Aaron Turon [Fri, 19 Feb 2016 18:49:14 +0000 (10:49 -0800)]
Refactor core specialization and subst translation code to avoid
danger of inference variables floating around without their inference
context.
The main insight here is that, when we are translating substitutions
between two impls, *we already know that the more specific impl holds*,
so we do not need to add its obligations to the parameter
environment. Instead, we can just thread through the inference context
we used to show select the more specific impl in the first place.
Aaron Turon [Tue, 16 Feb 2016 18:36:47 +0000 (10:36 -0800)]
Move specialization graph walks to iterators; make associated type
projection sensitive to "mode" (most importantly, trans vs middle).
This commit introduces several pieces of iteration infrastructure in the
specialization graph data structure, as well as various helpers for
finding the definition of a given item, given its kind and name.
In addition, associated type projection is now *mode-sensitive*, with
three possible modes:
- **Topmost**. This means that projection is only possible if there is a
non-`default` definition of the associated type directly on the
selected impl. This mode is a bit of a hack: it's used during early
coherence checking before we have built the specialization
graph (and therefore before we can walk up the specialization
parents to find other definitions). Eventually, this should be
replaced with a less "staged" construction of the specialization
graph.
- **AnyFinal**. Projection succeeds for any non-`default` associated
type definition, even if it is defined by a parent impl. Used
throughout typechecking.
- **Any**. Projection always succeeds. Used by trans.
The lasting distinction here is between `AnyFinal` and `Any` -- we wish
to treat `default` associated types opaquely for typechecking purposes.
In addition to the above, the commit includes a few other minor review fixes.
Aaron Turon [Tue, 29 Dec 2015 21:37:34 +0000 (13:37 -0800)]
Implement default associated type inheritance.
This commit leverages the specialization graph infrastructure to allow
specializing trait implementations to leave off associated types for
which their parents have provided defaults.
It also modifies the type projection code to avoid projecting associated
types unless either (1) all input types are fully known or (2) the
available associated type is "final", i.e. not marked `default`.
This restriction is required for soundness, due to examples like:
Aaron Turon [Mon, 28 Dec 2015 23:38:26 +0000 (15:38 -0800)]
Implement default method inheritance.
This commit leverages the specialization graph infrastructure to allow
specializing trait implementations to leave off methods for which their
parents have provided defaults.
It does not yet check that the `default` keyword is appropriately used
in such cases.
Aaron Turon [Tue, 22 Dec 2015 18:17:59 +0000 (10:17 -0800)]
Add specialization module.
The module contains a few important components:
- The `specialize` function, which determines whether one impl is a
specialization of another.
- The `SpecializationGraph`, a per-trait graph recording the
specialization tree. The main purpose of the graph is to allow
traversals upwards (to less specialized impls) for discovering
un-overridden defaults, and for ensuring that overridden items are
allowed to be overridden.
bors [Mon, 14 Mar 2016 18:38:23 +0000 (11:38 -0700)]
Auto merge of #30587 - oli-obk:eager_const_eval2, r=nikomatsakis
typestrong const integers
~~It would be great if someone could run crater on this PR, as this has a high danger of breaking valid code~~ Crater ran. Good to go.
----
So this PR does a few things:
1. ~~const eval array values when const evaluating an array expression~~
2. ~~const eval repeat value when const evaluating a repeat expression~~
3. ~~const eval all struct and tuple fields when evaluating a struct/tuple expression~~
4. remove the `ConstVal::Int` and `ConstVal::Uint` variants and replace them with a single enum (`ConstInt`) which has variants for all integral types
* `usize`/`isize` are also enums with variants for 32 and 64 bit. At creation and various usage steps there are assertions in place checking if the target bitwidth matches with the chosen enum variant
5. enum discriminants (`ty::Disr`) are now `ConstInt`
6. trans has its own `Disr` type now (newtype around `u64`)
This obviously can't be done without breaking changes (the ones that are noticable in stable)
We could probably write lints that find those situations and error on it for a cycle or two. But then again, those situations are rare and really bugs imo anyway:
```rust
let v10 = 10 as i8;
let v4 = 4 as isize;
assert_eq!(v10 << v4 as usize, 160 as i8);
```
stops compiling because 160 is not a valid i8
```rust
struct S<T, S> {
a: T,
b: u8,
c: S
}
let s = S { a: 0xff_ff_ff_ffu32, b: 1, c: 0xaa_aa_aa_aa as i32 };
```
stops compiling because `0xaa_aa_aa_aa` is not a valid i32
bors [Sun, 13 Mar 2016 16:27:17 +0000 (09:27 -0700)]
Auto merge of #32184 - ollie27:win_stdout, r=alexcrichton
Fixup stout/stderr on Windows
WriteConsoleW can fail if called with a large buffer so we need to slice
any stdout/stderr output.
However the current slicing has a few problems:
1. It slices by byte but still expects valid UTF-8.
2. The slicing happens even when not outputting to a console.
3. panic! output is not sliced.
This fixes these issues by moving the slice to right before
WriteConsoleW and slicing on a char boundary.
This defines the `_mm256_blendv_pd` and `_mm256_blendv_ps` intrinsics.
The `_mm256_blend_pd` and `_mm256_blend_ps` intrinsics are not available
as LLVM intrinsics. In Clang they are implemented using the
shufflevector builtin.
bors [Sun, 13 Mar 2016 12:33:28 +0000 (05:33 -0700)]
Auto merge of #31916 - nagisa:mir-passmgr-2, r=arielb1
Add Pass manager for MIR
A new PR, since rebasing the original one (https://github.com/rust-lang/rust/pull/31448) properly was a pain. Since then there has been several changes most notable of which:
1. Removed the pretty-printing with `#[rustc_mir(graphviz/pretty)]`, mostly because we now have `--unpretty=mir`, IMHO that’s the direction we should expand this functionality into;
2. Reverted the infercx change done for typeck, because typeck can make an infercx for itself by being a `MirMapPass`
bors [Sun, 13 Mar 2016 10:40:14 +0000 (03:40 -0700)]
Auto merge of #32182 - bluss:string-from-is-str-owned, r=alexcrichton
Call str::to_owned in String::from and uninline it
Call str::to_owned in String::from and uninline it
These methods were already effectively equal, but now one calls
the other, and neither is marked inline.
String::from does not need to be inlined, it can be without it just like
str::to_owned and String::clone are.
bors [Sun, 13 Mar 2016 05:55:14 +0000 (21:55 -0800)]
Auto merge of #32141 - jseyfried:fix_resolution_in_lexical_scopes, r=nikomatsakis
Fix name resolution in lexical scopes
Currently, `resolve_item_in_lexical_scope` does not check the "ribs" (type parameters and local variables). This can allow items that should be shadowed by type parameters to be named.
For example,
```rust
struct T { i: i32 }
fn f<T>() {
let t = T { i: 0 }; // This use of `T` resolves to the struct, not the type parameter
}
mod Foo {
pub fn f() {}
}
fn g<Foo>() {
Foo::f(); // This use of `Foo` resolves to the module, not the type parameter
}
```
This PR changes `resolve_item_in_lexical_scope` so that it fails when the item is shadowed by a rib (fixes #32120).
This is a [breaking-change], but it looks unlikely to cause breakage in practice.
bors [Sat, 12 Mar 2016 21:21:06 +0000 (13:21 -0800)]
Auto merge of #32112 - alexcrichton:fix-issues, r=aturon
std: Fix tracking issues and clean deprecated APIs
This PR fixes up a number of discrepancies found with tracking issues (some closed, some needed new ones, etc), and also cleans out all pre-1.8 deprecated APIs. The big beast here was dealing with `std::dynamic_lib`, and via many applications of a large hammer it's now out of the standard library.
Alex Crichton [Mon, 7 Mar 2016 23:42:29 +0000 (15:42 -0800)]
std: Clean out deprecated APIs
Removes all unstable and deprecated APIs prior to the 1.8 release. All APIs that
are deprecated in the 1.8 release are sticking around for the rest of this
cycle.
Some notable changes are:
* The `dynamic_lib` module was moved into `rustc_back` as the compiler still
relies on a few bits and pieces.
* The `DebugTuple` formatter now special-cases an empty struct name with only
one field to append a trailing comma.
bors [Sat, 12 Mar 2016 04:57:39 +0000 (20:57 -0800)]
Auto merge of #31925 - aturon:inherent-overlap, r=nikomatsakis
Forbid items with the same name from appearing in overlapping inherent impl blocks
For example, the following is now correctly illegal:
```rust
struct Foo;
impl Foo {
fn id() {}
}
impl Foo {
fn id() {}
}
```
"Overlapping" here is determined the same way it is for traits (and in fact shares the same code path): roughly, there must be some way of substituting any generic types to unify the impls, such that none of the `where` clauses are provably unsatisfiable under such a unification.
Along the way, this PR also introduces an `ImplHeader` abstraction (the first commit) that makes it easier to work with impls abstractly (without caring whether they are trait or inherent impl blocks); see the first commit.
bors [Fri, 11 Mar 2016 23:25:03 +0000 (15:25 -0800)]
Auto merge of #32132 - arcnmx:cargobuild-std-target, r=alexcrichton
cover more linux targets in libstd cargobuild
libstd/build.rs checked the target name against `"unknown-linux"`... That doesn't necessarily apply to all Linux targets as some toolchains for embedded targets will change that `unknown` field to some vendor name. Some shifting around was needed since Android is also a Linux target.