Some annotations like the "test" annotations might be of interest for
other projects, especially rls. Export all attributes in a new
attributes item.

Remove the AST structure

This is all in rustbuild already.

This is all not used any more

All of these should be handled by rustbuild in sanity.rs right now.

All of this should already be vendored in rustbuild if necessary or otherwise
it's just not used.

This is not used any more

None of this is used by rustbuild any more

This commit removes detection of CFG_OSTYPE and CFG_CPUTYPE from the configure
script, which means that the default value of `--build` is no longer present in
the configure script. All this logic is now available in rustbuild itself, so
there's no need to duplicate it.

In recent months there have been a few different people investigating how to make a plugin that
registers a MIR-pass – one that isn’t intended to be eventually merged into rustc proper.

The interface to register MIR passes was added primarily for miri (& later was
found to make prototyping of rustc-proper MIR passes a tiny bit faster). Since miri does not use
this interface anymore it seems like a good time to remove this "feature".

For prototyping purposes a similar interface can be added by developers themselves in their custom
rustc build.

similar to GCC's __attribute((used))__. This attribute prevents LLVM from
optimizing away a non-exported symbol, within a compilation unit (object file),
when there are no references to it.

This is better explained with an example:

```
#[used]
static LIVE: i32 = 0;

static REFERENCED: i32 = 0;

static DEAD: i32 = 0;

fn internal() {}

pub fn exported() -> &'static i32 {
    &REFERENCED
}
```

Without optimizations, LLVM pretty much preserves all the static variables and
functions within the compilation unit.

```
$ rustc --crate-type=lib --emit=obj symbols.rs && nm -C symbols.o
0000000000000000 t drop::h1be0f8f27a2ba94a
0000000000000000 r symbols::REFERENCED::hb3bdfd46050bc84c
0000000000000000 r symbols::DEAD::hc2ea8f9bd06f380b
0000000000000000 r symbols::LIVE::h0970cf9889edb56e
0000000000000000 T symbols::exported::h6f096c2b1fc292b2
0000000000000000 t symbols::internal::h0ac1aadbc1e3a494
```

With optimizations, LLVM will drop dead code. Here `internal` is dropped because
it's not a exported function/symbol (i.e. not `pub`lic). `DEAD` is dropped for
the same reason. `REFERENCED` is preserved, even though it's not exported,
because it's referenced by the `exported` function. Finally, `LIVE` survives
because of the `#[used]` attribute even though it's not exported or referenced.

```
$ rustc --crate-type=lib -C opt-level=3 --emit=obj symbols.rs && nm -C symbols.o
0000000000000000 r symbols::REFERENCED::hb3bdfd46050bc84c
0000000000000000 r symbols::LIVE::h0970cf9889edb56e
0000000000000000 T symbols::exported::h6f096c2b1fc292b2
```

Note that the linker knows nothing about `#[used]` and will drop `LIVE`
because no other object references to it.

```
$ echo 'fn main() {}' >> symbols.rs
$ rustc symbols.rs && nm -C symbols | grep LIVE
```

At this time, `#[used]` only works on `static` variables.

When declaring nested unsafe blocks (`unsafe {unsafe {}}`) that trigger
the "unnecessary `unsafe` block" error, point out the enclosing `unsafe
block` or `unsafe fn` that makes it unnecessary.

This commit fixes rust-lang#38749 by building documentation for the `proc_macro` crate by
default for configured hosts. Unfortunately did not turn out to be a trivial
fix. Currently rustbuild generates documentation into multiple locations: one
for std, one for test, and one for rustc. The initial fix for this issue simply
actually executed `cargo doc -p proc_macro` which was otherwise completely
elided before.

Unfortunately rustbuild was the left to merge two documentation trees together.
One for the standard library and one for the rustc tree (which only had docs for
the `proc_macro` crate). Rustdoc itself knows how to merge documentation files
(specifically around search indexes, etc) but rustbuild was unaware of this, so
an initial fix ended up destroying the sidebar and the search bar from the
libstd docs.

To solve this issue the method of documentation has been tweaked slightly in
rustbuild. The build system will not use symlinks (or directory junctions on
Windows) to generate all documentation into the same location initially. This'll
rely on rustdoc's logic to weave together all the output and ensure that it ends
up all consistent.

Closes rust-lang#38749

They report their `uname -m` as armv8l rather than aarch64.

Patch originally by Matthias Klose <doko@debian.org>

…r proc macros

This causes problems when first cloning and bootstrapping the repository
unfortunately, so let's ensure that Cargo sticks around in its own workspace.
Because Cargo is a submodule it's not available by default on the inital clone
of the rust-lang/rust repository. Normally it's the responsibility of the
rustbuild to take care of this, but unfortunately to build rustbuild itself we
need to resolve the workspace conflicts.

To deal with this we'll just have to ensure that all submodules are in their own
workspace, which sort of makes sense anyway as updates to dependencies as
bugfixes to Cargo should go to rust-lang/cargo instead of rust-lang/rust. In any
case this commit removes Cargo from the global workspace which should resolve
the issues that we've been seeing.

To actually perform this the `cargo` submodule has been moved to the top
directory to ensure it's outside the scope of `src/Cargo.toml` as a workspace.

This commit alters the compiler to exit quickly if the only output being emitted
is `dep-info`, which doesn't need a lot of other information to generate.

Closes rust-lang#40328

Fixes rust-lang#39957

Fixes rendering of the end of the `Configure and Make` section.

A task function is now given as a `fn` pointer to ensure that it carries
no state. Each fn can take two arguments, because that worked out to be
convenient -- these two arguments must be of some type that is
`DepGraphSafe`, a new trait that is intended to prevent "leaking"
information into the task that was derived from tracked state.

This intentionally leaves `DepGraph::in_task()`, the more common form,
alone. Eventually all uses of `DepGraph::in_task()` should be ported
to `with_task()`, but I wanted to start with a smaller subset.

Originally I wanted to use closures bound by an auto trait, but that
approach has some limitations:

- the trait cannot have a `read()` method; since the current method
  is unused, that may not be a problem.
- more importantly, we would want the auto trait to be "undefined" for all types
  *by default* -- that is, this use case doesn't really fit the typical
  auto trait scenario. For example, imagine that there is a `u32` loaded
  out of a `hir::Node` -- we don't really want to be passing that
  `u32` into the task!

This commit deletes the internal liblog in favor of the implementation that
lives on crates.io. Similarly it's also setting a convention for adding crates
to the compiler. The main restriction right now is that we want compiler
implementation details to be unreachable from normal Rust code (e.g. requires a
feature), and by default everything in the sysroot is reachable via `extern
crate`.

The proposal here is to require that crates pulled in have these lines in their
`src/lib.rs`:

    #![cfg_attr(rustbuild, feature(staged_api, rustc_private))]
    #![cfg_attr(rustbuild, unstable(feature = "rustc_private", issue = "27812"))]

This'll mean that by default they're not using these attributes but when
compiled as part of the compiler they do a few things:

* Mark themselves as entirely unstable via the `staged_api` feature and the
  `#![unstable]` attribute.
* Allow usage of other unstable crates via `feature(rustc_private)` which is
  required if the crate relies on any other crates to compile (other than std).

I can't find anything that'd cause unexpected EOF in the source, so let's try
taking a look at the error logs on failures.

cc rust-lang#40373

This allows limiting the number of linker jobs to avoid swapping when
linking LLVM with debug info.

The original motivation for hard links was to speed up the various stages of
rustbuild, but in the end this is causing problems on Windows (rust-lang#39504).

This commit tweaks the build system to use copies instead of hard links
unconditionally to ensure that the files accessed by Windows are always
disjoint.

Locally this added .3s to a noop build, so it shouldn't be too much of a
regression hopefully!

This commit is a random stab in the dark to fix the spurious failures on rust-lang#39518.
The leading theory of the spurious failures on Windows is that the compiler is
loading a path in the `deps` folder, passing it to `link.exe`, and then this is
racing with Cargo itself updating those paths.

This race, however, has a few unique properties:

* It's isolated to just libstd. Most crates are never passed to the linker and
  simultaneously being worked on by Cargo. Cargo's typical execution of the
  dependency graph never hits this problem.
* The crates are already all located in the sysroot in addition to the `deps`
  folder. This means that the compiler actually has two candidates of crates to
  load, and it's just arbitrarily rejecting one.

Together this means that we shouldn't need to fix this problem "in the large"
and we can instead just fix it in this isolated situation (hopefully). To solve
this the compiler's been updated to prefer crates from the sysroot to leave
Cargo's structure to itself.

We'll see if this actually allows the PR to land...

Keeps MIR cleaner, `StorageLive(_: !)` makes no sense anyway.

gdb will now reliably detect the lanugage as rust even before any
code is run.

Adds `get`/`get_mut` accessors and `drain`/`drain_enumerated` iterators
to IndexVec.

Implements TypeFoldable for IndexVec.

Fairly basic implementation of inlining for MIR. Uses conservative
heuristics for inlining.

…turner

Point to enclosing block/fn on nested unsafe

When declaring nested unsafe blocks (`unsafe {unsafe {}}`) that trigger
the "unnecessary `unsafe` block" error, point out the enclosing `unsafe
block` or `unsafe fn` that makes it unnecessary.

<img width="621" alt="" src="https://cloud.githubusercontent.com/assets/1606434/22139922/26ad468a-de9e-11e6-8884-2945be882ea8.png">

Fixes rust-lang#39144.

rustbuild: Use copies instead of hard links

The original motivation for hard links was to speed up the various stages of
rustbuild, but in the end this is causing problems on Windows (rust-lang#39504).

This commit tweaks the build system to use copies instead of hard links
unconditionally to ensure that the files accessed by Windows are always
disjoint.

Locally this added .3s to a noop build, so it shouldn't be too much of a
regression hopefully!

Closes rust-lang#39504

[MIR] Implement Inlining

Fairly basic implementation of inlining for MIR. Uses conservative
heuristics for inlining.

Doesn't handle a number of cases, but can be extended later. This is basically the same as the previous inlining PR, but without the span-related changes (as the bugs it was dealing with have since been fixed).

/cc @rust-lang/compiler

Delete more swaths of the configure script

This PR deletes more swaths of the `./configure` script which are either no longer necessary or already available in rustbuild (where an implementation is preferred)

Export attributes in save-analysis data

Since this is my first pull-request to rust, I would like to get some feedback about obvious errors in this implementation.

I would like to change the save-analysis data to include arbitrary attribute data.
A use-case I have in mind for this is identifying functions with `#[test]` annotations such that tools like rls can offer a test-runner feature. I described my idea here [rls#173](rust-lang/rls#173).

My changes contain:

1. track a vector of attributes in the various `*Data` types in `data.rs` and `external_data.rs`
2. implement lowering for `Attribute` and `MetaItem`
3. adjust `JsonDumper` to print the attributes

In the lowering of `Attribute` I remove the distinction between `MetaItem` and `NestedMetaItem`. I did this because this distinction is somewhat confusing. For example, `NestedMetaItemKind::Literal` has two identical spans, because both `NestedMetaItem` and `Lit` are defined as `Spanned<_>`.
My model is strictly more general, as it allows an `LitKind` instead of a `Symbol` for `MetaItem` and `Symbol`s are converted into a cooked string. As a consumer of the save-analysis data this shouldn't affect you much.

Example json output of `#[test]` annotation:
```
"attributes": [
  {
    "value": {
      "name": {
        "variant": "Str",
        "fields": [
          "test",
          "Cooked"
        ]
      },
      "kind": "Literal",
      "span": {
        "file_name": "test.rs",
        "byte_start": 2,
        "byte_end": 6,
        "line_start": 1,
        "line_end": 1,
        "column_start": 3,
        "column_end": 7
      }
    },
    "span": {
      "file_name": "test.rs",
      "byte_start": 0,
      "byte_end": 7,
      "line_start": 1,
      "line_end": 1,
      "column_start": 1,
      "column_end": 8
    }
  }
]
```

…tsakis

Add catch {} to AST

Part of rust-lang#39849. Builds on rust-lang#39864.

…elix

Fix suggestion span error with a line containing multibyte characters

This PR fixes broken suggestions caused by multibyte characters.

e.g. for this code, rustc provides a broken suggestion ([playground](https://is.gd/DWGLu7)):

```rust
fn main() {
    let tup = (1,);
    println!("☃{}", tup[0]);
}
```

```
error: cannot index a value of type `({integer},)`
 --> <anon>:3:21
  |
3 |     println!("☃{}", tup[0]);
  |                     ^^^^^^
  |
help: to access tuple elements, use tuple indexing syntax as shown
  |     println!("☃{}"tup.00]);

error: aborting due to previous error
```

`CodeSuggestion::splice_lines` is misusing `Loc.col` (`CharPos`) as a byte offset when slicing source.

Better docs of rusty parts of typeck

rustbuild: Build documentation for `proc_macro`

This commit fixes rust-lang#38749 by building documentation for the `proc_macro` crate by
default for configured hosts. Unfortunately did not turn out to be a trivial
fix. Currently rustbuild generates documentation into multiple locations: one
for std, one for test, and one for rustc. The initial fix for this issue simply
actually executed `cargo doc -p proc_macro` which was otherwise completely
elided before.

Unfortunately rustbuild was the left to merge two documentation trees together.
One for the standard library and one for the rustc tree (which only had docs for
the `proc_macro` crate). Rustdoc itself knows how to merge documentation files
(specifically around search indexes, etc) but rustbuild was unaware of this, so
an initial fix ended up destroying the sidebar and the search bar from the
libstd docs.

To solve this issue the method of documentation has been tweaked slightly in
rustbuild. The build system will not use symlinks (or directory junctions on
Windows) to generate all documentation into the same location initially. This'll
rely on rustdoc's logic to weave together all the output and ensure that it ends
up all consistent.

Closes rust-lang#38749

… r=alexcrichton

Restore creating the channel-rust-$channel-date.txt files

I have **not** run this (because I don't know how to 😇), but it *does* compile.

r? @alexcrichton

…akis

Remove ability for plugins to register a MIR pass

In recent months there have been a few different people investigating how to make a plugin that
registers a MIR-pass – one that isn’t intended to be eventually merged into rustc proper.

The interface to register MIR passes was added primarily for miri (& later was
found to make prototyping of rustc-proper MIR passes a tiny bit faster). Since miri does not use
this interface anymore it seems like a good time to remove this "feature".

For prototyping purposes a similar interface can be added by developers themselves in their custom
rustc build.

cc @nikomatsakis

LLVM: Update submodule to include SRet support patch for MSP430.

This patch is needed to fix rust-lang#38824 on MSP430.
I know that LLVM 4 is coming soon, but it would be great to have at least one working nightly before the update.

cc @awygle
r? @alexcrichton

…richton

Fix emscripten test detection

Without this change `rustbuild` will attempt to run `.js.map` files (if they exist) resulting in lots of sadness.

r? @alexcrichton

…alexcrichton

rustbuild: expose LLVM_PARALLEL_LINK_JOBS

This allows limiting the number of linker jobs to avoid swapping when linking LLVM with debug info.

Clean up rustdoc css

r? @rust-lang/docs

Fix incorrect span label formatting

Fix rust-lang#40157.

Don't put Cargo into the rustc workspace

This causes problems when first cloning and bootstrapping the repository
unfortunately, so let's ensure that Cargo sticks around in its own workspace.
Because Cargo is a submodule it's not available by default on the inital clone
of the rust-lang/rust repository. Normally it's the responsibility of the
rustbuild to take care of this, but unfortunately to build rustbuild itself we
need to resolve the workspace conflicts.

To deal with this we'll just have to ensure that all submodules are in their own
workspace, which sort of makes sense anyway as updates to dependencies as
bugfixes to Cargo should go to rust-lang/cargo instead of rust-lang/rust. In any
case this commit removes Cargo from the global workspace which should resolve
the issues that we've been seeing.

To actually perform this the `cargo` submodule has been moved to a new `vendor`
directory to ensure it's outside the scope of `src/Cargo.toml` as a workspace.

Closes rust-lang#40284

…, r=mw

first pass at isolating dep-graph tasks

This intentionally leaves `DepGraph::in_task()`, the more common form,
alone. Eventually all uses of `DepGraph::in_task()` should be ported
to `with_task()`, but I wanted to start with a smaller subset.

I also used `AssertDepGraphSafe` on the closures that are found in
trans. This is because the types there are non-trivial and I wanted to
lay down the mechanism and come back to the more subtle cases.

The current approach taken in this PR has a downside: it is necessary
to manually "reify" fn types into fn pointers when starting a task,
like so:

    dep_graph.with_task(..., task_fn as fn(_))

this is because `with_task` takes some type `T` that implements
`DepGraphTask` rather than taking a `fn()` type directly. *This* is so
that we can accept closure and also so that we can accept fns with
multiple arities. I am not sure this is the right approach.

Originally I wanted to use closures bound by an auto trait, but that
approach has some limitations:

- the trait cannot have a `read()` method; since the current method
  is unused, that may not be a problem.
- more importantly, we would want the auto trait to be "undefined" for all types
  *by default* -- that is, this use case doesn't really fit the typical
  auto trait scenario. For example, imagine that there is a `u32` loaded
  out of a `hir::Node` -- we don't really want to be passing that
  `u32` into the task!

Expect macro defs in save-analysis and add expn info to spans for att…

…r proc macros

r? @jseyfried

Allow lints to check Bodys directly

r? @eddyb

babysteps towards fixing https://github.com/Manishearth/rust-clippy/issues/1580 (disable certain lints in const environments, since they make no sense there (yet))

…r=nikomatsakis

Disallow subtyping between T and U in T: Unsize<U>.

Because `&mut T` can be coerced to `&mut U`, `T` and `U` must be unified invariantly. Fixes rust-lang#40288.
E.g. coercing `&mut [&'a X; N]` to `&mut [&'b X]` must require `'a` be equal to `'b`, otherwise you can convert between `&'a X` and `&'b X` (in either direction), potentially unsoundly lengthening lifetimes.

Subtyping here was introduced with `Unsize` in rust-lang#24619 (landed in 1.1, original PR is rust-lang#23785).

travis: Attempt to debug sccache failures

I can't find anything that'd cause unexpected EOF in the source, so let's try
taking a look at the error logs on failures.

rustc: Exit quickly on only `--emit dep-info`

This commit alters the compiler to exit quickly if the only output being emitted
is `dep-info`, which doesn't need a lot of other information to generate.

Closes rust-lang#40328

…akis

Update syntax for `pub(restricted)`

Update the syntax before stabilization.

cc rust-lang#32409
r? @nikomatsakis

save-analysis: cope with lack of method data after a type error

Fixes rust-lang#39957

r? @eddyb

Fix missing backtick typo

Fixes rendering of the end of the `Configure and Make` section.

Improve the LLVM IR we generate for trivial functions, especially #[naked] ones.

These two small changes fix edef1c/libfringe#68:
* Don't emit ZST allocas, such as when returning `()`
* Don't emit a branch from LLVM's entry block to MIR's `START_BLOCK` unless needed
  * That is, if a loop branches back to it, although I'm not sure that's even valid MIR

Give spans to individual path segments in AST

And use these spans in path resolution diagnostics.

The spans are spans of identifiers in segments, not whole segments. I'm not sure what spans are more useful in general, but identifier spans are a better fit for resolve errors.

HIR still doesn't have spans.

Fixes rust-lang#38927 (comment) rust-lang#38890 (comment)

r? @nrc @eddyb

Do not bother creating StorageLive for TyNever

Keeps MIR cleaner, `StorageLive(_: !)` makes no sense anyway.

r? @eddyb