Rollup of 10 pull requests

compiler/rustc_lint_defs/src/builtin.rs

@@ -3132,6 +3132,60 @@ declare_lint! {
     "detects unexpected names and values in `#[cfg]` conditions",
 }
 
+declare_lint! {
+    /// The `repr_transparent_external_private_fields` lint
+    /// detects types marked `#[repr(transparent)]` that (transitively)
+    /// contain an external ZST type marked `#[non_exhaustive]` or containing
+    /// private fields
+    ///
+    /// ### Example
+    ///
+    /// ```rust,ignore (needs external crate)
+    /// #![deny(repr_transparent_external_private_fields)]
+    /// use foo::NonExhaustiveZst;
+    ///
+    /// #[repr(transparent)]
+    /// struct Bar(u32, ([u32; 0], NonExhaustiveZst));
+    /// ```
+    ///
+    /// This will produce:
+    ///
+    /// ```text
+    /// error: zero-sized fields in repr(transparent) cannot contain external non-exhaustive types
+    ///  --> src/main.rs:5:28
+    ///   |
+    /// 5 | struct Bar(u32, ([u32; 0], NonExhaustiveZst));
+    ///   |                            ^^^^^^^^^^^^^^^^
+    ///   |
+    /// note: the lint level is defined here
+    ///  --> src/main.rs:1:9
+    ///   |
+    /// 1 | #![deny(repr_transparent_external_private_fields)]
+    ///   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+    ///   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+    ///   = note: for more information, see issue #78586 <https://github.com/rust-lang/rust/issues/78586>
+    ///   = note: this struct contains `NonExhaustiveZst`, which is marked with `#[non_exhaustive]`, and makes it not a breaking change to become non-zero-sized in the future.
+    /// ```
+    ///
+    /// ### Explanation
+    ///
+    /// Previous, Rust accepted fields that contain external private zero-sized types,
+    /// even though it should not be a breaking change to add a non-zero-sized field to
+    /// that private type.
+    ///
+    /// This is a [future-incompatible] lint to transition this
+    /// to a hard error in the future. See [issue #78586] for more details.
+    ///
+    /// [issue #78586]: https://github.com/rust-lang/rust/issues/78586
+    /// [future-incompatible]: ../index.md#future-incompatible-lints
+    pub REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS,
+    Warn,
+    "tranparent type contains an external ZST that is marked #[non_exhaustive] or contains private fields",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #78586 <https://github.com/rust-lang/rust/issues/78586>",
+    };
+}
+
 declare_lint_pass! {
     /// Does nothing as a lint pass, but registers some `Lint`s
     /// that are used by other parts of the compiler.
@@ -3237,6 +3291,7 @@ declare_lint_pass! {
         DEPRECATED_WHERE_CLAUSE_LOCATION,
         TEST_UNSTABLE_LINT,
         FFI_UNWIND_CALLS,
+        REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS,
     ]
 }
 

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -411,8 +411,14 @@ LLVMRustInlineAsm(LLVMTypeRef Ty, char *AsmString, size_t AsmStringLen,
 
 extern "C" bool LLVMRustInlineAsmVerify(LLVMTypeRef Ty, char *Constraints,
                                         size_t ConstraintsLen) {
+#if LLVM_VERSION_LT(15, 0)
   return InlineAsm::Verify(unwrap<FunctionType>(Ty),
                            StringRef(Constraints, ConstraintsLen));
+#else
+  // llvm::Error converts to true if it is an error.
+  return !llvm::errorToBool(InlineAsm::verify(
+      unwrap<FunctionType>(Ty), StringRef(Constraints, ConstraintsLen)));
+#endif
 }
 
 extern "C" void LLVMRustAppendModuleInlineAsm(LLVMModuleRef M, const char *Asm,

compiler/rustc_typeck/src/check/check.rs

@@ -17,6 +17,7 @@ use rustc_infer::infer::outlives::env::OutlivesEnvironment;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::{RegionVariableOrigin, TyCtxtInferExt};
 use rustc_infer::traits::Obligation;
+use rustc_lint::builtin::REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::layout::{LayoutError, MAX_SIMD_LANES};
 use rustc_middle::ty::subst::GenericArgKind;
@@ -1318,7 +1319,8 @@ pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, adt: ty::AdtD
         }
     }
 
-    // For each field, figure out if it's known to be a ZST and align(1)
+    // For each field, figure out if it's known to be a ZST and align(1), with "known"
+    // respecting #[non_exhaustive] attributes.
     let field_infos = adt.all_fields().map(|field| {
         let ty = field.ty(tcx, InternalSubsts::identity_for_item(tcx, field.did));
         let param_env = tcx.param_env(field.did);
@@ -1327,16 +1329,56 @@ pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, adt: ty::AdtD
         let span = tcx.hir().span_if_local(field.did).unwrap();
         let zst = layout.map_or(false, |layout| layout.is_zst());
         let align1 = layout.map_or(false, |layout| layout.align.abi.bytes() == 1);
-        (span, zst, align1)
+        if !zst {
+            return (span, zst, align1, None);
+        }
+
+        fn check_non_exhaustive<'tcx>(
+            tcx: TyCtxt<'tcx>,
+            t: Ty<'tcx>,
+        ) -> ControlFlow<(&'static str, DefId, SubstsRef<'tcx>, bool)> {
+            match t.kind() {
+                ty::Tuple(list) => list.iter().try_for_each(|t| check_non_exhaustive(tcx, t)),
+                ty::Array(ty, _) => check_non_exhaustive(tcx, *ty),
+                ty::Adt(def, subst) => {
+                    if !def.did().is_local() {
+                        let non_exhaustive = def.is_variant_list_non_exhaustive()
+                            || def
+                                .variants()
+                                .iter()
+                                .any(ty::VariantDef::is_field_list_non_exhaustive);
+                        let has_priv = def.all_fields().any(|f| !f.vis.is_public());
+                        if non_exhaustive || has_priv {
+                            return ControlFlow::Break((
+                                def.descr(),
+                                def.did(),
+                                subst,
+                                non_exhaustive,
+                            ));
+                        }
+                    }
+                    def.all_fields()
+                        .map(|field| field.ty(tcx, subst))
+                        .try_for_each(|t| check_non_exhaustive(tcx, t))
+                }
+                _ => ControlFlow::Continue(()),
+            }
+        }
+
+        (span, zst, align1, check_non_exhaustive(tcx, ty).break_value())
     });
 
-    let non_zst_fields =
-        field_infos.clone().filter_map(|(span, zst, _align1)| if !zst { Some(span) } else { None });
+    let non_zst_fields = field_infos
+        .clone()
+        .filter_map(|(span, zst, _align1, _non_exhaustive)| if !zst { Some(span) } else { None });
     let non_zst_count = non_zst_fields.clone().count();
     if non_zst_count >= 2 {
         bad_non_zero_sized_fields(tcx, adt, non_zst_count, non_zst_fields, sp);
     }
-    for (span, zst, align1) in field_infos {
+    let incompatible_zst_fields =
+        field_infos.clone().filter(|(_, _, _, opt)| opt.is_some()).count();
+    let incompat = incompatible_zst_fields + non_zst_count >= 2 && non_zst_count < 2;
+    for (span, zst, align1, non_exhaustive) in field_infos {
         if zst && !align1 {
             struct_span_err!(
                 tcx.sess,
@@ -1348,6 +1390,25 @@ pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, adt: ty::AdtD
             .span_label(span, "has alignment larger than 1")
             .emit();
         }
+        if incompat && let Some((descr, def_id, substs, non_exhaustive)) = non_exhaustive {
+            tcx.struct_span_lint_hir(
+                REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS,
+                tcx.hir().local_def_id_to_hir_id(adt.did().expect_local()),
+                span,
+                |lint| {
+                    let note = if non_exhaustive {
+                        "is marked with `#[non_exhaustive]`"
+                    } else {
+                        "contains private fields"
+                    };
+                    let field_ty = tcx.def_path_str_with_substs(def_id, substs);
+                    lint.build("zero-sized fields in repr(transparent) cannot contain external non-exhaustive types")
+                        .note(format!("this {descr} contains `{field_ty}`, which {note}, \
+                            and makes it not a breaking change to become non-zero-sized in the future."))
+                        .emit();
+                },
+            )
+        }
     }
 }
 

library/core/src/num/int_macros.rs

@@ -2,9 +2,10 @@ macro_rules! int_impl {
     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $BITS_MINUS_ONE:expr, $Min:expr, $Max:expr,
      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
-     $to_xe_bytes_doc:expr, $from_xe_bytes_doc:expr) => {
-        /// The smallest value that can be represented by this integer type,
-        #[doc = concat!("&minus;2<sup>", $BITS_MINUS_ONE, "</sup>.")]
+     $to_xe_bytes_doc:expr, $from_xe_bytes_doc:expr,
+     $bound_condition:expr) => {
+        /// The smallest value that can be represented by this integer type
+        #[doc = concat!("(&minus;2<sup>", $BITS_MINUS_ONE, "</sup>", $bound_condition, ")")]
         ///
         /// # Examples
         ///
@@ -16,8 +17,8 @@ macro_rules! int_impl {
         #[stable(feature = "assoc_int_consts", since = "1.43.0")]
         pub const MIN: Self = !0 ^ ((!0 as $UnsignedT) >> 1) as Self;
 
-        /// The largest value that can be represented by this integer type,
-        #[doc = concat!("2<sup>", $BITS_MINUS_ONE, "</sup> &minus; 1.")]
+        /// The largest value that can be represented by this integer type
+        #[doc = concat!("(2<sup>", $BITS_MINUS_ONE, "</sup> &minus; 1", $bound_condition, ")")]
         ///
         /// # Examples
         ///

library/core/src/num/mod.rs

@@ -196,25 +196,25 @@ macro_rules! widening_impl {
 
 impl i8 {
     int_impl! { i8, i8, u8, 8, 7, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
-    "[0x12]", "[0x12]", "", "" }
+    "[0x12]", "[0x12]", "", "", "" }
 }
 
 impl i16 {
     int_impl! { i16, i16, u16, 16, 15, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
-    "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
+    "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "", "" }
 }
 
 impl i32 {
     int_impl! { i32, i32, u32, 32, 31, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
     "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
-    "[0x12, 0x34, 0x56, 0x78]", "", "" }
+    "[0x12, 0x34, 0x56, 0x78]", "", "", "" }
 }
 
 impl i64 {
     int_impl! { i64, i64, u64, 64, 63, -9223372036854775808, 9223372036854775807, 12,
     "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
     "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
-    "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "" }
+    "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "", "" }
 }
 
 impl i128 {
@@ -225,22 +225,24 @@ impl i128 {
     "[0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, \
       0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
-      0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]", "", "" }
+      0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]", "", "", "" }
 }
 
 #[cfg(target_pointer_width = "16")]
 impl isize {
     int_impl! { isize, i16, usize, 16, 15, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234",
     "0x3412", "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]",
-    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 16-bit targets" }
 }
 
 #[cfg(target_pointer_width = "32")]
 impl isize {
     int_impl! { isize, i32, usize, 32, 31, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
     "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78]",
-    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 32-bit targets" }
 }
 
 #[cfg(target_pointer_width = "64")]
@@ -249,15 +251,16 @@ impl isize {
     12, "0xaa00000000006e1", "0x6e10aa",  "0x1234567890123456", "0x5634129078563412",
     "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
-    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 64-bit targets" }
 }
 
 /// If 6th bit set ascii is upper case.
 const ASCII_CASE_MASK: u8 = 0b0010_0000;
 
 impl u8 {
     uint_impl! { u8, u8, i8, NonZeroU8, 8, 255, 2, "0x82", "0xa", "0x12", "0x12", "0x48", "[0x12]",
-    "[0x12]", "", "" }
+    "[0x12]", "", "", "" }
     widening_impl! { u8, u16, 8, unsigned }
 
     /// Checks if the value is within the ASCII range.
@@ -810,7 +813,7 @@ impl u8 {
 
 impl u16 {
     uint_impl! { u16, u16, i16, NonZeroU16, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
-    "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
+    "[0x34, 0x12]", "[0x12, 0x34]", "", "", "" }
     widening_impl! { u16, u32, 16, unsigned }
 
     /// Checks if the value is a Unicode surrogate code point, which are disallowed values for [`char`].
@@ -841,7 +844,7 @@ impl u16 {
 
 impl u32 {
     uint_impl! { u32, u32, i32, NonZeroU32, 32, 4294967295, 8, "0x10000b3", "0xb301", "0x12345678",
-    "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]", "[0x12, 0x34, 0x56, 0x78]", "", "" }
+    "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]", "[0x12, 0x34, 0x56, 0x78]", "", "", "" }
     widening_impl! { u32, u64, 32, unsigned }
 }
 
@@ -850,7 +853,7 @@ impl u64 {
     "0x1234567890123456", "0x5634129078563412", "0x6a2c48091e6a2c48",
     "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
-    "", ""}
+    "", "", ""}
     widening_impl! { u64, u128, 64, unsigned }
 }
 
@@ -862,21 +865,23 @@ impl u128 {
       0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
       0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]",
-     "", ""}
+     "", "", ""}
 }
 
 #[cfg(target_pointer_width = "16")]
 impl usize {
     uint_impl! { usize, u16, isize, NonZeroUsize, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
     "[0x34, 0x12]", "[0x12, 0x34]",
-    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 16-bit targets" }
     widening_impl! { usize, u32, 16, unsigned }
 }
 #[cfg(target_pointer_width = "32")]
 impl usize {
     uint_impl! { usize, u32, isize, NonZeroUsize, 32, 4294967295, 8, "0x10000b3", "0xb301", "0x12345678",
     "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]", "[0x12, 0x34, 0x56, 0x78]",
-    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 32-bit targets" }
     widening_impl! { usize, u64, 32, unsigned }
 }
 
@@ -886,7 +891,8 @@ impl usize {
     "0x1234567890123456", "0x5634129078563412", "0x6a2c48091e6a2c48",
     "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
-    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 64-bit targets" }
     widening_impl! { usize, u128, 64, unsigned }
 }
 

library/core/src/num/uint_macros.rs

@@ -3,7 +3,8 @@ macro_rules! uint_impl {
         $BITS:expr, $MaxV:expr,
         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
-        $to_xe_bytes_doc:expr, $from_xe_bytes_doc:expr) => {
+        $to_xe_bytes_doc:expr, $from_xe_bytes_doc:expr,
+        $bound_condition:expr) => {
         /// The smallest value that can be represented by this integer type.
         ///
         /// # Examples
@@ -16,8 +17,8 @@ macro_rules! uint_impl {
         #[stable(feature = "assoc_int_consts", since = "1.43.0")]
         pub const MIN: Self = 0;
 
-        /// The largest value that can be represented by this integer type,
-        #[doc = concat!("2<sup>", $BITS, "</sup> &minus; 1.")]
+        /// The largest value that can be represented by this integer type
+        #[doc = concat!("(2<sup>", $BITS, "</sup> &minus; 1", $bound_condition, ")")]
         ///
         /// # Examples
         ///

src/bootstrap/builder.rs

@@ -697,6 +697,7 @@ impl<'a> Builder<'a> {
                 doc::RustcBook,
                 doc::CargoBook,
                 doc::Clippy,
+                doc::ClippyBook,
                 doc::Miri,
                 doc::EmbeddedBook,
                 doc::EditionGuide,

src/bootstrap/doc.rs

@@ -74,6 +74,7 @@ macro_rules! book {
 // and checking against it?).
 book!(
     CargoBook, "src/tools/cargo/src/doc", "cargo", submodule = "src/tools/cargo";
+    ClippyBook, "src/tools/clippy/book", "clippy";
     EditionGuide, "src/doc/edition-guide", "edition-guide", submodule;
     EmbeddedBook, "src/doc/embedded-book", "embedded-book", submodule;
     Nomicon, "src/doc/nomicon", "nomicon", submodule;