Auto merge of #45822 - kennytm:rollup, r=kennytm

Rollup of 9 pull requests

- Successful merges: #45470, #45588, #45682, #45714, #45751, #45764, #45778, #45782, #45784
- Failed merges:

src/bootstrap/install.rs

@@ -186,8 +186,11 @@ install!((self, builder, _config),
         install_cargo(builder, self.stage, self.target);
     };
     Rls, "rls", _config.extended, only_hosts: true, {
-        builder.ensure(dist::Rls { stage: self.stage, target: self.target });
-        install_rls(builder, self.stage, self.target);
+        if builder.ensure(dist::Rls { stage: self.stage, target: self.target }).is_some() {
+            install_rls(builder, self.stage, self.target);
+        } else {
+            println!("skipping Install RLS stage{} ({})", self.stage, self.target);
+        }
     };
     Analysis, "analysis", _config.extended, only_hosts: false, {
         builder.ensure(dist::Analysis {

src/doc/not_found.md

@@ -22,7 +22,7 @@ Some things that might be helpful to you though:
 # Reference
 
 * [The Rust official site](https://www.rust-lang.org)
-* [The Rust reference](https://doc.rust-lang.org/reference.html)
+* [The Rust reference](https://doc.rust-lang.org/reference/index.html)
 
 # Docs
 

src/librustc/hir/print.rs

@@ -1254,6 +1254,15 @@ impl<'a> State<'a> {
             Fixity::None => (prec + 1, prec + 1),
         };
 
+        let left_prec = match (&lhs.node, op.node) {
+            // These cases need parens: `x as i32 < y` has the parser thinking that `i32 < y` is
+            // the beginning of a path type. It starts trying to parse `x as (i32 < y ...` instead
+            // of `(x as i32) < ...`. We need to convince it _not_ to do that.
+            (&hir::ExprCast { .. }, hir::BinOp_::BiLt) |
+            (&hir::ExprCast { .. }, hir::BinOp_::BiShl) => parser::PREC_FORCE_PAREN,
+            _ => left_prec,
+        };
+
         self.print_expr_maybe_paren(lhs, left_prec)?;
         self.s.space()?;
         self.word_space(op.node.as_str())?;

src/librustc/infer/error_reporting/different_lifetimes.rs

@@ -21,25 +21,42 @@ use hir::intravisit::{self, Visitor, NestedVisitorMap};
 use infer::error_reporting::util::AnonymousArgInfo;
 
 impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
-    // This method prints the error message for lifetime errors when both the concerned regions
-    // are anonymous.
-    // Consider a case where we have
-    // fn foo(x: &mut Vec<&u8>, y: &u8)
-    //    { x.push(y); }.
-    // The example gives
-    // fn foo(x: &mut Vec<&u8>, y: &u8) {
-    //                    ---      --- these references are declared with different lifetimes...
-    //            x.push(y);
-    //            ^ ...but data from `y` flows into `x` here
-    // It has been extended for the case of structs too.
-    // Consider the example
-    // struct Ref<'a> { x: &'a u32 }
-    // fn foo(mut x: Vec<Ref>, y: Ref) {
-    //                   ---      --- these structs are declared with different lifetimes...
-    //               x.push(y);
-    //               ^ ...but data from `y` flows into `x` here
-    // }
-    // It will later be extended to trait objects.
+    /// Print the error message for lifetime errors when both the concerned regions are anonymous.
+    ///
+    /// Consider a case where we have
+    ///
+    /// ```no_run
+    /// fn foo(x: &mut Vec<&u8>, y: &u8) {
+    ///     x.push(y);
+    /// }
+    /// ```
+    ///
+    /// The example gives
+    ///
+    /// ```text
+    /// fn foo(x: &mut Vec<&u8>, y: &u8) {
+    ///                    ---      --- these references are declared with different lifetimes...
+    ///     x.push(y);
+    ///     ^ ...but data from `y` flows into `x` here
+    /// ```
+    ///
+    /// It has been extended for the case of structs too.
+    ///
+    /// Consider the example
+    ///
+    /// ```no_run
+    /// struct Ref<'a> { x: &'a u32 }
+    /// ```
+    ///
+    /// ```text
+    /// fn foo(mut x: Vec<Ref>, y: Ref) {
+    ///                   ---      --- these structs are declared with different lifetimes...
+    ///     x.push(y);
+    ///     ^ ...but data from `y` flows into `x` here
+    /// }
+    /// ````
+    ///
+    /// It will later be extended to trait objects.
     pub fn try_report_anon_anon_conflict(&self, error: &RegionResolutionError<'tcx>) -> bool {
         let (span, sub, sup) = match *error {
             ConcreteFailure(ref origin, sub, sup) => (origin.span(), sub, sup),

src/librustc/infer/error_reporting/named_anon_conflict.rs

@@ -16,18 +16,15 @@ use infer::region_inference::RegionResolutionError;
 use ty;
 
 impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
-    // This method generates the error message for the case when
-    // the function arguments consist of a named region and an anonymous
-    // region and corresponds to `ConcreteFailure(..)`
+    /// When given a `ConcreteFailure` for a function with arguments containing a named region and
+    /// an anonymous region, emit an descriptive diagnostic error.
     pub fn try_report_named_anon_conflict(&self, error: &RegionResolutionError<'tcx>) -> bool {
         let (span, sub, sup) = match *error {
             ConcreteFailure(ref origin, sub, sup) => (origin.span(), sub, sup),
             _ => return false, // inapplicable
         };
 
-        debug!("try_report_named_anon_conflict(sub={:?}, sup={:?})",
-               sub,
-               sup);
+        debug!("try_report_named_anon_conflict(sub={:?}, sup={:?})", sub, sup);
 
         // Determine whether the sub and sup consist of one named region ('a)
         // and one anonymous (elided) region. If so, find the parameter arg
@@ -53,10 +50,8 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
             };
 
         debug!("try_report_named_anon_conflict: named = {:?}", named);
-        debug!("try_report_named_anon_conflict: anon_arg_info = {:?}",
-               anon_arg_info);
-        debug!("try_report_named_anon_conflict: region_info = {:?}",
-               region_info);
+        debug!("try_report_named_anon_conflict: anon_arg_info = {:?}", anon_arg_info);
+        debug!("try_report_named_anon_conflict: region_info = {:?}", region_info);
 
         let (arg, new_ty, br, is_first, scope_def_id, is_impl_item) = (anon_arg_info.arg,
                                                                        anon_arg_info.arg_ty,
@@ -101,6 +96,5 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                 .span_label(span, format!("lifetime `{}` required", named))
                 .emit();
         return true;
-
     }
 }

src/librustc/infer/error_reporting/util.rs

@@ -221,6 +221,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                     _ => false,
                 }
             }
+            ty::ReEarlyBound(_) => true,
             _ => false,
         }
     }

src/librustc/session/config.rs

@@ -138,6 +138,34 @@ impl OutputType {
         }
     }
 
+    fn from_shorthand(shorthand: &str) -> Option<Self> {
+        Some(match shorthand {
+             "asm" => OutputType::Assembly,
+             "llvm-ir" => OutputType::LlvmAssembly,
+             "mir" => OutputType::Mir,
+             "llvm-bc" => OutputType::Bitcode,
+             "obj" => OutputType::Object,
+             "metadata" => OutputType::Metadata,
+             "link" => OutputType::Exe,
+             "dep-info" => OutputType::DepInfo,
+            _ => return None,
+        })
+    }
+
+    fn shorthands_display() -> String {
+        format!(
+            "`{}`, `{}`, `{}`, `{}`, `{}`, `{}`, `{}`, `{}`",
+            OutputType::Bitcode.shorthand(),
+            OutputType::Assembly.shorthand(),
+            OutputType::LlvmAssembly.shorthand(),
+            OutputType::Mir.shorthand(),
+            OutputType::Object.shorthand(),
+            OutputType::Metadata.shorthand(),
+            OutputType::Exe.shorthand(),
+            OutputType::DepInfo.shorthand(),
+        )
+    }
+
     pub fn extension(&self) -> &'static str {
         match *self {
             OutputType::Bitcode => "bc",
@@ -1488,19 +1516,13 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches)
         for list in matches.opt_strs("emit") {
             for output_type in list.split(',') {
                 let mut parts = output_type.splitn(2, '=');
-                let output_type = match parts.next().unwrap() {
-                    "asm" => OutputType::Assembly,
-                    "llvm-ir" => OutputType::LlvmAssembly,
-                    "mir" => OutputType::Mir,
-                    "llvm-bc" => OutputType::Bitcode,
-                    "obj" => OutputType::Object,
-                    "metadata" => OutputType::Metadata,
-                    "link" => OutputType::Exe,
-                    "dep-info" => OutputType::DepInfo,
-                    part => {
-                        early_error(error_format, &format!("unknown emission type: `{}`",
-                                                    part))
-                    }
+                let shorthand = parts.next().unwrap();
+                let output_type = match OutputType::from_shorthand(shorthand) {
+                    Some(output_type) => output_type,
+                    None => early_error(error_format, &format!(
+                        "unknown emission type: `{}` - expected one of: {}",
+                        shorthand, OutputType::shorthands_display(),
+                    )),
                 };
                 let path = parts.next().map(PathBuf::from);
                 output_types.insert(output_type, path);

src/librustdoc/test.rs

@@ -337,15 +337,23 @@ pub fn make_test(s: &str,
 
     let mut prog = String::new();
 
-    // First push any outer attributes from the example, assuming they
-    // are intended to be crate attributes.
-    prog.push_str(&crate_attrs);
+    if opts.attrs.is_empty() {
+        // If there aren't any attributes supplied by #![doc(test(attr(...)))], then allow some
+        // lints that are commonly triggered in doctests. The crate-level test attributes are
+        // commonly used to make tests fail in case they trigger warnings, so having this there in
+        // that case may cause some tests to pass when they shouldn't have.
+        prog.push_str("#![allow(unused)]\n");
+    }
 
-    // Next, any attributes for other aspects such as lints.
+    // Next, any attributes that came from the crate root via #![doc(test(attr(...)))].
     for attr in &opts.attrs {
         prog.push_str(&format!("#![{}]\n", attr));
     }
 
+    // Now push any outer attributes from the example, assuming they
+    // are intended to be crate attributes.
+    prog.push_str(&crate_attrs);
+
     // Don't inject `extern crate std` because it's already injected by the
     // compiler.
     if !s.contains("extern crate") && !opts.no_crate_inject && cratename != Some("std") {

src/libstd/sync/rwlock.rs

@@ -10,7 +10,6 @@
 
 use cell::UnsafeCell;
 use fmt;
-use marker;
 use mem;
 use ops::{Deref, DerefMut};
 use ptr;
@@ -102,7 +101,10 @@ pub struct RwLockReadGuard<'a, T: ?Sized + 'a> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, T: ?Sized> !marker::Send for RwLockReadGuard<'a, T> {}
+impl<'a, T: ?Sized> !Send for RwLockReadGuard<'a, T> {}
+
+#[stable(feature = "rwlock_guard_sync", since = "1.23.0")]
+unsafe impl<'a, T: ?Sized + Sync> Sync for RwLockReadGuard<'a, T> {}
 
 /// RAII structure used to release the exclusive write access of a lock when
 /// dropped.
@@ -121,7 +123,10 @@ pub struct RwLockWriteGuard<'a, T: ?Sized + 'a> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, T: ?Sized> !marker::Send for RwLockWriteGuard<'a, T> {}
+impl<'a, T: ?Sized> !Send for RwLockWriteGuard<'a, T> {}
+
+#[stable(feature = "rwlock_guard_sync", since = "1.23.0")]
+unsafe impl<'a, T: ?Sized + Sync> Sync for RwLockWriteGuard<'a, T> {}
 
 impl<T> RwLock<T> {
     /// Creates a new instance of an `RwLock<T>` which is unlocked.