Re: RFR(XS): 8143127: InvokerBytecodeGenerator emitConst should handle Byte, Short, Character

[Claes Redestad]

Hi Remi,

On 2015-11-17 22:13, Remi Forax wrote:
Hi Claes,
I fail to see how this code will not throw a CCE at runtime
   if (con instanceof Integer || con instanceof Byte || con instanceof Short || 
con instanceof Character) {
      emitIconstInsn((int) con);
      ...
(int)con is translated by the compiler to ((Integer)con).intValue()

you have to write something like that
   (con instanceof Character)? (char)con: ((Number)con).intValue()

Well, this is embarrassing. I was fooled by my own sanity testing since 
javac makes the unboxing+cast work when type is known:

Character c = 'a';
System.out.println((int)c);

but not when going through an Object reference:

Object o = 'a';
System.out.println((int)o);

This works better:

        if (con instanceof Integer) {
            emitIconstInsn((int) con);
            return;
        }
        if (con instanceof Byte) {
            emitIconstInsn((int)(byte)con);
            return;
        }
        if (con instanceof Short) {
            emitIconstInsn((int)(short)con);
            return;
        }
        if (con instanceof Character) {
            emitIconstInsn((int)(char)con);
            return;
        }

Updated in-place.

/Claes