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//! Types and friends for the LC-3 ISA.
//!
//! TODO!

// TODO: forbid
#![warn(
    bad_style,
    const_err,
    dead_code,
    improper_ctypes,
    legacy_directory_ownership,
    non_shorthand_field_patterns,
    no_mangle_generic_items,
    overflowing_literals,
    path_statements,
    patterns_in_fns_without_body,
    plugin_as_library,
    private_in_public,
    safe_extern_statics,
    unconditional_recursion,
    unused,
    unused_allocation,
    unused_lifetimes,
    unused_comparisons,
    unused_parens,
    while_true
)]
// TODO: deny
#![warn(
    missing_debug_implementations,
    intra_doc_link_resolution_failure,
    missing_docs,
    unsafe_code,
    trivial_casts,
    trivial_numeric_casts,
    unused_extern_crates,
    unused_import_braces,
    unused_qualifications,
    unused_results,
    rust_2018_idioms
)]
#![doc(test(attr(deny(warnings))))]
#![doc(html_logo_url = "")] // TODO!

// Mark the crate as no_std if the `no_std` feature is enabled.
#![cfg_attr(feature = "no_std", no_std)]

// Note: this feature is not tested by CI (still dependent on nightly Rust) but
// this is fine for now.
#![cfg_attr(feature = "nightly-const", feature(const_if_match))]
#![cfg_attr(feature = "nightly-const", feature(const_panic))]
#![cfg_attr(feature = "nightly-const", feature(const_fn))]

// Makes some an item const if the nightly-const feature is activated and not
// const otherwise.
macro_rules! nightly_const {
    ([$($vis:tt)*] => [$($rest:tt)*]) => (
        #[cfg(not(feature = "nightly-const"))]
        $($vis)* $($rest)*

        #[cfg(feature = "nightly-const")]
        $($vis)* const $($rest)*
    );
}

#[allow(unused_extern_crates)]
extern crate core; // makes rls actually look into the standard library (hack)

extern crate static_assertions as sa;

use core::mem::size_of;

/// Address type/size for the LC-3.
pub type Addr = u16;

/// Maximum possible address value.
pub const ADDR_MAX_VAL: Addr = Addr::max_value();

/// Word type/size for the LC-3.
pub type Word = u16;

/// Signed counterpart of the [`Word`] type.
pub type SignedWord = i16;

// Offer utility function for verifying bit lengths.
// Currently used for assembler.
pub use isa::check_signed_imm;

// Make sure our `Word` and `SignedWord` types are counterparts:
sa::const_assert!(size_of::<Word>() == size_of::<SignedWord>());

// And that `SignedWord` truly is signed:
sa::const_assert!({
    #[allow(trivial_numeric_casts)]
    ((-1) as SignedWord).is_negative()
});

pub const PSR: Addr = 0xFFFC;
pub const MCR: Addr = 0xFFFE;

pub const OS_START_ADDR: Addr = 0x0200; // TODO: should this go here?

pub const MEM_MAPPED_START_ADDR: Addr = 0xFE00;
pub const USER_PROGRAM_START_ADDR: Addr = 0x3000;

pub const TRAP_VECTOR_TABLE_START_ADDR: Addr = 0x0000;
pub const NUM_TRAP_VECTORS: Addr = 256;

pub const INTERRUPT_VECTOR_TABLE_START_ADDR: Addr = 0x0100;
// Exceptions: 0x0100 - 0x017F
pub const EXCEPTION_SERVICE_ROUTINES_START_ADDR: Addr = INTERRUPT_VECTOR_TABLE_START_ADDR;
pub const NUM_EXCEPTION_SERVICE_ROUTINES: Addr = 128;
// Interrupts: 0x0180 - 0x01FF
pub const INTERRUPT_SERVICE_ROUTINES_START_ADDR: Addr =
    INTERRUPT_VECTOR_TABLE_START_ADDR + NUM_EXCEPTION_SERVICE_ROUTINES;
pub const NUM_INTERRUPT_SERVICE_ROUTINES: Addr = 128;

pub const PRIVILEGE_MODE_VIOLATION_EXCEPTION_VECTOR: u8 = 0x00;
pub const ILLEGAL_OPCODE_EXCEPTION_VECTOR: u8 = 0x01;
pub const ACCESS_CONTROL_VIOLATION_EXCEPTION_VECTOR: u8 = 0x02; // TODO: Verify

/// Maximum possible word value.
pub const WORD_MAX_VAL: Word = Word::max_value();

/// Size of the LC-3 address space in [`Word`](Word)s.
pub const ADDR_SPACE_SIZE_IN_WORDS: usize = (ADDR_MAX_VAL as usize) + 1;

/// Size of the LC-3 address space in bytes.
pub const ADDR_SPACE_SIZE_IN_BYTES: usize = ADDR_SPACE_SIZE_IN_WORDS * size_of::<Word>();

mod fmt;
mod isa;
mod macros;
mod misc;

pub use isa::*;
pub use misc::util;