Unify the return value of GetByteSize to an llvm::Optional<uint64_t> (NFC-ish)

This cleanup patch unifies all methods called GetByteSize() in the
ValueObject hierarchy to return an optional, like the methods in
CompilerType do. This means fewer magic 0 values, which could fix bugs
down the road in languages where types can have a size of zero, such
as Swift and C (but not C++).

Differential Revision: https://reviews.llvm.org/D84285

This re-lands the patch with bogus :m_byte_size(0) initalizations removed.

1 files changed, 3 insertions, 3 deletions

diff --git a/lldb/source/Target/StackFrame.cpp b/lldb/source/Target/StackFrame.cpp
index 098aed9..22bca52 100644
--- a/lldb/source/Target/StackFrame.cpp
+++ b/lldb/source/Target/StackFrame.cpp
@@ -1408,7 +1408,7 @@ ValueObjectSP GetValueForOffset(StackFrame &frame, ValueObjectSP &parent,
     }
 
     int64_t child_offset = child_sp->GetByteOffset();
-    int64_t child_size = child_sp->GetByteSize();
+    int64_t child_size = child_sp->GetByteSize().getValueOr(0);
 
     if (offset >= child_offset && offset < (child_offset + child_size)) {
       return GetValueForOffset(frame, child_sp, offset - child_offset);
@@ -1441,8 +1441,8 @@ ValueObjectSP GetValueForDereferincingOffset(StackFrame &frame,
   }
 
   if (offset >= 0 && uint64_t(offset) >= pointee->GetByteSize()) {
-    int64_t index = offset / pointee->GetByteSize();
-    offset = offset % pointee->GetByteSize();
+    int64_t index = offset / pointee->GetByteSize().getValueOr(1);
+    offset = offset % pointee->GetByteSize().getValueOr(1);
     const bool can_create = true;
     pointee = base->GetSyntheticArrayMember(index, can_create);
   }