Misusing rustc_strict_coherence doesn't need to be an ICE

[jruderman]

I would prefer for this to produce a normal error instead of an ICE, because ICEs drastically slow down the fuzzer (at least with the way I'm using libfuzzer and a large corpus).

Code

#![feature(rustc_attrs)]
#[rustc_strict_coherence]
trait Foo {}
fn main() {}

Output

error: internal compiler error: compiler/rustc_middle/src/traits/specialization_graph.rs:69:13: To use strict_coherence you need to set with_negative_coherence feature flag

Full output with backtrace

error: internal compiler error: compiler/rustc_middle/src/traits/specialization_graph.rs:69:13: To use strict_coherence you need to set with_negative_coherence feature flag

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/0da281b6068a7d889ae89a9bd8991284cc9b7535/compiler/rustc_errors/src/lib.rs:1519:9
stack backtrace:
   0:        0x103c578a2 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h98e7719cdb057d8f
   1:        0x103caf74a - core::fmt::write::he324e6f3a7ef7ed0
   2:        0x103c4997c - std::io::Write::write_fmt::h295c914c323e508a
   3:        0x103c5766a - std::sys_common::backtrace::print::hb2f2bd76d0a1d9b2
   4:        0x103c5aa76 - std::panicking::default_hook::{{closure}}::h7f2a23a911934152
   5:        0x103c5a7c7 - std::panicking::default_hook::h576cf5867894044c
   6:        0x10e35b62d - rustc_driver[ba5c792b9438c2b]::DEFAULT_HOOK::{closure#0}::{closure#0}
   7:        0x103c5b271 - std::panicking::rust_panic_with_hook::hf0781b554a936fbf
   8:        0x112a47427 - std[8878bd7dd366d71b]::panicking::begin_panic::<rustc_errors[b0e16a209d58ca7d]::ExplicitBug>::{closure#0}
   9:        0x112a46d09 - std[8878bd7dd366d71b]::sys_common::backtrace::__rust_end_short_backtrace::<std[8878bd7dd366d71b]::panicking::begin_panic<rustc_errors[b0e16a209d58ca7d]::ExplicitBug>::{closure#0}, !>
  10:        0x1130ee929 - std[8878bd7dd366d71b]::panicking::begin_panic::<rustc_errors[b0e16a209d58ca7d]::ExplicitBug>
  11:        0x112a46cf9 - std[8878bd7dd366d71b]::panic::panic_any::<rustc_errors[b0e16a209d58ca7d]::ExplicitBug>
  12:        0x112a44f4c - <rustc_errors[b0e16a209d58ca7d]::HandlerInner>::bug::<&alloc[b73bea5876e24fb]::string::String>
  13:        0x112a446d7 - <rustc_errors[b0e16a209d58ca7d]::Handler>::bug::<&alloc[b73bea5876e24fb]::string::String>
  14:        0x112b84a72 - rustc_middle[298407787cc28eff]::ty::context::tls::with_context_opt::<rustc_middle[298407787cc28eff]::ty::context::tls::with_opt<rustc_middle[298407787cc28eff]::util::bug::opt_span_bug_fmt<rustc_span[73e074df7cba0abf]::span_encoding::Span>::{closure#0}, ()>::{closure#0}, ()>
  15:        0x112b86b71 - rustc_middle[298407787cc28eff]::util::bug::opt_span_bug_fmt::<rustc_span[73e074df7cba0abf]::span_encoding::Span>
  16:        0x1130f023e - rustc_middle[298407787cc28eff]::util::bug::bug_fmt
  17:        0x112bf9016 - <rustc_middle[298407787cc28eff]::traits::specialization_graph::OverlapMode>::get
  18:        0x110de7541 - rustc_hir_analysis[3f5a3f8b91adb05]::coherence::inherent_impls_overlap::crate_inherent_impls_overlap_check
  19:        0x111bda4a9 - rustc_query_system[fd3d689380a50de4]::query::plumbing::try_execute_query::<rustc_query_impl[f77634870212a75e]::plumbing::QueryCtxt, rustc_query_system[fd3d689380a50de4]::query::caches::DefaultCache<(), ()>>
  20:        0x111c44d09 - rustc_query_system[fd3d689380a50de4]::query::plumbing::get_query::<rustc_query_impl[f77634870212a75e]::queries::crate_inherent_impls_overlap_check, rustc_query_impl[f77634870212a75e]::plumbing::QueryCtxt>
  21:        0x110dbf344 - <rustc_session[43d2d941ace548e5]::session::Session>::track_errors::<rustc_hir_analysis[3f5a3f8b91adb05]::check_crate::{closure#3}, ()>
  22:        0x110d6e313 - rustc_hir_analysis[3f5a3f8b91adb05]::check_crate
  23:        0x10e433fda - rustc_interface[a666f6d755ed9279]::passes::analysis
  24:        0x111bcc26c - rustc_query_system[fd3d689380a50de4]::query::plumbing::try_execute_query::<rustc_query_impl[f77634870212a75e]::plumbing::QueryCtxt, rustc_query_system[fd3d689380a50de4]::query::caches::DefaultCache<(), core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>>>
  25:        0x111c463f9 - rustc_query_system[fd3d689380a50de4]::query::plumbing::get_query::<rustc_query_impl[f77634870212a75e]::queries::analysis, rustc_query_impl[f77634870212a75e]::plumbing::QueryCtxt>
  26:        0x10e2ea296 - <rustc_interface[a666f6d755ed9279]::passes::QueryContext>::enter::<rustc_driver[ba5c792b9438c2b]::run_compiler::{closure#1}::{closure#2}::{closure#3}, core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>>
  27:        0x10e32ea4d - rustc_span[73e074df7cba0abf]::with_source_map::<core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>, rustc_interface[a666f6d755ed9279]::interface::run_compiler<core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>, rustc_driver[ba5c792b9438c2b]::run_compiler::{closure#1}>::{closure#0}::{closure#1}>
  28:        0x10e31e34c - <scoped_tls[c17fceff1b2b43d8]::ScopedKey<rustc_span[73e074df7cba0abf]::SessionGlobals>>::set::<rustc_interface[a666f6d755ed9279]::interface::run_compiler<core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>, rustc_driver[ba5c792b9438c2b]::run_compiler::{closure#1}>::{closure#0}, core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>>
  29:        0x10e2ede5a - std[8878bd7dd366d71b]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[a666f6d755ed9279]::util::run_in_thread_pool_with_globals<rustc_interface[a666f6d755ed9279]::interface::run_compiler<core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>, rustc_driver[ba5c792b9438c2b]::run_compiler::{closure#1}>::{closure#0}, core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>>
  30:        0x10e2d3f7b - <<std[8878bd7dd366d71b]::thread::Builder>::spawn_unchecked_<rustc_interface[a666f6d755ed9279]::util::run_in_thread_pool_with_globals<rustc_interface[a666f6d755ed9279]::interface::run_compiler<core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>, rustc_driver[ba5c792b9438c2b]::run_compiler::{closure#1}>::{closure#0}, core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[13371b8ce97f01bb]::result::Result<(), rustc_errors[b0e16a209d58ca7d]::ErrorGuaranteed>>::{closure#1} as core[13371b8ce97f01bb]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  31:        0x103c64387 - std::sys::unix::thread::Thread::new::thread_start::hfd54df40dd14130e
  32:     0x7ff814d514e1 - __pthread_start

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.66.0-nightly (0da281b60 2022-10-27) running on x86_64-apple-darwin

query stack during panic:
#0 [crate_inherent_impls_overlap_check] check for overlap between inherent impls defined in this crate
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error

Version

rustc 1.66.0-nightly (0da281b60 2022-10-27)
binary: rustc
commit-hash: 0da281b6068a7d889ae89a9bd8991284cc9b7535
commit-date: 2022-10-27
host: x86_64-apple-darwin
release: 1.66.0-nightly
LLVM version: 15.0.2