Treat anonymous struct that is nested in another one.

j6t · j6t · commit 73a0ddf4abe5 · 2025-12-12T18:12:12.000+01:00
To determine whether an list of values is an array or an assortment of
anonymous structs or unions, we have to look at the names of the members.
But if the first member is itself anonymous, we have to inspect it
recursively. So, do that.
diff --git a/kdbg/gdbdriver.cpp b/kdbg/gdbdriver.cpp
@@ -1549,11 +1549,16 @@ static bool parseNested(const char*& s, ExprValue* variable)
 	 * anonymous structs or unions. It is sufficient to check just two
 	 * entries: if they have members with the same name, it is an array,
 	 * because two anonymous structs or unions cannot have the same member names.
+	 * Note that we must search for names recursively in the contained structs,
+	 * because they can be anonymous as well.
 	 * Also, if we find an empty struct, then this must be an array, because
 	 * empty structs cannot be anonymous.
 	 */
 	auto firstName = [](ExprValue* var) {
-	    return var->m_children.front()->m_name;
+	    do {
+		var = var->m_children.front();
+	    } while (var->m_nameKind == VarTree::NKanonymous);
+	    return var->m_name;
 	};
 	ExprValue* a = variable->m_children.front();
 	ExprValue* b = variable->m_children.back();
diff --git a/kdbg/testprogs/anonstruct.cpp b/kdbg/testprogs/anonstruct.cpp
@@ -48,11 +48,15 @@ struct OnlyUnions {
 		};
 	};
 	struct {
+		// nested anonymous struct
 		struct {
 			int used;
 			double avail;
 			double* data;
-		} member;
+		};
+		// need a named member, otherwise this struct
+		// is mistakenly regarded as an array of length 1
+		int member;
 	};
 };
 
