cleaned up some tests

Author: Kivooeo

tests/ui/binop/compound-assign-by-ref.rs

@@ -1,9 +1,8 @@
+//! Test compound assignment operators with reference right-hand side.
+
 //@ run-pass
 
 fn main() {
-    // test compound assignment operators with ref as right-hand side,
-    // for each operator, with various types as operands.
-
     // test AddAssign
     {
         let mut x = 3i8;

tests/ui/closures/fnonce-call-twice-error.rs

@@ -1,16 +1,15 @@
-// Testing guarantees provided by once functions.
-// This program would segfault if it were legal.
+//! Test that `FnOnce` closures cannot be called twice.
 
 use std::sync::Arc;
 
-fn foo<F:FnOnce()>(blk: F) {
+fn foo<F: FnOnce()>(blk: F) {
     blk();
     blk(); //~ ERROR use of moved value
 }
 
 fn main() {
     let x = Arc::new(true);
-    foo(move|| {
+    foo(move || {
         assert!(*x);
         drop(x);
     });

tests/ui/closures/fnonce-call-twice-error.stderr

@@ -1,18 +1,18 @@
 error[E0382]: use of moved value: `blk`
-  --> $DIR/once-cant-call-twice-on-heap.rs:8:5
+  --> $DIR/fnonce-call-twice-error.rs:7:5
    |
-LL | fn foo<F:FnOnce()>(blk: F) {
-   |                    --- move occurs because `blk` has type `F`, which does not implement the `Copy` trait
+LL | fn foo<F: FnOnce()>(blk: F) {
+   |                     --- move occurs because `blk` has type `F`, which does not implement the `Copy` trait
 LL |     blk();
    |     ----- `blk` moved due to this call
 LL |     blk();
    |     ^^^ value used here after move
    |
 note: `FnOnce` closures can only be called once
-  --> $DIR/once-cant-call-twice-on-heap.rs:6:10
+  --> $DIR/fnonce-call-twice-error.rs:5:11
    |
-LL | fn foo<F:FnOnce()>(blk: F) {
-   |          ^^^^^^^^ `F` is made to be an `FnOnce` closure here
+LL | fn foo<F: FnOnce()>(blk: F) {
+   |           ^^^^^^^^ `F` is made to be an `FnOnce` closure here
 LL |     blk();
    |     ----- this value implements `FnOnce`, which causes it to be moved when called
 

tests/ui/panics/oom-panic-unwind.rs

@@ -1,3 +1,5 @@
+//! Test that out-of-memory conditions trigger catchable panics with `-Z oom=panic`.
+
 //@ compile-flags: -Z oom=panic
 //@ run-pass
 //@ no-prefer-dynamic

tests/ui/traits/copy-requires-all-fields-copy.rs

@@ -1,3 +1,5 @@
+//! Test that `Copy` cannot be implemented if any field doesn't implement `Copy`.
+
 struct CantCopyThis;
 
 struct IWantToCopyThis {

tests/ui/traits/copy-requires-all-fields-copy.stderr

@@ -1,5 +1,5 @@
 error[E0204]: the trait `Copy` cannot be implemented for this type
-  --> $DIR/opt-in-copy.rs:7:15
+  --> $DIR/copy-requires-all-fields-copy.rs:9:15
    |
 LL |     but_i_cant: CantCopyThis,
    |     ------------------------ this field does not implement `Copy`
@@ -8,7 +8,7 @@ LL | impl Copy for IWantToCopyThis {}
    |               ^^^^^^^^^^^^^^^
 
 error[E0204]: the trait `Copy` cannot be implemented for this type
-  --> $DIR/opt-in-copy.rs:19:15
+  --> $DIR/copy-requires-all-fields-copy.rs:21:15
    |
 LL |     ButICant(CantCopyThisEither),
    |              ------------------ this field does not implement `Copy`

tests/ui/type-inference/direct-self-reference-occurs-check.rs

@@ -1,3 +1,7 @@
+//! Test that occurs check prevents direct self-reference in variable assignment.
+//!
+//! Regression test for <https://github.com/rust-lang/rust/issues/768>.
+
 fn main() {
     let f;
     f = Box::new(f);

tests/ui/type-inference/direct-self-reference-occurs-check.stderr

@@ -1,5 +1,5 @@
 error[E0275]: overflow assigning `Box<_>` to `_`
-  --> $DIR/occurs-check.rs:3:18
+  --> $DIR/direct-self-reference-occurs-check.rs:7:18
    |
 LL |     f = Box::new(f);
    |                  ^

tests/ui/type-inference/enum-self-reference-occurs-check.rs

@@ -1,11 +1,16 @@
-// From Issue #778
+//! Test that occurs check prevents infinite types with enum self-references.
+//!
+//! Regression test for <https://github.com/rust-lang/rust/issues/778>.
+
+enum Clam<T> {
+    A(T),
+}
 
-enum Clam<T> { A(T) }
 fn main() {
     let c;
     c = Clam::A(c);
     //~^ ERROR overflow assigning `Clam<_>` to `_`
     match c {
-        Clam::A::<isize>(_) => { }
+        Clam::A::<isize>(_) => {}
     }
 }

tests/ui/type-inference/enum-self-reference-occurs-check.stderr

@@ -1,5 +1,5 @@
 error[E0275]: overflow assigning `Clam<_>` to `_`
-  --> $DIR/occurs-check-3.rs:6:17
+  --> $DIR/enum-self-reference-occurs-check.rs:11:17
    |
 LL |     c = Clam::A(c);
    |                 ^