Rollup merge of #126717 - nnethercote:rustfmt-use-pre-cleanups, r=jieyouxu

Clean up some comments near `use` declarations

#125443 will reformat all `use` declarations in the repository. There are a few edge cases involving comments on `use` declarations that require care. This PR cleans up some clumsy comment cases, taking us a step closer to #125443 being able to merge.

r? ``@lqd``

Author: matthiaskrgr

compiler/rustc_builtin_macros/src/test.rs

@@ -1,6 +1,7 @@
+//! The expansion from a test function to the appropriate test struct for libtest
+//! Ideally, this code would be in libtest but for efficiency and error messages it lives here.
+
 use crate::errors;
-/// The expansion from a test function to the appropriate test struct for libtest
-/// Ideally, this code would be in libtest but for efficiency and error messages it lives here.
 use crate::util::{check_builtin_macro_attribute, warn_on_duplicate_attribute};
 use rustc_ast::ptr::P;
 use rustc_ast::{self as ast, attr, GenericParamKind};

compiler/rustc_codegen_gcc/tests/lang_tests_common.rs

@@ -1,4 +1,5 @@
 //! The common code for `tests/lang_tests_*.rs`
+
 use std::{
     env::{self, current_dir},
     path::{Path, PathBuf},

compiler/rustc_codegen_ssa/src/mir/locals.rs

@@ -1,6 +1,7 @@
 //! Locals are in a private module as updating `LocalRef::Operand` has to
 //! be careful wrt to subtyping. To deal with this we only allow updates by using
 //! `FunctionCx::overwrite_local` which handles it automatically.
+
 use crate::mir::{FunctionCx, LocalRef};
 use crate::traits::BuilderMethods;
 use rustc_index::IndexVec;

compiler/rustc_data_structures/src/base_n.rs

@@ -1,5 +1,6 @@
-/// Converts unsigned integers into a string representation with some base.
-/// Bases up to and including 36 can be used for case-insensitive things.
+//! Converts unsigned integers into a string representation with some base.
+//! Bases up to and including 36 can be used for case-insensitive things.
+
 use std::ascii;
 use std::fmt;
 

compiler/rustc_errors/src/markdown/mod.rs

@@ -1,6 +1,7 @@
 //! A simple markdown parser that can write formatted text to the terminal
 //!
 //! Entrypoint is `MdStream::parse_str(...)`
+
 use std::io;
 
 use termcolor::{Buffer, BufferWriter, ColorChoice};

compiler/rustc_expand/src/mbe/macro_check.rs

@@ -104,6 +104,7 @@
 //! Kleene operators under which a meta-variable is repeating is the concatenation of the stacks
 //! stored when entering a macro definition starting from the state in which the meta-variable is
 //! bound.
+
 use crate::errors;
 use crate::mbe::{KleeneToken, TokenTree};
 

compiler/rustc_fs_util/src/lib.rs

@@ -1,9 +1,7 @@
-// tidy-alphabetical-start
 use std::ffi::CString;
 use std::fs;
 use std::io;
 use std::path::{absolute, Path, PathBuf};
-// tidy-alphabetical-end
 
 // Unfortunately, on windows, it looks like msvcrt.dll is silently translating
 // verbatim paths under the hood to non-verbatim paths! This manifests itself as

compiler/rustc_hir_analysis/src/check/dropck.rs

@@ -1,6 +1,7 @@
 // FIXME(@lcnr): Move this module out of `rustc_hir_analysis`.
 //
 // We don't do any drop checking during hir typeck.
+
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{codes::*, struct_span_code_err, ErrorGuaranteed};
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;

compiler/rustc_hir_typeck/src/autoderef.rs

@@ -1,4 +1,5 @@
-//! Some helper functions for `AutoDeref`
+//! Some helper functions for `AutoDeref`.
+
 use super::method::MethodCallee;
 use super::{FnCtxt, PlaceOp};
 

compiler/rustc_hir_typeck/src/errors.rs

@@ -1,4 +1,5 @@
 //! Errors emitted by `rustc_hir_typeck`.
+
 use std::borrow::Cow;
 
 use crate::fluent_generated as fluent;