From b6548e83436936b5fce5384002e437aaf64c850e Mon Sep 17 00:00:00 2001
From: Bernhard Urban <lewurm@gmail.com>
Date: Thu, 26 Apr 2012 14:26:27 +0200
Subject: [PATCH] codegen: implement `newarray' and `arraylength'

the length is stored at offset 0.
---
 Mate/X86CodeGen.hs | 37 +++++++++++++++++++++++++++++++------
 tests/Array1.java  |  8 ++++++++
 2 files changed, 39 insertions(+), 6 deletions(-)
 create mode 100644 tests/Array1.java

diff --git a/Mate/X86CodeGen.hs b/Mate/X86CodeGen.hs
index 0e8d98e..c71494e 100644
--- a/Mate/X86CodeGen.hs
+++ b/Mate/X86CodeGen.hs
@@ -3,6 +3,7 @@
 module Mate.X86CodeGen where
 
 import Data.Binary
+import Data.BinaryState
 import Data.Int
 import Data.Maybe
 import qualified Data.Map as M
@@ -233,16 +234,31 @@ emitFromBB method cls hmap =  do
         call (trapaddr - w32_calladdr)
         add esp (4 :: Word32)
     emit DUP = push (Disp 0, esp)
+    emit ARRAYLENGTH = do
+        pop eax
+        push (Disp 0, eax)
+    emit (NEWARRAY typ) = do
+        let tsize = case decodeS (0 :: Integer) (B.pack [typ]) of
+                    T_INT -> 4
+                    _ -> error $ "newarray: type not implemented yet"
+        -- get length from stack, but leave it there
+        mov eax (Disp 0, esp)
+        mov ebx (tsize :: Word32)
+        -- multiple amount with native size of one element
+        mul ebx -- result is in eax
+        add eax (4 :: Word32) -- for "length" entry
+        -- push amount of bytes to allocate
+        push eax
+        callMalloc
+        pop eax -- ref to arraymemory
+        pop ebx -- length
+        mov (Disp 0, eax) ebx -- store length at offset 0
+        push eax -- push ref again
     emit (NEW objidx) = do
         let objname = buildClassID cls objidx
         amount <- liftIO $ getMethodSize objname
         push (amount :: Word32)
-        calladdr <- getCurrentOffset
-        let w32_calladdr = 5 + calladdr
-        let malloaddr = (fromIntegral getMallocAddr :: Word32)
-        call (malloaddr - w32_calladdr)
-        add esp (4 :: Word32)
-        push eax
+        callMalloc
         -- TODO(bernhard): save reference somewhere for GC
         -- set method table pointer
         mtable <- liftIO $ getMethodTable objname
@@ -329,6 +345,15 @@ emitFromBB method cls hmap =  do
         ret
     emit invalid = error $ "insn not implemented yet: " ++ (show invalid)
 
+    callMalloc :: CodeGen e s ()
+    callMalloc = do
+        calladdr <- getCurrentOffset
+        let w32_calladdr = 5 + calladdr
+        let malloaddr = (fromIntegral getMallocAddr :: Word32)
+        call (malloaddr - w32_calladdr)
+        add esp (4 :: Word32)
+        push eax
+
   -- for locals we use a different storage
   cArgs :: Word8 -> Word32
   cArgs x = if (x' >= thisMethodArgCnt)
diff --git a/tests/Array1.java b/tests/Array1.java
new file mode 100644
index 0000000..87cd795
--- /dev/null
+++ b/tests/Array1.java
@@ -0,0 +1,8 @@
+package tests;
+
+public class Array1 {
+	public static void main(String []args) {
+		int []arr = new int[0x8];
+		System.out.printf(arr.length);
+	}
+}
-- 
2.25.1