I've measured the time/memory consumption before and after - the difference is lost in statistical noise, so it's mostly a code simplification.
Sizes of `enum`s are not affected.
r? @nrc
I wonder if AST/HIR visitors could run faster if `P`s are systematically removed (except for cases where they control `enum` sizes). Theoretically they should.
Remaining unnecessary `P`s can't be easily removed because many folders accept `P<X>`s as arguments, but these folders can be converted to accept `X`s instead without loss of efficiency.
When I have a mood for some mindless refactoring again, I'll probably try to convert the folders, remove remaining `P`s and measure again.
This commit is the standard API stabilization commit for the 1.6 release cycle.
The list of issues and APIs below have all been through their cycle-long FCP and
the libs team decisions are listed below
Stabilized APIs
* `Read::read_exact`
* `ErrorKind::UnexpectedEof` (renamed from `UnexpectedEOF`)
* libcore -- this was a bit of a nuanced stabilization, the crate itself is now
marked as `#[stable]` and the methods appearing via traits for primitives like
`char` and `str` are now also marked as stable. Note that the extension traits
themeselves are marked as unstable as they're imported via the prelude. The
`try!` macro was also moved from the standard library into libcore to have the
same interface. Otherwise the functions all have copied stability from the
standard library now.
* `fs::DirBuilder`
* `fs::DirBuilder::new`
* `fs::DirBuilder::recursive`
* `fs::DirBuilder::create`
* `os::unix::fs::DirBuilderExt`
* `os::unix::fs::DirBuilderExt::mode`
* `vec::Drain`
* `vec::Vec::drain`
* `string::Drain`
* `string::String::drain`
* `vec_deque::Drain`
* `vec_deque::VecDeque::drain`
* `collections::hash_map::Drain`
* `collections::hash_map::HashMap::drain`
* `collections::hash_set::Drain`
* `collections::hash_set::HashSet::drain`
* `collections::binary_heap::Drain`
* `collections::binary_heap::BinaryHeap::drain`
* `Vec::extend_from_slice` (renamed from `push_all`)
* `Mutex::get_mut`
* `Mutex::into_inner`
* `RwLock::get_mut`
* `RwLock::into_inner`
* `Iterator::min_by_key` (renamed from `min_by`)
* `Iterator::max_by_key` (renamed from `max_by`)
Deprecated APIs
* `ErrorKind::UnexpectedEOF` (renamed to `UnexpectedEof`)
* `OsString::from_bytes`
* `OsStr::to_cstring`
* `OsStr::to_bytes`
* `fs::walk_dir` and `fs::WalkDir`
* `path::Components::peek`
* `slice::bytes::MutableByteVector`
* `slice::bytes::copy_memory`
* `Vec::push_all` (renamed to `extend_from_slice`)
* `Duration::span`
* `IpAddr`
* `SocketAddr::ip`
* `Read::tee`
* `io::Tee`
* `Write::broadcast`
* `io::Broadcast`
* `Iterator::min_by` (renamed to `min_by_key`)
* `Iterator::max_by` (renamed to `max_by_key`)
* `net::lookup_addr`
New APIs (still unstable)
* `<[T]>::sort_by_key` (added to mirror `min_by_key`)
Closes#27585Closes#27704Closes#27707Closes#27710Closes#27711Closes#27727Closes#27740Closes#27744Closes#27799Closes#27801
cc #27801 (doesn't close as `Chars` is still unstable)
Closes#28968
This commit is the standard API stabilization commit for the 1.6 release cycle.
The list of issues and APIs below have all been through their cycle-long FCP and
the libs team decisions are listed below
Stabilized APIs
* `Read::read_exact`
* `ErrorKind::UnexpectedEof` (renamed from `UnexpectedEOF`)
* libcore -- this was a bit of a nuanced stabilization, the crate itself is now
marked as `#[stable]` and the methods appearing via traits for primitives like
`char` and `str` are now also marked as stable. Note that the extension traits
themeselves are marked as unstable as they're imported via the prelude. The
`try!` macro was also moved from the standard library into libcore to have the
same interface. Otherwise the functions all have copied stability from the
standard library now.
* The `#![no_std]` attribute
* `fs::DirBuilder`
* `fs::DirBuilder::new`
* `fs::DirBuilder::recursive`
* `fs::DirBuilder::create`
* `os::unix::fs::DirBuilderExt`
* `os::unix::fs::DirBuilderExt::mode`
* `vec::Drain`
* `vec::Vec::drain`
* `string::Drain`
* `string::String::drain`
* `vec_deque::Drain`
* `vec_deque::VecDeque::drain`
* `collections::hash_map::Drain`
* `collections::hash_map::HashMap::drain`
* `collections::hash_set::Drain`
* `collections::hash_set::HashSet::drain`
* `collections::binary_heap::Drain`
* `collections::binary_heap::BinaryHeap::drain`
* `Vec::extend_from_slice` (renamed from `push_all`)
* `Mutex::get_mut`
* `Mutex::into_inner`
* `RwLock::get_mut`
* `RwLock::into_inner`
* `Iterator::min_by_key` (renamed from `min_by`)
* `Iterator::max_by_key` (renamed from `max_by`)
Deprecated APIs
* `ErrorKind::UnexpectedEOF` (renamed to `UnexpectedEof`)
* `OsString::from_bytes`
* `OsStr::to_cstring`
* `OsStr::to_bytes`
* `fs::walk_dir` and `fs::WalkDir`
* `path::Components::peek`
* `slice::bytes::MutableByteVector`
* `slice::bytes::copy_memory`
* `Vec::push_all` (renamed to `extend_from_slice`)
* `Duration::span`
* `IpAddr`
* `SocketAddr::ip`
* `Read::tee`
* `io::Tee`
* `Write::broadcast`
* `io::Broadcast`
* `Iterator::min_by` (renamed to `min_by_key`)
* `Iterator::max_by` (renamed to `max_by_key`)
* `net::lookup_addr`
New APIs (still unstable)
* `<[T]>::sort_by_key` (added to mirror `min_by_key`)
Closes#27585Closes#27704Closes#27707Closes#27710Closes#27711Closes#27727Closes#27740Closes#27744Closes#27799Closes#27801
cc #27801 (doesn't close as `Chars` is still unstable)
Closes#28968
See https://github.com/rust-lang/rfcs/pull/16 and https://github.com/rust-lang/rust/issues/15701
- Added syntax support for attributes on expressions and all syntax nodes in statement position.
- Extended `#[cfg]` folder to allow removal of statements, and
of expressions in optional positions like expression lists and trailing
block expressions.
- Extended lint checker to recognize lint levels on expressions and
locals.
- As per RFC, attributes are not yet accepted on `if` expressions.
Examples:
```rust
let x = y;
{
...
}
assert_eq!((1, #[cfg(unset)] 2, 3), (1, 3));
let FOO = 0;
```
Implementation wise, there are a few rough corners and open questions:
- The parser work ended up a bit ugly.
- The pretty printer change was based mostly on guessing.
- Similar to the `if` case, there are some places in the grammar where a new `Expr` node starts,
but where it seemed weird to accept attributes and hence the parser doesn't. This includes:
- const expressions in patterns
- in the middle of an postfix operator chain (that is, after `.`, before indexing, before calls)
- on range expressions, since `#[attr] x .. y` parses as `(#[attr] x) .. y`, which is inconsistent with
`#[attr] .. y` which would parse as `#[attr] (.. y)`
- Attributes are added as additional `Option<Box<Vec<Attribute>>>` fields in expressions and locals.
- Memory impact has not been measured yet.
- A cfg-away trailing expression in a block does not currently promote the previous `StmtExpr` in a block to a new trailing expr. That is to say, this won't work:
```rust
let x = {
#[cfg(foo)]
Foo { data: x }
#[cfg(not(foo))]
Foo { data: y }
};
```
- One-element tuples can have their inner expression removed to become Unit, but just Parenthesis can't. Eg, `(#[cfg(unset)] x,) == ()` but `(#[cfg(unset)] x) == error`. This seemed reasonable to me since tuples and unit are type constructors, but could probably be argued either way.
- Attributes on macro nodes are currently unconditionally dropped during macro expansion, which seemed fine since macro disappear at that point?
- Attributes on `ast::ExprParens` will be prepend-ed to the inner expression in the hir folder.
- The work on pretty printer tests for this did trigger, but not fix errors regarding macros:
- expression `foo![]` prints as `foo!()`
- expression `foo!{}` prints as `foo!()`
- statement `foo![];` prints as `foo!();`
- statement `foo!{};` prints as `foo!();`
- statement `foo!{}` triggers a `None` unwrap ICE.
The local item-path includes the local crates path to the extern crate
declaration which breaks cross-crate rustdoc links if the extern crate
is not linked into the crate root or renamed via `extern foo as bar`.
This PR allows the constant evaluation of index operations on constant arrays and repeat expressions. This allows index expressions to appear in the expression path of the length expression of a repeat expression or an array type.
An example is
```rust
const ARR: [usize; 5] = [1, 2, 3, 4, 5];
const ARR2: [usize; ARR[1]] = [42, 99];
```
In most other locations llvm's const evaluator figures it out already. This is not specific to index expressions and could be remedied in the future.
Fixes https://github.com/rust-lang/rust/issues/28692
Fixes https://github.com/rust-lang/rust/issues/28992
Fixes some other similar issues (see the tests)
[breaking-change], needs crater run (cc @brson or @alexcrichton )
The pattern with parens `UnitVariant(..)` for unit variants seems to be popular in rustc (see the second commit), but mostly used by one person (@nikomatsakis), according to git blame. If it causes breakage on crates.io I'll add an exceptional case for it.
nodes in statement position.
Extended #[cfg] folder to allow removal of statements, and
of expressions in optional positions like expression lists and trailing
block expressions.
Extended lint checker to recognize lint levels on expressions and
locals.
Trait references are always invariant, so all uses of subtyping between
them are equivalent to using equality.
Moreover, the overlap check was previously performed twice per impl
pair, once in each direction. It is now performed only once, and
internally uses the equality check.
On glium, a crate that spends some time in coherence, this change sped
up coherence checking by a few percent (not very significant).
r? @nikomatsakis
This patch implements the plan described in https://internals.rust-lang.org/t/privacy-and-its-interaction-with-docs-lints-and-stability/2880 with one deviation.
It turns out, that rustdoc needs the "directly public" set for its docs inlining logic, so the privacy pass have to produce three sets and not two. Three is arguably too many, so I merged them in one map:
`public_items/exported_items/reachable_items: NodeSet => access_levels: NodeMap<AccessLevel>`
r? @alexcrichton
Trait references are always invariant, so all uses of subtyping between
them are equivalent to using equality.
Moreover, the overlap check was previously performed twice per impl
pair, once in each direction. It is now performed only once, and
internally uses the equality check.
On glium, a crate that spends some time in coherence, this change sped
up coherence checking by a few percent (not very significant).
What this patch does:
- Stability annotations are now based on "exported items" supplied by rustc_privacy and not "public items". Exported items are as accessible for external crates as directly public items and should be annotated with stability attributes.
- Trait impls require annotations now.
- Reexports require annotations now.
- Crates themselves didn't require annotations, now they do.
- Exported macros are annotated now, but these annotations are not used yet.
- Some useless annotations are detected and result in errors
- Finally, some small bugs are fixed - deprecation propagates from stable deprecated parents, items in blocks are traversed correctly (fixes https://github.com/rust-lang/rust/issues/29034) + some code cleanup.
the const evaluator has a bool constant value, no need to use integers
the `fromb` function is very old. It took me a while of git-blame until i found where it was created. I think it was just a hack. All tests still pass.
I also forbade `&&` and `||` on integral types
[breaking change]
I'm not sure if those renames are ok. [TokenType::Tt* to TokenType::*](https://github.com/rust-lang/rust/pull/29582) was obvious, but for all those Item-enums it's less obvious to me what the right way forward is due to the underscore.
Handle them in `middle::reachable` instead (no optimizations so far, just drop all trait impl items into the reachable set, as before). Addresses the concerns from https://github.com/rust-lang/rust/pull/29291#discussion_r43672413
\+ In `middle::reachable` don't treat impls of `Drop` specially, they are subsumed by the general impl treatment.
\+ Add some tests checking reachability of trait methods written in UFCS form
\+ Minor refactoring in the second commit
r? @alexcrichton
Introduce a `SwitchInt` and restructure pattern matching to collect integers and characters into one master switch. This is aimed at #29227, but is not a complete fix. Whereas before we generated an if-else-if chain and, at least on my machine, just failed to compile, we now spend ~9sec compiling `rustc_abuse`. AFAICT this is basically just due to a need for more micro-optimization of the matching process: perf shows a fair amount of time just spent iterating over the candidate list. Still, it seemed worth opening a PR with this step alone, since it's a big step forward.
This branch implements a variant of trans that is based on MIR. It is very incomplete (intentionally), and had only the goal of laying out enough work to enable more incremental follow-on patches. Currently, only fns tagged with `#[rustc_mir]` use the new trans code. I plan to build up a meta-issue as well that tracks the various "not-yet-implemented" points. The only fn that has been tested so far is this amazingly complex "spike" fn:
```rust
#[rustc_mir]
fn sum(x: i32, y: i32) -> i32 {
x + y
}
```
In general, the most interesting commit is the last one. There are some points on which I would like feedback from @rust-lang/compiler:
- I did not use `Datum`. Originally, I thought that maybe just a `ValueRef` would be enough but I wound up with two very simple structures, `LvalueRef` and `OperandRef`, that just package up a `ValueRef` and a type. Because of MIR's structure, you don't wind up mixing by-ref and by-value so much, and I tend to think that a thinner abstraction layer is better here, but I'm not sure.
- Related to the above, I expect that sooner or later we will analyze temps (and maybe variables too) to find those whose address is never taken and which are word-sized and which perhaps meet a few other criteria. For those, we'll probably want to avoid the alloca, just because it means prettier code.
- I generally tried to re-use data structures from elsewhere in trans, though I'm sure we can trim these down.
- I didn't do any debuginfo primarily because it seems to want node-ids and we have only spans. I haven't really read into that code so I don't know what's going on there.
r? @nrc
The public set is expanded with trait items, impls and their items, foreign items, exported macros, variant fields, i.e. all the missing parts. Now it's a subset of the exported set.
This is needed for https://github.com/rust-lang/rust/pull/29083 because stability annotation pass uses the public set and all things listed above need to be annotated.
Rustdoc can now be migrated to the public set as well, I guess.
Exported set is now slightly more correct with regard to exported items in blocks - 1) blocks in foreign items are considered and 2) publicity is not inherited from the block's parent - if a function is public it doesn't mean structures defined in its body are public.
r? @alexcrichton or maybe someone else
Motivation:
- It is not actually a pattern
- It is not actually needed, except for...
Drawback:
- Slice patterns like `[a, _.., b]` are pretty-printed as `[a, .., b]`. Great loss :(
plugin-[breaking-change], as always
This fixes#29048 (though I think adding better transactional support would be a better fix for that issue, but that is more difficult). It also simplifies region inference and changes the model to a pure data flow one, as discussed in [this internals thread](https://internals.rust-lang.org/t/rough-thoughts-on-the-impl-of-region-inference-mir-etc/2800). I am not 100% sure though if this PR is the right thing to do -- or at least maybe not at this moment, so thoughts on that would be appreciated.
r? @pnkfelix
cc @arielb1
expansion already by growing the RHS to be bigger than LHS (all the way
to `'static` if necessary). This is needed because contraction doesn't
handle givens. Fixes#28934.
empty region, and they complicate region inference to no particular end.
They also lead in some cases to spurious errors like #29048 (though in
some cases these errors are helpful in tracking down missing
constraints).
Closes#29314
The code from #29314:
```rust
fn main() {
if let Some(b) = None {
()
} else {
1
};
}
```
now prints this:
```
test.rs:2:5: 6:6 error: `if let` arms have incompatible types: expected `()`, found `_` (expected (), found integral variable) [E0308]
test.rs:2 if let Some(b) = None {
test.rs:3 ()
test.rs:4 } else {
test.rs:5 1
test.rs:6 };
test.rs:2:5: 6:6 help: run `rustc --explain E0308` to see a detailed explanation
test.rs:4:12: 6:6 note: `if let` arm with an incompatible type
test.rs:4 } else {
test.rs:5 1
test.rs:6 };
error: aborting due to previous error
```
this has the funky side-effect of also allowing constant evaluation of function calls to functions that are not `const fn` as long as `check_const` didn't mark that function `NOT_CONST`
It's still not possible to call a normal function from a `const fn`, but let statements' initialization value can get const evaluated (this caused the fallout in the overflowing tests)
we can now do this:
```rust
const fn add(x: usize, y: usize) -> usize { x + y }
const ARR: [i32; add(1, 2)] = [5, 6, 7];
```
also added a test for destructuring in const fn args
```rust
const fn i((a, b): (u32, u32)) -> u32 { a + b } //~ ERROR: E0022
```
This is a **[breaking change]**, since it turns some runtime panics into compile-time errors. This statement is true for ANY improvement to the const evaluator.
This commit stabilizes and deprecates library APIs whose FCP has closed in the
last cycle, specifically:
Stabilized APIs:
* `fs::canonicalize`
* `Path::{metadata, symlink_metadata, canonicalize, read_link, read_dir, exists,
is_file, is_dir}` - all moved to inherent methods from the `PathExt` trait.
* `Formatter::fill`
* `Formatter::width`
* `Formatter::precision`
* `Formatter::sign_plus`
* `Formatter::sign_minus`
* `Formatter::alternate`
* `Formatter::sign_aware_zero_pad`
* `string::ParseError`
* `Utf8Error::valid_up_to`
* `Iterator::{cmp, partial_cmp, eq, ne, lt, le, gt, ge}`
* `<[T]>::split_{first,last}{,_mut}`
* `Condvar::wait_timeout` - note that `wait_timeout_ms` is not yet deprecated
but will be once 1.5 is released.
* `str::{R,}MatchIndices`
* `str::{r,}match_indices`
* `char::from_u32_unchecked`
* `VecDeque::insert`
* `VecDeque::shrink_to_fit`
* `VecDeque::as_slices`
* `VecDeque::as_mut_slices`
* `VecDeque::swap_remove_front` - (renamed from `swap_front_remove`)
* `VecDeque::swap_remove_back` - (renamed from `swap_back_remove`)
* `Vec::resize`
* `str::slice_mut_unchecked`
* `FileTypeExt`
* `FileTypeExt::{is_block_device, is_char_device, is_fifo, is_socket}`
* `BinaryHeap::from` - `from_vec` deprecated in favor of this
* `BinaryHeap::into_vec` - plus a `Into` impl
* `BinaryHeap::into_sorted_vec`
Deprecated APIs
* `slice::ref_slice`
* `slice::mut_ref_slice`
* `iter::{range_inclusive, RangeInclusive}`
* `std::dynamic_lib`
Closes#27706Closes#27725
cc #27726 (align not stabilized yet)
Closes#27734Closes#27737Closes#27742Closes#27743Closes#27772Closes#27774Closes#27777Closes#27781
cc #27788 (a few remaining methods though)
Closes#27790Closes#27793Closes#27796Closes#27810
cc #28147 (not all parts stabilized)
This commit stabilizes and deprecates library APIs whose FCP has closed in the
last cycle, specifically:
Stabilized APIs:
* `fs::canonicalize`
* `Path::{metadata, symlink_metadata, canonicalize, read_link, read_dir, exists,
is_file, is_dir}` - all moved to inherent methods from the `PathExt` trait.
* `Formatter::fill`
* `Formatter::width`
* `Formatter::precision`
* `Formatter::sign_plus`
* `Formatter::sign_minus`
* `Formatter::alternate`
* `Formatter::sign_aware_zero_pad`
* `string::ParseError`
* `Utf8Error::valid_up_to`
* `Iterator::{cmp, partial_cmp, eq, ne, lt, le, gt, ge}`
* `<[T]>::split_{first,last}{,_mut}`
* `Condvar::wait_timeout` - note that `wait_timeout_ms` is not yet deprecated
but will be once 1.5 is released.
* `str::{R,}MatchIndices`
* `str::{r,}match_indices`
* `char::from_u32_unchecked`
* `VecDeque::insert`
* `VecDeque::shrink_to_fit`
* `VecDeque::as_slices`
* `VecDeque::as_mut_slices`
* `VecDeque::swap_remove_front` - (renamed from `swap_front_remove`)
* `VecDeque::swap_remove_back` - (renamed from `swap_back_remove`)
* `Vec::resize`
* `str::slice_mut_unchecked`
* `FileTypeExt`
* `FileTypeExt::{is_block_device, is_char_device, is_fifo, is_socket}`
* `BinaryHeap::from` - `from_vec` deprecated in favor of this
* `BinaryHeap::into_vec` - plus a `Into` impl
* `BinaryHeap::into_sorted_vec`
Deprecated APIs
* `slice::ref_slice`
* `slice::mut_ref_slice`
* `iter::{range_inclusive, RangeInclusive}`
* `std::dynamic_lib`
Closes#27706Closes#27725
cc #27726 (align not stabilized yet)
Closes#27734Closes#27737Closes#27742Closes#27743Closes#27772Closes#27774Closes#27777Closes#27781
cc #27788 (a few remaining methods though)
Closes#27790Closes#27793Closes#27796Closes#27810
cc #28147 (not all parts stabilized)
trait definitions, and give prefence to the former. This is consistent
with what we do for selection. It also works around a limitation
that was leading to #28871.
This PR turns statically known erroneous code (e.g. numeric overflow) into a warning and continues normal code-generation to emit the same code that would have been generated without `check_const` detecting that the result can be computed at compile-time.
<del>It's not done yet, as I don't know how to properly emit a lint from trans. I can't seem to extract the real lint level of the item the erroneous expression is in.</del> It's an unconditional warning now.
r? @pnkfelix
cc @nikomatsakis
* [RFC 1229 text](https://github.com/rust-lang/rfcs/blob/master/text/1229-compile-time-asserts.md)
* RFC PR: rust-lang/rfcs#1229
* tracking issue: https://github.com/rust-lang/rust/issues/28238
Stricter checking of stability attributes + enforcement of their invariants at compile time
(+ removed dead file librustc_front/attr.rs)
I intended to enforce use of `reason` for unstable items as well (it normally presents for new items), but it turned out too intrusive, many older unstable items don't have `reason`s.
r? @aturon
I'm studying how stability works and do some refactoring along the way, so it's probably not the last PR.
Here is my attempt to resolve issue #28822, @Manishearth.
Please let me know if it's fine. And if not, what should I do instead?
This issue felt like quite a good start for some rust contributions. It allows me to get used to the workflow and codebase of rust in an easy-to-swallow manner. Are there any other issues you would recommend me to look at? :) Would love to do some more stuff!
