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matthiaskrgr opened this issue Sep 27, 2023 · 3 comments · Fixed by #116239
Closed

ICE: gvn: node .. is not reachable #116212

matthiaskrgr opened this issue Sep 27, 2023 · 3 comments · Fixed by #116239
Labels
A-mir-opt Area: MIR optimizations C-bug Category: This is a bug. F-never_type `#![feature(never_type)]` I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.

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@matthiaskrgr
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Code

rustc -Zmir-opt-level=5

#![feature(never_type)]

use std::{
    mem::{self, MaybeUninit},
    num,
    ptr::NonNull,
};

struct Foo {
    x: u8,
    y: !,
}

#[repr(i32)]
enum ZeroIsValid {
    Zero(u8) = 0,
    One() = 1,
}

fn test_panic_msg<T, F: (FnOnce() -> T) + 'static>(op: F, msg: &str) {
    use std::{env, panic, process};

    let our_loc = panic::Location::caller().line().to_string();
    let mut args = env::args();

    if let Some(loc) = args.next() {
        if loc == our_loc {
            op();
        } else {
        }
    } else {
    }
}

fn main() {
    unsafe {
        test_panic_msg(
            || MaybeUninit::<Foo>::uninit().assume_init(),
            "attempted to instantiate uninhabited type `Foo`",
        );
    }
}

Meta

rustc --version --verbose:

rustc 1.74.0-nightly (e7c502d93 2023-09-27)
binary: rustc
commit-hash: e7c502d9309ae6bc6a9750514ba7fe397844e84c
commit-date: 2023-09-27
host: x86_64-unknown-linux-gnu
release: 1.74.0-nightly
LLVM version: 17.0.0

Error output

<output>
Backtrace 

warning: unused imports: `num`, `ptr::NonNull`, `self`
 --> panic-uninitialized-zeroed.rs:4:11
  |
4 |     mem::{self, MaybeUninit},
  |           ^^^^
5 |     num,
  |     ^^^
6 |     ptr::NonNull,
  |     ^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: unused import: `process`
  --> panic-uninitialized-zeroed.rs:21:27
   |
21 |     use std::{env, panic, process};
   |                           ^^^^^^^

warning: unused variable: `msg`
  --> panic-uninitialized-zeroed.rs:20:59
   |
20 | fn test_panic_msg<T, F: (FnOnce() -> T) + 'static>(op: F, msg: &str) {
   |                                                           ^^^ help: if this is intentional, prefix it with an underscore: `_msg`
   |
   = note: `#[warn(unused_variables)]` on by default

warning: fields `x` and `y` are never read
  --> panic-uninitialized-zeroed.rs:10:5
   |
9  | struct Foo {
   |        --- fields in this struct
10 |     x: u8,
   |     ^
11 |     y: !,
   |     ^
   |
   = note: `#[warn(dead_code)]` on by default

warning: enum `ZeroIsValid` is never used
  --> panic-uninitialized-zeroed.rs:15:6
   |
15 | enum ZeroIsValid {
   |      ^^^^^^^^^^^

warning: the type `Foo` does not permit being left uninitialized
  --> panic-uninitialized-zeroed.rs:38:16
   |
38 |             || MaybeUninit::<Foo>::uninit().assume_init(),
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this code causes undefined behavior when executed
   |
note: integers must be initialized (in this struct field)
  --> panic-uninitialized-zeroed.rs:10:5
   |
10 |     x: u8,
   |     ^^^^^
   = note: `#[warn(invalid_value)]` on by default

thread 'rustc' panicked at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/compiler/rustc_data_structures/src/graph/dominators/mod.rs:357:9:
node Time { start: 0, finish: 0 } is not reachable
stack backtrace:
   0:     0x7f66bd96427c - std::backtrace_rs::backtrace::libunwind::trace::h9181ffa9c3d4a750
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7f66bd96427c - std::backtrace_rs::backtrace::trace_unsynchronized::hbdccfdb9f54804b7
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f66bd96427c - std::sys_common::backtrace::_print_fmt::h30ee71b03bdebb9c
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/sys_common/backtrace.rs:67:5
   3:     0x7f66bd96427c - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h0280fcf2819eb75f
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f66bd9c9edc - core::fmt::rt::Argument::fmt::h38e0d2b510ca52ee
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/core/src/fmt/rt.rs:138:9
   5:     0x7f66bd9c9edc - core::fmt::write::h1e7ff4b258ae9fa6
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/core/src/fmt/mod.rs:1114:21
   6:     0x7f66bd956f0e - std::io::Write::write_fmt::h39163702b180fff1
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/io/mod.rs:1763:15
   7:     0x7f66bd964064 - std::sys_common::backtrace::_print::h64c13a11b52a9754
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f66bd964064 - std::sys_common::backtrace::print::h8d0e9a5a6da703be
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f66bd966f43 - std::panicking::default_hook::{{closure}}::hc24f34219b71e6f9
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/panicking.rs:272:22
  10:     0x7f66bd966c64 - std::panicking::default_hook::h16c43f2915765f3b
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/panicking.rs:292:9
  11:     0x7f66c0b0156f - std[1ca7f2df6b6ff2b1]::panicking::update_hook::<alloc[b3660cac06f40a66]::boxed::Box<rustc_driver_impl[51ab906ef6457130]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7f66bd967771 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h13ad871b7a2770ec
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/alloc/src/boxed.rs:2021:9
  13:     0x7f66bd967771 - std::panicking::rust_panic_with_hook::h3e798fc3ade5e233
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/panicking.rs:735:13
  14:     0x7f66bd9674f1 - std::panicking::begin_panic_handler::{{closure}}::hc91a6a16511779fa
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/panicking.rs:609:13
  15:     0x7f66bd9647a6 - std::sys_common::backtrace::__rust_end_short_backtrace::hbdfb1f15edc4e2e0
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/sys_common/backtrace.rs:170:18
  16:     0x7f66bd967242 - rust_begin_unwind
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/panicking.rs:597:5
  17:     0x7f66bd9c6565 - core::panicking::panic_fmt::h319347a3509c4d57
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/core/src/panicking.rs:72:14
  18:     0x7f66bf274646 - <rustc_data_structures[22ffc45ba6767646]::graph::dominators::Dominators<rustc_mir_transform[6e3c3be53b107f58]::coverage::graph::BasicCoverageBlock>>::dominates
  19:     0x7f66c121974a - <core[23641ef65c6f6c3a]::iter::adapters::copied::Copied<core[23641ef65c6f6c3a]::slice::iter::Iter<rustc_middle[8318e585d4f56aca]::mir::Local>> as core[23641ef65c6f6c3a]::iter::traits::iterator::Iterator>::try_fold::<(), core[23641ef65c6f6c3a]::iter::traits::iterator::Iterator::find::check<rustc_middle[8318e585d4f56aca]::mir::Local, <rustc_mir_transform[6e3c3be53b107f58]::gvn::VnState>::try_as_local::{closure#0}>::{closure#0}, core[23641ef65c6f6c3a]::ops::control_flow::ControlFlow<rustc_middle[8318e585d4f56aca]::mir::Local>>
  20:     0x7f66c126baaa - <rustc_mir_transform[6e3c3be53b107f58]::gvn::VnState>::try_as_local
  21:     0x7f66c126dc14 - <rustc_mir_transform[6e3c3be53b107f58]::gvn::VnState>::simplify_place_value
  22:     0x7f66c126deba - <rustc_mir_transform[6e3c3be53b107f58]::gvn::VnState>::simplify_operand
  23:     0x7f66c1286ac3 - <rustc_mir_transform[6e3c3be53b107f58]::ssa::SsaLocals>::for_each_assignment_mut::<rustc_mir_transform[6e3c3be53b107f58]::gvn::propagate_ssa::{closure#0}>
  24:     0x7f66c126cc1b - <rustc_mir_transform[6e3c3be53b107f58]::gvn::GVN as rustc_middle[8318e585d4f56aca]::mir::MirPass>::run_pass
  25:     0x7f66bfc03261 - rustc_mir_transform[6e3c3be53b107f58]::pass_manager::run_passes
  26:     0x7f66bfc02903 - rustc_mir_transform[6e3c3be53b107f58]::optimized_mir
  27:     0x7f66bec7cdb8 - rustc_query_impl[13a0a52e862e93eb]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[13a0a52e862e93eb]::query_impl::optimized_mir::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8318e585d4f56aca]::query::erase::Erased<[u8; 8usize]>>
  28:     0x7f66bec7cd81 - <rustc_query_impl[13a0a52e862e93eb]::query_impl::optimized_mir::dynamic_query::{closure#2} as core[23641ef65c6f6c3a]::ops::function::FnOnce<(rustc_middle[8318e585d4f56aca]::ty::context::TyCtxt, rustc_span[ebfafd642cc98e77]::def_id::DefId)>>::call_once
  29:     0x7f66bec496c0 - rustc_query_system[bec01fb9f9ecbd97]::query::plumbing::try_execute_query::<rustc_query_impl[13a0a52e862e93eb]::DynamicConfig<rustc_query_system[bec01fb9f9ecbd97]::query::caches::DefaultCache<rustc_span[ebfafd642cc98e77]::def_id::DefId, rustc_middle[8318e585d4f56aca]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[13a0a52e862e93eb]::plumbing::QueryCtxt, false>
  30:     0x7f66c046f452 - rustc_query_impl[13a0a52e862e93eb]::query_impl::optimized_mir::get_query_non_incr::__rust_end_short_backtrace
  31:     0x7f66bf00db30 - <rustc_middle[8318e585d4f56aca]::ty::context::TyCtxt>::instance_mir
  32:     0x7f66bf8c7e82 - rustc_monomorphize[2491d3894988c5a0]::collector::collect_used_items
  33:     0x7f66bf8c5255 - rustc_monomorphize[2491d3894988c5a0]::collector::collect_items_rec
  34:     0x7f66bf8c5744 - rustc_monomorphize[2491d3894988c5a0]::collector::collect_items_rec
  35:     0x7f66bf8c5744 - rustc_monomorphize[2491d3894988c5a0]::collector::collect_items_rec
  36:     0x7f66bffeaf88 - rustc_data_structures[22ffc45ba6767646]::sync::parallel::disabled::par_for_each_in::<alloc[b3660cac06f40a66]::vec::Vec<rustc_middle[8318e585d4f56aca]::mir::mono::MonoItem>, rustc_monomorphize[2491d3894988c5a0]::collector::collect_crate_mono_items::{closure#1}::{closure#0}>
  37:     0x7f66bffea320 - <rustc_session[f5e7ce946b8d9f8]::session::Session>::time::<(), rustc_monomorphize[2491d3894988c5a0]::collector::collect_crate_mono_items::{closure#1}>
  38:     0x7f66bffe9f68 - rustc_monomorphize[2491d3894988c5a0]::collector::collect_crate_mono_items
  39:     0x7f66bffe8538 - rustc_monomorphize[2491d3894988c5a0]::partitioning::collect_and_partition_mono_items
  40:     0x7f66c00f8449 - rustc_query_impl[13a0a52e862e93eb]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[13a0a52e862e93eb]::query_impl::collect_and_partition_mono_items::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8318e585d4f56aca]::query::erase::Erased<[u8; 24usize]>>
  41:     0x7f66c00f841d - <rustc_query_impl[13a0a52e862e93eb]::query_impl::collect_and_partition_mono_items::dynamic_query::{closure#2} as core[23641ef65c6f6c3a]::ops::function::FnOnce<(rustc_middle[8318e585d4f56aca]::ty::context::TyCtxt, ())>>::call_once
  42:     0x7f66c026de27 - rustc_query_system[bec01fb9f9ecbd97]::query::plumbing::try_execute_query::<rustc_query_impl[13a0a52e862e93eb]::DynamicConfig<rustc_query_system[bec01fb9f9ecbd97]::query::caches::SingleCache<rustc_middle[8318e585d4f56aca]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[13a0a52e862e93eb]::plumbing::QueryCtxt, false>
  43:     0x7f66c048b652 - rustc_query_impl[13a0a52e862e93eb]::query_impl::collect_and_partition_mono_items::get_query_non_incr::__rust_end_short_backtrace
  44:     0x7f66bfcbe1eb - rustc_codegen_ssa[73e439ced0d37bbc]::base::codegen_crate::<rustc_codegen_llvm[e32e01179d21c37e]::LlvmCodegenBackend>
  45:     0x7f66bfcbdfef - <rustc_codegen_llvm[e32e01179d21c37e]::LlvmCodegenBackend as rustc_codegen_ssa[73e439ced0d37bbc]::traits::backend::CodegenBackend>::codegen_crate
  46:     0x7f66c00502a2 - <rustc_session[f5e7ce946b8d9f8]::session::Session>::time::<alloc[b3660cac06f40a66]::boxed::Box<dyn core[23641ef65c6f6c3a]::any::Any>, rustc_interface[442ada56983741ed]::passes::start_codegen::{closure#0}>
  47:     0x7f66c004fdfb - rustc_interface[442ada56983741ed]::passes::start_codegen
  48:     0x7f66c004a63a - <rustc_middle[8318e585d4f56aca]::ty::context::GlobalCtxt>::enter::<<rustc_interface[442ada56983741ed]::queries::Queries>::ongoing_codegen::{closure#0}, core[23641ef65c6f6c3a]::result::Result<alloc[b3660cac06f40a66]::boxed::Box<dyn core[23641ef65c6f6c3a]::any::Any>, rustc_span[ebfafd642cc98e77]::ErrorGuaranteed>>
  49:     0x7f66c00494ed - rustc_span[ebfafd642cc98e77]::set_source_map::<core[23641ef65c6f6c3a]::result::Result<(), rustc_span[ebfafd642cc98e77]::ErrorGuaranteed>, rustc_interface[442ada56983741ed]::interface::run_compiler<core[23641ef65c6f6c3a]::result::Result<(), rustc_span[ebfafd642cc98e77]::ErrorGuaranteed>, rustc_driver_impl[51ab906ef6457130]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  50:     0x7f66c0044070 - std[1ca7f2df6b6ff2b1]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[442ada56983741ed]::util::run_in_thread_with_globals<rustc_interface[442ada56983741ed]::interface::run_compiler<core[23641ef65c6f6c3a]::result::Result<(), rustc_span[ebfafd642cc98e77]::ErrorGuaranteed>, rustc_driver_impl[51ab906ef6457130]::run_compiler::{closure#1}>::{closure#0}, core[23641ef65c6f6c3a]::result::Result<(), rustc_span[ebfafd642cc98e77]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[23641ef65c6f6c3a]::result::Result<(), rustc_span[ebfafd642cc98e77]::ErrorGuaranteed>>
  51:     0x7f66c035d67e - <<std[1ca7f2df6b6ff2b1]::thread::Builder>::spawn_unchecked_<rustc_interface[442ada56983741ed]::util::run_in_thread_with_globals<rustc_interface[442ada56983741ed]::interface::run_compiler<core[23641ef65c6f6c3a]::result::Result<(), rustc_span[ebfafd642cc98e77]::ErrorGuaranteed>, rustc_driver_impl[51ab906ef6457130]::run_compiler::{closure#1}>::{closure#0}, core[23641ef65c6f6c3a]::result::Result<(), rustc_span[ebfafd642cc98e77]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[23641ef65c6f6c3a]::result::Result<(), rustc_span[ebfafd642cc98e77]::ErrorGuaranteed>>::{closure#1} as core[23641ef65c6f6c3a]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  52:     0x7f66bd9722d5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::habd582f39dd9789c
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/alloc/src/boxed.rs:2007:9
  53:     0x7f66bd9722d5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h6aa0cee9365e9c12
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/alloc/src/boxed.rs:2007:9
  54:     0x7f66bd9722d5 - std::sys::unix::thread::Thread::new::thread_start::ha6c33fae81256bd2
                               at /rustc/e7c502d9309ae6bc6a9750514ba7fe397844e84c/library/std/src/sys/unix/thread.rs:108:17
  55:     0x7f66bd68c9eb - <unknown>
  56:     0x7f66bd710dfc - <unknown>
  57:                0x0 - <unknown>

error: 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: please attach the file at `/tmp/im/icemaker_reduced/rustc-ice-2023-09-27T23:11:02.462425041Z-1940717.txt` to your bug report

note: compiler flags: -Z mir-opt-level=5

query stack during panic:
#0 [optimized_mir] optimizing MIR for `main::{closure#0}`
#1 [collect_and_partition_mono_items] collect_and_partition_mono_items
end of query stack
warning: 6 warnings emitted

@matthiaskrgr matthiaskrgr added I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. C-bug Category: This is a bug. F-never_type `#![feature(never_type)]` A-mir-opt Area: MIR optimizations labels Sep 27, 2023
@rustbot rustbot added the needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. label Sep 27, 2023
@matthiaskrgr
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#109597 cc @cjgillot

@matthiaskrgr
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reduced further:

#![feature(never_type)]

use std::mem::MaybeUninit;

struct Foo {
    x: u8,
    y: !,
}

fn test_panic_msg<T, F: (FnOnce() -> T) + 'static>(op: F) {
    op();
}

fn main() {
    unsafe {
        test_panic_msg(|| MaybeUninit::<Foo>::uninit().assume_init());
    }
}

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@matthiaskrgr

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@saethlin saethlin removed the needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. label Sep 28, 2023
@cjgillot cjgillot mentioned this issue Sep 28, 2023
Merged
@bors bors closed this as completed in 4f09f80 Sep 29, 2023
rust-timer added a commit to rust-lang-ci/rust that referenced this issue Sep 29, 2023
@rust-timer
Unrolled build for rust-lang#116239
191dc88 
Rollup merge of rust-lang#116239 - cjgillot:issue-116212, r=WaffleLapkin

Only visit reachable nodes in SsaLocals.

Fixes rust-lang#116212
RalfJung pushed a commit to RalfJung/miri that referenced this issue Sep 30, 2023
@matthiaskrgr
Rollup merge of #116239 - cjgillot:issue-116212, r=WaffleLapkin
3ced56b 
Only visit reachable nodes in SsaLocals.

Fixes rust-lang/rust#116212
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A-mir-opt Area: MIR optimizations C-bug Category: This is a bug. F-never_type `#![feature(never_type)]` I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.
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Only visit reachable nodes in SsaLocals. cjgillot/rust
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