working on disasm

a2/disasm.go

@@ -19,9 +19,13 @@ Disasm is a very simple disassembler for 6502 binary files.
 }
 
 var disasmAddress uint // disasm -a flag
+var symbolFile string  // disasm -s flag
+var printLabels bool   // disasm -p flag
 
 func init() {
 	cmdDisasm.Flag.UintVar(&disasmAddress, "a", 0, "The starting memory address.")
+	cmdDisasm.Flag.StringVar(&symbolFile, "s", "", "File of symbol definitions.")
+	cmdDisasm.Flag.BoolVar(&printLabels, "p", false, "Print labels for symbols.")
 }
 
 func runDisasm(cmd *commander.Command, args []string) error {
@@ -32,7 +36,7 @@ func runDisasm(cmd *commander.Command, args []string) error {
 
 	bytes, err := ioutil.ReadFile(args[0])
 	if err != nil {
-		return nil
+		return err
 	}
 	if len(bytes) > 0x10000 {
 		return fmt.Errorf("File %s is %04X bytes long, which is more than $10000.", args[0], len(bytes))
@@ -42,6 +46,18 @@ func runDisasm(cmd *commander.Command, args []string) error {
 			disasmAddress, len(bytes), int(disasmAddress)+len(bytes))
 	}
 
-	asm.DisasmBlock(bytes, uint16(disasmAddress), os.Stdout)
+	var s asm.Symbols
+	if symbolFile != "" {
+		s, err = asm.ReadSymbols(symbolFile)
+		if err != nil {
+			return err
+		}
+	} else {
+		if printLabels {
+			return fmt.Errorf("-p (print labels) specified without -s (symbol table file")
+		}
+	}
+
+	asm.DisasmBlock(bytes, uint16(disasmAddress), os.Stdout, s, 2, printLabels)
 	return nil
 }