src/librustc_driver/driver.rs

   1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use rustc::dep_graph::DepGraph;
  12 use rustc::hir::{self, map as hir_map};
  13 use rustc::hir::lowering::lower_crate;
  14 use rustc::ich::Fingerprint;
  15 use rustc_data_structures::stable_hasher::StableHasher;
  16 use rustc_mir as mir;
  17 use rustc::session::{Session, CompileResult, CrateDisambiguator};
  18 use rustc::session::CompileIncomplete;
  19 use rustc::session::config::{self, Input, OutputFilenames, OutputType};
  20 use rustc::session::search_paths::PathKind;
  21 use rustc::lint;
  22 use rustc::middle::{self, stability, reachable, resolve_lifetime};
  23 use rustc::middle::cstore::CrateStore;
  24 use rustc::middle::privacy::AccessLevels;
  25 use rustc::ty::{self, TyCtxt, Resolutions, AllArenas};
  26 use rustc::traits;
  27 use rustc::util::common::{ErrorReported, time, install_panic_hook};
  28 use rustc_allocator as allocator;
  29 use rustc_borrowck as borrowck;
  30 use rustc_incremental;
  31 use rustc_resolve::{MakeGlobMap, Resolver, ResolverArenas};
  32 use rustc_metadata::creader::CrateLoader;
  33 use rustc_metadata::cstore::{self, CStore};
  34 use rustc_trans_utils::trans_crate::TransCrate;
  35 use rustc_typeck as typeck;
  36 use rustc_privacy;
  37 use rustc_plugin::registry::Registry;
  38 use rustc_plugin as plugin;
  39 use rustc_passes::{self, ast_validation, loops, consts, hir_stats};
  40 use rustc_mir::const_eval::check_match;
  41 use super::Compilation;
  42
  43 use serialize::json;
  44
  45 use std::any::Any;
  46 use std::env;
  47 use std::ffi::{OsString, OsStr};
  48 use std::fs;
  49 use std::io::{self, Write};
  50 use std::iter;
  51 use std::path::{Path, PathBuf};
  52 use rustc_data_structures::sync::Lrc;
  53 use std::sync::mpsc;
  54 use syntax::{self, ast, attr, diagnostics, visit};
  55 use syntax::ext::base::ExtCtxt;
  56 use syntax::fold::Folder;
  57 use syntax::parse::{self, PResult};
  58 use syntax::util::node_count::NodeCounter;
  59 use syntax_pos::FileName;
  60 use syntax_ext;
  61
  62 use derive_registrar;
  63 use pretty::ReplaceBodyWithLoop;
  64
  65 use profile;
  66
  67 pub fn compile_input(trans: Box<TransCrate>,
  68                      sess: &Session,
  69                      cstore: &CStore,
  70                      input_path: &Option<PathBuf>,
  71                      input: &Input,
  72                      outdir: &Option<PathBuf>,
  73                      output: &Option<PathBuf>,
  74                      addl_plugins: Option<Vec<String>>,
  75                      control: &CompileController) -> CompileResult {
  76     macro_rules! controller_entry_point {
  77         ($point: ident, $tsess: expr, $make_state: expr, $phase_result: expr) => {{
  78             let state = &mut $make_state;
  79             let phase_result: &CompileResult = &$phase_result;
  80             if phase_result.is_ok() || control.$point.run_callback_on_error {
  81                 (control.$point.callback)(state);
  82             }
  83
  84             if control.$point.stop == Compilation::Stop {
  85                 // FIXME: shouldn't this return Err(CompileIncomplete::Stopped)
  86                 // if there are no errors?
  87                 return $tsess.compile_status();
  88             }
  89         }}
  90     }
  91
  92     if sess.profile_queries() {
  93         profile::begin();
  94     }
  95
  96     // We need nested scopes here, because the intermediate results can keep
  97     // large chunks of memory alive and we want to free them as soon as
  98     // possible to keep the peak memory usage low
  99     let (outputs, ongoing_trans, dep_graph) = {
 100         let krate = match phase_1_parse_input(control, sess, input) {
 101             Ok(krate) => krate,
 102             Err(mut parse_error) => {
 103                 parse_error.emit();
 104                 return Err(CompileIncomplete::Errored(ErrorReported));
 105             }
 106         };
 107
 108         let (krate, registry) = {
 109             let mut compile_state = CompileState::state_after_parse(input,
 110                                                                     sess,
 111                                                                     outdir,
 112                                                                     output,
 113                                                                     krate,
 114                                                                     &cstore);
 115             controller_entry_point!(after_parse,
 116                                     sess,
 117                                     compile_state,
 118                                     Ok(()));
 119
 120             (compile_state.krate.unwrap(), compile_state.registry)
 121         };
 122
 123         let outputs = build_output_filenames(input, outdir, output, &krate.attrs, sess);
 124         let crate_name =
 125             ::rustc_trans_utils::link::find_crate_name(Some(sess), &krate.attrs, input);
 126         install_panic_hook();
 127
 128         let ExpansionResult { expanded_crate, defs, analysis, resolutions, mut hir_forest } = {
 129             phase_2_configure_and_expand(
 130                 sess,
 131                 &cstore,
 132                 krate,
 133                 registry,
 134                 &crate_name,
 135                 addl_plugins,
 136                 control.make_glob_map,
 137                 |expanded_crate| {
 138                     let mut state = CompileState::state_after_expand(
 139                         input, sess, outdir, output, &cstore, expanded_crate, &crate_name,
 140                     );
 141                     controller_entry_point!(after_expand, sess, state, Ok(()));
 142                     Ok(())
 143                 }
 144             )?
 145         };
 146
 147         let output_paths = generated_output_paths(sess, &outputs, output.is_some(), &crate_name);
 148
 149         // Ensure the source file isn't accidentally overwritten during compilation.
 150         if let Some(ref input_path) = *input_path {
 151             if sess.opts.will_create_output_file() {
 152                 if output_contains_path(&output_paths, input_path) {
 153                     sess.err(&format!(
 154                         "the input file \"{}\" would be overwritten by the generated \
 155                         executable",
 156                         input_path.display()));
 157                     return Err(CompileIncomplete::Stopped);
 158                 }
 159                 if let Some(dir_path) = output_conflicts_with_dir(&output_paths) {
 160                     sess.err(&format!(
 161                         "the generated executable for the input file \"{}\" conflicts with the \
 162                         existing directory \"{}\"",
 163                         input_path.display(), dir_path.display()));
 164                     return Err(CompileIncomplete::Stopped);
 165                 }
 166             }
 167         }
 168
 169         write_out_deps(sess, &outputs, &output_paths);
 170         if sess.opts.output_types.contains_key(&OutputType::DepInfo) &&
 171             sess.opts.output_types.keys().count() == 1 {
 172             return Ok(())
 173         }
 174
 175         if let &Some(ref dir) = outdir {
 176             if fs::create_dir_all(dir).is_err() {
 177                 sess.err("failed to find or create the directory specified by --out-dir");
 178                 return Err(CompileIncomplete::Stopped);
 179             }
 180         }
 181
 182         let arenas = AllArenas::new();
 183
 184         // Construct the HIR map
 185         let hir_map = time(sess.time_passes(),
 186                            "indexing hir",
 187                            || hir_map::map_crate(sess, cstore, &mut hir_forest, &defs));
 188
 189         {
 190             hir_map.dep_graph.assert_ignored();
 191             controller_entry_point!(after_hir_lowering,
 192                                     sess,
 193                                     CompileState::state_after_hir_lowering(input,
 194                                                                   sess,
 195                                                                   outdir,
 196                                                                   output,
 197                                                                   &arenas,
 198                                                                   &cstore,
 199                                                                   &hir_map,
 200                                                                   &analysis,
 201                                                                   &resolutions,
 202                                                                   &expanded_crate,
 203                                                                   &hir_map.krate(),
 204                                                                   &outputs,
 205                                                                   &crate_name),
 206                                     Ok(()));
 207         }
 208
 209         let opt_crate = if control.keep_ast {
 210             Some(&expanded_crate)
 211         } else {
 212             drop(expanded_crate);
 213             None
 214         };
 215
 216         phase_3_run_analysis_passes(&*trans,
 217                                     control,
 218                                     sess,
 219                                     cstore,
 220                                     hir_map,
 221                                     analysis,
 222                                     resolutions,
 223                                     &arenas,
 224                                     &crate_name,
 225                                     &outputs,
 226                                     |tcx, analysis, rx, result| {
 227             {
 228                 // Eventually, we will want to track plugins.
 229                 tcx.dep_graph.with_ignore(|| {
 230                     let mut state = CompileState::state_after_analysis(input,
 231                                                                        sess,
 232                                                                        outdir,
 233                                                                        output,
 234                                                                        opt_crate,
 235                                                                        tcx.hir.krate(),
 236                                                                        &analysis,
 237                                                                        tcx,
 238                                                                        &crate_name);
 239                     (control.after_analysis.callback)(&mut state);
 240                 });
 241
 242                 if control.after_analysis.stop == Compilation::Stop {
 243                     return result.and_then(|_| Err(CompileIncomplete::Stopped));
 244                 }
 245             }
 246
 247             result?;
 248
 249             if log_enabled!(::log::Level::Info) {
 250                 println!("Pre-trans");
 251                 tcx.print_debug_stats();
 252             }
 253
 254             let ongoing_trans = phase_4_translate_to_llvm(&*trans, tcx, rx);
 255
 256             if log_enabled!(::log::Level::Info) {
 257                 println!("Post-trans");
 258                 tcx.print_debug_stats();
 259             }
 260
 261             if tcx.sess.opts.output_types.contains_key(&OutputType::Mir) {
 262                 if let Err(e) = mir::transform::dump_mir::emit_mir(tcx, &outputs) {
 263                     sess.err(&format!("could not emit MIR: {}", e));
 264                     sess.abort_if_errors();
 265                 }
 266             }
 267
 268             Ok((outputs.clone(), ongoing_trans, tcx.dep_graph.clone()))
 269         })??
 270     };
 271
 272     if sess.opts.debugging_opts.print_type_sizes {
 273         sess.code_stats.borrow().print_type_sizes();
 274     }
 275
 276     trans.join_trans_and_link(ongoing_trans, sess, &dep_graph, &outputs)?;
 277
 278     if sess.opts.debugging_opts.perf_stats {
 279         sess.print_perf_stats();
 280     }
 281
 282     controller_entry_point!(
 283         compilation_done,
 284         sess,
 285         CompileState::state_when_compilation_done(input, sess, outdir, output),
 286         Ok(())
 287     );
 288
 289     Ok(())
 290 }
 291
 292 pub fn source_name(input: &Input) -> FileName {
 293     match *input {
 294         Input::File(ref ifile) => ifile.clone().into(),
 295         Input::Str { ref name, .. } => name.clone(),
 296     }
 297 }
 298
 299 /// CompileController is used to customize compilation, it allows compilation to
 300 /// be stopped and/or to call arbitrary code at various points in compilation.
 301 /// It also allows for various flags to be set to influence what information gets
 302 /// collected during compilation.
 303 ///
 304 /// This is a somewhat higher level controller than a Session - the Session
 305 /// controls what happens in each phase, whereas the CompileController controls
 306 /// whether a phase is run at all and whether other code (from outside the
 307 /// compiler) is run between phases.
 308 ///
 309 /// Note that if compilation is set to stop and a callback is provided for a
 310 /// given entry point, the callback is called before compilation is stopped.
 311 ///
 312 /// Expect more entry points to be added in the future.
 313 pub struct CompileController<'a> {
 314     pub after_parse: PhaseController<'a>,
 315     pub after_expand: PhaseController<'a>,
 316     pub after_hir_lowering: PhaseController<'a>,
 317     pub after_analysis: PhaseController<'a>,
 318     pub compilation_done: PhaseController<'a>,
 319
 320     // FIXME we probably want to group the below options together and offer a
 321     // better API, rather than this ad-hoc approach.
 322     pub make_glob_map: MakeGlobMap,
 323     // Whether the compiler should keep the ast beyond parsing.
 324     pub keep_ast: bool,
 325     // -Zcontinue-parse-after-error
 326     pub continue_parse_after_error: bool,
 327
 328     /// Allows overriding default rustc query providers,
 329     /// after `default_provide` has installed them.
 330     pub provide: Box<Fn(&mut ty::maps::Providers) + 'a>,
 331     /// Same as `provide`, but only for non-local crates,
 332     /// applied after `default_provide_extern`.
 333     pub provide_extern: Box<Fn(&mut ty::maps::Providers) + 'a>,
 334 }
 335
 336 impl<'a> CompileController<'a> {
 337     pub fn basic() -> CompileController<'a> {
 338         CompileController {
 339             after_parse: PhaseController::basic(),
 340             after_expand: PhaseController::basic(),
 341             after_hir_lowering: PhaseController::basic(),
 342             after_analysis: PhaseController::basic(),
 343             compilation_done: PhaseController::basic(),
 344             make_glob_map: MakeGlobMap::No,
 345             keep_ast: false,
 346             continue_parse_after_error: false,
 347             provide: box |_| {},
 348             provide_extern: box |_| {},
 349         }
 350     }
 351 }
 352
 353 pub struct PhaseController<'a> {
 354     pub stop: Compilation,
 355     // If true then the compiler will try to run the callback even if the phase
 356     // ends with an error. Note that this is not always possible.
 357     pub run_callback_on_error: bool,
 358     pub callback: Box<Fn(&mut CompileState) + 'a>,
 359 }
 360
 361 impl<'a> PhaseController<'a> {
 362     pub fn basic() -> PhaseController<'a> {
 363         PhaseController {
 364             stop: Compilation::Continue,
 365             run_callback_on_error: false,
 366             callback: box |_| {},
 367         }
 368     }
 369 }
 370
 371 /// State that is passed to a callback. What state is available depends on when
 372 /// during compilation the callback is made. See the various constructor methods
 373 /// (`state_*`) in the impl to see which data is provided for any given entry point.
 374 pub struct CompileState<'a, 'tcx: 'a> {
 375     pub input: &'a Input,
 376     pub session: &'tcx Session,
 377     pub krate: Option<ast::Crate>,
 378     pub registry: Option<Registry<'a>>,
 379     pub cstore: Option<&'tcx CStore>,
 380     pub crate_name: Option<&'a str>,
 381     pub output_filenames: Option<&'a OutputFilenames>,
 382     pub out_dir: Option<&'a Path>,
 383     pub out_file: Option<&'a Path>,
 384     pub arenas: Option<&'tcx AllArenas<'tcx>>,
 385     pub expanded_crate: Option<&'a ast::Crate>,
 386     pub hir_crate: Option<&'a hir::Crate>,
 387     pub hir_map: Option<&'a hir_map::Map<'tcx>>,
 388     pub resolutions: Option<&'a Resolutions>,
 389     pub analysis: Option<&'a ty::CrateAnalysis>,
 390     pub tcx: Option<TyCtxt<'a, 'tcx, 'tcx>>,
 391 }
 392
 393 impl<'a, 'tcx> CompileState<'a, 'tcx> {
 394     fn empty(input: &'a Input,
 395              session: &'tcx Session,
 396              out_dir: &'a Option<PathBuf>)
 397              -> Self {
 398         CompileState {
 399             input,
 400             session,
 401             out_dir: out_dir.as_ref().map(|s| &**s),
 402             out_file: None,
 403             arenas: None,
 404             krate: None,
 405             registry: None,
 406             cstore: None,
 407             crate_name: None,
 408             output_filenames: None,
 409             expanded_crate: None,
 410             hir_crate: None,
 411             hir_map: None,
 412             resolutions: None,
 413             analysis: None,
 414             tcx: None,
 415         }
 416     }
 417
 418     fn state_after_parse(input: &'a Input,
 419                          session: &'tcx Session,
 420                          out_dir: &'a Option<PathBuf>,
 421                          out_file: &'a Option<PathBuf>,
 422                          krate: ast::Crate,
 423                          cstore: &'tcx CStore)
 424                          -> Self {
 425         CompileState {
 426             // Initialize the registry before moving `krate`
 427             registry: Some(Registry::new(&session, krate.span)),
 428             krate: Some(krate),
 429             cstore: Some(cstore),
 430             out_file: out_file.as_ref().map(|s| &**s),
 431             ..CompileState::empty(input, session, out_dir)
 432         }
 433     }
 434
 435     fn state_after_expand(input: &'a Input,
 436                           session: &'tcx Session,
 437                           out_dir: &'a Option<PathBuf>,
 438                           out_file: &'a Option<PathBuf>,
 439                           cstore: &'tcx CStore,
 440                           expanded_crate: &'a ast::Crate,
 441                           crate_name: &'a str)
 442                           -> Self {
 443         CompileState {
 444             crate_name: Some(crate_name),
 445             cstore: Some(cstore),
 446             expanded_crate: Some(expanded_crate),
 447             out_file: out_file.as_ref().map(|s| &**s),
 448             ..CompileState::empty(input, session, out_dir)
 449         }
 450     }
 451
 452     fn state_after_hir_lowering(input: &'a Input,
 453                                 session: &'tcx Session,
 454                                 out_dir: &'a Option<PathBuf>,
 455                                 out_file: &'a Option<PathBuf>,
 456                                 arenas: &'tcx AllArenas<'tcx>,
 457                                 cstore: &'tcx CStore,
 458                                 hir_map: &'a hir_map::Map<'tcx>,
 459                                 analysis: &'a ty::CrateAnalysis,
 460                                 resolutions: &'a Resolutions,
 461                                 krate: &'a ast::Crate,
 462                                 hir_crate: &'a hir::Crate,
 463                                 output_filenames: &'a OutputFilenames,
 464                                 crate_name: &'a str)
 465                                 -> Self {
 466         CompileState {
 467             crate_name: Some(crate_name),
 468             arenas: Some(arenas),
 469             cstore: Some(cstore),
 470             hir_map: Some(hir_map),
 471             analysis: Some(analysis),
 472             resolutions: Some(resolutions),
 473             expanded_crate: Some(krate),
 474             hir_crate: Some(hir_crate),
 475             output_filenames: Some(output_filenames),
 476             out_file: out_file.as_ref().map(|s| &**s),
 477             ..CompileState::empty(input, session, out_dir)
 478         }
 479     }
 480
 481     fn state_after_analysis(input: &'a Input,
 482                             session: &'tcx Session,
 483                             out_dir: &'a Option<PathBuf>,
 484                             out_file: &'a Option<PathBuf>,
 485                             krate: Option<&'a ast::Crate>,
 486                             hir_crate: &'a hir::Crate,
 487                             analysis: &'a ty::CrateAnalysis,
 488                             tcx: TyCtxt<'a, 'tcx, 'tcx>,
 489                             crate_name: &'a str)
 490                             -> Self {
 491         CompileState {
 492             analysis: Some(analysis),
 493             tcx: Some(tcx),
 494             expanded_crate: krate,
 495             hir_crate: Some(hir_crate),
 496             crate_name: Some(crate_name),
 497             out_file: out_file.as_ref().map(|s| &**s),
 498             ..CompileState::empty(input, session, out_dir)
 499         }
 500     }
 501
 502     fn state_when_compilation_done(input: &'a Input,
 503                                    session: &'tcx Session,
 504                                    out_dir: &'a Option<PathBuf>,
 505                                    out_file: &'a Option<PathBuf>)
 506                                    -> Self {
 507         CompileState {
 508             out_file: out_file.as_ref().map(|s| &**s),
 509             ..CompileState::empty(input, session, out_dir)
 510         }
 511     }
 512 }
 513
 514 pub fn phase_1_parse_input<'a>(control: &CompileController,
 515                                sess: &'a Session,
 516                                input: &Input)
 517                                -> PResult<'a, ast::Crate> {
 518     sess.diagnostic().set_continue_after_error(control.continue_parse_after_error);
 519
 520     if sess.profile_queries() {
 521         profile::begin();
 522     }
 523
 524     let krate = time(sess.time_passes(), "parsing", || {
 525         match *input {
 526             Input::File(ref file) => {
 527                 parse::parse_crate_from_file(file, &sess.parse_sess)
 528             }
 529             Input::Str { ref input, ref name } => {
 530                 parse::parse_crate_from_source_str(name.clone(),
 531                                                    input.clone(),
 532                                                    &sess.parse_sess)
 533             }
 534         }
 535     })?;
 536
 537     sess.diagnostic().set_continue_after_error(true);
 538
 539     if sess.opts.debugging_opts.ast_json_noexpand {
 540         println!("{}", json::as_json(&krate));
 541     }
 542
 543     if sess.opts.debugging_opts.input_stats {
 544         println!("Lines of code:             {}", sess.codemap().count_lines());
 545         println!("Pre-expansion node count:  {}", count_nodes(&krate));
 546     }
 547
 548     if let Some(ref s) = sess.opts.debugging_opts.show_span {
 549         syntax::show_span::run(sess.diagnostic(), s, &krate);
 550     }
 551
 552     if sess.opts.debugging_opts.hir_stats {
 553         hir_stats::print_ast_stats(&krate, "PRE EXPANSION AST STATS");
 554     }
 555
 556     Ok(krate)
 557 }
 558
 559 fn count_nodes(krate: &ast::Crate) -> usize {
 560     let mut counter = NodeCounter::new();
 561     visit::walk_crate(&mut counter, krate);
 562     counter.count
 563 }
 564
 565 // For continuing compilation after a parsed crate has been
 566 // modified
 567
 568 pub struct ExpansionResult {
 569     pub expanded_crate: ast::Crate,
 570     pub defs: hir_map::Definitions,
 571     pub analysis: ty::CrateAnalysis,
 572     pub resolutions: Resolutions,
 573     pub hir_forest: hir_map::Forest,
 574 }
 575
 576 pub struct InnerExpansionResult<'a> {
 577     pub expanded_crate: ast::Crate,
 578     pub resolver: Resolver<'a>,
 579     pub hir_forest: hir_map::Forest,
 580 }
 581
 582 /// Run the "early phases" of the compiler: initial `cfg` processing,
 583 /// loading compiler plugins (including those from `addl_plugins`),
 584 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
 585 /// harness if one is to be provided, injection of a dependency on the
 586 /// standard library and prelude, and name resolution.
 587 ///
 588 /// Returns `None` if we're aborting after handling -W help.
 589 pub fn phase_2_configure_and_expand<F>(sess: &Session,
 590                                        cstore: &CStore,
 591                                        krate: ast::Crate,
 592                                        registry: Option<Registry>,
 593                                        crate_name: &str,
 594                                        addl_plugins: Option<Vec<String>>,
 595                                        make_glob_map: MakeGlobMap,
 596                                        after_expand: F)
 597                                        -> Result<ExpansionResult, CompileIncomplete>
 598     where F: FnOnce(&ast::Crate) -> CompileResult {
 599     // Currently, we ignore the name resolution data structures for the purposes of dependency
 600     // tracking. Instead we will run name resolution and include its output in the hash of each
 601     // item, much like we do for macro expansion. In other words, the hash reflects not just
 602     // its contents but the results of name resolution on those contents. Hopefully we'll push
 603     // this back at some point.
 604     let mut crate_loader = CrateLoader::new(sess, &cstore, &crate_name);
 605     let resolver_arenas = Resolver::arenas();
 606     let result = phase_2_configure_and_expand_inner(sess, cstore, krate, registry, crate_name,
 607                                                     addl_plugins, make_glob_map, &resolver_arenas,
 608                                                     &mut crate_loader, after_expand);
 609     match result {
 610         Ok(InnerExpansionResult {expanded_crate, resolver, hir_forest}) => {
 611             Ok(ExpansionResult {
 612                 expanded_crate,
 613                 defs: resolver.definitions,
 614                 hir_forest,
 615                 resolutions: Resolutions {
 616                     freevars: resolver.freevars,
 617                     export_map: resolver.export_map,
 618                     trait_map: resolver.trait_map,
 619                     maybe_unused_trait_imports: resolver.maybe_unused_trait_imports,
 620                     maybe_unused_extern_crates: resolver.maybe_unused_extern_crates,
 621                 },
 622
 623                 analysis: ty::CrateAnalysis {
 624                     access_levels: Lrc::new(AccessLevels::default()),
 625                     name: crate_name.to_string(),
 626                     glob_map: if resolver.make_glob_map { Some(resolver.glob_map) } else { None },
 627                 },
 628             })
 629         }
 630         Err(x) => Err(x)
 631     }
 632 }
 633
 634 /// Same as phase_2_configure_and_expand, but doesn't let you keep the resolver
 635 /// around
 636 pub fn phase_2_configure_and_expand_inner<'a, F>(sess: &'a Session,
 637                                        cstore: &'a CStore,
 638                                        krate: ast::Crate,
 639                                        registry: Option<Registry>,
 640                                        crate_name: &str,
 641                                        addl_plugins: Option<Vec<String>>,
 642                                        make_glob_map: MakeGlobMap,
 643                                        resolver_arenas: &'a ResolverArenas<'a>,
 644                                        crate_loader: &'a mut CrateLoader,
 645                                        after_expand: F)
 646                                        -> Result<InnerExpansionResult<'a>, CompileIncomplete>
 647     where F: FnOnce(&ast::Crate) -> CompileResult,
 648 {
 649     let time_passes = sess.time_passes();
 650
 651     let (mut krate, features) = syntax::config::features(krate, &sess.parse_sess, sess.opts.test);
 652     // these need to be set "early" so that expansion sees `quote` if enabled.
 653     sess.init_features(features);
 654
 655     *sess.crate_types.borrow_mut() = collect_crate_types(sess, &krate.attrs);
 656
 657     let disambiguator = compute_crate_disambiguator(sess);
 658     *sess.crate_disambiguator.borrow_mut() = Some(disambiguator);
 659     rustc_incremental::prepare_session_directory(
 660         sess,
 661         &crate_name,
 662         disambiguator,
 663     );
 664
 665     if sess.opts.incremental.is_some() {
 666         time(time_passes, "garbage collect incremental cache directory", || {
 667             if let Err(e) = rustc_incremental::garbage_collect_session_directories(sess) {
 668                 warn!("Error while trying to garbage collect incremental \
 669                        compilation cache directory: {}", e);
 670             }
 671         });
 672     }
 673
 674     // If necessary, compute the dependency graph (in the background).
 675     let future_dep_graph = if sess.opts.build_dep_graph() {
 676         Some(rustc_incremental::load_dep_graph(sess, time_passes))
 677     } else {
 678         None
 679     };
 680
 681     time(time_passes, "recursion limit", || {
 682         middle::recursion_limit::update_limits(sess, &krate);
 683     });
 684
 685     krate = time(time_passes, "crate injection", || {
 686         let alt_std_name = sess.opts.alt_std_name.clone();
 687         syntax::std_inject::maybe_inject_crates_ref(krate, alt_std_name)
 688     });
 689
 690     let mut addl_plugins = Some(addl_plugins);
 691     let registrars = time(time_passes, "plugin loading", || {
 692         plugin::load::load_plugins(sess,
 693                                    &cstore,
 694                                    &krate,
 695                                    crate_name,
 696                                    addl_plugins.take().unwrap())
 697     });
 698
 699     let mut registry = registry.unwrap_or(Registry::new(sess, krate.span));
 700
 701     time(time_passes, "plugin registration", || {
 702         if sess.features_untracked().rustc_diagnostic_macros {
 703             registry.register_macro("__diagnostic_used",
 704                                     diagnostics::plugin::expand_diagnostic_used);
 705             registry.register_macro("__register_diagnostic",
 706                                     diagnostics::plugin::expand_register_diagnostic);
 707             registry.register_macro("__build_diagnostic_array",
 708                                     diagnostics::plugin::expand_build_diagnostic_array);
 709         }
 710
 711         for registrar in registrars {
 712             registry.args_hidden = Some(registrar.args);
 713             (registrar.fun)(&mut registry);
 714         }
 715     });
 716
 717     let whitelisted_legacy_custom_derives = registry.take_whitelisted_custom_derives();
 718     let Registry { syntax_exts, early_lint_passes, late_lint_passes, lint_groups,
 719                    llvm_passes, attributes, .. } = registry;
 720
 721     sess.track_errors(|| {
 722         let mut ls = sess.lint_store.borrow_mut();
 723         for pass in early_lint_passes {
 724             ls.register_early_pass(Some(sess), true, pass);
 725         }
 726         for pass in late_lint_passes {
 727             ls.register_late_pass(Some(sess), true, pass);
 728         }
 729
 730         for (name, to) in lint_groups {
 731             ls.register_group(Some(sess), true, name, to);
 732         }
 733
 734         *sess.plugin_llvm_passes.borrow_mut() = llvm_passes;
 735         *sess.plugin_attributes.borrow_mut() = attributes.clone();
 736     })?;
 737
 738     // Lint plugins are registered; now we can process command line flags.
 739     if sess.opts.describe_lints {
 740         super::describe_lints(&sess, &sess.lint_store.borrow(), true);
 741         return Err(CompileIncomplete::Stopped);
 742     }
 743
 744     let mut resolver = Resolver::new(sess,
 745                                      cstore,
 746                                      &krate,
 747                                      crate_name,
 748                                      make_glob_map,
 749                                      crate_loader,
 750                                      &resolver_arenas);
 751     resolver.whitelisted_legacy_custom_derives = whitelisted_legacy_custom_derives;
 752     syntax_ext::register_builtins(&mut resolver, syntax_exts, sess.features_untracked().quote);
 753
 754     krate = time(time_passes, "expansion", || {
 755         // Windows dlls do not have rpaths, so they don't know how to find their
 756         // dependencies. It's up to us to tell the system where to find all the
 757         // dependent dlls. Note that this uses cfg!(windows) as opposed to
 758         // targ_cfg because syntax extensions are always loaded for the host
 759         // compiler, not for the target.
 760         //
 761         // This is somewhat of an inherently racy operation, however, as
 762         // multiple threads calling this function could possibly continue
 763         // extending PATH far beyond what it should. To solve this for now we
 764         // just don't add any new elements to PATH which are already there
 765         // within PATH. This is basically a targeted fix at #17360 for rustdoc
 766         // which runs rustc in parallel but has been seen (#33844) to cause
 767         // problems with PATH becoming too long.
 768         let mut old_path = OsString::new();
 769         if cfg!(windows) {
 770             old_path = env::var_os("PATH").unwrap_or(old_path);
 771             let mut new_path = sess.host_filesearch(PathKind::All)
 772                                    .get_dylib_search_paths();
 773             for path in env::split_paths(&old_path) {
 774                 if !new_path.contains(&path) {
 775                     new_path.push(path);
 776                 }
 777             }
 778             env::set_var("PATH",
 779                 &env::join_paths(new_path.iter()
 780                                          .filter(|p| env::join_paths(iter::once(p)).is_ok()))
 781                      .unwrap());
 782         }
 783         let features = sess.features_untracked();
 784         let cfg = syntax::ext::expand::ExpansionConfig {
 785             features: Some(&features),
 786             recursion_limit: sess.recursion_limit.get(),
 787             trace_mac: sess.opts.debugging_opts.trace_macros,
 788             should_test: sess.opts.test,
 789             ..syntax::ext::expand::ExpansionConfig::default(crate_name.to_string())
 790         };
 791
 792         let mut ecx = ExtCtxt::new(&sess.parse_sess, cfg, &mut resolver);
 793         let err_count = ecx.parse_sess.span_diagnostic.err_count();
 794
 795         let krate = ecx.monotonic_expander().expand_crate(krate);
 796
 797         ecx.check_unused_macros();
 798
 799         let mut missing_fragment_specifiers: Vec<_> =
 800             ecx.parse_sess.missing_fragment_specifiers.borrow().iter().cloned().collect();
 801         missing_fragment_specifiers.sort();
 802         for span in missing_fragment_specifiers {
 803             let lint = lint::builtin::MISSING_FRAGMENT_SPECIFIER;
 804             let msg = "missing fragment specifier";
 805             sess.buffer_lint(lint, ast::CRATE_NODE_ID, span, msg);
 806         }
 807         if ecx.parse_sess.span_diagnostic.err_count() - ecx.resolve_err_count > err_count {
 808             ecx.parse_sess.span_diagnostic.abort_if_errors();
 809         }
 810         if cfg!(windows) {
 811             env::set_var("PATH", &old_path);
 812         }
 813         krate
 814     });
 815
 816     krate = time(time_passes, "maybe building test harness", || {
 817         syntax::test::modify_for_testing(&sess.parse_sess,
 818                                          &mut resolver,
 819                                          sess.opts.test,
 820                                          krate,
 821                                          sess.diagnostic(),
 822                                          &sess.features_untracked())
 823     });
 824
 825     // If we're actually rustdoc then there's no need to actually compile
 826     // anything, so switch everything to just looping
 827     if sess.opts.actually_rustdoc {
 828         krate = ReplaceBodyWithLoop::new(sess).fold_crate(krate);
 829     }
 830
 831     // If we're in rustdoc we're always compiling as an rlib, but that'll trip a
 832     // bunch of checks in the `modify` function below. For now just skip this
 833     // step entirely if we're rustdoc as it's not too useful anyway.
 834     if !sess.opts.actually_rustdoc {
 835         krate = time(time_passes, "maybe creating a macro crate", || {
 836             let crate_types = sess.crate_types.borrow();
 837             let num_crate_types = crate_types.len();
 838             let is_proc_macro_crate = crate_types.contains(&config::CrateTypeProcMacro);
 839             let is_test_crate = sess.opts.test;
 840             syntax_ext::proc_macro_registrar::modify(&sess.parse_sess,
 841                                                      &mut resolver,
 842                                                      krate,
 843                                                      is_proc_macro_crate,
 844                                                      is_test_crate,
 845                                                      num_crate_types,
 846                                                      sess.diagnostic())
 847         });
 848     }
 849
 850     krate = time(time_passes, "creating allocators", || {
 851         allocator::expand::modify(&sess.parse_sess,
 852                                   &mut resolver,
 853                                   krate,
 854                                   sess.diagnostic())
 855     });
 856
 857     after_expand(&krate)?;
 858
 859     if sess.opts.debugging_opts.input_stats {
 860         println!("Post-expansion node count: {}", count_nodes(&krate));
 861     }
 862
 863     if sess.opts.debugging_opts.hir_stats {
 864         hir_stats::print_ast_stats(&krate, "POST EXPANSION AST STATS");
 865     }
 866
 867     if sess.opts.debugging_opts.ast_json {
 868         println!("{}", json::as_json(&krate));
 869     }
 870
 871     time(time_passes,
 872          "AST validation",
 873          || ast_validation::check_crate(sess, &krate));
 874
 875     time(time_passes, "name resolution", || -> CompileResult {
 876         resolver.resolve_crate(&krate);
 877         Ok(())
 878     })?;
 879
 880     if resolver.found_unresolved_macro {
 881         sess.parse_sess.span_diagnostic.abort_if_errors();
 882     }
 883
 884     // Needs to go *after* expansion to be able to check the results of macro expansion.
 885     time(time_passes, "complete gated feature checking", || {
 886         sess.track_errors(|| {
 887             syntax::feature_gate::check_crate(&krate,
 888                                               &sess.parse_sess,
 889                                               &sess.features_untracked(),
 890                                               &attributes,
 891                                               sess.opts.unstable_features);
 892         })
 893     })?;
 894
 895     // Lower ast -> hir.
 896     // First, we need to collect the dep_graph.
 897     let dep_graph = match future_dep_graph {
 898         None => DepGraph::new_disabled(),
 899         Some(future) => {
 900             let prev_graph = time(time_passes, "blocked while dep-graph loading finishes", || {
 901                 future.open()
 902                       .expect("Could not join with background dep_graph thread")
 903                       .open(sess)
 904             });
 905             DepGraph::new(prev_graph)
 906         }
 907     };
 908     let hir_forest = time(time_passes, "lowering ast -> hir", || {
 909         let hir_crate = lower_crate(sess, cstore, &dep_graph, &krate, &mut resolver);
 910
 911         if sess.opts.debugging_opts.hir_stats {
 912             hir_stats::print_hir_stats(&hir_crate);
 913         }
 914
 915         hir_map::Forest::new(hir_crate, &dep_graph)
 916     });
 917
 918     time(time_passes,
 919          "early lint checks",
 920          || lint::check_ast_crate(sess, &krate));
 921
 922     // Discard hygiene data, which isn't required after lowering to HIR.
 923     if !sess.opts.debugging_opts.keep_hygiene_data {
 924         syntax::ext::hygiene::clear_markings();
 925     }
 926
 927     Ok(InnerExpansionResult {
 928         expanded_crate: krate,
 929         resolver,
 930         hir_forest,
 931     })
 932 }
 933
 934 pub fn default_provide(providers: &mut ty::maps::Providers) {
 935     hir::provide(providers);
 936     borrowck::provide(providers);
 937     mir::provide(providers);
 938     reachable::provide(providers);
 939     resolve_lifetime::provide(providers);
 940     rustc_privacy::provide(providers);
 941     typeck::provide(providers);
 942     ty::provide(providers);
 943     traits::provide(providers);
 944     reachable::provide(providers);
 945     rustc_passes::provide(providers);
 946     middle::region::provide(providers);
 947     cstore::provide(providers);
 948     lint::provide(providers);
 949 }
 950
 951 pub fn default_provide_extern(providers: &mut ty::maps::Providers) {
 952     cstore::provide_extern(providers);
 953 }
 954
 955 /// Run the resolution, typechecking, region checking and other
 956 /// miscellaneous analysis passes on the crate. Return various
 957 /// structures carrying the results of the analysis.
 958 pub fn phase_3_run_analysis_passes<'tcx, F, R>(trans: &TransCrate,
 959                                                control: &CompileController,
 960                                                sess: &'tcx Session,
 961                                                cstore: &'tcx CrateStore,
 962                                                hir_map: hir_map::Map<'tcx>,
 963                                                mut analysis: ty::CrateAnalysis,
 964                                                resolutions: Resolutions,
 965                                                arenas: &'tcx AllArenas<'tcx>,
 966                                                name: &str,
 967                                                output_filenames: &OutputFilenames,
 968                                                f: F)
 969                                                -> Result<R, CompileIncomplete>
 970     where F: for<'a> FnOnce(TyCtxt<'a, 'tcx, 'tcx>,
 971                             ty::CrateAnalysis,
 972                             mpsc::Receiver<Box<Any + Send>>,
 973                             CompileResult) -> R
 974 {
 975     let time_passes = sess.time_passes();
 976
 977     let query_result_on_disk_cache = time(time_passes,
 978         "load query result cache",
 979         || rustc_incremental::load_query_result_cache(sess));
 980
 981     time(time_passes,
 982          "looking for entry point",
 983          || middle::entry::find_entry_point(sess, &hir_map));
 984
 985     sess.plugin_registrar_fn.set(time(time_passes, "looking for plugin registrar", || {
 986         plugin::build::find_plugin_registrar(sess.diagnostic(), &hir_map)
 987     }));
 988     sess.derive_registrar_fn.set(derive_registrar::find(&hir_map));
 989
 990     time(time_passes,
 991          "loop checking",
 992          || loops::check_crate(sess, &hir_map));
 993
 994     let mut local_providers = ty::maps::Providers::default();
 995     default_provide(&mut local_providers);
 996     trans.provide(&mut local_providers);
 997     (control.provide)(&mut local_providers);
 998
 999     let mut extern_providers = local_providers;
1000     default_provide_extern(&mut extern_providers);
1001     trans.provide_extern(&mut extern_providers);
1002     (control.provide_extern)(&mut extern_providers);
1003
1004     let (tx, rx) = mpsc::channel();
1005
1006     TyCtxt::create_and_enter(sess,
1007                              cstore,
1008                              local_providers,
1009                              extern_providers,
1010                              arenas,
1011                              resolutions,
1012                              hir_map,
1013                              query_result_on_disk_cache,
1014                              name,
1015                              tx,
1016                              output_filenames,
1017                              |tcx| {
1018         // Do some initialization of the DepGraph that can only be done with the
1019         // tcx available.
1020         rustc_incremental::dep_graph_tcx_init(tcx);
1021
1022         time(sess.time_passes(), "attribute checking", || {
1023             hir::check_attr::check_crate(tcx)
1024         });
1025
1026         time(time_passes,
1027              "stability checking",
1028              || stability::check_unstable_api_usage(tcx));
1029
1030         // passes are timed inside typeck
1031         match typeck::check_crate(tcx) {
1032             Ok(x) => x,
1033             Err(x) => {
1034                 f(tcx, analysis, rx, Err(x));
1035                 return Err(x);
1036             }
1037         }
1038
1039         time(time_passes,
1040              "const checking",
1041              || consts::check_crate(tcx));
1042
1043         analysis.access_levels =
1044             time(time_passes, "privacy checking", || rustc_privacy::check_crate(tcx));
1045
1046         time(time_passes,
1047              "intrinsic checking",
1048              || middle::intrinsicck::check_crate(tcx));
1049
1050         time(time_passes,
1051              "match checking",
1052              || check_match::check_crate(tcx));
1053
1054         // this must run before MIR dump, because
1055         // "not all control paths return a value" is reported here.
1056         //
1057         // maybe move the check to a MIR pass?
1058         time(time_passes,
1059              "liveness checking",
1060              || middle::liveness::check_crate(tcx));
1061
1062         time(time_passes,
1063              "borrow checking",
1064              || borrowck::check_crate(tcx));
1065
1066         time(time_passes,
1067              "MIR borrow checking",
1068              || for def_id in tcx.body_owners() { tcx.mir_borrowck(def_id); });
1069
1070         time(time_passes,
1071              "MIR effect checking",
1072              || for def_id in tcx.body_owners() {
1073                  mir::transform::check_unsafety::check_unsafety(tcx, def_id)
1074              });
1075         // Avoid overwhelming user with errors if type checking failed.
1076         // I'm not sure how helpful this is, to be honest, but it avoids
1077         // a
1078         // lot of annoying errors in the compile-fail tests (basically,
1079         // lint warnings and so on -- kindck used to do this abort, but
1080         // kindck is gone now). -nmatsakis
1081         if sess.err_count() > 0 {
1082             return Ok(f(tcx, analysis, rx, sess.compile_status()));
1083         }
1084
1085         time(time_passes, "death checking", || middle::dead::check_crate(tcx));
1086
1087         time(time_passes, "unused lib feature checking", || {
1088             stability::check_unused_or_stable_features(tcx)
1089         });
1090
1091
1092         time(time_passes,
1093              "MIR linting",
1094              || for def_id in tcx.body_owners() {
1095                  mir::const_eval::check::check(tcx, def_id)
1096              });
1097
1098         time(time_passes, "lint checking", || lint::check_crate(tcx));
1099
1100         return Ok(f(tcx, analysis, rx, tcx.sess.compile_status()));
1101     })
1102 }
1103
1104 /// Run the translation phase to LLVM, after which the AST and analysis can
1105 /// be discarded.
1106 pub fn phase_4_translate_to_llvm<'a, 'tcx>(trans: &TransCrate,
1107                                            tcx: TyCtxt<'a, 'tcx, 'tcx>,
1108                                            rx: mpsc::Receiver<Box<Any + Send>>)
1109                                            -> Box<Any> {
1110     let time_passes = tcx.sess.time_passes();
1111
1112     time(time_passes,
1113          "resolving dependency formats",
1114          || ::rustc::middle::dependency_format::calculate(tcx));
1115
1116     let translation =
1117         time(time_passes, "translation", move || {
1118             trans.trans_crate(tcx, rx)
1119         });
1120     if tcx.sess.profile_queries() {
1121         profile::dump("profile_queries".to_string())
1122     }
1123
1124     translation
1125 }
1126
1127 fn escape_dep_filename(filename: &FileName) -> String {
1128     // Apparently clang and gcc *only* escape spaces:
1129     // http://llvm.org/klaus/clang/commit/9d50634cfc268ecc9a7250226dd5ca0e945240d4
1130     filename.to_string().replace(" ", "\\ ")
1131 }
1132
1133 // Returns all the paths that correspond to generated files.
1134 fn generated_output_paths(sess: &Session,
1135                           outputs: &OutputFilenames,
1136                           exact_name: bool,
1137                           crate_name: &str) -> Vec<PathBuf> {
1138     let mut out_filenames = Vec::new();
1139     for output_type in sess.opts.output_types.keys() {
1140         let file = outputs.path(*output_type);
1141         match *output_type {
1142             // If the filename has been overridden using `-o`, it will not be modified
1143             // by appending `.rlib`, `.exe`, etc., so we can skip this transformation.
1144             OutputType::Exe if !exact_name => {
1145                 for crate_type in sess.crate_types.borrow().iter() {
1146                     let p = ::rustc_trans_utils::link::filename_for_input(
1147                         sess,
1148                         *crate_type,
1149                         crate_name,
1150                         outputs
1151                     );
1152                     out_filenames.push(p);
1153                 }
1154             }
1155             OutputType::DepInfo if sess.opts.debugging_opts.dep_info_omit_d_target => {
1156                 // Don't add the dep-info output when omitting it from dep-info targets
1157             }
1158             _ => {
1159                 out_filenames.push(file);
1160             }
1161         }
1162     }
1163     out_filenames
1164 }
1165
1166 // Runs `f` on every output file path and returns the first non-None result, or None if `f`
1167 // returns None for every file path.
1168 fn check_output<F, T>(output_paths: &Vec<PathBuf>, f: F) -> Option<T>
1169         where F: Fn(&PathBuf) -> Option<T> {
1170             for output_path in output_paths {
1171                 if let Some(result) = f(output_path) {
1172                     return Some(result);
1173                 }
1174             }
1175             None
1176 }
1177
1178 pub fn output_contains_path(output_paths: &Vec<PathBuf>, input_path: &PathBuf) -> bool {
1179     let input_path = input_path.canonicalize().ok();
1180     if input_path.is_none() {
1181         return false
1182     }
1183     let check = |output_path: &PathBuf| {
1184         if output_path.canonicalize().ok() == input_path {
1185             Some(())
1186         } else { None }
1187     };
1188     check_output(output_paths, check).is_some()
1189 }
1190
1191 pub fn output_conflicts_with_dir(output_paths: &Vec<PathBuf>) -> Option<PathBuf> {
1192     let check = |output_path: &PathBuf| {
1193         if output_path.is_dir() {
1194             Some(output_path.clone())
1195         } else { None }
1196     };
1197     check_output(output_paths, check)
1198 }
1199
1200 fn write_out_deps(sess: &Session,
1201                   outputs: &OutputFilenames,
1202                   out_filenames: &Vec<PathBuf>) {
1203     // Write out dependency rules to the dep-info file if requested
1204     if !sess.opts.output_types.contains_key(&OutputType::DepInfo) {
1205         return;
1206     }
1207     let deps_filename = outputs.path(OutputType::DepInfo);
1208
1209     let result =
1210         (|| -> io::Result<()> {
1211             // Build a list of files used to compile the output and
1212             // write Makefile-compatible dependency rules
1213             let files: Vec<String> = sess.codemap()
1214                                          .files()
1215                                          .iter()
1216                                          .filter(|fmap| fmap.is_real_file())
1217                                          .filter(|fmap| !fmap.is_imported())
1218                                          .map(|fmap| escape_dep_filename(&fmap.name))
1219                                          .collect();
1220             let mut file = fs::File::create(&deps_filename)?;
1221             for path in out_filenames {
1222                 write!(file, "{}: {}\n\n", path.display(), files.join(" "))?;
1223             }
1224
1225             // Emit a fake target for each input file to the compilation. This
1226             // prevents `make` from spitting out an error if a file is later
1227             // deleted. For more info see #28735
1228             for path in files {
1229                 writeln!(file, "{}:", path)?;
1230             }
1231             Ok(())
1232         })();
1233
1234     match result {
1235         Ok(()) => {}
1236         Err(e) => {
1237             sess.fatal(&format!("error writing dependencies to `{}`: {}",
1238                                 deps_filename.display(),
1239                                 e));
1240         }
1241     }
1242 }
1243
1244 pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<config::CrateType> {
1245     // Unconditionally collect crate types from attributes to make them used
1246     let attr_types: Vec<config::CrateType> =
1247         attrs.iter()
1248              .filter_map(|a| {
1249                  if a.check_name("crate_type") {
1250                      match a.value_str() {
1251                          Some(ref n) if *n == "rlib" => {
1252                              Some(config::CrateTypeRlib)
1253                          }
1254                          Some(ref n) if *n == "dylib" => {
1255                              Some(config::CrateTypeDylib)
1256                          }
1257                          Some(ref n) if *n == "cdylib" => {
1258                              Some(config::CrateTypeCdylib)
1259                          }
1260                          Some(ref n) if *n == "lib" => {
1261                              Some(config::default_lib_output())
1262                          }
1263                          Some(ref n) if *n == "staticlib" => {
1264                              Some(config::CrateTypeStaticlib)
1265                          }
1266                          Some(ref n) if *n == "proc-macro" => {
1267                              Some(config::CrateTypeProcMacro)
1268                          }
1269                          Some(ref n) if *n == "bin" => Some(config::CrateTypeExecutable),
1270                          Some(_) => {
1271                              session.buffer_lint(lint::builtin::UNKNOWN_CRATE_TYPES,
1272                                                  ast::CRATE_NODE_ID,
1273                                                  a.span,
1274                                                  "invalid `crate_type` value");
1275                              None
1276                          }
1277                          _ => {
1278                              session.struct_span_err(a.span, "`crate_type` requires a value")
1279                                  .note("for example: `#![crate_type=\"lib\"]`")
1280                                  .emit();
1281                              None
1282                          }
1283                      }
1284                  } else {
1285                      None
1286                  }
1287              })
1288              .collect();
1289
1290     // If we're generating a test executable, then ignore all other output
1291     // styles at all other locations
1292     if session.opts.test {
1293         return vec![config::CrateTypeExecutable];
1294     }
1295
1296     // Only check command line flags if present. If no types are specified by
1297     // command line, then reuse the empty `base` Vec to hold the types that
1298     // will be found in crate attributes.
1299     let mut base = session.opts.crate_types.clone();
1300     if base.is_empty() {
1301         base.extend(attr_types);
1302         if base.is_empty() {
1303             base.push(::rustc_trans_utils::link::default_output_for_target(session));
1304         }
1305         base.sort();
1306         base.dedup();
1307     }
1308
1309     base.into_iter()
1310         .filter(|crate_type| {
1311             let res = !::rustc_trans_utils::link::invalid_output_for_target(session, *crate_type);
1312
1313             if !res {
1314                 session.warn(&format!("dropping unsupported crate type `{}` for target `{}`",
1315                                       *crate_type,
1316                                       session.opts.target_triple));
1317             }
1318
1319             res
1320         })
1321         .collect()
1322 }
1323
1324 pub fn compute_crate_disambiguator(session: &Session) -> CrateDisambiguator {
1325     use std::hash::Hasher;
1326
1327     // The crate_disambiguator is a 128 bit hash. The disambiguator is fed
1328     // into various other hashes quite a bit (symbol hashes, incr. comp. hashes,
1329     // debuginfo type IDs, etc), so we don't want it to be too wide. 128 bits
1330     // should still be safe enough to avoid collisions in practice.
1331     let mut hasher = StableHasher::<Fingerprint>::new();
1332
1333     let mut metadata = session.opts.cg.metadata.clone();
1334     // We don't want the crate_disambiguator to dependent on the order
1335     // -C metadata arguments, so sort them:
1336     metadata.sort();
1337     // Every distinct -C metadata value is only incorporated once:
1338     metadata.dedup();
1339
1340     hasher.write(b"metadata");
1341     for s in &metadata {
1342         // Also incorporate the length of a metadata string, so that we generate
1343         // different values for `-Cmetadata=ab -Cmetadata=c` and
1344         // `-Cmetadata=a -Cmetadata=bc`
1345         hasher.write_usize(s.len());
1346         hasher.write(s.as_bytes());
1347     }
1348
1349     // Also incorporate crate type, so that we don't get symbol conflicts when
1350     // linking against a library of the same name, if this is an executable.
1351     let is_exe = session.crate_types.borrow().contains(&config::CrateTypeExecutable);
1352     hasher.write(if is_exe { b"exe" } else { b"lib" });
1353
1354     CrateDisambiguator::from(hasher.finish())
1355
1356 }
1357
1358 pub fn build_output_filenames(input: &Input,
1359                               odir: &Option<PathBuf>,
1360                               ofile: &Option<PathBuf>,
1361                               attrs: &[ast::Attribute],
1362                               sess: &Session)
1363                               -> OutputFilenames {
1364     match *ofile {
1365         None => {
1366             // "-" as input file will cause the parser to read from stdin so we
1367             // have to make up a name
1368             // We want to toss everything after the final '.'
1369             let dirpath = match *odir {
1370                 Some(ref d) => d.clone(),
1371                 None => PathBuf::new(),
1372             };
1373
1374             // If a crate name is present, we use it as the link name
1375             let stem = sess.opts
1376                            .crate_name
1377                            .clone()
1378                            .or_else(|| attr::find_crate_name(attrs).map(|n| n.to_string()))
1379                            .unwrap_or(input.filestem());
1380
1381             OutputFilenames {
1382                 out_directory: dirpath,
1383                 out_filestem: stem,
1384                 single_output_file: None,
1385                 extra: sess.opts.cg.extra_filename.clone(),
1386                 outputs: sess.opts.output_types.clone(),
1387             }
1388         }
1389
1390         Some(ref out_file) => {
1391             let unnamed_output_types = sess.opts
1392                                            .output_types
1393                                            .values()
1394                                            .filter(|a| a.is_none())
1395                                            .count();
1396             let ofile = if unnamed_output_types > 1 {
1397                 sess.warn("due to multiple output types requested, the explicitly specified \
1398                            output file name will be adapted for each output type");
1399                 None
1400             } else {
1401                 Some(out_file.clone())
1402             };
1403             if *odir != None {
1404                 sess.warn("ignoring --out-dir flag due to -o flag");
1405             }
1406             if !sess.opts.cg.extra_filename.is_empty() {
1407                 sess.warn("ignoring -C extra-filename flag due to -o flag");
1408             }
1409
1410             let cur_dir = Path::new("");
1411
1412             OutputFilenames {
1413                 out_directory: out_file.parent().unwrap_or(cur_dir).to_path_buf(),
1414                 out_filestem: out_file.file_stem()
1415                                       .unwrap_or(OsStr::new(""))
1416                                       .to_str()
1417                                       .unwrap()
1418                                       .to_string(),
1419                 single_output_file: ofile,
1420                 extra: sess.opts.cg.extra_filename.clone(),
1421                 outputs: sess.opts.output_types.clone(),
1422             }
1423         }
1424     }
1425 }