Auto merge of rust-lang#92556 - matthiaskrgr:rollup-s9vopuj, r=matthi…

…askrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#91754 (Modifications to `std::io::Stdin` on Windows so that there is no longer a 4-byte buffer minimum in read().)
 - rust-lang#91884 (Constify `Box<T, A>` methods)
 - rust-lang#92107 (Actually set IMAGE_SCN_LNK_REMOVE for .rmeta)
 - rust-lang#92456 (Make the documentation of builtin macro attributes accessible)
 - rust-lang#92507 (Suggest single quotes when char expected, str provided)
 - rust-lang#92525 (intra-doc: Make `Receiver::into_iter` into a clickable link)
 - rust-lang#92532 (revert rust-lang#92254 "Bump gsgdt to 0.1.3")

Failed merges:

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

Cargo.lock

@@ -1505,9 +1505,9 @@ dependencies = [
 
 [[package]]
 name = "gsgdt"
-version = "0.1.3"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb958139bb971f37d2f5423436f137768f88b9c616b4c21d4f634dd129508d60"
+checksum = "a0d876ce7262df96262a2a19531da6ff9a86048224d49580a585fc5c04617825"
 dependencies = [
  "serde",
 ]

compiler/rustc_codegen_ssa/src/back/metadata.rs

@@ -6,8 +6,8 @@ use std::path::Path;
 
 use object::write::{self, StandardSegment, Symbol, SymbolSection};
 use object::{
-    elf, Architecture, BinaryFormat, Endianness, FileFlags, Object, ObjectSection, SectionFlags,
-    SectionKind, SymbolFlags, SymbolKind, SymbolScope,
+    elf, pe, Architecture, BinaryFormat, Endianness, FileFlags, Object, ObjectSection,
+    SectionFlags, SectionKind, SymbolFlags, SymbolKind, SymbolScope,
 };
 
 use snap::write::FrameEncoder;
@@ -216,13 +216,12 @@ pub fn create_rmeta_file(sess: &Session, metadata: &[u8]) -> Vec<u8> {
     );
     match file.format() {
         BinaryFormat::Coff => {
-            const IMAGE_SCN_LNK_REMOVE: u32 = 0;
             file.section_mut(section).flags =
-                SectionFlags::Coff { characteristics: IMAGE_SCN_LNK_REMOVE };
+                SectionFlags::Coff { characteristics: pe::IMAGE_SCN_LNK_REMOVE };
         }
         BinaryFormat::Elf => {
-            const SHF_EXCLUDE: u64 = 0x80000000;
-            file.section_mut(section).flags = SectionFlags::Elf { sh_flags: SHF_EXCLUDE };
+            file.section_mut(section).flags =
+                SectionFlags::Elf { sh_flags: elf::SHF_EXCLUDE as u64 };
         }
         _ => {}
     };

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -2041,11 +2041,11 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 if let ValuePairs::Types(ty::error::ExpectedFound { expected, found }) =
                     trace.values
                 {
-                    // If a tuple of length one was expected and the found expression has
-                    // parentheses around it, perhaps the user meant to write `(expr,)` to
-                    // build a tuple (issue #86100)
                     match (expected.kind(), found.kind()) {
                         (ty::Tuple(_), ty::Tuple(_)) => {}
+                        // If a tuple of length one was expected and the found expression has
+                        // parentheses around it, perhaps the user meant to write `(expr,)` to
+                        // build a tuple (issue #86100)
                         (ty::Tuple(_), _) if expected.tuple_fields().count() == 1 => {
                             if let Ok(code) = self.tcx.sess().source_map().span_to_snippet(span) {
                                 if let Some(code) =
@@ -2060,6 +2060,41 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                                 }
                             }
                         }
+                        // If a character was expected and the found expression is a string literal
+                        // containing a single character, perhaps the user meant to write `'c'` to
+                        // specify a character literal (issue #92479)
+                        (ty::Char, ty::Ref(_, r, _)) if r.is_str() => {
+                            if let Ok(code) = self.tcx.sess().source_map().span_to_snippet(span) {
+                                if let Some(code) =
+                                    code.strip_prefix('"').and_then(|s| s.strip_suffix('"'))
+                                {
+                                    if code.chars().nth(1).is_none() {
+                                        err.span_suggestion(
+                                            span,
+                                            "if you meant to write a `char` literal, use single quotes",
+                                            format!("'{}'", code),
+                                            Applicability::MachineApplicable,
+                                        );
+                                    }
+                                }
+                            }
+                        }
+                        // If a string was expected and the found expression is a character literal,
+                        // perhaps the user meant to write `"s"` to specify a string literal.
+                        (ty::Ref(_, r, _), ty::Char) if r.is_str() => {
+                            if let Ok(code) = self.tcx.sess().source_map().span_to_snippet(span) {
+                                if let Some(code) =
+                                    code.strip_prefix('\'').and_then(|s| s.strip_suffix('\''))
+                                {
+                                    err.span_suggestion(
+                                        span,
+                                        "if you meant to write a `str` literal, use double quotes",
+                                        format!("\"{}\"", code),
+                                        Applicability::MachineApplicable,
+                                    );
+                                }
+                            }
+                        }
                         _ => {}
                     }
                 }

compiler/rustc_middle/Cargo.toml

@@ -10,7 +10,7 @@ doctest = false
 rustc_arena = { path = "../rustc_arena" }
 bitflags = "1.2.1"
 either = "1.5.0"
-gsgdt = "0.1.3"
+gsgdt = "0.1.2"
 tracing = "0.1"
 rustc-rayon = "0.3.1"
 rustc-rayon-core = "0.3.1"

compiler/rustc_middle/src/mir/generic_graph.rs

@@ -55,7 +55,7 @@ fn bb_to_graph_node(block: BasicBlock, body: &Body<'_>, dark_mode: bool) -> Node
     data.terminator().kind.fmt_head(&mut terminator_head).unwrap();
     stmts.push(terminator_head);
 
-    Node::from_list(stmts, label, title, style)
+    Node::new(stmts, label, title, style)
 }
 
 // Must match `[0-9A-Za-z_]*`. This does not appear in the rendered graph, so

library/alloc/src/alloc.rs

@@ -323,17 +323,21 @@ unsafe fn exchange_malloc(size: usize, align: usize) -> *mut u8 {
 
 #[cfg_attr(not(test), lang = "box_free")]
 #[inline]
+#[rustc_const_unstable(feature = "const_box", issue = "92521")]
 // This signature has to be the same as `Box`, otherwise an ICE will happen.
 // When an additional parameter to `Box` is added (like `A: Allocator`), this has to be added here as
 // well.
 // For example if `Box` is changed to  `struct Box<T: ?Sized, A: Allocator>(Unique<T>, A)`,
 // this function has to be changed to `fn box_free<T: ?Sized, A: Allocator>(Unique<T>, A)` as well.
-pub(crate) unsafe fn box_free<T: ?Sized, A: Allocator>(ptr: Unique<T>, alloc: A) {
+pub(crate) const unsafe fn box_free<T: ?Sized, A: ~const Allocator + ~const Drop>(
+    ptr: Unique<T>,
+    alloc: A,
+) {
     unsafe {
         let size = size_of_val(ptr.as_ref());
         let align = min_align_of_val(ptr.as_ref());
         let layout = Layout::from_size_align_unchecked(size, align);
-        alloc.deallocate(ptr.cast().into(), layout)
+        alloc.deallocate(From::from(ptr.cast()), layout)
     }
 }
 
@@ -361,13 +365,22 @@ extern "Rust" {
 /// [`set_alloc_error_hook`]: ../../std/alloc/fn.set_alloc_error_hook.html
 /// [`take_alloc_error_hook`]: ../../std/alloc/fn.take_alloc_error_hook.html
 #[stable(feature = "global_alloc", since = "1.28.0")]
+#[rustc_const_unstable(feature = "const_alloc_error", issue = "92523")]
 #[cfg(all(not(no_global_oom_handling), not(test)))]
 #[rustc_allocator_nounwind]
 #[cold]
-pub fn handle_alloc_error(layout: Layout) -> ! {
-    unsafe {
-        __rust_alloc_error_handler(layout.size(), layout.align());
+pub const fn handle_alloc_error(layout: Layout) -> ! {
+    const fn ct_error(_: Layout) -> ! {
+        panic!("allocation failed");
     }
+
+    fn rt_error(layout: Layout) -> ! {
+        unsafe {
+            __rust_alloc_error_handler(layout.size(), layout.align());
+        }
+    }
+
+    unsafe { core::intrinsics::const_eval_select((layout,), ct_error, rt_error) }
 }
 
 // For alloc test `std::alloc::handle_alloc_error` can be used directly.