Commit Graph

134739 Commits

Author SHA1 Message Date
Tyler Mandry
3a46a6b997
Rollup merge of #79896 - GuillaumeGomez:more-elements-focus, r=Manishearth
Make search results tab and help button focusable with keyboard

Fixes https://github.com/rust-lang/rust/issues/79859.

I replaced the element with `button` tag, which allows to focus them (and "click" on them using "enter") using only the keyboard.

cc ``@sersorrel``

r? ``@Manishearth``
2020-12-10 21:33:17 -08:00
Tyler Mandry
c94345e3c2
Rollup merge of #79871 - Pratyush:patch-1, r=joshtriplett
Fix small typo in `wrapping_shl` documentation

Fixes a small typo in the documentation.
2020-12-10 21:33:15 -08:00
Tyler Mandry
c0cc91008a
Rollup merge of #79860 - rust-lang:frewsxcv-patch-2, r=jyn514
Clarify that String::split_at takes a byte index.

To someone skimming through the `String` docs and only reads the first line, the person could interpret "index" to be "char index". Later on in the docs it clarifies, but by adding "byte" it removes that ambiguity.
2020-12-10 21:33:14 -08:00
Tyler Mandry
8709ac81d3
Rollup merge of #79858 - sasurau4:doc/update-unstable-book-const-fn, r=oli-obk
Update const-fn doc in unstable-book

Fix #79691

I couldn't find suitable examples. It seems that `const_fn` feature-gate used only following place. 810324d1f3/compiler/rustc_ast_passes/src/feature_gate.rs (L560-L562)

And example like following emits [E0379](https://doc.rust-lang.org/error-index.html#E0379).

```rust
#![feature(const_fn)]

trait Foo {
    const fn bar() -> Self;
}
```

Any other suitable example exists, please let me know.
2020-12-10 21:33:12 -08:00
Tyler Mandry
dc90573454
Rollup merge of #79851 - camelid:better-error-for-default-fn, r=davidtwco
Clarify the 'default is only allowed on...' error

Code like

    impl Foo {
        default fn foo() {}
    }

will trigger the error

    error: `default` is only allowed on items in `impl` definitions
     --> src/lib.rs:5:5
      |
    5 |     default fn foo() {}
      |     -------^^^^^^^^^
      |     |
      |     `default` because of this

but that's very confusing! I *did* put it on an item in an impl!

So this commit changes the message to

    error: `default` is only allowed on items in trait impls
     --> src/lib.rs:5:5
      |
    5 |     default fn foo() {}
      |     -------^^^^^^^^^
      |     |
      |     `default` because of this
2020-12-10 21:33:10 -08:00
Tyler Mandry
17ec4b8258
Rollup merge of #79809 - Eric-Arellano:split-once, r=matklad
Dogfood `str_split_once()`

Part of https://github.com/rust-lang/rust/issues/74773.

Beyond increased clarity, this fixes some instances of a common confusion with how `splitn(2)` behaves: the first element will always be `Some()`, regardless of the delimiter, and even if the value is empty.

Given this code:

```rust
fn main() {
    let val = "...";
    let mut iter = val.splitn(2, '=');
    println!("Input: {:?}, first: {:?}, second: {:?}", val, iter.next(), iter.next());
}
```

We get:

```
Input: "no_delimiter", first: Some("no_delimiter"), second: None
Input: "k=v", first: Some("k"), second: Some("v")
Input: "=", first: Some(""), second: Some("")
```

Using `str_split_once()` makes more clear what happens when the delimiter is not found.
2020-12-10 21:33:08 -08:00
Tyler Mandry
8b9a59cb90
Rollup merge of #79698 - m-ou-se:libs-tracking-issue-template, r=KodrAus
Add tracking issue template for library features.

This adds a issue template for a library tracking issue.

There's already a template for tracking issues, but it's mostly geared towards compiler/language features. A separate template makes it a bit easier to make sure it matches with the process we use for library changes.

Main differences:
- Added a note about how small library features can be added without RFC, and removed the parts that assume there's an RFC.
- Merged the 'Steps' and 'History' sections: Library features are often small enough that there's no multiple steps planned ahead of time.
- Removed the section about avoiding large discussions and opening separate issues for problems with the feature. Library features are usually focussed enough that the discussion about a feature is best kept together in the tracking issue.
- Removed links to the rustc-dev-guide, which are specific to changes in the compiler and language.
2020-12-10 21:33:06 -08:00
Tyler Mandry
f3a3fc900c
Rollup merge of #79639 - sasurau4:feature/add-long-explanation-E0212, r=GuillaumeGomez
Add long explanation for E0212

Helps with #61137
2020-12-10 21:33:04 -08:00
Tyler Mandry
a8c19e1b48
Rollup merge of #79375 - vext01:kernel-copy-temps, r=bjorn3
Make the kernel_copy tests more robust/concurrent.

These tests write to the same filenames in /tmp and in some cases these files don't get cleaned up properly. This caused issues for us when different users run the tests on the same system, e.g.:

```
---- sys::unix::kernel_copy::tests::bench_file_to_file_copy stdout ----
thread 'sys::unix::kernel_copy::tests::bench_file_to_file_copy' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 13, kind: PermissionDenied, message: "Permission denied" }', library/std/src/sys/unix/kernel_copy/tests.rs:71:10
---- sys::unix::kernel_copy::tests::bench_file_to_socket_copy stdout ----
thread 'sys::unix::kernel_copy::tests::bench_file_to_socket_copy' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 13, kind: PermissionDenied, message: "Permission denied" }', library/std/src/sys/unix/kernel_copy/tests.rs💯10
```

Use `std::sys_common::io__test::tmpdir()` to solve this.

CC ``@the8472.``
2020-12-10 21:33:02 -08:00
Tyler Mandry
1b4ffe4705
Rollup merge of #77027 - termhn:mul_add_doc_change, r=m-ou-se
Improve documentation for `std::{f32,f64}::mul_add`

Makes it more clear that performance improvement is not guaranteed when using FMA, even when the target architecture supports it natively.
2020-12-10 21:32:59 -08:00
bors
0c9ef564a7 Auto merge of #79656 - jnqnfe:ordering, r=sfackler
Add some core::cmp::Ordering helpers

...to allow easier equal-to-or-greater-than and less-than-or-equal-to
comparisons.

Prior to Rust 1.42 a greater-than-or-equal-to comparison might be written
either as a match block, or a traditional conditional check like this:

```rust
if cmp == Ordering::Equal || cmp == Ordering::Greater {
    // Do something
}
```

Which requires two instances of `cmp`. Don't forget that while `cmp` here
is very short, it could be something much longer in real use cases.

From Rust 1.42 a nicer alternative is possible:

```rust
if matches!(cmp, Ordering::Equal | Ordering::Greater) {
    // Do something
}
```

The commit adds another alternative which may be even better in some cases:

```rust
if cmp.is_equal_or_greater() {
    // Do something
}
```

The earlier examples could be cleaner than they are if the variants of
`Ordering` are imported such that `Equal`, `Greater` and `Less` can be
referred to directly, but not everyone will want to do that.

The new solution can shorten lines, help avoid logic mistakes, and avoids
having to import `Ordering` / `Ordering::*`.
2020-12-11 03:08:32 +00:00
bors
8cef65fde3 Auto merge of #77801 - fusion-engineering-forks:pin-mutex, r=Mark-Simulacrum
Enforce no-move rule of ReentrantMutex using Pin and fix UB in stdio

A `sys_common::ReentrantMutex` may not be moved after initializing it with `.init()`. This was not enforced, but only stated as a requirement in the comments on the unsafe functions. This change enforces this no-moving rule using `Pin`, by changing `&self` to a `Pin` in the `init()` and `lock()` functions.

This uncovered a bug I introduced in #77154: stdio.rs (the only user of ReentrantMutex) called `init()` on its ReentrantMutexes while constructing them in the intializer of `SyncOnceCell::get_or_init`, which would move them afterwards. Interestingly, the ReentrantMutex unit tests already had the same bug, so this invalid usage has been tested on all (CI-tested) platforms for a long time. Apparently this doesn't break badly on any of the major platforms, but it does break the rules.\*

To be able to keep using SyncOnceCell, this adds a `SyncOnceCell::get_or_init_pin` function, which makes it possible to work with pinned values inside a (pinned) SyncOnceCell. Whether this function should be public or not and what its exact behaviour and interface should be if it would be public is something I'd like to leave for a separate issue or PR. In this PR, this function is internal-only and marked with `pub(crate)`.

\* Note: That bug is now included in 1.48, while this patch can only make it to ~~1.49~~ 1.50. We should consider the implications of 1.48 shipping with a wrong usage of `pthread_mutex_t` / `CRITICAL_SECTION` / .. which technically invokes UB according to their specification. The risk is very low, considering the objects are not 'used' (locked) before the move, and the ReentrantMutex unit tests have verified this works fine in practice.

Edit: This has been backported and included in 1.48. And soon 1.49 too.

---

In future changes, I want to push this usage of Pin further inside `sys` instead of only `sys_common`, and apply it to all 'unmovable' objects there (`Mutex`, `Condvar`, `RwLock`). Also, while `sys_common`'s mutexes and condvars are already taken care of by #77147 and #77648, its `RwLock` should still be made movable or get pinned.
2020-12-10 23:43:20 +00:00
Mara Bos
f7306b1b63 Add tracking issue template for library features. 2020-12-10 23:16:32 +01:00
Lyndon Brown
169c59ff0f Add some core::cmp::Ordering helpers
...to allow easier greater-than-or-equal-to and less-than-or-equal-to
comparisons, and variant checking without needing to import the enum,
similar to `Option::is_none()` / `Option::is_some()`, in situations where
you are dealing with an `Ordering` value. (Simple `PartialOrd` / `Ord`
based evaluation may not be suitable for all situations).

Prior to Rust 1.42 a greater-than-or-equal-to comparison might be written
either as a match block, or a traditional conditional check like this:

```rust
if cmp == Ordering::Equal || cmp == Ordering::Greater {
    // Do something
}
```

Which requires two instances of `cmp`. Don't forget that while `cmp` here
is very short, it could be something much longer in real use cases.

From Rust 1.42 a nicer alternative is possible:

```rust
if matches!(cmp, Ordering::Equal | Ordering::Greater) {
    // Do something
}
```

The commit adds another alternative which may be even better in some cases:

```rust
if cmp.is_ge() {
    // Do something
}
```

The earlier examples could be cleaner than they are if the variants of
`Ordering` are imported such that `Equal`, `Greater` and `Less` can be
referred to directly, but not everyone will want to do that.

The new solution can shorten lines, help avoid logic mistakes, and avoids
having to import `Ordering` / `Ordering::*`.
2020-12-10 20:32:12 +00:00
bors
d32c320d7e Auto merge of #79814 - lcnr:deque-f, r=Mark-Simulacrum
fix soundness issue in `make_contiguous`

fixes #79808
2020-12-10 17:49:42 +00:00
bors
80cc2ecf10 Auto merge of #79536 - davidtwco:focal-fossa-ci, r=pietroalbini
ci: use 20.04 on x86_64-gnu-nopt builder

Switch the `x86_64-gnu-nopt` builder to use Ubuntu 20.04.

Ubuntu 20.04 has a more recent gdb version than Ubuntu 16.04 (9.1 vs 7.11.1), which is required for rust-lang/rust#77177, as 16.04's gdb 7.11.1 crashes in some cases with Split DWARF. `x86_64-gnu-nopt` is chosen because it runs compare modes, which is how Split DWARF testing is implemented in rust-lang/rust#77177.

I've not confirmed that the issue is resolved with gdb 9.1 (Feb 2020), but system was using gdb 9.2 (May 2020) and that was fine and it seems more likely to me that the bug was resolved between gdb 7.11.1 (May 2016) and gdb 9.1.

Updating a builder to use 20.04 was suggested by `@Mark-Simulacrum` in https://github.com/rust-lang/rust/pull/77117#issuecomment-731846170. I'm not sure if this is the only change that is required - if more are necessary then I'm happy to do that.

r? `@pietroalbini`
cc `@Mark-Simulacrum`
2020-12-10 15:20:42 +00:00
David Wood
fb75c329c5
ci: use 20.04 on x86_64-gnu-nopt builder
This commit switches the x86_64-gnu-nopt builder to use Ubuntu 20.04,
which contains a more recent gdb version than Ubuntu 16.04 (newer gdb
versions fix a bug that Split DWARF can trigger, see
rust-lang/rust#77177 for motivation). x86_64-gnu-nopt is chosen because
it runs compare modes, which is how Split DWARF testing is implemented
in rust-lang/rust#77177.

Signed-off-by: David Wood <david@davidtw.co>
2020-12-10 15:04:48 +00:00
Daiki Ihara
caab16fa20 Update const-fn doc in unstable-book
Update src/doc/unstable-book/src/language-features/const-fn.md

Co-authored-by: Ivan Tham <pickfire@riseup.net>
2020-12-10 22:29:43 +09:00
bors
d7560e8968 Auto merge of #79801 - eddyb:scalar-transmute, r=nagisa
rustc_codegen_ssa: use bitcasts instead of type punning for scalar transmutes.

This specifically helps with `f32` <-> `u32` (`from_bits`, `to_bits`) in Rust-GPU (`rustc_codegen_spirv`), where (AFAIK) we don't yet have enough infrastructure to turn type punning memory accesses into SSA bitcasts.
(There may be more instances, but the one I've seen myself is `f32::signum` from `num-traits` inspecting e.g. the sign bit)

Sadly I've had to make an exception for `transmute`s between pointers and non-pointers, as LLVM disallows using `bitcast` for them.

r? `@nagisa` cc `@khyperia`
2020-12-10 12:55:12 +00:00
Eduard-Mihai Burtescu
718fba92b0 tests: codegen/transmute-scalar needs optimizations enabled. 2020-12-10 13:24:47 +02:00
bors
39b841dfe3 Auto merge of #79621 - usbalbin:constier_maybe_uninit, r=RalfJung
Constier maybe uninit

I was playing around trying to make `[T; N]::zip()` in #79451 be `const fn`. One of the things I bumped into was `MaybeUninit::assume_init`. Is there any reason for the intrinsic `assert_inhabited<T>()` and therefore `MaybeUninit::assume_init` not being `const`?

---

I have as best as I could tried to follow the instruction in [library/core/src/intrinsics.rs](https://github.com/rust-lang/rust/blob/master/library/core/src/intrinsics.rs#L11). I have no idea what I am doing but it seems to compile after some slight changes after the copy paste. Is this anywhere near how this should be done?

Also any ideas for name of the feature gate? I guess `const_maybe_assume_init` is quite misleading since I have added some more methods. Should I add test? If so what should be tested?
2020-12-10 10:46:38 +00:00
Guillaume Gomez
2363a20b98 Make search results tab and help button focusable with keyboard 2020-12-10 11:38:12 +01:00
bors
e413d89aa7 Auto merge of #79274 - the8472:probe-eperm, r=nagisa
implement better availability probing for copy_file_range

Followup to https://github.com/rust-lang/rust/pull/75428#discussion_r469616547

Previously syscall detection was overly pessimistic. Any attempt to copy to an immutable file (EPERM) would disable copy_file_range support for the whole process.

The change tries to copy_file_range on invalid file descriptors which will never run into the immutable file case and thus we can clearly distinguish syscall availability.
2020-12-10 03:11:27 +00:00
bors
58d2bad9f7 Auto merge of #78837 - petrochenkov:keyvalexpr, r=davidtwco
Accept arbitrary expressions in key-value attributes at parse time

Continuation of https://github.com/rust-lang/rust/pull/77271.

We now support arbitrary expressions in values of key-value attributes at parse time.
```
#[my_attr = EXPR]
```
Previously only unsuffixed literals and interpolated expressions (`$expr`) were accepted.

There are two immediate motivational cases for this:
- External doc strings (`#[doc = include_str!("my_doc.md")]`, eliminating the need in https://github.com/rust-lang/rust/issues/44732) and expanding macros in this position in general. Currently such macro expansions are supported in this position in interpolated `$expr`s (the `#[doc = $doc]` idiom).
- Paths (`#[namespace = foo::bar] extern "C++" { ... }`) like proposed in https://github.com/rust-lang/rust/pull/76734.

If the attribute in question survives expansion, then the value is still restricted to unsuffixed literals by a semantic check.
This restriction doesn't prevent the use cases listed above, so this PR keeps it in place for now.

Closes https://github.com/rust-lang/rust/issues/52607.
Previous attempt - https://github.com/rust-lang/rust/pull/67121.
Some more detailed write up on internals - https://internals.rust-lang.org/t/macro-expansion-points-in-attributes/11455.
Tracking issue - https://github.com/rust-lang/rust/issues/78835.
2020-12-10 00:42:22 +00:00
Pratyush Mishra
56d9784b5a
Fix typo in wrapping_shl documentation 2020-12-09 15:14:58 -08:00
bors
1cc4107109 Auto merge of #79867 - tmandry:rollup-7mubs3b, r=tmandry
Rollup of 12 pull requests

Successful merges:

 - #79732 (minor stylistic clippy cleanups)
 - #79750 (Fix trimming of lint docs)
 - #79777 (Remove `first_merge` from liveness debug logs)
 - #79795 (Privatize some of libcore unicode_internals)
 - #79803 (Update xsv to prevent random CI failures)
 - #79810 (Account for gaps in def path table during decoding)
 - #79818 (Fixes to Rust coverage)
 - #79824 (Strip prefix instead of replacing it with empty string)
 - #79826 (Simplify visit_{foreign,trait}_item)
 - #79844 (Move RWUTable to a separate module)
 - #79861 (Update LLVM submodule)
 - #79862 (Remove tab-lock and replace it with ctrl+up/down arrows to switch between search result tabs)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2020-12-09 22:21:55 +00:00
Tyler Mandry
f74f3b2f37
Rollup merge of #79862 - GuillaumeGomez:tab-lock, r=Manishearth
Remove tab-lock and replace it with ctrl+up/down arrows to switch between search result tabs

Fixes https://github.com/rust-lang/rust/issues/65212

What took the longest time was to update the help popup in the end.

r? `@Manishearth`
2020-12-09 13:38:38 -08:00
Tyler Mandry
8ffe7b6a81
Rollup merge of #79861 - tmiasko:llvm, r=cuviper
Update LLVM submodule

* [[msan] Fix bugs when instrumenting x86.avx512*_cvt* intrinsics](https://github.com/rust-lang/llvm-project/pull/84)
* [[X86][AVX512] Only lower to VPALIGNR if we have BWI (PR48322)](https://github.com/rust-lang/llvm-project/pull/85)
2020-12-09 13:38:36 -08:00
Tyler Mandry
b867d13d34
Rollup merge of #79844 - tmiasko:rwu-table-mod, r=lcnr
Move RWUTable to a separate module
2020-12-09 13:38:34 -08:00
Tyler Mandry
9ced8dc0f5
Rollup merge of #79826 - LingMan:match_if, r=lcnr
Simplify visit_{foreign,trait}_item

Using an `if` seems like a better semantic fit and saves a few lines.

Noticed while looking at https://github.com/rust-lang/rust/pull/79752, but that's already merged.
r? `@lcnr,` cc `@cjgillot`

`@rustbot` modify labels +C-cleanup +T-compiler
2020-12-09 13:38:33 -08:00
Tyler Mandry
666d1a8951
Rollup merge of #79824 - LingMan:no_replace, r=lcnr
Strip prefix instead of replacing it with empty string

r? `@lcnr,` since you reviewed my other PR in the area.
`@rustbot` modify labels +C-cleanup +T-compiler
2020-12-09 13:38:31 -08:00
Tyler Mandry
3b49a46c6b Rollup merge of #79818 - richkadel:llvm-coverage-counters-2.1.0, r=tmandry
Fixes to Rust coverage

Fixes: #79725

Some macros can create a situation where `fn_sig_span` and `body_span`
map to different files.

New documentation on coverage tests incorrectly assumed multiple test
binaries could just be listed at the end of the `llvm-cov` command,
but it turns out each binary needs a `--object` prefix.

This PR fixes the bug and updates the documentation to correct that
issue. It also fixes a few other minor issues in internal implementation
comments, and adds documentation on getting coverage results for doc
tests.
2020-12-09 13:38:27 -08:00
Tyler Mandry
a410af97a8
Rollup merge of #79810 - Aaron1011:fix/def-path-table-gap, r=lcnr
Account for gaps in def path table during decoding

When encoding a proc-macro crate, there may be gaps in the table (since
we only encode the crate root and proc-macro items). Account for this by
checking if the entry is present, rather than using `unwrap()`
2020-12-09 13:38:25 -08:00
Tyler Mandry
0994f353bf
Rollup merge of #79803 - jyn514:xsv, r=Mark-Simulacrum
Update xsv to prevent random CI failures

This fixes occasional proptest failures due to a bug in xsv, which
aren't related to bugs in the rust compiler.

See https://github.com/rust-lang/rust/pull/79751#issuecomment-740027046 for context.
2020-12-09 13:38:24 -08:00
Tyler Mandry
26e4cf0fc7
Rollup merge of #79795 - matklad:unicode-private, r=cramertj
Privatize some of libcore unicode_internals

My understanding is that these API are perma unstable, so it doesn't
make sense to pollute docs & IDE completion[1] with them.

[1]: https://github.com/rust-analyzer/rust-analyzer/issues/6738
2020-12-09 13:38:22 -08:00
Tyler Mandry
2cca5e11e0
Rollup merge of #79777 - tmiasko:remove-first-merge, r=lcnr
Remove `first_merge` from liveness debug logs
2020-12-09 13:38:20 -08:00
Tyler Mandry
287293732f
Rollup merge of #79750 - camelid:fix-lint-docs-trimming, r=Mark-Simulacrum
Fix trimming of lint docs

Fixes #79748.

It was removing all the indentation before.

r? `@Mark-Simulacrum`
2020-12-09 13:38:18 -08:00
Tyler Mandry
d95948c6d3
Rollup merge of #79732 - matthiaskrgr:cl12ppy, r=Dylan-DPC
minor stylistic clippy cleanups

simplify if let Some(_) = x  to  if x.is_some()  (clippy::redundant_pattern_matching)
don't create owned values for comparison (clippy::cmp_owned)
use .contains() or .any() instead of find(x).is_some() (clippy::search_is_some)
don't wrap code block in Ok()  (clipppy::unit_arg)
2020-12-09 13:38:12 -08:00
The8472
7647d03c33 Improve comment grammar 2020-12-09 21:31:37 +01:00
The8472
028754a2f7 implement better availability probing for copy_file_range
previously any attempt to copy to an immutable file (EPERM) would disable
copy_file_range support for the whole process.
2020-12-09 21:31:37 +01:00
Eduard-Mihai Burtescu
5c1d2ced03 tests: add 3 cases involving pointers to codegen/transmute-scalar. 2020-12-09 21:54:24 +02:00
bors
f0f68778f7 Auto merge of #77611 - oli-obk:atomic_miri_leakage, r=nagisa
Directly use raw pointers in `AtomicPtr` store/load

I was unable to find any reason for this limitation in the latest source of LLVM or in the documentation [here](http://llvm.org/docs/Atomics.html#libcalls-atomic).

fixes https://github.com/rust-lang/miri/issues/1574
2020-12-09 19:53:23 +00:00
Guillaume Gomez
570de0a3be Remove tab-lock and replace it with ctrl+up/down arrows to switch between search result tabs 2020-12-09 20:47:55 +01:00
Vadim Petrochenkov
31d72c2658 Accept arbitrary expressions in key-value attributes at parse time 2020-12-09 21:37:32 +03:00
Corey Farwell
33ae62c3d7
Clarify that String::split_at takes a byte index. 2020-12-09 13:17:54 -05:00
bors
c16d52db77 Auto merge of #79387 - woodruffw-forks:ww/peer-cred-pid-macos, r=Amanieu
ext/ucred: Support PID in peer creds on macOS

This is a follow-up to https://github.com/rust-lang/rust/pull/75148 (RFC: https://github.com/rust-lang/rust/issues/42839).

The original PR used `getpeereid` on macOS and the BSDs, since they don't (generally) support the `SO_PEERCRED` mechanism that Linux supplies.

This PR splits the macOS/iOS implementation of `peer_cred()` from that of the BSDs, since macOS supplies the `LOCAL_PEERPID` sockopt as a source of the missing PID. It also adds a `cfg`-gated tests that ensures that platforms with support for PIDs in `UCred` have the expected data.
2020-12-09 17:27:35 +00:00
bors
fa55f668e5 Auto merge of #79721 - Aaron1011:fix/reuse-def-path-hash, r=wesleywiser
Properly re-use def path hash in incremental mode

Fixes #79661

In incremental compilation mode, we update a `DefPathHash -> DefId`
mapping every time we create a `DepNode` for a foreign `DefId`.
This mapping is written out to the on-disk incremental cache, and is
read by the next compilation session to allow us to lazily decode
`DefId`s.

When we decode a `DepNode` from the current incremental cache, we need
to ensure that any previously-recorded `DefPathHash -> DefId` mapping
gets recorded in the new mapping that we write out. However, PR #74967
didn't do this in all cases, leading to us being unable to decode a
`DefPathHash` in certain circumstances.

This PR refactors some of the code around `DepNode` deserialization to
prevent this kind of mistake from happening again.
2020-12-09 13:54:07 +00:00
bors
cc03ee6702 Auto merge of #78679 - oli-obk:temp_lifetime, r=eddyb
Also generate `StorageDead` in constants

r? `@eddyb`

None of this special casing is actually necessary since we started promoting within constants and statics.

We may want to keep some of it around out of perf reasons, but it's not required for user visible behaviour

somewhat related: #68622
2020-12-09 11:31:32 +00:00
oli
84fe7cf24e Also generate StorageDead in constants 2020-12-09 10:59:10 +00:00
bors
c0bfe3485f Auto merge of #78363 - RalfJung:promotion, r=oli-obk
remove this weird special case from promotion

Promotion has a special case to ignore interior mutability under some specific circumstances. The purpose of this PR is to figure out what changes if we remove that. Since `Cell::new` and friends only get promoted inside `const`/`static` initializers these days, it actually is not easy to exploit this case: you need something like
```rust
const TEST_INTERIOR_MUT: () = {
    // The "0." case is already ruled out by not permitting any interior mutability in `const`.
    let _val: &'static _ = &(Cell::new(1), 2).1;
};
```

I assume something like `&Some(&(Cell::new(1), 2).1)` would hit the nested case inside `validate_rvalue`... though I am not sure why that would not just trigger nested promotion, first promoting the inner reference and then the outer one?

Fixes https://github.com/rust-lang/rust/issues/67534 (by simply rejecting that code^^)

r? `@oli-obk` (but for now this is not meant to be merged!)
Cc `@rust-lang/wg-const-eval`
2020-12-09 09:13:54 +00:00