Unclosed parentheses causes panic

[tuomas56]

When attempting to compile this expression, the compiler panics. If the parentheses are fixed, there is no panic:

a(b[c

Many variations on this also cause the same panic, for instance a(b[c), a(b[c, e, f);, a(b[c as d); etc. It also happens when the symbols are actually defined and when they are more complex expressions, i.e:

ptr::copy(&(*self.ptr)[self.length as *const T, &mut res as *mut T, 1);

Where I originally found it. The compiler reports the error:

error: incorrect close delimiter: `)`
   --> src/heap.rs:199:86
    |
199 |                 ptr::copy(&(*self.ptr)[self.length as *const T, &mut res as *mut T, 1);
    |                                                                                      ^
    |
note: unclosed delimiter
   --> src/heap.rs:199:39
    |
199 |                 ptr::copy(&(*self.ptr)[self.length as *const T, &mut res as *mut T, 1);
    |                                       ^

error: expected one of `!`, `(`, `::`, `<`, or `]`, found `,`
   --> src/heap.rs:199:63
    |
199 |                 ptr::copy(&(*self.ptr)[self.length as *const T, &mut res as *mut T, 1);
    |                                                               ^ expected one of `!`, `(`, `::`, `<`, or `]` here

And then panics:

error: internal compiler error: librustc/ich/impls_ty.rs:906: ty::TypeVariants::hash_stable() - Unexpected variant TyInfer(?0).

thread 'rustc' panicked at 'Box<Any>', librustc_errors/lib.rs:543:9
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
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:207
   3: std::panicking::default_hook
             at libstd/panicking.rs:223
   4: core::ops::function::Fn::call
   5: std::panicking::rust_panic_with_hook
             at libstd/panicking.rs:403
   6: std::panicking::begin_panic
   7: rustc_errors::Handler::bug
   8: rustc::session::opt_span_bug_fmt::{{closure}}
   9: rustc::ty::context::tls::with_opt::{{closure}}
  10: <std::thread::local::LocalKey<T>>::try_with
  11: <std::thread::local::LocalKey<T>>::with
  12: rustc::ty::context::tls::with
  13: rustc::ty::context::tls::with_opt
  14: rustc::session::opt_span_bug_fmt
  15: rustc::session::bug_fmt
  16: rustc::ich::impls_ty::<impl rustc_data_structures::stable_hasher::HashStable<rustc::ich::hcx::StableHashingContext<'a>> for rustc::ty::sty::TypeVariants<'gcx>>::hash_stable
  17: <T as rustc::dep_graph::dep_node::DepNodeParams<'a, 'gcx, 'tcx>>::to_fingerprint
  18: rustc::dep_graph::dep_node::DepNode::new
  19: rustc::ty::maps::<impl rustc::ty::maps::queries::dropck_outlives<'tcx>>::try_get
  20: rustc::ty::maps::TyCtxtAt::dropck_outlives
  21: rustc::traits::query::dropck_outlives::<impl rustc::infer::at::At<'cx, 'gcx, 'tcx>>::dropck_outlives
  22: rustc_typeck::check::dropck::check_safety_of_destructor_if_necessary
  23: rustc::hir::Pat::walk_
  24: <rustc_typeck::check::regionck::RegionCtxt<'a, 'gcx, 'tcx> as rustc::hir::intravisit::Visitor<'gcx>>::visit_local
  25: rustc::hir::intravisit::walk_expr
  26: <rustc_typeck::check::regionck::RegionCtxt<'a, 'gcx, 'tcx> as rustc::hir::intravisit::Visitor<'gcx>>::visit_expr
  27: rustc::hir::intravisit::walk_expr
  28: <rustc_typeck::check::regionck::RegionCtxt<'a, 'gcx, 'tcx> as rustc::hir::intravisit::Visitor<'gcx>>::visit_expr
  29: <rustc_typeck::check::regionck::RegionCtxt<'a, 'gcx, 'tcx> as rustc::hir::intravisit::Visitor<'gcx>>::visit_expr
  30: <rustc_typeck::check::regionck::RegionCtxt<'a, 'gcx, 'tcx> as rustc::hir::intravisit::Visitor<'gcx>>::visit_expr
  31: rustc_typeck::check::regionck::RegionCtxt::visit_fn_body
  32: rustc_typeck::check::regionck::<impl rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx>>::regionck_fn
  33: rustc::ty::context::tls::enter
  34: rustc::infer::InferCtxtBuilder::enter
  35: rustc_typeck::check::typeck_tables_of
  36: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::compute_result
  37: rustc::dep_graph::graph::DepGraph::with_task_impl
  38: rustc_errors::Handler::track_diagnostics
  39: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check
  40: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::force
  41: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::try_get
  42: rustc::ty::maps::TyCtxtAt::typeck_tables_of
  43: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::ensure
  44: rustc::session::Session::track_errors
  45: rustc_typeck::check::typeck_item_bodies
  46: rustc::dep_graph::graph::DepGraph::with_task_impl
  47: rustc_errors::Handler::track_diagnostics
  48: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check
  49: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::force
  50: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::try_get
  51: rustc::ty::maps::TyCtxtAt::typeck_item_bodies
  52: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_item_bodies
  53: rustc_typeck::check_crate
  54: <std::thread::local::LocalKey<T>>::with
  55: <std::thread::local::LocalKey<T>>::with
  56: rustc::ty::context::TyCtxt::create_and_enter
  57: rustc_driver::driver::compile_input
  58: rustc_driver::run_compiler_impl
  59: syntax::with_globals

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 1.26.0-nightly (adf2135ad 2018-03-17) running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=2 -C incremental --crate-type staticlib

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

[estebank]

I'm unable to repro on stable, beta or nightly. Are you still seeing the ICE?

[kolmodin]

Unable to repro.

$ rustc --version
rustc 1.31.1 (b6c32da9b 2018-12-18)

$ cat rust-issue-49148.rs 
fn a(n: int) {}

fn main() {
  let b = vec![];
  let c = 0;
  a(b[c;
}

$ rustc rust-issue-49148.rs 
$ rustc rust-issue-49148.rs 
error: incorrect close delimiter: `}`
 --> rust-issue-49148.rs:7:1
  |
3 | fn main() {
  |           - close delimiter possibly meant for this
...
6 |   a(b[c;
  |      - un-closed delimiter
7 | }
  | ^ incorrect close delimiter

error: expected one of `!`, `.`, `::`, `?`, `]`, `{`, or an operator, found `;`
 --> rust-issue-49148.rs:6:8
  |
6 |   a(b[c;
  |        ^ expected one of 7 possible tokens here

error[E0412]: cannot find type `int` in this scope
 --> rust-issue-49148.rs:1:9
  |
1 | fn a(n: int) {}
  |         ^^^ not found in this scope

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0412`.