Rollup of 8 pull requests

compiler/rustc_hir_typeck/src/closure.rs

@@ -14,7 +14,7 @@ use rustc_middle::span_bug;
 use rustc_middle::ty::visit::{TypeVisitable, TypeVisitableExt};
 use rustc_middle::ty::{self, GenericArgs, Ty, TyCtxt, TypeSuperVisitable, TypeVisitor};
 use rustc_span::def_id::LocalDefId;
-use rustc_span::Span;
+use rustc_span::{Span, DUMMY_SP};
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::error_reporting::traits::ArgKind;
 use rustc_trait_selection::traits;
@@ -539,6 +539,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// we identify the `FnOnce<Args, Output = ?Fut>` bound, and if the output type is
     /// an inference variable `?Fut`, we check if that is bounded by a `Future<Output = Ty>`
     /// projection.
+    ///
+    /// This function is actually best-effort with the return type; if we don't find a
+    /// `Future` projection, we still will return arguments that we extracted from the `FnOnce`
+    /// projection, and the output will be an unconstrained type variable instead.
     fn extract_sig_from_projection_and_future_bound(
         &self,
         cause_span: Option<Span>,
@@ -564,24 +568,43 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
 
         // FIXME: We may want to elaborate here, though I assume this will be exceedingly rare.
+        let mut return_ty = None;
         for bound in self.obligations_for_self_ty(return_vid) {
             if let Some(ret_projection) = bound.predicate.as_projection_clause()
                 && let Some(ret_projection) = ret_projection.no_bound_vars()
                 && self.tcx.is_lang_item(ret_projection.def_id(), LangItem::FutureOutput)
             {
-                let sig = projection.rebind(self.tcx.mk_fn_sig(
-                    input_tys,
-                    ret_projection.term.expect_type(),
-                    false,
-                    hir::Safety::Safe,
-                    Abi::Rust,
-                ));
-
-                return Some(ExpectedSig { cause_span, sig });
+                return_ty = Some(ret_projection.term.expect_type());
+                break;
             }
         }
 
-        None
+        // SUBTLE: If we didn't find a `Future<Output = ...>` bound for the return
+        // vid, we still want to attempt to provide inference guidance for the async
+        // closure's arguments. Instantiate a new vid to plug into the output type.
+        //
+        // You may be wondering, what if it's higher-ranked? Well, given that we
+        // found a type variable for the `FnOnce::Output` projection above, we know
+        // that the output can't mention any of the vars.
+        //
+        // Also note that we use a fresh var here for the signature since the signature
+        // records the output of the *future*, and `return_vid` above is the type
+        // variable of the future, not its output.
+        //
+        // FIXME: We probably should store this signature inference output in a way
+        // that does not misuse a `FnSig` type, but that can be done separately.
+        let return_ty =
+            return_ty.unwrap_or_else(|| self.next_ty_var(cause_span.unwrap_or(DUMMY_SP)));
+
+        let sig = projection.rebind(self.tcx.mk_fn_sig(
+            input_tys,
+            return_ty,
+            false,
+            hir::Safety::Safe,
+            Abi::Rust,
+        ));
+
+        return Some(ExpectedSig { cause_span, sig });
     }
 
     fn sig_of_closure(

compiler/rustc_middle/src/query/mod.rs

@@ -65,10 +65,9 @@ use crate::query::plumbing::{
 };
 use crate::traits::query::{
     CanonicalAliasGoal, CanonicalPredicateGoal, CanonicalTyGoal,
-    CanonicalTypeOpAscribeUserTypeGoal, CanonicalTypeOpEqGoal, CanonicalTypeOpNormalizeGoal,
-    CanonicalTypeOpProvePredicateGoal, CanonicalTypeOpSubtypeGoal, DropckConstraint,
-    DropckOutlivesResult, MethodAutoderefStepsResult, NoSolution, NormalizationResult,
-    OutlivesBound,
+    CanonicalTypeOpAscribeUserTypeGoal, CanonicalTypeOpNormalizeGoal,
+    CanonicalTypeOpProvePredicateGoal, DropckConstraint, DropckOutlivesResult,
+    MethodAutoderefStepsResult, NoSolution, NormalizationResult, OutlivesBound,
 };
 use crate::traits::{
     specialization_graph, CodegenObligationError, EvaluationResult, ImplSource,
@@ -2090,26 +2089,6 @@ rustc_queries! {
         desc { "evaluating `type_op_ascribe_user_type` `{:?}`", goal.value.value }
     }
 
-    /// Do not call this query directly: part of the `Eq` type-op
-    query type_op_eq(
-        goal: CanonicalTypeOpEqGoal<'tcx>
-    ) -> Result<
-        &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, ()>>,
-        NoSolution,
-    > {
-        desc { "evaluating `type_op_eq` `{:?}`", goal.value.value }
-    }
-
-    /// Do not call this query directly: part of the `Subtype` type-op
-    query type_op_subtype(
-        goal: CanonicalTypeOpSubtypeGoal<'tcx>
-    ) -> Result<
-        &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, ()>>,
-        NoSolution,
-    > {
-        desc { "evaluating `type_op_subtype` `{:?}`", goal.value.value }
-    }
-
     /// Do not call this query directly: part of the `ProvePredicate` type-op
     query type_op_prove_predicate(
         goal: CanonicalTypeOpProvePredicateGoal<'tcx>

compiler/rustc_mir_transform/src/coroutine/by_move_body.rs

@@ -78,6 +78,8 @@ use rustc_middle::mir::{self, dump_mir, MirPass};
 use rustc_middle::ty::{self, InstanceKind, Ty, TyCtxt, TypeVisitableExt};
 use rustc_target::abi::{FieldIdx, VariantIdx};
 
+use crate::pass_manager::validate_body;
+
 pub struct ByMoveBody;
 
 impl<'tcx> MirPass<'tcx> for ByMoveBody {
@@ -131,20 +133,40 @@ impl<'tcx> MirPass<'tcx> for ByMoveBody {
             |(parent_field_idx, parent_capture), (child_field_idx, child_capture)| {
                 // Store this set of additional projections (fields and derefs).
                 // We need to re-apply them later.
-                let child_precise_captures =
-                    &child_capture.place.projections[parent_capture.place.projections.len()..];
+                let mut child_precise_captures = child_capture.place.projections
+                    [parent_capture.place.projections.len()..]
+                    .to_vec();
 
-                // If the parent captures by-move, and the child captures by-ref, then we
-                // need to peel an additional `deref` off of the body of the child.
-                let needs_deref = child_capture.is_by_ref() && !parent_capture.is_by_ref();
-                if needs_deref {
-                    assert_ne!(
-                        coroutine_kind,
-                        ty::ClosureKind::FnOnce,
+                // If the parent capture is by-ref, then we need to apply an additional
+                // deref before applying any further projections to this place.
+                if parent_capture.is_by_ref() {
+                    child_precise_captures.insert(
+                        0,
+                        Projection { ty: parent_capture.place.ty(), kind: ProjectionKind::Deref },
+                    );
+                }
+                // If the child capture is by-ref, then we need to apply a "ref"
+                // projection (i.e. `&`) at the end. But wait! We don't have that
+                // as a projection kind. So instead, we can apply its dual and
+                // *peel* a deref off of the place when it shows up in the MIR body.
+                // Luckily, by construction this is always possible.
+                let peel_deref = if child_capture.is_by_ref() {
+                    assert!(
+                        parent_capture.is_by_ref() || coroutine_kind != ty::ClosureKind::FnOnce,
                         "`FnOnce` coroutine-closures return coroutines that capture from \
                         their body; it will always result in a borrowck error!"
                     );
-                }
+                    true
+                } else {
+                    false
+                };
+
+                // Regarding the behavior above, you may think that it's redundant to both
+                // insert a deref and then peel a deref if the parent and child are both
+                // captured by-ref. This would be correct, except for the case where we have
+                // precise capturing projections, since the inserted deref is to the *beginning*
+                // and the peeled deref is at the *end*. I cannot seem to actually find a
+                // case where this happens, though, but let's keep this code flexible.
 
                 // Finally, store the type of the parent's captured place. We need
                 // this when building the field projection in the MIR body later on.
@@ -164,7 +186,7 @@ impl<'tcx> MirPass<'tcx> for ByMoveBody {
                     (
                         FieldIdx::from_usize(parent_field_idx + num_args),
                         parent_capture_ty,
-                        needs_deref,
+                        peel_deref,
                         child_precise_captures,
                     ),
                 )
@@ -192,6 +214,10 @@ impl<'tcx> MirPass<'tcx> for ByMoveBody {
         let mut by_move_body = body.clone();
         MakeByMoveBody { tcx, field_remapping, by_move_coroutine_ty }.visit_body(&mut by_move_body);
         dump_mir(tcx, false, "coroutine_by_move", &0, &by_move_body, |_, _| Ok(()));
+
+        // Let's just always validate this body.
+        validate_body(tcx, &mut by_move_body, "Initial coroutine_by_move body".to_string());
+
         // FIXME: use query feeding to generate the body right here and then only store the `DefId` of the new body.
         by_move_body.source = mir::MirSource::from_instance(InstanceKind::CoroutineKindShim {
             coroutine_def_id: coroutine_def_id.to_def_id(),
@@ -202,7 +228,7 @@ impl<'tcx> MirPass<'tcx> for ByMoveBody {
 
 struct MakeByMoveBody<'tcx> {
     tcx: TyCtxt<'tcx>,
-    field_remapping: UnordMap<FieldIdx, (FieldIdx, Ty<'tcx>, bool, &'tcx [Projection<'tcx>])>,
+    field_remapping: UnordMap<FieldIdx, (FieldIdx, Ty<'tcx>, bool, Vec<Projection<'tcx>>)>,
     by_move_coroutine_ty: Ty<'tcx>,
 }
 
@@ -223,14 +249,14 @@ impl<'tcx> MutVisitor<'tcx> for MakeByMoveBody<'tcx> {
         if place.local == ty::CAPTURE_STRUCT_LOCAL
             && let Some((&mir::ProjectionElem::Field(idx, _), projection)) =
                 place.projection.split_first()
-            && let Some(&(remapped_idx, remapped_ty, needs_deref, bridging_projections)) =
+            && let Some(&(remapped_idx, remapped_ty, peel_deref, ref bridging_projections)) =
                 self.field_remapping.get(&idx)
         {
             // As noted before, if the parent closure captures a field by value, and
             // the child captures a field by ref, then for the by-move body we're
             // generating, we also are taking that field by value. Peel off a deref,
             // since a layer of ref'ing has now become redundant.
-            let final_projections = if needs_deref {
+            let final_projections = if peel_deref {
                 let Some((mir::ProjectionElem::Deref, projection)) = projection.split_first()
                 else {
                     bug!(

compiler/rustc_session/src/session.rs

@@ -1188,7 +1188,12 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
 
     // Sanitizers can only be used on platforms that we know have working sanitizer codegen.
     let supported_sanitizers = sess.target.options.supported_sanitizers;
-    let unsupported_sanitizers = sess.opts.unstable_opts.sanitizer - supported_sanitizers;
+    let mut unsupported_sanitizers = sess.opts.unstable_opts.sanitizer - supported_sanitizers;
+    // Niche: if `fixed-x18`, or effectively switching on `reserved-x18` flag, is enabled
+    // we should allow Shadow Call Stack sanitizer.
+    if sess.opts.unstable_opts.fixed_x18 && sess.target.arch == "aarch64" {
+        unsupported_sanitizers -= SanitizerSet::SHADOWCALLSTACK;
+    }
     match unsupported_sanitizers.into_iter().count() {
         0 => {}
         1 => {

compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs

@@ -16,12 +16,10 @@ use crate::traits::{ObligationCause, ObligationCtxt};
 
 pub mod ascribe_user_type;
 pub mod custom;
-pub mod eq;
 pub mod implied_outlives_bounds;
 pub mod normalize;
 pub mod outlives;
 pub mod prove_predicate;
-pub mod subtype;
 
 pub use rustc_middle::traits::query::type_op::*;
 

compiler/rustc_traits/src/type_op.rs

@@ -10,18 +10,14 @@ use rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
 use rustc_trait_selection::traits::query::type_op::ascribe_user_type::{
     type_op_ascribe_user_type_with_span, AscribeUserType,
 };
-use rustc_trait_selection::traits::query::type_op::eq::Eq;
 use rustc_trait_selection::traits::query::type_op::normalize::Normalize;
 use rustc_trait_selection::traits::query::type_op::prove_predicate::ProvePredicate;
-use rustc_trait_selection::traits::query::type_op::subtype::Subtype;
 use rustc_trait_selection::traits::{Normalized, Obligation, ObligationCause, ObligationCtxt};
 
 pub(crate) fn provide(p: &mut Providers) {
     *p = Providers {
         type_op_ascribe_user_type,
-        type_op_eq,
         type_op_prove_predicate,
-        type_op_subtype,
         type_op_normalize_ty,
         type_op_normalize_clause,
         type_op_normalize_fn_sig,
@@ -39,16 +35,6 @@ fn type_op_ascribe_user_type<'tcx>(
     })
 }
 
-fn type_op_eq<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, Eq<'tcx>>>,
-) -> Result<&'tcx Canonical<'tcx, QueryResponse<'tcx, ()>>, NoSolution> {
-    tcx.infer_ctxt().enter_canonical_trait_query(&canonicalized, |ocx, key| {
-        let (param_env, Eq { a, b }) = key.into_parts();
-        Ok(ocx.eq(&ObligationCause::dummy(), param_env, a, b)?)
-    })
-}
-
 fn type_op_normalize<'tcx, T>(
     ocx: &ObligationCtxt<'_, 'tcx>,
     key: ParamEnvAnd<'tcx, Normalize<T>>,
@@ -91,16 +77,6 @@ fn type_op_normalize_poly_fn_sig<'tcx>(
     tcx.infer_ctxt().enter_canonical_trait_query(&canonicalized, type_op_normalize)
 }
 
-fn type_op_subtype<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, Subtype<'tcx>>>,
-) -> Result<&'tcx Canonical<'tcx, QueryResponse<'tcx, ()>>, NoSolution> {
-    tcx.infer_ctxt().enter_canonical_trait_query(&canonicalized, |ocx, key| {
-        let (param_env, Subtype { sub, sup }) = key.into_parts();
-        Ok(ocx.sup(&ObligationCause::dummy(), param_env, sup, sub)?)
-    })
-}
-
 fn type_op_prove_predicate<'tcx>(
     tcx: TyCtxt<'tcx>,
     canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, ProvePredicate<'tcx>>>,

src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile

@@ -62,9 +62,9 @@ COPY host-x86_64/dist-x86_64-linux/build-clang.sh /tmp/
 RUN ./build-clang.sh
 ENV CC=clang CXX=clang++
 
-# rustc's LLVM needs zstd.
-COPY scripts/zstd.sh /tmp/
-RUN ./zstd.sh
+# Build zstd to enable `llvm.libzstd`.
+COPY host-x86_64/dist-x86_64-linux/build-zstd.sh /tmp/
+RUN ./build-zstd.sh
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh

src/ci/docker/host-x86_64/x86_64-gnu/Dockerfile

@@ -28,5 +28,6 @@ ENV RUST_CONFIGURE_ARGS \
  --build=x86_64-unknown-linux-gnu \
  --enable-sanitizers \
  --enable-profiler \
- --enable-compiler-docs
+ --enable-compiler-docs \
+ --set llvm.libzstd=true
 ENV SCRIPT python3 ../x.py --stage 2 test

src/doc/rustc/src/platform-support/android.md

@@ -61,3 +61,8 @@ Currently the `riscv64-linux-android` target requires the following architecture
 * `Zba` (address calculation instructions)
 * `Zbb` (base instructions)
 * `Zbs` (single-bit instructions)
+
+### aarch64-linux-android on Nightly compilers
+
+As soon as `-Zfixed-x18` compiler flag is supplied, the [`ShadowCallStack` sanitizer](https://releases.llvm.org/7.0.1/tools/clang/docs/ShadowCallStack.html)
+instrumentation is also made avaiable by supplying the second compiler flag `-Zsanitizer=shadow-call-stack`.

src/doc/unstable-book/src/compiler-flags/fixed-x18.md

@@ -1,7 +1,7 @@
 # `fixed-x18`
 
 This option prevents the compiler from using the x18 register. It is only
-supported on aarch64.
+supported on `aarch64`.
 
 From the [ABI spec][arm-abi]:
 
@@ -23,6 +23,11 @@ Currently, the `-Zsanitizer=shadow-call-stack` flag is only supported on
 platforms that always treat x18 as a reserved register, and the `-Zfixed-x18`
 flag is not required to use the sanitizer on such platforms. However, the
 sanitizer may be supported on targets where this is not the case in the future.
+One way to do so now on Nightly compilers is to explicitly supply this `-Zfixed-x18`
+flag with `aarch64` targets, so that the sanitizer is available for instrumentation
+on targets like `aarch64-unknown-none`, for instance. However, discretion is still
+required to make sure that the runtime support is in place for this sanitizer
+to be effective.
 
 It is undefined behavior for `-Zsanitizer=shadow-call-stack` code to call into
 code where x18 is a temporary register. On the other hand, when you are *not*

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

@@ -787,6 +787,10 @@ A runtime must be provided by the application or operating system.
 
 See the [Clang ShadowCallStack documentation][clang-scs] for more details.
 
+* `aarch64-unknown-none`
+
+In addition to support from a runtime by the application or operating system, the `-Zfixed-x18` flag is also mandatory.
+
 # ThreadSanitizer
 
 ThreadSanitizer is a data race detection tool. It is supported on the following

src/librustdoc/json/mod.rs

@@ -13,12 +13,15 @@ use std::io::{stdout, BufWriter, Write};
 use std::path::PathBuf;
 use std::rc::Rc;
 
-use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def_id::{DefId, DefIdSet};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
 use rustc_span::def_id::LOCAL_CRATE;
 use rustdoc_json_types as types;
+// It's important to use the FxHashMap from rustdoc_json_types here, instead of
+// the one from rustc_data_structures, as they're different types due to sysroots.
+// See #110051 and #127456 for details
+use rustdoc_json_types::FxHashMap;
 
 use crate::clean::types::{ExternalCrate, ExternalLocation};
 use crate::clean::ItemKind;
@@ -234,14 +237,11 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
         let index = (*self.index).clone().into_inner();
 
         debug!("Constructing Output");
-        // This needs to be the default HashMap for compatibility with the public interface for
-        // rustdoc-json-types
-        #[allow(rustc::default_hash_types)]
         let output = types::Crate {
             root: types::Id(format!("0:0:{}", e.name(self.tcx).as_u32())),
             crate_version: self.cache.crate_version.clone(),
             includes_private: self.cache.document_private,
-            index: index.into_iter().collect(),
+            index,
             paths: self
                 .cache
                 .paths

src/rustdoc-json-types/lib.rs

@@ -5,7 +5,7 @@
 
 use std::path::PathBuf;
 
-use rustc_hash::FxHashMap;
+pub use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
 
 /// The version of JSON output that this crate represents.

src/tools/compiletest/src/command-list.rs

@@ -138,6 +138,7 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "needs-force-clang-based-tests",
     "needs-git-hash",
     "needs-llvm-components",
+    "needs-llvm-zstd",
     "needs-profiler-support",
     "needs-relocation-model-pic",
     "needs-run-enabled",

src/tools/compiletest/src/header.rs

@@ -1203,6 +1203,107 @@ pub fn extract_llvm_version_from_binary(binary_path: &str) -> Option<u32> {
     None
 }
 
+/// For tests using the `needs-llvm-zstd` directive:
+/// - for local LLVM builds, try to find the static zstd library in the llvm-config system libs.
+/// - for `download-ci-llvm`, see if `lld` was built with zstd support.
+pub fn llvm_has_libzstd(config: &Config) -> bool {
+    // Strategy 1: works for local builds but not with `download-ci-llvm`.
+    //
+    // We check whether `llvm-config` returns the zstd library. Bootstrap's `llvm.libzstd` will only
+    // ask to statically link it when building LLVM, so we only check if the list of system libs
+    // contains a path to that static lib, and that it exists.
+    //
+    // See compiler/rustc_llvm/build.rs for more details and similar expectations.
+    fn is_zstd_in_config(llvm_bin_dir: &Path) -> Option<()> {
+        let llvm_config_path = llvm_bin_dir.join("llvm-config");
+        let output = Command::new(llvm_config_path).arg("--system-libs").output().ok()?;
+        assert!(output.status.success(), "running llvm-config --system-libs failed");
+
+        let libs = String::from_utf8(output.stdout).ok()?;
+        for lib in libs.split_whitespace() {
+            if lib.ends_with("libzstd.a") && Path::new(lib).exists() {
+                return Some(());
+            }
+        }
+
+        None
+    }
+
+    // Strategy 2: `download-ci-llvm`'s `llvm-config --system-libs` will not return any libs to
+    // use.
+    //
+    // The CI artifacts also don't contain the bootstrap config used to build them: otherwise we
+    // could have looked at the `llvm.libzstd` config.
+    //
+    // We infer whether `LLVM_ENABLE_ZSTD` was used to build LLVM as a byproduct of testing whether
+    // `lld` supports it. If not, an error will be emitted: "LLVM was not built with
+    // LLVM_ENABLE_ZSTD or did not find zstd at build time".
+    #[cfg(unix)]
+    fn is_lld_built_with_zstd(llvm_bin_dir: &Path) -> Option<()> {
+        let lld_path = llvm_bin_dir.join("lld");
+        if lld_path.exists() {
+            // We can't call `lld` as-is, it expects to be invoked by a compiler driver using a
+            // different name. Prepare a temporary symlink to do that.
+            let lld_symlink_path = llvm_bin_dir.join("ld.lld");
+            if !lld_symlink_path.exists() {
+                std::os::unix::fs::symlink(lld_path, &lld_symlink_path).ok()?;
+            }
+
+            // Run `lld` with a zstd flag. We expect this command to always error here, we don't
+            // want to link actual files and don't pass any.
+            let output = Command::new(&lld_symlink_path)
+                .arg("--compress-debug-sections=zstd")
+                .output()
+                .ok()?;
+            assert!(!output.status.success());
+
+            // Look for a specific error caused by LLVM not being built with zstd support. We could
+            // also look for the "no input files" message, indicating the zstd flag was accepted.
+            let stderr = String::from_utf8(output.stderr).ok()?;
+            let zstd_available = !stderr.contains("LLVM was not built with LLVM_ENABLE_ZSTD");
+
+            // We don't particularly need to clean the link up (so the previous commands could fail
+            // in theory but won't in practice), but we can try.
+            std::fs::remove_file(lld_symlink_path).ok()?;
+
+            if zstd_available {
+                return Some(());
+            }
+        }
+
+        None
+    }
+
+    #[cfg(not(unix))]
+    fn is_lld_built_with_zstd(llvm_bin_dir: &Path) -> Option<()> {
+        None
+    }
+
+    if let Some(llvm_bin_dir) = &config.llvm_bin_dir {
+        // Strategy 1: for local LLVM builds.
+        if is_zstd_in_config(llvm_bin_dir).is_some() {
+            return true;
+        }
+
+        // Strategy 2: for LLVM artifacts built on CI via `download-ci-llvm`.
+        //
+        // It doesn't work for cases where the artifacts don't contain the linker, but it's
+        // best-effort: CI has `llvm.libzstd` and `lld` enabled on the x64 linux artifacts, so it
+        // will at least work there.
+        //
+        // If this can be improved and expanded to less common cases in the future, it should.
+        if config.target == "x86_64-unknown-linux-gnu"
+            && config.host == config.target
+            && is_lld_built_with_zstd(llvm_bin_dir).is_some()
+        {
+            return true;
+        }
+    }
+
+    // Otherwise, all hope is lost.
+    false
+}
+
 /// Takes a directive of the form "<version1> [- <version2>]",
 /// returns the numeric representation of <version1> and <version2> as
 /// tuple: (<version1> as u32, <version2> as u32)

src/tools/compiletest/src/header/needs.rs

@@ -1,5 +1,5 @@
 use crate::common::{Config, Debugger, Sanitizer};
-use crate::header::IgnoreDecision;
+use crate::header::{llvm_has_libzstd, IgnoreDecision};
 
 pub(super) fn handle_needs(
     cache: &CachedNeedsConditions,
@@ -149,6 +149,11 @@ pub(super) fn handle_needs(
             condition: cache.symlinks,
             ignore_reason: "ignored if symlinks are unavailable",
         },
+        Need {
+            name: "needs-llvm-zstd",
+            condition: cache.llvm_zstd,
+            ignore_reason: "ignored if LLVM wasn't build with zstd for ELF section compression",
+        },
     ];
 
     let (name, comment) = match ln.split_once([':', ' ']) {
@@ -174,7 +179,7 @@ pub(super) fn handle_needs(
             } else {
                 return IgnoreDecision::Ignore {
                     reason: if let Some(comment) = comment {
-                        format!("{} ({comment})", need.ignore_reason)
+                        format!("{} ({})", need.ignore_reason, comment.trim())
                     } else {
                         need.ignore_reason.into()
                     },
@@ -215,6 +220,8 @@ pub(super) struct CachedNeedsConditions {
     rust_lld: bool,
     dlltool: bool,
     symlinks: bool,
+    /// Whether LLVM built with zstd, for the `needs-llvm-zstd` directive.
+    llvm_zstd: bool,
 }
 
 impl CachedNeedsConditions {
@@ -258,6 +265,7 @@ impl CachedNeedsConditions {
                 .join(if config.host.contains("windows") { "rust-lld.exe" } else { "rust-lld" })
                 .exists(),
 
+            llvm_zstd: llvm_has_libzstd(&config),
             dlltool: find_dlltool(&config),
             symlinks: has_symlinks(),
         }

src/tools/run-make-support/src/external_deps/rustdoc.rs

@@ -71,14 +71,8 @@ impl Rustdoc {
         self
     }
 
-    /// Specify path to the output folder.
-    pub fn output<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
-        self.cmd.arg("-o");
-        self.cmd.arg(path.as_ref());
-        self
-    }
-
     /// Specify output directory.
+    #[doc(alias = "output")]
     pub fn out_dir<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
         self.cmd.arg("--out-dir").arg(path.as_ref());
         self

src/tools/rust-analyzer/crates/hir-ty/src/lib.rs

@@ -15,8 +15,10 @@ extern crate rustc_abi;
 #[cfg(not(feature = "in-rust-tree"))]
 extern crate ra_ap_rustc_abi as rustc_abi;
 
-// Use the crates.io version unconditionally until the API settles enough that we can switch to
-// using the in-tree one.
+#[cfg(feature = "in-rust-tree")]
+extern crate rustc_pattern_analysis;
+
+#[cfg(not(feature = "in-rust-tree"))]
 extern crate ra_ap_rustc_pattern_analysis as rustc_pattern_analysis;
 
 mod builder;

tests/codegen/sanitizer/aarch64-shadow-call-stack-with-fixed-x18.rs

@@ -0,0 +1,19 @@
+//@ revisions: aarch64 android
+//@[aarch64] compile-flags: --target aarch64-unknown-none -Zfixed-x18 -Zsanitizer=shadow-call-stack
+//@[aarch64] needs-llvm-components: aarch64
+//@[android] compile-flags: --target aarch64-linux-android -Zsanitizer=shadow-call-stack
+//@[android] needs-llvm-components: aarch64
+
+#![allow(internal_features)]
+#![crate_type = "rlib"]
+#![feature(no_core, lang_items)]
+#![no_core]
+
+#[lang = "sized"]
+trait Sized {}
+
+// CHECK: ; Function Attrs:{{.*}}shadowcallstack
+#[no_mangle]
+pub fn foo() {}
+
+// CHECK: attributes #0 = {{.*}}shadowcallstack{{.*}}

tests/run-make/compressed-debuginfo-zstd/rmake.rs

@@ -0,0 +1,42 @@
+// Checks debuginfo compression both for the always-enabled zlib, and when the optional zstd is
+// enabled:
+// - via rustc's `debuginfo-compression`,
+// - and via rust-lld's `compress-debug-sections`
+
+//@ needs-llvm-zstd: we want LLVM/LLD to be built with zstd support
+//@ needs-rust-lld: the system linker will most likely not support zstd
+//@ only-linux
+//@ ignore-cross-compile
+
+use run_make_support::{llvm_readobj, run_in_tmpdir, Rustc};
+
+fn check_compression(compression: &str, to_find: &str) {
+    // check compressed debug sections via rustc flag
+    prepare_and_check(to_find, |rustc| {
+        rustc.arg(&format!("-Zdebuginfo-compression={compression}"))
+    });
+
+    // check compressed debug sections via rust-lld flag
+    prepare_and_check(to_find, |rustc| {
+        rustc.link_arg(&format!("-Wl,--compress-debug-sections={compression}"))
+    });
+}
+
+fn prepare_and_check<F: FnOnce(&mut Rustc) -> &mut Rustc>(to_find: &str, prepare_rustc: F) {
+    run_in_tmpdir(|| {
+        let mut rustc = Rustc::new();
+        rustc
+            .arg("-Zlinker-features=+lld")
+            .arg("-Clink-self-contained=+linker")
+            .arg("-Zunstable-options")
+            .arg("-Cdebuginfo=full")
+            .input("main.rs");
+        prepare_rustc(&mut rustc).run();
+        llvm_readobj().arg("-t").arg("main").run().assert_stdout_contains(to_find);
+    });
+}
+
+fn main() {
+    check_compression("zlib", "ZLIB");
+    check_compression("zstd", "ZSTD");
+}

tests/run-make/compressed-debuginfo/rmake.rs

@@ -1,11 +1,9 @@
-// Checks the `debuginfo-compression` option.
+// Checks the always enabled `debuginfo-compression` option: zlib.
 
 //@ only-linux
 //@ ignore-cross-compile
 
-// FIXME: This test isn't comprehensive and isn't covering all possible combinations.
-
-use run_make_support::{assert_contains, llvm_readobj, run_in_tmpdir, rustc};
+use run_make_support::{llvm_readobj, run_in_tmpdir, rustc};
 
 fn check_compression(compression: &str, to_find: &str) {
     run_in_tmpdir(|| {
@@ -17,19 +15,10 @@ fn check_compression(compression: &str, to_find: &str) {
             .arg(&format!("-Zdebuginfo-compression={compression}"))
             .input("foo.rs")
             .run();
-        let stderr = out.stderr_utf8();
-        if stderr.is_empty() {
-            llvm_readobj().arg("-t").arg("foo.o").run().assert_stdout_contains(to_find);
-        } else {
-            assert_contains(
-                stderr,
-                format!("unknown debuginfo compression algorithm {compression}"),
-            );
-        }
+        llvm_readobj().arg("-t").arg("foo.o").run().assert_stdout_contains(to_find);
     });
 }
 
 fn main() {
     check_compression("zlib", "ZLIB");
-    check_compression("zstd", "ZSTD");
 }

tests/run-make/deref-impl-rustdoc-ice/rmake.rs

@@ -12,5 +12,5 @@ use run_make_support::{cwd, rustc, rustdoc};
 fn main() {
     rustc().input("foo.rs").run();
     rustc().input("bar.rs").run();
-    rustdoc().input("baz.rs").library_search_path(cwd()).output(cwd()).run();
+    rustdoc().input("baz.rs").library_search_path(cwd()).out_dir(cwd()).run();
 }

tests/run-make/emit-shared-files/rmake.rs

@@ -13,7 +13,7 @@ fn main() {
     rustdoc()
         .arg("-Zunstable-options")
         .arg("--emit=invocation-specific")
-        .output("invocation-only")
+        .out_dir("invocation-only")
         .arg("--resource-suffix=-xxx")
         .args(&["--theme", "y.css"])
         .args(&["--extend-css", "z.css"])
@@ -34,7 +34,7 @@ fn main() {
     rustdoc()
         .arg("-Zunstable-options")
         .arg("--emit=toolchain-shared-resources")
-        .output("toolchain-only")
+        .out_dir("toolchain-only")
         .arg("--resource-suffix=-xxx")
         .args(&["--extend-css", "z.css"])
         .input("x.rs")
@@ -68,7 +68,7 @@ fn main() {
     rustdoc()
         .arg("-Zunstable-options")
         .arg("--emit=toolchain-shared-resources,unversioned-shared-resources")
-        .output("all-shared")
+        .out_dir("all-shared")
         .arg("--resource-suffix=-xxx")
         .args(&["--extend-css", "z.css"])
         .input("x.rs")

tests/run-make/exit-code/rmake.rs

@@ -16,7 +16,7 @@ fn main() {
         .run_fail()
         .assert_exit_code(101);
 
-    rustdoc().arg("success.rs").output("exit-code").run();
+    rustdoc().arg("success.rs").out_dir("exit-code").run();
 
     rustdoc().arg("--invalid-arg-foo").run_fail().assert_exit_code(1);
 

tests/run-make/rustdoc-determinism/rmake.rs

@@ -7,12 +7,12 @@ use run_make_support::{diff, rustdoc};
 
 fn main() {
     let foo_first = Path::new("foo_first");
-    rustdoc().input("foo.rs").output(&foo_first).run();
-    rustdoc().input("bar.rs").output(&foo_first).run();
+    rustdoc().input("foo.rs").out_dir(&foo_first).run();
+    rustdoc().input("bar.rs").out_dir(&foo_first).run();
 
     let bar_first = Path::new("bar_first");
-    rustdoc().input("bar.rs").output(&bar_first).run();
-    rustdoc().input("foo.rs").output(&bar_first).run();
+    rustdoc().input("bar.rs").out_dir(&bar_first).run();
+    rustdoc().input("foo.rs").out_dir(&bar_first).run();
 
     diff()
         .expected_file(foo_first.join("search-index.js"))

tests/run-make/rustdoc-io-error/rmake.rs

@@ -25,7 +25,7 @@ fn main() {
     permissions.set_readonly(true);
     rfs::set_permissions(&out_dir, permissions);
 
-    let output = rustdoc().input("foo.rs").output(&out_dir).env("RUST_BACKTRACE", "1").run_fail();
+    let output = rustdoc().input("foo.rs").out_dir(&out_dir).env("RUST_BACKTRACE", "1").run_fail();
 
     rfs::set_permissions(&out_dir, original_permissions);
 

tests/run-make/rustdoc-map-file/rmake.rs

@@ -6,7 +6,7 @@ fn main() {
         .input("foo.rs")
         .arg("-Zunstable-options")
         .arg("--generate-redirect-map")
-        .output(&out_dir)
+        .out_dir(&out_dir)
         .run();
     // FIXME (GuillaumeGomez): Port the python script to Rust as well.
     python_command().arg("validate_json.py").arg(&out_dir).run();

tests/run-make/rustdoc-output-path/rmake.rs

@@ -6,6 +6,6 @@ use run_make_support::rustdoc;
 
 fn main() {
     let out_dir = Path::new("foo/bar/doc");
-    rustdoc().input("foo.rs").output(&out_dir).run();
+    rustdoc().input("foo.rs").out_dir(&out_dir).run();
     assert!(out_dir.exists());
 }

tests/run-make/rustdoc-output-stdout/rmake.rs

@@ -10,7 +10,7 @@ fn main() {
     // First we check that we generate the JSON in the stdout.
     rustdoc()
         .input("foo.rs")
-        .output("-")
+        .out_dir("-")
         .arg("-Zunstable-options")
         .output_format("json")
         .run()

tests/run-make/rustdoc-scrape-examples-macros/rmake.rs

@@ -35,7 +35,7 @@ fn main() {
         .input("examples/ex.rs")
         .crate_name("ex")
         .crate_type("bin")
-        .output(&out_dir)
+        .out_dir(&out_dir)
         .extern_(crate_name, rust_lib_name(crate_name))
         .extern_(proc_crate_name, dylib_name.trim())
         .arg("-Zunstable-options")
@@ -49,7 +49,7 @@ fn main() {
         .input("src/lib.rs")
         .crate_name(crate_name)
         .crate_type("lib")
-        .output(&out_dir)
+        .out_dir(&out_dir)
         .arg("-Zunstable-options")
         .arg("--with-examples")
         .arg(&ex_dir)

tests/run-make/rustdoc-scrape-examples-remap/scrape.rs

@@ -20,7 +20,7 @@ pub fn scrape(extra_args: &[&str]) {
             .input(&dep)
             .crate_name(&dep_stem)
             .crate_type("bin")
-            .output(&out_dir)
+            .out_dir(&out_dir)
             .extern_(crate_name, format!("lib{crate_name}.rmeta"))
             .arg("-Zunstable-options")
             .arg("--scrape-examples-output-path")
@@ -35,7 +35,7 @@ pub fn scrape(extra_args: &[&str]) {
     let mut rustdoc = rustdoc();
     rustdoc
         .input("src/lib.rs")
-        .output(&out_dir)
+        .out_dir(&out_dir)
         .crate_name(crate_name)
         .crate_type("lib")
         .arg("-Zunstable-options");

tests/run-make/rustdoc-target-spec-json-path/rmake.rs

@@ -7,7 +7,7 @@ fn main() {
     rustc().crate_type("lib").input("dummy_core.rs").target("target.json").run();
     rustdoc()
         .input("my_crate.rs")
-        .output(out_dir)
+        .out_dir(out_dir)
         .library_search_path(cwd())
         .target("target.json")
         .run();

tests/run-make/rustdoc-themes/rmake.rs

@@ -27,6 +27,6 @@ fn main() {
     rfs::create_dir_all(&out_dir);
     rfs::write(&test_css, test_content);
 
-    rustdoc().output(&out_dir).input("foo.rs").arg("--theme").arg(&test_css).run();
+    rustdoc().out_dir(&out_dir).input("foo.rs").arg("--theme").arg(&test_css).run();
     htmldocck().arg(out_dir).arg("foo.rs").run();
 }

tests/run-make/rustdoc-with-out-dir-option/rmake.rs

@@ -2,6 +2,6 @@ use run_make_support::{htmldocck, rustdoc};
 
 fn main() {
     let out_dir = "rustdoc";
-    rustdoc().input("src/lib.rs").crate_name("foobar").crate_type("lib").output(&out_dir).run();
+    rustdoc().input("src/lib.rs").crate_name("foobar").crate_type("lib").out_dir(&out_dir).run();
     htmldocck().arg(out_dir).arg("src/lib.rs").run();
 }

tests/ui/abi/shadow-call-stack-without-fixed-x18.rs

@@ -0,0 +1,15 @@
+//@ compile-flags: --target aarch64-unknown-none -Zsanitizer=shadow-call-stack
+//@ error-pattern: shadow-call-stack sanitizer is not supported for this target
+//@ dont-check-compiler-stderr
+//@ needs-llvm-components: aarch64
+
+#![allow(internal_features)]
+#![crate_type = "rlib"]
+#![feature(no_core, lang_items)]
+#![no_core]
+
+#[lang = "sized"]
+trait Sized {}
+
+#[no_mangle]
+pub fn foo() {}

tests/ui/async-await/async-closures/move-out-of-ref.rs

@@ -0,0 +1,16 @@
+//@ compile-flags: -Zvalidate-mir
+//@ edition: 2021
+
+#![feature(async_closure)]
+
+// NOT copy.
+struct Ty;
+
+fn hello(x: &Ty) {
+    let c = async || {
+        *x;
+        //~^ ERROR cannot move out of `*x` which is behind a shared reference
+    };
+}
+
+fn main() {}

tests/ui/async-await/async-closures/move-out-of-ref.stderr

@@ -0,0 +1,18 @@
+error[E0507]: cannot move out of `*x` which is behind a shared reference
+  --> $DIR/move-out-of-ref.rs:11:9
+   |
+LL |         *x;
+   |         ^^ move occurs because `*x` has type `Ty`, which does not implement the `Copy` trait
+   |
+note: if `Ty` implemented `Clone`, you could clone the value
+  --> $DIR/move-out-of-ref.rs:7:1
+   |
+LL | struct Ty;
+   | ^^^^^^^^^ consider implementing `Clone` for this type
+...
+LL |         *x;
+   |         -- you could clone this value
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0507`.

tests/ui/async-await/async-closures/sig-from-bare-fn.rs

@@ -0,0 +1,49 @@
+//@ check-pass
+//@ edition: 2021
+
+// Make sure that we infer the args of an async closure even if it's passed to
+// a function that requires the async closure implement `Fn*` but does *not* have
+// a `Future` bound on the return type.
+
+#![feature(async_closure)]
+
+use std::future::Future;
+
+trait TryStream {
+    type Ok;
+    type Err;
+}
+
+trait TryFuture {
+    type Ok;
+    type Err;
+}
+
+impl<F, T, E> TryFuture for F where F: Future<Output = Result<T, E>> {
+    type Ok = T;
+    type Err = E;
+}
+
+trait TryStreamExt: TryStream {
+    fn try_for_each<F, Fut>(&self, f: F)
+    where
+        F: FnMut(Self::Ok) -> Fut,
+        Fut: TryFuture<Ok = (), Err = Self::Err>;
+}
+
+impl<S> TryStreamExt for S where S: TryStream {
+    fn try_for_each<F, Fut>(&self, f: F)
+    where
+        F: FnMut(Self::Ok) -> Fut,
+        Fut: TryFuture<Ok = (), Err = Self::Err>,
+    { }
+}
+
+fn test(stream: impl TryStream<Ok = &'static str, Err = ()>) {
+    stream.try_for_each(async |s| {
+        s.trim(); // Make sure we know the type of `s` at this point.
+        Ok(())
+    });
+}
+
+fn main() {}