Add Disassemble, fix bug in position calculation

* Disassemble structure can be used for dumping an object section
* Assembler position calculation was messing up, causing jump addresses
  to be wrong. This is fixed.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

src/main.rs

@@ -1,7 +1,6 @@
 #![allow(dead_code)]
 
 mod common;
-//mod syn;
 mod vm;
 
 use std::{convert::TryFrom, env, fs, io, process};
@@ -32,10 +31,31 @@ fn main() -> Result<()> {
         }
     };
     let obj = vm::obj::obj::Object::try_from(&ast)?;
-    //println!("{:#?}", obj);
     let mut vm = vm::vm::Vm::new();
     vm.load_object(obj, 1024 * 1024 * 64)?; // 64mb
     let status = vm.run()?;
-    println!("status: {}", status);
+    println!("{}", status);
     Ok(())
 }
+
+
+    /*
+fn dump(obj: &Object) {
+    use vm::obj::obj::Section;
+    use vm::visit::VisitInst;
+    let mut stdout = io::stdout();
+    for section in &obj.sections {
+        let mut disasm = match section {
+            Section::Code { start, contents, .. }
+            | Section::Data { start, contents, .. } => {
+                vm::disassemble::Disassemble::new(&mut stdout, contents, *start)
+            }
+            Section::Meta { .. } => continue,
+        };
+        while !disasm.is_done() {
+            disasm.visit_inst()?;
+        }
+        println!();
+    }
+}
+    */

src/vm/disassemble.rs

@@ -0,0 +1,294 @@
+use crate::vm::{
+    error::*,
+    inst::*,
+    mem::MemCursor,
+    reg::*,
+    visit::*,
+    vm::{Addr, HalfWord, Word},
+};
+use std::io::Write;
+
+const WIDTH: usize = 60;
+
+pub struct Disassemble<'w, 'o> {
+    writer: &'w mut dyn Write,
+    cursor: MemCursor<'o>,
+    addr_offset: Addr,
+}
+
+impl<'w, 'o> Disassemble<'w, 'o> {
+    pub fn new(writer: &'w mut dyn Write, content: &'o [u8], addr_offset: Addr) -> Self {
+        Disassemble {
+            writer,
+            cursor: MemCursor::new(content),
+            addr_offset,
+        }
+    }
+
+    pub fn is_done(&self) -> bool {
+        self.cursor.position() >= (self.cursor.get_ref().len() as u64)
+    }
+
+    fn adv(&mut self) -> Result<()> {
+        // note the () - this explicitly clones the cursor
+        let op = self.cursor().next_u16()?;
+        let next = self.cursor.position() + (inst_len(op) as u64);
+        self.cursor.set_position(next);
+        Ok(())
+    }
+
+    fn write_addr(&mut self, addr: Addr) {
+        write!(self.writer, "{:06x} | ", self.addr_offset + addr).unwrap();
+    }
+
+    fn write_bytes(&mut self, bytes: &[u8]) {
+        for b in bytes {
+            write!(self.writer, "{:02x} ", b).unwrap();
+        }
+    }
+
+    fn write_inst_bytes(&mut self, op: InstOp) {
+        let len = inst_len(op);
+        let start = self.cursor.position() as usize;
+        let end = start + len;
+        let bytes = &self.cursor.get_ref()[start..end];
+        self.write_bytes(bytes);
+    }
+
+    fn write_r1_r2_inst(&mut self, addr: Addr, op: InstOp, r1: Reg, r2: Reg) {
+        let len = inst_len(op);
+        let line_width = 6 + 3 + (3 * len);
+        let line_offset = WIDTH - line_width;
+        self.write_addr(addr);
+        self.write_inst_bytes(op);
+
+        let iname = inst_name(op).unwrap();
+        let r1name = reg_name(r1).unwrap().to_lowercase();
+        let r2name = reg_name(r2).unwrap().to_lowercase();
+
+        writeln!(
+            self.writer,
+            "{}| {:>10} %{} %{}",
+            " ".repeat(line_offset),
+            iname,
+            r1name,
+            r2name
+        )
+        .unwrap();
+    }
+
+    fn write_r1_inst(&mut self, addr: Addr, op: InstOp, r1: Reg) {
+        let line_width = 6 + 3 + (3 * inst_len(op));
+        let line_offset = WIDTH - line_width;
+        self.write_addr(addr);
+        self.write_inst_bytes(op);
+
+        let iname = inst_name(op).unwrap();
+        let r1name = reg_name(r1).unwrap().to_lowercase();
+
+        writeln!(
+            self.writer,
+            "{}| {:>10} %{}",
+            " ".repeat(line_offset),
+            iname,
+            r1name,
+        )
+        .unwrap();
+    }
+
+    fn write_r1_imm_inst(&mut self, addr: Addr, op: InstOp, r1: Reg, imm: Word) {
+        let line_width = 6 + 3 + (3 * inst_len(op));
+        let line_offset = WIDTH - line_width;
+        self.write_addr(addr);
+        self.write_inst_bytes(op);
+
+        let iname = inst_name(op).unwrap();
+        let r1name = reg_name(r1).unwrap().to_lowercase();
+
+        writeln!(
+            self.writer,
+            "{}| {:>10} %{} {:#X}",
+            " ".repeat(line_offset),
+            iname,
+            r1name,
+            imm,
+        )
+        .unwrap();
+    }
+}
+
+impl VisitInst for Disassemble<'_, '_> {
+    type Out = ();
+
+    fn cursor(&self) -> MemCursor {
+        self.cursor.clone()
+    }
+
+    fn add(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), ADD, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn mul(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), MUL, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn div(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), DIV, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn mod_(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), MOD, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn ineg(&mut self, r1: Reg) -> Result<Self::Out> {
+        self.write_r1_inst(self.cursor.position(), INEG, r1);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn and(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), AND, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn or(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), OR, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn inv(&mut self, r1: Reg) -> Result<Self::Out> {
+        self.write_r1_inst(self.cursor.position(), INV, r1);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn not(&mut self, r1: Reg) -> Result<Self::Out> {
+        self.write_r1_inst(self.cursor.position(), NOT, r1);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn xor(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), XOR, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn shl(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), SHL, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn shr(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), SHR, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn cmpeq(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), CMPEQ, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn cmplt(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), CMPLT, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn jmp(&mut self, r1: Reg) -> Result<Self::Out> {
+        self.write_r1_inst(self.cursor.position(), JMP, r1);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn jz(&mut self, r1: Reg) -> Result<Self::Out> {
+        self.write_r1_inst(self.cursor.position(), JZ, r1);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn jnz(&mut self, r1: Reg) -> Result<Self::Out> {
+        self.write_r1_inst(self.cursor.position(), JNZ, r1);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn load(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), LOAD, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn regcopy(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), REGCOPY, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn storeimm64(&mut self, r1: Reg, w1: Word) -> Result<Self::Out> {
+        self.write_r1_imm_inst(self.cursor.position(), STOREIMM64, r1, w1);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn storeimm32(&mut self, r1: Reg, w1: HalfWord) -> Result<Self::Out> {
+        self.write_r1_imm_inst(self.cursor.position(), STOREIMM32, r1, w1 as u64);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn memcopy(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), MEMCOPY, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn store(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out> {
+        self.write_r1_r2_inst(self.cursor.position(), STORE, r1, r2);
+        self.adv()?;
+        Ok(())
+    }
+
+    fn halt(&mut self) -> Result<Self::Out> {
+        let line_width = 6 + 3 + 3 + 3;
+        let line_offset = WIDTH - line_width;
+        self.write_addr(self.cursor.position());
+        self.write_inst_bytes(HALT);
+        writeln!(
+            self.writer,
+            "{}| {:>10}",
+            " ".repeat(line_offset),
+            "HALT",
+        ).unwrap();
+        self.adv()?;
+        Ok(())
+    }
+
+    fn nop(&mut self) -> Result<Self::Out> {
+        let line_width = 6 + 3 + 3 + 3;
+        let line_offset = WIDTH - line_width;
+        self.write_addr(self.cursor.position());
+        self.write_inst_bytes(NOP);
+        writeln!(
+            self.writer,
+            "{}| {:>10}",
+            " ".repeat(line_offset),
+            "NOP",
+        ).unwrap();
+        self.adv()?;
+        Ok(())
+    }
+}

src/vm/mem.rs

@@ -8,6 +8,7 @@ use std::{
 const R1_MASK: u16 = 0b1111_1100_0000_0000;
 const R2_MASK: u16 = 0b0000_0011_1111_0000;
 
+#[derive(Debug, Clone)]
 pub struct MemCursor<'mem> {
     cursor: Cursor<&'mem [u8]>,
 }

src/vm/mod.rs

@@ -1,3 +1,4 @@
+pub mod disassemble;
 pub mod error;
 pub mod flags;
 pub mod inst;

src/vm/obj/assemble/mod.rs

@@ -60,7 +60,6 @@ impl<'a> Assemble<'a> {
         for block in self.ast.iter() {
             let locals = Self::gather_symbols(block, false)?;
             self.symbols.replace_locals(locals);
-
             match block {
                 SectionBlock::Data { org, body } | SectionBlock::Code { org, body } => {
                     let mut bytes = Vec::new();
@@ -191,19 +190,20 @@ impl<'a> Assemble<'a> {
             Inst::Jnz(r1) => builder.op(JNZ).r1(*r1),
             Inst::Load(r1, r2) => builder.op(LOAD).r1(*r1).r2(*r2),
             Inst::Store(r1, r2) => builder.op(STORE).r1(*r1).r2(*r2),
-            Inst::StoreImm(r1, imm) => {
-                let imm = match imm {
-                    ImmValue::Number(num) => *num,
-                    ImmValue::Label(name) => {
-                        self.symbols.get(name).expect("TODO: value label not found")
-                    }
-                };
-                if imm <= (u32::max_value() as u64) {
-                    builder.op(STOREIMM32).r1(*r1).imm32(imm as u32)
+            Inst::StoreImm(r1, imm) => match imm {
+                ImmValue::Number(num) => {
+                    if *num > (u32::max_value() as u64) {
+                        builder.op(STOREIMM64).imm64(*num)
                     } else {
-                    builder.op(STOREIMM64).r1(*r1).imm64(imm)
+                        builder.op(STOREIMM32).imm32(*num as u32)
                     }
                 }
+                ImmValue::Label(name) => {
+                    let imm = self.symbols.get(name).expect("TODO: value label not found");
+                    builder.op(STOREIMM64).imm64(imm)
+                }
+            }
+            .r1(*r1),
             Inst::MemCopy(r1, r2) => builder.op(MEMCOPY).r1(*r1).r2(*r2),
             Inst::RegCopy(r1, r2) => builder.op(REGCOPY).r1(*r1).r2(*r2),
             Inst::Nop => builder.op(NOP),

src/vm/reg.rs

@@ -7,6 +7,15 @@ macro_rules! registers {
         $(
             pub const $variant: Reg = $value;
         )*
+
+        pub fn reg_name(reg: Reg) -> Option<&'static str> {
+            match reg {
+                $(
+                    $value => Some(stringify!($variant)),
+                )*
+                _ => None,
+            }
+        }
     };
 }
 
@@ -91,5 +100,6 @@ registers! {
     R47 = 61,
     R48 = 62,
     R49 = 63,
-    LAST_REG = R49,
 }
+
+pub const LAST_REG: Reg = R49;

src/vm/tick.rs

@@ -1,9 +1,8 @@
 use crate::vm::{error::*, flags::Flags, inst::*, reg::*, vm::*, visit::*, mem::MemCursor};
-use std::io::stdin;
 
 impl Vm {
     pub fn tick(&mut self) -> Result<()> {
-        let next_ip = visit_inst(self)?;
+        let next_ip = self.visit_inst()?;
         self.set_reg(IP, next_ip);
         Ok(())
     }
@@ -23,7 +22,7 @@ impl Vm {
     }
 }
 
-impl InstAcceptor for Vm {
+impl VisitInst for Vm {
     type Out = Addr;
 
     fn cursor(&self) -> MemCursor {

src/vm/visit.rs

@@ -6,7 +6,7 @@ use crate::vm::{
     vm::{HalfWord, Word},
 };
 
-pub trait InstAcceptor {
+pub trait VisitInst {
     type Out;
 
     fn cursor(&self) -> MemCursor;
@@ -35,22 +35,22 @@ pub trait InstAcceptor {
     fn store(&mut self, r1: Reg, r2: Reg) -> Result<Self::Out>;
     fn halt(&mut self) -> Result<Self::Out>;
     fn nop(&mut self) -> Result<Self::Out>;
-}
 
-pub fn visit_inst<A: InstAcceptor>(acceptor: &mut A) -> Result<A::Out> {
-    let mut cursor = acceptor.cursor();
+    fn visit_inst(&mut self) -> Result<Self::Out> {
+        let mut cursor = self.cursor();
+        //panic!("cursor pos: {}", cursor.position());
         let op = cursor.next_u16()?;
 
         macro_rules! r1_r2_inst {
             ($fun:ident) => {{
                 let (r1, r2) = cursor.next_regs()?;
-            acceptor.$fun(r1, r2)
+                self.$fun(r1, r2)
             }};
         }
         macro_rules! r1_inst {
             ($fun:ident) => {{
                 let r1 = cursor.next_reg()?;
-            acceptor.$fun(r1)
+                self.$fun(r1)
             }};
         }
 
@@ -79,17 +79,18 @@ pub fn visit_inst<A: InstAcceptor>(acceptor: &mut A) -> Result<A::Out> {
                 // skip
                 cursor.next_u32()?;
                 let imm = cursor.next_u64()?;
-            acceptor.storeimm64(r1, imm)
+                self.storeimm64(r1, imm)
             }
             STOREIMM32 => {
                 let r1 = cursor.next_reg()?;
                 let imm = cursor.next_u32()?;
-            acceptor.storeimm32(r1, imm)
+                self.storeimm32(r1, imm)
             }
             MEMCOPY => r1_r2_inst!(memcopy),
             STORE => r1_r2_inst!(store),
-        HALT => acceptor.halt(),
-        NOP => acceptor.nop(),
+            HALT => self.halt(),
+            NOP => self.nop(),
             _ => Err(VmError::IllegalOp { op }),
         }
     }
+}