From 918821897ac5548ea57e4d2630325e324de09d03 Mon Sep 17 00:00:00 2001
From: Bernhard Urban <lewurm@gmail.com>
Date: Tue, 28 Aug 2012 17:11:12 +0200
Subject: [PATCH] instanceOf: make decision at runtime

preperation for a serious instanceOf implementation
---
 Mate/ClassHierarchy.hs  | 30 ++++++++++++++++++++++++++++++
 Mate/Types.hs           |  5 +++--
 Mate/X86CodeGen.hs      | 24 ++++++++++++++++++------
 Mate/X86TrapHandling.hs | 14 ++++----------
 4 files changed, 55 insertions(+), 18 deletions(-)
 create mode 100644 Mate/ClassHierarchy.hs

diff --git a/Mate/ClassHierarchy.hs b/Mate/ClassHierarchy.hs
new file mode 100644
index 0000000..c501ed9
--- /dev/null
+++ b/Mate/ClassHierarchy.hs
@@ -0,0 +1,30 @@
+module Mate.ClassHierarchy
+  ( isInstanceOf
+  ) where
+
+import qualified Data.ByteString.Lazy as B
+import Control.Applicative
+import Text.Printf
+
+import Mate.NativeSizes
+import Mate.ClassPool
+
+
+data Class
+  = Class
+    { clMtable :: NativeWord
+    , clSuperClass :: Class
+    , clInterfaces :: [Interface]
+    }
+  | JavaLangObject
+    { clMtable :: NativeWord
+    }
+
+data Interface
+  = Interface
+    { ifSuperInterfaces :: [Interface]
+    }
+
+isInstanceOf :: NativeWord -> B.ByteString -> IO Bool
+isInstanceOf obj_mtable classname = do
+  (== obj_mtable) <$> getMethodTable classname
diff --git a/Mate/Types.hs b/Mate/Types.hs
index ec76a4c..7de8493 100644
--- a/Mate/Types.hs
+++ b/Mate/Types.hs
@@ -67,12 +67,13 @@ data RawMethod = RawMethod {
 type TrapMap = M.Map NativeWord TrapCause
 
 type TrapPatcher = CPtrdiff -> CodeGen () () CPtrdiff
+type TrapPatcherEax = CPtrdiff -> CPtrdiff -> CodeGen () () CPtrdiff
 
 data TrapCause
   = StaticMethod TrapPatcher -- for static calls
   | VirtualCall Bool MethodInfo (IO NativeWord) -- for invoke{interface,virtual}
-  | InstanceOf B.ByteString -- class name
-  | NewObject TrapPatcher -- class name
+  | InstanceOf TrapPatcherEax
+  | NewObject TrapPatcher
   | StaticField StaticFieldInfo
   | ObjectField TrapPatcher
 
diff --git a/Mate/X86CodeGen.hs b/Mate/X86CodeGen.hs
index 1097e85..fe1fe5d 100644
--- a/Mate/X86CodeGen.hs
+++ b/Mate/X86CodeGen.hs
@@ -28,6 +28,7 @@ import Mate.NativeSizes
 import Mate.Types
 import Mate.Utilities
 import Mate.ClassPool
+import Mate.ClassHierarchy
 import {-# SOURCE #-} Mate.MethodPool
 import Mate.Strings
 
@@ -202,12 +203,23 @@ emitFromBB cls method = do
       trapaddr <- getCurrentOffset
       -- place something like `mov edx $mtable_of_objref' instead
       emit32 (0x9090ffff :: Word32); nop
-      cmp eax edx
-      sete al
-      movzxb eax al
-      push eax
-      forceRegDump
-      return $ Just (trapaddr, InstanceOf $ buildClassID cls cpidx)
+      push (0 :: Word32)
+      let patcher reax reip = do
+            -- mtable <- liftIO $ getMethodTable (buildClassID cls cpidx)
+            -- mov edx mtable
+            emit32 (0x9090ffff :: Word32); nop
+            let classname = buildClassID cls cpidx
+            check <- liftIO $ isInstanceOf (fromIntegral reax) classname
+            if check
+              then push (1 :: Word32)
+              else push (0 :: Word32)
+            return (reip + 5)
+      -- cmp eax edx
+      -- sete al
+      -- movzxb eax al
+      -- push eax
+      -- forceRegDump
+      return $ Just (trapaddr, InstanceOf patcher)
     emit' (NEW objidx) = do
       let objname = buildClassID cls objidx
       trapaddr <- getCurrentOffset
diff --git a/Mate/X86TrapHandling.hs b/Mate/X86TrapHandling.hs
index 7a5c549..0df63b8 100644
--- a/Mate/X86TrapHandling.hs
+++ b/Mate/X86TrapHandling.hs
@@ -12,7 +12,7 @@ import qualified Data.ByteString.Lazy as B
 import Foreign
 import Foreign.C.Types
 
-import Harpy
+import Harpy hiding (fst)
 
 import Mate.Types
 import Mate.NativeSizes
@@ -38,8 +38,8 @@ mateHandler reip reax rebx resi = do
         staticFieldHandler reip >>= delTrue
     (Just (ObjectField patcher)) ->
         patchWithHarpy patcher reip >>= delTrue
-    (Just (InstanceOf cn))  ->
-        patchWithHarpy (`patchInstanceOf` cn) reip >>= delFalse
+    (Just (InstanceOf patcher))  ->
+        patchWithHarpy (patcher reax) reip >>= delFalse
     (Just (NewObject patcher))   ->
         patchWithHarpy patcher reip >>= delTrue
     (Just (VirtualCall False mi io_offset)) ->
@@ -72,7 +72,7 @@ patchWithHarpy patcher reip = do
   if mateDEBUG
     then mapM_ (printfJit . printf "patched: %s\n" . showAtt) $ snd right
     else return ()
-  return reip
+  return $ fst right
 
 withDisasm :: CodeGen e s CPtrdiff -> CodeGen e s (CPtrdiff, [Instruction])
 withDisasm patcher = do
@@ -91,12 +91,6 @@ staticFieldHandler reip = do
       return reip
     else error "staticFieldHandler: something is wrong here. abort.\n"
 
-patchInstanceOf :: CPtrdiff -> B.ByteString -> CodeGen e s CPtrdiff
-patchInstanceOf reip classname = do
-  mtable <- liftIO $ getMethodTable classname
-  mov edx mtable
-  return reip
-
 patchInvoke :: MethodInfo -> CPtrdiff -> CPtrdiff -> IO NativeWord -> CPtrdiff -> CodeGen e s CPtrdiff
 patchInvoke (MethodInfo methname _ msig)  method_table table2patch io_offset reip = do
   vmap <- liftIO $ getVirtualMap
-- 
2.25.1