Don't depend on python for RUST_BOOTSTRAP_CONFIG

src/bootstrap/bootstrap.py

@@ -1303,8 +1303,6 @@ def bootstrap(help_triggered):
     env["BOOTSTRAP_PARENT_ID"] = str(os.getpid())
     env["BOOTSTRAP_PYTHON"] = sys.executable
     env["RUSTC_BOOTSTRAP"] = '1'
-    if toml_path:
-        env["BOOTSTRAP_CONFIG"] = toml_path
     if build.rustc_commit is not None:
         env["BOOTSTRAP_DOWNLOAD_RUSTC"] = '1'
     run(args, env=env, verbose=build.verbose, is_bootstrap=True)

src/bootstrap/config.rs

@@ -657,7 +657,15 @@ impl Config {
             }
         };
 
-        let mut toml = flags.config.as_deref().map(get_toml).unwrap_or_else(TomlConfig::default);
+        // check --config first, then `$RUST_BOOTSTRAP_CONFIG` first, then `config.toml`
+        let toml_path = flags
+            .config
+            .clone()
+            .or_else(|| env::var_os("RUST_BOOTSTRAP_CONFIG").map(PathBuf::from))
+            .unwrap_or_else(|| PathBuf::from("config.toml"));
+        let mut toml =
+            if toml_path.exists() { get_toml(&toml_path) } else { TomlConfig::default() };
+
         if let Some(include) = &toml.profile {
             let mut include_path = config.src.clone();
             include_path.push("src");
@@ -669,9 +677,7 @@ impl Config {
         }
 
         config.changelog_seen = toml.changelog_seen;
-        if let Some(cfg) = flags.config {
-            config.config = cfg;
-        }
+        config.config = toml_path;
 
         let build = toml.build.unwrap_or_default();
 

src/bootstrap/flags.rs

@@ -3,7 +3,6 @@
 //! This module implements the command-line parsing of the build system which
 //! has various flags to configure how it's run.
 
-use std::env;
 use std::path::PathBuf;
 use std::process;
 
@@ -541,7 +540,6 @@ Arguments:
         // Get any optional paths which occur after the subcommand
         let mut paths = matches.free[1..].iter().map(|p| p.into()).collect::<Vec<PathBuf>>();
 
-        let cfg_file = env::var_os("BOOTSTRAP_CONFIG").map(PathBuf::from);
         let verbose = matches.opt_present("verbose");
 
         // User passed in -h/--help?
@@ -671,7 +669,7 @@ Arguments:
             } else {
                 None
             },
-            config: cfg_file,
+            config: matches.opt_str("config").map(PathBuf::from),
             jobs: matches.opt_str("jobs").map(|j| j.parse().expect("`jobs` should be a number")),
             cmd,
             incremental: matches.opt_present("incremental"),

src/bootstrap/lib.rs

@@ -629,7 +629,7 @@ impl Build {
         }
 
         if let Subcommand::Setup { profile } = &self.config.cmd {
-            return setup::setup(&self.config.src, *profile);
+            return setup::setup(&self.config, *profile);
         }
 
         {

src/bootstrap/setup.rs

@@ -1,5 +1,5 @@
-use crate::TargetSelection;
 use crate::{t, VERSION};
+use crate::{Config, TargetSelection};
 use std::env::consts::EXE_SUFFIX;
 use std::fmt::Write as _;
 use std::fs::File;
@@ -81,24 +81,22 @@ impl fmt::Display for Profile {
     }
 }
 
-pub fn setup(src_path: &Path, profile: Profile) {
-    let cfg_file = env::var_os("BOOTSTRAP_CONFIG").map(PathBuf::from);
+pub fn setup(config: &Config, profile: Profile) {
+    let path = &config.config;
 
-    if cfg_file.as_ref().map_or(false, |f| f.exists()) {
-        let file = cfg_file.unwrap();
+    if path.exists() {
         println!(
             "error: you asked `x.py` to setup a new config file, but one already exists at `{}`",
-            file.display()
+            path.display()
         );
-        println!("help: try adding `profile = \"{}\"` at the top of {}", profile, file.display());
+        println!("help: try adding `profile = \"{}\"` at the top of {}", profile, path.display());
         println!(
             "note: this will use the configuration in {}",
-            profile.include_path(src_path).display()
+            profile.include_path(&config.src).display()
         );
         std::process::exit(1);
     }
 
-    let path = cfg_file.unwrap_or_else(|| "config.toml".into());
     let settings = format!(
         "# Includes one of the default files in src/bootstrap/defaults\n\
     profile = \"{}\"\n\
@@ -107,7 +105,7 @@ pub fn setup(src_path: &Path, profile: Profile) {
     );
     t!(fs::write(path, settings));
 
-    let include_path = profile.include_path(src_path);
+    let include_path = profile.include_path(&config.src);
     println!("`x.py` will now use the configuration at {}", include_path.display());
 
     let build = TargetSelection::from_user(&env!("BUILD_TRIPLE"));
@@ -138,7 +136,7 @@ pub fn setup(src_path: &Path, profile: Profile) {
 
     println!();
 
-    t!(install_git_hook_maybe(src_path));
+    t!(install_git_hook_maybe(&config.src));
 
     println!();