Rollup of 13 pull requests

.gitignore

@@ -46,6 +46,7 @@ no_llvm_build
 /dist/
 /unicode-downloads
 /target
+/src/bootstrap/target
 /src/tools/x/target
 # Created by default with `src/ci/docker/run.sh`
 /obj/

compiler/rustc_attr/src/builtin.rs

@@ -15,6 +15,12 @@ use std::num::NonZeroU32;
 
 use crate::session_diagnostics::{self, IncorrectReprFormatGenericCause};
 
+/// The version placeholder that recently stabilized features contain inside the
+/// `since` field of the `#[stable]` attribute.
+///
+/// For more, see https://github.com/rust-lang/rust/pull/100591
+pub const VERSION_PLACEHOLDER: &str = "CURRENT_RUSTC_VERSION";
+
 pub fn is_builtin_attr(attr: &Attribute) -> bool {
     attr.is_doc_comment() || attr.ident().filter(|ident| is_builtin_attr_name(ident.name)).is_some()
 }
@@ -483,6 +489,12 @@ where
                         }
                     }
 
+                    if let Some(s) = since && s.as_str() == VERSION_PLACEHOLDER {
+                        let version = option_env!("CFG_VERSION").unwrap_or("<current>");
+                        let version = version.split(' ').next().unwrap();
+                        since = Some(Symbol::intern(&version));
+                    }
+
                     match (feature, since) {
                         (Some(feature), Some(since)) => {
                             let level = Stable { since, allowed_through_unstable_modules: false };

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -902,7 +902,11 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             hir::ExprKind::MethodCall(.., args, _) => {
                 // only the first closre parameter of the method. args[0] is MethodCall PathSegment
                 for i in 1..args.len() {
-                    if let hir::ExprKind::Closure(..) = args[i].kind {
+                    if let hir::ExprKind::Closure(hir::Closure {
+                        capture_clause: hir::CaptureBy::Ref,
+                        ..
+                    }) = args[i].kind
+                    {
                         closure_span = Some(args[i].span.shrink_to_lo());
                         break;
                     }
@@ -911,7 +915,11 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             hir::ExprKind::Block(blk, _) => {
                 if let Some(ref expr) = blk.expr {
                     // only when the block is a closure
-                    if let hir::ExprKind::Closure(..) = expr.kind {
+                    if let hir::ExprKind::Closure(hir::Closure {
+                        capture_clause: hir::CaptureBy::Ref,
+                        ..
+                    }) = expr.kind
+                    {
                         closure_span = Some(expr.span.shrink_to_lo());
                     }
                 }
@@ -921,7 +929,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         if let Some(closure_span) = closure_span {
             diag.span_suggestion_verbose(
                 closure_span,
-                format!("consider adding 'move' keyword before the nested closure"),
+                "consider adding 'move' keyword before the nested closure",
                 "move ",
                 Applicability::MaybeIncorrect,
             );

compiler/rustc_lint/src/builtin.rs

@@ -3173,3 +3173,81 @@ impl<'tcx> LateLintPass<'tcx> for NamedAsmLabels {
         }
     }
 }
+
+declare_lint! {
+    /// The `special_module_name` lint detects module
+    /// declarations for files that have a special meaning.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// mod lib;
+    ///
+    /// fn main() {
+    ///     lib::run();
+    /// }
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// Cargo recognizes `lib.rs` and `main.rs` as the root of a
+    /// library or binary crate, so declaring them as modules
+    /// will lead to miscompilation of the crate unless configured
+    /// explicitly.
+    ///
+    /// To access a library from a binary target within the same crate,
+    /// use `your_crate_name::` as the path path instead of `lib::`:
+    ///
+    /// ```rust,compile_fail
+    /// // bar/src/lib.rs
+    /// fn run() {
+    ///     // ...
+    /// }
+    ///
+    /// // bar/src/main.rs
+    /// fn main() {
+    ///     bar::run();
+    /// }
+    /// ```
+    ///
+    /// Binary targets cannot be used as libraries and so declaring
+    /// one as a module is not allowed.
+    pub SPECIAL_MODULE_NAME,
+    Warn,
+    "module declarations for files with a special meaning",
+}
+
+declare_lint_pass!(SpecialModuleName => [SPECIAL_MODULE_NAME]);
+
+impl EarlyLintPass for SpecialModuleName {
+    fn check_crate(&mut self, cx: &EarlyContext<'_>, krate: &ast::Crate) {
+        for item in &krate.items {
+            if let ast::ItemKind::Mod(
+                _,
+                ast::ModKind::Unloaded | ast::ModKind::Loaded(_, ast::Inline::No, _),
+            ) = item.kind
+            {
+                if item.attrs.iter().any(|a| a.has_name(sym::path)) {
+                    continue;
+                }
+
+                match item.ident.name.as_str() {
+                    "lib" => cx.struct_span_lint(SPECIAL_MODULE_NAME, item.span, |lint| {
+                        lint.build("found module declaration for lib.rs")
+                            .note("lib.rs is the root of this crate's library target")
+                            .help("to refer to it from other targets, use the library's name as the path")
+                            .emit()
+                    }),
+                    "main" => cx.struct_span_lint(SPECIAL_MODULE_NAME, item.span, |lint| {
+                        lint.build("found module declaration for main.rs")
+                            .note("a binary crate cannot be used as library")
+                            .emit()
+                    }),
+                    _ => continue
+                }
+            }
+        }
+    }
+}

compiler/rustc_lint/src/lib.rs

@@ -131,6 +131,7 @@ macro_rules! early_lint_passes {
                 UnusedBraces: UnusedBraces,
                 UnusedImportBraces: UnusedImportBraces,
                 UnsafeCode: UnsafeCode,
+                SpecialModuleName: SpecialModuleName,
                 AnonymousParameters: AnonymousParameters,
                 EllipsisInclusiveRangePatterns: EllipsisInclusiveRangePatterns::default(),
                 NonCamelCaseTypes: NonCamelCaseTypes,

compiler/rustc_passes/src/lib_features.rs

@@ -5,6 +5,7 @@
 //! collect them instead.
 
 use rustc_ast::{Attribute, MetaItemKind};
+use rustc_attr::VERSION_PLACEHOLDER;
 use rustc_errors::struct_span_err;
 use rustc_hir::intravisit::Visitor;
 use rustc_middle::hir::nested_filter;
@@ -54,7 +55,6 @@ impl<'tcx> LibFeatureCollector<'tcx> {
                         }
                     }
                 }
-                const VERSION_PLACEHOLDER: &str = "CURRENT_RUSTC_VERSION";
 
                 if let Some(s) = since && s.as_str() == VERSION_PLACEHOLDER {
                     let version = option_env!("CFG_VERSION").unwrap_or("<current>");

config.toml.example

@@ -666,6 +666,10 @@ changelog-seen = 2
 # target.
 #llvm-config = <none> (path)
 
+# Override detection of whether this is a Rust-patched LLVM. This would be used
+# in conjunction with either an llvm-config or build.submodules = false.
+#llvm-has-rust-patches = if llvm-config { false } else { true }
+
 # Normally the build system can find LLVM's FileCheck utility, but if
 # not, you can specify an explicit file name for it.
 #llvm-filecheck = "/path/to/llvm-version/bin/FileCheck"

library/core/src/num/nonzero.rs

@@ -309,8 +309,8 @@ macro_rules! nonzero_unsigned_operations {
     ( $( $Ty: ident($Int: ident); )+ ) => {
         $(
             impl $Ty {
-                /// Add an unsigned integer to a non-zero value.
-                /// Check for overflow and return [`None`] on overflow
+                /// Adds an unsigned integer to a non-zero value.
+                /// Checks for overflow and returns [`None`] on overflow.
                 /// As a consequence, the result cannot wrap to zero.
                 ///
                 ///
@@ -346,7 +346,7 @@ macro_rules! nonzero_unsigned_operations {
                     }
                 }
 
-                /// Add an unsigned integer to a non-zero value.
+                /// Adds an unsigned integer to a non-zero value.
                 #[doc = concat!("Return [`", stringify!($Int), "::MAX`] on overflow.")]
                 ///
                 /// # Examples
@@ -377,7 +377,7 @@ macro_rules! nonzero_unsigned_operations {
                     unsafe { $Ty::new_unchecked(self.get().saturating_add(other)) }
                 }
 
-                /// Add an unsigned integer to a non-zero value,
+                /// Adds an unsigned integer to a non-zero value,
                 /// assuming overflow cannot occur.
                 /// Overflow is unchecked, and it is undefined behaviour to overflow
                 /// *even if the result would wrap to a non-zero value*.
@@ -409,7 +409,7 @@ macro_rules! nonzero_unsigned_operations {
                 }
 
                 /// Returns the smallest power of two greater than or equal to n.
-                /// Check for overflow and return [`None`]
+                /// Checks for overflow and returns [`None`]
                 /// if the next power of two is greater than the type’s maximum value.
                 /// As a consequence, the result cannot wrap to zero.
                 ///
@@ -545,7 +545,7 @@ macro_rules! nonzero_signed_operations {
                 }
 
                 /// Checked absolute value.
-                /// Check for overflow and returns [`None`] if
+                /// Checks for overflow and returns [`None`] if
                 #[doc = concat!("`self == ", stringify!($Int), "::MIN`.")]
                 /// The result cannot be zero.
                 ///
@@ -740,8 +740,8 @@ macro_rules! nonzero_unsigned_signed_operations {
     ( $( $signedness:ident $Ty: ident($Int: ty); )+ ) => {
         $(
             impl $Ty {
-                /// Multiply two non-zero integers together.
-                /// Check for overflow and return [`None`] on overflow.
+                /// Multiplies two non-zero integers together.
+                /// Checks for overflow and returns [`None`] on overflow.
                 /// As a consequence, the result cannot wrap to zero.
                 ///
                 /// # Examples
@@ -777,7 +777,7 @@ macro_rules! nonzero_unsigned_signed_operations {
                     }
                 }
 
-                /// Multiply two non-zero integers together.
+                /// Multiplies two non-zero integers together.
                 #[doc = concat!("Return [`", stringify!($Int), "::MAX`] on overflow.")]
                 ///
                 /// # Examples
@@ -809,7 +809,7 @@ macro_rules! nonzero_unsigned_signed_operations {
                     unsafe { $Ty::new_unchecked(self.get().saturating_mul(other.get())) }
                 }
 
-                /// Multiply two non-zero integers together,
+                /// Multiplies two non-zero integers together,
                 /// assuming overflow cannot occur.
                 /// Overflow is unchecked, and it is undefined behaviour to overflow
                 /// *even if the result would wrap to a non-zero value*.
@@ -849,8 +849,8 @@ macro_rules! nonzero_unsigned_signed_operations {
                     unsafe { $Ty::new_unchecked(self.get().unchecked_mul(other.get())) }
                 }
 
-                /// Raise non-zero value to an integer power.
-                /// Check for overflow and return [`None`] on overflow.
+                /// Raises non-zero value to an integer power.
+                /// Checks for overflow and returns [`None`] on overflow.
                 /// As a consequence, the result cannot wrap to zero.
                 ///
                 /// # Examples

library/std/src/io/stdio.rs

@@ -986,10 +986,10 @@ pub fn set_output_capture(sink: Option<LocalStream>) -> Option<LocalStream> {
 /// otherwise. `label` identifies the stream in a panic message.
 ///
 /// This function is used to print error messages, so it takes extra
-/// care to avoid causing a panic when `local_s` is unusable.
-/// For instance, if the TLS key for the local stream is
-/// already destroyed, or if the local stream is locked by another
-/// thread, it will just fall back to the global stream.
+/// care to avoid causing a panic when `OUTPUT_CAPTURE` is unusable.
+/// For instance, if the TLS key for output capturing is already destroyed, or
+/// if the local stream is in use by another thread, it will just fall back to
+/// the global stream.
 ///
 /// However, if the actual I/O causes an error, this function does panic.
 fn print_to<T>(args: fmt::Arguments<'_>, global_s: fn() -> T, label: &str)

src/bootstrap/bootstrap.py

@@ -793,6 +793,8 @@ def set_dist_environment(self, url):
 
     def check_vendored_status(self):
         """Check that vendoring is configured properly"""
+        # keep this consistent with the equivalent check in rustbuild:
+        # https://github.com/rust-lang/rust/blob/a8a33cf27166d3eabaffc58ed3799e054af3b0c6/src/bootstrap/lib.rs#L399-L405
         if 'SUDO_USER' in os.environ and not self.use_vendored_sources:
             if os.getuid() == 0:
                 self.use_vendored_sources = True

src/bootstrap/config.rs

@@ -388,6 +388,7 @@ impl PartialEq<&str> for TargetSelection {
 pub struct Target {
     /// Some(path to llvm-config) if using an external LLVM.
     pub llvm_config: Option<PathBuf>,
+    pub llvm_has_rust_patches: Option<bool>,
     /// Some(path to FileCheck) if one was specified.
     pub llvm_filecheck: Option<PathBuf>,
     pub llvm_libunwind: Option<LlvmLibunwind>,
@@ -733,6 +734,7 @@ define_config! {
         default_linker: Option<PathBuf> = "default-linker",
         linker: Option<String> = "linker",
         llvm_config: Option<String> = "llvm-config",
+        llvm_has_rust_patches: Option<bool> = "llvm-has-rust-patches",
         llvm_filecheck: Option<String> = "llvm-filecheck",
         llvm_libunwind: Option<String> = "llvm-libunwind",
         android_ndk: Option<String> = "android-ndk",
@@ -1109,6 +1111,7 @@ impl Config {
                 if let Some(ref s) = cfg.llvm_config {
                     target.llvm_config = Some(config.src.join(s));
                 }
+                target.llvm_has_rust_patches = cfg.llvm_has_rust_patches;
                 if let Some(ref s) = cfg.llvm_filecheck {
                     target.llvm_filecheck = Some(config.src.join(s));
                 }

src/bootstrap/lib.rs

@@ -112,6 +112,7 @@ use std::path::{Path, PathBuf};
 use std::process::Command;
 use std::str;
 
+use config::Target;
 use filetime::FileTime;
 use once_cell::sync::OnceCell;
 
@@ -395,13 +396,18 @@ impl Build {
         let src = config.src.clone();
         let out = config.out.clone();
 
+        #[cfg(unix)]
+        // keep this consistent with the equivalent check in x.py:
+        // https://github.com/rust-lang/rust/blob/a8a33cf27166d3eabaffc58ed3799e054af3b0c6/src/bootstrap/bootstrap.py#L796-L797
         let is_sudo = match env::var_os("SUDO_USER") {
-            Some(sudo_user) => match env::var_os("USER") {
-                Some(user) => user != sudo_user,
-                None => false,
-            },
+            Some(_sudo_user) => {
+                let uid = unsafe { libc::getuid() };
+                uid == 0
+            }
             None => false,
         };
+        #[cfg(not(unix))]
+        let is_sudo = false;
 
         let ignore_git = config.ignore_git;
         let rust_info = channel::GitInfo::new(ignore_git, &src);
@@ -834,12 +840,13 @@ impl Build {
     ///
     /// If no custom `llvm-config` was specified then Rust's llvm will be used.
     fn is_rust_llvm(&self, target: TargetSelection) -> bool {
-        if self.config.llvm_from_ci && target == self.config.build {
-            return true;
-        }
-
         match self.config.target_config.get(&target) {
-            Some(ref c) => c.llvm_config.is_none(),
+            Some(Target { llvm_has_rust_patches: Some(patched), .. }) => *patched,
+            Some(Target { llvm_config, .. }) => {
+                // If the user set llvm-config we assume Rust is not patched,
+                // but first check to see if it was configured by llvm-from-ci.
+                (self.config.llvm_from_ci && target == self.config.build) || llvm_config.is_none()
+            }
             None => true,
         }
     }