Extend synthetic children to produce synthetic values (as in, those that GetValueAsUnsigned(), GetValueAsCString() would return)

The way to do this is to write a synthetic child provider for your type, and have it vend the (optional) get_value function.
If get_value is defined, and it returns a valid SBValue, that SBValue's value (as in lldb_private::Value) will be used as the synthetic ValueObject's Value

The rationale for doing things this way is twofold:

- there are many possible ways to define a "value" (SBData, a Python number, ...) but SBValue seems general enough as a thing that stores a "value", so we just trade values that way and that keeps our currency trivial
- we could introduce a new level of layering (ValueObjectSyntheticValue), a new kind of formatter (synthetic value producer), but that would complicate the model (can I have a dynamic with no synthetic children but synthetic value? synthetic value with synthetic children but no dynamic?), and I really couldn't see much benefit to be reaped from this added complexity in the matrix
On the other hand, just defining a synthetic child provider with a get_value but returning no actual children is easy enough that it's not a significant road-block to adoption of this feature

Comes with a test case

llvm-svn: 219330

1 files changed, 1 insertions, 1 deletions

diff --git a/lldb/source/Core/ValueObjectVariable.cpp b/lldb/source/Core/ValueObjectVariable.cpp
index 225dc02c8ad..aa8ade1aed1 100644
--- a/lldb/source/Core/ValueObjectVariable.cpp
+++ b/lldb/source/Core/ValueObjectVariable.cpp
@@ -234,7 +234,7 @@ ValueObjectVariable::UpdateValue ()
                     }
                 }
 
-                if (GetClangType().IsAggregateType())
+                if (!CanProvideValue())
                 {
                     // this value object represents an aggregate type whose
                     // children have values, but this object does not. So we