Rollup of 11 pull requests

.azure-pipelines/steps/run.yml

@@ -74,8 +74,9 @@ steps:
 # images, etc.
 - bash: |
     set -e
+    source src/ci/shared.sh
     sudo apt-get install -y python3-setuptools
-    pip3 install awscli --upgrade --user
+    retry pip3 install awscli --upgrade --user
     echo "##vso[task.prependpath]$HOME/.local/bin"
   displayName: Install awscli (Linux)
   condition: and(succeeded(), eq(variables['Agent.OS'], 'Linux'))

Cargo.lock

@@ -1813,6 +1813,7 @@ name = "panic_unwind"
 version = "0.0.0"
 dependencies = [
  "alloc 0.0.0",
+ "cfg-if 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
  "libc 0.2.54 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3338,6 +3339,7 @@ dependencies = [
  "alloc 0.0.0",
  "backtrace 0.3.29 (registry+https://github.com/rust-lang/crates.io-index)",
  "cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
  "dlmalloc 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3936,6 +3938,7 @@ name = "unwind"
 version = "0.0.0"
 dependencies = [
  "cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
  "libc 0.2.54 (registry+https://github.com/rust-lang/crates.io-index)",

README.md

@@ -130,9 +130,9 @@ build.
 
 MSVC builds of Rust additionally require an installation of Visual Studio 2017
 (or later) so `rustc` can use its linker.  The simplest way is to get the
-[Visual Studio Build Tools] and check the “C++ build tools” workload.
+[Visual Studio], check the “C++ build tools” and “Windows 10 SDK” workload.
 
-[Visual Studio Build Tools]: https://visualstudio.microsoft.com/downloads/#build-tools-for-visual-studio-2019
+[Visual Studio]: https://visualstudio.microsoft.com/downloads/
 
 (If you're installing cmake yourself, be careful that “C++ CMake tools for
 Windows” doesn't get included under “Individual components”.)

src/bootstrap/builder.rs

@@ -1693,10 +1693,6 @@ mod __test {
                     compiler: Compiler { host: a, stage: 1 },
                     target: b,
                 },
-                compile::Std {
-                    compiler: Compiler { host: a, stage: 2 },
-                    target: b,
-                },
             ]
         );
         assert_eq!(

src/bootstrap/doc.rs

@@ -46,10 +46,11 @@ macro_rules! book {
             }
 
             fn run(self, builder: &Builder<'_>) {
-                builder.ensure(Rustbook {
+                builder.ensure(RustbookSrc {
                     target: self.target,
                     name: INTERNER.intern_str($book_name),
                     version: $book_ver,
+                    src: doc_src(builder),
                 })
             }
         }
@@ -75,35 +76,8 @@ enum RustbookVersion {
     MdBook2,
 }
 
-#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
-struct Rustbook {
-    target: Interned<String>,
-    name: Interned<String>,
-    version: RustbookVersion,
-}
-
-impl Step for Rustbook {
-    type Output = ();
-
-    // rustbook is never directly called, and only serves as a shim for the nomicon and the
-    // reference.
-    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.never()
-    }
-
-    /// Invoke `rustbook` for `target` for the doc book `name`.
-    ///
-    /// This will not actually generate any documentation if the documentation has
-    /// already been generated.
-    fn run(self, builder: &Builder<'_>) {
-        let src = builder.src.join("src/doc");
-        builder.ensure(RustbookSrc {
-            target: self.target,
-            name: self.name,
-            src: INTERNER.intern_path(src),
-            version: self.version,
-        });
-    }
+fn doc_src(builder: &Builder<'_>) -> Interned<PathBuf> {
+    INTERNER.intern_path(builder.src.join("src/doc"))
 }
 
 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
@@ -274,33 +248,37 @@ impl Step for TheBook {
         let name = self.name;
 
         // build book
-        builder.ensure(Rustbook {
+        builder.ensure(RustbookSrc {
             target,
             name: INTERNER.intern_string(name.to_string()),
             version: RustbookVersion::MdBook2,
+            src: doc_src(builder),
         });
 
         // building older edition redirects
 
         let source_name = format!("{}/first-edition", name);
-        builder.ensure(Rustbook {
+        builder.ensure(RustbookSrc {
             target,
             name: INTERNER.intern_string(source_name),
             version: RustbookVersion::MdBook2,
+            src: doc_src(builder),
         });
 
         let source_name = format!("{}/second-edition", name);
-        builder.ensure(Rustbook {
+        builder.ensure(RustbookSrc {
             target,
             name: INTERNER.intern_string(source_name),
             version: RustbookVersion::MdBook2,
+            src: doc_src(builder),
         });
 
         let source_name = format!("{}/2018-edition", name);
-        builder.ensure(Rustbook {
+        builder.ensure(RustbookSrc {
             target,
             name: INTERNER.intern_string(source_name),
             version: RustbookVersion::MdBook2,
+            src: doc_src(builder),
         });
 
         // build the version info page and CSS
@@ -898,11 +876,6 @@ impl Step for UnstableBookGen {
     fn run(self, builder: &Builder<'_>) {
         let target = self.target;
 
-        builder.ensure(compile::Std {
-            compiler: builder.compiler(builder.top_stage, builder.config.build),
-            target,
-        });
-
         builder.info(&format!("Generating unstable book md files ({})", target));
         let out = builder.md_doc_out(target).join("unstable-book");
         builder.create_dir(&out);

src/bootstrap/lib.rs

@@ -270,14 +270,9 @@ pub struct Build {
 #[derive(Debug)]
 struct Crate {
     name: Interned<String>,
-    version: String,
     deps: HashSet<Interned<String>>,
     id: String,
     path: PathBuf,
-    doc_step: String,
-    build_step: String,
-    test_step: String,
-    bench_step: String,
 }
 
 impl Crate {

src/bootstrap/metadata.rs

@@ -20,7 +20,6 @@ struct Output {
 struct Package {
     id: String,
     name: String,
-    version: String,
     source: Option<String>,
     manifest_path: String,
 }
@@ -84,12 +83,7 @@ fn build_krate(features: &str, build: &mut Build, resolves: &mut Vec<ResolveNode
             let mut path = PathBuf::from(package.manifest_path);
             path.pop();
             build.crates.insert(name, Crate {
-                build_step: format!("build-crate-{}", name),
-                doc_step: format!("doc-crate-{}", name),
-                test_step: format!("test-crate-{}", name),
-                bench_step: format!("bench-crate-{}", name),
                 name,
-                version: package.version,
                 id: package.id,
                 deps: HashSet::new(),
                 path,

src/bootstrap/tool.rs

@@ -268,10 +268,6 @@ macro_rules! bootstrap_tool {
         }
 
         impl Tool {
-            pub fn get_mode(&self) -> Mode {
-                Mode::ToolBootstrap
-            }
-
             /// Whether this tool requires LLVM to run
             pub fn uses_llvm_tools(&self) -> bool {
                 match self {
@@ -345,6 +341,7 @@ bootstrap_tool!(
     Compiletest, "src/tools/compiletest", "compiletest", llvm_tools = true;
     BuildManifest, "src/tools/build-manifest", "build-manifest";
     RemoteTestClient, "src/tools/remote-test-client", "remote-test-client";
+    RemoteTestServer, "src/tools/remote-test-server", "remote-test-server";
     RustInstaller, "src/tools/rust-installer", "fabricate", is_external_tool = true;
     RustdocTheme, "src/tools/rustdoc-themes", "rustdoc-themes";
 );
@@ -397,40 +394,6 @@ impl Step for ErrorIndex {
     }
 }
 
-#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
-pub struct RemoteTestServer {
-    pub compiler: Compiler,
-    pub target: Interned<String>,
-}
-
-impl Step for RemoteTestServer {
-    type Output = PathBuf;
-
-    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/tools/remote-test-server")
-    }
-
-    fn make_run(run: RunConfig<'_>) {
-        run.builder.ensure(RemoteTestServer {
-            compiler: run.builder.compiler(run.builder.top_stage, run.builder.config.build),
-            target: run.target,
-        });
-    }
-
-    fn run(self, builder: &Builder<'_>) -> PathBuf {
-        builder.ensure(ToolBuild {
-            compiler: self.compiler,
-            target: self.target,
-            tool: "remote-test-server",
-            mode: Mode::ToolStd,
-            path: "src/tools/remote-test-server",
-            is_optional_tool: false,
-            source_type: SourceType::InTree,
-            extra_features: Vec::new(),
-        }).expect("expected to build -- essential tool")
-    }
-}
-
 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 pub struct Rustdoc {
     /// This should only ever be 0 or 2.
@@ -659,23 +622,14 @@ impl<'a> Builder<'a> {
     pub fn tool_cmd(&self, tool: Tool) -> Command {
         let mut cmd = Command::new(self.tool_exe(tool));
         let compiler = self.compiler(0, self.config.build);
-        self.prepare_tool_cmd(compiler, tool, &mut cmd);
-        cmd
-    }
-
-    /// Prepares the `cmd` provided to be able to run the `compiler` provided.
-    ///
-    /// Notably this munges the dynamic library lookup path to point to the
-    /// right location to run `compiler`.
-    fn prepare_tool_cmd(&self, compiler: Compiler, tool: Tool, cmd: &mut Command) {
         let host = &compiler.host;
+        // Prepares the `cmd` provided to be able to run the `compiler` provided.
+        //
+        // Notably this munges the dynamic library lookup path to point to the
+        // right location to run `compiler`.
         let mut lib_paths: Vec<PathBuf> = vec![
-            if compiler.stage == 0 {
-                self.build.rustc_snapshot_libdir()
-            } else {
-                PathBuf::from(&self.sysroot_libdir(compiler, compiler.host))
-            },
-            self.cargo_out(compiler, tool.get_mode(), *host).join("deps"),
+            self.build.rustc_snapshot_libdir(),
+            self.cargo_out(compiler, Mode::ToolBootstrap, *host).join("deps"),
         ];
 
         // On MSVC a tool may invoke a C compiler (e.g., compiletest in run-make
@@ -696,6 +650,7 @@ impl<'a> Builder<'a> {
             }
         }
 
-        add_lib_path(lib_paths, cmd);
+        add_lib_path(lib_paths, &mut cmd);
+        cmd
     }
 }

src/libcore/hint.rs

@@ -111,31 +111,31 @@ pub fn spin_loop() {
 /// This function is a no-op, and does not even read from `dummy`.
 #[inline]
 #[unstable(feature = "test", issue = "27812")]
+#[allow(unreachable_code)] // this makes #[cfg] a bit easier below.
 pub fn black_box<T>(dummy: T) -> T {
-    cfg_if! {
-        if #[cfg(any(
-            target_arch = "asmjs",
-            all(
-                target_arch = "wasm32",
-                target_os = "emscripten"
-            )
-        ))] {
-            #[inline]
-            unsafe fn black_box_impl<T>(d: T) -> T {
-                // these targets do not support inline assembly
-                let ret = crate::ptr::read_volatile(&d);
-                crate::mem::forget(d);
-                ret
-            }
-        } else {
-            #[inline]
-            unsafe fn black_box_impl<T>(d: T) -> T {
-                // we need to "use" the argument in some way LLVM can't
-                // introspect.
-                asm!("" : : "r"(&d));
-                d
-            }
-        }
+    // We need to "use" the argument in some way LLVM can't introspect, and on
+    // targets that support it we can typically leverage inline assembly to do
+    // this. LLVM's intepretation of inline assembly is that it's, well, a black
+    // box. This isn't the greatest implementation since it probably deoptimizes
+    // more than we want, but it's so far good enough.
+    #[cfg(not(any(
+        target_arch = "asmjs",
+        all(
+            target_arch = "wasm32",
+            target_os = "emscripten"
+        )
+    )))]
+    unsafe {
+        asm!("" : : "r"(&dummy));
+        return dummy;
+    }
+
+    // Not all platforms support inline assembly so try to do something without
+    // inline assembly which in theory still hinders at least some optimizations
+    // on those targets. This is the "best effort" scenario.
+    unsafe {
+        let ret = crate::ptr::read_volatile(&dummy);
+        crate::mem::forget(dummy);
+        ret
     }
-    unsafe { black_box_impl(dummy) }
 }