Avoid -Wshorten-64-to-32 warnings in a few places

...by explictily casting to int. Add a few comments explaining why we
can get at most INT_MAX many elements, and add Q_ASSERTS to check that
the assumptions actually hold.

Task-number: QTBUG-105055
Change-Id: I1769318a9c04b51efe45fe0cae9fc0d93cfec45e
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 5 insertions, 5 deletions

diff --git a/src/qml/memory/qv4mmdefs_p.h b/src/qml/memory/qv4mmdefs_p.h
index 395f0870e4..c873bfd5f8 100644
--- a/src/qml/memory/qv4mmdefs_p.h
+++ b/src/qml/memory/qv4mmdefs_p.h
@@ -178,17 +178,17 @@ struct HeapItem {
 
     bool isGray() const {
         Chunk *c = chunk();
-        uint index = this - c->realBase();
+        std::ptrdiff_t index = this - c->realBase();
         return Chunk::testBit(c->grayBitmap, index);
     }
     bool isBlack() const {
         Chunk *c = chunk();
-        uint index = this - c->realBase();
+        std::ptrdiff_t index = this - c->realBase();
         return Chunk::testBit(c->blackBitmap, index);
     }
     bool isInUse() const {
         Chunk *c = chunk();
-        uint index = this - c->realBase();
+        std::ptrdiff_t index = this - c->realBase();
         return Chunk::testBit(c->objectBitmap, index);
     }
 
@@ -207,10 +207,10 @@ struct HeapItem {
     // Doesn't report correctly for huge items
     size_t size() const {
         Chunk *c = chunk();
-        uint index = this - c->realBase();
+        std::ptrdiff_t index = this - c->realBase();
         Q_ASSERT(Chunk::testBit(c->objectBitmap, index));
         // ### optimize me
-        uint end = index + 1;
+        std::ptrdiff_t end = index + 1;
         while (end < Chunk::NumSlots && Chunk::testBit(c->extendsBitmap, end))
             ++end;
         return (end - index)*sizeof(HeapItem);