mem-cache: TempCacheBlk allocates and destroys its own data

This change is because I want to make CacheBlk::data private, so that
I can track all the places which write to it. But to keep that commit
smaller (it is pretty big, because of all the places which might
change it), I have split this into a commit of its own.

Change-Id: I15a2fc1752085ff3681f5c74ec90be3828a559ea
Reviewed-on: https://gem5-review.googlesource.com/11829
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

src/mem/cache/base.cc

@@ -113,8 +113,7 @@ BaseCache::BaseCache(const BaseCacheParams *p, unsigned blk_size)
     // forward snoops is overridden in init() once we can query
     // whether the connected master is actually snooping or not
 
-    tempBlock = new TempCacheBlk();
-    tempBlock->data = new uint8_t[blkSize];
+    tempBlock = new TempCacheBlk(blkSize);
 
     tags->setCache(this);
     if (prefetcher)
@@ -123,7 +122,6 @@ BaseCache::BaseCache(const BaseCacheParams *p, unsigned blk_size)
 
 BaseCache::~BaseCache()
 {
-    delete [] tempBlock->data;
     delete tempBlock;
 }
 

src/mem/cache/blk.hh

@@ -406,10 +406,17 @@ class TempCacheBlk final : public CacheBlk
     Addr _addr;
 
   public:
-    TempCacheBlk() : CacheBlk() {}
+    /**
+     * Creates a temporary cache block, with its own storage.
+     * @param size The size (in bytes) of this cache block.
+     */
+    TempCacheBlk(unsigned size) : CacheBlk()
+    {
+        data = new uint8_t[size];
+    }
     TempCacheBlk(const TempCacheBlk&) = delete;
     TempCacheBlk& operator=(const TempCacheBlk&) = delete;
-    ~TempCacheBlk() {};
+    ~TempCacheBlk() { delete [] data; };
 
     /**
      * Invalidate the block and clear all state.