Internal compiler error after a trait/struct rename.

[JTKBowers]

Rustc segfaults after a trait/struct rename.

I tried this code:

Reproducing

This bug only seems to occur when changing from one version of code to another. Both code snippets compile successfully with a clean build.

1. cargo new rustc-repr
2. Add the following to main.rs:

trait F {
    fn id(&self) -> u32;
}

struct ImplF {
    id: u32
}

impl F for ImplF {
    fn id(&self) -> u32 {
        self.id
    }
}

fn main() {
    println!("Hello, world!");
}

1. cargo run
2. Change main.rs to contain:

struct F {
    id: u32
}

impl F {
    fn id(&self) -> u32 {
        self.id
    }
}

fn main() {
    println!("Hello, world!");
}

1. cargo run

I expected to see this happen: Code compiling successfully

Instead, this happened: An internal compiler error occurs

Meta

rustc --version --verbose:

rustc 1.42.0 (b8cedc004 2020-03-09)
binary: rustc
commit-hash: b8cedc00407a4c56a3bda1ed605c6fc166655447
commit-date: 2020-03-09
host: x86_64-unknown-linux-gnu
release: 1.42.0
LLVM version: 9.0

Backtrace:

error: internal compiler error: src/librustc/dep_graph/graph.rs:687: DepNode Hir(rustc_repr[9782]::F[0]::id[0]) should have been pre-allocated but wasn't.

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:873:9
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.com-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: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:476
  12: std::panicking::begin_panic
  13: rustc_errors::HandlerInner::bug
  14: rustc_errors::Handler::bug
  15: rustc::util::bug::opt_span_bug_fmt::{{closure}}
  16: rustc::ty::context::tls::with_opt::{{closure}}
  17: rustc::ty::context::tls::with_opt
  18: rustc::util::bug::opt_span_bug_fmt
  19: rustc::util::bug::bug_fmt
  20: rustc::dep_graph::graph::DepGraph::try_mark_previous_green
  21: rustc::dep_graph::graph::DepGraph::try_mark_green
  22: rustc::dep_graph::graph::DepGraph::try_mark_green_and_read
  23: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  24: <rustc_typeck::outlives::implicit_infer::InferVisitor as rustc_hir::itemlikevisit::ItemLikeVisitor>::visit_item
  25: rustc_hir::hir::Crate::visit_all_item_likes
  26: rustc_typeck::outlives::inferred_outlives_crate
  27: rustc::ty::query::__query_compute::inferred_outlives_crate
  28: rustc::dep_graph::graph::DepGraph::with_task_impl
  29: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  30: rustc_typeck::outlives::inferred_outlives_of
  31: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::inferred_outlives_of>::compute
  32: rustc::dep_graph::graph::DepGraph::with_task_impl
  33: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query
  34: rustc::ty::query::plumbing::force_from_dep_node
  35: rustc::dep_graph::graph::DepGraph::try_mark_previous_green
  36: rustc::dep_graph::graph::DepGraph::try_mark_previous_green
  37: rustc::dep_graph::graph::DepGraph::try_mark_green
  38: rustc::dep_graph::graph::DepGraph::try_mark_green_and_read
  39: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  40: <rustc_typeck::collect::CollectItemTypesVisitor as rustc_hir::intravisit::Visitor>::visit_item
  41: rustc::hir::map::Map::visit_item_likes_in_module
  42: rustc_typeck::collect::collect_mod_item_types
  43: rustc::ty::query::__query_compute::collect_mod_item_types
  44: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::collect_mod_item_types>::compute
  45: rustc::dep_graph::graph::DepGraph::with_task_impl
  46: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  47: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::ensure_query
  48: rustc_typeck::check_crate
  49: rustc_interface::passes::analysis
  50: rustc::ty::query::__query_compute::analysis
  51: rustc::dep_graph::graph::DepGraph::with_task_impl
  52: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  53: rustc::ty::context::tls::enter_global
  54: rustc_interface::interface::run_compiler_in_existing_thread_pool
  55: scoped_tls::ScopedKey<T>::set
  56: syntax::with_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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 (b8cedc004 2020-03-09) running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=2 -C incremental --crate-type bin

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

query stack during panic:
#0 [type_of] processing `F::id`
#1 [inferred_outlives_crate] computing the inferred outlives predicates for items in this crate
#2 [inferred_outlives_of] processing `F`
#3 [predicates_of] processing `F`
#4 [collect_mod_item_types] collecting item types in top-level module
#5 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error

error: could not compile `rustc-repr`.

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

[jonas-schievink]

Duplicate of #62649