Generate docs for bootstrap itself

This verifies the intra-doc links are correct, and hopefully makes
things easier for new contributors.

src/bootstrap/builder.rs

@@ -264,7 +264,7 @@ impl PathSet {
 
     /// A convenience wrapper for Steps which know they have no aliases and all their sets contain only a single path.
     ///
-    /// This can be used with [`ShouldRun::krate`], [`ShouldRun::path`], or [`ShouldRun::alias`].
+    /// This can be used with [`ShouldRun::crate_or_deps`], [`ShouldRun::path`], or [`ShouldRun::alias`].
     #[track_caller]
     pub fn assert_single_path(&self) -> &TaskPath {
         match self {
@@ -787,6 +787,7 @@ impl<'a> Builder<'a> {
                 doc::EditionGuide,
                 doc::StyleGuide,
                 doc::Tidy,
+                doc::Bootstrap,
             ),
             Kind::Dist => describe!(
                 dist::Docs,

src/bootstrap/doc.rs

@@ -839,6 +839,8 @@ macro_rules! tool_doc {
                 )+
 
                 cargo.rustdocflag("--document-private-items");
+                // Since we always pass --document-private-items, there's no need to warn about linking to private items.
+                cargo.rustdocflag("-Arustdoc::private-intra-doc-links");
                 cargo.rustdocflag("--enable-index-page");
                 cargo.rustdocflag("--show-type-layout");
                 cargo.rustdocflag("--generate-link-to-definition");
@@ -882,7 +884,8 @@ tool_doc!(
         // "cargo-credential-wincred",
     ]
 );
-tool_doc!(Tidy, "tidy", "src/tools/tidy", ["tidy"]);
+tool_doc!(Tidy, "tidy", "src/tools/tidy", rustc_tool = false, ["tidy"]);
+tool_doc!(Bootstrap, "bootstrap", "src/bootstrap", rustc_tool = false, ["bootstrap"]);
 
 #[derive(Ord, PartialOrd, Debug, Copy, Clone, Hash, PartialEq, Eq)]
 pub struct ErrorIndex {

src/bootstrap/download.rs

@@ -123,7 +123,7 @@ impl Config {
     /// This is only required on NixOS and uses the PatchELF utility to
     /// change the interpreter/RPATH of ELF executables.
     ///
-    /// Please see https://nixos.org/patchelf.html for more information
+    /// Please see <https://nixos.org/patchelf.html> for more information
     fn fix_bin_or_dylib(&self, fname: &Path) {
         assert_eq!(SHOULD_FIX_BINS_AND_DYLIBS.get(), Some(&true));
         println!("attempting to patch {}", fname.display());

src/bootstrap/lib.rs

@@ -1011,6 +1011,8 @@ impl Build {
     }
 
     /// Return a `Group` guard for a [`Step`] that is built for each `--stage`.
+    ///
+    /// [`Step`]: crate::builder::Step
     fn msg(
         &self,
         action: impl Into<Kind>,
@@ -1035,6 +1037,8 @@ impl Build {
     }
 
     /// Return a `Group` guard for a [`Step`] that is only built once and isn't affected by `--stage`.
+    ///
+    /// [`Step`]: crate::builder::Step
     fn msg_unstaged(
         &self,
         action: impl Into<Kind>,

src/bootstrap/util.rs

@@ -488,7 +488,7 @@ fn absolute_windows(path: &std::path::Path) -> std::io::Result<std::path::PathBu
     }
 }
 
-/// Adapted from https://github.com/llvm/llvm-project/blob/782e91224601e461c019e0a4573bbccc6094fbcd/llvm/cmake/modules/HandleLLVMOptions.cmake#L1058-L1079
+/// Adapted from <https://github.com/llvm/llvm-project/blob/782e91224601e461c019e0a4573bbccc6094fbcd/llvm/cmake/modules/HandleLLVMOptions.cmake#L1058-L1079>
 ///
 /// When `clang-cl` is used with instrumentation, we need to add clang's runtime library resource
 /// directory to the linker flags, otherwise there will be linker errors about the profiler runtime