src/librustc_driver/driver.rs

   1 // Copyright 2012-2013 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::session::Session;
  12 use rustc::session::config::{mod, Input, OutputFilenames};
  13 use rustc::lint;
  14 use rustc::metadata::creader;
  15 use rustc::middle::{stability, ty, reachable};
  16 use rustc::middle::dependency_format;
  17 use rustc::middle;
  18 use rustc::plugin::load::Plugins;
  19 use rustc::plugin::registry::Registry;
  20 use rustc::plugin;
  21 use rustc::util::common::time;
  22 use rustc_trans::back::link;
  23 use rustc_trans::back::write;
  24 use rustc_trans::save;
  25 use rustc_trans::trans;
  26 use rustc_typeck as typeck;
  27
  28 use serialize::{json, Encodable};
  29
  30 use std::io;
  31 use std::io::fs;
  32 use std::os;
  33 use arena::TypedArena;
  34 use syntax::ast;
  35 use syntax::ast_map;
  36 use syntax::attr;
  37 use syntax::attr::{AttrMetaMethods};
  38 use syntax::diagnostics;
  39 use syntax::parse;
  40 use syntax::parse::token;
  41 use syntax;
  42
  43 pub fn compile_input(sess: Session,
  44                      cfg: ast::CrateConfig,
  45                      input: &Input,
  46                      outdir: &Option<Path>,
  47                      output: &Option<Path>,
  48                      addl_plugins: Option<Plugins>) {
  49     // These may be left in an incoherent state after a previous compile.
  50     // `clear_tables` and `get_ident_interner().clear()` can be used to free
  51     // memory, but they do not restore the initial state.
  52     syntax::ext::mtwt::reset_tables();
  53     token::reset_ident_interner();
  54
  55     // We need nested scopes here, because the intermediate results can keep
  56     // large chunks of memory alive and we want to free them as soon as
  57     // possible to keep the peak memory usage low
  58     let (outputs, trans, sess) = {
  59         let (outputs, expanded_crate, id) = {
  60             let krate = phase_1_parse_input(&sess, cfg, input);
  61             if stop_after_phase_1(&sess) { return; }
  62             let outputs = build_output_filenames(input,
  63                                                  outdir,
  64                                                  output,
  65                                                  krate.attrs.as_slice(),
  66                                                  &sess);
  67             let id = link::find_crate_name(Some(&sess), krate.attrs.as_slice(),
  68                                            input);
  69             let expanded_crate
  70                 = match phase_2_configure_and_expand(&sess, krate, id.as_slice(),
  71                                                      addl_plugins) {
  72                     None => return,
  73                     Some(k) => k
  74                 };
  75
  76             (outputs, expanded_crate, id)
  77         };
  78
  79         let mut forest = ast_map::Forest::new(expanded_crate);
  80         let ast_map = assign_node_ids_and_map(&sess, &mut forest);
  81
  82         write_out_deps(&sess, input, &outputs, id.as_slice());
  83
  84         if stop_after_phase_2(&sess) { return; }
  85
  86         let type_arena = TypedArena::new();
  87         let analysis = phase_3_run_analysis_passes(sess, ast_map, &type_arena, id);
  88         phase_save_analysis(&analysis.ty_cx.sess, analysis.ty_cx.map.krate(), &analysis, outdir);
  89         if stop_after_phase_3(&analysis.ty_cx.sess) { return; }
  90         let (tcx, trans) = phase_4_translate_to_llvm(analysis);
  91
  92         // Discard interned strings as they are no longer required.
  93         token::get_ident_interner().clear();
  94
  95         (outputs, trans, tcx.sess)
  96     };
  97     phase_5_run_llvm_passes(&sess, &trans, &outputs);
  98     if stop_after_phase_5(&sess) { return; }
  99     phase_6_link_output(&sess, &trans, &outputs);
 100 }
 101
 102 /// The name used for source code that doesn't originate in a file
 103 /// (e.g. source from stdin or a string)
 104 pub fn anon_src() -> String {
 105     "<anon>".to_string()
 106 }
 107
 108 pub fn source_name(input: &Input) -> String {
 109     match *input {
 110         // FIXME (#9639): This needs to handle non-utf8 paths
 111         Input::File(ref ifile) => ifile.as_str().unwrap().to_string(),
 112         Input::Str(_) => anon_src()
 113     }
 114 }
 115
 116 pub fn phase_1_parse_input(sess: &Session, cfg: ast::CrateConfig, input: &Input)
 117     -> ast::Crate {
 118     let krate = time(sess.time_passes(), "parsing", (), |_| {
 119         match *input {
 120             Input::File(ref file) => {
 121                 parse::parse_crate_from_file(&(*file), cfg.clone(), &sess.parse_sess)
 122             }
 123             Input::Str(ref src) => {
 124                 parse::parse_crate_from_source_str(anon_src().to_string(),
 125                                                    src.to_string(),
 126                                                    cfg.clone(),
 127                                                    &sess.parse_sess)
 128             }
 129         }
 130     });
 131
 132     if sess.opts.debugging_opts & config::AST_JSON_NOEXPAND != 0 {
 133         let mut stdout = io::BufferedWriter::new(io::stdout());
 134         let mut json = json::PrettyEncoder::new(&mut stdout);
 135         // unwrapping so IoError isn't ignored
 136         krate.encode(&mut json).unwrap();
 137     }
 138
 139     if sess.show_span() {
 140         syntax::show_span::run(sess.diagnostic(), &krate);
 141     }
 142
 143     krate
 144 }
 145
 146 // For continuing compilation after a parsed crate has been
 147 // modified
 148
 149 /// Run the "early phases" of the compiler: initial `cfg` processing,
 150 /// loading compiler plugins (including those from `addl_plugins`),
 151 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
 152 /// harness if one is to be provided and injection of a dependency on the
 153 /// standard library and prelude.
 154 ///
 155 /// Returns `None` if we're aborting after handling -W help.
 156 pub fn phase_2_configure_and_expand(sess: &Session,
 157                                     mut krate: ast::Crate,
 158                                     crate_name: &str,
 159                                     addl_plugins: Option<Plugins>)
 160                                     -> Option<ast::Crate> {
 161     let time_passes = sess.time_passes();
 162
 163     *sess.crate_types.borrow_mut() =
 164         collect_crate_types(sess, krate.attrs.as_slice());
 165     *sess.crate_metadata.borrow_mut() =
 166         collect_crate_metadata(sess, krate.attrs.as_slice());
 167
 168     time(time_passes, "gated feature checking", (), |_| {
 169         let (features, unknown_features) =
 170             syntax::feature_gate::check_crate(&sess.parse_sess.span_diagnostic, &krate);
 171
 172         for uf in unknown_features.iter() {
 173             sess.add_lint(lint::builtin::UNKNOWN_FEATURES,
 174                           ast::CRATE_NODE_ID,
 175                           *uf,
 176                           "unknown feature".to_string());
 177         }
 178
 179         sess.abort_if_errors();
 180         *sess.features.borrow_mut() = features;
 181     });
 182
 183     time(time_passes, "recursion limit", (), |_| {
 184         middle::recursion_limit::update_recursion_limit(sess, &krate);
 185     });
 186
 187     // strip before expansion to allow macros to depend on
 188     // configuration variables e.g/ in
 189     //
 190     //   #[macro_escape] #[cfg(foo)]
 191     //   mod bar { macro_rules! baz!(() => {{}}) }
 192     //
 193     // baz! should not use this definition unless foo is enabled.
 194
 195     krate = time(time_passes, "configuration 1", krate, |krate|
 196                  syntax::config::strip_unconfigured_items(sess.diagnostic(), krate));
 197
 198     krate = time(time_passes, "crate injection", krate, |krate|
 199                  syntax::std_inject::maybe_inject_crates_ref(krate,
 200                                                              sess.opts.alt_std_name.clone()));
 201
 202     let mut addl_plugins = Some(addl_plugins);
 203     let Plugins { macros, registrars }
 204         = time(time_passes, "plugin loading", (), |_|
 205                plugin::load::load_plugins(sess, &krate, addl_plugins.take().unwrap()));
 206
 207     let mut registry = Registry::new(&krate);
 208
 209     time(time_passes, "plugin registration", (), |_| {
 210         if sess.features.borrow().rustc_diagnostic_macros {
 211             registry.register_macro("__diagnostic_used",
 212                 diagnostics::plugin::expand_diagnostic_used);
 213             registry.register_macro("__register_diagnostic",
 214                 diagnostics::plugin::expand_register_diagnostic);
 215             registry.register_macro("__build_diagnostic_array",
 216                 diagnostics::plugin::expand_build_diagnostic_array);
 217         }
 218
 219         for &registrar in registrars.iter() {
 220             registrar(&mut registry);
 221         }
 222     });
 223
 224     let Registry { syntax_exts, lint_passes, lint_groups, .. } = registry;
 225
 226     {
 227         let mut ls = sess.lint_store.borrow_mut();
 228         for pass in lint_passes.into_iter() {
 229             ls.register_pass(Some(sess), true, pass);
 230         }
 231
 232         for (name, to) in lint_groups.into_iter() {
 233             ls.register_group(Some(sess), true, name, to);
 234         }
 235     }
 236
 237     // Lint plugins are registered; now we can process command line flags.
 238     if sess.opts.describe_lints {
 239         super::describe_lints(&*sess.lint_store.borrow(), true);
 240         return None;
 241     }
 242     sess.lint_store.borrow_mut().process_command_line(sess);
 243
 244     // Abort if there are errors from lint processing or a plugin registrar.
 245     sess.abort_if_errors();
 246
 247     krate = time(time_passes, "expansion", (krate, macros, syntax_exts),
 248         |(krate, macros, syntax_exts)| {
 249             // Windows dlls do not have rpaths, so they don't know how to find their
 250             // dependencies. It's up to us to tell the system where to find all the
 251             // dependent dlls. Note that this uses cfg!(windows) as opposed to
 252             // targ_cfg because syntax extensions are always loaded for the host
 253             // compiler, not for the target.
 254             let mut _old_path = String::new();
 255             if cfg!(windows) {
 256                 _old_path = os::getenv("PATH").unwrap_or(_old_path);
 257                 let mut new_path = sess.host_filesearch().get_dylib_search_paths();
 258                 new_path.extend(os::split_paths(_old_path.as_slice()).into_iter());
 259                 os::setenv("PATH", os::join_paths(new_path.as_slice()).unwrap());
 260             }
 261             let cfg = syntax::ext::expand::ExpansionConfig {
 262                 crate_name: crate_name.to_string(),
 263                 deriving_hash_type_parameter: sess.features.borrow().default_type_params,
 264                 enable_quotes: sess.features.borrow().quote,
 265                 recursion_limit: sess.recursion_limit.get(),
 266             };
 267             let ret = syntax::ext::expand::expand_crate(&sess.parse_sess,
 268                                               cfg,
 269                                               macros,
 270                                               syntax_exts,
 271                                               krate);
 272             if cfg!(windows) {
 273                 os::setenv("PATH", _old_path);
 274             }
 275             ret
 276         }
 277     );
 278
 279     // JBC: make CFG processing part of expansion to avoid this problem:
 280
 281     // strip again, in case expansion added anything with a #[cfg].
 282     krate = time(time_passes, "configuration 2", krate, |krate|
 283                  syntax::config::strip_unconfigured_items(sess.diagnostic(), krate));
 284
 285     krate = time(time_passes, "maybe building test harness", krate, |krate|
 286                  syntax::test::modify_for_testing(&sess.parse_sess,
 287                                                   &sess.opts.cfg,
 288                                                   krate,
 289                                                   sess.diagnostic()));
 290
 291     krate = time(time_passes, "prelude injection", krate, |krate|
 292                  syntax::std_inject::maybe_inject_prelude(krate));
 293
 294     time(time_passes, "checking that all macro invocations are gone", &krate, |krate|
 295          syntax::ext::expand::check_for_macros(&sess.parse_sess, krate));
 296
 297     Some(krate)
 298 }
 299
 300 pub fn assign_node_ids_and_map<'ast>(sess: &Session,
 301                                      forest: &'ast mut ast_map::Forest)
 302                                      -> ast_map::Map<'ast> {
 303     struct NodeIdAssigner<'a> {
 304         sess: &'a Session
 305     }
 306
 307     impl<'a> ast_map::FoldOps for NodeIdAssigner<'a> {
 308         fn new_id(&self, old_id: ast::NodeId) -> ast::NodeId {
 309             assert_eq!(old_id, ast::DUMMY_NODE_ID);
 310             self.sess.next_node_id()
 311         }
 312     }
 313
 314     let map = time(sess.time_passes(), "assigning node ids and indexing ast", forest, |forest|
 315                    ast_map::map_crate(forest, NodeIdAssigner { sess: sess }));
 316
 317     if sess.opts.debugging_opts & config::AST_JSON != 0 {
 318         let mut stdout = io::BufferedWriter::new(io::stdout());
 319         let mut json = json::PrettyEncoder::new(&mut stdout);
 320         // unwrapping so IoError isn't ignored
 321         map.krate().encode(&mut json).unwrap();
 322     }
 323
 324     map
 325 }
 326
 327 /// Run the resolution, typechecking, region checking and other
 328 /// miscellaneous analysis passes on the crate. Return various
 329 /// structures carrying the results of the analysis.
 330 pub fn phase_3_run_analysis_passes<'tcx>(sess: Session,
 331                                          ast_map: ast_map::Map<'tcx>,
 332                                          type_arena: &'tcx TypedArena<ty::TyS<'tcx>>,
 333                                          name: String) -> ty::CrateAnalysis<'tcx> {
 334     let time_passes = sess.time_passes();
 335     let krate = ast_map.krate();
 336
 337     time(time_passes, "external crate/lib resolution", (), |_|
 338          creader::read_crates(&sess, krate));
 339
 340     let lang_items = time(time_passes, "language item collection", (), |_|
 341                           middle::lang_items::collect_language_items(krate, &sess));
 342
 343     let middle::resolve::CrateMap {
 344         def_map,
 345         freevars,
 346         capture_mode_map,
 347         exp_map2,
 348         trait_map,
 349         external_exports,
 350         last_private_map
 351     } =
 352         time(time_passes, "resolution", (), |_|
 353              middle::resolve::resolve_crate(&sess, &lang_items, krate));
 354
 355     // Discard MTWT tables that aren't required past resolution.
 356     syntax::ext::mtwt::clear_tables();
 357
 358     let named_region_map = time(time_passes, "lifetime resolution", (),
 359                                 |_| middle::resolve_lifetime::krate(&sess, krate, &def_map));
 360
 361     time(time_passes, "looking for entry point", (),
 362          |_| middle::entry::find_entry_point(&sess, &ast_map));
 363
 364     sess.plugin_registrar_fn.set(
 365         time(time_passes, "looking for plugin registrar", (), |_|
 366             plugin::build::find_plugin_registrar(
 367                 sess.diagnostic(), krate)));
 368
 369     let region_map = time(time_passes, "region resolution", (), |_|
 370                           middle::region::resolve_crate(&sess, krate));
 371
 372     time(time_passes, "loop checking", (), |_|
 373          middle::check_loop::check_crate(&sess, krate));
 374
 375     let stability_index = time(time_passes, "stability index", (), |_|
 376                                stability::Index::build(krate));
 377
 378     time(time_passes, "static item recursion checking", (), |_|
 379          middle::check_static_recursion::check_crate(&sess, krate, &def_map, &ast_map));
 380
 381     let ty_cx = ty::mk_ctxt(sess,
 382                             type_arena,
 383                             def_map,
 384                             named_region_map,
 385                             ast_map,
 386                             freevars,
 387                             capture_mode_map,
 388                             region_map,
 389                             lang_items,
 390                             stability_index);
 391
 392     // passes are timed inside typeck
 393     typeck::check_crate(&ty_cx, trait_map);
 394
 395     time(time_passes, "check static items", (), |_|
 396          middle::check_static::check_crate(&ty_cx));
 397
 398     // These next two const passes can probably be merged
 399     time(time_passes, "const marking", (), |_|
 400          middle::const_eval::process_crate(&ty_cx));
 401
 402     time(time_passes, "const checking", (), |_|
 403          middle::check_const::check_crate(&ty_cx));
 404
 405     let maps = (external_exports, last_private_map);
 406     let (exported_items, public_items) =
 407             time(time_passes, "privacy checking", maps, |(a, b)|
 408                  middle::privacy::check_crate(&ty_cx, &exp_map2, a, b));
 409
 410     time(time_passes, "intrinsic checking", (), |_|
 411          middle::intrinsicck::check_crate(&ty_cx));
 412
 413     time(time_passes, "effect checking", (), |_|
 414          middle::effect::check_crate(&ty_cx));
 415
 416     time(time_passes, "match checking", (), |_|
 417          middle::check_match::check_crate(&ty_cx));
 418
 419     time(time_passes, "liveness checking", (), |_|
 420          middle::liveness::check_crate(&ty_cx));
 421
 422     time(time_passes, "borrow checking", (), |_|
 423          middle::borrowck::check_crate(&ty_cx));
 424
 425     time(time_passes, "rvalue checking", (), |_|
 426          middle::check_rvalues::check_crate(&ty_cx, krate));
 427
 428     // Avoid overwhelming user with errors if type checking failed.
 429     // I'm not sure how helpful this is, to be honest, but it avoids a
 430     // lot of annoying errors in the compile-fail tests (basically,
 431     // lint warnings and so on -- kindck used to do this abort, but
 432     // kindck is gone now). -nmatsakis
 433     ty_cx.sess.abort_if_errors();
 434
 435     let reachable_map =
 436         time(time_passes, "reachability checking", (), |_|
 437              reachable::find_reachable(&ty_cx, &exported_items));
 438
 439     time(time_passes, "death checking", (), |_| {
 440         middle::dead::check_crate(&ty_cx,
 441                                   &exported_items,
 442                                   &reachable_map)
 443     });
 444
 445     time(time_passes, "lint checking", (), |_|
 446          lint::check_crate(&ty_cx, &exported_items));
 447
 448     ty::CrateAnalysis {
 449         exp_map2: exp_map2,
 450         ty_cx: ty_cx,
 451         exported_items: exported_items,
 452         public_items: public_items,
 453         reachable: reachable_map,
 454         name: name,
 455     }
 456 }
 457
 458 pub fn phase_save_analysis(sess: &Session,
 459                            krate: &ast::Crate,
 460                            analysis: &ty::CrateAnalysis,
 461                            odir: &Option<Path>) {
 462     if (sess.opts.debugging_opts & config::SAVE_ANALYSIS) == 0 {
 463         return;
 464     }
 465     time(sess.time_passes(), "save analysis", krate, |krate|
 466          save::process_crate(sess, krate, analysis, odir));
 467 }
 468
 469 /// Run the translation phase to LLVM, after which the AST and analysis can
 470 /// be discarded.
 471 pub fn phase_4_translate_to_llvm<'tcx>(analysis: ty::CrateAnalysis<'tcx>)
 472                                        -> (ty::ctxt<'tcx>, trans::CrateTranslation) {
 473     let time_passes = analysis.ty_cx.sess.time_passes();
 474
 475     time(time_passes, "resolving dependency formats", (), |_|
 476          dependency_format::calculate(&analysis.ty_cx));
 477
 478     // Option dance to work around the lack of stack once closures.
 479     time(time_passes, "translation", analysis, |analysis|
 480          trans::trans_crate(analysis))
 481 }
 482
 483 /// Run LLVM itself, producing a bitcode file, assembly file or object file
 484 /// as a side effect.
 485 pub fn phase_5_run_llvm_passes(sess: &Session,
 486                                trans: &trans::CrateTranslation,
 487                                outputs: &OutputFilenames) {
 488     if sess.opts.cg.no_integrated_as {
 489         let output_type = config::OutputTypeAssembly;
 490
 491         time(sess.time_passes(), "LLVM passes", (), |_|
 492             write::run_passes(sess, trans, &[output_type], outputs));
 493
 494         write::run_assembler(sess, outputs);
 495
 496         // Remove assembly source, unless --save-temps was specified
 497         if !sess.opts.cg.save_temps {
 498             fs::unlink(&outputs.temp_path(config::OutputTypeAssembly)).unwrap();
 499         }
 500     } else {
 501         time(sess.time_passes(), "LLVM passes", (), |_|
 502             write::run_passes(sess,
 503                               trans,
 504                               sess.opts.output_types.as_slice(),
 505                               outputs));
 506     }
 507
 508     sess.abort_if_errors();
 509 }
 510
 511 /// Run the linker on any artifacts that resulted from the LLVM run.
 512 /// This should produce either a finished executable or library.
 513 pub fn phase_6_link_output(sess: &Session,
 514                            trans: &trans::CrateTranslation,
 515                            outputs: &OutputFilenames) {
 516     let old_path = os::getenv("PATH").unwrap_or_else(||String::new());
 517     let mut new_path = sess.host_filesearch().get_tools_search_paths();
 518     new_path.extend(os::split_paths(old_path.as_slice()).into_iter());
 519     os::setenv("PATH", os::join_paths(new_path.as_slice()).unwrap());
 520
 521     time(sess.time_passes(), "linking", (), |_|
 522          link::link_binary(sess,
 523                            trans,
 524                            outputs,
 525                            trans.link.crate_name.as_slice()));
 526
 527     os::setenv("PATH", old_path);
 528 }
 529
 530 pub fn stop_after_phase_3(sess: &Session) -> bool {
 531    if sess.opts.no_trans {
 532         debug!("invoked with --no-trans, returning early from compile_input");
 533         return true;
 534     }
 535     return false;
 536 }
 537
 538 pub fn stop_after_phase_1(sess: &Session) -> bool {
 539     if sess.opts.parse_only {
 540         debug!("invoked with --parse-only, returning early from compile_input");
 541         return true;
 542     }
 543     if sess.show_span() {
 544         return true;
 545     }
 546     return sess.opts.debugging_opts & config::AST_JSON_NOEXPAND != 0;
 547 }
 548
 549 pub fn stop_after_phase_2(sess: &Session) -> bool {
 550     if sess.opts.no_analysis {
 551         debug!("invoked with --no-analysis, returning early from compile_input");
 552         return true;
 553     }
 554     return sess.opts.debugging_opts & config::AST_JSON != 0;
 555 }
 556
 557 pub fn stop_after_phase_5(sess: &Session) -> bool {
 558     if !sess.opts.output_types.iter().any(|&i| i == config::OutputTypeExe) {
 559         debug!("not building executable, returning early from compile_input");
 560         return true;
 561     }
 562     return false;
 563 }
 564
 565 fn escape_dep_filename(filename: &str) -> String {
 566     // Apparently clang and gcc *only* escape spaces:
 567     // http://llvm.org/klaus/clang/commit/9d50634cfc268ecc9a7250226dd5ca0e945240d4
 568     filename.replace(" ", "\\ ")
 569 }
 570
 571 fn write_out_deps(sess: &Session,
 572                   input: &Input,
 573                   outputs: &OutputFilenames,
 574                   id: &str) {
 575
 576     let mut out_filenames = Vec::new();
 577     for output_type in sess.opts.output_types.iter() {
 578         let file = outputs.path(*output_type);
 579         match *output_type {
 580             config::OutputTypeExe => {
 581                 for output in sess.crate_types.borrow().iter() {
 582                     let p = link::filename_for_input(sess, *output,
 583                                                      id, &file);
 584                     out_filenames.push(p);
 585                 }
 586             }
 587             _ => { out_filenames.push(file); }
 588         }
 589     }
 590
 591     // Write out dependency rules to the dep-info file if requested with
 592     // --dep-info
 593     let deps_filename = match sess.opts.write_dependency_info {
 594         // Use filename from --dep-file argument if given
 595         (true, Some(ref filename)) => filename.clone(),
 596         // Use default filename: crate source filename with extension replaced
 597         // by ".d"
 598         (true, None) => match *input {
 599             Input::File(..) => outputs.with_extension("d"),
 600             Input::Str(..) => {
 601                 sess.warn("can not write --dep-info without a filename \
 602                            when compiling stdin.");
 603                 return
 604             },
 605         },
 606         _ => return,
 607     };
 608
 609     let result = (|| -> io::IoResult<()> {
 610         // Build a list of files used to compile the output and
 611         // write Makefile-compatible dependency rules
 612         let files: Vec<String> = sess.codemap().files.borrow()
 613                                    .iter().filter(|fmap| fmap.is_real_file())
 614                                    .map(|fmap| escape_dep_filename(fmap.name.as_slice()))
 615                                    .collect();
 616         let mut file = try!(io::File::create(&deps_filename));
 617         for path in out_filenames.iter() {
 618             try!(write!(&mut file as &mut Writer,
 619                           "{}: {}\n\n", path.display(), files.connect(" ")));
 620         }
 621         Ok(())
 622     })();
 623
 624     match result {
 625         Ok(()) => {}
 626         Err(e) => {
 627             sess.fatal(format!("error writing dependencies to `{}`: {}",
 628                                deps_filename.display(), e).as_slice());
 629         }
 630     }
 631 }
 632
 633 pub fn collect_crate_types(session: &Session,
 634                            attrs: &[ast::Attribute]) -> Vec<config::CrateType> {
 635     // Unconditionally collect crate types from attributes to make them used
 636     let attr_types: Vec<config::CrateType> = attrs.iter().filter_map(|a| {
 637         if a.check_name("crate_type") {
 638             match a.value_str() {
 639                 Some(ref n) if *n == "rlib" => {
 640                     Some(config::CrateTypeRlib)
 641                 }
 642                 Some(ref n) if *n == "dylib" => {
 643                     Some(config::CrateTypeDylib)
 644                 }
 645                 Some(ref n) if *n == "lib" => {
 646                     Some(config::default_lib_output())
 647                 }
 648                 Some(ref n) if *n == "staticlib" => {
 649                     Some(config::CrateTypeStaticlib)
 650                 }
 651                 Some(ref n) if *n == "bin" => Some(config::CrateTypeExecutable),
 652                 Some(_) => {
 653                     session.add_lint(lint::builtin::UNKNOWN_CRATE_TYPES,
 654                                      ast::CRATE_NODE_ID,
 655                                      a.span,
 656                                      "invalid `crate_type` \
 657                                       value".to_string());
 658                     None
 659                 }
 660                 _ => {
 661                     session.add_lint(lint::builtin::UNKNOWN_CRATE_TYPES,
 662                                      ast::CRATE_NODE_ID,
 663                                      a.span,
 664                                      "`crate_type` requires a \
 665                                       value".to_string());
 666                     None
 667                 }
 668             }
 669         } else {
 670             None
 671         }
 672     }).collect();
 673
 674     // If we're generating a test executable, then ignore all other output
 675     // styles at all other locations
 676     if session.opts.test {
 677         return vec!(config::CrateTypeExecutable)
 678     }
 679
 680     // Only check command line flags if present. If no types are specified by
 681     // command line, then reuse the empty `base` Vec to hold the types that
 682     // will be found in crate attributes.
 683     let mut base = session.opts.crate_types.clone();
 684     if base.len() == 0 {
 685         base.extend(attr_types.into_iter());
 686         if base.len() == 0 {
 687             base.push(link::default_output_for_target(session));
 688         }
 689         base.sort();
 690         base.dedup();
 691     }
 692
 693     base.into_iter().filter(|crate_type| {
 694         let res = !link::invalid_output_for_target(session, *crate_type);
 695
 696         if !res {
 697             session.warn(format!("dropping unsupported crate type `{}` \
 698                                    for target `{}`",
 699                                  *crate_type, session.opts.target_triple).as_slice());
 700         }
 701
 702         res
 703     }).collect()
 704 }
 705
 706 pub fn collect_crate_metadata(session: &Session,
 707                               _attrs: &[ast::Attribute]) -> Vec<String> {
 708     session.opts.cg.metadata.clone()
 709 }
 710
 711 pub fn build_output_filenames(input: &Input,
 712                               odir: &Option<Path>,
 713                               ofile: &Option<Path>,
 714                               attrs: &[ast::Attribute],
 715                               sess: &Session)
 716                            -> OutputFilenames {
 717     match *ofile {
 718         None => {
 719             // "-" as input file will cause the parser to read from stdin so we
 720             // have to make up a name
 721             // We want to toss everything after the final '.'
 722             let dirpath = match *odir {
 723                 Some(ref d) => d.clone(),
 724                 None => Path::new(".")
 725             };
 726
 727             // If a crate name is present, we use it as the link name
 728             let stem = sess.opts.crate_name.clone().or_else(|| {
 729                 attr::find_crate_name(attrs).map(|n| n.get().to_string())
 730             }).unwrap_or(input.filestem());
 731
 732             OutputFilenames {
 733                 out_directory: dirpath,
 734                 out_filestem: stem,
 735                 single_output_file: None,
 736                 extra: sess.opts.cg.extra_filename.clone(),
 737             }
 738         }
 739
 740         Some(ref out_file) => {
 741             let ofile = if sess.opts.output_types.len() > 1 {
 742                 sess.warn("ignoring specified output filename because multiple \
 743                            outputs were requested");
 744                 None
 745             } else {
 746                 Some(out_file.clone())
 747             };
 748             if *odir != None {
 749                 sess.warn("ignoring --out-dir flag due to -o flag.");
 750             }
 751             OutputFilenames {
 752                 out_directory: out_file.dir_path(),
 753                 out_filestem: out_file.filestem_str().unwrap().to_string(),
 754                 single_output_file: ofile,
 755                 extra: sess.opts.cg.extra_filename.clone(),
 756             }
 757         }
 758     }
 759 }