bootstrap: add build.tidy-extra-checks option

bootstrap.example.toml

@@ -467,6 +467,15 @@
 # Whether to use the precompiled stage0 libtest with compiletest.
 #build.compiletest-use-stage0-libtest = true
 
+# Default value for the `--extra-checks` flag of tidy.
+#
+# See `./x test tidy --help` for details.
+#
+# Note that if any value is manually given to bootstrap such as
+# `./x test tidy --extra-checks=js`, this value is ignored.
+# Use `--extra-checks=''` to temporarily disable all extra checks.
+#build.tidy-extra-checks = ""
+
 # Indicates whether ccache is used when building certain artifacts (e.g. LLVM).
 # Set to `true` to use the first `ccache` in PATH, or set an absolute path to use
 # a specific version.

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

@@ -1108,7 +1108,9 @@ impl Step for Tidy {
         if builder.config.cmd.bless() {
             cmd.arg("--bless");
         }
-        if let Some(s) = builder.config.cmd.extra_checks() {
+        if let Some(s) =
+            builder.config.cmd.extra_checks().or(builder.config.tidy_extra_checks.as_deref())
+        {
             cmd.arg(format!("--extra-checks={s}"));
         }
         let mut args = std::env::args_os();

src/bootstrap/src/core/config/config.rs

@@ -297,7 +297,8 @@ pub struct Config {
 
     /// Whether to use the precompiled stage0 libtest with compiletest.
     pub compiletest_use_stage0_libtest: bool,
-
+    /// Default value for `--extra-checks`
+    pub tidy_extra_checks: Option<String>,
     pub is_running_on_ci: bool,
 
     /// Cache for determining path modifications
@@ -744,6 +745,7 @@ impl Config {
             jobs,
             compiletest_diff_tool,
             compiletest_use_stage0_libtest,
+            tidy_extra_checks,
             mut ccache,
             exclude,
         } = toml.build.unwrap_or_default();
@@ -1010,6 +1012,7 @@ impl Config {
             optimized_compiler_builtins.unwrap_or(config.channel != "dev");
         config.compiletest_diff_tool = compiletest_diff_tool;
         config.compiletest_use_stage0_libtest = compiletest_use_stage0_libtest.unwrap_or(true);
+        config.tidy_extra_checks = tidy_extra_checks;
 
         let download_rustc = config.download_rustc_commit.is_some();
         config.explicit_stage_from_cli = flags_stage.is_some();

src/bootstrap/src/core/config/toml/build.rs

@@ -69,6 +69,7 @@ define_config! {
         jobs: Option<u32> = "jobs",
         compiletest_diff_tool: Option<String> = "compiletest-diff-tool",
         compiletest_use_stage0_libtest: Option<bool> = "compiletest-use-stage0-libtest",
+        tidy_extra_checks: Option<String> = "tidy-extra-checks",
         ccache: Option<StringOrBool> = "ccache",
         exclude: Option<Vec<PathBuf>> = "exclude",
     }