rustc 1.32.0-nightly "no errors encountered even though `delay_span_bug` issued"

[mqudsi]

I experienced the following trying to compile a crate with rustc 1.32.0-nightly (0c999ed 2018-12-03).

I put up a copy of the code in the state that caused this at neosmart/securestore-rs@rustc_crash.

thread 'rustc' panicked at 'index out of bounds: the len is 1 but the index is 1', /rustc/0c999ed132d67bf2520643e9bd619972cf3888ba/src/libcore/slice/mod.rs:2463:10
note: Run with `RUST_BACKTRACE=1` for a backtrace.
error: internal compiler error: cat_expr Errd
   --> securestore/src/lib.rs:76:87
    |
76  |       fn extract_keys(&self, iv: &Option<[u8; shared::IV_SIZE]>) -> Result<Keys, Error> {
    |  _______________________________________________________________________________________^
77  | |         let mut encryption_key = [0u8; shared::KEY_LENGTH];
78  | |         let mut hmac_key = [0u8; shared::KEY_LENGTH];
79  | |
...   |
117 | |         })
118 | |     }
    | |_____^

error: internal compiler error: cat_expr Errd
  --> securestore/src/lib.rs:80:15
   |
80 |         match &Self {
   |               ^^^^^

error: internal compiler error: cat_expr Errd
  --> securestore/src/lib.rs:80:16
   |
80 |         match &Self {
   |                ^^^^

error: internal compiler error: QualifyAndPromoteConstants: Mir had errors
   --> securestore/src/lib.rs:76:5
    |
76  | /     fn extract_keys(&self, iv: &Option<[u8; shared::IV_SIZE]>) -> Result<Keys, Error> {
77  | |         let mut encryption_key = [0u8; shared::KEY_LENGTH];
78  | |         let mut hmac_key = [0u8; shared::KEY_LENGTH];
79  | |
...   |
117 | |         })
118 | |     }
    | |_____^

error: internal compiler error: broken MIR in DefId(0/0:54 ~ securestore[d33c]::{{impl}}[1]::extract_keys[0]) ("return type"): bad type [type error]
   --> securestore/src/lib.rs:76:5
    |
76  | /     fn extract_keys(&self, iv: &Option<[u8; shared::IV_SIZE]>) -> Result<Keys, Error> {
77  | |         let mut encryption_key = [0u8; shared::KEY_LENGTH];
78  | |         let mut hmac_key = [0u8; shared::KEY_LENGTH];
79  | |
...   |
117 | |         })
118 | |     }
    | |_____^

error: internal compiler error: broken MIR in DefId(0/0:54 ~ securestore[d33c]::{{impl}}[1]::extract_keys[0]) (LocalDecl { mutability: Mut, is_user_variable: None, internal: false, is_block_tail: None, ty: [type error], user_ty: UserTypeProjections { contents: [] }, name: None, source_info: SourceInfo { span: securestore/src/lib.rs:76:5: 118:6, scope: scope[0] }, visibility_scope: scope[0] }): bad type [type error]
   --> securestore/src/lib.rs:76:5
    |
76  | /     fn extract_keys(&self, iv: &Option<[u8; shared::IV_SIZE]>) -> Result<Keys, Error> {
77  | |         let mut encryption_key = [0u8; shared::KEY_LENGTH];
78  | |         let mut hmac_key = [0u8; shared::KEY_LENGTH];
79  | |
...   |
117 | |         })
118 | |     }
    | |_____^

thread 'rustc' panicked at 'no errors encountered even though `delay_span_bug` issued', src/librustc_errors/lib.rs:334:17
stack backtrace:
   0:     0x7fe8be6d5c63 - std::sys::unix::backtrace::tracing::imp::unwind_backtrace::h8c27c4880bde890a
                               at src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1:     0x7fe8be6cd378 - std::sys_common::backtrace::_print::h94ad143e1a1f23ce
                               at src/libstd/sys_common/backtrace.rs:71
   2:     0x7fe8be6d26d2 - std::panicking::default_hook::{{closure}}::he4263dcd9a70a0a9
                               at src/libstd/sys_common/backtrace.rs:59
                               at src/libstd/panicking.rs:211
   3:     0x7fe8be6d243d - std::panicking::default_hook::he81ae3ee90693fac
                               at src/libstd/panicking.rs:227
   4:     0x7fe8baea7cd3 - rustc::util::common::panic_hook::h6ff7d65005b5c4d4
   5:     0x7fe8be6d2eb9 - std::panicking::rust_panic_with_hook::h0031c4eeabc83ca7
                               at src/libstd/panicking.rs:495
   6:     0x7fe8b9aee744 - std::panicking::begin_panic::hf7a210e797c2ef35
   7:     0x7fe8b9b00cb4 - <rustc_errors::Handler as core::ops::drop::Drop>::drop::h80f0d43cd8b57bf2
   8:     0x7fe8beab4711 - core::ptr::real_drop_in_place::ha1ba247982bc728d
   9:     0x7fe8beabac34 - rustc_driver::run_compiler_with_pool::h6807732b01150746
  10:     0x7fe8be9f5aa5 - <scoped_tls::ScopedKey<T>>::set::hde11c7bf316bfff6
  11:     0x7fe8beab91ea - rustc_driver::run_compiler::h2dda64ccf7980290
  12:     0x7fe8bea136de - rustc_driver::monitor::{{closure}}::h54c6ce747624f597
  13:     0x7fe8be6ef2e9 - __rust_maybe_catch_panic
                               at src/libpanic_unwind/lib.rs:102
  14:     0x7fe8bea04070 - <F as alloc::boxed::FnBox<A>>::call_box::h1b30e7f5bf58f422
  15:     0x7fe8be6e280d - std::sys::unix::thread::Thread::new::thread_start::h9ba17bb7e4aabdcb
                               at /rustc/0c999ed132d67bf2520643e9bd619972cf3888ba/src/liballoc/boxed.rs:683
                               at src/libstd/sys_common/thread.rs:24
                               at src/libstd/sys/unix/thread.rs:90
  16:     0x7fe8b8ad76da - start_thread
  17:     0x7fe8be39188e - __clone
  18:                0x0 - <unknown>
thread panicked while panicking. aborting.
error: Could not compile `securestore`.

Caused by:
  process didn't exit successfully: `rustc --edition=2018 --crate-name securestore securestore/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C debuginfo=2 -C metadata=0749cce87946a744 -C extra-filename=-0749cce87946a744 --out-dir /mnt/d/GIT/securestore-rs/target/debug/deps -C incremental=/mnt/d/GIT/securestore-rs/target/debug/incremental -L dependency=/mnt/d/GIT/securestore-rs/target/debug/deps --extern openssl=/mnt/d/GIT/securestore-rs/target/debug/deps/libopenssl-2e68a25d4040a661.rlib --extern serde=/mnt/d/GIT/securestore-rs/target/debug/deps/libserde-40d2f6e887424bea.rlib --extern serde_derive=/mnt/d/GIT/securestore-rs/target/debug/deps/libserde_derive-f6d311be5ca0118f.so --extern serde_json=/mnt/d/GIT/securestore-rs/target/debug/deps/libserde_json-e41670aa8ec886a9.rlib -C target-cpu=native -C target-feature=+avx2` (signal: 4, SIGILL: illegal instruction)

[mqudsi]

Distilling extract_keys to the following reveals the problem:

    fn extract_keys(&self, iv: &Option<[u8; shared::IV_SIZE]>) -> Result<Keys, Error> {
        let mut encryption_key = [0u8; shared::KEY_LENGTH];
        let mut hmac_key = [0u8; shared::KEY_LENGTH];

        match &Self {
            KeySource::Generate => {
            },
            KeySource::File(path) => {
            },
            KeySource::Password(password) => {
            }
        };

        Ok(Keys {
            encryption: encryption_key,
            hmac: hmac_key,
        })
    }

The error in the code is using match &Self instead of match &self. Correcting that makes the crash disappear.

[Centril]

@mqudsi is this a regression from stable or beta to nightly?

[dlrobertson]

I'm able to reproduce this with the following

enum Test { }

impl Test {
    fn ice(&self) {
        match &Self {
            _ => { println!("ICE"); }
        }
    }
}

[Centril]

In that case it seems like a
Duplicate of #56199.

[dlrobertson]

It would indeed appear so

[mqudsi]

Thanks.

[folex]

Happened to me on 1.51.0-nightly

error: internal compiler error: failed to process buffered lint here
  --> /home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/fluence-fork-libp2p-secio-0.26.0/src/codec/len_prefix.rs:73:25
   |
73 |                         log::error!("data length {} exceeds allowed maximum {}", data.len(), max_len)
   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: delayed at /rustc/04caa632dd10c2bf64b69524c7f9c4c30a436877/compiler/rustc_lint/src/early.rs:384:18
   = note: this error: internal compiler error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

thread 'rustc' panicked at 'no errors encountered even though `delay_span_bug` issued', compiler/rustc_errors/src/lib.rs:974:13
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 1.51.0-nightly (04caa632d 2021-01-30) running on x86_64-unknown-linux-gnu

note: compiler flags: -C embed-bitcode=no -C debuginfo=2 --crate-type lib

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

query stack during panic:
end of query stack
error: could not compile `fluence-fork-libp2p-secio`

[mqudsi]

@folex do you have a repro? I'm guessing it's a different cause.