Auto merge of #103398 - Dylan-DPC:rollup-cj6w00o, r=Dylan-DPC

Rollup of 7 pull requests

Successful merges:

 - #102602 (Slightly tweak comments wrt `lint_overflowing_range_endpoint`)
 - #103190 (rustdoc: render bounds of cross-crate GAT params)
 - #103224 (Allow semicolon after closure within parentheses in macros)
 - #103280 ((#102929) Implement `String::leak` (attempt 2))
 - #103329 (Add a forgotten check for NonNull::new_unchecked's precondition)
 - #103346 (Adjust argument type for mutable with_metadata_of (#75091))
 - #103360 (Reduce false positives in msys2 detection)

Failed merges:

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

compiler/rustc_lint/src/types.rs

@@ -116,8 +116,8 @@ impl TypeLimits {
     }
 }
 
-/// Attempts to special-case the overflowing literal lint when it occurs as a range endpoint.
-/// Returns `true` iff the lint was overridden.
+/// Attempts to special-case the overflowing literal lint when it occurs as a range endpoint (`expr..MAX+1`).
+/// Returns `true` iff the lint was emitted.
 fn lint_overflowing_range_endpoint<'tcx>(
     cx: &LateContext<'tcx>,
     lit: &hir::Lit,
@@ -140,44 +140,46 @@ fn lint_overflowing_range_endpoint<'tcx>(
         return false;
     }
 
-    let mut overwritten = false;
     // We can suggest using an inclusive range
     // (`..=`) instead only if it is the `end` that is
     // overflowing and only by 1.
-    if eps[1].expr.hir_id == expr.hir_id && lit_val - 1 == max
-        && let Ok(start) = cx.sess().source_map().span_to_snippet(eps[0].span)
-    {
-        cx.struct_span_lint(
-            OVERFLOWING_LITERALS,
-            struct_expr.span,
-            fluent::lint::range_endpoint_out_of_range,
-            |lint| {
-                use ast::{LitIntType, LitKind};
+    if !(eps[1].expr.hir_id == expr.hir_id && lit_val - 1 == max) {
+        return false;
+    };
+    let Ok(start) = cx.sess().source_map().span_to_snippet(eps[0].span) else { return false };
 
-                lint.set_arg("ty", ty);
+    cx.struct_span_lint(
+        OVERFLOWING_LITERALS,
+        struct_expr.span,
+        fluent::lint::range_endpoint_out_of_range,
+        |lint| {
+            use ast::{LitIntType, LitKind};
 
-                // We need to preserve the literal's suffix,
-                // as it may determine typing information.
-                let suffix = match lit.node {
-                    LitKind::Int(_, LitIntType::Signed(s)) => s.name_str(),
-                    LitKind::Int(_, LitIntType::Unsigned(s)) => s.name_str(),
-                    LitKind::Int(_, LitIntType::Unsuffixed) => "",
-                    _ => bug!(),
-                };
-                let suggestion = format!("{}..={}{}", start, lit_val - 1, suffix);
-                lint.span_suggestion(
-                    struct_expr.span,
-                    fluent::lint::suggestion,
-                    suggestion,
-                    Applicability::MachineApplicable,
-                );
-                overwritten = true;
+            lint.set_arg("ty", ty);
 
-                lint
-            },
-        );
-    }
-    overwritten
+            // We need to preserve the literal's suffix,
+            // as it may determine typing information.
+            let suffix = match lit.node {
+                LitKind::Int(_, LitIntType::Signed(s)) => s.name_str(),
+                LitKind::Int(_, LitIntType::Unsigned(s)) => s.name_str(),
+                LitKind::Int(_, LitIntType::Unsuffixed) => "",
+                _ => bug!(),
+            };
+            let suggestion = format!("{}..={}{}", start, lit_val - 1, suffix);
+            lint.span_suggestion(
+                struct_expr.span,
+                fluent::lint::suggestion,
+                suggestion,
+                Applicability::MachineApplicable,
+            );
+
+            lint
+        },
+    );
+
+    // We've just emitted a lint, special cased for `(...)..MAX+1` ranges,
+    // return `true` so the callers don't also emit a lint
+    true
 }
 
 // For `isize` & `usize`, be conservative with the warnings, so that the
@@ -358,7 +360,7 @@ fn lint_int_literal<'tcx>(
         }
 
         if lint_overflowing_range_endpoint(cx, lit, v, max, e, t.name_str()) {
-            // The overflowing literal lint was overridden.
+            // The overflowing literal lint was emited by `lint_overflowing_range_endpoint`.
             return;
         }
 
@@ -427,7 +429,7 @@ fn lint_uint_literal<'tcx>(
             }
         }
         if lint_overflowing_range_endpoint(cx, lit, lit_val, max, e, t.name_str()) {
-            // The overflowing literal lint was overridden.
+            // The overflowing literal lint was emited by `lint_overflowing_range_endpoint`.
             return;
         }
         if let Some(repr_str) = get_bin_hex_repr(cx, lit) {

compiler/rustc_parse/src/parser/expr.rs

@@ -2051,6 +2051,10 @@ impl<'a> Parser<'a> {
 
         if self.token.kind == TokenKind::Semi
             && matches!(self.token_cursor.frame.delim_sp, Some((Delimiter::Parenthesis, _)))
+            // HACK: This is needed so we can detect whether we're inside a macro,
+            // where regular assumptions about what tokens can follow other tokens
+            // don't necessarily apply.
+            && self.subparser_name.is_none()
         {
             // It is likely that the closure body is a block but where the
             // braces have been removed. We will recover and eat the next

library/alloc/src/rc.rs

@@ -1386,7 +1386,7 @@ impl<T: ?Sized> Rc<T> {
             Self::allocate_for_layout(
                 Layout::for_value(&*ptr),
                 |layout| Global.allocate(layout),
-                |mem| mem.with_metadata_of(ptr as *mut RcBox<T>),
+                |mem| mem.with_metadata_of(ptr as *const RcBox<T>),
             )
         }
     }

library/alloc/src/string.rs

@@ -67,7 +67,7 @@ use core::str::Utf8Chunks;
 use crate::borrow::{Cow, ToOwned};
 use crate::boxed::Box;
 use crate::collections::TryReserveError;
-use crate::str::{self, Chars, Utf8Error};
+use crate::str::{self, from_utf8_unchecked_mut, Chars, Utf8Error};
 #[cfg(not(no_global_oom_handling))]
 use crate::str::{from_boxed_utf8_unchecked, FromStr};
 use crate::vec::Vec;
@@ -1849,6 +1849,35 @@ impl String {
         let slice = self.vec.into_boxed_slice();
         unsafe { from_boxed_utf8_unchecked(slice) }
     }
+
+    /// Consumes and leaks the `String`, returning a mutable reference to the contents,
+    /// `&'a mut str`.
+    ///
+    /// This is mainly useful for data that lives for the remainder of
+    /// the program's life. Dropping the returned reference will cause a memory
+    /// leak.
+    ///
+    /// It does not reallocate or shrink the `String`,
+    /// so the leaked allocation may include unused capacity that is not part
+    /// of the returned slice.
+    ///
+    /// # Examples
+    ///
+    /// Simple usage:
+    ///
+    /// ```
+    /// #![feature(string_leak)]
+    ///
+    /// let x = String::from("bucket");
+    /// let static_ref: &'static mut str = x.leak();
+    /// assert_eq!(static_ref, "bucket");
+    /// ```
+    #[unstable(feature = "string_leak", issue = "102929")]
+    #[inline]
+    pub fn leak(self) -> &'static mut str {
+        let slice = self.vec.leak();
+        unsafe { from_utf8_unchecked_mut(slice) }
+    }
 }
 
 impl FromUtf8Error {

library/alloc/src/sync.rs

@@ -1204,7 +1204,7 @@ impl<T: ?Sized> Arc<T> {
             Self::allocate_for_layout(
                 Layout::for_value(&*ptr),
                 |layout| Global.allocate(layout),
-                |mem| mem.with_metadata_of(ptr as *mut ArcInner<T>),
+                |mem| mem.with_metadata_of(ptr as *const ArcInner<T>),
             )
         }
     }

library/core/src/ptr/mut_ptr.rs

@@ -80,10 +80,14 @@ impl<T: ?Sized> *mut T {
     #[unstable(feature = "set_ptr_value", issue = "75091")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
     #[inline]
-    pub fn with_metadata_of<U>(self, mut val: *mut U) -> *mut U
+    pub fn with_metadata_of<U>(self, val: *const U) -> *mut U
     where
         U: ?Sized,
     {
+        // Prepare in the type system that we will replace the pointer value with a mutable
+        // pointer, taking the mutable provenance from the `self` pointer.
+        let mut val = val as *mut U;
+        // Pointer to the pointer value within the value.
         let target = &mut val as *mut *mut U as *mut *mut u8;
         // SAFETY: In case of a thin pointer, this operations is identical
         // to a simple assignment. In case of a fat pointer, with the current

library/core/src/ptr/non_null.rs

@@ -2,6 +2,7 @@ use crate::cmp::Ordering;
 use crate::convert::From;
 use crate::fmt;
 use crate::hash;
+use crate::intrinsics::assert_unsafe_precondition;
 use crate::marker::Unsize;
 use crate::mem::{self, MaybeUninit};
 use crate::num::NonZeroUsize;
@@ -195,7 +196,10 @@ impl<T: ?Sized> NonNull<T> {
     #[inline]
     pub const unsafe fn new_unchecked(ptr: *mut T) -> Self {
         // SAFETY: the caller must guarantee that `ptr` is non-null.
-        unsafe { NonNull { pointer: ptr as _ } }
+        unsafe {
+            assert_unsafe_precondition!([T: ?Sized](ptr: *mut T) => !ptr.is_null());
+            NonNull { pointer: ptr as _ }
+        }
     }
 
     /// Creates a new `NonNull` if `ptr` is non-null.

library/std/src/sys/windows/c.rs

@@ -129,6 +129,8 @@ pub const FIONBIO: c_ulong = 0x8004667e;
 
 pub const MAX_PATH: usize = 260;
 
+pub const FILE_TYPE_PIPE: u32 = 3;
+
 #[repr(C)]
 #[derive(Copy)]
 pub struct WIN32_FIND_DATAW {
@@ -1114,6 +1116,7 @@ extern "system" {
         lpFileInformation: LPVOID,
         dwBufferSize: DWORD,
     ) -> BOOL;
+    pub fn GetFileType(hfile: HANDLE) -> DWORD;
     pub fn SleepConditionVariableSRW(
         ConditionVariable: PCONDITION_VARIABLE,
         SRWLock: PSRWLOCK,

library/std/src/sys/windows/io.rs

@@ -120,6 +120,11 @@ unsafe fn handle_is_console(handle: BorrowedHandle<'_>) -> bool {
 }
 
 unsafe fn msys_tty_on(handle: c::HANDLE) -> bool {
+    // Early return if the handle is not a pipe.
+    if c::GetFileType(handle) != c::FILE_TYPE_PIPE {
+        return false;
+    }
+
     const SIZE: usize = size_of::<c::FILE_NAME_INFO>() + c::MAX_PATH * size_of::<c::WCHAR>();
     let mut name_info_bytes = Align8([0u8; SIZE]);
     let res = c::GetFileInformationByHandleEx(
@@ -137,11 +142,13 @@ unsafe fn msys_tty_on(handle: c::HANDLE) -> bool {
     let name_ptr = name_info_bytes.0.as_ptr().offset(size_of::<c::DWORD>() as isize).cast::<u16>();
     let s = core::slice::from_raw_parts(name_ptr, name_len);
     let name = String::from_utf16_lossy(s);
+    // Get the file name only.
+    let name = name.rsplit('\\').next().unwrap_or(&name);
     // This checks whether 'pty' exists in the file name, which indicates that
     // a pseudo-terminal is attached. To mitigate against false positives
     // (e.g., an actual file name that contains 'pty'), we also require that
-    // either the strings 'msys-' or 'cygwin-' are in the file name as well.)
-    let is_msys = name.contains("msys-") || name.contains("cygwin-");
+    // the file name begins with either the strings 'msys-' or 'cygwin-'.)
+    let is_msys = name.starts_with("msys-") || name.starts_with("cygwin-");
     let is_pty = name.contains("-pty");
     is_msys && is_pty
 }

src/librustdoc/clean/mod.rs

@@ -1201,21 +1201,19 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
             }
 
             if let ty::TraitContainer = assoc_item.container {
-                // FIXME(fmease): `tcx.explicit_item_bounds` does not contain the bounds of GATs,
-                //                e.g. the bounds `Copy`, `Display` & (implicitly) `Sized` in
-                //                `type Assoc<T: Copy> where T: Display`. This also means that we
-                //                later incorrectly render `where T: ?Sized`.
-                //
-                //                The result of `tcx.explicit_predicates_of` *does* contain them but
-                //                it does not contain the other bounds / predicates we need.
-                //                Either merge those two interned lists somehow or refactor
-                //                `clean_ty_generics` to call `explicit_item_bounds` by itself.
                 let bounds = tcx.explicit_item_bounds(assoc_item.def_id);
-                let predicates = ty::GenericPredicates { parent: None, predicates: bounds };
-                let mut generics =
-                    clean_ty_generics(cx, tcx.generics_of(assoc_item.def_id), predicates);
-                // Filter out the bounds that are (likely?) directly attached to the associated type,
-                // as opposed to being located in the where clause.
+                let predicates = tcx.explicit_predicates_of(assoc_item.def_id).predicates;
+                let predicates =
+                    tcx.arena.alloc_from_iter(bounds.into_iter().chain(predicates).copied());
+                let mut generics = clean_ty_generics(
+                    cx,
+                    tcx.generics_of(assoc_item.def_id),
+                    ty::GenericPredicates { parent: None, predicates },
+                );
+                // Move bounds that are (likely) directly attached to the associated type
+                // from the where clause to the associated type.
+                // There is no guarantee that this is what the user actually wrote but we have
+                // no way of knowing.
                 let mut bounds = generics
                     .where_predicates
                     .drain_filter(|pred| match *pred {
@@ -1273,6 +1271,24 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
                     }
                     None => bounds.push(GenericBound::maybe_sized(cx)),
                 }
+                // Move bounds that are (likely) directly attached to the parameters of the
+                // (generic) associated type from the where clause to the respective parameter.
+                // There is no guarantee that this is what the user actually wrote but we have
+                // no way of knowing.
+                let mut where_predicates = Vec::new();
+                for mut pred in generics.where_predicates {
+                    if let WherePredicate::BoundPredicate { ty: Generic(arg), bounds, .. } = &mut pred
+                    && let Some(GenericParamDef {
+                        kind: GenericParamDefKind::Type { bounds: param_bounds, .. },
+                        ..
+                    }) = generics.params.iter_mut().find(|param| &param.name == arg)
+                    {
+                        param_bounds.extend(mem::take(bounds));
+                    } else {
+                        where_predicates.push(pred);
+                    }
+                }
+                generics.where_predicates = where_predicates;
 
                 if tcx.impl_defaultness(assoc_item.def_id).has_value() {
                     AssocTypeItem(

src/test/rustdoc/inline_cross/assoc_item_trait_bounds.out0.html

@@ -0,0 +1 @@
+<h4 class="code-header">type <a href="#associatedtype.Out0" class="associatedtype">Out0</a>: <a class="trait" href="../assoc_item_trait_bounds/trait.Support.html" title="trait assoc_item_trait_bounds::Support">Support</a>&lt;Item = <a class="primitive" href="{{channel}}/std/primitive.unit.html">()</a>&gt;</h4>

src/test/rustdoc/inline_cross/assoc_item_trait_bounds.out2.html

@@ -0,0 +1 @@
+<h4 class="code-header">type <a href="#associatedtype.Out2" class="associatedtype">Out2</a>&lt;T&gt;: <a class="trait" href="../assoc_item_trait_bounds/trait.Support.html" title="trait assoc_item_trait_bounds::Support">Support</a>&lt;Item = T&gt;</h4>

src/test/rustdoc/inline_cross/assoc_item_trait_bounds.rs

@@ -1,13 +1,10 @@
 // Regression test for issues #77763, #84579 and #102142.
 #![crate_name = "main"]
 
-// aux-build:assoc_item_trait_bounds_with_bindings.rs
+// aux-build:assoc_item_trait_bounds.rs
 // build-aux-docs
 // ignore-cross-compile
-extern crate assoc_item_trait_bounds_with_bindings as aux;
-
-// FIXME(fmease): Don't render an incorrect `T: ?Sized` where-clause for parameters
-//                of GATs like `Main::Out{2,4}`. Add a snapshot test once it's fixed.
+extern crate assoc_item_trait_bounds as aux;
 
 // @has main/trait.Main.html
 // @has - '//*[@id="associatedtype.Out0"]' 'type Out0: Support<Item = ()>'
@@ -24,11 +21,15 @@ extern crate assoc_item_trait_bounds_with_bindings as aux;
 // @has - '//*[@id="associatedtype.Out11"]' "type Out11: for<'r, 's> Helper<A<'s> = &'s (), B<'r> = ()>"
 // @has - '//*[@id="associatedtype.Out12"]' "type Out12: for<'w> Helper<B<'w> = Cow<'w, str>, A<'w> = bool>"
 // @has - '//*[@id="associatedtype.Out13"]' "type Out13: for<'fst, 'snd> Aid<'snd, Result<'fst> = &'fst mut str>"
+// @has - '//*[@id="associatedtype.Out14"]' "type Out14<P: Copy + Eq, Q: ?Sized>"
 //
-// Snapshots: Check that we do not render any where-clauses for those associated types since all of
-// the trait bounds contained within were moved to the bounds of the respective item.
+// Snapshots:
+// Check that we don't render any where-clauses for the following associated types since
+// all corresponding projection equality predicates should have already been re-sugared
+// to associated type bindings:
 //
 // @snapshot out0 - '//*[@id="associatedtype.Out0"]/*[@class="code-header"]'
+// @snapshot out2 - '//*[@id="associatedtype.Out2"]/*[@class="code-header"]'
 // @snapshot out9 - '//*[@id="associatedtype.Out9"]/*[@class="code-header"]'
 //
 // @has - '//*[@id="tymethod.make"]' \

src/test/rustdoc/inline_cross/assoc_item_trait_bounds_with_bindings.out0.html

@@ -1 +0,0 @@
-<h4 class="code-header">type <a href="#associatedtype.Out0" class="associatedtype">Out0</a>: <a class="trait" href="../assoc_item_trait_bounds_with_bindings/trait.Support.html" title="trait assoc_item_trait_bounds_with_bindings::Support">Support</a>&lt;Item = <a class="primitive" href="{{channel}}/std/primitive.unit.html">()</a>&gt;</h4>

src/test/rustdoc/inline_cross/auxiliary/assoc_item_trait_bounds.rs

@@ -15,6 +15,7 @@ pub trait Main {
     type Out11: for<'r, 's> Helper<A<'s> = &'s (), B<'r> = ()>;
     type Out12: for<'w> Helper<B<'w> = std::borrow::Cow<'w, str>, A<'w> = bool>;
     type Out13: for<'fst, 'snd> Aid<'snd, Result<'fst> = &'fst mut str>;
+    type Out14<P: Copy + Eq, Q: ?Sized>;
 
     fn make<F>(_: F, _: impl FnMut(&str) -> bool)
     where

src/test/ui/parser/semi-after-closure-in-macro.rs

@@ -0,0 +1,14 @@
+// check-pass
+
+// Checks that the fix in #103222 doesn't also disqualify semicolons after
+// closures within parentheses *in macros*, where they're totally allowed.
+
+macro_rules! m {
+    (($expr:expr ; )) => {
+        $expr
+    };
+}
+
+fn main() {
+    let x = m!(( ||() ; ));
+}