Introduce a way for Languages to specify whether values of "reference types" are "nil" (not pointing to anything) or uninitialized (never made to point at anything)
This latter determination may or may not be possible on a per-language basis; and neither is mandatory to implement for any language
Use this knowledge in the ValueObjectPrinter to generalize the notion of IsObjCNil() and the respective printout
llvm-svn: 252663
diff --git a/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp b/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp
index e8d008c..1cec626 100644
--- a/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp
+++ b/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp
@@ -863,3 +863,15 @@
return false;
}
+
+bool
+ObjCLanguage::IsNilReference (ValueObject& valobj)
+{
+ const uint32_t mask = eTypeIsObjC | eTypeIsPointer;
+ bool isObjCpointer = (((valobj.GetCompilerType().GetTypeInfo(nullptr)) & mask) == mask);
+ if (!isObjCpointer)
+ return false;
+ bool canReadValue = true;
+ bool isZero = valobj.GetValueAsUnsigned(0,&canReadValue) == 0;
+ return canReadValue && isZero;
+}
diff --git a/lldb/source/Plugins/Language/ObjC/ObjCLanguage.h b/lldb/source/Plugins/Language/ObjC/ObjCLanguage.h
index 0f96ff8..e30aa18 100644
--- a/lldb/source/Plugins/Language/ObjC/ObjCLanguage.h
+++ b/lldb/source/Plugins/Language/ObjC/ObjCLanguage.h
@@ -153,6 +153,9 @@
GetFormatterPrefixSuffix (ValueObject& valobj, ConstString type_hint,
std::string& prefix, std::string& suffix) override;
+ bool
+ IsNilReference (ValueObject& valobj) override;
+
//------------------------------------------------------------------
// Static Functions
//------------------------------------------------------------------