Auto merge of #159920 - JonathanBrouwer:rollup-qmClLNO, r=JonathanBrouwer

Rollup of 25 pull requests

Successful merges:

 - #138618 (Support using const pointers in asm `const` operand)
 - #157962 (Lower paths to functions in const args as ConstKind::Error)
 - #158404 (trait_solver: normalize next-gen region constraints)
 - #158709 (rustdoc: warn on improperly interleaved HTML/MD)
 - #159174 (Fix implicit_provenance_casts warnings on Xous)
 - #159179 (enable `unreachable_cfg_select_predicates` lint as part of `unused` lint group)
 - #159518 (iter: extend step_by specialization to cover StepBy<RangeIter<{integer}>>)
 - #159673 (bootstrap: forward -fdebug-prefix-map when using cc)
 - #159700 (Split non-local `semicolon_in_expressions_from_macros` into a separate lint)
 - #159720 (document #[global_allocator] constraints)
 - #159732 (optimization: don't look for diagnostic/canonical items without rustc_attrs enabled)
 - #159738 (implement `CovariantUnsafeCell`)
 - #159740 (reuse regular exported_non_generic_symbols logic in Miri)
 - #159780 (check `extern "custom"` function pointers)
 - #159785 (Share _Unwind_Exception definition between native and wasm)
 - #159786 (rustdoc-js: ignore editor temp files in test folder discovery)
 - #159819 (std::sync::poison: disable auto_cfg on PoisonError::new)
 - #155388 (stepping into where-clauses during normalization may be productive)
 - #155914 (when bailing on ambiguity, don't force other results to ambig)
 - #159204 (Add support to caller_location to rustc_public)
 - #159439 (Fix(lib/fs/win): Fall back on Win32 delete for `Dir::remove_file`)
 - #159676 (Update wasm-component-ld to 0.5.27)
 - #159695 (proc_macro: Fix cfg_attr inner attrs in file modules)
 - #159730 (allow accessing the contents of UnsafeCell without going through get)
 - #159809 (Avoid `#[target_features]`)

Author: bors

Cargo.lock

@@ -4509,6 +4509,7 @@ dependencies = [
  "rustc_middle",
  "rustc_session",
  "rustc_span",
+ "rustc_symbol_mangling",
  "rustc_target",
  "serde",
  "serde_json",
@@ -6336,9 +6337,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-component-ld"
-version = "0.5.26"
+version = "0.5.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "51a12709376d4ce64f472699500db3b0e5902cc2bef16fb6ca3098bfdac032fa"
+checksum = "5fd1ba338b2c06654988a76b13f38cad9a1c738e3275bf71ecf70eeac5d98eb4"
 dependencies = [
  "anyhow",
  "clap",
@@ -6347,12 +6348,12 @@ dependencies = [
  "libc",
  "tempfile",
  "wasi-preview1-component-adapter-provider",
- "wasmparser 0.253.0",
+ "wasmparser 0.254.0",
  "wat",
  "windows-sys 0.61.2",
  "winsplit",
- "wit-component 0.253.0",
- "wit-parser 0.253.0",
+ "wit-component 0.254.0",
+ "wit-parser 0.254.0",
 ]
 
 [[package]]
@@ -6384,12 +6385,12 @@ dependencies = [
 
 [[package]]
 name = "wasm-encoder"
-version = "0.253.0"
+version = "0.254.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59972d6cd272259de647b7c1f1912e45e289c75ffd4be04e10695507cd7e1b59"
+checksum = "09480d646178e5fdd12bb06e812d0af9a3a191dbc9cd697fdc86687beade7393"
 dependencies = [
  "leb128fmt",
- "wasmparser 0.253.0",
+ "wasmparser 0.254.0",
 ]
 
 [[package]]
@@ -6406,14 +6407,14 @@ dependencies = [
 
 [[package]]
 name = "wasm-metadata"
-version = "0.253.0"
+version = "0.254.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b3f45816ef616806f48498bcd831377de578c4fa51db0c83ab8ceb78cc13523b"
+checksum = "b01df5f3b4ca7881e843f3bc0fb8a3905d79c68692250dcb8e33e698705ccdb6"
 dependencies = [
  "anyhow",
  "indexmap",
- "wasm-encoder 0.253.0",
- "wasmparser 0.253.0",
+ "wasm-encoder 0.254.0",
+ "wasmparser 0.254.0",
 ]
 
 [[package]]
@@ -6450,9 +6451,9 @@ dependencies = [
 
 [[package]]
 name = "wasmparser"
-version = "0.253.0"
+version = "0.254.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "19db11f87d2486580e1e8b6f494c54df7e0566b87d0b599db843c24019667339"
+checksum = "d5769a29f799fbab136aaf65b4fe5384cd7d93fe6fc9ba0dcb6c8382a1f16e27"
 dependencies = [
  "bitflags",
  "hashbrown 0.17.0",
@@ -6463,22 +6464,22 @@ dependencies = [
 
 [[package]]
 name = "wast"
-version = "253.0.0"
+version = "254.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d3264542f8965c5d84fb1085d924bfba9a6314bb228eff13a2de14d7627664d0"
+checksum = "e7ed4dfc8f6b9fc38b231065e2cdfbf7359af5ab945990abf09658dcc63c3e32"
 dependencies = [
  "bumpalo",
  "leb128fmt",
  "memchr",
  "unicode-width 0.2.2",
- "wasm-encoder 0.253.0",
+ "wasm-encoder 0.254.0",
 ]
 
 [[package]]
 name = "wat"
-version = "1.253.0"
+version = "1.254.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4bfc5ce906144200c972ec617470aa35bd847472e170b26dde3e80541c674055"
+checksum = "7127f7f9b8f127c879991cecd35f494e4628bae1b0874c681414d8d8831e952c"
 dependencies = [
  "wast",
 ]
@@ -6926,9 +6927,9 @@ dependencies = [
 
 [[package]]
 name = "wit-component"
-version = "0.253.0"
+version = "0.254.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dbbd2500ac3488489ee8c6e59b79d7e47e6da5bfb019efd35d5dca57b78af624"
+checksum = "b0e65bb94c369b3c4741ce3d1d2704b1fec93db7c540df0e521a097e7ceeb5be"
 dependencies = [
  "anyhow",
  "bitflags",
@@ -6937,10 +6938,10 @@ dependencies = [
  "serde",
  "serde_derive",
  "serde_json",
- "wasm-encoder 0.253.0",
- "wasm-metadata 0.253.0",
- "wasmparser 0.253.0",
- "wit-parser 0.253.0",
+ "wasm-encoder 0.254.0",
+ "wasm-metadata 0.254.0",
+ "wasmparser 0.254.0",
+ "wit-parser 0.254.0",
 ]
 
 [[package]]
@@ -6963,9 +6964,9 @@ dependencies = [
 
 [[package]]
 name = "wit-parser"
-version = "0.253.0"
+version = "0.254.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d997b8e5920fcbeec742b58e583325d6419a6aca617ae8075c406a61c65ba8a"
+checksum = "1655131e4f7d3f0cb141f6eca71315ca40eff0f3d4de7cff0a82bacedd8c89b4"
 dependencies = [
  "anyhow",
  "hashbrown 0.17.0",
@@ -6977,7 +6978,7 @@ dependencies = [
  "serde_derive",
  "serde_json",
  "unicode-ident",
- "wasmparser 0.253.0",
+ "wasmparser 0.254.0",
 ]
 
 [[package]]

compiler/rustc_ast/src/ast.rs

@@ -2339,27 +2339,7 @@ pub struct FnSig {
 impl FnSig {
     /// Return a span encompassing the header, or where to insert it if empty.
     pub fn header_span(&self) -> Span {
-        match self.header.ext {
-            Extern::Implicit(span) | Extern::Explicit(_, span) => {
-                return self.span.with_hi(span.hi());
-            }
-            Extern::None => {}
-        }
-
-        match self.header.safety {
-            Safety::Unsafe(span) | Safety::Safe(span) => return self.span.with_hi(span.hi()),
-            Safety::Default => {}
-        };
-
-        if let Some(coroutine_kind) = self.header.coroutine_kind {
-            return self.span.with_hi(coroutine_kind.span().hi());
-        }
-
-        if let Const::Yes(span) = self.header.constness {
-            return self.span.with_hi(span.hi());
-        }
-
-        self.span.shrink_to_lo()
+        self.header.span().unwrap_or(self.span.shrink_to_lo())
     }
 
     /// The span of the header's safety, or where to insert it if empty.
@@ -2382,6 +2362,19 @@ impl FnSig {
     pub fn extern_span(&self) -> Span {
         self.header.ext.span().unwrap_or(self.safety_span().shrink_to_hi())
     }
+
+    pub fn as_borrowed(&self) -> BorrowedFnSig<'_> {
+        BorrowedFnSig { header: self.header, decl: &self.decl, span: self.span }
+    }
+}
+
+/// A borrowed version of `FnSig`, used to share logic between function declarations and function
+/// pointer types.
+#[derive(Clone, Debug)]
+pub struct BorrowedFnSig<'a> {
+    pub header: FnHeader,
+    pub decl: &'a FnDecl,
+    pub span: Span,
 }
 
 /// A constraint on an associated item.
@@ -2487,6 +2480,16 @@ pub struct FnPtrTy {
     pub decl_span: Span,
 }
 
+impl FnPtrTy {
+    pub fn header(&self) -> FnHeader {
+        FnHeader { constness: Const::No, coroutine_kind: None, safety: self.safety, ext: self.ext }
+    }
+
+    pub fn as_borrowed_fn_sig<'a>(&'a self) -> BorrowedFnSig<'a> {
+        BorrowedFnSig { header: self.header(), decl: &self.decl, span: self.decl_span }
+    }
+}
+
 #[derive(Clone, Encodable, Decodable, Debug, Walkable)]
 pub struct UnsafeBinderTy {
     pub generic_params: ThinVec<GenericParam>,
@@ -3402,6 +3405,15 @@ pub enum AttrStyle {
     Inner,
 }
 
+impl AttrStyle {
+    pub fn line_doc_comment_prefix(self) -> &'static str {
+        match self {
+            AttrStyle::Outer => "///",
+            AttrStyle::Inner => "//!",
+        }
+    }
+}
+
 /// A list of attributes.
 pub type AttrVec = ThinVec<Attribute>;
 
@@ -3836,6 +3848,30 @@ impl FnHeader {
             || matches!(constness, Const::Yes(_))
             || !matches!(ext, Extern::None)
     }
+
+    pub fn span(&self) -> Option<Span> {
+        let mut spans = smallvec::SmallVec::<[Span; 4]>::new();
+
+        match self.ext {
+            Extern::Implicit(span) | Extern::Explicit(_, span) => spans.push(span),
+            Extern::None => {}
+        }
+
+        match self.safety {
+            Safety::Unsafe(span) | Safety::Safe(span) => spans.push(span),
+            Safety::Default => {}
+        };
+
+        if let Some(coroutine_kind) = self.coroutine_kind {
+            spans.push(coroutine_kind.span());
+        }
+
+        if let Const::Yes(span) = self.constness {
+            spans.push(span)
+        }
+
+        spans.into_iter().reduce(Span::to)
+    }
 }
 
 impl Default for FnHeader {