Template type param as bitfield leads to panic

[fitzgen]

Input C/C++ Header

template <class T>
class TemplatizedBitfield {
    T t : 6;
};

Bindgen Invocation

$ bindgen input.hpp

Actual Results

thread 'main' panicked at 'Bitfield without layout? Gah!', /checkout/src/libcore/option.rs:839:4
stack backtrace:
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace
             at /checkout/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::_print
             at /checkout/src/libstd/sys_common/backtrace.rs:69
   2: std::panicking::default_hook::{{closure}}
             at /checkout/src/libstd/sys_common/backtrace.rs:58
             at /checkout/src/libstd/panicking.rs:381
   3: std::panicking::default_hook
             at /checkout/src/libstd/panicking.rs:397
   4: std::panicking::rust_panic_with_hook
             at /checkout/src/libstd/panicking.rs:577
   5: std::panicking::begin_panic
             at /checkout/src/libstd/panicking.rs:538
   6: std::panicking::begin_panic_fmt
             at /checkout/src/libstd/panicking.rs:522
   7: rust_begin_unwind
             at /checkout/src/libstd/panicking.rs:498
   8: core::panicking::panic_fmt
             at /checkout/src/libcore/panicking.rs:71
   9: core::option::expect_failed
             at /checkout/src/libcore/option.rs:839
  10: <core::option::Option<T>>::expect
             at /checkout/src/libcore/option.rs:302
  11: bindgen::ir::comp::bitfields_to_allocation_units
             at ./src/ir/comp.rs:573
  12: bindgen::ir::comp::raw_fields_to_fields_and_bitfield_units
             at ./src/ir/comp.rs:501
  13: bindgen::ir::comp::CompFields::compute_bitfield_units
             at ./src/ir/comp.rs:698
  14: bindgen::ir::comp::CompInfo::compute_bitfield_units
             at ./src/ir/comp.rs:1476
  15: bindgen::ir::context::BindgenContext::compute_bitfield_units::{{closure}}
             at ./src/ir/context.rs:996
  16: bindgen::ir::context::BindgenContext::with_loaned_item
             at ./src/ir/context.rs:979
  17: bindgen::ir::context::BindgenContext::compute_bitfield_units
             at ./src/ir/context.rs:995
  18: bindgen::ir::context::BindgenContext::gen
             at ./src/ir/context.rs:1170
  19: bindgen::codegen::codegen
             at ./src/codegen/mod.rs:3358
  20: bindgen::Bindings::generate
             at ./src/lib.rs:1635
  21: bindgen::Builder::generate
             at ./src/lib.rs:1097
  22: bindgen::main::{{closure}}
             at ./src/main.rs:55
  23: std::panicking::try::do_call
             at /checkout/src/libstd/panicking.rs:480
  24: __rust_maybe_catch_panic
             at /checkout/src/libpanic_unwind/lib.rs:99
  25: std::panicking::try
             at /checkout/src/libstd/panicking.rs:459
  26: std::panic::catch_unwind
             at /checkout/src/libstd/panic.rs:361
  27: bindgen::main
             at ./src/main.rs:54
  28: __rust_maybe_catch_panic
             at /checkout/src/libpanic_unwind/lib.rs:99
  29: std::rt::lang_start
             at /checkout/src/libstd/panicking.rs:459
             at /checkout/src/libstd/panic.rs:361
             at /checkout/src/libstd/rt.rs:59
  30: main
  31: __libc_start_main
  32: _start

Expected Results

No panic. Perhaps the templatized struct is opaque, or we don't emit bitfield accessors for it.