Auto merge of #62910 - petrochenkov:buildwarn2, r=Mark-Simulacrum

cleanup: Remove lint annotations in specific crates that are already enforced by rustbuild

Remove some random unnecessary lint `allow`s.

Deny `unused_lifetimes` through rustbuild.

r? @Mark-Simulacrum

src/bootstrap/bin/main.rs

@@ -5,7 +5,8 @@
 //! parent directory, and otherwise documentation can be found throughout the `build`
 //! directory in each respective module.
 
-#![deny(warnings)]
+// NO-RUSTC-WRAPPER
+#![deny(warnings, rust_2018_idioms, unused_lifetimes)]
 
 use std::env;
 

src/bootstrap/bin/rustc.rs

@@ -15,7 +15,8 @@
 //! switching compilers for the bootstrap and for build scripts will probably
 //! never get replaced.
 
-#![deny(warnings)]
+// NO-RUSTC-WRAPPER
+#![deny(warnings, rust_2018_idioms, unused_lifetimes)]
 
 use std::env;
 use std::ffi::OsString;
@@ -126,8 +127,11 @@ fn main() {
 
     if env::var_os("RUSTC_DENY_WARNINGS").is_some() &&
        env::var_os("RUSTC_EXTERNAL_TOOL").is_none() {
+        // When extending this list, search for `NO-RUSTC-WRAPPER` and add the new lints
+        // there as well, some code doesn't go through this `rustc` wrapper.
         cmd.arg("-Dwarnings");
         cmd.arg("-Drust_2018_idioms");
+        cmd.arg("-Dunused_lifetimes");
         // cfg(not(bootstrap)): Remove this during the next stage 0 compiler update.
         // `-Drustc::internal` is a new feature and `rustc_version` mis-reports the `stage`.
         let cfg_not_bootstrap = stage != "0" && crate_name != Some("rustc_version");

src/bootstrap/bin/rustdoc.rs

@@ -2,7 +2,8 @@
 //!
 //! See comments in `src/bootstrap/rustc.rs` for more information.
 
-#![deny(warnings)]
+// NO-RUSTC-WRAPPER
+#![deny(warnings, rust_2018_idioms, unused_lifetimes)]
 
 use std::env;
 use std::process::Command;

src/bootstrap/lib.rs

@@ -103,8 +103,9 @@
 //! More documentation can be found in each respective module below, and you can
 //! also check out the `src/bootstrap/README.md` file for more information.
 
-#![deny(rust_2018_idioms)]
-#![deny(warnings)]
+// NO-RUSTC-WRAPPER
+#![deny(warnings, rust_2018_idioms, unused_lifetimes)]
+
 #![feature(core_intrinsics)]
 #![feature(drain_filter)]
 
@@ -1312,7 +1313,7 @@ fn chmod(path: &Path, perms: u32) {
 fn chmod(_path: &Path, _perms: u32) {}
 
 
-impl<'a> Compiler {
+impl Compiler {
     pub fn with_stage(mut self, stage: u32) -> Compiler {
         self.stage = stage;
         self

src/build_helper/lib.rs

@@ -1,4 +1,5 @@
-#![deny(rust_2018_idioms)]
+// NO-RUSTC-WRAPPER
+#![deny(warnings, rust_2018_idioms, unused_lifetimes)]
 
 use std::fs::File;
 use std::path::{Path, PathBuf};

src/liballoc/lib.rs

@@ -62,8 +62,6 @@
 #![warn(missing_docs)]
 #![warn(missing_debug_implementations)]
 #![deny(intra_doc_link_resolution_failure)] // rustdoc is run without -D warnings
-
-#![deny(rust_2018_idioms)]
 #![allow(explicit_outlives_requirements)]
 
 #![cfg_attr(not(test), feature(generator_trait))]

src/liballoc/string.rs

@@ -1838,6 +1838,7 @@ impl PartialEq for String {
 macro_rules! impl_eq {
     ($lhs:ty, $rhs: ty) => {
         #[stable(feature = "rust1", since = "1.0.0")]
+        #[allow(unused_lifetimes)]
         impl<'a, 'b> PartialEq<$rhs> for $lhs {
             #[inline]
             fn eq(&self, other: &$rhs) -> bool { PartialEq::eq(&self[..], &other[..]) }
@@ -1846,6 +1847,7 @@ macro_rules! impl_eq {
         }
 
         #[stable(feature = "rust1", since = "1.0.0")]
+        #[allow(unused_lifetimes)]
         impl<'a, 'b> PartialEq<$lhs> for $rhs {
             #[inline]
             fn eq(&self, other: &$lhs) -> bool { PartialEq::eq(&self[..], &other[..]) }

src/liballoc/tests/lib.rs

@@ -8,7 +8,6 @@
 #![feature(trusted_len)]
 #![feature(try_reserve)]
 #![feature(unboxed_closures)]
-#![deny(rust_2018_idioms)]
 
 use std::hash::{Hash, Hasher};
 use std::collections::hash_map::DefaultHasher;

src/libarena/lib.rs

@@ -11,9 +11,6 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/",
        test(no_crate_inject, attr(deny(warnings))))]
 
-#![deny(rust_2018_idioms)]
-#![deny(unused_lifetimes)]
-
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(raw_vec_internals)]

src/libcore/array.rs

@@ -217,7 +217,7 @@ where
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, 'b, A, B, const N: usize> PartialEq<[B; N]> for [A; N]
+impl<A, B, const N: usize> PartialEq<[B; N]> for [A; N]
 where
     A: PartialEq<B>,
     [A; N]: LengthAtMost32,
@@ -234,7 +234,7 @@ where
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, 'b, A, B, const N: usize> PartialEq<[B]> for [A; N]
+impl<A, B, const N: usize> PartialEq<[B]> for [A; N]
 where
     A: PartialEq<B>,
     [A; N]: LengthAtMost32,
@@ -250,7 +250,7 @@ where
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, 'b, A, B, const N: usize> PartialEq<[A; N]> for [B]
+impl<A, B, const N: usize> PartialEq<[A; N]> for [B]
 where
     B: PartialEq<A>,
     [A; N]: LengthAtMost32,
@@ -266,7 +266,7 @@ where
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, 'b, A, B, const N: usize> PartialEq<&'b [B]> for [A; N]
+impl<'b, A, B, const N: usize> PartialEq<&'b [B]> for [A; N]
 where
     A: PartialEq<B>,
     [A; N]: LengthAtMost32,
@@ -282,7 +282,7 @@ where
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, 'b, A, B, const N: usize> PartialEq<[A; N]> for &'b [B]
+impl<'b, A, B, const N: usize> PartialEq<[A; N]> for &'b [B]
 where
     B: PartialEq<A>,
     [A; N]: LengthAtMost32,
@@ -298,7 +298,7 @@ where
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, 'b, A, B, const N: usize> PartialEq<&'b mut [B]> for [A; N]
+impl<'b, A, B, const N: usize> PartialEq<&'b mut [B]> for [A; N]
 where
     A: PartialEq<B>,
     [A; N]: LengthAtMost32,
@@ -314,7 +314,7 @@ where
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, 'b, A, B, const N: usize> PartialEq<[A; N]> for &'b mut [B]
+impl<'b, A, B, const N: usize> PartialEq<[A; N]> for &'b mut [B]
 where
     B: PartialEq<A>,
     [A; N]: LengthAtMost32,

src/libcore/lib.rs

@@ -62,8 +62,6 @@
 #![warn(missing_docs)]
 #![warn(missing_debug_implementations)]
 #![deny(intra_doc_link_resolution_failure)] // rustdoc is run without -D warnings
-
-#![deny(rust_2018_idioms)]
 #![allow(explicit_outlives_requirements)]
 
 #![feature(allow_internal_unstable)]

src/libcore/pin.rs

@@ -775,7 +775,7 @@ where
 {}
 
 #[stable(feature = "pin", since = "1.33.0")]
-impl<'a, P, U> DispatchFromDyn<Pin<U>> for Pin<P>
+impl<P, U> DispatchFromDyn<Pin<U>> for Pin<P>
 where
     P: DispatchFromDyn<U>,
 {}

src/libcore/ptr/unique.rs

@@ -172,7 +172,7 @@ impl<T: ?Sized> From<&T> for Unique<T> {
 }
 
 #[unstable(feature = "ptr_internals", issue = "0")]
-impl<'a, T: ?Sized> From<NonNull<T>> for Unique<T> {
+impl<T: ?Sized> From<NonNull<T>> for Unique<T> {
     #[inline]
     fn from(p: NonNull<T>) -> Self {
         unsafe { Unique::new_unchecked(p.as_ptr()) }

src/libcore/tests/lib.rs

@@ -32,7 +32,6 @@
 #![feature(const_fn)]
 #![feature(iter_partition_in_place)]
 #![feature(iter_is_partitioned)]
-#![warn(rust_2018_idioms)]
 
 extern crate test;
 

src/libfmt_macros/lib.rs

@@ -8,9 +8,6 @@
        html_playground_url = "https://play.rust-lang.org/",
        test(attr(deny(warnings))))]
 
-#![deny(rust_2018_idioms)]
-#![deny(unused_lifetimes)]
-
 #![feature(nll)]
 #![feature(rustc_private)]
 #![feature(unicode_internals)]

src/libgraphviz/lib.rs

@@ -274,8 +274,6 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/",
        test(attr(allow(unused_variables), deny(warnings))))]
 
-#![deny(rust_2018_idioms)]
-
 #![feature(nll)]
 
 use LabelText::*;

src/libpanic_abort/lib.rs

@@ -10,7 +10,6 @@
 #![panic_runtime]
 
 #![allow(unused_features)]
-#![deny(rust_2018_idioms)]
 
 #![feature(core_intrinsics)]
 #![feature(libc)]

src/libpanic_unwind/lib.rs

@@ -17,8 +17,6 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/",
        issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/")]
 
-#![deny(rust_2018_idioms)]
-
 #![feature(core_intrinsics)]
 #![feature(lang_items)]
 #![feature(libc)]

src/libproc_macro/bridge/scoped_cell.rs

@@ -5,6 +5,7 @@ use std::mem;
 use std::ops::{Deref, DerefMut};
 
 /// Type lambda application, with a lifetime.
+#[allow(unused_lifetimes)]
 pub trait ApplyL<'a> {
     type Out;
 }

src/libproc_macro/lib.rs

@@ -17,8 +17,6 @@
        test(no_crate_inject, attr(deny(warnings))),
        test(attr(allow(dead_code, deprecated, unused_variables, unused_mut))))]
 
-#![deny(rust_2018_idioms)]
-
 #![feature(nll)]
 #![feature(staged_api)]
 #![feature(const_fn)]

src/libprofiler_builtins/lib.rs

@@ -7,4 +7,3 @@
 #![allow(unused_features)]
 #![feature(nll)]
 #![feature(staged_api)]
-#![deny(rust_2018_idioms)]

src/librustc/error_codes.rs

@@ -1,5 +1,3 @@
-#![allow(non_snake_case)]
-
 // Error messages for EXXXX errors.
 // Each message should start and end with a new line, and be wrapped to 80 characters.
 // In vim you can `:set tw=80` and use `gq` to wrap paragraphs. Use `:set tw=0` to disable.

src/librustc/lib.rs

@@ -28,9 +28,6 @@
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
 
-#![deny(rust_2018_idioms)]
-#![deny(unused_lifetimes)]
-
 #![feature(arbitrary_self_types)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
@@ -81,8 +78,7 @@ extern crate libc;
 
 // Use the test crate here so we depend on getopts through it. This allow tools to link to both
 // librustc_driver and libtest.
-#[allow(unused_extern_crates)]
-extern crate test;
+extern crate test as _;
 
 #[macro_use]
 mod macros;

src/librustc/session/config.rs

@@ -1628,7 +1628,7 @@ impl RustcOptGroup {
 // *unstable* options, i.e., options that are only enabled when the
 // user also passes the `-Z unstable-options` debugging flag.
 mod opt {
-    // The `fn opt_u` etc below are written so that we can use them
+    // The `fn flag*` etc below are written so that we can use them
     // in the future; do not warn about them not being used right now.
     #![allow(dead_code)]