Added int instruction which calls a trap.

This is work-in-progress on skx#1, because it lays the groundwork
for a series of traps but doesn't implement any itself.

They will come next.

compiler/compiler.go

@@ -160,6 +160,9 @@ func (p *Compiler) Compile() {
  case token.GOTO:
  p.jumpOp(opcode.JUMP_TO)
 
+ case token.TRAP:
+ p.trapOp()
+
  case token.JMP:
  p.jumpOp(opcode.JUMP_TO)
 
@@ -462,7 +465,8 @@ func (p *Compiler) callOp() {
  switch p.curToken.Type {
 
  case token.INT:
- addr, _ := strconv.Atoi(p.curToken.Literal)
+ addr, _ := strconv.ParseInt(p.curToken.Literal, 0, 64)
+
  len1 := addr % 256
  len2 := (addr - len1) / 256
 
@@ -481,6 +485,28 @@ func (p *Compiler) callOp() {
 
 }
 
+// trapOp inserts an interrupt call / trap
+func (p *Compiler) trapOp() {
+
+ // advance to the target
+ p.nextToken()
+
+ // The jump might be an absolute target, or a label.
+ switch p.curToken.Type {
+
+ case token.INT:
+ addr, _ := strconv.ParseInt(p.curToken.Literal, 0, 64)
+ len1 := addr % 256
+ len2 := (addr - len1) / 256
+
+ p.bytecode = append(p.bytecode, byte(opcode.TRAP_OP))
+ p.bytecode = append(p.bytecode, byte(len1))
+ p.bytecode = append(p.bytecode, byte(len2))
+ default:
+ fmt.Printf("Fail!")
+ }
+}
+
 // jumpOp inserts a direct jump
 func (p *Compiler) jumpOp(operator int) {
 
@@ -494,7 +520,7 @@ func (p *Compiler) jumpOp(operator int) {
  switch p.curToken.Type {
 
  case token.INT:
- addr, _ := strconv.Atoi(p.curToken.Literal)
+ addr, _ := strconv.ParseInt(p.curToken.Literal, 0, 64)
  len1 := addr % 256
  len2 := (addr - len1) / 256
 
@@ -626,8 +652,7 @@ func (p *Compiler) storeOp() {
  p.bytecode = append(p.bytecode, reg)
 
  // Convert to low/high
- i, _ := strconv.Atoi(p.curToken.Literal)
-
+ i, _ := strconv.ParseInt(p.curToken.Literal, 0, 64)
  len1 := i % 256
  len2 := (i - len1) / 256
  p.bytecode = append(p.bytecode, byte(len1))
@@ -702,7 +727,7 @@ func (p *Compiler) cmpOp() {
  p.bytecode = append(p.bytecode, reg)
 
  // Convert to low/high
- i, _ := strconv.Atoi(p.curToken.Literal)
+ i, _ := strconv.ParseInt(p.curToken.Literal, 0, 64)
 
  len1 := i % 256
  len2 := (i - len1) / 256

cpu/cpu.go

@@ -716,6 +716,12 @@ func (c *CPU) Run() {
  // jump to the call address
  c.ip = addr
 
+ case 0x80:
+ debugPrintf("TRAP\n")
+ c.ip += 1
+
+ addr := c.read2Val()
+ fmt.Printf("Calling trap %04X\n", addr)
  default:
  fmt.Printf("Unrecognized/Unimplemented opcode %02X at IP %04X\n", instruction, c.ip)
  os.Exit(1)

opcode/opcode.go

@@ -60,4 +60,7 @@ var (
  STACK_POP = 0x71
  STACK_RET = 0x72
  STACK_CALL = 0x73
+
+ // Interrupt / trap
+ TRAP_OP = 0x80
 )

token/token.go

@@ -71,6 +71,7 @@ const (
  NOP = "NOP"
  RANDOM = "RANDOM"
  SYSTEM = "SYSTEM"
+ TRAP = "TRAP"
 )
 
 // reversed keywords
@@ -124,6 +125,7 @@ var keywords = map[string]TokenType{
  "concat": CONCAT,
  "DATA": DATA,
  "DB": DB,
+ "int": TRAP,
  "memcpy": MEMCPY,
  "nop": NOP,
  "random": RANDOM,