Jonathan Turner [Wed, 17 Aug 2016 13:25:24 +0000 (06:25 -0700)]
Rollup merge of #35610 - JessRudder:33637-doc-update-for-str-representaton, r=steveklabnik
Add note to docs for &str that example is to demo internals only
r? @steveklabnik
This adds a note below the &str representation example explaining that the example provided should not be used under normal circumstances..
Would it make sense to point people in the direction of the method(s) they should use instead? I left it out in the interest of not complicating the documentation, but, there's definitely an argument to be made for adding a bit of guidance in there.
bors [Wed, 17 Aug 2016 05:52:55 +0000 (22:52 -0700)]
Auto merge of #35605 - eddyb:substs, r=nikomatsakis
Remove the ParamSpace separation from formal and actual generics in rustc.
This is the first step towards enabling the typesystem implemented by `rustc` to be extended
(with generic modules, HKT associated types, generics over constants, etc.).
The current implementation splits all formal (`ty::Generics`) and actual (`Substs`) lifetime and type parameters (and even `where` clauses) into 3 "parameter spaces":
* `TypeSpace` for `enum`, `struct`, `trait` and `impl`
* `SelfSpace` for `Self` in a `trait`
* `FnSpace` for functions and methods
For example, in `<X as Trait<A, B>>::method::<T, U>`, the `Substs` are `[[A, B], [X], [T, U]]`.
The representation uses a single `Vec` with 2 indices where it's split into the 3 "parameter spaces".
Such a simplistic approach doesn't scale beyond the Rust 1.0 typesystem, and its existence was mainly motivated by keeping code manipulating generic parameters correct, across all possible situations.
Summary of changes:
* `ty::Generics` are uniformly stored and can be queried with `tcx.lookup_generics(def_id)`
* the `typeck::collect` changes for this resulted in a function to lazily compute the `ty::Generics` for a local node, given only its `DefId` - this can be further generalized to other kinds of type information
* `ty::Generics` and `ty::GenericPredicates` now contain only their own parameters (or `where` clauses, respectively), and refer to their "parent", forming a linked list
* right now most items have one level of nesting, only associated items and variants having two
* in the future, if `<X as mod1<A>::mod2<B>::mod3::Trait<C>>::Assoc<Y>` is supported, it would be represented by item with the path `mod1::mod2::mod3::Trait::Assoc`, and 4 levels of generics: `mod1` with `[A]`, `mod2` with `[B]`, `Trait` with `[X, C]` and `Assoc` with `[Y]`
* `Substs` gets two new APIs for working with arbitrary items:
* `Substs::for_item(def_id, mk_region, mk_type)` will construct `Substs` expected by the definition `def_id`, calling `mk_region` for lifetime parameters and `mk_type` for type parameters, and it's guaranteed to *always* return `Substs` compatible with `def_id`
* `substs.rebase_onto(from_base_def_id, to_base_substs)` can be used if `substs` is for an item nested within `from_base_def_id` (e.g. an associated item), to replace the "outer parameters" with `to_base_substs` - for example, you can translate a method's `Substs` between a `trait` and an `impl` (in both directions) if you have the `DefId` of one and `Substs` for the other
* trait objects, without a `Self` in their `Substs`, use *solely* `ExistentialTraitRef` now, letting `TraitRef` assume it *always* has a `Self` present
* both `TraitRef` and `ExistentialTraitRef` get methods which do operations on their `Substs` which are valid only for traits (or trait objects, respectively)
* `Substs` loses its "parameter spaces" distinction, with effectively no code creating `Substs` in an ad-hoc manner, or inspecting them, without knowing what shape they have already
Future plans:
* combine both lifetimes and types in a single `Vec<Kind<'tcx>>` where `Kind` would be a tagged pointer that can be `Ty<'tcx>`, `&'tcx ty::Region` or, in the future, potentially-polymorphic constants
* this would require some performance investigation, if it implies a lot of dynamic checks
* introduce an abstraction for `(T, Substs)`, where the `Substs` are even more hidden away from code
manipulating it; a precedent for this is `Instance` in trans, which has `T = DefId`; @nikomatsakis also referred to this, as "lazy substitution", when `T = Ty`
* rewrite type pretty-printing to fully take advantage of this to inject actual in the exact places of formal generic parameters in any paths
* extend the set of type-level information (e.g. beyond `ty::Generics`) that can be lazily queried during `typeck` and introduce a way to do those queries from code that can't refer to `typeck` directly
* this is almost unrelated but is necessary for DAG-shaped recursion between constant evaluation and type-level information, i.e. for implementing generics over constants
r? @nikomatsakis
cc @rust-lang/compiler
cc @nrc Could get any perf numbers ahead of merging this?
bors [Wed, 17 Aug 2016 02:44:10 +0000 (19:44 -0700)]
Auto merge of #35559 - frewsxcv:slice-iter-as-ref, r=alexcrichton
Implement `AsRef<[T]>` for `std::slice::Iter`.
`AsRef` is designed for conversions that are "cheap" (as per
the API docs). It is the case that retrieving the underlying
data of `std::slice::Iter` is cheap. In my opinion, there's no
ambiguity about what slice data will be returned, otherwise,
I would be more cautious about implementing `AsRef`.
bors [Tue, 16 Aug 2016 23:35:10 +0000 (16:35 -0700)]
Auto merge of #35538 - cgswords:libproc_macro, r=nrc
Kicking off libproc_macro
This PR introduces `libproc_macro`, which is currently quite bare-bones (just a few macro construction tools and an initial `quote!` macro).
This PR also introduces a few test cases for it, and an additional `shim` file (at `src/libsyntax/ext/proc_macro_shim.rs` to allow a facsimile usage of Macros 2.0 *today*!
Corey Farwell [Wed, 10 Aug 2016 00:49:41 +0000 (20:49 -0400)]
Implement `AsRef<[T]>` for `std::slice::Iter`.
`AsRef` is designed for conversions that are "cheap" (as per
the API docs). It is the case that retrieving the underlying
data of `std::slice::Iter` is cheap. In my opinion, there's no
ambiguity about what slice data will be returned, otherwise,
I would be more cautious about implementing `AsRef`.
bors [Tue, 16 Aug 2016 07:12:12 +0000 (00:12 -0700)]
Auto merge of #35162 - canndrew:bang_type_coerced, r=nikomatsakis
Implement the `!` type
This implements the never type (`!`) and hides it behind the feature gate `#[feature(never_type)]`. With the feature gate off, things should build as normal (although some error messages may be different). With the gate on, `!` is usable as a type and diverging type variables (ie. types that are unconstrained by anything in the code) will default to `!` instead of `()`.
bors [Mon, 15 Aug 2016 15:35:18 +0000 (08:35 -0700)]
Auto merge of #35340 - michaelwoerister:incr-comp-cli-args, r=nikomatsakis
Take commandline arguments into account for incr. comp.
Implements the conservative strategy described in https://github.com/rust-lang/rust/issues/33727.
From now one, every time a new commandline option is added, one has to specify if it influences the incremental compilation cache. I've tried to implement this as automatic as possible: One just has to added either the `[TRACKED]` or the `[UNTRACKED]` marker next to the field. The `Options`, `CodegenOptions`, and `DebuggingOptions` definitions in `session::config` show plenty of examples.
The PR removes some cruft from `session::config::Options`, mostly unnecessary copies of flags also present in `DebuggingOptions` or `CodeGenOptions` in the same struct.
One notable removal is the `cfg` field that contained the values passed via `--cfg` commandline arguments. I chose to remove it because (1) its content is only a subset of what later is stored in `hir::Crate::config` and it's pretty likely that reading the cfgs from `Options` would not be what you wanted, and (2) we could not incorporate it into the dep-tracking hash of the `Options` struct because of how the test framework works, leaving us with a piece of untracked but vital data.
It is now recommended (just as before) to access the crate config via the `krate()` method in the HIR map.
Because the `cfg` field is not present in the `Options` struct any more, some methods in the `CompilerCalls` trait now take the crate config as an explicit parameter -- which might constitute a breaking change for plugin authors.
bors [Mon, 15 Aug 2016 01:36:33 +0000 (18:36 -0700)]
Auto merge of #35427 - cardoe:arm-musl-targets, r=alexcrichton
add GNU make files for arm-unknown-linux-musleabi
For Yocto (Embedded Linux meta distro) Rust is provided via the [meta-rust layer](https://github.com/meta-rust/meta-rust). In this project there have been patches to add `arm-unknown-linux-musleabi`. Rust recently acquired that support via #35060 but only for rustbuild. meta-rust is currently only able to build Rust support with the existing GNU Makefiles. This adds `arm-unknown-linux-musleabi` support to Rust for the GNU Makefiles until meta-rust is able to sort out why using rustbuild does not work for it.
bors [Sun, 14 Aug 2016 19:28:48 +0000 (12:28 -0700)]
Auto merge of #35409 - eddyb:mir-storage-stmts, r=nikomatsakis
[MIR] Add Storage{Live,Dead} statements to emit llvm.lifetime.{start,end}.
Storage live ranges are tracked for all MIR variables and temporaries with a drop scope.
`StorageLive` is lowered to `llvm.lifetime.start` and `StorageDead` to `llvm.lifetime.end`.
There are some improvements possible here, such as:
* pack multiple storage liveness statements by using the index of first local + `u64` bitset
* enforce that locals are not directly accessed outside their storage live range
* shrink storage live ranges for never-borrowed locals to initialization -> last use
* emit storage liveness statements for *all* temporaries
* however, the remaining ones are *always* SSA immediates, so they'd be noop in MIR trans
* could have a flag on the temporary that its storage is irrelevant (a la C's old `register`)
* would also deny borrows if necessary
* this seems like an overcompliation and with packing & optimizations it may be pointless
Even in the current state, it helps stage2 `rustc` compile `boiler` without overflowing (see #35408).
A later addition fixes #26764 and closes #27372 by emitting `.section` directives for dylib metadata to avoid them being allocated into memory or read as `.note`. For this PR, those bugs were tripping valgrind.
Rollup merge of #35620 - cvubrugier:master, r=Manishearth
book: fix the hidden find() functions in error-handling.md
The hidden find() functions always returns None. Consequently, one of the
examples using find() prints "No file extension found" instead of
"File extension: rs" which is the expected output.
This patch fixes the issue by implementing find() with std::str::find().
Rollup merge of #35611 - jonathandturner:ptr-helper, r=nikomatsakis
Improve &-ptr printing
This PR replaces printing `&-ptr` with a more readable description. To do so it uses a few heuristics.
If the name of the type is unknown, too long (longer than just saying "reference"), or too complex (a type with explicit lifetime annotations), it will instead opt to print either "reference" or "mutable reference", depending on the mutability of the type.
Before:
```
error[E0308]: mismatched types
--> src/test/compile-fail/issue-7061.rs:14:46
|
14 | fn foo(&'a mut self) -> Box<BarStruct> { self }
| ^^^^ expected box, found &-ptr
|
= note: expected type `Box<BarStruct>`
= note: found type `&'a mut BarStruct`
error: aborting due to previous error
```
After:
```
error[E0308]: mismatched types
--> src/test/compile-fail/issue-7061.rs:14:46
|
14 | fn foo(&'a mut self) -> Box<BarStruct> { self }
| ^^^^ expected box, found mutable reference
|
= note: expected type `Box<BarStruct>`
= note: found type `&'a mut BarStruct`
Rollup merge of #35574 - badboy:emscripten-test-fixes, r=brson
Emscripten test fixes
This picks up parts of #31623 to disable certain tests that emscripten can't run, as threads/processes are not supported.
I re-applied @tomaka's changes manually, I can rebase those commits with his credentials if he wants.
It also disables jemalloc for emscripten (at least in Rustbuild, I have to check if there is another setting for the same thing in the old makefile approach).
This should not impact anything for normal builds.
Question: How can I only underline the function name ? I have observed the debug output and the struct of item, but I can't find the `Span` for function name. Should I modify the struct I get to save function name's position or there is another way to get it ? (I can only find `Span`s for function attributes, inputs, outputs, blocks)
Rollup merge of #35539 - cgswords:ts_concat, r=nrc
Implemented a smarter TokenStream concatenation system
The new algorithm performs 'aggressive compacting' during concatenation as follows:
- If the nodes' combined total total length is less than 32, we copy both of
them into a new vector and build a new leaf node.
- If one node is an internal node and the other is a 'small' leaf (length<32),
we recur down the internal node on the appropriate side.
- Otherwise, we construct a new internal node that points to them as left and
right.
This should produce notably better behavior than the current concatenation implementation.
Rollup merge of #35444 - alexcrichton:optimize-catch-unwind, r=brson
std: Optimize panic::catch_unwind slightly
The previous implementation of this function was overly conservative with
liberal usage of `Option` and `.unwrap()` which in theory never triggers. This
commit essentially removes the `Option`s in favor of unsafe implementations,
improving the code generation of the fast path for LLVM to see through what's
happening more clearly.
Rollup merge of #35392 - malbarbo:cell-from, r=brson
Implement From for Cell, RefCell and UnsafeCell
Considering that `From` is implemented for `Box`, `Rc` and `Arc`, it seems [reasonable](https://internals.rust-lang.org/t/implementing-from-t-for-other-std-types/3744) to implement it for `Cell`, `RefCell` and `UnsafeCell`.
bors [Sun, 14 Aug 2016 06:37:11 +0000 (23:37 -0700)]
Auto merge of #35453 - jseyfried:hygienize_metavariables, r=nrc
macros: Make metavariables hygienic
This PR makes metavariables hygienic. For example, consider:
```rust
macro_rules! foo {
($x:tt) => { // Suppose that this token tree argument is always a metavariable.
macro_rules! bar { ($x:expr, $y:expr) => { ($x, $y) } }
}
}
fn main() {
foo!($z); // This currently compiles.
foo!($y); // This is an error today but compiles after this PR.
}
```
Today, the `macro_rules! bar { ... }` definition is only valid when the metavariable passed to `foo` is not `$y` (since it unhygienically conflicts with the `$y` in the definition of `bar`) or `$x` (c.f. #35450).
After this PR, the definition of `bar` is always valid (and `bar!(a, b)` always expands to `(a, b)` as expected).
This can break code that was allowed in #34925 (landed two weeks ago). For example,
```rust
macro_rules! outer {
($t:tt) => {
macro_rules! inner { ($i:item) => { $t } }
}
}
outer!($i); // This `$i` should not interact with the `$i` in the definition of `inner!`.
inner!(fn main() {}); // After this PR, this is an error ("unknown macro variable `i`").
```
Due to the severe limitations on nested `macro_rules!` before #34925, this is not a breaking change for stable/beta.
bors [Sat, 13 Aug 2016 16:52:49 +0000 (09:52 -0700)]
Auto merge of #35414 - jupp0r:feature/test-threads-flag, r=alexcrichton
Add --test-threads option to test binaries
This change allows parallelism of test runs to be specified by a
command line flag names --test-threads in addition to the existing
environment variable RUST_TEST_THREADS. Fixes #25636.
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