[lldb-mi] Fix expansion of anonymous structures and unions

A variable of type:
    struct S {
       union {
           int            i1;
           unsigned u1;
       };
       union {
           int            i2;
           unsigned u2;
       };
    };
had been impossible to evaluate in lldb-mi, because MI assigns '??' as the
variable name to each of the unnamed unions after "-var-list-children" command.
Also '??' incorrectly goes to 'exp' field which is treated by IDE as a
structure field name and is displayed in watch window.

The patch fixes this returning empty string as type name for unnamed union and
assigning $N to variable name, where N is the field number in the parent entity.

Patch from evgeny.leviant@gmail.com
Reviewed by: clayborg, abidh
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D13947

llvm-svn: 251176

1 files changed, 3 insertions, 1 deletions

diff --git a/lldb/tools/lldb-mi/MICmdCmdVar.cpp b/lldb/tools/lldb-mi/MICmdCmdVar.cpp
index c9153360cc3..c0a1e51098c 100644
--- a/lldb/tools/lldb-mi/MICmdCmdVar.cpp
+++ b/lldb/tools/lldb-mi/MICmdCmdVar.cpp
@@ -1015,7 +1015,9 @@ CMICmdCmdVarListChildren::Execute()
         lldb::SBValue member = rValue.GetChildAtIndex(i);
         const CMICmnLLDBUtilSBValue utilValue(member);
         const CMIUtilString strExp = utilValue.GetName();
-        const CMIUtilString name(CMIUtilString::Format("%s.%s", rVarObjName.c_str(), strExp.c_str()));
+        const CMIUtilString name(strExp.empty() ?
+            CMIUtilString::Format("%s.$%u", rVarObjName.c_str(), i) :
+            CMIUtilString::Format("%s.%s", rVarObjName.c_str(), strExp.c_str()));
         const MIuint nChildren = member.GetNumChildren();
         const CMIUtilString strThreadId(CMIUtilString::Format("%u", member.GetThread().GetIndexID()));