src/librustc_driver/driver.rs

   1 // Copyright 2012-2015 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 use rustc::dep_graph::DepGraph;
  12 use rustc::hir::{self, map as hir_map};
  13 use rustc::hir::lowering::lower_crate;
  14 use rustc::ich::Fingerprint;
  15 use rustc_data_structures::stable_hasher::StableHasher;
  16 use rustc_mir as mir;
  17 use rustc::session::{Session, CompileResult};
  18 use rustc::session::CompileIncomplete;
  19 use rustc::session::config::{self, Input, OutputFilenames, OutputType};
  20 use rustc::session::search_paths::PathKind;
  21 use rustc::lint;
  22 use rustc::middle::{self, stability, reachable};
  23 use rustc::middle::cstore::CrateStore;
  24 use rustc::middle::privacy::AccessLevels;
  25 use rustc::mir::transform::{MIR_CONST, MIR_VALIDATED, MIR_OPTIMIZED, Passes};
  26 use rustc::ty::{self, TyCtxt, Resolutions, GlobalArenas};
  27 use rustc::traits;
  28 use rustc::util::common::{ErrorReported, time};
  29 use rustc_allocator as allocator;
  30 use rustc_borrowck as borrowck;
  31 use rustc_incremental;
  32 use rustc_resolve::{MakeGlobMap, Resolver};
  33 use rustc_metadata::creader::CrateLoader;
  34 use rustc_metadata::cstore::{self, CStore};
  35 use rustc_trans as trans;
  36 use rustc_trans_utils::trans_crate::TransCrate;
  37 use rustc_typeck as typeck;
  38 use rustc_privacy;
  39 use rustc_plugin::registry::Registry;
  40 use rustc_plugin as plugin;
  41 use rustc_passes::{ast_validation, no_asm, loops, consts, static_recursion, hir_stats};
  42 use rustc_const_eval::{self, check_match};
  43 use super::Compilation;
  44 use ::DefaultTransCrate;
  45
  46 use serialize::json;
  47
  48 use std::any::Any;
  49 use std::env;
  50 use std::ffi::{OsString, OsStr};
  51 use std::fs;
  52 use std::io::{self, Write};
  53 use std::iter;
  54 use std::path::{Path, PathBuf};
  55 use std::rc::Rc;
  56 use std::sync::mpsc;
  57 use syntax::{ast, diagnostics, visit};
  58 use syntax::attr;
  59 use syntax::ext::base::ExtCtxt;
  60 use syntax::parse::{self, PResult};
  61 use syntax::symbol::Symbol;
  62 use syntax::util::node_count::NodeCounter;
  63 use syntax;
  64 use syntax_ext;
  65 use arena::DroplessArena;
  66
  67 use derive_registrar;
  68
  69 use profile;
  70
  71 pub fn compile_input(sess: &Session,
  72                      cstore: &CStore,
  73                      input: &Input,
  74                      outdir: &Option<PathBuf>,
  75                      output: &Option<PathBuf>,
  76                      addl_plugins: Option<Vec<String>>,
  77                      control: &CompileController) -> CompileResult {
  78     use rustc::session::config::CrateType;
  79
  80     macro_rules! controller_entry_point {
  81         ($point: ident, $tsess: expr, $make_state: expr, $phase_result: expr) => {{
  82             let state = &mut $make_state;
  83             let phase_result: &CompileResult = &$phase_result;
  84             if phase_result.is_ok() || control.$point.run_callback_on_error {
  85                 (control.$point.callback)(state);
  86             }
  87
  88             if control.$point.stop == Compilation::Stop {
  89                 // FIXME: shouldn't this return Err(CompileIncomplete::Stopped)
  90                 // if there are no errors?
  91                 return $tsess.compile_status();
  92             }
  93         }}
  94     }
  95
  96     if cfg!(not(feature="llvm")) {
  97         for cty in sess.opts.crate_types.iter() {
  98             match *cty {
  99                 CrateType::CrateTypeRlib | CrateType::CrateTypeDylib |
 100                 CrateType::CrateTypeExecutable => {},
 101                 _ => {
 102                     sess.parse_sess.span_diagnostic.warn(
 103                         &format!("LLVM unsupported, so output type {} is not supported", cty)
 104                     );
 105                 },
 106             }
 107         }
 108
 109         sess.abort_if_errors();
 110     }
 111
 112     if sess.profile_queries() {
 113         profile::begin();
 114     }
 115
 116     // We need nested scopes here, because the intermediate results can keep
 117     // large chunks of memory alive and we want to free them as soon as
 118     // possible to keep the peak memory usage low
 119     let (outputs, trans, dep_graph) = {
 120         let krate = match phase_1_parse_input(control, sess, input) {
 121             Ok(krate) => krate,
 122             Err(mut parse_error) => {
 123                 parse_error.emit();
 124                 return Err(CompileIncomplete::Errored(ErrorReported));
 125             }
 126         };
 127
 128         let (krate, registry) = {
 129             let mut compile_state = CompileState::state_after_parse(input,
 130                                                                     sess,
 131                                                                     outdir,
 132                                                                     output,
 133                                                                     krate,
 134                                                                     &cstore);
 135             controller_entry_point!(after_parse,
 136                                     sess,
 137                                     compile_state,
 138                                     Ok(()));
 139
 140             (compile_state.krate.unwrap(), compile_state.registry)
 141         };
 142
 143         let outputs = build_output_filenames(input, outdir, output, &krate.attrs, sess);
 144         let crate_name =
 145             ::rustc_trans_utils::link::find_crate_name(Some(sess), &krate.attrs, input);
 146         let ExpansionResult { expanded_crate, defs, analysis, resolutions, mut hir_forest } = {
 147             phase_2_configure_and_expand(
 148                 sess,
 149                 &cstore,
 150                 krate,
 151                 registry,
 152                 &crate_name,
 153                 addl_plugins,
 154                 control.make_glob_map,
 155                 |expanded_crate| {
 156                     let mut state = CompileState::state_after_expand(
 157                         input, sess, outdir, output, &cstore, expanded_crate, &crate_name,
 158                     );
 159                     controller_entry_point!(after_expand, sess, state, Ok(()));
 160                     Ok(())
 161                 }
 162             )?
 163         };
 164
 165         write_out_deps(sess, &outputs, &crate_name);
 166         if sess.opts.output_types.contains_key(&OutputType::DepInfo) &&
 167             sess.opts.output_types.keys().count() == 1 {
 168             return Ok(())
 169         }
 170
 171         let arena = DroplessArena::new();
 172         let arenas = GlobalArenas::new();
 173
 174         // Construct the HIR map
 175         let hir_map = time(sess.time_passes(),
 176                            "indexing hir",
 177                            || hir_map::map_crate(sess, cstore, &mut hir_forest, &defs));
 178
 179         {
 180             let _ignore = hir_map.dep_graph.in_ignore();
 181             controller_entry_point!(after_hir_lowering,
 182                                     sess,
 183                                     CompileState::state_after_hir_lowering(input,
 184                                                                   sess,
 185                                                                   outdir,
 186                                                                   output,
 187                                                                   &arena,
 188                                                                   &arenas,
 189                                                                   &cstore,
 190                                                                   &hir_map,
 191                                                                   &analysis,
 192                                                                   &resolutions,
 193                                                                   &expanded_crate,
 194                                                                   &hir_map.krate(),
 195                                                                   &outputs,
 196                                                                   &crate_name),
 197                                     Ok(()));
 198         }
 199
 200         time(sess.time_passes(), "attribute checking", || {
 201             hir::check_attr::check_crate(sess, &expanded_crate);
 202         });
 203
 204         let opt_crate = if control.keep_ast {
 205             Some(&expanded_crate)
 206         } else {
 207             drop(expanded_crate);
 208             None
 209         };
 210
 211         phase_3_run_analysis_passes(sess,
 212                                     cstore,
 213                                     hir_map,
 214                                     analysis,
 215                                     resolutions,
 216                                     &arena,
 217                                     &arenas,
 218                                     &crate_name,
 219                                     &outputs,
 220                                     |tcx, analysis, rx, result| {
 221             {
 222                 // Eventually, we will want to track plugins.
 223                 let _ignore = tcx.dep_graph.in_ignore();
 224
 225                 let mut state = CompileState::state_after_analysis(input,
 226                                                                    sess,
 227                                                                    outdir,
 228                                                                    output,
 229                                                                    opt_crate,
 230                                                                    tcx.hir.krate(),
 231                                                                    &analysis,
 232                                                                    tcx,
 233                                                                    &crate_name);
 234                 (control.after_analysis.callback)(&mut state);
 235
 236                 if control.after_analysis.stop == Compilation::Stop {
 237                     return result.and_then(|_| Err(CompileIncomplete::Stopped));
 238                 }
 239             }
 240
 241             result?;
 242
 243             if log_enabled!(::log::LogLevel::Info) {
 244                 println!("Pre-trans");
 245                 tcx.print_debug_stats();
 246             }
 247
 248             let trans = phase_4_translate_to_llvm::<DefaultTransCrate>(tcx, rx);
 249
 250             if log_enabled!(::log::LogLevel::Info) {
 251                 println!("Post-trans");
 252                 tcx.print_debug_stats();
 253             }
 254
 255             if tcx.sess.opts.output_types.contains_key(&OutputType::Mir) {
 256                 if let Err(e) = mir::transform::dump_mir::emit_mir(tcx, &outputs) {
 257                     sess.err(&format!("could not emit MIR: {}", e));
 258                     sess.abort_if_errors();
 259                 }
 260             }
 261
 262             Ok((outputs.clone(), trans, tcx.dep_graph.clone()))
 263         })??
 264     };
 265
 266     if sess.opts.debugging_opts.print_type_sizes {
 267         sess.code_stats.borrow().print_type_sizes();
 268     }
 269
 270     let (phase5_result, trans) =
 271         phase_5_run_llvm_passes::<DefaultTransCrate>(sess, &dep_graph, trans);
 272
 273     controller_entry_point!(after_llvm,
 274                             sess,
 275                             CompileState::state_after_llvm(input, sess, outdir, output, &trans),
 276                             phase5_result);
 277     phase5_result?;
 278
 279     // Run the linker on any artifacts that resulted from the LLVM run.
 280     // This should produce either a finished executable or library.
 281     time(sess.time_passes(), "linking", || {
 282         DefaultTransCrate::link_binary(sess, &trans, &outputs)
 283     });
 284
 285     // Now that we won't touch anything in the incremental compilation directory
 286     // any more, we can finalize it (which involves renaming it)
 287     #[cfg(feature="llvm")]
 288     rustc_incremental::finalize_session_directory(sess, trans.link.crate_hash);
 289
 290     if sess.opts.debugging_opts.perf_stats {
 291         sess.print_perf_stats();
 292     }
 293
 294     controller_entry_point!(
 295         compilation_done,
 296         sess,
 297         CompileState::state_when_compilation_done(input, sess, outdir, output),
 298         Ok(())
 299     );
 300
 301     Ok(())
 302 }
 303
 304 fn keep_hygiene_data(sess: &Session) -> bool {
 305     sess.opts.debugging_opts.keep_hygiene_data
 306 }
 307
 308
 309 /// The name used for source code that doesn't originate in a file
 310 /// (e.g. source from stdin or a string)
 311 pub fn anon_src() -> String {
 312     "<anon>".to_string()
 313 }
 314
 315 pub fn source_name(input: &Input) -> String {
 316     match *input {
 317         // FIXME (#9639): This needs to handle non-utf8 paths
 318         Input::File(ref ifile) => ifile.to_str().unwrap().to_string(),
 319         Input::Str { ref name, .. } => name.clone(),
 320     }
 321 }
 322
 323 /// CompileController is used to customize compilation, it allows compilation to
 324 /// be stopped and/or to call arbitrary code at various points in compilation.
 325 /// It also allows for various flags to be set to influence what information gets
 326 /// collected during compilation.
 327 ///
 328 /// This is a somewhat higher level controller than a Session - the Session
 329 /// controls what happens in each phase, whereas the CompileController controls
 330 /// whether a phase is run at all and whether other code (from outside the
 331 /// compiler) is run between phases.
 332 ///
 333 /// Note that if compilation is set to stop and a callback is provided for a
 334 /// given entry point, the callback is called before compilation is stopped.
 335 ///
 336 /// Expect more entry points to be added in the future.
 337 pub struct CompileController<'a> {
 338     pub after_parse: PhaseController<'a>,
 339     pub after_expand: PhaseController<'a>,
 340     pub after_hir_lowering: PhaseController<'a>,
 341     pub after_analysis: PhaseController<'a>,
 342     pub after_llvm: PhaseController<'a>,
 343     pub compilation_done: PhaseController<'a>,
 344
 345     // FIXME we probably want to group the below options together and offer a
 346     // better API, rather than this ad-hoc approach.
 347     pub make_glob_map: MakeGlobMap,
 348     // Whether the compiler should keep the ast beyond parsing.
 349     pub keep_ast: bool,
 350     // -Zcontinue-parse-after-error
 351     pub continue_parse_after_error: bool,
 352 }
 353
 354 impl<'a> CompileController<'a> {
 355     pub fn basic() -> CompileController<'a> {
 356         CompileController {
 357             after_parse: PhaseController::basic(),
 358             after_expand: PhaseController::basic(),
 359             after_hir_lowering: PhaseController::basic(),
 360             after_analysis: PhaseController::basic(),
 361             after_llvm: PhaseController::basic(),
 362             compilation_done: PhaseController::basic(),
 363             make_glob_map: MakeGlobMap::No,
 364             keep_ast: false,
 365             continue_parse_after_error: false,
 366         }
 367     }
 368 }
 369
 370 pub struct PhaseController<'a> {
 371     pub stop: Compilation,
 372     // If true then the compiler will try to run the callback even if the phase
 373     // ends with an error. Note that this is not always possible.
 374     pub run_callback_on_error: bool,
 375     pub callback: Box<Fn(&mut CompileState) + 'a>,
 376 }
 377
 378 impl<'a> PhaseController<'a> {
 379     pub fn basic() -> PhaseController<'a> {
 380         PhaseController {
 381             stop: Compilation::Continue,
 382             run_callback_on_error: false,
 383             callback: box |_| {},
 384         }
 385     }
 386 }
 387
 388 /// State that is passed to a callback. What state is available depends on when
 389 /// during compilation the callback is made. See the various constructor methods
 390 /// (`state_*`) in the impl to see which data is provided for any given entry point.
 391 pub struct CompileState<'a, 'tcx: 'a> {
 392     pub input: &'a Input,
 393     pub session: &'tcx Session,
 394     pub krate: Option<ast::Crate>,
 395     pub registry: Option<Registry<'a>>,
 396     pub cstore: Option<&'tcx CStore>,
 397     pub crate_name: Option<&'a str>,
 398     pub output_filenames: Option<&'a OutputFilenames>,
 399     pub out_dir: Option<&'a Path>,
 400     pub out_file: Option<&'a Path>,
 401     pub arena: Option<&'tcx DroplessArena>,
 402     pub arenas: Option<&'tcx GlobalArenas<'tcx>>,
 403     pub expanded_crate: Option<&'a ast::Crate>,
 404     pub hir_crate: Option<&'a hir::Crate>,
 405     pub hir_map: Option<&'a hir_map::Map<'tcx>>,
 406     pub resolutions: Option<&'a Resolutions>,
 407     pub analysis: Option<&'a ty::CrateAnalysis>,
 408     pub tcx: Option<TyCtxt<'a, 'tcx, 'tcx>>,
 409     pub trans: Option<&'a trans::CrateTranslation>,
 410 }
 411
 412 impl<'a, 'tcx> CompileState<'a, 'tcx> {
 413     fn empty(input: &'a Input,
 414              session: &'tcx Session,
 415              out_dir: &'a Option<PathBuf>)
 416              -> Self {
 417         CompileState {
 418             input,
 419             session,
 420             out_dir: out_dir.as_ref().map(|s| &**s),
 421             out_file: None,
 422             arena: None,
 423             arenas: None,
 424             krate: None,
 425             registry: None,
 426             cstore: None,
 427             crate_name: None,
 428             output_filenames: None,
 429             expanded_crate: None,
 430             hir_crate: None,
 431             hir_map: None,
 432             resolutions: None,
 433             analysis: None,
 434             tcx: None,
 435             trans: None,
 436         }
 437     }
 438
 439     fn state_after_parse(input: &'a Input,
 440                          session: &'tcx Session,
 441                          out_dir: &'a Option<PathBuf>,
 442                          out_file: &'a Option<PathBuf>,
 443                          krate: ast::Crate,
 444                          cstore: &'tcx CStore)
 445                          -> Self {
 446         CompileState {
 447             // Initialize the registry before moving `krate`
 448             registry: Some(Registry::new(&session, krate.span)),
 449             krate: Some(krate),
 450             cstore: Some(cstore),
 451             out_file: out_file.as_ref().map(|s| &**s),
 452             ..CompileState::empty(input, session, out_dir)
 453         }
 454     }
 455
 456     fn state_after_expand(input: &'a Input,
 457                           session: &'tcx Session,
 458                           out_dir: &'a Option<PathBuf>,
 459                           out_file: &'a Option<PathBuf>,
 460                           cstore: &'tcx CStore,
 461                           expanded_crate: &'a ast::Crate,
 462                           crate_name: &'a str)
 463                           -> Self {
 464         CompileState {
 465             crate_name: Some(crate_name),
 466             cstore: Some(cstore),
 467             expanded_crate: Some(expanded_crate),
 468             out_file: out_file.as_ref().map(|s| &**s),
 469             ..CompileState::empty(input, session, out_dir)
 470         }
 471     }
 472
 473     fn state_after_hir_lowering(input: &'a Input,
 474                                 session: &'tcx Session,
 475                                 out_dir: &'a Option<PathBuf>,
 476                                 out_file: &'a Option<PathBuf>,
 477                                 arena: &'tcx DroplessArena,
 478                                 arenas: &'tcx GlobalArenas<'tcx>,
 479                                 cstore: &'tcx CStore,
 480                                 hir_map: &'a hir_map::Map<'tcx>,
 481                                 analysis: &'a ty::CrateAnalysis,
 482                                 resolutions: &'a Resolutions,
 483                                 krate: &'a ast::Crate,
 484                                 hir_crate: &'a hir::Crate,
 485                                 output_filenames: &'a OutputFilenames,
 486                                 crate_name: &'a str)
 487                                 -> Self {
 488         CompileState {
 489             crate_name: Some(crate_name),
 490             arena: Some(arena),
 491             arenas: Some(arenas),
 492             cstore: Some(cstore),
 493             hir_map: Some(hir_map),
 494             analysis: Some(analysis),
 495             resolutions: Some(resolutions),
 496             expanded_crate: Some(krate),
 497             hir_crate: Some(hir_crate),
 498             output_filenames: Some(output_filenames),
 499             out_file: out_file.as_ref().map(|s| &**s),
 500             ..CompileState::empty(input, session, out_dir)
 501         }
 502     }
 503
 504     fn state_after_analysis(input: &'a Input,
 505                             session: &'tcx Session,
 506                             out_dir: &'a Option<PathBuf>,
 507                             out_file: &'a Option<PathBuf>,
 508                             krate: Option<&'a ast::Crate>,
 509                             hir_crate: &'a hir::Crate,
 510                             analysis: &'a ty::CrateAnalysis,
 511                             tcx: TyCtxt<'a, 'tcx, 'tcx>,
 512                             crate_name: &'a str)
 513                             -> Self {
 514         CompileState {
 515             analysis: Some(analysis),
 516             tcx: Some(tcx),
 517             expanded_crate: krate,
 518             hir_crate: Some(hir_crate),
 519             crate_name: Some(crate_name),
 520             out_file: out_file.as_ref().map(|s| &**s),
 521             ..CompileState::empty(input, session, out_dir)
 522         }
 523     }
 524
 525     fn state_after_llvm(input: &'a Input,
 526                         session: &'tcx Session,
 527                         out_dir: &'a Option<PathBuf>,
 528                         out_file: &'a Option<PathBuf>,
 529                         trans: &'a trans::CrateTranslation)
 530                         -> Self {
 531         CompileState {
 532             trans: Some(trans),
 533             out_file: out_file.as_ref().map(|s| &**s),
 534             ..CompileState::empty(input, session, out_dir)
 535         }
 536     }
 537
 538     fn state_when_compilation_done(input: &'a Input,
 539                                    session: &'tcx Session,
 540                                    out_dir: &'a Option<PathBuf>,
 541                                    out_file: &'a Option<PathBuf>)
 542                                    -> Self {
 543         CompileState {
 544             out_file: out_file.as_ref().map(|s| &**s),
 545             ..CompileState::empty(input, session, out_dir)
 546         }
 547     }
 548 }
 549
 550 pub fn phase_1_parse_input<'a>(control: &CompileController,
 551                                sess: &'a Session,
 552                                input: &Input)
 553                                -> PResult<'a, ast::Crate> {
 554     sess.diagnostic().set_continue_after_error(control.continue_parse_after_error);
 555
 556     if sess.profile_queries() {
 557         profile::begin();
 558     }
 559
 560     let krate = time(sess.time_passes(), "parsing", || {
 561         match *input {
 562             Input::File(ref file) => {
 563                 parse::parse_crate_from_file(file, &sess.parse_sess)
 564             }
 565             Input::Str { ref input, ref name } => {
 566                 parse::parse_crate_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
 567             }
 568         }
 569     })?;
 570
 571     sess.diagnostic().set_continue_after_error(true);
 572
 573     if sess.opts.debugging_opts.ast_json_noexpand {
 574         println!("{}", json::as_json(&krate));
 575     }
 576
 577     if sess.opts.debugging_opts.input_stats {
 578         println!("Lines of code:             {}", sess.codemap().count_lines());
 579         println!("Pre-expansion node count:  {}", count_nodes(&krate));
 580     }
 581
 582     if let Some(ref s) = sess.opts.debugging_opts.show_span {
 583         syntax::show_span::run(sess.diagnostic(), s, &krate);
 584     }
 585
 586     if sess.opts.debugging_opts.hir_stats {
 587         hir_stats::print_ast_stats(&krate, "PRE EXPANSION AST STATS");
 588     }
 589
 590     Ok(krate)
 591 }
 592
 593 fn count_nodes(krate: &ast::Crate) -> usize {
 594     let mut counter = NodeCounter::new();
 595     visit::walk_crate(&mut counter, krate);
 596     counter.count
 597 }
 598
 599 // For continuing compilation after a parsed crate has been
 600 // modified
 601
 602 pub struct ExpansionResult {
 603     pub expanded_crate: ast::Crate,
 604     pub defs: hir_map::Definitions,
 605     pub analysis: ty::CrateAnalysis,
 606     pub resolutions: Resolutions,
 607     pub hir_forest: hir_map::Forest,
 608 }
 609
 610 /// Run the "early phases" of the compiler: initial `cfg` processing,
 611 /// loading compiler plugins (including those from `addl_plugins`),
 612 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
 613 /// harness if one is to be provided, injection of a dependency on the
 614 /// standard library and prelude, and name resolution.
 615 ///
 616 /// Returns `None` if we're aborting after handling -W help.
 617 pub fn phase_2_configure_and_expand<F>(sess: &Session,
 618                                        cstore: &CStore,
 619                                        krate: ast::Crate,
 620                                        registry: Option<Registry>,
 621                                        crate_name: &str,
 622                                        addl_plugins: Option<Vec<String>>,
 623                                        make_glob_map: MakeGlobMap,
 624                                        after_expand: F)
 625                                        -> Result<ExpansionResult, CompileIncomplete>
 626     where F: FnOnce(&ast::Crate) -> CompileResult,
 627 {
 628     let time_passes = sess.time_passes();
 629
 630     let (mut krate, features) = syntax::config::features(krate, &sess.parse_sess, sess.opts.test);
 631     // these need to be set "early" so that expansion sees `quote` if enabled.
 632     *sess.features.borrow_mut() = features;
 633
 634     *sess.crate_types.borrow_mut() = collect_crate_types(sess, &krate.attrs);
 635
 636     let disambiguator = Symbol::intern(&compute_crate_disambiguator(sess));
 637     *sess.crate_disambiguator.borrow_mut() = Some(disambiguator);
 638     rustc_incremental::prepare_session_directory(
 639         sess,
 640         &crate_name,
 641         &disambiguator.as_str(),
 642     );
 643
 644     let dep_graph = if sess.opts.build_dep_graph() {
 645         let prev_dep_graph = time(time_passes, "load prev dep-graph", || {
 646             rustc_incremental::load_dep_graph(sess)
 647         });
 648
 649         DepGraph::new(prev_dep_graph)
 650     } else {
 651         DepGraph::new_disabled()
 652     };
 653
 654     time(time_passes, "recursion limit", || {
 655         middle::recursion_limit::update_limits(sess, &krate);
 656     });
 657
 658     krate = time(time_passes, "crate injection", || {
 659         let alt_std_name = sess.opts.alt_std_name.clone();
 660         syntax::std_inject::maybe_inject_crates_ref(krate, alt_std_name)
 661     });
 662
 663     let mut addl_plugins = Some(addl_plugins);
 664     let registrars = time(time_passes, "plugin loading", || {
 665         plugin::load::load_plugins(sess,
 666                                    &cstore,
 667                                    &krate,
 668                                    crate_name,
 669                                    addl_plugins.take().unwrap())
 670     });
 671
 672     let mut registry = registry.unwrap_or(Registry::new(sess, krate.span));
 673
 674     time(time_passes, "plugin registration", || {
 675         if sess.features.borrow().rustc_diagnostic_macros {
 676             registry.register_macro("__diagnostic_used",
 677                                     diagnostics::plugin::expand_diagnostic_used);
 678             registry.register_macro("__register_diagnostic",
 679                                     diagnostics::plugin::expand_register_diagnostic);
 680             registry.register_macro("__build_diagnostic_array",
 681                                     diagnostics::plugin::expand_build_diagnostic_array);
 682         }
 683
 684         for registrar in registrars {
 685             registry.args_hidden = Some(registrar.args);
 686             (registrar.fun)(&mut registry);
 687         }
 688     });
 689
 690     let whitelisted_legacy_custom_derives = registry.take_whitelisted_custom_derives();
 691     let Registry { syntax_exts, early_lint_passes, late_lint_passes, lint_groups,
 692                    llvm_passes, attributes, .. } = registry;
 693
 694     sess.track_errors(|| {
 695         let mut ls = sess.lint_store.borrow_mut();
 696         for pass in early_lint_passes {
 697             ls.register_early_pass(Some(sess), true, pass);
 698         }
 699         for pass in late_lint_passes {
 700             ls.register_late_pass(Some(sess), true, pass);
 701         }
 702
 703         for (name, to) in lint_groups {
 704             ls.register_group(Some(sess), true, name, to);
 705         }
 706
 707         *sess.plugin_llvm_passes.borrow_mut() = llvm_passes;
 708         *sess.plugin_attributes.borrow_mut() = attributes.clone();
 709     })?;
 710
 711     // Lint plugins are registered; now we can process command line flags.
 712     if sess.opts.describe_lints {
 713         super::describe_lints(&sess.lint_store.borrow(), true);
 714         return Err(CompileIncomplete::Stopped);
 715     }
 716
 717     // Currently, we ignore the name resolution data structures for the purposes of dependency
 718     // tracking. Instead we will run name resolution and include its output in the hash of each
 719     // item, much like we do for macro expansion. In other words, the hash reflects not just
 720     // its contents but the results of name resolution on those contents. Hopefully we'll push
 721     // this back at some point.
 722     let mut crate_loader = CrateLoader::new(sess, &cstore, crate_name);
 723     let resolver_arenas = Resolver::arenas();
 724     let mut resolver = Resolver::new(sess,
 725                                      cstore,
 726                                      &krate,
 727                                      crate_name,
 728                                      make_glob_map,
 729                                      &mut crate_loader,
 730                                      &resolver_arenas);
 731     resolver.whitelisted_legacy_custom_derives = whitelisted_legacy_custom_derives;
 732     syntax_ext::register_builtins(&mut resolver, syntax_exts, sess.features.borrow().quote);
 733
 734     krate = time(time_passes, "expansion", || {
 735         // Windows dlls do not have rpaths, so they don't know how to find their
 736         // dependencies. It's up to us to tell the system where to find all the
 737         // dependent dlls. Note that this uses cfg!(windows) as opposed to
 738         // targ_cfg because syntax extensions are always loaded for the host
 739         // compiler, not for the target.
 740         //
 741         // This is somewhat of an inherently racy operation, however, as
 742         // multiple threads calling this function could possibly continue
 743         // extending PATH far beyond what it should. To solve this for now we
 744         // just don't add any new elements to PATH which are already there
 745         // within PATH. This is basically a targeted fix at #17360 for rustdoc
 746         // which runs rustc in parallel but has been seen (#33844) to cause
 747         // problems with PATH becoming too long.
 748         let mut old_path = OsString::new();
 749         if cfg!(windows) {
 750             old_path = env::var_os("PATH").unwrap_or(old_path);
 751             let mut new_path = sess.host_filesearch(PathKind::All)
 752                                    .get_dylib_search_paths();
 753             for path in env::split_paths(&old_path) {
 754                 if !new_path.contains(&path) {
 755                     new_path.push(path);
 756                 }
 757             }
 758             env::set_var("PATH",
 759                 &env::join_paths(new_path.iter()
 760                                          .filter(|p| env::join_paths(iter::once(p)).is_ok()))
 761                      .unwrap());
 762         }
 763         let features = sess.features.borrow();
 764         let cfg = syntax::ext::expand::ExpansionConfig {
 765             features: Some(&features),
 766             recursion_limit: sess.recursion_limit.get(),
 767             trace_mac: sess.opts.debugging_opts.trace_macros,
 768             should_test: sess.opts.test,
 769             ..syntax::ext::expand::ExpansionConfig::default(crate_name.to_string())
 770         };
 771
 772         let mut ecx = ExtCtxt::new(&sess.parse_sess, cfg, &mut resolver);
 773         let err_count = ecx.parse_sess.span_diagnostic.err_count();
 774
 775         let krate = ecx.monotonic_expander().expand_crate(krate);
 776
 777         ecx.check_unused_macros();
 778
 779         let mut missing_fragment_specifiers: Vec<_> =
 780             ecx.parse_sess.missing_fragment_specifiers.borrow().iter().cloned().collect();
 781         missing_fragment_specifiers.sort();
 782         for span in missing_fragment_specifiers {
 783             let lint = lint::builtin::MISSING_FRAGMENT_SPECIFIER;
 784             let msg = "missing fragment specifier";
 785             sess.buffer_lint(lint, ast::CRATE_NODE_ID, span, msg);
 786         }
 787         if ecx.parse_sess.span_diagnostic.err_count() - ecx.resolve_err_count > err_count {
 788             ecx.parse_sess.span_diagnostic.abort_if_errors();
 789         }
 790         if cfg!(windows) {
 791             env::set_var("PATH", &old_path);
 792         }
 793         krate
 794     });
 795
 796     krate = time(time_passes, "maybe building test harness", || {
 797         syntax::test::modify_for_testing(&sess.parse_sess,
 798                                          &mut resolver,
 799                                          sess.opts.test,
 800                                          krate,
 801                                          sess.diagnostic())
 802     });
 803
 804     // If we're in rustdoc we're always compiling as an rlib, but that'll trip a
 805     // bunch of checks in the `modify` function below. For now just skip this
 806     // step entirely if we're rustdoc as it's not too useful anyway.
 807     if !sess.opts.actually_rustdoc {
 808         krate = time(time_passes, "maybe creating a macro crate", || {
 809             let crate_types = sess.crate_types.borrow();
 810             let num_crate_types = crate_types.len();
 811             let is_proc_macro_crate = crate_types.contains(&config::CrateTypeProcMacro);
 812             let is_test_crate = sess.opts.test;
 813             syntax_ext::proc_macro_registrar::modify(&sess.parse_sess,
 814                                                      &mut resolver,
 815                                                      krate,
 816                                                      is_proc_macro_crate,
 817                                                      is_test_crate,
 818                                                      num_crate_types,
 819                                                      sess.diagnostic())
 820         });
 821     }
 822
 823     krate = time(time_passes, "creating allocators", || {
 824         allocator::expand::modify(&sess.parse_sess,
 825                                   &mut resolver,
 826                                   krate,
 827                                   sess.diagnostic())
 828     });
 829
 830     after_expand(&krate)?;
 831
 832     if sess.opts.debugging_opts.input_stats {
 833         println!("Post-expansion node count: {}", count_nodes(&krate));
 834     }
 835
 836     if sess.opts.debugging_opts.hir_stats {
 837         hir_stats::print_ast_stats(&krate, "POST EXPANSION AST STATS");
 838     }
 839
 840     if sess.opts.debugging_opts.ast_json {
 841         println!("{}", json::as_json(&krate));
 842     }
 843
 844     time(time_passes,
 845          "checking for inline asm in case the target doesn't support it",
 846          || no_asm::check_crate(sess, &krate));
 847
 848     time(time_passes,
 849          "AST validation",
 850          || ast_validation::check_crate(sess, &krate));
 851
 852     time(time_passes, "name resolution", || -> CompileResult {
 853         resolver.resolve_crate(&krate);
 854         Ok(())
 855     })?;
 856
 857     if resolver.found_unresolved_macro {
 858         sess.parse_sess.span_diagnostic.abort_if_errors();
 859     }
 860
 861     // Needs to go *after* expansion to be able to check the results of macro expansion.
 862     time(time_passes, "complete gated feature checking", || {
 863         sess.track_errors(|| {
 864             syntax::feature_gate::check_crate(&krate,
 865                                               &sess.parse_sess,
 866                                               &sess.features.borrow(),
 867                                               &attributes,
 868                                               sess.opts.unstable_features);
 869         })
 870     })?;
 871
 872     // Lower ast -> hir.
 873     let hir_forest = time(time_passes, "lowering ast -> hir", || {
 874         let hir_crate = lower_crate(sess, cstore, &dep_graph, &krate, &mut resolver);
 875
 876         if sess.opts.debugging_opts.hir_stats {
 877             hir_stats::print_hir_stats(&hir_crate);
 878         }
 879
 880         hir_map::Forest::new(hir_crate, &dep_graph)
 881     });
 882
 883     time(time_passes,
 884          "early lint checks",
 885          || lint::check_ast_crate(sess, &krate));
 886
 887     // Discard hygiene data, which isn't required after lowering to HIR.
 888     if !keep_hygiene_data(sess) {
 889         syntax::ext::hygiene::clear_markings();
 890     }
 891
 892     Ok(ExpansionResult {
 893         expanded_crate: krate,
 894         defs: resolver.definitions,
 895         analysis: ty::CrateAnalysis {
 896             access_levels: Rc::new(AccessLevels::default()),
 897             name: crate_name.to_string(),
 898             glob_map: if resolver.make_glob_map { Some(resolver.glob_map) } else { None },
 899         },
 900         resolutions: Resolutions {
 901             freevars: resolver.freevars,
 902             export_map: resolver.export_map,
 903             trait_map: resolver.trait_map,
 904             maybe_unused_trait_imports: resolver.maybe_unused_trait_imports,
 905             maybe_unused_extern_crates: resolver.maybe_unused_extern_crates,
 906         },
 907         hir_forest,
 908     })
 909 }
 910
 911 /// Run the resolution, typechecking, region checking and other
 912 /// miscellaneous analysis passes on the crate. Return various
 913 /// structures carrying the results of the analysis.
 914 pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
 915                                                cstore: &'tcx CrateStore,
 916                                                hir_map: hir_map::Map<'tcx>,
 917                                                mut analysis: ty::CrateAnalysis,
 918                                                resolutions: Resolutions,
 919                                                arena: &'tcx DroplessArena,
 920                                                arenas: &'tcx GlobalArenas<'tcx>,
 921                                                name: &str,
 922                                                output_filenames: &OutputFilenames,
 923                                                f: F)
 924                                                -> Result<R, CompileIncomplete>
 925     where F: for<'a> FnOnce(TyCtxt<'a, 'tcx, 'tcx>,
 926                             ty::CrateAnalysis,
 927                             mpsc::Receiver<Box<Any + Send>>,
 928                             CompileResult) -> R
 929 {
 930     macro_rules! try_with_f {
 931         ($e: expr, ($($t:tt)*)) => {
 932             match $e {
 933                 Ok(x) => x,
 934                 Err(x) => {
 935                     f($($t)*, Err(x));
 936                     return Err(x);
 937                 }
 938             }
 939         }
 940     }
 941
 942     let time_passes = sess.time_passes();
 943
 944     let named_region_map = time(time_passes,
 945                                 "lifetime resolution",
 946                                 || middle::resolve_lifetime::krate(sess, cstore, &hir_map))?;
 947
 948     time(time_passes,
 949          "looking for entry point",
 950          || middle::entry::find_entry_point(sess, &hir_map));
 951
 952     sess.plugin_registrar_fn.set(time(time_passes, "looking for plugin registrar", || {
 953         plugin::build::find_plugin_registrar(sess.diagnostic(), &hir_map)
 954     }));
 955     sess.derive_registrar_fn.set(derive_registrar::find(&hir_map));
 956
 957     time(time_passes,
 958          "loop checking",
 959          || loops::check_crate(sess, &hir_map));
 960
 961     time(time_passes,
 962               "static item recursion checking",
 963               || static_recursion::check_crate(sess, &hir_map))?;
 964
 965     let mut local_providers = ty::maps::Providers::default();
 966     borrowck::provide(&mut local_providers);
 967     mir::provide(&mut local_providers);
 968     reachable::provide(&mut local_providers);
 969     rustc_privacy::provide(&mut local_providers);
 970     DefaultTransCrate::provide_local(&mut local_providers);
 971     typeck::provide(&mut local_providers);
 972     ty::provide(&mut local_providers);
 973     traits::provide(&mut local_providers);
 974     reachable::provide(&mut local_providers);
 975     rustc_const_eval::provide(&mut local_providers);
 976     middle::region::provide(&mut local_providers);
 977     cstore::provide_local(&mut local_providers);
 978     lint::provide(&mut local_providers);
 979
 980     let mut extern_providers = ty::maps::Providers::default();
 981     cstore::provide(&mut extern_providers);
 982     DefaultTransCrate::provide_extern(&mut extern_providers);
 983     ty::provide_extern(&mut extern_providers);
 984     traits::provide_extern(&mut extern_providers);
 985     // FIXME(eddyb) get rid of this once we replace const_eval with miri.
 986     rustc_const_eval::provide(&mut extern_providers);
 987
 988     // Setup the MIR passes that we want to run.
 989     let mut passes = Passes::new();
 990     passes.push_hook(mir::transform::dump_mir::DumpMir);
 991
 992     // Remove all `EndRegion` statements that are not involved in borrows.
 993     passes.push_pass(MIR_CONST, mir::transform::clean_end_regions::CleanEndRegions);
 994
 995     // What we need to do constant evaluation.
 996     passes.push_pass(MIR_CONST, mir::transform::simplify::SimplifyCfg::new("initial"));
 997     passes.push_pass(MIR_CONST, mir::transform::type_check::TypeckMir);
 998     passes.push_pass(MIR_CONST, mir::transform::rustc_peek::SanityCheck);
 999
1000     // We compute "constant qualifications" between MIR_CONST and MIR_VALIDATED.
1001
1002     // What we need to run borrowck etc.
1003
1004     passes.push_pass(MIR_VALIDATED, mir::transform::qualify_consts::QualifyAndPromoteConstants);
1005     passes.push_pass(MIR_VALIDATED, mir::transform::simplify::SimplifyCfg::new("qualify-consts"));
1006     passes.push_pass(MIR_VALIDATED, mir::transform::nll::NLL);
1007
1008     // borrowck runs between MIR_VALIDATED and MIR_OPTIMIZED.
1009
1010     passes.push_pass(MIR_OPTIMIZED, mir::transform::no_landing_pads::NoLandingPads);
1011     passes.push_pass(MIR_OPTIMIZED,
1012                      mir::transform::simplify_branches::SimplifyBranches::new("initial"));
1013
1014     // These next passes must be executed together
1015     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_call_guards::CriticalCallEdges);
1016     passes.push_pass(MIR_OPTIMIZED, mir::transform::elaborate_drops::ElaborateDrops);
1017     passes.push_pass(MIR_OPTIMIZED, mir::transform::no_landing_pads::NoLandingPads);
1018     // AddValidation needs to run after ElaborateDrops and before EraseRegions, and it needs
1019     // an AllCallEdges pass right before it.
1020     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_call_guards::AllCallEdges);
1021     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_validation::AddValidation);
1022     passes.push_pass(MIR_OPTIMIZED, mir::transform::simplify::SimplifyCfg::new("elaborate-drops"));
1023     // No lifetime analysis based on borrowing can be done from here on out.
1024
1025     // From here on out, regions are gone.
1026     passes.push_pass(MIR_OPTIMIZED, mir::transform::erase_regions::EraseRegions);
1027
1028     // Optimizations begin.
1029     passes.push_pass(MIR_OPTIMIZED, mir::transform::inline::Inline);
1030     passes.push_pass(MIR_OPTIMIZED, mir::transform::instcombine::InstCombine);
1031     passes.push_pass(MIR_OPTIMIZED, mir::transform::deaggregator::Deaggregator);
1032     passes.push_pass(MIR_OPTIMIZED, mir::transform::copy_prop::CopyPropagation);
1033     passes.push_pass(MIR_OPTIMIZED, mir::transform::simplify::SimplifyLocals);
1034
1035     passes.push_pass(MIR_OPTIMIZED, mir::transform::generator::StateTransform);
1036     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_call_guards::CriticalCallEdges);
1037     passes.push_pass(MIR_OPTIMIZED, mir::transform::dump_mir::Marker("PreTrans"));
1038
1039     let (tx, rx) = mpsc::channel();
1040
1041     TyCtxt::create_and_enter(sess,
1042                              cstore,
1043                              local_providers,
1044                              extern_providers,
1045                              Rc::new(passes),
1046                              arenas,
1047                              arena,
1048                              resolutions,
1049                              named_region_map,
1050                              hir_map,
1051                              name,
1052                              tx,
1053                              output_filenames,
1054                              |tcx| {
1055         // Do some initialization of the DepGraph that can only be done with the
1056         // tcx available.
1057         rustc_incremental::dep_graph_tcx_init(tcx);
1058
1059         time(time_passes,
1060              "stability checking",
1061              || stability::check_unstable_api_usage(tcx));
1062
1063         // passes are timed inside typeck
1064         try_with_f!(typeck::check_crate(tcx), (tcx, analysis, rx));
1065
1066         time(time_passes,
1067              "const checking",
1068              || consts::check_crate(tcx));
1069
1070         analysis.access_levels =
1071             time(time_passes, "privacy checking", || rustc_privacy::check_crate(tcx));
1072
1073         time(time_passes,
1074              "intrinsic checking",
1075              || middle::intrinsicck::check_crate(tcx));
1076
1077         time(time_passes,
1078              "match checking",
1079              || check_match::check_crate(tcx));
1080
1081         // this must run before MIR dump, because
1082         // "not all control paths return a value" is reported here.
1083         //
1084         // maybe move the check to a MIR pass?
1085         time(time_passes,
1086              "liveness checking",
1087              || middle::liveness::check_crate(tcx));
1088
1089         time(time_passes,
1090              "borrow checking",
1091              || borrowck::check_crate(tcx));
1092
1093         time(time_passes,
1094              "MIR borrow checking",
1095              || for def_id in tcx.body_owners() { tcx.mir_borrowck(def_id) });
1096
1097         time(time_passes,
1098              "MIR effect checking",
1099              || for def_id in tcx.body_owners() {
1100                  mir::transform::check_unsafety::check_unsafety(tcx, def_id)
1101              });
1102         // Avoid overwhelming user with errors if type checking failed.
1103         // I'm not sure how helpful this is, to be honest, but it avoids
1104         // a
1105         // lot of annoying errors in the compile-fail tests (basically,
1106         // lint warnings and so on -- kindck used to do this abort, but
1107         // kindck is gone now). -nmatsakis
1108         if sess.err_count() > 0 {
1109             return Ok(f(tcx, analysis, rx, sess.compile_status()));
1110         }
1111
1112         time(time_passes, "death checking", || middle::dead::check_crate(tcx));
1113
1114         time(time_passes, "unused lib feature checking", || {
1115             stability::check_unused_or_stable_features(tcx)
1116         });
1117
1118         time(time_passes, "lint checking", || lint::check_crate(tcx));
1119
1120         return Ok(f(tcx, analysis, rx, tcx.sess.compile_status()));
1121     })
1122 }
1123
1124 /// Run the translation phase to LLVM, after which the AST and analysis can
1125 /// be discarded.
1126 pub fn phase_4_translate_to_llvm<'a, 'tcx, Trans: TransCrate>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1127                                            rx: mpsc::Receiver<Box<Any + Send>>)
1128                                            -> <Trans as TransCrate>::OngoingCrateTranslation {
1129     let time_passes = tcx.sess.time_passes();
1130
1131     time(time_passes,
1132          "resolving dependency formats",
1133          || ::rustc::middle::dependency_format::calculate(tcx));
1134
1135     let translation =
1136         time(time_passes, "translation", move || {
1137             Trans::trans_crate(tcx, rx)
1138         });
1139     if tcx.sess.profile_queries() {
1140         profile::dump("profile_queries".to_string())
1141     }
1142
1143     translation
1144 }
1145
1146 /// Run LLVM itself, producing a bitcode file, assembly file or object file
1147 /// as a side effect.
1148 pub fn phase_5_run_llvm_passes<Trans: TransCrate>(sess: &Session,
1149                                dep_graph: &DepGraph,
1150                                trans: <Trans as TransCrate>::OngoingCrateTranslation)
1151                                -> (CompileResult, <Trans as TransCrate>::TranslatedCrate) {
1152     let trans = Trans::join_trans(trans, sess, dep_graph);
1153
1154     if sess.opts.debugging_opts.incremental_info {
1155         Trans::dump_incremental_data(&trans);
1156     }
1157
1158     time(sess.time_passes(),
1159          "serialize work products",
1160          move || rustc_incremental::save_work_products(sess, dep_graph));
1161
1162     (sess.compile_status(), trans)
1163 }
1164
1165 fn escape_dep_filename(filename: &str) -> String {
1166     // Apparently clang and gcc *only* escape spaces:
1167     // http://llvm.org/klaus/clang/commit/9d50634cfc268ecc9a7250226dd5ca0e945240d4
1168     filename.replace(" ", "\\ ")
1169 }
1170
1171 fn write_out_deps(sess: &Session, outputs: &OutputFilenames, crate_name: &str) {
1172     let mut out_filenames = Vec::new();
1173     for output_type in sess.opts.output_types.keys() {
1174         let file = outputs.path(*output_type);
1175         match *output_type {
1176             OutputType::Exe => {
1177                 for output in sess.crate_types.borrow().iter() {
1178                     let p = ::rustc_trans_utils::link::filename_for_input(
1179                         sess,
1180                         *output,
1181                         crate_name,
1182                         outputs
1183                     );
1184                     out_filenames.push(p);
1185                 }
1186             }
1187             _ => {
1188                 out_filenames.push(file);
1189             }
1190         }
1191     }
1192
1193     // Write out dependency rules to the dep-info file if requested
1194     if !sess.opts.output_types.contains_key(&OutputType::DepInfo) {
1195         return;
1196     }
1197     let deps_filename = outputs.path(OutputType::DepInfo);
1198
1199     let result =
1200         (|| -> io::Result<()> {
1201             // Build a list of files used to compile the output and
1202             // write Makefile-compatible dependency rules
1203             let files: Vec<String> = sess.codemap()
1204                                          .files()
1205                                          .iter()
1206                                          .filter(|fmap| fmap.is_real_file())
1207                                          .filter(|fmap| !fmap.is_imported())
1208                                          .map(|fmap| escape_dep_filename(&fmap.name))
1209                                          .collect();
1210             let mut file = fs::File::create(&deps_filename)?;
1211             for path in &out_filenames {
1212                 write!(file, "{}: {}\n\n", path.display(), files.join(" "))?;
1213             }
1214
1215             // Emit a fake target for each input file to the compilation. This
1216             // prevents `make` from spitting out an error if a file is later
1217             // deleted. For more info see #28735
1218             for path in files {
1219                 writeln!(file, "{}:", path)?;
1220             }
1221             Ok(())
1222         })();
1223
1224     match result {
1225         Ok(()) => {}
1226         Err(e) => {
1227             sess.fatal(&format!("error writing dependencies to `{}`: {}",
1228                                 deps_filename.display(),
1229                                 e));
1230         }
1231     }
1232 }
1233
1234 pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<config::CrateType> {
1235     // Unconditionally collect crate types from attributes to make them used
1236     let attr_types: Vec<config::CrateType> =
1237         attrs.iter()
1238              .filter_map(|a| {
1239                  if a.check_name("crate_type") {
1240                      match a.value_str() {
1241                          Some(ref n) if *n == "rlib" => {
1242                              Some(config::CrateTypeRlib)
1243                          }
1244                          Some(ref n) if *n == "dylib" => {
1245                              Some(config::CrateTypeDylib)
1246                          }
1247                          Some(ref n) if *n == "cdylib" => {
1248                              Some(config::CrateTypeCdylib)
1249                          }
1250                          Some(ref n) if *n == "lib" => {
1251                              Some(config::default_lib_output())
1252                          }
1253                          Some(ref n) if *n == "staticlib" => {
1254                              Some(config::CrateTypeStaticlib)
1255                          }
1256                          Some(ref n) if *n == "proc-macro" => {
1257                              Some(config::CrateTypeProcMacro)
1258                          }
1259                          Some(ref n) if *n == "bin" => Some(config::CrateTypeExecutable),
1260                          Some(_) => {
1261                              session.buffer_lint(lint::builtin::UNKNOWN_CRATE_TYPES,
1262                                                  ast::CRATE_NODE_ID,
1263                                                  a.span,
1264                                                  "invalid `crate_type` value");
1265                              None
1266                          }
1267                          _ => {
1268                              session.struct_span_err(a.span, "`crate_type` requires a value")
1269                                  .note("for example: `#![crate_type=\"lib\"]`")
1270                                  .emit();
1271                              None
1272                          }
1273                      }
1274                  } else {
1275                      None
1276                  }
1277              })
1278              .collect();
1279
1280     // If we're generating a test executable, then ignore all other output
1281     // styles at all other locations
1282     if session.opts.test {
1283         return vec![config::CrateTypeExecutable];
1284     }
1285
1286     // Only check command line flags if present. If no types are specified by
1287     // command line, then reuse the empty `base` Vec to hold the types that
1288     // will be found in crate attributes.
1289     let mut base = session.opts.crate_types.clone();
1290     if base.is_empty() {
1291         base.extend(attr_types);
1292         if base.is_empty() {
1293             base.push(::rustc_trans_utils::link::default_output_for_target(session));
1294         }
1295         base.sort();
1296         base.dedup();
1297     }
1298
1299     base.into_iter()
1300         .filter(|crate_type| {
1301             let res = !::rustc_trans_utils::link::invalid_output_for_target(session, *crate_type);
1302
1303             if !res {
1304                 session.warn(&format!("dropping unsupported crate type `{}` for target `{}`",
1305                                       *crate_type,
1306                                       session.opts.target_triple));
1307             }
1308
1309             res
1310         })
1311         .collect()
1312 }
1313
1314 pub fn compute_crate_disambiguator(session: &Session) -> String {
1315     use std::hash::Hasher;
1316
1317     // The crate_disambiguator is a 128 bit hash. The disambiguator is fed
1318     // into various other hashes quite a bit (symbol hashes, incr. comp. hashes,
1319     // debuginfo type IDs, etc), so we don't want it to be too wide. 128 bits
1320     // should still be safe enough to avoid collisions in practice.
1321     // FIXME(mw): It seems that the crate_disambiguator is used everywhere as
1322     //            a hex-string instead of raw bytes. We should really use the
1323     //            smaller representation.
1324     let mut hasher = StableHasher::<Fingerprint>::new();
1325
1326     let mut metadata = session.opts.cg.metadata.clone();
1327     // We don't want the crate_disambiguator to dependent on the order
1328     // -C metadata arguments, so sort them:
1329     metadata.sort();
1330     // Every distinct -C metadata value is only incorporated once:
1331     metadata.dedup();
1332
1333     hasher.write(b"metadata");
1334     for s in &metadata {
1335         // Also incorporate the length of a metadata string, so that we generate
1336         // different values for `-Cmetadata=ab -Cmetadata=c` and
1337         // `-Cmetadata=a -Cmetadata=bc`
1338         hasher.write_usize(s.len());
1339         hasher.write(s.as_bytes());
1340     }
1341
1342     // If this is an executable, add a special suffix, so that we don't get
1343     // symbol conflicts when linking against a library of the same name.
1344     let is_exe = session.crate_types.borrow().contains(&config::CrateTypeExecutable);
1345
1346     format!("{}{}", hasher.finish().to_hex(), if is_exe { "-exe" } else {""})
1347 }
1348
1349 pub fn build_output_filenames(input: &Input,
1350                               odir: &Option<PathBuf>,
1351                               ofile: &Option<PathBuf>,
1352                               attrs: &[ast::Attribute],
1353                               sess: &Session)
1354                               -> OutputFilenames {
1355     match *ofile {
1356         None => {
1357             // "-" as input file will cause the parser to read from stdin so we
1358             // have to make up a name
1359             // We want to toss everything after the final '.'
1360             let dirpath = match *odir {
1361                 Some(ref d) => d.clone(),
1362                 None => PathBuf::new(),
1363             };
1364
1365             // If a crate name is present, we use it as the link name
1366             let stem = sess.opts
1367                            .crate_name
1368                            .clone()
1369                            .or_else(|| attr::find_crate_name(attrs).map(|n| n.to_string()))
1370                            .unwrap_or(input.filestem());
1371
1372             OutputFilenames {
1373                 out_directory: dirpath,
1374                 out_filestem: stem,
1375                 single_output_file: None,
1376                 extra: sess.opts.cg.extra_filename.clone(),
1377                 outputs: sess.opts.output_types.clone(),
1378             }
1379         }
1380
1381         Some(ref out_file) => {
1382             let unnamed_output_types = sess.opts
1383                                            .output_types
1384                                            .values()
1385                                            .filter(|a| a.is_none())
1386                                            .count();
1387             let ofile = if unnamed_output_types > 1 {
1388                 sess.warn("due to multiple output types requested, the explicitly specified \
1389                            output file name will be adapted for each output type");
1390                 None
1391             } else {
1392                 Some(out_file.clone())
1393             };
1394             if *odir != None {
1395                 sess.warn("ignoring --out-dir flag due to -o flag.");
1396             }
1397
1398             let cur_dir = Path::new("");
1399
1400             OutputFilenames {
1401                 out_directory: out_file.parent().unwrap_or(cur_dir).to_path_buf(),
1402                 out_filestem: out_file.file_stem()
1403                                       .unwrap_or(OsStr::new(""))
1404                                       .to_str()
1405                                       .unwrap()
1406                                       .to_string(),
1407                 single_output_file: ofile,
1408                 extra: sess.opts.cg.extra_filename.clone(),
1409                 outputs: sess.opts.output_types.clone(),
1410             }
1411         }
1412     }
1413 }