// BeforeExecute receives each cpu.Instruction just before the program
// counter is incremented and the instruction executed.
func (d *Debugger) BeforeExecute(in cpu.Instruction) {
d.doBreakpoints(in)
if d.run {
return
}
fmt.Println(d.cpu)
var symbols []string
if in.IsAbsolute() {
symbols = d.symbols.labelsFor(in.Op16)
}
if len(symbols) > 0 {
fmt.Printf("Next: %v (%s)\n", in, strings.Join(symbols, ","))
} else {
fmt.Println("Next:", in)
}
for !d.commandLoop(in) {
// next
}
}
func (d *Debugger) doBreakpoints(in cpu.Instruction) {
inName := in.Name()
if inName == d.breakInstruction {
fmt.Printf("Breakpoint for instruction %s\n", inName)
d.run = false
}
if d.breakAddress && d.cpu.PC == d.breakAddressValue {
fmt.Printf("Breakpoint for PC address = $%04X\n", d.breakAddressValue)
d.run = false
}
d.checkRegBreakpoint("A", d.breakRegA, d.breakRegAValue, d.cpu.AC)
d.checkRegBreakpoint("X", d.breakRegX, d.breakRegXValue, d.cpu.X)
d.checkRegBreakpoint("Y", d.breakRegY, d.breakRegYValue, d.cpu.Y)
}