src/bootstrap/tool.rs

   1 use std::collections::HashSet;
   2 use std::env;
   3 use std::fs;
   4 use std::path::PathBuf;
   5 use std::process::{exit, Command};
   6
   7 use build_helper::t;
   8
   9 use crate::builder::{Builder, Cargo as CargoCommand, RunConfig, ShouldRun, Step};
  10 use crate::cache::Interned;
  11 use crate::channel;
  12 use crate::channel::GitInfo;
  13 use crate::compile;
  14 use crate::toolstate::ToolState;
  15 use crate::util::{add_dylib_path, exe};
  16 use crate::Compiler;
  17 use crate::Mode;
  18
  19 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
  20 pub enum SourceType {
  21     InTree,
  22     Submodule,
  23 }
  24
  25 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
  26 struct ToolBuild {
  27     compiler: Compiler,
  28     target: Interned<String>,
  29     tool: &'static str,
  30     path: &'static str,
  31     mode: Mode,
  32     is_optional_tool: bool,
  33     source_type: SourceType,
  34     extra_features: Vec<String>,
  35 }
  36
  37 impl Step for ToolBuild {
  38     type Output = Option<PathBuf>;
  39
  40     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
  41         run.never()
  42     }
  43
  44     /// Builds a tool in `src/tools`
  45     ///
  46     /// This will build the specified tool with the specified `host` compiler in
  47     /// `stage` into the normal cargo output directory.
  48     fn run(self, builder: &Builder<'_>) -> Option<PathBuf> {
  49         let compiler = self.compiler;
  50         let target = self.target;
  51         let tool = self.tool;
  52         let path = self.path;
  53         let is_optional_tool = self.is_optional_tool;
  54
  55         match self.mode {
  56             Mode::ToolRustc => builder.ensure(compile::Rustc { compiler, target }),
  57             Mode::ToolStd => builder.ensure(compile::Std { compiler, target }),
  58             Mode::ToolBootstrap => {} // uses downloaded stage0 compiler libs
  59             _ => panic!("unexpected Mode for tool build"),
  60         }
  61
  62         let cargo = prepare_tool_cargo(
  63             builder,
  64             compiler,
  65             self.mode,
  66             target,
  67             "build",
  68             path,
  69             self.source_type,
  70             &self.extra_features,
  71         );
  72
  73         builder.info(&format!("Building stage{} tool {} ({})", compiler.stage, tool, target));
  74         let mut duplicates = Vec::new();
  75         let is_expected = compile::stream_cargo(builder, cargo, vec![], &mut |msg| {
  76             // Only care about big things like the RLS/Cargo for now
  77             match tool {
  78                 "rls" | "cargo" | "clippy-driver" | "miri" | "rustfmt" => {}
  79
  80                 _ => return,
  81             }
  82             let (id, features, filenames) = match msg {
  83                 compile::CargoMessage::CompilerArtifact {
  84                     package_id,
  85                     features,
  86                     filenames,
  87                     target: _,
  88                 } => (package_id, features, filenames),
  89                 _ => return,
  90             };
  91             let features = features.iter().map(|s| s.to_string()).collect::<Vec<_>>();
  92
  93             for path in filenames {
  94                 let val = (tool, PathBuf::from(&*path), features.clone());
  95                 // we're only interested in deduplicating rlibs for now
  96                 if val.1.extension().and_then(|s| s.to_str()) != Some("rlib") {
  97                     continue;
  98                 }
  99
 100                 // Don't worry about compiles that turn out to be host
 101                 // dependencies or build scripts. To skip these we look for
 102                 // anything that goes in `.../release/deps` but *doesn't* go in
 103                 // `$target/release/deps`. This ensure that outputs in
 104                 // `$target/release` are still considered candidates for
 105                 // deduplication.
 106                 if let Some(parent) = val.1.parent() {
 107                     if parent.ends_with("release/deps") {
 108                         let maybe_target = parent
 109                             .parent()
 110                             .and_then(|p| p.parent())
 111                             .and_then(|p| p.file_name())
 112                             .and_then(|p| p.to_str())
 113                             .unwrap();
 114                         if maybe_target != &*target {
 115                             continue;
 116                         }
 117                     }
 118                 }
 119
 120                 // Record that we've built an artifact for `id`, and if one was
 121                 // already listed then we need to see if we reused the same
 122                 // artifact or produced a duplicate.
 123                 let mut artifacts = builder.tool_artifacts.borrow_mut();
 124                 let prev_artifacts = artifacts.entry(target).or_default();
 125                 let prev = match prev_artifacts.get(&*id) {
 126                     Some(prev) => prev,
 127                     None => {
 128                         prev_artifacts.insert(id.to_string(), val);
 129                         continue;
 130                     }
 131                 };
 132                 if prev.1 == val.1 {
 133                     return; // same path, same artifact
 134                 }
 135
 136                 // If the paths are different and one of them *isn't* inside of
 137                 // `release/deps`, then it means it's probably in
 138                 // `$target/release`, or it's some final artifact like
 139                 // `libcargo.rlib`. In these situations Cargo probably just
 140                 // copied it up from `$target/release/deps/libcargo-xxxx.rlib`,
 141                 // so if the features are equal we can just skip it.
 142                 let prev_no_hash = prev.1.parent().unwrap().ends_with("release/deps");
 143                 let val_no_hash = val.1.parent().unwrap().ends_with("release/deps");
 144                 if prev.2 == val.2 || !prev_no_hash || !val_no_hash {
 145                     return;
 146                 }
 147
 148                 // ... and otherwise this looks like we duplicated some sort of
 149                 // compilation, so record it to generate an error later.
 150                 duplicates.push((id.to_string(), val, prev.clone()));
 151             }
 152         });
 153
 154         if is_expected && !duplicates.is_empty() {
 155             println!(
 156                 "duplicate artifacts found when compiling a tool, this \
 157                       typically means that something was recompiled because \
 158                       a transitive dependency has different features activated \
 159                       than in a previous build:\n"
 160             );
 161             println!(
 162                 "the following dependencies are duplicated although they \
 163                       have the same features enabled:"
 164             );
 165             for (id, cur, prev) in duplicates.drain_filter(|(_, cur, prev)| cur.2 == prev.2) {
 166                 println!("  {}", id);
 167                 // same features
 168                 println!("    `{}` ({:?})\n    `{}` ({:?})", cur.0, cur.1, prev.0, prev.1);
 169             }
 170             println!("the following dependencies have different features:");
 171             for (id, cur, prev) in duplicates {
 172                 println!("  {}", id);
 173                 let cur_features: HashSet<_> = cur.2.into_iter().collect();
 174                 let prev_features: HashSet<_> = prev.2.into_iter().collect();
 175                 println!(
 176                     "    `{}` additionally enabled features {:?} at {:?}",
 177                     cur.0,
 178                     &cur_features - &prev_features,
 179                     cur.1
 180                 );
 181                 println!(
 182                     "    `{}` additionally enabled features {:?} at {:?}",
 183                     prev.0,
 184                     &prev_features - &cur_features,
 185                     prev.1
 186                 );
 187             }
 188             println!();
 189             println!(
 190                 "to fix this you will probably want to edit the local \
 191                       src/tools/rustc-workspace-hack/Cargo.toml crate, as \
 192                       that will update the dependency graph to ensure that \
 193                       these crates all share the same feature set"
 194             );
 195             panic!("tools should not compile multiple copies of the same crate");
 196         }
 197
 198         builder.save_toolstate(
 199             tool,
 200             if is_expected { ToolState::TestFail } else { ToolState::BuildFail },
 201         );
 202
 203         if !is_expected {
 204             if !is_optional_tool {
 205                 exit(1);
 206             } else {
 207                 None
 208             }
 209         } else {
 210             let cargo_out =
 211                 builder.cargo_out(compiler, self.mode, target).join(exe(tool, &compiler.host));
 212             let bin = builder.tools_dir(compiler).join(exe(tool, &compiler.host));
 213             builder.copy(&cargo_out, &bin);
 214             Some(bin)
 215         }
 216     }
 217 }
 218
 219 pub fn prepare_tool_cargo(
 220     builder: &Builder<'_>,
 221     compiler: Compiler,
 222     mode: Mode,
 223     target: Interned<String>,
 224     command: &'static str,
 225     path: &'static str,
 226     source_type: SourceType,
 227     extra_features: &[String],
 228 ) -> CargoCommand {
 229     let mut cargo = builder.cargo(compiler, mode, source_type, target, command);
 230     let dir = builder.src.join(path);
 231     cargo.arg("--manifest-path").arg(dir.join("Cargo.toml"));
 232
 233     let mut features = extra_features.to_vec();
 234     if builder.build.config.cargo_native_static {
 235         if path.ends_with("cargo")
 236             || path.ends_with("rls")
 237             || path.ends_with("clippy")
 238             || path.ends_with("miri")
 239             || path.ends_with("rustfmt")
 240         {
 241             cargo.env("LIBZ_SYS_STATIC", "1");
 242             features.push("rustc-workspace-hack/all-static".to_string());
 243         }
 244     }
 245
 246     // if tools are using lzma we want to force the build script to build its
 247     // own copy
 248     cargo.env("LZMA_API_STATIC", "1");
 249
 250     // CFG_RELEASE is needed by rustfmt (and possibly other tools) which
 251     // import rustc-ap-rustc_attr which requires this to be set for the
 252     // `#[cfg(version(...))]` attribute.
 253     cargo.env("CFG_RELEASE", builder.rust_release());
 254     cargo.env("CFG_RELEASE_CHANNEL", &builder.config.channel);
 255     cargo.env("CFG_VERSION", builder.rust_version());
 256     cargo.env("CFG_RELEASE_NUM", channel::CFG_RELEASE_NUM);
 257
 258     let info = GitInfo::new(builder.config.ignore_git, &dir);
 259     if let Some(sha) = info.sha() {
 260         cargo.env("CFG_COMMIT_HASH", sha);
 261     }
 262     if let Some(sha_short) = info.sha_short() {
 263         cargo.env("CFG_SHORT_COMMIT_HASH", sha_short);
 264     }
 265     if let Some(date) = info.commit_date() {
 266         cargo.env("CFG_COMMIT_DATE", date);
 267     }
 268     if !features.is_empty() {
 269         cargo.arg("--features").arg(&features.join(", "));
 270     }
 271     cargo
 272 }
 273
 274 macro_rules! bootstrap_tool {
 275     ($(
 276         $name:ident, $path:expr, $tool_name:expr
 277         $(,is_external_tool = $external:expr)*
 278         $(,is_unstable_tool = $unstable:expr)*
 279         $(,features = $features:expr)*
 280         ;
 281     )+) => {
 282         #[derive(Copy, PartialEq, Eq, Clone)]
 283         pub enum Tool {
 284             $(
 285                 $name,
 286             )+
 287         }
 288
 289         impl<'a> Builder<'a> {
 290             pub fn tool_exe(&self, tool: Tool) -> PathBuf {
 291                 match tool {
 292                     $(Tool::$name =>
 293                         self.ensure($name {
 294                             compiler: self.compiler(0, self.config.build),
 295                             target: self.config.build,
 296                         }),
 297                     )+
 298                 }
 299             }
 300         }
 301
 302         $(
 303             #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 304         pub struct $name {
 305             pub compiler: Compiler,
 306             pub target: Interned<String>,
 307         }
 308
 309         impl Step for $name {
 310             type Output = PathBuf;
 311
 312             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 313                 run.path($path)
 314             }
 315
 316             fn make_run(run: RunConfig<'_>) {
 317                 run.builder.ensure($name {
 318                     // snapshot compiler
 319                     compiler: run.builder.compiler(0, run.builder.config.build),
 320                     target: run.target,
 321                 });
 322             }
 323
 324             fn run(self, builder: &Builder<'_>) -> PathBuf {
 325                 builder.ensure(ToolBuild {
 326                     compiler: self.compiler,
 327                     target: self.target,
 328                     tool: $tool_name,
 329                     mode: if false $(|| $unstable)* {
 330                         // use in-tree libraries for unstable features
 331                         Mode::ToolStd
 332                     } else {
 333                         Mode::ToolBootstrap
 334                     },
 335                     path: $path,
 336                     is_optional_tool: false,
 337                     source_type: if false $(|| $external)* {
 338                         SourceType::Submodule
 339                     } else {
 340                         SourceType::InTree
 341                     },
 342                     extra_features: {
 343                         // FIXME(#60643): avoid this lint by using `_`
 344                         let mut _tmp = Vec::new();
 345                         $(_tmp.extend($features);)*
 346                         _tmp
 347                     },
 348                 }).expect("expected to build -- essential tool")
 349             }
 350         }
 351         )+
 352     }
 353 }
 354
 355 bootstrap_tool!(
 356     Rustbook, "src/tools/rustbook", "rustbook";
 357     UnstableBookGen, "src/tools/unstable-book-gen", "unstable-book-gen";
 358     Tidy, "src/tools/tidy", "tidy";
 359     Linkchecker, "src/tools/linkchecker", "linkchecker";
 360     CargoTest, "src/tools/cargotest", "cargotest";
 361     Compiletest, "src/tools/compiletest", "compiletest", is_unstable_tool = true;
 362     BuildManifest, "src/tools/build-manifest", "build-manifest";
 363     RemoteTestClient, "src/tools/remote-test-client", "remote-test-client";
 364     RustInstaller, "src/tools/rust-installer", "fabricate", is_external_tool = true;
 365     RustdocTheme, "src/tools/rustdoc-themes", "rustdoc-themes";
 366     ExpandYamlAnchors, "src/tools/expand-yaml-anchors", "expand-yaml-anchors";
 367 );
 368
 369 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 370 pub struct ErrorIndex {
 371     pub compiler: Compiler,
 372 }
 373
 374 impl ErrorIndex {
 375     pub fn command(builder: &Builder<'_>, compiler: Compiler) -> Command {
 376         let mut cmd = Command::new(builder.ensure(ErrorIndex { compiler }));
 377         add_dylib_path(
 378             vec![PathBuf::from(&builder.sysroot_libdir(compiler, compiler.host))],
 379             &mut cmd,
 380         );
 381         cmd
 382     }
 383 }
 384
 385 impl Step for ErrorIndex {
 386     type Output = PathBuf;
 387
 388     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 389         run.path("src/tools/error_index_generator")
 390     }
 391
 392     fn make_run(run: RunConfig<'_>) {
 393         // Compile the error-index in the same stage as rustdoc to avoid
 394         // recompiling rustdoc twice if we can.
 395         let stage = if run.builder.top_stage >= 2 { run.builder.top_stage } else { 0 };
 396         run.builder
 397             .ensure(ErrorIndex { compiler: run.builder.compiler(stage, run.builder.config.build) });
 398     }
 399
 400     fn run(self, builder: &Builder<'_>) -> PathBuf {
 401         builder
 402             .ensure(ToolBuild {
 403                 compiler: self.compiler,
 404                 target: self.compiler.host,
 405                 tool: "error_index_generator",
 406                 mode: Mode::ToolRustc,
 407                 path: "src/tools/error_index_generator",
 408                 is_optional_tool: false,
 409                 source_type: SourceType::InTree,
 410                 extra_features: Vec::new(),
 411             })
 412             .expect("expected to build -- essential tool")
 413     }
 414 }
 415
 416 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 417 pub struct RemoteTestServer {
 418     pub compiler: Compiler,
 419     pub target: Interned<String>,
 420 }
 421
 422 impl Step for RemoteTestServer {
 423     type Output = PathBuf;
 424
 425     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 426         run.path("src/tools/remote-test-server")
 427     }
 428
 429     fn make_run(run: RunConfig<'_>) {
 430         run.builder.ensure(RemoteTestServer {
 431             compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
 432             target: run.target,
 433         });
 434     }
 435
 436     fn run(self, builder: &Builder<'_>) -> PathBuf {
 437         builder
 438             .ensure(ToolBuild {
 439                 compiler: self.compiler,
 440                 target: self.target,
 441                 tool: "remote-test-server",
 442                 mode: Mode::ToolStd,
 443                 path: "src/tools/remote-test-server",
 444                 is_optional_tool: false,
 445                 source_type: SourceType::InTree,
 446                 extra_features: Vec::new(),
 447             })
 448             .expect("expected to build -- essential tool")
 449     }
 450 }
 451
 452 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 453 pub struct Rustdoc {
 454     /// This should only ever be 0 or 2.
 455     /// We sometimes want to reference the "bootstrap" rustdoc, which is why this option is here.
 456     pub compiler: Compiler,
 457 }
 458
 459 impl Step for Rustdoc {
 460     type Output = PathBuf;
 461     const DEFAULT: bool = true;
 462     const ONLY_HOSTS: bool = true;
 463
 464     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 465         run.path("src/tools/rustdoc").path("src/librustdoc")
 466     }
 467
 468     fn make_run(run: RunConfig<'_>) {
 469         run.builder
 470             .ensure(Rustdoc { compiler: run.builder.compiler(run.builder.top_stage, run.host) });
 471     }
 472
 473     fn run(self, builder: &Builder<'_>) -> PathBuf {
 474         let target_compiler = self.compiler;
 475         if target_compiler.stage == 0 {
 476             if !target_compiler.is_snapshot(builder) {
 477                 panic!("rustdoc in stage 0 must be snapshot rustdoc");
 478             }
 479             return builder.initial_rustc.with_file_name(exe("rustdoc", &target_compiler.host));
 480         }
 481         let target = target_compiler.host;
 482         // Similar to `compile::Assemble`, build with the previous stage's compiler. Otherwise
 483         // we'd have stageN/bin/rustc and stageN/bin/rustdoc be effectively different stage
 484         // compilers, which isn't what we want. Rustdoc should be linked in the same way as the
 485         // rustc compiler it's paired with, so it must be built with the previous stage compiler.
 486         let build_compiler = builder.compiler(target_compiler.stage - 1, builder.config.build);
 487
 488         // The presence of `target_compiler` ensures that the necessary libraries (codegen backends,
 489         // compiler libraries, ...) are built. Rustdoc does not require the presence of any
 490         // libraries within sysroot_libdir (i.e., rustlib), though doctests may want it (since
 491         // they'll be linked to those libraries). As such, don't explicitly `ensure` any additional
 492         // libraries here. The intuition here is that If we've built a compiler, we should be able
 493         // to build rustdoc.
 494
 495         let cargo = prepare_tool_cargo(
 496             builder,
 497             build_compiler,
 498             Mode::ToolRustc,
 499             target,
 500             "build",
 501             "src/tools/rustdoc",
 502             SourceType::InTree,
 503             &[],
 504         );
 505
 506         builder.info(&format!(
 507             "Building rustdoc for stage{} ({})",
 508             target_compiler.stage, target_compiler.host
 509         ));
 510         builder.run(&mut cargo.into());
 511
 512         // Cargo adds a number of paths to the dylib search path on windows, which results in
 513         // the wrong rustdoc being executed. To avoid the conflicting rustdocs, we name the "tool"
 514         // rustdoc a different name.
 515         let tool_rustdoc = builder
 516             .cargo_out(build_compiler, Mode::ToolRustc, target)
 517             .join(exe("rustdoc_tool_binary", &target_compiler.host));
 518
 519         // don't create a stage0-sysroot/bin directory.
 520         if target_compiler.stage > 0 {
 521             let sysroot = builder.sysroot(target_compiler);
 522             let bindir = sysroot.join("bin");
 523             t!(fs::create_dir_all(&bindir));
 524             let bin_rustdoc = bindir.join(exe("rustdoc", &*target_compiler.host));
 525             let _ = fs::remove_file(&bin_rustdoc);
 526             builder.copy(&tool_rustdoc, &bin_rustdoc);
 527             bin_rustdoc
 528         } else {
 529             tool_rustdoc
 530         }
 531     }
 532 }
 533
 534 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 535 pub struct Cargo {
 536     pub compiler: Compiler,
 537     pub target: Interned<String>,
 538 }
 539
 540 impl Step for Cargo {
 541     type Output = PathBuf;
 542     const DEFAULT: bool = true;
 543     const ONLY_HOSTS: bool = true;
 544
 545     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 546         let builder = run.builder;
 547         run.path("src/tools/cargo").default_condition(builder.config.extended)
 548     }
 549
 550     fn make_run(run: RunConfig<'_>) {
 551         run.builder.ensure(Cargo {
 552             compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
 553             target: run.target,
 554         });
 555     }
 556
 557     fn run(self, builder: &Builder<'_>) -> PathBuf {
 558         builder
 559             .ensure(ToolBuild {
 560                 compiler: self.compiler,
 561                 target: self.target,
 562                 tool: "cargo",
 563                 mode: Mode::ToolRustc,
 564                 path: "src/tools/cargo",
 565                 is_optional_tool: false,
 566                 source_type: SourceType::Submodule,
 567                 extra_features: Vec::new(),
 568             })
 569             .expect("expected to build -- essential tool")
 570     }
 571 }
 572
 573 macro_rules! tool_extended {
 574     (($sel:ident, $builder:ident),
 575        $($name:ident,
 576        $toolstate:ident,
 577        $path:expr,
 578        $tool_name:expr,
 579        stable = $stable:expr,
 580        $(in_tree = $in_tree:expr,)*
 581        $extra_deps:block;)+) => {
 582         $(
 583             #[derive(Debug, Clone, Hash, PartialEq, Eq)]
 584         pub struct $name {
 585             pub compiler: Compiler,
 586             pub target: Interned<String>,
 587             pub extra_features: Vec<String>,
 588         }
 589
 590         impl Step for $name {
 591             type Output = Option<PathBuf>;
 592             const DEFAULT: bool = true; // Overwritten below
 593             const ONLY_HOSTS: bool = true;
 594
 595             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 596                 let builder = run.builder;
 597                 run.path($path).default_condition(
 598                     builder.config.extended
 599                         && builder.config.tools.as_ref().map_or(
 600                             // By default, on nightly/dev enable all tools, else only
 601                             // build stable tools.
 602                             $stable || builder.build.unstable_features(),
 603                             // If `tools` is set, search list for this tool.
 604                             |tools| {
 605                                 tools.iter().any(|tool| match tool.as_ref() {
 606                                     "clippy" => $tool_name == "clippy-driver",
 607                                     x => $tool_name == x,
 608                             })
 609                         }),
 610                 )
 611             }
 612
 613             fn make_run(run: RunConfig<'_>) {
 614                 run.builder.ensure($name {
 615                     compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
 616                     target: run.target,
 617                     extra_features: Vec::new(),
 618                 });
 619             }
 620
 621             #[allow(unused_mut)]
 622             fn run(mut $sel, $builder: &Builder<'_>) -> Option<PathBuf> {
 623                 $extra_deps
 624                 $builder.ensure(ToolBuild {
 625                     compiler: $sel.compiler,
 626                     target: $sel.target,
 627                     tool: $tool_name,
 628                     mode: Mode::ToolRustc,
 629                     path: $path,
 630                     extra_features: $sel.extra_features,
 631                     is_optional_tool: true,
 632                     source_type: if false $(|| $in_tree)* {
 633                         SourceType::InTree
 634                     } else {
 635                         SourceType::Submodule
 636                     },
 637                 })
 638             }
 639         }
 640         )+
 641     }
 642 }
 643
 644 // Note: tools need to be also added to `Builder::get_step_descriptions` in `build.rs`
 645 // to make `./x.py build <tool>` work.
 646 tool_extended!((self, builder),
 647     Cargofmt, rustfmt, "src/tools/rustfmt", "cargo-fmt", stable=true, {};
 648     CargoClippy, clippy, "src/tools/clippy", "cargo-clippy", stable=true, in_tree=true, {};
 649     Clippy, clippy, "src/tools/clippy", "clippy-driver", stable=true, in_tree=true, {};
 650     Miri, miri, "src/tools/miri", "miri", stable=false, {};
 651     CargoMiri, miri, "src/tools/miri/cargo-miri", "cargo-miri", stable=false, {};
 652     Rls, rls, "src/tools/rls", "rls", stable=true, {
 653         builder.ensure(Clippy {
 654             compiler: self.compiler,
 655             target: self.target,
 656             extra_features: Vec::new(),
 657         });
 658         self.extra_features.push("clippy".to_owned());
 659     };
 660     Rustfmt, rustfmt, "src/tools/rustfmt", "rustfmt", stable=true, {};
 661 );
 662
 663 impl<'a> Builder<'a> {
 664     /// Gets a `Command` which is ready to run `tool` in `stage` built for
 665     /// `host`.
 666     pub fn tool_cmd(&self, tool: Tool) -> Command {
 667         let mut cmd = Command::new(self.tool_exe(tool));
 668         let compiler = self.compiler(0, self.config.build);
 669         let host = &compiler.host;
 670         // Prepares the `cmd` provided to be able to run the `compiler` provided.
 671         //
 672         // Notably this munges the dynamic library lookup path to point to the
 673         // right location to run `compiler`.
 674         let mut lib_paths: Vec<PathBuf> = vec![
 675             self.build.rustc_snapshot_libdir(),
 676             self.cargo_out(compiler, Mode::ToolBootstrap, *host).join("deps"),
 677         ];
 678
 679         // On MSVC a tool may invoke a C compiler (e.g., compiletest in run-make
 680         // mode) and that C compiler may need some extra PATH modification. Do
 681         // so here.
 682         if compiler.host.contains("msvc") {
 683             let curpaths = env::var_os("PATH").unwrap_or_default();
 684             let curpaths = env::split_paths(&curpaths).collect::<Vec<_>>();
 685             for &(ref k, ref v) in self.cc[&compiler.host].env() {
 686                 if k != "PATH" {
 687                     continue;
 688                 }
 689                 for path in env::split_paths(v) {
 690                     if !curpaths.contains(&path) {
 691                         lib_paths.push(path);
 692                     }
 693                 }
 694             }
 695         }
 696
 697         add_dylib_path(lib_paths, &mut cmd);
 698         cmd
 699     }
 700 }