ICE: '!impl_self_ty.has_infer_types()' in MIR from const underneath impl<T> { ... }

[mexus]

I tried this code:

struct TestStruct<T>(T);

impl<T> TestStruct<T> {
    const SOME_CONST: u8 = 1;

    fn call(&mut self) {
        let item = self.0;
        something(&item, &Self::SOME_CONST);
    }
}

fn something<T1, T2>(_: T1, _: T2) {
    unimplemented!()
}

I expected to see this happen: cannot move out of borrowed content for the let item = self.0; line..

Instead, this happened:

thread 'main' panicked at 'assertion failed: !impl_self_ty.has_infer_types()', librustc_mir/borrow_check/nll/type_check/mod.rs:1033:21                                    
note: Run with `RUST_BACKTRACE=1` for a backtrace.                                                                                                                        
                                                                                                                                                                          
error: internal compiler error: unexpected panic                                                                                                                          

I also tried CARGO_INCREMENTAL=0 but it didn't affect the build (apart from the -C incremental argument to disappear).

My rust version:

rustc 1.31.0-nightly (424a749a0 2018-10-21)
binary: rustc
commit-hash: 424a749a01224239ba2c8850f16007d57db0a242
commit-date: 2018-10-21
host: x86_64-unknown-linux-gnu
release: 1.31.0-nightly
LLVM version: 8.0

Here's a run with backtrace enabled:

     Running `rustc --crate-name ice src/lib.rs --color always --crate-type lib --emit=dep-info,metadata -C debuginfo=2 -C metadata=2a9b80ba2717f3bb -C extra-filename=-2a9b80ba2717f3bb --out-dir /home/mexus/test/rust/ice/target/debug/deps -C incremental=/home/mexus/test/rust/ice/target/debug/incremental -L dependency=/home/mexus/test/rust/ice/target/debug/deps`
thread 'main' panicked at 'assertion failed: !impl_self_ty.has_infer_types()', librustc_mir/borrow_check/nll/type_check/mod.rs:1033:21                                    
stack backtrace:                                                                                                                                                          
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace                                                                                                           
             at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49                                                                                                             
   1: std::sys_common::backtrace::print                                                                                                                                   
             at libstd/sys_common/backtrace.rs:71                                                                                                                         
             at libstd/sys_common/backtrace.rs:59                                                                                                                         
   2: std::panicking::default_hook::{{closure}}                                                                                                                           
             at libstd/panicking.rs:211                                                                                                                                   
   3: std::panicking::default_hook                                                                                                                                        
             at libstd/panicking.rs:227                                                                                                                                   
   4: rustc::util::common::panic_hook                                                                                                                                     
   5: std::panicking::rust_panic_with_hook                                                                                                                                
             at libstd/panicking.rs:480                                                                                                                                   
   6: std::panicking::begin_panic                                                                                                                                         
   7: rustc_mir::borrow_check::nll::type_check::TypeChecker::relate_type_and_user_type                                                                                    
   8: <rustc_mir::borrow_check::nll::type_check::TypeVerifier<'a, 'b, 'gcx, 'tcx> as rustc::mir::visit::Visitor<'tcx>>::visit_constant                                    
   9: <rustc_mir::borrow_check::nll::type_check::TypeVerifier<'a, 'b, 'gcx, 'tcx> as rustc::mir::visit::Visitor<'tcx>>::visit_rvalue                                      
  10: <rustc_mir::borrow_check::nll::type_check::TypeVerifier<'a, 'b, 'gcx, 'tcx> as rustc::mir::visit::Visitor<'tcx>>::visit_mir                                         
  11: rustc_mir::borrow_check::nll::type_check::type_check_internal                                                                                                       
  12: rustc::ty::context::tls::with_related_context                                                                                                                       
  13: rustc::infer::InferCtxtBuilder::enter                                                                                                                               
  14: <rustc_mir::borrow_check::nll::type_check::TypeckMir as rustc_mir::transform::MirPass>::run_pass                                                                    
  15: rustc_mir::transform::mir_const::{{closure}}                                                                                                                        
  16: rustc_mir::transform::mir_const                                                                                                                                     
  17: rustc::ty::query::__query_compute::mir_const                                                                                                                        
  18: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors<'tcx> for rustc::ty::query::queries::mir_const<'tcx>>::compute                                     
  19: rustc::ty::context::tls::with_context                                                                                                                               
  20: rustc::dep_graph::graph::DepGraph::with_task_impl                                                                                                                   
  21: rustc::ty::context::tls::with_related_context                                                                                                                       
  22: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job                                                                 
  23: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::get_query                                                                            
  24: rustc::ty::query::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::mir_const                                                                                      
  25: rustc_mir::transform::mir_validated                                                                                                                                 
  26: rustc::ty::query::__query_compute::mir_validated                                                                                                                    
  27: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors<'tcx> for rustc::ty::query::queries::mir_validated<'tcx>>::compute                                 
  28: rustc::ty::context::tls::with_context                                                                                                                               
  29: rustc::dep_graph::graph::DepGraph::with_task_impl                                                                                                                   
  30: rustc::ty::context::tls::with_related_context                                                                                                                       
  31: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job                                                                 
  32: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::get_query                                                                            
  33: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::ensure_query                                                                         
  34: rustc_borrowck::borrowck::borrowck                                                                                                                                  
  35: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors<'tcx> for rustc::ty::query::queries::borrowck<'tcx>>::compute                                      
  36: rustc::ty::context::tls::with_context                                                                                                                               
  37: rustc::dep_graph::graph::DepGraph::with_task_impl                                                                                                                   
  38: rustc::ty::context::tls::with_related_context                                                                                                                       
  39: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job                                                                 
  40: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::get_query                                                                            
  41: rustc::ty::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::par_body_owners                                                                                       
  42: rustc_borrowck::borrowck::check_crate                                                                                                                               
  43: rustc::util::common::time                                                                                                                                           
  44: rustc::ty::context::tls::enter_context                                                                                                                              
  45: <std::thread::local::LocalKey<T>>::with                                                                                                                             
  46: rustc::ty::context::TyCtxt::create_and_enter                                                                                                                        
  47: rustc_driver::driver::compile_input                                                                                                                                 
  48: rustc_driver::run_compiler_with_pool                                                                                                                                
  49: rustc_driver::driver::spawn_thread_pool                                                                                                                             
  50: rustc_driver::run_compiler                                                                                                                                          
  51: <scoped_tls::ScopedKey<T>>::set                                                                                                                                     
  52: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once                                                                                     
  53: __rust_maybe_catch_panic                                                                                                                                            
             at libpanic_unwind/lib.rs:102                                                                                                                                
  54: rustc_driver::run                                                                                                                                                   
  55: rustc_driver::main                                                                                                                                                  
  56: std::rt::lang_start::{{closure}}                                                                                                                                    
  57: std::panicking::try::do_call                                                                                                                                        
             at libstd/rt.rs:59                                                                                                                                           
             at libstd/panicking.rs:310                                                                                                                                   
  58: __rust_maybe_catch_panic                                                                                                                                            
             at libpanic_unwind/lib.rs:102                                                                                                                                
  59: std::rt::lang_start_internal                                                                                                                                        
             at libstd/panicking.rs:289                                                                                                                                   
             at libstd/panic.rs:392                                                                                                                                       
             at libstd/rt.rs:58                                                                                                                                           
  60: main                                                                                                                                                                
  61: __libc_start_main                                                                                                                                                   
  62: <unknown>                                                                                                                                                           
query stack during panic:                                                                                                                                                 
#0 [mir_const] processing `<TestStruct<T>>::call`                                                                                                                         
#1 [mir_validated] processing `<TestStruct<T>>::call`                                                                                                                     
#2 [borrowck] processing `<TestStruct<T>>::call`                                                                                                                          
end of query stack                                                                                                                                                        
                                                                                                                                                                          
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 1.31.0-nightly (424a749a0 2018-10-21) running on x86_64-unknown-linux-gnu                                                                                     
                                                                                                                                                                          
note: compiler flags: -C debuginfo=2 -C incremental --crate-type lib                                                                                                      
                                                                                                                                                                          
note: some of the compiler flags provided by cargo are hidden                                                                                                             
                                                                                                                                                                          
error: Could not compile `ice`.                                                                                                                                           

Caused by:
  process didn't exit successfully: `rustc --crate-name ice src/lib.rs --color always --crate-type lib --emit=dep-info,metadata -C debuginfo=2 -C metadata=2a9b80ba2717f3bb -C extra-filename=-2a9b80ba2717f3bb --out-dir /home/mexus/test/rust/ice/target/debug/deps -C incremental=/home/mexus/test/rust/ice/target/debug/incremental -L dependency=/home/mexus/test/rust/ice/target/debug/deps` (exit code: 101)

Here's a playground link with the examples:
https://play.rust-lang.org/?version=nightly&mode=debug&edition=2015&gist=3a4690e53464d2c8f0a4824b9f31d31d

[mexus]

I see there are a couple of probably related issues (at least seems to be MIR-related), but I'm not quite sure and, and since they don't provide a minimal example I've decided to file an issue :)

[pnkfelix]

Worth noting that this is happening on the 2015 edition without #![feature(nll)]. (Do we need a separate tag to distinguish bugs that are presumably caused by MIR-typeck ?

[mexus]

I confirm that either with the feature enabled or edition set to 2018 there problem doesn't reproduce

[pnkfelix]

closing as duplicate of #55219