loader: Support layers that don't have an extension entrypoint

Change all layers and loader interface to init dispatch tables on
GPA("GetXXXProcAddr").  After that initialization rest of dispatch
tables are inited via unwrapped object using the GPA in the dispatch
table.  This also allows App generated GPA calls that the loader can't resolve
to function correctly.

1 files changed, 25 insertions, 16 deletions

diff --git a/layers/basic.cpp b/layers/basic.cpp
index 0742cb21..1ba3188e 100644
--- a/layers/basic.cpp
+++ b/layers/basic.cpp
@@ -58,7 +58,7 @@ static VkLayerInstanceDispatchTable * initLayerInstanceTable(const VkBaseLayerOb
         return it->second;
     }
 
-    layer_init_instance_dispatch_table(pTable, (PFN_vkGetInstanceProcAddr) instancew->pGPA, (VkInstance) instancew->nextObject);
+    layer_init_instance_dispatch_table(pTable, instancew);
 
     return pTable;
 }
@@ -79,7 +79,7 @@ static VkLayerDispatchTable * initLayerTable(const VkBaseLayerObject *devw)
         return it->second;
     }
 
-    layer_initialize_dispatch_table(pTable, (PFN_vkGetDeviceProcAddr) devw->pGPA, (VkDevice) devw->nextObject);
+    layer_initialize_dispatch_table(pTable, devw);
 
     return pTable;
 }
@@ -207,21 +207,25 @@ VK_LAYER_EXPORT void * VKAPI vkGetDeviceProcAddr(VkDevice device, const char* pN
     if (device == NULL)
         return NULL;
 
-    initLayerTable((const VkBaseLayerObject *) device);
-
-    if (!strcmp("vkGetDeviceProcAddr", pName))
+    /* loader uses this to force layer initialization; device object is wrapped */
+    if (!strcmp("vkGetDeviceProcAddr", pName)) {
+        initLayerTable((const VkBaseLayerObject *) device);
         return (void *) vkGetDeviceProcAddr;
+    }
+
     if (!strcmp("vkGetFormatInfo", pName))
         return (void *) vkGetFormatInfo;
     if (!strcmp("vkDestroyDevice", pName))
         return (void *) vkDestroyDevice;
     if (!strcmp("vkLayerExtension1", pName))
         return (void *) vkLayerExtension1;
-    else {
-        VkBaseLayerObject* devw = (VkBaseLayerObject *) device;
-        if (devw->pGPA == NULL)
+    else
+    {
+        VkLayerDispatchTable **ppDisp = (VkLayerDispatchTable **) device;
+        VkLayerDispatchTable* pTable = tableMap[*ppDisp];
+        if (pTable->GetDeviceProcAddr == NULL)
             return NULL;
-        return devw->pGPA((VkObject) devw->nextObject, pName);
+        return pTable->GetDeviceProcAddr(device, pName);
     }
 }
 
@@ -230,10 +234,12 @@ VK_LAYER_EXPORT void * VKAPI vkGetInstanceProcAddr(VkInstance instance, const ch
     if (instance == NULL)
         return NULL;
 
-    initLayerInstanceTable((const VkBaseLayerObject *) instance);
-
-    if (!strcmp("vkGetInstanceProcAddr", pName))
+    /* loader uses this to force layer initialization; instance object is wrapped */
+    if (!strcmp("vkGetInstanceProcAddr", pName)) {
+        initLayerInstanceTable((const VkBaseLayerObject *) instance);
         return (void *) vkGetInstanceProcAddr;
+    }
+
     if (!strcmp("vkDestroyInstance", pName))
         return (void *) vkDestroyInstance;
     if (!strcmp("vkEnumeratePhysicalDevices", pName))
@@ -242,10 +248,13 @@ VK_LAYER_EXPORT void * VKAPI vkGetInstanceProcAddr(VkInstance instance, const ch
         return (void*) vkGetGlobalExtensionInfo;
     if (!strcmp("vkCreateDevice", pName))
         return (void *) vkCreateDevice;
-    else {
-        VkBaseLayerObject* instancew = (VkBaseLayerObject *) instance;
-        if (instancew->pGPA == NULL)
+    else
+    {
+        VkLayerInstanceDispatchTable **ppDisp = (VkLayerInstanceDispatchTable **) instance;
+        VkLayerInstanceDispatchTable* pTable = tableInstanceMap[*ppDisp];
+        if (pTable->GetInstanceProcAddr == NULL)
             return NULL;
-        return instancew->pGPA((VkObject) instancew->nextObject, pName);
+        return pTable->GetInstanceProcAddr(instance, pName);
     }
+
 }