src/bootstrap/builder.rs

   1 // Copyright 2017 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 std::any::Any;
  12 use std::cell::RefCell;
  13 use std::collections::BTreeSet;
  14 use std::env;
  15 use std::fmt::Debug;
  16 use std::fs;
  17 use std::hash::Hash;
  18 use std::ops::Deref;
  19 use std::path::{Path, PathBuf};
  20 use std::process::Command;
  21
  22 use compile;
  23 use install;
  24 use dist;
  25 use util::{exe, libdir, add_lib_path};
  26 use {Build, Mode};
  27 use cache::{INTERNER, Interned, Cache};
  28 use check;
  29 use flags::Subcommand;
  30 use doc;
  31 use tool;
  32 use native;
  33
  34 pub use Compiler;
  35
  36 pub struct Builder<'a> {
  37     pub build: &'a Build,
  38     pub top_stage: u32,
  39     pub kind: Kind,
  40     cache: Cache,
  41     stack: RefCell<Vec<Box<Any>>>,
  42 }
  43
  44 impl<'a> Deref for Builder<'a> {
  45     type Target = Build;
  46
  47     fn deref(&self) -> &Self::Target {
  48         self.build
  49     }
  50 }
  51
  52 pub trait Step: 'static + Clone + Debug + PartialEq + Eq + Hash {
  53     /// `PathBuf` when directories are created or to return a `Compiler` once
  54     /// it's been assembled.
  55     type Output: Clone;
  56
  57     const DEFAULT: bool = false;
  58
  59     /// Run this rule for all hosts without cross compiling.
  60     const ONLY_HOSTS: bool = false;
  61
  62     /// Run this rule for all targets, but only with the native host.
  63     const ONLY_BUILD_TARGETS: bool = false;
  64
  65     /// Only run this step with the build triple as host and target.
  66     const ONLY_BUILD: bool = false;
  67
  68     /// Primary function to execute this rule. Can call `builder.ensure(...)`
  69     /// with other steps to run those.
  70     fn run(self, builder: &Builder) -> Self::Output;
  71
  72     /// When bootstrap is passed a set of paths, this controls whether this rule
  73     /// will execute. However, it does not get called in a "default" context
  74     /// when we are not passed any paths; in that case, make_run is called
  75     /// directly.
  76     fn should_run(run: ShouldRun) -> ShouldRun;
  77
  78     /// Build up a "root" rule, either as a default rule or from a path passed
  79     /// to us.
  80     ///
  81     /// When path is `None`, we are executing in a context where no paths were
  82     /// passed. When `./x.py build` is run, for example, this rule could get
  83     /// called if it is in the correct list below with a path of `None`.
  84     fn make_run(_run: RunConfig) {
  85         // It is reasonable to not have an implementation of make_run for rules
  86         // who do not want to get called from the root context. This means that
  87         // they are likely dependencies (e.g., sysroot creation) or similar, and
  88         // as such calling them from ./x.py isn't logical.
  89         unimplemented!()
  90     }
  91 }
  92
  93 pub struct RunConfig<'a> {
  94     pub builder: &'a Builder<'a>,
  95     pub host: Interned<String>,
  96     pub target: Interned<String>,
  97     pub path: Option<&'a Path>,
  98 }
  99
 100 struct StepDescription {
 101     default: bool,
 102     only_hosts: bool,
 103     only_build_targets: bool,
 104     only_build: bool,
 105     should_run: fn(ShouldRun) -> ShouldRun,
 106     make_run: fn(RunConfig),
 107 }
 108
 109 impl StepDescription {
 110     fn from<S: Step>() -> StepDescription {
 111         StepDescription {
 112             default: S::DEFAULT,
 113             only_hosts: S::ONLY_HOSTS,
 114             only_build_targets: S::ONLY_BUILD_TARGETS,
 115             only_build: S::ONLY_BUILD,
 116             should_run: S::should_run,
 117             make_run: S::make_run,
 118         }
 119     }
 120
 121     fn maybe_run(&self, builder: &Builder, path: Option<&Path>) {
 122         let build = builder.build;
 123         let hosts = if self.only_build_targets || self.only_build {
 124             build.build_triple()
 125         } else {
 126             &build.hosts
 127         };
 128
 129         // Determine the targets participating in this rule.
 130         let targets = if self.only_hosts {
 131             if build.config.run_host_only {
 132                 &[]
 133             } else if self.only_build {
 134                 build.build_triple()
 135             } else {
 136                 &build.hosts
 137             }
 138         } else {
 139             &build.targets
 140         };
 141
 142         for host in hosts {
 143             for target in targets {
 144                 let run = RunConfig {
 145                     builder,
 146                     path,
 147                     host: *host,
 148                     target: *target,
 149                 };
 150                 (self.make_run)(run);
 151             }
 152         }
 153     }
 154
 155     fn run(v: &[StepDescription], builder: &Builder, paths: &[PathBuf]) {
 156         let should_runs = v.iter().map(|desc| {
 157             (desc.should_run)(ShouldRun::new(builder))
 158         }).collect::<Vec<_>>();
 159         if paths.is_empty() {
 160             for (desc, should_run) in v.iter().zip(should_runs) {
 161                 if desc.default && should_run.is_really_default {
 162                     desc.maybe_run(builder, None);
 163                 }
 164             }
 165         } else {
 166             for path in paths {
 167                 let mut attempted_run = false;
 168                 for (desc, should_run) in v.iter().zip(&should_runs) {
 169                     if should_run.run(path) {
 170                         attempted_run = true;
 171                         desc.maybe_run(builder, Some(path));
 172                     }
 173                 }
 174
 175                 if !attempted_run {
 176                     eprintln!("Warning: no rules matched {}.", path.display());
 177                 }
 178             }
 179         }
 180     }
 181 }
 182
 183 #[derive(Clone)]
 184 pub struct ShouldRun<'a> {
 185     pub builder: &'a Builder<'a>,
 186     // use a BTreeSet to maintain sort order
 187     paths: BTreeSet<PathBuf>,
 188
 189     // If this is a default rule, this is an additional constraint placed on
 190     // it's run. Generally something like compiler docs being enabled.
 191     is_really_default: bool,
 192 }
 193
 194 impl<'a> ShouldRun<'a> {
 195     fn new(builder: &'a Builder) -> ShouldRun<'a> {
 196         ShouldRun {
 197             builder,
 198             paths: BTreeSet::new(),
 199             is_really_default: true, // by default no additional conditions
 200         }
 201     }
 202
 203     pub fn default_condition(mut self, cond: bool) -> Self {
 204         self.is_really_default = cond;
 205         self
 206     }
 207
 208     pub fn krate(mut self, name: &str) -> Self {
 209         for (_, krate_path) in self.builder.crates(name) {
 210             self.paths.insert(PathBuf::from(krate_path));
 211         }
 212         self
 213     }
 214
 215     pub fn path(mut self, path: &str) -> Self {
 216         self.paths.insert(PathBuf::from(path));
 217         self
 218     }
 219
 220     // allows being more explicit about why should_run in Step returns the value passed to it
 221     pub fn never(self) -> ShouldRun<'a> {
 222         self
 223     }
 224
 225     fn run(&self, path: &Path) -> bool {
 226         self.paths.iter().any(|p| path.ends_with(p))
 227     }
 228 }
 229
 230 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 231 pub enum Kind {
 232     Build,
 233     Test,
 234     Bench,
 235     Dist,
 236     Doc,
 237     Install,
 238 }
 239
 240 impl<'a> Builder<'a> {
 241     fn get_step_descriptions(kind: Kind) -> Vec<StepDescription> {
 242         macro_rules! describe {
 243             ($($rule:ty),+ $(,)*) => {{
 244                 vec![$(StepDescription::from::<$rule>()),+]
 245             }};
 246         }
 247         match kind {
 248             Kind::Build => describe!(compile::Std, compile::Test, compile::Rustc,
 249                 compile::StartupObjects, tool::BuildManifest, tool::Rustbook, tool::ErrorIndex,
 250                 tool::UnstableBookGen, tool::Tidy, tool::Linkchecker, tool::CargoTest,
 251                 tool::Compiletest, tool::RemoteTestServer, tool::RemoteTestClient,
 252                 tool::RustInstaller, tool::Cargo, tool::Rls, tool::Rustdoc, tool::Clippy,
 253                 native::Llvm, tool::Rustfmt, tool::Miri),
 254             Kind::Test => describe!(check::Tidy, check::Bootstrap, check::DefaultCompiletest,
 255                 check::HostCompiletest, check::Crate, check::CrateLibrustc, check::Rustdoc,
 256                 check::Linkcheck, check::Cargotest, check::Cargo, check::Rls, check::Docs,
 257                 check::ErrorIndex, check::Distcheck, check::Rustfmt, check::Miri, check::Clippy),
 258             Kind::Bench => describe!(check::Crate, check::CrateLibrustc),
 259             Kind::Doc => describe!(doc::UnstableBook, doc::UnstableBookGen, doc::TheBook,
 260                 doc::Standalone, doc::Std, doc::Test, doc::Rustc, doc::ErrorIndex, doc::Nomicon,
 261                 doc::Reference, doc::Rustdoc, doc::CargoBook),
 262             Kind::Dist => describe!(dist::Docs, dist::Mingw, dist::Rustc, dist::DebuggerScripts,
 263                 dist::Std, dist::Analysis, dist::Src, dist::PlainSourceTarball, dist::Cargo,
 264                 dist::Rls, dist::Rustfmt, dist::Extended, dist::HashSign,
 265                 dist::DontDistWithMiriEnabled),
 266             Kind::Install => describe!(install::Docs, install::Std, install::Cargo, install::Rls,
 267                 install::Rustfmt, install::Analysis, install::Src, install::Rustc),
 268         }
 269     }
 270
 271     pub fn get_help(build: &Build, subcommand: &str) -> Option<String> {
 272         let kind = match subcommand {
 273             "build" => Kind::Build,
 274             "doc" => Kind::Doc,
 275             "test" => Kind::Test,
 276             "bench" => Kind::Bench,
 277             "dist" => Kind::Dist,
 278             "install" => Kind::Install,
 279             _ => return None,
 280         };
 281
 282         let builder = Builder {
 283             build,
 284             top_stage: build.config.stage.unwrap_or(2),
 285             kind,
 286             cache: Cache::new(),
 287             stack: RefCell::new(Vec::new()),
 288         };
 289
 290         let builder = &builder;
 291         let mut should_run = ShouldRun::new(builder);
 292         for desc in Builder::get_step_descriptions(builder.kind) {
 293             should_run = (desc.should_run)(should_run);
 294         }
 295         let mut help = String::from("Available paths:\n");
 296         for path in should_run.paths {
 297             help.push_str(format!("    ./x.py {} {}\n", subcommand, path.display()).as_str());
 298         }
 299         Some(help)
 300     }
 301
 302     pub fn run(build: &Build) {
 303         let (kind, paths) = match build.config.cmd {
 304             Subcommand::Build { ref paths } => (Kind::Build, &paths[..]),
 305             Subcommand::Doc { ref paths } => (Kind::Doc, &paths[..]),
 306             Subcommand::Test { ref paths, .. } => (Kind::Test, &paths[..]),
 307             Subcommand::Bench { ref paths, .. } => (Kind::Bench, &paths[..]),
 308             Subcommand::Dist { ref paths } => (Kind::Dist, &paths[..]),
 309             Subcommand::Install { ref paths } => (Kind::Install, &paths[..]),
 310             Subcommand::Clean { .. } => panic!(),
 311         };
 312
 313         let builder = Builder {
 314             build,
 315             top_stage: build.config.stage.unwrap_or(2),
 316             kind,
 317             cache: Cache::new(),
 318             stack: RefCell::new(Vec::new()),
 319         };
 320
 321         StepDescription::run(&Builder::get_step_descriptions(builder.kind), &builder, paths);
 322     }
 323
 324     pub fn default_doc(&self, paths: Option<&[PathBuf]>) {
 325         let paths = paths.unwrap_or(&[]);
 326         StepDescription::run(&Builder::get_step_descriptions(Kind::Doc), self, paths);
 327     }
 328
 329     /// Obtain a compiler at a given stage and for a given host. Explicitly does
 330     /// not take `Compiler` since all `Compiler` instances are meant to be
 331     /// obtained through this function, since it ensures that they are valid
 332     /// (i.e., built and assembled).
 333     pub fn compiler(&self, stage: u32, host: Interned<String>) -> Compiler {
 334         self.ensure(compile::Assemble { target_compiler: Compiler { stage, host } })
 335     }
 336
 337     pub fn sysroot(&self, compiler: Compiler) -> Interned<PathBuf> {
 338         self.ensure(compile::Sysroot { compiler })
 339     }
 340
 341     /// Returns the libdir where the standard library and other artifacts are
 342     /// found for a compiler's sysroot.
 343     pub fn sysroot_libdir(
 344         &self, compiler: Compiler, target: Interned<String>
 345     ) -> Interned<PathBuf> {
 346         #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 347         struct Libdir {
 348             compiler: Compiler,
 349             target: Interned<String>,
 350         }
 351         impl Step for Libdir {
 352             type Output = Interned<PathBuf>;
 353
 354             fn should_run(run: ShouldRun) -> ShouldRun {
 355                 run.never()
 356             }
 357
 358             fn run(self, builder: &Builder) -> Interned<PathBuf> {
 359                 let compiler = self.compiler;
 360                 let lib = if compiler.stage >= 2 && builder.build.config.libdir_relative.is_some() {
 361                     builder.build.config.libdir_relative.clone().unwrap()
 362                 } else {
 363                     PathBuf::from("lib")
 364                 };
 365                 let sysroot = builder.sysroot(self.compiler).join(lib)
 366                     .join("rustlib").join(self.target).join("lib");
 367                 let _ = fs::remove_dir_all(&sysroot);
 368                 t!(fs::create_dir_all(&sysroot));
 369                 INTERNER.intern_path(sysroot)
 370             }
 371         }
 372         self.ensure(Libdir { compiler, target })
 373     }
 374
 375     /// Returns the compiler's libdir where it stores the dynamic libraries that
 376     /// it itself links against.
 377     ///
 378     /// For example this returns `<sysroot>/lib` on Unix and `<sysroot>/bin` on
 379     /// Windows.
 380     pub fn rustc_libdir(&self, compiler: Compiler) -> PathBuf {
 381         if compiler.is_snapshot(self) {
 382             self.build.rustc_snapshot_libdir()
 383         } else {
 384             self.sysroot(compiler).join(libdir(&compiler.host))
 385         }
 386     }
 387
 388     /// Adds the compiler's directory of dynamic libraries to `cmd`'s dynamic
 389     /// library lookup path.
 390     pub fn add_rustc_lib_path(&self, compiler: Compiler, cmd: &mut Command) {
 391         // Windows doesn't need dylib path munging because the dlls for the
 392         // compiler live next to the compiler and the system will find them
 393         // automatically.
 394         if cfg!(windows) {
 395             return
 396         }
 397
 398         add_lib_path(vec![self.rustc_libdir(compiler)], cmd);
 399     }
 400
 401     /// Get a path to the compiler specified.
 402     pub fn rustc(&self, compiler: Compiler) -> PathBuf {
 403         if compiler.is_snapshot(self) {
 404             self.initial_rustc.clone()
 405         } else {
 406             self.sysroot(compiler).join("bin").join(exe("rustc", &compiler.host))
 407         }
 408     }
 409
 410     pub fn rustdoc(&self, host: Interned<String>) -> PathBuf {
 411         self.ensure(tool::Rustdoc { host })
 412     }
 413
 414     pub fn rustdoc_cmd(&self, host: Interned<String>) -> Command {
 415         let mut cmd = Command::new(&self.out.join("bootstrap/debug/rustdoc"));
 416         let compiler = self.compiler(self.top_stage, host);
 417         cmd.env("RUSTC_STAGE", compiler.stage.to_string())
 418            .env("RUSTC_SYSROOT", self.sysroot(compiler))
 419            .env("RUSTC_LIBDIR", self.sysroot_libdir(compiler, self.build.build))
 420            .env("CFG_RELEASE_CHANNEL", &self.build.config.channel)
 421            .env("RUSTDOC_REAL", self.rustdoc(host))
 422            .env("RUSTDOC_CRATE_VERSION", self.build.rust_version())
 423            .env("RUSTC_BOOTSTRAP", "1");
 424         if let Some(linker) = self.build.linker(host) {
 425             cmd.env("RUSTC_TARGET_LINKER", linker);
 426         }
 427         cmd
 428     }
 429
 430     /// Prepares an invocation of `cargo` to be run.
 431     ///
 432     /// This will create a `Command` that represents a pending execution of
 433     /// Cargo. This cargo will be configured to use `compiler` as the actual
 434     /// rustc compiler, its output will be scoped by `mode`'s output directory,
 435     /// it will pass the `--target` flag for the specified `target`, and will be
 436     /// executing the Cargo command `cmd`.
 437     pub fn cargo(&self,
 438              compiler: Compiler,
 439              mode: Mode,
 440              target: Interned<String>,
 441              cmd: &str) -> Command {
 442         let mut cargo = Command::new(&self.initial_cargo);
 443         let out_dir = self.stage_out(compiler, mode);
 444         cargo.env("CARGO_TARGET_DIR", out_dir)
 445              .arg(cmd)
 446              .arg("--target").arg(target);
 447
 448         // If we were invoked from `make` then that's already got a jobserver
 449         // set up for us so no need to tell Cargo about jobs all over again.
 450         if env::var_os("MAKEFLAGS").is_none() && env::var_os("MFLAGS").is_none() {
 451              cargo.arg("-j").arg(self.jobs().to_string());
 452         }
 453
 454         // FIXME: Temporary fix for https://github.com/rust-lang/cargo/issues/3005
 455         // Force cargo to output binaries with disambiguating hashes in the name
 456         cargo.env("__CARGO_DEFAULT_LIB_METADATA", &self.config.channel);
 457
 458         let stage;
 459         if compiler.stage == 0 && self.local_rebuild {
 460             // Assume the local-rebuild rustc already has stage1 features.
 461             stage = 1;
 462         } else {
 463             stage = compiler.stage;
 464         }
 465
 466         // Customize the compiler we're running. Specify the compiler to cargo
 467         // as our shim and then pass it some various options used to configure
 468         // how the actual compiler itself is called.
 469         //
 470         // These variables are primarily all read by
 471         // src/bootstrap/bin/{rustc.rs,rustdoc.rs}
 472         cargo.env("RUSTBUILD_NATIVE_DIR", self.native_dir(target))
 473              .env("RUSTC", self.out.join("bootstrap/debug/rustc"))
 474              .env("RUSTC_REAL", self.rustc(compiler))
 475              .env("RUSTC_STAGE", stage.to_string())
 476              .env("RUSTC_DEBUG_ASSERTIONS",
 477                   self.config.rust_debug_assertions.to_string())
 478              .env("RUSTC_SYSROOT", self.sysroot(compiler))
 479              .env("RUSTC_LIBDIR", self.rustc_libdir(compiler))
 480              .env("RUSTC_RPATH", self.config.rust_rpath.to_string())
 481              .env("RUSTDOC", self.out.join("bootstrap/debug/rustdoc"))
 482              .env("RUSTDOC_REAL", if cmd == "doc" || cmd == "test" {
 483                  self.rustdoc(compiler.host)
 484              } else {
 485                  PathBuf::from("/path/to/nowhere/rustdoc/not/required")
 486              })
 487              .env("TEST_MIRI", self.config.test_miri.to_string());
 488
 489         if let Some(n) = self.config.rust_codegen_units {
 490             cargo.env("RUSTC_CODEGEN_UNITS", n.to_string());
 491         }
 492
 493         if let Some(host_linker) = self.build.linker(compiler.host) {
 494             cargo.env("RUSTC_HOST_LINKER", host_linker);
 495         }
 496         if let Some(target_linker) = self.build.linker(target) {
 497             cargo.env("RUSTC_TARGET_LINKER", target_linker);
 498         }
 499
 500         if mode != Mode::Tool {
 501             // Tools don't get debuginfo right now, e.g. cargo and rls don't
 502             // get compiled with debuginfo.
 503             cargo.env("RUSTC_DEBUGINFO", self.config.rust_debuginfo.to_string())
 504                  .env("RUSTC_DEBUGINFO_LINES", self.config.rust_debuginfo_lines.to_string())
 505                  .env("RUSTC_FORCE_UNSTABLE", "1");
 506
 507             // Currently the compiler depends on crates from crates.io, and
 508             // then other crates can depend on the compiler (e.g. proc-macro
 509             // crates). Let's say, for example that rustc itself depends on the
 510             // bitflags crate. If an external crate then depends on the
 511             // bitflags crate as well, we need to make sure they don't
 512             // conflict, even if they pick the same version of bitflags. We'll
 513             // want to make sure that e.g. a plugin and rustc each get their
 514             // own copy of bitflags.
 515
 516             // Cargo ensures that this works in general through the -C metadata
 517             // flag. This flag will frob the symbols in the binary to make sure
 518             // they're different, even though the source code is the exact
 519             // same. To solve this problem for the compiler we extend Cargo's
 520             // already-passed -C metadata flag with our own. Our rustc.rs
 521             // wrapper around the actual rustc will detect -C metadata being
 522             // passed and frob it with this extra string we're passing in.
 523             cargo.env("RUSTC_METADATA_SUFFIX", "rustc");
 524         }
 525
 526         if let Some(x) = self.crt_static(target) {
 527             cargo.env("RUSTC_CRT_STATIC", x.to_string());
 528         }
 529
 530         // Enable usage of unstable features
 531         cargo.env("RUSTC_BOOTSTRAP", "1");
 532         self.add_rust_test_threads(&mut cargo);
 533
 534         // Almost all of the crates that we compile as part of the bootstrap may
 535         // have a build script, including the standard library. To compile a
 536         // build script, however, it itself needs a standard library! This
 537         // introduces a bit of a pickle when we're compiling the standard
 538         // library itself.
 539         //
 540         // To work around this we actually end up using the snapshot compiler
 541         // (stage0) for compiling build scripts of the standard library itself.
 542         // The stage0 compiler is guaranteed to have a libstd available for use.
 543         //
 544         // For other crates, however, we know that we've already got a standard
 545         // library up and running, so we can use the normal compiler to compile
 546         // build scripts in that situation.
 547         //
 548         // If LLVM support is disabled we need to use the snapshot compiler to compile
 549         // build scripts, as the new compiler doesnt support executables.
 550         if mode == Mode::Libstd || !self.build.config.llvm_enabled {
 551             cargo.env("RUSTC_SNAPSHOT", &self.initial_rustc)
 552                  .env("RUSTC_SNAPSHOT_LIBDIR", self.rustc_snapshot_libdir());
 553         } else {
 554             cargo.env("RUSTC_SNAPSHOT", self.rustc(compiler))
 555                  .env("RUSTC_SNAPSHOT_LIBDIR", self.rustc_libdir(compiler));
 556         }
 557
 558         // Ignore incremental modes except for stage0, since we're
 559         // not guaranteeing correctness across builds if the compiler
 560         // is changing under your feet.`
 561         if self.config.incremental && compiler.stage == 0 {
 562             let incr_dir = self.incremental_dir(compiler);
 563             cargo.env("RUSTC_INCREMENTAL", incr_dir);
 564         }
 565
 566         if let Some(ref on_fail) = self.config.on_fail {
 567             cargo.env("RUSTC_ON_FAIL", on_fail);
 568         }
 569
 570         cargo.env("RUSTC_VERBOSE", format!("{}", self.verbosity));
 571
 572         // Throughout the build Cargo can execute a number of build scripts
 573         // compiling C/C++ code and we need to pass compilers, archivers, flags, etc
 574         // obtained previously to those build scripts.
 575         // Build scripts use either the `cc` crate or `configure/make` so we pass
 576         // the options through environment variables that are fetched and understood by both.
 577         //
 578         // FIXME: the guard against msvc shouldn't need to be here
 579         if !target.contains("msvc") {
 580             let cc = self.cc(target);
 581             cargo.env(format!("CC_{}", target), cc)
 582                  .env("CC", cc);
 583
 584             let cflags = self.cflags(target).join(" ");
 585             cargo.env(format!("CFLAGS_{}", target), cflags.clone())
 586                  .env("CFLAGS", cflags.clone());
 587
 588             if let Some(ar) = self.ar(target) {
 589                 let ranlib = format!("{} s", ar.display());
 590                 cargo.env(format!("AR_{}", target), ar)
 591                      .env("AR", ar)
 592                      .env(format!("RANLIB_{}", target), ranlib.clone())
 593                      .env("RANLIB", ranlib);
 594             }
 595
 596             if let Ok(cxx) = self.cxx(target) {
 597                 cargo.env(format!("CXX_{}", target), cxx)
 598                      .env("CXX", cxx)
 599                      .env(format!("CXXFLAGS_{}", target), cflags.clone())
 600                      .env("CXXFLAGS", cflags);
 601             }
 602         }
 603
 604         if mode == Mode::Libstd && self.config.extended && compiler.is_final_stage(self) {
 605             cargo.env("RUSTC_SAVE_ANALYSIS", "api".to_string());
 606         }
 607
 608         // For `cargo doc` invocations, make rustdoc print the Rust version into the docs
 609         cargo.env("RUSTDOC_CRATE_VERSION", self.build.rust_version());
 610
 611         // Environment variables *required* throughout the build
 612         //
 613         // FIXME: should update code to not require this env var
 614         cargo.env("CFG_COMPILER_HOST_TRIPLE", target);
 615
 616         // Set this for all builds to make sure doc builds also get it.
 617         cargo.env("CFG_RELEASE_CHANNEL", &self.build.config.channel);
 618
 619         if self.is_very_verbose() {
 620             cargo.arg("-v");
 621         }
 622         if self.config.rust_optimize {
 623             // FIXME: cargo bench does not accept `--release`
 624             if cmd != "bench" {
 625                 cargo.arg("--release");
 626             }
 627
 628             if mode != Mode::Libstd && // FIXME(#45320)
 629                mode != Mode::Libtest && // FIXME(#45511)
 630                self.config.rust_codegen_units.is_none() &&
 631                self.build.is_rust_llvm(compiler.host)
 632             {
 633                 cargo.env("RUSTC_THINLTO", "1");
 634             }
 635         }
 636         if self.config.locked_deps {
 637             cargo.arg("--locked");
 638         }
 639         if self.config.vendor || self.is_sudo {
 640             cargo.arg("--frozen");
 641         }
 642
 643         self.ci_env.force_coloring_in_ci(&mut cargo);
 644
 645         cargo
 646     }
 647
 648     /// Ensure that a given step is built, returning it's output. This will
 649     /// cache the step, so it is safe (and good!) to call this as often as
 650     /// needed to ensure that all dependencies are built.
 651     pub fn ensure<S: Step>(&'a self, step: S) -> S::Output {
 652         {
 653             let mut stack = self.stack.borrow_mut();
 654             for stack_step in stack.iter() {
 655                 // should skip
 656                 if stack_step.downcast_ref::<S>().map_or(true, |stack_step| *stack_step != step) {
 657                     continue;
 658                 }
 659                 let mut out = String::new();
 660                 out += &format!("\n\nCycle in build detected when adding {:?}\n", step);
 661                 for el in stack.iter().rev() {
 662                     out += &format!("\t{:?}\n", el);
 663                 }
 664                 panic!(out);
 665             }
 666             if let Some(out) = self.cache.get(&step) {
 667                 self.build.verbose(&format!("{}c {:?}", "  ".repeat(stack.len()), step));
 668
 669                 return out;
 670             }
 671             self.build.verbose(&format!("{}> {:?}", "  ".repeat(stack.len()), step));
 672             stack.push(Box::new(step.clone()));
 673         }
 674         let out = step.clone().run(self);
 675         {
 676             let mut stack = self.stack.borrow_mut();
 677             let cur_step = stack.pop().expect("step stack empty");
 678             assert_eq!(cur_step.downcast_ref(), Some(&step));
 679         }
 680         self.build.verbose(&format!("{}< {:?}", "  ".repeat(self.stack.borrow().len()), step));
 681         self.cache.put(step, out.clone());
 682         out
 683     }
 684 }