Auto merge of #141765 - matthiaskrgr:rollup-4hug83b, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - rust-lang/rust#141703 (Structurally normalize types as needed in `projection_ty_core`)
 - rust-lang/rust#141719 (Add tls_model for cygwin and enable has_thread_local)
 - rust-lang/rust#141736 (resolve stage0 sysroot from rustc)
 - rust-lang/rust#141746 (Rework `#[doc(cfg(..))]` checks as distinct pass in rustdoc)
 - rust-lang/rust#141749 (Remove RUSTC_RETRY_LINKER_ON_SEGFAULT hack)

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

5 files changed, 58 insertions, 98 deletions

diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index 8c512257120..3c95ebf9ffa 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -474,17 +474,18 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             let projected_ty = curr_projected_ty.projection_ty_core(
                 tcx,
                 proj,
-                |this, field, ()| {
-                    let ty = this.field_ty(tcx, field);
-                    self.structurally_resolve(ty, locations)
-                },
-                |_, _| unreachable!(),
+                |ty| self.structurally_resolve(ty, locations),
+                |ty, variant_index, field, ()| PlaceTy::field_ty(tcx, ty, variant_index, field),
+                |_| unreachable!(),
             );
             curr_projected_ty = projected_ty;
         }
         trace!(?curr_projected_ty);
 
-        let ty = curr_projected_ty.ty;
+        // Need to renormalize `a` as typecheck may have failed to normalize
+        // higher-ranked aliases if normalization was ambiguous due to inference.
+        let a = self.normalize(a, locations);
+        let ty = self.normalize(curr_projected_ty.ty, locations);
         self.relate_types(ty, v.xform(ty::Contravariant), a, locations, category)?;
 
         Ok(())
@@ -1852,7 +1853,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             | ProjectionElem::Downcast(..) => {}
             ProjectionElem::Field(field, fty) => {
                 let fty = self.normalize(fty, location);
-                let ty = base_ty.field_ty(tcx, field);
+                let ty = PlaceTy::field_ty(tcx, base_ty.ty, base_ty.variant_index, field);
                 let ty = self.normalize(ty, location);
                 debug!(?fty, ?ty);
 
diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index b802284eb32..58fa3c392ca 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -6,7 +6,7 @@ use std::fs::{File, OpenOptions, read};
 use std::io::{BufWriter, Write};
 use std::ops::{ControlFlow, Deref};
 use std::path::{Path, PathBuf};
-use std::process::{ExitStatus, Output, Stdio};
+use std::process::{Output, Stdio};
 use std::{env, fmt, fs, io, mem, str};
 
 use cc::windows_registry;
@@ -736,13 +736,10 @@ fn link_natively(
 
     // Invoke the system linker
     info!("{cmd:?}");
-    let retry_on_segfault = env::var("RUSTC_RETRY_LINKER_ON_SEGFAULT").is_ok();
     let unknown_arg_regex =
         Regex::new(r"(unknown|unrecognized) (command line )?(option|argument)").unwrap();
     let mut prog;
-    let mut i = 0;
     loop {
-        i += 1;
         prog = sess.time("run_linker", || exec_linker(sess, &cmd, out_filename, flavor, tmpdir));
         let Ok(ref output) = prog else {
             break;
@@ -858,54 +855,7 @@ fn link_natively(
             continue;
         }
 
-        // Here's a terribly awful hack that really shouldn't be present in any
-        // compiler. Here an environment variable is supported to automatically
-        // retry the linker invocation if the linker looks like it segfaulted.
-        //
-        // Gee that seems odd, normally segfaults are things we want to know
-        // about!  Unfortunately though in rust-lang/rust#38878 we're
-        // experiencing the linker segfaulting on Travis quite a bit which is
-        // causing quite a bit of pain to land PRs when they spuriously fail
-        // due to a segfault.
-        //
-        // The issue #38878 has some more debugging information on it as well,
-        // but this unfortunately looks like it's just a race condition in
-        // macOS's linker with some thread pool working in the background. It
-        // seems that no one currently knows a fix for this so in the meantime
-        // we're left with this...
-        if !retry_on_segfault || i > 3 {
-            break;
-        }
-        let msg_segv = "clang: error: unable to execute command: Segmentation fault: 11";
-        let msg_bus = "clang: error: unable to execute command: Bus error: 10";
-        if out.contains(msg_segv) || out.contains(msg_bus) {
-            warn!(
-                ?cmd, %out,
-                "looks like the linker segfaulted when we tried to call it, \
-                 automatically retrying again",
-            );
-            continue;
-        }
-
-        if is_illegal_instruction(&output.status) {
-            warn!(
-                ?cmd, %out, status = %output.status,
-                "looks like the linker hit an illegal instruction when we \
-                 tried to call it, automatically retrying again.",
-            );
-            continue;
-        }
-
-        #[cfg(unix)]
-        fn is_illegal_instruction(status: &ExitStatus) -> bool {
-            use std::os::unix::prelude::*;
-            status.signal() == Some(libc::SIGILL)
-        }
-
-        #[cfg(not(unix))]
-        fn is_illegal_instruction(_status: &ExitStatus) -> bool {
-            false
-        }
+        break;
     }
 
     match prog {
diff --git a/compiler/rustc_middle/src/mir/statement.rs b/compiler/rustc_middle/src/mir/statement.rs
index d59b6df44ed..06e41e64fdc 100644
--- a/compiler/rustc_middle/src/mir/statement.rs
+++ b/compiler/rustc_middle/src/mir/statement.rs
@@ -88,26 +88,31 @@ impl<'tcx> PlaceTy<'tcx> {
     ///
     /// Note that the resulting type has not been normalized.
     #[instrument(level = "debug", skip(tcx), ret)]
-    pub fn field_ty(self, tcx: TyCtxt<'tcx>, f: FieldIdx) -> Ty<'tcx> {
-        if let Some(variant_index) = self.variant_index {
-            match *self.ty.kind() {
+    pub fn field_ty(
+        tcx: TyCtxt<'tcx>,
+        self_ty: Ty<'tcx>,
+        variant_idx: Option<VariantIdx>,
+        f: FieldIdx,
+    ) -> Ty<'tcx> {
+        if let Some(variant_index) = variant_idx {
+            match *self_ty.kind() {
                 ty::Adt(adt_def, args) if adt_def.is_enum() => {
                     adt_def.variant(variant_index).fields[f].ty(tcx, args)
                 }
                 ty::Coroutine(def_id, args) => {
                     let mut variants = args.as_coroutine().state_tys(def_id, tcx);
                     let Some(mut variant) = variants.nth(variant_index.into()) else {
-                        bug!("variant {variant_index:?} of coroutine out of range: {self:?}");
+                        bug!("variant {variant_index:?} of coroutine out of range: {self_ty:?}");
                     };
 
-                    variant
-                        .nth(f.index())
-                        .unwrap_or_else(|| bug!("field {f:?} out of range: {self:?}"))
+                    variant.nth(f.index()).unwrap_or_else(|| {
+                        bug!("field {f:?} out of range of variant: {self_ty:?} {variant_idx:?}")
+                    })
                 }
-                _ => bug!("can't downcast non-adt non-coroutine type: {self:?}"),
+                _ => bug!("can't downcast non-adt non-coroutine type: {self_ty:?}"),
             }
         } else {
-            match self.ty.kind() {
+            match self_ty.kind() {
                 ty::Adt(adt_def, args) if !adt_def.is_enum() => {
                     adt_def.non_enum_variant().fields[f].ty(tcx, args)
                 }
@@ -116,26 +121,25 @@ impl<'tcx> PlaceTy<'tcx> {
                     .upvar_tys()
                     .get(f.index())
                     .copied()
-                    .unwrap_or_else(|| bug!("field {f:?} out of range: {self:?}")),
+                    .unwrap_or_else(|| bug!("field {f:?} out of range: {self_ty:?}")),
                 ty::CoroutineClosure(_, args) => args
                     .as_coroutine_closure()
                     .upvar_tys()
                     .get(f.index())
                     .copied()
-                    .unwrap_or_else(|| bug!("field {f:?} out of range: {self:?}")),
+                    .unwrap_or_else(|| bug!("field {f:?} out of range: {self_ty:?}")),
                 // Only prefix fields (upvars and current state) are
                 // accessible without a variant index.
-                ty::Coroutine(_, args) => args
-                    .as_coroutine()
-                    .prefix_tys()
-                    .get(f.index())
-                    .copied()
-                    .unwrap_or_else(|| bug!("field {f:?} out of range: {self:?}")),
+                ty::Coroutine(_, args) => {
+                    args.as_coroutine().prefix_tys().get(f.index()).copied().unwrap_or_else(|| {
+                        bug!("field {f:?} out of range of prefixes for {self_ty}")
+                    })
+                }
                 ty::Tuple(tys) => tys
                     .get(f.index())
                     .copied()
-                    .unwrap_or_else(|| bug!("field {f:?} out of range: {self:?}")),
-                _ => bug!("can't project out of {self:?}"),
+                    .unwrap_or_else(|| bug!("field {f:?} out of range: {self_ty:?}")),
+                _ => bug!("can't project out of {self_ty:?}"),
             }
         }
     }
@@ -148,11 +152,11 @@ impl<'tcx> PlaceTy<'tcx> {
         elems.iter().fold(self, |place_ty, &elem| place_ty.projection_ty(tcx, elem))
     }
 
-    /// Convenience wrapper around `projection_ty_core` for
-    /// `PlaceElem`, where we can just use the `Ty` that is already
-    /// stored inline on field projection elems.
+    /// Convenience wrapper around `projection_ty_core` for `PlaceElem`,
+    /// where we can just use the `Ty` that is already stored inline on
+    /// field projection elems.
     pub fn projection_ty(self, tcx: TyCtxt<'tcx>, elem: PlaceElem<'tcx>) -> PlaceTy<'tcx> {
-        self.projection_ty_core(tcx, &elem, |_, _, ty| ty, |_, ty| ty)
+        self.projection_ty_core(tcx, &elem, |ty| ty, |_, _, _, ty| ty, |ty| ty)
     }
 
     /// `place_ty.projection_ty_core(tcx, elem, |...| { ... })`
@@ -164,8 +168,9 @@ impl<'tcx> PlaceTy<'tcx> {
         self,
         tcx: TyCtxt<'tcx>,
         elem: &ProjectionElem<V, T>,
-        mut handle_field: impl FnMut(&Self, FieldIdx, T) -> Ty<'tcx>,
-        mut handle_opaque_cast_and_subtype: impl FnMut(&Self, T) -> Ty<'tcx>,
+        mut structurally_normalize: impl FnMut(Ty<'tcx>) -> Ty<'tcx>,
+        mut handle_field: impl FnMut(Ty<'tcx>, Option<VariantIdx>, FieldIdx, T) -> Ty<'tcx>,
+        mut handle_opaque_cast_and_subtype: impl FnMut(T) -> Ty<'tcx>,
     ) -> PlaceTy<'tcx>
     where
         V: ::std::fmt::Debug,
@@ -176,16 +181,16 @@ impl<'tcx> PlaceTy<'tcx> {
         }
         let answer = match *elem {
             ProjectionElem::Deref => {
-                let ty = self.ty.builtin_deref(true).unwrap_or_else(|| {
+                let ty = structurally_normalize(self.ty).builtin_deref(true).unwrap_or_else(|| {
                     bug!("deref projection of non-dereferenceable ty {:?}", self)
                 });
                 PlaceTy::from_ty(ty)
             }
             ProjectionElem::Index(_) | ProjectionElem::ConstantIndex { .. } => {
-                PlaceTy::from_ty(self.ty.builtin_index().unwrap())
+                PlaceTy::from_ty(structurally_normalize(self.ty).builtin_index().unwrap())
             }
             ProjectionElem::Subslice { from, to, from_end } => {
-                PlaceTy::from_ty(match self.ty.kind() {
+                PlaceTy::from_ty(match structurally_normalize(self.ty).kind() {
                     ty::Slice(..) => self.ty,
                     ty::Array(inner, _) if !from_end => Ty::new_array(tcx, *inner, to - from),
                     ty::Array(inner, size) if from_end => {
@@ -201,17 +206,18 @@ impl<'tcx> PlaceTy<'tcx> {
             ProjectionElem::Downcast(_name, index) => {
                 PlaceTy { ty: self.ty, variant_index: Some(index) }
             }
-            ProjectionElem::Field(f, fty) => PlaceTy::from_ty(handle_field(&self, f, fty)),
-            ProjectionElem::OpaqueCast(ty) => {
-                PlaceTy::from_ty(handle_opaque_cast_and_subtype(&self, ty))
-            }
-            ProjectionElem::Subtype(ty) => {
-                PlaceTy::from_ty(handle_opaque_cast_and_subtype(&self, ty))
-            }
+            ProjectionElem::Field(f, fty) => PlaceTy::from_ty(handle_field(
+                structurally_normalize(self.ty),
+                self.variant_index,
+                f,
+                fty,
+            )),
+            ProjectionElem::OpaqueCast(ty) => PlaceTy::from_ty(handle_opaque_cast_and_subtype(ty)),
+            ProjectionElem::Subtype(ty) => PlaceTy::from_ty(handle_opaque_cast_and_subtype(ty)),
 
             // FIXME(unsafe_binders): Rename `handle_opaque_cast_and_subtype` to be more general.
             ProjectionElem::UnwrapUnsafeBinder(ty) => {
-                PlaceTy::from_ty(handle_opaque_cast_and_subtype(&self, ty))
+                PlaceTy::from_ty(handle_opaque_cast_and_subtype(ty))
             }
         };
         debug!("projection_ty self: {:?} elem: {:?} yields: {:?}", self, elem, answer);
diff --git a/compiler/rustc_mir_build/src/builder/custom/parse/instruction.rs b/compiler/rustc_mir_build/src/builder/custom/parse/instruction.rs
index 494ee33fd8b..9825b947fe0 100644
--- a/compiler/rustc_mir_build/src/builder/custom/parse/instruction.rs
+++ b/compiler/rustc_mir_build/src/builder/custom/parse/instruction.rs
@@ -323,9 +323,9 @@ impl<'a, 'tcx> ParseCtxt<'a, 'tcx> {
     fn parse_place_inner(&self, expr_id: ExprId) -> PResult<(Place<'tcx>, PlaceTy<'tcx>)> {
         let (parent, proj) = parse_by_kind!(self, expr_id, expr, "place",
             @call(mir_field, args) => {
-                let (parent, ty) = self.parse_place_inner(args[0])?;
+                let (parent, place_ty) = self.parse_place_inner(args[0])?;
                 let field = FieldIdx::from_u32(self.parse_integer_literal(args[1])? as u32);
-                let field_ty = ty.field_ty(self.tcx, field);
+                let field_ty = PlaceTy::field_ty(self.tcx, place_ty.ty, place_ty.variant_index, field);
                 let proj = PlaceElem::Field(field, field_ty);
                 let place = parent.project_deeper(&[proj], self.tcx);
                 return Ok((place, PlaceTy::from_ty(field_ty)));
diff --git a/compiler/rustc_target/src/spec/base/cygwin.rs b/compiler/rustc_target/src/spec/base/cygwin.rs
index 819d1d68a71..d6ae0a905bf 100644
--- a/compiler/rustc_target/src/spec/base/cygwin.rs
+++ b/compiler/rustc_target/src/spec/base/cygwin.rs
@@ -1,7 +1,8 @@
 use std::borrow::Cow;
 
 use crate::spec::{
-    BinaryFormat, Cc, DebuginfoKind, LinkerFlavor, Lld, SplitDebuginfo, TargetOptions, cvs,
+    BinaryFormat, Cc, DebuginfoKind, LinkerFlavor, Lld, SplitDebuginfo, TargetOptions, TlsModel,
+    cvs,
 };
 
 pub(crate) fn opts() -> TargetOptions {
@@ -44,6 +45,8 @@ pub(crate) fn opts() -> TargetOptions {
         eh_frame_header: false,
         debuginfo_kind: DebuginfoKind::Dwarf,
         supported_split_debuginfo: Cow::Borrowed(&[SplitDebuginfo::Off]),
+        tls_model: TlsModel::Emulated,
+        has_thread_local: true,
         ..Default::default()
     }
 }