1 files changed, 350 insertions, 0 deletions
diff --git a/src/bootstrap/setup.rs b/src/bootstrap/setup.rs
new file mode 100644
index 000000000..a5a39a5a3
--- /dev/null
+++ b/src/bootstrap/setup.rs
@@ -0,0 +1,350 @@
+use crate::{t, VERSION};
+use crate::{Config, TargetSelection};
+use std::env::consts::EXE_SUFFIX;
+use std::fmt::Write as _;
+use std::fs::File;
+use std::path::{Path, PathBuf, MAIN_SEPARATOR};
+use std::process::Command;
+use std::str::FromStr;
+use std::{
+    env, fmt, fs,
+    io::{self, Write},
+};
+
+#[derive(Clone, Copy, Eq, PartialEq)]
+pub enum Profile {
+    Compiler,
+    Codegen,
+    Library,
+    Tools,
+    User,
+}
+
+impl Profile {
+    fn include_path(&self, src_path: &Path) -> PathBuf {
+        PathBuf::from(format!("{}/src/bootstrap/defaults/config.{}.toml", src_path.display(), self))
+    }
+
+    pub fn all() -> impl Iterator<Item = Self> {
+        use Profile::*;
+        // N.B. these are ordered by how they are displayed, not alphabetically
+        [Library, Compiler, Codegen, Tools, User].iter().copied()
+    }
+
+    pub fn purpose(&self) -> String {
+        use Profile::*;
+        match self {
+            Library => "Contribute to the standard library",
+            Compiler => "Contribute to the compiler itself",
+            Codegen => "Contribute to the compiler, and also modify LLVM or codegen",
+            Tools => "Contribute to tools which depend on the compiler, but do not modify it directly (e.g. rustdoc, clippy, miri)",
+            User => "Install Rust from source",
+        }
+        .to_string()
+    }
+
+    pub fn all_for_help(indent: &str) -> String {
+        let mut out = String::new();
+        for choice in Profile::all() {
+            writeln!(&mut out, "{}{}: {}", indent, choice, choice.purpose()).unwrap();
+        }
+        out
+    }
+}
+
+impl FromStr for Profile {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "lib" | "library" => Ok(Profile::Library),
+            "compiler" => Ok(Profile::Compiler),
+            "llvm" | "codegen" => Ok(Profile::Codegen),
+            "maintainer" | "user" => Ok(Profile::User),
+            "tools" | "tool" | "rustdoc" | "clippy" | "miri" | "rustfmt" | "rls" => {
+                Ok(Profile::Tools)
+            }
+            _ => Err(format!("unknown profile: '{}'", s)),
+        }
+    }
+}
+
+impl fmt::Display for Profile {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Profile::Compiler => write!(f, "compiler"),
+            Profile::Codegen => write!(f, "codegen"),
+            Profile::Library => write!(f, "library"),
+            Profile::User => write!(f, "user"),
+            Profile::Tools => write!(f, "tools"),
+        }
+    }
+}
+
+pub fn setup(config: &Config, profile: Profile) {
+    let path = &config.config;
+
+    if path.exists() {
+        eprintln!(
+            "error: you asked `x.py` to setup a new config file, but one already exists at `{}`",
+            path.display()
+        );
+        eprintln!("help: try adding `profile = \"{}\"` at the top of {}", profile, path.display());
+        eprintln!(
+            "note: this will use the configuration in {}",
+            profile.include_path(&config.src).display()
+        );
+        crate::detail_exit(1);
+    }
+
+    let settings = format!(
+        "# Includes one of the default files in src/bootstrap/defaults\n\
+    profile = \"{}\"\n\
+    changelog-seen = {}\n",
+        profile, VERSION
+    );
+    t!(fs::write(path, settings));
+
+    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"));
+    let stage_path =
+        ["build", build.rustc_target_arg(), "stage1"].join(&MAIN_SEPARATOR.to_string());
+
+    println!();
+
+    if !rustup_installed() && profile != Profile::User {
+        eprintln!("`rustup` is not installed; cannot link `stage1` toolchain");
+    } else if stage_dir_exists(&stage_path[..]) {
+        attempt_toolchain_link(&stage_path[..]);
+    }
+
+    let suggestions = match profile {
+        Profile::Codegen | Profile::Compiler => &["check", "build", "test"][..],
+        Profile::Tools => &[
+            "check",
+            "build",
+            "test src/test/rustdoc*",
+            "test src/tools/clippy",
+            "test src/tools/miri",
+            "test src/tools/rustfmt",
+        ],
+        Profile::Library => &["check", "build", "test library/std", "doc"],
+        Profile::User => &["dist", "build"],
+    };
+
+    println!();
+
+    t!(install_git_hook_maybe(&config));
+
+    println!();
+
+    println!("To get started, try one of the following commands:");
+    for cmd in suggestions {
+        println!("- `x.py {}`", cmd);
+    }
+
+    if profile != Profile::User {
+        println!(
+            "For more suggestions, see https://rustc-dev-guide.rust-lang.org/building/suggested.html"
+        );
+    }
+}
+
+fn rustup_installed() -> bool {
+    Command::new("rustup")
+        .arg("--version")
+        .stdout(std::process::Stdio::null())
+        .output()
+        .map_or(false, |output| output.status.success())
+}
+
+fn stage_dir_exists(stage_path: &str) -> bool {
+    match fs::create_dir(&stage_path) {
+        Ok(_) => true,
+        Err(_) => Path::new(&stage_path).exists(),
+    }
+}
+
+fn attempt_toolchain_link(stage_path: &str) {
+    if toolchain_is_linked() {
+        return;
+    }
+
+    if !ensure_stage1_toolchain_placeholder_exists(stage_path) {
+        eprintln!(
+            "Failed to create a template for stage 1 toolchain or confirm that it already exists"
+        );
+        return;
+    }
+
+    if try_link_toolchain(&stage_path) {
+        println!(
+            "Added `stage1` rustup toolchain; try `cargo +stage1 build` on a separate rust project to run a newly-built toolchain"
+        );
+    } else {
+        eprintln!("`rustup` failed to link stage 1 build to `stage1` toolchain");
+        eprintln!(
+            "To manually link stage 1 build to `stage1` toolchain, run:\n
+            `rustup toolchain link stage1 {}`",
+            &stage_path
+        );
+    }
+}
+
+fn toolchain_is_linked() -> bool {
+    match Command::new("rustup")
+        .args(&["toolchain", "list"])
+        .stdout(std::process::Stdio::piped())
+        .output()
+    {
+        Ok(toolchain_list) => {
+            if !String::from_utf8_lossy(&toolchain_list.stdout).contains("stage1") {
+                return false;
+            }
+            // The toolchain has already been linked.
+            println!(
+                "`stage1` toolchain already linked; not attempting to link `stage1` toolchain"
+            );
+        }
+        Err(_) => {
+            // In this case, we don't know if the `stage1` toolchain has been linked;
+            // but `rustup` failed, so let's not go any further.
+            println!(
+                "`rustup` failed to list current toolchains; not attempting to link `stage1` toolchain"
+            );
+        }
+    }
+    true
+}
+
+fn try_link_toolchain(stage_path: &str) -> bool {
+    Command::new("rustup")
+        .stdout(std::process::Stdio::null())
+        .args(&["toolchain", "link", "stage1", &stage_path])
+        .output()
+        .map_or(false, |output| output.status.success())
+}
+
+fn ensure_stage1_toolchain_placeholder_exists(stage_path: &str) -> bool {
+    let pathbuf = PathBuf::from(stage_path);
+
+    if fs::create_dir_all(pathbuf.join("lib")).is_err() {
+        return false;
+    };
+
+    let pathbuf = pathbuf.join("bin");
+    if fs::create_dir_all(&pathbuf).is_err() {
+        return false;
+    };
+
+    let pathbuf = pathbuf.join(format!("rustc{}", EXE_SUFFIX));
+
+    if pathbuf.exists() {
+        return true;
+    }
+
+    // Take care not to overwrite the file
+    let result = File::options().append(true).create(true).open(&pathbuf);
+    if result.is_err() {
+        return false;
+    }
+
+    return true;
+}
+
+// Used to get the path for `Subcommand::Setup`
+pub fn interactive_path() -> io::Result<Profile> {
+    fn abbrev_all() -> impl Iterator<Item = ((String, String), Profile)> {
+        ('a'..)
+            .zip(1..)
+            .map(|(letter, number)| (letter.to_string(), number.to_string()))
+            .zip(Profile::all())
+    }
+
+    fn parse_with_abbrev(input: &str) -> Result<Profile, String> {
+        let input = input.trim().to_lowercase();
+        for ((letter, number), profile) in abbrev_all() {
+            if input == letter || input == number {
+                return Ok(profile);
+            }
+        }
+        input.parse()
+    }
+
+    println!("Welcome to the Rust project! What do you want to do with x.py?");
+    for ((letter, _), profile) in abbrev_all() {
+        println!("{}) {}: {}", letter, profile, profile.purpose());
+    }
+    let template = loop {
+        print!(
+            "Please choose one ({}): ",
+            abbrev_all().map(|((l, _), _)| l).collect::<Vec<_>>().join("/")
+        );
+        io::stdout().flush()?;
+        let mut input = String::new();
+        io::stdin().read_line(&mut input)?;
+        if input.is_empty() {
+            eprintln!("EOF on stdin, when expecting answer to question.  Giving up.");
+            crate::detail_exit(1);
+        }
+        break match parse_with_abbrev(&input) {
+            Ok(profile) => profile,
+            Err(err) => {
+                eprintln!("error: {}", err);
+                eprintln!("note: press Ctrl+C to exit");
+                continue;
+            }
+        };
+    };
+    Ok(template)
+}
+
+// install a git hook to automatically run tidy --bless, if they want
+fn install_git_hook_maybe(config: &Config) -> io::Result<()> {
+    let mut input = String::new();
+    println!(
+        "Rust's CI will automatically fail if it doesn't pass `tidy`, the internal tool for ensuring code quality.
+If you'd like, x.py can install a git hook for you that will automatically run `tidy --bless` before
+pushing your code to ensure your code is up to par. If you decide later that this behavior is
+undesirable, simply delete the `pre-push` file from .git/hooks."
+    );
+
+    let should_install = loop {
+        print!("Would you like to install the git hook?: [y/N] ");
+        io::stdout().flush()?;
+        input.clear();
+        io::stdin().read_line(&mut input)?;
+        break match input.trim().to_lowercase().as_str() {
+            "y" | "yes" => true,
+            "n" | "no" | "" => false,
+            _ => {
+                eprintln!("error: unrecognized option '{}'", input.trim());
+                eprintln!("note: press Ctrl+C to exit");
+                continue;
+            }
+        };
+    };
+
+    if should_install {
+        let src = config.src.join("src").join("etc").join("pre-push.sh");
+        let git =
+            t!(config.git().args(&["rev-parse", "--git-common-dir"]).output().map(|output| {
+                assert!(output.status.success(), "failed to run `git`");
+                PathBuf::from(t!(String::from_utf8(output.stdout)).trim())
+            }));
+        let dst = git.join("hooks").join("pre-push");
+        match fs::hard_link(src, &dst) {
+            Err(e) => eprintln!(
+                "error: could not create hook {}: do you already have the git hook installed?\n{}",
+                dst.display(),
+                e
+            ),
+            Ok(_) => println!("Linked `src/etc/pre-push.sh` to `.git/hooks/pre-push`"),
+        };
+    } else {
+        println!("Ok, skipping installation!");
+    }
+    Ok(())
+}