Merge branch 'master' of git://github.com/rust-lang/rust

* 'master' of git://github.com/rust-lang/rust: (70 commits)
  sanitizer-dylib: only run where std for x86_64-linux is available
  travis: Fix build order of dist-x86-linux
  fix the sanitizer-dylib test on non x86_64 linux hosts
  dist-x86-linux: install newer kernel headers
  enable sanitizers on build job that tests x86_64 linux
  enable sanitizers on x86_64-linux releases
  use helper function in the rebuild logic of the rustc_*san crates
  build/test the sanitizers only when --enable-sanitizers is used
  sanitizer support
  Add missing urls on join_paths
  Add test for #27433
  Add more examples, get everything passing at last.
  Remove some leftover makefiles.
  Add more test for rustdoc --test
  Rename manifest_version to manifest-version
  reference: clarify #[cfg] section
  Bump stable release date
  rustbuild: Clean build/dist on `make clean`
  Add missing urls for current_dir
  review nits
  ...

10 files changed, 203 insertions, 74 deletions

diff --git a/src/bootstrap/channel.rs b/src/bootstrap/channel.rs
index 585d9f51b92..81e745bc76c 100644
--- a/src/bootstrap/channel.rs
+++ b/src/bootstrap/channel.rs
@@ -15,55 +15,45 @@
 //! `package_vers`, and otherwise indicating to the compiler what it should
 //! print out as part of its version information.
 
-use std::fs::File;
-use std::io::prelude::*;
 use std::process::Command;
 
 use build_helper::output;
 
 use Build;
 
-pub fn collect(build: &mut Build) {
-    // Currently the canonical source for the release number (e.g. 1.10.0) and
-    // the prerelease version (e.g. `.1`) is in `mk/main.mk`. We "parse" that
-    // here to learn about those numbers.
-    let mut main_mk = String::new();
-    t!(t!(File::open(build.src.join("mk/main.mk"))).read_to_string(&mut main_mk));
-    let mut release_num = "";
-    let mut prerelease_version = "";
-    for line in main_mk.lines() {
-        if line.starts_with("CFG_RELEASE_NUM") {
-            release_num = line.split('=').skip(1).next().unwrap().trim();
-        }
-        if line.starts_with("CFG_PRERELEASE_VERSION") {
-            prerelease_version = line.split('=').skip(1).next().unwrap().trim();
-        }
-    }
+// The version number
+const CFG_RELEASE_NUM: &'static str = "1.17.0";
+
+// An optional number to put after the label, e.g. '.2' -> '-beta.2'
+// Be sure to make this starts with a dot to conform to semver pre-release
+// versions (section 9)
+const CFG_PRERELEASE_VERSION: &'static str = ".1";
 
-    build.release_num = release_num.to_string();
-    build.prerelease_version = release_num.to_string();
+pub fn collect(build: &mut Build) {
+    build.release_num = CFG_RELEASE_NUM.to_string();
+    build.prerelease_version = CFG_RELEASE_NUM.to_string();
 
     // Depending on the channel, passed in `./configure --release-channel`,
     // determine various properties of the build.
     match &build.config.channel[..] {
         "stable" => {
-            build.release = release_num.to_string();
+            build.release = CFG_RELEASE_NUM.to_string();
             build.package_vers = build.release.clone();
             build.unstable_features = false;
         }
         "beta" => {
-            build.release = format!("{}-beta{}", release_num,
-                                   prerelease_version);
+            build.release = format!("{}-beta{}", CFG_RELEASE_NUM,
+                                   CFG_PRERELEASE_VERSION);
             build.package_vers = "beta".to_string();
             build.unstable_features = false;
         }
         "nightly" => {
-            build.release = format!("{}-nightly", release_num);
+            build.release = format!("{}-nightly", CFG_RELEASE_NUM);
             build.package_vers = "nightly".to_string();
             build.unstable_features = true;
         }
         _ => {
-            build.release = format!("{}-dev", release_num);
+            build.release = format!("{}-dev", CFG_RELEASE_NUM);
             build.package_vers = build.release.clone();
             build.unstable_features = true;
         }
diff --git a/src/bootstrap/check.rs b/src/bootstrap/check.rs
index 19aac0f36bb..cbfbcbe4f0c 100644
--- a/src/bootstrap/check.rs
+++ b/src/bootstrap/check.rs
@@ -26,7 +26,7 @@ use build_helper::output;
 
 use {Build, Compiler, Mode};
 use dist;
-use util::{self, dylib_path, dylib_path_var};
+use util::{self, dylib_path, dylib_path_var, exe};
 
 const ADB_TEST_DIR: &'static str = "/data/tmp";
 
@@ -221,6 +221,12 @@ pub fn compiletest(build: &Build,
            .arg("--llvm-cxxflags").arg("");
     }
 
+    if build.qemu_rootfs(target).is_some() {
+        cmd.arg("--qemu-test-client")
+           .arg(build.tool(&Compiler::new(0, &build.config.build),
+                           "qemu-test-client"));
+    }
+
     // Running a C compiler on MSVC requires a few env vars to be set, to be
     // sure to set them here.
     //
@@ -236,6 +242,10 @@ pub fn compiletest(build: &Build,
     cmd.env("RUSTC_BOOTSTRAP", "1");
     build.add_rust_test_threads(&mut cmd);
 
+    if build.config.sanitizers {
+        cmd.env("SANITIZER_SUPPORT", "1");
+    }
+
     cmd.arg("--adb-path").arg("adb");
     cmd.arg("--adb-test-dir").arg(ADB_TEST_DIR);
     if target.contains("android") {
@@ -403,9 +413,9 @@ pub fn krate(build: &Build,
     dylib_path.insert(0, build.sysroot_libdir(&compiler, target));
     cargo.env(dylib_path_var(), env::join_paths(&dylib_path).unwrap());
 
-    if target.contains("android") {
-        cargo.arg("--no-run");
-    } else if target.contains("emscripten") {
+    if target.contains("android") ||
+       target.contains("emscripten") ||
+       build.qemu_rootfs(target).is_some() {
         cargo.arg("--no-run");
     }
 
@@ -423,6 +433,9 @@ pub fn krate(build: &Build,
     } else if target.contains("emscripten") {
         build.run(&mut cargo);
         krate_emscripten(build, &compiler, target, mode);
+    } else if build.qemu_rootfs(target).is_some() {
+        build.run(&mut cargo);
+        krate_qemu(build, &compiler, target, mode);
     } else {
         cargo.args(&build.flags.cmd.test_args());
         build.run(&mut cargo);
@@ -480,23 +493,46 @@ fn krate_emscripten(build: &Build,
                     compiler: &Compiler,
                     target: &str,
                     mode: Mode) {
-     let mut tests = Vec::new();
-     let out_dir = build.cargo_out(compiler, mode, target);
-     find_tests(&out_dir, target, &mut tests);
-     find_tests(&out_dir.join("deps"), target, &mut tests);
-
-     for test in tests {
-         let test_file_name = test.to_string_lossy().into_owned();
-         println!("running {}", test_file_name);
-         let nodejs = build.config.nodejs.as_ref().expect("nodejs not configured");
-         let mut cmd = Command::new(nodejs);
-         cmd.arg(&test_file_name);
-         if build.config.quiet_tests {
-             cmd.arg("--quiet");
-         }
-         build.run(&mut cmd);
-     }
- }
+    let mut tests = Vec::new();
+    let out_dir = build.cargo_out(compiler, mode, target);
+    find_tests(&out_dir, target, &mut tests);
+    find_tests(&out_dir.join("deps"), target, &mut tests);
+
+    for test in tests {
+        let test_file_name = test.to_string_lossy().into_owned();
+        println!("running {}", test_file_name);
+        let nodejs = build.config.nodejs.as_ref().expect("nodejs not configured");
+        let mut cmd = Command::new(nodejs);
+        cmd.arg(&test_file_name);
+        if build.config.quiet_tests {
+            cmd.arg("--quiet");
+        }
+        build.run(&mut cmd);
+    }
+}
+
+fn krate_qemu(build: &Build,
+              compiler: &Compiler,
+              target: &str,
+              mode: Mode) {
+    let mut tests = Vec::new();
+    let out_dir = build.cargo_out(compiler, mode, target);
+    find_tests(&out_dir, target, &mut tests);
+    find_tests(&out_dir.join("deps"), target, &mut tests);
+
+    let tool = build.tool(&Compiler::new(0, &build.config.build),
+                          "qemu-test-client");
+    for test in tests {
+        let mut cmd = Command::new(&tool);
+        cmd.arg("run")
+           .arg(&test);
+        if build.config.quiet_tests {
+            cmd.arg("--quiet");
+        }
+        cmd.args(&build.flags.cmd.test_args());
+        build.run(&mut cmd);
+    }
+}
 
 
 fn find_tests(dir: &Path,
@@ -516,13 +552,15 @@ fn find_tests(dir: &Path,
     }
 }
 
-pub fn android_copy_libs(build: &Build,
-                         compiler: &Compiler,
-                         target: &str) {
-    if !target.contains("android") {
-        return
+pub fn emulator_copy_libs(build: &Build, compiler: &Compiler, target: &str) {
+    if target.contains("android") {
+        android_copy_libs(build, compiler, target)
+    } else if let Some(s) = build.qemu_rootfs(target) {
+        qemu_copy_libs(build, compiler, target, s)
     }
+}
 
+fn android_copy_libs(build: &Build, compiler: &Compiler, target: &str) {
     println!("Android copy libs to emulator ({})", target);
     build.run(Command::new("adb").arg("wait-for-device"));
     build.run(Command::new("adb").arg("remount"));
@@ -548,6 +586,39 @@ pub fn android_copy_libs(build: &Build,
     }
 }
 
+fn qemu_copy_libs(build: &Build,
+                  compiler: &Compiler,
+                  target: &str,
+                  rootfs: &Path) {
+    println!("QEMU copy libs to emulator ({})", target);
+    assert!(target.starts_with("arm"), "only works with arm for now");
+    t!(fs::create_dir_all(build.out.join("tmp")));
+
+    // Copy our freshly compiled test server over to the rootfs
+    let server = build.cargo_out(compiler, Mode::Tool, target)
+                      .join(exe("qemu-test-server", target));
+    t!(fs::copy(&server, rootfs.join("testd")));
+
+    // Spawn the emulator and wait for it to come online
+    let tool = build.tool(&Compiler::new(0, &build.config.build),
+                          "qemu-test-client");
+    build.run(Command::new(&tool)
+                      .arg("spawn-emulator")
+                      .arg(rootfs)
+                      .arg(build.out.join("tmp")));
+
+    // Push all our dylibs to the emulator
+    for f in t!(build.sysroot_libdir(compiler, target).read_dir()) {
+        let f = t!(f);
+        let name = f.file_name().into_string().unwrap();
+        if util::is_dylib(&name) {
+            build.run(Command::new(&tool)
+                              .arg("push")
+                              .arg(f.path()));
+        }
+    }
+}
+
 /// Run "distcheck", a 'make check' from a tarball
 pub fn distcheck(build: &Build) {
     if build.config.build != "x86_64-unknown-linux-gnu" {
diff --git a/src/bootstrap/clean.rs b/src/bootstrap/clean.rs
index e7655458aed..a66ed46fe46 100644
--- a/src/bootstrap/clean.rs
+++ b/src/bootstrap/clean.rs
@@ -24,6 +24,7 @@ use Build;
 pub fn clean(build: &Build) {
     rm_rf(build, "tmp".as_ref());
     rm_rf(build, &build.out.join("tmp"));
+    rm_rf(build, &build.out.join("dist"));
 
     for host in build.config.host.iter() {
         let entries = match build.out.join(host).read_dir() {
diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
index 776b91028a1..0b1a1f39d8d 100644
--- a/src/bootstrap/compile.rs
+++ b/src/bootstrap/compile.rs
@@ -51,6 +51,17 @@ pub fn std(build: &Build, target: &str, compiler: &Compiler) {
     if compiler.stage == 0 && build.local_rebuild && !build.config.use_jemalloc {
         features.push_str(" force_alloc_system");
     }
+
+    if compiler.stage != 0 && build.config.sanitizers {
+        // This variable is used by the sanitizer runtime crates, e.g.
+        // rustc_lsan, to build the sanitizer runtime from C code
+        // When this variable is missing, those crates won't compile the C code,
+        // so we don't set this variable during stage0 where llvm-config is
+        // missing
+        // We also only build the runtimes when --enable-sanitizers (or its
+        // config.toml equivalent) is used
+        cargo.env("LLVM_CONFIG", build.llvm_config(target));
+    }
     cargo.arg("--features").arg(features)
          .arg("--manifest-path")
          .arg(build.src.join("src/rustc/std_shim/Cargo.toml"));
@@ -382,10 +393,10 @@ fn add_to_sysroot(out_dir: &Path, sysroot_dst: &Path) {
 ///
 /// This will build the specified tool with the specified `host` compiler in
 /// `stage` into the normal cargo output directory.
-pub fn tool(build: &Build, stage: u32, host: &str, tool: &str) {
-    println!("Building stage{} tool {} ({})", stage, tool, host);
+pub fn tool(build: &Build, stage: u32, target: &str, tool: &str) {
+    println!("Building stage{} tool {} ({})", stage, tool, target);
 
-    let compiler = Compiler::new(stage, host);
+    let compiler = Compiler::new(stage, &build.config.build);
 
     // FIXME: need to clear out previous tool and ideally deps, may require
     //        isolating output directories or require a pseudo shim step to
@@ -396,7 +407,7 @@ pub fn tool(build: &Build, stage: u32, host: &str, tool: &str) {
     // let out_dir = build.cargo_out(stage, &host, Mode::Librustc, target);
     // build.clear_if_dirty(&out_dir, &libstd_stamp(build, stage, &host, target));
 
-    let mut cargo = build.cargo(&compiler, Mode::Tool, host, "build");
+    let mut cargo = build.cargo(&compiler, Mode::Tool, target, "build");
     cargo.arg("--manifest-path")
          .arg(build.src.join(format!("src/tools/{}/Cargo.toml", tool)));
 
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index aa2bc38143d..47f505ad37e 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -48,6 +48,7 @@ pub struct Config {
     pub target_config: HashMap<String, Target>,
     pub full_bootstrap: bool,
     pub extended: bool,
+    pub sanitizers: bool,
 
     // llvm codegen options
     pub llvm_assertions: bool,
@@ -114,6 +115,7 @@ pub struct Target {
     pub cxx: Option<PathBuf>,
     pub ndk: Option<PathBuf>,
     pub musl_root: Option<PathBuf>,
+    pub qemu_rootfs: Option<PathBuf>,
 }
 
 /// Structure of the `config.toml` file that configuration is read from.
@@ -149,6 +151,7 @@ struct Build {
     full_bootstrap: Option<bool>,
     extended: Option<bool>,
     verbose: Option<usize>,
+    sanitizers: Option<bool>,
 }
 
 /// TOML representation of various global install decisions.
@@ -223,6 +226,7 @@ struct TomlTarget {
     cxx: Option<String>,
     android_ndk: Option<String>,
     musl_root: Option<String>,
+    qemu_rootfs: Option<String>,
 }
 
 impl Config {
@@ -294,6 +298,7 @@ impl Config {
         set(&mut config.full_bootstrap, build.full_bootstrap);
         set(&mut config.extended, build.extended);
         set(&mut config.verbose, build.verbose);
+        set(&mut config.sanitizers, build.sanitizers);
 
         if let Some(ref install) = toml.install {
             config.prefix = install.prefix.clone().map(PathBuf::from);
@@ -362,6 +367,7 @@ impl Config {
                 target.cxx = cfg.cxx.clone().map(PathBuf::from);
                 target.cc = cfg.cc.clone().map(PathBuf::from);
                 target.musl_root = cfg.musl_root.clone().map(PathBuf::from);
+                target.qemu_rootfs = cfg.qemu_rootfs.clone().map(PathBuf::from);
 
                 config.target_config.insert(triple.clone(), target);
             }
@@ -437,6 +443,7 @@ impl Config {
                 ("VENDOR", self.vendor),
                 ("FULL_BOOTSTRAP", self.full_bootstrap),
                 ("EXTENDED", self.extended),
+                ("SANITIZERS", self.sanitizers),
             }
 
             match key {
@@ -564,6 +571,12 @@ impl Config {
                                                .map(|s| s.to_string())
                                                .collect();
                 }
+                "CFG_QEMU_ARMHF_ROOTFS" if value.len() > 0 => {
+                    let target = "arm-unknown-linux-gnueabihf".to_string();
+                    let target = self.target_config.entry(target)
+                                     .or_insert(Target::default());
+                    target.qemu_rootfs = Some(parse_configure_path(value));
+                }
                 _ => {}
             }
         }
diff --git a/src/bootstrap/config.toml.example b/src/bootstrap/config.toml.example
index 42bc20c24e5..5f4303a728c 100644
--- a/src/bootstrap/config.toml.example
+++ b/src/bootstrap/config.toml.example
@@ -127,6 +127,9 @@
 # Verbosity level: 0 == not verbose, 1 == verbose, 2 == very verbose
 #verbose = 0
 
+# Build the sanitizer runtimes
+#sanitizers = false
+
 # =============================================================================
 # General install configuration options
 # =============================================================================
diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
index 9327cc0cf7f..2da2892150b 100644
--- a/src/bootstrap/dist.rs
+++ b/src/bootstrap/dist.rs
@@ -381,13 +381,11 @@ pub fn rust_src(build: &Build) {
         "README.md",
         "RELEASES.md",
         "configure",
-        "Makefile.in",
         "x.py",
     ];
     let src_dirs = [
         "man",
         "src",
-        "mk"
     ];
 
     let filter_fn = move |path: &Path| {
@@ -517,9 +515,7 @@ pub fn cargo(build: &Build, stage: u32, target: &str) {
 
     let branch = match &build.config.channel[..] {
         "stable" |
-        "beta" => {
-            build.release.split(".").take(2).collect::<Vec<_>>().join(".")
-        }
+        "beta" => format!("rust-{}", build.release_num),
         _ => "master".to_string(),
     };
 
diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index df1218752d1..ba6b34343f0 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -599,7 +599,8 @@ impl Build {
     /// Get the space-separated set of activated features for the standard
     /// library.
     fn std_features(&self) -> String {
-        let mut features = "panic-unwind".to_string();
+        let mut features = "panic-unwind asan lsan msan tsan".to_string();
+
         if self.config.debug_jemalloc {
             features.push_str(" debug-jemalloc");
         }
@@ -878,6 +879,17 @@ impl Build {
             .map(|p| &**p)
     }
 
+    /// Returns the root of the "rootfs" image that this target will be using,
+    /// if one was configured.
+    ///
+    /// If `Some` is returned then that means that tests for this target are
+    /// emulated with QEMU and binaries will need to be shipped to the emulator.
+    fn qemu_rootfs(&self, target: &str) -> Option<&Path> {
+        self.config.target_config.get(target)
+            .and_then(|t| t.qemu_rootfs.as_ref())
+            .map(|p| &**p)
+    }
+
     /// Path to the python interpreter to use
     fn python(&self) -> &Path {
         self.config.python.as_ref().unwrap()
diff --git a/src/bootstrap/mk/Makefile.in b/src/bootstrap/mk/Makefile.in
index d6f6a7772c9..536095503e0 100644
--- a/src/bootstrap/mk/Makefile.in
+++ b/src/bootstrap/mk/Makefile.in
@@ -9,11 +9,12 @@
 # except according to those terms.
 
 include config.mk
-include $(CFG_SRC_DIR)mk/util.mk
 
 ifdef VERBOSE
+Q :=
 BOOTSTRAP_ARGS := -v
 else
+Q := @
 BOOTSTRAP_ARGS :=
 endif
 
diff --git a/src/bootstrap/step.rs b/src/bootstrap/step.rs
index 3932a7cf8c5..ee5b61062fe 100644
--- a/src/bootstrap/step.rs
+++ b/src/bootstrap/step.rs
@@ -295,7 +295,7 @@ pub fn build_rules<'a>(build: &'a Build) -> Rules {
                  .dep(|s| s.name("libtest"))
                  .dep(|s| s.name("tool-compiletest").target(s.host).stage(0))
                  .dep(|s| s.name("test-helpers"))
-                 .dep(|s| s.name("android-copy-libs"))
+                 .dep(|s| s.name("emulator-copy-libs"))
                  .default(mode != "pretty") // pretty tests don't run everywhere
                  .run(move |s| {
                      check::compiletest(build, &s.compiler(), s.target, mode, dir)
@@ -333,7 +333,7 @@ pub fn build_rules<'a>(build: &'a Build) -> Rules {
              .dep(|s| s.name("tool-compiletest").target(s.host).stage(0))
              .dep(|s| s.name("test-helpers"))
              .dep(|s| s.name("debugger-scripts"))
-             .dep(|s| s.name("android-copy-libs"))
+             .dep(|s| s.name("emulator-copy-libs"))
              .run(move |s| check::compiletest(build, &s.compiler(), s.target,
                                          "debuginfo-gdb", "debuginfo"));
         let mut rule = rules.test("check-debuginfo", "src/test/debuginfo");
@@ -387,14 +387,14 @@ pub fn build_rules<'a>(build: &'a Build) -> Rules {
     for (krate, path, _default) in krates("std_shim") {
         rules.test(&krate.test_step, path)
              .dep(|s| s.name("libtest"))
-             .dep(|s| s.name("android-copy-libs"))
+             .dep(|s| s.name("emulator-copy-libs"))
              .run(move |s| check::krate(build, &s.compiler(), s.target,
                                         Mode::Libstd, TestKind::Test,
                                         Some(&krate.name)));
     }
     rules.test("check-std-all", "path/to/nowhere")
          .dep(|s| s.name("libtest"))
-         .dep(|s| s.name("android-copy-libs"))
+         .dep(|s| s.name("emulator-copy-libs"))
          .default(true)
          .run(move |s| check::krate(build, &s.compiler(), s.target,
                                     Mode::Libstd, TestKind::Test, None));
@@ -403,14 +403,14 @@ pub fn build_rules<'a>(build: &'a Build) -> Rules {
     for (krate, path, _default) in krates("std_shim") {
         rules.bench(&krate.bench_step, path)
              .dep(|s| s.name("libtest"))
-             .dep(|s| s.name("android-copy-libs"))
+             .dep(|s| s.name("emulator-copy-libs"))
              .run(move |s| check::krate(build, &s.compiler(), s.target,
                                         Mode::Libstd, TestKind::Bench,
                                         Some(&krate.name)));
     }
     rules.bench("bench-std-all", "path/to/nowhere")
          .dep(|s| s.name("libtest"))
-         .dep(|s| s.name("android-copy-libs"))
+         .dep(|s| s.name("emulator-copy-libs"))
          .default(true)
          .run(move |s| check::krate(build, &s.compiler(), s.target,
                                     Mode::Libstd, TestKind::Bench, None));
@@ -418,21 +418,21 @@ pub fn build_rules<'a>(build: &'a Build) -> Rules {
     for (krate, path, _default) in krates("test_shim") {
         rules.test(&krate.test_step, path)
              .dep(|s| s.name("libtest"))
-             .dep(|s| s.name("android-copy-libs"))
+             .dep(|s| s.name("emulator-copy-libs"))
              .run(move |s| check::krate(build, &s.compiler(), s.target,
                                         Mode::Libtest, TestKind::Test,
                                         Some(&krate.name)));
     }
     rules.test("check-test-all", "path/to/nowhere")
          .dep(|s| s.name("libtest"))
-         .dep(|s| s.name("android-copy-libs"))
+         .dep(|s| s.name("emulator-copy-libs"))
          .default(true)
          .run(move |s| check::krate(build, &s.compiler(), s.target,
                                     Mode::Libtest, TestKind::Test, None));
     for (krate, path, _default) in krates("rustc-main") {
         rules.test(&krate.test_step, path)
              .dep(|s| s.name("librustc"))
-             .dep(|s| s.name("android-copy-libs"))
+             .dep(|s| s.name("emulator-copy-libs"))
              .host(true)
              .run(move |s| check::krate(build, &s.compiler(), s.target,
                                         Mode::Librustc, TestKind::Test,
@@ -440,7 +440,7 @@ pub fn build_rules<'a>(build: &'a Build) -> Rules {
     }
     rules.test("check-rustc-all", "path/to/nowhere")
          .dep(|s| s.name("librustc"))
-         .dep(|s| s.name("android-copy-libs"))
+         .dep(|s| s.name("emulator-copy-libs"))
          .default(true)
          .host(true)
          .run(move |s| check::krate(build, &s.compiler(), s.target,
@@ -481,9 +481,34 @@ pub fn build_rules<'a>(build: &'a Build) -> Rules {
 
     rules.build("test-helpers", "src/rt/rust_test_helpers.c")
          .run(move |s| native::test_helpers(build, s.target));
-    rules.test("android-copy-libs", "path/to/nowhere")
+
+    // Some test suites are run inside emulators, and most of our test binaries
+    // are linked dynamically which means we need to ship the standard library
+    // and such to the emulator ahead of time. This step represents this and is
+    // a dependency of all test suites.
+    //
+    // Most of the time this step is a noop (the `check::emulator_copy_libs`
+    // only does work if necessary). For some steps such as shipping data to
+    // QEMU we have to build our own tools so we've got conditional dependencies
+    // on those programs as well. Note that the QEMU client is built for the
+    // build target (us) and the server is built for the target.
+    rules.test("emulator-copy-libs", "path/to/nowhere")
          .dep(|s| s.name("libtest"))
-         .run(move |s| check::android_copy_libs(build, &s.compiler(), s.target));
+         .dep(move |s| {
+             if build.qemu_rootfs(s.target).is_some() {
+                s.name("tool-qemu-test-client").target(s.host).stage(0)
+             } else {
+                 Step::noop()
+             }
+         })
+         .dep(move |s| {
+             if build.qemu_rootfs(s.target).is_some() {
+                s.name("tool-qemu-test-server")
+             } else {
+                 Step::noop()
+             }
+         })
+         .run(move |s| check::emulator_copy_libs(build, &s.compiler(), s.target));
 
     rules.test("check-bootstrap", "src/bootstrap")
          .default(true)
@@ -516,6 +541,12 @@ pub fn build_rules<'a>(build: &'a Build) -> Rules {
     rules.build("tool-build-manifest", "src/tools/build-manifest")
          .dep(|s| s.name("libstd"))
          .run(move |s| compile::tool(build, s.stage, s.target, "build-manifest"));
+    rules.build("tool-qemu-test-server", "src/tools/qemu-test-server")
+         .dep(|s| s.name("libstd"))
+         .run(move |s| compile::tool(build, s.stage, s.target, "qemu-test-server"));
+    rules.build("tool-qemu-test-client", "src/tools/qemu-test-client")
+         .dep(|s| s.name("libstd"))
+         .run(move |s| compile::tool(build, s.stage, s.target, "qemu-test-client"));
 
     // ========================================================================
     // Documentation targets