Auto merge of #82045 - Dylan-DPC:rollup-244l0sb, r=Dylan-DPC

Rollup of 10 pull requests

Successful merges:

 - #79775 (Fix injected errors when running doctests on a crate named after a keyword)
 - #81012 (Stabilize the partition_point feature)
 - #81479 (Allow casting mut array ref to mut ptr)
 - #81506 (HWAddressSanitizer support)
 - #81741 (Increment `self.index` before calling `Iterator::self.a.__iterator_ge…)
 - #81850 (use RWlock when accessing os::env)
 - #81911 (GAT/const_generics: Allow with_opt_const_param to return GAT param def_id)
 - #82022 (Push a `char` instead of a `str` with len one into a String)
 - #82023 (Remove unnecessary lint allow attrs on example)
 - #82030 (Use `Iterator::all` instead of open-coding it)

Failed merges:

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

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -53,6 +53,9 @@ pub fn sanitize(cx: &CodegenCx<'ll, '_>, no_sanitize: SanitizerSet, llfn: &'ll V
     if enabled.contains(SanitizerSet::THREAD) {
         llvm::Attribute::SanitizeThread.apply_llfn(Function, llfn);
     }
+    if enabled.contains(SanitizerSet::HWADDRESS) {
+        llvm::Attribute::SanitizeHWAddress.apply_llfn(Function, llfn);
+    }
 }
 
 /// Tell LLVM to emit or not emit the information necessary to unwind the stack for the function.

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -440,6 +440,8 @@ pub(crate) unsafe fn optimize_with_new_llvm_pass_manager(
             sanitize_memory_recover: config.sanitizer_recover.contains(SanitizerSet::MEMORY),
             sanitize_memory_track_origins: config.sanitizer_memory_track_origins as c_int,
             sanitize_thread: config.sanitizer.contains(SanitizerSet::THREAD),
+            sanitize_hwaddress: config.sanitizer.contains(SanitizerSet::HWADDRESS),
+            sanitize_hwaddress_recover: config.sanitizer_recover.contains(SanitizerSet::HWADDRESS),
         })
     } else {
         None
@@ -652,6 +654,10 @@ unsafe fn add_sanitizer_passes(config: &ModuleConfig, passes: &mut Vec<&'static
     if config.sanitizer.contains(SanitizerSet::THREAD) {
         passes.push(llvm::LLVMRustCreateThreadSanitizerPass());
     }
+    if config.sanitizer.contains(SanitizerSet::HWADDRESS) {
+        let recover = config.sanitizer_recover.contains(SanitizerSet::HWADDRESS);
+        passes.push(llvm::LLVMRustCreateHWAddressSanitizerPass(recover));
+    }
 }
 
 pub(crate) fn link(

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -131,6 +131,7 @@ pub enum Attribute {
     ReturnsTwice = 25,
     ReadNone = 26,
     InaccessibleMemOnly = 27,
+    SanitizeHWAddress = 28,
 }
 
 /// LLVMIntPredicate
@@ -439,6 +440,8 @@ pub struct SanitizerOptions {
     pub sanitize_memory_recover: bool,
     pub sanitize_memory_track_origins: c_int,
     pub sanitize_thread: bool,
+    pub sanitize_hwaddress: bool,
+    pub sanitize_hwaddress_recover: bool,
 }
 
 /// LLVMRelocMode
@@ -2128,6 +2131,7 @@ extern "C" {
         Recover: bool,
     ) -> &'static mut Pass;
     pub fn LLVMRustCreateThreadSanitizerPass() -> &'static mut Pass;
+    pub fn LLVMRustCreateHWAddressSanitizerPass(Recover: bool) -> &'static mut Pass;
     pub fn LLVMRustAddPass(PM: &PassManager<'_>, Pass: &'static mut Pass);
     pub fn LLVMRustAddLastExtensionPasses(
         PMB: &PassManagerBuilder,

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -893,6 +893,9 @@ fn link_sanitizers(sess: &Session, crate_type: CrateType, linker: &mut dyn Linke
     if sanitizer.contains(SanitizerSet::THREAD) {
         link_sanitizer_runtime(sess, linker, "tsan");
     }
+    if sanitizer.contains(SanitizerSet::HWADDRESS) {
+        link_sanitizer_runtime(sess, linker, "hwasan");
+    }
 }
 
 fn link_sanitizer_runtime(sess: &Session, linker: &mut dyn Linker, name: &str) {

compiler/rustc_llvm/llvm-wrapper/LLVMWrapper.h

@@ -85,6 +85,7 @@ enum LLVMRustAttribute {
   ReturnsTwice = 25,
   ReadNone = 26,
   InaccessibleMemOnly = 27,
+  SanitizeHWAddress = 28,
 };
 
 typedef struct OpaqueRustString *RustStringRef;

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -33,6 +33,7 @@
 #include "llvm/Support/TimeProfiler.h"
 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
+#include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
 #include "llvm/Transforms/Utils/CanonicalizeAliases.h"
 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
 
@@ -133,6 +134,12 @@ extern "C" LLVMPassRef LLVMRustCreateThreadSanitizerPass() {
   return wrap(createThreadSanitizerLegacyPassPass());
 }
 
+extern "C" LLVMPassRef LLVMRustCreateHWAddressSanitizerPass(bool Recover) {
+  const bool CompileKernel = false;
+
+  return wrap(createHWAddressSanitizerLegacyPassPass(CompileKernel, Recover));
+}
+
 extern "C" LLVMRustPassKind LLVMRustPassKind(LLVMPassRef RustPass) {
   assert(RustPass);
   Pass *Pass = unwrap(RustPass);
@@ -722,6 +729,8 @@ struct LLVMRustSanitizerOptions {
   bool SanitizeMemoryRecover;
   int  SanitizeMemoryTrackOrigins;
   bool SanitizeThread;
+  bool SanitizeHWAddress;
+  bool SanitizeHWAddressRecover;
 };
 
 extern "C" void
@@ -886,6 +895,23 @@ LLVMRustOptimizeWithNewPassManager(
               /*CompileKernel=*/false, SanitizerOptions->SanitizeAddressRecover));
         }
       );
+#endif
+    }
+    if (SanitizerOptions->SanitizeHWAddress) {
+#if LLVM_VERSION_GE(11, 0)
+      OptimizerLastEPCallbacks.push_back(
+        [SanitizerOptions](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
+          MPM.addPass(HWAddressSanitizerPass(
+              /*CompileKernel=*/false, SanitizerOptions->SanitizeHWAddressRecover));
+        }
+      );
+#else
+      PipelineStartEPCallbacks.push_back(
+        [SanitizerOptions](ModulePassManager &MPM) {
+          MPM.addPass(HWAddressSanitizerPass(
+              /*CompileKernel=*/false, SanitizerOptions->SanitizeHWAddressRecover));
+        }
+      );
 #endif
     }
   }

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -205,6 +205,8 @@ static Attribute::AttrKind fromRust(LLVMRustAttribute Kind) {
     return Attribute::ReadNone;
   case InaccessibleMemOnly:
     return Attribute::InaccessibleMemOnly;
+  case SanitizeHWAddress:
+    return Attribute::SanitizeHWAddress;
   }
   report_fatal_error("bad AttributeKind");
 }

compiler/rustc_mir/src/borrow_check/type_check/mod.rs

@@ -2191,19 +2191,18 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                     CastKind::Pointer(PointerCast::ArrayToPointer) => {
                         let ty_from = op.ty(body, tcx);
 
-                        let opt_ty_elem = match ty_from.kind() {
+                        let opt_ty_elem_mut = match ty_from.kind() {
-                            ty::RawPtr(ty::TypeAndMut {
+                            ty::RawPtr(ty::TypeAndMut { mutbl: array_mut, ty: array_ty }) => {
-                                mutbl: hir::Mutability::Not,
+                                match array_ty.kind() {
-                                ty: array_ty,
+                                    ty::Array(ty_elem, _) => Some((ty_elem, *array_mut)),
-                            }) => match array_ty.kind() {
+                                    _ => None,
-                                ty::Array(ty_elem, _) => Some(ty_elem),
+                                }
-                                _ => None,
+                            }
-                            },
                             _ => None,
                         };
 
-                        let ty_elem = match opt_ty_elem {
+                        let (ty_elem, ty_mut) = match opt_ty_elem_mut {
-                            Some(ty_elem) => ty_elem,
+                            Some(ty_elem_mut) => ty_elem_mut,
                             None => {
                                 span_mirbug!(
                                     self,
@@ -2215,11 +2214,10 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                             }
                         };
 
-                        let ty_to = match ty.kind() {
+                        let (ty_to, ty_to_mut) = match ty.kind() {
-                            ty::RawPtr(ty::TypeAndMut {
+                            ty::RawPtr(ty::TypeAndMut { mutbl: ty_to_mut, ty: ty_to }) => {
-                                mutbl: hir::Mutability::Not,
+                                (ty_to, *ty_to_mut)
-                                ty: ty_to,
+                            }
-                            }) => ty_to,
                             _ => {
                                 span_mirbug!(
                                     self,
@@ -2231,6 +2229,17 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                             }
                         };
 
+                        if ty_to_mut == Mutability::Mut && ty_mut == Mutability::Not {
+                            span_mirbug!(
+                                self,
+                                rvalue,
+                                "ArrayToPointer cast from const {:?} to mut {:?}",
+                                ty,
+                                ty_to
+                            );
+                            return;
+                        }
+
                         if let Err(terr) = self.sub_types(
                             ty_elem,
                             ty_to,

compiler/rustc_session/src/config.rs

@@ -43,6 +43,7 @@ bitflags! {
         const LEAK    = 1 << 1;
         const MEMORY  = 1 << 2;
         const THREAD  = 1 << 3;
+        const HWADDRESS  = 1 << 4;
     }
 }
 
@@ -56,6 +57,7 @@ impl fmt::Display for SanitizerSet {
                 SanitizerSet::LEAK => "leak",
                 SanitizerSet::MEMORY => "memory",
                 SanitizerSet::THREAD => "thread",
+                SanitizerSet::HWADDRESS => "hwaddress",
                 _ => panic!("unrecognized sanitizer {:?}", s),
             };
             if !first {
@@ -73,12 +75,18 @@ impl IntoIterator for SanitizerSet {
     type IntoIter = std::vec::IntoIter<SanitizerSet>;
 
     fn into_iter(self) -> Self::IntoIter {
-        [SanitizerSet::ADDRESS, SanitizerSet::LEAK, SanitizerSet::MEMORY, SanitizerSet::THREAD]
+        [
-            .iter()
+            SanitizerSet::ADDRESS,
-            .copied()
+            SanitizerSet::LEAK,
-            .filter(|&s| self.contains(s))
+            SanitizerSet::MEMORY,
-            .collect::<Vec<_>>()
+            SanitizerSet::THREAD,
-            .into_iter()
+            SanitizerSet::HWADDRESS,
+        ]
+        .iter()
+        .copied()
+        .filter(|&s| self.contains(s))
+        .collect::<Vec<_>>()
+        .into_iter()
     }
 }
 

compiler/rustc_session/src/options.rs

@@ -253,7 +253,7 @@ macro_rules! options {
         pub const parse_passes: &str = "a space-separated list of passes, or `all`";
         pub const parse_panic_strategy: &str = "either `unwind` or `abort`";
         pub const parse_relro_level: &str = "one of: `full`, `partial`, or `off`";
-        pub const parse_sanitizers: &str = "comma separated list of sanitizers: `address`, `leak`, `memory` or `thread`";
+        pub const parse_sanitizers: &str = "comma separated list of sanitizers: `address`, `hwaddress`, `leak`, `memory` or `thread`";
         pub const parse_sanitizer_memory_track_origins: &str = "0, 1, or 2";
         pub const parse_cfguard: &str =
             "either a boolean (`yes`, `no`, `on`, `off`, etc), `checks`, or `nochecks`";
@@ -476,6 +476,7 @@ macro_rules! options {
                         "leak" => SanitizerSet::LEAK,
                         "memory" => SanitizerSet::MEMORY,
                         "thread" => SanitizerSet::THREAD,
+                        "hwaddress" => SanitizerSet::HWADDRESS,
                         _ => return false,
                     }
                 }

compiler/rustc_session/src/session.rs

@@ -1126,7 +1126,8 @@ impl Session {
         self.opts.optimize != config::OptLevel::No
         // AddressSanitizer uses lifetimes to detect use after scope bugs.
         // MemorySanitizer uses lifetimes to detect use of uninitialized stack variables.
-        || self.opts.debugging_opts.sanitizer.intersects(SanitizerSet::ADDRESS | SanitizerSet::MEMORY)
+        // HWAddressSanitizer will use lifetimes to detect use after scope bugs in the future.
+        || self.opts.debugging_opts.sanitizer.intersects(SanitizerSet::ADDRESS | SanitizerSet::MEMORY | SanitizerSet::HWADDRESS)
     }
 
     pub fn link_dead_code(&self) -> bool {
@@ -1562,6 +1563,8 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
         "x86_64-unknown-freebsd",
         "x86_64-unknown-linux-gnu",
     ];
+    const HWASAN_SUPPORTED_TARGETS: &[&str] =
+        &["aarch64-linux-android", "aarch64-unknown-linux-gnu"];
 
     // Sanitizers can only be used on some tested platforms.
     for s in sess.opts.debugging_opts.sanitizer {
@@ -1570,6 +1573,7 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
             SanitizerSet::LEAK => LSAN_SUPPORTED_TARGETS,
             SanitizerSet::MEMORY => MSAN_SUPPORTED_TARGETS,
             SanitizerSet::THREAD => TSAN_SUPPORTED_TARGETS,
+            SanitizerSet::HWADDRESS => HWASAN_SUPPORTED_TARGETS,
             _ => panic!("unrecognized sanitizer {}", s),
         };
         if !supported_targets.contains(&&*sess.opts.target_triple.triple()) {

compiler/rustc_span/src/symbol.rs

@@ -593,6 +593,7 @@ symbols! {
         html_no_source,
         html_playground_url,
         html_root_url,
+        hwaddress,
         i,
         i128,
         i128_type,

compiler/rustc_typeck/src/check/cast.rs

@@ -765,9 +765,8 @@ impl<'a, 'tcx> CastCheck<'tcx> {
         m_expr: ty::TypeAndMut<'tcx>,
         m_cast: ty::TypeAndMut<'tcx>,
     ) -> Result<CastKind, CastError> {
-        // array-ptr-cast.
+        // array-ptr-cast: allow mut-to-mut, mut-to-const, const-to-const
-
+        if m_expr.mutbl == hir::Mutability::Mut || m_cast.mutbl == hir::Mutability::Not {
-        if m_expr.mutbl == hir::Mutability::Not && m_cast.mutbl == hir::Mutability::Not {
             if let ty::Array(ety, _) = m_expr.ty.kind() {
                 // Due to the limitations of LLVM global constants,
                 // region pointers end up pointing at copies of

compiler/rustc_typeck/src/check/upvar.rs

@@ -1211,7 +1211,7 @@ fn construct_place_string(tcx: TyCtxt<'_>, place: &Place<'tcx>) -> String {
             ProjectionKind::Subslice => String::from("Subslice"),
         };
         if i != 0 {
-            projections_str.push_str(",");
+            projections_str.push(',');
         }
         projections_str.push_str(proj.as_str());
     }
@@ -1382,14 +1382,8 @@ fn determine_place_ancestry_relation(
     // Assume of length of projections_b = m
     let projections_b = &place_b.projections;
 
-    let mut same_initial_projections = true;
+    let same_initial_projections =
-
+        projections_a.iter().zip(projections_b.iter()).all(|(proj_a, proj_b)| proj_a == proj_b);
-    for (proj_a, proj_b) in projections_a.iter().zip(projections_b.iter()) {
-        if proj_a != proj_b {
-            same_initial_projections = false;
-            break;
-        }
-    }
 
     if same_initial_projections {
         // First min(n, m) projections are the same

compiler/rustc_typeck/src/collect.rs

@@ -2709,10 +2709,12 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs {
                         codegen_fn_attrs.no_sanitize |= SanitizerSet::MEMORY;
                     } else if item.has_name(sym::thread) {
                         codegen_fn_attrs.no_sanitize |= SanitizerSet::THREAD;
+                    } else if item.has_name(sym::hwaddress) {
+                        codegen_fn_attrs.no_sanitize |= SanitizerSet::HWADDRESS;
                     } else {
                         tcx.sess
                             .struct_span_err(item.span(), "invalid argument for `no_sanitize`")
-                            .note("expected one of: `address`, `memory` or `thread`")
+                            .note("expected one of: `address`, `hwaddress`, `memory` or `thread`")
                             .emit();
                     }
                 }

compiler/rustc_typeck/src/collect/type_of.rs

@@ -29,6 +29,73 @@ pub(super) fn opt_const_param_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<
         let parent_node = tcx.hir().get(parent_node_id);
 
         match parent_node {
+            // This match arm is for when the def_id appears in a GAT whose
+            // path can't be resolved without typechecking e.g.
+            //
+            // trait Foo {
+            //   type Assoc<const N: usize>;
+            //   fn foo() -> Self::Assoc<3>;
+            // }
+            //
+            // In the above code we would call this query with the def_id of 3 and
+            // the parent_node we match on would be the hir node for Self::Assoc<3>
+            //
+            // `Self::Assoc<3>` cant be resolved without typchecking here as we
+            // didnt write <Self as Foo>::Assoc<3>. If we did then another match
+            // arm would handle this.
+            //
+            // I believe this match arm is only needed for GAT but I am not 100% sure - BoxyUwU
+            Node::Ty(hir_ty @ Ty { kind: TyKind::Path(QPath::TypeRelative(_, segment)), .. }) => {
+                // Find the Item containing the associated type so we can create an ItemCtxt.
+                // Using the ItemCtxt convert the HIR for the unresolved assoc type into a
+                // ty which is a fully resolved projection.
+                // For the code example above, this would mean converting Self::Assoc<3>
+                // into a ty::Projection(<Self as Foo>::Assoc<3>)
+                let item_hir_id = tcx
+                    .hir()
+                    .parent_iter(hir_id)
+                    .filter(|(_, node)| matches!(node, Node::Item(_)))
+                    .map(|(id, _)| id)
+                    .next()
+                    .unwrap();
+                let item_did = tcx.hir().local_def_id(item_hir_id).to_def_id();
+                let item_ctxt = &ItemCtxt::new(tcx, item_did) as &dyn crate::astconv::AstConv<'_>;
+                let ty = item_ctxt.ast_ty_to_ty(hir_ty);
+
+                // Iterate through the generics of the projection to find the one that corresponds to
+                // the def_id that this query was called with. We filter to only const args here as a
+                // precaution for if it's ever allowed to elide lifetimes in GAT's. It currently isn't
+                // but it can't hurt to be safe ^^
+                if let ty::Projection(projection) = ty.kind() {
+                    let generics = tcx.generics_of(projection.item_def_id);
+
+                    let arg_index = segment
+                        .args
+                        .and_then(|args| {
+                            args.args
+                                .iter()
+                                .filter(|arg| arg.is_const())
+                                .position(|arg| arg.id() == hir_id)
+                        })
+                        .unwrap_or_else(|| {
+                            bug!("no arg matching AnonConst in segment");
+                        });
+
+                    return generics
+                        .params
+                        .iter()
+                        .filter(|param| matches!(param.kind, ty::GenericParamDefKind::Const))
+                        .nth(arg_index)
+                        .map(|param| param.def_id);
+                }
+
+                // I dont think it's possible to reach this but I'm not 100% sure - BoxyUwU
+                tcx.sess.delay_span_bug(
+                    tcx.def_span(def_id),
+                    "unexpected non-GAT usage of an anon const",
+                );
+                return None;
+            }
             Node::Expr(&Expr {
                 kind:
                     ExprKind::MethodCall(segment, ..) | ExprKind::Path(QPath::TypeRelative(_, segment)),

compiler/rustc_typeck/src/lib.rs

@@ -56,6 +56,7 @@ This API is completely unstable and subject to change.
 */
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![feature(bindings_after_at)]
 #![feature(bool_to_option)]
 #![feature(box_syntax)]
 #![feature(crate_visibility_modifier)]

library/alloc/src/boxed.rs

@@ -99,13 +99,11 @@
 //! pub struct Foo;
 //!
 //! #[no_mangle]
-//! #[allow(improper_ctypes_definitions)]
 //! pub extern "C" fn foo_new() -> Box<Foo> {
 //!     Box::new(Foo)
 //! }
 //!
 //! #[no_mangle]
-//! #[allow(improper_ctypes_definitions)]
 //! pub extern "C" fn foo_delete(_: Option<Box<Foo>>) {}
 //! ```
 //!

library/core/src/iter/adapters/zip.rs

@@ -198,12 +198,13 @@ where
                 Some((self.a.__iterator_get_unchecked(i), self.b.__iterator_get_unchecked(i)))
             }
         } else if A::may_have_side_effect() && self.index < self.a.size() {
-            // match the base implementation's potential side effects
+            let i = self.index;
-            // SAFETY: we just checked that `self.index` < `self.a.len()`
-            unsafe {
-                self.a.__iterator_get_unchecked(self.index);
-            }
             self.index += 1;
+            // match the base implementation's potential side effects
+            // SAFETY: we just checked that `i` < `self.a.len()`
+            unsafe {
+                self.a.__iterator_get_unchecked(i);
+            }
             None
         } else {
             None

library/core/src/slice/mod.rs

@@ -2082,6 +2082,12 @@ impl<T> [T] {
     /// [`Result::Err`] is returned, containing the index where a matching
     /// element could be inserted while maintaining sorted order.
     ///
+    /// See also [`binary_search_by`], [`binary_search_by_key`], and [`partition_point`].
+    ///
+    /// [`binary_search_by`]: #method.binary_search_by
+    /// [`binary_search_by_key`]: #method.binary_search_by_key
+    /// [`partition_point`]: #method.partition_point
+    ///
     /// # Examples
     ///
     /// Looks up a series of four elements. The first is found, with a
@@ -2129,6 +2135,12 @@ impl<T> [T] {
     /// [`Result::Err`] is returned, containing the index where a matching
     /// element could be inserted while maintaining sorted order.
     ///
+    /// See also [`binary_search`], [`binary_search_by_key`], and [`partition_point`].
+    ///
+    /// [`binary_search`]: #method.binary_search
+    /// [`binary_search_by_key`]: #method.binary_search_by_key
+    /// [`partition_point`]: #method.partition_point
+    ///
     /// # Examples
     ///
     /// Looks up a series of four elements. The first is found, with a
@@ -2186,7 +2198,12 @@ impl<T> [T] {
     /// [`Result::Err`] is returned, containing the index where a matching
     /// element could be inserted while maintaining sorted order.
     ///
+    /// See also [`binary_search`], [`binary_search_by`], and [`partition_point`].
+    ///
     /// [`sort_by_key`]: #method.sort_by_key
+    /// [`binary_search`]: #method.binary_search
+    /// [`binary_search_by`]: #method.binary_search_by
+    /// [`partition_point`]: #method.partition_point
     ///
     /// # Examples
     ///
@@ -3399,11 +3416,15 @@ impl<T> [T] {
     /// If this slice is not partitioned, the returned result is unspecified and meaningless,
     /// as this method performs a kind of binary search.
     ///
+    /// See also [`binary_search`], [`binary_search_by`], and [`binary_search_by_key`].
+    ///
+    /// [`binary_search`]: #method.binary_search
+    /// [`binary_search_by`]: #method.binary_search_by
+    /// [`binary_search_by_key`]: #method.binary_search_by_key
+    ///
     /// # Examples
     ///
     /// ```
-    /// #![feature(partition_point)]
-    ///
     /// let v = [1, 2, 3, 3, 5, 6, 7];
     /// let i = v.partition_point(|&x| x < 5);
     ///
@@ -3411,7 +3432,7 @@ impl<T> [T] {
     /// assert!(v[..i].iter().all(|&x| x < 5));
     /// assert!(v[i..].iter().all(|&x| !(x < 5)));
     /// ```
-    #[unstable(feature = "partition_point", reason = "new API", issue = "73831")]
+    #[stable(feature = "partition_point", since = "1.52.0")]
     pub fn partition_point<P>(&self, mut pred: P) -> usize
     where
         P: FnMut(&T) -> bool,

library/core/tests/lib.rs

@@ -67,7 +67,6 @@
 #![feature(option_result_unwrap_unchecked)]
 #![feature(option_unwrap_none)]
 #![feature(peekable_peek_mut)]
-#![feature(partition_point)]
 #![feature(once_cell)]
 #![feature(unsafe_block_in_unsafe_fn)]
 #![feature(int_bits_const)]

library/std/src/sys/unix/os.rs

@@ -22,6 +22,7 @@ use crate::str;
 use crate::sys::cvt;
 use crate::sys::fd;
 use crate::sys_common::mutex::{StaticMutex, StaticMutexGuard};
+use crate::sys_common::rwlock::{RWLockReadGuard, StaticRWLock};
 use crate::vec;
 
 use libc::{c_char, c_int, c_void};
@@ -490,20 +491,20 @@ pub unsafe fn environ() -> *mut *const *const c_char {
     extern "C" {
         static mut environ: *const *const c_char;
     }
-    &mut environ
+    ptr::addr_of_mut!(environ)
 }
 
-pub unsafe fn env_lock() -> StaticMutexGuard {
+static ENV_LOCK: StaticRWLock = StaticRWLock::new();
-    // It is UB to attempt to acquire this mutex reentrantly!
+
-    static ENV_LOCK: StaticMutex = StaticMutex::new();
+pub fn env_read_lock() -> RWLockReadGuard {
-    ENV_LOCK.lock()
+    ENV_LOCK.read_with_guard()
 }
 
 /// Returns a vector of (variable, value) byte-vector pairs for all the
 /// environment variables of the current process.
 pub fn env() -> Env {
     unsafe {
-        let _guard = env_lock();
+        let _guard = env_read_lock();
         let mut environ = *environ();
         let mut result = Vec::new();
         if !environ.is_null() {
@@ -540,7 +541,7 @@ pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
     // always None as well
     let k = CString::new(k.as_bytes())?;
     unsafe {
-        let _guard = env_lock();
+        let _guard = env_read_lock();
         let s = libc::getenv(k.as_ptr()) as *const libc::c_char;
         let ret = if s.is_null() {
             None
@@ -556,7 +557,7 @@ pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {
     let v = CString::new(v.as_bytes())?;
 
     unsafe {
-        let _guard = env_lock();
+        let _guard = ENV_LOCK.write_with_guard();
         cvt(libc::setenv(k.as_ptr(), v.as_ptr(), 1)).map(drop)
     }
 }
@@ -565,7 +566,7 @@ pub fn unsetenv(n: &OsStr) -> io::Result<()> {
     let nbuf = CString::new(n.as_bytes())?;
 
     unsafe {
-        let _guard = env_lock();
+        let _guard = ENV_LOCK.write_with_guard();
         cvt(libc::unsetenv(nbuf.as_ptr())).map(drop)
     }
 }

library/std/src/sys/unix/process/process_unix.rs

@@ -47,7 +47,7 @@ impl Command {
         // a lock any more because the parent won't do anything and the child is
         // in its own process.
         let result = unsafe {
-            let _env_lock = sys::os::env_lock();
+            let _env_lock = sys::os::env_read_lock();
             cvt(libc::fork())?
         };
 
@@ -124,7 +124,7 @@ impl Command {
                     // Similar to when forking, we want to ensure that access to
                     // the environment is synchronized, so make sure to grab the
                     // environment lock before we try to exec.
-                    let _lock = sys::os::env_lock();
+                    let _lock = sys::os::env_read_lock();
 
                     let Err(e) = self.do_exec(theirs, envp.as_ref());
                     e
@@ -404,7 +404,7 @@ impl Command {
             cvt_nz(libc::posix_spawnattr_setflags(attrs.0.as_mut_ptr(), flags as _))?;
 
             // Make sure we synchronize access to the global `environ` resource
-            let _env_lock = sys::os::env_lock();
+            let _env_lock = sys::os::env_read_lock();
             let envp = envp.map(|c| c.as_ptr()).unwrap_or_else(|| *sys::os::environ() as *const _);
             cvt_nz(libc::posix_spawnp(
                 &mut p.pid,

library/std/src/sys_common/rwlock.rs

@@ -86,3 +86,62 @@ impl RWLock {
         self.0.destroy()
     }
 }
+
+// the cfg annotations only exist due to dead code warnings. the code itself is portable
+#[cfg(unix)]
+pub struct StaticRWLock(RWLock);
+
+#[cfg(unix)]
+impl StaticRWLock {
+    pub const fn new() -> StaticRWLock {
+        StaticRWLock(RWLock::new())
+    }
+
+    /// Acquires shared access to the underlying lock, blocking the current
+    /// thread to do so.
+    ///
+    /// The lock is automatically unlocked when the returned guard is dropped.
+    #[inline]
+    pub fn read_with_guard(&'static self) -> RWLockReadGuard {
+        // Safety: All methods require static references, therefore self
+        // cannot be moved between invocations.
+        unsafe {
+            self.0.read();
+        }
+        RWLockReadGuard(&self.0)
+    }
+
+    /// Acquires write access to the underlying lock, blocking the current thread
+    /// to do so.
+    ///
+    /// The lock is automatically unlocked when the returned guard is dropped.
+    #[inline]
+    pub fn write_with_guard(&'static self) -> RWLockWriteGuard {
+        // Safety: All methods require static references, therefore self
+        // cannot be moved between invocations.
+        unsafe {
+            self.0.write();
+        }
+        RWLockWriteGuard(&self.0)
+    }
+}
+
+#[cfg(unix)]
+pub struct RWLockReadGuard(&'static RWLock);
+
+#[cfg(unix)]
+impl Drop for RWLockReadGuard {
+    fn drop(&mut self) {
+        unsafe { self.0.read_unlock() }
+    }
+}
+
+#[cfg(unix)]
+pub struct RWLockWriteGuard(&'static RWLock);
+
+#[cfg(unix)]
+impl Drop for RWLockWriteGuard {
+    fn drop(&mut self) {
+        unsafe { self.0.write_unlock() }
+    }
+}

src/bootstrap/configure.py

@@ -51,7 +51,7 @@ o("option-checking", None, "complain about unrecognized options in this configur
 o("ninja", "llvm.ninja", "build LLVM using the Ninja generator (for MSVC, requires building in the correct environment)")
 o("locked-deps", "build.locked-deps", "force Cargo.lock to be up to date")
 o("vendor", "build.vendor", "enable usage of vendored Rust crates")
-o("sanitizers", "build.sanitizers", "build the sanitizer runtimes (asan, lsan, msan, tsan)")
+o("sanitizers", "build.sanitizers", "build the sanitizer runtimes (asan, lsan, msan, tsan, hwasan)")
 o("dist-src", "rust.dist-src", "when building tarballs enables building a source tarball")
 o("cargo-native-static", "build.cargo-native-static", "static native libraries in cargo")
 o("profiler", "build.profiler", "build the profiler runtime")

src/bootstrap/native.rs

@@ -804,7 +804,7 @@ fn supported_sanitizers(
         "aarch64-apple-darwin" => darwin_libs("osx", &["asan", "lsan", "tsan"]),
         "aarch64-fuchsia" => common_libs("fuchsia", "aarch64", &["asan"]),
         "aarch64-unknown-linux-gnu" => {
-            common_libs("linux", "aarch64", &["asan", "lsan", "msan", "tsan"])
+            common_libs("linux", "aarch64", &["asan", "lsan", "msan", "tsan", "hwasan"])
         }
         "x86_64-apple-darwin" => darwin_libs("osx", &["asan", "lsan", "tsan"]),
         "x86_64-fuchsia" => common_libs("fuchsia", "x86_64", &["asan"]),

src/doc/unstable-book/src/compiler-flags/sanitizer.md

@@ -7,12 +7,15 @@ The tracking issue for this feature is: [#39699](https://github.com/rust-lang/ru
 This feature allows for use of one of following sanitizers:
 
 * [AddressSanitizer][clang-asan] a fast memory error detector.
+* [HWAddressSanitizer][clang-hwasan] a memory error detector similar to
+  AddressSanitizer, but based on partial hardware assistance.
 * [LeakSanitizer][clang-lsan] a run-time memory leak detector.
 * [MemorySanitizer][clang-msan] a detector of uninitialized reads.
 * [ThreadSanitizer][clang-tsan] a fast data race detector.
 
-To enable a sanitizer compile with `-Zsanitizer=address`, `-Zsanitizer=leak`,
+To enable a sanitizer compile with `-Zsanitizer=address`,
-`-Zsanitizer=memory` or `-Zsanitizer=thread`.
+`-Zsanitizer=hwaddress`, `-Zsanitizer=leak`, `-Zsanitizer=memory` or
+`-Zsanitizer=thread`.
 
 # AddressSanitizer
 
@@ -174,6 +177,86 @@ Shadow byte legend (one shadow byte represents 8 application bytes):
 ==39249==ABORTING
 ```
 
+# HWAddressSanitizer
+
+HWAddressSanitizer is a newer variant of AddressSanitizer that consumes much
+less memory.
+
+HWAddressSanitizer is supported on the following targets:
+
+* `aarch64-linux-android`
+* `aarch64-unknown-linux-gnu`
+
+HWAddressSanitizer requires `tagged-globals` target feature to instrument
+globals. To enable this target feature compile with `-C
+target-feature=+tagged-globals`
+
+## Example
+
+Heap buffer overflow:
+
+```rust
+fn main() {
+    let xs = vec![0, 1, 2, 3];
+    let _y = unsafe { *xs.as_ptr().offset(4) };
+}
+```
+
+```shell
+$ rustc main.rs -Zsanitizer=hwaddress -C target-feature=+tagged-globals -C
+linker=aarch64-linux-gnu-gcc -C link-arg=-fuse-ld=lld --target
+aarch64-unknown-linux-gnu
+```
+
+```shell
+$ ./main
+==241==ERROR: HWAddressSanitizer: tag-mismatch on address 0xefdeffff0050 at pc 0xaaaae0ae4a98
+READ of size 4 at 0xefdeffff0050 tags: 2c/00 (ptr/mem) in thread T0
+    #0 0xaaaae0ae4a94  (/.../main+0x54a94)
+    ...
+
+[0xefdeffff0040,0xefdeffff0060) is a small allocated heap chunk; size: 32 offset: 16
+0xefdeffff0050 is located 0 bytes to the right of 16-byte region [0xefdeffff0040,0xefdeffff0050)
+allocated here:
+    #0 0xaaaae0acb80c  (/.../main+0x3b80c)
+    ...
+
+Thread: T0 0xeffe00002000 stack: [0xffffc28ad000,0xffffc30ad000) sz: 8388608 tls: [0xffffaa10a020,0xffffaa10a7d0)
+Memory tags around the buggy address (one tag corresponds to 16 bytes):
+  0xfefcefffef80: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefcefffef90: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefcefffefa0: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefcefffefb0: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefcefffefc0: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefcefffefd0: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefcefffefe0: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefcefffeff0: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+=>0xfefceffff000: d7  d7  05  00  2c [00] 00  00  00  00  00  00  00  00  00  00
+  0xfefceffff010: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefceffff020: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefceffff030: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefceffff040: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefceffff050: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefceffff060: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefceffff070: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+  0xfefceffff080: 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
+Tags for short granules around the buggy address (one tag corresponds to 16 bytes):
+  0xfefcefffeff0: ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..
+=>0xfefceffff000: ..  ..  8c  ..  .. [..] ..  ..  ..  ..  ..  ..  ..  ..  ..  ..
+  0xfefceffff010: ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..  ..
+See https://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html#short-granules for a description of short granule tags
+Registers where the failure occurred (pc 0xaaaae0ae4a98):
+    x0  2c00efdeffff0050  x1  0000000000000004  x2  0000000000000004  x3  0000000000000000
+    x4  0000fffefc30ac37  x5  000000000000005d  x6  00000ffffc30ac37  x7  0000efff00000000
+    x8  2c00efdeffff0050  x9  0200efff00000000  x10 0000000000000000  x11 0200efff00000000
+    x12 0200effe00000310  x13 0200effe00000310  x14 0000000000000008  x15 5d00ffffc30ac360
+    x16 0000aaaae0ad062c  x17 0000000000000003  x18 0000000000000001  x19 0000ffffc30ac658
+    x20 4e00ffffc30ac6e0  x21 0000aaaae0ac5e10  x22 0000000000000000  x23 0000000000000000
+    x24 0000000000000000  x25 0000000000000000  x26 0000000000000000  x27 0000000000000000
+    x28 0000000000000000  x29 0000ffffc30ac5a0  x30 0000aaaae0ae4a98
+SUMMARY: HWAddressSanitizer: tag-mismatch (/.../main+0x54a94)
+```
+
 # LeakSanitizer
 
 LeakSanitizer is run-time memory leak detector.
@@ -321,11 +404,13 @@ Sanitizers produce symbolized stacktraces when llvm-symbolizer binary is in `PAT
 
 * [Sanitizers project page](https://github.com/google/sanitizers/wiki/)
 * [AddressSanitizer in Clang][clang-asan]
+* [HWAddressSanitizer in Clang][clang-hwasan]
 * [LeakSanitizer in Clang][clang-lsan]
 * [MemorySanitizer in Clang][clang-msan]
 * [ThreadSanitizer in Clang][clang-tsan]
 
 [clang-asan]: https://clang.llvm.org/docs/AddressSanitizer.html
+[clang-hwasan]: https://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html
 [clang-lsan]: https://clang.llvm.org/docs/LeakSanitizer.html
 [clang-msan]: https://clang.llvm.org/docs/MemorySanitizer.html
 [clang-tsan]: https://clang.llvm.org/docs/ThreadSanitizer.html

src/librustdoc/doctest.rs

@@ -546,9 +546,12 @@ crate fn make_test(
     // compiler.
     if !already_has_extern_crate && !opts.no_crate_inject && cratename != Some("std") {
         if let Some(cratename) = cratename {
-            // Make sure its actually used if not included.
+            // Don't inject `extern crate` if the crate is never used.
+            // NOTE: this is terribly inaccurate because it doesn't actually
+            // parse the source, but only has false positives, not false
+            // negatives.
             if s.contains(cratename) {
-                prog.push_str(&format!("extern crate {};\n", cratename));
+                prog.push_str(&format!("extern crate r#{};\n", cratename));
                 line_offset += 1;
             }
         }

src/librustdoc/doctest/tests.rs

@@ -38,7 +38,7 @@ fn make_test_crate_name() {
     let input = "use asdf::qwop;
 assert_eq!(2+2, 4);";
     let expected = "#![allow(unused)]
-extern crate asdf;
+extern crate r#asdf;
 fn main() {
 use asdf::qwop;
 assert_eq!(2+2, 4);
@@ -128,7 +128,7 @@ fn make_test_opts_attrs() {
     let input = "use asdf::qwop;
 assert_eq!(2+2, 4);";
     let expected = "#![feature(sick_rad)]
-extern crate asdf;
+extern crate r#asdf;
 fn main() {
 use asdf::qwop;
 assert_eq!(2+2, 4);
@@ -141,7 +141,7 @@ assert_eq!(2+2, 4);
     opts.attrs.push("feature(hella_dope)".to_string());
     let expected = "#![feature(sick_rad)]
 #![feature(hella_dope)]
-extern crate asdf;
+extern crate r#asdf;
 fn main() {
 use asdf::qwop;
 assert_eq!(2+2, 4);
@@ -250,7 +250,7 @@ assert_eq!(asdf::foo, 4);";
 
     let expected = "#![allow(unused)]
 extern crate hella_qwop;
-extern crate asdf;
+extern crate r#asdf;
 fn main() {
 assert_eq!(asdf::foo, 4);
 }"

src/test/rustdoc/playground-arg.rs

@@ -11,4 +11,4 @@
 pub fn dummy() {}
 
 // ensure that `extern crate foo;` was inserted into code snips automatically:
-// @matches foo/index.html '//a[@class="test-arrow"][@href="https://example.com/?code=%23!%5Ballow(unused)%5D%0Aextern%20crate%20foo%3B%0Afn%20main()%20%7B%0Ause%20foo%3A%3Adummy%3B%0Adummy()%3B%0A%7D&edition=2015"]' "Run"
+// @matches foo/index.html '//a[@class="test-arrow"][@href="https://example.com/?code=%23!%5Ballow(unused)%5D%0Aextern%20crate%20r%23foo%3B%0Afn%20main()%20%7B%0Ause%20foo%3A%3Adummy%3B%0Adummy()%3B%0A%7D&edition=2015"]' "Run"

src/test/ui/array-slice-vec/vector-cast-weirdness.rs

@@ -1,7 +1,11 @@
 // Issue #14893. Tests that casts from vectors don't behave strangely in the
 // presence of the `_` type shorthand notation.
+//
 // Update: after a change to the way casts are done, we have more type information
 // around and so the errors here are no longer exactly the same.
+//
+// Update: With PR #81479 some of the previously rejected cases are now allowed.
+// New test cases added.
 
 struct X {
     y: [u8; 2],
@@ -12,13 +16,19 @@ fn main() {
 
     // No longer a type mismatch - the `_` can be fully resolved by type inference.
     let p1: *const u8 = &x1.y as *const _;
+    let p1: *mut u8 = &x1.y as *mut _;
+    //~^ ERROR: casting `&[u8; 2]` as `*mut u8` is invalid
     let t1: *const [u8; 2] = &x1.y as *const _;
+    let t1: *mut [u8; 2] = &x1.y as *mut _;
+    //~^ ERROR: casting `&[u8; 2]` as `*mut [u8; 2]` is invalid
     let h1: *const [u8; 2] = &x1.y as *const [u8; 2];
+    let t1: *mut [u8; 2] = &x1.y as *mut [u8; 2];
+    //~^ ERROR: casting `&[u8; 2]` as `*mut [u8; 2]` is invalid
 
     let mut x1 = X { y: [0, 0] };
 
-    // This is still an error since we don't allow casts from &mut [T; n] to *mut T.
+    let p1: *mut u8 = &mut x1.y as *mut _;
-    let p1: *mut u8 = &mut x1.y as *mut _;  //~ ERROR casting
+    let p2: *const u8 = &mut x1.y as *const _;
     let t1: *mut [u8; 2] = &mut x1.y as *mut _;
     let h1: *mut [u8; 2] = &mut x1.y as *mut [u8; 2];
 }

src/test/ui/array-slice-vec/vector-cast-weirdness.stderr

@@ -1,9 +1,21 @@
-error[E0606]: casting `&mut [u8; 2]` as `*mut u8` is invalid
+error[E0606]: casting `&[u8; 2]` as `*mut u8` is invalid
-  --> $DIR/vector-cast-weirdness.rs:21:23
+  --> $DIR/vector-cast-weirdness.rs:19:23
    |
-LL |     let p1: *mut u8 = &mut x1.y as *mut _;
+LL |     let p1: *mut u8 = &x1.y as *mut _;
-   |                       ^^^^^^^^^^^^^^^^^^^
+   |                       ^^^^^^^^^^^^^^^
 
-error: aborting due to previous error
+error[E0606]: casting `&[u8; 2]` as `*mut [u8; 2]` is invalid
+  --> $DIR/vector-cast-weirdness.rs:22:28
+   |
+LL |     let t1: *mut [u8; 2] = &x1.y as *mut _;
+   |                            ^^^^^^^^^^^^^^^
+
+error[E0606]: casting `&[u8; 2]` as `*mut [u8; 2]` is invalid
+  --> $DIR/vector-cast-weirdness.rs:25:28
+   |
+LL |     let t1: *mut [u8; 2] = &x1.y as *mut [u8; 2];
+   |                            ^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0606`.

src/test/ui/generic-associated-types/const-generics-gat-in-trait-return-type-1.rs

@@ -0,0 +1,22 @@
+// run-pass
+#![feature(generic_associated_types)]
+#![allow(incomplete_features)]
+
+// This test unsures that with_opt_const_param returns the
+// def_id of the N param in the Foo::Assoc GAT.
+
+trait Foo {
+    type Assoc<const N: usize>;
+    fn foo(&self) -> Self::Assoc<3>;
+}
+
+impl Foo for () {
+    type Assoc<const N: usize> = [(); N];
+    fn foo(&self) -> Self::Assoc<3> {
+        [(); 3]
+    }
+}
+
+fn main() {
+    assert_eq!(().foo(), [(); 3]);
+}

src/test/ui/generic-associated-types/const-generics-gat-in-trait-return-type-2.rs

@@ -0,0 +1,22 @@
+// run-pass
+#![feature(generic_associated_types)]
+#![allow(incomplete_features)]
+
+// This test unsures that with_opt_const_param returns the
+// def_id of the N param in the Foo::Assoc GAT.
+
+trait Foo {
+    type Assoc<const N: usize>;
+    fn foo<const N: usize>(&self) -> Self::Assoc<N>;
+}
+
+impl Foo for () {
+    type Assoc<const N: usize> = [(); N];
+    fn foo<const N: usize>(&self) -> Self::Assoc<N> {
+        [(); N]
+    }
+}
+
+fn main() {
+    assert_eq!(().foo::<10>(), [(); 10]);
+}

src/test/ui/generic-associated-types/const-generics-gat-in-trait-return-type-3.rs

@@ -0,0 +1,27 @@
+// run-pass
+#![feature(generic_associated_types)]
+#![allow(incomplete_features)]
+
+// This test unsures that with_opt_const_param returns the
+// def_id of the N param in the Bar::Assoc GAT.
+
+trait Bar {
+    type Assoc<const N: usize>;
+}
+trait Foo: Bar {
+    fn foo(&self) -> Self::Assoc<3>;
+}
+
+impl Bar for () {
+    type Assoc<const N: usize> = [(); N];
+}
+
+impl Foo for () {
+    fn foo(&self) -> Self::Assoc<3> {
+        [(); 3]
+    }
+}
+
+fn main() {
+    assert_eq!(().foo(), [(); 3]);
+}

src/test/ui/invalid/invalid-no-sanitize.stderr

@@ -4,7 +4,7 @@ error: invalid argument for `no_sanitize`
 LL | #[no_sanitize(brontosaurus)]
    |               ^^^^^^^^^^^^
    |
-   = note: expected one of: `address`, `memory` or `thread`
+   = note: expected one of: `address`, `hwaddress`, `memory` or `thread`
 
 error: aborting due to previous error
 

src/test/ui/sanitize/hwaddress.rs

@@ -0,0 +1,19 @@
+// needs-sanitizer-support
+// needs-sanitizer-hwaddress
+//
+// compile-flags: -Z sanitizer=hwaddress -O -g
+//
+// run-fail
+// error-pattern: HWAddressSanitizer: tag-mismatch
+
+#![feature(test)]
+
+use std::hint::black_box;
+
+fn main() {
+    let xs = vec![0, 1, 2, 3];
+    // Avoid optimizing everything out.
+    let xs = black_box(xs.as_ptr());
+    let code = unsafe { *xs.offset(4) };
+    std::process::exit(code);
+}

src/tools/compiletest/src/header.rs

@@ -48,6 +48,7 @@ impl EarlyProps {
         let has_lsan = util::LSAN_SUPPORTED_TARGETS.contains(&&*config.target);
         let has_msan = util::MSAN_SUPPORTED_TARGETS.contains(&&*config.target);
         let has_tsan = util::TSAN_SUPPORTED_TARGETS.contains(&&*config.target);
+        let has_hwasan = util::HWASAN_SUPPORTED_TARGETS.contains(&&*config.target);
 
         iter_header(testfile, None, rdr, &mut |ln| {
             // we should check if any only-<platform> exists and if it exists
@@ -101,6 +102,10 @@ impl EarlyProps {
                     props.ignore = true;
                 }
 
+                if !has_hwasan && config.parse_name_directive(ln, "needs-sanitizer-hwaddress") {
+                    props.ignore = true;
+                }
+
                 if config.target == "wasm32-unknown-unknown" && config.parse_check_run_results(ln) {
                     props.ignore = true;
                 }

src/tools/compiletest/src/util.rs

@@ -110,6 +110,9 @@ pub const TSAN_SUPPORTED_TARGETS: &[&str] = &[
     "x86_64-unknown-linux-gnu",
 ];
 
+pub const HWASAN_SUPPORTED_TARGETS: &[&str] =
+    &["aarch64-linux-android", "aarch64-unknown-linux-gnu"];
+
 const BIG_ENDIAN: &[&str] = &[
     "aarch64_be",
     "armebv7r",