loader: Move CreateDevice to device table

Discovered an issue where a layer was doing cleanup
in it's DestroyDevice function but the CreateDevice
was never called.
This happened because the extension was only enabled
on the device chain and the device chain doesn't actually
call CreateDevice. That happens on the Instance chain.
Making it so that we can call down the device chain -
which is terminated by the ICD.
We need to know the real device object to construct the
device chain heiarchy and when calling down the device
chain it should end with the ICD doing the actual device
object creation.

This patch fixes the issue by using the
same process as CreateInstance. The loader will call
the ICD's CreateDevice and pass that in the *pDevice
argument. The layers then ignore the PhysicalDevice parameter
and use the *pDevice to access the device chain.
To prevent the ICD from being called twice needed to
stub in a special loader_GetDeviceChainProcAddr to provide
a stub for only CreateDevice as the end of the chain.

integrate review feedback.

1 files changed, 7 insertions, 4 deletions

diff --git a/layers/screenshot.cpp b/layers/screenshot.cpp
index d46205b3..f7927df3 100644
--- a/layers/screenshot.cpp
+++ b/layers/screenshot.cpp
@@ -311,8 +311,8 @@ VK_LAYER_EXPORT VkResult VKAPI vkCreateDevice(
     const VkDeviceCreateInfo *pCreateInfo,
     VkDevice                 *pDevice)
 {
-    VkLayerInstanceDispatchTable *pInstanceTable = get_dispatch_table(screenshot_instance_table_map, gpu);
-    VkResult result = pInstanceTable->CreateDevice(gpu, pCreateInfo, pDevice);
+    VkLayerDispatchTable *pDisp  = get_dispatch_table(screenshot_device_table_map, *pDevice);
+    VkResult result = pDisp->CreateDevice(gpu, pCreateInfo, pDevice);
 
     if (result == VK_SUCCESS) {
         createDeviceRegisterExtensions(pCreateInfo, *pDevice);
@@ -321,6 +321,8 @@ VK_LAYER_EXPORT VkResult VKAPI vkCreateDevice(
     return result;
 }
 
+/* TODO: Probably need a DestroyDevice as well */
+
 #define SCREENSHOT_LAYER_EXT_ARRAY_SIZE 2
 static const VkExtensionProperties ssExts[SCREENSHOT_LAYER_EXT_ARRAY_SIZE] = {
     {
@@ -561,6 +563,9 @@ VK_LAYER_EXPORT void* VKAPI vkGetDeviceProcAddr(
         initDeviceTable(screenshot_device_table_map, (const VkBaseLayerObject *) dev);
         return (void *) vkGetDeviceProcAddr;
     }
+    if (!strcmp(funcName, "vkCreateDevice"))
+        return (void*) vkCreateDevice;
+
     if (!strcmp(funcName, "vkGetDeviceQueue"))
         return (void*) vkGetDeviceQueue;
 
@@ -610,8 +615,6 @@ VK_LAYER_EXPORT void* VKAPI vkGetInstanceProcAddr(
         return (void *) vkDestroyInstance;
     if (!strcmp(funcName, "vkCreateInstance"))
         return (void*) vkCreateInstance;
-    if (!strcmp(funcName, "vkCreateDevice"))
-        return (void*) vkCreateDevice;
 
     if (get_dispatch_table(screenshot_instance_table_map, instance)->GetInstanceProcAddr == NULL)
         return NULL;