[Soot-list] Question regarding Java Bytecode

[Bernhard Berger]

Hi everybody,

today soot greeted me with a nice exception located somewhere deep in
the coffie-source. Since the bytecode I am analyzing is not generated by
a default java compiler the Bytecode might be the culprit. The stack
trace is the following one:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 6
 at soot.coffi.ByteCode.locateInstr(ByteCode.java:1104)
 at soot.coffi.ByteCode.locateInstr(ByteCode.java:1108)
 at soot.coffi.ByteCode.locateInstr(ByteCode.java:1108)
 at soot.coffi.ByteCode.locateInst(ByteCode.java:1097)
 at soot.coffi.ClassFile.parseMethod(ClassFile.java:1248)
 at soot.coffi.CoffiMethodSource.getBody(CoffiMethodSource.java:78)
 at soot.SootMethod.getBodyFromMethodSource(SootMethod.java:82)
 at soot.SootMethod.retrieveActiveBody(SootMethod.java:315)
 at soot.PackManager.retrieveAllBodies(PackManager.java:989)
 at soot.PackManager.runPacks(PackManager.java:338)
 at soot.Main.run(Main.java:198)
 at soot.Main.main(Main.java:141) 

I took a look at the method's Bytecode and its exception table sind soot
handles links exception table to the corresponding Bytecode instructions
at this point. I think the Bytecode is not correct at this point but I'm
not a Bytecode expert. Perhaps someone can support my theory.

javap gives me the following output for the method in question:

public java.lang.String getPluginsPath();
  Code:
   0:   aload_0
   1:   monitorenter
   2:   aload_0
   3:   monitorexit
   4:   ldc     #209; //String 
   6:   areturn
  Exception table:
   from   to  target type
     2     2     7   any

I consulted the JVM-spec and it states for the exception table:
The value of the handler_pc (target in this case) item indicates the
start of the exception handler. The value of the item must be a valid
index into the code array and must be the index of the opcode of an
instruction.

Therefore the Bytecode is not corret, since the handler_pc does not
point to a valid address. Am I correct? If the Bytecode is invalid I am
going to blame the author of the tool that generated the Bytecode. :-)

Regards from Bremen, Germany

Bernhard