Rustup to rustc 1.42.0-nightly (005cf38f7 2019-12-22)

[oli-obk]

No description provided.

[RalfJung]

@bors r+

[bors]

📌 Commit c335eca has been approved by RalfJung

[bors]

⌛ Testing commit c335eca with merge d7871e5...

[bors]

💔 Test failed - status-appveyor

[oli-obk]

We're hitting https://github.com/rust-lang/rust/blob/3982d3514efbb65b3efac6bb006b3fa496d16663/src/librustc_mir/interpret/place.rs#L533 now

Probably https://github.com/solson/miri/blob/87f20fede528a2a99c06e6aae480adac91f5ecc2/tests/run-pass/vec-matching-fold.rs#L12

[oli-obk]

I can't figure out how to build a self-contained const eval repro :(

[RalfJung]

I don't understand that assertion anyway... why does it make any sense?

[oli-obk]

I don't understand that assertion anyway... why does it make any sense?

Good question, I haven't looked into it at all yet.

[bjorn3]

When using for example:

match &[0, 1] as &[u8] {
    [x, y, a @ ..] => {}
    _ => {}
}

There will be a _4 = &(*_1)[0 of 2]; for x. This is equivalent to ConstantIndex { offset: 0, min_length: 2, from_end: false }. The assertion says that the offset must be less than min_length. So for example _4 = &(*_1)[2 of 2]; would not be allowed.

[oli-obk]

Thanks, I now have a minimal repro that works on just nightly without miri

#![feature(slice_patterns)]

fn main() {
    match &[0, 1] as &[i32] {
        [a @ .., x] => {}
        &[] => {}
    }
}

Since from_end is true, the index is 1 and min_length is also 1 because a could be empty for all the pattern knows.

[oli-obk]

Fix PR: rust-lang/rust#67546

[bors]

☔ The latest upstream changes (presumably #1118) made this pull request unmergeable. Please resolve the merge conflicts.

[RalfJung]

@bors r+

[bors]

📌 Commit 1ffa62f has been approved by RalfJung

[bors]

⌛ Testing commit 1ffa62f with merge 5744aea...

[bors]

💔 Test failed - status-appveyor

[RalfJung]

@bors r+
(can't test locally as the toolchain download takes hours despite my 50 MBit/s connection :/ stupid AWS )

[bors]

📌 Commit bac2615 has been approved by RalfJung

[bors]

⌛ Testing commit bac2615 with merge b1e97df...

[bors]

☀️ Test successful - checks-travis, status-appveyor
Approved by: RalfJung
Pushing b1e97df to master...