)
 615                      -> Compilation {
 616         RustcDefaultCalls::print_crate_info(sess, Some(input), odir, ofile)
 617             .and_then(|| RustcDefaultCalls::list_metadata(sess, cstore, matches, input))
 618     }
 619
 620     fn build_controller(&mut self,
 621                         sess: &Session,
 622                         matches: &getopts::Matches)
 623                         -> CompileController<'a> {
 624         let mut control = CompileController::basic();
 625
 626         control.keep_ast = sess.opts.debugging_opts.keep_ast;
 627         control.continue_parse_after_error = sess.opts.debugging_opts.continue_parse_after_error;
 628
 629         if let Some((ppm, opt_uii)) = parse_pretty(sess, matches) {
 630             if ppm.needs_ast_map(&opt_uii) {
 631                 control.after_hir_lowering.stop = Compilation::Stop;
 632
 633                 control.after_parse.callback = box move |state| {
 634                     state.krate = Some(pretty::fold_crate(state.krate.take().unwrap(), ppm));
 635                 };
 636                 control.after_hir_lowering.callback = box move |state| {
 637                     pretty::print_after_hir_lowering(state.session,
 638                                                      state.cstore.unwrap(),
 639                                                      state.hir_map.unwrap(),
 640                                                      state.analysis.unwrap(),
 641                                                      state.resolutions.unwrap(),
 642                                                      state.input,
 643                                                      &state.expanded_crate.take().unwrap(),
 644                                                      state.crate_name.unwrap(),
 645                                                      ppm,
 646                                                      state.arena.unwrap(),
 647                                                      state.arenas.unwrap(),
 648                                                      state.output_filenames.unwrap(),
 649                                                      opt_uii.clone(),
 650                                                      state.out_file);
 651                 };
 652             } else {
 653                 control.after_parse.stop = Compilation::Stop;
 654
 655                 control.after_parse.callback = box move |state| {
 656                     let krate = pretty::fold_crate(state.krate.take().unwrap(), ppm);
 657                     pretty::print_after_parsing(state.session,
 658                                                 state.input,
 659                                                 &krate,
 660                                                 ppm,
 661                                                 state.out_file);
 662                 };
 663             }
 664
 665             return control;
 666         }
 667
 668         if sess.opts.debugging_opts.parse_only ||
 669            sess.opts.debugging_opts.show_span.is_some() ||
 670            sess.opts.debugging_opts.ast_json_noexpand {
 671             control.after_parse.stop = Compilation::Stop;
 672         }
 673
 674         if sess.opts.debugging_opts.no_analysis ||
 675            sess.opts.debugging_opts.ast_json {
 676             control.after_hir_lowering.stop = Compilation::Stop;
 677         }
 678
 679         if !sess.opts.output_types.keys().any(|&i| i == OutputType::Exe ||
 680                                                    i == OutputType::Metadata) {
 681             control.after_llvm.stop = Compilation::Stop;
 682         }
 683
 684         if save_analysis(sess) {
 685             enable_save_analysis(&mut control);
 686         }
 687
 688         if sess.print_fuel_crate.is_some() {
 689             let old_callback = control.compilation_done.callback;
 690             control.compilation_done.callback = box move |state| {
 691                 old_callback(state);
 692                 let sess = state.session;
 693                 println!("Fuel used by {}: {}",
 694                     sess.print_fuel_crate.as_ref().unwrap(),
 695                     sess.print_fuel.get());
 696             }
 697         }
 698         control
 699     }
 700 }
 701
 702 pub fn enable_save_analysis(control: &mut CompileController) {
 703     control.keep_ast = true;
 704     control.after_analysis.callback = box |state| {
 705         time(state.session.time_passes(), "save analysis", || {
 706             save::process_crate(state.tcx.unwrap(),
 707                                 state.expanded_crate.unwrap(),
 708                                 state.analysis.unwrap(),
 709                                 state.crate_name.unwrap(),
 710                                 None,
 711                                 DumpHandler::new(state.out_dir,
 712                                                  state.crate_name.unwrap()))
 713         });
 714     };
 715     control.after_analysis.run_callback_on_error = true;
 716     control.make_glob_map = resolve::MakeGlobMap::Yes;
 717 }
 718
 719 fn save_analysis(sess: &Session) -> bool {
 720     sess.opts.debugging_opts.save_analysis
 721 }
 722
 723 impl RustcDefaultCalls {
 724     pub fn list_metadata(sess: &Session,
 725                          cstore: &CrateStore,
 726                          matches: &getopts::Matches,
 727                          input: &Input)
 728                          -> Compilation {
 729         let r = matches.opt_strs("Z");
 730         if r.contains(&("ls".to_string())) {
 731             match input {
 732                 &Input::File(ref ifile) => {
 733                     let path = &(*ifile);
 734                     let mut v = Vec::new();
 735                     locator::list_file_metadata(&sess.target.target,
 736                                                 path,
 737                                                 cstore.metadata_loader(),
 738                                                 &mut v)
 739                             .unwrap();
 740                     println!("{}", String::from_utf8(v).unwrap());
 741                 }
 742                 &Input::Str { .. } => {
 743                     early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
 744                 }
 745             }
 746             return Compilation::Stop;
 747         }
 748
 749         return Compilation::Continue;
 750     }
 751
 752
 753     fn print_crate_info(sess: &Session,
 754                         input: Option<&Input>,
 755                         odir: &Option<PathBuf>,
 756                         ofile: &Option<PathBuf>)
 757                         -> Compilation {
 758         // PrintRequest::NativeStaticLibs is special - printed during linking
 759         // (empty iterator returns true)
 760         if sess.opts.prints.iter().all(|&p| p==PrintRequest::NativeStaticLibs) {
 761             return Compilation::Continue;
 762         }
 763
 764         let attrs = match input {
 765             None => None,
 766             Some(input) => {
 767                 let result = parse_crate_attrs(sess, input);
 768                 match result {
 769                     Ok(attrs) => Some(attrs),
 770                     Err(mut parse_error) => {
 771                         parse_error.emit();
 772                         return Compilation::Stop;
 773                     }
 774                 }
 775             }
 776         };
 777         for req in &sess.opts.prints {
 778             match *req {
 779                 PrintRequest::TargetList => {
 780                     let mut targets = rustc_back::target::get_targets().collect::<Vec<String>>();
 781                     targets.sort();
 782                     println!("{}", targets.join("\n"));
 783                 },
 784                 PrintRequest::Sysroot => println!("{}", sess.sysroot().display()),
 785                 PrintRequest::TargetSpec => println!("{}", sess.target.target.to_json().pretty()),
 786                 PrintRequest::FileNames |
 787                 PrintRequest::CrateName => {
 788                     let input = match input {
 789                         Some(input) => input,
 790                         None => early_error(ErrorOutputType::default(), "no input file provided"),
 791                     };
 792                     let attrs = attrs.as_ref().unwrap();
 793                     let t_outputs = driver::build_output_filenames(input, odir, ofile, attrs, sess);
 794                     let id = rustc_trans_utils::link::find_crate_name(Some(sess), attrs, input);
 795                     if *req == PrintRequest::CrateName {
 796                         println!("{}", id);
 797                         continue;
 798                     }
 799                     let crate_types = driver::collect_crate_types(sess, attrs);
 800                     for &style in &crate_types {
 801                         let fname = rustc_trans_utils::link::filename_for_input(
 802                             sess,
 803                             style,
 804                             &id,
 805                             &t_outputs
 806                         );
 807                         println!("{}",
 808                                  fname.file_name()
 809                                       .unwrap()
 810                                       .to_string_lossy());
 811                     }
 812                 }
 813                 PrintRequest::Cfg => {
 814                     let allow_unstable_cfg = UnstableFeatures::from_environment()
 815                         .is_nightly_build();
 816
 817                     let mut cfgs = Vec::new();
 818                     for &(name, ref value) in sess.parse_sess.config.iter() {
 819                         let gated_cfg = GatedCfg::gate(&ast::MetaItem {
 820                             name,
 821                             node: ast::MetaItemKind::Word,
 822                             span: DUMMY_SP,
 823                         });
 824
 825                         // Note that crt-static is a specially recognized cfg
 826                         // directive that's printed out here as part of
 827                         // rust-lang/rust#37406, but in general the
 828                         // `target_feature` cfg is gated under
 829                         // rust-lang/rust#29717. For now this is just
 830                         // specifically allowing the crt-static cfg and that's
 831                         // it, this is intended to get into Cargo and then go
 832                         // through to build scripts.
 833                         let value = value.as_ref().map(|s| s.as_str());
 834                         let value = value.as_ref().map(|s| s.as_ref());
 835                         if name != "target_feature" || value != Some("crt-static") {
 836                             if !allow_unstable_cfg && gated_cfg.is_some() {
 837                                 continue;
 838                             }
 839                         }
 840
 841                         cfgs.push(if let Some(value) = value {
 842                             format!("{}=\"{}\"", name, value)
 843                         } else {
 844                             format!("{}", name)
 845                         });
 846                     }
 847
 848                     cfgs.sort();
 849                     for cfg in cfgs {
 850                         println!("{}", cfg);
 851                     }
 852                 }
 853                 PrintRequest::RelocationModels => {
 854                     println!("Available relocation models:");
 855                     for &(name, _) in rustc_trans::back::write::RELOC_MODEL_ARGS.iter() {
 856                         println!("    {}", name);
 857                     }
 858                     println!("");
 859                 }
 860                 PrintRequest::CodeModels => {
 861                     println!("Available code models:");
 862                     for &(name, _) in rustc_trans::back::write::CODE_GEN_MODEL_ARGS.iter(){
 863                         println!("    {}", name);
 864                     }
 865                     println!("");
 866                 }
 867                 PrintRequest::TargetCPUs | PrintRequest::TargetFeatures => {
 868                     rustc_trans::print(*req, sess);
 869                 }
 870                 PrintRequest::NativeStaticLibs => {
 871                     println!("Native static libs can be printed only during linking");
 872                 }
 873             }
 874         }
 875         return Compilation::Stop;
 876     }
 877 }
 878
 879 /// Returns a version string such as "0.12.0-dev".
 880 fn release_str() -> Option<&'static str> {
 881     option_env!("CFG_RELEASE")
 882 }
 883
 884 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 885 fn commit_hash_str() -> Option<&'static str> {
 886     option_env!("CFG_VER_HASH")
 887 }
 888
 889 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 890 fn commit_date_str() -> Option<&'static str> {
 891     option_env!("CFG_VER_DATE")
 892 }
 893
 894 /// Prints version information
 895 pub fn version(binary: &str, matches: &getopts::Matches) {
 896     let verbose = matches.opt_present("verbose");
 897
 898     println!("{} {}",
 899              binary,
 900              option_env!("CFG_VERSION").unwrap_or("unknown version"));
 901     if verbose {
 902         fn unw(x: Option<&str>) -> &str {
 903             x.unwrap_or("unknown")
 904         }
 905         println!("binary: {}", binary);
 906         println!("commit-hash: {}", unw(commit_hash_str()));
 907         println!("commit-date: {}", unw(commit_date_str()));
 908         println!("host: {}", config::host_triple());
 909         println!("release: {}", unw(release_str()));
 910         rustc_trans::print_version();
 911     }
 912 }
 913
 914 fn usage(verbose: bool, include_unstable_options: bool) {
 915     let groups = if verbose {
 916         config::rustc_optgroups()
 917     } else {
 918         config::rustc_short_optgroups()
 919     };
 920     let mut options = getopts::Options::new();
 921     for option in groups.iter().filter(|x| include_unstable_options || x.is_stable()) {
 922         (option.apply)(&mut options);
 923     }
 924     let message = format!("Usage: rustc [OPTIONS] INPUT");
 925     let nightly_help = if nightly_options::is_nightly_build() {
 926         "\n    -Z help             Print internal options for debugging rustc"
 927     } else {
 928         ""
 929     };
 930     let verbose_help = if verbose {
 931         ""
 932     } else {
 933         "\n    --help -v           Print the full set of options rustc accepts"
 934     };
 935     println!("{}\nAdditional help:
 936     -C help             Print codegen options
 937     -W help             \
 938               Print 'lint' options and default settings{}{}\n",
 939              options.usage(&message),
 940              nightly_help,
 941              verbose_help);
 942 }
 943
 944 fn describe_lints(lint_store: &lint::LintStore, loaded_plugins: bool) {
 945     println!("
 946 Available lint options:
 947     -W <foo>           Warn about <foo>
 948     -A <foo>           \
 949               Allow <foo>
 950     -D <foo>           Deny <foo>
 951     -F <foo>           Forbid <foo> \
 952               (deny <foo> and all attempts to override)
 953
 954 ");
 955
 956     fn sort_lints(lints: Vec<(&'static Lint, bool)>) -> Vec<&'static Lint> {
 957         let mut lints: Vec<_> = lints.into_iter().map(|(x, _)| x).collect();
 958         lints.sort_by(|x: &&Lint, y: &&Lint| {
 959             match x.default_level.cmp(&y.default_level) {
 960                 // The sort doesn't case-fold but it's doubtful we care.
 961                 Equal => x.name.cmp(y.name),
 962                 r => r,
 963             }
 964         });
 965         lints
 966     }
 967
 968     fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
 969                         -> Vec<(&'static str, Vec<lint::LintId>)> {
 970         let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
 971         lints.sort_by(|&(x, _): &(&'static str, Vec<lint::LintId>),
 972                        &(y, _): &(&'static str, Vec<lint::LintId>)| {
 973             x.cmp(y)
 974         });
 975         lints
 976     }
 977
 978     let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints()
 979                                                    .iter()
 980                                                    .cloned()
 981                                                    .partition(|&(_, p)| p);
 982     let plugin = sort_lints(plugin);
 983     let builtin = sort_lints(builtin);
 984
 985     let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups()
 986                                                                  .iter()
 987                                                                  .cloned()
 988                                                                  .partition(|&(.., p)| p);
 989     let plugin_groups = sort_lint_groups(plugin_groups);
 990     let builtin_groups = sort_lint_groups(builtin_groups);
 991
 992     let max_name_len = plugin.iter()
 993                              .chain(&builtin)
 994                              .map(|&s| s.name.chars().count())
 995                              .max()
 996                              .unwrap_or(0);
 997     let padded = |x: &str| {
 998         let mut s = repeat(" ")
 999                         .take(max_name_len - x.chars().count())
1000                         .collect::<String>();
1001         s.push_str(x);
1002         s
1003     };
1004
1005     println!("Lint checks provided by rustc:\n");
1006     println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
1007     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
1008
1009     let print_lints = |lints: Vec<&Lint>| {
1010         for lint in lints {
1011             let name = lint.name_lower().replace("_", "-");
1012             println!("    {}  {:7.7}  {}",
1013                      padded(&name),
1014                      lint.default_level.as_str(),
1015                      lint.desc);
1016         }
1017         println!("\n");
1018     };
1019
1020     print_lints(builtin);
1021
1022
1023
1024     let max_name_len = max("warnings".len(),
1025                            plugin_groups.iter()
1026                                         .chain(&builtin_groups)
1027                                         .map(|&(s, _)| s.chars().count())
1028                                         .max()
1029                                         .unwrap_or(0));
1030
1031     let padded = |x: &str| {
1032         let mut s = repeat(" ")
1033                         .take(max_name_len - x.chars().count())
1034                         .collect::<String>();
1035         s.push_str(x);
1036         s
1037     };
1038
1039     println!("Lint groups provided by rustc:\n");
1040     println!("    {}  {}", padded("name"), "sub-lints");
1041     println!("    {}  {}", padded("----"), "---------");
1042     println!("    {}  {}", padded("warnings"), "all built-in lints");
1043
1044     let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
1045         for (name, to) in lints {
1046             let name = name.to_lowercase().replace("_", "-");
1047             let desc = to.into_iter()
1048                          .map(|x| x.to_string().replace("_", "-"))
1049                          .collect::<Vec<String>>()
1050                          .join(", ");
1051             println!("    {}  {}", padded(&name), desc);
1052         }
1053         println!("\n");
1054     };
1055
1056     print_lint_groups(builtin_groups);
1057
1058     match (loaded_plugins, plugin.len(), plugin_groups.len()) {
1059         (false, 0, _) | (false, _, 0) => {
1060             println!("Compiler plugins can provide additional lints and lint groups. To see a \
1061                       listing of these, re-run `rustc -W help` with a crate filename.");
1062         }
1063         (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
1064         (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
1065         (true, l, g) => {
1066             if l > 0 {
1067                 println!("Lint checks provided by plugins loaded by this crate:\n");
1068                 print_lints(plugin);
1069             }
1070             if g > 0 {
1071                 println!("Lint groups provided by plugins loaded by this crate:\n");
1072                 print_lint_groups(plugin_groups);
1073             }
1074         }
1075     }
1076 }
1077
1078 fn describe_debug_flags() {
1079     println!("\nAvailable debug options:\n");
1080     print_flag_list("-Z", config::DB_OPTIONS);
1081 }
1082
1083 fn describe_codegen_flags() {
1084     println!("\nAvailable codegen options:\n");
1085     print_flag_list("-C", config::CG_OPTIONS);
1086 }
1087
1088 fn print_flag_list<T>(cmdline_opt: &str,
1089                       flag_list: &[(&'static str, T, Option<&'static str>, &'static str)]) {
1090     let max_len = flag_list.iter()
1091                            .map(|&(name, _, opt_type_desc, _)| {
1092                                let extra_len = match opt_type_desc {
1093                                    Some(..) => 4,
1094                                    None => 0,
1095                                };
1096                                name.chars().count() + extra_len
1097                            })
1098                            .max()
1099                            .unwrap_or(0);
1100
1101     for &(name, _, opt_type_desc, desc) in flag_list {
1102         let (width, extra) = match opt_type_desc {
1103             Some(..) => (max_len - 4, "=val"),
1104             None => (max_len, ""),
1105         };
1106         println!("    {} {:>width$}{} -- {}",
1107                  cmdline_opt,
1108                  name.replace("_", "-"),
1109                  extra,
1110                  desc,
1111                  width = width);
1112     }
1113 }
1114
1115 /// Process command line options. Emits messages as appropriate. If compilation
1116 /// should continue, returns a getopts::Matches object parsed from args,
1117 /// otherwise returns None.
1118 ///
1119 /// The compiler's handling of options is a little complicated as it ties into
1120 /// our stability story, and it's even *more* complicated by historical
1121 /// accidents. The current intention of each compiler option is to have one of
1122 /// three modes:
1123 ///
1124 /// 1. An option is stable and can be used everywhere.
1125 /// 2. An option is unstable, but was historically allowed on the stable
1126 ///    channel.
1127 /// 3. An option is unstable, and can only be used on nightly.
1128 ///
1129 /// Like unstable library and language features, however, unstable options have
1130 /// always required a form of "opt in" to indicate that you're using them. This
1131 /// provides the easy ability to scan a code base to check to see if anything
1132 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
1133 ///
1134 /// All options behind `-Z` are considered unstable by default. Other top-level
1135 /// options can also be considered unstable, and they were unlocked through the
1136 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
1137 /// instability in both cases, though.
1138 ///
1139 /// So with all that in mind, the comments below have some more detail about the
1140 /// contortions done here to get things to work out correctly.
1141 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
1142     // Throw away the first argument, the name of the binary
1143     let args = &args[1..];
1144
1145     if args.is_empty() {
1146         // user did not write `-v` nor `-Z unstable-options`, so do not
1147         // include that extra information.
1148         usage(false, false);
1149         return None;
1150     }
1151
1152     // Parse with *all* options defined in the compiler, we don't worry about
1153     // option stability here we just want to parse as much as possible.
1154     let mut options = getopts::Options::new();
1155     for option in config::rustc_optgroups() {
1156         (option.apply)(&mut options);
1157     }
1158     let matches = match options.parse(args) {
1159         Ok(m) => m,
1160         Err(f) => early_error(ErrorOutputType::default(), &f.to_string()),
1161     };
1162
1163     // For all options we just parsed, we check a few aspects:
1164     //
1165     // * If the option is stable, we're all good
1166     // * If the option wasn't passed, we're all good
1167     // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
1168     //   ourselves), then we require the `-Z unstable-options` flag to unlock
1169     //   this option that was passed.
1170     // * If we're a nightly compiler, then unstable options are now unlocked, so
1171     //   we're good to go.
1172     // * Otherwise, if we're a truly unstable option then we generate an error
1173     //   (unstable option being used on stable)
1174     // * If we're a historically stable-but-should-be-unstable option then we
1175     //   emit a warning that we're going to turn this into an error soon.
1176     nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
1177
1178     if matches.opt_present("h") || matches.opt_present("help") {
1179         // Only show unstable options in --help if we *really* accept unstable
1180         // options, which catches the case where we got `-Z unstable-options` on
1181         // the stable channel of Rust which was accidentally allowed
1182         // historically.
1183         usage(matches.opt_present("verbose"),
1184               nightly_options::is_unstable_enabled(&matches));
1185         return None;
1186     }
1187
1188     // Don't handle -W help here, because we might first load plugins.
1189     let r = matches.opt_strs("Z");
1190     if r.iter().any(|x| *x == "help") {
1191         describe_debug_flags();
1192         return None;
1193     }
1194
1195     let cg_flags = matches.opt_strs("C");
1196     if cg_flags.iter().any(|x| *x == "help") {
1197         describe_codegen_flags();
1198         return None;
1199     }
1200
1201     if cg_flags.iter().any(|x| *x == "no-stack-check") {
1202         early_warn(ErrorOutputType::default(),
1203                    "the --no-stack-check flag is deprecated and does nothing");
1204     }
1205
1206     if cg_flags.contains(&"passes=list".to_string()) {
1207         rustc_trans::print_passes();
1208         return None;
1209     }
1210
1211     if matches.opt_present("version") {
1212         version("rustc", &matches);
1213         return None;
1214     }
1215
1216     Some(matches)
1217 }
1218
1219 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1220     match *input {
1221         Input::File(ref ifile) => {
1222             parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess)
1223         }
1224         Input::Str { ref name, ref input } => {
1225             parse::parse_crate_attrs_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
1226         }
1227     }
1228 }
1229
1230 /// Runs `f` in a suitable thread for running `rustc`; returns a
1231 /// `Result` with either the return value of `f` or -- if a panic
1232 /// occurs -- the panic value.
1233 pub fn in_rustc_thread<F, R>(f: F) -> Result<R, Box<Any + Send>>
1234     where F: FnOnce() -> R + Send + 'static,
1235           R: Send + 'static,
1236 {
1237     // Temporarily have stack size set to 16MB to deal with nom-using crates failing
1238     const STACK_SIZE: usize = 16 * 1024 * 1024; // 16MB
1239
1240     let mut cfg = thread::Builder::new().name("rustc".to_string());
1241
1242     // FIXME: Hacks on hacks. If the env is trying to override the stack size
1243     // then *don't* set it explicitly.
1244     if env::var_os("RUST_MIN_STACK").is_none() {
1245         cfg = cfg.stack_size(STACK_SIZE);
1246     }
1247
1248     let thread = cfg.spawn(f);
1249     thread.unwrap().join()
1250 }
1251
1252 /// Run a procedure which will detect panics in the compiler and print nicer
1253 /// error messages rather than just failing the test.
1254 ///
1255 /// The diagnostic emitter yielded to the procedure should be used for reporting
1256 /// errors of the compiler.
1257 pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
1258     struct Sink(Arc<Mutex<Vec<u8>>>);
1259     impl Write for Sink {
1260         fn write(&mut self, data: &[u8]) -> io::Result<usize> {
1261             Write::write(&mut *self.0.lock().unwrap(), data)
1262         }
1263         fn flush(&mut self) -> io::Result<()> {
1264             Ok(())
1265         }
1266     }
1267
1268     let data = Arc::new(Mutex::new(Vec::new()));
1269     let err = Sink(data.clone());
1270
1271     let result = in_rustc_thread(move || {
1272         io::set_panic(Some(box err));
1273         f()
1274     });
1275
1276     if let Err(value) = result {
1277         // Thread panicked without emitting a fatal diagnostic
1278         if !value.is::<errors::FatalError>() {
1279             let emitter =
1280                 Box::new(errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto, None));
1281             let handler = errors::Handler::with_emitter(true, false, emitter);
1282
1283             // a .span_bug or .bug call has already printed what
1284             // it wants to print.
1285             if !value.is::<errors::ExplicitBug>() {
1286                 handler.emit(&MultiSpan::new(),
1287                              "unexpected panic",
1288                              errors::Level::Bug);
1289             }
1290
1291             let xs = ["the compiler unexpectedly panicked. this is a bug.".to_string(),
1292                       format!("we would appreciate a bug report: {}", BUG_REPORT_URL),
1293                       format!("rustc {} running on {}",
1294                               option_env!("CFG_VERSION").unwrap_or("unknown_version"),
1295                               config::host_triple())];
1296             for note in &xs {
1297                 handler.emit(&MultiSpan::new(),
1298                              &note,
1299                              errors::Level::Note);
1300             }
1301             if match env::var_os("RUST_BACKTRACE") {
1302                 Some(val) => &val != "0",
1303                 None => false,
1304             } {
1305                 handler.emit(&MultiSpan::new(),
1306                              "run with `RUST_BACKTRACE=1` for a backtrace",
1307                              errors::Level::Note);
1308             }
1309
1310             writeln!(io::stderr(), "{}", str::from_utf8(&data.lock().unwrap()).unwrap()).unwrap();
1311         }
1312
1313         exit_on_err();
1314     }
1315 }
1316
1317 fn exit_on_err() -> ! {
1318     // Panic so the process returns a failure code, but don't pollute the
1319     // output with some unnecessary panic messages, we've already
1320     // printed everything that we needed to.
1321     io::set_panic(Some(box io::sink()));
1322     panic!();
1323 }
1324
1325 pub fn diagnostics_registry() -> errors::registry::Registry {
1326     use errors::registry::Registry;
1327
1328     let mut all_errors = Vec::new();
1329     all_errors.extend_from_slice(&rustc::DIAGNOSTICS);
1330     all_errors.extend_from_slice(&rustc_typeck::DIAGNOSTICS);
1331     all_errors.extend_from_slice(&rustc_borrowck::DIAGNOSTICS);
1332     all_errors.extend_from_slice(&rustc_resolve::DIAGNOSTICS);
1333     all_errors.extend_from_slice(&rustc_privacy::DIAGNOSTICS);
1334     all_errors.extend_from_slice(&rustc_trans::DIAGNOSTICS);
1335     all_errors.extend_from_slice(&rustc_const_eval::DIAGNOSTICS);
1336     all_errors.extend_from_slice(&rustc_metadata::DIAGNOSTICS);
1337     all_errors.extend_from_slice(&rustc_passes::DIAGNOSTICS);
1338     all_errors.extend_from_slice(&rustc_plugin::DIAGNOSTICS);
1339     all_errors.extend_from_slice(&rustc_mir::DIAGNOSTICS);
1340     all_errors.extend_from_slice(&syntax::DIAGNOSTICS);
1341
1342     Registry::new(&all_errors)
1343 }
1344
1345 pub fn get_args() -> Vec<String> {
1346     env::args_os().enumerate()
1347         .map(|(i, arg)| arg.into_string().unwrap_or_else(|arg| {
1348              early_error(ErrorOutputType::default(),
1349                          &format!("Argument {} is not valid Unicode: {:?}", i, arg))
1350          }))
1351         .collect()
1352 }
1353
1354 pub fn main() {
1355     env_logger::init().unwrap();
1356     let result = run(|| run_compiler(&get_args(),
1357                                      &mut RustcDefaultCalls,
1358                                      None,
1359                                      None));
1360     process::exit(result as i32);
1361 }