src/bootstrap/tool.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::fs;
  12 use std::env;
  13 use std::iter;
  14 use std::path::PathBuf;
  15 use std::process::{Command, exit};
  16 use std::collections::HashSet;
  17
  18 use Mode;
  19 use Compiler;
  20 use builder::{Step, RunConfig, ShouldRun, Builder};
  21 use util::{exe, add_lib_path};
  22 use compile::{self, libtest_stamp, libstd_stamp, librustc_stamp};
  23 use native;
  24 use channel::GitInfo;
  25 use cache::Interned;
  26 use toolstate::ToolState;
  27
  28 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
  29 pub struct CleanTools {
  30     pub compiler: Compiler,
  31     pub target: Interned<String>,
  32     pub cause: Mode,
  33 }
  34
  35 impl Step for CleanTools {
  36     type Output = ();
  37
  38     fn should_run(run: ShouldRun) -> ShouldRun {
  39         run.never()
  40     }
  41
  42     fn run(self, builder: &Builder) {
  43         let compiler = self.compiler;
  44         let target = self.target;
  45         let cause = self.cause;
  46
  47         // This is for the original compiler, but if we're forced to use stage 1, then
  48         // std/test/rustc stamps won't exist in stage 2, so we need to get those from stage 1, since
  49         // we copy the libs forward.
  50         let tools_dir = builder.stage_out(compiler, Mode::ToolRustc);
  51         let compiler = if builder.force_use_stage1(compiler, target) {
  52             builder.compiler(1, compiler.host)
  53         } else {
  54             compiler
  55         };
  56
  57         for &cur_mode in &[Mode::Std, Mode::Test, Mode::Rustc] {
  58             let stamp = match cur_mode {
  59                 Mode::Std => libstd_stamp(builder, compiler, target),
  60                 Mode::Test => libtest_stamp(builder, compiler, target),
  61                 Mode::Rustc => librustc_stamp(builder, compiler, target),
  62                 _ => panic!(),
  63             };
  64
  65             if builder.clear_if_dirty(&tools_dir, &stamp) {
  66                 break;
  67             }
  68
  69             // If we are a rustc tool, and std changed, we also need to clear ourselves out -- our
  70             // dependencies depend on std. Therefore, we iterate up until our own mode.
  71             if cause == cur_mode {
  72                 break;
  73             }
  74         }
  75     }
  76 }
  77
  78 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
  79 struct ToolBuild {
  80     compiler: Compiler,
  81     target: Interned<String>,
  82     tool: &'static str,
  83     path: &'static str,
  84     mode: Mode,
  85     is_ext_tool: bool,
  86     extra_features: Vec<String>,
  87 }
  88
  89 impl Step for ToolBuild {
  90     type Output = Option<PathBuf>;
  91
  92     fn should_run(run: ShouldRun) -> ShouldRun {
  93         run.never()
  94     }
  95
  96     /// Build a tool in `src/tools`
  97     ///
  98     /// This will build the specified tool with the specified `host` compiler in
  99     /// `stage` into the normal cargo output directory.
 100     fn run(self, builder: &Builder) -> Option<PathBuf> {
 101         let compiler = self.compiler;
 102         let target = self.target;
 103         let tool = self.tool;
 104         let path = self.path;
 105         let is_ext_tool = self.is_ext_tool;
 106
 107         match self.mode {
 108             Mode::ToolRustc => {
 109                 builder.ensure(compile::Rustc { compiler, target })
 110             }
 111             Mode::ToolStd => {
 112                 builder.ensure(compile::Std { compiler, target })
 113             }
 114             Mode::ToolBootstrap => {} // uses downloaded stage0 compiler libs
 115             _ => panic!("unexpected Mode for tool build")
 116         }
 117
 118         let mut cargo = prepare_tool_cargo(builder, compiler, self.mode, target, "build", path);
 119         cargo.arg("--features").arg(self.extra_features.join(" "));
 120
 121         let _folder = builder.fold_output(|| format!("stage{}-{}", compiler.stage, tool));
 122         builder.info(&format!("Building stage{} tool {} ({})", compiler.stage, tool, target));
 123         let mut duplicates = Vec::new();
 124         let is_expected = compile::stream_cargo(builder, &mut cargo, &mut |msg| {
 125             // Only care about big things like the RLS/Cargo for now
 126             match tool {
 127                 | "rls"
 128                 | "cargo"
 129                 | "clippy-driver"
 130                 => {}
 131
 132                 _ => return,
 133             }
 134             let (id, features, filenames) = match msg {
 135                 compile::CargoMessage::CompilerArtifact {
 136                     package_id,
 137                     features,
 138                     filenames
 139                 } => {
 140                     (package_id, features, filenames)
 141                 }
 142                 _ => return,
 143             };
 144             let features = features.iter().map(|s| s.to_string()).collect::<Vec<_>>();
 145
 146             for path in filenames {
 147                 let val = (tool, PathBuf::from(&*path), features.clone());
 148                 // we're only interested in deduplicating rlibs for now
 149                 if val.1.extension().and_then(|s| s.to_str()) != Some("rlib") {
 150                     continue
 151                 }
 152
 153                 // Don't worry about libs that turn out to be host dependencies
 154                 // or build scripts, we only care about target dependencies that
 155                 // are in `deps`.
 156                 if let Some(maybe_target) = val.1
 157                     .parent()                   // chop off file name
 158                     .and_then(|p| p.parent())   // chop off `deps`
 159                     .and_then(|p| p.parent())   // chop off `release`
 160                     .and_then(|p| p.file_name())
 161                     .and_then(|p| p.to_str())
 162                 {
 163                     if maybe_target != &*target {
 164                         continue
 165                     }
 166                 }
 167
 168                 let mut artifacts = builder.tool_artifacts.borrow_mut();
 169                 let prev_artifacts = artifacts
 170                     .entry(target)
 171                     .or_insert_with(Default::default);
 172                 if let Some(prev) = prev_artifacts.get(&*id) {
 173                     if prev.1 != val.1 {
 174                         duplicates.push((
 175                             id.to_string(),
 176                             val,
 177                             prev.clone(),
 178                         ));
 179                     }
 180                     return
 181                 }
 182                 prev_artifacts.insert(id.to_string(), val);
 183             }
 184         });
 185
 186         if is_expected && duplicates.len() != 0 {
 187             println!("duplicate artfacts found when compiling a tool, this \
 188                       typically means that something was recompiled because \
 189                       a transitive dependency has different features activated \
 190                       than in a previous build:\n");
 191             println!("the following dependencies are duplicated although they \
 192                       have the same features enabled:");
 193             for (id, cur, prev) in duplicates.drain_filter(|(_, cur, prev)| cur.2 == prev.2) {
 194                 println!("  {}", id);
 195                 // same features
 196                 println!("    `{}` ({:?})\n    `{}` ({:?})", cur.0, cur.1, prev.0, prev.1);
 197             }
 198             println!("the following dependencies have different features:");
 199             for (id, cur, prev) in duplicates {
 200                 println!("  {}", id);
 201                 let cur_features: HashSet<_> = cur.2.into_iter().collect();
 202                 let prev_features: HashSet<_> = prev.2.into_iter().collect();
 203                 println!("    `{}` additionally enabled features {:?} at {:?}",
 204                          cur.0, &cur_features - &prev_features, cur.1);
 205                 println!("    `{}` additionally enabled features {:?} at {:?}",
 206                          prev.0, &prev_features - &cur_features, prev.1);
 207             }
 208             println!("");
 209             panic!("tools should not compile multiple copies of the same crate");
 210         }
 211
 212         builder.save_toolstate(tool, if is_expected {
 213             ToolState::TestFail
 214         } else {
 215             ToolState::BuildFail
 216         });
 217
 218         if !is_expected {
 219             if !is_ext_tool {
 220                 exit(1);
 221             } else {
 222                 return None;
 223             }
 224         } else {
 225             let cargo_out = builder.cargo_out(compiler, self.mode, target)
 226                 .join(exe(tool, &compiler.host));
 227             let bin = builder.tools_dir(compiler).join(exe(tool, &compiler.host));
 228             builder.copy(&cargo_out, &bin);
 229             Some(bin)
 230         }
 231     }
 232 }
 233
 234 pub fn prepare_tool_cargo(
 235     builder: &Builder,
 236     compiler: Compiler,
 237     mode: Mode,
 238     target: Interned<String>,
 239     command: &'static str,
 240     path: &'static str,
 241 ) -> Command {
 242     let mut cargo = builder.cargo(compiler, mode, target, command);
 243     let dir = builder.src.join(path);
 244     cargo.arg("--manifest-path").arg(dir.join("Cargo.toml"));
 245
 246     // We don't want to build tools dynamically as they'll be running across
 247     // stages and such and it's just easier if they're not dynamically linked.
 248     cargo.env("RUSTC_NO_PREFER_DYNAMIC", "1");
 249
 250     if let Some(dir) = builder.openssl_install_dir(target) {
 251         cargo.env("OPENSSL_STATIC", "1");
 252         cargo.env("OPENSSL_DIR", dir);
 253         cargo.env("LIBZ_SYS_STATIC", "1");
 254     }
 255
 256     // if tools are using lzma we want to force the build script to build its
 257     // own copy
 258     cargo.env("LZMA_API_STATIC", "1");
 259
 260     cargo.env("CFG_RELEASE_CHANNEL", &builder.config.channel);
 261     cargo.env("CFG_VERSION", builder.rust_version());
 262
 263     let info = GitInfo::new(&builder.config, &dir);
 264     if let Some(sha) = info.sha() {
 265         cargo.env("CFG_COMMIT_HASH", sha);
 266     }
 267     if let Some(sha_short) = info.sha_short() {
 268         cargo.env("CFG_SHORT_COMMIT_HASH", sha_short);
 269     }
 270     if let Some(date) = info.commit_date() {
 271         cargo.env("CFG_COMMIT_DATE", date);
 272     }
 273     cargo
 274 }
 275
 276 macro_rules! tool {
 277     ($($name:ident, $path:expr, $tool_name:expr, $mode:expr $(,llvm_tools = $llvm:expr)*;)+) => {
 278         #[derive(Copy, Clone)]
 279         pub enum Tool {
 280             $(
 281                 $name,
 282             )+
 283         }
 284
 285         impl Tool {
 286             pub fn get_mode(&self) -> Mode {
 287                 let mode = match self {
 288                     $(Tool::$name => $mode,)+
 289                 };
 290                 mode
 291             }
 292
 293             /// Whether this tool requires LLVM to run
 294             pub fn uses_llvm_tools(&self) -> bool {
 295                 match self {
 296                     $(Tool::$name => false $(|| $llvm)*,)+
 297                 }
 298             }
 299         }
 300
 301         impl<'a> Builder<'a> {
 302             pub fn tool_exe(&self, tool: Tool) -> PathBuf {
 303                 let stage = self.tool_default_stage(tool);
 304                 match tool {
 305                     $(Tool::$name =>
 306                         self.ensure($name {
 307                             compiler: self.compiler(stage, self.config.build),
 308                             target: self.config.build,
 309                         }),
 310                     )+
 311                 }
 312             }
 313
 314             pub fn tool_default_stage(&self, tool: Tool) -> u32 {
 315                 // Compile the error-index in the same stage as rustdoc to avoid
 316                 // recompiling rustdoc twice if we can. Otherwise compile
 317                 // everything else in stage0 as there's no need to rebootstrap
 318                 // everything.
 319                 match tool {
 320                     Tool::ErrorIndex if self.top_stage >= 2 => self.top_stage,
 321                     _ => 0,
 322                 }
 323             }
 324         }
 325
 326         $(
 327             #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 328         pub struct $name {
 329             pub compiler: Compiler,
 330             pub target: Interned<String>,
 331         }
 332
 333         impl Step for $name {
 334             type Output = PathBuf;
 335
 336             fn should_run(run: ShouldRun) -> ShouldRun {
 337                 run.path($path)
 338             }
 339
 340             fn make_run(run: RunConfig) {
 341                 run.builder.ensure($name {
 342                     compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
 343                     target: run.target,
 344                 });
 345             }
 346
 347             fn run(self, builder: &Builder) -> PathBuf {
 348                 builder.ensure(ToolBuild {
 349                     compiler: self.compiler,
 350                     target: self.target,
 351                     tool: $tool_name,
 352                     mode: $mode,
 353                     path: $path,
 354                     is_ext_tool: false,
 355                     extra_features: Vec::new(),
 356                 }).expect("expected to build -- essential tool")
 357             }
 358         }
 359         )+
 360     }
 361 }
 362
 363 tool!(
 364     Rustbook, "src/tools/rustbook", "rustbook", Mode::ToolBootstrap;
 365     ErrorIndex, "src/tools/error_index_generator", "error_index_generator", Mode::ToolRustc;
 366     UnstableBookGen, "src/tools/unstable-book-gen", "unstable-book-gen", Mode::ToolBootstrap;
 367     Tidy, "src/tools/tidy", "tidy", Mode::ToolBootstrap;
 368     Linkchecker, "src/tools/linkchecker", "linkchecker", Mode::ToolBootstrap;
 369     CargoTest, "src/tools/cargotest", "cargotest", Mode::ToolBootstrap;
 370     Compiletest, "src/tools/compiletest", "compiletest", Mode::ToolBootstrap, llvm_tools = true;
 371     BuildManifest, "src/tools/build-manifest", "build-manifest", Mode::ToolBootstrap;
 372     RemoteTestClient, "src/tools/remote-test-client", "remote-test-client", Mode::ToolBootstrap;
 373     RustInstaller, "src/tools/rust-installer", "fabricate", Mode::ToolBootstrap;
 374     RustdocTheme, "src/tools/rustdoc-themes", "rustdoc-themes", Mode::ToolBootstrap;
 375 );
 376
 377 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 378 pub struct RemoteTestServer {
 379     pub compiler: Compiler,
 380     pub target: Interned<String>,
 381 }
 382
 383 impl Step for RemoteTestServer {
 384     type Output = PathBuf;
 385
 386     fn should_run(run: ShouldRun) -> ShouldRun {
 387         run.path("src/tools/remote-test-server")
 388     }
 389
 390     fn make_run(run: RunConfig) {
 391         run.builder.ensure(RemoteTestServer {
 392             compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
 393             target: run.target,
 394         });
 395     }
 396
 397     fn run(self, builder: &Builder) -> PathBuf {
 398         builder.ensure(ToolBuild {
 399             compiler: self.compiler,
 400             target: self.target,
 401             tool: "remote-test-server",
 402             mode: Mode::ToolStd,
 403             path: "src/tools/remote-test-server",
 404             is_ext_tool: false,
 405             extra_features: Vec::new(),
 406         }).expect("expected to build -- essential tool")
 407     }
 408 }
 409
 410 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 411 pub struct Rustdoc {
 412     pub host: Interned<String>,
 413 }
 414
 415 impl Step for Rustdoc {
 416     type Output = PathBuf;
 417     const DEFAULT: bool = true;
 418     const ONLY_HOSTS: bool = true;
 419
 420     fn should_run(run: ShouldRun) -> ShouldRun {
 421         run.path("src/tools/rustdoc")
 422     }
 423
 424     fn make_run(run: RunConfig) {
 425         run.builder.ensure(Rustdoc {
 426             host: run.host,
 427         });
 428     }
 429
 430     fn run(self, builder: &Builder) -> PathBuf {
 431         let target_compiler = builder.compiler(builder.top_stage, self.host);
 432         let target = target_compiler.host;
 433         let build_compiler = if target_compiler.stage == 0 {
 434             builder.compiler(0, builder.config.build)
 435         } else if target_compiler.stage >= 2 {
 436             // Past stage 2, we consider the compiler to be ABI-compatible and hence capable of
 437             // building rustdoc itself.
 438             builder.compiler(target_compiler.stage, builder.config.build)
 439         } else {
 440             // Similar to `compile::Assemble`, build with the previous stage's compiler. Otherwise
 441             // we'd have stageN/bin/rustc and stageN/bin/rustdoc be effectively different stage
 442             // compilers, which isn't what we want.
 443             builder.compiler(target_compiler.stage - 1, builder.config.build)
 444         };
 445
 446         builder.ensure(compile::Rustc { compiler: build_compiler, target });
 447         builder.ensure(compile::Rustc {
 448             compiler: build_compiler,
 449             target: builder.config.build,
 450         });
 451
 452         let mut cargo = prepare_tool_cargo(builder,
 453                                            build_compiler,
 454                                            Mode::ToolRustc,
 455                                            target,
 456                                            "build",
 457                                            "src/tools/rustdoc");
 458
 459         // Most tools don't get debuginfo, but rustdoc should.
 460         cargo.env("RUSTC_DEBUGINFO", builder.config.rust_debuginfo.to_string())
 461              .env("RUSTC_DEBUGINFO_LINES", builder.config.rust_debuginfo_lines.to_string());
 462
 463         let _folder = builder.fold_output(|| format!("stage{}-rustdoc", target_compiler.stage));
 464         builder.info(&format!("Building rustdoc for stage{} ({})",
 465             target_compiler.stage, target_compiler.host));
 466         builder.run(&mut cargo);
 467
 468         // Cargo adds a number of paths to the dylib search path on windows, which results in
 469         // the wrong rustdoc being executed. To avoid the conflicting rustdocs, we name the "tool"
 470         // rustdoc a different name.
 471         let tool_rustdoc = builder.cargo_out(build_compiler, Mode::ToolRustc, target)
 472             .join(exe("rustdoc_tool_binary", &target_compiler.host));
 473
 474         // don't create a stage0-sysroot/bin directory.
 475         if target_compiler.stage > 0 {
 476             let sysroot = builder.sysroot(target_compiler);
 477             let bindir = sysroot.join("bin");
 478             t!(fs::create_dir_all(&bindir));
 479             let bin_rustdoc = bindir.join(exe("rustdoc", &*target_compiler.host));
 480             let _ = fs::remove_file(&bin_rustdoc);
 481             builder.copy(&tool_rustdoc, &bin_rustdoc);
 482             bin_rustdoc
 483         } else {
 484             tool_rustdoc
 485         }
 486     }
 487 }
 488
 489 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 490 pub struct Cargo {
 491     pub compiler: Compiler,
 492     pub target: Interned<String>,
 493 }
 494
 495 impl Step for Cargo {
 496     type Output = PathBuf;
 497     const DEFAULT: bool = true;
 498     const ONLY_HOSTS: bool = true;
 499
 500     fn should_run(run: ShouldRun) -> ShouldRun {
 501         let builder = run.builder;
 502         run.path("src/tools/cargo").default_condition(builder.config.extended)
 503     }
 504
 505     fn make_run(run: RunConfig) {
 506         run.builder.ensure(Cargo {
 507             compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
 508             target: run.target,
 509         });
 510     }
 511
 512     fn run(self, builder: &Builder) -> PathBuf {
 513         builder.ensure(native::Openssl {
 514             target: self.target,
 515         });
 516         // Cargo depends on procedural macros, which requires a full host
 517         // compiler to be available, so we need to depend on that.
 518         builder.ensure(compile::Rustc {
 519             compiler: self.compiler,
 520             target: builder.config.build,
 521         });
 522         builder.ensure(ToolBuild {
 523             compiler: self.compiler,
 524             target: self.target,
 525             tool: "cargo",
 526             mode: Mode::ToolRustc,
 527             path: "src/tools/cargo",
 528             is_ext_tool: false,
 529             extra_features: Vec::new(),
 530         }).expect("expected to build -- essential tool")
 531     }
 532 }
 533
 534 macro_rules! tool_extended {
 535     (($sel:ident, $builder:ident),
 536        $($name:ident,
 537        $toolstate:ident,
 538        $path:expr,
 539        $tool_name:expr,
 540        $extra_deps:block;)+) => {
 541         $(
 542             #[derive(Debug, Clone, Hash, PartialEq, Eq)]
 543         pub struct $name {
 544             pub compiler: Compiler,
 545             pub target: Interned<String>,
 546             pub extra_features: Vec<String>,
 547         }
 548
 549         impl Step for $name {
 550             type Output = Option<PathBuf>;
 551             const DEFAULT: bool = true;
 552             const ONLY_HOSTS: bool = true;
 553
 554             fn should_run(run: ShouldRun) -> ShouldRun {
 555                 let builder = run.builder;
 556                 run.path($path).default_condition(builder.config.extended)
 557             }
 558
 559             fn make_run(run: RunConfig) {
 560                 run.builder.ensure($name {
 561                     compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
 562                     target: run.target,
 563                     extra_features: Vec::new(),
 564                 });
 565             }
 566
 567             #[allow(unused_mut)]
 568             fn run(mut $sel, $builder: &Builder) -> Option<PathBuf> {
 569                 $extra_deps
 570                 $builder.ensure(ToolBuild {
 571                     compiler: $sel.compiler,
 572                     target: $sel.target,
 573                     tool: $tool_name,
 574                     mode: Mode::ToolRustc,
 575                     path: $path,
 576                     extra_features: $sel.extra_features,
 577                     is_ext_tool: true,
 578                 })
 579             }
 580         }
 581         )+
 582     }
 583 }
 584
 585 tool_extended!((self, builder),
 586     Cargofmt, rustfmt, "src/tools/rustfmt", "cargo-fmt", {};
 587     CargoClippy, clippy, "src/tools/clippy", "cargo-clippy", {
 588         // Clippy depends on procedural macros (serde), which requires a full host
 589         // compiler to be available, so we need to depend on that.
 590         builder.ensure(compile::Rustc {
 591             compiler: self.compiler,
 592             target: builder.config.build,
 593         });
 594     };
 595     Clippy, clippy, "src/tools/clippy", "clippy-driver", {
 596         // Clippy depends on procedural macros (serde), which requires a full host
 597         // compiler to be available, so we need to depend on that.
 598         builder.ensure(compile::Rustc {
 599             compiler: self.compiler,
 600             target: builder.config.build,
 601         });
 602     };
 603     Miri, miri, "src/tools/miri", "miri", {};
 604     Rls, rls, "src/tools/rls", "rls", {
 605         let clippy = builder.ensure(Clippy {
 606             compiler: self.compiler,
 607             target: self.target,
 608             extra_features: Vec::new(),
 609         });
 610         if clippy.is_some() {
 611             self.extra_features.push("clippy".to_owned());
 612         }
 613         builder.ensure(native::Openssl {
 614             target: self.target,
 615         });
 616         // RLS depends on procedural macros, which requires a full host
 617         // compiler to be available, so we need to depend on that.
 618         builder.ensure(compile::Rustc {
 619             compiler: self.compiler,
 620             target: builder.config.build,
 621         });
 622     };
 623     Rustfmt, rustfmt, "src/tools/rustfmt", "rustfmt", {};
 624 );
 625
 626 impl<'a> Builder<'a> {
 627     /// Get a `Command` which is ready to run `tool` in `stage` built for
 628     /// `host`.
 629     pub fn tool_cmd(&self, tool: Tool) -> Command {
 630         let mut cmd = Command::new(self.tool_exe(tool));
 631         let compiler = self.compiler(self.tool_default_stage(tool), self.config.build);
 632         self.prepare_tool_cmd(compiler, tool, &mut cmd);
 633         cmd
 634     }
 635
 636     /// Prepares the `cmd` provided to be able to run the `compiler` provided.
 637     ///
 638     /// Notably this munges the dynamic library lookup path to point to the
 639     /// right location to run `compiler`.
 640     fn prepare_tool_cmd(&self, compiler: Compiler, tool: Tool, cmd: &mut Command) {
 641         let host = &compiler.host;
 642         let mut lib_paths: Vec<PathBuf> = vec![
 643             if compiler.stage == 0 {
 644                 self.build.rustc_snapshot_libdir()
 645             } else {
 646                 PathBuf::from(&self.sysroot_libdir(compiler, compiler.host))
 647             },
 648             self.cargo_out(compiler, tool.get_mode(), *host).join("deps"),
 649         ];
 650
 651         // On MSVC a tool may invoke a C compiler (e.g. compiletest in run-make
 652         // mode) and that C compiler may need some extra PATH modification. Do
 653         // so here.
 654         if compiler.host.contains("msvc") {
 655             let curpaths = env::var_os("PATH").unwrap_or_default();
 656             let curpaths = env::split_paths(&curpaths).collect::<Vec<_>>();
 657             for &(ref k, ref v) in self.cc[&compiler.host].env() {
 658                 if k != "PATH" {
 659                     continue
 660                 }
 661                 for path in env::split_paths(v) {
 662                     if !curpaths.contains(&path) {
 663                         lib_paths.push(path);
 664                     }
 665                 }
 666             }
 667         }
 668
 669         // Add the llvm/bin directory to PATH since it contains lots of
 670         // useful, platform-independent tools
 671         if tool.uses_llvm_tools() {
 672             if let Some(llvm_bin_path) = self.llvm_bin_path() {
 673                 if host.contains("windows") {
 674                     // On Windows, PATH and the dynamic library path are the same,
 675                     // so we just add the LLVM bin path to lib_path
 676                     lib_paths.push(llvm_bin_path);
 677                 } else {
 678                     let old_path = env::var_os("PATH").unwrap_or_default();
 679                     let new_path = env::join_paths(iter::once(llvm_bin_path)
 680                             .chain(env::split_paths(&old_path)))
 681                         .expect("Could not add LLVM bin path to PATH");
 682                     cmd.env("PATH", new_path);
 683                 }
 684             }
 685         }
 686
 687         add_lib_path(lib_paths, cmd);
 688     }
 689
 690     fn llvm_bin_path(&self) -> Option<PathBuf> {
 691         if self.config.llvm_enabled && !self.config.dry_run {
 692             let llvm_config = self.ensure(native::Llvm {
 693                 target: self.config.build,
 694                 emscripten: false,
 695             });
 696
 697             // Add the llvm/bin directory to PATH since it contains lots of
 698             // useful, platform-independent tools
 699             let llvm_bin_path = llvm_config.parent()
 700                 .expect("Expected llvm-config to be contained in directory");
 701             assert!(llvm_bin_path.is_dir());
 702             Some(llvm_bin_path.to_path_buf())
 703         } else {
 704             None
 705         }
 706     }
 707 }