+{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
-module Mate.BasicBlocks where
+#include "debug.h"
+module Mate.BasicBlocks(
+ BlockID,
+ BasicBlock (..),
+ BBEnd (..),
+ MapBB,
+#ifdef DBG_BB
+ printMapBB,
+#endif
+ parseMethod,
+ testCFG -- added by hs to perform benches from outside
+ )where
import Data.Binary
-import System.Environment
+import Data.Int
+import Data.List
import qualified Data.Map as M
import qualified Data.ByteString.Lazy as B
-import JVM.Common
import JVM.ClassFile
import JVM.Converter
-import JVM.Dump
import JVM.Assembler
+import Mate.Types
+import Mate.Debug
import Mate.Utilities
-type Name = String -- use "virtual register id" instead?
-data Type = JInt | JFloat -- add more
-type Variable = (Type,Name)
+#ifdef DEBUG
+import Text.Printf
+#endif
--- Represents a CFG node
-data BasicBlock = BasicBlock {
- inputs :: [Variable],
- outputs :: [Variable],
- code :: [Instruction] }
+-- for immediate representation to determine BBs
+type Offset = (Int, Maybe BBEnd) -- (offset in bytecode, offset to jump target)
+type OffIns = (Offset, Instruction)
--- Represents a Control-Flow-Graph as
--- Adjacency list (add matrix representation if appropriate)
-type CFList = [(BasicBlock, [BasicBlock])]
+#ifdef DBG_BB
+printMapBB :: Maybe MapBB -> IO ()
+printMapBB Nothing = putStrLn "No BasicBlock"
+printMapBB (Just hmap) = do
+ putStr "BlockIDs: "
+ let keys = fst $ unzip $ M.toList hmap
+ mapM_ (putStr . (flip (++)) ", " . show) keys
+ putStrLn "\n\nBasicBlocks:"
+ printMapBB' keys hmap
+ where
+ printMapBB' :: [BlockID] -> MapBB -> IO ()
+ printMapBB' [] _ = return ()
+ printMapBB' (i:is) hmap' = case M.lookup i hmap' of
+ Just bb -> do
+ putStrLn $ "Block " ++ (show i)
+ mapM_ putStrLn (map ((++) "\t" . show) $ code bb)
+ case successor bb of
+ Return -> putStrLn ""
+ FallThrough t1 -> putStrLn $ "Sucessor: " ++ (show t1) ++ "\n"
+ OneTarget t1 -> putStrLn $ "Sucessor: " ++ (show t1) ++ "\n"
+ TwoTarget t1 t2 -> putStrLn $ "Sucessor: " ++ (show t1) ++ ", " ++ (show t2) ++ "\n"
+ printMapBB' is hmap
+ Nothing -> error $ "BlockID " ++ show i ++ " not found."
+#endif
-main = do
- args <- getArgs
- case args of
- [clspath] -> parseFile clspath "fib" -- TODO
- _ -> error "Synopsis: dump-class File.class"
+#if 0
+#ifdef DBG_BB
+testInstance :: String -> B.ByteString -> MethodSignature -> IO ()
+testInstance cf method sig = do
+ cls <- parseClassFile cf
+ hmap <- parseMethod cls method sig
+ printMapBB hmap
+#endif
+#ifdef DBG_BB
+test_main :: IO ()
+test_main = do
+ test_01
+ test_02
+ test_03
+ test_04
-parseFile :: String -> B.ByteString -> IO ()
-parseFile clspath method = do
- --clsFile <- decodeFile clspath
- --putStrLn $ showListIx $ M.assocs $ constsPool (clsFile :: Class Pointers)
- cls <- parseClassFile clspath
- --dumpClass cls
- let mainmethod = lookupMethod method cls -- "main|([Ljava/lang/String;)V" cf
- mapM_ putStrLn (testCFG mainmethod)
+test_01, test_02, test_03, test_04 :: IO ()
+test_01 = testInstance "./tests/Fib.class" "fib"
+test_02 = testInstance "./tests/While.class" "f"
+test_03 = testInstance "./tests/While.class" "g"
+test_04 = testInstance "./tests/Fac.class" "fac"
+#endif
+#endif
-test_01 = parseFile "./tests/Fib.class" "fib"
-test_02 = parseFile "./tests/While.class" "f"
-test_03 = parseFile "./tests/While.class" "g"
+parseMethod :: Class Direct -> B.ByteString -> MethodSignature -> IO (Maybe MapBB)
+parseMethod cls method sig = do
+ let maybe_bb = testCFG $ lookupMethodSig method sig cls
+ let msig = methodSignature $ classMethods cls !! 1
+ printfBb "BB: analysing \"%s\"\n" $ toString (method `B.append` ": " `B.append` encode msig)
+#ifdef DBG_BB
+ printMapBB maybe_bb
+#endif
+ -- small example how to get information about
+ -- exceptions of a method
+ -- TODO: remove ;-)
+ let (Just m) = lookupMethodSig method sig cls
+ case attrByName m "Code" of
+ Nothing -> printfBb "exception: no handler for this method\n"
+ Just exceptionstream -> printfBb "exception: \"%s\"\n" (show $ codeExceptions $ decodeMethod exceptionstream)
+ return maybe_bb
-testCFG :: Maybe (Method Resolved) -> [String]
+
+testCFG :: Maybe (Method Direct) -> Maybe MapBB
testCFG (Just m) = case attrByName m "Code" of
- Nothing -> error "no code"
- Just bytecode -> let code = decodeMethod bytecode
- instructions = codeInstructions code
- in buildCFG instructions
-testCFG _ = error "no method to build cfg"
+ Nothing -> Nothing
+ Just bytecode -> Just $ buildCFG $ codeInstructions $ decodeMethod bytecode
+testCFG _ = Nothing
+
+
+buildCFG :: [Instruction] -> MapBB
+buildCFG xs = buildCFG' M.empty xs' xs'
+ where
+ xs' :: [OffIns]
+ xs' = markBackwardTargets $ calculateInstructionOffset xs
+
+-- get already calculated jmp-targets and mark the predecessor of the
+-- target-instruction as "FallThrough". we just care about backwards
+-- jumps here (forward jumps are handled in buildCFG')
+markBackwardTargets :: [OffIns] -> [OffIns]
+markBackwardTargets [] = []
+markBackwardTargets (x:[]) = [x]
+markBackwardTargets insns@(x@((x_off,x_bbend),x_ins):y@((y_off,_),_):xs) =
+ x_new:markBackwardTargets (y:xs)
+ where
+ x_new = if isTarget then checkX y_off else x
+ checkX w16 = case x_bbend of
+ Just _ -> x -- already marked, don't change
+ Nothing -> ((x_off, Just $ FallThrough w16), x_ins) -- mark previous insn
+
+ -- look through all remaining insns in the stream if there is a jmp to `y'
+ isTarget = case find cmpOffset insns of Just _ -> True; Nothing -> False
+ cmpOffset ((_,Just (OneTarget w16)),_) = w16 == y_off
+ cmpOffset ((_,Just (TwoTarget _ w16)),_) = w16 == y_off
+ cmpOffset _ = False
+
+
+buildCFG' :: MapBB -> [OffIns] -> [OffIns] -> MapBB
+buildCFG' hmap [] _ = hmap
+buildCFG' hmap (((off, entry), _):xs) insns = buildCFG' (insertlist entryi hmap) xs insns
+ where
+ insertlist :: [BlockID] -> MapBB -> MapBB
+ insertlist [] hmap' = hmap'
+ insertlist (y:ys) hmap' = insertlist ys newhmap
+ where
+ newhmap = if M.member y hmap' then hmap' else M.insert y value hmap'
+ value = parseBasicBlock y insns
+
+ entryi :: [BlockID]
+ entryi = if off == 0 then 0:ys else ys -- also consider the entrypoint
+ where ys = case entry of
+ Just (TwoTarget t1 t2) -> [t1, t2]
+ Just (OneTarget t) -> [t]
+ Just (FallThrough t) -> [t]
+ Just Return -> []
+ Nothing -> []
+
+
+parseBasicBlock :: Int -> [OffIns] -> BasicBlock
+parseBasicBlock i insns = BasicBlock insonly endblock
+ where
+ startlist = dropWhile (\((x,_),_) -> x < i) insns
+ (Just ((_, Just endblock),_), is) = takeWhilePlusOne validins startlist
+ insonly = snd $ unzip is
+
+ -- also take last (non-matched) element and return it
+ takeWhilePlusOne :: (a -> Bool) -> [a] -> (Maybe a,[a])
+ takeWhilePlusOne _ [] = (Nothing,[])
+ takeWhilePlusOne p (x:xs)
+ | p x = let (lastins, list) = takeWhilePlusOne p xs in (lastins, x:list)
+ | otherwise = (Just x,[x])
+
+ validins :: ((Int, Maybe BBEnd), Instruction) -> Bool
+ validins ((_,x),_) = case x of Just _ -> False; Nothing -> True
+
+
+calculateInstructionOffset :: [Instruction] -> [OffIns]
+calculateInstructionOffset = cio' (0, Nothing)
+ where
+ newoffset :: Instruction -> Int -> Offset
+ newoffset x off = (off + fromIntegral (B.length $ encodeInstructions [x]), Nothing)
+ addW16Signed :: Int -> Word16 -> Int
+ addW16Signed i w16 = i + fromIntegral s16
+ where s16 = fromIntegral w16 :: Int16
-buildCFG :: [Instruction] -> [String]
-buildCFG xs = map show xs
+ cio' :: Offset -> [Instruction] -> [OffIns]
+ cio' _ [] = []
+ -- TODO(bernhard): add more instruction with offset (IF_ACMP, JSR, ...)
+ cio' (off,_) (x:xs) = case x of
+ IF _ w16 -> twotargets w16
+ IF_ICMP _ w16 -> twotargets w16
+ IF_ACMP _ w16 -> twotargets w16
+ IFNONNULL w16 -> twotargets w16
+ IFNULL w16 -> twotargets w16
+ GOTO w16 -> onetarget w16
+ IRETURN -> notarget
+ ARETURN -> notarget
+ RETURN -> notarget
+ _ -> ((off, Nothing), x):next
+ where
+ notarget = ((off, Just Return), x):next
+ onetarget w16 = ((off, Just $ OneTarget (off `addW16Signed` w16)), x):next
+ twotargets w16 = ((off, Just $ TwoTarget (off + 3) (off `addW16Signed` w16)), x):next
+ next = cio' (newoffset x off) xs