make cargo submodule optional

src/bootstrap/src/core/build_steps/doc.rs

@@ -888,12 +888,11 @@ impl Step for Rustc {
 macro_rules! tool_doc {
     (
         $tool: ident,
-        $should_run: literal,
         $path: literal,
         $(rustc_tool = $rustc_tool:literal, )?
-        $(in_tree = $in_tree:literal ,)?
         $(is_library = $is_library:expr,)?
         $(crates = $crates:expr)?
+        $(, submodule $(= $submodule:literal)? )?
        ) => {
         #[derive(Debug, Clone, Hash, PartialEq, Eq)]
         pub struct $tool {
@@ -907,7 +906,7 @@ macro_rules! tool_doc {
 
             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
                 let builder = run.builder;
-                run.crate_or_deps($should_run).default_condition(builder.config.compiler_docs)
+                run.path($path).default_condition(builder.config.compiler_docs)
             }
 
             fn make_run(run: RunConfig<'_>) {
@@ -921,6 +920,15 @@ macro_rules! tool_doc {
             /// 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 source_type = SourceType::InTree;
+                $(
+                    let _ = source_type; // silence the "unused variable" warning
+                    let source_type = SourceType::Submodule;
+
+                    let path = Path::new(submodule_helper!( $path, submodule $( = $submodule )? ));
+                    builder.update_submodule(&path);
+                )?
+
                 let stage = builder.top_stage;
                 let target = self.target;
 
@@ -941,12 +949,6 @@ macro_rules! tool_doc {
                     builder.ensure(compile::Rustc::new(compiler, target));
                 }
 
-                let source_type = if true $(&& $in_tree)? {
-                    SourceType::InTree
-                } else {
-                    SourceType::Submodule
-                };
-
                 // Build cargo command.
                 let mut cargo = prepare_tool_cargo(
                     builder,
@@ -1008,21 +1010,14 @@ macro_rules! tool_doc {
     }
 }
 
-tool_doc!(Rustdoc, "rustdoc-tool", "src/tools/rustdoc", crates = ["rustdoc", "rustdoc-json-types"]);
-tool_doc!(
-    Rustfmt,
-    "rustfmt-nightly",
-    "src/tools/rustfmt",
-    crates = ["rustfmt-nightly", "rustfmt-config_proc_macro"]
-);
-tool_doc!(Clippy, "clippy", "src/tools/clippy", crates = ["clippy_config", "clippy_utils"]);
-tool_doc!(Miri, "miri", "src/tools/miri", crates = ["miri"]);
+tool_doc!(Rustdoc, "src/tools/rustdoc", crates = ["rustdoc", "rustdoc-json-types"]);
+tool_doc!(Rustfmt, "src/tools/rustfmt", crates = ["rustfmt-nightly", "rustfmt-config_proc_macro"]);
+tool_doc!(Clippy, "src/tools/clippy", crates = ["clippy_config", "clippy_utils"]);
+tool_doc!(Miri, "src/tools/miri", crates = ["miri"]);
 tool_doc!(
     Cargo,
-    "cargo",
     "src/tools/cargo",
     rustc_tool = false,
-    in_tree = false,
     crates = [
         "cargo",
         "cargo-credential",
@@ -1034,20 +1029,19 @@ tool_doc!(
         "crates-io",
         "mdman",
         "rustfix",
-    ]
+    ],
+    submodule = "src/tools/cargo"
 );
-tool_doc!(Tidy, "tidy", "src/tools/tidy", rustc_tool = false, crates = ["tidy"]);
+tool_doc!(Tidy, "src/tools/tidy", rustc_tool = false, crates = ["tidy"]);
 tool_doc!(
     Bootstrap,
-    "bootstrap",
     "src/bootstrap",
     rustc_tool = false,
     is_library = true,
     crates = ["bootstrap"]
 );
 tool_doc!(
     RunMakeSupport,
-    "run_make_support",
     "src/tools/run-make-support",
     rustc_tool = false,
     is_library = true,

src/bootstrap/src/core/build_steps/test.rs

@@ -2983,6 +2983,9 @@ impl Step for Bootstrap {
         let compiler = builder.compiler(0, host);
         let _guard = builder.msg(Kind::Test, 0, "bootstrap", host, host);
 
+        // Some tests require cargo submodule to be present.
+        builder.build.update_submodule(Path::new("src/tools/cargo"));
+
         let mut check_bootstrap = Command::new(builder.python());
         check_bootstrap
             .args(["-m", "unittest", "bootstrap_test.py"])

src/bootstrap/src/core/build_steps/tool.rs

@@ -654,6 +654,8 @@ impl Step for Cargo {
     }
 
     fn run(self, builder: &Builder<'_>) -> PathBuf {
+        builder.build.update_submodule(Path::new("src/tools/cargo"));
+
         builder.ensure(ToolBuild {
             compiler: self.compiler,
             target: self.target,

src/bootstrap/src/core/build_steps/vendor.rs

@@ -1,5 +1,5 @@
 use crate::core::builder::{Builder, RunConfig, ShouldRun, Step};
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::process::Command;
 
 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
@@ -34,6 +34,9 @@ impl Step for Vendor {
             cmd.arg("--versioned-dirs");
         }
 
+        // cargo submodule must be present for `x vendor` to work.
+        builder.build.update_submodule(Path::new("src/tools/cargo"));
+
         // Sync these paths by default.
         for p in [
             "src/tools/cargo/Cargo.toml",

src/bootstrap/src/core/metadata.rs

@@ -67,9 +67,9 @@ pub fn build(build: &mut Build) {
 
 /// Invokes `cargo metadata` to get package metadata of each workspace member.
 ///
-/// Note that `src/tools/cargo` is no longer a workspace member but we still
-/// treat it as one here, by invoking an additional `cargo metadata` command.
-fn workspace_members(build: &Build) -> impl Iterator<Item = Package> {
+/// This is used to resolve specific crate paths in `fn should_run` to compile
+/// particular crate (e.g., `x build sysroot` to build library/sysroot).
+fn workspace_members(build: &Build) -> Vec<Package> {
     let collect_metadata = |manifest_path| {
         let mut cargo = Command::new(&build.initial_cargo);
         cargo
@@ -88,13 +88,5 @@ fn workspace_members(build: &Build) -> impl Iterator<Item = Package> {
     };
 
     // Collects `metadata.packages` from all workspaces.
-    let packages = collect_metadata("Cargo.toml");
-    let cargo_packages = collect_metadata("src/tools/cargo/Cargo.toml");
-    let ra_packages = collect_metadata("src/tools/rust-analyzer/Cargo.toml");
-    let bootstrap_packages = collect_metadata("src/bootstrap/Cargo.toml");
-
-    // We only care about the root package from `src/tool/cargo` workspace.
-    let cargo_package = cargo_packages.into_iter().find(|pkg| pkg.name == "cargo").into_iter();
-
-    packages.into_iter().chain(cargo_package).chain(ra_packages).chain(bootstrap_packages)
+    collect_metadata("Cargo.toml")
 }

src/bootstrap/src/lib.rs

@@ -469,8 +469,7 @@ impl Build {
 
             // Make sure we update these before gathering metadata so we don't get an error about missing
             // Cargo.toml files.
-            let rust_submodules =
-                ["src/tools/cargo", "src/doc/book", "library/backtrace", "library/stdarch"];
+            let rust_submodules = ["src/doc/book", "library/backtrace", "library/stdarch"];
             for s in rust_submodules {
                 build.update_submodule(Path::new(s));
             }