Suppress errors in const eval during trait selection

[b-naber]

Continues the work of #81339

Addressed most of the points that were raised in the previous PR. The main worry in the previous implementation was the duplication of query results that only differed in their Reveal type and the resulting duplication for on disk encoding, this should be solved by the current implementation.

On the other hand, this adds quite a bit of complexity, especially on the error reporting side, since cached errors with Reveal::Selection can now be used by Reveal::UserFacing to report an error. I'm not sure whether this is worth it (or whether this actually improves performance for that matter). Could also use better abstractions for hiding the deduplication logic in the trait selection code, but I'd like to wait for perf results before investing more time.

This needs a perf-run, if anybody reading this could request one that'd be great.

r? @oli-obk

cc @lcnr @RalfJung

[rust-highfive]

Some changes occured to the CTFE / Miri engine

cc @rust-lang/miri

Some changes occured to rustc_codegen_cranelift

cc @bjorn3

Some changes occured to the CTFE / Miri engine

cc @rust-lang/miri

[rust-log-analyzer]

The job mingw-check failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

configure: rust.debug-assertions := True
configure: rust.overflow-checks := True
configure: llvm.assertions      := True
configure: dist.missing-tools   := True
configure: build.configure-args := ['--enable-sccache', '--disable-manage-submodu ...
configure: writing `config.toml` in current directory
configure: 
configure: run `python /checkout/x.py --help`
configure: 
---
skip untracked path src/llvm-project/ during rustfmt invocations
Diff in /checkout/compiler/rustc_codegen_cranelift/src/constant.rs at line 65:
                             );
                         }
                         ErrorHandled::Silent(_) => {
-                            span_bug!(
-                                constant.span,
-                                "codegen encountered silent error",
-                            );
+                            span_bug!(constant.span, "codegen encountered silent error",);
                     }
                 }
                 }
Running `"/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/rustfmt" "--config-path" "/checkout" "--edition" "2018" "--unstable-features" "--skip-children" "--check" "/checkout/compiler/rustc_codegen_cranelift/src/pretty_clif.rs" "/checkout/compiler/rustc_codegen_cranelift/src/constant.rs" "/checkout/compiler/rustc_codegen_cranelift/src/unsize.rs" "/checkout/compiler/rustc_codegen_cranelift/src/trap.rs" "/checkout/compiler/rustc_codegen_cranelift/src/debuginfo/unwind.rs" "/checkout/compiler/rustc_codegen_cranelift/build_sysroot/src/lib.rs" "/checkout/compiler/rustc_codegen_cranelift/src/debuginfo/line_info.rs" "/checkout/compiler/rustc_codegen_cranelift/src/cast.rs"` failed.
If you're running `tidy`, try again with `--bless`. Or, if you just want to format code, run `./x.py fmt` instead.

[RalfJung]

@bors try @rust-timer queue Am 7. Januar 2022 20:06:36 UTC schrieb Rust Log Analyzer ***@***.***>: The job *|mingw-check|* failed! Check out the build log: (web) <https://github.com/rust-lang/rust/runs/4743106270?check_suite_focus=true> (plain) <https://github.com/rust-lang/rust/commit/614301aa25bb38ab392278db224958d73ad32058/checks/4743106270/logs> /Click to see the possible cause of the failure (guessed by this bot)/ |Checking cargo_metadata v0.14.0 Checking rustfix v0.5.1 Checking rustc-workspace-hack v1.0.0 (/checkout/src/tools/rustc-workspace-hack) Checking clippy_lints v0.1.59 (/checkout/src/tools/clippy/clippy_lints) error: hidden lifetime parameters in types are deprecated | | 137 | result: Result<ConstValue<'tcx>, ErrorHandled>, | ^^^^^^^^^^^^- help: indicate the anonymous lifetime: `<'_>` | = note: `-D elided-lifetimes-in-paths` implied by `-D warnings` error: could not compile `clippy_lints` due to previous error Build completed unsuccessfully in 0:03:53 | — Reply to this email directly, view it on GitHub <#92653 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACQXBFLUD7H7LIOXSKXEYDUU5BUZANCNFSM5LPP66BQ>. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit bbfaef6 with merge 7229268871b1d61e92f9b7c1e49da8560ab48bb7...

[bors]

☀️ Try build successful - checks-actions
Build commit: 7229268871b1d61e92f9b7c1e49da8560ab48bb7 (7229268871b1d61e92f9b7c1e49da8560ab48bb7)

[rust-timer]

Queued 7229268871b1d61e92f9b7c1e49da8560ab48bb7 with parent e012a19, future comparison URL.

[rust-timer]

Finished benchmarking commit (7229268871b1d61e92f9b7c1e49da8560ab48bb7): comparison url.

Summary: This change led to very large relevant mixed results 🤷 in compiler performance.

• Moderate improvement in instruction counts (up to -1.1% on incr-full builds of coercions)
• Very large regression in instruction counts (up to 12.0% on incr-full builds of issue-46449)

If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR led to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf +perf-regression

[b-naber]

Closing in favor of #92674