Update bootstrap for in-tree rustfmt

- Add rustfmt to `x.py check`
- Update Cargo.lock
- Remove rustfmt from the toolstate list
- Make rustfmt an in-tree tool
- Give an error on `x.py test rustfmt` if rustfmt fails to build or if tests fail
- Don't call `save_toolstate` when testing rustfmt

src/bootstrap/builder.rs

@@ -379,6 +379,7 @@ impl<'a> Builder<'a> {
                 check::Clippy,
                 check::Miri,
                 check::Rls,
+                check::Rustfmt,
                 check::Bootstrap
             ),
             Kind::Test => describe!(

src/bootstrap/check.rs

@@ -363,13 +363,14 @@ macro_rules! tool_check_step {
 }
 
 tool_check_step!(Rustdoc, "src/tools/rustdoc", "src/librustdoc", SourceType::InTree);
-// Clippy is a hybrid. It is an external tool, but uses a git subtree instead
+// Clippy and Rustfmt are hybrids. They are external tools, but use a git subtree instead
 // of a submodule. Since the SourceType only drives the deny-warnings
 // behavior, treat it as in-tree so that any new warnings in clippy will be
 // rejected.
 tool_check_step!(Clippy, "src/tools/clippy", SourceType::InTree);
 tool_check_step!(Miri, "src/tools/miri", SourceType::Submodule);
 tool_check_step!(Rls, "src/tools/rls", SourceType::Submodule);
+tool_check_step!(Rustfmt, "src/tools/rustfmt", SourceType::InTree);
 
 tool_check_step!(Bootstrap, "src/bootstrap", SourceType::InTree, false);
 

src/bootstrap/test.rs

@@ -319,15 +319,9 @@ impl Step for Rustfmt {
         let host = self.host;
         let compiler = builder.compiler(stage, host);
 
-        let build_result = builder.ensure(tool::Rustfmt {
-            compiler,
-            target: self.host,
-            extra_features: Vec::new(),
-        });
-        if build_result.is_none() {
-            eprintln!("failed to test rustfmt: could not build");
-            return;
-        }
+        builder
+            .ensure(tool::Rustfmt { compiler, target: self.host, extra_features: Vec::new() })
+            .expect("in-tree tool");
 
         let mut cargo = tool::prepare_tool_cargo(
             builder,
@@ -346,9 +340,7 @@ impl Step for Rustfmt {
 
         cargo.add_rustc_lib_path(builder, compiler);
 
-        if try_run(builder, &mut cargo.into()) {
-            builder.save_toolstate("rustfmt", ToolState::TestPass);
-        }
+        builder.run(&mut cargo.into());
     }
 }
 

src/bootstrap/tool.rs

@@ -726,7 +726,7 @@ macro_rules! tool_extended {
 // Note: tools need to be also added to `Builder::get_step_descriptions` in `builder.rs`
 // to make `./x.py build <tool>` work.
 tool_extended!((self, builder),
-    Cargofmt, rustfmt, "src/tools/rustfmt", "cargo-fmt", stable=true, {};
+    Cargofmt, rustfmt, "src/tools/rustfmt", "cargo-fmt", stable=true, in_tree=true, {};
     CargoClippy, clippy, "src/tools/clippy", "cargo-clippy", stable=true, in_tree=true, {};
     Clippy, clippy, "src/tools/clippy", "clippy-driver", stable=true, in_tree=true, {};
     Miri, miri, "src/tools/miri", "miri", stable=false, {};
@@ -740,7 +740,7 @@ tool_extended!((self, builder),
         self.extra_features.push("clippy".to_owned());
     };
     RustDemangler, rust_demangler, "src/tools/rust-demangler", "rust-demangler", stable=false, in_tree=true, {};
-    Rustfmt, rustfmt, "src/tools/rustfmt", "rustfmt", stable=true, {};
+    Rustfmt, rustfmt, "src/tools/rustfmt", "rustfmt", stable=true, in_tree=true, {};
     RustAnalyzer, rust_analyzer, "src/tools/rust-analyzer/crates/rust-analyzer", "rust-analyzer", stable=false, {};
 );
 

src/bootstrap/toolstate.rs

@@ -77,7 +77,6 @@ static STABLE_TOOLS: &[(&str, &str)] = &[
     ("rust-by-example", "src/doc/rust-by-example"),
     ("edition-guide", "src/doc/edition-guide"),
     ("rls", "src/tools/rls"),
-    ("rustfmt", "src/tools/rustfmt"),
 ];
 
 // These tools are permitted to not build on the beta/stable channels.
@@ -278,10 +277,9 @@ impl Builder<'_> {
         if self.config.dry_run {
             return;
         }
-        // Toolstate isn't tracked for clippy, but since most tools do, we avoid
-        // checking in all the places we could save toolstate and just do so
-        // here.
-        if tool == "clippy-driver" {
+        // Toolstate isn't tracked for clippy or rustfmt, but since most tools do, we avoid checking
+        // in all the places we could save toolstate and just do so here.
+        if tool == "clippy-driver" || tool == "rustfmt" {
             return;
         }
         if let Some(ref path) = self.config.save_toolstates {

src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh

@@ -15,7 +15,6 @@ python3 "$X_PY" test --stage 2 --no-fail-fast \
     src/doc/embedded-book \
     src/doc/edition-guide \
     src/tools/rls \
-    src/tools/rustfmt \
     src/tools/miri \
 
 set -e
@@ -24,3 +23,4 @@ set -e
 cat /tmp/toolstate/toolstates.json
 python3 "$X_PY" test --stage 2 check-tools
 python3 "$X_PY" test --stage 2 src/tools/clippy
+python3 "$X_PY" test --stage 2 src/tools/rustfmt