Merge from rustc

Author: The Miri Cronjob Bot

compiler/rustc_ast/src/ast.rs

@@ -1633,6 +1633,9 @@ pub enum ExprKind {
     /// An `if` block, with an optional `else` block.
     ///
     /// `if expr { block } else { expr }`
+    ///
+    /// If present, the "else" expr is always `ExprKind::Block` (for `else`) or
+    /// `ExprKind::If` (for `else if`).
     If(P<Expr>, P<Block>, Option<P<Expr>>),
     /// A while loop, with an optional label.
     ///

compiler/rustc_ast_lowering/src/lib.rs

@@ -55,8 +55,8 @@ use rustc_errors::{DiagArgFromDisplay, DiagCtxtHandle, StashKey};
 use rustc_hir::def::{DefKind, LifetimeRes, Namespace, PartialRes, PerNS, Res};
 use rustc_hir::def_id::{CRATE_DEF_ID, LOCAL_CRATE, LocalDefId};
 use rustc_hir::{
-    self as hir, ConstArg, GenericArg, HirId, ItemLocalMap, LangItem, LifetimeSource,
-    LifetimeSyntax, ParamName, TraitCandidate,
+    self as hir, AngleBrackets, ConstArg, GenericArg, HirId, ItemLocalMap, LangItem,
+    LifetimeSource, LifetimeSyntax, ParamName, TraitCandidate,
 };
 use rustc_index::{Idx, IndexSlice, IndexVec};
 use rustc_macros::extension;
@@ -1087,7 +1087,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         match arg {
             ast::GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.lower_lifetime(
                 lt,
-                LifetimeSource::Path { with_angle_brackets: true },
+                LifetimeSource::Path { angle_brackets: hir::AngleBrackets::Full },
                 lt.ident.into(),
             )),
             ast::GenericArg::Type(ty) => {
@@ -1779,13 +1779,13 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         &mut self,
         id: NodeId,
         span: Span,
-        with_angle_brackets: bool,
+        angle_brackets: AngleBrackets,
     ) -> &'hir hir::Lifetime {
         self.new_named_lifetime(
             id,
             id,
             Ident::new(kw::UnderscoreLifetime, span),
-            LifetimeSource::Path { with_angle_brackets },
+            LifetimeSource::Path { angle_brackets },
             LifetimeSyntax::Hidden,
         )
     }

compiler/rustc_ast_lowering/src/path.rs

@@ -432,27 +432,31 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         // Note: these spans are used for diagnostics when they can't be inferred.
         // See rustc_resolve::late::lifetimes::LifetimeContext::add_missing_lifetime_specifiers_label
-        let (elided_lifetime_span, with_angle_brackets) = if generic_args.span.is_empty() {
-            // If there are no brackets, use the identifier span.
+        let (elided_lifetime_span, angle_brackets) = if generic_args.span.is_empty() {
+            // No brackets, e.g. `Path`: use an empty span just past the end of the identifier.
             // HACK: we use find_ancestor_inside to properly suggest elided spans in paths
             // originating from macros, since the segment's span might be from a macro arg.
-            (segment_ident_span.find_ancestor_inside(path_span).unwrap_or(path_span), false)
-        } else if generic_args.is_empty() {
-            // If there are brackets, but not generic arguments, then use the opening bracket
-            (generic_args.span.with_hi(generic_args.span.lo() + BytePos(1)), true)
+            (
+                segment_ident_span.find_ancestor_inside(path_span).unwrap_or(path_span),
+                hir::AngleBrackets::Missing,
+            )
         } else {
-            // Else use an empty span right after the opening bracket.
-            (generic_args.span.with_lo(generic_args.span.lo() + BytePos(1)).shrink_to_lo(), true)
+            // Brackets, e.g. `Path<>` or `Path<T>`: use an empty span just after the `<`.
+            (
+                generic_args.span.with_lo(generic_args.span.lo() + BytePos(1)).shrink_to_lo(),
+                if generic_args.is_empty() {
+                    hir::AngleBrackets::Empty
+                } else {
+                    hir::AngleBrackets::Full
+                },
+            )
         };
 
         generic_args.args.insert_many(
             0,
             (start..end).map(|id| {
-                let l = self.lower_lifetime_hidden_in_path(
-                    id,
-                    elided_lifetime_span,
-                    with_angle_brackets,
-                );
+                let l =
+                    self.lower_lifetime_hidden_in_path(id, elided_lifetime_span, angle_brackets);
                 GenericArg::Lifetime(l)
             }),
         );

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -240,6 +240,11 @@ pub fn print_crate<'a>(
     let mut s =
         State { s: pp::Printer::new(), comments: Some(Comments::new(sm, filename, input)), ann };
 
+    // We need to print shebang before anything else
+    // otherwise the resulting code will not compile
+    // and shebang will be useless.
+    s.maybe_print_shebang();
+
     if is_expanded && !krate.attrs.iter().any(|attr| attr.has_name(sym::no_core)) {
         // We need to print `#![no_std]` (and its feature gate) so that
         // compiling pretty-printed source won't inject libstd again.
@@ -560,6 +565,20 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
         self.word(st)
     }
 
+    fn maybe_print_shebang(&mut self) {
+        if let Some(cmnt) = self.peek_comment() {
+            // Comment is a shebang if it's:
+            // Isolated, starts with #! and doesn't continue with `[`
+            // See [rustc_lexer::strip_shebang] and [gather_comments] from pprust/state.rs for details
+            if cmnt.style == CommentStyle::Isolated
+                && cmnt.lines.first().map_or(false, |l| l.starts_with("#!"))
+            {
+                let cmnt = self.next_comment().unwrap();
+                self.print_comment(cmnt);
+            }
+        }
+    }
+
     fn print_inner_attributes(&mut self, attrs: &[ast::Attribute]) -> bool {
         self.print_either_attributes(attrs, ast::AttrStyle::Inner, false, true)
     }

compiler/rustc_borrowck/src/constraints/mod.rs

@@ -7,7 +7,7 @@ use rustc_middle::ty::{RegionVid, TyCtxt, VarianceDiagInfo};
 use rustc_span::Span;
 use tracing::{debug, instrument};
 
-use crate::region_infer::{ConstraintSccs, RegionDefinition, RegionTracker};
+use crate::region_infer::{AnnotatedSccs, ConstraintSccs, RegionDefinition, SccAnnotations};
 use crate::type_check::Locations;
 use crate::universal_regions::UniversalRegions;
 
@@ -61,12 +61,14 @@ impl<'tcx> OutlivesConstraintSet<'tcx> {
         &self,
         static_region: RegionVid,
         definitions: &IndexVec<RegionVid, RegionDefinition<'tcx>>,
-    ) -> ConstraintSccs {
+    ) -> AnnotatedSccs {
         let constraint_graph = self.graph(definitions.len());
         let region_graph = &constraint_graph.region_graph(self, static_region);
-        ConstraintSccs::new_with_annotation(&region_graph, |r| {
-            RegionTracker::new(r, &definitions[r])
-        })
+        let mut annotation_visitor = SccAnnotations::new(definitions);
+        (
+            ConstraintSccs::new_with_annotation(&region_graph, &mut annotation_visitor),
+            annotation_visitor.scc_to_annotation,
+        )
     }
 
     /// This method handles Universe errors by rewriting the constraint
@@ -79,12 +81,12 @@ impl<'tcx> OutlivesConstraintSet<'tcx> {
     /// eventually go away.
     ///
     /// For a more precise definition, see the documentation for
-    /// [`RegionTracker::has_incompatible_universes()`].
+    /// [`crate::region_infer::RegionTracker`].
     ///
     /// This edge case used to be handled during constraint propagation
     /// by iterating over the strongly connected components in the constraint
     /// graph while maintaining a set of bookkeeping mappings similar
-    /// to what is stored in `RegionTracker` and manually adding 'sttaic as
+    /// to what is stored in `RegionTracker` and manually adding 'static as
     /// needed.
     ///
     /// It was rewritten as part of the Polonius project with the goal of moving
@@ -108,9 +110,9 @@ impl<'tcx> OutlivesConstraintSet<'tcx> {
         &mut self,
         universal_regions: &UniversalRegions<'tcx>,
         definitions: &IndexVec<RegionVid, RegionDefinition<'tcx>>,
-    ) -> ConstraintSccs {
+    ) -> AnnotatedSccs {
         let fr_static = universal_regions.fr_static;
-        let sccs = self.compute_sccs(fr_static, definitions);
+        let (sccs, annotations) = self.compute_sccs(fr_static, definitions);
 
         // Changed to `true` if we added any constraints to `self` and need to
         // recompute SCCs.
@@ -124,7 +126,7 @@ impl<'tcx> OutlivesConstraintSet<'tcx> {
                 continue;
             }
 
-            let annotation = sccs.annotation(scc);
+            let annotation = annotations[scc];
 
             // If this SCC participates in a universe violation,
             // e.g. if it reaches a region with a universe smaller than
@@ -154,7 +156,7 @@ impl<'tcx> OutlivesConstraintSet<'tcx> {
             self.compute_sccs(fr_static, definitions)
         } else {
             // If we didn't add any back-edges; no more work needs doing
-            sccs
+            (sccs, annotations)
         }
     }
 }

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -47,12 +47,13 @@ mod reverse_sccs;
 
 pub(crate) mod values;
 
-pub(crate) type ConstraintSccs = Sccs<RegionVid, ConstraintSccIndex, RegionTracker>;
+pub(crate) type ConstraintSccs = Sccs<RegionVid, ConstraintSccIndex>;
+pub(crate) type AnnotatedSccs = (ConstraintSccs, IndexVec<ConstraintSccIndex, RegionTracker>);
 
 /// An annotation for region graph SCCs that tracks
-/// the values of its elements.
+/// the values of its elements. This annotates a single SCC.
 #[derive(Copy, Debug, Clone)]
-pub struct RegionTracker {
+pub(crate) struct RegionTracker {
     /// The largest universe of a placeholder reached from this SCC.
     /// This includes placeholders within this SCC.
     max_placeholder_universe_reached: UniverseIndex,
@@ -97,6 +98,32 @@ impl scc::Annotation for RegionTracker {
     }
 }
 
+/// A Visitor for SCC annotation construction.
+pub(crate) struct SccAnnotations<'d, 'tcx, A: scc::Annotation> {
+    pub(crate) scc_to_annotation: IndexVec<ConstraintSccIndex, A>,
+    definitions: &'d IndexVec<RegionVid, RegionDefinition<'tcx>>,
+}
+
+impl<'d, 'tcx, A: scc::Annotation> SccAnnotations<'d, 'tcx, A> {
+    pub(crate) fn new(definitions: &'d IndexVec<RegionVid, RegionDefinition<'tcx>>) -> Self {
+        Self { scc_to_annotation: IndexVec::new(), definitions }
+    }
+}
+
+impl scc::Annotations<RegionVid> for SccAnnotations<'_, '_, RegionTracker> {
+    fn new(&self, element: RegionVid) -> RegionTracker {
+        RegionTracker::new(element, &self.definitions[element])
+    }
+
+    fn annotate_scc(&mut self, scc: ConstraintSccIndex, annotation: RegionTracker) {
+        let idx = self.scc_to_annotation.push(annotation);
+        assert!(idx == scc);
+    }
+
+    type Ann = RegionTracker;
+    type SccIdx = ConstraintSccIndex;
+}
+
 impl RegionTracker {
     pub(crate) fn new(rvid: RegionVid, definition: &RegionDefinition<'_>) -> Self {
         let (representative_is_placeholder, representative_is_existential) = match definition.origin
@@ -166,6 +193,8 @@ pub struct RegionInferenceContext<'tcx> {
     /// compute the values of each region.
     constraint_sccs: ConstraintSccs,
 
+    scc_annotations: IndexVec<ConstraintSccIndex, RegionTracker>,
+
     /// Reverse of the SCC constraint graph --  i.e., an edge `A -> B` exists if
     /// `B: A`. This is used to compute the universal regions that are required
     /// to outlive a given SCC. Computed lazily.
@@ -446,7 +475,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
 
         let definitions = create_definitions(infcx, &universal_regions);
 
-        let constraint_sccs =
+        let (constraint_sccs, scc_annotations) =
             outlives_constraints.add_outlives_static(&universal_regions, &definitions);
         let constraints = Frozen::freeze(outlives_constraints);
         let constraint_graph = Frozen::freeze(constraints.graph(definitions.len()));
@@ -472,6 +501,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             constraints,
             constraint_graph,
             constraint_sccs,
+            scc_annotations,
             rev_scc_graph: None,
             member_constraints,
             member_constraints_applied: Vec::new(),
@@ -798,7 +828,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
 
         // If the member region lives in a higher universe, we currently choose
         // the most conservative option by leaving it unchanged.
-        if !self.constraint_sccs().annotation(scc).min_universe().is_root() {
+        if !self.scc_universe(scc).is_root() {
             return;
         }
 
@@ -874,8 +904,8 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// in `scc_a`. Used during constraint propagation, and only once
     /// the value of `scc_b` has been computed.
     fn universe_compatible(&self, scc_b: ConstraintSccIndex, scc_a: ConstraintSccIndex) -> bool {
-        let a_annotation = self.constraint_sccs().annotation(scc_a);
-        let b_annotation = self.constraint_sccs().annotation(scc_b);
+        let a_annotation = self.scc_annotations[scc_a];
+        let b_annotation = self.scc_annotations[scc_b];
         let a_universe = a_annotation.min_universe();
 
         // If scc_b's declared universe is a subset of
@@ -991,7 +1021,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             "lower_bound = {:?} r_scc={:?} universe={:?}",
             lower_bound,
             r_scc,
-            self.constraint_sccs.annotation(r_scc).min_universe()
+            self.scc_universe(r_scc)
         );
         // If the type test requires that `T: 'a` where `'a` is a
         // placeholder from another universe, that effectively requires
@@ -1472,7 +1502,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// The minimum universe of any variable reachable from this
     /// SCC, inside or outside of it.
     fn scc_universe(&self, scc: ConstraintSccIndex) -> UniverseIndex {
-        self.constraint_sccs().annotation(scc).min_universe()
+        self.scc_annotations[scc].min_universe()
     }
 
     /// Checks the final value for the free region `fr` to see if it
@@ -2216,7 +2246,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// they *must* be equal (though not having the same repr does not
     /// mean they are unequal).
     fn scc_representative(&self, scc: ConstraintSccIndex) -> RegionVid {
-        self.constraint_sccs.annotation(scc).representative
+        self.scc_annotations[scc].representative
     }
 
     pub(crate) fn liveness_constraints(&self) -> &LivenessValues {

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -273,6 +273,12 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
         ("aarch64", "fpmr") => None, // only existed in 18
         ("arm", "fp16") => Some(LLVMFeature::new("fullfp16")),
         // Filter out features that are not supported by the current LLVM version
+        ("loongarch64", "div32" | "lam-bh" | "lamcas" | "ld-seq-sa" | "scq")
+            if get_version().0 < 20 =>
+        {
+            None
+        }
+        // Filter out features that are not supported by the current LLVM version
         ("riscv32" | "riscv64", "zacas") if get_version().0 < 20 => None,
         // Enable the evex512 target feature if an avx512 target feature is enabled.
         ("x86", s) if s.starts_with("avx512") => {