Auto merge of rust-lang#139452 - GuillaumeGomez:rollup-u9edkjo, r=GuillaumeGomez

Rollup of 6 pull requests

Successful merges:

 - rust-lang#138562 (Optimize slice {Chunks,Windows}::nth)
 - rust-lang#138876 (Trusty: Implement `write_vectored` for stdio )
 - rust-lang#139072 (Add `slice::align_to_uninit_mut`)
 - rust-lang#139367 (Add `*_value` methods to proc_macro lib)
 - rust-lang#139391 (Check if merged attributes list is empty in expr)
 - rust-lang#139414 (Fix typo in `RawList`'s documentation)

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

Author: bors

Cargo.lock

@@ -3150,6 +3150,12 @@ version = "2.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "357703d41365b4b27c590e3ed91eabb1b663f07c4c084095e60cbed4362dff0d"
 
+[[package]]
+name = "rustc-literal-escaper"
+version = "0.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0041b6238913c41fe704213a4a9329e2f685a156d1781998128b4149c230ad04"
+
 [[package]]
 name = "rustc-main"
 version = "0.0.0"
@@ -3242,10 +3248,10 @@ version = "0.0.0"
 dependencies = [
  "bitflags",
  "memchr",
+ "rustc-literal-escaper",
  "rustc_ast_ir",
  "rustc_data_structures",
  "rustc_index",
- "rustc_lexer",
  "rustc_macros",
  "rustc_serialize",
  "rustc_span",
@@ -4200,6 +4206,7 @@ name = "rustc_parse"
 version = "0.0.0"
 dependencies = [
  "bitflags",
+ "rustc-literal-escaper",
  "rustc_ast",
  "rustc_ast_pretty",
  "rustc_data_structures",
@@ -4222,6 +4229,7 @@ dependencies = [
 name = "rustc_parse_format"
 version = "0.0.0"
 dependencies = [
+ "rustc-literal-escaper",
  "rustc_index",
  "rustc_lexer",
 ]

compiler/rustc_ast/Cargo.toml

@@ -7,10 +7,10 @@ edition = "2024"
 # tidy-alphabetical-start
 bitflags = "2.4.1"
 memchr = "2.7.4"
+rustc-literal-escaper = "0.0.2"
 rustc_ast_ir = { path = "../rustc_ast_ir" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_index = { path = "../rustc_index" }
-rustc_lexer = { path = "../rustc_lexer" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_span = { path = "../rustc_span" }

compiler/rustc_ast/src/util/literal.rs

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

compiler/rustc_ast_lowering/src/expr.rs

@@ -74,14 +74,16 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     // Merge attributes into the inner expression.
                     if !e.attrs.is_empty() {
                         let old_attrs = self.attrs.get(&ex.hir_id.local_id).copied().unwrap_or(&[]);
-                        self.attrs.insert(
-                            ex.hir_id.local_id,
-                            &*self.arena.alloc_from_iter(
-                                self.lower_attrs_vec(&e.attrs, e.span)
-                                    .into_iter()
-                                    .chain(old_attrs.iter().cloned()),
-                            ),
+                        let attrs = &*self.arena.alloc_from_iter(
+                            self.lower_attrs_vec(&e.attrs, e.span)
+                                .into_iter()
+                                .chain(old_attrs.iter().cloned()),
                         );
+                        if attrs.is_empty() {
+                            return ex;
+                        }
+
+                        self.attrs.insert(ex.hir_id.local_id, attrs);
                     }
                     return ex;
                 }

compiler/rustc_lexer/src/lib.rs

@@ -26,7 +26,6 @@
 // tidy-alphabetical-end
 
 mod cursor;
-pub mod unescape;
 
 #[cfg(test)]
 mod tests;