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 #![cfg_attr(not(feature="llvm"), allow(dead_code))]
  12
  13 use rustc::hir::{self, map as hir_map};
  14 use rustc::hir::lowering::lower_crate;
  15 use rustc::ich::Fingerprint;
  16 use rustc_data_structures::stable_hasher::StableHasher;
  17 use rustc_mir as mir;
  18 use rustc::session::{Session, CompileResult};
  19 use rustc::session::CompileIncomplete;
  20 use rustc::session::config::{self, Input, OutputFilenames, OutputType};
  21 use rustc::session::search_paths::PathKind;
  22 use rustc::lint;
  23 use rustc::middle::{self, stability, reachable};
  24 use rustc::middle::privacy::AccessLevels;
  25 use rustc::mir::transform::{MIR_CONST, MIR_VALIDATED, MIR_OPTIMIZED, Passes};
  26 use rustc::ty::{self, TyCtxt, Resolutions, GlobalArenas};
  27 use rustc::traits;
  28 use rustc::util::common::{ErrorReported, time};
  29 use rustc::util::nodemap::NodeSet;
  30 use rustc_allocator as allocator;
  31 use rustc_borrowck as borrowck;
  32 use rustc_incremental::{self, IncrementalHashesMap};
  33 use rustc_resolve::{MakeGlobMap, Resolver};
  34 use rustc_metadata::creader::CrateLoader;
  35 use rustc_metadata::cstore::{self, CStore};
  36 use rustc_trans::back::write;
  37 use rustc_trans as trans;
  38 use rustc_typeck as typeck;
  39 use rustc_privacy;
  40 use rustc_plugin::registry::Registry;
  41 use rustc_plugin as plugin;
  42 use rustc_passes::{ast_validation, no_asm, loops, consts, static_recursion, hir_stats};
  43 use rustc_const_eval::{self, check_match};
  44 use super::Compilation;
  45
  46 use serialize::json;
  47
  48 use std::env;
  49 use std::ffi::{OsString, OsStr};
  50 use std::fs;
  51 use std::io::{self, Write};
  52 use std::iter;
  53 use std::path::{Path, PathBuf};
  54 use std::rc::Rc;
  55 use syntax::{ast, diagnostics, visit};
  56 use syntax::attr;
  57 use syntax::ext::base::ExtCtxt;
  58 use syntax::parse::{self, PResult};
  59 use syntax::symbol::Symbol;
  60 use syntax::util::node_count::NodeCounter;
  61 use syntax;
  62 use syntax_ext;
  63 use arena::DroplessArena;
  64
  65 use derive_registrar;
  66
  67 use profile;
  68
  69 pub fn compile_input(sess: &Session,
  70                      cstore: &CStore,
  71                      input: &Input,
  72                      outdir: &Option<PathBuf>,
  73                      output: &Option<PathBuf>,
  74                      addl_plugins: Option<Vec<String>>,
  75                      control: &CompileController) -> CompileResult {
  76     use rustc_trans::back::write::OngoingCrateTranslation;
  77     macro_rules! controller_entry_point {
  78         ($point: ident, $tsess: expr, $make_state: expr, $phase_result: expr) => {{
  79             let state = &mut $make_state;
  80             let phase_result: &CompileResult = &$phase_result;
  81             if phase_result.is_ok() || control.$point.run_callback_on_error {
  82                 (control.$point.callback)(state);
  83             }
  84
  85             if control.$point.stop == Compilation::Stop {
  86                 // FIXME: shouldn't this return Err(CompileIncomplete::Stopped)
  87                 // if there are no errors?
  88                 return $tsess.compile_status();
  89             }
  90         }}
  91     }
  92
  93     if cfg!(not(feature="llvm")) {
  94         use rustc::session::config::CrateType;
  95         if !sess.opts.debugging_opts.no_trans && sess.opts.output_types.should_trans() {
  96             sess.err("LLVM is not supported by this rustc. Please use -Z no-trans to compile")
  97         }
  98
  99         if sess.opts.crate_types.iter().all(|&t|{
 100             t != CrateType::CrateTypeRlib && t != CrateType::CrateTypeExecutable
 101         }) && !sess.opts.crate_types.is_empty() {
 102             sess.err(
 103                 "LLVM is not supported by this rustc, so non rlib libraries are not supported"
 104             );
 105         }
 106
 107         sess.abort_if_errors();
 108     }
 109
 110     if sess.profile_queries() {
 111         profile::begin();
 112     }
 113
 114     // We need nested scopes here, because the intermediate results can keep
 115     // large chunks of memory alive and we want to free them as soon as
 116     // possible to keep the peak memory usage low
 117     let (outputs, trans): (OutputFilenames, OngoingCrateTranslation) = {
 118         let krate = match phase_1_parse_input(control, sess, input) {
 119             Ok(krate) => krate,
 120             Err(mut parse_error) => {
 121                 parse_error.emit();
 122                 return Err(CompileIncomplete::Errored(ErrorReported));
 123             }
 124         };
 125
 126         let (krate, registry) = {
 127             let mut compile_state = CompileState::state_after_parse(input,
 128                                                                     sess,
 129                                                                     outdir,
 130                                                                     output,
 131                                                                     krate,
 132                                                                     &cstore);
 133             controller_entry_point!(after_parse,
 134                                     sess,
 135                                     compile_state,
 136                                     Ok(()));
 137
 138             (compile_state.krate.unwrap(), compile_state.registry)
 139         };
 140
 141         let outputs = build_output_filenames(input, outdir, output, &krate.attrs, sess);
 142         let crate_name =
 143             ::rustc_trans_utils::link::find_crate_name(Some(sess), &krate.attrs, input);
 144         let ExpansionResult { expanded_crate, defs, analysis, resolutions, mut hir_forest } = {
 145             phase_2_configure_and_expand(
 146                 sess, &cstore, krate, registry, &crate_name, addl_plugins, control.make_glob_map,
 147                 |expanded_crate| {
 148                     let mut state = CompileState::state_after_expand(
 149                         input, sess, outdir, output, &cstore, expanded_crate, &crate_name,
 150                     );
 151                     controller_entry_point!(after_expand, sess, state, Ok(()));
 152                     Ok(())
 153                 }
 154             )?
 155         };
 156
 157         write_out_deps(sess, &outputs, &crate_name);
 158         if sess.opts.output_types.contains_key(&OutputType::DepInfo) &&
 159             sess.opts.output_types.keys().count() == 1 {
 160             return Ok(())
 161         }
 162
 163         let arena = DroplessArena::new();
 164         let arenas = GlobalArenas::new();
 165
 166         // Construct the HIR map
 167         let hir_map = time(sess.time_passes(),
 168                            "indexing hir",
 169                            || hir_map::map_crate(&mut hir_forest, defs));
 170
 171         {
 172             let _ignore = hir_map.dep_graph.in_ignore();
 173             controller_entry_point!(after_hir_lowering,
 174                                     sess,
 175                                     CompileState::state_after_hir_lowering(input,
 176                                                                   sess,
 177                                                                   outdir,
 178                                                                   output,
 179                                                                   &arena,
 180                                                                   &arenas,
 181                                                                   &cstore,
 182                                                                   &hir_map,
 183                                                                   &analysis,
 184                                                                   &resolutions,
 185                                                                   &expanded_crate,
 186                                                                   &hir_map.krate(),
 187                                                                   &crate_name),
 188                                     Ok(()));
 189         }
 190
 191         time(sess.time_passes(), "attribute checking", || {
 192             hir::check_attr::check_crate(sess, &expanded_crate);
 193         });
 194
 195         let opt_crate = if control.keep_ast {
 196             Some(&expanded_crate)
 197         } else {
 198             drop(expanded_crate);
 199             None
 200         };
 201
 202         phase_3_run_analysis_passes(sess,
 203                                     hir_map,
 204                                     analysis,
 205                                     resolutions,
 206                                     &arena,
 207                                     &arenas,
 208                                     &crate_name,
 209                                     |tcx, analysis, incremental_hashes_map, result| {
 210             {
 211                 // Eventually, we will want to track plugins.
 212                 let _ignore = tcx.dep_graph.in_ignore();
 213
 214                 let mut state = CompileState::state_after_analysis(input,
 215                                                                    sess,
 216                                                                    outdir,
 217                                                                    output,
 218                                                                    opt_crate,
 219                                                                    tcx.hir.krate(),
 220                                                                    &analysis,
 221                                                                    tcx,
 222                                                                    &crate_name);
 223                 (control.after_analysis.callback)(&mut state);
 224
 225                 if control.after_analysis.stop == Compilation::Stop {
 226                     return result.and_then(|_| Err(CompileIncomplete::Stopped));
 227                 }
 228             }
 229
 230             result?;
 231
 232             if log_enabled!(::log::LogLevel::Info) {
 233                 println!("Pre-trans");
 234                 tcx.print_debug_stats();
 235             }
 236
 237             let trans = phase_4_translate_to_llvm(tcx, analysis, incremental_hashes_map,
 238                                                   &outputs);
 239
 240             if log_enabled!(::log::LogLevel::Info) {
 241                 println!("Post-trans");
 242                 tcx.print_debug_stats();
 243             }
 244
 245             if tcx.sess.opts.output_types.contains_key(&OutputType::Mir) {
 246                 if let Err(e) = mir::transform::dump_mir::emit_mir(tcx, &outputs) {
 247                     sess.err(&format!("could not emit MIR: {}", e));
 248                     sess.abort_if_errors();
 249                 }
 250             }
 251
 252             Ok((outputs, trans))
 253         })??
 254     };
 255
 256     if cfg!(not(feature="llvm")) {
 257         let (_, _) = (outputs, trans);
 258         sess.fatal("LLVM is not supported by this rustc");
 259     }
 260
 261     #[cfg(feature="llvm")]
 262     {
 263         if sess.opts.debugging_opts.print_type_sizes {
 264             sess.code_stats.borrow().print_type_sizes();
 265         }
 266
 267         let (phase5_result, trans) = phase_5_run_llvm_passes(sess, trans);
 268
 269         controller_entry_point!(after_llvm,
 270                                 sess,
 271                                 CompileState::state_after_llvm(input, sess, outdir, output, &trans),
 272                                 phase5_result);
 273         phase5_result?;
 274
 275         phase_6_link_output(sess, &trans, &outputs);
 276
 277         // Now that we won't touch anything in the incremental compilation directory
 278         // any more, we can finalize it (which involves renaming it)
 279         rustc_incremental::finalize_session_directory(sess, trans.link.crate_hash);
 280
 281         if sess.opts.debugging_opts.perf_stats {
 282             sess.print_perf_stats();
 283         }
 284
 285         controller_entry_point!(
 286             compilation_done,
 287             sess,
 288             CompileState::state_when_compilation_done(input, sess, outdir, output),
 289             Ok(())
 290         );
 291
 292         Ok(())
 293     }
 294 }
 295
 296 fn keep_hygiene_data(sess: &Session) -> bool {
 297     sess.opts.debugging_opts.keep_hygiene_data
 298 }
 299
 300
 301 /// The name used for source code that doesn't originate in a file
 302 /// (e.g. source from stdin or a string)
 303 pub fn anon_src() -> String {
 304     "<anon>".to_string()
 305 }
 306
 307 pub fn source_name(input: &Input) -> String {
 308     match *input {
 309         // FIXME (#9639): This needs to handle non-utf8 paths
 310         Input::File(ref ifile) => ifile.to_str().unwrap().to_string(),
 311         Input::Str { ref name, .. } => name.clone(),
 312     }
 313 }
 314
 315 /// CompileController is used to customize compilation, it allows compilation to
 316 /// be stopped and/or to call arbitrary code at various points in compilation.
 317 /// It also allows for various flags to be set to influence what information gets
 318 /// collected during compilation.
 319 ///
 320 /// This is a somewhat higher level controller than a Session - the Session
 321 /// controls what happens in each phase, whereas the CompileController controls
 322 /// whether a phase is run at all and whether other code (from outside the
 323 /// compiler) is run between phases.
 324 ///
 325 /// Note that if compilation is set to stop and a callback is provided for a
 326 /// given entry point, the callback is called before compilation is stopped.
 327 ///
 328 /// Expect more entry points to be added in the future.
 329 pub struct CompileController<'a> {
 330     pub after_parse: PhaseController<'a>,
 331     pub after_expand: PhaseController<'a>,
 332     pub after_hir_lowering: PhaseController<'a>,
 333     pub after_analysis: PhaseController<'a>,
 334     pub after_llvm: PhaseController<'a>,
 335     pub compilation_done: PhaseController<'a>,
 336
 337     // FIXME we probably want to group the below options together and offer a
 338     // better API, rather than this ad-hoc approach.
 339     pub make_glob_map: MakeGlobMap,
 340     // Whether the compiler should keep the ast beyond parsing.
 341     pub keep_ast: bool,
 342     // -Zcontinue-parse-after-error
 343     pub continue_parse_after_error: bool,
 344 }
 345
 346 impl<'a> CompileController<'a> {
 347     pub fn basic() -> CompileController<'a> {
 348         CompileController {
 349             after_parse: PhaseController::basic(),
 350             after_expand: PhaseController::basic(),
 351             after_hir_lowering: PhaseController::basic(),
 352             after_analysis: PhaseController::basic(),
 353             after_llvm: PhaseController::basic(),
 354             compilation_done: PhaseController::basic(),
 355             make_glob_map: MakeGlobMap::No,
 356             keep_ast: false,
 357             continue_parse_after_error: false,
 358         }
 359     }
 360 }
 361
 362 pub struct PhaseController<'a> {
 363     pub stop: Compilation,
 364     // If true then the compiler will try to run the callback even if the phase
 365     // ends with an error. Note that this is not always possible.
 366     pub run_callback_on_error: bool,
 367     pub callback: Box<Fn(&mut CompileState) + 'a>,
 368 }
 369
 370 impl<'a> PhaseController<'a> {
 371     pub fn basic() -> PhaseController<'a> {
 372         PhaseController {
 373             stop: Compilation::Continue,
 374             run_callback_on_error: false,
 375             callback: box |_| {},
 376         }
 377     }
 378 }
 379
 380 /// State that is passed to a callback. What state is available depends on when
 381 /// during compilation the callback is made. See the various constructor methods
 382 /// (`state_*`) in the impl to see which data is provided for any given entry point.
 383 pub struct CompileState<'a, 'tcx: 'a> {
 384     pub input: &'a Input,
 385     pub session: &'tcx Session,
 386     pub krate: Option<ast::Crate>,
 387     pub registry: Option<Registry<'a>>,
 388     pub cstore: Option<&'a CStore>,
 389     pub crate_name: Option<&'a str>,
 390     pub output_filenames: Option<&'a OutputFilenames>,
 391     pub out_dir: Option<&'a Path>,
 392     pub out_file: Option<&'a Path>,
 393     pub arena: Option<&'tcx DroplessArena>,
 394     pub arenas: Option<&'tcx GlobalArenas<'tcx>>,
 395     pub expanded_crate: Option<&'a ast::Crate>,
 396     pub hir_crate: Option<&'a hir::Crate>,
 397     pub hir_map: Option<&'a hir_map::Map<'tcx>>,
 398     pub resolutions: Option<&'a Resolutions>,
 399     pub analysis: Option<&'a ty::CrateAnalysis>,
 400     pub tcx: Option<TyCtxt<'a, 'tcx, 'tcx>>,
 401     pub trans: Option<&'a trans::CrateTranslation>,
 402 }
 403
 404 impl<'a, 'tcx> CompileState<'a, 'tcx> {
 405     fn empty(input: &'a Input,
 406              session: &'tcx Session,
 407              out_dir: &'a Option<PathBuf>)
 408              -> Self {
 409         CompileState {
 410             input,
 411             session,
 412             out_dir: out_dir.as_ref().map(|s| &**s),
 413             out_file: None,
 414             arena: None,
 415             arenas: None,
 416             krate: None,
 417             registry: None,
 418             cstore: None,
 419             crate_name: None,
 420             output_filenames: None,
 421             expanded_crate: None,
 422             hir_crate: None,
 423             hir_map: None,
 424             resolutions: None,
 425             analysis: None,
 426             tcx: None,
 427             trans: None,
 428         }
 429     }
 430
 431     fn state_after_parse(input: &'a Input,
 432                          session: &'tcx Session,
 433                          out_dir: &'a Option<PathBuf>,
 434                          out_file: &'a Option<PathBuf>,
 435                          krate: ast::Crate,
 436                          cstore: &'a CStore)
 437                          -> Self {
 438         CompileState {
 439             // Initialize the registry before moving `krate`
 440             registry: Some(Registry::new(&session, krate.span)),
 441             krate: Some(krate),
 442             cstore: Some(cstore),
 443             out_file: out_file.as_ref().map(|s| &**s),
 444             ..CompileState::empty(input, session, out_dir)
 445         }
 446     }
 447
 448     fn state_after_expand(input: &'a Input,
 449                           session: &'tcx Session,
 450                           out_dir: &'a Option<PathBuf>,
 451                           out_file: &'a Option<PathBuf>,
 452                           cstore: &'a CStore,
 453                           expanded_crate: &'a ast::Crate,
 454                           crate_name: &'a str)
 455                           -> Self {
 456         CompileState {
 457             crate_name: Some(crate_name),
 458             cstore: Some(cstore),
 459             expanded_crate: Some(expanded_crate),
 460             out_file: out_file.as_ref().map(|s| &**s),
 461             ..CompileState::empty(input, session, out_dir)
 462         }
 463     }
 464
 465     fn state_after_hir_lowering(input: &'a Input,
 466                                 session: &'tcx Session,
 467                                 out_dir: &'a Option<PathBuf>,
 468                                 out_file: &'a Option<PathBuf>,
 469                                 arena: &'tcx DroplessArena,
 470                                 arenas: &'tcx GlobalArenas<'tcx>,
 471                                 cstore: &'a CStore,
 472                                 hir_map: &'a hir_map::Map<'tcx>,
 473                                 analysis: &'a ty::CrateAnalysis,
 474                                 resolutions: &'a Resolutions,
 475                                 krate: &'a ast::Crate,
 476                                 hir_crate: &'a hir::Crate,
 477                                 crate_name: &'a str)
 478                                 -> Self {
 479         CompileState {
 480             crate_name: Some(crate_name),
 481             arena: Some(arena),
 482             arenas: Some(arenas),
 483             cstore: Some(cstore),
 484             hir_map: Some(hir_map),
 485             analysis: Some(analysis),
 486             resolutions: Some(resolutions),
 487             expanded_crate: Some(krate),
 488             hir_crate: Some(hir_crate),
 489             out_file: out_file.as_ref().map(|s| &**s),
 490             ..CompileState::empty(input, session, out_dir)
 491         }
 492     }
 493
 494     fn state_after_analysis(input: &'a Input,
 495                             session: &'tcx Session,
 496                             out_dir: &'a Option<PathBuf>,
 497                             out_file: &'a Option<PathBuf>,
 498                             krate: Option<&'a ast::Crate>,
 499                             hir_crate: &'a hir::Crate,
 500                             analysis: &'a ty::CrateAnalysis,
 501                             tcx: TyCtxt<'a, 'tcx, 'tcx>,
 502                             crate_name: &'a str)
 503                             -> Self {
 504         CompileState {
 505             analysis: Some(analysis),
 506             tcx: Some(tcx),
 507             expanded_crate: krate,
 508             hir_crate: Some(hir_crate),
 509             crate_name: Some(crate_name),
 510             out_file: out_file.as_ref().map(|s| &**s),
 511             ..CompileState::empty(input, session, out_dir)
 512         }
 513     }
 514
 515     fn state_after_llvm(input: &'a Input,
 516                         session: &'tcx Session,
 517                         out_dir: &'a Option<PathBuf>,
 518                         out_file: &'a Option<PathBuf>,
 519                         trans: &'a trans::CrateTranslation)
 520                         -> Self {
 521         CompileState {
 522             trans: Some(trans),
 523             out_file: out_file.as_ref().map(|s| &**s),
 524             ..CompileState::empty(input, session, out_dir)
 525         }
 526     }
 527
 528     fn state_when_compilation_done(input: &'a Input,
 529                                    session: &'tcx Session,
 530                                    out_dir: &'a Option<PathBuf>,
 531                                    out_file: &'a Option<PathBuf>)
 532                                    -> Self {
 533         CompileState {
 534             out_file: out_file.as_ref().map(|s| &**s),
 535             ..CompileState::empty(input, session, out_dir)
 536         }
 537     }
 538 }
 539
 540 pub fn phase_1_parse_input<'a>(control: &CompileController,
 541                                sess: &'a Session,
 542                                input: &Input)
 543                                -> PResult<'a, ast::Crate> {
 544     sess.diagnostic().set_continue_after_error(control.continue_parse_after_error);
 545
 546     if sess.profile_queries() {
 547         profile::begin();
 548     }
 549
 550     let krate = time(sess.time_passes(), "parsing", || {
 551         match *input {
 552             Input::File(ref file) => {
 553                 parse::parse_crate_from_file(file, &sess.parse_sess)
 554             }
 555             Input::Str { ref input, ref name } => {
 556                 parse::parse_crate_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
 557             }
 558         }
 559     })?;
 560
 561     sess.diagnostic().set_continue_after_error(true);
 562
 563     if sess.opts.debugging_opts.ast_json_noexpand {
 564         println!("{}", json::as_json(&krate));
 565     }
 566
 567     if sess.opts.debugging_opts.input_stats {
 568         println!("Lines of code:             {}", sess.codemap().count_lines());
 569         println!("Pre-expansion node count:  {}", count_nodes(&krate));
 570     }
 571
 572     if let Some(ref s) = sess.opts.debugging_opts.show_span {
 573         syntax::show_span::run(sess.diagnostic(), s, &krate);
 574     }
 575
 576     if sess.opts.debugging_opts.hir_stats {
 577         hir_stats::print_ast_stats(&krate, "PRE EXPANSION AST STATS");
 578     }
 579
 580     Ok(krate)
 581 }
 582
 583 fn count_nodes(krate: &ast::Crate) -> usize {
 584     let mut counter = NodeCounter::new();
 585     visit::walk_crate(&mut counter, krate);
 586     counter.count
 587 }
 588
 589 // For continuing compilation after a parsed crate has been
 590 // modified
 591
 592 pub struct ExpansionResult {
 593     pub expanded_crate: ast::Crate,
 594     pub defs: hir_map::Definitions,
 595     pub analysis: ty::CrateAnalysis,
 596     pub resolutions: Resolutions,
 597     pub hir_forest: hir_map::Forest,
 598 }
 599
 600 /// Run the "early phases" of the compiler: initial `cfg` processing,
 601 /// loading compiler plugins (including those from `addl_plugins`),
 602 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
 603 /// harness if one is to be provided, injection of a dependency on the
 604 /// standard library and prelude, and name resolution.
 605 ///
 606 /// Returns `None` if we're aborting after handling -W help.
 607 pub fn phase_2_configure_and_expand<F>(sess: &Session,
 608                                        cstore: &CStore,
 609                                        krate: ast::Crate,
 610                                        registry: Option<Registry>,
 611                                        crate_name: &str,
 612                                        addl_plugins: Option<Vec<String>>,
 613                                        make_glob_map: MakeGlobMap,
 614                                        after_expand: F)
 615                                        -> Result<ExpansionResult, CompileIncomplete>
 616     where F: FnOnce(&ast::Crate) -> CompileResult,
 617 {
 618     let time_passes = sess.time_passes();
 619
 620     let (mut krate, features) = syntax::config::features(krate, &sess.parse_sess, sess.opts.test);
 621     // these need to be set "early" so that expansion sees `quote` if enabled.
 622     *sess.features.borrow_mut() = features;
 623
 624     *sess.crate_types.borrow_mut() = collect_crate_types(sess, &krate.attrs);
 625     *sess.crate_disambiguator.borrow_mut() = Symbol::intern(&compute_crate_disambiguator(sess));
 626
 627     time(time_passes, "recursion limit", || {
 628         middle::recursion_limit::update_limits(sess, &krate);
 629     });
 630
 631     krate = time(time_passes, "crate injection", || {
 632         let alt_std_name = sess.opts.alt_std_name.clone();
 633         syntax::std_inject::maybe_inject_crates_ref(krate, alt_std_name)
 634     });
 635
 636     let mut addl_plugins = Some(addl_plugins);
 637     let registrars = time(time_passes, "plugin loading", || {
 638         plugin::load::load_plugins(sess,
 639                                    &cstore,
 640                                    &krate,
 641                                    crate_name,
 642                                    addl_plugins.take().unwrap())
 643     });
 644
 645     let mut registry = registry.unwrap_or(Registry::new(sess, krate.span));
 646
 647     time(time_passes, "plugin registration", || {
 648         if sess.features.borrow().rustc_diagnostic_macros {
 649             registry.register_macro("__diagnostic_used",
 650                                     diagnostics::plugin::expand_diagnostic_used);
 651             registry.register_macro("__register_diagnostic",
 652                                     diagnostics::plugin::expand_register_diagnostic);
 653             registry.register_macro("__build_diagnostic_array",
 654                                     diagnostics::plugin::expand_build_diagnostic_array);
 655         }
 656
 657         for registrar in registrars {
 658             registry.args_hidden = Some(registrar.args);
 659             (registrar.fun)(&mut registry);
 660         }
 661     });
 662
 663     let whitelisted_legacy_custom_derives = registry.take_whitelisted_custom_derives();
 664     let Registry { syntax_exts, early_lint_passes, late_lint_passes, lint_groups,
 665                    llvm_passes, attributes, .. } = registry;
 666
 667     sess.track_errors(|| {
 668         let mut ls = sess.lint_store.borrow_mut();
 669         for pass in early_lint_passes {
 670             ls.register_early_pass(Some(sess), true, pass);
 671         }
 672         for pass in late_lint_passes {
 673             ls.register_late_pass(Some(sess), true, pass);
 674         }
 675
 676         for (name, to) in lint_groups {
 677             ls.register_group(Some(sess), true, name, to);
 678         }
 679
 680         *sess.plugin_llvm_passes.borrow_mut() = llvm_passes;
 681         *sess.plugin_attributes.borrow_mut() = attributes.clone();
 682     })?;
 683
 684     // Lint plugins are registered; now we can process command line flags.
 685     if sess.opts.describe_lints {
 686         super::describe_lints(&sess.lint_store.borrow(), true);
 687         return Err(CompileIncomplete::Stopped);
 688     }
 689
 690     // Currently, we ignore the name resolution data structures for the purposes of dependency
 691     // tracking. Instead we will run name resolution and include its output in the hash of each
 692     // item, much like we do for macro expansion. In other words, the hash reflects not just
 693     // its contents but the results of name resolution on those contents. Hopefully we'll push
 694     // this back at some point.
 695     let _ignore = sess.dep_graph.in_ignore();
 696     let mut crate_loader = CrateLoader::new(sess, &cstore, crate_name);
 697     crate_loader.preprocess(&krate);
 698     let resolver_arenas = Resolver::arenas();
 699     let mut resolver = Resolver::new(sess,
 700                                      &krate,
 701                                      crate_name,
 702                                      make_glob_map,
 703                                      &mut crate_loader,
 704                                      &resolver_arenas);
 705     resolver.whitelisted_legacy_custom_derives = whitelisted_legacy_custom_derives;
 706     syntax_ext::register_builtins(&mut resolver, syntax_exts, sess.features.borrow().quote);
 707
 708     krate = time(time_passes, "expansion", || {
 709         // Windows dlls do not have rpaths, so they don't know how to find their
 710         // dependencies. It's up to us to tell the system where to find all the
 711         // dependent dlls. Note that this uses cfg!(windows) as opposed to
 712         // targ_cfg because syntax extensions are always loaded for the host
 713         // compiler, not for the target.
 714         //
 715         // This is somewhat of an inherently racy operation, however, as
 716         // multiple threads calling this function could possibly continue
 717         // extending PATH far beyond what it should. To solve this for now we
 718         // just don't add any new elements to PATH which are already there
 719         // within PATH. This is basically a targeted fix at #17360 for rustdoc
 720         // which runs rustc in parallel but has been seen (#33844) to cause
 721         // problems with PATH becoming too long.
 722         let mut old_path = OsString::new();
 723         if cfg!(windows) {
 724             old_path = env::var_os("PATH").unwrap_or(old_path);
 725             let mut new_path = sess.host_filesearch(PathKind::All)
 726                                    .get_dylib_search_paths();
 727             for path in env::split_paths(&old_path) {
 728                 if !new_path.contains(&path) {
 729                     new_path.push(path);
 730                 }
 731             }
 732             env::set_var("PATH",
 733                 &env::join_paths(new_path.iter()
 734                                          .filter(|p| env::join_paths(iter::once(p)).is_ok()))
 735                      .unwrap());
 736         }
 737         let features = sess.features.borrow();
 738         let cfg = syntax::ext::expand::ExpansionConfig {
 739             features: Some(&features),
 740             recursion_limit: sess.recursion_limit.get(),
 741             trace_mac: sess.opts.debugging_opts.trace_macros,
 742             should_test: sess.opts.test,
 743             ..syntax::ext::expand::ExpansionConfig::default(crate_name.to_string())
 744         };
 745
 746         let mut ecx = ExtCtxt::new(&sess.parse_sess, cfg, &mut resolver);
 747         let err_count = ecx.parse_sess.span_diagnostic.err_count();
 748
 749         let krate = ecx.monotonic_expander().expand_crate(krate);
 750
 751         ecx.check_unused_macros();
 752
 753         let mut missing_fragment_specifiers: Vec<_> =
 754             ecx.parse_sess.missing_fragment_specifiers.borrow().iter().cloned().collect();
 755         missing_fragment_specifiers.sort();
 756         for span in missing_fragment_specifiers {
 757             let lint = lint::builtin::MISSING_FRAGMENT_SPECIFIER;
 758             let msg = "missing fragment specifier";
 759             sess.buffer_lint(lint, ast::CRATE_NODE_ID, span, msg);
 760         }
 761         if ecx.parse_sess.span_diagnostic.err_count() - ecx.resolve_err_count > err_count {
 762             ecx.parse_sess.span_diagnostic.abort_if_errors();
 763         }
 764         if cfg!(windows) {
 765             env::set_var("PATH", &old_path);
 766         }
 767         krate
 768     });
 769
 770     krate = time(time_passes, "maybe building test harness", || {
 771         syntax::test::modify_for_testing(&sess.parse_sess,
 772                                          &mut resolver,
 773                                          sess.opts.test,
 774                                          krate,
 775                                          sess.diagnostic())
 776     });
 777
 778     // If we're in rustdoc we're always compiling as an rlib, but that'll trip a
 779     // bunch of checks in the `modify` function below. For now just skip this
 780     // step entirely if we're rustdoc as it's not too useful anyway.
 781     if !sess.opts.actually_rustdoc {
 782         krate = time(time_passes, "maybe creating a macro crate", || {
 783             let crate_types = sess.crate_types.borrow();
 784             let num_crate_types = crate_types.len();
 785             let is_proc_macro_crate = crate_types.contains(&config::CrateTypeProcMacro);
 786             let is_test_crate = sess.opts.test;
 787             syntax_ext::proc_macro_registrar::modify(&sess.parse_sess,
 788                                                      &mut resolver,
 789                                                      krate,
 790                                                      is_proc_macro_crate,
 791                                                      is_test_crate,
 792                                                      num_crate_types,
 793                                                      sess.diagnostic())
 794         });
 795     }
 796
 797     krate = time(time_passes, "creating allocators", || {
 798         allocator::expand::modify(&sess.parse_sess,
 799                                   &mut resolver,
 800                                   krate,
 801                                   sess.diagnostic())
 802     });
 803
 804     after_expand(&krate)?;
 805
 806     if sess.opts.debugging_opts.input_stats {
 807         println!("Post-expansion node count: {}", count_nodes(&krate));
 808     }
 809
 810     if sess.opts.debugging_opts.hir_stats {
 811         hir_stats::print_ast_stats(&krate, "POST EXPANSION AST STATS");
 812     }
 813
 814     if sess.opts.debugging_opts.ast_json {
 815         println!("{}", json::as_json(&krate));
 816     }
 817
 818     time(time_passes,
 819          "checking for inline asm in case the target doesn't support it",
 820          || no_asm::check_crate(sess, &krate));
 821
 822     time(time_passes,
 823          "AST validation",
 824          || ast_validation::check_crate(sess, &krate));
 825
 826     time(time_passes, "name resolution", || -> CompileResult {
 827         resolver.resolve_crate(&krate);
 828         Ok(())
 829     })?;
 830
 831     if resolver.found_unresolved_macro {
 832         sess.parse_sess.span_diagnostic.abort_if_errors();
 833     }
 834
 835     // Needs to go *after* expansion to be able to check the results of macro expansion.
 836     time(time_passes, "complete gated feature checking", || {
 837         sess.track_errors(|| {
 838             syntax::feature_gate::check_crate(&krate,
 839                                               &sess.parse_sess,
 840                                               &sess.features.borrow(),
 841                                               &attributes,
 842                                               sess.opts.unstable_features);
 843         })
 844     })?;
 845
 846     // Lower ast -> hir.
 847     let hir_forest = time(time_passes, "lowering ast -> hir", || {
 848         let hir_crate = lower_crate(sess, &krate, &mut resolver);
 849
 850         if sess.opts.debugging_opts.hir_stats {
 851             hir_stats::print_hir_stats(&hir_crate);
 852         }
 853
 854         hir_map::Forest::new(hir_crate, &sess.dep_graph)
 855     });
 856
 857     time(time_passes,
 858          "early lint checks",
 859          || lint::check_ast_crate(sess, &krate));
 860
 861     // Discard hygiene data, which isn't required after lowering to HIR.
 862     if !keep_hygiene_data(sess) {
 863         syntax::ext::hygiene::clear_markings();
 864     }
 865
 866     Ok(ExpansionResult {
 867         expanded_crate: krate,
 868         defs: resolver.definitions,
 869         analysis: ty::CrateAnalysis {
 870             access_levels: Rc::new(AccessLevels::default()),
 871             reachable: Rc::new(NodeSet()),
 872             name: crate_name.to_string(),
 873             glob_map: if resolver.make_glob_map { Some(resolver.glob_map) } else { None },
 874         },
 875         resolutions: Resolutions {
 876             freevars: resolver.freevars,
 877             export_map: resolver.export_map,
 878             trait_map: resolver.trait_map,
 879             maybe_unused_trait_imports: resolver.maybe_unused_trait_imports,
 880             maybe_unused_extern_crates: resolver.maybe_unused_extern_crates,
 881         },
 882         hir_forest,
 883     })
 884 }
 885
 886 /// Run the resolution, typechecking, region checking and other
 887 /// miscellaneous analysis passes on the crate. Return various
 888 /// structures carrying the results of the analysis.
 889 pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
 890                                                hir_map: hir_map::Map<'tcx>,
 891                                                mut analysis: ty::CrateAnalysis,
 892                                                resolutions: Resolutions,
 893                                                arena: &'tcx DroplessArena,
 894                                                arenas: &'tcx GlobalArenas<'tcx>,
 895                                                name: &str,
 896                                                f: F)
 897                                                -> Result<R, CompileIncomplete>
 898     where F: for<'a> FnOnce(TyCtxt<'a, 'tcx, 'tcx>,
 899                             ty::CrateAnalysis,
 900                             IncrementalHashesMap,
 901                             CompileResult) -> R
 902 {
 903     macro_rules! try_with_f {
 904         ($e: expr, ($t: expr, $a: expr, $h: expr)) => {
 905             match $e {
 906                 Ok(x) => x,
 907                 Err(x) => {
 908                     f($t, $a, $h, Err(x));
 909                     return Err(x);
 910                 }
 911             }
 912         }
 913     }
 914
 915     let time_passes = sess.time_passes();
 916
 917     let lang_items = time(time_passes, "language item collection", || {
 918         sess.track_errors(|| {
 919             middle::lang_items::collect_language_items(&sess, &hir_map)
 920         })
 921     })?;
 922
 923     let named_region_map = time(time_passes,
 924                                 "lifetime resolution",
 925                                 || middle::resolve_lifetime::krate(sess, &hir_map))?;
 926
 927     time(time_passes,
 928          "looking for entry point",
 929          || middle::entry::find_entry_point(sess, &hir_map));
 930
 931     sess.plugin_registrar_fn.set(time(time_passes, "looking for plugin registrar", || {
 932         plugin::build::find_plugin_registrar(sess.diagnostic(), &hir_map)
 933     }));
 934     sess.derive_registrar_fn.set(derive_registrar::find(&hir_map));
 935
 936     time(time_passes,
 937          "loop checking",
 938          || loops::check_crate(sess, &hir_map));
 939
 940     time(time_passes,
 941               "static item recursion checking",
 942               || static_recursion::check_crate(sess, &hir_map))?;
 943
 944     let index = stability::Index::new(&sess);
 945
 946     let mut local_providers = ty::maps::Providers::default();
 947     borrowck::provide(&mut local_providers);
 948     mir::provide(&mut local_providers);
 949     reachable::provide(&mut local_providers);
 950     rustc_privacy::provide(&mut local_providers);
 951     trans::provide(&mut local_providers);
 952     typeck::provide(&mut local_providers);
 953     ty::provide(&mut local_providers);
 954     traits::provide(&mut local_providers);
 955     reachable::provide(&mut local_providers);
 956     rustc_const_eval::provide(&mut local_providers);
 957     middle::region::provide(&mut local_providers);
 958     cstore::provide_local(&mut local_providers);
 959     lint::provide(&mut local_providers);
 960
 961     let mut extern_providers = ty::maps::Providers::default();
 962     cstore::provide(&mut extern_providers);
 963     trans::provide(&mut extern_providers);
 964     ty::provide_extern(&mut extern_providers);
 965     traits::provide_extern(&mut extern_providers);
 966     // FIXME(eddyb) get rid of this once we replace const_eval with miri.
 967     rustc_const_eval::provide(&mut extern_providers);
 968
 969     // Setup the MIR passes that we want to run.
 970     let mut passes = Passes::new();
 971     passes.push_hook(mir::transform::dump_mir::DumpMir);
 972
 973     // Remove all `EndRegion` statements that are not involved in borrows.
 974     passes.push_pass(MIR_CONST, mir::transform::clean_end_regions::CleanEndRegions);
 975
 976     // What we need to do constant evaluation.
 977     passes.push_pass(MIR_CONST, mir::transform::simplify::SimplifyCfg::new("initial"));
 978     passes.push_pass(MIR_CONST, mir::transform::type_check::TypeckMir);
 979     passes.push_pass(MIR_CONST, mir::transform::rustc_peek::SanityCheck);
 980
 981     // We compute "constant qualifications" between MIR_CONST and MIR_VALIDATED.
 982
 983     // What we need to run borrowck etc.
 984
 985     passes.push_pass(MIR_VALIDATED, mir::transform::qualify_consts::QualifyAndPromoteConstants);
 986
 987     // FIXME: ariel points SimplifyBranches should run after
 988     // mir-borrowck; otherwise code within `if false { ... }` would
 989     // not be checked.
 990     passes.push_pass(MIR_VALIDATED,
 991                      mir::transform::simplify_branches::SimplifyBranches::new("initial"));
 992     passes.push_pass(MIR_VALIDATED, mir::transform::simplify::SimplifyCfg::new("qualify-consts"));
 993     passes.push_pass(MIR_VALIDATED, mir::transform::nll::NLL);
 994
 995     // borrowck runs between MIR_VALIDATED and MIR_OPTIMIZED.
 996
 997     // These next passes must be executed together
 998     passes.push_pass(MIR_OPTIMIZED, mir::transform::no_landing_pads::NoLandingPads);
 999     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_call_guards::CriticalCallEdges);
1000     passes.push_pass(MIR_OPTIMIZED, mir::transform::elaborate_drops::ElaborateDrops);
1001     passes.push_pass(MIR_OPTIMIZED, mir::transform::no_landing_pads::NoLandingPads);
1002     // AddValidation needs to run after ElaborateDrops and before EraseRegions, and it needs
1003     // an AllCallEdges pass right before it.
1004     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_call_guards::AllCallEdges);
1005     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_validation::AddValidation);
1006     passes.push_pass(MIR_OPTIMIZED, mir::transform::simplify::SimplifyCfg::new("elaborate-drops"));
1007     // No lifetime analysis based on borrowing can be done from here on out.
1008
1009     // From here on out, regions are gone.
1010     passes.push_pass(MIR_OPTIMIZED, mir::transform::erase_regions::EraseRegions);
1011
1012     // Optimizations begin.
1013     passes.push_pass(MIR_OPTIMIZED, mir::transform::inline::Inline);
1014     passes.push_pass(MIR_OPTIMIZED, mir::transform::instcombine::InstCombine);
1015     passes.push_pass(MIR_OPTIMIZED, mir::transform::deaggregator::Deaggregator);
1016     passes.push_pass(MIR_OPTIMIZED, mir::transform::copy_prop::CopyPropagation);
1017     passes.push_pass(MIR_OPTIMIZED, mir::transform::simplify::SimplifyLocals);
1018
1019     passes.push_pass(MIR_OPTIMIZED, mir::transform::generator::StateTransform);
1020     passes.push_pass(MIR_OPTIMIZED, mir::transform::add_call_guards::CriticalCallEdges);
1021     passes.push_pass(MIR_OPTIMIZED, mir::transform::dump_mir::Marker("PreTrans"));
1022
1023     TyCtxt::create_and_enter(sess,
1024                              local_providers,
1025                              extern_providers,
1026                              Rc::new(passes),
1027                              arenas,
1028                              arena,
1029                              resolutions,
1030                              named_region_map,
1031                              hir_map,
1032                              lang_items,
1033                              index,
1034                              name,
1035                              |tcx| {
1036         let incremental_hashes_map =
1037             time(time_passes,
1038                  "compute_incremental_hashes_map",
1039                  || rustc_incremental::compute_incremental_hashes_map(tcx));
1040
1041         time(time_passes,
1042              "load_dep_graph",
1043              || rustc_incremental::load_dep_graph(tcx, &incremental_hashes_map));
1044
1045         time(time_passes, "stability index", || {
1046             tcx.stability.borrow_mut().build(tcx)
1047         });
1048
1049         time(time_passes,
1050              "stability checking",
1051              || stability::check_unstable_api_usage(tcx));
1052
1053         // passes are timed inside typeck
1054         try_with_f!(typeck::check_crate(tcx), (tcx, analysis, incremental_hashes_map));
1055
1056         time(time_passes,
1057              "const checking",
1058              || consts::check_crate(tcx));
1059
1060         analysis.access_levels =
1061             time(time_passes, "privacy checking", || rustc_privacy::check_crate(tcx));
1062
1063         time(time_passes,
1064              "intrinsic checking",
1065              || middle::intrinsicck::check_crate(tcx));
1066
1067         time(time_passes,
1068              "effect checking",
1069              || middle::effect::check_crate(tcx));
1070
1071         time(time_passes,
1072              "match checking",
1073              || check_match::check_crate(tcx));
1074
1075         // this must run before MIR dump, because
1076         // "not all control paths return a value" is reported here.
1077         //
1078         // maybe move the check to a MIR pass?
1079         time(time_passes,
1080              "liveness checking",
1081              || middle::liveness::check_crate(tcx));
1082
1083         time(time_passes,
1084              "borrow checking",
1085              || borrowck::check_crate(tcx));
1086
1087         time(time_passes,
1088              "MIR borrow checking",
1089              || for def_id in tcx.body_owners() { tcx.mir_borrowck(def_id) });
1090
1091         // Avoid overwhelming user with errors if type checking failed.
1092         // I'm not sure how helpful this is, to be honest, but it avoids
1093         // a
1094         // lot of annoying errors in the compile-fail tests (basically,
1095         // lint warnings and so on -- kindck used to do this abort, but
1096         // kindck is gone now). -nmatsakis
1097         if sess.err_count() > 0 {
1098             return Ok(f(tcx, analysis, incremental_hashes_map, sess.compile_status()));
1099         }
1100
1101         analysis.reachable =
1102             time(time_passes,
1103                  "reachability checking",
1104                  || reachable::find_reachable(tcx));
1105
1106         time(time_passes, "death checking", || middle::dead::check_crate(tcx));
1107
1108         time(time_passes, "unused lib feature checking", || {
1109             stability::check_unused_or_stable_features(tcx)
1110         });
1111
1112         time(time_passes, "lint checking", || lint::check_crate(tcx));
1113
1114         return Ok(f(tcx, analysis, incremental_hashes_map, tcx.sess.compile_status()));
1115     })
1116 }
1117
1118 /// Run the translation phase to LLVM, after which the AST and analysis can
1119 /// be discarded.
1120 pub fn phase_4_translate_to_llvm<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1121                                            analysis: ty::CrateAnalysis,
1122                                            incremental_hashes_map: IncrementalHashesMap,
1123                                            output_filenames: &OutputFilenames)
1124                                            -> write::OngoingCrateTranslation {
1125     let time_passes = tcx.sess.time_passes();
1126
1127     time(time_passes,
1128          "resolving dependency formats",
1129          || ::rustc::middle::dependency_format::calculate(tcx));
1130
1131     let translation =
1132         time(time_passes,
1133              "translation",
1134              move || trans::trans_crate(tcx, analysis, incremental_hashes_map, output_filenames));
1135
1136     if tcx.sess.profile_queries() {
1137         profile::dump("profile_queries".to_string())
1138     }
1139
1140     translation
1141 }
1142
1143 /// Run LLVM itself, producing a bitcode file, assembly file or object file
1144 /// as a side effect.
1145 #[cfg(feature="llvm")]
1146 pub fn phase_5_run_llvm_passes(sess: &Session,
1147                                trans: write::OngoingCrateTranslation)
1148                                -> (CompileResult, trans::CrateTranslation) {
1149     let trans = trans.join(sess);
1150
1151     if sess.opts.debugging_opts.incremental_info {
1152         write::dump_incremental_data(&trans);
1153     }
1154
1155     time(sess.time_passes(),
1156          "serialize work products",
1157          move || rustc_incremental::save_work_products(sess));
1158
1159     (sess.compile_status(), trans)
1160 }
1161
1162 /// Run the linker on any artifacts that resulted from the LLVM run.
1163 /// This should produce either a finished executable or library.
1164 #[cfg(feature="llvm")]
1165 pub fn phase_6_link_output(sess: &Session,
1166                            trans: &trans::CrateTranslation,
1167                            outputs: &OutputFilenames) {
1168     time(sess.time_passes(), "linking", || {
1169         ::rustc_trans::back::link::link_binary(sess, trans, outputs, &trans.crate_name.as_str())
1170     });
1171 }
1172
1173 fn escape_dep_filename(filename: &str) -> String {
1174     // Apparently clang and gcc *only* escape spaces:
1175     // http://llvm.org/klaus/clang/commit/9d50634cfc268ecc9a7250226dd5ca0e945240d4
1176     filename.replace(" ", "\\ ")
1177 }
1178
1179 fn write_out_deps(sess: &Session, outputs: &OutputFilenames, crate_name: &str) {
1180     let mut out_filenames = Vec::new();
1181     for output_type in sess.opts.output_types.keys() {
1182         let file = outputs.path(*output_type);
1183         match *output_type {
1184             OutputType::Exe => {
1185                 for output in sess.crate_types.borrow().iter() {
1186                     let p = ::rustc_trans_utils::link::filename_for_input(
1187                         sess,
1188                         *output,
1189                         crate_name,
1190                         outputs
1191                     );
1192                     out_filenames.push(p);
1193                 }
1194             }
1195             _ => {
1196                 out_filenames.push(file);
1197             }
1198         }
1199     }
1200
1201     // Write out dependency rules to the dep-info file if requested
1202     if !sess.opts.output_types.contains_key(&OutputType::DepInfo) {
1203         return;
1204     }
1205     let deps_filename = outputs.path(OutputType::DepInfo);
1206
1207     let result =
1208         (|| -> io::Result<()> {
1209             // Build a list of files used to compile the output and
1210             // write Makefile-compatible dependency rules
1211             let files: Vec<String> = sess.codemap()
1212                                          .files()
1213                                          .iter()
1214                                          .filter(|fmap| fmap.is_real_file())
1215                                          .filter(|fmap| !fmap.is_imported())
1216                                          .map(|fmap| escape_dep_filename(&fmap.name))
1217                                          .collect();
1218             let mut file = fs::File::create(&deps_filename)?;
1219             for path in &out_filenames {
1220                 write!(file, "{}: {}\n\n", path.display(), files.join(" "))?;
1221             }
1222
1223             // Emit a fake target for each input file to the compilation. This
1224             // prevents `make` from spitting out an error if a file is later
1225             // deleted. For more info see #28735
1226             for path in files {
1227                 writeln!(file, "{}:", path)?;
1228             }
1229             Ok(())
1230         })();
1231
1232     match result {
1233         Ok(()) => {}
1234         Err(e) => {
1235             sess.fatal(&format!("error writing dependencies to `{}`: {}",
1236                                 deps_filename.display(),
1237                                 e));
1238         }
1239     }
1240 }
1241
1242 pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<config::CrateType> {
1243     // Unconditionally collect crate types from attributes to make them used
1244     let attr_types: Vec<config::CrateType> =
1245         attrs.iter()
1246              .filter_map(|a| {
1247                  if a.check_name("crate_type") {
1248                      match a.value_str() {
1249                          Some(ref n) if *n == "rlib" => {
1250                              Some(config::CrateTypeRlib)
1251                          }
1252                          Some(ref n) if *n == "dylib" => {
1253                              Some(config::CrateTypeDylib)
1254                          }
1255                          Some(ref n) if *n == "cdylib" => {
1256                              Some(config::CrateTypeCdylib)
1257                          }
1258                          Some(ref n) if *n == "lib" => {
1259                              Some(config::default_lib_output())
1260                          }
1261                          Some(ref n) if *n == "staticlib" => {
1262                              Some(config::CrateTypeStaticlib)
1263                          }
1264                          Some(ref n) if *n == "proc-macro" => {
1265                              Some(config::CrateTypeProcMacro)
1266                          }
1267                          Some(ref n) if *n == "bin" => Some(config::CrateTypeExecutable),
1268                          Some(_) => {
1269                              session.buffer_lint(lint::builtin::UNKNOWN_CRATE_TYPES,
1270                                                  ast::CRATE_NODE_ID,
1271                                                  a.span,
1272                                                  "invalid `crate_type` value");
1273                              None
1274                          }
1275                          _ => {
1276                              session.struct_span_err(a.span, "`crate_type` requires a value")
1277                                  .note("for example: `#![crate_type=\"lib\"]`")
1278                                  .emit();
1279                              None
1280                          }
1281                      }
1282                  } else {
1283                      None
1284                  }
1285              })
1286              .collect();
1287
1288     // If we're generating a test executable, then ignore all other output
1289     // styles at all other locations
1290     if session.opts.test {
1291         return vec![config::CrateTypeExecutable];
1292     }
1293
1294     // Only check command line flags if present. If no types are specified by
1295     // command line, then reuse the empty `base` Vec to hold the types that
1296     // will be found in crate attributes.
1297     let mut base = session.opts.crate_types.clone();
1298     if base.is_empty() {
1299         base.extend(attr_types);
1300         if base.is_empty() {
1301             base.push(::rustc_trans_utils::link::default_output_for_target(session));
1302         }
1303         base.sort();
1304         base.dedup();
1305     }
1306
1307     base.into_iter()
1308         .filter(|crate_type| {
1309             let res = !::rustc_trans_utils::link::invalid_output_for_target(session, *crate_type);
1310
1311             if !res {
1312                 session.warn(&format!("dropping unsupported crate type `{}` for target `{}`",
1313                                       *crate_type,
1314                                       session.opts.target_triple));
1315             }
1316
1317             res
1318         })
1319         .collect()
1320 }
1321
1322 pub fn compute_crate_disambiguator(session: &Session) -> String {
1323     use std::hash::Hasher;
1324
1325     // The crate_disambiguator is a 128 bit hash. The disambiguator is fed
1326     // into various other hashes quite a bit (symbol hashes, incr. comp. hashes,
1327     // debuginfo type IDs, etc), so we don't want it to be too wide. 128 bits
1328     // should still be safe enough to avoid collisions in practice.
1329     // FIXME(mw): It seems that the crate_disambiguator is used everywhere as
1330     //            a hex-string instead of raw bytes. We should really use the
1331     //            smaller representation.
1332     let mut hasher = StableHasher::<Fingerprint>::new();
1333
1334     let mut metadata = session.opts.cg.metadata.clone();
1335     // We don't want the crate_disambiguator to dependent on the order
1336     // -C metadata arguments, so sort them:
1337     metadata.sort();
1338     // Every distinct -C metadata value is only incorporated once:
1339     metadata.dedup();
1340
1341     hasher.write(b"metadata");
1342     for s in &metadata {
1343         // Also incorporate the length of a metadata string, so that we generate
1344         // different values for `-Cmetadata=ab -Cmetadata=c` and
1345         // `-Cmetadata=a -Cmetadata=bc`
1346         hasher.write_usize(s.len());
1347         hasher.write(s.as_bytes());
1348     }
1349
1350     // If this is an executable, add a special suffix, so that we don't get
1351     // symbol conflicts when linking against a library of the same name.
1352     let is_exe = session.crate_types.borrow().contains(&config::CrateTypeExecutable);
1353
1354     format!("{}{}", hasher.finish().to_hex(), if is_exe { "-exe" } else {""})
1355 }
1356
1357 pub fn build_output_filenames(input: &Input,
1358                               odir: &Option<PathBuf>,
1359                               ofile: &Option<PathBuf>,
1360                               attrs: &[ast::Attribute],
1361                               sess: &Session)
1362                               -> OutputFilenames {
1363     match *ofile {
1364         None => {
1365             // "-" as input file will cause the parser to read from stdin so we
1366             // have to make up a name
1367             // We want to toss everything after the final '.'
1368             let dirpath = match *odir {
1369                 Some(ref d) => d.clone(),
1370                 None => PathBuf::new(),
1371             };
1372
1373             // If a crate name is present, we use it as the link name
1374             let stem = sess.opts
1375                            .crate_name
1376                            .clone()
1377                            .or_else(|| attr::find_crate_name(attrs).map(|n| n.to_string()))
1378                            .unwrap_or(input.filestem());
1379
1380             OutputFilenames {
1381                 out_directory: dirpath,
1382                 out_filestem: stem,
1383                 single_output_file: None,
1384                 extra: sess.opts.cg.extra_filename.clone(),
1385                 outputs: sess.opts.output_types.clone(),
1386             }
1387         }
1388
1389         Some(ref out_file) => {
1390             let unnamed_output_types = sess.opts
1391                                            .output_types
1392                                            .values()
1393                                            .filter(|a| a.is_none())
1394                                            .count();
1395             let ofile = if unnamed_output_types > 1 {
1396                 sess.warn("due to multiple output types requested, the explicitly specified \
1397                            output file name will be adapted for each output type");
1398                 None
1399             } else {
1400                 Some(out_file.clone())
1401             };
1402             if *odir != None {
1403                 sess.warn("ignoring --out-dir flag due to -o flag.");
1404             }
1405
1406             let cur_dir = Path::new("");
1407
1408             OutputFilenames {
1409                 out_directory: out_file.parent().unwrap_or(cur_dir).to_path_buf(),
1410                 out_filestem: out_file.file_stem()
1411                                       .unwrap_or(OsStr::new(""))
1412                                       .to_str()
1413                                       .unwrap()
1414                                       .to_string(),
1415                 single_output_file: ofile,
1416                 extra: sess.opts.cg.extra_filename.clone(),
1417                 outputs: sess.opts.output_types.clone(),
1418             }
1419         }
1420     }
1421 }