SIGSEGV in rust nightly 2021-01-07 (rustc 1.51.0-nightly)

[vlisivka]

Code for AVR target. Code compiled on Fedora 33. Code reduced by comby-reducer.

rapt-reduced.tar.gz

Program requires nightly 2021-01-07. I cannot use newer version of rustc to check, because of unrelated bug in llvm for AVR target(LLVM ERROR: Not supported instr: <MCInst 296 <MCOperand Reg:1> <MCOperand Imm:15> <MCOperand Reg:39>).

Code

#![no_std]
#![no_main]
use arduino_uno::prelude::*;
use arduino_uno::Serial;
use atmega328p_hal::port::mode;
use atmega328p_hal::port::Pin;
use avr_hal_generic::usart::{Usart, UsartOps};
use avr_std_stub as _;
mod line_buffer;
use line_buffer::LineBuffer;
mod atoi;
use atoi::atoi_u8;
const MAX_BUF_LEN: usize = 128;
static mut LINE_BUFFER: [u8; MAX_BUF_LEN] = [0; MAX_BUF_LEN];
enum PinState {
    InputFloating(Pin<mode::Input<mode::Floating>>),
    InputAnalog(Pin<mode::Input<mode::PullUp>>),
    Output(Pin<mode::Output>),
    TriState(Pin<mode::TriState>),
}
fn error<USART, PD0, PD1, CLOCK>(serial: &mut Usart<USART, PD0, PD1, CLOCK>, message: &str) where    USART: UsartOps<PD0, PD1>, {}
#[arduino_uno::entry]
fn main() -> ! {
    let peripherals = arduino_uno::Peripherals::take().unwrap();
    let mut pins = arduino_uno::Pins::new(peripherals.PORTB, peripherals.PORTC, peripherals.PORTD);
    let serial_rx = pins.d0;
    let serial_tx = pins.d1.into_output(&mut pins.ddr);
    let mut serial = Serial::new(peripherals.USART0, serial_rx, serial_tx, 115200.into_baudrate());
    let mut line_buffer = unsafe { LineBuffer::new(&mut LINE_BUFFER) };
    let mut pin_state = [
        PinState::TriState(pins.d3.into_tri_state(&pins.ddr).downgrade()),
        PinState::TriState(pins.d4.into_tri_state(&pins.ddr).downgrade()),
        PinState::TriState(pins.d5.into_tri_state(&pins.ddr).downgrade()),
        PinState::TriState(pins.d6.into_tri_state(&pins.ddr).downgrade()),
        PinState::TriState(pins.d7.into_tri_state(&pins.ddr).downgrade()),
        PinState::TriState(pins.d8.into_tri_state(&pins.ddr).downgrade()),
        PinState::TriState(pins.d9.into_tri_state(&pins.ddr).downgrade()),
        PinState::TriState(pins.d10.into_tri_state(&pins.ddr).downgrade()),
        PinState::TriState(pins.d11.into_tri_state(&pins.ddr).downgrade()),
        PinState::TriState(pins.d12.into_tri_state(&pins.ddr).downgrade()),
        PinState::TriState(pins.d13.into_tri_state(&pins.ddr).downgrade()),
    ];
    loop {
        ufmt::uwrite!(&mut serial, "\x1B[1mrapt>\x1B[0m ").void_unwrap();
        if line_buffer.read_line(&mut serial) > 0 {
            for command in line_buffer.words() {
                match command {
                    [b'r', tail @ ..] => {
                        match atoi_u8(tail) {
                            Some(pin_number) if (pin_number as usize) < pin_state.len() => {
                                match &pin_state[pin_number as usize] {
                                    PinState::InputFloating(pin) => {
                                        ufmt::uwrite!(serial, "p{}={}\r\n", pin_number, pin.is_high().unwrap()).void_unwrap();
                                    }
                                    PinState::InputAnalog(pin) => {
                                        ufmt::uwrite!(serial, "p{}={}\r\n", pin_number, pin.is_high().unwrap() ).void_unwrap();
                                    }
                                    PinState::TriState(pin) => {
                                        ufmt::uwrite!(serial, "p{}={}\r\n", pin_number, pin.is_high().unwrap()).void_unwrap();
                                    }
                                    _ => {}
                                }
                            }
                            _ => {}
                        }
                    }
                    [b'w', tail @ .., val] => {
                        match atoi_u8(tail) {
                            Some(pin_number) if (pin_number as usize) < pin_state.len() => {
                                match &mut pin_state[pin_number as usize] {
                                    PinState::Output(ref mut pin) => {
                                        let v = match val {
                                            b'l' | b'L' => false,
                                            b'h' | b'H' =>true,
                                            _ => {
                                                continue;
                                            }
                                        };
                                        ufmt::uwrite!(serial, "p{}={}\r\n", pin_number, v).void_unwrap();
                                    }
                                    PinState::TriState(ref mut pin) => {
                                        let v = match val {
                                            b'l' | b'L' => {
                                                pin.set_low().expect("");
                                                false
                                            }
                                            b'h' | b'H' => {
                                                pin.set_high().expect("");
                                                true
                                            }
                                            _ => {
                                                continue;
                                            }
                                        };
                                        ufmt::uwrite!(serial, "p{}={}\r\n", pin_number, v).void_unwrap();
                                    }
                                    _ => {}
                                }
                            }
                            _ => {}
                        }
                    }
                    _ => error(&mut serial, ""),
                }
            }
        }
    }
}

Meta

rustc --version --verbose:

rustc 1.51.0-nightly (c2de47a9a 2021-01-06)
binary: rustc
commit-hash: c2de47a9aa4c9812884f341f1852e9c9610f5f7a
commit-date: 2021-01-06
host: x86_64-unknown-linux-gnu
release: 1.51.0-nightly

Error output

  process didn't exit successfully: `rustc --crate-name rapt --edition=2018 src/main.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type bin --emit=dep-info,link -C opt-level=s -C panic=abort -C lto -C codegen-units=1 -C debuginfo=2 -C metadata=874b614425088d6c -C extra-filename=-874b614425088d6c --out-dir /home/vlisivka/workspace/rapt/target/avr-atmega328p/release/deps --target /home/vlisivka/workspace/rapt/avr-atmega328p.json -L dependency=/home/vlisivka/workspace/rapt/target/avr-atmega328p/release/deps -L dependency=/home/vlisivka/workspace/rapt/target/release/deps --extern arduino_uno=/home/vlisivka/workspace/rapt/target/avr-atmega328p/release/deps/libarduino_uno-2a2559e92b4f8b94.rlib --extern atmega328p_hal=/home/vlisivka/workspace/rapt/target/avr-atmega328p/release/deps/libatmega328p_hal-9252c4cc0359dc4c.rlib --extern avr_hal_generic=/home/vlisivka/workspace/rapt/target/avr-atmega328p/release/deps/libavr_hal_generic-8b1481097f48b6ab.rlib --extern avr_std_stub=/home/vlisivka/workspace/rapt/target/avr-atmega328p/release/deps/libavr_std_stub-9b4b6bb91705909d.rlib --extern 'noprelude:compiler_builtins=/home/vlisivka/workspace/rapt/target/avr-atmega328p/release/deps/libcompiler_builtins-6ac0a51c4b9ecfe7.rlib' --extern 'noprelude:core=/home/vlisivka/workspace/rapt/target/avr-atmega328p/release/deps/libcore-627006de141c21fe.rlib' --extern nb=/home/vlisivka/workspace/rapt/target/avr-atmega328p/release/deps/libnb-949e9a646194f61f.rlib --extern ufmt=/home/vlisivka/workspace/rapt/target/avr-atmega328p/release/deps/libufmt-e2008be75bc74481.rlib -Z unstable-options` (signal: 11, SIGSEGV: invalid memory reference)

Backtrace

<backtrace>