Auto merge of rust-lang#124452 - matthiaskrgr:rollup-psvo04i, r=matth…

…iaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#123942 (`x vendor`)
 - rust-lang#124165 (add test for incremental ICE: slice-pattern-const.rs rust-lang#83085)
 - rust-lang#124210 (Abort a process when FD ownership is violated)
 - rust-lang#124242 (bootstrap: Describe build_steps modules)
 - rust-lang#124406 (Remove unused `[patch]` for clippy_lints)
 - rust-lang#124429 (bootstrap: Document `struct Builder` and its fields)
 - rust-lang#124447 (Unconditionally call `really_init` on GNU/Linux)

r? `@ghost`
`@rustbot` modify labels: rollup

Cargo.toml

@@ -112,6 +112,3 @@ strip = true
 rustc-std-workspace-core = { path = 'library/rustc-std-workspace-core' }
 rustc-std-workspace-alloc = { path = 'library/rustc-std-workspace-alloc' }
 rustc-std-workspace-std = { path = 'library/rustc-std-workspace-std' }
-
-[patch."https://github.com/rust-lang/rust-clippy"]
-clippy_lints = { path = "src/tools/clippy/clippy_lints" }

library/core/src/intrinsics.rs

@@ -2767,7 +2767,7 @@ pub const unsafe fn typed_swap<T>(x: *mut T, y: *mut T) {
 #[unstable(feature = "core_intrinsics", issue = "none")]
 #[inline(always)]
 #[cfg_attr(not(bootstrap), rustc_intrinsic)] // just make it a regular fn in bootstrap
-pub(crate) const fn ub_checks() -> bool {
+pub const fn ub_checks() -> bool {
     cfg!(debug_assertions)
 }
 

library/core/src/lib.rs

@@ -193,6 +193,7 @@
 #![feature(str_split_inclusive_remainder)]
 #![feature(str_split_remainder)]
 #![feature(strict_provenance)]
+#![feature(ub_checks)]
 #![feature(unchecked_shifts)]
 #![feature(utf16_extra)]
 #![feature(utf16_extra_const)]
@@ -370,7 +371,8 @@ pub mod hint;
 pub mod intrinsics;
 pub mod mem;
 pub mod ptr;
-mod ub_checks;
+#[unstable(feature = "ub_checks", issue = "none")]
+pub mod ub_checks;
 
 /* Core language traits */
 

library/core/src/ub_checks.rs

@@ -46,6 +46,8 @@ use crate::intrinsics::{self, const_eval_select};
 /// variables cannot be optimized out in MIR, an innocent-looking `let` can produce enough
 /// debuginfo to have a measurable compile-time impact on debug builds.
 #[allow_internal_unstable(const_ub_checks)] // permit this to be called in stably-const fn
+#[macro_export]
+#[unstable(feature = "ub_checks", issue = "none")]
 macro_rules! assert_unsafe_precondition {
     ($kind:ident, $message:expr, ($($name:ident:$ty:ty = $arg:expr),*$(,)?) => $e:expr $(,)?) => {
         {
@@ -75,11 +77,13 @@ macro_rules! assert_unsafe_precondition {
         }
     };
 }
-pub(crate) use assert_unsafe_precondition;
+#[unstable(feature = "ub_checks", issue = "none")]
+pub use assert_unsafe_precondition;
 
 /// Checking library UB is always enabled when UB-checking is done
 /// (and we use a reexport so that there is no unnecessary wrapper function).
-pub(crate) use intrinsics::ub_checks as check_library_ub;
+#[unstable(feature = "ub_checks", issue = "none")]
+pub use intrinsics::ub_checks as check_library_ub;
 
 /// Determines whether we should check for language UB.
 ///

library/std/src/lib.rs

@@ -356,6 +356,7 @@
 #![feature(str_internals)]
 #![feature(strict_provenance)]
 #![feature(strict_provenance_atomic_ptr)]
+#![feature(ub_checks)]
 // tidy-alphabetical-end
 //
 // Library features (alloc):

library/std/src/os/fd/owned.rs

@@ -176,7 +176,10 @@ impl Drop for OwnedFd {
             // something like EINTR), we might close another valid file descriptor
             // opened after we closed ours.
             #[cfg(not(target_os = "hermit"))]
-            let _ = libc::close(self.fd);
+            {
+                crate::sys::fs::debug_assert_fd_is_open(self.fd);
+                let _ = libc::close(self.fd);
+            }
             #[cfg(target_os = "hermit")]
             let _ = hermit_abi::close(self.fd);
         }

library/std/src/sys/pal/unix/args.rs

@@ -98,12 +98,10 @@ mod imp {
     }
 
     #[inline(always)]
-    pub unsafe fn init(_argc: isize, _argv: *const *const u8) {
-        // On Linux-GNU, we rely on `ARGV_INIT_ARRAY` below to initialize
-        // `ARGC` and `ARGV`. But in Miri that does not actually happen so we
-        // still initialize here.
-        #[cfg(any(miri, not(all(target_os = "linux", target_env = "gnu"))))]
-        really_init(_argc, _argv);
+    pub unsafe fn init(argc: isize, argv: *const *const u8) {
+        // on GNU/Linux if we are main then we will init argv and argc twice, it "duplicates work"
+        // BUT edge-cases are real: only using .init_array can break most emulators, dlopen, etc.
+        really_init(argc, argv);
     }
 
     /// glibc passes argc, argv, and envp to functions in .init_array, as a non-standard extension.

library/std/src/sys/pal/unix/fs.rs

@@ -864,8 +864,40 @@ impl Iterator for ReadDir {
     }
 }
 
+/// Aborts the process if a file desceriptor is not open, if debug asserts are enabled
+///
+/// Many IO syscalls can't be fully trusted about EBADF error codes because those
+/// might get bubbled up from a remote FUSE server rather than the file descriptor
+/// in the current process being invalid.
+///
+/// So we check file flags instead which live on the file descriptor and not the underlying file.
+/// The downside is that it costs an extra syscall, so we only do it for debug.
+#[inline]
+pub(crate) fn debug_assert_fd_is_open(fd: RawFd) {
+    use crate::sys::os::errno;
+
+    // this is similar to assert_unsafe_precondition!() but it doesn't require const
+    if core::ub_checks::check_library_ub() {
+        if unsafe { libc::fcntl(fd, libc::F_GETFD) } == -1 && errno() == libc::EBADF {
+            rtabort!("IO Safety violation: owned file descriptor already closed");
+        }
+    }
+}
+
 impl Drop for Dir {
     fn drop(&mut self) {
+        // dirfd isn't supported everywhere
+        #[cfg(not(any(
+            miri,
+            target_os = "redox",
+            target_os = "nto",
+            target_os = "vita",
+            target_os = "hurd",
+        )))]
+        {
+            let fd = unsafe { libc::dirfd(self.0) };
+            debug_assert_fd_is_open(fd);
+        }
         let r = unsafe { libc::closedir(self.0) };
         assert!(
             r == 0 || crate::io::Error::last_os_error().is_interrupted(),

src/bootstrap/bootstrap.py

@@ -1035,14 +1035,8 @@ def check_vendored_status(self):
         if self.use_vendored_sources:
             vendor_dir = os.path.join(self.rust_root, 'vendor')
             if not os.path.exists(vendor_dir):
-                sync_dirs = "--sync ./src/tools/cargo/Cargo.toml " \
-                            "--sync ./src/tools/rust-analyzer/Cargo.toml " \
-                            "--sync ./compiler/rustc_codegen_cranelift/Cargo.toml " \
-                            "--sync ./compiler/rustc_codegen_gcc/Cargo.toml " \
-                            "--sync ./src/bootstrap/Cargo.toml "
                 eprint('ERROR: vendoring required, but vendor directory does not exist.')
-                eprint('       Run `cargo vendor {}` to initialize the '
-                      'vendor directory.'.format(sync_dirs))
+                eprint('       Run `x.py vendor` to initialize the vendor directory.')
                 eprint('       Alternatively, use the pre-vendored `rustc-src` dist component.')
                 eprint('       To get a stable/beta/nightly version, download it from: ')
                 eprint('       '

src/bootstrap/src/core/build_steps/clean.rs

@@ -1,4 +1,4 @@
-//! Implementation of `make clean` in rustbuild.
+//! `./x.py clean`
 //!
 //! Responsible for cleaning out a build directory of all old and stale
 //! artifacts to prepare for a fresh build. Currently doesn't remove the

src/bootstrap/src/core/build_steps/mod.rs

@@ -14,3 +14,4 @@ pub(crate) mod synthetic_targets;
 pub(crate) mod test;
 pub(crate) mod tool;
 pub(crate) mod toolstate;
+pub(crate) mod vendor;

src/bootstrap/src/core/build_steps/run.rs

@@ -1,3 +1,8 @@
+//! Build-and-run steps for in-repo tools
+//!
+//! A bit of a hodge-podge as e.g. if a tool's a test fixture it should be in `build_steps::test`.
+//! If it can be reached from `./x.py run` it can go here.
+
 use std::path::PathBuf;
 use std::process::Command;
 

src/bootstrap/src/core/build_steps/setup.rs

@@ -1,3 +1,10 @@
+//! First time setup of a dev environment
+//!
+//! These are build-and-run steps for `./x.py setup`, which allows quickly setting up the directory
+//! for modifying, building, and running the compiler and library. Running arbitrary configuration
+//! allows setting up things that cannot be simply captured inside the config.toml, in addition to
+//! leading people away from manually editing most of the config.toml values.
+
 use crate::core::builder::{Builder, RunConfig, ShouldRun, Step};
 use crate::t;
 use crate::utils::change_tracker::CONFIG_CHANGE_HISTORY;
@@ -25,6 +32,8 @@ pub enum Profile {
     None,
 }
 
+static PROFILE_DIR: &str = "src/bootstrap/defaults";
+
 /// A list of historical hashes of `src/etc/rust_analyzer_settings.json`.
 /// New entries should be appended whenever this is updated so we can detect
 /// outdated vs. user-modified settings files.
@@ -41,7 +50,7 @@ static RUST_ANALYZER_SETTINGS: &str = include_str!("../../../../etc/rust_analyze
 
 impl Profile {
     fn include_path(&self, src_path: &Path) -> PathBuf {
-        PathBuf::from(format!("{}/src/bootstrap/defaults/config.{}.toml", src_path.display(), self))
+        PathBuf::from(format!("{}/{PROFILE_DIR}/config.{}.toml", src_path.display(), self))
     }
 
     pub fn all() -> impl Iterator<Item = Self> {
@@ -220,7 +229,7 @@ fn setup_config_toml(path: &PathBuf, profile: Profile, config: &Config) {
 
     let latest_change_id = CONFIG_CHANGE_HISTORY.last().unwrap().change_id;
     let settings = format!(
-        "# Includes one of the default files in src/bootstrap/defaults\n\
+        "# Includes one of the default files in {PROFILE_DIR}\n\
     profile = \"{profile}\"\n\
     change-id = {latest_change_id}\n"
     );

src/bootstrap/src/core/build_steps/suggest.rs

@@ -1,3 +1,5 @@
+//! Attempt to magically identify good tests to run
+
 #![cfg_attr(feature = "build-metrics", allow(unused))]
 
 use clap::Parser;

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

@@ -1,7 +1,7 @@
-//! Implementation of the test-related targets of the build system.
+//! Build-and-run steps for `./x.py test` test fixtures
 //!
-//! This file implements the various regression test suites that we execute on
-//! our CI.
+//! `./x.py test` (aka [`Kind::Test`]) is currently allowed to reach build steps in other modules.
+//! However, this contains ~all test parts we expect people to be able to build and run locally.
 
 use std::env;
 use std::ffi::OsStr;

src/bootstrap/src/core/build_steps/toolstate.rs

@@ -1,3 +1,9 @@
+//! [Toolstate] checks to keep tools building
+//!
+//! Reachable via `./x.py test` but mostly relevant for CI, since it isn't run locally by default.
+//!
+//! [Toolstate]: https://forge.rust-lang.org/infra/toolstate.html
+
 use crate::core::builder::{Builder, RunConfig, ShouldRun, Step};
 use crate::utils::helpers::t;
 use serde_derive::{Deserialize, Serialize};

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

@@ -0,0 +1,61 @@
+use crate::core::builder::{Builder, RunConfig, ShouldRun, Step};
+use std::path::PathBuf;
+use std::process::Command;
+
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
+pub(crate) struct Vendor {
+    sync_args: Vec<PathBuf>,
+    versioned_dirs: bool,
+    root_dir: PathBuf,
+}
+
+impl Step for Vendor {
+    type Output = ();
+    const DEFAULT: bool = true;
+    const ONLY_HOSTS: bool = true;
+
+    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+        run.alias("placeholder").default_condition(true)
+    }
+
+    fn make_run(run: RunConfig<'_>) {
+        run.builder.ensure(Vendor {
+            sync_args: run.builder.config.cmd.vendor_sync_args(),
+            versioned_dirs: run.builder.config.cmd.vendor_versioned_dirs(),
+            root_dir: run.builder.src.clone(),
+        });
+    }
+
+    fn run(self, builder: &Builder<'_>) -> Self::Output {
+        let mut cmd = Command::new(&builder.initial_cargo);
+        cmd.arg("vendor");
+
+        if self.versioned_dirs {
+            cmd.arg("--versioned-dirs");
+        }
+
+        // Sync these paths by default.
+        for p in [
+            "src/tools/cargo/Cargo.toml",
+            "src/tools/rust-analyzer/Cargo.toml",
+            "compiler/rustc_codegen_cranelift/Cargo.toml",
+            "compiler/rustc_codegen_gcc/Cargo.toml",
+            "src/bootstrap/Cargo.toml",
+        ] {
+            cmd.arg("--sync").arg(builder.src.join(p));
+        }
+
+        // Also sync explicitly requested paths.
+        for sync_arg in self.sync_args {
+            cmd.arg("--sync").arg(sync_arg);
+        }
+
+        // Will read the libstd Cargo.toml
+        // which uses the unstable `public-dependency` feature.
+        cmd.env("RUSTC_BOOTSTRAP", "1");
+
+        cmd.current_dir(self.root_dir);
+
+        builder.run(&mut cmd);
+    }
+}

src/bootstrap/src/core/builder.rs

@@ -14,8 +14,9 @@ use std::sync::OnceLock;
 use std::time::{Duration, Instant};
 
 use crate::core::build_steps::tool::{self, SourceType};
-use crate::core::build_steps::{check, clean, compile, dist, doc, install, run, setup, test};
-use crate::core::build_steps::{clippy, llvm};
+use crate::core::build_steps::{
+    check, clean, clippy, compile, dist, doc, install, llvm, run, setup, test, vendor,
+};
 use crate::core::config::flags::{Color, Subcommand};
 use crate::core::config::{DryRun, SplitDebuginfo, TargetSelection};
 use crate::prepare_behaviour_dump_dir;
@@ -34,13 +35,34 @@ use once_cell::sync::Lazy;
 #[cfg(test)]
 mod tests;
 
+/// Builds and performs different [`Self::kind`]s of stuff and actions, taking
+/// into account build configuration from e.g. config.toml.
 pub struct Builder<'a> {
+    /// Build configuration from e.g. config.toml.
     pub build: &'a Build,
+
+    /// The stage to use. Either implicitly determined based on subcommand, or
+    /// explicitly specified with `--stage N`. Normally this is the stage we
+    /// use, but sometimes we want to run steps with a lower stage than this.
     pub top_stage: u32,
+
+    /// What to build or what action to perform.
     pub kind: Kind,
+
+    /// A cache of outputs of [`Step`]s so we can avoid running steps we already
+    /// ran.
     cache: Cache,
+
+    /// A stack of [`Step`]s to run before we can run this builder. The output
+    /// of steps is cached in [`Self::cache`].
     stack: RefCell<Vec<Box<dyn Any>>>,
+
+    /// The total amount of time we spent running [`Step`]s in [`Self::stack`].
     time_spent_on_dependencies: Cell<Duration>,
+
+    /// The paths passed on the command line. Used by steps to figure out what
+    /// to do. For example: with `./x check foo bar` we get `paths=["foo",
+    /// "bar"]`.
     pub paths: Vec<PathBuf>,
 }
 
@@ -638,6 +660,7 @@ pub enum Kind {
     Run,
     Setup,
     Suggest,
+    Vendor,
 }
 
 impl Kind {
@@ -658,6 +681,7 @@ impl Kind {
             Kind::Run => "run",
             Kind::Setup => "setup",
             Kind::Suggest => "suggest",
+            Kind::Vendor => "vendor",
         }
     }
 
@@ -921,6 +945,7 @@ impl<'a> Builder<'a> {
             ),
             Kind::Setup => describe!(setup::Profile, setup::Hook, setup::Link, setup::Vscode),
             Kind::Clean => describe!(clean::CleanAll, clean::Rustc, clean::Std),
+            Kind::Vendor => describe!(vendor::Vendor),
             // special-cased in Build::build()
             Kind::Format | Kind::Suggest => vec![],
         }
@@ -993,6 +1018,7 @@ impl<'a> Builder<'a> {
                 Kind::Setup,
                 path.as_ref().map_or([].as_slice(), |path| std::slice::from_ref(path)),
             ),
+            Subcommand::Vendor { .. } => (Kind::Vendor, &paths[..]),
         };
 
         Self::new_internal(build, kind, paths.to_owned())