From: Bernhard Urban <lewurm@gmail.com>
Date: Mon, 23 Apr 2012 23:17:12 +0000 (+0200)
Subject: codegen: fix bug in calling conv
X-Git-Url: http://wien.tomnetworks.com/gitweb/?p=mate.git;a=commitdiff_plain;h=01ca2a0efa092664d7dd83fb8ac03d4ed550531d

codegen: fix bug in calling conv

the callee used elements of the callers stack as storage for local vars.
don't do that.
---

diff --git a/Makefile b/Makefile
index fb4b5bc..9e1a9b4 100644
--- a/Makefile
+++ b/Makefile
@@ -33,6 +33,10 @@ test: mate $(CLASS_FILES)
 	@printf "should be:  0x%08x\n" 0x55
 	./$< tests/Static3 | grep mainresult
 	@printf "should be:  0x%08x\n" 0x6dd
+	./$< tests/CallConv1 | grep mainresult
+	@printf "should be:  0x%08x\n" 0x1337
+	./$< tests/CallConv2 | grep mainresult
+	@printf "should be:  0x%08x\n" 0x1337
 
 %.class: %.java
 	$(JAVAC) $<
diff --git a/Mate/MethodPool.hs b/Mate/MethodPool.hs
index aff4dfe..c76cf91 100644
--- a/Mate/MethodPool.hs
+++ b/Mate/MethodPool.hs
@@ -105,7 +105,7 @@ compileBB hmap methodinfo = do
 
   -- TODO(bernhard): replace parsing with some kind of classpool
   cls <- getClassFile (cName methodinfo)
-  let ebb = emitFromBB cls hmap
+  let ebb = emitFromBB (methName methodinfo) cls hmap
   (_, Right ((entry, _, _, new_tmap), disasm)) <- runCodeGen ebb () ()
   let w32_entry = ((fromIntegral $ ptrToIntPtr entry) :: Word32)
 
diff --git a/Mate/X86CodeGen.hs b/Mate/X86CodeGen.hs
index ac51092..5720084 100644
--- a/Mate/X86CodeGen.hs
+++ b/Mate/X86CodeGen.hs
@@ -96,7 +96,7 @@ testCase cf method = do
       case hmap of
         Nothing -> error "sorry, no code generation"
         Just hmap' -> do
-              let ebb = emitFromBB cls hmap'
+              let ebb = emitFromBB method cls hmap'
               (_, Right ((entry, bbstarts, end, _), disasm)) <- runCodeGen ebb () ()
               let int_entry = ((fromIntegral $ ptrToIntPtr entry) :: Int)
               printf "disasm:\n"
@@ -115,13 +115,16 @@ type BBStarts = M.Map BlockID Int
 type CompileInfo = (EntryPoint, BBStarts, Int, TMap)
 
 
-emitFromBB :: Class Resolved -> MapBB -> CodeGen e s (CompileInfo, [Instruction])
-emitFromBB cls hmap =  do
+emitFromBB :: B.ByteString -> Class Resolved -> MapBB -> CodeGen e s (CompileInfo, [Instruction])
+emitFromBB method cls hmap =  do
         llmap <- sequence [newNamedLabel ("bb_" ++ show x) | (x,_) <- M.toList hmap]
         let lmap = zip (Prelude.fst $ unzip $ M.toList hmap) llmap
         ep <- getEntryPoint
         push ebp
         mov ebp esp
+        -- TODO(bernhard): determine a reasonable value.
+        --                 e.g. (locals used) * 4
+        sub esp (0x60 :: Word32)
 
         (calls, bbstarts) <- efBB (0,(hmap M.! 0)) M.empty M.empty lmap
         d <- disassemble
@@ -205,9 +208,14 @@ emitFromBB cls hmap =  do
     emit (ICONST_5) = push (5 :: Word32)
     emit (ILOAD_ x) = do
         push (Disp (cArgs_ x), ebp)
+    emit (ILOAD x) = do
+        push (Disp (cArgs x), ebp)
     emit (ISTORE_ x) = do
         pop eax
         mov (Disp (cArgs_ x), ebp) eax
+    emit (ISTORE x) = do
+        pop eax
+        mov (Disp (cArgs x), ebp) eax
     emit IADD = do pop ebx; pop eax; add eax ebx; push eax
     emit ISUB = do pop ebx; pop eax; sub eax ebx; push eax
     emit IMUL = do pop ebx; pop eax; mul ebx; push eax
@@ -247,8 +255,22 @@ emitFromBB cls hmap =  do
         ret
     emit invalid = error $ "insn not implemented yet: " ++ (show invalid)
 
-  cArgs x = (8 + 4 * (fromIntegral x))
-  cArgs_ x = (8 + 4 * case x of I0 -> 0; I1 -> 1; I2 -> 2; I3 -> 3)
+  -- for locals we use a different storage
+  cArgs :: Word8 -> Word32
+  cArgs x = if (x' >= thisMethodArgCnt)
+      -- TODO(bernhard): maybe s/(-4)/(-8)/
+      then fromIntegral $ (-4) * (x' - thisMethodArgCnt + 1)
+      else 8 + (4 * x')
+    where x' = fromIntegral x
+
+  cArgs_ :: IMM -> Word32
+  cArgs_ x = cArgs $ case x of I0 -> 0; I1 -> 1; I2 -> 2; I3 -> 3
+
+  thisMethodArgCnt :: Word32
+  thisMethodArgCnt = fromIntegral $ length args
+    where
+    (Just m) = lookupMethod method cls
+    (MethodSignature args _) = methodSignature m
 
   -- sign extension from w8 to w32 (over s8)
   --   unfortunately, hs-java is using Word8 everywhere (while
diff --git a/tests/CallConv1.java b/tests/CallConv1.java
new file mode 100644
index 0000000..acb6a56
--- /dev/null
+++ b/tests/CallConv1.java
@@ -0,0 +1,21 @@
+package tests;
+
+public class CallConv1 {
+	public static void main(String []args) {
+		int sum = 0;
+		sum += manyVars(0x1348);
+		id(sum); // 0x1337
+	}
+
+	public static int id(int a) {
+		return a;
+	}
+
+	public static int manyVars(int a) {
+		int b = 0x22;
+		int c = 0x33;
+		int d = 0x44;
+
+		return (((a - b) - c) + d);
+	}
+}
diff --git a/tests/CallConv2.java b/tests/CallConv2.java
new file mode 100644
index 0000000..ef8e3f8
--- /dev/null
+++ b/tests/CallConv2.java
@@ -0,0 +1,20 @@
+package tests;
+
+public class CallConv2 {
+	public static void main(String []args) {
+		int sum = 0;
+		sum += manyVars(0x125A, 0x11, 0x33, 0x44);
+		id(sum); // 0x1337
+	}
+
+	public static int id(int a) {
+		return a;
+	}
+
+	public static int manyVars(int a, int b, int c, int d) {
+		int x = 0x88;
+		int y = 0x55;
+
+		return ((((a - b) - c) + d) + x + y);
+	}
+}