Remove #[macro_use] extern crate tracing from rustc_lint.

And rearrange some `use` item lists while adding the `use tracing::*`
items.

Author: nnethercote

compiler/rustc_lint/src/builtin.rs

@@ -21,6 +21,7 @@
 //! `late_lint_methods!` invocation in `lib.rs`.
 
 use crate::fluent_generated as fluent;
+use crate::nonstandard_style::{method_context, MethodLateContext};
 use crate::{
     errors::BuiltinEllipsisInclusiveRangePatterns,
     lints::{
@@ -70,10 +71,8 @@ use rustc_target::abi::Abi;
 use rustc_trait_selection::infer::{InferCtxtExt, TyCtxtInferExt};
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
 use rustc_trait_selection::traits::{self, misc::type_allowed_to_implement_copy};
-
-use crate::nonstandard_style::{method_context, MethodLateContext};
-
 use std::fmt::Write;
+use tracing::debug;
 
 // hardwired lints from rustc_lint_defs
 pub use rustc_session::lint::builtin::*;

compiler/rustc_lint/src/context.rs

@@ -39,10 +39,10 @@ use rustc_span::edit_distance::find_best_match_for_names;
 use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::Span;
 use rustc_target::abi;
-
 use std::cell::Cell;
 use std::iter;
 use std::slice;
+use tracing::debug;
 
 mod diagnostics;
 

compiler/rustc_lint/src/context/diagnostics.rs

@@ -8,6 +8,7 @@ use rustc_middle::middle::stability;
 use rustc_session::lint::BuiltinLintDiag;
 use rustc_session::Session;
 use rustc_span::BytePos;
+use tracing::debug;
 
 mod check_cfg;
 

compiler/rustc_lint/src/early.rs

@@ -26,6 +26,7 @@ use rustc_session::lint::{BufferedEarlyLint, LintBuffer, LintPass};
 use rustc_session::Session;
 use rustc_span::symbol::Ident;
 use rustc_span::Span;
+use tracing::debug;
 
 macro_rules! lint_callback { ($cx:expr, $f:ident, $($args:expr),*) => ({
     $cx.pass.$f(&$cx.context, $($args),*);

compiler/rustc_lint/src/foreign_modules.rs

@@ -1,3 +1,5 @@
+use crate::lints::{BuiltinClashingExtern, BuiltinClashingExternSub};
+use crate::{types, LintVec};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_data_structures::unord::{UnordMap, UnordSet};
 use rustc_hir as hir;
@@ -8,9 +10,7 @@ use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
 use rustc_session::declare_lint;
 use rustc_span::{sym, Span, Symbol};
 use rustc_target::abi::FIRST_VARIANT;
-
-use crate::lints::{BuiltinClashingExtern, BuiltinClashingExternSub};
-use crate::{types, LintVec};
+use tracing::{debug, instrument};
 
 pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { clashing_extern_declarations, ..*providers };

compiler/rustc_lint/src/internal.rs

@@ -15,6 +15,7 @@ use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::hygiene::{ExpnKind, MacroKind};
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
+use tracing::debug;
 
 declare_tool_lint! {
     /// The `default_hash_type` lint detects use of [`std::collections::HashMap`]/[`std::collections::HashSet`],

compiler/rustc_lint/src/late.rs

@@ -26,9 +26,9 @@ use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::lint::LintPass;
 use rustc_session::Session;
 use rustc_span::Span;
-
 use std::any::Any;
 use std::cell::Cell;
+use tracing::debug;
 
 /// Extract the [`LintStore`] from [`Session`].
 ///

compiler/rustc_lint/src/levels.rs

@@ -1,4 +1,7 @@
-use crate::errors::{CheckNameUnknownTool, RequestedLevel, UnsupportedGroup};
+use crate::errors::{
+    CheckNameUnknownTool, MalformedAttribute, MalformedAttributeSub, OverruledAttribute,
+    OverruledAttributeSub, RequestedLevel, UnknownToolInScopedLint, UnsupportedGroup,
+};
 use crate::lints::{
     DeprecatedLintNameFromCommandLine, RemovedLintFromCommandLine, RenamedLintFromCommandLine,
     UnknownLintFromCommandLine,
@@ -41,11 +44,7 @@ use rustc_session::parse::feature_err;
 use rustc_session::Session;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{Span, DUMMY_SP};
-
-use crate::errors::{
-    MalformedAttribute, MalformedAttributeSub, OverruledAttribute, OverruledAttributeSub,
-    UnknownToolInScopedLint,
-};
+use tracing::{debug, instrument};
 
 /// Collection of lint levels for the whole crate.
 /// This is used by AST-based lints, which do not

compiler/rustc_lint/src/lib.rs

@@ -39,9 +39,6 @@
 #![feature(rustc_attrs)]
 #![allow(internal_features)]
 
-#[macro_use]
-extern crate tracing;
-
 mod async_fn_in_trait;
 pub mod builtin;
 mod context;

compiler/rustc_lint/src/types.rs

@@ -31,9 +31,9 @@ use rustc_span::{Span, Symbol};
 use rustc_target::abi::{Abi, Size, WrappingRange};
 use rustc_target::abi::{Integer, TagEncoding, Variants};
 use rustc_target::spec::abi::Abi as SpecAbi;
-
 use std::iter;
 use std::ops::ControlFlow;
+use tracing::debug;
 
 declare_lint! {
     /// The `unused_comparisons` lint detects comparisons made useless by

compiler/rustc_lint/src/unused.rs

@@ -22,6 +22,7 @@ use rustc_span::symbol::{kw, sym};
 use rustc_span::{BytePos, Span};
 use std::iter;
 use std::ops::ControlFlow;
+use tracing::instrument;
 
 declare_lint! {
     /// The `unused_must_use` lint detects unused result of a type flagged as