Rollup merge of #86737 - jyn514:doc-tools, r=Mark-Simulacrum

Document rustfmt on nightly-rustc

- Refactor the doc step for Rustdoc into a macro
- Call the macro for both rustdoc and rustfmt
- Add a `recursion_limit` macro to avoid overflow errors

This does not currently pass --document-private-items for rustfmt due to https://github.com/rust-lang/cargo/pull/8422#issuecomment-871082935.

r? `@Mark-Simulacrum` cc `@calebcartwright`

3 files changed, 82 insertions, 67 deletions

diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index b4c5a2abc9c..56ecc6e68a9 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -465,6 +465,7 @@ impl<'a> Builder<'a> {
                 doc::Std,
                 doc::Rustc,
                 doc::Rustdoc,
+                doc::Rustfmt,
                 doc::ErrorIndex,
                 doc::Nomicon,
                 doc::Reference,
diff --git a/src/bootstrap/doc.rs b/src/bootstrap/doc.rs
index 634332df863..8603361362c 100644
--- a/src/bootstrap/doc.rs
+++ b/src/bootstrap/doc.rs
@@ -593,84 +593,97 @@ impl Step for Rustc {
     }
 }
 
-#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
-pub struct Rustdoc {
-    stage: u32,
-    target: TargetSelection,
-}
-
-impl Step for Rustdoc {
-    type Output = ();
-    const DEFAULT: bool = true;
-    const ONLY_HOSTS: bool = true;
-
-    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.krate("rustdoc-tool")
-    }
-
-    fn make_run(run: RunConfig<'_>) {
-        run.builder.ensure(Rustdoc { stage: run.builder.top_stage, target: run.target });
-    }
-
-    /// Generates compiler documentation.
-    ///
-    /// This will generate all documentation for compiler and dependencies.
-    /// Compiler documentation is distributed separately, so we make sure
-    /// we do not merge it with the other documentation from std, test and
-    /// proc_macros. This is largely just a wrapper around `cargo doc`.
-    fn run(self, builder: &Builder<'_>) {
-        let stage = self.stage;
-        let target = self.target;
-        builder.info(&format!("Documenting stage{} rustdoc ({})", stage, target));
-
-        // This is the intended out directory for compiler documentation.
-        let out = builder.compiler_doc_out(target);
-        t!(fs::create_dir_all(&out));
+macro_rules! tool_doc {
+    ($tool: ident, $should_run: literal, $path: literal, [$($krate: literal),+ $(,)?] $(, binary=$bin:expr)?) => {
+        #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
+        pub struct $tool {
+            stage: u32,
+            target: TargetSelection,
+        }
 
-        let compiler = builder.compiler(stage, builder.config.build);
+        impl Step for $tool {
+            type Output = ();
+            const DEFAULT: bool = true;
+            const ONLY_HOSTS: bool = true;
 
-        if !builder.config.compiler_docs {
-            builder.info("\tskipping - compiler/librustdoc docs disabled");
-            return;
-        }
+            fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+                run.krate($should_run)
+            }
 
-        // Build rustc docs so that we generate relative links.
-        builder.ensure(Rustc { stage, target });
+            fn make_run(run: RunConfig<'_>) {
+                run.builder.ensure($tool { stage: run.builder.top_stage, target: run.target });
+            }
 
-        // Build rustdoc.
-        builder.ensure(tool::Rustdoc { compiler });
+            /// Generates compiler documentation.
+            ///
+            /// This will generate all documentation for compiler and dependencies.
+            /// Compiler documentation is distributed separately, so we make sure
+            /// we do not merge it with the other documentation from std, test and
+            /// proc_macros. This is largely just a wrapper around `cargo doc`.
+            fn run(self, builder: &Builder<'_>) {
+                let stage = self.stage;
+                let target = self.target;
+                builder.info(&format!("Documenting stage{} {} ({})", stage, stringify!($tool).to_lowercase(), target));
 
-        // Symlink compiler docs to the output directory of rustdoc documentation.
-        let out_dir = builder.stage_out(compiler, Mode::ToolRustc).join(target.triple).join("doc");
-        t!(fs::create_dir_all(&out_dir));
-        t!(symlink_dir_force(&builder.config, &out, &out_dir));
+                // This is the intended out directory for compiler documentation.
+                let out = builder.compiler_doc_out(target);
+                t!(fs::create_dir_all(&out));
 
-        // Build cargo command.
-        let mut cargo = prepare_tool_cargo(
-            builder,
-            compiler,
-            Mode::ToolRustc,
-            target,
-            "doc",
-            "src/tools/rustdoc",
-            SourceType::InTree,
-            &[],
-        );
+                let compiler = builder.compiler(stage, builder.config.build);
 
-        cargo.arg("-Zskip-rustdoc-fingerprint");
-        // Only include compiler crates, no dependencies of those, such as `libc`.
-        cargo.arg("--no-deps");
-        cargo.arg("-p").arg("rustdoc");
-        cargo.arg("-p").arg("rustdoc-json-types");
+                if !builder.config.compiler_docs {
+                    builder.info("\tskipping - compiler/tool docs disabled");
+                    return;
+                }
 
-        cargo.rustdocflag("--document-private-items");
-        cargo.rustdocflag("--enable-index-page");
-        cargo.rustdocflag("--show-type-layout");
-        cargo.rustdocflag("-Zunstable-options");
-        builder.run(&mut cargo.into());
+                // Build rustc docs so that we generate relative links.
+                builder.ensure(Rustc { stage, target });
+
+                // Symlink compiler docs to the output directory of rustdoc documentation.
+                let out_dir = builder.stage_out(compiler, Mode::ToolRustc).join(target.triple).join("doc");
+                t!(fs::create_dir_all(&out_dir));
+                t!(symlink_dir_force(&builder.config, &out, &out_dir));
+
+                // Build cargo command.
+                let mut cargo = prepare_tool_cargo(
+                    builder,
+                    compiler,
+                    Mode::ToolRustc,
+                    target,
+                    "doc",
+                    $path,
+                    SourceType::InTree,
+                    &[],
+                );
+
+                cargo.arg("-Zskip-rustdoc-fingerprint");
+                // Only include compiler crates, no dependencies of those, such as `libc`.
+                cargo.arg("--no-deps");
+                $(
+                    cargo.arg("-p").arg($krate);
+                )+
+
+                $(if !$bin {
+                    cargo.rustdocflag("--document-private-items");
+                })?
+                cargo.rustdocflag("--enable-index-page");
+                cargo.rustdocflag("--show-type-layout");
+                cargo.rustdocflag("-Zunstable-options");
+                builder.run(&mut cargo.into());
+            }
+        }
     }
 }
 
+tool_doc!(Rustdoc, "rustdoc-tool", "src/tools/rustdoc", ["rustdoc", "rustdoc-json-types"]);
+tool_doc!(
+    Rustfmt,
+    "rustfmt-nightly",
+    "src/tools/rustfmt",
+    ["rustfmt-nightly", "rustfmt-config_proc_macro"],
+    binary = true
+);
+
 #[derive(Ord, PartialOrd, Debug, Copy, Clone, Hash, PartialEq, Eq)]
 pub struct ErrorIndex {
     pub target: TargetSelection,
diff --git a/src/tools/rustfmt/src/lib.rs b/src/tools/rustfmt/src/lib.rs
index cde5d390cf2..ce8a45eea65 100644
--- a/src/tools/rustfmt/src/lib.rs
+++ b/src/tools/rustfmt/src/lib.rs
@@ -1,6 +1,7 @@
 #![feature(rustc_private)]
 #![deny(rust_2018_idioms)]
 #![warn(unreachable_pub)]
+#![recursion_limit = "256"]
 
 #[macro_use]
 extern crate derive_new;