Index: lldb/unittests/Process/Utility/CMakeLists.txt
===================================================================
--- lldb/unittests/Process/Utility/CMakeLists.txt
+++ lldb/unittests/Process/Utility/CMakeLists.txt
@@ -15,9 +15,10 @@
   ${NETBSD_SOURCES})
 
 add_lldb_unittest(ProcessUtilityTests
-  RegisterContextTest.cpp
+  DynamicRegisterInfoTest.cpp
   LinuxProcMapsTest.cpp
   MemoryTagManagerAArch64MTETest.cpp
+  RegisterContextTest.cpp
   ${PLATFORM_SOURCES}
 
   LINK_LIBS
Index: lldb/unittests/Process/Utility/DynamicRegisterInfoTest.cpp
===================================================================
--- /dev/null
+++ lldb/unittests/Process/Utility/DynamicRegisterInfoTest.cpp
@@ -0,0 +1,91 @@
+//===-- DynamicRegisterInfoTest.cpp ---------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+#include "Plugins/Process/Utility/DynamicRegisterInfo.h"
+
+#include "lldb/Utility/ArchSpec.h"
+
+using namespace lldb_private;
+
+TEST(DynamicRegisterInfoTest, finalize_regs) {
+  DynamicRegisterInfo info;
+  ConstString group{"group"};
+
+  uint32_t regnums[3] = {LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM,
+                         LLDB_INVALID_REGNUM};
+
+  // Add regular registers
+  struct RegisterInfo new_reg {
+    "b1", nullptr, 8, LLDB_INVALID_INDEX32, lldb::eEncodingUint,
+        lldb::eFormatUnsigned,
+        {LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM, 0, 0},
+        nullptr, nullptr, nullptr, 0
+  };
+  info.AddRegister(new_reg, group);
+  new_reg.name = "b2";
+  new_reg.kinds[lldb::eRegisterKindProcessPlugin]++;
+  new_reg.kinds[lldb::eRegisterKindLLDB]++;
+  info.AddRegister(new_reg, group);
+
+  // Add a few sub-registers
+  new_reg.name = "s1";
+  new_reg.byte_size = 4;
+  new_reg.kinds[lldb::eRegisterKindProcessPlugin]++;
+  new_reg.kinds[lldb::eRegisterKindLLDB]++;
+  regnums[0] = 0;
+  new_reg.value_regs = regnums;
+  info.AddRegister(new_reg, group);
+
+  new_reg.name = "s2";
+  new_reg.kinds[lldb::eRegisterKindProcessPlugin]++;
+  new_reg.kinds[lldb::eRegisterKindLLDB]++;
+  regnums[0] = 1;
+  info.AddRegister(new_reg, group);
+
+  // Add a register with weird invalidation
+  new_reg.name = "x";
+  new_reg.kinds[lldb::eRegisterKindProcessPlugin]++;
+  new_reg.kinds[lldb::eRegisterKindLLDB]++;
+  new_reg.value_regs = nullptr;
+  regnums[0] = 1;
+  regnums[1] = 0;
+  new_reg.invalidate_regs = regnums;
+  info.AddRegister(new_reg, group);
+
+  info.Finalize(lldb_private::ArchSpec());
+
+  const RegisterInfo *added_reg = info.GetRegisterInfoAtIndex(0);
+  ASSERT_NE(added_reg, nullptr);
+  EXPECT_EQ(added_reg->byte_offset, 0U);
+
+  added_reg = info.GetRegisterInfoAtIndex(1);
+  ASSERT_NE(added_reg, nullptr);
+  EXPECT_EQ(added_reg->byte_offset, 8U);
+
+  added_reg = info.GetRegisterInfoAtIndex(2);
+  ASSERT_NE(added_reg, nullptr);
+  EXPECT_EQ(added_reg->byte_offset, 0U);
+  EXPECT_EQ(added_reg->value_regs[0], 0U);
+  EXPECT_EQ(added_reg->value_regs[1], LLDB_INVALID_REGNUM);
+
+  added_reg = info.GetRegisterInfoAtIndex(3);
+  ASSERT_NE(added_reg, nullptr);
+  EXPECT_EQ(added_reg->byte_offset, 8U);
+  EXPECT_EQ(added_reg->value_regs[0], 1U);
+  EXPECT_EQ(added_reg->value_regs[1], LLDB_INVALID_REGNUM);
+
+  added_reg = info.GetRegisterInfoAtIndex(4);
+  ASSERT_NE(added_reg, nullptr);
+  EXPECT_EQ(added_reg->byte_offset, 16U);
+  EXPECT_EQ(added_reg->invalidate_regs[0], 0U);
+  EXPECT_EQ(added_reg->invalidate_regs[1], 1U);
+  EXPECT_EQ(added_reg->invalidate_regs[2], LLDB_INVALID_REGNUM);
+}