Auto merge of #138595 - jhpratt:rollup-09pvfzu, r=jhpratt

Rollup of 9 pull requests

Successful merges:

 - #136355 (Add `*_value` methods to proc_macro lib)
 - #137621 (Add std support to cygwin target)
 - #137793 (Stablize anonymous pipe)
 - #138341 (std: Mention clone-on-write mutation in Arc<T>)
 - #138517 (Improve upvar analysis for deref of child capture)
 - #138584 (Update Rust Foundation links in Readme)
 - #138586 (Document `#![register_tool]`)
 - #138590 (Flatten and simplify some control flow 🫓)
 - #138592 (update change entry for #137147)

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

Author: bors

Cargo.lock

@@ -2082,6 +2082,13 @@ version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4ee93343901ab17bd981295f2cf0026d4ad018c7c31ba84549a4ddbb47a45104"
 
+[[package]]
+name = "literal-escaper"
+version = "0.0.0"
+dependencies = [
+ "rustc-std-workspace-std 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "lld-wrapper"
 version = "0.1.0"
@@ -3148,6 +3155,12 @@ version = "1.0.1"
 name = "rustc-std-workspace-std"
 version = "1.0.1"
 
+[[package]]
+name = "rustc-std-workspace-std"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aba676a20abe46e5b0f1b0deae474aaaf31407e6c71147159890574599da04ef"
+
 [[package]]
 name = "rustc_abi"
 version = "0.0.0"
@@ -3186,6 +3199,7 @@ name = "rustc_ast"
 version = "0.0.0"
 dependencies = [
  "bitflags",
+ "literal-escaper",
  "memchr",
  "rustc_ast_ir",
  "rustc_data_structures",
@@ -3895,6 +3909,7 @@ name = "rustc_lexer"
 version = "0.0.0"
 dependencies = [
  "expect-test",
+ "literal-escaper",
  "memchr",
  "unicode-properties",
  "unicode-xid",
@@ -4157,6 +4172,7 @@ name = "rustc_parse"
 version = "0.0.0"
 dependencies = [
  "bitflags",
+ "literal-escaper",
  "rustc_ast",
  "rustc_ast_pretty",
  "rustc_data_structures",
@@ -4179,6 +4195,7 @@ dependencies = [
 name = "rustc_parse_format"
 version = "0.0.0"
 dependencies = [
+ "literal-escaper",
  "rustc_index",
  "rustc_lexer",
 ]

README.md

@@ -67,11 +67,11 @@ See [LICENSE-APACHE](LICENSE-APACHE), [LICENSE-MIT](LICENSE-MIT), and
 trademarks and logos (the "Rust Trademarks").
 
 If you want to use these names or brands, please read the
-[media guide][media-guide].
+[Rust language trademark policy][trademark-policy].
 
 Third-party logos may be subject to third-party copyrights and trademarks. See
 [Licenses][policies-licenses] for details.
 
-[rust-foundation]: https://foundation.rust-lang.org/
-[media-guide]: https://foundation.rust-lang.org/policies/logo-policy-and-media-guide/
+[rust-foundation]: https://rustfoundation.org/
+[trademark-policy]: https://rustfoundation.org/policy/rust-trademark-policy/
 [policies-licenses]: https://www.rust-lang.org/policies/licenses

compiler/rustc_ast/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2024"
 [dependencies]
 # tidy-alphabetical-start
 bitflags = "2.4.1"
+literal-escaper = { path = "../../library/literal-escaper" }
 memchr = "2.7.4"
 rustc_ast_ir = { path = "../rustc_ast_ir" }
 rustc_data_structures = { path = "../rustc_data_structures" }

compiler/rustc_ast/src/util/literal.rs

@@ -2,7 +2,7 @@
 
 use std::{ascii, fmt, str};
 
-use rustc_lexer::unescape::{
+use literal_escaper::{
     MixedUnit, Mode, byte_from_char, unescape_byte, unescape_char, unescape_mixed, unescape_unicode,
 };
 use rustc_span::{Span, Symbol, kw, sym};

compiler/rustc_borrowck/src/lib.rs

@@ -2479,19 +2479,15 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         let body = self.body;
         for local in body.mut_vars_and_args_iter().filter(|local| !self.used_mut.contains(local)) {
             let local_decl = &body.local_decls[local];
-            let lint_root = match &body.source_scopes[local_decl.source_info.scope].local_data {
-                ClearCrossCrate::Set(data) => data.lint_root,
-                _ => continue,
+            let ClearCrossCrate::Set(SourceScopeLocalData { lint_root, .. }) =
+                body.source_scopes[local_decl.source_info.scope].local_data
+            else {
+                continue;
             };
 
             // Skip over locals that begin with an underscore or have no name
-            match self.local_names[local] {
-                Some(name) => {
-                    if name.as_str().starts_with('_') {
-                        continue;
-                    }
-                }
-                None => continue,
+            if self.local_names[local].is_none_or(|name| name.as_str().starts_with('_')) {
+                continue;
             }
 
             let span = local_decl.source_info.span;

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -153,10 +153,9 @@ pub(super) fn maybe_check_static_with_link_section(tcx: TyCtxt<'_>, id: LocalDef
     }
 
     // If `#[link_section]` is missing, then nothing to verify
-    let attrs = tcx.codegen_fn_attrs(id);
-    if attrs.link_section.is_none() {
+    let Some(link_section) = tcx.codegen_fn_attrs(id).link_section else {
         return;
-    }
+    };
 
     // For the wasm32 target statics with `#[link_section]` other than `.init_array`
     // are placed into custom sections of the final output file, but this isn't like
@@ -182,11 +181,8 @@ pub(super) fn maybe_check_static_with_link_section(tcx: TyCtxt<'_>, id: LocalDef
     //  continue to work, but would no longer be necessary.
 
     if let Ok(alloc) = tcx.eval_static_initializer(id.to_def_id())
-        && alloc.inner().provenance().ptrs().len() != 0
-        && attrs
-            .link_section
-            .map(|link_section| !link_section.as_str().starts_with(".init_array"))
-            .unwrap()
+        && !alloc.inner().provenance().ptrs().is_empty()
+        && !link_section.as_str().starts_with(".init_array")
     {
         let msg = "statics with a custom `#[link_section]` must be a \
                         simple list of bytes on the wasm target with no \

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -1532,30 +1532,29 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             if self.may_coerce(blk_ty, *elem_ty)
                 && blk.stmts.is_empty()
                 && blk.rules == hir::BlockCheckMode::DefaultBlock
+                && let source_map = self.tcx.sess.source_map()
+                && let Ok(snippet) = source_map.span_to_snippet(blk.span)
+                && snippet.starts_with('{')
+                && snippet.ends_with('}')
             {
-                let source_map = self.tcx.sess.source_map();
-                if let Ok(snippet) = source_map.span_to_snippet(blk.span) {
-                    if snippet.starts_with('{') && snippet.ends_with('}') {
-                        diag.multipart_suggestion_verbose(
-                            "to create an array, use square brackets instead of curly braces",
-                            vec![
-                                (
-                                    blk.span
-                                        .shrink_to_lo()
-                                        .with_hi(rustc_span::BytePos(blk.span.lo().0 + 1)),
-                                    "[".to_string(),
-                                ),
-                                (
-                                    blk.span
-                                        .shrink_to_hi()
-                                        .with_lo(rustc_span::BytePos(blk.span.hi().0 - 1)),
-                                    "]".to_string(),
-                                ),
-                            ],
-                            Applicability::MachineApplicable,
-                        );
-                    }
-                }
+                diag.multipart_suggestion_verbose(
+                    "to create an array, use square brackets instead of curly braces",
+                    vec![
+                        (
+                            blk.span
+                                .shrink_to_lo()
+                                .with_hi(rustc_span::BytePos(blk.span.lo().0 + 1)),
+                            "[".to_string(),
+                        ),
+                        (
+                            blk.span
+                                .shrink_to_hi()
+                                .with_lo(rustc_span::BytePos(blk.span.hi().0 - 1)),
+                            "]".to_string(),
+                        ),
+                    ],
+                    Applicability::MachineApplicable,
+                );
             }
         }
     }

compiler/rustc_hir_typeck/src/upvar.rs

@@ -1862,8 +1862,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 ///
 /// (1.) Are we borrowing data owned by the parent closure? We can determine if
 /// that is the case by checking if the parent capture is by move, EXCEPT if we
-/// apply a deref projection, which means we're reborrowing a reference that we
-/// captured by move.
+/// apply a deref projection of an immutable reference, reborrows of immutable
+/// references which aren't restricted to the LUB of the lifetimes of the deref
+/// chain. This is why `&'short mut &'long T` can be reborrowed as `&'long T`.
 ///
 /// ```rust
 /// let x = &1i32; // Let's call this lifetime `'1`.
@@ -1902,10 +1903,22 @@ fn should_reborrow_from_env_of_parent_coroutine_closure<'tcx>(
 ) -> bool {
     // (1.)
     (!parent_capture.is_by_ref()
-        && !matches!(
-            child_capture.place.projections.get(parent_capture.place.projections.len()),
-            Some(Projection { kind: ProjectionKind::Deref, .. })
-        ))
+        // This is just inlined `place.deref_tys()` but truncated to just
+        // the child projections. Namely, look for a `&T` deref, since we
+        // can always extend `&'short mut &'long T` to `&'long T`.
+        && !child_capture
+            .place
+            .projections
+            .iter()
+            .enumerate()
+            .skip(parent_capture.place.projections.len())
+            .any(|(idx, proj)| {
+                matches!(proj.kind, ProjectionKind::Deref)
+                    && matches!(
+                        child_capture.place.ty_before_projection(idx).kind(),
+                        ty::Ref(.., ty::Mutability::Not)
+                    )
+            }))
         // (2.)
         || matches!(child_capture.info.capture_kind, UpvarCapture::ByRef(ty::BorrowKind::Mutable))
 }

compiler/rustc_lexer/Cargo.toml

@@ -16,6 +16,7 @@ Rust lexer used by rustc. No stability guarantees are provided.
 [dependencies]
 memchr = "2.7.4"
 unicode-xid = "0.2.0"
+literal-escaper = { path = "../../library/literal-escaper" }
 
 [dependencies.unicode-properties]
 version = "0.1.0"

compiler/rustc_lexer/src/lib.rs

@@ -26,11 +26,13 @@
 // tidy-alphabetical-end
 
 mod cursor;
-pub mod unescape;
 
 #[cfg(test)]
 mod tests;
 
+// FIXME: This is needed for rust-analyzer. Remove this dependency once rust-analyzer uses
+// `literal-escaper`.
+pub use literal_escaper as unescape;
 use unicode_properties::UnicodeEmoji;
 pub use unicode_xid::UNICODE_VERSION as UNICODE_XID_VERSION;