use thiserror::Error;
use super::span::MemorySpan;
use crate::run_thread::ThreadToken;
use crate::mlock::ClaimId;
use asm::data::literal::DebugMsg;
use asm::data::Register;

#[derive(Error,Debug)]
pub enum Fault {
    #[error("Bad instruction at addr {addr:#10x}: {cause}")]
    BadInstruction {
        addr : u32,
        cause: InstrError,
    },

    #[error("Runtime hit a barrier instruction: {msg}")]
    Barrier {
        msg: DebugMsg,
    },

    #[error("User fault: {msg}")]
    FaultInstr {
        msg: DebugMsg,
    },

    #[error("Memory region {area:?} is locked by thread {owner:?}")]
    MemoryLocked {
        area: MemorySpan,
        owner: ThreadToken
    },

    #[error("Memory claim {claim:?} owned by thread {owner:?} does not exist")]
    ClaimNotExist {
        claim: ClaimId,
        owner: ThreadToken
    },

    #[error("Register does not exist: {reg:?}")]
    RegisterNotExist {
        reg: Register,
    },

    #[error("Register is read-only: {reg:?}")]
    RegisterNotWritable {
        reg: Register,
    },
}

#[derive(Error,Debug)]
pub enum InstrError {
    #[error("Instruction not recognized")]
    UnknownInstruction,

    #[error("Invalid bit span")]
    BadBitSpan,

    #[error("Operands data size differs")]
    UnevenOperandSize,
}