Compiler panic: Yet another 'index out of bounds: the len is 12 but the index is 12'

[IvanUkhov]

Hello,

The following code:

use std::default::Default;

type Foo = u16;

#[deriving(Default)]
struct Bar {
    pub foo: Foo,
}

fn main() {
    let baz = 0u;
    match baz {
        _ => assert!(0, 0),
    }
}

makes the compiler panic:

<std macros>:8:12: 13:23 error: mismatched types: expected `bool`, found `_` (expected bool, found integral variable)
<std macros>:8         if !$cond {
<std macros>:9             panic!($($arg),+)
<std macros>:10         }
<std macros>:11     );
<std macros>:12 )
error: internal compiler error: unexpected panic
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 'index out of bounds: the len is 12 but the index is 12', /Users/rustbuild/src/rust-buildbot/slave/nightly-mac/build/src/libsyntax/lib.rs:1

The backtrace is as follows:

   1:        0x105e915f2 - rt::backtrace::imp::write::he31e36fe59b39292ugt
   2:        0x105e946ad - failure::on_fail::h7c2689f722982652nCt
   3:        0x1060ff575 - unwind::begin_unwind_inner::h09866e00e97d31fbI2c
   4:        0x1060ff1bf - unwind::begin_unwind_fmt::h443e47d11b48984fTZc
   5:        0x1060fef62 - rust_begin_unwind
   6:        0x106149bfc - panicking::panic_fmt::hc979f6c0b0157f68RQl
   7:        0x106152341 - panicking::panic_bounds_check::hfad71607541b5567pPl
   8:        0x103e5a1e5 - codemap::FileMap::get_line::h40447e4b57225531m4E
   9:        0x103e888d3 - diagnostic::emit::hd3a2cf9de9dee335wvG
  10:        0x103e85168 - diagnostic::EmitterWriter.Emitter::emit::h8d15319a02e5e7a2lrG
  11:        0x103e83955 - diagnostic::Handler::emit::h444f90359ca9a887F8F
  12:        0x103e5637b - diagnostic::SpanHandler::span_err::he607876660b5f38fEWF
  13:        0x103208f8d - middle::typeck::infer::error_reporting::InferCtxt<'a, 'tcx>.ErrorReporting<'tcx>::report_type_error::h295fd9075d7add0fEMv
  14:        0x1030a12d4 - middle::typeck::check::demand::suptype::h60784e61bbbd5b6eyCd
  15:        0x1031b806d - middle::typeck::check::check_expr_has_type::closure.110801
  16:        0x1031b6216 - middle::typeck::check::check_expr_with_unifier::h8837607ae16c10b8Nzm
  17:        0x1031b0442 - middle::typeck::check::check_expr_with_unifier::h8837607ae16c10b8Nzm
  18:        0x1030a44c2 - middle::typeck::check::_match::check_match::h405380e6f6849c885P8
  19:        0x1031b06f3 - middle::typeck::check::check_expr_with_unifier::h8837607ae16c10b8Nzm
  20:        0x10316a4cf - middle::typeck::check::check_block_with_expected::he7085b8c57c115ecvzo
  21:        0x103143f70 - middle::typeck::check::check_fn::h604cf1058f7c9abce0i
  22:        0x103166b1e - middle::typeck::check::check_bare_fn::h42d50bc38b24ab59jPi
  23:        0x103162ad1 - middle::typeck::check::check_item::ha935ead12b2c5b2ft9i
  24:        0x103166840 - middle::typeck::check::check_item_types::h466c6c16edcec5c9tOi
  25:        0x1034ea896 - util::common::time::h12864813766357117792
  26:        0x1034e9d14 - middle::typeck::check_crate::h1acd5e14d073c903cwM
  27:        0x102ad79a3 - driver::driver::phase_3_run_analysis_passes::h098de55f4a14acee2eS
  28:        0x102acbecc - driver::driver::compile_input::h814765d870318dcf8VR
  29:        0x102b49e65 - driver::run_compiler::h54cbb685f3e65071gUT
  30:        0x102b4863e - driver::run::closure.59668
  31:        0x1029605ae - task::TaskBuilder::try_future::closure.38921
  32:        0x105e1f2e4 - task::TaskBuilder::spawn_internal::closure.24355
  33:        0x1060fcddd - task::Task::spawn::closure.5917
  34:        0x1061616ac - rust_try_inner
  35:        0x106161696 - rust_try
  36:        0x1060fceb7 - unwind::try::h207282f5be16daac3Qc
  37:        0x1060fcc8c - task::Task::run::h7eee475ba5444e2993b
  38:        0x1060fc98f - task::Task::spawn::closure.5893
  39:        0x1060fe627 - thread::thread_start::hc58864c152053492Wnc
  40:     0x7fff986072fc - _pthread_body
  41:     0x7fff98607279 - _pthread_body

It seems there are quite many bug reports with similar panic messages. I hope my snippet of code can shed some more light on the problem. Thank you.

Regards,
Ivan

[huonw]

Thanks for filing; as you note, this has many duplicates (e.g. #14091, and all the bugs linked on that issue). Closing.