Auto merge of #42445 - Mark-Simulacrum:rollup, r=Mark-Simulacrum

Rollup of 4 pull requests

- Successful merges: #42304, #42415, #42429, #42438
- Failed merges:

Author: bors

src/bootstrap/compile.rs

@@ -276,6 +276,10 @@ pub fn rustc(build: &Build, target: &str, compiler: &Compiler) {
     if build.is_rust_llvm(target) {
         cargo.env("LLVM_RUSTLLVM", "1");
     }
+    if let Some(ref cfg_file) = build.flags.config {
+        let cfg_path = t!(PathBuf::from(cfg_file).canonicalize());
+        cargo.env("CFG_LLVM_TOML", cfg_path.into_os_string());
+    }
     cargo.env("LLVM_CONFIG", build.llvm_config(target));
     let target_config = build.config.target_config.get(target);
     if let Some(s) = target_config.and_then(|c| c.llvm_config.as_ref()) {

src/libcore/marker.rs

@@ -205,7 +205,7 @@ pub trait Unsize<T: ?Sized> {
 /// but not `Copy`.
 ///
 /// [`Clone`] is a supertrait of `Copy`, so everything which is `Copy` must also implement
-/// [`Clone`]. If a type is `Copy` then its [`Clone`] implementation need only return `*self`
+/// [`Clone`]. If a type is `Copy` then its [`Clone`] implementation only needs to return `*self`
 /// (see the example above).
 ///
 /// ## When can my type be `Copy`?

src/librustc/diagnostics.rs

@@ -1631,7 +1631,7 @@ fn takes_u8(_: u8) {}
 
 fn main() {
     unsafe { takes_u8(::std::mem::transmute(0u16)); }
-    // error: transmute called with differently sized types
+    // error: transmute called with types of different sizes
 }
 ```
 

src/librustc/middle/intrinsicck.rs

@@ -86,17 +86,16 @@ impl<'a, 'tcx> ExprVisitor<'a, 'tcx> {
             // Special-case transmutting from `typeof(function)` and
             // `Option<typeof(function)>` to present a clearer error.
             let from = unpack_option_like(self.tcx.global_tcx(), from);
-            match (&from.sty, sk_to) {
-                (&ty::TyFnDef(..), SizeSkeleton::Known(size_to))
-                        if size_to == Pointer.size(self.tcx) => {
+            if let (&ty::TyFnDef(..), SizeSkeleton::Known(size_to)) = (&from.sty, sk_to) {
+                if size_to == Pointer.size(self.tcx) {
                     struct_span_err!(self.tcx.sess, span, E0591,
-                                     "`{}` is zero-sized and can't be transmuted to `{}`",
-                                     from, to)
-                        .span_note(span, "cast with `as` to a pointer instead")
+                                     "can't transmute zero-sized type")
+                        .note(&format!("source type: {}", from))
+                        .note(&format!("target type: {}", to))
+                        .help("cast with `as` to a pointer instead")
                         .emit();
                     return;
                 }
-                _ => {}
             }
         }
 
@@ -111,7 +110,7 @@ impl<'a, 'tcx> ExprVisitor<'a, 'tcx> {
                 }
                 Err(LayoutError::Unknown(bad)) => {
                     if bad == ty {
-                        format!("size can vary")
+                        format!("this type's size can vary")
                     } else {
                         format!("size can vary because of {}", bad)
                     }
@@ -121,14 +120,9 @@ impl<'a, 'tcx> ExprVisitor<'a, 'tcx> {
         };
 
         struct_span_err!(self.tcx.sess, span, E0512,
-                  "transmute called with differently sized types: \
-                   {} ({}) to {} ({})",
-                  from, skeleton_string(from, sk_from),
-                  to, skeleton_string(to, sk_to))
-            .span_label(span,
-                format!("transmuting between {} and {}",
-                    skeleton_string(from, sk_from),
-                    skeleton_string(to, sk_to)))
+            "transmute called with types of different sizes")
+            .note(&format!("source type: {} ({})", from, skeleton_string(from, sk_from)))
+            .note(&format!("target type: {} ({})", to, skeleton_string(to, sk_to)))
             .emit();
     }
 }

src/librustc/middle/resolve_lifetime.rs

@@ -1363,7 +1363,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
             m.push_str(&(if n == 1 {
                 help_name
             } else {
-                format!("one of {}'s {} elided {}lifetimes", help_name, n,
+                format!("one of {}'s {} {}lifetimes", help_name, n,
                         if have_bound_regions { "free " } else { "" } )
             })[..]);
 

src/librustc_llvm/build.rs

@@ -61,6 +61,11 @@ fn main() {
 
     println!("cargo:rerun-if-changed={}", llvm_config.display());
 
+    if let Some(cfg_toml) = env::var_os("CFG_LLVM_TOML") {
+        let cfg_path = PathBuf::from(cfg_toml);
+        println!("cargo:rerun-if-changed={}", cfg_path.display());
+    }
+
     // Test whether we're cross-compiling LLVM. This is a pretty rare case
     // currently where we're producing an LLVM for a different platform than
     // what this build script is currently running on.

src/test/compile-fail/E0512.rs

@@ -12,5 +12,4 @@ fn takes_u8(_: u8) {}
 
 fn main() {
     unsafe { takes_u8(::std::mem::transmute(0u16)); } //~ ERROR E0512
-                                                      //~| transmuting between 16 bits and 8 bits
 }

src/test/compile-fail/issue-21174.rs

@@ -15,7 +15,7 @@ trait Trait<'a> {
 
 fn foo<'a, T: Trait<'a>>(value: T::A) {
     let new: T::B = unsafe { std::mem::transmute(value) };
-//~^ ERROR: transmute called with differently sized types
+//~^ ERROR: transmute called with types of different sizes
 }
 
 fn main() { }

src/test/compile-fail/issue-26638.rs

@@ -10,7 +10,7 @@
 
 fn parse_type(iter: Box<Iterator<Item=&str>+'static>) -> &str { iter.next() }
 //~^ ERROR missing lifetime specifier [E0106]
-//~^^ HELP 2 elided lifetimes
+//~^^ HELP 2 lifetimes
 
 fn parse_type_2(iter: fn(&u8)->&u8) -> &str { iter() }
 //~^ ERROR missing lifetime specifier [E0106]

src/test/compile-fail/issue-28625.rs

@@ -17,7 +17,7 @@ struct ArrayPeano<T: Bar> {
 }
 
 fn foo<T>(a: &ArrayPeano<T>) -> &[T] where T: Bar {
-    unsafe { std::mem::transmute(a) } //~ ERROR transmute called with differently sized types
+    unsafe { std::mem::transmute(a) } //~ ERROR transmute called with types of different sizes
 }
 
 impl Bar for () {