fix: handle unions as well

Author: Nerixyz

lldb/source/Plugins/SymbolFile/NativePDB/UdtRecordCompleter.cpp

@@ -467,12 +467,19 @@ void UdtRecordCompleter::Record::ConstructRecord() {
       if (iter->second.empty())
         continue;
 
-      // For structs, if the new fields come after the already added ones
-      // without overlap, go back to the root struct.
-      if (iter->first <= offset && record.kind == Member::Struct &&
-          is_last_end_offset(iter))
-        parent = &record;
-      else {
+      // If the new fields come after the already added ones
+      // without overlap, go back to the root.
+      if (iter->first <= offset && is_last_end_offset(iter)) {
+        if (record.kind == Member::Struct)
+          parent = &record;
+        else {
+          lldbassert(record.kind == Member::Union &&
+                     "Current record must be a union");
+          lldbassert(!record.fields.empty());
+          // For unions, append the field to the last struct
+          parent = record.fields.back().get();
+        }
+      } else {
         parent = iter->second.back();
         iter->second.pop_back();
       }

lldb/unittests/SymbolFile/NativePDB/UdtRecordCompleterTests.cpp

@@ -275,24 +275,21 @@ TEST_F(UdtRecordCompleterRecordTests, TestNestedStructInUnionInStructInUnion) {
   //       m4;
   //       union {
   //           m5;
-  //           struct {
-  //               m6;
-  //               m7;
-  //           };
+  //           m6;
   //       };
+  //       m7;
   //   };
   // };
   Record record;
   record.start_offset = 0;
   AddField(&record.record, "m1", 0, 4, Member::Field);
   AddField(&record.record, "m2", 0, 2, Member::Field);
-  Member *s1 = AddField(&record.record, "", 0, 0, Member::Struct);
-  AddField(s1, "m3", 0, 2, Member::Field);
-  AddField(s1, "m4", 2, 4, Member::Field);
-  Member *u1 = AddField(s1, "", 6, 0, Member::Union);
-  AddField(u1, "m5", 6, 2, Member::Field);
-  Member *s2 = AddField(u1, "", 0, 0, Member::Struct, 6);
-  AddField(s2, "m6", 6, 2, Member::Field);
-  AddField(s2, "m7", 8, 2, Member::Field);
+  Member *s = AddField(&record.record, "", 0, 0, Member::Struct);
+  AddField(s, "m3", 0, 2, Member::Field);
+  AddField(s, "m4", 2, 4, Member::Field);
+  Member *u = AddField(s, "", 6, 0, Member::Union);
+  AddField(u, "m5", 6, 2, Member::Field);
+  AddField(u, "m6", 6, 2, Member::Field);
+  AddField(s, "m7", 8, 2, Member::Field);
   EXPECT_EQ(WrappedRecord(this->record), WrappedRecord(record));
 }