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, compile_result_from_err_count};
  17 use rustc::session::config::{self, Input, OutputFilenames, OutputType,
  18                              OutputTypes};
  19 use rustc::session::search_paths::PathKind;
  20 use rustc::lint;
  21 use rustc::middle::{self, dependency_format, stability, reachable};
  22 use rustc::middle::privacy::AccessLevels;
  23 use rustc::ty::{self, TyCtxt, Resolutions, GlobalArenas};
  24 use rustc::util::common::time;
  25 use rustc::util::nodemap::NodeSet;
  26 use rustc::util::fs::rename_or_copy_remove;
  27 use rustc_borrowck as borrowck;
  28 use rustc_incremental::{self, IncrementalHashesMap};
  29 use rustc_resolve::{MakeGlobMap, Resolver};
  30 use rustc_metadata::creader::CrateLoader;
  31 use rustc_metadata::cstore::{self, CStore};
  32 use rustc_trans::back::{link, write};
  33 use rustc_trans as trans;
  34 use rustc_typeck as typeck;
  35 use rustc_privacy;
  36 use rustc_plugin::registry::Registry;
  37 use rustc_plugin as plugin;
  38 use rustc_passes::{ast_validation, no_asm, loops, consts,
  39                    static_recursion, hir_stats, mir_stats};
  40 use rustc_const_eval::{self, check_match};
  41 use super::Compilation;
  42
  43 use serialize::json;
  44
  45 use std::env;
  46 use std::ffi::{OsString, OsStr};
  47 use std::fs;
  48 use std::io::{self, Write};
  49 use std::iter;
  50 use std::path::{Path, PathBuf};
  51 use std::rc::Rc;
  52 use syntax::{ast, diagnostics, visit};
  53 use syntax::attr;
  54 use syntax::ext::base::ExtCtxt;
  55 use syntax::parse::{self, PResult};
  56 use syntax::symbol::Symbol;
  57 use syntax::util::node_count::NodeCounter;
  58 use syntax;
  59 use syntax_ext;
  60 use arena::DroplessArena;
  61
  62 use derive_registrar;
  63
  64 pub fn compile_input(sess: &Session,
  65                      cstore: &CStore,
  66                      input: &Input,
  67                      outdir: &Option<PathBuf>,
  68                      output: &Option<PathBuf>,
  69                      addl_plugins: Option<Vec<String>>,
  70                      control: &CompileController) -> CompileResult {
  71     macro_rules! controller_entry_point {
  72         ($point: ident, $tsess: expr, $make_state: expr, $phase_result: expr) => {{
  73             let state = &mut $make_state;
  74             let phase_result: &CompileResult = &$phase_result;
  75             if phase_result.is_ok() || control.$point.run_callback_on_error {
  76                 (control.$point.callback)(state);
  77             }
  78
  79             if control.$point.stop == Compilation::Stop {
  80                 return compile_result_from_err_count($tsess.err_count());
  81             }
  82         }}
  83     }
  84
  85     // We need nested scopes here, because the intermediate results can keep
  86     // large chunks of memory alive and we want to free them as soon as
  87     // possible to keep the peak memory usage low
  88     let (outputs, trans) = {
  89         let krate = match phase_1_parse_input(sess, input) {
  90             Ok(krate) => krate,
  91             Err(mut parse_error) => {
  92                 parse_error.emit();
  93                 return Err(1);
  94             }
  95         };
  96
  97         let (krate, registry) = {
  98             let mut compile_state = CompileState::state_after_parse(input,
  99                                                                     sess,
 100                                                                     outdir,
 101                                                                     output,
 102                                                                     krate,
 103                                                                     &cstore);
 104             controller_entry_point!(after_parse,
 105                                     sess,
 106                                     compile_state,
 107                                     Ok(()));
 108
 109             (compile_state.krate.unwrap(), compile_state.registry)
 110         };
 111
 112         let outputs = build_output_filenames(input, outdir, output, &krate.attrs, sess);
 113         let crate_name = link::find_crate_name(Some(sess), &krate.attrs, input);
 114         let ExpansionResult { expanded_crate, defs, analysis, resolutions, mut hir_forest } = {
 115             phase_2_configure_and_expand(
 116                 sess, &cstore, krate, registry, &crate_name, addl_plugins, control.make_glob_map,
 117                 |expanded_crate| {
 118                     let mut state = CompileState::state_after_expand(
 119                         input, sess, outdir, output, &cstore, expanded_crate, &crate_name,
 120                     );
 121                     controller_entry_point!(after_expand, sess, state, Ok(()));
 122                     Ok(())
 123                 }
 124             )?
 125         };
 126
 127         write_out_deps(sess, &outputs, &crate_name);
 128         if sess.opts.output_types.contains_key(&OutputType::DepInfo) &&
 129             sess.opts.output_types.keys().count() == 1 {
 130             return Ok(())
 131         }
 132
 133         let arena = DroplessArena::new();
 134         let arenas = GlobalArenas::new();
 135
 136         // Construct the HIR map
 137         let hir_map = time(sess.time_passes(),
 138                            "indexing hir",
 139                            || hir_map::map_crate(&mut hir_forest, defs));
 140
 141         {
 142             let _ignore = hir_map.dep_graph.in_ignore();
 143             controller_entry_point!(after_hir_lowering,
 144                                     sess,
 145                                     CompileState::state_after_hir_lowering(input,
 146                                                                   sess,
 147                                                                   outdir,
 148                                                                   output,
 149                                                                   &arena,
 150                                                                   &arenas,
 151                                                                   &cstore,
 152                                                                   &hir_map,
 153                                                                   &analysis,
 154                                                                   &resolutions,
 155                                                                   &expanded_crate,
 156                                                                   &hir_map.krate(),
 157                                                                   &crate_name),
 158                                     Ok(()));
 159         }
 160
 161         time(sess.time_passes(), "attribute checking", || {
 162             hir::check_attr::check_crate(sess, &expanded_crate);
 163         });
 164
 165         let opt_crate = if keep_ast(sess) {
 166             Some(&expanded_crate)
 167         } else {
 168             drop(expanded_crate);
 169             None
 170         };
 171
 172         phase_3_run_analysis_passes(sess,
 173                                     hir_map,
 174                                     analysis,
 175                                     resolutions,
 176                                     &arena,
 177                                     &arenas,
 178                                     &crate_name,
 179                                     |tcx, analysis, incremental_hashes_map, result| {
 180             {
 181                 // Eventually, we will want to track plugins.
 182                 let _ignore = tcx.dep_graph.in_ignore();
 183
 184                 let mut state = CompileState::state_after_analysis(input,
 185                                                                    sess,
 186                                                                    outdir,
 187                                                                    output,
 188                                                                    opt_crate,
 189                                                                    tcx.hir.krate(),
 190                                                                    &analysis,
 191                                                                    tcx,
 192                                                                    &crate_name);
 193                 (control.after_analysis.callback)(&mut state);
 194
 195                 if control.after_analysis.stop == Compilation::Stop {
 196                     return result.and_then(|_| Err(0usize));
 197                 }
 198             }
 199
 200             result?;
 201
 202             if log_enabled!(::log::LogLevel::Info) {
 203                 println!("Pre-trans");
 204                 tcx.print_debug_stats();
 205             }
 206             let trans = phase_4_translate_to_llvm(tcx, analysis, &incremental_hashes_map);
 207
 208             if log_enabled!(::log::LogLevel::Info) {
 209                 println!("Post-trans");
 210                 tcx.print_debug_stats();
 211             }
 212
 213             if tcx.sess.opts.output_types.contains_key(&OutputType::Mir) {
 214                 if let Err(e) = mir::transform::dump_mir::emit_mir(tcx, &outputs) {
 215                     sess.err(&format!("could not emit MIR: {}", e));
 216                     sess.abort_if_errors();
 217                 }
 218             }
 219
 220             Ok((outputs, trans))
 221         })??
 222     };
 223
 224     if sess.opts.debugging_opts.print_type_sizes {
 225         sess.code_stats.borrow().print_type_sizes();
 226     }
 227
 228     if ::std::env::var("SKIP_LLVM").is_ok() { ::std::process::exit(0); }
 229
 230     let phase5_result = phase_5_run_llvm_passes(sess, &trans, &outputs);
 231
 232     controller_entry_point!(after_llvm,
 233                             sess,
 234                             CompileState::state_after_llvm(input, sess, outdir, output, &trans),
 235                             phase5_result);
 236     phase5_result?;
 237
 238     write::cleanup_llvm(&trans);
 239
 240     phase_6_link_output(sess, &trans, &outputs);
 241
 242     // Now that we won't touch anything in the incremental compilation directory
 243     // any more, we can finalize it (which involves renaming it)
 244     rustc_incremental::finalize_session_directory(sess, trans.link.crate_hash);
 245
 246     if sess.opts.debugging_opts.perf_stats {
 247         sess.print_perf_stats();
 248     }
 249
 250     controller_entry_point!(compilation_done,
 251                             sess,
 252                             CompileState::state_when_compilation_done(input, sess, outdir, output),
 253                             Ok(()));
 254
 255     Ok(())
 256 }
 257
 258 fn keep_hygiene_data(sess: &Session) -> bool {
 259     sess.opts.debugging_opts.keep_hygiene_data
 260 }
 261
 262 fn keep_ast(sess: &Session) -> bool {
 263     sess.opts.debugging_opts.keep_ast || ::save_analysis(sess)
 264 }
 265
 266 /// The name used for source code that doesn't originate in a file
 267 /// (e.g. source from stdin or a string)
 268 pub fn anon_src() -> String {
 269     "<anon>".to_string()
 270 }
 271
 272 pub fn source_name(input: &Input) -> String {
 273     match *input {
 274         // FIXME (#9639): This needs to handle non-utf8 paths
 275         Input::File(ref ifile) => ifile.to_str().unwrap().to_string(),
 276         Input::Str { ref name, .. } => name.clone(),
 277     }
 278 }
 279
 280 /// CompileController is used to customise compilation, it allows compilation to
 281 /// be stopped and/or to call arbitrary code at various points in compilation.
 282 /// It also allows for various flags to be set to influence what information gets
 283 /// collected during compilation.
 284 ///
 285 /// This is a somewhat higher level controller than a Session - the Session
 286 /// controls what happens in each phase, whereas the CompileController controls
 287 /// whether a phase is run at all and whether other code (from outside the
 288 /// the compiler) is run between phases.
 289 ///
 290 /// Note that if compilation is set to stop and a callback is provided for a
 291 /// given entry point, the callback is called before compilation is stopped.
 292 ///
 293 /// Expect more entry points to be added in the future.
 294 pub struct CompileController<'a> {
 295     pub after_parse: PhaseController<'a>,
 296     pub after_expand: PhaseController<'a>,
 297     pub after_hir_lowering: PhaseController<'a>,
 298     pub after_analysis: PhaseController<'a>,
 299     pub after_llvm: PhaseController<'a>,
 300     pub compilation_done: PhaseController<'a>,
 301
 302     pub make_glob_map: MakeGlobMap,
 303 }
 304
 305 impl<'a> CompileController<'a> {
 306     pub fn basic() -> CompileController<'a> {
 307         CompileController {
 308             after_parse: PhaseController::basic(),
 309             after_expand: PhaseController::basic(),
 310             after_hir_lowering: PhaseController::basic(),
 311             after_analysis: PhaseController::basic(),
 312             after_llvm: PhaseController::basic(),
 313             compilation_done: PhaseController::basic(),
 314             make_glob_map: MakeGlobMap::No,
 315         }
 316     }
 317 }
 318
 319 pub struct PhaseController<'a> {
 320     pub stop: Compilation,
 321     // If true then the compiler will try to run the callback even if the phase
 322     // ends with an error. Note that this is not always possible.
 323     pub run_callback_on_error: bool,
 324     pub callback: Box<Fn(&mut CompileState) + 'a>,
 325 }
 326
 327 impl<'a> PhaseController<'a> {
 328     pub fn basic() -> PhaseController<'a> {
 329         PhaseController {
 330             stop: Compilation::Continue,
 331             run_callback_on_error: false,
 332             callback: box |_| {},
 333         }
 334     }
 335 }
 336
 337 /// State that is passed to a callback. What state is available depends on when
 338 /// during compilation the callback is made. See the various constructor methods
 339 /// (`state_*`) in the impl to see which data is provided for any given entry point.
 340 pub struct CompileState<'a, 'tcx: 'a> {
 341     pub input: &'a Input,
 342     pub session: &'tcx Session,
 343     pub krate: Option<ast::Crate>,
 344     pub registry: Option<Registry<'a>>,
 345     pub cstore: Option<&'a CStore>,
 346     pub crate_name: Option<&'a str>,
 347     pub output_filenames: Option<&'a OutputFilenames>,
 348     pub out_dir: Option<&'a Path>,
 349     pub out_file: Option<&'a Path>,
 350     pub arena: Option<&'tcx DroplessArena>,
 351     pub arenas: Option<&'tcx GlobalArenas<'tcx>>,
 352     pub expanded_crate: Option<&'a ast::Crate>,
 353     pub hir_crate: Option<&'a hir::Crate>,
 354     pub hir_map: Option<&'a hir_map::Map<'tcx>>,
 355     pub resolutions: Option<&'a Resolutions>,
 356     pub analysis: Option<&'a ty::CrateAnalysis>,
 357     pub tcx: Option<TyCtxt<'a, 'tcx, 'tcx>>,
 358     pub trans: Option<&'a trans::CrateTranslation>,
 359 }
 360
 361 impl<'a, 'tcx> CompileState<'a, 'tcx> {
 362     fn empty(input: &'a Input,
 363              session: &'tcx Session,
 364              out_dir: &'a Option<PathBuf>)
 365              -> Self {
 366         CompileState {
 367             input: input,
 368             session: session,
 369             out_dir: out_dir.as_ref().map(|s| &**s),
 370             out_file: None,
 371             arena: None,
 372             arenas: None,
 373             krate: None,
 374             registry: None,
 375             cstore: None,
 376             crate_name: None,
 377             output_filenames: None,
 378             expanded_crate: None,
 379             hir_crate: None,
 380             hir_map: None,
 381             resolutions: None,
 382             analysis: None,
 383             tcx: None,
 384             trans: None,
 385         }
 386     }
 387
 388     fn state_after_parse(input: &'a Input,
 389                          session: &'tcx Session,
 390                          out_dir: &'a Option<PathBuf>,
 391                          out_file: &'a Option<PathBuf>,
 392                          krate: ast::Crate,
 393                          cstore: &'a CStore)
 394                          -> Self {
 395         CompileState {
 396             // Initialize the registry before moving `krate`
 397             registry: Some(Registry::new(&session, krate.span)),
 398             krate: Some(krate),
 399             cstore: Some(cstore),
 400             out_file: out_file.as_ref().map(|s| &**s),
 401             ..CompileState::empty(input, session, out_dir)
 402         }
 403     }
 404
 405     fn state_after_expand(input: &'a Input,
 406                           session: &'tcx Session,
 407                           out_dir: &'a Option<PathBuf>,
 408                           out_file: &'a Option<PathBuf>,
 409                           cstore: &'a CStore,
 410                           expanded_crate: &'a ast::Crate,
 411                           crate_name: &'a str)
 412                           -> Self {
 413         CompileState {
 414             crate_name: Some(crate_name),
 415             cstore: Some(cstore),
 416             expanded_crate: Some(expanded_crate),
 417             out_file: out_file.as_ref().map(|s| &**s),
 418             ..CompileState::empty(input, session, out_dir)
 419         }
 420     }
 421
 422     fn state_after_hir_lowering(input: &'a Input,
 423                                 session: &'tcx Session,
 424                                 out_dir: &'a Option<PathBuf>,
 425                                 out_file: &'a Option<PathBuf>,
 426                                 arena: &'tcx DroplessArena,
 427                                 arenas: &'tcx GlobalArenas<'tcx>,
 428                                 cstore: &'a CStore,
 429                                 hir_map: &'a hir_map::Map<'tcx>,
 430                                 analysis: &'a ty::CrateAnalysis,
 431                                 resolutions: &'a Resolutions,
 432                                 krate: &'a ast::Crate,
 433                                 hir_crate: &'a hir::Crate,
 434                                 crate_name: &'a str)
 435                                 -> Self {
 436         CompileState {
 437             crate_name: Some(crate_name),
 438             arena: Some(arena),
 439             arenas: Some(arenas),
 440             cstore: Some(cstore),
 441             hir_map: Some(hir_map),
 442             analysis: Some(analysis),
 443             resolutions: Some(resolutions),
 444             expanded_crate: Some(krate),
 445             hir_crate: Some(hir_crate),
 446             out_file: out_file.as_ref().map(|s| &**s),
 447             ..CompileState::empty(input, session, out_dir)
 448         }
 449     }
 450
 451     fn state_after_analysis(input: &'a Input,
 452                             session: &'tcx Session,
 453                             out_dir: &'a Option<PathBuf>,
 454                             out_file: &'a Option<PathBuf>,
 455                             krate: Option<&'a ast::Crate>,
 456                             hir_crate: &'a hir::Crate,
 457                             analysis: &'a ty::CrateAnalysis,
 458                             tcx: TyCtxt<'a, 'tcx, 'tcx>,
 459                             crate_name: &'a str)
 460                             -> Self {
 461         CompileState {
 462             analysis: Some(analysis),
 463             tcx: Some(tcx),
 464             expanded_crate: krate,
 465             hir_crate: Some(hir_crate),
 466             crate_name: Some(crate_name),
 467             out_file: out_file.as_ref().map(|s| &**s),
 468             ..CompileState::empty(input, session, out_dir)
 469         }
 470     }
 471
 472
 473     fn state_after_llvm(input: &'a Input,
 474                         session: &'tcx Session,
 475                         out_dir: &'a Option<PathBuf>,
 476                         out_file: &'a Option<PathBuf>,
 477                         trans: &'a trans::CrateTranslation)
 478                         -> Self {
 479         CompileState {
 480             trans: Some(trans),
 481             out_file: out_file.as_ref().map(|s| &**s),
 482             ..CompileState::empty(input, session, out_dir)
 483         }
 484     }
 485
 486     fn state_when_compilation_done(input: &'a Input,
 487                                     session: &'tcx Session,
 488                                     out_dir: &'a Option<PathBuf>,
 489                                     out_file: &'a Option<PathBuf>)
 490                                     -> Self {
 491         CompileState {
 492             out_file: out_file.as_ref().map(|s| &**s),
 493             ..CompileState::empty(input, session, out_dir)
 494         }
 495     }
 496 }
 497
 498 pub fn phase_1_parse_input<'a>(sess: &'a Session, input: &Input) -> PResult<'a, ast::Crate> {
 499     let continue_after_error = sess.opts.debugging_opts.continue_parse_after_error;
 500     sess.diagnostic().set_continue_after_error(continue_after_error);
 501
 502     let krate = time(sess.time_passes(), "parsing", || {
 503         match *input {
 504             Input::File(ref file) => {
 505                 parse::parse_crate_from_file(file, &sess.parse_sess)
 506             }
 507             Input::Str { ref input, ref name } => {
 508                 parse::parse_crate_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
 509             }
 510         }
 511     })?;
 512
 513     sess.diagnostic().set_continue_after_error(true);
 514
 515     if sess.opts.debugging_opts.ast_json_noexpand {
 516         println!("{}", json::as_json(&krate));
 517     }
 518
 519     if sess.opts.debugging_opts.input_stats {
 520         println!("Lines of code:             {}", sess.codemap().count_lines());
 521         println!("Pre-expansion node count:  {}", count_nodes(&krate));
 522     }
 523
 524     if let Some(ref s) = sess.opts.debugging_opts.show_span {
 525         syntax::show_span::run(sess.diagnostic(), s, &krate);
 526     }
 527
 528     if sess.opts.debugging_opts.hir_stats {
 529         hir_stats::print_ast_stats(&krate, "PRE EXPANSION AST STATS");
 530     }
 531
 532     Ok(krate)
 533 }
 534
 535 fn count_nodes(krate: &ast::Crate) -> usize {
 536     let mut counter = NodeCounter::new();
 537     visit::walk_crate(&mut counter, krate);
 538     counter.count
 539 }
 540
 541 // For continuing compilation after a parsed crate has been
 542 // modified
 543
 544 pub struct ExpansionResult {
 545     pub expanded_crate: ast::Crate,
 546     pub defs: hir_map::Definitions,
 547     pub analysis: ty::CrateAnalysis,
 548     pub resolutions: Resolutions,
 549     pub hir_forest: hir_map::Forest,
 550 }
 551
 552 /// Run the "early phases" of the compiler: initial `cfg` processing,
 553 /// loading compiler plugins (including those from `addl_plugins`),
 554 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
 555 /// harness if one is to be provided, injection of a dependency on the
 556 /// standard library and prelude, and name resolution.
 557 ///
 558 /// Returns `None` if we're aborting after handling -W help.
 559 pub fn phase_2_configure_and_expand<F>(sess: &Session,
 560                                        cstore: &CStore,
 561                                        krate: ast::Crate,
 562                                        registry: Option<Registry>,
 563                                        crate_name: &str,
 564                                        addl_plugins: Option<Vec<String>>,
 565                                        make_glob_map: MakeGlobMap,
 566                                        after_expand: F)
 567                                        -> Result<ExpansionResult, usize>
 568     where F: FnOnce(&ast::Crate) -> CompileResult,
 569 {
 570     let time_passes = sess.time_passes();
 571
 572     let (mut krate, features) = syntax::config::features(krate, &sess.parse_sess, sess.opts.test);
 573     // these need to be set "early" so that expansion sees `quote` if enabled.
 574     *sess.features.borrow_mut() = features;
 575
 576     *sess.crate_types.borrow_mut() = collect_crate_types(sess, &krate.attrs);
 577     *sess.crate_disambiguator.borrow_mut() = Symbol::intern(&compute_crate_disambiguator(sess));
 578
 579     time(time_passes, "recursion limit", || {
 580         middle::recursion_limit::update_limits(sess, &krate);
 581     });
 582
 583     krate = time(time_passes, "crate injection", || {
 584         let alt_std_name = sess.opts.alt_std_name.clone();
 585         syntax::std_inject::maybe_inject_crates_ref(krate, alt_std_name)
 586     });
 587
 588     let mut addl_plugins = Some(addl_plugins);
 589     let registrars = time(time_passes, "plugin loading", || {
 590         plugin::load::load_plugins(sess,
 591                                    &cstore,
 592                                    &krate,
 593                                    crate_name,
 594                                    addl_plugins.take().unwrap())
 595     });
 596
 597     let mut registry = registry.unwrap_or(Registry::new(sess, krate.span));
 598
 599     time(time_passes, "plugin registration", || {
 600         if sess.features.borrow().rustc_diagnostic_macros {
 601             registry.register_macro("__diagnostic_used",
 602                                     diagnostics::plugin::expand_diagnostic_used);
 603             registry.register_macro("__register_diagnostic",
 604                                     diagnostics::plugin::expand_register_diagnostic);
 605             registry.register_macro("__build_diagnostic_array",
 606                                     diagnostics::plugin::expand_build_diagnostic_array);
 607         }
 608
 609         for registrar in registrars {
 610             registry.args_hidden = Some(registrar.args);
 611             (registrar.fun)(&mut registry);
 612         }
 613     });
 614
 615     let whitelisted_legacy_custom_derives = registry.take_whitelisted_custom_derives();
 616     let Registry { syntax_exts, early_lint_passes, late_lint_passes, lint_groups,
 617                    llvm_passes, attributes, .. } = registry;
 618
 619     sess.track_errors(|| {
 620         let mut ls = sess.lint_store.borrow_mut();
 621         for pass in early_lint_passes {
 622             ls.register_early_pass(Some(sess), true, pass);
 623         }
 624         for pass in late_lint_passes {
 625             ls.register_late_pass(Some(sess), true, pass);
 626         }
 627
 628         for (name, to) in lint_groups {
 629             ls.register_group(Some(sess), true, name, to);
 630         }
 631
 632         *sess.plugin_llvm_passes.borrow_mut() = llvm_passes;
 633         *sess.plugin_attributes.borrow_mut() = attributes.clone();
 634     })?;
 635
 636     // Lint plugins are registered; now we can process command line flags.
 637     if sess.opts.describe_lints {
 638         super::describe_lints(&sess.lint_store.borrow(), true);
 639         return Err(0);
 640     }
 641     sess.track_errors(|| sess.lint_store.borrow_mut().process_command_line(sess))?;
 642
 643     // Currently, we ignore the name resolution data structures for the purposes of dependency
 644     // tracking. Instead we will run name resolution and include its output in the hash of each
 645     // item, much like we do for macro expansion. In other words, the hash reflects not just
 646     // its contents but the results of name resolution on those contents. Hopefully we'll push
 647     // this back at some point.
 648     let _ignore = sess.dep_graph.in_ignore();
 649     let mut crate_loader = CrateLoader::new(sess, &cstore, crate_name);
 650     crate_loader.preprocess(&krate);
 651     let resolver_arenas = Resolver::arenas();
 652     let mut resolver = Resolver::new(sess,
 653                                      &krate,
 654                                      crate_name,
 655                                      make_glob_map,
 656                                      &mut crate_loader,
 657                                      &resolver_arenas);
 658     resolver.whitelisted_legacy_custom_derives = whitelisted_legacy_custom_derives;
 659     syntax_ext::register_builtins(&mut resolver, syntax_exts, sess.features.borrow().quote);
 660
 661     krate = time(time_passes, "expansion", || {
 662         // Windows dlls do not have rpaths, so they don't know how to find their
 663         // dependencies. It's up to us to tell the system where to find all the
 664         // dependent dlls. Note that this uses cfg!(windows) as opposed to
 665         // targ_cfg because syntax extensions are always loaded for the host
 666         // compiler, not for the target.
 667         //
 668         // This is somewhat of an inherently racy operation, however, as
 669         // multiple threads calling this function could possibly continue
 670         // extending PATH far beyond what it should. To solve this for now we
 671         // just don't add any new elements to PATH which are already there
 672         // within PATH. This is basically a targeted fix at #17360 for rustdoc
 673         // which runs rustc in parallel but has been seen (#33844) to cause
 674         // problems with PATH becoming too long.
 675         let mut old_path = OsString::new();
 676         if cfg!(windows) {
 677             old_path = env::var_os("PATH").unwrap_or(old_path);
 678             let mut new_path = sess.host_filesearch(PathKind::All)
 679                                    .get_dylib_search_paths();
 680             for path in env::split_paths(&old_path) {
 681                 if !new_path.contains(&path) {
 682                     new_path.push(path);
 683                 }
 684             }
 685             env::set_var("PATH",
 686                 &env::join_paths(new_path.iter()
 687                                          .filter(|p| env::join_paths(iter::once(p)).is_ok()))
 688                      .unwrap());
 689         }
 690         let features = sess.features.borrow();
 691         let cfg = syntax::ext::expand::ExpansionConfig {
 692             features: Some(&features),
 693             recursion_limit: sess.recursion_limit.get(),
 694             trace_mac: sess.opts.debugging_opts.trace_macros,
 695             should_test: sess.opts.test,
 696             ..syntax::ext::expand::ExpansionConfig::default(crate_name.to_string())
 697         };
 698
 699         let mut ecx = ExtCtxt::new(&sess.parse_sess, cfg, &mut resolver);
 700         let err_count = ecx.parse_sess.span_diagnostic.err_count();
 701
 702         let krate = ecx.monotonic_expander().expand_crate(krate);
 703
 704         let mut missing_fragment_specifiers: Vec<_> =
 705             ecx.parse_sess.missing_fragment_specifiers.borrow().iter().cloned().collect();
 706         missing_fragment_specifiers.sort();
 707         for span in missing_fragment_specifiers {
 708             let lint = lint::builtin::MISSING_FRAGMENT_SPECIFIER;
 709             let msg = "missing fragment specifier".to_string();
 710             sess.add_lint(lint, ast::CRATE_NODE_ID, span, msg);
 711         }
 712         if ecx.parse_sess.span_diagnostic.err_count() - ecx.resolve_err_count > err_count {
 713             ecx.parse_sess.span_diagnostic.abort_if_errors();
 714         }
 715         if cfg!(windows) {
 716             env::set_var("PATH", &old_path);
 717         }
 718         krate
 719     });
 720
 721     krate = time(time_passes, "maybe building test harness", || {
 722         syntax::test::modify_for_testing(&sess.parse_sess,
 723                                          &mut resolver,
 724                                          sess.opts.test,
 725                                          krate,
 726                                          sess.diagnostic())
 727     });
 728
 729     // If we're in rustdoc we're always compiling as an rlib, but that'll trip a
 730     // bunch of checks in the `modify` function below. For now just skip this
 731     // step entirely if we're rustdoc as it's not too useful anyway.
 732     if !sess.opts.actually_rustdoc {
 733         krate = time(time_passes, "maybe creating a macro crate", || {
 734             let crate_types = sess.crate_types.borrow();
 735             let num_crate_types = crate_types.len();
 736             let is_proc_macro_crate = crate_types.contains(&config::CrateTypeProcMacro);
 737             let is_test_crate = sess.opts.test;
 738             syntax_ext::proc_macro_registrar::modify(&sess.parse_sess,
 739                                                      &mut resolver,
 740                                                      krate,
 741                                                      is_proc_macro_crate,
 742                                                      is_test_crate,
 743                                                      num_crate_types,
 744                                                      sess.diagnostic())
 745         });
 746     }
 747
 748     after_expand(&krate)?;
 749
 750     if sess.opts.debugging_opts.input_stats {
 751         println!("Post-expansion node count: {}", count_nodes(&krate));
 752     }
 753
 754     if sess.opts.debugging_opts.hir_stats {
 755         hir_stats::print_ast_stats(&krate, "POST EXPANSION AST STATS");
 756     }
 757
 758     if sess.opts.debugging_opts.ast_json {
 759         println!("{}", json::as_json(&krate));
 760     }
 761
 762     time(time_passes,
 763          "checking for inline asm in case the target doesn't support it",
 764          || no_asm::check_crate(sess, &krate));
 765
 766     time(time_passes,
 767          "early lint checks",
 768          || lint::check_ast_crate(sess, &krate));
 769
 770     time(time_passes,
 771          "AST validation",
 772          || ast_validation::check_crate(sess, &krate));
 773
 774     time(time_passes, "name resolution", || -> CompileResult {
 775         resolver.resolve_crate(&krate);
 776         Ok(())
 777     })?;
 778
 779     if resolver.found_unresolved_macro {
 780         sess.parse_sess.span_diagnostic.abort_if_errors();
 781     }
 782
 783     // Needs to go *after* expansion to be able to check the results of macro expansion.
 784     time(time_passes, "complete gated feature checking", || {
 785         sess.track_errors(|| {
 786             syntax::feature_gate::check_crate(&krate,
 787                                               &sess.parse_sess,
 788                                               &sess.features.borrow(),
 789                                               &attributes,
 790                                               sess.opts.unstable_features);
 791         })
 792     })?;
 793
 794     // Lower ast -> hir.
 795     let hir_forest = time(time_passes, "lowering ast -> hir", || {
 796         let hir_crate = lower_crate(sess, &krate, &mut resolver);
 797
 798         if sess.opts.debugging_opts.hir_stats {
 799             hir_stats::print_hir_stats(&hir_crate);
 800         }
 801
 802         hir_map::Forest::new(hir_crate, &sess.dep_graph)
 803     });
 804
 805     // Discard hygiene data, which isn't required after lowering to HIR.
 806     if !keep_hygiene_data(sess) {
 807         syntax::ext::hygiene::clear_markings();
 808     }
 809
 810     Ok(ExpansionResult {
 811         expanded_crate: krate,
 812         defs: resolver.definitions,
 813         analysis: ty::CrateAnalysis {
 814             access_levels: Rc::new(AccessLevels::default()),
 815             reachable: Rc::new(NodeSet()),
 816             name: crate_name.to_string(),
 817             glob_map: if resolver.make_glob_map { Some(resolver.glob_map) } else { None },
 818         },
 819         resolutions: Resolutions {
 820             freevars: resolver.freevars,
 821             export_map: resolver.export_map,
 822             trait_map: resolver.trait_map,
 823             maybe_unused_trait_imports: resolver.maybe_unused_trait_imports,
 824         },
 825         hir_forest: hir_forest,
 826     })
 827 }
 828
 829 /// Run the resolution, typechecking, region checking and other
 830 /// miscellaneous analysis passes on the crate. Return various
 831 /// structures carrying the results of the analysis.
 832 pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
 833                                                hir_map: hir_map::Map<'tcx>,
 834                                                mut analysis: ty::CrateAnalysis,
 835                                                resolutions: Resolutions,
 836                                                arena: &'tcx DroplessArena,
 837                                                arenas: &'tcx GlobalArenas<'tcx>,
 838                                                name: &str,
 839                                                f: F)
 840                                                -> Result<R, usize>
 841     where F: for<'a> FnOnce(TyCtxt<'a, 'tcx, 'tcx>,
 842                             ty::CrateAnalysis,
 843                             IncrementalHashesMap,
 844                             CompileResult) -> R
 845 {
 846     macro_rules! try_with_f {
 847         ($e: expr, ($t: expr, $a: expr, $h: expr)) => {
 848             match $e {
 849                 Ok(x) => x,
 850                 Err(x) => {
 851                     f($t, $a, $h, Err(x));
 852                     return Err(x);
 853                 }
 854             }
 855         }
 856     }
 857
 858     let time_passes = sess.time_passes();
 859
 860     let lang_items = time(time_passes, "language item collection", || {
 861         sess.track_errors(|| {
 862             middle::lang_items::collect_language_items(&sess, &hir_map)
 863         })
 864     })?;
 865
 866     let named_region_map = time(time_passes,
 867                                 "lifetime resolution",
 868                                 || middle::resolve_lifetime::krate(sess, &hir_map))?;
 869
 870     time(time_passes,
 871          "looking for entry point",
 872          || middle::entry::find_entry_point(sess, &hir_map));
 873
 874     sess.plugin_registrar_fn.set(time(time_passes, "looking for plugin registrar", || {
 875         plugin::build::find_plugin_registrar(sess.diagnostic(), &hir_map)
 876     }));
 877     sess.derive_registrar_fn.set(derive_registrar::find(&hir_map));
 878
 879     let region_map = time(time_passes,
 880                           "region resolution",
 881                           || middle::region::resolve_crate(sess, &hir_map));
 882
 883     time(time_passes,
 884          "loop checking",
 885          || loops::check_crate(sess, &hir_map));
 886
 887     time(time_passes,
 888               "static item recursion checking",
 889               || static_recursion::check_crate(sess, &hir_map))?;
 890
 891     let index = stability::Index::new(&hir_map);
 892
 893     let mut local_providers = ty::maps::Providers::default();
 894     borrowck::provide(&mut local_providers);
 895     mir::provide(&mut local_providers);
 896     reachable::provide(&mut local_providers);
 897     rustc_privacy::provide(&mut local_providers);
 898     typeck::provide(&mut local_providers);
 899     ty::provide(&mut local_providers);
 900     reachable::provide(&mut local_providers);
 901     rustc_const_eval::provide(&mut local_providers);
 902
 903     let mut extern_providers = ty::maps::Providers::default();
 904     cstore::provide(&mut extern_providers);
 905     ty::provide_extern(&mut extern_providers);
 906     // FIXME(eddyb) get rid of this once we replace const_eval with miri.
 907     rustc_const_eval::provide(&mut extern_providers);
 908
 909     TyCtxt::create_and_enter(sess,
 910                              local_providers,
 911                              extern_providers,
 912                              arenas,
 913                              arena,
 914                              resolutions,
 915                              named_region_map,
 916                              hir_map,
 917                              region_map,
 918                              lang_items,
 919                              index,
 920                              name,
 921                              |tcx| {
 922         let incremental_hashes_map =
 923             time(time_passes,
 924                  "compute_incremental_hashes_map",
 925                  || rustc_incremental::compute_incremental_hashes_map(tcx));
 926         time(time_passes,
 927              "load_dep_graph",
 928              || rustc_incremental::load_dep_graph(tcx, &incremental_hashes_map));
 929
 930         time(time_passes, "stability index", || {
 931             tcx.stability.borrow_mut().build(tcx)
 932         });
 933
 934         time(time_passes,
 935              "stability checking",
 936              || stability::check_unstable_api_usage(tcx));
 937
 938         // passes are timed inside typeck
 939         try_with_f!(typeck::check_crate(tcx), (tcx, analysis, incremental_hashes_map));
 940
 941         time(time_passes,
 942              "const checking",
 943              || consts::check_crate(tcx));
 944
 945         analysis.access_levels =
 946             time(time_passes, "privacy checking", || rustc_privacy::check_crate(tcx));
 947
 948         time(time_passes,
 949              "intrinsic checking",
 950              || middle::intrinsicck::check_crate(tcx));
 951
 952         time(time_passes,
 953              "effect checking",
 954              || middle::effect::check_crate(tcx));
 955
 956         time(time_passes,
 957              "match checking",
 958              || check_match::check_crate(tcx));
 959
 960         // this must run before MIR dump, because
 961         // "not all control paths return a value" is reported here.
 962         //
 963         // maybe move the check to a MIR pass?
 964         time(time_passes,
 965              "liveness checking",
 966              || middle::liveness::check_crate(tcx));
 967
 968         time(time_passes,
 969              "MIR dump",
 970              || mir::mir_map::build_mir_for_crate(tcx));
 971
 972         if sess.opts.debugging_opts.mir_stats {
 973             mir_stats::print_mir_stats(tcx, "PRE CLEANUP MIR STATS");
 974         }
 975
 976         time(time_passes, "MIR cleanup and validation", || {
 977             let mut passes = sess.mir_passes.borrow_mut();
 978             // Push all the built-in validation passes.
 979             // NB: if you’re adding an *optimisation* it ought to go to another set of passes
 980             // in stage 4 below.
 981             passes.push_hook(box mir::transform::dump_mir::DumpMir);
 982             passes.push_pass(box mir::transform::simplify::SimplifyCfg::new("initial"));
 983             passes.push_pass(box mir::transform::type_check::TypeckMir);
 984             passes.push_pass(box mir::transform::qualify_consts::QualifyAndPromoteConstants);
 985             passes.push_pass(
 986                 box mir::transform::simplify_branches::SimplifyBranches::new("initial"));
 987             passes.push_pass(box mir::transform::simplify::SimplifyCfg::new("qualify-consts"));
 988             // And run everything.
 989             passes.run_passes(tcx);
 990         });
 991
 992         time(time_passes,
 993              "borrow checking",
 994              || borrowck::check_crate(tcx));
 995
 996         // Avoid overwhelming user with errors if type checking failed.
 997         // I'm not sure how helpful this is, to be honest, but it avoids
 998         // a
 999         // lot of annoying errors in the compile-fail tests (basically,
1000         // lint warnings and so on -- kindck used to do this abort, but
1001         // kindck is gone now). -nmatsakis
1002         if sess.err_count() > 0 {
1003             return Ok(f(tcx, analysis, incremental_hashes_map, Err(sess.err_count())));
1004         }
1005
1006         analysis.reachable =
1007             time(time_passes,
1008                  "reachability checking",
1009                  || reachable::find_reachable(tcx));
1010
1011         time(time_passes, "death checking", || middle::dead::check_crate(tcx));
1012
1013         time(time_passes, "unused lib feature checking", || {
1014             stability::check_unused_or_stable_features(tcx)
1015         });
1016
1017         time(time_passes, "lint checking", || lint::check_crate(tcx));
1018
1019         // The above three passes generate errors w/o aborting
1020         if sess.err_count() > 0 {
1021             return Ok(f(tcx, analysis, incremental_hashes_map, Err(sess.err_count())));
1022         }
1023
1024         Ok(f(tcx, analysis, incremental_hashes_map, Ok(())))
1025     })
1026 }
1027
1028 /// Run the translation phase to LLVM, after which the AST and analysis can
1029 /// be discarded.
1030 pub fn phase_4_translate_to_llvm<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1031                                            analysis: ty::CrateAnalysis,
1032                                            incremental_hashes_map: &IncrementalHashesMap)
1033                                            -> trans::CrateTranslation {
1034     let time_passes = tcx.sess.time_passes();
1035
1036     time(time_passes,
1037          "resolving dependency formats",
1038          || dependency_format::calculate(&tcx.sess));
1039
1040     if tcx.sess.opts.debugging_opts.mir_stats {
1041         mir_stats::print_mir_stats(tcx, "PRE OPTIMISATION MIR STATS");
1042     }
1043
1044     // Run the passes that transform the MIR into a more suitable form for translation to LLVM
1045     // code.
1046     time(time_passes, "MIR optimisations", || {
1047         let mut passes = ::rustc::mir::transform::Passes::new();
1048         passes.push_hook(box mir::transform::dump_mir::DumpMir);
1049         passes.push_pass(box mir::transform::no_landing_pads::NoLandingPads);
1050         passes.push_pass(box mir::transform::simplify::SimplifyCfg::new("no-landing-pads"));
1051
1052         // From here on out, regions are gone.
1053         passes.push_pass(box mir::transform::erase_regions::EraseRegions);
1054
1055         passes.push_pass(box mir::transform::add_call_guards::AddCallGuards);
1056         passes.push_pass(box borrowck::ElaborateDrops);
1057         passes.push_pass(box mir::transform::no_landing_pads::NoLandingPads);
1058         passes.push_pass(box mir::transform::simplify::SimplifyCfg::new("elaborate-drops"));
1059
1060         // No lifetime analysis based on borrowing can be done from here on out.
1061         passes.push_pass(box mir::transform::inline::Inline);
1062         passes.push_pass(box mir::transform::instcombine::InstCombine::new());
1063         passes.push_pass(box mir::transform::deaggregator::Deaggregator);
1064         passes.push_pass(box mir::transform::copy_prop::CopyPropagation);
1065
1066         passes.push_pass(box mir::transform::simplify::SimplifyLocals);
1067         passes.push_pass(box mir::transform::add_call_guards::AddCallGuards);
1068         passes.push_pass(box mir::transform::dump_mir::Marker("PreTrans"));
1069
1070         passes.run_passes(tcx);
1071     });
1072
1073     if tcx.sess.opts.debugging_opts.mir_stats {
1074         mir_stats::print_mir_stats(tcx, "POST OPTIMISATION MIR STATS");
1075     }
1076
1077     let translation =
1078         time(time_passes,
1079              "translation",
1080              move || trans::trans_crate(tcx, analysis, &incremental_hashes_map));
1081
1082     time(time_passes,
1083          "assert dep graph",
1084          || rustc_incremental::assert_dep_graph(tcx));
1085
1086     time(time_passes,
1087          "serialize dep graph",
1088          || rustc_incremental::save_dep_graph(tcx,
1089                                               &incremental_hashes_map,
1090                                               &translation.metadata.hashes,
1091                                               translation.link.crate_hash));
1092     translation
1093 }
1094
1095 /// Run LLVM itself, producing a bitcode file, assembly file or object file
1096 /// as a side effect.
1097 pub fn phase_5_run_llvm_passes(sess: &Session,
1098                                trans: &trans::CrateTranslation,
1099                                outputs: &OutputFilenames) -> CompileResult {
1100     if sess.opts.cg.no_integrated_as ||
1101         (sess.target.target.options.no_integrated_as &&
1102          (outputs.outputs.contains_key(&OutputType::Object) ||
1103           outputs.outputs.contains_key(&OutputType::Exe)))
1104     {
1105         let output_types = OutputTypes::new(&[(OutputType::Assembly, None)]);
1106         time(sess.time_passes(),
1107              "LLVM passes",
1108              || write::run_passes(sess, trans, &output_types, outputs));
1109
1110         write::run_assembler(sess, outputs);
1111
1112         // HACK the linker expects the object file to be named foo.0.o but
1113         // `run_assembler` produces an object named just foo.o. Rename it if we
1114         // are going to build an executable
1115         if sess.opts.output_types.contains_key(&OutputType::Exe) {
1116             let f = outputs.path(OutputType::Object);
1117             rename_or_copy_remove(&f,
1118                      f.with_file_name(format!("{}.0.o",
1119                                               f.file_stem().unwrap().to_string_lossy()))).unwrap();
1120         }
1121
1122         // Remove assembly source, unless --save-temps was specified
1123         if !sess.opts.cg.save_temps {
1124             fs::remove_file(&outputs.temp_path(OutputType::Assembly, None)).unwrap();
1125         }
1126     } else {
1127         time(sess.time_passes(),
1128              "LLVM passes",
1129              || write::run_passes(sess, trans, &sess.opts.output_types, outputs));
1130     }
1131
1132     time(sess.time_passes(),
1133          "serialize work products",
1134          move || rustc_incremental::save_work_products(sess));
1135
1136     if sess.err_count() > 0 {
1137         Err(sess.err_count())
1138     } else {
1139         Ok(())
1140     }
1141 }
1142
1143 /// Run the linker on any artifacts that resulted from the LLVM run.
1144 /// This should produce either a finished executable or library.
1145 pub fn phase_6_link_output(sess: &Session,
1146                            trans: &trans::CrateTranslation,
1147                            outputs: &OutputFilenames) {
1148     time(sess.time_passes(),
1149          "linking",
1150          || link::link_binary(sess, trans, outputs, &trans.crate_name.as_str()));
1151 }
1152
1153 fn escape_dep_filename(filename: &str) -> String {
1154     // Apparently clang and gcc *only* escape spaces:
1155     // http://llvm.org/klaus/clang/commit/9d50634cfc268ecc9a7250226dd5ca0e945240d4
1156     filename.replace(" ", "\\ ")
1157 }
1158
1159 fn write_out_deps(sess: &Session, outputs: &OutputFilenames, crate_name: &str) {
1160     let mut out_filenames = Vec::new();
1161     for output_type in sess.opts.output_types.keys() {
1162         let file = outputs.path(*output_type);
1163         match *output_type {
1164             OutputType::Exe => {
1165                 for output in sess.crate_types.borrow().iter() {
1166                     let p = link::filename_for_input(sess, *output, crate_name, outputs);
1167                     out_filenames.push(p);
1168                 }
1169             }
1170             _ => {
1171                 out_filenames.push(file);
1172             }
1173         }
1174     }
1175
1176     // Write out dependency rules to the dep-info file if requested
1177     if !sess.opts.output_types.contains_key(&OutputType::DepInfo) {
1178         return;
1179     }
1180     let deps_filename = outputs.path(OutputType::DepInfo);
1181
1182     let result =
1183         (|| -> io::Result<()> {
1184             // Build a list of files used to compile the output and
1185             // write Makefile-compatible dependency rules
1186             let files: Vec<String> = sess.codemap()
1187                                          .files
1188                                          .borrow()
1189                                          .iter()
1190                                          .filter(|fmap| fmap.is_real_file())
1191                                          .filter(|fmap| !fmap.is_imported())
1192                                          .map(|fmap| escape_dep_filename(&fmap.name))
1193                                          .collect();
1194             let mut file = fs::File::create(&deps_filename)?;
1195             for path in &out_filenames {
1196                 write!(file, "{}: {}\n\n", path.display(), files.join(" "))?;
1197             }
1198
1199             // Emit a fake target for each input file to the compilation. This
1200             // prevents `make` from spitting out an error if a file is later
1201             // deleted. For more info see #28735
1202             for path in files {
1203                 writeln!(file, "{}:", path)?;
1204             }
1205             Ok(())
1206         })();
1207
1208     match result {
1209         Ok(()) => {}
1210         Err(e) => {
1211             sess.fatal(&format!("error writing dependencies to `{}`: {}",
1212                                 deps_filename.display(),
1213                                 e));
1214         }
1215     }
1216 }
1217
1218 pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<config::CrateType> {
1219     // Unconditionally collect crate types from attributes to make them used
1220     let attr_types: Vec<config::CrateType> =
1221         attrs.iter()
1222              .filter_map(|a| {
1223                  if a.check_name("crate_type") {
1224                      match a.value_str() {
1225                          Some(ref n) if *n == "rlib" => {
1226                              Some(config::CrateTypeRlib)
1227                          }
1228                          Some(ref n) if *n == "dylib" => {
1229                              Some(config::CrateTypeDylib)
1230                          }
1231                          Some(ref n) if *n == "cdylib" => {
1232                              Some(config::CrateTypeCdylib)
1233                          }
1234                          Some(ref n) if *n == "lib" => {
1235                              Some(config::default_lib_output())
1236                          }
1237                          Some(ref n) if *n == "staticlib" => {
1238                              Some(config::CrateTypeStaticlib)
1239                          }
1240                          Some(ref n) if *n == "proc-macro" => {
1241                              Some(config::CrateTypeProcMacro)
1242                          }
1243                          Some(ref n) if *n == "bin" => Some(config::CrateTypeExecutable),
1244                          Some(_) => {
1245                              session.add_lint(lint::builtin::UNKNOWN_CRATE_TYPES,
1246                                               ast::CRATE_NODE_ID,
1247                                               a.span,
1248                                               "invalid `crate_type` value".to_string());
1249                              None
1250                          }
1251                          _ => {
1252                              session.struct_span_err(a.span, "`crate_type` requires a value")
1253                                  .note("for example: `#![crate_type=\"lib\"]`")
1254                                  .emit();
1255                              None
1256                          }
1257                      }
1258                  } else {
1259                      None
1260                  }
1261              })
1262              .collect();
1263
1264     // If we're generating a test executable, then ignore all other output
1265     // styles at all other locations
1266     if session.opts.test {
1267         return vec![config::CrateTypeExecutable];
1268     }
1269
1270     // Only check command line flags if present. If no types are specified by
1271     // command line, then reuse the empty `base` Vec to hold the types that
1272     // will be found in crate attributes.
1273     let mut base = session.opts.crate_types.clone();
1274     if base.is_empty() {
1275         base.extend(attr_types);
1276         if base.is_empty() {
1277             base.push(link::default_output_for_target(session));
1278         }
1279         base.sort();
1280         base.dedup();
1281     }
1282
1283     base.into_iter()
1284         .filter(|crate_type| {
1285             let res = !link::invalid_output_for_target(session, *crate_type);
1286
1287             if !res {
1288                 session.warn(&format!("dropping unsupported crate type `{}` for target `{}`",
1289                                       *crate_type,
1290                                       session.opts.target_triple));
1291             }
1292
1293             res
1294         })
1295         .collect()
1296 }
1297
1298 pub fn compute_crate_disambiguator(session: &Session) -> String {
1299     use std::hash::Hasher;
1300
1301     // The crate_disambiguator is a 128 bit hash. The disambiguator is fed
1302     // into various other hashes quite a bit (symbol hashes, incr. comp. hashes,
1303     // debuginfo type IDs, etc), so we don't want it to be too wide. 128 bits
1304     // should still be safe enough to avoid collisions in practice.
1305     // FIXME(mw): It seems that the crate_disambiguator is used everywhere as
1306     //            a hex-string instead of raw bytes. We should really use the
1307     //            smaller representation.
1308     let mut hasher = StableHasher::<Fingerprint>::new();
1309
1310     let mut metadata = session.opts.cg.metadata.clone();
1311     // We don't want the crate_disambiguator to dependent on the order
1312     // -C metadata arguments, so sort them:
1313     metadata.sort();
1314     // Every distinct -C metadata value is only incorporated once:
1315     metadata.dedup();
1316
1317     hasher.write(b"metadata");
1318     for s in &metadata {
1319         // Also incorporate the length of a metadata string, so that we generate
1320         // different values for `-Cmetadata=ab -Cmetadata=c` and
1321         // `-Cmetadata=a -Cmetadata=bc`
1322         hasher.write_usize(s.len());
1323         hasher.write(s.as_bytes());
1324     }
1325
1326     // If this is an executable, add a special suffix, so that we don't get
1327     // symbol conflicts when linking against a library of the same name.
1328     let is_exe = session.crate_types.borrow().contains(&config::CrateTypeExecutable);
1329
1330     format!("{}{}", hasher.finish().to_hex(), if is_exe { "-exe" } else {""})
1331 }
1332
1333 pub fn build_output_filenames(input: &Input,
1334                               odir: &Option<PathBuf>,
1335                               ofile: &Option<PathBuf>,
1336                               attrs: &[ast::Attribute],
1337                               sess: &Session)
1338                               -> OutputFilenames {
1339     match *ofile {
1340         None => {
1341             // "-" as input file will cause the parser to read from stdin so we
1342             // have to make up a name
1343             // We want to toss everything after the final '.'
1344             let dirpath = match *odir {
1345                 Some(ref d) => d.clone(),
1346                 None => PathBuf::new(),
1347             };
1348
1349             // If a crate name is present, we use it as the link name
1350             let stem = sess.opts
1351                            .crate_name
1352                            .clone()
1353                            .or_else(|| attr::find_crate_name(attrs).map(|n| n.to_string()))
1354                            .unwrap_or(input.filestem());
1355
1356             OutputFilenames {
1357                 out_directory: dirpath,
1358                 out_filestem: stem,
1359                 single_output_file: None,
1360                 extra: sess.opts.cg.extra_filename.clone(),
1361                 outputs: sess.opts.output_types.clone(),
1362             }
1363         }
1364
1365         Some(ref out_file) => {
1366             let unnamed_output_types = sess.opts
1367                                            .output_types
1368                                            .values()
1369                                            .filter(|a| a.is_none())
1370                                            .count();
1371             let ofile = if unnamed_output_types > 1 {
1372                 sess.warn("due to multiple output types requested, the explicitly specified \
1373                            output file name will be adapted for each output type");
1374                 None
1375             } else {
1376                 Some(out_file.clone())
1377             };
1378             if *odir != None {
1379                 sess.warn("ignoring --out-dir flag due to -o flag.");
1380             }
1381
1382             let cur_dir = Path::new("");
1383
1384             OutputFilenames {
1385                 out_directory: out_file.parent().unwrap_or(cur_dir).to_path_buf(),
1386                 out_filestem: out_file.file_stem()
1387                                       .unwrap_or(OsStr::new(""))
1388                                       .to_str()
1389                                       .unwrap()
1390                                       .to_string(),
1391                 single_output_file: ofile,
1392                 extra: sess.opts.cg.extra_filename.clone(),
1393                 outputs: sess.opts.output_types.clone(),
1394             }
1395         }
1396     }
1397 }