Rollup of 7 pull requests

compiler/rustc_data_structures/src/steal.rs

@@ -57,6 +57,7 @@ impl<T> Steal<T> {
     ///
     /// This should not be used within rustc as it leaks information not tracked
     /// by the query system, breaking incremental compilation.
+    #[cfg_attr(not(bootstrap), rustc_lint_untracked_query_information)]
     pub fn is_stolen(&self) -> bool {
         self.value.borrow().is_none()
     }

compiler/rustc_feature/src/builtin_attrs.rs

@@ -793,6 +793,12 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         rustc_lint_query_instability, Normal, template!(Word),
         WarnFollowing, EncodeCrossCrate::Yes, INTERNAL_UNSTABLE
     ),
+    // Used by the `rustc::untracked_query_information` lint to warn methods which
+    // might not be stable during incremental compilation.
+    rustc_attr!(
+        rustc_lint_untracked_query_information, Normal, template!(Word),
+        WarnFollowing, EncodeCrossCrate::Yes, INTERNAL_UNSTABLE
+    ),
     // Used by the `rustc::diagnostic_outside_of_impl` lints to assist in changes to diagnostic
     // APIs. Any function with this attribute will be checked by that lint.
     rustc_attr!(

compiler/rustc_lint/messages.ftl

@@ -699,6 +699,9 @@ lint_ptr_null_checks_ref = references are not nullable, so checking them for nul
 lint_query_instability = using `{$query}` can result in unstable query results
     .note = if you believe this case to be fine, allow this lint and add a comment explaining your rationale
 
+lint_query_untracked = `{$method}` accesses information that is not tracked by the query system
+    .note = if you believe this case to be fine, allow this lint and add a comment explaining your rationale
+
 lint_range_endpoint_out_of_range = range endpoint is out of range for `{$ty}`
 
 lint_range_use_inclusive_range = use an inclusive range instead

compiler/rustc_lint/src/internal.rs

@@ -17,8 +17,8 @@ use tracing::debug;
 
 use crate::lints::{
     BadOptAccessDiag, DefaultHashTypesDiag, DiagOutOfImpl, LintPassByHand, NonExistentDocKeyword,
-    NonGlobImportTypeIrInherent, QueryInstability, SpanUseEqCtxtDiag, TyQualified, TykindDiag,
-    TykindKind, TypeIrInherentUsage, UntranslatableDiag,
+    NonGlobImportTypeIrInherent, QueryInstability, QueryUntracked, SpanUseEqCtxtDiag, TyQualified,
+    TykindDiag, TykindKind, TypeIrInherentUsage, UntranslatableDiag,
 };
 use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
 
@@ -88,7 +88,18 @@ declare_tool_lint! {
     report_in_external_macro: true
 }
 
-declare_lint_pass!(QueryStability => [POTENTIAL_QUERY_INSTABILITY]);
+declare_tool_lint! {
+    /// The `untracked_query_information` lint detects use of methods which leak information not
+    /// tracked by the query system, such as whether a `Steal<T>` value has already been stolen. In
+    /// order not to break incremental compilation, such methods must be used very carefully or not
+    /// at all.
+    pub rustc::UNTRACKED_QUERY_INFORMATION,
+    Allow,
+    "require explicit opt-in when accessing information not tracked by the query system",
+    report_in_external_macro: true
+}
+
+declare_lint_pass!(QueryStability => [POTENTIAL_QUERY_INSTABILITY, UNTRACKED_QUERY_INFORMATION]);
 
 impl LateLintPass<'_> for QueryStability {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
@@ -102,6 +113,13 @@ impl LateLintPass<'_> for QueryStability {
                     QueryInstability { query: cx.tcx.item_name(def_id) },
                 );
             }
+            if cx.tcx.has_attr(def_id, sym::rustc_lint_untracked_query_information) {
+                cx.emit_span_lint(
+                    UNTRACKED_QUERY_INFORMATION,
+                    span,
+                    QueryUntracked { method: cx.tcx.item_name(def_id) },
+                );
+            }
         }
     }
 }

compiler/rustc_lint/src/lib.rs

@@ -609,6 +609,7 @@ fn register_internals(store: &mut LintStore) {
         vec![
             LintId::of(DEFAULT_HASH_TYPES),
             LintId::of(POTENTIAL_QUERY_INSTABILITY),
+            LintId::of(UNTRACKED_QUERY_INFORMATION),
             LintId::of(USAGE_OF_TY_TYKIND),
             LintId::of(PASS_BY_VALUE),
             LintId::of(LINT_PASS_IMPL_WITHOUT_MACRO),

compiler/rustc_lint/src/lints.rs

@@ -894,6 +894,13 @@ pub(crate) struct QueryInstability {
     pub query: Symbol,
 }
 
+#[derive(LintDiagnostic)]
+#[diag(lint_query_untracked)]
+#[note]
+pub(crate) struct QueryUntracked {
+    pub method: Symbol,
+}
+
 #[derive(LintDiagnostic)]
 #[diag(lint_span_use_eq_ctxt)]
 pub(crate) struct SpanUseEqCtxtDiag;

compiler/rustc_passes/src/check_attr.rs

@@ -125,7 +125,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 [sym::inline, ..] => self.check_inline(hir_id, attr, span, target),
                 [sym::coverage, ..] => self.check_coverage(attr, span, target),
                 [sym::optimize, ..] => self.check_optimize(hir_id, attr, target),
-                [sym::no_sanitize, ..] => self.check_no_sanitize(hir_id, attr, span, target),
+                [sym::no_sanitize, ..] => {
+                    self.check_applied_to_fn_or_method(hir_id, attr, span, target)
+                }
                 [sym::non_exhaustive, ..] => self.check_non_exhaustive(hir_id, attr, span, target),
                 [sym::marker, ..] => self.check_marker(hir_id, attr, span, target),
                 [sym::target_feature, ..] => {
@@ -166,10 +168,13 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     self.check_rustc_legacy_const_generics(hir_id, attr, span, target, item)
                 }
                 [sym::rustc_lint_query_instability, ..] => {
-                    self.check_rustc_lint_query_instability(hir_id, attr, span, target)
+                    self.check_applied_to_fn_or_method(hir_id, attr, span, target)
+                }
+                [sym::rustc_lint_untracked_query_information, ..] => {
+                    self.check_applied_to_fn_or_method(hir_id, attr, span, target)
                 }
                 [sym::rustc_lint_diagnostics, ..] => {
-                    self.check_rustc_lint_diagnostics(hir_id, attr, span, target)
+                    self.check_applied_to_fn_or_method(hir_id, attr, span, target)
                 }
                 [sym::rustc_lint_opt_ty, ..] => self.check_rustc_lint_opt_ty(attr, span, target),
                 [sym::rustc_lint_opt_deny_field_access, ..] => {
@@ -452,11 +457,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
     }
 
-    /// Checks that `#[no_sanitize(..)]` is applied to a function or method.
-    fn check_no_sanitize(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) {
-        self.check_applied_to_fn_or_method(hir_id, attr, span, target)
-    }
-
     fn check_generic_attr(
         &self,
         hir_id: HirId,
@@ -1635,30 +1635,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
     }
 
-    /// Checks that the `#[rustc_lint_query_instability]` attribute is only applied to a function
-    /// or method.
-    fn check_rustc_lint_query_instability(
-        &self,
-        hir_id: HirId,
-        attr: &Attribute,
-        span: Span,
-        target: Target,
-    ) {
-        self.check_applied_to_fn_or_method(hir_id, attr, span, target)
-    }
-
-    /// Checks that the `#[rustc_lint_diagnostics]` attribute is only applied to a function or
-    /// method.
-    fn check_rustc_lint_diagnostics(
-        &self,
-        hir_id: HirId,
-        attr: &Attribute,
-        span: Span,
-        target: Target,
-    ) {
-        self.check_applied_to_fn_or_method(hir_id, attr, span, target)
-    }
-
     /// Checks that the `#[rustc_lint_opt_ty]` attribute is only applied to a struct.
     fn check_rustc_lint_opt_ty(&self, attr: &Attribute, span: Span, target: Target) {
         match target {

compiler/rustc_span/src/symbol.rs

@@ -1653,6 +1653,7 @@ symbols! {
         rustc_lint_opt_deny_field_access,
         rustc_lint_opt_ty,
         rustc_lint_query_instability,
+        rustc_lint_untracked_query_information,
         rustc_macro_transparency,
         rustc_main,
         rustc_mir,

compiler/rustc_target/src/spec/mod.rs

@@ -1645,6 +1645,7 @@ supported_targets! {
     ("x86_64-unknown-haiku", x86_64_unknown_haiku),
 
     ("i686-unknown-hurd-gnu", i686_unknown_hurd_gnu),
+    ("x86_64-unknown-hurd-gnu", x86_64_unknown_hurd_gnu),
 
     ("aarch64-apple-darwin", aarch64_apple_darwin),
     ("arm64e-apple-darwin", arm64e_apple_darwin),

compiler/rustc_target/src/spec/targets/x86_64_unknown_hurd_gnu.rs

@@ -0,0 +1,26 @@
+use crate::spec::{base, Cc, LinkerFlavor, Lld, StackProbeType, Target};
+
+pub fn target() -> Target {
+    let mut base = base::hurd_gnu::opts();
+    base.cpu = "x86-64".into();
+    base.plt_by_default = false;
+    base.max_atomic_width = Some(64);
+    base.add_pre_link_args(LinkerFlavor::Gnu(Cc::Yes, Lld::No), &["-m64"]);
+    base.stack_probes = StackProbeType::Inline;
+    base.supports_xray = true;
+
+    Target {
+        llvm_target: "x86_64-unknown-hurd-gnu".into(),
+        metadata: crate::spec::TargetMetadata {
+            description: Some("64-bit GNU/Hurd".into()),
+            tier: Some(3),
+            host_tools: Some(true),
+            std: Some(true),
+        },
+        pointer_width: 64,
+        data_layout:
+            "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128".into(),
+        arch: "x86_64".into(),
+        options: base,
+    }
+}

library/core/src/ptr/mod.rs

@@ -2277,6 +2277,14 @@ impl<F: FnPtr> fmt::Debug for F {
 /// `addr_of!(expr)` is equivalent to `&raw const expr`. The macro is *soft-deprecated*;
 /// use `&raw const` instead.
 ///
+/// It is still an open question under which conditions writing through an `addr_of!`-created
+/// pointer is permitted. If the place `expr` evaluates to is based on a raw pointer, then the
+/// result of `addr_of!` inherits all permissions from that raw pointer. However, if the place is
+/// based on a reference, local variable, or `static`, then until all details are decided, the same
+/// rules as for shared references apply: it is UB to write through a pointer created with this
+/// operation, except for bytes located inside an `UnsafeCell`. Use `&raw mut` (or [`addr_of_mut`])
+/// to create a raw pointer that definitely permits mutation.
+///
 /// Creating a reference with `&`/`&mut` is only allowed if the pointer is properly aligned
 /// and points to initialized data. For cases where those requirements do not hold,
 /// raw pointers should be used instead. However, `&expr as *const _` creates a reference

src/bootstrap/src/core/build_steps/check.rs

@@ -91,8 +91,8 @@ impl Step for Std {
         // We skip populating the sysroot in non-zero stage because that'll lead
         // to rlib/rmeta conflicts if std gets built during this session.
         if compiler.stage == 0 {
-            let libdir = builder.sysroot_libdir(compiler, target);
-            let hostdir = builder.sysroot_libdir(compiler, compiler.host);
+            let libdir = builder.sysroot_target_libdir(compiler, target);
+            let hostdir = builder.sysroot_target_libdir(compiler, compiler.host);
             add_to_sysroot(builder, &libdir, &hostdir, &libstd_stamp(builder, compiler, target));
         }
         drop(_guard);
@@ -257,8 +257,8 @@ impl Step for Rustc {
             false,
         );
 
-        let libdir = builder.sysroot_libdir(compiler, target);
-        let hostdir = builder.sysroot_libdir(compiler, compiler.host);
+        let libdir = builder.sysroot_target_libdir(compiler, target);
+        let hostdir = builder.sysroot_target_libdir(compiler, compiler.host);
         add_to_sysroot(builder, &libdir, &hostdir, &librustc_stamp(builder, compiler, target));
     }
 }

src/bootstrap/src/core/build_steps/compile.rs

@@ -240,7 +240,7 @@ impl Step for Std {
                 .join("bin");
             if src_sysroot_bin.exists() {
                 let target_sysroot_bin =
-                    builder.sysroot_libdir(compiler, target).parent().unwrap().join("bin");
+                    builder.sysroot_target_libdir(compiler, target).parent().unwrap().join("bin");
                 t!(fs::create_dir_all(&target_sysroot_bin));
                 builder.cp_link_r(&src_sysroot_bin, &target_sysroot_bin);
             }
@@ -354,7 +354,7 @@ fn copy_third_party_objects(
             && (target.contains("linux") || target.contains("fuchsia"))
     {
         let libunwind_path =
-            copy_llvm_libunwind(builder, target, &builder.sysroot_libdir(*compiler, target));
+            copy_llvm_libunwind(builder, target, &builder.sysroot_target_libdir(*compiler, target));
         target_deps.push((libunwind_path, DependencyType::Target));
     }
 
@@ -367,7 +367,8 @@ fn copy_self_contained_objects(
     compiler: &Compiler,
     target: TargetSelection,
 ) -> Vec<(PathBuf, DependencyType)> {
-    let libdir_self_contained = builder.sysroot_libdir(*compiler, target).join("self-contained");
+    let libdir_self_contained =
+        builder.sysroot_target_libdir(*compiler, target).join("self-contained");
     t!(fs::create_dir_all(&libdir_self_contained));
     let mut target_deps = vec![];
 
@@ -675,8 +676,8 @@ impl Step for StdLink {
             let hostdir = sysroot.join(lib).join("rustlib").join(compiler.host).join("lib");
             (libdir, hostdir)
         } else {
-            let libdir = builder.sysroot_libdir(target_compiler, target);
-            let hostdir = builder.sysroot_libdir(target_compiler, compiler.host);
+            let libdir = builder.sysroot_target_libdir(target_compiler, target);
+            let hostdir = builder.sysroot_target_libdir(target_compiler, compiler.host);
             (libdir, hostdir)
         };
 
@@ -743,7 +744,7 @@ fn copy_sanitizers(
     }
 
     let mut target_deps = Vec::new();
-    let libdir = builder.sysroot_libdir(*compiler, target);
+    let libdir = builder.sysroot_target_libdir(*compiler, target);
 
     for runtime in &runtimes {
         let dst = libdir.join(&runtime.name);
@@ -821,7 +822,7 @@ impl Step for StartupObjects {
 
         let src_dir = &builder.src.join("library").join("rtstartup");
         let dst_dir = &builder.native_dir(target).join("rtstartup");
-        let sysroot_dir = &builder.sysroot_libdir(for_compiler, target);
+        let sysroot_dir = &builder.sysroot_target_libdir(for_compiler, target);
         t!(fs::create_dir_all(dst_dir));
 
         for file in &["rsbegin", "rsend"] {
@@ -1273,10 +1274,17 @@ fn rustc_llvm_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelect
     }
 }
 
+/// `RustcLink` copies all of the rlibs from the rustc build into the previous stage's sysroot.
+/// This is necessary for tools using `rustc_private`, where the previous compiler will build
+/// a tool against the next compiler.
+/// To build a tool against a compiler, the rlibs of that compiler that it links against
+/// must be in the sysroot of the compiler that's doing the compiling.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 struct RustcLink {
+    /// The compiler whose rlibs we are copying around.
     pub compiler: Compiler,
-    pub target_compiler: Compiler,
+    /// This is the compiler into whose sysroot we want to copy the rlibs into.
+    pub previous_stage_compiler: Compiler,
     pub target: TargetSelection,
     /// Not actually used; only present to make sure the cache invalidation is correct.
     crates: Vec<String>,
@@ -1286,7 +1294,7 @@ impl RustcLink {
     fn from_rustc(rustc: Rustc, host_compiler: Compiler) -> Self {
         Self {
             compiler: host_compiler,
-            target_compiler: rustc.compiler,
+            previous_stage_compiler: rustc.compiler,
             target: rustc.target,
             crates: rustc.crates,
         }
@@ -1303,12 +1311,12 @@ impl Step for RustcLink {
     /// Same as `std_link`, only for librustc
     fn run(self, builder: &Builder<'_>) {
         let compiler = self.compiler;
-        let target_compiler = self.target_compiler;
+        let previous_stage_compiler = self.previous_stage_compiler;
         let target = self.target;
         add_to_sysroot(
             builder,
-            &builder.sysroot_libdir(target_compiler, target),
-            &builder.sysroot_libdir(target_compiler, compiler.host),
+            &builder.sysroot_target_libdir(previous_stage_compiler, target),
+            &builder.sysroot_target_libdir(previous_stage_compiler, compiler.host),
             &librustc_stamp(builder, compiler, target),
         );
     }
@@ -1845,7 +1853,7 @@ impl Step for Assemble {
         let sysroot = builder.sysroot(target_compiler);
         let rustc_libdir = builder.rustc_libdir(target_compiler);
         t!(fs::create_dir_all(&rustc_libdir));
-        let src_libdir = builder.sysroot_libdir(build_compiler, host);
+        let src_libdir = builder.sysroot_target_libdir(build_compiler, host);
         for f in builder.read_dir(&src_libdir) {
             let filename = f.file_name().into_string().unwrap();
             if (is_dylib(&filename) || is_debug_info(&filename)) && !proc_macros.contains(&filename)
@@ -1858,7 +1866,7 @@ impl Step for Assemble {
 
         // We prepend this bin directory to the user PATH when linking Rust binaries. To
         // avoid shadowing the system LLD we rename the LLD we provide to `rust-lld`.
-        let libdir = builder.sysroot_libdir(target_compiler, target_compiler.host);
+        let libdir = builder.sysroot_target_libdir(target_compiler, target_compiler.host);
         let libdir_bin = libdir.parent().unwrap().join("bin");
         t!(fs::create_dir_all(&libdir_bin));
         if let Some(lld_install) = lld_install {

src/bootstrap/src/core/build_steps/dist.rs

@@ -459,7 +459,8 @@ impl Step for Rustc {
 
             // Copy over lld if it's there
             if builder.config.lld_enabled {
-                let src_dir = builder.sysroot_libdir(compiler, host).parent().unwrap().join("bin");
+                let src_dir =
+                    builder.sysroot_target_libdir(compiler, host).parent().unwrap().join("bin");
                 let rust_lld = exe("rust-lld", compiler.host);
                 builder.copy_link(&src_dir.join(&rust_lld), &dst_dir.join(&rust_lld));
                 let self_contained_lld_src_dir = src_dir.join("gcc-ld");

src/bootstrap/src/core/build_steps/format.rs

@@ -93,7 +93,6 @@ fn get_modified_rs_files(build: &Builder<'_>) -> Result<Option<Vec<String>>, Str
     if !verify_rustfmt_version(build) {
         return Ok(None);
     }
-
     get_git_modified_files(&build.config.git_config(), Some(&build.config.src), &["rs"])
 }