Deny the overflowing_literals lint for all editions

[ollie27]

The overflowing_literals was made deny by default for the 2018 edition by #54507, however I'm not aware of any reason it can't be made deny by default for the 2015 edition as well.

[rust-highfive]

r? @nikomatsakis

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[rust-highfive]

The job x86_64-gnu-llvm-5.0 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

travis_time:end:0de321d0:start=1541197078263157112,finish=1541197137001122189,duration=58737965077
$ git checkout -qf FETCH_HEAD
travis_fold:end:git.checkout

Encrypted environment variables have been removed for security reasons.
See https://docs.travis-ci.com/user/pull-requests/#Pull-Requests-and-Security-Restrictions
$ export SCCACHE_BUCKET=rust-lang-ci-sccache2
$ export SCCACHE_REGION=us-west-1
Setting environment variables from .travis.yml
$ export IMAGE=x86_64-gnu-llvm-5.0
---
[00:51:22] .................................................................................................... 100/4983
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[00:51:48] ..................................................................i...........i..................... 800/4983
[00:51:51] ....................................................................................iiiii........... 900/4983
[00:51:55] .................................................................................................... 1000/4983
---
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[00:52:50] ..................................................................iiiiiiiii......................... 2600/4983
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[00:53:04] .................................................................................................... 3000/4983
[00:53:07] .............i...................................................................................... 3100/4983
---
travis_time:start:test_codegen
Check compiletest suite=codegen mode=codegen (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
[01:06:55] 
[01:06:55] running 115 tests
[01:06:58] i..ii...iii..iii.....i...i.........i..iii...........i.....i.....ii...i..i.ii..............i...ii..ii 100/115
[01:06:58] .i....iiii.....
[01:06:58] 
[01:06:58]  finished in 3.577
[01:06:58] travis_fold:end:test_codegen

---
travis_time:start:test_debuginfo
Check compiletest suite=debuginfo mode=debuginfo-both (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
[01:07:13] 
[01:07:13] running 118 tests
[01:07:38] .iiiii...i.....i..i...i..i.i..i.i..i.....i..i....i..........iiii.........i.i....i...i.......ii.i.i.i 100/118
[01:07:42] ......iii.i.....ii
[01:07:42] 
[01:07:42]  finished in 28.620
[01:07:42] travis_fold:end:test_debuginfo

---
[01:42:30] 
[01:42:30] failures:
[01:42:30] 
[01:42:30] ---- /checkout/src/doc/rustc/src/lints/listing/warn-by-default.md - Warn_by_default_lints::overflowing_literals (line 293) stdout ----
[01:42:30] error: literal out of range for u8
[01:42:30]   |
[01:42:30]   |
[01:42:30] 3 | let x: u8 = 1000;
[01:42:30]   |
[01:42:30]   = note: #[deny(overflowing_literals)] on by default
[01:42:30] 
[01:42:30] thread '/checkout/src/doc/rustc/src/lints/listing/warn-by-default.md - Warn_by_default_lints::overflowing_literals (line 293)' panicked at 'couldn't compile the test', librustdoc/test.rs:332:13
---
[01:42:30] 
[01:42:30] 
[01:42:30] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[01:42:30] Build completed unsuccessfully in 0:54:59
[01:42:30] Makefile:58: recipe for target 'check' failed
[01:42:30] make: *** [check] Error 1
3552496 ./obj
3406820 ./obj/build
2767728 ./obj/build/x86_64-unknown-linux-gnu
1195164 ./.git
---
163176 ./.git/modules/src/tools/lldb/objects
163168 ./.git/modules/src/tools/lldb/objects/pack
151412 ./src/tools/clang
150348 ./obj/build/bootstrap/debug/incremental
149112 ./src/llvm-emscripte"$EXE" ]; then printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" "$CORE"; gdb --batch -q -c "$CORE" "$EXE" -iex 'set auto-load off' -iex 'dir src/' -iex 'set sysroot .' -ex bt -ex q; echo travis_fold":"end:crashlog; fi; done || true

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[nikomatsakis]

Nominating for @rust-lang/lang team discussion -- do we want to do this, and -- if so -- what procedure is required? My guess is "yes", we do want to, but we need at least an FCP, and maybe a crater run to assess overall impact?

[nikomatsakis]

Or perhaps that was done already, I forget?

[Centril]

@nikomatsakis I don't recall any crater run being done; I did some looking around and couldn't find any such run so I think it wasn't done. To be on the safe side I think we need at least such a crater run to be done.

I think if crater shows up 0 or some very very low number then it could be feasible.

[scottmcm]

I still want this, and we can do it regardless of crater because it's just a lint level.

Obviously running a crater run for it is nice -- and is relatively cheap, since it's just a check run with -Doverflowing_literals -- but I feel like any code we're really worried about that's doing this is probably already allowing the lint, so changing the default level wouldn't break them anyway.

[aturon]

We discussed this in the lang team meeting today. Generally everyone is in favor, but we would like to see a crater run just to assess whether it'd be helpful to adjust some key crates before this gets fully rolled out.

[aturon]

@bors try

[bors]

⌛ Trying commit b049141773332c40635f9da831beb9e81d6387db with merge dc13be39fae8d4c607889b27de374b52586485a3...

[bors]

☀️ Test successful - status-travis
State: approved= try=True

[Mark-Simulacrum]

@craterbot run start=master#653da4fd006c97625247acd7e076d0782cdc149b end=try#dc13be39fae8d4c607889b27de374b52586485a3 mode=check-only

I think this should be the right config but not entirely certain (lints are odd, sometimes). Crater queue is empty anyway.

[craterbot]

👌 Experiment pr-55632 created and queued.
🔍 You can check out the queue and this experiment's details.

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[craterbot]

🚧 Experiment pr-55632 is now running on agent aws-2.

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[craterbot]

🎉 Experiment pr-55632 is completed!
📰 Open the full report.

⚠️ If you notice any spurious failure please add them to the blacklist!
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[ollie27]

32 regressions. 2 were spurious:

• indiv0.colonize.9c580424ebb2deb88aa0eff7cfcbf9ac49ccac8b
• pierrechevalier83.chess-rs.cb808de3ce3728138286d989a70d00ef2c3f8468

20 are bugs in the crates and code that the compiler should never have accepted in the first place:

• iryna-0.1.4
• ozone-0.1.0
• pdf-extract-0.4.6
• pnetlink-0.0.3
• way-cooler-background-0.1.0
• way-cooler-bg-0.2.1
• wc-bg-0.3.0
• BigTuna08.rustyIMGs.d9e4e713cde687a1d90ff6f322c40e8745b68d37
• Damezuma.rust-realtime-chat.b87eab7e4ce199927b2b8c334e330055e33f9d33
• IHultman.Idea.0bb6753884a9fa5635b1e049f9300936767f2009
• Niedzwiedzw.dummy-i2c-rust.b726623e759e33702ac0087d322abcee16b4a68a
• fChristenson.nes-emulator.522c12dc9b70240911959eb1abd505dca2d93bae
• ikurek.PEA-Projekt2.a69ecf369221768be633c1af62fefbce2b28ec9a
• ioncodes.Xiu.a645fadb116de275c2a9af8e76d6001a58d2156b
• ishanjain28.pulseaudio-dlna.708f0e8159463bdbedb23d26965662505b3fcc03
• kodipe.website.00a5428f80e683e7d50aeff27502c3b20695a8f8
• linde12.chip8.cbff4529fb7e76758a14ae835e8243a2aa01e91b
• nzsc-org.nzsc_single_player_cli.9e73d05c5a5a82d2342a460c592bdc40383484da
• sebglazebrook.ping-rs.b4208ffff37cdfcdf8671ef369f10e4d498c79b8
• way-cooler.way-cooler-bg.9dde66b52f4f113ce8721a5b6ad4dd8e42049f1d

10 are hex or binary signed literals that could be considered false positives (#24361):

• dmx-termios-0.3.0
• elftools-0.1.0
• http-box-0.1.5
• wdg-base64-0.4.7
• BProg.des_chipher_rust.eee15a535be9988a131fe5195e26bd305e26efb6
• GChicha.RustBoy.0fbe3b6d145b6083bd2cebdd3fcca00631c21112
• NishanthSpShetty.Stack-VM.171b03b1ab3655798c0f969124f58efb1f4cb425
• Vallium.rubik-rs.ad968e6d79a90c2c9763786d8dac3d58ab1248e7
• excelciordan.rust_float_pt.9bf5ad5f346d7354940b8ccb3e7026f9f60eced1
• javierbg.DaMaGed.4c416b7e035fb9a5bdaaa4c734033d307eb2c162

At least it's clear that we need to make overflowing literals a hard error at some point, at least for decimal and for binary and hex when you specify too many bits.

[Centril]

@ollie27 could you reach out to affected regressed crates (with PRs perhaps) so that we can move ahead?

[Centril]

Failed in rollup #58637, @bors r-

[ollie27]

That should be fixed now.

[Centril]

@bors r+

[bors]

📌 Commit e7296fd has been approved by Centril

[BurntSushi]

FWIW, this broke byteorder's test suite. It looks like many of its doc tests were (incorrectly) using overflowing literals. I don't set allow(overflowing_literals), but it looks like lint errors aren't reported via cargo test --doc, so I didn't even know anything was wrong.

Obviously, I will just fix the doc tests here, but I'm curious why this change was made in Rust 2015. The original RFC seems to target Rust 2018, probably because this is a breaking change, no? Have we converted lints to deny before?

More pragmatically, there may be other breakage in the ecosystem that is being missed because it seems like the initial crater run didn't catch this.

[Mark-Simulacrum]

FWIW we can probably do another crater run in rustdoc mode (I think that'll catch the lint errors, but not sure). How did you notice that it was broken?

[BurntSushi]

@Dylan-DPC did a crater run: BurntSushi/byteorder#144

I'm not too familiar with crater and what it can and can't catch, so I'm not sure why it wasn't caught before. But if there's a rustdoc mode, then that might explain things.

I also usually have daily cron jobs setup on CI, but it wasn't enabled for byteorder. I added that back in, so that would have caught it too once the new nightly was released.

[BurntSushi]

I think #41574 would have helped catch the bug on my end as soon as the overflowing literal made it into the doc test.

[Mark-Simulacrum]

Yeah, that would've been the beta crater run -- interestingly, not the rustdoc mode. (https://crater-reports.s3.amazonaws.com/beta-1.34-1/beta-2019-02-27/reg/byteorder-1.2.7/log.txt is the relevant log).

I think crater presumably invokes rustdoc with that flag? Not sure why it wasn't caught in crater on this PR though.