src/bootstrap/tool.rs

   1 use std::fs;
   2 use std::env;
   3 use std::path::PathBuf;
   4 use std::process::{Command, exit};
   5 use std::collections::HashSet;
   6
   7 use build_helper::t;
   8
   9 use crate::Mode;
  10 use crate::Compiler;
  11 use crate::builder::{Step, RunConfig, ShouldRun, Builder};
  12 use crate::util::{exe, add_lib_path};
  13 use crate::compile;
  14 use crate::channel::GitInfo;
  15 use crate::channel;
  16 use crate::cache::Interned;
  17 use crate::toolstate::ToolState;
  18
  19 #[derive(Debug, 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 => {
  57                 builder.ensure(compile::Rustc { compiler, target })
  58             }
  59             Mode::ToolStd => {
  60                 builder.ensure(compile::Std { compiler, target })
  61             }
  62             Mode::ToolBootstrap => {} // uses downloaded stage0 compiler libs
  63             _ => panic!("unexpected Mode for tool build")
  64         }
  65
  66         let mut cargo = prepare_tool_cargo(
  67             builder,
  68             compiler,
  69             self.mode,
  70             target,
  71             "build",
  72             path,
  73             self.source_type,
  74             &self.extra_features,
  75         );
  76
  77         builder.info(&format!("Building stage{} tool {} ({})", compiler.stage, tool, target));
  78         let mut duplicates = Vec::new();
  79         let is_expected = compile::stream_cargo(builder, &mut cargo, vec![], &mut |msg| {
  80             // Only care about big things like the RLS/Cargo for now
  81             match tool {
  82                 | "rls"
  83                 | "cargo"
  84                 | "clippy-driver"
  85                 | "miri"
  86                 | "rustfmt"
  87                 => {}
  88
  89                 _ => return,
  90             }
  91             let (id, features, filenames) = match msg {
  92                 compile::CargoMessage::CompilerArtifact {
  93                     package_id,
  94                     features,
  95                     filenames,
  96                     target: _,
  97                 } => {
  98                     (package_id, features, filenames)
  99                 }
 100                 _ => return,
 101             };
 102             let features = features.iter().map(|s| s.to_string()).collect::<Vec<_>>();
 103
 104             for path in filenames {
 105                 let val = (tool, PathBuf::from(&*path), features.clone());
 106                 // we're only interested in deduplicating rlibs for now
 107                 if val.1.extension().and_then(|s| s.to_str()) != Some("rlib") {
 108                     continue
 109                 }
 110
 111                 // Don't worry about compiles that turn out to be host
 112                 // dependencies or build scripts. To skip these we look for
 113                 // anything that goes in `.../release/deps` but *doesn't* go in
 114                 // `$target/release/deps`. This ensure that outputs in
 115                 // `$target/release` are still considered candidates for
 116                 // deduplication.
 117                 if let Some(parent) = val.1.parent() {
 118                     if parent.ends_with("release/deps") {
 119                         let maybe_target = parent
 120                             .parent()
 121                             .and_then(|p| p.parent())
 122                             .and_then(|p| p.file_name())
 123                             .and_then(|p| p.to_str())
 124                             .unwrap();
 125                         if maybe_target != &*target {
 126                             continue;
 127                         }
 128                     }
 129                 }
 130
 131                 // Record that we've built an artifact for `id`, and if one was
 132                 // already listed then we need to see if we reused the same
 133                 // artifact or produced a duplicate.
 134                 let mut artifacts = builder.tool_artifacts.borrow_mut();
 135                 let prev_artifacts = artifacts
 136                     .entry(target)
 137                     .or_default();
 138                 let prev = match prev_artifacts.get(&*id) {
 139                     Some(prev) => prev,
 140                     None => {
 141                         prev_artifacts.insert(id.to_string(), val);
 142                         continue;
 143                     }
 144                 };
 145                 if prev.1 == val.1 {
 146                     return; // same path, same artifact
 147                 }
 148
 149                 // If the paths are different and one of them *isn't* inside of
 150                 // `release/deps`, then it means it's probably in
 151                 // `$target/release`, or it's some final artifact like
 152                 // `libcargo.rlib`. In these situations Cargo probably just
 153                 // copied it up from `$target/release/deps/libcargo-xxxx.rlib`,
 154                 // so if the features are equal we can just skip it.
 155                 let prev_no_hash = prev.1.parent().unwrap().ends_with("release/deps");
 156                 let val_no_hash = val.1.parent().unwrap().ends_with("release/deps");
 157                 if prev.2 == val.2 || !prev_no_hash || !val_no_hash {
 158                     return;
 159                 }
 160
 161                 // ... and otherwise this looks like we duplicated some sort of
 162                 // compilation, so record it to generate an error later.
 163                 duplicates.push((
 164                     id.to_string(),
 165                     val,
 166                     prev.clone(),
 167                 ));
 168             }
 169         });
 170
 171         if is_expected && !duplicates.is_empty() {
 172             println!("duplicate artifacts found when compiling a tool, this \
 173                       typically means that something was recompiled because \
 174                       a transitive dependency has different features activated \
 175                       than in a previous build:\n");
 176             println!("the following dependencies are duplicated although they \
 177                       have the same features enabled:");
 178             for (id, cur, prev) in duplicates.drain_filter(|(_, cur, prev)| cur.2 == prev.2) {
 179                 println!("  {}", id);
 180                 // same features
 181                 println!("    `{}` ({:?})\n    `{}` ({:?})", cur.0, cur.1, prev.0, prev.1);
 182             }
 183             println!("the following dependencies have different features:");
 184             for (id, cur, prev) in duplicates {
 185                 println!("  {}", id);
 186                 let cur_features: HashSet<_> = cur.2.into_iter().collect();
 187                 let prev_features: HashSet<_> = prev.2.into_iter().collect();
 188                 println!("    `{}` additionally enabled features {:?} at {:?}",
 189                          cur.0, &cur_features - &prev_features, cur.1);
 190                 println!("    `{}` additionally enabled features {:?} at {:?}",
 191                          prev.0, &prev_features - &cur_features, prev.1);
 192             }
 193             println!();
 194             println!("to fix this you will probably want to edit the local \
 195                       src/tools/rustc-workspace-hack/Cargo.toml crate, as \
 196                       that will update the dependency graph to ensure that \
 197                       these crates all share the same feature set");
 198             panic!("tools should not compile multiple copies of the same crate");
 199         }
 200
 201         builder.save_toolstate(tool, if is_expected {
 202             ToolState::TestFail
 203         } else {
 204             ToolState::BuildFail
 205         });
 206
 207         if !is_expected {
 208             if !is_optional_tool {
 209                 exit(1);
 210             } else {
 211                 None
 212             }
 213         } else {
 214             let cargo_out = builder.cargo_out(compiler, self.mode, target)
 215                 .join(exe(tool, &compiler.host));
 216             let bin = builder.tools_dir(compiler).join(exe(tool, &compiler.host));
 217             builder.copy(&cargo_out, &bin);
 218             Some(bin)
 219         }
 220     }
 221 }
 222
 223 pub fn prepare_tool_cargo(
 224     builder: &Builder<'_>,
 225     compiler: Compiler,
 226     mode: Mode,
 227     target: Interned<String>,
 228     command: &'static str,
 229     path: &'static str,
 230     source_type: SourceType,
 231     extra_features: &[String],
 232 ) -> Command {
 233     let mut cargo = builder.cargo(compiler, mode, target, command);
 234     let dir = builder.src.join(path);
 235     cargo.arg("--manifest-path").arg(dir.join("Cargo.toml"));
 236
 237     // We don't want to build tools dynamically as they'll be running across
 238     // stages and such and it's just easier if they're not dynamically linked.
 239     cargo.env("RUSTC_NO_PREFER_DYNAMIC", "1");
 240
 241     if source_type == SourceType::Submodule {
 242         cargo.env("RUSTC_EXTERNAL_TOOL", "1");
 243     }
 244
 245     let mut features = extra_features.iter().cloned().collect::<Vec<_>>();
 246     if builder.build.config.cargo_native_static {
 247         if path.ends_with("cargo") ||
 248             path.ends_with("rls") ||
 249             path.ends_with("clippy") ||
 250             path.ends_with("miri") ||
 251             path.ends_with("rustfmt")
 252         {
 253             cargo.env("LIBZ_SYS_STATIC", "1");
 254             features.push("rustc-workspace-hack/all-static".to_string());
 255         }
 256     }
 257
 258     // if tools are using lzma we want to force the build script to build its
 259     // own copy
 260     cargo.env("LZMA_API_STATIC", "1");
 261
 262     cargo.env("CFG_RELEASE_CHANNEL", &builder.config.channel);
 263     cargo.env("CFG_VERSION", builder.rust_version());
 264     cargo.env("CFG_RELEASE_NUM", channel::CFG_RELEASE_NUM);
 265
 266     let info = GitInfo::new(builder.config.ignore_git, &dir);
 267     if let Some(sha) = info.sha() {
 268         cargo.env("CFG_COMMIT_HASH", sha);
 269     }
 270     if let Some(sha_short) = info.sha_short() {
 271         cargo.env("CFG_SHORT_COMMIT_HASH", sha_short);
 272     }
 273     if let Some(date) = info.commit_date() {
 274         cargo.env("CFG_COMMIT_DATE", date);
 275     }
 276     if !features.is_empty() {
 277         cargo.arg("--features").arg(&features.join(", "));
 278     }
 279     cargo
 280 }
 281
 282 macro_rules! bootstrap_tool {
 283     ($(
 284         $name:ident, $path:expr, $tool_name:expr
 285         $(,llvm_tools = $llvm:expr)*
 286         $(,is_external_tool = $external:expr)*
 287         ;
 288     )+) => {
 289         #[derive(Copy, PartialEq, Eq, Clone)]
 290         pub enum Tool {
 291             $(
 292                 $name,
 293             )+
 294         }
 295
 296         impl Tool {
 297             /// Whether this tool requires LLVM to run
 298             pub fn uses_llvm_tools(&self) -> bool {
 299                 match self {
 300                     $(Tool::$name => false $(|| $llvm)*,)+
 301                 }
 302             }
 303         }
 304
 305         impl<'a> Builder<'a> {
 306             pub fn tool_exe(&self, tool: Tool) -> PathBuf {
 307                 match tool {
 308                     $(Tool::$name =>
 309                         self.ensure($name {
 310                             compiler: self.compiler(0, self.config.build),
 311                             target: self.config.build,
 312                         }),
 313                     )+
 314                 }
 315             }
 316         }
 317
 318         $(
 319             #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 320         pub struct $name {
 321             pub compiler: Compiler,
 322             pub target: Interned<String>,
 323         }
 324
 325         impl Step for $name {
 326             type Output = PathBuf;
 327
 328             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 329                 run.path($path)
 330             }
 331
 332             fn make_run(run: RunConfig<'_>) {
 333                 run.builder.ensure($name {
 334                     // snapshot compiler
 335                     compiler: run.builder.compiler(0, run.builder.config.build),
 336                     target: run.target,
 337                 });
 338             }
 339
 340             fn run(self, builder: &Builder<'_>) -> PathBuf {
 341                 builder.ensure(ToolBuild {
 342                     compiler: self.compiler,
 343                     target: self.target,
 344                     tool: $tool_name,
 345                     mode: Mode::ToolBootstrap,
 346                     path: $path,
 347                     is_optional_tool: false,
 348                     source_type: if false $(|| $external)* {
 349                         SourceType::Submodule
 350                     } else {
 351                         SourceType::InTree
 352                     },
 353                     extra_features: Vec::new(),
 354                 }).expect("expected to build -- essential tool")
 355             }
 356         }
 357         )+
 358     }
 359 }
 360
 361 bootstrap_tool!(
 362     Rustbook, "src/tools/rustbook", "rustbook";
 363     UnstableBookGen, "src/tools/unstable-book-gen", "unstable-book-gen";
 364     Tidy, "src/tools/tidy", "tidy";
 365     Linkchecker, "src/tools/linkchecker", "linkchecker";
 366     CargoTest, "src/tools/cargotest", "cargotest";
 367     Compiletest, "src/tools/compiletest", "compiletest", llvm_tools = true;
 368     BuildManifest, "src/tools/build-manifest", "build-manifest";
 369     RemoteTestClient, "src/tools/remote-test-client", "remote-test-client";
 370     RustInstaller, "src/tools/rust-installer", "fabricate", is_external_tool = true;
 371     RustdocTheme, "src/tools/rustdoc-themes", "rustdoc-themes";
 372 );
 373
 374 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 375 pub struct ErrorIndex {
 376     pub compiler: Compiler,
 377 }
 378
 379 impl ErrorIndex {
 380     pub fn command(builder: &Builder<'_>, compiler: Compiler) -> Command {
 381         let mut cmd = Command::new(builder.ensure(ErrorIndex {
 382             compiler
 383         }));
 384         add_lib_path(
 385             vec![PathBuf::from(&builder.sysroot_libdir(compiler, compiler.host))],
 386             &mut cmd,
 387         );
 388         cmd
 389     }
 390 }
 391
 392 impl Step for ErrorIndex {
 393     type Output = PathBuf;
 394
 395     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 396         run.path("src/tools/error_index_generator")
 397     }
 398
 399     fn make_run(run: RunConfig<'_>) {
 400         // Compile the error-index in the same stage as rustdoc to avoid
 401         // recompiling rustdoc twice if we can.
 402         let stage = if run.builder.top_stage >= 2 { run.builder.top_stage } else { 0 };
 403         run.builder.ensure(ErrorIndex {
 404             compiler: run.builder.compiler(stage, run.builder.config.build),
 405         });
 406     }
 407
 408     fn run(self, builder: &Builder<'_>) -> PathBuf {
 409         builder.ensure(ToolBuild {
 410             compiler: self.compiler,
 411             target: self.compiler.host,
 412             tool: "error_index_generator",
 413             mode: Mode::ToolRustc,
 414             path: "src/tools/error_index_generator",
 415             is_optional_tool: false,
 416             source_type: SourceType::InTree,
 417             extra_features: Vec::new(),
 418         }).expect("expected to build -- essential tool")
 419     }
 420 }
 421
 422 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 423 pub struct RemoteTestServer {
 424     pub compiler: Compiler,
 425     pub target: Interned<String>,
 426 }
 427
 428 impl Step for RemoteTestServer {
 429     type Output = PathBuf;
 430
 431     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 432         run.path("src/tools/remote-test-server")
 433     }
 434
 435     fn make_run(run: RunConfig<'_>) {
 436         run.builder.ensure(RemoteTestServer {
 437             compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
 438             target: run.target,
 439         });
 440     }
 441
 442     fn run(self, builder: &Builder<'_>) -> PathBuf {
 443         builder.ensure(ToolBuild {
 444             compiler: self.compiler,
 445             target: self.target,
 446             tool: "remote-test-server",
 447             mode: Mode::ToolStd,
 448             path: "src/tools/remote-test-server",
 449             is_optional_tool: false,
 450             source_type: SourceType::InTree,
 451             extra_features: Vec::new(),
 452         }).expect("expected to build -- essential tool")
 453     }
 454 }
 455
 456 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 457 pub struct Rustdoc {
 458     /// This should only ever be 0 or 2.
 459     /// We sometimes want to reference the "bootstrap" rustdoc, which is why this option is here.
 460     pub compiler: Compiler,
 461 }
 462
 463 impl Step for Rustdoc {
 464     type Output = PathBuf;
 465     const DEFAULT: bool = true;
 466     const ONLY_HOSTS: bool = true;
 467
 468     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 469         run.path("src/tools/rustdoc")
 470     }
 471
 472     fn make_run(run: RunConfig<'_>) {
 473         run.builder.ensure(Rustdoc {
 474             compiler: run.builder.compiler(run.builder.top_stage, run.host),
 475         });
 476     }
 477
 478     fn run(self, builder: &Builder<'_>) -> PathBuf {
 479         let target_compiler = self.compiler;
 480         if target_compiler.stage == 0 {
 481             if !target_compiler.is_snapshot(builder) {
 482                 panic!("rustdoc in stage 0 must be snapshot rustdoc");
 483             }
 484             return builder.initial_rustc.with_file_name(exe("rustdoc", &target_compiler.host));
 485         }
 486         let target = target_compiler.host;
 487         // Similar to `compile::Assemble`, build with the previous stage's compiler. Otherwise
 488         // we'd have stageN/bin/rustc and stageN/bin/rustdoc be effectively different stage
 489         // compilers, which isn't what we want. Rustdoc should be linked in the same way as the
 490         // rustc compiler it's paired with, so it must be built with the previous stage compiler.
 491         let build_compiler = builder.compiler(target_compiler.stage - 1, builder.config.build);
 492
 493         // The presence of `target_compiler` ensures that the necessary libraries (codegen backends,
 494         // compiler libraries, ...) are built. Rustdoc does not require the presence of any
 495         // libraries within sysroot_libdir (i.e., rustlib), though doctests may want it (since
 496         // they'll be linked to those libraries). As such, don't explicitly `ensure` any additional
 497         // libraries here. The intuition here is that If we've built a compiler, we should be able
 498         // to build rustdoc.
 499
 500         let mut cargo = prepare_tool_cargo(
 501             builder,
 502             build_compiler,
 503             Mode::ToolRustc,
 504             target,
 505             "build",
 506             "src/tools/rustdoc",
 507             SourceType::InTree,
 508             &[],
 509         );
 510
 511         builder.info(&format!("Building rustdoc for stage{} ({})",
 512             target_compiler.stage, target_compiler.host));
 513         builder.run(&mut cargo);
 514
 515         // Cargo adds a number of paths to the dylib search path on windows, which results in
 516         // the wrong rustdoc being executed. To avoid the conflicting rustdocs, we name the "tool"
 517         // rustdoc a different name.
 518         let tool_rustdoc = builder.cargo_out(build_compiler, Mode::ToolRustc, target)
 519             .join(exe("rustdoc_tool_binary", &target_compiler.host));
 520
 521         // don't create a stage0-sysroot/bin directory.
 522         if target_compiler.stage > 0 {
 523             let sysroot = builder.sysroot(target_compiler);
 524             let bindir = sysroot.join("bin");
 525             t!(fs::create_dir_all(&bindir));
 526             let bin_rustdoc = bindir.join(exe("rustdoc", &*target_compiler.host));
 527             let _ = fs::remove_file(&bin_rustdoc);
 528             builder.copy(&tool_rustdoc, &bin_rustdoc);
 529             bin_rustdoc
 530         } else {
 531             tool_rustdoc
 532         }
 533     }
 534 }
 535
 536 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 537 pub struct Cargo {
 538     pub compiler: Compiler,
 539     pub target: Interned<String>,
 540 }
 541
 542 impl Step for Cargo {
 543     type Output = PathBuf;
 544     const DEFAULT: bool = true;
 545     const ONLY_HOSTS: bool = true;
 546
 547     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 548         let builder = run.builder;
 549         run.path("src/tools/cargo").default_condition(builder.config.extended)
 550     }
 551
 552     fn make_run(run: RunConfig<'_>) {
 553         run.builder.ensure(Cargo {
 554             compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
 555             target: run.target,
 556         });
 557     }
 558
 559     fn run(self, builder: &Builder<'_>) -> PathBuf {
 560         // Cargo depends on procedural macros, so make sure the host
 561         // libstd/libproc_macro is available.
 562         builder.ensure(compile::Test {
 563             compiler: self.compiler,
 564             target: builder.config.build,
 565         });
 566         builder.ensure(ToolBuild {
 567             compiler: self.compiler,
 568             target: self.target,
 569             tool: "cargo",
 570             mode: Mode::ToolRustc,
 571             path: "src/tools/cargo",
 572             is_optional_tool: false,
 573             source_type: SourceType::Submodule,
 574             extra_features: Vec::new(),
 575         }).expect("expected to build -- essential tool")
 576     }
 577 }
 578
 579 macro_rules! tool_extended {
 580     (($sel:ident, $builder:ident),
 581        $($name:ident,
 582        $toolstate:ident,
 583        $path:expr,
 584        $tool_name:expr,
 585        $extra_deps:block;)+) => {
 586         $(
 587             #[derive(Debug, Clone, Hash, PartialEq, Eq)]
 588         pub struct $name {
 589             pub compiler: Compiler,
 590             pub target: Interned<String>,
 591             pub extra_features: Vec<String>,
 592         }
 593
 594         impl Step for $name {
 595             type Output = Option<PathBuf>;
 596             const DEFAULT: bool = true;
 597             const ONLY_HOSTS: bool = true;
 598
 599             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
 600                 let builder = run.builder;
 601                 run.path($path).default_condition(builder.config.extended)
 602             }
 603
 604             fn make_run(run: RunConfig<'_>) {
 605                 run.builder.ensure($name {
 606                     compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
 607                     target: run.target,
 608                     extra_features: Vec::new(),
 609                 });
 610             }
 611
 612             #[allow(unused_mut)]
 613             fn run(mut $sel, $builder: &Builder<'_>) -> Option<PathBuf> {
 614                 $extra_deps
 615                 $builder.ensure(ToolBuild {
 616                     compiler: $sel.compiler,
 617                     target: $sel.target,
 618                     tool: $tool_name,
 619                     mode: Mode::ToolRustc,
 620                     path: $path,
 621                     extra_features: $sel.extra_features,
 622                     is_optional_tool: true,
 623                     source_type: SourceType::Submodule,
 624                 })
 625             }
 626         }
 627         )+
 628     }
 629 }
 630
 631 tool_extended!((self, builder),
 632     Cargofmt, rustfmt, "src/tools/rustfmt", "cargo-fmt", {};
 633     CargoClippy, clippy, "src/tools/clippy", "cargo-clippy", {
 634         // Clippy depends on procedural macros, so make sure that's built for
 635         // the compiler itself.
 636         builder.ensure(compile::Test {
 637             compiler: self.compiler,
 638             target: builder.config.build,
 639         });
 640     };
 641     Clippy, clippy, "src/tools/clippy", "clippy-driver", {
 642         // Clippy depends on procedural macros, so make sure that's built for
 643         // the compiler itself.
 644         builder.ensure(compile::Test {
 645             compiler: self.compiler,
 646             target: builder.config.build,
 647         });
 648     };
 649     Miri, miri, "src/tools/miri", "miri", {};
 650     CargoMiri, miri, "src/tools/miri", "cargo-miri", {
 651         // Miri depends on procedural macros, so make sure that's built for
 652         // the compiler itself.
 653         builder.ensure(compile::Test {
 654             compiler: self.compiler,
 655             target: builder.config.build,
 656         });
 657     };
 658     Rls, rls, "src/tools/rls", "rls", {
 659         let clippy = builder.ensure(Clippy {
 660             compiler: self.compiler,
 661             target: self.target,
 662             extra_features: Vec::new(),
 663         });
 664         if clippy.is_some() {
 665             self.extra_features.push("clippy".to_owned());
 666         }
 667         // RLS depends on procedural macros, so make sure that's built for
 668         // the compiler itself.
 669         builder.ensure(compile::Test {
 670             compiler: self.compiler,
 671             target: builder.config.build,
 672         });
 673     };
 674     Rustfmt, rustfmt, "src/tools/rustfmt", "rustfmt", {};
 675 );
 676
 677 impl<'a> Builder<'a> {
 678     /// Gets a `Command` which is ready to run `tool` in `stage` built for
 679     /// `host`.
 680     pub fn tool_cmd(&self, tool: Tool) -> Command {
 681         let mut cmd = Command::new(self.tool_exe(tool));
 682         let compiler = self.compiler(0, self.config.build);
 683         let host = &compiler.host;
 684         // Prepares the `cmd` provided to be able to run the `compiler` provided.
 685         //
 686         // Notably this munges the dynamic library lookup path to point to the
 687         // right location to run `compiler`.
 688         let mut lib_paths: Vec<PathBuf> = vec![
 689             self.build.rustc_snapshot_libdir(),
 690             self.cargo_out(compiler, Mode::ToolBootstrap, *host).join("deps"),
 691         ];
 692
 693         // On MSVC a tool may invoke a C compiler (e.g., compiletest in run-make
 694         // mode) and that C compiler may need some extra PATH modification. Do
 695         // so here.
 696         if compiler.host.contains("msvc") {
 697             let curpaths = env::var_os("PATH").unwrap_or_default();
 698             let curpaths = env::split_paths(&curpaths).collect::<Vec<_>>();
 699             for &(ref k, ref v) in self.cc[&compiler.host].env() {
 700                 if k != "PATH" {
 701                     continue
 702                 }
 703                 for path in env::split_paths(v) {
 704                     if !curpaths.contains(&path) {
 705                         lib_paths.push(path);
 706                     }
 707                 }
 708             }
 709         }
 710
 711         add_lib_path(lib_paths, &mut cmd);
 712         cmd
 713     }
 714 }