core: vendor lazy_static and spin for no_std support

tracing-core/Cargo.toml

@@ -32,11 +32,3 @@ std = []
 [badges]
 azure-devops = { project = "tracing/tracing", pipeline = "tokio-rs.tracing", build = "1" }
 maintenance = { status = "actively-developed" }
-
-[dependencies]
-lazy_static = "1"
-
-[target.'cfg(not(feature = "std"))'.dependencies]
-spin = "0.5"
-lazy_static = { version = "1", features = ["spin_no_std"] }
-

tracing-core/src/callsite.rs

@@ -1,5 +1,6 @@
 //! Callsites represent the source locations from which spans or events
 //! originate.
+use crate::lazy_static;
 use crate::stdlib::{
     fmt,
     hash::{Hash, Hasher},

tracing-core/src/lazy_static/LICENSE

@@ -0,0 +1,26 @@
+
+Copyright (c) 2010 The Rust Project Developers
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

tracing-core/src/lazy_static/core_lazy.rs

@@ -0,0 +1,30 @@
+// Copyright 2016 lazy-static.rs Developers
+//
+// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
+// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
+// http://opensource.org/licenses/MIT>, at your option. This file may not be
+// copied, modified, or distributed except according to those terms.
+
+use crate::spin::Once;
+
+pub struct Lazy<T: Sync>(Once<T>);
+
+impl<T: Sync> Lazy<T> {
+    pub const INIT: Self = Lazy(Once::INIT);
+
+    #[inline(always)]
+    pub fn get<F>(&'static self, builder: F) -> &T
+    where
+        F: FnOnce() -> T,
+    {
+        self.0.call_once(builder)
+    }
+}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! __lazy_static_create {
+    ($NAME:ident, $T:ty) => {
+        static $NAME: $crate::lazy::Lazy<$T> = $crate::lazy::Lazy::INIT;
+    };
+}

tracing-core/src/lazy_static/inline_lazy.rs

@@ -0,0 +1,58 @@
+// Copyright 2016 lazy-static.rs Developers
+//
+// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
+// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
+// http://opensource.org/licenses/MIT>, at your option. This file may not be
+// copied, modified, or distributed except according to those terms.
+
+use std::cell::Cell;
+use std::hint::unreachable_unchecked;
+use std::prelude::v1::*;
+use std::sync::Once;
+#[allow(deprecated)]
+pub use std::sync::ONCE_INIT;
+
+// FIXME: Replace Option<T> with MaybeUninit<T> (stable since 1.36.0)
+#[allow(missing_debug_implementations)]
+pub struct Lazy<T: Sync>(Cell<Option<T>>, Once);
+
+impl<T: Sync> Lazy<T> {
+    #[allow(deprecated)]
+    pub const INIT: Self = Lazy(Cell::new(None), ONCE_INIT);
+
+    #[inline(always)]
+    pub fn get<F>(&'static self, f: F) -> &T
+    where
+        F: FnOnce() -> T,
+    {
+        self.1.call_once(|| {
+            self.0.set(Some(f()));
+        });
+
+        // `self.0` is guaranteed to be `Some` by this point
+        // The `Once` will catch and propagate panics
+        unsafe {
+            match *self.0.as_ptr() {
+                Some(ref x) => x,
+                None => {
+                    debug_assert!(
+                        false,
+                        "attempted to derefence an uninitialized lazy static. This is a bug"
+                    );
+
+                    unreachable_unchecked()
+                }
+            }
+        }
+    }
+}
+
+unsafe impl<T: Sync> Sync for Lazy<T> {}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! __lazy_static_create {
+    ($NAME:ident, $T:ty) => {
+        static $NAME: $crate::lazy_static::lazy::Lazy<$T> = $crate::lazy_static::lazy::Lazy::INIT;
+    };
+}

tracing-core/src/lazy_static/mod.rs

@@ -0,0 +1,104 @@
+// Copyright 2016 lazy-static.rs Developers
+//
+// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
+// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
+// http://opensource.org/licenses/MIT>, at your option. This file may not be
+// copied, modified, or distributed except according to those terms.
+
+/*!
+A macro for declaring lazily evaluated statics.
+Using this macro, it is possible to have `static`s that require code to be
+executed at runtime in order to be initialized.
+This includes anything requiring heap allocations, like vectors or hash maps,
+as well as anything that requires function calls to be computed.
+*/
+
+#[cfg(feature = "std")]
+#[path = "inline_lazy.rs"]
+#[doc(hidden)]
+pub mod lazy;
+
+#[cfg(not(feature = "std"))]
+#[path = "core_lazy.rs"]
+#[doc(hidden)]
+pub mod lazy;
+
+#[doc(hidden)]
+pub use core::ops::Deref as __Deref;
+
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+macro_rules! __lazy_static_internal {
+    // optional visibility restrictions are wrapped in `()` to allow for
+    // explicitly passing otherwise implicit information about private items
+    ($(#[$attr:meta])* ($($vis:tt)*) static ref $N:ident : $T:ty = $e:expr; $($t:tt)*) => {
+        __lazy_static_internal!(@MAKE TY, $(#[$attr])*, ($($vis)*), $N);
+        __lazy_static_internal!(@TAIL, $N : $T = $e);
+        lazy_static!($($t)*);
+    };
+    (@TAIL, $N:ident : $T:ty = $e:expr) => {
+        impl $crate::lazy_static::__Deref for $N {
+            type Target = $T;
+            fn deref(&self) -> &$T {
+                #[inline(always)]
+                fn __static_ref_initialize() -> $T { $e }
+
+                #[inline(always)]
+                fn __stability() -> &'static $T {
+                    __lazy_static_create!(LAZY, $T);
+                    LAZY.get(__static_ref_initialize)
+                }
+                __stability()
+            }
+        }
+        impl $crate::lazy_static::LazyStatic for $N {
+            fn initialize(lazy: &Self) {
+                let _ = &**lazy;
+            }
+        }
+    };
+    // `vis` is wrapped in `()` to prevent parsing ambiguity
+    (@MAKE TY, $(#[$attr:meta])*, ($($vis:tt)*), $N:ident) => {
+        #[allow(missing_copy_implementations)]
+        #[allow(non_camel_case_types)]
+        #[allow(dead_code)]
+        $(#[$attr])*
+        $($vis)* struct $N {__private_field: ()}
+        #[doc(hidden)]
+        $($vis)* static $N: $N = $N {__private_field: ()};
+    };
+    () => ()
+}
+
+#[macro_export(local_inner_macros)]
+/// lazy_static (suppress docs_missing warning)
+macro_rules! lazy_static {
+    ($(#[$attr:meta])* static ref $N:ident : $T:ty = $e:expr; $($t:tt)*) => {
+        // use `()` to explicitly forward the information about private items
+        __lazy_static_internal!($(#[$attr])* () static ref $N : $T = $e; $($t)*);
+    };
+    ($(#[$attr:meta])* pub static ref $N:ident : $T:ty = $e:expr; $($t:tt)*) => {
+        __lazy_static_internal!($(#[$attr])* (pub) static ref $N : $T = $e; $($t)*);
+    };
+    ($(#[$attr:meta])* pub ($($vis:tt)+) static ref $N:ident : $T:ty = $e:expr; $($t:tt)*) => {
+        __lazy_static_internal!($(#[$attr])* (pub ($($vis)+)) static ref $N : $T = $e; $($t)*);
+    };
+    () => ()
+}
+
+/// Support trait for enabling a few common operation on lazy static values.
+///
+/// This is implemented by each defined lazy static, and
+/// used by the free functions in this crate.
+pub trait LazyStatic {
+    #[doc(hidden)]
+    fn initialize(lazy: &Self);
+}
+
+/// Takes a shared reference to a lazy static and initializes
+/// it if it has not been already.
+///
+/// This can be used to control the initialization point of a lazy static.
+pub fn initialize<T: LazyStatic>(lazy: &T) {
+    LazyStatic::initialize(lazy);
+}

tracing-core/src/lib.rs

@@ -95,9 +95,6 @@
 #[cfg(not(feature = "std"))]
 extern crate alloc;
 
-#[macro_use]
-extern crate lazy_static;
-
 /// Statically constructs an [`Identifier`] for the provided [`Callsite`].
 ///
 /// This may be used in contexts, such as static initializers, where the
@@ -219,6 +216,14 @@ pub mod span;
 pub(crate) mod stdlib;
 pub mod subscriber;
 
+// Vendored version of spin 0.5.2 (0387621)
+// `mutex` and `once` modules only
+#[cfg(not(feature = "std"))]
+pub mod spin;
+
+// Vendored version of lazy_static 1.4.0 (4216696)
+pub mod lazy_static;
+
 #[doc(inline)]
 pub use self::{
     callsite::Callsite,

tracing-core/src/spin/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Mathijs van de Nes
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

tracing-core/src/spin/mod.rs

@@ -0,0 +1,11 @@
+//! Synchronization primitives based on spinning
+
+#[cfg(test)]
+#[macro_use]
+extern crate std;
+
+pub use mutex::*;
+pub use once::*;
+
+mod mutex;
+mod once;