ICE instead of syntax error while calling super()

[plazmoid]

I tried to call default trait implementation from overriden method. Googling was not so useful as wanted so I started playing with "super" keyword and found this bug.

Code

fn main() {
    super();
}

Meta

Bug appears both on stable and nightly

rustc --version --verbose:

rustc 1.50.0 (cb75ad5db 2021-02-10)
binary: rustc
commit-hash: cb75ad5db02783e8b0222fee363c5f63f7e2cf5b
commit-date: 2021-02-10
host: x86_64-unknown-linux-gnu
release: 1.50.0

rustc 1.52.0-nightly (e9920ef77 2021-02-11)
binary: rustc
commit-hash: e9920ef7749d11fc71cc32ca4ba055bcfeaab945
commit-date: 2021-02-11
host: x86_64-unknown-linux-gnu
release: 1.52.0-nightly
LLVM version: 11.0.1

Error output

thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', compiler/rustc_resolve/src/late/diagnostics.rs:138:36
note: run with `RUST_BACKTRACE=1` environment variable to display a 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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.50.0 (cb75ad5db 2021-02-10) running on x86_64-unknown-linux-gnu

query stack during panic:
end of query stack

Backtrace

stack backtrace:
   0: rust_begin_unwind
             at /rustc/cb75ad5db02783e8b0222fee363c5f63f7e2cf5b/library/std/src/panicking.rs:493:5
   1: core::panicking::panic_fmt
             at /rustc/cb75ad5db02783e8b0222fee363c5f63f7e2cf5b/library/core/src/panicking.rs:92:14
   2: core::panicking::panic
             at /rustc/cb75ad5db02783e8b0222fee363c5f63f7e2cf5b/library/core/src/panicking.rs:50:5
   3: rustc_resolve::late::diagnostics::<impl rustc_resolve::late::LateResolutionVisitor>::smart_resolve_report_errors
   4: rustc_resolve::late::LateResolutionVisitor::smart_resolve_path_fragment
   5: rustc_resolve::late::LateResolutionVisitor::resolve_expr
   6: rustc_resolve::late::LateResolutionVisitor::resolve_expr
   7: <rustc_resolve::late::LateResolutionVisitor as rustc_ast::visit::Visitor>::visit_block
   8: <rustc_resolve::late::LateResolutionVisitor as rustc_ast::visit::Visitor>::visit_fn
   9: rustc_ast::visit::walk_item
  10: rustc_resolve::late::LateResolutionVisitor::resolve_item
  11: rustc_resolve::Resolver::resolve_crate
  12: rustc_interface::passes::configure_and_expand_inner
  13: rustc_interface::passes::configure_and_expand::{{closure}}
  14: rustc_data_structures::box_region::PinnedGenerator<I,A,R>::new
  15: rustc_interface::passes::configure_and_expand
  16: rustc_interface::queries::Queries::expansion
  17: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  18: rustc_span::with_source_map
  19: rustc_interface::interface::create_compiler_and_run
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[hameerabbasi]

Bisected:

********************************************************************************
Regression in nightly-2020-06-05
********************************************************************************

fetching https://static.rust-lang.org/dist/2020-06-04/channel-rust-nightly-git-commit-hash.txt
nightly manifest 2020-06-04: 40 B / 40 B [===============] 100.00 % 720.31 KB/s converted 2020-06-04 to 56daaf669ebc3d5083db5cded719f780dc31104e
fetching https://static.rust-lang.org/dist/2020-06-05/channel-rust-nightly-git-commit-hash.txt
nightly manifest 2020-06-05: 40 B / 40 B [===============] 100.00 % 778.59 KB/s converted 2020-06-05 to 47c3158c3d797f75f0f7b2b2a977179668919dab
looking for regression commit between 2020-06-04 and 2020-06-05
opening existing repository at "rust.git"
refreshing repository
fetching (via local git) commits from 56daaf669ebc3d5083db5cded719f780dc31104e to 47c3158c3d797f75f0f7b2b2a977179668919dab
opening existing repository at "rust.git"
refreshing repository
looking up first commit
looking up second commit
checking that commits are by bors and thus have ci artifacts...
finding bors merge commits
found 6 bors merge commits in the specified range
  commit[0] 2020-06-03UTC: Auto merge of #72948 - Dylan-DPC:rollup-fazhw00, r=Dylan-DPC
  commit[1] 2020-06-03UTC: Auto merge of #72754 - lcnr:predicate-fold, r=nikomatsakis
  commit[2] 2020-06-04UTC: Auto merge of #72618 - Aaron1011:feature/early-sourcemap, r=petrochenkov
  commit[3] 2020-06-04UTC: Auto merge of #72975 - Dylan-DPC:rollup-6zvco5x, r=Dylan-DPC
  commit[4] 2020-06-04UTC: Auto merge of #72882 - marmeladema:save-analysis-hir-tree, r=Xanewok
  commit[5] 2020-06-04UTC: Auto merge of #72995 - Dylan-DPC:rollup-7gsyb8x, r=Dylan-DPC
ERROR: no commits between 56daaf669ebc3d5083db5cded719f780dc31104e and 47c3158c3d797f75f0f7b2b2a977179668919dab within last 167 days

[jyn514]

Relevant code:

rust/compiler/rustc_resolve/src/late/diagnostics.rs

Line 138 in d1206f9

let item_str = path.last().unwrap().ident;

In case it helps, the merges in nightly-2020-06-05 were #72948, #72754, #72618, #72975, #72882, and #72995.

Playground: https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=0ccab6c6b67a5c848dffdd6a369f2438

[camelid]

Error from just before the regression was introduced (run with nightly-2020-06-01):

error[E0433]: failed to resolve: there are too many leading `super` keywords
 --> <anon>:2:5
  |
2 |     super();
  |     ^^^^^ there are too many leading `super` keywords

error: aborting due to previous error

For more information about this error, try `rustc --explain E0433`.

[camelid]

Assigning P-medium and removing I-prioritize as discussed in the prioritization working group.

[osa1]

@rustbot claim