Implemented an assembler

src/asm/compilerX86.go

@@ -0,0 +1,54 @@
+package asm
+
+import (
+	"encoding/binary"
+
+	"git.urbach.dev/cli/q/src/x86"
+)
+
+type compilerX86 struct {
+	*compiler
+}
+
+func (c *compilerX86) Compile(instr Instruction) {
+	switch instr := instr.(type) {
+	case *Call:
+		c.code = x86.Call(c.code, 0)
+		end := len(c.code)
+
+		c.Defer(func() {
+			address, exists := c.labels[instr.Label]
+
+			if !exists {
+				panic("unknown label: " + instr.Label)
+			}
+
+			offset := address - end
+			binary.LittleEndian.PutUint32(c.code[end-4:end], uint32(offset))
+		})
+	case *Label:
+		c.labels[instr.Name] = len(c.code)
+	case *MoveRegisterLabel:
+		c.code = x86.LoadAddress(c.code, instr.Destination, 0)
+		end := len(c.code)
+
+		c.Defer(func() {
+			address, exists := c.labels[instr.Label]
+
+			if !exists {
+				panic("unknown label: " + instr.Label)
+			}
+
+			offset := address - end
+			binary.LittleEndian.PutUint32(c.code[end-4:end], uint32(offset))
+		})
+	case *MoveRegisterNumber:
+		c.code = x86.MoveRegisterNumber(c.code, instr.Destination, instr.Number)
+	case *MoveRegisterRegister:
+		c.code = x86.MoveRegisterRegister(c.code, instr.Destination, instr.Source)
+	case *Return:
+		c.code = x86.Return(c.code)
+	case *Syscall:
+		c.code = x86.Syscall(c.code)
+	}
+}