Auto merge of #52830 - matthewjasper:bootstrap-prep, r=matthewjasper
[NLL] Fix some things for bootstrap
Some changes that are required when bootstrapping rustc with NLL enabled.
* Remove a bunch of unused `mut`s that aren't needed, but the existing lint doesn't catch.
* Rewrite a function call to satisfy NLL borrowck. Note that the borrow is two-phase, but gets activated immediately by an unsizing coercion.
Auto merge of #52805 - ljedrz:format_str_literal, r=petrochenkov
Don't format!() string literals
Prefer `to_string()` to `format!()` take 2, this time targetting string literals. In some cases (`&format!("...")` -> `"..."`) also removes allocations. Occurences of `format!("")` are changed to `String::new()`.
Auto merge of #52738 - ljedrz:push_to_extend, r=eddyb
Replace push loops with extend() where possible
Or set the vector capacity where I couldn't do it.
According to my [simple benchmark](https://gist.github.com/ljedrz/568e97621b749849684c1da71c27dceb) `extend`ing a vector can be over **10 times** faster than `push`ing to it in a loop:
10 elements (6.1 times faster):
```
test bench_extension ... bench: 75 ns/iter (+/- 23)
test bench_push_loop ... bench: 458 ns/iter (+/- 142)
```
100 elements (11.12 times faster):
```
test bench_extension ... bench: 87 ns/iter (+/- 26)
test bench_push_loop ... bench: 968 ns/iter (+/- 3,528)
```
1000 elements (11.04 times faster):
```
test bench_extension ... bench: 311 ns/iter (+/- 9)
test bench_push_loop ... bench: 3,436 ns/iter (+/- 233)
```
Seems like a good idea to use `extend` as much as possible.
Auto merge of #51361 - oli-obk:sanity_check_consts, r=nikomatsakis
Do a basic sanity check for all constant values
## Motivation and high level overview
There has been some back and forth in this PR between @RalfJung and me in here about the motivation for this change and the stance it takes on unsafe coding guidelines.
The initial implementation ran its checks on every value read (so `*x`, `y = x`, ...). In unsafe code that isn't reasonable, because we might be invalidating invariants for a short time in order to build up a proper value.
The current implementation is a lint that runs its checks statics and constants. There is no need to check array lengths and enum variants, because it's a hard error to end up with anything but a number, and that one even has to have the required bits to be defined.
## What checks are done?
* Some type related checks
* `char` needs to be a correct unicode character as defined by `char::from_u32`
* A reference to a ZST must have the correct alignment (and be nonzero)
* A reference to anything is dereferenced and its value is checked
* Layout checks use the information from `ty::Layout` to check
* all fields of structs
* all elements of arrays
* enum discriminants
* the fields of an enum variant (the variant is decided by the discriminant)
* whether any union field succeeds in being checked (if none match the memory pattern, the check fails)
* if the value is in the range described by the layout (e.g. for `NonZero*` types)
Changing the layout of a type will thus automatically cause the checks to check for the new layout.
Auto merge of #52751 - QuietMisdreavus:you-shall-not-pass, r=GuillaumeGomez
rustdoc: rework how default passes are chosen
This is a refactor that changes how we select default passes, and changes the set of passes used for `--document-private-items`. It's groundwork for a bigger refactor i want to do.
The major changes:
* There are now two sets of "default passes": one set for "no flags given" and one for "document private items".
* These sets can be selected by a new `DefaultPassOption` enum, which is selected from based on the presence of `--no-defaults` or `--document-private-items` CLI flags, or their associated crate attributes.
* When printing the list of passes, we also print the list of passes for `--document-private-items` in addition to the "default defaults".
* I added `propagate-doc-cfg` and `strip-priv-imports` to the "document private items" set. The former is to ensure items are properly tagged with the full set of cfg flags even when "document private items" is active. The latter is based on feedback and personal experience navigating the `rustc` docs, which use that flag. `strip-priv-imports` only removes non-pub `use` statements, so it should be harmless from a documentation standpoint to remove those items from "private items" documentation.
Auto merge of #52355 - pietroalbini:zfeature, r=eddyb
Add the -Zcrate-attr=foo unstable rustc option
This PR adds a new unstable option to `rustc`: `-Zcrate-attr=foo`. The option can be used to inject crate-level attributes from the CLI, and it's meant to be used by tools like Crater that needs to add their own attributes to a crate without changing the source code.
The exact reason I need this is to implement "edition runs" in Crater: we need to add the preview feature flag to every crate, and editing the crates' source code on the fly might produce unexpected results, while a compiler flag is more reliable.
cc https://github.com/rust-lang-nursery/crater/issues/282 @Mark-Simulacrum
Auto merge of #52546 - nikomatsakis:issue-52050, r=pnkfelix
do not overwrite child def-id in place but rather remove/insert
When inserting a node N into the tree of impls, we sometimes find than an existing node C should be replaced with N. We used to overwrite C in place with the new def-id N -- but since the lists of def-ids are separated by simplified type, that could lead to N being inserted in the wrong place. This meant we might miss conflicts. We are now not trying to be so smart -- we remove C and then add N later.
Fixes #52050
r? @aturon -- do you still remember this code at all? :)
Auto merge of #52711 - eddyb:unsized-manuallydrop, r=nikomatsakis
Change ManuallyDrop<T> to a lang item.
This PR implements the approach @RalfJung proposes in https://internals.rust-lang.org/t/pre-rfc-unions-drop-types-and-manuallydrop/8025 (lang item `struct` instead of `union`).
A followup PR can easily solve #47034 as well, by just adding a few `?Sized` to `libcore/mem.rs`.
- #52702 (Suggest fix when encountering different mutability from impl to trait)
- #52703 (Improve a few vectors - calculate capacity or build from iterators)
- #52740 (Suggest underscore when using dashes in crate namet push fork)
- #52759 (Impl Send & Sync for JoinHandle)
- #52760 (rustc_metadata: test loading atoi instead of cos)
- #52763 (Omit the vendor component in Fuchsia triple)
- #52765 (Remove unused "-Zenable_nonzeroing_move_hints" flag)
- #52769 (Incorporate a stray test)
- #52777 (Fix doc comment for 'ptr::copy_to' method)
- #52779 (revert accidental atty downgrade)
- #52781 (Use a slice where a vector is not necessary)
Rollup merge of #52769 - sinkuu:stray_test, r=alexcrichton
Incorporate a stray test
`liballoc/repeat-generic-slice.rs` doesn't seem to be tested (I think it was intended to be placed in `run-pass`). This PR incorporates the test into `liballoc/tests`.
Rollup merge of #52763 - petrhosek:fuchsia-triple, r=alexcrichton
Omit the vendor component in Fuchsia triple
Previously, using unknown as the vendor value would lead to the same
result, but with the multiarch runtimes support in Clang, the target is
now used to locate the runtime libraries and so the format is important.
The denormalized format with omitted vendor component is the format we
use with Clang and should be using for Rust as well.
Rollup merge of #52760 - cuviper:test_loading_atoi, r=alexcrichton
rustc_metadata: test loading atoi instead of cos
Some platforms don't actually have `libm` already linked in the test
infrastructure, and then `dynamic_lib::tests::test_loading_cosine` would
fail to find the "cos" symbol. Every platform running this test should
have `libc` and "atoi" though, so try to use that symbol instead.
Rollup merge of #52759 - stjepang:impl-send-sync-for-joinhandle, r=TimNN
Impl Send & Sync for JoinHandle
This is just a cosmetic change - it slightly relaxes and clarifies the public API without effectively promising any new guarantees.
Currently we have [these auto trait implementations](https://doc.rust-lang.org/nightly/std/thread/struct.JoinHandle.html#synthetic-implementations):
```rust
impl<T: Send> Send for JoinHandle<T> {}
impl<T: Sync> Sync for JoinHandle<T> {}
```
Bound `T: Send` doesn't make much sense because `JoinHandle<T>` can be created only when `T: Send`. Note that [`JoinHandle::<T>::join`](https://doc.rust-lang.org/nightly/std/thread/struct.JoinHandle.html#method.join) doesn't require `T: Send` so why should the `Send` impl?
And the `Sync` impl doesn't need `T: Sync` because `JoinHandle<T>` cannot even share `T` - it can only send it to the thread that calls `join`.
Auto merge of #52678 - matthewjasper:better-spans, r=nikomatsakis
[NLL] Use better spans in some errors
* Use the span of the discriminant and patterns for "fake" statements created to properly check matches. I plan to special case these soon, but this felt like a good first step
* Use the span of the statement, rather than the initialization, when reporting move errors for `let x = ...`, which avoids giving an unhelpful suggestion to use `&{ }`.
Auto merge of #52770 - pietroalbini:bump-bootstrap, r=Mark-Simulacrum
Bump bootstrap compiler
This PR bumps the bootstrap compiler to the latest beta, `beta-2017-07-27`. That should be the latest beta with relevant changes (the only nominated PR at the moment is a docs change).
Auto merge of #52733 - pnkfelix:issue-51348-make-temp-for-each-candidate-in-arm, r=nikomatsakis
[NLL] make temp for each candidate in `match` arm
In NLL, `ref mut` patterns leverage the two-phase borrow infrastructure to allow the shared borrows within a guard before the "activation" of the mutable borrow when we begin execution of the match arm's body. (There is further discussion of this on PR #50783.)
To accommodate the restrictions we impose on two-phase borrows (namely that there is a one-to-one mapping between each activation and the original initialization), this PR is making separate temps for each candidate pattern. So in an arm like this:
```rust
PatA(_, ref mut ident) |
PatB(ref mut ident) |
PatC(_, _, ref mut ident) |
PatD(ref mut ident) if guard_stuff(ident) => ...
```
instead of 3 temps (two for the guard and one for the arm body), we now have 4 + 2 temps associated with `ident`: one for each candidate plus the actual temp that the guard uses directly, and then the sixth is the temp used in the arm body.
Auto merge of #52681 - pnkfelix:z-borrowck-migrate, r=nikomatsakis
Add `-Z borrowck=migrate`
This adds `-Z borrowck=migrate`, which represents the way we want to migrate to NLL under Rust versions to come. It also hooks this new mode into `--edition 2018`, which means we're officially turning NLL on in the 2018 edition.
The basic idea of `-Z borrowck=migrate` that there are cases where NLL is fixing old soundness bugs in the borrow-checker, but in order to avoid just breaking code by immediately rejecting the programs that hit those soundness bugs, we instead use the following strategy:
If your code is accepted by NLL, then we accept it.
If your code is rejected by both NLL and the old AST-borrowck, then we reject it.
If your code is rejected by NLL but accepted by the old AST-borrowck, then we emit the new NLL errors as **warnings**.
These warnings will be turned into hard errors in the future, and they say so in these diagnostics.
Petr Hosek [Fri, 27 Jul 2018 00:57:20 +0000 (17:57 -0700)]
Omit the vendor component in Fuchsia triple
Previously, using unknown as the vendor value would lead to the same
result, but with the multiarch runtimes support in Clang, the target is
now used to locate the runtime libraries and so the format is important.
The denormalized format with omitted vendor component is the format we
use with Clang and should be using for Rust as well.
Josh Stone [Fri, 27 Jul 2018 00:20:02 +0000 (17:20 -0700)]
rustc_metadata: test loading atoi instead of cos
Some platforms don't actually have `libm` already linked in the test
infrastructure, and then `dynamic_lib::tests::test_loading_cosine` would
fail to find the "cos" symbol. Every platform running this test should
have `libc` and "atoi" though, so try to use that symbol instead.