Internal Compiler Error in CTFE engine

[arturoc]

thread 'rustc' panicked at 'places should be checked on creation: InterpErrorInfo { kind: can't access mutable globals in ConstProp, backtrace: None }', src/librustc_mir/interpret/operand.rs:237:25
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/libunwind.rs:86
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:78
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:59
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1069
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1532
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:62
   7: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:49
   8: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:198
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:218
  10: rustc_driver::report_ice
  11: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:481
  12: rust_begin_unwind
             at src/libstd/panicking.rs:385
  13: core::panicking::panic_fmt
             at src/libcore/panicking.rs:89
  14: core::option::expect_none_failed
             at src/libcore/option.rs:1272
  15: rustc_mir::interpret::operand::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::try_read_immediate
  16: rustc_mir::interpret::step::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::eval_rvalue_into_place
  17: <rustc_mir::transform::const_prop::ConstPropagator as rustc_middle::mir::visit::MutVisitor>::visit_statement
  18: <rustc_mir::transform::const_prop::ConstPropagator as rustc_middle::mir::visit::MutVisitor>::visit_body
  19: <rustc_mir::transform::const_prop::ConstProp as rustc_mir::transform::MirPass>::run_pass
  20: rustc_mir::transform::run_passes
  21: rustc_mir::transform::run_optimization_passes
  22: rustc_mir::transform::optimized_mir
  23: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  24: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  25: rustc_query_system::query::plumbing::get_query
  26: rustc_mir::monomorphize::collector::collect_items_rec
  27: rustc_mir::monomorphize::collector::collect_items_rec
  28: rustc_mir::monomorphize::collector::collect_items_rec
  29: rustc_mir::monomorphize::collector::collect_items_rec
  30: rustc_mir::monomorphize::collector::collect_items_rec
  31: rustc_mir::monomorphize::collector::collect_items_rec
  32: rustc_mir::monomorphize::collector::collect_items_rec
  33: rustc_mir::monomorphize::collector::collect_items_rec
  34: rustc_session::utils::<impl rustc_session::session::Session>::time
  35: rustc_mir::monomorphize::collector::collect_crate_mono_items
  36: rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items
  37: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::collect_and_partition_mono_items>::compute
  38: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  39: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  40: rustc_query_system::query::plumbing::get_query
  41: rustc_codegen_ssa::base::codegen_crate
  42: <rustc_codegen_llvm::LlvmCodegenBackend as rustc_codegen_ssa::traits::backend::CodegenBackend>::codegen_crate
  43: rustc_interface::passes::start_codegen
  44: rustc_middle::ty::context::tls::enter_global
  45: rustc_interface::queries::Queries::ongoing_codegen
  46: rustc_interface::interface::run_compiler_in_existing_thread_pool
  47: scoped_tls::ScopedKey<T>::set
  48: rustc_ast::attr::with_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

error: internal compiler error: unexpected panic

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

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.45.0-nightly (fa51f810e 2020-04-29) running on x86_64-unknown-linux-gnu

note: compiler flags: -C opt-level=3 -C bitcode-in-rlib=no -C codegen-units=16 -C debuginfo=2 -C incremental -C link-arg=-fuse-ld=lld --crate-type lib

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [optimized_mir] processing `window::glfw_window::EventsPoll::new`
#1 [collect_and_partition_mono_items] collect_and_partition_mono_items
end of query stack

The specified method, EventsPoll::new looks like:

static mut GLFW: Option<glfw::Glfw> = None;
pub fn new() -> Result<EventsPoll>{
        //TODO: Give the option to choose FAIL / LOG?
        let glfw = unsafe{ if let Some(glfw) = GLFW {
            glfw
        }else{
            let glfw = glfw::init(glfw::LOG_ERRORS)
                .map_err(|e| util::Error::with_cause("Error initializing glfw", e))?;
            GLFW = Some(glfw);
            glfw
        }};

        Ok(EventsPoll( Arc::new( RwLock::new(EventsPollData{
            glfw,
            should_close: 1,
        }))))
}

might be related with the static mut?, but haven't tried to replicate it on a smaller example, will report back if i do so

[jonas-schievink]

cc @wesleywiser @felix91gr

Would be good to find out if this was caused by #71518, and to find an MCVE, so:

@rustbot ping cleanup

[rustbot]

Hey Cleanup Crew ICE-breakers! This bug has been identified as a good
"Cleanup ICE-breaking candidate". In case it's useful, here are some
instructions for tackling these sorts of bugs. Maybe take a look?
Thanks! <3

cc @AminArria @chrissimpkins @contrun @DutchGhost @elshize @ethanboxx @h-michael @HallerPatrick @hdhoang @hellow554 @imtsuki @jakevossen5 @kanru @KarlK90 @LeSeulArtichaut @MAdrianMattocks @matheus-consoli @mental32 @nmccarty @Noah-Kennedy @pard68 @PeytonT @pierreN @Redblueflame @RobbieClarken @RobertoSnap @robjtede @SarthakSingh31 @senden9 @shekohex @sinato @spastorino @turboladen @woshilapin @yerke

[felix91gr]

Imma try to bisect this, it's as good an opportunity as any to learn about it!

[wesleywiser]

@felix91gr here's a minimal example that is self-contained and shows the issue:

use std::sync::{Arc, RwLock};

#[derive(Copy, Clone)]
pub struct Glfw;

fn fun_call<T>(val: T) -> T { val }

static mut GLFW: Option<Glfw> = None;
pub fn new() -> Result<Arc<RwLock<Glfw>>, Box<dyn std::error::Error>> {
    //TODO: Give the option to choose FAIL / LOG?
    let glfw = unsafe { if let Some(glfw) = GLFW {
        glfw
    } else {
        let glfw = fun_call(Glfw);
        GLFW = Some(glfw);
        glfw
    }};

    Ok(Arc::new(RwLock::new(glfw)))
}

[felix91gr]

Bisect shows the ICE was introduced between the nightlies of the 26th (no ICE) and the 27th (ICE is present).

My pc is trying to find the particular commit still, but if that takes too long (like if it has to compile rustc (I have no idea, this is my first time bisecting)) I'll leave it to people with beefier computers :3

That said, @jonas-schievink I think you can at least rest assured-ish because our PR was merged on the 29th (according to Github).