From 4fb80fe158f07c13c188795a7a54ec082841dc23 Mon Sep 17 00:00:00 2001
From: Michael Sippel <micha@fragmental.art>
Date: Sun, 12 May 2024 04:21:17 +0200
Subject: [PATCH] add disassembly & display functions
---
src/assembler.rs | 34 +++++++++++++++++++++++++++++++++-
src/linker.rs | 15 +++++++++++++++
src/vm.rs | 14 ++++++++++++++
3 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/src/assembler.rs b/src/assembler.rs
index 74a3049..4e1f560 100644
--- a/src/assembler.rs
+++ b/src/assembler.rs
@@ -5,7 +5,7 @@ use {
}
};
-#[derive(Clone)]
+#[derive(Clone, Debug)]
pub enum AssemblyWord {
Symbol( LinkAddr ),
Lit( VM_Word )
@@ -25,6 +25,38 @@ impl AssemblyWord {
}
}
+pub fn disassemble(bytecode: &Vec< AssemblyWord >) -> Vec< String > {
+ let mut words = bytecode.iter();
+ let mut result = Vec::new();
+
+ let mut remaining_params = 0;
+
+ while let Some(w) = words.next() {
+ match w {
+ AssemblyWord::Symbol( addr ) => {
+ result.push( format!("{}", addr) );
+ remaining_params -= 1;
+ }
+ AssemblyWord::Lit(w) => {
+ if remaining_params == 0 {
+ if *w < 18 {
+ let inst : VM_Instruction = unsafe { std::mem::transmute(*w) };
+ result.push(format!("{:?}", inst));
+ remaining_params = inst.param_length();
+ } else {
+ result.push(format!("invalid opcode {}", w));
+ }
+ } else {
+ remaining_params -= 1;
+ result.push(format!("{}", w));
+ }
+ }
+ }
+ }
+
+ result
+}
+
pub struct Assembler {
words: Vec< AssemblyWord >,
}
diff --git a/src/linker.rs b/src/linker.rs
index 1095954..5c48f5b 100644
--- a/src/linker.rs
+++ b/src/linker.rs
@@ -12,6 +12,21 @@ pub enum LinkAddr {
}
}
+impl std::fmt::Display for LinkAddr {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
+ match self {
+ LinkAddr::Absolute(addr) =>
+ write!(f, "{:x}", addr),
+ LinkAddr::Relative{ symbol, offset } =>
+ if *offset == 0 {
+ write!(f, "{}", symbol)
+ } else {
+ write!(f, "{}+{:x}", symbol, offset)
+ }
+ }
+ }
+}
+
pub struct Section {
addr: VM_Word,
data: Vec< AssemblyWord >
diff --git a/src/vm.rs b/src/vm.rs
index 1e27a86..0d71434 100644
--- a/src/vm.rs
+++ b/src/vm.rs
@@ -12,6 +12,20 @@ pub enum VM_Instruction {
BitwiseNot,
}
+impl VM_Instruction {
+ pub fn param_length(&self) -> usize {
+ match self {
+ VM_Instruction::Jmp |
+ VM_Instruction::Call |
+ VM_Instruction::Branch |
+ VM_Instruction::Lit => {
+ 1
+ },
+ _ => 0
+ }
+ }
+}
+
pub struct VM {
pub data_stack: Vec< VM_Word >,
pub call_stack: Vec< VM_Word >,