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::hir::{self, map as hir_map};
  12 use rustc::hir::lowering::lower_crate;
  13 use rustc::ich::Fingerprint;
  14 use rustc_data_structures::stable_hasher::StableHasher;
  15 use rustc_mir as mir;
  16 use rustc::session::{Session, CompileResult};
  17 use rustc::session::CompileIncomplete;
  18 use rustc::session::config::{self, Input, OutputFilenames, OutputType,
  19                              OutputTypes};
  20 use rustc::session::search_paths::PathKind;
  21 use rustc::lint;
  22 use rustc::middle::{self, dependency_format, stability, reachable};
  23 use rustc::middle::privacy::AccessLevels;
  24 use rustc::mir::transform::{MIR_CONST, MIR_VALIDATED, MIR_OPTIMIZED, Passes};
  25 use rustc::ty::{self, TyCtxt, Resolutions, GlobalArenas};
  26 use rustc::traits;
  27 use rustc::util::common::{ErrorReported, time};
  28 use rustc::util::nodemap::NodeSet;
  29 use rustc::util::fs::rename_or_copy_remove;
  30 use rustc_borrowck as borrowck;
  31 use rustc_incremental::{self, IncrementalHashesMap};
  32 use rustc_resolve::{MakeGlobMap, Resolver};
  33 use rustc_metadata::creader::CrateLoader;
  34 use rustc_metadata::cstore::{self, CStore};
  35 use rustc_trans::back::{link, write};
  36 use rustc_trans as trans;
  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
  45 use serialize::json;
  46
  47 use std::env;
  48 use std::ffi::{OsString, OsStr};
  49 use std::fs;
  50 use std::io::{self, Write};
  51 use std::iter;
  52 use std::path::{Path, PathBuf};
  53 use std::rc::Rc;
  54 use syntax::{ast, diagnostics, visit};
  55 use syntax::attr;
  56 use syntax::ext::base::ExtCtxt;
  57 use syntax::parse::{self, PResult};
  58 use syntax::symbol::Symbol;
  59 use syntax::util::node_count::NodeCounter;
  60 use syntax;
  61 use syntax_ext;
  62 use arena::DroplessArena;
  63
  64 use derive_registrar;
  65
  66 pub fn compile_input(sess: &Session,
  67                      cstore: &CStore,
  68                      input: &Input,
  69                      outdir: &Option<PathBuf>,
  70                      output: &Option<PathBuf>,
  71                      addl_plugins: Option<Vec<String>>,
  72                      control: &CompileController) -> CompileResult {
  73     macro_rules! controller_entry_point {
  74         ($point: ident, $tsess: expr, $make_state: expr, $phase_result: expr) => {{
  75             let state = &mut $make_state;
  76             let phase_result: &CompileResult = &$phase_result;
  77             if phase_result.is_ok() || control.$point.run_callback_on_error {
  78                 (control.$point.callback)(state);
  79             }
  80
  81             if control.$point.stop == Compilation::Stop {
  82                 // FIXME: shouldn't this return Err(CompileIncomplete::Stopped)
  83                 // if there are no errors?
  84                 return $tsess.compile_status();
  85             }
  86         }}
  87     }
  88
  89     // We need nested scopes here, because the intermediate results can keep
  90     // large chunks of memory alive and we want to free them as soon as
  91     // possible to keep the peak memory usage low
  92     let (outputs, trans) = {
  93         let krate = match phase_1_parse_input(sess, input) {
  94             Ok(krate) => krate,
  95             Err(mut parse_error) => {
  96                 parse_error.emit();
  97                 return Err(CompileIncomplete::Errored(ErrorReported));
  98             }
  99         };
 100
 101         let (krate, registry) = {
 102             let mut compile_state = CompileState::state_after_parse(input,
 103                                                                     sess,
 104                                                                     outdir,
 105                                                                     output,
 106                                                                     krate,
 107                                                                     &cstore);
 108             controller_entry_point!(after_parse,
 109                                     sess,
 110                                     compile_state,
 111                                     Ok(()));
 112
 113             (compile_state.krate.unwrap(), compile_state.registry)
 114         };
 115
 116         let outputs = build_output_filenames(input, outdir, output, &krate.attrs, sess);
 117         let crate_name = link::find_crate_name(Some(sess), &krate.attrs, input);
 118         let ExpansionResult { expanded_crate, defs, analysis, resolutions, mut hir_forest } = {
 119             phase_2_configure_and_expand(
 120                 sess, &cstore, krate, registry, &crate_name, addl_plugins, control.make_glob_map,
 121                 |expanded_crate| {
 122                     let mut state = CompileState::state_after_expand(
 123                         input, sess, outdir, output, &cstore, expanded_crate, &crate_name,
 124                     );
 125                     controller_entry_point!(after_expand, sess, state, Ok(()));
 126                     Ok(())
 127                 }
 128             )?
 129         };
 130
 131         write_out_deps(sess, &outputs, &crate_name);
 132         if sess.opts.output_types.contains_key(&OutputType::DepInfo) &&
 133             sess.opts.output_types.keys().count() == 1 {
 134             return Ok(())
 135         }
 136
 137         let arena = DroplessArena::new();
 138         let arenas = GlobalArenas::new();
 139
 140         // Construct the HIR map
 141         let hir_map = time(sess.time_passes(),
 142                            "indexing hir",
 143                            || hir_map::map_crate(&mut hir_forest, defs));
 144
 145         {
 146             let _ignore = hir_map.dep_graph.in_ignore();
 147             controller_entry_point!(after_hir_lowering,
 148                                     sess,
 149                                     CompileState::state_after_hir_lowering(input,
 150                                                                   sess,
 151                                                                   outdir,
 152                                                                   output,
 153                                                                   &arena,
 154                                                                   &arenas,
 155                                                                   &cstore,
 156                                                                   &hir_map,
 157                                                                   &analysis,
 158                                                                   &resolutions,
 159                                                                   &expanded_crate,
 160                                                                   &hir_map.krate(),
 161                                                                   &crate_name),
 162                                     Ok(()));
 163         }
 164
 165         time(sess.time_passes(), "attribute checking", || {
 166             hir::check_attr::check_crate(sess, &expanded_crate);
 167         });
 168
 169         let opt_crate = if keep_ast(sess) {
 170             Some(&expanded_crate)
 171         } else {
 172             drop(expanded_crate);
 173             None
 174         };
 175
 176         phase_3_run_analysis_passes(sess,
 177                                     hir_map,
 178                                     analysis,
 179                                     resolutions,
 180                                     &arena,
 181                                     &arenas,
 182                                     &crate_name,
 183                                     |tcx, analysis, incremental_hashes_map, result| {
 184             {
 185                 // Eventually, we will want to track plugins.
 186                 let _ignore = tcx.dep_graph.in_ignore();
 187
 188                 let mut state = CompileState::state_after_analysis(input,
 189                                                                    sess,
 190                                                                    outdir,
 191                                                                    output,
 192                                                                    opt_crate,
 193                                                                    tcx.hir.krate(),
 194                                                                    &analysis,
 195                                                                    tcx,
 196                                                                    &crate_name);
 197                 (control.after_analysis.callback)(&mut state);
 198
 199                 if control.after_analysis.stop == Compilation::Stop {
 200                     return result.and_then(|_| Err(CompileIncomplete::Stopped));
 201                 }
 202             }
 203
 204             result?;
 205
 206             if log_enabled!(::log::LogLevel::Info) {
 207                 println!("Pre-trans");
 208                 tcx.print_debug_stats();
 209             }
 210             let trans = phase_4_translate_to_llvm(tcx, analysis, &incremental_hashes_map,
 211                                                   &outputs);
 212
 213             if log_enabled!(::log::LogLevel::Info) {
 214                 println!("Post-trans");
 215                 tcx.print_debug_stats();
 216             }
 217
 218             if tcx.sess.opts.output_types.contains_key(&OutputType::Mir) {
 219                 if let Err(e) = mir::transform::dump_mir::emit_mir(tcx, &outputs) {
 220                     sess.err(&format!("could not emit MIR: {}", e));
 221                     sess.abort_if_errors();
 222                 }
 223             }
 224
 225             Ok((outputs, trans))
 226         })??
 227     };
 228
 229     if sess.opts.debugging_opts.print_type_sizes {
 230         sess.code_stats.borrow().print_type_sizes();
 231     }
 232
 233     let phase5_result = phase_5_run_llvm_passes(sess, &trans, &outputs);
 234
 235     controller_entry_point!(after_llvm,
 236                             sess,
 237                             CompileState::state_after_llvm(input, sess, outdir, output, &trans),
 238                             phase5_result);
 239     phase5_result?;
 240
 241     write::cleanup_llvm(&trans);
 242
 243     phase_6_link_output(sess, &trans, &outputs);
 244
 245     // Now that we won't touch anything in the incremental compilation directory
 246     // any more, we can finalize it (which involves renaming it)
 247     rustc_incremental::finalize_session_directory(sess, trans.link.crate_hash);
 248
 249     if sess.opts.debugging_opts.perf_stats {
 250         sess.print_perf_stats();
 251     }
 252
 253     controller_entry_point!(compilation_done,
 254                             sess,
 255                             CompileState::state_when_compilation_done(input, sess, outdir, output),
 256                             Ok(()));
 257
 258     Ok(())
 259 }
 260
 261 fn keep_hygiene_data(sess: &Session) -> bool {
 262     sess.opts.debugging_opts.keep_hygiene_data
 263 }
 264
 265 fn keep_ast(sess: &Session) -> bool {
 266     sess.opts.debugging_opts.keep_ast || ::save_analysis(sess)
 267 }
 268
 269 /// The name used for source code that doesn't originate in a file
 270 /// (e.g. source from stdin or a string)
 271 pub fn anon_src() -> String {
 272     "<anon>".to_string()
 273 }
 274
 275 pub fn source_name(input: &Input) -> String {
 276     match *input {
 277         // FIXME (#9639): This needs to handle non-utf8 paths
 278         Input::File(ref ifile) => ifile.to_str().unwrap().to_string(),
 279         Input::Str { ref name, .. } => name.clone(),
 280     }
 281 }
 282
 283 /// CompileController is used to customise compilation, it allows compilation to
 284 /// be stopped and/or to call arbitrary code at various points in compilation.
 285 /// It also allows for various flags to be set to influence what information gets
 286 /// collected during compilation.
 287 ///
 288 /// This is a somewhat higher level controller than a Session - the Session
 289 /// controls what happens in each phase, whereas the CompileController controls
 290 /// whether a phase is run at all and whether other code (from outside the
 291 /// the compiler) is run between phases.
 292 ///
 293 /// Note that if compilation is set to stop and a callback is provided for a
 294 /// given entry point, the callback is called before compilation is stopped.
 295 ///
 296 /// Expect more entry points to be added in the future.
 297 pub struct CompileController<'a> {
 298     pub after_parse: PhaseController<'a>,
 299     pub after_expand: PhaseController<'a>,
 300     pub after_hir_lowering: PhaseController<'a>,
 301     pub after_analysis: PhaseController<'a>,
 302     pub after_llvm: PhaseController<'a>,
 303     pub compilation_done: PhaseController<'a>,
 304
 305     pub make_glob_map: MakeGlobMap,
 306 }
 307
 308 impl<'a> CompileController<'a> {
 309     pub fn basic() -> CompileController<'a> {
 310         CompileController {
 311             after_parse: PhaseController::basic(),
 312             after_expand: PhaseController::basic(),
 313             after_hir_lowering: PhaseController::basic(),
 314             after_analysis: PhaseController::basic(),
 315             after_llvm: PhaseController::basic(),
 316             compilation_done: PhaseController::basic(),
 317             make_glob_map: MakeGlobMap::No,
 318         }
 319     }
 320 }
 321
 322 pub struct PhaseController<'a> {
 323     pub stop: Compilation,
 324     // If true then the compiler will try to run the callback even if the phase
 325     // ends with an error. Note that this is not always possible.
 326     pub run_callback_on_error: bool,
 327     pub callback: Box<Fn(&mut CompileState) + 'a>,
 328 }
 329
 330 impl<'a> PhaseController<'a> {
 331     pub fn basic() -> PhaseController<'a> {
 332         PhaseController {
 333             stop: Compilation::Continue,
 334             run_callback_on_error: false,
 335             callback: box |_| {},
 336         }
 337     }
 338 }
 339
 340 /// State that is passed to a callback. What state is available depends on when
 341 /// during compilation the callback is made. See the various constructor methods
 342 /// (`state_*`) in the impl to see which data is provided for any given entry point.
 343 pub struct CompileState<'a, 'tcx: 'a> {
 344     pub input: &'a Input,
 345     pub session: &'tcx Session,
 346     pub krate: Option<ast::Crate>,
 347     pub registry: Option<Registry<'a>>,
 348     pub cstore: Option<&'a CStore>,
 349     pub crate_name: Option<&'a str>,
 350     pub output_filenames: Option<&'a OutputFilenames>,
 351     pub out_dir: Option<&'a Path>,
 352     pub out_file: Option<&'a Path>,
 353     pub arena: Option<&'tcx DroplessArena>,
 354     pub arenas: Option<&'tcx GlobalArenas<'tcx>>,
 355     pub expanded_crate: Option<&'a ast::Crate>,
 356     pub hir_crate: Option<&'a hir::Crate>,
 357     pub hir_map: Option<&'a hir_map::Map<'tcx>>,
 358     pub resolutions: Option<&'a Resolutions>,
 359     pub analysis: Option<&'a ty::CrateAnalysis>,
 360     pub tcx: Option<TyCtxt<'a, 'tcx, 'tcx>>,
 361     pub trans: Option<&'a trans::CrateTranslation>,
 362 }
 363
 364 impl<'a, 'tcx> CompileState<'a, 'tcx> {
 365     fn empty(input: &'a Input,
 366              session: &'tcx Session,
 367              out_dir: &'a Option<PathBuf>)
 368              -> Self {
 369         CompileState {
 370             input: input,
 371             session: session,
 372             out_dir: out_dir.as_ref().map(|s| &**s),
 373             out_file: None,
 374             arena: None,
 375             arenas: None,
 376             krate: None,
 377             registry: None,
 378             cstore: None,
 379             crate_name: None,
 380             output_filenames: None,
 381             expanded_crate: None,
 382             hir_crate: None,
 383             hir_map: None,
 384             resolutions: None,
 385             analysis: None,
 386             tcx: None,
 387             trans: None,
 388         }
 389     }
 390
 391     fn state_after_parse(input: &'a Input,
 392                          session: &'tcx Session,
 393                          out_dir: &'a Option<PathBuf>,
 394                          out_file: &'a Option<PathBuf>,
 395                          krate: ast::Crate,
 396                          cstore: &'a CStore)
 397                          -> Self {
 398         CompileState {
 399             // Initialize the registry before moving `krate`
 400             registry: Some(Registry::new(&session, krate.span)),
 401             krate: Some(krate),
 402             cstore: Some(cstore),
 403             out_file: out_file.as_ref().map(|s| &**s),
 404             ..CompileState::empty(input, session, out_dir)
 405         }
 406     }
 407
 408     fn state_after_expand(input: &'a Input,
 409                           session: &'tcx Session,
 410                           out_dir: &'a Option<PathBuf>,
 411                           out_file: &'a Option<PathBuf>,
 412                           cstore: &'a CStore,
 413                           expanded_crate: &'a ast::Crate,
 414                           crate_name: &'a str)
 415                           -> Self {
 416         CompileState {
 417             crate_name: Some(crate_name),
 418             cstore: Some(cstore),
 419             expanded_crate: Some(expanded_crate),
 420             out_file: out_file.as_ref().map(|s| &**s),
 421             ..CompileState::empty(input, session, out_dir)
 422         }
 423     }
 424
 425     fn state_after_hir_lowering(input: &'a Input,
 426                                 session: &'tcx Session,
 427                                 out_dir: &'a Option<PathBuf>,
 428                                 out_file: &'a Option<PathBuf>,
 429                                 arena: &'tcx DroplessArena,
 430                                 arenas: &'tcx GlobalArenas<'tcx>,
 431                                 cstore: &'a CStore,
 432                                 hir_map: &'a hir_map::Map<'tcx>,
 433                                 analysis: &'a ty::CrateAnalysis,
 434                                 resolutions: &'a Resolutions,
 435                                 krate: &'a ast::Crate,
 436                                 hir_crate: &'a hir::Crate,
 437                                 crate_name: &'a str)
 438                                 -> Self {
 439         CompileState {
 440             crate_name: Some(crate_name),
 441             arena: Some(arena),
 442             arenas: Some(arenas),
 443             cstore: Some(cstore),
 444             hir_map: Some(hir_map),
 445             analysis: Some(analysis),
 446             resolutions: Some(resolutions),
 447             expanded_crate: Some(krate),
 448             hir_crate: Some(hir_crate),
 449             out_file: out_file.as_ref().map(|s| &**s),
 450             ..CompileState::empty(input, session, out_dir)
 451         }
 452     }
 453
 454     fn state_after_analysis(input: &'a Input,
 455                             session: &'tcx Session,
 456                             out_dir: &'a Option<PathBuf>,
 457                             out_file: &'a Option<PathBuf>,
 458                             krate: Option<&'a ast::Crate>,
 459                             hir_crate: &'a hir::Crate,
 460                             analysis: &'a ty::CrateAnalysis,
 461                             tcx: TyCtxt<'a, 'tcx, 'tcx>,
 462                             crate_name: &'a str)
 463                             -> Self {
 464         CompileState {
 465             analysis: Some(analysis),
 466             tcx: Some(tcx),
 467             expanded_crate: krate,
 468             hir_crate: Some(hir_crate),
 469             crate_name: Some(crate_name),
 470             out_file: out_file.as_ref().map(|s| &**s),
 471             ..CompileState::empty(input, session, out_dir)
 472         }
 473     }
 474
 475
 476     fn state_after_llvm(input: &'a Input,
 477                         session: &'tcx Session,
 478                         out_dir: &'a Option<PathBuf>,
 479                         out_file: &'a Option<PathBuf>,
 480                         trans: &'a trans::CrateTranslation)
 481                         -> Self {
 482         CompileState {
 483             trans: Some(trans),
 484             out_file: out_file.as_ref().map(|s| &**s),
 485             ..CompileState::empty(input, session, out_dir)
 486         }
 487     }
 488
 489     fn state_when_compilation_done(input: &'a Input,
 490                                     session: &'tcx Session,
 491                                     out_dir: &'a Option<PathBuf>,
 492                                     out_file: &'a Option<PathBuf>)
 493                                     -> Self {
 494         CompileState {
 495             out_file: out_file.as_ref().map(|s| &**s),
 496             ..CompileState::empty(input, session, out_dir)
 497         }
 498     }
 499 }
 500
 501 pub fn phase_1_parse_input<'a>(sess: &'a Session, input: &Input) -> PResult<'a, ast::Crate> {
 502     let continue_after_error = sess.opts.debugging_opts.continue_parse_after_error;
 503     sess.diagnostic().set_continue_after_error(continue_after_error);
 504
 505     let krate = time(sess.time_passes(), "parsing", || {
 506         match *input {
 507             Input::File(ref file) => {
 508                 parse::parse_crate_from_file(file, &sess.parse_sess)
 509             }
 510             Input::Str { ref input, ref name } => {
 511                 parse::parse_crate_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
 512             }
 513         }
 514     })?;
 515
 516     sess.diagnostic().set_continue_after_error(true);
 517
 518     if sess.opts.debugging_opts.ast_json_noexpand {
 519         println!("{}", json::as_json(&krate));
 520     }
 521
 522     if sess.opts.debugging_opts.input_stats {
 523         println!("Lines of code:             {}", sess.codemap().count_lines());
 524         println!("Pre-expansion node count:  {}", count_nodes(&krate));
 525     }
 526
 527     if let Some(ref s) = sess.opts.debugging_opts.show_span {
 528         syntax::show_span::run(sess.diagnostic(), s, &krate);
 529     }
 530
 531     if sess.opts.debugging_opts.hir_stats {
 532         hir_stats::print_ast_stats(&krate, "PRE EXPANSION AST STATS");
 533     }
 534
 535     Ok(krate)
 536 }
 537
 538 fn count_nodes(krate: &ast::Crate) -> usize {
 539     let mut counter = NodeCounter::new();
 540     visit::walk_crate(&mut counter, krate);
 541     counter.count
 542 }
 543
 544 // For continuing compilation after a parsed crate has been
 545 // modified
 546
 547 pub struct ExpansionResult {
 548     pub expanded_crate: ast::Crate,
 549     pub defs: hir_map::Definitions,
 550     pub analysis: ty::CrateAnalysis,
 551     pub resolutions: Resolutions,
 552     pub hir_forest: hir_map::Forest,
 553 }
 554
 555 /// Run the "early phases" of the compiler: initial `cfg` processing,
 556 /// loading compiler plugins (including those from `addl_plugins`),
 557 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
 558 /// harness if one is to be provided, injection of a dependency on the
 559 /// standard library and prelude, and name resolution.
 560 ///
 561 /// Returns `None` if we're aborting after handling -W help.
 562 pub fn phase_2_configure_and_expand<F>(sess: &Session,
 563                                        cstore: &CStore,
 564                                        krate: ast::Crate,
 565                                        registry: Option<Registry>,
 566                                        crate_name: &str,
 567                                        addl_plugins: Option<Vec<String>>,
 568                                        make_glob_map: MakeGlobMap,
 569                                        after_expand: F)
 570                                        -> Result<ExpansionResult, CompileIncomplete>
 571     where F: FnOnce(&ast::Crate) -> CompileResult,
 572 {
 573     let time_passes = sess.time_passes();
 574
 575     let (mut krate, features) = syntax::config::features(krate, &sess.parse_sess, sess.opts.test);
 576     // these need to be set "early" so that expansion sees `quote` if enabled.
 577     *sess.features.borrow_mut() = features;
 578
 579     *sess.crate_types.borrow_mut() = collect_crate_types(sess, &krate.attrs);
 580     *sess.crate_disambiguator.borrow_mut() = Symbol::intern(&compute_crate_disambiguator(sess));
 581
 582     time(time_passes, "recursion limit", || {
 583         middle::recursion_limit::update_limits(sess, &krate);
 584     });
 585
 586     krate = time(time_passes, "crate injection", || {
 587         let alt_std_name = sess.opts.alt_std_name.clone();
 588         syntax::std_inject::maybe_inject_crates_ref(krate, alt_std_name)
 589     });
 590
 591     let mut addl_plugins = Some(addl_plugins);
 592     let registrars = time(time_passes, "plugin loading", || {
 593         plugin::load::load_plugins(sess,
 594                                    &cstore,
 595                                    &krate,
 596                                    crate_name,
 597                                    addl_plugins.take().unwrap())
 598     });
 599
 600     let mut registry = registry.unwrap_or(Registry::new(sess, krate.span));
 601
 602     time(time_passes, "plugin registration", || {
 603         if sess.features.borrow().rustc_diagnostic_macros {
 604             registry.register_macro("__diagnostic_used",
 605                                     diagnostics::plugin::expand_diagnostic_used);
 606             registry.register_macro("__register_diagnostic",
 607                                     diagnostics::plugin::expand_register_diagnostic);
 608             registry.register_macro("__build_diagnostic_array",
 609                                     diagnostics::plugin::expand_build_diagnostic_array);
 610         }
 611
 612         for registrar in registrars {
 613             registry.args_hidden = Some(registrar.args);
 614             (registrar.fun)(&mut registry);
 615         }
 616     });
 617
 618     let whitelisted_legacy_custom_derives = registry.take_whitelisted_custom_derives();
 619     let Registry { syntax_exts, early_lint_passes, late_lint_passes, lint_groups,
 620                    llvm_passes, attributes, .. } = registry;
 621
 622     sess.track_errors(|| {
 623         let mut ls = sess.lint_store.borrow_mut();
 624         for pass in early_lint_passes {
 625             ls.register_early_pass(Some(sess), true, pass);
 626         }
 627         for pass in late_lint_passes {
 628             ls.register_late_pass(Some(sess), true, pass);
 629         }
 630
 631         for (name, to) in lint_groups {
 632             ls.register_group(Some(sess), true, name, to);
 633         }
 634
 635         *sess.plugin_llvm_passes.borrow_mut() = llvm_passes;
 636         *sess.plugin_attributes.borrow_mut() = attributes.clone();
 637     })?;
 638
 639     // Lint plugins are registered; now we can process command line flags.
 640     if sess.opts.describe_lints {
 641         super::describe_lints(&sess.lint_store.borrow(), true);
 642         return Err(CompileIncomplete::Stopped);
 643     }
 644     sess.track_errors(|| sess.lint_store.borrow_mut().process_command_line(sess))?;
 645
 646     // Currently, we ignore the name resolution data structures for the purposes of dependency
 647     // tracking. Instead we will run name resolution and include its output in the hash of each
 648     // item, much like we do for macro expansion. In other words, the hash reflects not just
 649     // its contents but the results of name resolution on those contents. Hopefully we'll push
 650     // this back at some point.
 651     let _ignore = sess.dep_graph.in_ignore();
 652     let mut crate_loader = CrateLoader::new(sess, &cstore, crate_name);
 653     crate_loader.preprocess(&krate);
 654     let resolver_arenas = Resolver::arenas();
 655     let mut resolver = Resolver::new(sess,
 656                                      &krate,
 657                                      crate_name,
 658                                      make_glob_map,
 659                                      &mut crate_loader,
 660                                      &resolver_arenas);
 661     resolver.whitelisted_legacy_custom_derives = whitelisted_legacy_custom_derives;
 662     syntax_ext::register_builtins(&mut resolver, syntax_exts, sess.features.borrow().quote);
 663
 664     krate = time(time_passes, "expansion", || {
 665         // Windows dlls do not have rpaths, so they don't know how to find their
 666         // dependencies. It's up to us to tell the system where to find all the
 667         // dependent dlls. Note that this uses cfg!(windows) as opposed to
 668         // targ_cfg because syntax extensions are always loaded for the host
 669         // compiler, not for the target.
 670         //
 671         // This is somewhat of an inherently racy operation, however, as
 672         // multiple threads calling this function could possibly continue
 673         // extending PATH far beyond what it should. To solve this for now we
 674         // just don't add any new elements to PATH which are already there
 675         // within PATH. This is basically a targeted fix at #17360 for rustdoc
 676         // which runs rustc in parallel but has been seen (#33844) to cause
 677         // problems with PATH becoming too long.
 678         let mut old_path = OsString::new();
 679         if cfg!(windows) {
 680             old_path = env::var_os("PATH").unwrap_or(old_path);
 681             let mut new_path = sess.host_filesearch(PathKind::All)
 682                                    .get_dylib_search_paths();
 683             for path in env::split_paths(&old_path) {
 684                 if !new_path.contains(&path) {
 685                     new_path.push(path);
 686                 }
 687             }
 688             env::set_var("PATH",
 689                 &env::join_paths(new_path.iter()
 690                                          .filter(|p| env::join_paths(iter::once(p)).is_ok()))
 691                      .unwrap());
 692         }
 693         let features = sess.features.borrow();
 694         let cfg = syntax::ext::expand::ExpansionConfig {
 695             features: Some(&features),
 696             recursion_limit: sess.recursion_limit.get(),
 697             trace_mac: sess.opts.debugging_opts.trace_macros,
 698             should_test: sess.opts.test,
 699             ..syntax::ext::expand::ExpansionConfig::default(crate_name.to_string())
 700         };
 701
 702         let mut ecx = ExtCtxt::new(&sess.parse_sess, cfg, &mut resolver);
 703         let err_count = ecx.parse_sess.span_diagnostic.err_count();
 704
 705         let krate = ecx.monotonic_expander().expand_crate(krate);
 706
 707         ecx.check_unused_macros();
 708
 709         let mut missing_fragment_specifiers: Vec<_> =
 710             ecx.parse_sess.missing_fragment_specifiers.borrow().iter().cloned().collect();
 711         missing_fragment_specifiers.sort();
 712         for span in missing_fragment_specifiers {
 713             let lint = lint::builtin::MISSING_FRAGMENT_SPECIFIER;
 714             let msg = "missing fragment specifier".to_string();
 715             sess.add_lint(lint, ast::CRATE_NODE_ID, span, msg);
 716         }
 717         if ecx.parse_sess.span_diagnostic.err_count() - ecx.resolve_err_count > err_count {
 718             ecx.parse_sess.span_diagnostic.abort_if_errors();
 719         }
 720         if cfg!(windows) {
 721             env::set_var("PATH", &old_path);
 722         }
 723         krate
 724     });
 725
 726     krate = time(time_passes, "maybe building test harness", || {
 727         syntax::test::modify_for_testing(&sess.parse_sess,
 728                                          &mut resolver,
 729                                          sess.opts.test,
 730                                          krate,
 731                                          sess.diagnostic())
 732     });
 733
 734     // If we're in rustdoc we're always compiling as an rlib, but that'll trip a
 735     // bunch of checks in the `modify` function below. For now just skip this
 736     // step entirely if we're rustdoc as it's not too useful anyway.
 737     if !sess.opts.actually_rustdoc {
 738         krate = time(time_passes, "maybe creating a macro crate", || {
 739             let crate_types = sess.crate_types.borrow();
 740             let num_crate_types = crate_types.len();
 741             let is_proc_macro_crate = crate_types.contains(&config::CrateTypeProcMacro);
 742             let is_test_crate = sess.opts.test;
 743             syntax_ext::proc_macro_registrar::modify(&sess.parse_sess,
 744                                                      &mut resolver,
 745                                                      krate,
 746                                                      is_proc_macro_crate,
 747                                                      is_test_crate,
 748                                                      num_crate_types,
 749                                                      sess.diagnostic())
 750         });
 751     }
 752
 753     after_expand(&krate)?;
 754
 755     if sess.opts.debugging_opts.input_stats {
 756         println!("Post-expansion node count: {}", count_nodes(&krate));
 757     }
 758
 759     if sess.opts.debugging_opts.hir_stats {
 760         hir_stats::print_ast_stats(&krate, "POST EXPANSION AST STATS");
 761     }
 762
 763     if sess.opts.debugging_opts.ast_json {
 764         println!("{}", json::as_json(&krate));
 765     }
 766
 767     time(time_passes,
 768          "checking for inline asm in case the target doesn't support it",
 769          || no_asm::check_crate(sess, &krate));
 770
 771     time(time_passes,
 772          "early lint checks",
 773          || lint::check_ast_crate(sess, &krate));
 774
 775     time(time_passes,
 776          "AST validation",
 777          || ast_validation::check_crate(sess, &krate));
 778
 779     time(time_passes, "name resolution", || -> CompileResult {
 780         resolver.resolve_crate(&krate);
 781         Ok(())
 782     })?;
 783
 784     if resolver.found_unresolved_macro {
 785         sess.parse_sess.span_diagnostic.abort_if_errors();
 786     }
 787
 788     // Needs to go *after* expansion to be able to check the results of macro expansion.
 789     time(time_passes, "complete gated feature checking", || {
 790         sess.track_errors(|| {
 791             syntax::feature_gate::check_crate(&krate,
 792                                               &sess.parse_sess,
 793                                               &sess.features.borrow(),
 794                                               &attributes,
 795                                               sess.opts.unstable_features);
 796         })
 797     })?;
 798
 799     // Lower ast -> hir.
 800     let hir_forest = time(time_passes, "lowering ast -> hir", || {
 801         let hir_crate = lower_crate(sess, &krate, &mut resolver);
 802
 803         if sess.opts.debugging_opts.hir_stats {
 804             hir_stats::print_hir_stats(&hir_crate);
 805         }
 806
 807         hir_map::Forest::new(hir_crate, &sess.dep_graph)
 808     });
 809
 810     // Discard hygiene data, which isn't required after lowering to HIR.
 811     if !keep_hygiene_data(sess) {
 812         syntax::ext::hygiene::clear_markings();
 813     }
 814
 815     Ok(ExpansionResult {
 816         expanded_crate: krate,
 817         defs: resolver.definitions,
 818         analysis: ty::CrateAnalysis {
 819             access_levels: Rc::new(AccessLevels::default()),
 820             reachable: Rc::new(NodeSet()),
 821             name: crate_name.to_string(),
 822             glob_map: if resolver.make_glob_map { Some(resolver.glob_map) } else { None },
 823         },
 824         resolutions: Resolutions {
 825             freevars: resolver.freevars,
 826             export_map: resolver.export_map,
 827             trait_map: resolver.trait_map,
 828             maybe_unused_trait_imports: resolver.maybe_unused_trait_imports,
 829         },
 830         hir_forest: hir_forest,
 831     })
 832 }
 833
 834 /// Run the resolution, typechecking, region checking and other
 835 /// miscellaneous analysis passes on the crate. Return various
 836 /// structures carrying the results of the analysis.
 837 pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
 838                                                hir_map: hir_map::Map<'tcx>,
 839                                                mut analysis: ty::CrateAnalysis,
 840                                                resolutions: Resolutions,
 841                                                arena: &'tcx DroplessArena,
 842                                                arenas: &'tcx GlobalArenas<'tcx>,
 843                                                name: &str,
 844                                                f: F)
 845                                                -> Result<R, CompileIncomplete>
 846     where F: for<'a> FnOnce(TyCtxt<'a, 'tcx, 'tcx>,
 847                             ty::CrateAnalysis,
 848                             IncrementalHashesMap,
 849                             CompileResult) -> R
 850 {
 851     macro_rules! try_with_f {
 852         ($e: expr, ($t: expr, $a: expr, $h: expr)) => {
 853             match $e {
 854                 Ok(x) => x,
 855                 Err(x) => {
 856                     f($t, $a, $h, Err(x));
 857                     return Err(x);
 858                 }
 859             }
 860         }
 861     }
 862
 863     let time_passes = sess.time_passes();
 864
 865     let lang_items = time(time_passes, "language item collection", || {
 866         sess.track_errors(|| {
 867             middle::lang_items::collect_language_items(&sess, &hir_map)
 868         })
 869     })?;
 870
 871     let named_region_map = time(time_passes,
 872                                 "lifetime resolution",
 873                                 || middle::resolve_lifetime::krate(sess, &hir_map))?;
 874
 875     time(time_passes,
 876          "looking for entry point",
 877          || middle::entry::find_entry_point(sess, &hir_map));
 878
 879     sess.plugin_registrar_fn.set(time(time_passes, "looking for plugin registrar", || {
 880         plugin::build::find_plugin_registrar(sess.diagnostic(), &hir_map)
 881     }));
 882     sess.derive_registrar_fn.set(derive_registrar::find(&hir_map));
 883
 884     time(time_passes,
 885          "loop checking",
 886          || loops::check_crate(sess, &hir_map));
 887
 888     time(time_passes,
 889               "static item recursion checking",
 890               || static_recursion::check_crate(sess, &hir_map))?;
 891
 892     let index = stability::Index::new(&sess);
 893
 894     let mut local_providers = ty::maps::Providers::default();
 895     borrowck::provide(&mut local_providers);
 896     mir::provide(&mut local_providers);
 897     reachable::provide(&mut local_providers);
 898     rustc_privacy::provide(&mut local_providers);
 899     trans::provide(&mut local_providers);
 900     typeck::provide(&mut local_providers);
 901     ty::provide(&mut local_providers);
 902     traits::provide(&mut local_providers);
 903     reachable::provide(&mut local_providers);
 904     rustc_const_eval::provide(&mut local_providers);
 905     middle::region::provide(&mut local_providers);
 906     cstore::provide_local(&mut local_providers);
 907
 908     let mut extern_providers = ty::maps::Providers::default();
 909     cstore::provide(&mut extern_providers);
 910     trans::provide(&mut extern_providers);
 911     ty::provide_extern(&mut extern_providers);
 912     traits::provide_extern(&mut extern_providers);
 913     // FIXME(eddyb) get rid of this once we replace const_eval with miri.
 914     rustc_const_eval::provide(&mut extern_providers);
 915
 916     // Setup the MIR passes that we want to run.
 917     let mut passes = Passes::new();
 918     passes.push_hook(mir::transform::dump_mir::DumpMir);
 919
 920     // Remove all `EndRegion` statements that are not involved in borrows.
 921     passes.push_pass(MIR_CONST, mir::transform::clean_end_regions::CleanEndRegions);
 922
 923     // What we need to do constant evaluation.
 924     passes.push_pass(MIR_CONST, mir::transform::simplify::SimplifyCfg::new("initial"));
 925     passes.push_pass(MIR_CONST, mir::transform::type_check::TypeckMir);
 926     passes.push_pass(MIR_CONST, mir::transform::rustc_peek::SanityCheck);
 927
 928     // What we need to run borrowck etc.
 929     passes.push_pass(MIR_VALIDATED, mir::transform::qualify_consts::QualifyAndPromoteConstants);
 930     passes.push_pass(MIR_VALIDATED,
 931                      mir::transform::simplify_branches::SimplifyBranches::new("initial"));
 932     passes.push_pass(MIR_VALIDATED, mir::transform::simplify::SimplifyCfg::new("qualify-consts"));
 933
 934     // Optimizations begin.
 935     passes.push_pass(MIR_OPTIMIZED, mir::transform::no_landing_pads::NoLandingPads);
 936     passes.push_pass(MIR_OPTIMIZED, mir::transform::simplify::SimplifyCfg::new("no-landing-pads"));
 937
 938     // From here on out, regions are gone.
 939     passes.push_pass(MIR_OPTIMIZED, mir::transform::erase_regions::EraseRegions);
 940     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_call_guards::AddCallGuards);
 941     passes.push_pass(MIR_OPTIMIZED, mir::transform::elaborate_drops::ElaborateDrops);
 942     passes.push_pass(MIR_OPTIMIZED, mir::transform::no_landing_pads::NoLandingPads);
 943     passes.push_pass(MIR_OPTIMIZED, mir::transform::simplify::SimplifyCfg::new("elaborate-drops"));
 944
 945     // No lifetime analysis based on borrowing can be done from here on out.
 946     passes.push_pass(MIR_OPTIMIZED, mir::transform::inline::Inline);
 947     passes.push_pass(MIR_OPTIMIZED, mir::transform::instcombine::InstCombine);
 948     passes.push_pass(MIR_OPTIMIZED, mir::transform::deaggregator::Deaggregator);
 949     passes.push_pass(MIR_OPTIMIZED, mir::transform::copy_prop::CopyPropagation);
 950     passes.push_pass(MIR_OPTIMIZED, mir::transform::simplify::SimplifyLocals);
 951     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_call_guards::AddCallGuards);
 952     passes.push_pass(MIR_OPTIMIZED, mir::transform::dump_mir::Marker("PreTrans"));
 953
 954     TyCtxt::create_and_enter(sess,
 955                              local_providers,
 956                              extern_providers,
 957                              Rc::new(passes),
 958                              arenas,
 959                              arena,
 960                              resolutions,
 961                              named_region_map,
 962                              hir_map,
 963                              lang_items,
 964                              index,
 965                              name,
 966                              |tcx| {
 967         let incremental_hashes_map =
 968             time(time_passes,
 969                  "compute_incremental_hashes_map",
 970                  || rustc_incremental::compute_incremental_hashes_map(tcx));
 971
 972         time(time_passes,
 973              "load_dep_graph",
 974              || rustc_incremental::load_dep_graph(tcx, &incremental_hashes_map));
 975
 976         time(time_passes, "stability index", || {
 977             tcx.stability.borrow_mut().build(tcx)
 978         });
 979
 980         time(time_passes,
 981              "stability checking",
 982              || stability::check_unstable_api_usage(tcx));
 983
 984         // passes are timed inside typeck
 985         try_with_f!(typeck::check_crate(tcx), (tcx, analysis, incremental_hashes_map));
 986
 987         time(time_passes,
 988              "const checking",
 989              || consts::check_crate(tcx));
 990
 991         analysis.access_levels =
 992             time(time_passes, "privacy checking", || rustc_privacy::check_crate(tcx));
 993
 994         time(time_passes,
 995              "intrinsic checking",
 996              || middle::intrinsicck::check_crate(tcx));
 997
 998         time(time_passes,
 999              "effect checking",
1000              || middle::effect::check_crate(tcx));
1001
1002         time(time_passes,
1003              "match checking",
1004              || check_match::check_crate(tcx));
1005
1006         // this must run before MIR dump, because
1007         // "not all control paths return a value" is reported here.
1008         //
1009         // maybe move the check to a MIR pass?
1010         time(time_passes,
1011              "liveness checking",
1012              || middle::liveness::check_crate(tcx));
1013
1014         time(time_passes,
1015              "borrow checking",
1016              || borrowck::check_crate(tcx));
1017
1018         // Avoid overwhelming user with errors if type checking failed.
1019         // I'm not sure how helpful this is, to be honest, but it avoids
1020         // a
1021         // lot of annoying errors in the compile-fail tests (basically,
1022         // lint warnings and so on -- kindck used to do this abort, but
1023         // kindck is gone now). -nmatsakis
1024         if sess.err_count() > 0 {
1025             return Ok(f(tcx, analysis, incremental_hashes_map, sess.compile_status()));
1026         }
1027
1028         analysis.reachable =
1029             time(time_passes,
1030                  "reachability checking",
1031                  || reachable::find_reachable(tcx));
1032
1033         time(time_passes, "death checking", || middle::dead::check_crate(tcx));
1034
1035         time(time_passes, "unused lib feature checking", || {
1036             stability::check_unused_or_stable_features(tcx)
1037         });
1038
1039         time(time_passes, "lint checking", || lint::check_crate(tcx));
1040
1041         return Ok(f(tcx, analysis, incremental_hashes_map, tcx.sess.compile_status()));
1042     })
1043 }
1044
1045 /// Run the translation phase to LLVM, after which the AST and analysis can
1046 /// be discarded.
1047 pub fn phase_4_translate_to_llvm<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1048                                            analysis: ty::CrateAnalysis,
1049                                            incremental_hashes_map: &IncrementalHashesMap,
1050                                            output_filenames: &OutputFilenames)
1051                                            -> trans::CrateTranslation {
1052     let time_passes = tcx.sess.time_passes();
1053
1054     time(time_passes,
1055          "resolving dependency formats",
1056          || dependency_format::calculate(tcx));
1057
1058     let translation =
1059         time(time_passes,
1060              "translation",
1061              move || trans::trans_crate(tcx, analysis, &incremental_hashes_map, output_filenames));
1062
1063     time(time_passes,
1064          "assert dep graph",
1065          || rustc_incremental::assert_dep_graph(tcx));
1066
1067     time(time_passes,
1068          "serialize dep graph",
1069          || rustc_incremental::save_dep_graph(tcx,
1070                                               &incremental_hashes_map,
1071                                               &translation.metadata.hashes,
1072                                               translation.link.crate_hash));
1073     translation
1074 }
1075
1076 /// Run LLVM itself, producing a bitcode file, assembly file or object file
1077 /// as a side effect.
1078 pub fn phase_5_run_llvm_passes(sess: &Session,
1079                                trans: &trans::CrateTranslation,
1080                                outputs: &OutputFilenames) -> CompileResult {
1081     if sess.opts.cg.no_integrated_as ||
1082         (sess.target.target.options.no_integrated_as &&
1083          (outputs.outputs.contains_key(&OutputType::Object) ||
1084           outputs.outputs.contains_key(&OutputType::Exe)))
1085     {
1086         let output_types = OutputTypes::new(&[(OutputType::Assembly, None)]);
1087         time(sess.time_passes(),
1088              "LLVM passes",
1089              || write::run_passes(sess, trans, &output_types, outputs));
1090
1091         write::run_assembler(sess, outputs);
1092
1093         // HACK the linker expects the object file to be named foo.0.o but
1094         // `run_assembler` produces an object named just foo.o. Rename it if we
1095         // are going to build an executable
1096         if sess.opts.output_types.contains_key(&OutputType::Exe) {
1097             let f = outputs.path(OutputType::Object);
1098             rename_or_copy_remove(&f,
1099                      f.with_file_name(format!("{}.0.o",
1100                                               f.file_stem().unwrap().to_string_lossy()))).unwrap();
1101         }
1102
1103         // Remove assembly source, unless --save-temps was specified
1104         if !sess.opts.cg.save_temps {
1105             fs::remove_file(&outputs.temp_path(OutputType::Assembly, None)).unwrap();
1106         }
1107     } else {
1108         time(sess.time_passes(),
1109              "LLVM passes",
1110              || write::run_passes(sess, trans, &sess.opts.output_types, outputs));
1111     }
1112
1113     time(sess.time_passes(),
1114          "serialize work products",
1115          move || rustc_incremental::save_work_products(sess));
1116
1117     sess.compile_status()
1118 }
1119
1120 /// Run the linker on any artifacts that resulted from the LLVM run.
1121 /// This should produce either a finished executable or library.
1122 pub fn phase_6_link_output(sess: &Session,
1123                            trans: &trans::CrateTranslation,
1124                            outputs: &OutputFilenames) {
1125     time(sess.time_passes(),
1126          "linking",
1127          || link::link_binary(sess, trans, outputs, &trans.crate_name.as_str()));
1128 }
1129
1130 fn escape_dep_filename(filename: &str) -> String {
1131     // Apparently clang and gcc *only* escape spaces:
1132     // http://llvm.org/klaus/clang/commit/9d50634cfc268ecc9a7250226dd5ca0e945240d4
1133     filename.replace(" ", "\\ ")
1134 }
1135
1136 fn write_out_deps(sess: &Session, outputs: &OutputFilenames, crate_name: &str) {
1137     let mut out_filenames = Vec::new();
1138     for output_type in sess.opts.output_types.keys() {
1139         let file = outputs.path(*output_type);
1140         match *output_type {
1141             OutputType::Exe => {
1142                 for output in sess.crate_types.borrow().iter() {
1143                     let p = link::filename_for_input(sess, *output, crate_name, outputs);
1144                     out_filenames.push(p);
1145                 }
1146             }
1147             _ => {
1148                 out_filenames.push(file);
1149             }
1150         }
1151     }
1152
1153     // Write out dependency rules to the dep-info file if requested
1154     if !sess.opts.output_types.contains_key(&OutputType::DepInfo) {
1155         return;
1156     }
1157     let deps_filename = outputs.path(OutputType::DepInfo);
1158
1159     let result =
1160         (|| -> io::Result<()> {
1161             // Build a list of files used to compile the output and
1162             // write Makefile-compatible dependency rules
1163             let files: Vec<String> = sess.codemap()
1164                                          .files()
1165                                          .iter()
1166                                          .filter(|fmap| fmap.is_real_file())
1167                                          .filter(|fmap| !fmap.is_imported())
1168                                          .map(|fmap| escape_dep_filename(&fmap.name))
1169                                          .collect();
1170             let mut file = fs::File::create(&deps_filename)?;
1171             for path in &out_filenames {
1172                 write!(file, "{}: {}\n\n", path.display(), files.join(" "))?;
1173             }
1174
1175             // Emit a fake target for each input file to the compilation. This
1176             // prevents `make` from spitting out an error if a file is later
1177             // deleted. For more info see #28735
1178             for path in files {
1179                 writeln!(file, "{}:", path)?;
1180             }
1181             Ok(())
1182         })();
1183
1184     match result {
1185         Ok(()) => {}
1186         Err(e) => {
1187             sess.fatal(&format!("error writing dependencies to `{}`: {}",
1188                                 deps_filename.display(),
1189                                 e));
1190         }
1191     }
1192 }
1193
1194 pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<config::CrateType> {
1195     // Unconditionally collect crate types from attributes to make them used
1196     let attr_types: Vec<config::CrateType> =
1197         attrs.iter()
1198              .filter_map(|a| {
1199                  if a.check_name("crate_type") {
1200                      match a.value_str() {
1201                          Some(ref n) if *n == "rlib" => {
1202                              Some(config::CrateTypeRlib)
1203                          }
1204                          Some(ref n) if *n == "dylib" => {
1205                              Some(config::CrateTypeDylib)
1206                          }
1207                          Some(ref n) if *n == "cdylib" => {
1208                              Some(config::CrateTypeCdylib)
1209                          }
1210                          Some(ref n) if *n == "lib" => {
1211                              Some(config::default_lib_output())
1212                          }
1213                          Some(ref n) if *n == "staticlib" => {
1214                              Some(config::CrateTypeStaticlib)
1215                          }
1216                          Some(ref n) if *n == "proc-macro" => {
1217                              Some(config::CrateTypeProcMacro)
1218                          }
1219                          Some(ref n) if *n == "bin" => Some(config::CrateTypeExecutable),
1220                          Some(_) => {
1221                              session.add_lint(lint::builtin::UNKNOWN_CRATE_TYPES,
1222                                               ast::CRATE_NODE_ID,
1223                                               a.span,
1224                                               "invalid `crate_type` value".to_string());
1225                              None
1226                          }
1227                          _ => {
1228                              session.struct_span_err(a.span, "`crate_type` requires a value")
1229                                  .note("for example: `#![crate_type=\"lib\"]`")
1230                                  .emit();
1231                              None
1232                          }
1233                      }
1234                  } else {
1235                      None
1236                  }
1237              })
1238              .collect();
1239
1240     // If we're generating a test executable, then ignore all other output
1241     // styles at all other locations
1242     if session.opts.test {
1243         return vec![config::CrateTypeExecutable];
1244     }
1245
1246     // Only check command line flags if present. If no types are specified by
1247     // command line, then reuse the empty `base` Vec to hold the types that
1248     // will be found in crate attributes.
1249     let mut base = session.opts.crate_types.clone();
1250     if base.is_empty() {
1251         base.extend(attr_types);
1252         if base.is_empty() {
1253             base.push(link::default_output_for_target(session));
1254         }
1255         base.sort();
1256         base.dedup();
1257     }
1258
1259     base.into_iter()
1260         .filter(|crate_type| {
1261             let res = !link::invalid_output_for_target(session, *crate_type);
1262
1263             if !res {
1264                 session.warn(&format!("dropping unsupported crate type `{}` for target `{}`",
1265                                       *crate_type,
1266                                       session.opts.target_triple));
1267             }
1268
1269             res
1270         })
1271         .collect()
1272 }
1273
1274 pub fn compute_crate_disambiguator(session: &Session) -> String {
1275     use std::hash::Hasher;
1276
1277     // The crate_disambiguator is a 128 bit hash. The disambiguator is fed
1278     // into various other hashes quite a bit (symbol hashes, incr. comp. hashes,
1279     // debuginfo type IDs, etc), so we don't want it to be too wide. 128 bits
1280     // should still be safe enough to avoid collisions in practice.
1281     // FIXME(mw): It seems that the crate_disambiguator is used everywhere as
1282     //            a hex-string instead of raw bytes. We should really use the
1283     //            smaller representation.
1284     let mut hasher = StableHasher::<Fingerprint>::new();
1285
1286     let mut metadata = session.opts.cg.metadata.clone();
1287     // We don't want the crate_disambiguator to dependent on the order
1288     // -C metadata arguments, so sort them:
1289     metadata.sort();
1290     // Every distinct -C metadata value is only incorporated once:
1291     metadata.dedup();
1292
1293     hasher.write(b"metadata");
1294     for s in &metadata {
1295         // Also incorporate the length of a metadata string, so that we generate
1296         // different values for `-Cmetadata=ab -Cmetadata=c` and
1297         // `-Cmetadata=a -Cmetadata=bc`
1298         hasher.write_usize(s.len());
1299         hasher.write(s.as_bytes());
1300     }
1301
1302     // If this is an executable, add a special suffix, so that we don't get
1303     // symbol conflicts when linking against a library of the same name.
1304     let is_exe = session.crate_types.borrow().contains(&config::CrateTypeExecutable);
1305
1306     format!("{}{}", hasher.finish().to_hex(), if is_exe { "-exe" } else {""})
1307 }
1308
1309 pub fn build_output_filenames(input: &Input,
1310                               odir: &Option<PathBuf>,
1311                               ofile: &Option<PathBuf>,
1312                               attrs: &[ast::Attribute],
1313                               sess: &Session)
1314                               -> OutputFilenames {
1315     match *ofile {
1316         None => {
1317             // "-" as input file will cause the parser to read from stdin so we
1318             // have to make up a name
1319             // We want to toss everything after the final '.'
1320             let dirpath = match *odir {
1321                 Some(ref d) => d.clone(),
1322                 None => PathBuf::new(),
1323             };
1324
1325             // If a crate name is present, we use it as the link name
1326             let stem = sess.opts
1327                            .crate_name
1328                            .clone()
1329                            .or_else(|| attr::find_crate_name(attrs).map(|n| n.to_string()))
1330                            .unwrap_or(input.filestem());
1331
1332             OutputFilenames {
1333                 out_directory: dirpath,
1334                 out_filestem: stem,
1335                 single_output_file: None,
1336                 extra: sess.opts.cg.extra_filename.clone(),
1337                 outputs: sess.opts.output_types.clone(),
1338             }
1339         }
1340
1341         Some(ref out_file) => {
1342             let unnamed_output_types = sess.opts
1343                                            .output_types
1344                                            .values()
1345                                            .filter(|a| a.is_none())
1346                                            .count();
1347             let ofile = if unnamed_output_types > 1 {
1348                 sess.warn("due to multiple output types requested, the explicitly specified \
1349                            output file name will be adapted for each output type");
1350                 None
1351             } else {
1352                 Some(out_file.clone())
1353             };
1354             if *odir != None {
1355                 sess.warn("ignoring --out-dir flag due to -o flag.");
1356             }
1357
1358             let cur_dir = Path::new("");
1359
1360             OutputFilenames {
1361                 out_directory: out_file.parent().unwrap_or(cur_dir).to_path_buf(),
1362                 out_filestem: out_file.file_stem()
1363                                       .unwrap_or(OsStr::new(""))
1364                                       .to_str()
1365                                       .unwrap()
1366                                       .to_string(),
1367                 single_output_file: ofile,
1368                 extra: sess.opts.cg.extra_filename.clone(),
1369                 outputs: sess.opts.output_types.clone(),
1370             }
1371         }
1372     }
1373 }