Auto merge of #42856 - Mark-Simulacrum:rollup, r=Mark-Simulacrum

Rollup of 8 pull requests

- Successful merges: #42777, #42783, #42787, #42821, #42822, #42825, #42829, #42833
- Failed merges:

Author: bors

src/bootstrap/check.rs

@@ -265,7 +265,7 @@ pub fn compiletest(build: &Build,
         let llvm_components = output(Command::new(&llvm_config).arg("--components"));
         let llvm_cxxflags = output(Command::new(&llvm_config).arg("--cxxflags"));
         cmd.arg("--cc").arg(build.cc(target))
-           .arg("--cxx").arg(build.cxx(target))
+           .arg("--cxx").arg(build.cxx(target).unwrap())
            .arg("--cflags").arg(build.cflags(target).join(" "))
            .arg("--llvm-components").arg(llvm_components.trim())
            .arg("--llvm-cxxflags").arg(llvm_cxxflags.trim());

src/bootstrap/compile.rs

@@ -291,7 +291,7 @@ pub fn rustc(build: &Build, target: &str, compiler: &Compiler) {
        !target.contains("windows") &&
        !target.contains("apple") {
         cargo.env("LLVM_STATIC_STDCPP",
-                  compiler_file(build.cxx(target), "libstdc++.a"));
+                  compiler_file(build.cxx(target).unwrap(), "libstdc++.a"));
     }
     if build.config.llvm_link_shared {
         cargo.env("LLVM_LINK_SHARED", "1");

src/bootstrap/lib.rs

@@ -452,6 +452,10 @@ impl Build {
             cargo.env(format!("CC_{}", target), self.cc(target))
                  .env(format!("AR_{}", target), self.ar(target).unwrap()) // only msvc is None
                  .env(format!("CFLAGS_{}", target), self.cflags(target).join(" "));
+
+            if let Ok(cxx) = self.cxx(target) {
+                 cargo.env(format!("CXX_{}", target), cxx);
+            }
         }
 
         if self.config.extended && compiler.is_final_stage(self) {
@@ -838,13 +842,13 @@ impl Build {
         self.cc[target].1.as_ref().map(|p| &**p)
     }
 
-    /// Returns the path to the C++ compiler for the target specified, may panic
-    /// if no C++ compiler was configured for the target.
-    fn cxx(&self, target: &str) -> &Path {
+    /// Returns the path to the C++ compiler for the target specified.
+    fn cxx(&self, target: &str) -> Result<&Path, String> {
         match self.cxx.get(target) {
-            Some(p) => p.path(),
-            None => panic!("\n\ntarget `{}` is not configured as a host,
-                            only as a target\n\n", target),
+            Some(p) => Ok(p.path()),
+            None => Err(format!(
+                    "target `{}` is not configured as a host, only as a target",
+                    target))
         }
     }
 

src/bootstrap/native.rs

@@ -155,7 +155,7 @@ pub fn llvm(build: &Build, target: &str) {
         }
 
         let cc = build.cc(target);
-        let cxx = build.cxx(target);
+        let cxx = build.cxx(target).unwrap();
 
         // Handle msvc + ninja + ccache specially (this is what the bots use)
         if target.contains("msvc") &&

src/bootstrap/sanity.rs

@@ -139,7 +139,7 @@ pub fn check(build: &mut Build) {
         }
     }
     for host in build.config.host.iter() {
-        need_cmd(build.cxx(host).as_ref());
+        need_cmd(build.cxx(host).unwrap().as_ref());
     }
 
     // The msvc hosts don't use jemalloc, turn it off globally to

src/liballoc/boxed.rs

@@ -42,8 +42,10 @@
 //! Recursive structures must be boxed, because if the definition of `Cons`
 //! looked like this:
 //!
-//! ```rust,ignore
+//! ```compile_fail,E0072
+//! # enum List<T> {
 //! Cons(T, List<T>),
+//! # }
 //! ```
 //!
 //! It wouldn't work. This is because the size of a `List` depends on how many

src/liballoc/fmt.rs

@@ -230,7 +230,7 @@
 //! There are a number of related macros in the `format!` family. The ones that
 //! are currently implemented are:
 //!
-//! ```ignore
+//! ```ignore (only-for-syntax-highlight)
 //! format!      // described above
 //! write!       // first argument is a &mut io::Write, the destination
 //! writeln!     // same as write but appends a newline

src/liballoc/raw_vec.rs

@@ -244,7 +244,11 @@ impl<T, A: Alloc> RawVec<T, A> {
     ///
     /// # Examples
     ///
-    /// ```ignore
+    /// ```
+    /// # #![feature(alloc)]
+    /// # extern crate alloc;
+    /// # use std::ptr;
+    /// # use alloc::raw_vec::RawVec;
     /// struct MyVec<T> {
     ///     buf: RawVec<T>,
     ///     len: usize,
@@ -261,6 +265,10 @@ impl<T, A: Alloc> RawVec<T, A> {
     ///         self.len += 1;
     ///     }
     /// }
+    /// # fn main() {
+    /// #   let mut vec = MyVec { buf: RawVec::new(), len: 0 };
+    /// #   vec.push(1);
+    /// # }
     /// ```
     #[inline(never)]
     #[cold]
@@ -440,13 +448,17 @@ impl<T, A: Alloc> RawVec<T, A> {
     ///
     /// # Examples
     ///
-    /// ```ignore
+    /// ```
+    /// # #![feature(alloc)]
+    /// # extern crate alloc;
+    /// # use std::ptr;
+    /// # use alloc::raw_vec::RawVec;
     /// struct MyVec<T> {
     ///     buf: RawVec<T>,
     ///     len: usize,
     /// }
     ///
-    /// impl<T> MyVec<T> {
+    /// impl<T: Clone> MyVec<T> {
     ///     pub fn push_all(&mut self, elems: &[T]) {
     ///         self.buf.reserve(self.len, elems.len());
     ///         // reserve would have aborted or panicked if the len exceeded
@@ -459,6 +471,10 @@ impl<T, A: Alloc> RawVec<T, A> {
     ///         }
     ///     }
     /// }
+    /// # fn main() {
+    /// #   let mut vector = MyVec { buf: RawVec::new(), len: 0 };
+    /// #   vector.push_all(&[1, 3, 5, 7, 9]);
+    /// # }
     /// ```
     pub fn reserve(&mut self, used_cap: usize, needed_extra_cap: usize) {
         unsafe {

src/liballoc/rc.rs

@@ -273,7 +273,7 @@ struct RcBox<T: ?Sized> {
 /// See the [module-level documentation](./index.html) for more details.
 ///
 /// The inherent methods of `Rc` are all associated functions, which means
-/// that you have to call them as e.g. [`Rc::get_mut(&value)`][get_mut] instead of
+/// that you have to call them as e.g. [`Rc::get_mut(&mut value)`][get_mut] instead of
 /// `value.get_mut()`. This avoids conflicts with methods of the inner
 /// type `T`.
 ///

src/liballoc/string.rs

@@ -124,7 +124,7 @@ use boxed::Box;
 /// similar, but without the UTF-8 constraint. The second implication is that
 /// you cannot index into a `String`:
 ///
-/// ```ignore
+/// ```compile_fail,E0277
 /// let s = "hello";
 ///
 /// println!("The first letter of s is {}", s[0]); // ERROR!!!