save-analysis causes ICE

[jonhoo]

When running cargo-udeps on noria in the noria/ subdirectory, a call to rustc with -Z save-analysis causes the following ICE:

thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/librustc_typeck/check/mod.rs:840:14
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.life-white.uk-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.life-white.uk-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:77
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:59
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1052
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1426
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:62
   7: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:49
   8: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:204
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:224
  10: rustc_driver::report_ice
  11: <alloc::boxed::Box<F> as core::ops::function::Fn<A>>::call
             at /rustc/698fcd38fa9548e64a2092ff48c9d15ceb57d40c/src/liballoc/boxed.rs:1029
  12: proc_macro::bridge::client::<impl proc_macro::bridge::Bridge>::enter::{{closure}}::{{closure}}
             at /rustc/698fcd38fa9548e64a2092ff48c9d15ceb57d40c/src/libproc_macro/bridge/client.rs:305
  13: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:476
  14: rust_begin_unwind
             at src/libstd/panicking.rs:380
  15: core::panicking::panic_fmt
             at src/libcore/panicking.rs:85
  16: core::panicking::panic
             at src/libcore/panicking.rs:52
  17: rustc_typeck::check::has_typeck_tables
  18: rustc::ty::query::__query_compute::has_typeck_tables
  19: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::has_typeck_tables>::compute
  20: rustc::dep_graph::graph::DepGraph::with_task_impl
  21: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  22: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_ty
  23: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_item
  24: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_item
  25: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_mod
  26: rustc::dep_graph::graph::DepGraph::with_ignore
  27: rustc::ty::context::tls::enter_global
  28: rustc_interface::interface::run_compiler_in_existing_thread_pool
  29: scoped_tls::ScopedKey<T>::set
  30: syntax::with_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

error: internal compiler error: unexpected panic

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 1.42.0-nightly (698fcd38f 2020-01-26) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z save-analysis -C debuginfo=2 -C incremental -C target-cpu=native --crate-type lib

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

query stack during panic:
#0 [has_typeck_tables] processing `<controller::Controller<A> as tower_service::Service<controller::ControllerRequest>>::Future::{{opaque}}#0`
end of query stack
error: could not compile `noria`.

Caused by:
  process didn't exit successfully: `rustc --edition=2018 --crate-name noria noria/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata -C debuginfo=2 -C metadata=0715f59924125db7 -C extra-filename=-0715f59924125db7 --out-dir /home/jon/.cargo-target/debug/deps -C incremental=/home/jon/.cargo-target/debug/incremental -L dependency=/home/jon/.cargo-target/debug/deps --extern arccstr=/home/jon/.cargo-target/debug/deps/libarccstr-3299b99c3963ea5d.rmeta --extern assert_infrequent=/home/jon/.cargo-target/debug/deps/libassert_infrequent-f9c4e668a370aafe.rmeta --extern async_bincode=/home/jon/.cargo-target/debug/deps/libasync_bincode-4faa92d746814f53.rmeta --extern bincode=/home/jon/.cargo-target/debug/deps/libbincode-47b650c80911238a.rmeta --extern bufstream=/home/jon/.cargo-target/debug/deps/libbufstream-e0c6c4aa7ef08edc.rmeta --extern byteorder=/home/jon/.cargo-target/debug/deps/libbyteorder-ab79fc25ad9848f0.rmeta --extern chrono=/home/jon/.cargo-target/debug/deps/libchrono-891148d6cdd9335c.rmeta --extern failure=/home/jon/.cargo-target/debug/deps/libfailure-9ff4c9d45b2bf666.rmeta --extern fnv=/home/jon/.cargo-target/debug/deps/libfnv-0cb134456c2698a3.rmeta --extern futures_util=/home/jon/.cargo-target/debug/deps/libfutures_util-8ab4380e642f05cd.rmeta --extern hyper=/home/jon/.cargo-target/debug/deps/libhyper-565ad34723db5faf.rmeta --extern net2=/home/jon/.cargo-target/debug/deps/libnet2-0316f6e42f83f45e.rmeta --extern nom_sql=/home/jon/.cargo-target/debug/deps/libnom_sql-5df647292a5cb9b4.rmeta --extern petgraph=/home/jon/.cargo-target/debug/deps/libpetgraph-a8fd5219bda290c4.rmeta --extern pin_project=/home/jon/.cargo-target/debug/deps/libpin_project-043910174a645244.rmeta --extern serde=/home/jon/.cargo-target/debug/deps/libserde-93719e869579b218.rmeta --extern serde_derive=/home/jon/.cargo-target/debug/deps/libserde_derive-f3903af2230c892b.so --extern serde_json=/home/jon/.cargo-target/debug/deps/libserde_json-034ac1fb1bcd2a16.rmeta --extern slab=/home/jon/.cargo-target/debug/deps/libslab-13e99d19418a3886.rmeta --extern slog=/home/jon/.cargo-target/debug/deps/libslog-2ae66f5c5e69ef5f.rmeta --extern slog_term=/home/jon/.cargo-target/debug/deps/libslog_term-4e25763582e9062e.rmeta --extern tokio=/home/jon/.cargo-target/debug/deps/libtokio-539efbaf98693041.rmeta --extern tokio_tower=/home/jon/.cargo-target/debug/deps/libtokio_tower-111b44b21527362d.rmeta --extern tower=/home/jon/.cargo-target/debug/deps/libtower-b8ea60d3ed6b6523.rmeta --extern tower_balance=/home/jon/.cargo-target/debug/deps/libtower_balance-028ac6bbc18ac3e0.rmeta --extern tower_buffer=/home/jon/.cargo-target/debug/deps/libtower_buffer-512073f502368f5a.rmeta --extern tower_discover=/home/jon/.cargo-target/debug/deps/libtower_discover-0b2fd0d49c16c4a0.rmeta --extern tower_service=/home/jon/.cargo-target/debug/deps/libtower_service-1e31e61c59e4c14c.rmeta --extern tower_util=/home/jon/.cargo-target/debug/deps/libtower_util-d7bae5364a8b2ad9.rmeta --extern tracing=/home/jon/.cargo-target/debug/deps/libtracing-719e9d0019dd5f23.rmeta --extern vec_map=/home/jon/.cargo-target/debug/deps/libvec_map-de61a4a46db7f9e0.rmeta --extern zookeeper=/home/jon/.cargo-target/debug/deps/libzookeeper-8aec0169da355c97.rmeta -C target-cpu=native -L native=/home/jon/.cargo-target/debug/build/backtrace-sys-20eee53aeca624cf/out -Z save-analysis` (exit code: 101)

I'm not exactly sure what additional information to provide? I filed an issue with cargo-udeps, and was forwarded here since it is an ICE.

[est31]

I've minimized it a bit: bug_68621.zip

It still uses external crates but the example itself is very small.

[hellow554]

#[feature(type_alias_impl_trait)]

trait Trait {}

trait Service {
    type Future: Trait;
}

struct Struct;

impl Service for Struct {
    type Future = impl Trait;
}

fn main() {}

compile it with: rustc -Z save-analysis main.rs

Although impl Trait is behind a feature gate it will ICE without the feature gate!

@rustbot modify labels: F-type_alias_impl_trait

---

ICE code:

rust/src/librustc_typeck/check/mod.rs

Lines 832 to 842 in 343432a

	fn has_typeck_tables(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
	// Closures' tables come from their outermost function,
	// as they are part of the same "inference environment".
	let outer_def_id = tcx.closure_base_def_id(def_id);
	if outer_def_id != def_id {
	return tcx.has_typeck_tables(outer_def_id);
	}
	let id = tcx.hir().as_local_hir_id(def_id).unwrap();
	primary_body_of(tcx, id).is_some()
	}