Auto merge of #134590 - matthiaskrgr:rollup-8lz2s62, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #123604 (Abstract `ProcThreadAttributeList` into its own struct)
 - #128780 (Add `--doctest-compilation-args` option to add compilation flags to doctest compilation)
 - #133782 (Precedence improvements: closures and jumps)
 - #134509 (Arbitrary self types v2: niche deshadowing test)
 - #134524 (Arbitrary self types v2: no deshadow pre feature.)
 - #134539 (Restrict `#[non_exaustive]` on structs with default field values)
 - #134586 (Also lint on option of function pointer comparisons)

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

Author: bors

compiler/rustc_ast/src/ast.rs

@@ -1322,11 +1322,15 @@ impl Expr {
     }
 
     pub fn precedence(&self) -> ExprPrecedence {
-        match self.kind {
-            ExprKind::Closure(..) => ExprPrecedence::Closure,
+        match &self.kind {
+            ExprKind::Closure(closure) => {
+                match closure.fn_decl.output {
+                    FnRetTy::Default(_) => ExprPrecedence::Jump,
+                    FnRetTy::Ty(_) => ExprPrecedence::Unambiguous,
+                }
+            }
 
             ExprKind::Break(..)
-            | ExprKind::Continue(..)
             | ExprKind::Ret(..)
             | ExprKind::Yield(..)
             | ExprKind::Yeet(..)
@@ -1360,6 +1364,7 @@ impl Expr {
             | ExprKind::Block(..)
             | ExprKind::Call(..)
             | ExprKind::ConstBlock(_)
+            | ExprKind::Continue(..)
             | ExprKind::Field(..)
             | ExprKind::ForLoop { .. }
             | ExprKind::FormatArgs(..)

compiler/rustc_ast/src/util/parser.rs

@@ -231,8 +231,7 @@ impl AssocOp {
 
 #[derive(Clone, Copy, PartialEq, PartialOrd)]
 pub enum ExprPrecedence {
-    Closure,
-    // return, break, yield
+    // return, break, yield, closures
     Jump,
     // = += -= *= /= %= &= |= ^= <<= >>=
     Assign,

compiler/rustc_hir/src/hir.rs

@@ -1943,11 +1943,15 @@ pub struct Expr<'hir> {
 
 impl Expr<'_> {
     pub fn precedence(&self) -> ExprPrecedence {
-        match self.kind {
-            ExprKind::Closure { .. } => ExprPrecedence::Closure,
+        match &self.kind {
+            ExprKind::Closure(closure) => {
+                match closure.fn_decl.output {
+                    FnRetTy::DefaultReturn(_) => ExprPrecedence::Jump,
+                    FnRetTy::Return(_) => ExprPrecedence::Unambiguous,
+                }
+            }
 
             ExprKind::Break(..)
-            | ExprKind::Continue(..)
             | ExprKind::Ret(..)
             | ExprKind::Yield(..)
             | ExprKind::Become(..) => ExprPrecedence::Jump,
@@ -1973,6 +1977,7 @@ impl Expr<'_> {
             | ExprKind::Block(..)
             | ExprKind::Call(..)
             | ExprKind::ConstBlock(_)
+            | ExprKind::Continue(..)
             | ExprKind::Field(..)
             | ExprKind::If(..)
             | ExprKind::Index(..)
@@ -1990,7 +1995,7 @@ impl Expr<'_> {
             | ExprKind::UnsafeBinderCast(..)
             | ExprKind::Err(_) => ExprPrecedence::Unambiguous,
 
-            ExprKind::DropTemps(ref expr, ..) => expr.precedence(),
+            ExprKind::DropTemps(expr, ..) => expr.precedence(),
         }
     }
 

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -1329,6 +1329,15 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         mutbl: hir::Mutability,
         track_unstable_candidates: bool,
     ) -> Result<(), MethodError<'tcx>> {
+        // The errors emitted by this function are part of
+        // the arbitrary self types work, and should not impact
+        // other users.
+        if !self.tcx.features().arbitrary_self_types()
+            && !self.tcx.features().arbitrary_self_types_pointers()
+        {
+            return Ok(());
+        }
+
         // We don't want to remember any of the diagnostic hints from this
         // shadow search, but we do need to provide Some/None for the
         // unstable_candidates in order to reflect the behavior of the

compiler/rustc_lint/src/types.rs

@@ -4,7 +4,7 @@ use std::ops::ControlFlow;
 use rustc_abi::{BackendRepr, ExternAbi, TagEncoding, Variants, WrappingRange};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::DiagMessage;
-use rustc_hir::{Expr, ExprKind};
+use rustc_hir::{Expr, ExprKind, LangItem};
 use rustc_middle::bug;
 use rustc_middle::ty::layout::{LayoutOf, SizeSkeleton};
 use rustc_middle::ty::{
@@ -444,7 +444,25 @@ fn lint_fn_pointer<'tcx>(
     let (l_ty, l_ty_refs) = peel_refs(l_ty);
     let (r_ty, r_ty_refs) = peel_refs(r_ty);
 
-    if !l_ty.is_fn() || !r_ty.is_fn() {
+    if l_ty.is_fn() && r_ty.is_fn() {
+        // both operands are function pointers, fallthrough
+    } else if let ty::Adt(l_def, l_args) = l_ty.kind()
+        && let ty::Adt(r_def, r_args) = r_ty.kind()
+        && cx.tcx.is_lang_item(l_def.did(), LangItem::Option)
+        && cx.tcx.is_lang_item(r_def.did(), LangItem::Option)
+        && let Some(l_some_arg) = l_args.get(0)
+        && let Some(r_some_arg) = r_args.get(0)
+        && l_some_arg.expect_ty().is_fn()
+        && r_some_arg.expect_ty().is_fn()
+    {
+        // both operands are `Option<{function ptr}>`
+        return cx.emit_span_lint(
+            UNPREDICTABLE_FUNCTION_POINTER_COMPARISONS,
+            e.span,
+            UnpredictableFunctionPointerComparisons::Warn,
+        );
+    } else {
+        // types are not function pointers, nothing to do
         return;
     }
 

compiler/rustc_passes/messages.ftl

@@ -566,6 +566,10 @@ passes_no_sanitize =
     `#[no_sanitize({$attr_str})]` should be applied to {$accepted_kind}
     .label = not {$accepted_kind}
 
+passes_non_exaustive_with_default_field_values =
+    `#[non_exhaustive]` can't be used to annotate items with default field values
+    .label = this struct has default field values
+
 passes_non_exported_macro_invalid_attrs =
     attribute should be applied to function or closure
     .label = not a function or closure

compiler/rustc_passes/src/check_attr.rs

@@ -124,7 +124,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 [sym::coverage, ..] => self.check_coverage(attr, span, target),
                 [sym::optimize, ..] => self.check_optimize(hir_id, attr, span, target),
                 [sym::no_sanitize, ..] => self.check_no_sanitize(attr, span, target),
-                [sym::non_exhaustive, ..] => self.check_non_exhaustive(hir_id, attr, span, target),
+                [sym::non_exhaustive, ..] => self.check_non_exhaustive(hir_id, attr, span, target, item),
                 [sym::marker, ..] => self.check_marker(hir_id, attr, span, target),
                 [sym::target_feature, ..] => {
                     self.check_target_feature(hir_id, attr, span, target, attrs)
@@ -685,9 +685,30 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
     }
 
     /// Checks if the `#[non_exhaustive]` attribute on an `item` is valid.
-    fn check_non_exhaustive(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) {
+    fn check_non_exhaustive(
+        &self,
+        hir_id: HirId,
+        attr: &Attribute,
+        span: Span,
+        target: Target,
+        item: Option<ItemLike<'_>>,
+    ) {
         match target {
-            Target::Struct | Target::Enum | Target::Variant => {}
+            Target::Struct => {
+                if let Some(ItemLike::Item(hir::Item {
+                    kind: hir::ItemKind::Struct(hir::VariantData::Struct { fields, .. }, _),
+                    ..
+                })) = item
+                    && !fields.is_empty()
+                    && fields.iter().any(|f| f.default.is_some())
+                {
+                    self.dcx().emit_err(errors::NonExhaustiveWithDefaultFieldValues {
+                        attr_span: attr.span,
+                        defn_span: span,
+                    });
+                }
+            }
+            Target::Enum | Target::Variant => {}
             // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
             // `#[non_exhaustive]` attribute with just a lint, because we previously
             // erroneously allowed it and some crates used it accidentally, to be compatible

compiler/rustc_passes/src/errors.rs

@@ -119,6 +119,15 @@ pub(crate) struct NonExhaustiveWrongLocation {
     pub defn_span: Span,
 }
 
+#[derive(Diagnostic)]
+#[diag(passes_non_exaustive_with_default_field_values)]
+pub(crate) struct NonExhaustiveWithDefaultFieldValues {
+    #[primary_span]
+    pub attr_span: Span,
+    #[label]
+    pub defn_span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(passes_should_be_applied_to_trait)]
 pub(crate) struct AttrShouldBeAppliedToTrait {

library/std/src/os/windows/process.rs

@@ -4,13 +4,14 @@
 
 #![stable(feature = "process_extensions", since = "1.2.0")]
 
-use crate::ffi::OsStr;
+use crate::ffi::{OsStr, c_void};
+use crate::mem::MaybeUninit;
 use crate::os::windows::io::{
     AsHandle, AsRawHandle, BorrowedHandle, FromRawHandle, IntoRawHandle, OwnedHandle, RawHandle,
 };
 use crate::sealed::Sealed;
 use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
-use crate::{process, sys};
+use crate::{io, marker, process, ptr, sys};
 
 #[stable(feature = "process_extensions", since = "1.2.0")]
 impl FromRawHandle for process::Stdio {
@@ -295,41 +296,25 @@ pub trait CommandExt: Sealed {
     #[unstable(feature = "windows_process_extensions_async_pipes", issue = "98289")]
     fn async_pipes(&mut self, always_async: bool) -> &mut process::Command;
 
-    /// Set a raw attribute on the command, providing extended configuration options for Windows
-    /// processes.
+    /// Executes the command as a child process with the given
+    /// [`ProcThreadAttributeList`], returning a handle to it.
     ///
-    /// This method allows you to specify custom attributes for a child process on Windows systems
-    /// using raw attribute values. Raw attributes provide extended configurability for process
-    /// creation, but their usage can be complex and potentially unsafe.
-    ///
-    /// The `attribute` parameter specifies the raw attribute to be set, while the `value`
-    /// parameter holds the value associated with that attribute. Please refer to the
-    /// [`windows-rs` documentation] or the [Win32 API documentation] for detailed information
-    /// about available attributes and their meanings.
-    ///
-    /// [`windows-rs` documentation]: https://microsoft.github.io/windows-docs-rs/doc/windows/
-    /// [Win32 API documentation]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-updateprocthreadattribute
+    /// This method enables the customization of attributes for the spawned
+    /// child process on Windows systems.
+    /// Attributes offer extended configurability for process creation,
+    /// but their usage can be intricate and potentially unsafe.
     ///
     /// # Note
     ///
-    /// The maximum number of raw attributes is the value of [`u32::MAX`].
-    /// If this limit is exceeded, the call to [`process::Command::spawn`] will return an `Error`
-    /// indicating that the maximum number of attributes has been exceeded.
-    ///
-    /// # Safety
-    ///
-    /// The usage of raw attributes is potentially unsafe and should be done with caution.
-    /// Incorrect attribute values or improper configuration can lead to unexpected behavior or
-    /// errors.
+    /// By default, stdin, stdout, and stderr are inherited from the parent
+    /// process.
     ///
     /// # Example
     ///
-    /// The following example demonstrates how to create a child process with a specific parent
-    /// process ID using a raw attribute.
-    ///
-    /// ```rust
+    /// ```
     /// #![feature(windows_process_extensions_raw_attribute)]
-    /// use std::os::windows::{process::CommandExt, io::AsRawHandle};
+    /// use std::os::windows::io::AsRawHandle;
+    /// use std::os::windows::process::{CommandExt, ProcThreadAttributeList};
     /// use std::process::Command;
     ///
     /// # struct ProcessDropGuard(std::process::Child);
@@ -338,36 +323,27 @@ pub trait CommandExt: Sealed {
     /// #         let _ = self.0.kill();
     /// #     }
     /// # }
-    ///
+    /// #
     /// let parent = Command::new("cmd").spawn()?;
-    ///
-    /// let mut child_cmd = Command::new("cmd");
+    /// let parent_process_handle = parent.as_raw_handle();
+    /// # let parent = ProcessDropGuard(parent);
     ///
     /// const PROC_THREAD_ATTRIBUTE_PARENT_PROCESS: usize = 0x00020000;
+    /// let mut attribute_list = ProcThreadAttributeList::build()
+    ///     .attribute(PROC_THREAD_ATTRIBUTE_PARENT_PROCESS, &parent_process_handle)
+    ///     .finish()
+    ///     .unwrap();
     ///
-    /// unsafe {
-    ///     child_cmd.raw_attribute(PROC_THREAD_ATTRIBUTE_PARENT_PROCESS, parent.as_raw_handle() as isize);
-    /// }
+    /// let mut child = Command::new("cmd").spawn_with_attributes(&attribute_list)?;
     /// #
-    /// # let parent = ProcessDropGuard(parent);
-    ///
-    /// let mut child = child_cmd.spawn()?;
-    ///
     /// # child.kill()?;
     /// # Ok::<(), std::io::Error>(())
     /// ```
-    ///
-    /// # Safety Note
-    ///
-    /// Remember that improper use of raw attributes can lead to undefined behavior or security
-    /// vulnerabilities. Always consult the documentation and ensure proper attribute values are
-    /// used.
     #[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
-    unsafe fn raw_attribute<T: Copy + Send + Sync + 'static>(
+    fn spawn_with_attributes(
         &mut self,
-        attribute: usize,
-        value: T,
-    ) -> &mut process::Command;
+        attribute_list: &ProcThreadAttributeList<'_>,
+    ) -> io::Result<process::Child>;
 }
 
 #[stable(feature = "windows_process_extensions", since = "1.16.0")]
@@ -401,13 +377,13 @@ impl CommandExt for process::Command {
         self
     }
 
-    unsafe fn raw_attribute<T: Copy + Send + Sync + 'static>(
+    fn spawn_with_attributes(
         &mut self,
-        attribute: usize,
-        value: T,
-    ) -> &mut process::Command {
-        unsafe { self.as_inner_mut().raw_attribute(attribute, value) };
-        self
+        attribute_list: &ProcThreadAttributeList<'_>,
+    ) -> io::Result<process::Child> {
+        self.as_inner_mut()
+            .spawn_with_attributes(sys::process::Stdio::Inherit, true, Some(attribute_list))
+            .map(process::Child::from_inner)
     }
 }
 
@@ -447,3 +423,245 @@ impl ExitCodeExt for process::ExitCode {
         process::ExitCode::from_inner(From::from(raw))
     }
 }
+
+/// A wrapper around windows [`ProcThreadAttributeList`][1].
+///
+/// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-initializeprocthreadattributelist>
+#[derive(Debug)]
+#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
+pub struct ProcThreadAttributeList<'a> {
+    attribute_list: Box<[MaybeUninit<u8>]>,
+    _lifetime_marker: marker::PhantomData<&'a ()>,
+}
+
+#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
+impl<'a> ProcThreadAttributeList<'a> {
+    /// Creates a new builder for constructing a [`ProcThreadAttributeList`].
+    pub fn build() -> ProcThreadAttributeListBuilder<'a> {
+        ProcThreadAttributeListBuilder::new()
+    }
+
+    /// Returns a pointer to the underling attribute list.
+    #[doc(hidden)]
+    pub fn as_ptr(&self) -> *const MaybeUninit<u8> {
+        self.attribute_list.as_ptr()
+    }
+}
+
+#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
+impl<'a> Drop for ProcThreadAttributeList<'a> {
+    /// Deletes the attribute list.
+    ///
+    /// This method calls [`DeleteProcThreadAttributeList`][1] to delete the
+    /// underlying attribute list.
+    ///
+    /// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-deleteprocthreadattributelist>
+    fn drop(&mut self) {
+        let lp_attribute_list = self.attribute_list.as_mut_ptr().cast::<c_void>();
+        unsafe { sys::c::DeleteProcThreadAttributeList(lp_attribute_list) }
+    }
+}
+
+/// Builder for constructing a [`ProcThreadAttributeList`].
+#[derive(Clone, Debug)]
+#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
+pub struct ProcThreadAttributeListBuilder<'a> {
+    attributes: alloc::collections::BTreeMap<usize, ProcThreadAttributeValue>,
+    _lifetime_marker: marker::PhantomData<&'a ()>,
+}
+
+#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
+impl<'a> ProcThreadAttributeListBuilder<'a> {
+    fn new() -> Self {
+        ProcThreadAttributeListBuilder {
+            attributes: alloc::collections::BTreeMap::new(),
+            _lifetime_marker: marker::PhantomData,
+        }
+    }
+
+    /// Sets an attribute on the attribute list.
+    ///
+    /// The `attribute` parameter specifies the raw attribute to be set, while
+    /// the `value` parameter holds the value associated with that attribute.
+    /// Please refer to the [Windows documentation][1] for a list of valid attributes.
+    ///
+    /// # Note
+    ///
+    /// The maximum number of attributes is the value of [`u32::MAX`]. If this
+    /// limit is exceeded, the call to [`Self::finish`] will return an `Error`
+    /// indicating that the maximum number of attributes has been exceeded.
+    ///
+    /// # Safety Note
+    ///
+    /// Remember that improper use of attributes can lead to undefined behavior
+    /// or security vulnerabilities. Always consult the documentation and ensure
+    /// proper attribute values are used.
+    ///
+    /// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-updateprocthreadattribute#parameters>
+    pub fn attribute<T>(self, attribute: usize, value: &'a T) -> Self {
+        unsafe {
+            self.raw_attribute(
+                attribute,
+                ptr::addr_of!(*value).cast::<c_void>(),
+                crate::mem::size_of::<T>(),
+            )
+        }
+    }
+
+    /// Sets a raw attribute on the attribute list.
+    ///
+    /// This function is useful for setting attributes with pointers or sizes
+    /// that cannot be derived directly from their values.
+    ///
+    /// # Safety
+    ///
+    /// This function is marked as `unsafe` because it deals with raw pointers
+    /// and sizes. It is the responsibility of the caller to ensure the value
+    /// lives longer than the resulting [`ProcThreadAttributeList`] as well as
+    /// the validity of the size parameter.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// #![feature(windows_process_extensions_raw_attribute)]
+    /// use std::ffi::c_void;
+    /// use std::os::windows::process::{CommandExt, ProcThreadAttributeList};
+    /// use std::os::windows::raw::HANDLE;
+    /// use std::process::Command;
+    ///
+    /// #[repr(C)]
+    /// pub struct COORD {
+    ///     pub X: i16,
+    ///     pub Y: i16,
+    /// }
+    ///
+    /// extern "system" {
+    ///     fn CreatePipe(
+    ///         hreadpipe: *mut HANDLE,
+    ///         hwritepipe: *mut HANDLE,
+    ///         lppipeattributes: *const c_void,
+    ///         nsize: u32,
+    ///     ) -> i32;
+    ///     fn CreatePseudoConsole(
+    ///         size: COORD,
+    ///         hinput: HANDLE,
+    ///         houtput: HANDLE,
+    ///         dwflags: u32,
+    ///         phpc: *mut isize,
+    ///     ) -> i32;
+    ///     fn CloseHandle(hobject: HANDLE) -> i32;
+    /// }
+    ///
+    /// let [mut input_read_side, mut output_write_side, mut output_read_side, mut input_write_side] =
+    ///     [unsafe { std::mem::zeroed::<HANDLE>() }; 4];
+    ///
+    /// unsafe {
+    ///     CreatePipe(&mut input_read_side, &mut input_write_side, std::ptr::null(), 0);
+    ///     CreatePipe(&mut output_read_side, &mut output_write_side, std::ptr::null(), 0);
+    /// }
+    ///
+    /// let size = COORD { X: 60, Y: 40 };
+    /// let mut h_pc = unsafe { std::mem::zeroed() };
+    /// unsafe { CreatePseudoConsole(size, input_read_side, output_write_side, 0, &mut h_pc) };
+    ///
+    /// unsafe { CloseHandle(input_read_side) };
+    /// unsafe { CloseHandle(output_write_side) };
+    ///
+    /// const PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE: usize = 131094;
+    ///
+    /// let attribute_list = unsafe {
+    ///     ProcThreadAttributeList::build()
+    ///         .raw_attribute(
+    ///             PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE,
+    ///             h_pc as *const c_void,
+    ///             std::mem::size_of::<isize>(),
+    ///         )
+    ///         .finish()?
+    /// };
+    ///
+    /// let mut child = Command::new("cmd").spawn_with_attributes(&attribute_list)?;
+    /// #
+    /// # child.kill()?;
+    /// # Ok::<(), std::io::Error>(())
+    /// ```
+    pub unsafe fn raw_attribute<T>(
+        mut self,
+        attribute: usize,
+        value_ptr: *const T,
+        value_size: usize,
+    ) -> Self {
+        self.attributes.insert(attribute, ProcThreadAttributeValue {
+            ptr: value_ptr.cast::<c_void>(),
+            size: value_size,
+        });
+        self
+    }
+
+    /// Finalizes the construction of the `ProcThreadAttributeList`.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error if the maximum number of attributes is exceeded
+    /// or if there is an I/O error during initialization.
+    pub fn finish(&self) -> io::Result<ProcThreadAttributeList<'a>> {
+        // To initialize our ProcThreadAttributeList, we need to determine
+        // how many bytes to allocate for it. The Windows API simplifies this
+        // process by allowing us to call `InitializeProcThreadAttributeList`
+        // with a null pointer to retrieve the required size.
+        let mut required_size = 0;
+        let Ok(attribute_count) = self.attributes.len().try_into() else {
+            return Err(io::const_error!(
+                io::ErrorKind::InvalidInput,
+                "maximum number of ProcThreadAttributes exceeded",
+            ));
+        };
+        unsafe {
+            sys::c::InitializeProcThreadAttributeList(
+                ptr::null_mut(),
+                attribute_count,
+                0,
+                &mut required_size,
+            )
+        };
+
+        let mut attribute_list = vec![MaybeUninit::uninit(); required_size].into_boxed_slice();
+
+        // Once we've allocated the necessary memory, it's safe to invoke
+        // `InitializeProcThreadAttributeList` to properly initialize the list.
+        sys::cvt(unsafe {
+            sys::c::InitializeProcThreadAttributeList(
+                attribute_list.as_mut_ptr().cast::<c_void>(),
+                attribute_count,
+                0,
+                &mut required_size,
+            )
+        })?;
+
+        // # Add our attributes to the buffer.
+        // It's theoretically possible for the attribute count to exceed a u32
+        // value. Therefore, we ensure that we don't add more attributes than
+        // the buffer was initialized for.
+        for (&attribute, value) in self.attributes.iter().take(attribute_count as usize) {
+            sys::cvt(unsafe {
+                sys::c::UpdateProcThreadAttribute(
+                    attribute_list.as_mut_ptr().cast::<c_void>(),
+                    0,
+                    attribute,
+                    value.ptr,
+                    value.size,
+                    ptr::null_mut(),
+                    ptr::null_mut(),
+                )
+            })?;
+        }
+
+        Ok(ProcThreadAttributeList { attribute_list, _lifetime_marker: marker::PhantomData })
+    }
+}
+
+/// Wrapper around the value data to be used as a Process Thread Attribute.
+#[derive(Clone, Debug)]
+struct ProcThreadAttributeValue {
+    ptr: *const c_void,
+    size: usize,
+}

library/std/src/process/tests.rs

@@ -450,7 +450,7 @@ fn test_creation_flags() {
 fn test_proc_thread_attributes() {
     use crate::mem;
     use crate::os::windows::io::AsRawHandle;
-    use crate::os::windows::process::CommandExt;
+    use crate::os::windows::process::{CommandExt, ProcThreadAttributeList};
     use crate::sys::c::{BOOL, CloseHandle, HANDLE};
     use crate::sys::cvt;
 
@@ -490,12 +490,14 @@ fn test_proc_thread_attributes() {
 
     let mut child_cmd = Command::new("cmd");
 
-    unsafe {
-        child_cmd
-            .raw_attribute(PROC_THREAD_ATTRIBUTE_PARENT_PROCESS, parent.0.as_raw_handle() as isize);
-    }
+    let parent_process_handle = parent.0.as_raw_handle();
+
+    let mut attribute_list = ProcThreadAttributeList::build()
+        .attribute(PROC_THREAD_ATTRIBUTE_PARENT_PROCESS, &parent_process_handle)
+        .finish()
+        .unwrap();
 
-    let child = ProcessDropGuard(child_cmd.spawn().unwrap());
+    let child = ProcessDropGuard(child_cmd.spawn_with_attributes(&mut attribute_list).unwrap());
 
     let h_snapshot = unsafe { CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0) };
 

library/std/src/sys/pal/windows/process.rs

@@ -10,10 +10,10 @@ use crate::collections::BTreeMap;
 use crate::env::consts::{EXE_EXTENSION, EXE_SUFFIX};
 use crate::ffi::{OsStr, OsString};
 use crate::io::{self, Error, ErrorKind};
-use crate::mem::MaybeUninit;
 use crate::num::NonZero;
 use crate::os::windows::ffi::{OsStrExt, OsStringExt};
 use crate::os::windows::io::{AsHandle, AsRawHandle, BorrowedHandle, FromRawHandle, IntoRawHandle};
+use crate::os::windows::process::ProcThreadAttributeList;
 use crate::path::{Path, PathBuf};
 use crate::sync::Mutex;
 use crate::sys::args::{self, Arg};
@@ -162,7 +162,6 @@ pub struct Command {
     stdout: Option<Stdio>,
     stderr: Option<Stdio>,
     force_quotes_enabled: bool,
-    proc_thread_attributes: BTreeMap<usize, ProcThreadAttributeValue>,
 }
 
 pub enum Stdio {
@@ -194,7 +193,6 @@ impl Command {
             stdout: None,
             stderr: None,
             force_quotes_enabled: false,
-            proc_thread_attributes: Default::default(),
         }
     }
 
@@ -248,21 +246,19 @@ impl Command {
         self.cwd.as_ref().map(Path::new)
     }
 
-    pub unsafe fn raw_attribute<T: Copy + Send + Sync + 'static>(
+    pub fn spawn(
         &mut self,
-        attribute: usize,
-        value: T,
-    ) {
-        self.proc_thread_attributes.insert(attribute, ProcThreadAttributeValue {
-            size: mem::size_of::<T>(),
-            data: Box::new(value),
-        });
+        default: Stdio,
+        needs_stdin: bool,
+    ) -> io::Result<(Process, StdioPipes)> {
+        self.spawn_with_attributes(default, needs_stdin, None)
     }
 
-    pub fn spawn(
+    pub fn spawn_with_attributes(
         &mut self,
         default: Stdio,
         needs_stdin: bool,
+        proc_thread_attribute_list: Option<&ProcThreadAttributeList<'_>>,
     ) -> io::Result<(Process, StdioPipes)> {
         let maybe_env = self.env.capture_if_changed();
 
@@ -355,18 +351,18 @@ impl Command {
 
         let si_ptr: *mut c::STARTUPINFOW;
 
-        let mut proc_thread_attribute_list;
         let mut si_ex;
 
-        if !self.proc_thread_attributes.is_empty() {
+        if let Some(proc_thread_attribute_list) = proc_thread_attribute_list {
             si.cb = mem::size_of::<c::STARTUPINFOEXW>() as u32;
             flags |= c::EXTENDED_STARTUPINFO_PRESENT;
 
-            proc_thread_attribute_list =
-                make_proc_thread_attribute_list(&self.proc_thread_attributes)?;
             si_ex = c::STARTUPINFOEXW {
                 StartupInfo: si,
-                lpAttributeList: proc_thread_attribute_list.0.as_mut_ptr() as _,
+                // SAFETY: Casting this `*const` pointer to a `*mut` pointer is "safe"
+                // here because windows does not internally mutate the attribute list.
+                // Ideally this should be reflected in the interface of the `windows-sys` crate.
+                lpAttributeList: proc_thread_attribute_list.as_ptr().cast::<c_void>().cast_mut(),
             };
             si_ptr = (&raw mut si_ex) as _;
         } else {
@@ -896,79 +892,6 @@ fn make_dirp(d: Option<&OsString>) -> io::Result<(*const u16, Vec<u16>)> {
     }
 }
 
-struct ProcThreadAttributeList(Box<[MaybeUninit<u8>]>);
-
-impl Drop for ProcThreadAttributeList {
-    fn drop(&mut self) {
-        let lp_attribute_list = self.0.as_mut_ptr() as _;
-        unsafe { c::DeleteProcThreadAttributeList(lp_attribute_list) }
-    }
-}
-
-/// Wrapper around the value data to be used as a Process Thread Attribute.
-struct ProcThreadAttributeValue {
-    data: Box<dyn Send + Sync>,
-    size: usize,
-}
-
-fn make_proc_thread_attribute_list(
-    attributes: &BTreeMap<usize, ProcThreadAttributeValue>,
-) -> io::Result<ProcThreadAttributeList> {
-    // To initialize our ProcThreadAttributeList, we need to determine
-    // how many bytes to allocate for it. The Windows API simplifies this process
-    // by allowing us to call `InitializeProcThreadAttributeList` with
-    // a null pointer to retrieve the required size.
-    let mut required_size = 0;
-    let Ok(attribute_count) = attributes.len().try_into() else {
-        return Err(io::const_error!(
-            ErrorKind::InvalidInput,
-            "maximum number of ProcThreadAttributes exceeded",
-        ));
-    };
-    unsafe {
-        c::InitializeProcThreadAttributeList(
-            ptr::null_mut(),
-            attribute_count,
-            0,
-            &mut required_size,
-        )
-    };
-
-    let mut proc_thread_attribute_list =
-        ProcThreadAttributeList(vec![MaybeUninit::uninit(); required_size].into_boxed_slice());
-
-    // Once we've allocated the necessary memory, it's safe to invoke
-    // `InitializeProcThreadAttributeList` to properly initialize the list.
-    cvt(unsafe {
-        c::InitializeProcThreadAttributeList(
-            proc_thread_attribute_list.0.as_mut_ptr() as *mut _,
-            attribute_count,
-            0,
-            &mut required_size,
-        )
-    })?;
-
-    // # Add our attributes to the buffer.
-    // It's theoretically possible for the attribute count to exceed a u32 value.
-    // Therefore, we ensure that we don't add more attributes than the buffer was initialized for.
-    for (&attribute, value) in attributes.iter().take(attribute_count as usize) {
-        let value_ptr = (&raw const *value.data) as _;
-        cvt(unsafe {
-            c::UpdateProcThreadAttribute(
-                proc_thread_attribute_list.0.as_mut_ptr() as _,
-                0,
-                attribute,
-                value_ptr,
-                value.size,
-                ptr::null_mut(),
-                ptr::null_mut(),
-            )
-        })?;
-    }
-
-    Ok(proc_thread_attribute_list)
-}
-
 pub struct CommandArgs<'a> {
     iter: crate::slice::Iter<'a, Arg>,
 }

src/doc/rustdoc/src/unstable-features.md

@@ -315,7 +315,7 @@ Markdown file, the URL given to `--markdown-playground-url` will take precedence
 `--playground-url` and `#![doc(html_playground_url = "url")]` are present when rendering crate docs,
 the attribute will take precedence.
 
-### `--sort-modules-by-appearance`: control how items on module pages are sorted
+## `--sort-modules-by-appearance`: control how items on module pages are sorted
 
 Using this flag looks like this:
 
@@ -328,7 +328,7 @@ some consideration for their stability, and names that end in a number). Giving
 `rustdoc` will disable this sorting and instead make it print the items in the order they appear in
 the source.
 
-### `--show-type-layout`: add a section to each type's docs describing its memory layout
+## `--show-type-layout`: add a section to each type's docs describing its memory layout
 
 * Tracking issue: [#113248](https://github.com/rust-lang/rust/issues/113248)
 
@@ -346,7 +346,7 @@ of that type will take in memory.
 Note that most layout information is **completely unstable** and may even differ
 between compilations.
 
-### `--resource-suffix`: modifying the name of CSS/JavaScript in crate docs
+## `--resource-suffix`: modifying the name of CSS/JavaScript in crate docs
 
  * Tracking issue: [#54765](https://github.com/rust-lang/rust/issues/54765)
 
@@ -361,7 +361,7 @@ all these files are linked from every page, changing where they are can be cumbe
 specially cache them. This flag will rename all these files in the output to include the suffix in
 the filename. For example, `light.css` would become `light-suf.css` with the above command.
 
-### `--extern-html-root-url`: control how rustdoc links to non-local crates
+## `--extern-html-root-url`: control how rustdoc links to non-local crates
 
 Using this flag looks like this:
 
@@ -376,7 +376,7 @@ flags to control that behavior. When the `--extern-html-root-url` flag is given
 one of your dependencies, rustdoc use that URL for those docs. Keep in mind that if those docs exist
 in the output directory, those local docs will still override this flag.
 
-### `-Z force-unstable-if-unmarked`
+## `-Z force-unstable-if-unmarked`
 
 Using this flag looks like this:
 
@@ -389,7 +389,7 @@ This is an internal flag intended for the standard library and compiler that app
 allows `rustdoc` to be able to generate documentation for the compiler crates and the standard
 library, as an equivalent command-line argument is provided to `rustc` when building those crates.
 
-### `--index-page`: provide a top-level landing page for docs
+## `--index-page`: provide a top-level landing page for docs
 
 This feature allows you to generate an index-page with a given markdown file. A good example of it
 is the [rust documentation index](https://doc.rust-lang.org/nightly/index.html).
@@ -398,18 +398,18 @@ With this, you'll have a page which you can customize as much as you want at the
 
 Using `index-page` option enables `enable-index-page` option as well.
 
-### `--enable-index-page`: generate a default index page for docs
+## `--enable-index-page`: generate a default index page for docs
 
 This feature allows the generation of a default index-page which lists the generated crates.
 
-### `--nocapture`: disable output capture for test
+## `--nocapture`: disable output capture for test
 
 When this flag is used with `--test`, the output (stdout and stderr) of your tests won't be
 captured by rustdoc. Instead, the output will be directed to your terminal,
 as if you had run the test executable manually. This is especially useful
 for debugging your tests!
 
-### `--check`: only checks the documentation
+## `--check`: only checks the documentation
 
 When this flag is supplied, rustdoc will type check and lint your code, but will not generate any
 documentation or run your doctests.
@@ -420,7 +420,7 @@ Using this flag looks like:
 rustdoc -Z unstable-options --check src/lib.rs
 ```
 
-### `--static-root-path`: control how static files are loaded in HTML output
+## `--static-root-path`: control how static files are loaded in HTML output
 
 Using this flag looks like this:
 
@@ -435,7 +435,7 @@ JavaScript, and font files in a single location, rather than duplicating it once
 files like the search index will still load from the documentation root, but anything that gets
 renamed with `--resource-suffix` will load from the given path.
 
-### `--persist-doctests`: persist doctest executables after running
+## `--persist-doctests`: persist doctest executables after running
 
  * Tracking issue: [#56925](https://github.com/rust-lang/rust/issues/56925)
 
@@ -449,7 +449,7 @@ This flag allows you to keep doctest executables around after they're compiled o
 Usually, rustdoc will immediately discard a compiled doctest after it's been tested, but
 with this option, you can keep those binaries around for farther testing.
 
-### `--show-coverage`: calculate the percentage of items with documentation
+## `--show-coverage`: calculate the percentage of items with documentation
 
  * Tracking issue: [#58154](https://github.com/rust-lang/rust/issues/58154)
 
@@ -500,7 +500,7 @@ Calculating code examples follows these rules:
   * typedef
 2. If one of the previously listed items has a code example, then it'll be counted.
 
-#### JSON output
+### JSON output
 
 When using `--output-format json` with this option, it will display the coverage information in
 JSON format. For example, here is the JSON for a file with one documented item and one
@@ -522,7 +522,7 @@ Note that the third item is the crate root, which in this case is undocumented.
 If you want the JSON output to be displayed on `stdout` instead of having a file generated, you can
 use `-o -`.
 
-### `-w`/`--output-format`: output format
+## `-w`/`--output-format`: output format
 
 `--output-format json` emits documentation in the experimental
 [JSON format](https://doc.rust-lang.org/nightly/nightly-rustc/rustdoc_json_types/). `--output-format html` has no effect,
@@ -542,7 +542,7 @@ It can also be used with `--show-coverage`. Take a look at its
 [documentation](#--show-coverage-calculate-the-percentage-of-items-with-documentation) for more
 information.
 
-### `--enable-per-target-ignores`: allow `ignore-foo` style filters for doctests
+## `--enable-per-target-ignores`: allow `ignore-foo` style filters for doctests
 
  * Tracking issue: [#64245](https://github.com/rust-lang/rust/issues/64245)
 
@@ -577,7 +577,7 @@ struct Foo;
 In older versions, this will be ignored on all targets, but on newer versions `ignore-gnu` will
 override `ignore`.
 
-### `--runtool`, `--runtool-arg`: program to run tests with; args to pass to it
+## `--runtool`, `--runtool-arg`: program to run tests with; args to pass to it
 
  * Tracking issue: [#64245](https://github.com/rust-lang/rust/issues/64245)
 
@@ -596,7 +596,7 @@ $ rustdoc src/lib.rs -Z unstable-options --runtool valgrind
 
 Another use case would be to run a test inside an emulator, or through a Virtual Machine.
 
-### `--with-examples`: include examples of uses of items as documentation
+## `--with-examples`: include examples of uses of items as documentation
 
  * Tracking issue: [#88791](https://github.com/rust-lang/rust/issues/88791)
 
@@ -625,7 +625,7 @@ crate being documented (`foobar`) and a path to output the calls
 To scrape examples from test code, e.g. functions marked `#[test]`, then
 add the `--scrape-tests` flag.
 
-### `--generate-link-to-definition`: Generate links on types in source code
+## `--generate-link-to-definition`: Generate links on types in source code
 
  * Tracking issue: [#89095](https://github.com/rust-lang/rust/issues/89095)
 
@@ -664,3 +664,80 @@ Similar to cargo `build.rustc-wrapper` option, this flag takes a `rustc` wrapper
 The first argument to the program will be the test builder program.
 
 This flag can be passed multiple times to nest wrappers.
+
+## Passing arguments to rustc when compiling doctests
+
+You can use the `--doctest-compilation-args` flag if you want to add options when compiling the
+doctest. For example if you have:
+
+```rust,no_run
+/// ```
+/// #![deny(warnings)]
+/// #![feature(async_await)]
+///
+/// let x = 12;
+/// ```
+pub struct Bar;
+```
+
+And you run `rustdoc --test` on it, you will get:
+
+```console
+running 1 test
+test foo.rs - Bar (line 1) ... FAILED
+
+failures:
+
+---- foo.rs - Bar (line 1) stdout ----
+error: the feature `async_await` has been stable since 1.39.0 and no longer requires an attribute to enable
+ --> foo.rs:2:12
+  |
+3 | #![feature(async_await)]
+  |            ^^^^^^^^^^^
+  |
+note: the lint level is defined here
+ --> foo.rs:1:9
+  |
+2 | #![deny(warnings)]
+  |         ^^^^^^^^
+  = note: `#[deny(stable_features)]` implied by `#[deny(warnings)]`
+
+error: aborting due to 1 previous error
+
+Couldn't compile the test.
+
+failures:
+    foo.rs - Bar (line 1)
+
+test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.03s
+```
+
+But if you can limit the lint level to warning by using `--doctest_compilation_args=--cap-lints=warn`:
+
+```console
+$ rustdoc --test --doctest_compilation_args=--cap-lints=warn file.rs
+
+running 1 test
+test tests/rustdoc-ui/doctest/rustflags.rs - Bar (line 5) ... ok
+
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.06s
+```
+
+The parsing of arguments works as follows: if it encounters a `"` or a `'`, it will continue
+until it finds the character unescaped (without a prepending `\`). If not inside a string, a
+whitespace character will also split arguments. Example:
+
+```text
+"hello 'a'\" ok" how are   'you today?'
+```
+
+will be split as follows:
+
+```text
+[
+    "hello 'a'\" ok",
+    "how",
+    "are",
+    "you today?",
+]
+```

src/librustdoc/config.rs

@@ -172,6 +172,9 @@ pub(crate) struct Options {
     /// This is mainly useful for other tools that reads that debuginfo to figure out
     /// how to call the compiler with the same arguments.
     pub(crate) expanded_args: Vec<String>,
+
+    /// Arguments to be used when compiling doctests.
+    pub(crate) doctest_compilation_args: Vec<String>,
 }
 
 impl fmt::Debug for Options {
@@ -774,6 +777,7 @@ impl Options {
         let scrape_examples_options = ScrapeExamplesOptions::new(matches, dcx);
         let with_examples = matches.opt_strs("with-examples");
         let call_locations = crate::scrape_examples::load_call_locations(with_examples, dcx);
+        let doctest_compilation_args = matches.opt_strs("doctest-compilation-args");
 
         let unstable_features =
             rustc_feature::UnstableFeatures::from_environment(crate_name.as_deref());
@@ -819,6 +823,7 @@ impl Options {
             scrape_examples_options,
             unstable_features,
             expanded_args: args,
+            doctest_compilation_args,
         };
         let render_options = RenderOptions {
             output,

src/librustdoc/doctest.rs

@@ -50,6 +50,46 @@ pub(crate) struct GlobalTestOptions {
     pub(crate) args_file: PathBuf,
 }
 
+/// Function used to split command line arguments just like a shell would.
+fn split_args(args: &str) -> Vec<String> {
+    let mut out = Vec::new();
+    let mut iter = args.chars();
+    let mut current = String::new();
+
+    while let Some(c) = iter.next() {
+        if c == '\\' {
+            if let Some(c) = iter.next() {
+                // If it's escaped, even a quote or a whitespace will be ignored.
+                current.push(c);
+            }
+        } else if c == '"' || c == '\'' {
+            while let Some(new_c) = iter.next() {
+                if new_c == c {
+                    break;
+                } else if new_c == '\\' {
+                    if let Some(c) = iter.next() {
+                        // If it's escaped, even a quote will be ignored.
+                        current.push(c);
+                    }
+                } else {
+                    current.push(new_c);
+                }
+            }
+        } else if " \n\t\r".contains(c) {
+            if !current.is_empty() {
+                out.push(current.clone());
+                current.clear();
+            }
+        } else {
+            current.push(c);
+        }
+    }
+    if !current.is_empty() {
+        out.push(current);
+    }
+    out
+}
+
 pub(crate) fn generate_args_file(file_path: &Path, options: &RustdocOptions) -> Result<(), String> {
     let mut file = File::create(file_path)
         .map_err(|error| format!("failed to create args file: {error:?}"))?;
@@ -78,6 +118,10 @@ pub(crate) fn generate_args_file(file_path: &Path, options: &RustdocOptions) ->
         content.push(format!("-Z{unstable_option_str}"));
     }
 
+    for compilation_args in &options.doctest_compilation_args {
+        content.extend(split_args(compilation_args));
+    }
+
     let content = content.join("\n");
 
     file.write_all(content.as_bytes())

src/librustdoc/doctest/tests.rs

@@ -379,3 +379,25 @@ fn main() {
     let (output, len) = make_test(input, None, false, &opts, None);
     assert_eq!((output, len), (expected, 1));
 }
+
+#[test]
+fn check_split_args() {
+    fn compare(input: &str, expected: &[&str]) {
+        let output = super::split_args(input);
+        let expected = expected.iter().map(|s| s.to_string()).collect::<Vec<_>>();
+        assert_eq!(expected, output, "test failed for {input:?}");
+    }
+
+    compare("'a' \"b\"c", &["a", "bc"]);
+    compare("'a' \"b \"c d", &["a", "b c", "d"]);
+    compare("'a' \"b\\\"c\"", &["a", "b\"c"]);
+    compare("'a\"'", &["a\""]);
+    compare("\"a'\"", &["a'"]);
+    compare("\\ a", &[" a"]);
+    compare("\\\\", &["\\"]);
+    compare("a'", &["a"]);
+    compare("a          ", &["a"]);
+    compare("a          b", &["a", "b"]);
+    compare("a\n\t \rb", &["a", "b"]);
+    compare("a\n\t1 \rb", &["a", "1", "b"]);
+}

src/librustdoc/lib.rs

@@ -642,6 +642,15 @@ fn opts() -> Vec<RustcOptGroup> {
             "Includes trait implementations and other crate info from provided path. Only use with --merge=finalize",
             "path/to/doc.parts/<crate-name>",
         ),
+        opt(Unstable, Flag, "", "html-no-source", "Disable HTML source code pages generation", ""),
+        opt(
+            Unstable,
+            Multi,
+            "",
+            "doctest-compilation-args",
+            "",
+            "add arguments to be used when compiling doctests",
+        ),
         // deprecated / removed options
         opt(Unstable, FlagMulti, "", "disable-minification", "removed", ""),
         opt(
@@ -684,7 +693,6 @@ fn opts() -> Vec<RustcOptGroup> {
             "removed, see issue #44136 <https://github.com/rust-lang/rust/issues/44136> for more information",
             "[rust]",
         ),
-        opt(Unstable, Flag, "", "html-no-source", "Disable HTML source code pages generation", ""),
     ]
 }
 

tests/run-make/rustdoc-default-output/output-default.stdout

@@ -189,6 +189,10 @@ Options:
         --include-parts-dir path/to/doc.parts/<crate-name>
                         Includes trait implementations and other crate info
                         from provided path. Only use with --merge=finalize
+        --html-no-source 
+                        Disable HTML source code pages generation
+        --doctest-compilation-args add arguments to be used when compiling doctests
+                        
         --disable-minification 
                         removed
         --plugin-path DIR
@@ -209,8 +213,6 @@ Options:
                         removed, see issue #44136
                         <https://github.com/rust-lang/rust/issues/44136> for
                         more information
-        --html-no-source 
-                        Disable HTML source code pages generation
 
     @path               Read newline separated options from `path`
 

tests/rustdoc-ui/doctest/rustflags-multiple-args.rs

@@ -0,0 +1,17 @@
+// This test checks that the test behave when `--doctest-compilation-args` is passed
+// multiple times.
+
+//@ check-pass
+//@ compile-flags: --test -Zunstable-options --doctest-compilation-args=--cfg=testcase_must_be_present
+//@ compile-flags: --doctest-compilation-args=--cfg=another
+//@ normalize-stdout-test: "tests/rustdoc-ui/doctest" -> "$$DIR"
+//@ normalize-stdout-test: "finished in \d+\.\d+s" -> "finished in $$TIME"
+
+/// ```
+/// #[cfg(testcase_must_be_present)]
+/// #[cfg(another)]
+/// fn must_be_present() {}
+///
+/// fn main() { must_be_present() }
+/// ```
+pub struct Bar;

tests/rustdoc-ui/doctest/rustflags-multiple-args.stdout

@@ -0,0 +1,6 @@
+
+running 1 test
+test $DIR/rustflags-multiple-args.rs - Bar (line 10) ... ok
+
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+

tests/rustdoc-ui/doctest/rustflags.rs

@@ -0,0 +1,12 @@
+//@ check-pass
+//@ compile-flags: --test -Zunstable-options --doctest-compilation-args=--cfg=testcase_must_be_present
+//@ normalize-stdout-test: "tests/rustdoc-ui/doctest" -> "$$DIR"
+//@ normalize-stdout-test: "finished in \d+\.\d+s" -> "finished in $$TIME"
+
+/// ```
+/// #[cfg(testcase_must_be_present)]
+/// fn must_be_present() {}
+///
+/// fn main() { must_be_present() }
+/// ```
+pub struct Bar;

tests/rustdoc-ui/doctest/rustflags.stdout

@@ -0,0 +1,6 @@
+
+running 1 test
+test $DIR/rustflags.rs - Bar (line 6) ... ok
+
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+

tests/ui-fulldeps/pprust-parenthesis-insertion.rs

@@ -68,6 +68,12 @@ static EXPRS: &[&str] = &[
     // These mean different things.
     "return - 2",
     "(return) - 2",
+    // Closures and jumps have equal precedence.
+    "|| return break 2",
+    "return break || 2",
+    // Closures with a return type have especially high precedence.
+    "|| -> T { x } + 1",
+    "(|| { x }) + 1",
     // These mean different things.
     "if let _ = true && false {}",
     "if let _ = (true && false) {}",

tests/ui/lint/fn-ptr-comparisons-some.rs

@@ -0,0 +1,17 @@
+// This test checks that we lint on Option of fn ptr.
+//
+// https://github.com/rust-lang/rust/issues/134527.
+//
+//@ check-pass
+
+unsafe extern "C" fn func() {}
+
+type FnPtr = unsafe extern "C" fn();
+
+fn main() {
+    let _ = Some::<FnPtr>(func) == Some(func as unsafe extern "C" fn());
+    //~^ WARN function pointer comparisons
+
+    // Undecided as of https://github.com/rust-lang/rust/pull/134536
+    assert_eq!(Some::<FnPtr>(func), Some(func as unsafe extern "C" fn()));
+}

tests/ui/lint/fn-ptr-comparisons-some.stderr

@@ -0,0 +1,13 @@
+warning: function pointer comparisons do not produce meaningful results since their addresses are not guaranteed to be unique
+  --> $DIR/fn-ptr-comparisons-some.rs:12:13
+   |
+LL |     let _ = Some::<FnPtr>(func) == Some(func as unsafe extern "C" fn());
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the address of the same function can vary between different codegen units
+   = note: furthermore, different functions could have the same address after being merged together
+   = note: for more information visit <https://doc.rust-lang.org/nightly/core/ptr/fn.fn_addr_eq.html>
+   = note: `#[warn(unpredictable_function_pointer_comparisons)]` on by default
+
+warning: 1 warning emitted
+

tests/ui/self/arbitrary_self_types_niche_deshadowing.rs

@@ -0,0 +1,63 @@
+//@ run-pass
+
+#![allow(dead_code)]
+#![allow(incomplete_features)]
+
+#![feature(arbitrary_self_types)]
+#![feature(arbitrary_self_types_pointers)]
+#![feature(pin_ergonomics)]
+
+use std::pin::Pin;
+use std::pin::pin;
+use std::marker::PhantomData;
+
+struct A;
+
+impl A {
+    fn m(self: *const SmartPtr<Self>) -> usize { 2 }
+    fn n(self: *const SmartPtr<Self>) -> usize { 2 }
+
+    fn o(self: Pin<&SmartPtr2<Self>>) -> usize { 2 }
+    fn p(self: Pin<&SmartPtr2<Self>>) -> usize { 2 }
+}
+
+struct SmartPtr<T>(T);
+
+impl<T> core::ops::Receiver for SmartPtr<T> {
+    type Target = *mut T;
+}
+
+impl<T> SmartPtr<T> {
+    // In general we try to detect cases where a method in a smart pointer
+    // "shadows" a method in the referent (in this test, A).
+    // This method "shadows" the 'n' method in the inner type A
+    // We do not attempt to produce an error in these shadowing cases
+    // since the type signature of this method and the corresponding
+    // method in A are pretty unlikely to occur in practice,
+    // and because it shows up conflicts between *const::cast and *mut::cast.
+    fn n(self: *mut Self) -> usize { 1 }
+}
+
+struct SmartPtr2<'a, T>(T, PhantomData<&'a T>);
+
+impl<'a, T> core::ops::Receiver for SmartPtr2<'a, T> {
+    type Target = Pin<&'a mut T>;
+}
+
+impl<T> SmartPtr2<'_, T> {
+    // Similarly, this method shadows the method in A
+    // Can only happen with the unstable feature pin_ergonomics
+    fn p(self: Pin<&mut Self>) -> usize { 1 }
+}
+
+fn main() {
+    let mut sm = SmartPtr(A);
+    let smp: *mut SmartPtr<A> = &mut sm as *mut SmartPtr<A>;
+    assert_eq!(smp.m(), 2);
+    assert_eq!(smp.n(), 1);
+
+    let smp: Pin<&mut SmartPtr2<A>> = pin!(SmartPtr2(A, PhantomData));
+    assert_eq!(smp.o(), 2);
+    let smp: Pin<&mut SmartPtr2<A>> = pin!(SmartPtr2(A, PhantomData));
+    assert_eq!(smp.p(), 1);
+}

tests/ui/self/arbitrary_self_types_pin_getref.feature.stderr

@@ -0,0 +1,16 @@
+error[E0034]: multiple applicable items in scope
+  --> $DIR/arbitrary_self_types_pin_getref.rs:23:22
+   |
+LL |     let _ = pinned_a.get_ref();
+   |                      ^^^^^^^ multiple `get_ref` found
+   |
+note: candidate #1 is defined in an impl for the type `A`
+  --> $DIR/arbitrary_self_types_pin_getref.rs:17:5
+   |
+LL |     fn get_ref(self: &Pin<&A>) {}  // note &Pin
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: candidate #2 is defined in an impl for the type `Pin<&'a T>`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0034`.

tests/ui/self/arbitrary_self_types_pin_getref.rs

@@ -0,0 +1,25 @@
+// Confirms that Pin::get_ref can no longer shadow methods in pointees
+// once arbitrary_self_types is enabled.
+//
+//@ revisions: default feature
+#![cfg_attr(feature, feature(arbitrary_self_types))]
+
+//@[default] check-pass
+
+#![allow(dead_code)]
+
+use std::pin::Pin;
+use std::pin::pin;
+
+struct A;
+
+impl A {
+    fn get_ref(self: &Pin<&A>) {}  // note &Pin
+}
+
+fn main() {
+    let pinned_a: Pin<&mut A> = pin!(A);
+    let pinned_a: Pin<&A> = pinned_a.as_ref();
+    let _ = pinned_a.get_ref();
+    //[feature]~^ ERROR: multiple applicable items
+}

tests/ui/structs/default-field-values-non_exhaustive.rs

@@ -0,0 +1,18 @@
+#![feature(default_field_values)]
+
+#[derive(Default)]
+#[non_exhaustive] //~ ERROR `#[non_exhaustive]` can't be used to annotate items with default field values
+struct Foo {
+    x: i32 = 42 + 3,
+}
+
+#[derive(Default)]
+enum Bar {
+    #[non_exhaustive]
+    #[default]
+    Baz { //~ ERROR default variant must be exhaustive
+        x: i32 = 42 + 3,
+    }
+}
+
+fn main () {}

tests/ui/structs/default-field-values-non_exhaustive.stderr

@@ -0,0 +1,23 @@
+error: default variant must be exhaustive
+  --> $DIR/default-field-values-non_exhaustive.rs:13:5
+   |
+LL |     #[non_exhaustive]
+   |     ----------------- declared `#[non_exhaustive]` here
+LL |     #[default]
+LL |     Baz {
+   |     ^^^
+   |
+   = help: consider a manual implementation of `Default`
+
+error: `#[non_exhaustive]` can't be used to annotate items with default field values
+  --> $DIR/default-field-values-non_exhaustive.rs:4:1
+   |
+LL |   #[non_exhaustive]
+   |   ^^^^^^^^^^^^^^^^^
+LL | / struct Foo {
+LL | |     x: i32 = 42 + 3,
+LL | | }
+   | |_- this struct has default field values
+
+error: aborting due to 2 previous errors
+