Commit Graph

38161 Commits

Author SHA1 Message Date
Niko Matsakis
ac94ae5883 Update Rustdoc to deal with the Fn return type being an associated type. 2015-01-28 05:15:24 -05:00
Niko Matsakis
7bd19112ee Patch variance bug: appearing in a binding is an invariant position (at least right now). 2015-01-28 05:15:24 -05:00
Niko Matsakis
47c2d31038 Extract expectations from the projection obligation, which includes
all relevant information.
2015-01-28 05:15:24 -05:00
Niko Matsakis
25a27977fa Add Clone to the list of bounds for a TypeFolder. (Kill?) 2015-01-28 05:15:24 -05:00
Niko Matsakis
7d68250eb4 When pretty-printing object types, include the output associated type 2015-01-28 05:15:24 -05:00
Niko Matsakis
006f3eacae Fix a latent bug in trait dispatch where we sometimes counted associated types
when constructing the vtable-index. Not good.
2015-01-28 05:15:23 -05:00
Niko Matsakis
07cdb85331 Move return type an associated type of the Fn* traits. Mostly this involves tweaking things in
the compiler that assumed two input types to assume two ouputs; we also have to teach `project.rs`
to project `Output` from the unboxed closure and fn traits.
2015-01-28 05:15:23 -05:00
Niko Matsakis
c61d7889b4 Add the notion of normalizing a parameter environment and ensure that
all parameter environments are normalized. Correspondingly, stop
normalizing predicates we extract out of the environment. Fixes #21664.
2015-01-28 05:13:53 -05:00
Niko Matsakis
c73a1d0a2c Change list of predicates in ParameterEnvironment to a Vec. 2015-01-28 05:13:53 -05:00
Felix S. Klock II
d85520202a In unsize_unique_expr, do not convert scratch value to lvalue.
Fix the issue-20055-box-trait.rs test to actually test `Box<Trait>`.

Fix #21695.
2015-01-28 10:22:26 +01:00
Ms2ger
7aa2735393 Remove unnecessary to_string() call. 2015-01-28 09:42:16 +01:00
Ms2ger
4ad677e5b6 Remove a custom variant of iter::Cloned. 2015-01-28 09:42:16 +01:00
Ms2ger
f88c94d8d2 Simplify the implementation of segments_name_eq. 2015-01-28 09:39:28 +01:00
Ms2ger
d0a9a39b1e Rename found_ast to FoundAst and qualify uses.
This matches contemporary Rust style.
2015-01-28 09:37:04 +01:00
bors
06410ef9fb Auto merge of #21158 - alkor:issue-21131, r=nick29581
Closes #21131
2015-01-28 07:32:53 +00:00
bors
a530cc9706 Auto merge of #21248 - brson:feature-staging, r=alexcrichton
This implements the remaining bits of 'feature staging', as described in [RFC 507](https://github.com/rust-lang/rfcs/blob/master/text/0507-release-channels.md).

This is not quite done, but the substance of the work is complete so submitting for early review.

Key changes:
* `unstable`, `stable` and `deprecated` attributes all require 'feature' and 'since', and support an optional 'reason'.
* The `unstable` lint is removed.
* A new 'stability checking' pass warns when a used unstable library feature has not been activated with the `feature` attribute. At 1.0 beta this will become an error.
* A new 'unused feature checking' pass emits a lint ('unused_feature', renamed from 'unknown_feature') for any features that were activated but not used.
* A new tidy script `featureck.py` performs some global sanity checking, particularly that 'since' numbers agree, and also prints out a summary of features.

Differences from RFC:
* As implemented `unstable` requires a `since` attribute. I do not know if this is useful. I included it in the original sed script and just left it.
* RFC didn't specify the name of the optional 'reason' attribute.
* This continues to use 'unstable', 'stable' and 'deprecated' names (the 'nice' names) instead of 'staged_unstable', but only activates them with the crate-level 'staged_api' attribute.

I intend to update the RFC based on the outcome of this PR.

Issues:
* The unused feature check doesn't account for language features - i.e. you can activate a language feature, not use it, and not get the error.

Open questions:
* All unstable and deprecated features are named 'unnamed_feature', which i picked just because it is uniquely greppable. This is the 'catch-all' feature. What should it be?
* All stable features are named 'grandfathered'. What should this be?

TODO:
* Add check that all `deprecated` attributes are paired with a `stable` attribute in order to preserve the knowledge about when a feature became stable.
* Update rustdoc in various ways.
* Remove obsolete stability discussion from reference.
* Add features for 'path', 'io', 'os', 'hash' and 'rand'.

cc #20445 @alexcrichton @aturon
2015-01-28 03:59:14 +00:00
Jorge Aparicio
57dd4ea78d fix #[cfg(test)] warnings 2015-01-27 22:58:45 -05:00
John Hodge
1c502f1d43 README.md - Fix source tarball link 2015-01-28 10:12:54 +08:00
Brian Anderson
94404070d6 discuss.rust-lang.org -> internals.rust-lang.org 2015-01-27 15:44:05 -08:00
Jonathan Reem
83f8088108 Add an implementation of Zeroable for Unique<T>
This allows the use of `NonZero<Unique<T>>` for owned,
non-null raw pointers.

cc https://github.com/Gankro/collect-rs/pull/103
2015-01-27 18:17:04 -05:00
Manish Goregaokar
249c29fe27 Rollup merge of #21666 - tshepang:rm-unloved-file, r=brson
See 579eb24
2015-01-28 04:40:48 +05:30
bors
92ff8ea528 Auto merge of #21523 - nikomatsakis:issue-21245-japaric-ti-failure, r=eddyb
This also includes some miscellaneous cleanup. This is kind of a band-aid but it fixes the problems @japaric was encountering.

r? @eddyb
2015-01-27 23:08:13 +00:00
Manish Goregaokar
78567f1244 Rollup merge of #21667 - nagisa:sbook-links, r=Gankro
Fixes #21665

r? @steveklabnik
2015-01-28 04:37:50 +05:30
Manish Goregaokar
1df030059b Rollup merge of #21676 - Victory:fix-deprication-in-random, r=alexcrichton
Cleanup mention of uint, use usize/us instead. This includes the example `println!("{}", 2u * x);`
2015-01-28 04:35:57 +05:30
Brian Anderson
7122305053 Merge remote-tracking branch 'rust-lang/master'
Conflicts:
	src/libcore/cell.rs
	src/librustc_driver/test.rs
	src/libstd/old_io/net/tcp.rs
	src/libstd/old_io/process.rs
2015-01-27 15:05:04 -08:00
Manish Goregaokar
2ac91a382d Rollup merge of #21686 - richo:python-fixes, r=alexcrichton
While waiting on some builds I started cleaning up the various python bits and pieces.

I'm going to keep poking, want to ping me before the next rollup?
2015-01-28 04:34:40 +05:30
Manish Goregaokar
28b0271f89 Rollup merge of #21658 - Manishearth:index_on_unimplemented, r=Gankro
Helps issues like [these](http://www.reddit.com/r/rust/comments/2tpefm/unable_to_access_array_elements/)

r? @Gankro

rollup-worthy
2015-01-28 04:32:20 +05:30
Niko Matsakis
093926e841 Check and extract bindings from trait definitions.
Fixes #21636.
2015-01-27 15:39:58 -05:00
Felix S. Klock II
5b66c6dfa4 Test cases for issue #20055.
Note that I have not yet managed to expose any bug in
`trans::expr::into_fat_ptr`; it would be good to try to do so (or show
that the use of `.to_lvalue_datum` there is sound).
2015-01-27 18:20:43 +01:00
Felix S. Klock II
326443105b trans: When coercing to Box<Trait> or Box<[T]>, leave datum in its original L-/R-value state.
This fixes a subtle issue where temporaries were being allocated (but
not necessarily initialized) to the (parent) terminating scope of a
match expression; in particular, the code to zero out the temporary
emitted by `datum.store_to` is only attached to the particular
match-arm for that temporary, but when going down other arms of the
match expression, the temporary may falsely appear to have been
initialized, depending on what the stack held at that location, and
thus may have its destructor erroneously run at the end of the
terminating scope.

Test cases to appear in a follow-up commit.

Fix #20055
2015-01-27 18:12:34 +01:00
Manish Goregaokar
335e8af98a Rollup merge of #21625 - carols10cents:sliceext-examples, r=alexcrichton
Hi! I added some examples to some SliceExt methods that didn't have any.

I'm looking forward to feedback and I'm happy to change anything-- it looks like the doc conventions are still a bit in flux, based on the discussions going on in [rfc 505](https://github.com/rust-lang/rfcs/pull/505).

I was most unsure about examples for methods that return iterators over slices... I wanted to use asserts on the result of calling `.next()` like in [this permutations example](804c1446b3/src/libcollections/slice.rs (L608-L617)), but then it gets all cluttered up with lifetime stuff... so I went with iterating and printing and mentioning what the expected printed output is like in [this chunks example](804c1446b3/src/libcollections/slice.rs (L297-L304))... any ideas for the best ways to do this are appreciated.

Thank you! ❤️
2015-01-27 22:24:04 +05:30
Manish Goregaokar
4af4b377a0 Rollup merge of #21624 - emanueLczirai:vim_syntastic_fix, r=sanxiyn
when saving .rs files under vim
do not fail to run the syntax checker
error: Unrecognized option: 'parse-only'.

due to this commit
953f294ea3
which removed the deprecated flag --parse-only
2015-01-27 22:24:04 +05:30
Manish Goregaokar
36d0e90e6b Rollup merge of #21623 - dinfuehr:patch-1, r=alexcrichton 2015-01-27 22:24:03 +05:30
Manish Goregaokar
cb63bcb98c Rollup merge of #21618 - snowe2010:documentation, r=Gankro
Lifetime elision with two input references is not clear.
Closes #21284
2015-01-27 22:24:03 +05:30
Manish Goregaokar
54cdae693c Rollup merge of #21612 - bombless:patch-3, r=alexcrichton 2015-01-27 22:24:03 +05:30
Manish Goregaokar
3cda6afac4 Rollup merge of #21608 - JeffBelgum:collections-reform-issue-19986-add-append-and-split-off, r=Gankro
@brson @Gankro
2015-01-27 22:24:03 +05:30
Manish Goregaokar
51ff9e82ec Rollup merge of #21602 - japaric:derive-copy, r=alexcrichton 2015-01-27 22:24:02 +05:30
Manish Goregaokar
8418725b0d Rollup merge of #21597 - iKevinY:mobile-api-docs, r=cmr
This PR removes the `min-width` rule from `body` so that no horizontal scrolling is necessary on mobile, and also hides out-of-band information on mobile to create more room for the in-band information.
2015-01-27 22:24:02 +05:30
Manish Goregaokar
e7bcb27939 Rollup merge of #21591 - GuillaumeGomez:hash, r=alexcrichton
Fixes #21547 issue.
2015-01-27 22:24:02 +05:30
Edward Wang
2c6440e2a2 borrowck: aliasability violation with closure captures can happen
It was considered to be impossible but actually it can
happen for nested closures. Also, because there must
be nested closures when this happens, we can use more
targeted help message.

Closes #21390
Closes #21600
2015-01-27 23:55:07 +08:00
Vojtech Kral
c155208de4 Thread native name setting, fix #10302 2015-01-27 16:00:26 +01:00
Niko Matsakis
8d6786cd6c Adjust error messages due to having more type information available. 2015-01-27 09:40:45 -05:00
Niko Matsakis
45e5627ef9 Update debug messages to match the new names of the methods they are in. 2015-01-27 09:40:45 -05:00
Niko Matsakis
c7ef9c1edf Fix two type inference failures uncovered by japaric corresponding to
UFCS form. In both cases the problems came about because we were
failing to process pending trait obligations. So change code to
process pending trait obligations before coercions to ensure maximum
type information is available (and also adjust shift to do something
similar).

Fixes #21245.
2015-01-27 09:40:45 -05:00
Niko Matsakis
60db57e7ec Cleanup the unification engine to use associated types, making the code much easier to read. 2015-01-27 09:40:45 -05:00
Jorge Aparicio
bce81e2464 cleanup: s/v.slice*()/&v[a..b]/g + remove redundant as_slice() calls 2015-01-27 09:03:06 -05:00
bors
777435990e Auto merge of #21586 - pyfisch:patch-1, r=alexcrichton
Spellfix for `Debug` trait documentation. Change "most all types should implement this" to "all types should implement this". Same fix for deprecated `Show` trait.
2015-01-27 14:03:06 +00:00
bors
d77f6d5366 Auto merge of #21657 - pnkfelix:block-remainder-extents, r=nikomatsakis
Add `CodeExtent::Remainder` variant; pre-req for new scoping/drop rules.

This new enum variant introduces finer-grain code extents, i.e. we now track that a binding lives only for a suffix of a block, and (importantly) will be dropped when it goes out of scope *before* the bindings that occurred earlier in the block.

Both of these notions are neatly captured by marking the block (and each suffix) as an enclosing scope of the next suffix beneath it.

This is work that is part of the foundation for issue #8861.

(It actually has been seen in earlier posted pull requests, in particular #21022; I have just factored it out into its own PR to ease my own near-future rebasing, and also get people used to the new rules.)

----

These finer grained scopes do mean that some code is newly rejected by `rustc`; for example:

```rust
let mut map : HashMap<u8, &u8> = HashMap::new();
let tmp = Box::new(2);
map.insert(43, &*tmp);
```

This will now fail to compile with a message that `*tmp` does not live long enough, because the scope of `tmp` is now strictly smaller than
that of `map`, and the use of `&u8` in map's type requires that the borrowed references are all to data that live at least as long as the map.

The usual fix for a case like this is to move the binding for `tmp` up above that of `map`; note that you can still leave the initialization in the original spot, like so:

```rust
let tmp;
let mut map : HashMap<u8, &u8> = HashMap::new();
tmp = box 2;
map.insert(43, &*tmp);
```

Similarly, one can encounter an analogous situation with `Vec`: one would need to rewrite:

```rust
let mut vec = Vec::new();
let tmp = 'c';
vec.push(&tmp);
```

as:

```rust
let tmp;
let mut vec = Vec::new();
tmp = 'c';
vec.push(&tmp);
```

----

In some corner cases, it does not suffice to reorder the bindings; in particular, when the types for both bindings need to reflect exactly the *same* code extent, and a parent/child relationship between them does not work.

In pnkfelix's experience this has arisen most often when mixing uses of cyclic data structures while also allowing a lifetime parameter `'a` to flow into a type parameter context where the type is *invariant* with respect to the type parameter. An important instance of this is `arena::TypedArena<T>`, which is invariant with respect to `T`.

(The reason that variance is relevant is this: *if* `TypedArena` were covariant with respect to its type parameter, then we could assign it
the longer lifetime when it is initialized, and then convert it to a subtype (via covariance) with a shorter lifetime when necessary.  But `TypedArena` is invariant with respect to its type parameter, and thus if `S` is a subtype of `T` (in particular, if `S` has a lifetime parameter that is shorter than that of `T`), then a `TypedArena<S>` is unrelated to `TypedArena<T>`.)

Concretely, consider code like this:

```rust
struct Node<'a> { sibling: Option<&'a Node<'a>> }
struct Context<'a> {
    // because of this field, `Context<'a>` is invariant with respect to `'a`.
    arena: &'a TypedArena<Node<'a>>,
    ...
}
fn new_ctxt<'a>(arena: &'a TypedArena<Node<'a>>) -> Context<'a> { ... }
fn use_ctxt<'a>(fcx: &'a Context<'a>) { ... }

let arena = TypedArena::new();
let ctxt = new_ctxt(&arena);

use_ctxt(&ctxt);
```

In these situations, if you try to introduce two bindings via two distinct `let` statements, each is (with this commit) assigned a distinct extent, and the region inference system cannot find a single region to assign to the lifetime `'a` that works for both of the bindings. So you get an error that `ctxt` does not live long enough; but moving its binding up above that of `arena` just shifts the error so now the compiler complains that `arena` does not live long enough.

 * SO: What to do? The easiest fix in this case is to ensure that the two bindings *do* get assigned the same static extent, by stuffing both
bindings into the same let statement, like so:

```rust
let (arena, ctxt): (TypedArena, Context);
arena = TypedArena::new();
ctxt = new_ctxt(&arena);

use_ctxt(&ctxt);
```

----

Due to the new code restrictions outlined above, this is a ...

[breaking-change]
2015-01-27 11:07:26 +00:00
Felix S. Klock II
d6bf04a22e Add CodeExtent::Remainder variant; pre-req for new scoping/drop rules.
This new variant introduces finer-grain code extents, i.e. we now
track that a binding lives only for a suffix of a block, and
(importantly) will be dropped when it goes out of scope *before* the
bindings that occurred earlier in the block.

Both of these notions are neatly captured by marking the block (and
each suffix) as an enclosing scope of the next suffix beneath it.

This is work that is part of the foundation for issue #8861.

(It actually has been seen in earlier posted pull requests; I have
just factored it out into its own PR to ease my own rebasing.)

----

These finer grained scopes do mean that some code is newly rejected by
`rustc`; for example:

```rust
let mut map : HashMap<u8, &u8> = HashMap::new();
let tmp = Box::new(2);
map.insert(43, &*tmp);
```

This will now fail to compile with a message that `*tmp` does not live
long enough, because the scope of `tmp` is now strictly smaller than
that of `map`, and the use of `&u8` in map's type requires that the
borrowed references are all to data that live at least as long as the
map.

The usual fix for a case like this is to move the binding for `tmp`
up above that of `map`; note that you can still leave the initialization
in the original spot, like so:

```rust
let tmp;
let mut map : HashMap<u8, &u8> = HashMap::new();
tmp = box 2;
map.insert(43, &*tmp);
```

Similarly, one can encounter an analogous situation with `Vec`: one
would need to rewrite:

```rust
let mut vec = Vec::new();
let tmp = 'c';
vec.push(&tmp);
```

as:

```
let tmp;
let mut vec = Vec::new();
tmp = 'c';
vec.push(&tmp);
```

----

In some corner cases, it does not suffice to reorder the bindings; in
particular, when the types for both bindings need to reflect exactly
the *same* code extent, and a parent/child relationship between them
does not work.

In pnkfelix's experience this has arisen most often when mixing uses
of cyclic data structures while also allowing a lifetime parameter
`'a` to flow into a type parameter context where the type is
*invariant* with respect to the type parameter. An important instance
of this is `arena::TypedArena<T>`, which is invariant with respect
to `T`.

(The reason that variance is relevant is this: *if* `TypedArena` were
covariant with respect to its type parameter, then we could assign it
the longer lifetime when it is initialized, and then convert it to a
subtype (via covariance) with a shorter lifetime when necessary.  But
`TypedArena` is invariant with respect to its type parameter, and thus
if `S` is a subtype of `T` (in particular, if `S` has a lifetime
parameter that is shorter than that of `T`), then a `TypedArena<S>` is
unrelated to `TypedArena<T>`.)

Concretely, consider code like this:

```rust
struct Node<'a> { sibling: Option<&'a Node<'a>> }
struct Context<'a> {
    // because of this field, `Context<'a>` is invariant with respect to `'a`.
    arena: &'a TypedArena<Node<'a>>,
    ...
}
fn new_ctxt<'a>(arena: &'a TypedArena<Node<'a>>) -> Context<'a> { ... }
fn use_ctxt<'a>(fcx: &'a Context<'a>) { ... }

let arena = TypedArena::new();
let ctxt = new_ctxt(&arena);

use_ctxt(&ctxt);
```

In these situations, if you try to introduce two bindings via two
distinct `let` statements, each is (with this commit) assigned a
distinct extent, and the region inference system cannot find a single
region to assign to the lifetime `'a` that works for both of the
bindings. So you get an error that `ctxt` does not live long enough;
but moving its binding up above that of `arena` just shifts the error
so now the compiler complains that `arena` does not live long enough.

SO: What to do? The easiest fix in this case is to ensure that the two
bindings *do* get assigned the same static extent, by stuffing both
bindings into the same let statement, like so:

```rust
let (arena, ctxt): (TypedArena, Context);
arena = TypedArena::new();
ctxt = new_ctxt(&arena);

use_ctxt(&ctxt);
```

Due to the new code rejections outlined above, this is a ...

[breaking-change]
2015-01-27 10:26:52 +01:00
Felix S. Klock II
43d08f861a accommodate new scoping rules in librustc_driver unit tests. 2015-01-27 10:26:52 +01:00