tests: add implicit layer tests

Change-Id: I84e70b2eaafc59fa8d2c3642c87f3b908532445a
diff --git a/tests/layers/test.cpp b/tests/layers/test.cpp
new file mode 100644
index 0000000..11f79cb
--- /dev/null
+++ b/tests/layers/test.cpp
@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2015-2016 Valve Corporation
+ * Copyright (c) 2015-2016 LunarG, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Author: Jeremy Hayes <jeremy@lunarg.com>
+ */
+
+#include <cassert>
+#include <iostream>
+#include <unordered_map>
+
+#include "vk_dispatch_table_helper.h"
+#include "vk_layer_data.h"
+#include "vk_layer_extension_utils.h"
+
+namespace test
+{
+
+struct layer_data {
+    VkInstance instance;
+    VkLayerInstanceDispatchTable *instance_dispatch_table;
+
+    layer_data() : instance(VK_NULL_HANDLE), instance_dispatch_table(nullptr) {};
+};
+
+static std::unordered_map<void *, layer_data *> layer_data_map;
+
+VKAPI_ATTR VkResult VKAPI_CALL CreateInstance(const VkInstanceCreateInfo* pCreateInfo, const VkAllocationCallbacks* pAllocator,
+		VkInstance* pInstance)
+{
+    VkLayerInstanceCreateInfo *chain_info = get_chain_info(pCreateInfo, VK_LAYER_LINK_INFO);
+    assert(chain_info != nullptr);
+
+    assert(chain_info->u.pLayerInfo != nullptr);
+    PFN_vkGetInstanceProcAddr fpGetInstanceProcAddr = chain_info->u.pLayerInfo->pfnNextGetInstanceProcAddr;
+    assert(fpGetInstanceProcAddr != nullptr);
+
+    PFN_vkCreateInstance fpCreateInstance = (PFN_vkCreateInstance) fpGetInstanceProcAddr(NULL, "vkCreateInstance");
+    if (fpCreateInstance == nullptr)
+    {
+        return VK_ERROR_INITIALIZATION_FAILED;
+    }
+
+    chain_info->u.pLayerInfo = chain_info->u.pLayerInfo->pNext;
+    VkResult result = fpCreateInstance(pCreateInfo, pAllocator, pInstance);
+    if (result != VK_SUCCESS)
+    {
+        return result;
+    }
+
+    layer_data *instance_data = get_my_data_ptr(get_dispatch_key(*pInstance), layer_data_map);
+    instance_data->instance = *pInstance;
+    instance_data->instance_dispatch_table = new VkLayerInstanceDispatchTable;
+    layer_init_instance_dispatch_table(*pInstance, instance_data->instance_dispatch_table, fpGetInstanceProcAddr);
+
+    // Marker for testing.
+    std::cout << "VK_LAYER_LUNARG_test: CreateInstance" << '\n';
+
+    return result;
+}
+
+VKAPI_ATTR void VKAPI_CALL DestroyInstance(VkInstance instance, const VkAllocationCallbacks *pAllocator)
+{
+    dispatch_key key = get_dispatch_key(instance);
+    layer_data *instance_data = get_my_data_ptr(key, layer_data_map);
+    instance_data->instance_dispatch_table->DestroyInstance(instance, pAllocator);
+
+    delete instance_data->instance_dispatch_table;
+    layer_data_map.erase(key);
+
+    // Marker for testing.
+    std::cout << "VK_LAYER_LUNARG_test: DestroyInstance" << '\n';
+}
+
+VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL GetInstanceProcAddr(VkInstance instance, const char* funcName)
+{
+    // Return the functions that are intercepted by this layer.
+    static const struct
+    {
+        const char *name;
+        PFN_vkVoidFunction proc;
+    } core_instance_commands[] =
+    {
+        { "vkGetInstanceProcAddr", reinterpret_cast<PFN_vkVoidFunction>(GetInstanceProcAddr) },
+        { "vkCreateInstance", reinterpret_cast<PFN_vkVoidFunction>(CreateInstance) },
+        { "vkDestroyInstance", reinterpret_cast<PFN_vkVoidFunction>(DestroyInstance) }
+    };
+
+    for (size_t i = 0; i < ARRAY_SIZE(core_instance_commands); i++)
+    {
+        if (!strcmp(core_instance_commands[i].name, funcName))
+        {
+            return core_instance_commands[i].proc;
+        }
+    }
+
+    // Only call down the chain for Vulkan commands that this layer does not intercept.
+    layer_data *instance_data = get_my_data_ptr(get_dispatch_key(instance), layer_data_map);
+    VkLayerInstanceDispatchTable *pTable = instance_data->instance_dispatch_table;
+    if (pTable->GetInstanceProcAddr == nullptr)
+    {
+        return nullptr;
+    }
+
+    return pTable->GetInstanceProcAddr(instance, funcName);
+}
+
+}
+
+VK_LAYER_EXPORT VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL vkGetInstanceProcAddr(VkInstance instance, const char* funcName)
+{
+    return test::GetInstanceProcAddr(instance, funcName);
+}
+
+VK_LAYER_EXPORT VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL vkGetDeviceProcAddr(VkDevice device, const char *funcName)
+{
+    return nullptr;
+}
+
+VK_LAYER_EXPORT VKAPI_ATTR VkResult VKAPI_CALL vkEnumerateInstanceExtensionProperties(const char *pLayerName, uint32_t *pCount, VkExtensionProperties *pProperties)
+{
+    return VK_ERROR_LAYER_NOT_PRESENT;
+}
+
+VK_LAYER_EXPORT VKAPI_ATTR VkResult VKAPI_CALL vkEnumerateInstanceLayerProperties(uint32_t *pCount, VkLayerProperties *pProperties)
+{
+    return VK_ERROR_LAYER_NOT_PRESENT;
+}