src/bootstrap/builder.rs

   1 use std::any::Any;
   2 use std::cell::{Cell, RefCell};
   3 use std::collections::BTreeSet;
   4 use std::collections::HashMap;
   5 use std::env;
   6 use std::fmt::Debug;
   7 use std::fs;
   8 use std::hash::Hash;
   9 use std::ops::Deref;
  10 use std::path::{Path, PathBuf};
  11 use std::process::Command;
  12 use std::time::{Duration, Instant};
  13
  14 use build_helper::t;
  15
  16 use crate::cache::{Cache, Interned, INTERNER};
  17 use crate::check;
  18 use crate::compile;
  19 use crate::dist;
  20 use crate::doc;
  21 use crate::flags::Subcommand;
  22 use crate::install;
  23 use crate::native;
  24 use crate::test;
  25 use crate::tool;
  26 use crate::util::{self, add_lib_path, exe, libdir};
  27 use crate::{Build, DocTests, Mode, GitRepo};
  28
  29 pub use crate::Compiler;
  30
  31 use petgraph::graph::NodeIndex;
  32 use petgraph::Graph;
  33
  34 pub struct Builder<'a> {
  35     pub build: &'a Build,
  36     pub top_stage: u32,
  37     pub kind: Kind,
  38     cache: Cache,
  39     stack: RefCell<Vec<Box<dyn Any>>>,
  40     time_spent_on_dependencies: Cell<Duration>,
  41     pub paths: Vec<PathBuf>,
  42     graph_nodes: RefCell<HashMap<String, NodeIndex>>,
  43     graph: RefCell<Graph<String, bool>>,
  44     parent: Cell<Option<NodeIndex>>,
  45 }
  46
  47 impl<'a> Deref for Builder<'a> {
  48     type Target = Build;
  49
  50     fn deref(&self) -> &Self::Target {
  51         self.build
  52     }
  53 }
  54
  55 pub trait Step: 'static + Clone + Debug + PartialEq + Eq + Hash {
  56     /// `PathBuf` when directories are created or to return a `Compiler` once
  57     /// it's been assembled.
  58     type Output: Clone;
  59
  60     const DEFAULT: bool = false;
  61
  62     /// If true, then this rule should be skipped if --target was specified, but --host was not
  63     const ONLY_HOSTS: bool = false;
  64
  65     /// Primary function to execute this rule. Can call `builder.ensure()`
  66     /// with other steps to run those.
  67     fn run(self, builder: &Builder<'_>) -> Self::Output;
  68
  69     /// When bootstrap is passed a set of paths, this controls whether this rule
  70     /// will execute. However, it does not get called in a "default" context
  71     /// when we are not passed any paths; in that case, `make_run` is called
  72     /// directly.
  73     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_>;
  74
  75     /// Builds up a "root" rule, either as a default rule or from a path passed
  76     /// to us.
  77     ///
  78     /// When path is `None`, we are executing in a context where no paths were
  79     /// passed. When `./x.py build` is run, for example, this rule could get
  80     /// called if it is in the correct list below with a path of `None`.
  81     fn make_run(_run: RunConfig<'_>) {
  82         // It is reasonable to not have an implementation of make_run for rules
  83         // who do not want to get called from the root context. This means that
  84         // they are likely dependencies (e.g., sysroot creation) or similar, and
  85         // as such calling them from ./x.py isn't logical.
  86         unimplemented!()
  87     }
  88 }
  89
  90 pub struct RunConfig<'a> {
  91     pub builder: &'a Builder<'a>,
  92     pub host: Interned<String>,
  93     pub target: Interned<String>,
  94     pub path: PathBuf,
  95 }
  96
  97 struct StepDescription {
  98     default: bool,
  99     only_hosts: bool,
 100     should_run: fn(ShouldRun<'_>) -> ShouldRun<'_>,
 101     make_run: fn(RunConfig<'_>),
 102     name: &'static str,
 103 }
 104
 105 #[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq)]
 106 pub enum PathSet {
 107     Set(BTreeSet<PathBuf>),
 108     Suite(PathBuf),
 109 }
 110
 111 impl PathSet {
 112     fn empty() -> PathSet {
 113         PathSet::Set(BTreeSet::new())
 114     }
 115
 116     fn one<P: Into<PathBuf>>(path: P) -> PathSet {
 117         let mut set = BTreeSet::new();
 118         set.insert(path.into());
 119         PathSet::Set(set)
 120     }
 121
 122     fn has(&self, needle: &Path) -> bool {
 123         match self {
 124             PathSet::Set(set) => set.iter().any(|p| p.ends_with(needle)),
 125             PathSet::Suite(suite) => suite.ends_with(needle),
 126         }
 127     }
 128
 129     fn path(&self, builder: &Builder<'_>) -> PathBuf {
 130         match self {
 131             PathSet::Set(set) => set
 132                 .iter()
 133                 .next()
 134                 .unwrap_or(&builder.build.src)
 135                 .to_path_buf(),
 136             PathSet::Suite(path) => PathBuf::from(path),
 137         }
 138     }
 139 }
 140
 141 impl StepDescription {
 142     fn from<S: Step>() -> StepDescription {
 143         StepDescription {
 144             default: S::DEFAULT,
 145             only_hosts: S::ONLY_HOSTS,
 146             should_run: S::should_run,
 147             make_run: S::make_run,
 148             name: unsafe { ::std::intrinsics::type_name::<S>() },
 149         }
 150     }
 151
 152     fn maybe_run(&self, builder: &Builder<'_>, pathset: &PathSet) {
 153         if builder.config.exclude.iter().any(|e| pathset.has(e)) {
 154             eprintln!("Skipping {:?} because it is excluded", pathset);
 155             return;
 156         } else if !builder.config.exclude.is_empty() {
 157             eprintln!(
 158                 "{:?} not skipped for {:?} -- not in {:?}",
 159                 pathset, self.name, builder.config.exclude
 160             );
 161         }
 162         let hosts = &builder.hosts;
 163
 164         // Determine the targets participating in this rule.
 165         let targets = if self.only_hosts {
 166             if builder.config.skip_only_host_steps {
 167                 return; // don't run anything
 168             } else {
 169                 &builder.hosts
 170             }
 171         } else {
 172             &builder.targets
 173         };
 174
 175         for host in hosts {
 176             for target in targets {
 177                 let run = RunConfig {
 178                     builder,
 179                     path: pathset.path(builder),
 180                     host: *host,
 181                     target: *target,
 182                 };
 183                 (self.make_run)(run);
 184             }
 185         }
 186     }
 187
 188     fn run(v: &[StepDescription], builder: &Builder<'_>, paths: &[PathBuf]) {
 189         let should_runs = v
 190             .iter()
 191             .map(|desc| (desc.should_run)(ShouldRun::new(builder)))
 192             .collect::<Vec<_>>();
 193
 194         // sanity checks on rules
 195         for (desc, should_run) in v.iter().zip(&should_runs) {
 196             assert!(
 197                 !should_run.paths.is_empty(),
 198                 "{:?} should have at least one pathset",
 199                 desc.name
 200             );
 201         }
 202
 203         if paths.is_empty() {
 204             for (desc, should_run) in v.iter().zip(should_runs) {
 205                 if desc.default && should_run.is_really_default {
 206                     for pathset in &should_run.paths {
 207                         desc.maybe_run(builder, pathset);
 208                     }
 209                 }
 210             }
 211         } else {
 212             for path in paths {
 213                 // strip CurDir prefix if present
 214                 let path = match path.strip_prefix(".") {
 215                     Ok(p) => p,
 216                     Err(_) => path,
 217                 };
 218
 219                 let mut attempted_run = false;
 220                 for (desc, should_run) in v.iter().zip(&should_runs) {
 221                     if let Some(suite) = should_run.is_suite_path(path) {
 222                         attempted_run = true;
 223                         desc.maybe_run(builder, suite);
 224                     } else if let Some(pathset) = should_run.pathset_for_path(path) {
 225                         attempted_run = true;
 226                         desc.maybe_run(builder, pathset);
 227                     }
 228                 }
 229
 230                 if !attempted_run {
 231                     panic!("Error: no rules matched {}.", path.display());
 232                 }
 233             }
 234         }
 235     }
 236 }
 237
 238 #[derive(Clone)]
 239 pub struct ShouldRun<'a> {
 240     pub builder: &'a Builder<'a>,
 241     // use a BTreeSet to maintain sort order
 242     paths: BTreeSet<PathSet>,
 243
 244     // If this is a default rule, this is an additional constraint placed on
 245     // its run. Generally something like compiler docs being enabled.
 246     is_really_default: bool,
 247 }
 248
 249 impl<'a> ShouldRun<'a> {
 250     fn new(builder: &'a Builder<'_>) -> ShouldRun<'a> {
 251         ShouldRun {
 252             builder,
 253             paths: BTreeSet::new(),
 254             is_really_default: true, // by default no additional conditions
 255         }
 256     }
 257
 258     pub fn default_condition(mut self, cond: bool) -> Self {
 259         self.is_really_default = cond;
 260         self
 261     }
 262
 263     // Unlike `krate` this will create just one pathset. As such, it probably shouldn't actually
 264     // ever be used, but as we transition to having all rules properly handle passing krate(...) by
 265     // actually doing something different for every crate passed.
 266     pub fn all_krates(mut self, name: &str) -> Self {
 267         let mut set = BTreeSet::new();
 268         for krate in self.builder.in_tree_crates(name) {
 269             set.insert(PathBuf::from(&krate.path));
 270         }
 271         self.paths.insert(PathSet::Set(set));
 272         self
 273     }
 274
 275     pub fn krate(mut self, name: &str) -> Self {
 276         for krate in self.builder.in_tree_crates(name) {
 277             self.paths.insert(PathSet::one(&krate.path));
 278         }
 279         self
 280     }
 281
 282     // single, non-aliased path
 283     pub fn path(self, path: &str) -> Self {
 284         self.paths(&[path])
 285     }
 286
 287     // multiple aliases for the same job
 288     pub fn paths(mut self, paths: &[&str]) -> Self {
 289         self.paths
 290             .insert(PathSet::Set(paths.iter().map(PathBuf::from).collect()));
 291         self
 292     }
 293
 294     pub fn is_suite_path(&self, path: &Path) -> Option<&PathSet> {
 295         self.paths.iter().find(|pathset| match pathset {
 296             PathSet::Suite(p) => path.starts_with(p),
 297             PathSet::Set(_) => false,
 298         })
 299     }
 300
 301     pub fn suite_path(mut self, suite: &str) -> Self {
 302         self.paths.insert(PathSet::Suite(PathBuf::from(suite)));
 303         self
 304     }
 305
 306     // allows being more explicit about why should_run in Step returns the value passed to it
 307     pub fn never(mut self) -> ShouldRun<'a> {
 308         self.paths.insert(PathSet::empty());
 309         self
 310     }
 311
 312     fn pathset_for_path(&self, path: &Path) -> Option<&PathSet> {
 313         self.paths.iter().find(|pathset| pathset.has(path))
 314     }
 315 }
 316
 317 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 318 pub enum Kind {
 319     Build,
 320     Check,
 321     Clippy,
 322     Fix,
 323     Test,
 324     Bench,
 325     Dist,
 326     Doc,
 327     Install,
 328 }
 329
 330 impl<'a> Builder<'a> {
 331     fn get_step_descriptions(kind: Kind) -> Vec<StepDescription> {
 332         macro_rules! describe {
 333             ($($rule:ty),+ $(,)?) => {{
 334                 vec![$(StepDescription::from::<$rule>()),+]
 335             }};
 336         }
 337         match kind {
 338             Kind::Build => describe!(
 339                 compile::Std,
 340                 compile::Test,
 341                 compile::Rustc,
 342                 compile::CodegenBackend,
 343                 compile::StartupObjects,
 344                 tool::BuildManifest,
 345                 tool::Rustbook,
 346                 tool::ErrorIndex,
 347                 tool::UnstableBookGen,
 348                 tool::Tidy,
 349                 tool::Linkchecker,
 350                 tool::CargoTest,
 351                 tool::Compiletest,
 352                 tool::RemoteTestServer,
 353                 tool::RemoteTestClient,
 354                 tool::RustInstaller,
 355                 tool::Cargo,
 356                 tool::Rls,
 357                 tool::Rustdoc,
 358                 tool::Clippy,
 359                 native::Llvm,
 360                 tool::Rustfmt,
 361                 tool::Miri,
 362                 native::Lld
 363             ),
 364             Kind::Check | Kind::Clippy | Kind::Fix => describe!(
 365                 check::Std,
 366                 check::Test,
 367                 check::Rustc,
 368                 check::CodegenBackend,
 369                 check::Rustdoc
 370             ),
 371             Kind::Test => describe!(
 372                 test::Tidy,
 373                 test::Ui,
 374                 test::CompileFail,
 375                 test::RunFail,
 376                 test::RunPassValgrind,
 377                 test::MirOpt,
 378                 test::Codegen,
 379                 test::CodegenUnits,
 380                 test::Assembly,
 381                 test::Incremental,
 382                 test::Debuginfo,
 383                 test::UiFullDeps,
 384                 test::Rustdoc,
 385                 test::Pretty,
 386                 test::RunFailPretty,
 387                 test::RunPassValgrindPretty,
 388                 test::Crate,
 389                 test::CrateLibrustc,
 390                 test::CrateRustdoc,
 391                 test::Linkcheck,
 392                 test::Cargotest,
 393                 test::Cargo,
 394                 test::Rls,
 395                 test::ErrorIndex,
 396                 test::Distcheck,
 397                 test::RunMakeFullDeps,
 398                 test::Nomicon,
 399                 test::Reference,
 400                 test::RustdocBook,
 401                 test::RustByExample,
 402                 test::TheBook,
 403                 test::UnstableBook,
 404                 test::RustcBook,
 405                 test::RustcGuide,
 406                 test::EmbeddedBook,
 407                 test::EditionGuide,
 408                 test::Rustfmt,
 409                 test::Miri,
 410                 test::Clippy,
 411                 test::CompiletestTest,
 412                 test::RustdocJSStd,
 413                 test::RustdocJSNotStd,
 414                 test::RustdocTheme,
 415                 test::RustdocUi,
 416                 // Run bootstrap close to the end as it's unlikely to fail
 417                 test::Bootstrap,
 418                 // Run run-make last, since these won't pass without make on Windows
 419                 test::RunMake,
 420             ),
 421             Kind::Bench => describe!(test::Crate, test::CrateLibrustc),
 422             Kind::Doc => describe!(
 423                 doc::UnstableBook,
 424                 doc::UnstableBookGen,
 425                 doc::TheBook,
 426                 doc::Standalone,
 427                 doc::Std,
 428                 doc::Test,
 429                 doc::WhitelistedRustc,
 430                 doc::Rustc,
 431                 doc::Rustdoc,
 432                 doc::ErrorIndex,
 433                 doc::Nomicon,
 434                 doc::Reference,
 435                 doc::RustdocBook,
 436                 doc::RustByExample,
 437                 doc::RustcBook,
 438                 doc::CargoBook,
 439                 doc::EmbeddedBook,
 440                 doc::EditionGuide,
 441             ),
 442             Kind::Dist => describe!(
 443                 dist::Docs,
 444                 dist::RustcDocs,
 445                 dist::Mingw,
 446                 dist::Rustc,
 447                 dist::DebuggerScripts,
 448                 dist::Std,
 449                 dist::Analysis,
 450                 dist::Src,
 451                 dist::PlainSourceTarball,
 452                 dist::Cargo,
 453                 dist::Rls,
 454                 dist::Rustfmt,
 455                 dist::Clippy,
 456                 dist::Miri,
 457                 dist::LlvmTools,
 458                 dist::Lldb,
 459                 dist::Extended,
 460                 dist::HashSign
 461             ),
 462             Kind::Install => describe!(
 463                 install::Docs,
 464                 install::Std,
 465                 install::Cargo,
 466                 install::Rls,
 467                 install::Rustfmt,
 468                 install::Clippy,
 469                 install::Miri,
 470                 install::Analysis,
 471                 install::Src,
 472                 install::Rustc
 473             ),
 474         }
 475     }
 476
 477     pub fn get_help(build: &Build, subcommand: &str) -> Option<String> {
 478         let kind = match subcommand {
 479             "build" => Kind::Build,
 480             "doc" => Kind::Doc,
 481             "test" => Kind::Test,
 482             "bench" => Kind::Bench,
 483             "dist" => Kind::Dist,
 484             "install" => Kind::Install,
 485             _ => return None,
 486         };
 487
 488         let builder = Builder {
 489             build,
 490             top_stage: build.config.stage.unwrap_or(2),
 491             kind,
 492             cache: Cache::new(),
 493             stack: RefCell::new(Vec::new()),
 494             time_spent_on_dependencies: Cell::new(Duration::new(0, 0)),
 495             paths: vec![],
 496             graph_nodes: RefCell::new(HashMap::new()),
 497             graph: RefCell::new(Graph::new()),
 498             parent: Cell::new(None),
 499         };
 500
 501         let builder = &builder;
 502         let mut should_run = ShouldRun::new(builder);
 503         for desc in Builder::get_step_descriptions(builder.kind) {
 504             should_run = (desc.should_run)(should_run);
 505         }
 506         let mut help = String::from("Available paths:\n");
 507         for pathset in should_run.paths {
 508             if let PathSet::Set(set) = pathset {
 509                 set.iter().for_each(|path| {
 510                     help.push_str(
 511                         format!("    ./x.py {} {}\n", subcommand, path.display()).as_str(),
 512                     )
 513                 })
 514             }
 515         }
 516         Some(help)
 517     }
 518
 519     pub fn new(build: &Build) -> Builder<'_> {
 520         let (kind, paths) = match build.config.cmd {
 521             Subcommand::Build { ref paths } => (Kind::Build, &paths[..]),
 522             Subcommand::Check { ref paths } => (Kind::Check, &paths[..]),
 523             Subcommand::Clippy { ref paths } => (Kind::Clippy, &paths[..]),
 524             Subcommand::Fix { ref paths } => (Kind::Fix, &paths[..]),
 525             Subcommand::Doc { ref paths } => (Kind::Doc, &paths[..]),
 526             Subcommand::Test { ref paths, .. } => (Kind::Test, &paths[..]),
 527             Subcommand::Bench { ref paths, .. } => (Kind::Bench, &paths[..]),
 528             Subcommand::Dist { ref paths } => (Kind::Dist, &paths[..]),
 529             Subcommand::Install { ref paths } => (Kind::Install, &paths[..]),
 530             Subcommand::Clean { .. } => panic!(),
 531         };
 532
 533         let builder = Builder {
 534             build,
 535             top_stage: build.config.stage.unwrap_or(2),
 536             kind,
 537             cache: Cache::new(),
 538             stack: RefCell::new(Vec::new()),
 539             time_spent_on_dependencies: Cell::new(Duration::new(0, 0)),
 540             paths: paths.to_owned(),
 541             graph_nodes: RefCell::new(HashMap::new()),
 542             graph: RefCell::new(Graph::new()),
 543             parent: Cell::new(None),
 544         };
 545
 546         builder
 547     }
 548
 549     pub fn execute_cli(&self) -> Graph<String, bool> {
 550         self.run_step_descriptions(&Builder::get_step_descriptions(self.kind), &self.paths);
 551         self.graph.borrow().clone()
 552     }
 553
 554     pub fn default_doc(&self, paths: Option<&[PathBuf]>) {
 555         let paths = paths.unwrap_or(&[]);
 556         self.run_step_descriptions(&Builder::get_step_descriptions(Kind::Doc), paths);
 557     }
 558
 559     fn run_step_descriptions(&self, v: &[StepDescription], paths: &[PathBuf]) {
 560         StepDescription::run(v, self, paths);
 561     }
 562
 563     /// Obtain a compiler at a given stage and for a given host. Explicitly does
 564     /// not take `Compiler` since all `Compiler` instances are meant to be
 565     /// obtained through this function, since it ensures that they are valid
 566     /// (i.e., built and assembled).
 567     pub fn compiler(&self, stage: u32, host: Interned<String>) -> Compiler {
 568         self.ensure(compile::Assemble {
 569             target_compiler: Compiler { stage, host },
 570         })
 571     }
 572
 573     /// Similar to `compiler`, except handles the full-bootstrap option to
 574     /// silently use the stage1 compiler instead of a stage2 compiler if one is
 575     /// requested.
 576     ///
 577     /// Note that this does *not* have the side effect of creating
 578     /// `compiler(stage, host)`, unlike `compiler` above which does have such
 579     /// a side effect. The returned compiler here can only be used to compile
 580     /// new artifacts, it can't be used to rely on the presence of a particular
 581     /// sysroot.
 582     ///
 583     /// See `force_use_stage1` for documentation on what each argument is.
 584     pub fn compiler_for(
 585         &self,
 586         stage: u32,
 587         host: Interned<String>,
 588         target: Interned<String>,
 589     ) -> Compiler {
 590         if self.build.force_use_stage1(Compiler { stage, host }, target) {
 591             self.compiler(1, self.config.build)
 592         } else {
 593             self.compiler(stage, host)
 594         }
 595     }
 596
 597     pub fn sysroot(&self, compiler: Compiler) -> Interned<PathBuf> {
 598         self.ensure(compile::Sysroot { compiler })
 599     }
 600
 601     /// Returns the libdir where the standard library and other artifacts are
 602     /// found for a compiler's sysroot.
 603     pub fn sysroot_libdir(
 604         &self,
 605         compiler: Compiler,
 606         target: Interned<String>,
 607     ) -> Interned<PathBuf> {
 608         #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 609         struct Libdir {
 610             compiler: Compiler,
 611             target: Interned<String>,
 612         }
 613         impl Step for Libdir {
 614             type Output = Interned<PathBuf>;
 615
 616             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 617                 run.never()
 618             }
 619
 620             fn run(self, builder: &Builder<'_>) -> Interned<PathBuf> {
 621                 let compiler = self.compiler;
 622                 let config = &builder.build.config;
 623                 let lib = if compiler.stage >= 1 && config.libdir_relative().is_some() {
 624                     builder.build.config.libdir_relative().unwrap()
 625                 } else {
 626                     Path::new("lib")
 627                 };
 628                 let sysroot = builder
 629                     .sysroot(self.compiler)
 630                     .join(lib)
 631                     .join("rustlib")
 632                     .join(self.target)
 633                     .join("lib");
 634                 let _ = fs::remove_dir_all(&sysroot);
 635                 t!(fs::create_dir_all(&sysroot));
 636                 INTERNER.intern_path(sysroot)
 637             }
 638         }
 639         self.ensure(Libdir { compiler, target })
 640     }
 641
 642     pub fn sysroot_codegen_backends(&self, compiler: Compiler) -> PathBuf {
 643         self.sysroot_libdir(compiler, compiler.host)
 644             .with_file_name(self.config.rust_codegen_backends_dir.clone())
 645     }
 646
 647     /// Returns the compiler's libdir where it stores the dynamic libraries that
 648     /// it itself links against.
 649     ///
 650     /// For example this returns `<sysroot>/lib` on Unix and `<sysroot>/bin` on
 651     /// Windows.
 652     pub fn rustc_libdir(&self, compiler: Compiler) -> PathBuf {
 653         if compiler.is_snapshot(self) {
 654             self.rustc_snapshot_libdir()
 655         } else {
 656             match self.config.libdir_relative() {
 657                 Some(relative_libdir) if compiler.stage >= 1
 658                     => self.sysroot(compiler).join(relative_libdir),
 659                 _ => self.sysroot(compiler).join(libdir(&compiler.host))
 660             }
 661         }
 662     }
 663
 664     /// Returns the compiler's relative libdir where it stores the dynamic libraries that
 665     /// it itself links against.
 666     ///
 667     /// For example this returns `lib` on Unix and `bin` on
 668     /// Windows.
 669     pub fn libdir_relative(&self, compiler: Compiler) -> &Path {
 670         if compiler.is_snapshot(self) {
 671             libdir(&self.config.build).as_ref()
 672         } else {
 673             match self.config.libdir_relative() {
 674                 Some(relative_libdir) if compiler.stage >= 1
 675                     => relative_libdir,
 676                 _ => libdir(&compiler.host).as_ref()
 677             }
 678         }
 679     }
 680
 681     /// Adds the compiler's directory of dynamic libraries to `cmd`'s dynamic
 682     /// library lookup path.
 683     pub fn add_rustc_lib_path(&self, compiler: Compiler, cmd: &mut Command) {
 684         // Windows doesn't need dylib path munging because the dlls for the
 685         // compiler live next to the compiler and the system will find them
 686         // automatically.
 687         if cfg!(windows) {
 688             return;
 689         }
 690
 691         add_lib_path(vec![self.rustc_libdir(compiler)], cmd);
 692     }
 693
 694     /// Gets a path to the compiler specified.
 695     pub fn rustc(&self, compiler: Compiler) -> PathBuf {
 696         if compiler.is_snapshot(self) {
 697             self.initial_rustc.clone()
 698         } else {
 699             self.sysroot(compiler)
 700                 .join("bin")
 701                 .join(exe("rustc", &compiler.host))
 702         }
 703     }
 704
 705     /// Gets the paths to all of the compiler's codegen backends.
 706     fn codegen_backends(&self, compiler: Compiler) -> impl Iterator<Item = PathBuf> {
 707         fs::read_dir(self.sysroot_codegen_backends(compiler))
 708             .into_iter()
 709             .flatten()
 710             .filter_map(Result::ok)
 711             .map(|entry| entry.path())
 712     }
 713
 714     pub fn rustdoc(&self, compiler: Compiler) -> PathBuf {
 715         self.ensure(tool::Rustdoc { compiler })
 716     }
 717
 718     pub fn rustdoc_cmd(&self, compiler: Compiler) -> Command {
 719         let mut cmd = Command::new(&self.out.join("bootstrap/debug/rustdoc"));
 720         cmd.env("RUSTC_STAGE", compiler.stage.to_string())
 721             .env("RUSTC_SYSROOT", self.sysroot(compiler))
 722             // Note that this is *not* the sysroot_libdir because rustdoc must be linked
 723             // equivalently to rustc.
 724             .env("RUSTDOC_LIBDIR", self.rustc_libdir(compiler))
 725             .env("CFG_RELEASE_CHANNEL", &self.config.channel)
 726             .env("RUSTDOC_REAL", self.rustdoc(compiler))
 727             .env("RUSTDOC_CRATE_VERSION", self.rust_version())
 728             .env("RUSTC_BOOTSTRAP", "1");
 729
 730         // Remove make-related flags that can cause jobserver problems.
 731         cmd.env_remove("MAKEFLAGS");
 732         cmd.env_remove("MFLAGS");
 733
 734         if let Some(linker) = self.linker(compiler.host) {
 735             cmd.env("RUSTC_TARGET_LINKER", linker);
 736         }
 737         cmd
 738     }
 739
 740     /// Prepares an invocation of `cargo` to be run.
 741     ///
 742     /// This will create a `Command` that represents a pending execution of
 743     /// Cargo. This cargo will be configured to use `compiler` as the actual
 744     /// rustc compiler, its output will be scoped by `mode`'s output directory,
 745     /// it will pass the `--target` flag for the specified `target`, and will be
 746     /// executing the Cargo command `cmd`.
 747     pub fn cargo(
 748         &self,
 749         compiler: Compiler,
 750         mode: Mode,
 751         target: Interned<String>,
 752         cmd: &str,
 753     ) -> Command {
 754         let mut cargo = Command::new(&self.initial_cargo);
 755         let out_dir = self.stage_out(compiler, mode);
 756
 757         // command specific path, we call clear_if_dirty with this
 758         let mut my_out = match cmd {
 759             "build" => self.cargo_out(compiler, mode, target),
 760
 761             // This is the intended out directory for crate documentation.
 762             "doc" | "rustdoc" =>  self.crate_doc_out(target),
 763
 764             _ => self.stage_out(compiler, mode),
 765         };
 766
 767         // This is for the original compiler, but if we're forced to use stage 1, then
 768         // std/test/rustc stamps won't exist in stage 2, so we need to get those from stage 1, since
 769         // we copy the libs forward.
 770         let cmp = self.compiler_for(compiler.stage, compiler.host, target);
 771
 772         let libstd_stamp = match cmd {
 773             "check" | "clippy" | "fix" => check::libstd_stamp(self, cmp, target),
 774             _ => compile::libstd_stamp(self, cmp, target),
 775         };
 776
 777         let libtest_stamp = match cmd {
 778             "check" | "clippy" | "fix" => check::libtest_stamp(self, cmp, target),
 779             _ => compile::libtest_stamp(self, cmp, target),
 780         };
 781
 782         let librustc_stamp = match cmd {
 783             "check" | "clippy" | "fix" => check::librustc_stamp(self, cmp, target),
 784             _ => compile::librustc_stamp(self, cmp, target),
 785         };
 786
 787         if cmd == "doc" || cmd == "rustdoc" {
 788             if mode == Mode::Rustc || mode == Mode::ToolRustc || mode == Mode::Codegen {
 789                 // This is the intended out directory for compiler documentation.
 790                 my_out = self.compiler_doc_out(target);
 791             }
 792             let rustdoc = self.rustdoc(compiler);
 793             self.clear_if_dirty(&my_out, &rustdoc);
 794         } else if cmd != "test" {
 795             match mode {
 796                 Mode::Std => {
 797                     self.clear_if_dirty(&my_out, &self.rustc(compiler));
 798                     for backend in self.codegen_backends(compiler) {
 799                         self.clear_if_dirty(&my_out, &backend);
 800                     }
 801                 },
 802                 Mode::Test => {
 803                     self.clear_if_dirty(&my_out, &libstd_stamp);
 804                 },
 805                 Mode::Rustc => {
 806                     self.clear_if_dirty(&my_out, &self.rustc(compiler));
 807                     self.clear_if_dirty(&my_out, &libstd_stamp);
 808                     self.clear_if_dirty(&my_out, &libtest_stamp);
 809                 },
 810                 Mode::Codegen => {
 811                     self.clear_if_dirty(&my_out, &librustc_stamp);
 812                 },
 813                 Mode::ToolBootstrap => { },
 814                 Mode::ToolStd => {
 815                     self.clear_if_dirty(&my_out, &libstd_stamp);
 816                 },
 817                 Mode::ToolTest => {
 818                     self.clear_if_dirty(&my_out, &libstd_stamp);
 819                     self.clear_if_dirty(&my_out, &libtest_stamp);
 820                 },
 821                 Mode::ToolRustc => {
 822                     self.clear_if_dirty(&my_out, &libstd_stamp);
 823                     self.clear_if_dirty(&my_out, &libtest_stamp);
 824                     self.clear_if_dirty(&my_out, &librustc_stamp);
 825                 },
 826             }
 827         }
 828
 829         cargo
 830             .env("CARGO_TARGET_DIR", out_dir)
 831             .arg(cmd);
 832
 833         // See comment in librustc_llvm/build.rs for why this is necessary, largely llvm-config
 834         // needs to not accidentally link to libLLVM in stage0/lib.
 835         cargo.env("REAL_LIBRARY_PATH_VAR", &util::dylib_path_var());
 836         if let Some(e) = env::var_os(util::dylib_path_var()) {
 837             cargo.env("REAL_LIBRARY_PATH", e);
 838         }
 839
 840         if cmd != "install" {
 841             cargo.arg("--target")
 842                  .arg(target);
 843         } else {
 844             assert_eq!(target, compiler.host);
 845         }
 846
 847         // Set a flag for `check`/`clippy`/`fix`, so that certain build
 848         // scripts can do less work (e.g. not building/requiring LLVM).
 849         if cmd == "check" || cmd == "clippy" || cmd == "fix" {
 850             cargo.env("RUST_CHECK", "1");
 851         }
 852
 853         match mode {
 854             Mode::Std | Mode::Test | Mode::ToolBootstrap | Mode::ToolStd | Mode::ToolTest=> {},
 855             Mode::Rustc | Mode::Codegen | Mode::ToolRustc => {
 856                 // Build proc macros both for the host and the target
 857                 if target != compiler.host && cmd != "check" {
 858                     cargo.arg("-Zdual-proc-macros");
 859                     cargo.env("RUST_DUAL_PROC_MACROS", "1");
 860                 }
 861             },
 862         }
 863
 864         cargo.arg("-j").arg(self.jobs().to_string());
 865         // Remove make-related flags to ensure Cargo can correctly set things up
 866         cargo.env_remove("MAKEFLAGS");
 867         cargo.env_remove("MFLAGS");
 868
 869         // FIXME: Temporary fix for https://github.com/rust-lang/cargo/issues/3005
 870         // Force cargo to output binaries with disambiguating hashes in the name
 871         let mut metadata = if compiler.stage == 0 {
 872             // Treat stage0 like a special channel, whether it's a normal prior-
 873             // release rustc or a local rebuild with the same version, so we
 874             // never mix these libraries by accident.
 875             "bootstrap".to_string()
 876         } else {
 877             self.config.channel.to_string()
 878         };
 879         // We want to make sure that none of the dependencies between
 880         // std/test/rustc unify with one another. This is done for weird linkage
 881         // reasons but the gist of the problem is that if librustc, libtest, and
 882         // libstd all depend on libc from crates.io (which they actually do) we
 883         // want to make sure they all get distinct versions. Things get really
 884         // weird if we try to unify all these dependencies right now, namely
 885         // around how many times the library is linked in dynamic libraries and
 886         // such. If rustc were a static executable or if we didn't ship dylibs
 887         // this wouldn't be a problem, but we do, so it is. This is in general
 888         // just here to make sure things build right. If you can remove this and
 889         // things still build right, please do!
 890         match mode {
 891             Mode::Std => metadata.push_str("std"),
 892             Mode::Test => metadata.push_str("test"),
 893             _ => {},
 894         }
 895         cargo.env("__CARGO_DEFAULT_LIB_METADATA", &metadata);
 896
 897         let stage;
 898         if compiler.stage == 0 && self.local_rebuild {
 899             // Assume the local-rebuild rustc already has stage1 features.
 900             stage = 1;
 901         } else {
 902             stage = compiler.stage;
 903         }
 904
 905         let mut extra_args = env::var(&format!("RUSTFLAGS_STAGE_{}", stage)).unwrap_or_default();
 906         if stage != 0 {
 907             let s = env::var("RUSTFLAGS_STAGE_NOT_0").unwrap_or_default();
 908             if !extra_args.is_empty() {
 909                 extra_args.push_str(" ");
 910             }
 911             extra_args.push_str(&s);
 912         }
 913
 914         if cmd == "clippy" {
 915             extra_args.push_str("-Zforce-unstable-if-unmarked -Zunstable-options \
 916                 --json-rendered=termcolor");
 917         }
 918
 919         if !extra_args.is_empty() {
 920             cargo.env(
 921                 "RUSTFLAGS",
 922                 format!(
 923                     "{} {}",
 924                     env::var("RUSTFLAGS").unwrap_or_default(),
 925                     extra_args
 926                 ),
 927             );
 928         }
 929
 930         let want_rustdoc = self.doc_tests != DocTests::No;
 931
 932         // We synthetically interpret a stage0 compiler used to build tools as a
 933         // "raw" compiler in that it's the exact snapshot we download. Normally
 934         // the stage0 build means it uses libraries build by the stage0
 935         // compiler, but for tools we just use the precompiled libraries that
 936         // we've downloaded
 937         let use_snapshot = mode == Mode::ToolBootstrap;
 938         assert!(!use_snapshot || stage == 0 || self.local_rebuild);
 939
 940         let maybe_sysroot = self.sysroot(compiler);
 941         let sysroot = if use_snapshot {
 942             self.rustc_snapshot_sysroot()
 943         } else {
 944             &maybe_sysroot
 945         };
 946         let libdir = self.rustc_libdir(compiler);
 947
 948         // Customize the compiler we're running. Specify the compiler to cargo
 949         // as our shim and then pass it some various options used to configure
 950         // how the actual compiler itself is called.
 951         //
 952         // These variables are primarily all read by
 953         // src/bootstrap/bin/{rustc.rs,rustdoc.rs}
 954         cargo
 955             .env("RUSTBUILD_NATIVE_DIR", self.native_dir(target))
 956             .env("RUSTC", self.out.join("bootstrap/debug/rustc"))
 957             .env("RUSTC_REAL", self.rustc(compiler))
 958             .env("RUSTC_STAGE", stage.to_string())
 959             .env(
 960                 "RUSTC_DEBUG_ASSERTIONS",
 961                 self.config.rust_debug_assertions.to_string(),
 962             )
 963             .env("RUSTC_SYSROOT", &sysroot)
 964             .env("RUSTC_LIBDIR", &libdir)
 965             .env("RUSTC_RPATH", self.config.rust_rpath.to_string())
 966             .env("RUSTDOC", self.out.join("bootstrap/debug/rustdoc"))
 967             .env(
 968                 "RUSTDOC_REAL",
 969                 if cmd == "doc" || cmd == "rustdoc" || (cmd == "test" && want_rustdoc) {
 970                     self.rustdoc(compiler)
 971                 } else {
 972                     PathBuf::from("/path/to/nowhere/rustdoc/not/required")
 973                 },
 974             )
 975             .env("RUSTC_ERROR_METADATA_DST", self.extended_error_dir());
 976
 977         if let Some(host_linker) = self.linker(compiler.host) {
 978             cargo.env("RUSTC_HOST_LINKER", host_linker);
 979         }
 980         if let Some(target_linker) = self.linker(target) {
 981             cargo.env("RUSTC_TARGET_LINKER", target_linker);
 982         }
 983         if let Some(ref error_format) = self.config.rustc_error_format {
 984             cargo.env("RUSTC_ERROR_FORMAT", error_format);
 985         }
 986         if !(["build", "check", "clippy", "fix", "rustc"].contains(&cmd)) && want_rustdoc {
 987             cargo.env("RUSTDOC_LIBDIR", self.rustc_libdir(compiler));
 988         }
 989
 990         let debuginfo_level = match mode {
 991             Mode::Rustc | Mode::Codegen => self.config.rust_debuginfo_level_rustc,
 992             Mode::Std | Mode::Test => self.config.rust_debuginfo_level_std,
 993             Mode::ToolBootstrap | Mode::ToolStd |
 994             Mode::ToolTest | Mode::ToolRustc => self.config.rust_debuginfo_level_tools,
 995         };
 996         cargo.env("RUSTC_DEBUGINFO_LEVEL", debuginfo_level.to_string());
 997
 998         if !mode.is_tool() {
 999             cargo.env("RUSTC_FORCE_UNSTABLE", "1");
1000
1001             // Currently the compiler depends on crates from crates.io, and
1002             // then other crates can depend on the compiler (e.g., proc-macro
1003             // crates). Let's say, for example that rustc itself depends on the
1004             // bitflags crate. If an external crate then depends on the
1005             // bitflags crate as well, we need to make sure they don't
1006             // conflict, even if they pick the same version of bitflags. We'll
1007             // want to make sure that e.g., a plugin and rustc each get their
1008             // own copy of bitflags.
1009
1010             // Cargo ensures that this works in general through the -C metadata
1011             // flag. This flag will frob the symbols in the binary to make sure
1012             // they're different, even though the source code is the exact
1013             // same. To solve this problem for the compiler we extend Cargo's
1014             // already-passed -C metadata flag with our own. Our rustc.rs
1015             // wrapper around the actual rustc will detect -C metadata being
1016             // passed and frob it with this extra string we're passing in.
1017             cargo.env("RUSTC_METADATA_SUFFIX", "rustc");
1018         }
1019
1020         if let Some(x) = self.crt_static(target) {
1021             cargo.env("RUSTC_CRT_STATIC", x.to_string());
1022         }
1023
1024         if let Some(x) = self.crt_static(compiler.host) {
1025             cargo.env("RUSTC_HOST_CRT_STATIC", x.to_string());
1026         }
1027
1028         if let Some(map) = self.build.debuginfo_map(GitRepo::Rustc) {
1029             cargo.env("RUSTC_DEBUGINFO_MAP", map);
1030         }
1031
1032         // Enable usage of unstable features
1033         cargo.env("RUSTC_BOOTSTRAP", "1");
1034         self.add_rust_test_threads(&mut cargo);
1035
1036         // Almost all of the crates that we compile as part of the bootstrap may
1037         // have a build script, including the standard library. To compile a
1038         // build script, however, it itself needs a standard library! This
1039         // introduces a bit of a pickle when we're compiling the standard
1040         // library itself.
1041         //
1042         // To work around this we actually end up using the snapshot compiler
1043         // (stage0) for compiling build scripts of the standard library itself.
1044         // The stage0 compiler is guaranteed to have a libstd available for use.
1045         //
1046         // For other crates, however, we know that we've already got a standard
1047         // library up and running, so we can use the normal compiler to compile
1048         // build scripts in that situation.
1049         if mode == Mode::Std {
1050             cargo
1051                 .env("RUSTC_SNAPSHOT", &self.initial_rustc)
1052                 .env("RUSTC_SNAPSHOT_LIBDIR", self.rustc_snapshot_libdir());
1053         } else {
1054             cargo
1055                 .env("RUSTC_SNAPSHOT", self.rustc(compiler))
1056                 .env("RUSTC_SNAPSHOT_LIBDIR", self.rustc_libdir(compiler));
1057         }
1058
1059         if self.config.incremental {
1060             cargo.env("CARGO_INCREMENTAL", "1");
1061         } else {
1062             // Don't rely on any default setting for incr. comp. in Cargo
1063             cargo.env("CARGO_INCREMENTAL", "0");
1064         }
1065
1066         if let Some(ref on_fail) = self.config.on_fail {
1067             cargo.env("RUSTC_ON_FAIL", on_fail);
1068         }
1069
1070         if self.config.print_step_timings {
1071             cargo.env("RUSTC_PRINT_STEP_TIMINGS", "1");
1072         }
1073
1074         if self.config.backtrace_on_ice {
1075             cargo.env("RUSTC_BACKTRACE_ON_ICE", "1");
1076         }
1077
1078         cargo.env("RUSTC_VERBOSE", self.verbosity.to_string());
1079
1080         if self.config.deny_warnings {
1081             cargo.env("RUSTC_DENY_WARNINGS", "1");
1082         }
1083
1084         // Throughout the build Cargo can execute a number of build scripts
1085         // compiling C/C++ code and we need to pass compilers, archivers, flags, etc
1086         // obtained previously to those build scripts.
1087         // Build scripts use either the `cc` crate or `configure/make` so we pass
1088         // the options through environment variables that are fetched and understood by both.
1089         //
1090         // FIXME: the guard against msvc shouldn't need to be here
1091         if target.contains("msvc") {
1092             if let Some(ref cl) = self.config.llvm_clang_cl {
1093                 cargo.env("CC", cl).env("CXX", cl);
1094             }
1095         } else {
1096             let ccache = self.config.ccache.as_ref();
1097             let ccacheify = |s: &Path| {
1098                 let ccache = match ccache {
1099                     Some(ref s) => s,
1100                     None => return s.display().to_string(),
1101                 };
1102                 // FIXME: the cc-rs crate only recognizes the literal strings
1103                 // `ccache` and `sccache` when doing caching compilations, so we
1104                 // mirror that here. It should probably be fixed upstream to
1105                 // accept a new env var or otherwise work with custom ccache
1106                 // vars.
1107                 match &ccache[..] {
1108                     "ccache" | "sccache" => format!("{} {}", ccache, s.display()),
1109                     _ => s.display().to_string(),
1110                 }
1111             };
1112             let cc = ccacheify(&self.cc(target));
1113             cargo.env(format!("CC_{}", target), &cc);
1114
1115             let cflags = self.cflags(target, GitRepo::Rustc).join(" ");
1116             cargo
1117                 .env(format!("CFLAGS_{}", target), cflags.clone());
1118
1119             if let Some(ar) = self.ar(target) {
1120                 let ranlib = format!("{} s", ar.display());
1121                 cargo
1122                     .env(format!("AR_{}", target), ar)
1123                     .env(format!("RANLIB_{}", target), ranlib);
1124             }
1125
1126             if let Ok(cxx) = self.cxx(target) {
1127                 let cxx = ccacheify(&cxx);
1128                 cargo
1129                     .env(format!("CXX_{}", target), &cxx)
1130                     .env(format!("CXXFLAGS_{}", target), cflags);
1131             }
1132         }
1133
1134         if (cmd == "build" || cmd == "rustc")
1135             && mode == Mode::Std
1136             && self.config.extended
1137             && compiler.is_final_stage(self)
1138         {
1139             cargo.env("RUSTC_SAVE_ANALYSIS", "api".to_string());
1140         }
1141
1142         // For `cargo doc` invocations, make rustdoc print the Rust version into the docs
1143         cargo.env("RUSTDOC_CRATE_VERSION", self.rust_version());
1144
1145         // Environment variables *required* throughout the build
1146         //
1147         // FIXME: should update code to not require this env var
1148         cargo.env("CFG_COMPILER_HOST_TRIPLE", target);
1149
1150         // Set this for all builds to make sure doc builds also get it.
1151         cargo.env("CFG_RELEASE_CHANNEL", &self.config.channel);
1152
1153         // This one's a bit tricky. As of the time of this writing the compiler
1154         // links to the `winapi` crate on crates.io. This crate provides raw
1155         // bindings to Windows system functions, sort of like libc does for
1156         // Unix. This crate also, however, provides "import libraries" for the
1157         // MinGW targets. There's an import library per dll in the windows
1158         // distribution which is what's linked to. These custom import libraries
1159         // are used because the winapi crate can reference Windows functions not
1160         // present in the MinGW import libraries.
1161         //
1162         // For example MinGW may ship libdbghelp.a, but it may not have
1163         // references to all the functions in the dbghelp dll. Instead the
1164         // custom import library for dbghelp in the winapi crates has all this
1165         // information.
1166         //
1167         // Unfortunately for us though the import libraries are linked by
1168         // default via `-ldylib=winapi_foo`. That is, they're linked with the
1169         // `dylib` type with a `winapi_` prefix (so the winapi ones don't
1170         // conflict with the system MinGW ones). This consequently means that
1171         // the binaries we ship of things like rustc_codegen_llvm (aka the rustc_codegen_llvm
1172         // DLL) when linked against *again*, for example with procedural macros
1173         // or plugins, will trigger the propagation logic of `-ldylib`, passing
1174         // `-lwinapi_foo` to the linker again. This isn't actually available in
1175         // our distribution, however, so the link fails.
1176         //
1177         // To solve this problem we tell winapi to not use its bundled import
1178         // libraries. This means that it will link to the system MinGW import
1179         // libraries by default, and the `-ldylib=foo` directives will still get
1180         // passed to the final linker, but they'll look like `-lfoo` which can
1181         // be resolved because MinGW has the import library. The downside is we
1182         // don't get newer functions from Windows, but we don't use any of them
1183         // anyway.
1184         if !mode.is_tool() {
1185             cargo.env("WINAPI_NO_BUNDLED_LIBRARIES", "1");
1186         }
1187
1188         for _ in 1..self.verbosity {
1189             cargo.arg("-v");
1190         }
1191
1192         match (mode, self.config.rust_codegen_units_std, self.config.rust_codegen_units) {
1193             (Mode::Std, Some(n), _) |
1194             (Mode::Test, Some(n), _) |
1195             (_, _, Some(n)) => {
1196                 cargo.env("RUSTC_CODEGEN_UNITS", n.to_string());
1197             }
1198             _ => {
1199                 // Don't set anything
1200             }
1201         }
1202
1203         if self.config.rust_optimize {
1204             // FIXME: cargo bench/install do not accept `--release`
1205             if cmd != "bench" && cmd != "install" {
1206                 cargo.arg("--release");
1207             }
1208         }
1209
1210         if self.config.locked_deps {
1211             cargo.arg("--locked");
1212         }
1213         if self.config.vendor || self.is_sudo {
1214             cargo.arg("--frozen");
1215         }
1216
1217         self.ci_env.force_coloring_in_ci(&mut cargo);
1218
1219         cargo
1220     }
1221
1222     /// Ensure that a given step is built, returning its output. This will
1223     /// cache the step, so it is safe (and good!) to call this as often as
1224     /// needed to ensure that all dependencies are built.
1225     pub fn ensure<S: Step>(&'a self, step: S) -> S::Output {
1226         {
1227             let mut stack = self.stack.borrow_mut();
1228             for stack_step in stack.iter() {
1229                 // should skip
1230                 if stack_step
1231                     .downcast_ref::<S>()
1232                     .map_or(true, |stack_step| *stack_step != step)
1233                 {
1234                     continue;
1235                 }
1236                 let mut out = String::new();
1237                 out += &format!("\n\nCycle in build detected when adding {:?}\n", step);
1238                 for el in stack.iter().rev() {
1239                     out += &format!("\t{:?}\n", el);
1240                 }
1241                 panic!(out);
1242             }
1243             if let Some(out) = self.cache.get(&step) {
1244                 self.verbose(&format!("{}c {:?}", "  ".repeat(stack.len()), step));
1245
1246                 {
1247                     let mut graph = self.graph.borrow_mut();
1248                     let parent = self.parent.get();
1249                     let us = *self
1250                         .graph_nodes
1251                         .borrow_mut()
1252                         .entry(format!("{:?}", step))
1253                         .or_insert_with(|| graph.add_node(format!("{:?}", step)));
1254                     if let Some(parent) = parent {
1255                         graph.add_edge(parent, us, false);
1256                     }
1257                 }
1258
1259                 return out;
1260             }
1261             self.verbose(&format!("{}> {:?}", "  ".repeat(stack.len()), step));
1262             stack.push(Box::new(step.clone()));
1263         }
1264
1265         let prev_parent = self.parent.get();
1266
1267         {
1268             let mut graph = self.graph.borrow_mut();
1269             let parent = self.parent.get();
1270             let us = *self
1271                 .graph_nodes
1272                 .borrow_mut()
1273                 .entry(format!("{:?}", step))
1274                 .or_insert_with(|| graph.add_node(format!("{:?}", step)));
1275             self.parent.set(Some(us));
1276             if let Some(parent) = parent {
1277                 graph.add_edge(parent, us, true);
1278             }
1279         }
1280
1281         let (out, dur) = {
1282             let start = Instant::now();
1283             let zero = Duration::new(0, 0);
1284             let parent = self.time_spent_on_dependencies.replace(zero);
1285             let out = step.clone().run(self);
1286             let dur = start.elapsed();
1287             let deps = self.time_spent_on_dependencies.replace(parent + dur);
1288             (out, dur - deps)
1289         };
1290
1291         self.parent.set(prev_parent);
1292
1293         if self.config.print_step_timings && dur > Duration::from_millis(100) {
1294             println!(
1295                 "[TIMING] {:?} -- {}.{:03}",
1296                 step,
1297                 dur.as_secs(),
1298                 dur.subsec_nanos() / 1_000_000
1299             );
1300         }
1301
1302         {
1303             let mut stack = self.stack.borrow_mut();
1304             let cur_step = stack.pop().expect("step stack empty");
1305             assert_eq!(cur_step.downcast_ref(), Some(&step));
1306         }
1307         self.verbose(&format!(
1308             "{}< {:?}",
1309             "  ".repeat(self.stack.borrow().len()),
1310             step
1311         ));
1312         self.cache.put(step, out.clone());
1313         out
1314     }
1315 }
1316
1317 #[cfg(test)]
1318 mod tests;