chore: remove *all* extern crate statements

Depends on #1737

This branch removes all remaining `extern crate` statements. Most of
these are in old code and were not removed when updating to Rust 2018.
Whoops!

Our MSRV no longer requires `extern crate`, so we don't need these. The
exception is `extern crate` statements for `std` and `alloc`, which are
still the way these libraries are included explicitly when building for
`no_std` platforms.

In some cases, the tests had to explicitly import the `span!` and
`event!` macros at every use, because their names conflict with the
`span` and `event` modules in the test support code. Oh well.

tracing-core/src/callsite.rs

@@ -67,6 +67,7 @@ pub use self::inner::{rebuild_interest_cache, register};
 #[cfg(feature = "std")]
 mod inner {
  use super::*;
+ use lazy_static::lazy_static;
  use std::sync::RwLock;
  use std::vec::Vec;
 

tracing-core/src/collect.rs

@@ -239,8 +239,7 @@ pub trait Collect: 'static {
  /// but values for them won't be recorded at this time.
  ///
  /// ```rust,ignore
- /// #[macro_use]
- /// extern crate tracing;
+ /// # use tracing::span;
  ///
  /// let mut span = span!("my_span", foo = 3, bar, baz);
  ///

tracing-core/src/lib.rs

@@ -274,11 +274,6 @@ macro_rules! metadata {
  };
 }
 
-// std uses lazy_static from crates.io
-#[cfg(feature = "std")]
-#[macro_use]
-extern crate lazy_static;
-
 // Facade module: `no_std` uses spinlocks, `std` uses the mutexes in the standard library
 #[cfg(not(feature = "std"))]
 #[doc(hidden)]

tracing-serde/README.md

@@ -53,10 +53,6 @@ tracing-serde = "0.1"
 Next, add this to your crate:
 
 ```rust
-#[macro_use]
-extern crate tracing;
-extern crate tracing_serde;
-
 use tracing_serde::AsSerde;
 ```
 

tracing/benches/global_subscriber.rs

@@ -1,6 +1,3 @@
-extern crate criterion;
-extern crate tracing;
-
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 use tracing::Level;
 

tracing/benches/subscriber.rs

@@ -1,6 +1,3 @@
-extern crate criterion;
-extern crate tracing;
-
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 use tracing::Level;
 

tracing/src/level_filters.rs

@@ -65,7 +65,7 @@ pub use tracing_core::{metadata::ParseLevelFilterError, LevelFilter};
 /// [module-level documentation]: self#compile-time-filters
 pub const STATIC_MAX_LEVEL: LevelFilter = MAX_LEVEL;
 
-cfg_if! {
+cfg_if::cfg_if! {
  if #[cfg(all(not(debug_assertions), feature = "release_max_level_off"))] {
  const MAX_LEVEL: LevelFilter = LevelFilter::OFF;
  } else if #[cfg(all(not(debug_assertions), feature = "release_max_level_error"))] {

tracing/src/lib.rs

@@ -929,9 +929,6 @@
  while_true
 )]
 
-#[macro_use]
-extern crate cfg_if;
-
 #[cfg(feature = "log")]
 #[doc(hidden)]
 pub use log;

tracing/test-log-support/src/lib.rs

@@ -1,4 +1,3 @@
-extern crate log;
 use log::{LevelFilter, Log, Metadata, Record};
 use std::sync::{Arc, Mutex};
 

tracing/test-log-support/tests/log_no_trace.rs

@@ -1,9 +1,5 @@
-#[macro_use]
-extern crate tracing;
-extern crate test_log_support;
-
 use test_log_support::Test;
-use tracing::Level;
+use tracing::{debug, error, info, trace, warn, Level};
 
 #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
 #[test]

tracing/test-log-support/tests/log_with_trace.rs

@@ -1,6 +1,4 @@
-#[macro_use]
-extern crate tracing;
-extern crate test_log_support;
+use tracing::{debug, error, info, span, trace, warn, Level};
 
 use test_log_support::Test;
 use tracing::Level;

tracing/test-log-support/tests/span_activity_filtered_separately.rs

@@ -1,9 +1,5 @@
-#[macro_use]
-extern crate tracing;
-extern crate test_log_support;
-
 use test_log_support::Test;
-use tracing::Level;
+use tracing::{debug, error, info, span, trace, warn, Level};
 
 #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
 #[test]

tracing/test-log-support/tests/span_lifecycle_can_be_enabled.rs

@@ -1,6 +1,4 @@
-#[macro_use]
-extern crate tracing;
-extern crate test_log_support;
+use tracing::{debug, error, info, span, trace, warn, Level};
 
 use test_log_support::Test;
 use tracing::Level;

tracing/test-log-support/tests/span_lifecycle_defaults_off.rs

@@ -1,6 +1,4 @@
-#[macro_use]
-extern crate tracing;
-extern crate test_log_support;
+use tracing::{debug, error, info, span, trace, warn, Level};
 
 use test_log_support::Test;
 use tracing::Level;

tracing/test-log-support/tests/span_lifecycle_is_trace.rs

@@ -1,6 +1,4 @@
-#[macro_use]
-extern crate tracing;
-extern crate test_log_support;
+use tracing::{debug, error, info, span, trace, warn, Level};
 
 use test_log_support::Test;
 use tracing::Level;

tracing/test_static_max_level_features/tests/test.rs

@@ -1,5 +1,4 @@
-#[macro_use]
-extern crate tracing;
+use tracing::{debug, error, info, trace, warn, Level};
 
 use std::sync::{Arc, Mutex};
 use tracing::span::{Attributes, Record};

tracing/tests/collector.rs

@@ -5,9 +5,6 @@
 // The alternative would be for each of these tests to be defined in a separate
 // file, which is :(
 #![cfg(feature = "std")]
-
-#[macro_use]
-extern crate tracing;
 use tracing::{
  collect::{with_default, Collect, Interest},
  field::display,
@@ -34,7 +31,7 @@ fn event_macros_dont_infinite_loop() {
 
  fn enabled(&self, meta: &Metadata<'_>) -> bool {
  assert!(meta.fields().iter().any(|f| f.name() == "foo"));
- event!(Level::TRACE, bar = false);
+ tracing::event!(Level::TRACE, bar = false);
  true
  }
 
@@ -48,7 +45,7 @@ fn event_macros_dont_infinite_loop() {
 
  fn event(&self, event: &Event<'_>) {
  assert!(event.metadata().fields().iter().any(|f| f.name() == "foo"));
- event!(Level::TRACE, baz = false);
+ tracing::event!(Level::TRACE, baz = false);
  }
 
  fn enter(&self, _: &Id) {}
@@ -61,7 +58,7 @@ fn event_macros_dont_infinite_loop() {
  }
 
  with_default(TestCollector, || {
- event!(Level::TRACE, foo = false);
+ tracing::event!(Level::TRACE, foo = false);
  })
 }
 
@@ -85,7 +82,7 @@ fn boxed_collector() {
 
  with_default(collector, || {
  let from = "my span";
- let span = span!(
+ let span = tracing::span!(
  Level::TRACE,
  "foo",
  bar = format_args!("hello from {}", from)
@@ -123,7 +120,7 @@ fn arced_collector() {
  // Test using a clone of the `Arc`ed collector
  with_default(collector.clone(), || {
  let from = "my span";
- let span = span!(
+ let span = tracing::span!(
  Level::TRACE,
  "foo",
  bar = format_args!("hello from {}", from)

tracing/tests/event.rs

@@ -5,17 +5,15 @@
 // The alternative would be for each of these tests to be defined in a separate
 // file, which is :(
 #![cfg(feature = "std")]
-
-#[macro_use]
-extern crate tracing;
 mod support;
 
 use self::support::*;
 
 use tracing::{
  collect::with_default,
+ debug, error,
  field::{debug, display},
- Level,
+ info, trace, warn, Level,
 };
 
 macro_rules! event_without_message {
@@ -61,13 +59,16 @@ event_without_message! {nonzeroi32_event_without_message: std::num::NonZeroI32::
 fn event_with_message() {
  let (collector, handle) = collector::mock()
  .event(event::mock().with_fields(field::mock("message").with_value(
- &tracing::field::debug(format_args!("hello from my event! yak shaved = {:?}", true)),
+ &tracing::field::debug(format_args!(
+ "hello from my tracing::event! yak shaved = {:?}",
+ true
+ )),
  )))
  .done()
  .run_with_handle();
 
  with_default(collector, || {
- debug!("hello from my event! yak shaved = {:?}", true);
+ debug!("hello from my tracing::event! yak shaved = {:?}", true);
  });
 
  handle.assert_finished();
@@ -84,7 +85,7 @@ fn message_without_delims() {
  .and(field::mock("question").with_value(&"life, the universe, and everything"))
  .and(
  field::mock("message").with_value(&tracing::field::debug(format_args!(
- "hello from my event! tricky? {:?}!",
+ "hello from my tracing::event! tricky? {:?}!",
  true
  ))),
  )
@@ -155,7 +156,7 @@ fn one_with_everything() {
  .run_with_handle();
 
  with_default(collector, || {
- event!(
+ tracing::event!(
  target: "whatever",
  Level::ERROR,
  { foo = 666, bar = false, like_a_butterfly = 42.0 },
@@ -181,7 +182,7 @@ fn moved_field() {
  .run_with_handle();
  with_default(collector, || {
  let from = "my event";
- event!(Level::INFO, foo = display(format!("hello from {}", from)))
+ tracing::event!(Level::INFO, foo = display(format!("hello from {}", from)))
  });
 
  handle.assert_finished();
@@ -202,7 +203,7 @@ fn dotted_field_name() {
  .done()
  .run_with_handle();
  with_default(collector, || {
- event!(Level::INFO, foo.bar = true, foo.baz = false);
+ tracing::event!(Level::INFO, foo.bar = true, foo.baz = false);
  });
 
  handle.assert_finished();
@@ -224,7 +225,7 @@ fn borrowed_field() {
  with_default(collector, || {
  let from = "my event";
  let mut message = format!("hello from {}", from);
- event!(Level::INFO, foo = display(&message));
+ tracing::event!(Level::INFO, foo = display(&message));
  message.push_str(", which happened!");
  });
 
@@ -286,7 +287,7 @@ fn display_shorthand() {
  .done()
  .run_with_handle();
  with_default(collector, || {
- event!(Level::TRACE, my_field = %"hello world");
+ tracing::event!(Level::TRACE, my_field = %"hello world");
  });
 
  handle.assert_finished();
@@ -306,7 +307,7 @@ fn debug_shorthand() {
  .done()
  .run_with_handle();
  with_default(collector, || {
- event!(Level::TRACE, my_field = ?"hello world");
+ tracing::event!(Level::TRACE, my_field = ?"hello world");
  });
 
  handle.assert_finished();
@@ -327,7 +328,7 @@ fn both_shorthands() {
  .done()
  .run_with_handle();
  with_default(collector, || {
- event!(Level::TRACE, display_field = %"hello world", debug_field = ?"hello world");
+ tracing::event!(Level::TRACE, display_field = %"hello world", debug_field = ?"hello world");
  });
 
  handle.assert_finished();
@@ -343,8 +344,8 @@ fn explicit_child() {
  .run_with_handle();
 
  with_default(collector, || {
- let foo = span!(Level::TRACE, "foo");
- event!(parent: foo.id(), Level::TRACE, "bar");
+ let foo = tracing::span!(Level::TRACE, "foo");
+ tracing::event!(parent: foo.id(), Level::TRACE, "bar");
  });
 
  handle.assert_finished();
@@ -364,7 +365,7 @@ fn explicit_child_at_levels() {
  .run_with_handle();
 
  with_default(collector, || {
- let foo = span!(Level::TRACE, "foo");
+ let foo = tracing::span!(Level::TRACE, "foo");
  trace!(parent: foo.id(), "a");
  debug!(parent: foo.id(), "b");
  info!(parent: foo.id(), "c");

tracing/tests/filter_caching_is_lexically_scoped.rs

@@ -11,12 +11,10 @@
 #[cfg(not(feature = "std"))]
 extern crate std;
 
-#[macro_use]
-extern crate tracing;
 mod support;
 
 use self::support::*;
-use tracing::Level;
+use tracing::{span, Level};
 
 use std::sync::{
  atomic::{AtomicUsize, Ordering},

tracing/tests/filters_are_not_reevaluated_for_the_same_span.rs

@@ -10,13 +10,10 @@
 
 #[cfg(not(feature = "std"))]
 extern crate std;
-
-#[macro_use]
-extern crate tracing;
 mod support;
 
 use self::support::*;
-use tracing::Level;
+use tracing::{span, Level};
 
 use std::sync::{
  atomic::{AtomicUsize, Ordering},

tracing/tests/filters_are_reevaluated_for_different_call_sites.rs

@@ -11,12 +11,10 @@
 #[cfg(not(feature = "std"))]
 extern crate std;
 
-#[macro_use]
-extern crate tracing;
+use tracing::{span, Level};
 mod support;
 
 use self::support::*;
-use tracing::Level;
 
 use std::sync::{
  atomic::{AtomicUsize, Ordering},

tracing/tests/macros.rs

@@ -1,8 +1,9 @@
 #![deny(warnings)]
-use tracing::Level;
+use tracing::{
+ callsite, debug, debug_span, error, error_span, event, info, info_span, span, trace,
+ trace_span, warn, warn_span, Level,
+};
 
-#[macro_use]
-extern crate tracing;
 // Tests that macros work across various invocation syntax.
 //
 // These are quite repetitive, and _could_ be generated by a macro. However,