small stuff

src/arch/x86_64/encode.rs

@@ -7,7 +7,7 @@ pub struct Encoder {
     pub missing: Vec<(usize, Symbol)>,
 }
 
-pub fn encode_program(p: &Program<X86_64>) -> Result<LinkedProgram<u64>, CompilerMsg> {
+pub fn compile(p: &Program<X86_64>) -> Result<LinkedProgram<u64>, CompilerMsg> {
     let mut encoder = Encoder::new(p.sym_count());
 
     p.encode_data(&mut encoder.data, &mut encoder.sym_tab);
@@ -24,7 +24,7 @@ pub fn encode_program(p: &Program<X86_64>) -> Result<LinkedProgram<u64>, Compile
         let addr = encoder
             .sym_tab
             .get(sym)
-            .ok_or(CompilerMsg::from(format!("unknown symbol {sym:?}")))?;
+            .ok_or(CompilerMsg::from(format!("missing symbol {sym:?}")))?;
         encoder.data[pos..pos + 4].copy_from_slice(&addr_offset(pos, addr))
     }
 
@@ -37,12 +37,12 @@ pub fn encode_program(p: &Program<X86_64>) -> Result<LinkedProgram<u64>, Compile
 type BInstr = crate::backend::Instr<X86_64>;
 fn compile_instr(encoder: &mut Encoder, instr: &BInstr) -> Result<(), CompilerMsg> {
     match instr {
-        BInstr::Copy { dst, src } => todo!(),
         BInstr::Asm(asm) => {
             for i in &asm.instrs {
                 encoder.asm(*i)?;
             }
         }
+        _ => todo!(),
     }
     Ok(())
 }
@@ -95,13 +95,7 @@ impl Encoder {
             0x8d,
             0x05 | (dst.base() << 3),
         ]);
-        let Some(addr) = self.sym_tab.get(sym) else {
+        self.sym_offset4(sym);
-            let pos = self.data.len();
-            self.data.extend([0; 4]);
-            self.missing.push((pos, sym));
-            return;
-        };
-        self.data.extend(addr_offset(self.data.len(), addr));
     }
 
     pub fn int(&mut self, code: u8) {
@@ -112,6 +106,17 @@ impl Encoder {
         self.data.extend([0x0f, 0x05])
     }
 
+    /// inserts a 32 bit offset from a symbol
+    pub fn sym_offset4(&mut self, sym: Symbol) {
+        let Some(addr) = self.sym_tab.get(sym) else {
+            let pos = self.data.len();
+            self.data.extend([0; 4]);
+            self.missing.push((pos, sym));
+            return;
+        };
+        self.data.extend(addr_offset(self.data.len(), addr));
+    }
+
     pub fn asm(&mut self, instr: Instr) -> Result<(), CompilerMsg> {
         match instr {
             Instr::Mov { dst, src } => self.mov(dst, src)?,

src/arch/x86_64/mod.rs

@@ -21,6 +21,6 @@ impl Arch for X86_64 {
     type Asm = Asm;
     type Addr = u64;
     fn compile(p: &Program<Self>) -> Result<LinkedProgram<Self::Addr>, CompilerMsg> {
-        encode_program(p)
+        compile(p)
     }
 }

src/backend/ir/mod.rs

@@ -24,7 +24,10 @@ pub struct Func<A: Arch> {
 }
 
 pub enum Instr<A: Arch> {
+    Set { dst: VarId, src: Vec<u8> },
+    Call { dst: FnId, args: Vec<VarId> },
     Copy { dst: VarId, src: VarId },
+    Free(VarId),
     Asm(A::Asm),
 }