forked from AbleOS/holey-bytes
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@ -6,12 +6,19 @@ mod macros;
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use {alloc::vec::Vec, hashbrown::HashSet};
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/// Assembler
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///
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/// - Opcode-generic, instruction-type-specific methods are named `i_param_<type>`
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/// - You likely won't need to use them, but they are here, just in case :)
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/// - Instruction-specific methods are named `i_<instruction>`
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#[derive(Default)]
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pub struct Assembler {
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pub buf: Vec<u8>,
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pub sub: HashSet<usize>,
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}
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// Implement both assembler and generate module for text-code-based one
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macros::impl_both!(
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bbbb(p0: R, p1: R, p2: R, p3: R)
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=> [DIR, DIRF, FMAF],
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@ -31,7 +38,9 @@ macros::impl_both!(
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);
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impl Assembler {
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// Special-cased
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// Special-cased for text-assembler
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//
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// `p2` is not a register, but the instruction is still BBB
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#[inline(always)]
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pub fn i_brc(&mut self, p0: u8, p1: u8, p2: u8) {
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self.i_param_bbb(hbbytecode::opcode::BRC, p0, p1, p2)
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@ -39,20 +48,49 @@ impl Assembler {
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/// Append 12 zeroes (UN) at the end
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pub fn finalise(&mut self) {
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// HBVM lore:
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//
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// In reference HBVM implementation checks are done in
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// a separate phase before execution.
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//
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// This way execution will be much faster as they have to
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// be done only once.
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//
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// There was an issue. You cannot statically check register values and
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// `JAL` instruction could hop at the end of program to some byte, which
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// will be interpreted as opcode and VM in attempt to decode the instruction
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// performed out-of-bounds read which leads to undefined behaviour.
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//
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// Several options were considered to overcome this, but inserting some data at
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// program's end which when executed would lead to undesired behaviour, though
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// not undefined behaviour.
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//
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// Newly created `UN` (as UNreachable) was chosen as
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// - It was a good idea to add some equivalent to `ud2` anyways
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// - Its zeroes
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// - What if you somehow reached that code, it will appropriately bail :)
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self.buf.extend([0; 12]);
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}
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}
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/// Immediate value
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///
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/// # Implementor notice
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/// It should insert exactly 8 bytes, otherwise output will be malformed.
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/// This is not checked in any way
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pub trait Imm {
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/// Insert immediate value
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fn insert(&self, asm: &mut Assembler);
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}
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/// Implement immediate values
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macro_rules! impl_imm_le_bytes {
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($($ty:ty),* $(,)?) => {
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$(
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impl Imm for $ty {
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#[inline(always)]
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fn insert(&self, asm: &mut Assembler) {
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// Convert to little-endian bytes, insert.
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asm.buf.extend(self.to_le_bytes());
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}
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}
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@ -1,5 +1,9 @@
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//! Macros to generate [`crate::Assembler`]
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/// Incremental token-tree muncher to implement specific instruction
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/// functions based on generic function for instruction type
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macro_rules! impl_asm_opcodes {
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(
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( // End case
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$generic:ident
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($($param_i:ident: $param_ty:ty),*)
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=> []
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@ -10,6 +14,7 @@ macro_rules! impl_asm_opcodes {
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($($param_i:ident: $param_ty:ty),*)
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=> [$opcode:ident, $($rest:tt)*]
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) => {
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// Instruction-specific function
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paste::paste! {
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#[inline(always)]
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pub fn [<i_ $opcode:lower>](&mut self, $($param_i: $param_ty),*) {
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@ -17,6 +22,7 @@ macro_rules! impl_asm_opcodes {
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}
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}
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// And recurse!
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macros::asm::impl_asm_opcodes!(
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$generic($($param_i: $param_ty),*)
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=> [$($rest)*]
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@ -24,16 +30,21 @@ macro_rules! impl_asm_opcodes {
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};
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}
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/// Numeric value insert
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macro_rules! impl_asm_insert {
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// Immediate - this is trait-based,
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// the insertion is delegated to its implementation
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($self:expr, $id:ident, I) => {
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Imm::insert(&$id, $self)
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};
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// Other numbers, just insert their bytes, little endian
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($self:expr, $id:ident, $_:ident) => {
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$self.buf.extend($id.to_le_bytes())
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};
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}
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/// Implement assembler
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macro_rules! impl_asm {
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(
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$(
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@ -44,11 +55,13 @@ macro_rules! impl_asm {
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) => {
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paste::paste! {
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$(
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fn [<i_param_ $ityn>](&mut self, opcode: u8, $($param_i: macros::asm::ident_map_ty!($param_ty)),*) {
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// Opcode-generic functions specific for instruction types
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pub fn [<i_param_ $ityn>](&mut self, opcode: u8, $($param_i: macros::asm::ident_map_ty!($param_ty)),*) {
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self.buf.push(opcode);
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$(macros::asm::impl_asm_insert!(self, $param_i, $param_ty);)*
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}
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// Generate opcode-specific functions calling the opcode-generic ones
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macros::asm::impl_asm_opcodes!(
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[<i_param_ $ityn>]($($param_i: macros::asm::ident_map_ty!($param_ty)),*)
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=> [$($opcode,)*]
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@ -58,14 +71,12 @@ macro_rules! impl_asm {
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};
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}
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/// Map operand type to Rust type
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#[rustfmt::skip]
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macro_rules! ident_map_ty {
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(R) => { u8 };
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(I) => { impl Imm };
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($id:ident) => { $id };
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(R) => { u8 }; // Register is just u8
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(I) => { impl Imm }; // Immediate is anything implementing the trait
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($id:ident) => { $id }; // Anything else → identity map
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}
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pub(crate) use {ident_map_ty, impl_asm, impl_asm_opcodes};
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#[allow(clippy::single_component_path_imports)]
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pub(crate) use impl_asm_insert;
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pub(crate) use {ident_map_ty, impl_asm, impl_asm_insert, impl_asm_opcodes};
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@ -1,6 +1,50 @@
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//! And here the land of macros begin.
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//!
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//! They do not bite, really. Have you seen what Yandros is writing?
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pub mod asm;
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pub mod text;
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#[allow(rustdoc::invalid_rust_codeblocks)]
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/// Generate code for both programmatic-interface assembler and
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/// textural interface.
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///
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/// Some people claim:
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/// > Write programs to handle text streams, because that is a universal interface.
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///
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/// We at AbleCorp believe that nice programatic API is nicer than piping some text
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/// into a program. It's less error-prone and faster.
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///
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/// # Syntax
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/// ```no_run
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/// impl_both!(
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/// INSTRUCTION_TYPE(p0: TYPE, p1: TYPE, …)
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/// => [INSTRUCTION_A, INSTRUCTION_B, …],
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/// …
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/// );
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/// ```
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/// - Instruction type determines opcode-generic, instruction-type-specific
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/// function. Name: `i_param_INSTRUCTION_TYPE`
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/// - Per-instructions there will be generated opcode-specific functions calling the generic ones
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/// - Operand types
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/// - R: Register (u8)
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/// - I: Immediate (implements [`crate::Imm`] trait)
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/// - Other types are identity-mapped
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///
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/// # Text assembler
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/// Text assembler generated simply calls methods in the [`crate::Assembler`] type.
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/// # Syntax
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/// ```text
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/// instruction op1, op2, …
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/// …
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/// ```
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/// - Opcode names are lowercase
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/// - Registers are prefixed with `r` followed by number
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/// - Operands are separated by `,`
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/// - Instructions are separated by either line feed or `;` (αυτό δεν είναι ερωτηματικό!)
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/// - Labels are defined by their names followed by colon `label:`
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/// - Labels are referenced simply by their names
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/// - Immediates are numbers, can be negative, floats are not yet supported
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macro_rules! impl_both {
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($($tt:tt)*) => {
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impl Assembler {
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@ -1,3 +1,7 @@
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//! Macros to generate text-code assembler at [`crate::text`]
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// Refering in module which generates a module to that module — is that even legal? :D
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/// Generate text code based assembler
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macro_rules! gen_text {
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(
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$(
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@ -6,6 +10,7 @@ macro_rules! gen_text {
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=> [$($opcode:ident),* $(,)?],
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)*
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) => {
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/// Text code based assembler
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pub mod text {
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use {
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crate::{
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@ -18,6 +23,7 @@ macro_rules! gen_text {
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};
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paste::paste!(literify::literify! {
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/// Assembly token
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#[derive(Clone, Copy, Debug, PartialEq, Eq, Logos)]
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#[logos(extras = Rodeo)]
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#[logos(skip r"[ \t\t]+")]
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@ -59,6 +65,7 @@ macro_rules! gen_text {
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}
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});
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/// Type of error
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#[derive(Copy, Clone, Debug, PartialEq, Eq)]
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pub enum ErrorKind {
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UnexpectedToken,
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@ -67,12 +74,14 @@ macro_rules! gen_text {
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InvalidSymbol,
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}
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/// Text assembly error
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#[derive(Clone, Debug, PartialEq, Eq)]
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pub struct Error {
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pub kind: ErrorKind,
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pub span: Span,
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}
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/// Parse code and insert instructions
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pub fn assemble(asm: &mut Assembler, code: &str) -> Result<(), Error> {
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pub struct TextAsm<'a> {
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asm: &'a mut Assembler,
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@ -93,8 +102,10 @@ macro_rules! gen_text {
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fn run(&mut self) -> Result<(), ErrorKind> {
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loop {
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match self.lexer.next() {
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// Got an opcode
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Some(Ok(Token::Opcode(op))) => {
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match op {
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// Take all the opcodes and match them to their corresponding functions
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$(
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$(hbbytecode::opcode::$opcode)|* => paste::paste!({
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param_extract_itm!(self, $($param_i: $param_ty),*);
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@ -112,12 +123,16 @@ macro_rules! gen_text {
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self.asm.i_param_bbb(op, p0, p1, p2);
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}
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// Already matched in Logos, should not be able to obtain
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// invalid opcode.
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_ => unreachable!(),
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}
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}
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// Insert label to table
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Some(Ok(Token::Label(lbl))) => {
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self.symloc.insert(lbl, self.asm.buf.len());
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}
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// Instruction separator (LF, ;)
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Some(Ok(Token::ISep)) => (),
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Some(Ok(_)) => return Err(ErrorKind::UnexpectedToken),
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Some(Err(())) => return Err(ErrorKind::InvalidToken),
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@ -136,15 +151,20 @@ macro_rules! gen_text {
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asm.run()
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.map_err(|kind| Error { kind, span: asm.lexer.span() })?;
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// Walk table and substitute labels
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// for their addresses
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for &loc in &asm.asm.sub {
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// Extract indices from the code and get addresses from table
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let val = asm.symloc
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.get(
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&Spur::try_from_usize(bytemuck::pod_read_unaligned::<u64>(&asm.asm.buf[loc..loc+core::mem::size_of::<u64>()]) as _)
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.unwrap()
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&Spur::try_from_usize(bytemuck::pod_read_unaligned::<u64>(
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&asm.asm.buf[loc..loc + core::mem::size_of::<u64>()]) as _
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).unwrap()
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)
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.ok_or(Error { kind: ErrorKind::InvalidSymbol, span: 0..0 })?
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.to_le_bytes();
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// New address
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asm.asm.buf[loc..]
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.iter_mut()
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.zip(val)
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@ -154,6 +174,13 @@ macro_rules! gen_text {
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Ok(())
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}
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// Fun fact: this is a little hack
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// It may slow the things a little bit down, but
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// it made the macro to be made pretty nice.
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//
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// If you have any idea how to get rid of this,
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// contributions are welcome :)
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// I *likely* won't try anymore.
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enum InternalImm {
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Const(u64),
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Named(Spur),
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@ -163,9 +190,14 @@ macro_rules! gen_text {
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#[inline]
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fn insert(&self, asm: &mut Assembler) {
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match self {
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// Constant immediate, just put it in
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Self::Const(a) => a.insert(asm),
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// Label
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Self::Named(a) => {
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// Insert to the sub table that substitution will be
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// requested
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asm.sub.insert(asm.buf.len());
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// Insert value from interner in place
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asm.buf.extend((a.into_usize() as u64).to_le_bytes());
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},
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}
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@ -175,42 +207,57 @@ macro_rules! gen_text {
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};
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}
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/// Extract item by pattern, otherwise return [`ErrorKind::UnexpectedToken`]
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macro_rules! extract_pat {
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($self:expr, $pat:pat) => {
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let $pat = $self.next()?
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else { return Err(ErrorKind::UnexpectedToken) };
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else { return Err(ErrorKind::UnexpectedToken) };
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};
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}
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/// Extract operand from code
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macro_rules! extract {
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// Register (require prefixing with r)
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($self:expr, R, $id:ident) => {
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extract_pat!($self, Token::Register($id));
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};
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// Immediate
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($self:expr, I, $id:ident) => {
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let $id = match $self.next()? {
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// Either straight up integer
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Token::Integer(a) => InternalImm::Const(a),
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// …or a label
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Token::Symbol(a) => InternalImm::Named(a),
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_ => return Err(ErrorKind::UnexpectedToken),
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};
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};
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// Get u8, if not fitting, the token is claimed invalid
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($self:expr, u8, $id:ident) => {
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extract_pat!($self, Token::Integer($id));
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let $id = u8::try_from($id).map_err(|_| ErrorKind::InvalidToken)?;
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};
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// Get u16, if not fitting, the token is claimed invalid
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($self:expr, u16, $id:ident) => {
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extract_pat!($self, Token::Integer($id));
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let $id = u16::try_from($id).map_err(|_| ErrorKind::InvalidToken)?;
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};
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}
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/// Parameter extract incremental token-tree muncher
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///
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/// What else would it mean?
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macro_rules! param_extract_itm {
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($self:expr, $($id:ident: $ty:ident)? $(, $($tt:tt)*)?) => {
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// Extract pattern
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$(extract!($self, $ty, $id);)?
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$(
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// Require operand separator
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extract_pat!($self, Token::PSep);
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// And go to the next (recursive)
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// …munch munch… yummy token trees.
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param_extract_itm!($self, $($tt)*);
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)?
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};
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|
|
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@ -39,7 +39,9 @@ impl Memory {
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/// Maps host's memory into VM's memory
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///
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/// # Safety
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/// Who knows.
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/// - Your faith in the gods of UB
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/// - Addr-san claims it's fine but who knows is she isn't lying :ferrisSus:
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/// - Alright, Miri-sama is also fine with this, who knows why
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pub unsafe fn map(
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&mut self,
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host: *mut u8,
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@ -49,13 +51,14 @@ impl Memory {
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) -> Result<(), MapError> {
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let mut current_pt = self.root_pt;
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// Decide on what level depth are we going
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let lookup_depth = match pagesize {
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PageSize::Size4K => 4,
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PageSize::Size2M => 3,
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PageSize::Size1G => 2,
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};
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// Lookup pagetable above
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// Walk pagetable levels
|
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for lvl in (0..lookup_depth).rev() {
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let entry = (*current_pt)
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.table
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@ -63,8 +66,12 @@ impl Memory {
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let ptr = entry.ptr();
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match entry.permission() {
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// Still not on target and already seeing empty entry?
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// No worries! Let's create one (allocates).
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Permission::Empty => {
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// Increase children count
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(*current_pt).childen += 1;
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let table = Box::into_raw(Box::new(paging::PtPointedData {
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pt: PageTable::default(),
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}));
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|
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@ -72,28 +79,39 @@ impl Memory {
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core::ptr::write(entry, PtEntry::new(table, Permission::Node));
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current_pt = table as _;
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}
|
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// Continue walking
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Permission::Node => current_pt = ptr as _,
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_ => return Err(MapError::AlreadyMapped),
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|
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// There is some entry on place of node
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_ => return Err(MapError::PageOnNode),
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}
|
||||
}
|
||||
|
||||
let node = (*current_pt)
|
||||
.table
|
||||
.get_unchecked_mut(addr_extract_index(target, 4 - lookup_depth));
|
||||
|
||||
// Check if node is not mapped
|
||||
if node.permission() != Permission::Empty {
|
||||
return Err(MapError::AlreadyMapped);
|
||||
}
|
||||
|
||||
// Write entry
|
||||
(*current_pt).childen += 1;
|
||||
core::ptr::write(
|
||||
(*current_pt)
|
||||
.table
|
||||
.get_unchecked_mut(addr_extract_index(target, 4 - lookup_depth)),
|
||||
PtEntry::new(host.cast(), perm),
|
||||
);
|
||||
core::ptr::write(node, PtEntry::new(host.cast(), perm));
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Unmaps pages from VM's memory
|
||||
///
|
||||
/// If errors, it only means there is no entry to unmap and in most cases
|
||||
/// just should be ignored.
|
||||
pub fn unmap(&mut self, addr: u64) -> Result<(), NothingToUnmap> {
|
||||
let mut current_pt = self.root_pt;
|
||||
let mut page_tables = [core::ptr::null_mut(); 5];
|
||||
|
||||
// Walk page table in reverse
|
||||
for lvl in (0..5).rev() {
|
||||
let entry = unsafe {
|
||||
(*current_pt)
|
||||
|
|
@ -103,30 +121,42 @@ impl Memory {
|
|||
|
||||
let ptr = entry.ptr();
|
||||
match entry.permission() {
|
||||
// Nothing is there, throw an error, not critical!
|
||||
Permission::Empty => return Err(NothingToUnmap),
|
||||
// Node – Save to visited pagetables and continue walking
|
||||
Permission::Node => {
|
||||
page_tables[lvl as usize] = entry;
|
||||
current_pt = ptr as _
|
||||
}
|
||||
// Page entry – zero it out!
|
||||
// Zero page entry is completely valid entry with
|
||||
// empty permission - no UB here!
|
||||
_ => unsafe {
|
||||
core::ptr::write(entry, Default::default());
|
||||
core::ptr::write_bytes(entry, 0, 1);
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
// Now walk in order visited page tables
|
||||
for entry in page_tables.into_iter() {
|
||||
// Level not visited, skip.
|
||||
if entry.is_null() {
|
||||
continue;
|
||||
}
|
||||
|
||||
unsafe {
|
||||
let children = &mut (*(*entry).ptr()).pt.childen;
|
||||
*children -= 1;
|
||||
if *children == 0 {
|
||||
core::mem::drop(Box::from_raw((*entry).ptr() as *mut PageTable));
|
||||
}
|
||||
|
||||
core::ptr::write(entry, Default::default());
|
||||
// Decrease children count
|
||||
*children -= 1;
|
||||
|
||||
// If there are no children, deallocate.
|
||||
if *children == 0 {
|
||||
let _ = Box::from_raw((*entry).ptr() as *mut PageTable);
|
||||
|
||||
// Zero visited entry
|
||||
core::ptr::write_bytes(entry, 0, 1);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -149,12 +179,7 @@ impl Memory {
|
|||
addr,
|
||||
target,
|
||||
count,
|
||||
|perm| {
|
||||
matches!(
|
||||
perm,
|
||||
Permission::Readonly | Permission::Write | Permission::Exec
|
||||
)
|
||||
},
|
||||
perm_check::readable,
|
||||
|src, dst, count| core::ptr::copy_nonoverlapping(src, dst, count),
|
||||
traph,
|
||||
)
|
||||
|
|
@ -177,7 +202,7 @@ impl Memory {
|
|||
addr,
|
||||
source.cast_mut(),
|
||||
count,
|
||||
|perm| perm == Permission::Write,
|
||||
perm_check::writable,
|
||||
|dst, src, count| core::ptr::copy_nonoverlapping(src, dst, count),
|
||||
traph,
|
||||
)
|
||||
|
|
@ -188,8 +213,7 @@ impl Memory {
|
|||
///
|
||||
/// # Safety
|
||||
/// - Same as for [`Self::load`] and [`Self::store`]
|
||||
/// - Your faith in the gods of UB
|
||||
/// - Addr-san claims it's fine but who knows is she isn't lying :ferrisSus:
|
||||
/// - This function has been rewritten and is now pretty much boring
|
||||
pub unsafe fn block_copy(
|
||||
&mut self,
|
||||
mut src: u64,
|
||||
|
|
@ -209,17 +233,13 @@ impl Memory {
|
|||
count: usize,
|
||||
traph: &mut impl HandlePageFault,
|
||||
) -> Result<(), BlkCopyError> {
|
||||
// Load to buffer
|
||||
self.memory_access(
|
||||
MemoryAccessReason::Load,
|
||||
src,
|
||||
buf,
|
||||
STACK_BUFFER_SIZE,
|
||||
|perm| {
|
||||
matches!(
|
||||
perm,
|
||||
Permission::Readonly | Permission::Write | Permission::Exec
|
||||
)
|
||||
},
|
||||
count,
|
||||
perm_check::readable,
|
||||
|src, dst, count| core::ptr::copy(src, dst, count),
|
||||
traph,
|
||||
)
|
||||
|
|
@ -228,12 +248,13 @@ impl Memory {
|
|||
addr,
|
||||
})?;
|
||||
|
||||
// Store from buffer
|
||||
self.memory_access(
|
||||
MemoryAccessReason::Store,
|
||||
dst,
|
||||
buf,
|
||||
count,
|
||||
|perm| perm == Permission::Write,
|
||||
perm_check::writable,
|
||||
|dst, src, count| core::ptr::copy(src, dst, count),
|
||||
traph,
|
||||
)
|
||||
|
|
@ -246,24 +267,37 @@ impl Memory {
|
|||
}
|
||||
}
|
||||
|
||||
const STACK_BUFFER_SIZE: usize = 4096;
|
||||
// Buffer size (defaults to 4 KiB, a smallest page size on most platforms)
|
||||
const BUF_SIZE: usize = 4096;
|
||||
|
||||
// Decide if to use stack-allocated buffer or to heap allocate
|
||||
// Deallocation is again decided on size at the end of the function
|
||||
let mut buf = MaybeUninit::<[u8; STACK_BUFFER_SIZE]>::uninit();
|
||||
// This should be equal to `BUF_SIZE`
|
||||
#[repr(align(4096))]
|
||||
struct AlignedBuf([MaybeUninit<u8>; BUF_SIZE]);
|
||||
|
||||
let n_buffers = count / STACK_BUFFER_SIZE;
|
||||
let rem = count % STACK_BUFFER_SIZE;
|
||||
// Safety: Assuming uninit of array of MaybeUninit is sound
|
||||
let mut buf = AlignedBuf(MaybeUninit::uninit().assume_init());
|
||||
|
||||
// Calculate how many times we need to copy buffer-sized blocks if any and the rest.
|
||||
let n_buffers = count / BUF_SIZE;
|
||||
let rem = count % BUF_SIZE;
|
||||
|
||||
// Copy buffer-sized blocks
|
||||
for _ in 0..n_buffers {
|
||||
self.act(src, dst, buf.as_mut_ptr().cast(), STACK_BUFFER_SIZE, traph)?;
|
||||
src += STACK_BUFFER_SIZE as u64;
|
||||
dst += STACK_BUFFER_SIZE as u64;
|
||||
self.act(src, dst, buf.0.as_mut_ptr().cast(), BUF_SIZE, traph)?;
|
||||
src += BUF_SIZE as u64;
|
||||
dst += BUF_SIZE as u64;
|
||||
}
|
||||
|
||||
self.act(src, dst, buf.as_mut_ptr().cast(), rem, traph)
|
||||
// Copy the rest (if any)
|
||||
if rem != 0 {
|
||||
self.act(src, dst, buf.0.as_mut_ptr().cast(), rem, traph)?;
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
// Everyone behold, the holy function, the god of HBVM memory accesses!
|
||||
|
||||
/// Split address to pages, check their permissions and feed pointers with offset
|
||||
/// to a specified function.
|
||||
///
|
||||
|
|
@ -279,10 +313,11 @@ impl Memory {
|
|||
action: fn(*mut u8, *mut u8, usize),
|
||||
traph: &mut impl HandlePageFault,
|
||||
) -> Result<(), u64> {
|
||||
// Create new splitter
|
||||
let mut pspl = AddrPageLookuper::new(src, len, self.root_pt);
|
||||
loop {
|
||||
match pspl.next() {
|
||||
// Page found
|
||||
// Page is found
|
||||
Some(Ok(AddrPageLookupOk {
|
||||
vaddr,
|
||||
ptr,
|
||||
|
|
@ -293,12 +328,13 @@ impl Memory {
|
|||
return Err(vaddr);
|
||||
}
|
||||
|
||||
// Perform memory action and bump dst pointer
|
||||
// Perform specified memory action and bump destination pointer
|
||||
action(ptr, dst, size);
|
||||
dst = unsafe { dst.add(size) };
|
||||
}
|
||||
// No page found
|
||||
Some(Err(AddrPageLookupError { addr, size })) => {
|
||||
// Execute page fault handler
|
||||
// Attempt to execute page fault handler
|
||||
if traph.page_fault(reason, self, addr, size, dst) {
|
||||
// Shift the splitter address
|
||||
pspl.bump(size);
|
||||
|
|
@ -306,16 +342,17 @@ impl Memory {
|
|||
// Bump dst pointer
|
||||
dst = unsafe { dst.add(size as _) };
|
||||
} else {
|
||||
return Err(addr); // Unhandleable
|
||||
return Err(addr); // Unhandleable, VM will yield.
|
||||
}
|
||||
}
|
||||
// No remaining pages, we are done!
|
||||
None => return Ok(()),
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// Result from address split
|
||||
/// Good result from address split
|
||||
struct AddrPageLookupOk {
|
||||
/// Virtual address
|
||||
vaddr: u64,
|
||||
|
|
@ -330,6 +367,7 @@ struct AddrPageLookupOk {
|
|||
perm: Permission,
|
||||
}
|
||||
|
||||
/// Errornous address split result
|
||||
struct AddrPageLookupError {
|
||||
/// Address of failure
|
||||
addr: u64,
|
||||
|
|
@ -351,7 +389,7 @@ struct AddrPageLookuper {
|
|||
}
|
||||
|
||||
impl AddrPageLookuper {
|
||||
/// Create a new page splitter
|
||||
/// Create a new page lookuper
|
||||
pub const fn new(addr: u64, size: usize, pagetable: *const PageTable) -> Self {
|
||||
Self {
|
||||
addr,
|
||||
|
|
@ -430,7 +468,11 @@ impl Iterator for AddrPageLookuper {
|
|||
}
|
||||
}
|
||||
|
||||
fn addr_extract_index(addr: u64, lvl: u8) -> usize {
|
||||
/// Extract index in page table on specified level
|
||||
///
|
||||
/// The level shall not be larger than 4, otherwise
|
||||
/// the output of the function is unspecified (yes, it can also panic :)
|
||||
pub fn addr_extract_index(addr: u64, lvl: u8) -> usize {
|
||||
debug_assert!(lvl <= 4);
|
||||
usize::try_from((addr >> (lvl * 9 + 12)) & ((1 << 9) - 1)).expect("?conradluget a better CPU")
|
||||
}
|
||||
|
|
@ -462,24 +504,36 @@ impl PageSize {
|
|||
|
||||
/// Unhandled load access trap
|
||||
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
|
||||
#[display(fmt = "Load access error at address {_0:#x}")]
|
||||
pub struct LoadError(u64);
|
||||
|
||||
/// Unhandled store access trap
|
||||
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
|
||||
#[display(fmt = "Store access error at address {_0:#x}")]
|
||||
pub struct StoreError(u64);
|
||||
|
||||
/// There was no entry in page table to unmap
|
||||
///
|
||||
/// No worry, don't panic, nothing bad has happened,
|
||||
/// but if you are 120% sure there should be something,
|
||||
/// double-check your addresses.
|
||||
#[derive(Clone, Copy, Display, Debug)]
|
||||
#[display(fmt = "There was no entry to unmap")]
|
||||
pub struct NothingToUnmap;
|
||||
|
||||
/// Reason to access memory
|
||||
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
|
||||
pub enum MemoryAccessReason {
|
||||
Load,
|
||||
Store,
|
||||
}
|
||||
|
||||
/// Error occured when copying a block of memory
|
||||
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
|
||||
pub struct BlkCopyError {
|
||||
/// Kind of access
|
||||
access_reason: MemoryAccessReason,
|
||||
/// VM Address
|
||||
addr: u64,
|
||||
}
|
||||
|
||||
|
|
@ -504,7 +558,34 @@ impl From<StoreError> for VmRunError {
|
|||
}
|
||||
}
|
||||
|
||||
/// Error mapping
|
||||
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
|
||||
pub enum MapError {
|
||||
/// Entry was already mapped
|
||||
#[display(fmt = "There is already a page mapped on specified address")]
|
||||
AlreadyMapped,
|
||||
/// When walking a page entry was
|
||||
/// encounterd.
|
||||
#[display(fmt = "There was a page mapped on the way instead of node")]
|
||||
PageOnNode,
|
||||
}
|
||||
|
||||
/// Permisison checks
|
||||
pub mod perm_check {
|
||||
use super::paging::Permission;
|
||||
|
||||
/// Page is readable
|
||||
#[inline(always)]
|
||||
pub fn readable(perm: Permission) -> bool {
|
||||
matches!(
|
||||
perm,
|
||||
Permission::Readonly | Permission::Write | Permission::Exec
|
||||
)
|
||||
}
|
||||
|
||||
/// Page is writable
|
||||
#[inline(always)]
|
||||
pub fn writable(perm: Permission) -> bool {
|
||||
perm == Permission::Write
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -5,6 +5,10 @@ use super::{Memory, MemoryAccessReason, PageSize};
|
|||
/// Handle VM traps
|
||||
pub trait HandlePageFault {
|
||||
/// Handle page fault
|
||||
///
|
||||
/// Return true if handling was sucessful,
|
||||
/// otherwise the program will be interrupted and will
|
||||
/// yield an error.
|
||||
fn page_fault(
|
||||
&mut self,
|
||||
reason: MemoryAccessReason,
|
||||
|
|
|
|||
6
spec.md
6
spec.md
|
|
@ -173,9 +173,9 @@
|
|||
### Unconditional jump
|
||||
- Type BBD
|
||||
|
||||
| Opcode | Name | Action |
|
||||
|:------:|:----:|:-------------------------------------------------:|
|
||||
| 33 | JAL | Save current PC to `#0` and jump at `#1 + imm #2` |
|
||||
| Opcode | Name | Action |
|
||||
|:------:|:----:|:--------------------------------------------------:|
|
||||
| 33 | JAL | Save PC past JAL to `#0` and jump at `#1 + imm #2` |
|
||||
|
||||
### Conditional jumps
|
||||
- Type BBD
|
||||
|
|
|
|||
Loading…
Reference in a new issue