Add bootstrap step for building sanitizer runtimes

src/bootstrap/builder.rs

@@ -343,6 +343,7 @@ impl<'a> Builder<'a> {
                 tool::Rustdoc,
                 tool::Clippy,
                 native::Llvm,
+                native::Sanitizers,
                 tool::Rustfmt,
                 tool::Miri,
                 native::Lld

src/bootstrap/check.rs

@@ -45,7 +45,7 @@ impl Step for Std {
         let compiler = builder.compiler(0, builder.config.build);
 
         let mut cargo = builder.cargo(compiler, Mode::Std, target, cargo_subcommand(builder.kind));
-        std_cargo(builder, &compiler, target, &mut cargo);
+        std_cargo(builder, target, &mut cargo);
 
         builder.info(&format!("Checking std artifacts ({} -> {})", &compiler.host, target));
         run_cargo(

src/bootstrap/compile.rs

@@ -87,7 +87,7 @@ impl Step for Std {
         target_deps.extend(copy_third_party_objects(builder, &compiler, target).into_iter());
 
         let mut cargo = builder.cargo(compiler, Mode::Std, target, "build");
-        std_cargo(builder, &compiler, target, &mut cargo);
+        std_cargo(builder, target, &mut cargo);
 
         builder.info(&format!(
             "Building stage{} std artifacts ({} -> {})",
@@ -153,17 +153,18 @@ fn copy_third_party_objects(
         copy_and_stamp(Path::new(&src), "libunwind.a");
     }
 
+    if builder.config.sanitizers && compiler.stage != 0 {
+        // The sanitizers are only copied in stage1 or above,
+        // to avoid creating dependency on LLVM.
+        target_deps.extend(copy_sanitizers(builder, &compiler, target));
+    }
+
     target_deps
 }
 
 /// Configure cargo to compile the standard library, adding appropriate env vars
 /// and such.
-pub fn std_cargo(
-    builder: &Builder<'_>,
-    compiler: &Compiler,
-    target: Interned<String>,
-    cargo: &mut Cargo,
-) {
+pub fn std_cargo(builder: &Builder<'_>, target: Interned<String>, cargo: &mut Cargo) {
     if let Some(target) = env::var_os("MACOSX_STD_DEPLOYMENT_TARGET") {
         cargo.env("MACOSX_DEPLOYMENT_TARGET", target);
     }
@@ -206,19 +207,6 @@ pub fn std_cargo(
         let mut features = builder.std_features();
         features.push_str(&compiler_builtins_c_feature);
 
-        if compiler.stage != 0 && builder.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
-            let llvm_config = builder.ensure(native::Llvm { target: builder.config.build });
-            cargo.env("LLVM_CONFIG", llvm_config);
-            cargo.env("RUSTC_BUILD_SANITIZERS", "1");
-        }
-
         cargo
             .arg("--features")
             .arg(features)
@@ -276,31 +264,43 @@ impl Step for StdLink {
         let libdir = builder.sysroot_libdir(target_compiler, target);
         let hostdir = builder.sysroot_libdir(target_compiler, compiler.host);
         add_to_sysroot(builder, &libdir, &hostdir, &libstd_stamp(builder, compiler, target));
-
-        if builder.config.sanitizers && compiler.stage != 0 && target == "x86_64-apple-darwin" {
-            // The sanitizers are only built in stage1 or above, so the dylibs will
-            // be missing in stage0 and causes panic. See the `std()` function above
-            // for reason why the sanitizers are not built in stage0.
-            copy_apple_sanitizer_dylibs(builder, &builder.native_dir(target), "osx", &libdir);
-        }
     }
 }
 
-fn copy_apple_sanitizer_dylibs(
+/// Copies sanitizer runtime libraries into target libdir.
+fn copy_sanitizers(
     builder: &Builder<'_>,
-    native_dir: &Path,
-    platform: &str,
-    into: &Path,
-) {
-    for &sanitizer in &["asan", "tsan"] {
-        let filename = format!("lib__rustc__clang_rt.{}_{}_dynamic.dylib", sanitizer, platform);
-        let mut src_path = native_dir.join(sanitizer);
-        src_path.push("build");
-        src_path.push("lib");
-        src_path.push("darwin");
-        src_path.push(&filename);
-        builder.copy(&src_path, &into.join(filename));
+    compiler: &Compiler,
+    target: Interned<String>,
+) -> Vec<PathBuf> {
+    let runtimes: Vec<native::SanitizerRuntime> = builder.ensure(native::Sanitizers { target });
+
+    if builder.config.dry_run {
+        return Vec::new();
     }
+
+    let mut target_deps = Vec::new();
+    let libdir = builder.sysroot_libdir(*compiler, target);
+
+    for runtime in &runtimes {
+        let dst = libdir.join(&runtime.name);
+        builder.copy(&runtime.path, &dst);
+
+        if target == "x86_64-apple-darwin" {
+            // Update the library install name reflect the fact it has been renamed.
+            let status = Command::new("install_name_tool")
+                .arg("-id")
+                .arg(format!("@rpath/{}", runtime.name))
+                .arg(&dst)
+                .status()
+                .expect("failed to execute `install_name_tool`");
+            assert!(status.success());
+        }
+
+        target_deps.push(dst);
+    }
+
+    target_deps
 }
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]

src/bootstrap/doc.rs

@@ -449,7 +449,7 @@ impl Step for Std {
 
         let run_cargo_rustdoc_for = |package: &str| {
             let mut cargo = builder.cargo(compiler, Mode::Std, target, "rustdoc");
-            compile::std_cargo(builder, &compiler, target, &mut cargo);
+            compile::std_cargo(builder, target, &mut cargo);
 
             // Keep a whitelist so we do not build internal stdlib crates, these will be
             // build by the rustc step later if enabled.

src/bootstrap/native.rs

@@ -546,3 +546,118 @@ impl Step for TestHelpers {
             .compile("rust_test_helpers");
     }
 }
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub struct Sanitizers {
+    pub target: Interned<String>,
+}
+
+impl Step for Sanitizers {
+    type Output = Vec<SanitizerRuntime>;
+
+    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+        run.path("src/llvm-project/compiler-rt").path("src/sanitizers")
+    }
+
+    fn make_run(run: RunConfig<'_>) {
+        run.builder.ensure(Sanitizers { target: run.target });
+    }
+
+    /// Builds sanitizer runtime libraries.
+    fn run(self, builder: &Builder<'_>) -> Self::Output {
+        let compiler_rt_dir = builder.src.join("src/llvm-project/compiler-rt");
+        if !compiler_rt_dir.exists() {
+            return Vec::new();
+        }
+
+        let out_dir = builder.native_dir(self.target).join("sanitizers");
+        let runtimes = supported_sanitizers(&out_dir, self.target);
+        if runtimes.is_empty() {
+            return runtimes;
+        }
+
+        let llvm_config = builder.ensure(Llvm { target: builder.config.build });
+        if builder.config.dry_run {
+            return runtimes;
+        }
+
+        let done_stamp = out_dir.join("sanitizers-finished-building");
+        if done_stamp.exists() {
+            builder.info(&format!(
+                "Assuming that sanitizers rebuild is not necessary. \
+                To force a rebuild, remove the file `{}`",
+                done_stamp.display()
+            ));
+            return runtimes;
+        }
+
+        builder.info(&format!("Building sanitizers for {}", self.target));
+        let _time = util::timeit(&builder);
+
+        let mut cfg = cmake::Config::new(&compiler_rt_dir);
+        cfg.target(&self.target);
+        cfg.host(&builder.config.build);
+        cfg.profile("Release");
+
+        cfg.define("CMAKE_C_COMPILER_TARGET", self.target);
+        cfg.define("COMPILER_RT_BUILD_BUILTINS", "OFF");
+        cfg.define("COMPILER_RT_BUILD_CRT", "OFF");
+        cfg.define("COMPILER_RT_BUILD_LIBFUZZER", "OFF");
+        cfg.define("COMPILER_RT_BUILD_PROFILE", "OFF");
+        cfg.define("COMPILER_RT_BUILD_SANITIZERS", "ON");
+        cfg.define("COMPILER_RT_BUILD_XRAY", "OFF");
+        cfg.define("COMPILER_RT_DEFAULT_TARGET_ONLY", "ON");
+        cfg.define("COMPILER_RT_USE_LIBCXX", "OFF");
+        cfg.define("LLVM_CONFIG_PATH", &llvm_config);
+
+        t!(fs::create_dir_all(&out_dir));
+        cfg.out_dir(out_dir);
+
+        for runtime in &runtimes {
+            cfg.build_target(&runtime.cmake_target);
+            cfg.build();
+        }
+
+        t!(fs::write(&done_stamp, b""));
+
+        runtimes
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct SanitizerRuntime {
+    /// CMake target used to build the runtime.
+    pub cmake_target: String,
+    /// Path to the built runtime library.
+    pub path: PathBuf,
+    /// Library filename that will be used rustc.
+    pub name: String,
+}
+
+/// Returns sanitizers available on a given target.
+fn supported_sanitizers(out_dir: &Path, target: Interned<String>) -> Vec<SanitizerRuntime> {
+    let mut result = Vec::new();
+    match &*target {
+        "x86_64-apple-darwin" => {
+            for s in &["asan", "lsan", "tsan"] {
+                result.push(SanitizerRuntime {
+                    cmake_target: format!("clang_rt.{}_osx_dynamic", s),
+                    path: out_dir
+                        .join(&format!("build/lib/darwin/libclang_rt.{}_osx_dynamic.dylib", s)),
+                    name: format!("librustc_rt.{}.dylib", s),
+                });
+            }
+        }
+        "x86_64-unknown-linux-gnu" => {
+            for s in &["asan", "lsan", "msan", "tsan"] {
+                result.push(SanitizerRuntime {
+                    cmake_target: format!("clang_rt.{}-x86_64", s),
+                    path: out_dir.join(&format!("build/lib/linux/libclang_rt.{}-x86_64.a", s)),
+                    name: format!("librustc_rt.{}.a", s),
+                });
+            }
+        }
+        _ => {}
+    }
+    result
+}

src/bootstrap/test.rs

@@ -1659,7 +1659,7 @@ impl Step for Crate {
         let mut cargo = builder.cargo(compiler, mode, target, test_kind.subcommand());
         match mode {
             Mode::Std => {
-                compile::std_cargo(builder, &compiler, target, &mut cargo);
+                compile::std_cargo(builder, target, &mut cargo);
             }
             Mode::Rustc => {
                 builder.ensure(compile::Rustc { compiler, target });