Merging upstream version 1.73.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

2 files changed, 103 insertions, 24 deletions

diff --git a/compiler/rustc_abi/src/layout.rs b/compiler/rustc_abi/src/layout.rs
index f6875d895..a8a1a9057 100644
--- a/compiler/rustc_abi/src/layout.rs
+++ b/compiler/rustc_abi/src/layout.rs
@@ -40,6 +40,8 @@ pub trait LayoutCalculator {
             largest_niche,
             align,
             size,
+            max_repr_align: None,
+            unadjusted_abi_align: align.abi,
         }
     }
 
@@ -122,6 +124,8 @@ pub trait LayoutCalculator {
             largest_niche: None,
             align: dl.i8_align,
             size: Size::ZERO,
+            max_repr_align: None,
+            unadjusted_abi_align: dl.i8_align.abi,
         }
     }
 
@@ -256,8 +260,7 @@ pub trait LayoutCalculator {
                 }
                 _ => assert!(
                     start == Bound::Unbounded && end == Bound::Unbounded,
-                    "nonscalar layout for layout_scalar_valid_range type: {:#?}",
-                    st,
+                    "nonscalar layout for layout_scalar_valid_range type: {st:#?}",
                 ),
             }
 
@@ -289,6 +292,9 @@ pub trait LayoutCalculator {
             }
 
             let mut align = dl.aggregate_align;
+            let mut max_repr_align = repr.align;
+            let mut unadjusted_abi_align = align.abi;
+
             let mut variant_layouts = variants
                 .iter_enumerated()
                 .map(|(j, v)| {
@@ -296,6 +302,8 @@ pub trait LayoutCalculator {
                     st.variants = Variants::Single { index: j };
 
                     align = align.max(st.align);
+                    max_repr_align = max_repr_align.max(st.max_repr_align);
+                    unadjusted_abi_align = unadjusted_abi_align.max(st.unadjusted_abi_align);
 
                     Some(st)
                 })
@@ -422,6 +430,8 @@ pub trait LayoutCalculator {
                 largest_niche,
                 size,
                 align,
+                max_repr_align,
+                unadjusted_abi_align,
             };
 
             Some(TmpLayout { layout, variants: variant_layouts })
@@ -452,10 +462,13 @@ pub trait LayoutCalculator {
             min = 0;
             max = 0;
         }
-        assert!(min <= max, "discriminant range is {}...{}", min, max);
+        assert!(min <= max, "discriminant range is {min}...{max}");
         let (min_ity, signed) = discr_range_of_repr(min, max); //Integer::repr_discr(tcx, ty, &repr, min, max);
 
         let mut align = dl.aggregate_align;
+        let mut max_repr_align = repr.align;
+        let mut unadjusted_abi_align = align.abi;
+
         let mut size = Size::ZERO;
 
         // We're interested in the smallest alignment, so start large.
@@ -498,6 +511,8 @@ pub trait LayoutCalculator {
                 }
                 size = cmp::max(size, st.size);
                 align = align.max(st.align);
+                max_repr_align = max_repr_align.max(st.max_repr_align);
+                unadjusted_abi_align = unadjusted_abi_align.max(st.unadjusted_abi_align);
                 Some(st)
             })
             .collect::<Option<IndexVec<VariantIdx, _>>>()?;
@@ -521,8 +536,7 @@ pub trait LayoutCalculator {
             // space necessary to represent would have to be discarded (or layout is wrong
             // on thinking it needs 16 bits)
             panic!(
-                "layout decided on a larger discriminant type ({:?}) than typeck ({:?})",
-                min_ity, typeck_ity
+                "layout decided on a larger discriminant type ({min_ity:?}) than typeck ({typeck_ity:?})"
             );
             // However, it is fine to make discr type however large (as an optimisation)
             // after this point – we’ll just truncate the value we load in codegen.
@@ -691,6 +705,8 @@ pub trait LayoutCalculator {
             abi,
             align,
             size,
+            max_repr_align,
+            unadjusted_abi_align,
         };
 
         let tagged_layout = TmpLayout { layout: tagged_layout, variants: layout_variants };
@@ -730,10 +746,7 @@ pub trait LayoutCalculator {
         let dl = self.current_data_layout();
         let dl = dl.borrow();
         let mut align = if repr.pack.is_some() { dl.i8_align } else { dl.aggregate_align };
-
-        if let Some(repr_align) = repr.align {
-            align = align.max(AbiAndPrefAlign::new(repr_align));
-        }
+        let mut max_repr_align = repr.align;
 
         // If all the non-ZST fields have the same ABI and union ABI optimizations aren't
         // disabled, we can use that common ABI for the union as a whole.
@@ -748,9 +761,12 @@ pub trait LayoutCalculator {
         let mut size = Size::ZERO;
         let only_variant = &variants[FIRST_VARIANT];
         for field in only_variant {
-            assert!(field.0.is_sized());
+            if field.0.is_unsized() {
+                self.delay_bug("unsized field in union".to_string());
+            }
 
             align = align.max(field.align());
+            max_repr_align = max_repr_align.max(field.max_repr_align());
             size = cmp::max(size, field.size());
 
             if field.0.is_zst() {
@@ -787,6 +803,14 @@ pub trait LayoutCalculator {
         if let Some(pack) = repr.pack {
             align = align.min(AbiAndPrefAlign::new(pack));
         }
+        // The unadjusted ABI alignment does not include repr(align), but does include repr(pack).
+        // See documentation on `LayoutS::unadjusted_abi_align`.
+        let unadjusted_abi_align = align.abi;
+        if let Some(repr_align) = repr.align {
+            align = align.max(AbiAndPrefAlign::new(repr_align));
+        }
+        // `align` must not be modified after this, or `unadjusted_abi_align` could be inaccurate.
+        let align = align;
 
         // If all non-ZST fields have the same ABI, we may forward that ABI
         // for the union as a whole, unless otherwise inhibited.
@@ -809,6 +833,8 @@ pub trait LayoutCalculator {
             largest_niche: None,
             align,
             size: size.align_to(align.abi),
+            max_repr_align,
+            unadjusted_abi_align,
         })
     }
 }
@@ -829,6 +855,7 @@ fn univariant(
 ) -> Option<LayoutS> {
     let pack = repr.pack;
     let mut align = if pack.is_some() { dl.i8_align } else { dl.aggregate_align };
+    let mut max_repr_align = repr.align;
     let mut inverse_memory_index: IndexVec<u32, FieldIdx> = fields.indices().collect();
     let optimize = !repr.inhibit_struct_field_reordering_opt();
     if optimize && fields.len() > 1 {
@@ -997,6 +1024,7 @@ fn univariant(
         };
         offset = offset.align_to(field_align.abi);
         align = align.max(field_align);
+        max_repr_align = max_repr_align.max(field.max_repr_align());
 
         debug!("univariant offset: {:?} field: {:#?}", offset, field);
         offsets[i] = offset;
@@ -1018,9 +1046,16 @@ fn univariant(
 
         offset = offset.checked_add(field.size(), dl)?;
     }
+
+    // The unadjusted ABI alignment does not include repr(align), but does include repr(pack).
+    // See documentation on `LayoutS::unadjusted_abi_align`.
+    let unadjusted_abi_align = align.abi;
     if let Some(repr_align) = repr.align {
         align = align.max(AbiAndPrefAlign::new(repr_align));
     }
+    // `align` must not be modified after this point, or `unadjusted_abi_align` could be inaccurate.
+    let align = align;
+
     debug!("univariant min_size: {:?}", offset);
     let min_size = offset;
     // As stated above, inverse_memory_index holds field indices by increasing offset.
@@ -1036,6 +1071,7 @@ fn univariant(
         inverse_memory_index.into_iter().map(FieldIdx::as_u32).collect()
     };
     let size = min_size.align_to(align.abi);
+    let mut layout_of_single_non_zst_field = None;
     let mut abi = Abi::Aggregate { sized };
     // Unpack newtype ABIs and find scalar pairs.
     if sized && size.bytes() > 0 {
@@ -1045,6 +1081,8 @@ fn univariant(
         match (non_zst_fields.next(), non_zst_fields.next(), non_zst_fields.next()) {
             // We have exactly one non-ZST field.
             (Some((i, field)), None, None) => {
+                layout_of_single_non_zst_field = Some(field);
+
                 // Field fills the struct and it has a scalar or scalar pair ABI.
                 if offsets[i].bytes() == 0 && align.abi == field.align().abi && size == field.size()
                 {
@@ -1102,6 +1140,19 @@ fn univariant(
     if fields.iter().any(|f| f.abi().is_uninhabited()) {
         abi = Abi::Uninhabited;
     }
+
+    let unadjusted_abi_align = if repr.transparent() {
+        match layout_of_single_non_zst_field {
+            Some(l) => l.unadjusted_abi_align(),
+            None => {
+                // `repr(transparent)` with all ZST fields.
+                align.abi
+            }
+        }
+    } else {
+        unadjusted_abi_align
+    };
+
     Some(LayoutS {
         variants: Variants::Single { index: FIRST_VARIANT },
         fields: FieldsShape::Arbitrary { offsets, memory_index },
@@ -1109,6 +1160,8 @@ fn univariant(
         largest_niche,
         align,
         size,
+        max_repr_align,
+        unadjusted_abi_align,
     })
 }
 
diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
index e1b9987f5..12dd1542d 100644
--- a/compiler/rustc_abi/src/lib.rs
+++ b/compiler/rustc_abi/src/lib.rs
@@ -1,4 +1,5 @@
 #![cfg_attr(feature = "nightly", feature(step_trait, rustc_attrs, min_specialization))]
+#![cfg_attr(all(not(bootstrap), feature = "nightly"), allow(internal_features))]
 
 use std::fmt;
 #[cfg(feature = "nightly")]
@@ -332,7 +333,7 @@ impl TargetDataLayout {
             16 => 1 << 15,
             32 => 1 << 31,
             64 => 1 << 47,
-            bits => panic!("obj_size_bound: unknown pointer bit size {}", bits),
+            bits => panic!("obj_size_bound: unknown pointer bit size {bits}"),
         }
     }
 
@@ -342,7 +343,7 @@ impl TargetDataLayout {
             16 => I16,
             32 => I32,
             64 => I64,
-            bits => panic!("ptr_sized_integer: unknown pointer bit size {}", bits),
+            bits => panic!("ptr_sized_integer: unknown pointer bit size {bits}"),
         }
     }
 
@@ -399,7 +400,7 @@ impl FromStr for Endian {
         match s {
             "little" => Ok(Self::Little),
             "big" => Ok(Self::Big),
-            _ => Err(format!(r#"unknown endian: "{}""#, s)),
+            _ => Err(format!(r#"unknown endian: "{s}""#)),
         }
     }
 }
@@ -456,7 +457,7 @@ impl Size {
     pub fn bits(self) -> u64 {
         #[cold]
         fn overflow(bytes: u64) -> ! {
-            panic!("Size::bits: {} bytes in bits doesn't fit in u64", bytes)
+            panic!("Size::bits: {bytes} bytes in bits doesn't fit in u64")
         }
 
         self.bytes().checked_mul(8).unwrap_or_else(|| overflow(self.bytes()))
@@ -1179,17 +1180,12 @@ impl FieldsShape {
                 unreachable!("FieldsShape::offset: `Primitive`s have no fields")
             }
             FieldsShape::Union(count) => {
-                assert!(
-                    i < count.get(),
-                    "tried to access field {} of union with {} fields",
-                    i,
-                    count
-                );
+                assert!(i < count.get(), "tried to access field {i} of union with {count} fields");
                 Size::ZERO
             }
             FieldsShape::Array { stride, count } => {
                 let i = u64::try_from(i).unwrap();
-                assert!(i < count);
+                assert!(i < count, "tried to access field {i} of array with {count} fields");
                 stride * i
             }
             FieldsShape::Arbitrary { ref offsets, .. } => offsets[FieldIdx::from_usize(i)],
@@ -1294,7 +1290,7 @@ impl Abi {
                 Primitive::Int(_, signed) => signed,
                 _ => false,
             },
-            _ => panic!("`is_signed` on non-scalar ABI {:?}", self),
+            _ => panic!("`is_signed` on non-scalar ABI {self:?}"),
         }
     }
 
@@ -1345,7 +1341,6 @@ impl Abi {
 
     /// Discard validity range information and allow undef.
     pub fn to_union(&self) -> Self {
-        assert!(self.is_sized());
         match *self {
             Abi::Scalar(s) => Abi::Scalar(s.to_union()),
             Abi::ScalarPair(s1, s2) => Abi::ScalarPair(s1.to_union(), s2.to_union()),
@@ -1531,6 +1526,16 @@ pub struct LayoutS {
 
     pub align: AbiAndPrefAlign,
     pub size: Size,
+
+    /// The largest alignment explicitly requested with `repr(align)` on this type or any field.
+    /// Only used on i686-windows, where the argument passing ABI is different when alignment is
+    /// requested, even if the requested alignment is equal to the natural alignment.
+    pub max_repr_align: Option<Align>,
+
+    /// The alignment the type would have, ignoring any `repr(align)` but including `repr(packed)`.
+    /// Only used on aarch64-linux, where the argument passing ABI ignores the requested alignment
+    /// in some cases.
+    pub unadjusted_abi_align: Align,
 }
 
 impl LayoutS {
@@ -1545,6 +1550,8 @@ impl LayoutS {
             largest_niche,
             size,
             align,
+            max_repr_align: None,
+            unadjusted_abi_align: align.abi,
         }
     }
 }
@@ -1554,7 +1561,16 @@ impl fmt::Debug for LayoutS {
         // This is how `Layout` used to print before it become
         // `Interned<LayoutS>`. We print it like this to avoid having to update
         // expected output in a lot of tests.
-        let LayoutS { size, align, abi, fields, largest_niche, variants } = self;
+        let LayoutS {
+            size,
+            align,
+            abi,
+            fields,
+            largest_niche,
+            variants,
+            max_repr_align,
+            unadjusted_abi_align,
+        } = self;
         f.debug_struct("Layout")
             .field("size", size)
             .field("align", align)
@@ -1562,6 +1578,8 @@ impl fmt::Debug for LayoutS {
             .field("fields", fields)
             .field("largest_niche", largest_niche)
             .field("variants", variants)
+            .field("max_repr_align", max_repr_align)
+            .field("unadjusted_abi_align", unadjusted_abi_align)
             .finish()
     }
 }
@@ -1602,6 +1620,14 @@ impl<'a> Layout<'a> {
         self.0.0.size
     }
 
+    pub fn max_repr_align(self) -> Option<Align> {
+        self.0.0.max_repr_align
+    }
+
+    pub fn unadjusted_abi_align(self) -> Align {
+        self.0.0.unadjusted_abi_align
+    }
+
     /// Whether the layout is from a type that implements [`std::marker::PointerLike`].
     ///
     /// Currently, that means that the type is pointer-sized, pointer-aligned,