[lldb] Upgrade CompilerType::GetBitSize to return llvm::Expected (#129601)

This patch pushes the error handling boundary for the GetBitSize()
methods from Runtime into the Type and CompilerType APIs. This makes it
easier to diagnose problems thanks to more meaningful error messages
being available. GetBitSize() is often the first thing LLDB asks about a
type, so this method is particularly important for a better user
experience.

rdar://145667239

1 files changed, 6 insertions, 4 deletions

diff --git a/lldb/source/Commands/CommandObjectWatchpoint.cpp b/lldb/source/Commands/CommandObjectWatchpoint.cpp
index 766d650..20f4b91 100644
--- a/lldb/source/Commands/CommandObjectWatchpoint.cpp
+++ b/lldb/source/Commands/CommandObjectWatchpoint.cpp
@@ -867,9 +867,10 @@ protected:
       if (addr_type == eAddressTypeLoad) {
         // We're in business.
         // Find out the size of this variable.
-        size = m_option_watchpoint.watch_size.GetCurrentValue() == 0
-                   ? valobj_sp->GetByteSize().value_or(0)
-                   : m_option_watchpoint.watch_size.GetCurrentValue();
+        size =
+            m_option_watchpoint.watch_size.GetCurrentValue() == 0
+                ? llvm::expectedToOptional(valobj_sp->GetByteSize()).value_or(0)
+                : m_option_watchpoint.watch_size.GetCurrentValue();
       }
       compiler_type = valobj_sp->GetCompilerType();
     } else {
@@ -1080,7 +1081,8 @@ protected:
     /// of the expression, so convert to that if we found a valid type.
     CompilerType compiler_type(valobj_sp->GetCompilerType());
 
-    std::optional<uint64_t> valobj_size = valobj_sp->GetByteSize();
+    std::optional<uint64_t> valobj_size =
+        llvm::expectedToOptional(valobj_sp->GetByteSize());
     // Set the type as a uint8_t array if the size being watched is
     // larger than the ValueObject's size (which is probably the size
     // of a pointer).