Rollup of 6 pull requests

compiler/rustc_abi/src/layout/ty.rs

@@ -120,6 +120,7 @@ pub trait TyAbiInterface<'a, C>: Sized + std::fmt::Debug + std::fmt::Display {
     fn is_tuple(this: TyAndLayout<'a, Self>) -> bool;
     fn is_unit(this: TyAndLayout<'a, Self>) -> bool;
     fn is_transparent(this: TyAndLayout<'a, Self>) -> bool;
+    fn is_complex_number(this: TyAndLayout<'a, Self>, cx: &C) -> bool;
     fn is_scalable_vector(this: TyAndLayout<'a, Self>) -> bool;
     /// See [`TyAndLayout::pass_indirectly_in_non_rustic_abis`] for details.
     fn is_pass_indirectly_in_non_rustic_abis_flag_set(this: TyAndLayout<'a, Self>) -> bool;
@@ -227,6 +228,13 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
         Ty::is_transparent(self)
     }
 
+    pub fn is_complex_number<C>(self, cx: &C) -> bool
+    where
+        Ty: TyAbiInterface<'a, C> + Copy,
+    {
+        Ty::is_complex_number(self.peel_transparent_wrappers(cx), cx)
+    }
+
     pub fn is_scalable_vector<C>(self) -> bool
     where
         Ty: TyAbiInterface<'a, C>,
@@ -291,6 +299,26 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
         found
     }
 
+    pub fn complex_float<C>(&self, cx: &C) -> Option<Float>
+    where
+        Ty: TyAbiInterface<'a, C> + Copy,
+    {
+        if !Ty::is_complex_number(*self, cx) {
+            return None;
+        }
+
+        let BackendRepr::ScalarPair { a, b, .. } = self.backend_repr else {
+            return None;
+        };
+
+        debug_assert_eq!(a, b);
+
+        match a.primitive() {
+            Primitive::Float(f) => Some(f),
+            _ => None,
+        }
+    }
+
     /// Whether this type/layout has any padding that is dependent on a variant, i.e. has bytes that
     /// are padding for some, but not all, valid values of this type.
     pub fn has_variant_dependent_padding<C>(&self, cx: &C) -> bool

compiler/rustc_attr_ir/src/lang_items.rs

@@ -232,6 +232,8 @@ language_item_table! {
     VaArgSafe,               sym::va_arg_safe,         va_arg_safe,                Target::Trait,          GenericRequirement::None;
     VaList,                  sym::va_list,             va_list,                    Target::Struct,         GenericRequirement::None;
 
+    Complex,                 sym::complex,             complex,                    Target::Struct,         GenericRequirement::Exact(1);
+
     Deref,                   sym::deref,               deref_trait,                Target::Trait,          GenericRequirement::Exact(0);
     DerefMut,                sym::deref_mut,           deref_mut_trait,            Target::Trait,          GenericRequirement::Exact(0);
     DerefPure,               sym::deref_pure,          deref_pure_trait,           Target::Trait,          GenericRequirement::Exact(0);

compiler/rustc_attr_parsing/src/attributes/rustc_internal.rs

@@ -1132,7 +1132,7 @@ pub(crate) struct RustcDocPrimitiveParser;
 
 impl SingleAttributeParser for RustcDocPrimitiveParser {
     const PATH: &[Symbol] = &[sym::rustc_doc_primitive];
-    const ALLOWED_TARGETS: AllowedTargets<'_> = AllowedTargets::AllowList(&[Allow(Target::Mod)]);
+    const ALLOWED_TARGETS: AllowedTargets<'_> = AllowedTargets::AllowList(&[Allow(Target::Const)]);
     const TEMPLATE: AttributeTemplate = template!(NameValueStr: "primitive name");
     const STABILITY: AttributeStability = unstable!(
         rustc_attrs,

compiler/rustc_codegen_llvm/src/asm.rs

@@ -1,7 +1,7 @@
 use std::assert_matches;
 use std::fmt::Write;
 
-use rustc_abi::{BackendRepr, Float, Integer, Primitive, Scalar, Size};
+use rustc_abi::{BackendRepr, Endian, Float, Integer, Primitive, Scalar, Size};
 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_codegen_ssa::mir::operand::OperandValue;
 use rustc_codegen_ssa::traits::*;
@@ -12,6 +12,7 @@ use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::{bug, span_bug};
 use rustc_span::{Pos, Span, Symbol, sym};
 use rustc_target::asm::*;
+use rustc_target::spec::HasTargetSpec;
 use smallvec::SmallVec;
 use tracing::debug;
 
@@ -1244,24 +1245,16 @@ fn llvm_fixup_input<'ll, 'tcx>(
         (
             PowerPC(PowerPCInlineAsmRegClass::vreg | PowerPCInlineAsmRegClass::vsreg),
             BackendRepr::Scalar(s),
-        ) if s.primitive() == Primitive::Float(Float::F32) => {
-            let value = bx.insert_element(
-                bx.const_undef(bx.type_vector(bx.type_f32(), 4)),
+        ) if let Primitive::Float(float @ (Float::F32 | Float::F64)) = s.primitive() => {
+            let num_lanes = 16 / float.size().bytes();
+            bx.insert_element(
+                bx.const_undef(bx.type_vector(bx.type_from_float(float), num_lanes)),
                 value,
-                bx.const_usize(0),
-            );
-            bx.bitcast(value, bx.type_vector(bx.type_f32(), 4))
-        }
-        (
-            PowerPC(PowerPCInlineAsmRegClass::vreg | PowerPCInlineAsmRegClass::vsreg),
-            BackendRepr::Scalar(s),
-        ) if s.primitive() == Primitive::Float(Float::F64) => {
-            let value = bx.insert_element(
-                bx.const_undef(bx.type_vector(bx.type_f64(), 2)),
-                value,
-                bx.const_usize(0),
-            );
-            bx.bitcast(value, bx.type_vector(bx.type_f64(), 2))
+                bx.const_usize(match bx.target_spec().endian {
+                    Endian::Little => num_lanes - 1,
+                    Endian::Big => 0,
+                }),
+            )
         }
         _ => value,
     }
@@ -1416,16 +1409,15 @@ fn llvm_fixup_output<'ll, 'tcx>(
         (
             PowerPC(PowerPCInlineAsmRegClass::vreg | PowerPCInlineAsmRegClass::vsreg),
             BackendRepr::Scalar(s),
-        ) if s.primitive() == Primitive::Float(Float::F32) => {
-            let value = bx.bitcast(value, bx.type_vector(bx.type_f32(), 4));
-            bx.extract_element(value, bx.const_usize(0))
-        }
-        (
-            PowerPC(PowerPCInlineAsmRegClass::vreg | PowerPCInlineAsmRegClass::vsreg),
-            BackendRepr::Scalar(s),
-        ) if s.primitive() == Primitive::Float(Float::F64) => {
-            let value = bx.bitcast(value, bx.type_vector(bx.type_f64(), 2));
-            bx.extract_element(value, bx.const_usize(0))
+        ) if let Primitive::Float(float @ (Float::F32 | Float::F64)) = s.primitive() => {
+            let num_lanes = 16 / float.size().bytes();
+            bx.extract_element(
+                value,
+                bx.const_usize(match bx.target_spec().endian {
+                    Endian::Little => num_lanes - 1,
+                    Endian::Big => 0,
+                }),
+            )
         }
         _ => value,
     }
@@ -1566,11 +1558,9 @@ fn llvm_fixup_output_type<'ll, 'tcx>(
         (
             PowerPC(PowerPCInlineAsmRegClass::vreg | PowerPCInlineAsmRegClass::vsreg),
             BackendRepr::Scalar(s),
-        ) if s.primitive() == Primitive::Float(Float::F32) => cx.type_vector(cx.type_f32(), 4),
-        (
-            PowerPC(PowerPCInlineAsmRegClass::vreg | PowerPCInlineAsmRegClass::vsreg),
-            BackendRepr::Scalar(s),
-        ) if s.primitive() == Primitive::Float(Float::F64) => cx.type_vector(cx.type_f64(), 2),
+        ) if let Primitive::Float(float @ (Float::F32 | Float::F64)) = s.primitive() => {
+            cx.type_vector(cx.type_from_float(float), 16 / float.size().bytes())
+        }
         _ => layout.llvm_type(cx),
     }
 }

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -374,7 +374,8 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) {
     cfg.has_reliable_f16 = match (target_arch, target_os) {
         // Unsupported <https://github.com/llvm/llvm-project/issues/94434> (fixed in llvm22)
         (Arch::Arm64EC, _) if major < 22 => false,
-        // MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054>
+        // MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054> resolved in GCC 16
+        // but our toolchain hasn't been updated.
         (Arch::X86_64, Os::Windows) if *target_env == Env::Gnu && *target_abi != CfgAbi::Llvm => {
             false
         }
@@ -401,8 +402,10 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) {
         (Arch::PowerPC | Arch::PowerPC64, _) => false,
         // ABI unsupported  <https://github.com/llvm/llvm-project/issues/41838> (fixed in llvm22)
         (Arch::Sparc, _) if major < 22 => false,
-        // MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054>
-        (Arch::X86_64, Os::Windows) if *target_env == Env::Gnu && *target_abi != CfgAbi::Llvm => {
+        // MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054> (fixed in llvm23)
+        (Arch::X86_64, Os::Windows)
+            if *target_env == Env::Gnu && *target_abi != CfgAbi::Llvm && major < 23 =>
+        {
             false
         }
         // There are no known problems on other platforms, so the only requirement is that symbols

compiler/rustc_hir_typeck/src/diagnostics.rs

@@ -819,10 +819,13 @@ pub(crate) struct OutsideLoop<'a> {
     applicability = "maybe-incorrect"
 )]
 pub(crate) struct OutsideLoopSuggestion {
-    #[suggestion_part(code = "'block: ")]
+    #[suggestion_part(code = "{block_prefix}")]
     pub block_span: Span,
     #[suggestion_part(code = " 'block")]
     pub break_spans: Vec<Span>,
+    #[suggestion_part(code = " }}")]
+    pub wrap_end: Option<Span>,
+    pub block_prefix: &'static str,
 }
 
 #[derive(Diagnostic)]

compiler/rustc_hir_typeck/src/loops.rs

@@ -31,7 +31,10 @@ enum Context {
         kind: hir::CoroutineDesugaring,
         source: hir::CoroutineSource,
     },
-    UnlabeledBlock(Span),
+    UnlabeledBlock {
+        label_span: Span,
+        wrap_end: Option<Span>,
+    },
     UnlabeledIfBlock(Span),
     LabeledBlock,
     /// E.g. The labeled block inside `['_'; 'block: { break 'block 1 + 2; }]`.
@@ -50,6 +53,7 @@ struct BlockInfo {
     name: String,
     spans: Vec<Span>,
     suggs: Vec<Span>,
+    wrap_end: Option<Span>,
 }
 
 #[derive(PartialEq)]
@@ -118,7 +122,7 @@ impl<'hir> Visitor<'hir> for CheckLoopVisitor<'hir> {
                             ck_loop.cx_stack.last(),
                             Some(&Normal)
                                 | Some(&AnonConst)
-                                | Some(&UnlabeledBlock(_))
+                                | Some(&UnlabeledBlock { .. })
                                 | Some(&UnlabeledIfBlock(_))
                         )
                     {
@@ -177,10 +181,16 @@ impl<'hir> Visitor<'hir> for CheckLoopVisitor<'hir> {
                 None,
             ) if matches!(
                 self.cx_stack.last(),
-                Some(&Normal) | Some(&AnonConst) | Some(&UnlabeledBlock(_))
+                Some(&Normal) | Some(&AnonConst) | Some(&UnlabeledBlock { .. })
             ) =>
             {
-                self.with_context(UnlabeledBlock(b.span.shrink_to_lo()), |v| v.visit_block(b));
+                // An unlabeled block targeted by `break` may comes from a `try` block.
+                // Since `try 'block: {}` is invalid, nest a labeled block inside its body.
+                let wrap_end = b.targeted_by_break.then(|| b.span.shrink_to_hi());
+                self.with_context(
+                    UnlabeledBlock { label_span: b.span.shrink_to_lo(), wrap_end },
+                    |v| v.visit_block(b),
+                );
             }
             hir::ExprKind::Break(break_destination, ref opt_expr) => {
                 if let Some(e) = opt_expr {
@@ -365,21 +375,22 @@ impl<'hir> CheckLoopVisitor<'hir> {
                     source,
                 });
             }
-            UnlabeledBlock(block_span)
-                if br_cx_kind == BreakContextKind::Break && block_span.eq_ctxt(break_span) =>
+            UnlabeledBlock { label_span, wrap_end }
+                if br_cx_kind == BreakContextKind::Break && label_span.eq_ctxt(break_span) =>
             {
-                let block = self.block_breaks.entry(block_span).or_insert_with(|| BlockInfo {
+                let block = self.block_breaks.entry(label_span).or_insert_with(|| BlockInfo {
                     name: br_cx_kind.to_string(),
                     spans: vec![],
                     suggs: vec![],
+                    wrap_end,
                 });
                 block.spans.push(span);
                 block.suggs.push(break_span);
             }
             UnlabeledIfBlock(_) if br_cx_kind == BreakContextKind::Break => {
                 self.require_break_cx(br_cx_kind, span, break_span, cx_pos - 1);
             }
-            Normal | AnonConst | Fn | UnlabeledBlock(_) | UnlabeledIfBlock(_) | ConstBlock => {
+            Normal | AnonConst | Fn | UnlabeledBlock { .. } | UnlabeledIfBlock(_) | ConstBlock => {
                 self.tcx.dcx().emit_err(OutsideLoop {
                     spans: vec![span],
                     name: &br_cx_kind.to_string(),
@@ -415,6 +426,8 @@ impl<'hir> CheckLoopVisitor<'hir> {
                 suggestion: Some(OutsideLoopSuggestion {
                     block_span: *s,
                     break_spans: block.suggs.clone(),
+                    block_prefix: if block.wrap_end.is_some() { "{ 'block: " } else { "'block: " },
+                    wrap_end: block.wrap_end,
                 }),
             });
         }

compiler/rustc_middle/src/ty/layout.rs

@@ -1213,6 +1213,20 @@ where
         matches!(this.ty.kind(), ty::Adt(def, _) if def.repr().transparent())
     }
 
+    /// Does this type have a layout compatible with C `_Complex`?
+    ///
+    /// The value must be of type `core::num::Complex<T>` where `T` is numeric.
+    fn is_complex_number(this: TyAndLayout<'tcx>, cx: &C) -> bool {
+        let ty::Adt(def, generic_args) = this.ty.kind() else { return false };
+
+        if !cx.tcx().is_lang_item(def.did(), LangItem::Complex) {
+            return false;
+        }
+
+        // Only Complex<{ float }> and Complex<{ integer }> have special layout.
+        generic_args.type_at(0).is_numeric()
+    }
+
     fn is_scalable_vector(this: TyAndLayout<'tcx>) -> bool {
         this.ty.is_scalable_vector()
     }

compiler/rustc_passes/src/check_attr.rs

@@ -44,7 +44,7 @@ use rustc_session::lint::builtin::{
     MALFORMED_DIAGNOSTIC_FORMAT_LITERALS, MISPLACED_DIAGNOSTIC_ATTRIBUTES, UNUSED_ATTRIBUTES,
 };
 use rustc_span::edition::Edition;
-use rustc_span::{DUMMY_SP, Ident, Span, Symbol, sym};
+use rustc_span::{DUMMY_SP, Ident, Span, Symbol, kw, sym};
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::infer::{TyCtxtInferExt, ValuePairs};
 use rustc_trait_selection::traits::{ObligationCtxt, TraitErrors};
@@ -1024,18 +1024,11 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
             hir::Node::Item(item) => Some(&item.kind),
             _ => None,
         };
-        match item_kind {
-            Some(ItemKind::Mod(_, module)) => {
-                if !module.item_ids.is_empty() {
-                    self.dcx()
-                        .emit_err(diagnostics::DocKeywordAttributeEmptyMod { span, attr_name });
-                    return;
-                }
-            }
-            _ => {
-                self.dcx().emit_err(diagnostics::DocKeywordAttributeNotMod { span, attr_name });
-                return;
-            }
+        if let Some(ItemKind::Const(ident, _gen, _ty, _rhs)) = item_kind
+            && ident.name == kw::Underscore
+        {
+        } else {
+            self.dcx().emit_err(diagnostics::DocKeywordAttributeNotAnonConst { span, attr_name });
         }
     }
 

compiler/rustc_passes/src/diagnostics.rs

@@ -73,16 +73,8 @@ pub(crate) struct DocAliasNotAnAlias {
 }
 
 #[derive(Diagnostic)]
-#[diag("`#[doc({$attr_name} = \"...\")]` should be used on empty modules")]
-pub(crate) struct DocKeywordAttributeEmptyMod {
-    #[primary_span]
-    pub span: Span,
-    pub attr_name: &'static str,
-}
-
-#[derive(Diagnostic)]
-#[diag("`#[doc({$attr_name} = \"...\")]` should be used on modules")]
-pub(crate) struct DocKeywordAttributeNotMod {
+#[diag("`#[doc({$attr_name} = \"...\")]` should be used on anonymous constants")]
+pub(crate) struct DocKeywordAttributeNotAnonConst {
     #[primary_span]
     pub span: Span,
     pub attr_name: &'static str,

compiler/rustc_span/src/symbol.rs

@@ -654,6 +654,7 @@ symbols! {
         compiler_copy,
         compiler_fence,
         compiler_move,
+        complex,
         concat,
         concat_bytes,
         conservative_impl_trait,

compiler/rustc_target/src/callconv/x86.rs

@@ -1,5 +1,5 @@
 use rustc_abi::{
-    AddressSpace, Align, BackendRepr, HasDataLayout, Primitive, Reg, RegKind, TyAndLayout,
+    AddressSpace, Align, BackendRepr, Float, HasDataLayout, Primitive, Reg, RegKind, TyAndLayout,
 };
 
 use crate::callconv::{ArgAttribute, FnAbi, PassMode, TyAbiInterface};
@@ -32,7 +32,14 @@ where
             // https://www.angelcode.com/dev/callconv/callconv.html
             // Clang's ABI handling is in lib/CodeGen/TargetInfo.cpp
             let t = cx.target_spec();
-            if t.abi_return_struct_as_int || opts.reg_struct_return {
+            if let Some(Float::F16) = fn_abi.ret.layout.complex_float(cx) {
+                // `_Complex _Float16` is returned as `<2 x half>`.
+                let kind = RegKind::Vector { hint_vector_elem: Primitive::Float(Float::F16) };
+                fn_abi.ret.cast_to(Reg { kind, size: fn_abi.ret.layout.size });
+            } else if t.abi_return_struct_as_int
+                || opts.reg_struct_return
+                || fn_abi.ret.layout.is_complex_number(cx)
+            {
                 // According to Clang, everyone but MSVC returns single-element
                 // float aggregates directly in a floating-point register.
                 if fn_abi.ret.layout.is_single_fp_element(cx) {