internal compiler error: Type parameter `Self/SelfSpace.0` (Self/SelfSpace/0) out of range when substituting

[scottmcm]

I was trying to figure out how to write things with traits and hit an ICE. It looked similar to #28344, but that was closed well before 1.8, so hopefully this is useful.

I tried this code:

use std::ops::{AddAssign, Mul};

struct Vec3<T:Default>(T,T,T);

trait DotProduct {
    type Output;
    fn dot(&self, &Self) -> Self::Output;
}

impl<T:Default> DotProduct for Vec3<T> where T : Mul, <T as Mul>::Output : AddAssign+Default {
    type Output = <T as Mul>::Output;
    fn dot(&self, rhs: &Self) -> Self::Output {
        <T as Mul>::Output::default()
    }
}

And this happened:

compiler_panic.rs:13:6: 13:33 error: internal compiler error: Type parameter `Self/SelfSpace.0` (Self/SelfSpace/0) out of range when substituting (root type=Some(Self)) substs=Substs[types=[[];[];[]], regions=[[];[];[]]]
compiler_panic.rs:13            <T as Mul>::Output::default()
                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~
note: the compiler unexpectedly panicked. this is a bug.

Meta

rustc --version --verbose:

rustc 1.8.0 (db2939409 2016-04-11)
binary: rustc
commit-hash: db2939409db26ab4904372c82492cd3488e4c44e
commit-date: 2016-04-11
host: x86_64-pc-windows-gnu
release: 1.8.0

Backtrace:

stack backtrace:
   0:         0x61cc34dc - strncmp
   1:         0x61cc2b5c - strncmp
   2:         0x61c84d6f - strncmp
   3:         0x67e9b9fb - strncmp
   4:         0x67e9b991 - strncmp
   5:         0x67f16665 - strncmp
   6:           0x9b96e0 - strncmp
   7:           0xa7af85 - strncmp
   8:           0xa793ca - strncmp
   9:           0xa81c26 - strncmp
  10:           0xa80e38 - strncmp
  11:           0xa8756e - strncmp
  12:           0xa1a9f5 - strncmp
  13:           0x9d9440 - strncmp
  14:           0xa0b816 - strncmp
  15:           0x9dfad2 - strncmp
  16:           0x9f7c3d - strncmp
  17:           0x9acf31 - strncmp
  18:           0x9a3d90 - strncmp
  19:           0x9a053d - strncmp
  20:           0x9b1a89 - strncmp
  21:           0x99b343 - strncmp
  22:           0x98eb58 - strncmp
  23:           0x985947 - strncmp
  24:         0x6b34a430 - strncmp
  25:         0x6b3488ac - strncmp
  26:         0x6b3455f7 - strncmp
  27:         0x6b317f4d - strncmp
  28:         0x6b306226 - strncmp
  29:         0x6b30376b - strncmp
  30:         0x61caf9ba - strncmp
  31:         0x6b30400c - strncmp
  32:         0x61cc1209 - strncmp
  33:         0x77125a4c - strncmp

[mitaa]

Hopefully a more useful playpen backtrace (nightly):

stack backtrace:
   1:     0x7f5820eff610 - std::sys::backtrace::tracing::imp::write::h9fb600083204ae7f
   2:     0x7f5820f0cd0b - std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::hca543c34f11229ac
   3:     0x7f5820f0c8ac - std::panicking::default_hook::hc2c969e7453d080c
   4:     0x7f5820ed18bf - std::sys_common::unwind::begin_unwind_inner::h30e12d15ce2b2e25
   5:     0x7f581a7a3ed8 - std::sys_common::unwind::begin_unwind::h24c4c0fa2cfe995a
   6:     0x7f581a7a3e7b - syntax::errors::Handler::span_bug::h1c6b996df38ae8d7
   7:     0x7f581a7a3d4a - rustc::session::opt_span_bug_fmt::_$u7b$$u7b$closure$u7d$$u7d$::hf0fb5697f8f25f40
   8:     0x7f581a7a3bf2 - rustc::session::opt_span_bug_fmt::hc581ba88c4e2ec53
   9:     0x7f581a7a3b34 - rustc::session::span_bug_fmt::h4591bcbadfc38558
  10:     0x7f581a88518d - _<ty..subst..SubstFolder<'a, 'tcx> as ty..fold..TypeFolder<'tcx>>::fold_ty::hce07f4b40d3cacb2
  11:     0x7f581b66495b - _<check..FnCtxt<'a, 'tcx> as astconv..AstConv<'tcx>>::ty_infer::h36a2788135ab3af5
  12:     0x7f581b7090c6 - _<std..iter..Map<I, F> as std..iter..Iterator>::next::h0128742a87f770ca
  13:     0x7f581b70766b - rustc_typeck::astconv::create_substs_for_ast_path::h6fa21d9ce590a57f
  14:     0x7f581b70dbba - rustc_typeck::astconv::create_substs_for_ast_trait_ref::h03de7676f19db52c
  15:     0x7f581b70cf0c - rustc_typeck::astconv::ast_path_to_mono_trait_ref::h8a557d894b7dff9f
  16:     0x7f581b712ace - rustc_typeck::astconv::qpath_to_ty::h233b0002fda3dbc0
  17:     0x7f581b6af872 - rustc_typeck::astconv::finish_resolving_def_to_ty::hf17fb92b2d6f4861
  18:     0x7f581b6821e3 - rustc_typeck::check::resolve_ty_and_def_ufcs::hb950623f3fdffcaa
  19:     0x7f581b67f9fd - rustc_typeck::check::check_expr_with_expectation_and_lvalue_pref::hdaa9a3d5d214eeb7
  20:     0x7f581b69273a - rustc_typeck::check::callee::check_call::h581c68eea83787eb
  21:     0x7f581b67b71e - rustc_typeck::check::check_expr_with_expectation_and_lvalue_pref::hdaa9a3d5d214eeb7
  22:     0x7f581b6599a7 - rustc_typeck::check::check_block_with_expected::hc05ff1e7fff64a1e
  23:     0x7f581b651459 - rustc_typeck::check::check_fn::hb43882d54094ac4a
  24:     0x7f581b64ed0c - rustc_typeck::check::check_bare_fn::h7e4c2ad58d1814dd
  25:     0x7f581b65e04f - rustc_typeck::check::check_method_body::h7863cacbf117e455
  26:     0x7f581b649d3e - rustc_typeck::check::check_item_body::h7ffec660fc242796
  27:     0x7f581b641ab1 - rustc_typeck::check::check_item_bodies::ha729008a2e67410e
  28:     0x7f581b63901f - rustc_typeck::check_crate::hb08ba31a6a5f65b5
  29:     0x7f582145b850 - rustc_driver::driver::phase_3_run_analysis_passes::_$u7b$$u7b$closure$u7d$$u7d$::h5a042a091cd7658c
  30:     0x7f5821459a5b - rustc::ty::context::TyCtxt::create_and_enter::h3f9051bcccbd93e4
  31:     0x7f582145650e - rustc_driver::driver::phase_3_run_analysis_passes::h9c723484c588a35b
  32:     0x7f5821428f5f - rustc_driver::driver::compile_input::h0629572e6f316b31
  33:     0x7f582140f4d4 - rustc_driver::run_compiler::h8902aebf8b1849a8
  34:     0x7f582140c941 - std::sys_common::unwind::try::try_fn::h4c74456035d0fcc7
  35:     0x7f5820efcdab - __rust_try
  36:     0x7f5820efcd3d - std::sys_common::unwind::inner_try::h47a4d9cd4a369dcd
  37:     0x7f582140d18a - _<F as std..boxed..FnBox<A>>::call_box::h27f542a39f1d61ef
  38:     0x7f5820f0aea4 - std::sys::thread::Thread::new::thread_start::h6f266e069bf4ec2b
  39:     0x7f5818d8a423 - start_thread
  40:     0x7f5820b69cbc - clone
  41:                0x0 - <unknown>

[kbknapp]

Got the same error from:

trait Ice<'a, T=&'a i32> {
    fn foo() -> T;
}

fn foo<'a, T>() -> T where T: Ice<'a> {
    Ice::foo()
}

Backtrace:

thread 'rustc' panicked at 'Box<Any>', ../src/libsyntax/errors/mod.rs:545
stack backtrace:
   1:     0x7f04f913a160 - std::sys::backtrace::tracing::imp::write::h9fb600083204ae7f
   2:     0x7f04f9147d6b - std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::hca543c34f11229ac
   3:     0x7f04f914790c - std::panicking::default_hook::hc2c969e7453d080c
   4:     0x7f04f910d338 - std::panicking::rust_panic_with_hook::hfe203e3083c2b544
   5:     0x7f04f56d34c8 - std::panicking::begin_panic::hf2bac3a63b4cf82e
   6:     0x7f04f56d33cf - syntax::errors::Handler::span_bug::h1878d6587b8bfd95
   7:     0x7f04f56d322d - rustc::session::opt_span_bug_fmt::_$u7b$$u7b$closure$u7d$$u7d$::hf0fb5697f8f25f40
   8:     0x7f04f56d313d - rustc::session::opt_span_bug_fmt::hc581ba88c4e2ec53
   9:     0x7f04f56d2ff4 - rustc::session::span_bug_fmt::h4591bcbadfc38558
  10:     0x7f04f592287e - _<ty..subst..SubstFolder<'a, 'gcx, 'tcx> as ty..fold..TypeFolder<'gcx, 'tcx>>::fold_region::h04b91b1acd88fd7a
  11:     0x7f04f57c9b97 - _<ty..subst..SubstFolder<'a, 'gcx, 'tcx> as ty..fold..TypeFolder<'gcx, 'tcx>>::fold_ty::h85d957d19ba2e322
  12:     0x7f04f57c966f - rustc::infer::InferCtxt::type_vars_for_defs::h7fb1ca6642fcbdb6
  13:     0x7f04f7ef2206 - rustc_typeck::check::FnCtxt::instantiate_path::hae3b9f0a269ab36f
  14:     0x7f04f7ed50b2 - rustc_typeck::check::FnCtxt::check_expr_with_expectation_and_lvalue_pref::hf7a336bf3f6d489c
  15:     0x7f04f7efaf91 - rustc_typeck::check::callee::_<impl check..FnCtxt<'a, 'gcx, 'tcx>>::check_call::hb1af81fdd6670b2d
  16:     0x7f04f7ed0920 - rustc_typeck::check::FnCtxt::check_expr_with_expectation_and_lvalue_pref::hf7a336bf3f6d489c
  17:     0x7f04f7eacded - rustc_typeck::check::FnCtxt::check_block_with_expected::hb3119871f6a1bbfa
  18:     0x7f04f7ea3d32 - rustc_typeck::check::check_fn::h4bb517663c83e412
  19:     0x7f04f7ea07fe - rustc_typeck::check::check_bare_fn::ha3f2d22e33abb8cf
  20:     0x7f04f7e9c272 - rustc_typeck::check::check_item_body::h7ffec660fc242796
  21:     0x7f04f7e92eb9 - rustc_typeck::check::check_item_bodies::ha729008a2e67410e
  22:     0x7f04f7e8bee6 - rustc_typeck::check_crate::hab54f1dbb6479f2b
  23:     0x7f04f969bf8c - rustc_driver::driver::phase_3_run_analysis_passes::_$u7b$$u7b$closure$u7d$$u7d$::he8e0792bce031dff
  24:     0x7f04f9699fda - rustc::ty::context::TyCtxt::create_and_enter::h9e0841510a9ae184
  25:     0x7f04f965d141 - rustc_driver::driver::compile_input::h0629572e6f316b31
  26:     0x7f04f964d41d - rustc_driver::run_compiler::h8902aebf8b1849a8
  27:     0x7f04f964a51e - std::panicking::try::call::hb9e578062982aefa
  28:     0x7f04f915650b - __rust_try
  29:     0x7f04f91564ae - __rust_maybe_catch_panic
  30:     0x7f04f964b004 - _<F as std..boxed..FnBox<A>>::call_box::h27f542a39f1d61ef
  31:     0x7f04f9145e74 - std::sys::thread::Thread::new::thread_start::h6f266e069bf4ec2b
  32:     0x7f04f0dba473 - start_thread
  33:     0x7f04f8d9dacc - clone
  34:                0x0 - <unknown>

error: Could not compile `ice`.

To learn more, run the command again with --verbose.

version:

rustc 1.10.0-nightly (22ac88f1a 2016-05-11)
binary: rustc
commit-hash: 22ac88f1a47a82195a49fbff3cf24a2c395d7a81
commit-date: 2016-05-11
host: x86_64-unknown-linux-gnu
release: 1.10.0-nightly

[Mark-Simulacrum]

No longer ICEs.