Auto merge of #96548 - Dylan-DPC:rollup-m3xkqxg, r=Dylan-DPC

Rollup of 5 pull requests

Successful merges:

 - #96477 (Update data layout string for wasm64-unknown-unknown)
 - #96481 (HashMap doc: Don't use monospace font for 'Entry Api')
 - #96492 (Revert "Re-export core::ffi types from std::ffi")
 - #96516 (Revert diagnostic duplication and accidental stabilization)
 - #96523 (Add ``@feat.00`` symbol to symbols.o for COFF)

Failed merges:

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

Author: bors

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1700,6 +1700,29 @@ fn add_linked_symbol_object(
         // We handle the name decoration of COFF targets in `symbol_export.rs`, so disable the
         // default mangler in `object` crate.
         file.set_mangling(object::write::Mangling::None);
+
+        // Add feature flags to the object file. On MSVC this is optional but LLD will complain if
+        // not present.
+        let mut feature = 0;
+
+        if file.architecture() == object::Architecture::I386 {
+            // Indicate that all SEH handlers are registered in .sxdata section.
+            // We don't have generate any code, so we don't need .sxdata section but LLD still
+            // expects us to set this bit (see #96498).
+            // Reference: https://docs.microsoft.com/en-us/windows/win32/debug/pe-format
+            feature |= 1;
+        }
+
+        file.add_symbol(object::write::Symbol {
+            name: "@feat.00".into(),
+            value: feature,
+            size: 0,
+            kind: object::SymbolKind::Data,
+            scope: object::SymbolScope::Compilation,
+            weak: false,
+            section: object::write::SymbolSection::Absolute,
+            flags: object::SymbolFlags::None,
+        });
     }
 
     for (sym, kind) in symbols.iter() {

compiler/rustc_target/src/spec/wasm64_unknown_unknown.rs

@@ -36,7 +36,7 @@ pub fn target() -> Target {
     Target {
         llvm_target: "wasm64-unknown-unknown".into(),
         pointer_width: 64,
-        data_layout: "e-m:e-p:64:64-i64:64-n32:64-S128-ni:1:10:20".into(),
+        data_layout: "e-m:e-p:64:64-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20".into(),
         arch: "wasm64".into(),
         options,
     }

compiler/rustc_typeck/src/check/check.rs

@@ -102,6 +102,12 @@ pub(super) fn check_fn<'a, 'tcx>(
             DUMMY_SP,
             param_env,
         ));
+    // HACK(oli-obk): we rewrite the declared return type, too, so that we don't end up inferring all
+    // unconstrained RPIT to have `()` as their hidden type. This would happen because further down we
+    // compare the ret_coercion with declared_ret_ty, and anything uninferred would be inferred to the
+    // opaque type itself. That again would cause writeback to assume we have a recursive call site
+    // and do the sadly stabilized fallback to `()`.
+    let declared_ret_ty = ret_ty;
     fcx.ret_coercion = Some(RefCell::new(CoerceMany::new(ret_ty)));
     fcx.ret_type_span = Some(decl.output.span());
 

library/alloc/tests/c_str.rs

@@ -1,5 +1,6 @@
 use std::borrow::Cow::{Borrowed, Owned};
-use std::ffi::{c_char, CStr};
+use std::ffi::CStr;
+use std::os::raw::c_char;
 
 #[test]
 fn to_str() {

library/std/src/collections/hash/map.rs

@@ -136,7 +136,7 @@ use crate::sys;
 /// ]);
 /// ```
 ///
-/// `HashMap` implements an [`Entry API`](#method.entry), which allows
+/// `HashMap` implements an [`Entry` API](#method.entry), which allows
 /// for complex methods of getting, setting, updating and removing keys and
 /// their values:
 ///

library/std/src/ffi/mod.rs

@@ -171,15 +171,6 @@ pub use self::os_str::{OsStr, OsString};
 #[stable(feature = "core_c_void", since = "1.30.0")]
 pub use core::ffi::c_void;
 
-#[unstable(feature = "core_ffi_c", issue = "94501")]
-pub use core::ffi::{
-    c_char, c_double, c_float, c_int, c_long, c_longlong, c_schar, c_short, c_uchar, c_uint,
-    c_ulong, c_ulonglong, c_ushort,
-};
-
-#[unstable(feature = "c_size_t", issue = "88345")]
-pub use core::ffi::{c_ptrdiff_t, c_size_t, c_ssize_t};
-
 #[unstable(
     feature = "c_variadic",
     reason = "the `c_variadic` feature has not been properly tested on \

library/std/src/lib.rs

@@ -307,7 +307,6 @@
 // Only for re-exporting:
 #![feature(assert_matches)]
 #![feature(async_iterator)]
-#![feature(c_size_t)]
 #![feature(c_variadic)]
 #![feature(cfg_accessible)]
 #![feature(cfg_eval)]

src/test/run-make/issue-96498/Makefile

@@ -0,0 +1,8 @@
+# only-windows
+# needs-rust-lld
+
+-include ../../run-make-fulldeps/tools.mk
+
+# Ensure that LLD can link
+all:
+	$(RUSTC) -C linker=rust-lld foo.rs

src/test/run-make/issue-96498/foo.rs

@@ -0,0 +1,4 @@
+#![crate_type = "cdylib"]
+
+#[no_mangle]
+extern "C" fn foo() {}

src/test/ui/associated-types/impl-trait-return-missing-constraint.rs

@@ -24,7 +24,6 @@ fn bar() -> impl Bar {
 
 fn baz() -> impl Bar<Item = i32> {
     //~^ ERROR type mismatch resolving `<impl Bar as Foo>::Item == i32`
-    //~| ERROR type mismatch resolving `<impl Bar as Foo>::Item == i32`
     bar()
 }