Rollup of 8 pull requests

src/doc/book/testing.md

@@ -586,3 +586,45 @@ you add more examples.
 
 We haven’t covered all of the details with writing documentation tests. For more,
 please see the [Documentation chapter](documentation.html).
+
+# Testing and concurrency
+
+One thing that is important to note when writing tests are run concurrently
+using threads. For this reason you should take care that your tests are written
+in such a way as to not depend on each-other, or on any shared state. "Shared
+state" can also include the environment, such as the current working directory,
+or environment variables.
+
+If this is an issue it is possible to control this concurrency, either by
+setting the environment variable `RUST_TEST_THREADS`, or by passing the argument
+`--test-threads` to the tests:
+
+```bash
+$ RUST_TEST_THREADS=1 cargo test   # Run tests with no concurrency
+...
+$ cargo test -- --test-threads=1   # Same as above
+...
+```
+
+# Test output
+
+By default Rust's test library captures and discards output to standard
+out/error, e.g. output from `println!()`. This too can be controlled using the
+environment or a switch:
+
+
+```bash
+$ RUST_TEST_NOCAPTURE=1 cargo test   # Preserve stdout/stderr
+...
+$ cargo test -- --nocapture          # Same as above
+...
+```
+
+However a better method avoiding capture is to use logging rather than raw
+output. Rust has a [standard logging API][log], which provides a frontend to
+multiple logging implementations. This can be used in conjunction with the
+default [env_logger] to output any debugging information in a manner that can be
+controlled at runtime.
+
+[log]: https://crates.io/crates/log
+[env_logger]: https://crates.io/crates/env_logger

src/doc/index.md

@@ -17,7 +17,7 @@ the language.
 
 [**The Rust Reference**][ref]. While Rust does not have a
 specification, the reference tries to describe its working in
-detail. It tends to be out of date.
+detail.
 
 [**Standard Library API Reference**][api]. Documentation for the
 standard library.

src/librustc_const_eval/diagnostics.rs

@@ -40,7 +40,9 @@ Ensure the ordering of the match arm is correct and remove any superfluous
 arms.
 "##,
 
-/*E0002: r##"
+E0002: r##"
+## Note: this error code is no longer emitted by the compiler.
+
 This error indicates that an empty match expression is invalid because the type
 it is matching on is non-empty (there exist values of this type). In safe code
 it is impossible to create an instance of an empty type, so empty match
@@ -68,10 +70,11 @@ fn foo(x: Option<String>) {
     }
 }
 ```
-"##,*/
+"##,
 
+E0003: r##"
+## Note: this error code is no longer emitted by the compiler.
 
-/*E0003: r##"
 Not-a-Number (NaN) values cannot be compared for equality and hence can never
 match the input to a match expression. So, the following will not compile:
 
@@ -98,7 +101,6 @@ match number {
 }
 ```
 "##,
-*/
 
 E0004: r##"
 This error indicates that the compiler cannot guarantee a matching pattern for

src/librustc_typeck/check/method/suggest.rs

@@ -308,7 +308,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
 
             let limit = if candidates.len() == 5 { 5 } else { 4 };
             for (i, trait_did) in candidates.iter().take(limit).enumerate() {
-                err.help(&format!("candidate #{}: `use {}`",
+                err.help(&format!("candidate #{}: `use {};`",
                                   i + 1,
                                   self.tcx.item_path_str(*trait_did)));
             }

src/librustc_typeck/coherence/overlap.rs

@@ -14,7 +14,7 @@
 
 use hir::def_id::DefId;
 use rustc::traits::{self, Reveal};
-use rustc::ty::{self, TyCtxt};
+use rustc::ty::{self, TyCtxt, TypeFoldable};
 use syntax::ast;
 use rustc::dep_graph::DepNode;
 use rustc::hir;
@@ -134,6 +134,12 @@ impl<'cx, 'tcx, 'v> intravisit::Visitor<'v> for OverlapChecker<'cx, 'tcx> {
                 let trait_ref = self.tcx.impl_trait_ref(impl_def_id).unwrap();
                 let trait_def_id = trait_ref.def_id;
 
+                if trait_ref.references_error() {
+                    debug!("coherence: skipping impl {:?} with error {:?}",
+                           impl_def_id, trait_ref);
+                    return
+                }
+
                 let _task =
                     self.tcx.dep_graph.in_task(DepNode::CoherenceOverlapCheck(trait_def_id));