ICE with a fixed-size array of unsized elements

[apasel422]

foo.rs:

#![crate_type = "lib"]
fn foo(a: [[u8], ..5]) {}

Compilation output:

> rustc --version=verbose
rustc 0.13.0-nightly (770378a31 2014-11-20 23:02:01 +0000)
binary: rustc
commit-hash: 770378a313a573776b16237a46b75bafa49072c1
commit-date: 2014-11-20 23:02:01 +0000
host: x86_64-unknown-linux-gnu
release: 0.13.0-nightly
> RUST_BACKTRACE=1 rustc -g foo.rs
error: internal compiler error: trying to take the sizing type of [[u8], ..5], an unsized type
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' panicked at 'Box<Any>', /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/libsyntax/diagnostic.rs:180

stack backtrace:
   1:     0x7f20abdc19c0 - rt::backtrace::imp::write::h38e72df4f68c2a0fB9s
   2:     0x7f20abdc4b60 - failure::on_fail::hfed62fa5028805c5uwt
   3:     0x7f20ac58ac80 - unwind::begin_unwind_inner::hd2440d158cff1c59nbd
   4:     0x7f20a9c520d0 - unwind::begin_unwind::h17290044112077471032
   5:     0x7f20a9c52800 - diagnostic::Handler::bug::h8fa91ae0c865994546F
   6:     0x7f20aac633b0 - session::Session::bug::h05a03c91b32e6800Kv1
   7:     0x7f20ac943230 - trans::type_of::sizing_type_of::h3534ab6bd94e52d0qmp
   8:     0x7f20ac9532a0 - trans::datum::Datum<'tcx, K>::shallow_copy_raw::h16566536734899422380
   9:     0x7f20ac9e0530 - trans::_match::store_arg::h3d2ddccad4775a94Qdy
  10:     0x7f20ac9e14b0 - trans::base::trans_closure::h427ba3d717d7f5ba7Au
  11:     0x7f20ac922890 - trans::base::trans_fn::h63d2777387d1a1cfXMu
  12:     0x7f20ac91f960 - trans::base::trans_item::h61310fa89585fcd9H8u
  13:     0x7f20ac9ec290 - trans::base::trans_crate::h80c040a30f021e9016v
  14:     0x7f20aca969f0 - driver::driver::phase_4_translate_to_llvm::h49b60a5096822567npS
  15:     0x7f20aca83c70 - driver::driver::compile_input::h56e37c9f95bced56dWR
  16:     0x7f20acb08560 - driver::run_compiler::hae38ed40c1a5e42bHUT
  17:     0x7f20acb08450 - driver::run::closure.59803
  18:     0x7f20ac915000 - task::TaskBuilder<S>::try_future::closure.39059
  19:     0x7f20ac914df0 - task::TaskBuilder<S>::spawn_internal::closure.39030
  20:     0x7f20ace28b10 - task::NativeSpawner.Spawner::spawn::closure.2471
  21:     0x7f20ac5e34c0 - rust_try_inner
  22:     0x7f20ac5e34b0 - rust_try
  23:     0x7f20ac5885e0 - unwind::try::h13cddac141b4f78fIZc
  24:     0x7f20ac588470 - task::Task::run::hafaf90f81703a435y5b
  25:     0x7f20ace28850 - task::NativeSpawner.Spawner::spawn::closure.2397
  26:     0x7f20ac589c90 - thread::thread_start::hda75e847cb45320fEqc
  27:     0x7f20a6e3afe0 - start_thread
  28:     0x7f20ac250819 - __clone
  29:                0x0 - <unknown>

This only happens when -g is specified, and is possibly related to #18866.

[erickt]

Visiting for triage. I've updated the code to:

#![crate_type = "lib"]
fn foo(a: [[u8]; 5]) {}

But it still ICE's with:

bad2.rs:2:1: 2:24 warning: function is never used: `foo`, #[warn(dead_code)] on by default
bad2.rs:2 fn foo(a: [[u8]; 5]) {}
          ^~~~~~~~~~~~~~~~~~~~~~~
bad2.rs:2:8: 2:9 warning: unused variable: `a`, #[warn(unused_variables)] on by default
bad2.rs:2 fn foo(a: [[u8]; 5]) {}
                 ^
error: internal compiler error: trying to take the sizing type of [u8], an unsized type
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'Box<Any>', /Users/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-mac/build/src/libsyntax/diagnostic.rs:182

stack backtrace:
   1:        0x1127f14b5 - sys::backtrace::write::h64ca2fb259c4ae97lCt
   2:        0x11281394f - failure::on_fail::h64ff5ae6887860cc0Hz
   3:        0x11277f5ca - rt::unwind::begin_unwind_inner::h1d4bc098fd350446Qpz
   4:        0x1104930b7 - rt::unwind::begin_unwind::h1123425023578864118
   5:        0x110493a28 - diagnostic::Handler::bug::h6d2bfe842975d6e0tWF
   6:        0x10fa93788 - session::Session::bug::h5da8d79b0a6f5276iRq
   7:        0x10f1ca848 - trans::type_of::sizing_type_of::h9a9144f41b95ef26nUo
   8:        0x10f1c9bb4 - trans::type_of::sizing_type_of::h9a9144f41b95ef26nUo
   9:        0x10f1de841 - trans::common::type_is_immediate::h6bb1c0a049852e45tUk
  10:        0x10f25c889 - trans::type_of::type_of_rust_fn::hbbe004d99dfebef2xQo
  11:        0x10f2640e1 - trans::base::decl_rust_fn::h1e048b4bd74ce022s1r
  12:        0x10f27561e - trans::base::register_fn::h0ee69c538bdaf7b2dEu
  13:        0x10f192908 - trans::base::get_item_val::h697b171366de28ecc1u
  14:        0x10f18fce7 - trans::base::trans_item::hdbddd5abd5742b0cEwu
  15:        0x10f27902c - trans::base::trans_crate::h6077c32a4f7ba4e9lsv
  16:        0x10f035b3e - driver::phase_4_translate_to_llvm::ha92297f2357a645fPFa
  17:        0x10f011f4b - driver::compile_input::h31580cbd7ea87613xba
  18:        0x10f0dcfda - monitor::unboxed_closure.22557
  19:        0x10f0db735 - thunk::F.Invoke<A, R>::invoke::h6367419564961841226
  20:        0x10f0da510 - rt::unwind::try::try_fn::h7763956589852599824
  21:        0x11287a2a9 - rust_try_inner
  22:        0x11287a296 - rust_try
  23:        0x10f0dac0c - thunk::F.Invoke<A, R>::invoke::h16724184168577887652
  24:        0x112801154 - sys::thread::thread_start::hbd8f2f8bdd3a3baadrw
  25:     0x7fff9358c2fc - _pthread_body
  26:     0x7fff9358c279 - _pthread_body

[vadimcn]

Another repro:

static x: u8 = (*b"12345")[1];
fn main() {}

[apasel422]

Neither of the following snippets cause an ICE as of rustc 1.0.0-nightly (083b8a404 2015-04-05) (built 2015-04-05):

#![crate_type = "lib"]
fn foo(a: [[u8]; 5]) {}

static x: u8 = (*b"12345")[1];
fn main() {}