Rollup of 5 pull requests

library/core/src/char/methods.rs

@@ -804,6 +804,9 @@ impl char {
     /// ```
     /// assert!(' '.is_whitespace());
     ///
+    /// // line break
+    /// assert!('\n'.is_whitespace());
+    ///
     /// // a non-breaking space
     /// assert!('\u{A0}'.is_whitespace());
     ///

library/core/src/macros/mod.rs

@@ -909,7 +909,10 @@ pub(crate) mod builtin {
     /// Inspects an environment variable at compile time.
     ///
     /// This macro will expand to the value of the named environment variable at
-    /// compile time, yielding an expression of type `&'static str`.
+    /// compile time, yielding an expression of type `&'static str`. Use
+    /// [`std::env::var`] instead if you want to read the value at runtime.
+    ///
+    /// [`std::env::var`]: ../std/env/fn.var.html
     ///
     /// If the environment variable is not defined, then a compilation error
     /// will be emitted. To not emit a compile error, use the [`option_env!`]
@@ -950,7 +953,10 @@ pub(crate) mod builtin {
     /// expand into an expression of type `Option<&'static str>` whose value is
     /// `Some` of the value of the environment variable. If the environment
     /// variable is not present, then this will expand to `None`. See
-    /// [`Option<T>`][Option] for more information on this type.
+    /// [`Option<T>`][Option] for more information on this type.  Use
+    /// [`std::env::var`] instead if you want to read the value at runtime.
+    ///
+    /// [`std::env::var`]: ../std/env/fn.var.html
     ///
     /// A compile time error is never emitted when using this macro regardless
     /// of whether the environment variable is present or not.

library/core/src/slice/mod.rs

@@ -814,7 +814,7 @@ impl<T> [T] {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn chunks(&self, chunk_size: usize) -> Chunks<'_, T> {
-        assert_ne!(chunk_size, 0);
+        assert_ne!(chunk_size, 0, "chunks cannot have a size of zero");
         Chunks::new(self, chunk_size)
     }
 
@@ -852,7 +852,7 @@ impl<T> [T] {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<'_, T> {
-        assert_ne!(chunk_size, 0);
+        assert_ne!(chunk_size, 0, "chunks cannot have a size of zero");
         ChunksMut::new(self, chunk_size)
     }
 

library/core/src/str/mod.rs

@@ -1832,14 +1832,14 @@ impl str {
     /// Returns a string slice with leading and trailing whitespace removed.
     ///
     /// 'Whitespace' is defined according to the terms of the Unicode Derived
-    /// Core Property `White_Space`.
+    /// Core Property `White_Space`, which includes newlines.
     ///
     /// # Examples
     ///
     /// Basic usage:
     ///
     /// ```
-    /// let s = " Hello\tworld\t";
+    /// let s = "\n Hello\tworld\t\n";
     ///
     /// assert_eq!("Hello\tworld", s.trim());
     /// ```
@@ -1855,7 +1855,7 @@ impl str {
     /// Returns a string slice with leading whitespace removed.
     ///
     /// 'Whitespace' is defined according to the terms of the Unicode Derived
-    /// Core Property `White_Space`.
+    /// Core Property `White_Space`, which includes newlines.
     ///
     /// # Text directionality
     ///
@@ -1869,8 +1869,8 @@ impl str {
     /// Basic usage:
     ///
     /// ```
-    /// let s = " Hello\tworld\t";
-    /// assert_eq!("Hello\tworld\t", s.trim_start());
+    /// let s = "\n Hello\tworld\t\n";
+    /// assert_eq!("Hello\tworld\t\n", s.trim_start());
     /// ```
     ///
     /// Directionality:
@@ -1894,7 +1894,7 @@ impl str {
     /// Returns a string slice with trailing whitespace removed.
     ///
     /// 'Whitespace' is defined according to the terms of the Unicode Derived
-    /// Core Property `White_Space`.
+    /// Core Property `White_Space`, which includes newlines.
     ///
     /// # Text directionality
     ///
@@ -1908,8 +1908,8 @@ impl str {
     /// Basic usage:
     ///
     /// ```
-    /// let s = " Hello\tworld\t";
-    /// assert_eq!(" Hello\tworld", s.trim_end());
+    /// let s = "\n Hello\tworld\t\n";
+    /// assert_eq!("\n Hello\tworld", s.trim_end());
     /// ```
     ///
     /// Directionality:

src/test/ui/lang-items/lang-item-generic-requirements.rs

@@ -1,5 +1,5 @@
-// Checks that declaring a lang item with the wrong number
-// of generic arguments errors rather than crashing (issue #83893, #87573, part of #9307, #79559).
+// Checks that declaring a lang item with the wrong number of generic arguments errors rather than
+// crashing (issue #83474, #83893, #87573, part of #9307, #79559).
 
 #![feature(lang_items, no_core)]
 #![no_core]
@@ -25,6 +25,10 @@ struct MyPhantomData<T, U>;
 //~^ ERROR parameter `T` is never used
 //~| ERROR parameter `U` is never used
 
+#[lang = "owned_box"]
+//~^ ERROR `owned_box` language item must be applied to a struct with at least 1 generic argument
+struct Foo;
+
 // When the `start` lang item is missing generics very odd things can happen, especially when
 // it comes to cross-crate monomorphization
 #[lang = "start"]
@@ -48,6 +52,9 @@ fn ice() {
 
     // Use phantomdata
     let _ = MyPhantomData::<(), i32>;
+
+    // Use Foo
+    let _: () = Foo;
 }
 
 // use `start`

src/test/ui/lang-items/lang-item-generic-requirements.stderr

@@ -32,8 +32,17 @@ LL |
 LL | struct MyPhantomData<T, U>;
    |                     ------ this struct has 2 generic arguments
 
+error[E0718]: `owned_box` language item must be applied to a struct with at least 1 generic argument
+  --> $DIR/lang-item-generic-requirements.rs:28:1
+   |
+LL | #[lang = "owned_box"]
+   | ^^^^^^^^^^^^^^^^^^^^^
+LL |
+LL | struct Foo;
+   |           - this struct has 0 generic arguments
+
 error[E0718]: `start` language item must be applied to a function with 1 generic argument
-  --> $DIR/lang-item-generic-requirements.rs:30:1
+  --> $DIR/lang-item-generic-requirements.rs:34:1
    |
 LL | #[lang = "start"]
    | ^^^^^^^^^^^^^^^^^
@@ -59,7 +68,7 @@ LL | struct MyPhantomData<T, U>;
    = help: consider removing `U` or referring to it in a field
    = help: if you intended `U` to be a const parameter, use `const U: usize` instead
 
-error: aborting due to 7 previous errors
+error: aborting due to 8 previous errors
 
 Some errors have detailed explanations: E0392, E0718.
 For more information about an error, try `rustc --explain E0392`.

src/tools/compiletest/src/main.rs

@@ -744,12 +744,10 @@ fn make_test_name(
     testpaths: &TestPaths,
     revision: Option<&String>,
 ) -> test::TestName {
-    // Convert a complete path to something like
-    //
-    //    ui/foo/bar/baz.rs
-    let path = PathBuf::from(config.src_base.file_name().unwrap())
-        .join(&testpaths.relative_dir)
-        .join(&testpaths.file.file_name().unwrap());
+    // Print the name of the file, relative to the repository root.
+    // `src_base` looks like `/path/to/rust/src/test/ui`
+    let root_directory = config.src_base.parent().unwrap().parent().unwrap().parent().unwrap();
+    let path = testpaths.file.strip_prefix(root_directory).unwrap();
     let debugger = match config.debugger {
         Some(d) => format!("-{}", d),
         None => String::new(),