assert panics in unwrap lint

[wiomoc]

Clippy panics during linting of this code:

trait IsErr {
    fn is_err(&self, err: &str) -> bool;
}

impl<T> IsErr for Option<T> {
    fn is_err(&self, _err: &str) -> bool {
        true
    }
}

fn main() {
    let t = Some(1);

    if t.is_err("") {
        t.unwrap();
    }
}

rust-clippy/clippy_lints/src/unwrap.rs

Line 113 in ceddf34

assert!(args.len() == 1);

Something like this should do the trick:

is_type_diagnostic_item(cx, ty, sym!(option_type))
        && ["is_some", "is_none"].contains(&&*name)
        || is_type_diagnostic_item(cx, ty, sym!(result_type))
            && ["is_ok", "is_err"].contains(&&*name)

[matthiaskrgr]

Backtrace:

thread 'rustc' panicked at 'assertion failed: args.len() == 1', src/tools/clippy/clippy_lints/src/unwrap.rs:107:17
stack backtrace:
   0:     0x7f37a12a89e4 - backtrace::backtrace::libunwind::trace::hfcd33194db0151d4
                               at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/libunwind.rs:86
   1:     0x7f37a12a89e4 - backtrace::backtrace::trace_unsynchronized::hfd1904bbbd5335b5
                               at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/mod.rs:66
   2:     0x7f37a12a89e4 - std::sys_common::backtrace::_print_fmt::h8476c57b177b254e
                               at src/libstd/sys_common/backtrace.rs:78
   3:     0x7f37a12a89e4 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h73acbc5f6d4b1044
                               at src/libstd/sys_common/backtrace.rs:59
   4:     0x7f37a12e69dc - core::fmt::write::hdf236390fbd68d3d
                               at src/libcore/fmt/mod.rs:1069
   5:     0x7f37a129a3e3 - std::io::Write::write_fmt::h5722fa40bb2afafd
                               at src/libstd/io/mod.rs:1532
   6:     0x7f37a12ada05 - std::sys_common::backtrace::_print::ha468e873aada7c78
                               at src/libstd/sys_common/backtrace.rs:62
   7:     0x7f37a12ada05 - std::sys_common::backtrace::print::h149365a2f029de62
                               at src/libstd/sys_common/backtrace.rs:49
   8:     0x7f37a12ada05 - std::panicking::default_hook::{{closure}}::hb4a33f9e05934a52
                               at src/libstd/panicking.rs:198
   9:     0x7f37a12ad742 - std::panicking::default_hook::hc4535d7b0c743abd
                               at src/libstd/panicking.rs:218
  10:     0x55e625dbf881 - clippy_driver::report_clippy_ice::hedcde3cb12415fe4
  11:     0x7f37a12ae0bd - std::panicking::rust_panic_with_hook::haa34a96a6dbd5a2e
                               at src/libstd/panicking.rs:481
  12:     0x55e625eef9be - std::panicking::begin_panic::hf5950fe05dd10ed4
  13:     0x55e625e3abc2 - clippy_lints::unwrap::collect_unwrap_info::h316849687a130d62
  14:     0x55e625e3ac28 - clippy_lints::unwrap::UnwrappableVariablesVisitor::visit_branch::hb622d8882af7b05f
  15:     0x55e625e3b241 - <clippy_lints::unwrap::UnwrappableVariablesVisitor as rustc_hir::intravisit::Visitor>::visit_expr::h81cac39daa53a72a
  16:     0x55e625e3b6a3 - <clippy_lints::unwrap::UnwrappableVariablesVisitor as rustc_hir::intravisit::Visitor>::visit_expr::h81cac39daa53a72a
  17:     0x55e625f31776 - rustc_hir::intravisit::walk_fn::he136b21fd714fa62
  18:     0x55e625e3b806 - <clippy_lints::unwrap::Unwrap as rustc_lint::passes::LateLintPass>::check_fn::hc58848258ce8d661
  19:     0x7f37a37e44c2 - <rustc_lint::late::LateLintPassObjects as rustc_lint::passes::LateLintPass>::check_fn::ha9b477af3ee26aa4
  20:     0x7f37a1b980b6 - rustc_hir::intravisit::walk_item::hd7aca0a3280e0d01
  21:     0x7f37a1becd04 - rustc_hir::intravisit::Visitor::visit_nested_item::hef50697ada24f512
  22:     0x7f37a1b9156e - rustc_hir::intravisit::walk_crate::h87301c8e316eae69
  23:     0x7f37a1bc12c7 - rustc_lint::late::late_lint_pass_crate::h3987dcacf48988b9
  24:     0x7f37a1bc4490 - rustc_session::utils::<impl rustc_session::session::Session>::time::h0a01190aa57bb50d
  25:     0x7f37a1bc8c60 - rustc_session::utils::<impl rustc_session::session::Session>::time::hddabeeb6d45418e6
  26:     0x7f37a1b46595 - <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::h57f965df9e864a4d
  27:     0x7f37a1bc4ca8 - rustc_session::utils::<impl rustc_session::session::Session>::time::h0c71c337234b0974
  28:     0x7f37a1c6fa4b - rustc_interface::passes::analysis::h6d809b9127d1df5d
  29:     0x7f37a18b71fb - rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::analysis>::compute::he31be01f92f630cb
  30:     0x7f37a1a02927 - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl::h8b90ad06db3eaeca
  31:     0x7f37a1885d58 - rustc_data_structures::stack::ensure_sufficient_stack::h7cb8d36df1565b9a
  32:     0x7f37a1a09e1c - rustc_query_system::query::plumbing::get_query_impl::h3655d22c01adc2a8
  33:     0x7f37a18b7407 - rustc_middle::ty::context::tls::enter_global::h172f152fc22b01e3
  34:     0x7f37a1883b49 - rustc_interface::interface::run_compiler_in_existing_thread_pool::h24d68d75bb23a364
  35:     0x7f37a18c2f2d - scoped_tls::ScopedKey<T>::set::h017a7c9423dcc2fe
  36:     0x7f37a18bc872 - rustc_ast::attr::with_globals::hb07e6b9f2e998c0a
  37:     0x7f37a18cac05 - std::sys_common::backtrace::__rust_begin_short_backtrace::h1d61d8d2633208cc
  38:     0x7f37a1a112fe - core::ops::function::FnOnce::call_once{{vtable.shim}}::h8fafb950fdaeaae0
  39:     0x7f37a12be0ca - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::ha26a994a135d55de
                               at /rustc/a08c47310c7d49cbdc5d7afb38408ba519967ecd/src/liballoc/boxed.rs:1034
  40:     0x7f37a12be0ca - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h677072ad3ba2806b
                               at /rustc/a08c47310c7d49cbdc5d7afb38408ba519967ecd/src/liballoc/boxed.rs:1034
  41:     0x7f37a12be0ca - std::sys::unix::thread::Thread::new::thread_start::h7c46ce580f54dd0e
                               at src/libstd/sys/unix/thread.rs:87
  42:     0x7f37a11d246f - start_thread
  43:     0x7f37a10e83d3 - clone
  44:                0x0 - <unknown>

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-clippy/issues/new

note: Clippy version: clippy 0.0.212 (a08c473 2020-05-07)

query stack during panic:
#0 [analysis] running analysis passes on this crate
end of query stack