coverage: Tidy up run-coverage tests in several small ways

tests/run-coverage-rustdoc/doctest.coverage

@@ -10,6 +10,8 @@ $DIR/auxiliary/doctest_crate.rs:
    LL|      3|}
 
 $DIR/doctest.rs:
+   LL|       |// aux-build:doctest_crate.rs
+   LL|       |
    LL|       |//! This test ensures that code from doctests is properly re-mapped.
    LL|       |//! See <https://github.com/rust-lang/rust/issues/79417> for more info.
    LL|       |//!
@@ -78,7 +80,7 @@ $DIR/doctest.rs:
    LL|       |//!     doctest_main()
    LL|       |//! }
    LL|       |//! ```
-   LL|       |// aux-build:doctest_crate.rs
+   LL|       |
    LL|       |/// doctest attached to fn testing external code:
    LL|       |/// ```
    LL|      1|/// extern crate doctest_crate;

tests/run-coverage-rustdoc/doctest.rs

@@ -1,3 +1,5 @@
+// aux-build:doctest_crate.rs
+
 //! This test ensures that code from doctests is properly re-mapped.
 //! See <https://github.com/rust-lang/rust/issues/79417> for more info.
 //!
@@ -63,7 +65,7 @@
 //!     doctest_main()
 //! }
 //! ```
-// aux-build:doctest_crate.rs
+
 /// doctest attached to fn testing external code:
 /// ```
 /// extern crate doctest_crate;

tests/run-coverage/assert.coverage

@@ -7,7 +7,7 @@
                                                   ^1
    LL|      3|}
    LL|       |
-   LL|      1|fn main() -> Result<(),u8> {
+   LL|      1|fn main() -> Result<(), u8> {
    LL|      1|    let mut countdown = 10;
    LL|     11|    while countdown > 0 {
    LL|     11|        if countdown == 1 {

tests/run-coverage/assert.rs

@@ -6,7 +6,7 @@ fn might_fail_assert(one_plus_one: u32) {
     assert_eq!(1 + 1, one_plus_one, "the argument was wrong");
 }
 
-fn main() -> Result<(),u8> {
+fn main() -> Result<(), u8> {
     let mut countdown = 10;
     while countdown > 0 {
         if countdown == 1 {

tests/run-coverage/async2.coverage

@@ -1,11 +1,5 @@
    LL|       |// compile-flags: --edition=2018
    LL|       |
-   LL|       |use core::{
-   LL|       |    future::Future,
-   LL|       |    marker::Send,
-   LL|       |    pin::Pin,
-   LL|       |};
-   LL|       |
    LL|      1|fn non_async_func() {
    LL|      1|    println!("non_async_func was covered");
    LL|      1|    let b = true;
@@ -15,9 +9,6 @@
                    ^0
    LL|      1|}
    LL|       |
-   LL|       |
-   LL|       |
-   LL|       |
    LL|      1|async fn async_func() {
    LL|      1|    println!("async_func was covered");
    LL|      1|    let b = true;
@@ -27,9 +18,6 @@
                    ^0
    LL|      1|}
    LL|       |
-   LL|       |
-   LL|       |
-   LL|       |
    LL|      1|async fn async_func_just_println() {
    LL|      1|    println!("async_func_just_println was covered");
    LL|      1|}

tests/run-coverage/async2.rs

@@ -1,11 +1,5 @@
 // compile-flags: --edition=2018
 
-use core::{
-    future::Future,
-    marker::Send,
-    pin::Pin,
-};
-
 fn non_async_func() {
     println!("non_async_func was covered");
     let b = true;
@@ -14,9 +8,6 @@ fn non_async_func() {
     }
 }
 
-
-
-
 async fn async_func() {
     println!("async_func was covered");
     let b = true;
@@ -25,9 +16,6 @@ async fn async_func() {
     }
 }
 
-
-
-
 async fn async_func_just_println() {
     println!("async_func_just_println was covered");
 }

tests/run-coverage/auxiliary/inline_always_with_dead_code.rs

@@ -4,9 +4,9 @@
 
 mod foo {
     #[inline(always)]
-    pub fn called() { }
+    pub fn called() {}
 
-    fn uncalled() { }
+    fn uncalled() {}
 }
 
 pub mod bar {

tests/run-coverage/auxiliary/unused_mod_helper.rs

@@ -1,3 +1,4 @@
+#[allow(dead_code)]
 pub fn never_called_function() {
     println!("I am never called");
 }

tests/run-coverage/auxiliary/used_crate.rs

@@ -1,6 +1,8 @@
 #![allow(unused_assignments, unused_variables)]
+// Verify that coverage works with optimizations:
 // compile-flags: -C opt-level=3
-use std::fmt::Debug; // ^^ validates coverage now works with optimizations
+
+use std::fmt::Debug;
 
 pub fn used_function() {
     // Initialize test constants in a way that cannot be determined at compile time, to ensure
@@ -42,6 +44,7 @@ pub fn unused_function() {
     }
 }
 
+#[allow(dead_code)]
 fn unused_private_function() {
     let is_true = std::env::args().len() == 1;
     let mut countdown = 2;

tests/run-coverage/auxiliary/used_inline_crate.rs

@@ -1,7 +1,7 @@
 #![allow(unused_assignments, unused_variables)]
-
+// Verify that coverage works with optimizations:
 // compile-flags: -C opt-level=3
-// ^^ validates coverage now works with optimizations
+
 use std::fmt::Debug;
 
 pub fn used_function() {
@@ -29,12 +29,6 @@ pub fn used_inline_function() {
     use_this_lib_crate();
 }
 
-
-
-
-
-
-
 #[inline(always)]
 pub fn used_only_from_bin_crate_generic_function<T: Debug>(arg: T) {
     println!("used_only_from_bin_crate_generic_function with {:?}", arg);
@@ -71,6 +65,7 @@ pub fn unused_function() {
 }
 
 #[inline(always)]
+#[allow(dead_code)]
 fn unused_private_function() {
     let is_true = std::env::args().len() == 1;
     let mut countdown = 2;

tests/run-coverage/closure.coverage

@@ -1,11 +1,16 @@
    LL|       |#![allow(unused_assignments, unused_variables)]
    LL|       |// compile-flags: -C opt-level=2
-   LL|      1|fn main() { // ^^ fix described in rustc_middle/mir/mono.rs
+   LL|       |
+   LL|       |// This test used to be sensitive to certain coverage-specific hacks in
+   LL|       |// `rustc_middle/mir/mono.rs`, but those hacks were later cleaned up by
+   LL|       |// <https://github.com/rust-lang/rust/pull/83666>.
+   LL|       |
+   LL|      1|fn main() {
    LL|      1|    // Initialize test constants in a way that cannot be determined at compile time, to ensure
    LL|      1|    // rustc and LLVM cannot optimize out statements (or coverage counters) downstream from
    LL|      1|    // dependent conditions.
    LL|      1|    let is_true = std::env::args().len() == 1;
-   LL|      1|    let is_false = ! is_true;
+   LL|      1|    let is_false = !is_true;
    LL|      1|
    LL|      1|    let mut some_string = Some(String::from("the string content"));
    LL|      1|    println!(

tests/run-coverage/closure.rs

@@ -1,11 +1,16 @@
 #![allow(unused_assignments, unused_variables)]
 // compile-flags: -C opt-level=2
-fn main() { // ^^ fix described in rustc_middle/mir/mono.rs
+
+// This test used to be sensitive to certain coverage-specific hacks in
+// `rustc_middle/mir/mono.rs`, but those hacks were later cleaned up by
+// <https://github.com/rust-lang/rust/pull/83666>.
+
+fn main() {
     // Initialize test constants in a way that cannot be determined at compile time, to ensure
     // rustc and LLVM cannot optimize out statements (or coverage counters) downstream from
     // dependent conditions.
     let is_true = std::env::args().len() == 1;
-    let is_false = ! is_true;
+    let is_false = !is_true;
 
     let mut some_string = Some(String::from("the string content"));
     println!(

tests/run-coverage/closure_macro_async.coverage

@@ -42,7 +42,7 @@
    LL|       |
    LL|       |#[no_coverage]
    LL|       |fn main() {
-   LL|       |    executor::block_on(test());
+   LL|       |    executor::block_on(test()).unwrap();
    LL|       |}
    LL|       |
    LL|       |mod executor {
@@ -57,16 +57,12 @@
    LL|       |        let mut future = unsafe { Pin::new_unchecked(&mut future) };
    LL|       |        use std::hint::unreachable_unchecked;
    LL|       |        static VTABLE: RawWakerVTable = RawWakerVTable::new(
-   LL|       |
    LL|       |            #[no_coverage]
    LL|       |            |_| unsafe { unreachable_unchecked() }, // clone
-   LL|       |
    LL|       |            #[no_coverage]
    LL|       |            |_| unsafe { unreachable_unchecked() }, // wake
-   LL|       |
    LL|       |            #[no_coverage]
    LL|       |            |_| unsafe { unreachable_unchecked() }, // wake_by_ref
-   LL|       |
    LL|       |            #[no_coverage]
    LL|       |            |_| (),
    LL|       |        );

tests/run-coverage/closure_macro_async.rs

@@ -41,7 +41,7 @@ pub async fn test() -> Result<(), String> {
 
 #[no_coverage]
 fn main() {
-    executor::block_on(test());
+    executor::block_on(test()).unwrap();
 }
 
 mod executor {
@@ -56,16 +56,12 @@ mod executor {
         let mut future = unsafe { Pin::new_unchecked(&mut future) };
         use std::hint::unreachable_unchecked;
         static VTABLE: RawWakerVTable = RawWakerVTable::new(
-
             #[no_coverage]
             |_| unsafe { unreachable_unchecked() }, // clone
-
             #[no_coverage]
             |_| unsafe { unreachable_unchecked() }, // wake
-
             #[no_coverage]
             |_| unsafe { unreachable_unchecked() }, // wake_by_ref
-
             #[no_coverage]
             |_| (),
         );

tests/run-coverage/conditions.coverage

@@ -59,7 +59,6 @@
    LL|       |        }
    LL|      0|    }
    LL|       |
-   LL|       |
    LL|      1|    let mut countdown = 0;
    LL|      1|    if true {
    LL|      1|        countdown = 1;

tests/run-coverage/conditions.rs

@@ -55,7 +55,6 @@ fn main() {
         }
     }
 
-
     let mut countdown = 0;
     if true {
         countdown = 1;

tests/run-coverage/dead_code.coverage

@@ -1,4 +1,4 @@
-   LL|       |#![allow(unused_assignments, unused_variables)]
+   LL|       |#![allow(dead_code, unused_assignments, unused_variables)]
    LL|       |
    LL|      0|pub fn unused_pub_fn_not_in_library() {
    LL|      0|    // Initialize test constants in a way that cannot be determined at compile time, to ensure

tests/run-coverage/dead_code.rs

@@ -1,4 +1,4 @@
-#![allow(unused_assignments, unused_variables)]
+#![allow(dead_code, unused_assignments, unused_variables)]
 
 pub fn unused_pub_fn_not_in_library() {
     // Initialize test constants in a way that cannot be determined at compile time, to ensure

tests/run-coverage/drop_trait.coverage

@@ -11,7 +11,7 @@
    LL|      2|    }
    LL|       |}
    LL|       |
-   LL|      1|fn main() -> Result<(),u8> {
+   LL|      1|fn main() -> Result<(), u8> {
    LL|      1|    let _firecracker = Firework { strength: 1 };
    LL|      1|
    LL|      1|    let _tnt = Firework { strength: 100 };

tests/run-coverage/drop_trait.rs

@@ -11,7 +11,7 @@ impl Drop for Firework {
     }
 }
 
-fn main() -> Result<(),u8> {
+fn main() -> Result<(), u8> {
     let _firecracker = Firework { strength: 1 };
 
     let _tnt = Firework { strength: 100 };

tests/run-coverage/generics.coverage

@@ -41,7 +41,7 @@
   ------------------
    LL|       |}
    LL|       |
-   LL|      1|fn main() -> Result<(),u8> {
+   LL|      1|fn main() -> Result<(), u8> {
    LL|      1|    let mut firecracker = Firework { strength: 1 };
    LL|      1|    firecracker.set_strength(2);
    LL|      1|
@@ -54,10 +54,6 @@
    LL|      1|        return Err(1);
    LL|      0|    }
    LL|      0|
-   LL|      0|
-   LL|      0|
-   LL|      0|
-   LL|      0|
    LL|      0|    let _ = Firework { strength: 1000 };
    LL|      0|
    LL|      0|    Ok(())

tests/run-coverage/generics.rs

@@ -19,7 +19,7 @@ impl<T> Drop for Firework<T> where T: Copy + std::fmt::Display {
     }
 }
 
-fn main() -> Result<(),u8> {
+fn main() -> Result<(), u8> {
     let mut firecracker = Firework { strength: 1 };
     firecracker.set_strength(2);
 
@@ -32,10 +32,6 @@ fn main() -> Result<(),u8> {
         return Err(1);
     }
 
-
-
-
-
     let _ = Firework { strength: 1000 };
 
     Ok(())

tests/run-coverage/issue-85461.coverage

@@ -5,9 +5,9 @@ $DIR/auxiliary/inline_always_with_dead_code.rs:
    LL|       |
    LL|       |mod foo {
    LL|       |    #[inline(always)]
-   LL|      2|    pub fn called() { }
+   LL|      2|    pub fn called() {}
    LL|       |
-   LL|      0|    fn uncalled() { }
+   LL|      0|    fn uncalled() {}
    LL|       |}
    LL|       |
    LL|       |pub mod bar {
@@ -24,6 +24,7 @@ $DIR/auxiliary/inline_always_with_dead_code.rs:
 
 $DIR/issue-85461.rs:
    LL|       |// Regression test for #85461: MSVC sometimes fail to link with dead code and #[inline(always)]
+   LL|       |
    LL|       |// aux-build:inline_always_with_dead_code.rs
    LL|       |extern crate inline_always_with_dead_code;
    LL|       |

tests/run-coverage/issue-85461.rs

@@ -1,4 +1,5 @@
 // Regression test for #85461: MSVC sometimes fail to link with dead code and #[inline(always)]
+
 // aux-build:inline_always_with_dead_code.rs
 extern crate inline_always_with_dead_code;