avoid test-wide allowance of unused/dead code

tests/run-pass/bitop-beyond-alignment.rs

@@ -8,14 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(dead_code)]
-
 use std::mem;
 
 enum Tag<A> {
     Tag2(A)
 }
 
+#[allow(dead_code)]
 struct Rec {
     c8: u8,
     t: Tag<u64>

tests/run-pass/dst-field-align.rs

@@ -1,5 +1,4 @@
-#![allow(dead_code)]
-
+#[allow(dead_code)]
 struct Foo<T: ?Sized> {
     a: u16,
     b: T
@@ -17,6 +16,7 @@ struct Baz<T: ?Sized> {
     a: T
 }
 
+#[allow(dead_code)]
 struct HasDrop<T: ?Sized> {
     ptr: Box<usize>,
     data: T

tests/run-pass/foreign-fn-linkname.rs

@@ -1,7 +1,5 @@
 //ignore-windows: Uses POSIX APIs
-
 #![feature(rustc_private)]
-#![allow(unused_extern_crates)] // rustc bug https://github.com/rust-lang/rust/issues/56098
 
 extern crate libc;
 

tests/run-pass/issue-15063.rs

@@ -1,5 +1,4 @@
-#![allow(dead_code)]
-
+#[allow(dead_code)]
 enum Two { A, B }
 impl Drop for Two {
     fn drop(&mut self) {

tests/run-pass/issue-35815.rs

@@ -1,7 +1,6 @@
-#![allow(dead_code)]
-
 use std::mem;
 
+#[allow(dead_code)]
 struct Foo<T: ?Sized> {
     a: i64,
     b: bool,

tests/run-pass/issue-53728.rs

@@ -1,14 +1,16 @@
-#![allow(dead_code)]
-
 #[repr(u16)]
+#[allow(dead_code)]
 enum DeviceKind {
     Nil = 0,
 }
+
 #[repr(packed)]
+#[allow(dead_code)]
 struct DeviceInfo {
     endianness: u8,
     device_kind: DeviceKind,
 }
+
 fn main() {
     let _x = None::<(DeviceInfo, u8)>;
     let _y = None::<(DeviceInfo, u16)>;

tests/run-pass/libc.rs

@@ -2,14 +2,12 @@
 // compile-flags: -Zmiri-disable-isolation
 
 #![feature(rustc_private)]
-#![allow(unused)] // necessary on macos due to conditional compilation
-
-use std::path::PathBuf;
 
 extern crate libc;
 
-fn tmp() -> PathBuf {
-    std::env::var("MIRI_TEMP").map(PathBuf::from).unwrap_or_else(|_| std::env::temp_dir())
+#[cfg(target_os = "linux")]
+fn tmp() -> std::path::PathBuf {
+    std::env::var("MIRI_TEMP").map(std::path::PathBuf::from).unwrap_or_else(|_| std::env::temp_dir())
 }
 
 #[cfg(target_os = "linux")]

tests/run-pass/packed_struct.rs

@@ -1,4 +1,3 @@
-#![allow(dead_code)]
 #![feature(unsize, coerce_unsized)]
 
 #[repr(packed)]
@@ -8,12 +7,14 @@ struct S {
 }
 
 #[repr(packed)]
+#[allow(dead_code)]
 struct Test1<'a> {
     x: u8,
     other: &'a u32,
 }
 
 #[repr(packed)]
+#[allow(dead_code)]
 struct Test2<'a> {
     x: u8,
     other: &'a Test1<'a>,
@@ -26,6 +27,7 @@ fn test(t: Test2) {
 
 fn test_unsizing() {
     #[repr(packed)]
+    #[allow(dead_code)]
     struct UnalignedPtr<'a, T: ?Sized>
     where T: 'a,
     {

tests/run-pass/regions-mock-trans.rs

@@ -2,8 +2,6 @@
 
 #![feature(rustc_private)]
 
-#![allow(dead_code)]
-
 extern crate libc;
 use std::mem;
 
@@ -13,11 +11,13 @@ struct Bcx<'a> {
     fcx: &'a Fcx<'a>
 }
 
+#[allow(dead_code)]
 struct Fcx<'a> {
     arena: &'a Arena,
     ccx: &'a Ccx
 }
 
+#[allow(dead_code)]
 struct Ccx {
     x: isize
 }

tests/run-pass/rfc1623.rs

@@ -1,4 +1,4 @@
-#![allow(dead_code)]
+#![allow(dead_code)] // tons of unused statics here...
 
 // very simple test for a 'static static with default lifetime
 static STATIC_STR: &str = "&'static str";

tests/run-pass/small_enum_size_bug.rs

@@ -1,5 +1,4 @@
-#![allow(dead_code)]
-
+#[allow(dead_code)]
 enum E {
     A = 1,
     B = 2,

tests/run-pass/static_mut.rs

@@ -1,8 +1,7 @@
-#![allow(dead_code)]
-
 static mut FOO: i32 = 42;
 static BAR: Foo = Foo(unsafe { &FOO as *const _} );
 
+#[allow(dead_code)]
 struct Foo(*const i32);
 
 unsafe impl Sync for Foo {}

tests/run-pass/tag-align-dyn-u64.rs

@@ -8,14 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(dead_code)]
-
 use std::mem;
 
 enum Tag<A> {
     Tag2(A)
 }
 
+#[allow(dead_code)]
 struct Rec {
     c8: u8,
     t: Tag<u64>

tests/run-pass/union.rs

@@ -1,5 +1,4 @@
 #![feature(untagged_unions)]
-#![allow(dead_code, unused_variables)]
 
 fn main() {
     a();
@@ -9,6 +8,7 @@ fn main() {
 }
 
 fn a() {
+    #[allow(dead_code)]
     union U {
         f1: u32,
         f2: f32,
@@ -27,6 +27,7 @@ fn b() {
         y: u32,
     }
 
+    #[allow(dead_code)]
     union U {
         s: S,
         both: u64,
@@ -82,7 +83,7 @@ fn d() {
     unsafe {
         match u {
             MyUnion { f1: 10 } => { }
-            MyUnion { f2 } => { panic!("foo"); }
+            MyUnion { f2: _f2 } => { panic!("foo"); }
         }
     }
 }