+ trapaddr <- getCurrentOffset
+ mov eax (Addr 0x00000000) -- it's a trap
+ push eax
+ return $ Just (trapaddr, StaticField $ buildStaticFieldID cls cpidx)
+
+ emit' (GETFIELD x) = do
+ pop eax -- this pointer
+ -- like: 099db064 ff b0 e4 14 00 00 pushl 5348(%eax)
+ trapaddr <- emitSigIllTrap 6
+ let patcher reip = do
+ let (cname, fname) = buildFieldOffset cls x
+ offset <- liftIO $ fromIntegral <$> getFieldOffset cname fname
+ push32RelEax (Disp offset) -- get field
+ return reip
+ return $ Just (trapaddr, ObjectField patcher)
+ emit' (PUTFIELD x) = do
+ pop ebx -- value to write
+ pop eax -- this pointer
+ -- like: 4581fc6b 89 98 30 7b 00 00 movl %ebx,31536(%eax)
+ trapaddr <- emitSigIllTrap 6
+ let patcher reip = do
+ let (cname, fname) = buildFieldOffset cls x
+ offset <- liftIO $ fromIntegral <$> getFieldOffset cname fname
+ mov32RelEbxEax (Disp offset) -- set field
+ return reip
+ return $ Just (trapaddr, ObjectField patcher)
+
+ emit' (INSTANCEOF cpidx) = do
+ pop eax
+ -- place something like `mov edx $mtable_of_objref' instead
+ trapaddr <- emitSigIllTrap 4
+ push (0 :: Word32)
+ let patcher reax reip = do
+ emitSigIllTrap 4
+ let classname = buildClassID cls cpidx
+ check <- liftIO $ isInstanceOf (fromIntegral reax) classname
+ if check
+ then push (1 :: Word32)
+ else push (0 :: Word32)
+ return (reip + 4)
+ return $ Just (trapaddr, InstanceOf patcher)
+ emit' (NEW objidx) = do
+ let objname = buildClassID cls objidx
+ -- place something like `push $objsize' instead
+ trapaddr <- emitSigIllTrap 5
+ callMalloc
+ -- 0x13371337 is just a placeholder; will be replaced with mtable ptr
+ mov (Disp 0, eax) (0x13371337 :: Word32)
+ mov (Disp 4, eax) (0x1337babe :: Word32)
+ let patcher reip = do
+ objsize <- liftIO $ getObjectSize objname
+ push32 objsize
+ callMalloc
+ mtable <- liftIO $ getMethodTable objname
+ mov (Disp 0, eax) mtable
+ mov (Disp 4, eax) (0x1337babe :: Word32)
+ return reip
+ return $ Just (trapaddr, NewObject patcher)
+
+ emit' ATHROW = do
+ trapaddr <- emitSigIllTrap 2
+ let patcher resp reip = do
+ error "no athrow for you, sorry"
+ emitSigIllTrap 2
+ return reip
+ return $ Just (trapaddr, ThrowException patcher)
+