Auto merge of #93921 - matthiaskrgr:rollup-wn3jlxj, r=matthiaskrgr

Rollup of 10 pull requests

Successful merges:

 - #90955 (Rename `FilenameTooLong` to `InvalidFilename` and also use it for Windows' `ERROR_INVALID_NAME`)
 - #91607 (Make `span_extend_to_prev_str()` more robust)
 - #92895 (Remove some unused functionality)
 - #93635 (Add missing platform-specific information on current_dir and set_current_dir)
 - #93660 (rustdoc-json: Add some tests for typealias item)
 - #93782 (Split `pauth` target feature)
 - #93868 (Fix incorrect register conflict detection in asm!)
 - #93888 (Implement `AsFd` for `&T` and `&mut T`.)
 - #93909 (Fix typo: explicitely -> explicitly)
 - #93910 (fix mention of moved function in `rustc_hir` docs)

Failed merges:

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

13 files changed, 139 insertions, 66 deletions

diff --git a/compiler/rustc_ast_lowering/src/asm.rs b/compiler/rustc_ast_lowering/src/asm.rs
index 89d411d4b36..5a85356d96d 100644
--- a/compiler/rustc_ast_lowering/src/asm.rs
+++ b/compiler/rustc_ast_lowering/src/asm.rs
@@ -373,7 +373,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                                     err.emit();
                                 }
                                 Entry::Vacant(v) => {
-                                    v.insert(idx);
+                                    if r == reg {
+                                        v.insert(idx);
+                                    }
                                 }
                             }
                         };
diff --git a/compiler/rustc_builtin_macros/src/standard_library_imports.rs b/compiler/rustc_builtin_macros/src/standard_library_imports.rs
index e106f6014a3..3571517d2b2 100644
--- a/compiler/rustc_builtin_macros/src/standard_library_imports.rs
+++ b/compiler/rustc_builtin_macros/src/standard_library_imports.rs
@@ -11,7 +11,6 @@ pub fn inject(
     mut krate: ast::Crate,
     resolver: &mut dyn ResolverExpand,
     sess: &Session,
-    alt_std_name: Option<Symbol>,
 ) -> ast::Crate {
     let edition = sess.parse_sess.edition;
 
@@ -53,7 +52,7 @@ pub fn inject(
                 span,
                 ident,
                 vec![cx.attribute(cx.meta_word(span, sym::macro_use))],
-                ast::ItemKind::ExternCrate(alt_std_name),
+                ast::ItemKind::ExternCrate(None),
             ),
         );
     }
diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs
index 7f82ce307d5..2472789601e 100644
--- a/compiler/rustc_codegen_llvm/src/attributes.rs
+++ b/compiler/rustc_codegen_llvm/src/attributes.rs
@@ -322,12 +322,33 @@ pub fn from_fn_attrs<'ll, 'tcx>(
     // The target doesn't care; the subtarget reads our attribute.
     apply_tune_cpu_attr(cx, llfn);
 
-    let mut function_features = codegen_fn_attrs
-        .target_features
+    let function_features =
+        codegen_fn_attrs.target_features.iter().map(|f| f.as_str()).collect::<Vec<&str>>();
+
+    if let Some(f) = llvm_util::check_tied_features(
+        cx.tcx.sess,
+        &function_features.iter().map(|f| (*f, true)).collect(),
+    ) {
+        let span = cx
+            .tcx
+            .get_attrs(instance.def_id())
+            .iter()
+            .find(|a| a.has_name(rustc_span::sym::target_feature))
+            .map_or_else(|| cx.tcx.def_span(instance.def_id()), |a| a.span);
+        let msg = format!(
+            "the target features {} must all be either enabled or disabled together",
+            f.join(", ")
+        );
+        let mut err = cx.tcx.sess.struct_span_err(span, &msg);
+        err.help("add the missing features in a `target_feature` attribute");
+        err.emit();
+        return;
+    }
+
+    let mut function_features = function_features
         .iter()
-        .flat_map(|f| {
-            let feature = f.as_str();
-            llvm_util::to_llvm_feature(cx.tcx.sess, feature)
+        .flat_map(|feat| {
+            llvm_util::to_llvm_feature(cx.tcx.sess, feat)
                 .into_iter()
                 .map(|f| format!("+{}", f))
                 .collect::<Vec<String>>()
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index f91fad2d9c9..727d079d83d 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -2,8 +2,8 @@ use crate::back::write::create_informational_target_machine;
 use crate::{llvm, llvm_util};
 use libc::c_int;
 use libloading::Library;
-use rustc_codegen_ssa::target_features::supported_target_features;
-use rustc_data_structures::fx::FxHashSet;
+use rustc_codegen_ssa::target_features::{supported_target_features, tied_target_features};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_fs_util::path_to_c_string;
 use rustc_middle::bug;
 use rustc_session::config::PrintRequest;
@@ -191,10 +191,30 @@ pub fn to_llvm_feature<'a>(sess: &Session, s: &'a str) -> Vec<&'a str> {
         ("aarch64", "frintts") => vec!["fptoint"],
         ("aarch64", "fcma") => vec!["complxnum"],
         ("aarch64", "pmuv3") => vec!["perfmon"],
+        ("aarch64", "paca") => vec!["pauth"],
+        ("aarch64", "pacg") => vec!["pauth"],
         (_, s) => vec![s],
     }
 }
 
+// Given a map from target_features to whether they are enabled or disabled,
+// ensure only valid combinations are allowed.
+pub fn check_tied_features(
+    sess: &Session,
+    features: &FxHashMap<&str, bool>,
+) -> Option<&'static [&'static str]> {
+    for tied in tied_target_features(sess) {
+        // Tied features must be set to the same value, or not set at all
+        let mut tied_iter = tied.iter();
+        let enabled = features.get(tied_iter.next().unwrap());
+
+        if tied_iter.any(|f| enabled != features.get(f)) {
+            return Some(tied);
+        }
+    }
+    None
+}
+
 pub fn target_features(sess: &Session) -> Vec<Symbol> {
     let target_machine = create_informational_target_machine(sess);
     supported_target_features(sess)
@@ -395,15 +415,19 @@ pub fn llvm_global_features(sess: &Session) -> Vec<String> {
         Some(_) | None => {}
     };
 
+    fn strip(s: &str) -> &str {
+        s.strip_prefix(&['+', '-']).unwrap_or(s)
+    }
+
     let filter = |s: &str| {
         if s.is_empty() {
             return vec![];
         }
-        let feature = if s.starts_with('+') || s.starts_with('-') {
-            &s[1..]
-        } else {
+        let feature = strip(s);
+        if feature == s {
             return vec![s.to_string()];
-        };
+        }
+
         // Rustc-specific feature requests like `+crt-static` or `-crt-static`
         // are not passed down to LLVM.
         if RUSTC_SPECIFIC_FEATURES.contains(&feature) {
@@ -420,8 +444,17 @@ pub fn llvm_global_features(sess: &Session) -> Vec<String> {
     features.extend(sess.target.features.split(',').flat_map(&filter));
 
     // -Ctarget-features
-    features.extend(sess.opts.cg.target_feature.split(',').flat_map(&filter));
-
+    let feats: Vec<&str> = sess.opts.cg.target_feature.split(',').collect();
+    // LLVM enables based on the last occurence of a feature
+    if let Some(f) =
+        check_tied_features(sess, &feats.iter().map(|f| (strip(f), !f.starts_with("-"))).collect())
+    {
+        sess.err(&format!(
+            "Target features {} must all be enabled or disabled together",
+            f.join(", ")
+        ));
+    }
+    features.extend(feats.iter().flat_map(|&f| filter(f)));
     features
 }
 
diff --git a/compiler/rustc_codegen_ssa/src/target_features.rs b/compiler/rustc_codegen_ssa/src/target_features.rs
index 63cc6faf9ec..f31b0ee592e 100644
--- a/compiler/rustc_codegen_ssa/src/target_features.rs
+++ b/compiler/rustc_codegen_ssa/src/target_features.rs
@@ -74,8 +74,10 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
     ("ssbs", Some(sym::aarch64_target_feature)),
     // FEAT_SB
     ("sb", Some(sym::aarch64_target_feature)),
-    // FEAT_PAUTH
-    ("pauth", Some(sym::aarch64_target_feature)),
+    // FEAT_PAUTH (address authentication)
+    ("paca", Some(sym::aarch64_target_feature)),
+    // FEAT_PAUTH (generic authentication)
+    ("pacg", Some(sym::aarch64_target_feature)),
     // FEAT_DPB
     ("dpb", Some(sym::aarch64_target_feature)),
     // FEAT_DPB2
@@ -137,6 +139,8 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
     ("v8.7a", Some(sym::aarch64_target_feature)),
 ];
 
+const AARCH64_TIED_FEATURES: &[&[&str]] = &[&["paca", "pacg"]];
+
 const X86_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
     ("adx", Some(sym::adx_target_feature)),
     ("aes", None),
@@ -256,6 +260,13 @@ pub fn supported_target_features(sess: &Session) -> &'static [(&'static str, Opt
     }
 }
 
+pub fn tied_target_features(sess: &Session) -> &'static [&'static [&'static str]] {
+    match &*sess.target.arch {
+        "aarch64" => AARCH64_TIED_FEATURES,
+        _ => &[],
+    }
+}
+
 pub(crate) fn provide(providers: &mut Providers) {
     providers.supported_target_features = |tcx, cnum| {
         assert_eq!(cnum, LOCAL_CRATE);
diff --git a/compiler/rustc_hir/src/itemlikevisit.rs b/compiler/rustc_hir/src/itemlikevisit.rs
index 0db562f91a6..db70002c2d6 100644
--- a/compiler/rustc_hir/src/itemlikevisit.rs
+++ b/compiler/rustc_hir/src/itemlikevisit.rs
@@ -8,7 +8,7 @@ use super::{ForeignItem, ImplItem, Item, TraitItem};
 ///
 /// 1. **Shallow visit**: Get a simple callback for every item (or item-like thing) in the HIR.
 ///    - Example: find all items with a `#[foo]` attribute on them.
-///    - How: Implement `ItemLikeVisitor` and call `tcx.hir().krate().visit_all_item_likes()`.
+///    - How: Implement `ItemLikeVisitor` and call `tcx.hir().visit_all_item_likes()`.
 ///    - Pro: Efficient; just walks the lists of item-like things, not the nodes themselves.
 ///    - Con: Don't get information about nesting
 ///    - Con: Don't have methods for specific bits of HIR, like "on
@@ -19,9 +19,9 @@ use super::{ForeignItem, ImplItem, Item, TraitItem};
 ///    - Example: Examine each expression to look for its type and do some check or other.
 ///    - How: Implement `intravisit::Visitor` and override the `nested_visit_map()` method
 ///      to return `NestedVisitorMap::OnlyBodies` and use
-///      `tcx.hir().krate().visit_all_item_likes(&mut visitor.as_deep_visitor())`. Within
-///      your `intravisit::Visitor` impl, implement methods like `visit_expr()` (don't forget
-///      to invoke `intravisit::walk_expr()` to keep walking the subparts).
+///      `tcx.hir().visit_all_item_likes(&mut visitor.as_deep_visitor())`. Within your
+///      `intravisit::Visitor` impl, implement methods like `visit_expr()` (don't forget to invoke
+///      `intravisit::walk_expr()` to keep walking the subparts).
 ///    - Pro: Visitor methods for any kind of HIR node, not just item-like things.
 ///    - Pro: Integrates well into dependency tracking.
 ///    - Con: Don't get information about nesting between items
diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index f5a4e11de16..66e1e78b285 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -286,8 +286,7 @@ pub fn configure_and_expand(
     rustc_builtin_macros::register_builtin_macros(resolver);
 
     krate = sess.time("crate_injection", || {
-        let alt_std_name = sess.opts.alt_std_name.as_ref().map(|s| Symbol::intern(s));
-        rustc_builtin_macros::standard_library_imports::inject(krate, resolver, sess, alt_std_name)
+        rustc_builtin_macros::standard_library_imports::inject(krate, resolver, sess)
     });
 
     util::check_attr_crate_type(sess, &krate.attrs, &mut resolver.lint_buffer());
diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index 6d9183eda9d..f74cadfebac 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -118,7 +118,7 @@ fn get_stack_size() -> Option<usize> {
 /// Like a `thread::Builder::spawn` followed by a `join()`, but avoids the need
 /// for `'static` bounds.
 #[cfg(not(parallel_compiler))]
-pub fn scoped_thread<F: FnOnce() -> R + Send, R: Send>(cfg: thread::Builder, f: F) -> R {
+fn scoped_thread<F: FnOnce() -> R + Send, R: Send>(cfg: thread::Builder, f: F) -> R {
     // SAFETY: join() is called immediately, so any closure captures are still
     // alive.
     match unsafe { cfg.spawn_unchecked(f) }.unwrap().join() {
@@ -379,7 +379,7 @@ fn sysroot_candidates() -> Vec<PathBuf> {
     }
 }
 
-pub fn get_codegen_sysroot(maybe_sysroot: &Option<PathBuf>, backend_name: &str) -> MakeBackendFn {
+fn get_codegen_sysroot(maybe_sysroot: &Option<PathBuf>, backend_name: &str) -> MakeBackendFn {
     // For now we only allow this function to be called once as it'll dlopen a
     // few things, which seems to work best if we only do that once. In
     // general this assertion never trips due to the once guard in `get_codegen_backend`,
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index c7edcb077b9..1f657218a64 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -453,28 +453,28 @@ impl<'a> Resolver<'a> {
                 // edit:
                 // only do this if the const and usage of the non-constant value are on the same line
                 // the further the two are apart, the higher the chance of the suggestion being wrong
-                // also make sure that the pos for the suggestion is not 0 (ICE #90878)
 
-                let sp =
-                    self.session.source_map().span_extend_to_prev_str(ident.span, current, true);
-
-                let pos_for_suggestion = sp.lo().0.saturating_sub(current.len() as u32);
+                let sp = self
+                    .session
+                    .source_map()
+                    .span_extend_to_prev_str(ident.span, current, true, false);
 
-                if sp.lo().0 == 0
-                    || pos_for_suggestion == 0
-                    || self.session.source_map().is_multiline(sp)
-                {
-                    err.span_label(ident.span, &format!("this would need to be a `{}`", sugg));
-                } else {
-                    let sp = sp.with_lo(BytePos(pos_for_suggestion));
-                    err.span_suggestion(
-                        sp,
-                        &format!("consider using `{}` instead of `{}`", sugg, current),
-                        format!("{} {}", sugg, ident),
-                        Applicability::MaybeIncorrect,
-                    );
-                    err.span_label(span, "non-constant value");
+                match sp {
+                    Some(sp) if !self.session.source_map().is_multiline(sp) => {
+                        let sp = sp.with_lo(BytePos(sp.lo().0 - (current.len() as u32)));
+                        err.span_suggestion(
+                            sp,
+                            &format!("consider using `{}` instead of `{}`", sugg, current),
+                            format!("{} {}", sugg, ident),
+                            Applicability::MaybeIncorrect,
+                        );
+                        err.span_label(span, "non-constant value");
+                    }
+                    _ => {
+                        err.span_label(ident.span, &format!("this would need to be a `{}`", sugg));
+                    }
                 }
+
                 err
             }
             ResolutionError::BindingShadowsSomethingUnacceptable {
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 8630ffec241..79962d5db89 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -770,7 +770,6 @@ impl Default for Options {
             externs: Externs(BTreeMap::new()),
             extern_dep_specs: ExternDepSpecs(BTreeMap::new()),
             crate_name: None,
-            alt_std_name: None,
             libs: Vec::new(),
             unstable_features: UnstableFeatures::Disallow,
             debug_assertions: true,
@@ -2382,7 +2381,6 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
         unstable_features: UnstableFeatures::from_environment(crate_name.as_deref()),
         extern_dep_specs,
         crate_name,
-        alt_std_name: None,
         libs,
         debug_assertions,
         actually_rustdoc: false,
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 550da9e0580..ae1b638c344 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -184,10 +184,6 @@ top_level_options!(
         externs: Externs [UNTRACKED],
         extern_dep_specs: ExternDepSpecs [UNTRACKED],
         crate_name: Option<String> [TRACKED],
-        /// An optional name to use as the crate for std during std injection,
-        /// written `extern crate name as std`. Defaults to `std`. Used by
-        /// out-of-tree drivers.
-        alt_std_name: Option<String> [TRACKED],
         /// Indicates how the compiler should treat unstable features.
         unstable_features: UnstableFeatures [TRACKED],
 
diff --git a/compiler/rustc_span/src/source_map.rs b/compiler/rustc_span/src/source_map.rs
index 7414d201f51..95177102dcf 100644
--- a/compiler/rustc_span/src/source_map.rs
+++ b/compiler/rustc_span/src/source_map.rs
@@ -629,26 +629,41 @@ impl SourceMap {
     }
 
     /// Extends the given `Span` to just after the previous occurrence of `pat` when surrounded by
-    /// whitespace. Returns the same span if no character could be found or if an error occurred
-    /// while retrieving the code snippet.
-    pub fn span_extend_to_prev_str(&self, sp: Span, pat: &str, accept_newlines: bool) -> Span {
+    /// whitespace. Returns None if the pattern could not be found or if an error occurred while
+    /// retrieving the code snippet.
+    pub fn span_extend_to_prev_str(
+        &self,
+        sp: Span,
+        pat: &str,
+        accept_newlines: bool,
+        include_whitespace: bool,
+    ) -> Option<Span> {
         // assure that the pattern is delimited, to avoid the following
         //     fn my_fn()
         //           ^^^^ returned span without the check
         //     ---------- correct span
+        let prev_source = self.span_to_prev_source(sp).ok()?;
         for ws in &[" ", "\t", "\n"] {
             let pat = pat.to_owned() + ws;
-            if let Ok(prev_source) = self.span_to_prev_source(sp) {
-                let prev_source = prev_source.rsplit(&pat).next().unwrap_or("").trim_start();
-                if prev_source.is_empty() && sp.lo().0 != 0 {
-                    return sp.with_lo(BytePos(sp.lo().0 - 1));
-                } else if accept_newlines || !prev_source.contains('\n') {
-                    return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
+            if let Some(pat_pos) = prev_source.rfind(&pat) {
+                let just_after_pat_pos = pat_pos + pat.len() - 1;
+                let just_after_pat_plus_ws = if include_whitespace {
+                    just_after_pat_pos
+                        + prev_source[just_after_pat_pos..]
+                            .find(|c: char| !c.is_whitespace())
+                            .unwrap_or(0)
+                } else {
+                    just_after_pat_pos
+                };
+                let len = prev_source.len() - just_after_pat_plus_ws;
+                let prev_source = &prev_source[just_after_pat_plus_ws..];
+                if accept_newlines || !prev_source.trim_start().contains('\n') {
+                    return Some(sp.with_lo(BytePos(sp.lo().0 - len as u32)));
                 }
             }
         }
 
-        sp
+        None
     }
 
     /// Returns the source snippet as `String` after the given `Span`.
@@ -927,7 +942,7 @@ impl SourceMap {
     }
 
     pub fn generate_fn_name_span(&self, span: Span) -> Option<Span> {
-        let prev_span = self.span_extend_to_prev_str(span, "fn", true);
+        let prev_span = self.span_extend_to_prev_str(span, "fn", true, true).unwrap_or(span);
         if let Ok(snippet) = self.span_to_snippet(prev_span) {
             debug!(
                 "generate_fn_name_span: span={:?}, prev_span={:?}, snippet={:?}",
@@ -968,8 +983,7 @@ impl SourceMap {
     pub fn generate_local_type_param_snippet(&self, span: Span) -> Option<(Span, String)> {
         // Try to extend the span to the previous "fn" keyword to retrieve the function
         // signature.
-        let sugg_span = self.span_extend_to_prev_str(span, "fn", false);
-        if sugg_span != span {
+        if let Some(sugg_span) = self.span_extend_to_prev_str(span, "fn", false, true) {
             if let Ok(snippet) = self.span_to_snippet(sugg_span) {
                 // Consume the function name.
                 let mut offset = snippet
diff --git a/compiler/rustc_typeck/src/check/method/suggest.rs b/compiler/rustc_typeck/src/check/method/suggest.rs
index a17553b920f..8aa22852a6f 100644
--- a/compiler/rustc_typeck/src/check/method/suggest.rs
+++ b/compiler/rustc_typeck/src/check/method/suggest.rs
@@ -1819,7 +1819,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 [] => {}
                 [trait_info] => {
                     let msg = format!(
-                        "the trait `{}` defines an item `{}`, but is explicitely unimplemented",
+                        "the trait `{}` defines an item `{}`, but is explicitly unimplemented",
                         self.tcx.def_path_str(trait_info.def_id),
                         item_name
                     );
@@ -1827,7 +1827,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
                 trait_infos => {
                     let mut msg = format!(
-                        "the following traits define an item `{}`, but are explicitely unimplemented:",
+                        "the following traits define an item `{}`, but are explicitly unimplemented:",
                         item_name
                     );
                     for trait_info in trait_infos {