---

yaml
---
r: 196061
b: refs/heads/beta
c: c054ae2
h: refs/heads/master
i:
  196059: 9422fb6
v: v3

Author: alexcrichton

[refs]

@@ -29,7 +29,7 @@ refs/tags/0.12.0: f0c419429ef30723ceaf6b42f9b5a2aeb5d2e2d1
 refs/heads/automation-fail: 1bf06495443584539b958873e04cc2f864ab10e4
 refs/heads/batch: b7fd822592a4fb577552d93010c4a4e14f314346
 refs/heads/building: 126db549b038c84269a1e4fe46f051b2c15d6970
-refs/heads/beta: ee3dffac4939c24d8c6412dc12dc1bd388494f40
+refs/heads/beta: c054ae2fa498ee32f5f26cba4cd3e442df4c59e9
 refs/heads/windistfix: 7608dbad651f02e837ed05eef3d74a6662a6e928
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
 refs/heads/tmp: 9de34a84bb300bab1bf0227f577331620cd60511

branches/beta/AUTHORS.txt

@@ -606,7 +606,7 @@ Peter Schuller <[email protected]>
 Peter Williams <[email protected]>
 Peter Zotov <[email protected]>
 Petter Remen <[email protected]>
-Phil Dawes <[email protected]>
+Phil Dawes <[email protected]>
 Phil Ruffwind <[email protected]>
 Philip Munksgaard <[email protected]>
 Philipp Brüschweiler <[email protected]>

branches/beta/configure

@@ -404,7 +404,7 @@ case $CFG_OSTYPE in
         CFG_OSTYPE=pc-windows-gnu
         ;;
 
-# Thad's Cygwin identifers below
+# Thad's Cygwin identifiers below
 
 #   Vista 32 bit
     CYGWIN_NT-6.0)
@@ -526,7 +526,8 @@ VAL_OPTIONS=""
 opt valgrind 0 "run tests with valgrind (memcheck by default)"
 opt helgrind 0 "run tests with helgrind instead of memcheck"
 opt valgrind-rpass 1 "run rpass-valgrind tests with valgrind"
-opt docs     1 "build documentation"
+opt docs     1 "build standard library documentation"
+opt compiler-docs     0 "build compiler documentation"
 opt optimize 1 "build optimized rust code"
 opt optimize-cxx 1 "build optimized C++ code"
 opt optimize-llvm 1 "build optimized LLVM"

branches/beta/mk/crates.mk

@@ -122,17 +122,34 @@ ONLY_RLIB_rustc_bitflags := 1
 # You should not need to edit below this line
 ################################################################################
 
+# On channels where the only usable crate is std, only build documentation for
+# std. This keeps distributions small and doesn't clutter up the API docs with
+# confusing internal details from the crates behind the facade.
+#
+# (Disabled while cmr figures out how to change rustdoc to make reexports work
+# slightly nicer. Otherwise, all cross-crate links to Vec will go to
+# libcollections, breaking them, and [src] links for anything reexported will
+# not work.)
+
+#ifeq ($(CFG_RELEASE_CHANNEL),stable)
+#DOC_CRATES := std
+#else
+#ifeq ($(CFG_RELEASE_CHANNEL),beta)
+#DOC_CRATES := std
+#else
 DOC_CRATES := $(filter-out rustc, \
-              $(filter-out rustc_trans, \
-              $(filter-out rustc_typeck, \
-              $(filter-out rustc_borrowck, \
-              $(filter-out rustc_resolve, \
-              $(filter-out rustc_driver, \
-              $(filter-out rustc_privacy, \
-              $(filter-out rustc_lint, \
-              $(filter-out log, \
-              $(filter-out getopts, \
-              $(filter-out syntax, $(CRATES))))))))))))
+	   $(filter-out rustc_trans, \
+	   $(filter-out rustc_typeck, \
+	   $(filter-out rustc_borrowck, \
+	   $(filter-out rustc_resolve, \
+	   $(filter-out rustc_driver, \
+	   $(filter-out rustc_privacy, \
+	   $(filter-out rustc_lint, \
+	   $(filter-out log, \
+	   $(filter-out getopts, \
+	   $(filter-out syntax, $(CRATES))))))))))))
+#endif
+#endif
 COMPILER_DOC_CRATES := rustc rustc_trans rustc_borrowck rustc_resolve \
                        rustc_typeck rustc_driver syntax rustc_privacy \
                        rustc_lint

branches/beta/mk/docs.mk

@@ -259,7 +259,10 @@ doc/$(1)/index.html: $$(LIB_DOC_DEP_$(1)) doc/$(1)/
 endef
 
 $(foreach crate,$(DOC_CRATES),$(eval $(call DEF_LIB_DOC,$(crate),DOC_TARGETS)))
-$(foreach crate,$(COMPILER_DOC_CRATES),$(eval $(call DEF_LIB_DOC,$(crate),COMPILER_DOC_TARGETS)))
+
+ifdef CFG_COMPILER_DOCS
+  $(foreach crate,$(COMPILER_DOC_CRATES),$(eval $(call DEF_LIB_DOC,$(crate),COMPILER_DOC_TARGETS)))
+endif
 
 ifdef CFG_DISABLE_DOCS
   $(info cfg: disabling doc build (CFG_DISABLE_DOCS))

branches/beta/mk/platform.mk

@@ -179,7 +179,7 @@ define CFG_MAKE_TOOLCHAIN
 
   ifeq ($$(findstring $(HOST_$(1)),arm aarch64 mips mipsel powerpc),)
 
-  # On Bitrig, we need the relocation model to be PIC for everthing
+  # On Bitrig, we need the relocation model to be PIC for everything
   ifeq (,$(filter $(OSTYPE_$(1)),bitrig))
     LLVM_MC_RELOCATION_MODEL="pic"
   else

branches/beta/mk/target.mk

@@ -132,7 +132,7 @@ endef
 # on $$(TSREQ$(1)_T_$(2)_H_$(3)), to ensure that no products will be
 # put into the target area until after the get-snapshot.py script has
 # had its chance to clean it out; otherwise the other products will be
-# inadvertantly included in the clean out.
+# inadvertently included in the clean out.
 SNAPSHOT_RUSTC_POST_CLEANUP=$(HBIN0_H_$(CFG_BUILD))/rustc$(X_$(CFG_BUILD))
 
 define TARGET_HOST_RULES

branches/beta/mk/tests.mk

@@ -166,7 +166,7 @@ $(foreach file,$(wildcard $(S)src/doc/trpl/*.md), \
 ######################################################################
 
 # The main testing target. Tests lots of stuff.
-check: cleantmptestlogs cleantestlibs all check-stage2 tidy
+check: check-sanitycheck cleantmptestlogs cleantestlibs all check-stage2 tidy
 	$(Q)$(CFG_PYTHON) $(S)src/etc/check-summary.py tmp/*.log
 
 # As above but don't bother running tidy.
@@ -193,6 +193,11 @@ check-docs: cleantestlibs cleantmptestlogs check-stage2-docs
 # Not run as part of the normal test suite, but tested by bors on checkin.
 check-secondary: check-build-compiletest check-build-lexer-verifier check-lexer check-pretty
 
+.PHONY: check-sanitycheck
+
+check-sanitycheck:
+	$(Q)$(CFG_PYTHON) $(S)src/etc/check-sanitycheck.py
+
 # check + check-secondary.
 #
 # Issue #17883: build check-secondary first so hidden dependencies in

branches/beta/src/compiletest/compiletest.rs

@@ -18,7 +18,6 @@
 #![feature(std_misc)]
 #![feature(test)]
 #![feature(path_ext)]
-#![feature(convert)]
 #![feature(str_char)]
 
 #![deny(warnings)]

branches/beta/src/doc/reference.md

@@ -977,17 +977,13 @@ An example of `use` declarations:
 
 ```
 # #![feature(core)]
-use std::iter::range_step;
 use std::option::Option::{Some, None};
 use std::collections::hash_map::{self, HashMap};
 
 fn foo<T>(_: T){}
 fn bar(map1: HashMap<String, usize>, map2: hash_map::HashMap<String, usize>){}
 
 fn main() {
-    // Equivalent to 'std::iter::range_step(0, 10, 2);'
-    range_step(0, 10, 2);
-
     // Equivalent to 'foo(vec![std::option::Option::Some(1.0f64),
     // std::option::Option::None]);'
     foo(vec![Some(1.0f64), None]);
@@ -1188,12 +1184,15 @@ the guarantee that these issues are never caused by safe code.
 
 * Data races
 * Dereferencing a null/dangling raw pointer
-* Mutating an immutable value/reference without `UnsafeCell`
 * Reads of [undef](http://llvm.org/docs/LangRef.html#undefined-values)
   (uninitialized) memory
 * Breaking the [pointer aliasing
   rules](http://llvm.org/docs/LangRef.html#pointer-aliasing-rules)
   with raw pointers (a subset of the rules used by C)
+* `&mut` and `&` follow LLVM’s scoped [noalias] model, except if the `&T`
+  contains an `UnsafeCell<U>`. Unsafe code must not violate these aliasing
+  guarantees.
+* Mutating an immutable value/reference without `UnsafeCell<U>`
 * Invoking undefined behavior via compiler intrinsics:
   * Indexing outside of the bounds of an object with `std::ptr::offset`
     (`offset` intrinsic), with
@@ -1210,6 +1209,8 @@ the guarantee that these issues are never caused by safe code.
   code. Rust's failure system is not compatible with exception handling in
   other languages. Unwinding must be caught and handled at FFI boundaries.
 
+[noalias]: http://llvm.org/docs/LangRef.html#noalias
+
 ##### Behaviour not considered unsafe
 
 This is a list of behaviour not considered *unsafe* in Rust terms, but that may

branches/beta/src/doc/trpl/SUMMARY.md

@@ -13,7 +13,6 @@
     * [Looping](looping.md)
     * [Strings](strings.md)
     * [Arrays, Vectors, and Slices](arrays-vectors-and-slices.md)
-    * [Standard Input](standard-input.md)
 * [Intermediate Rust](intermediate.md)
     * [Crates and Modules](crates-and-modules.md)
     * [Testing](testing.md)
@@ -43,5 +42,6 @@
     * [Intrinsics](intrinsics.md)
     * [Lang items](lang-items.md)
     * [Link args](link-args.md)
+    * [Benchmark Tests](benchmark-tests.md)
 * [Conclusion](conclusion.md)
 * [Glossary](glossary.md)

branches/beta/src/doc/trpl/arrays-vectors-and-slices.md

@@ -99,5 +99,4 @@ You can also take a slice of a vector, `String`, or `&str`, because they are
 backed by arrays. Slices have type `&[T]`, which we'll talk about when we cover
 generics.
 
-We have now learned all of the most basic Rust concepts. Next, we learn how to
-get input from the keyboard.
+We have now learned all of the most basic Rust concepts.

branches/beta/src/doc/trpl/associated-types.md

@@ -170,7 +170,7 @@ let obj = Box::new(graph) as Box<Graph>;
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 ```
 
-We can’t create a trait object like this, becuase we don’t know the associated
+We can’t create a trait object like this, because we don’t know the associated
 types. Instead, we can write this:
 
 ```rust

branches/beta/src/doc/trpl/benchmark-tests.md

@@ -0,0 +1,152 @@
+% Benchmark tests
+
+Rust supports benchmark tests, which can test the performance of your
+code. Let's make our `src/lib.rs` look like this (comments elided):
+
+```{rust,ignore}
+#![feature(test)]
+
+extern crate test;
+
+pub fn add_two(a: i32) -> i32 {
+    a + 2
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use test::Bencher;
+
+    #[test]
+    fn it_works() {
+        assert_eq!(4, add_two(2));
+    }
+
+    #[bench]
+    fn bench_add_two(b: &mut Bencher) {
+        b.iter(|| add_two(2));
+    }
+}
+```
+
+Note the `test` feature gate, which enables this unstable feature.
+
+We've imported the `test` crate, which contains our benchmarking support.
+We have a new function as well, with the `bench` attribute. Unlike regular
+tests, which take no arguments, benchmark tests take a `&mut Bencher`. This
+`Bencher` provides an `iter` method, which takes a closure. This closure
+contains the code we'd like to benchmark.
+
+We can run benchmark tests with `cargo bench`:
+
+```bash
+$ cargo bench
+   Compiling adder v0.0.1 (file:///home/steve/tmp/adder)
+     Running target/release/adder-91b3e234d4ed382a
+
+running 2 tests
+test tests::it_works ... ignored
+test tests::bench_add_two ... bench:         1 ns/iter (+/- 0)
+
+test result: ok. 0 passed; 0 failed; 1 ignored; 1 measured
+```
+
+Our non-benchmark test was ignored. You may have noticed that `cargo bench`
+takes a bit longer than `cargo test`. This is because Rust runs our benchmark
+a number of times, and then takes the average. Because we're doing so little
+work in this example, we have a `1 ns/iter (+/- 0)`, but this would show
+the variance if there was one.
+
+Advice on writing benchmarks:
+
+
+* Move setup code outside the `iter` loop; only put the part you want to measure inside
+* Make the code do "the same thing" on each iteration; do not accumulate or change state
+* Make the outer function idempotent too; the benchmark runner is likely to run
+  it many times
+*  Make the inner `iter` loop short and fast so benchmark runs are fast and the
+   calibrator can adjust the run-length at fine resolution
+* Make the code in the `iter` loop do something simple, to assist in pinpointing
+  performance improvements (or regressions)
+
+## Gotcha: optimizations
+
+There's another tricky part to writing benchmarks: benchmarks compiled with
+optimizations activated can be dramatically changed by the optimizer so that
+the benchmark is no longer benchmarking what one expects. For example, the
+compiler might recognize that some calculation has no external effects and
+remove it entirely.
+
+```{rust,ignore}
+#![feature(test)]
+
+extern crate test;
+use test::Bencher;
+
+#[bench]
+fn bench_xor_1000_ints(b: &mut Bencher) {
+    b.iter(|| {
+        (0..1000).fold(0, |old, new| old ^ new);
+    });
+}
+```
+
+gives the following results
+
+```text
+running 1 test
+test bench_xor_1000_ints ... bench:         0 ns/iter (+/- 0)
+
+test result: ok. 0 passed; 0 failed; 0 ignored; 1 measured
+```
+
+The benchmarking runner offers two ways to avoid this. Either, the closure that
+the `iter` method receives can return an arbitrary value which forces the
+optimizer to consider the result used and ensures it cannot remove the
+computation entirely. This could be done for the example above by adjusting the
+`b.iter` call to
+
+```rust
+# struct X;
+# impl X { fn iter<T, F>(&self, _: F) where F: FnMut() -> T {} } let b = X;
+b.iter(|| {
+    // note lack of `;` (could also use an explicit `return`).
+    (0..1000).fold(0, |old, new| old ^ new)
+});
+```
+
+Or, the other option is to call the generic `test::black_box` function, which
+is an opaque "black box" to the optimizer and so forces it to consider any
+argument as used.
+
+```rust
+#![feature(test)]
+
+extern crate test;
+
+# fn main() {
+# struct X;
+# impl X { fn iter<T, F>(&self, _: F) where F: FnMut() -> T {} } let b = X;
+b.iter(|| {
+    let n = test::black_box(1000);
+
+    (0..n).fold(0, |a, b| a ^ b)
+})
+# }
+```
+
+Neither of these read or modify the value, and are very cheap for small values.
+Larger values can be passed indirectly to reduce overhead (e.g.
+`black_box(&huge_struct)`).
+
+Performing either of the above changes gives the following benchmarking results
+
+```text
+running 1 test
+test bench_xor_1000_ints ... bench:       131 ns/iter (+/- 3)
+
+test result: ok. 0 passed; 0 failed; 0 ignored; 1 measured
+```
+
+However, the optimizer can still modify a testcase in an undesirable manner
+even when using either of the above.

branches/beta/src/doc/trpl/concurrency.md

@@ -280,13 +280,15 @@ it returns an `Result<T, E>`, and because this is just an example, we `unwrap()`
 it to get a reference to the data. Real code would have more robust error handling
 here. We're then free to mutate it, since we have the lock.
 
-This timer bit is a bit awkward, however. We have picked a reasonable amount of
-time to wait, but it's entirely possible that we've picked too high, and that
-we could be taking less time. It's also possible that we've picked too low,
-and that we aren't actually finishing this computation.
-
-Rust's standard library provides a few more mechanisms for two threads to
-synchronize with each other. Let's talk about one: channels.
+Lastly, while the threads are running, we wait on a short timer. But
+this is not ideal: we may have picked a reasonable amount of time to
+wait but it's more likely we'll either be waiting longer than
+necessary or not long enough, depending on just how much time the
+threads actually take to finish computing when the program runs.
+
+A more precise alternative to the timer would be to use one of the
+mechanisms provided by the Rust standard library for synchronizing
+threads with each other. Let's talk about one of them: channels.
 
 ## Channels