util: Fixup and add Dispatch Table header

Fixes the vk_layer_dispatch_table.h header file so that they can be used
in other projects. The contents of this header and
 vk_dispatch_table_helper.h have been moved into a new header
 vul_dispatch_table.h.

The structs VulDeviceDispatchTable and VulInstanceDispatchTable
struct contain function pointers for the device and instance, respectively.

The functions vul_init_device_dispatch_table and
vul_init_instance_dispatch_table fill out the aforementioned structs,
making the task of setting up the disptach table in a layer much simpler.

scripts/generators/dispatch_table_generator.py

@@ -0,0 +1,93 @@
+#!/usr/bin/python3 -i
+#
+# Copyright 2023 The Khronos Group Inc.
+# Copyright 2023 Valve Corporation
+# Copyright 2023 LunarG, Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+import os
+from generators.base_generator import BaseGenerator
+
+class DispatchTableOutputGenerator(BaseGenerator):
+    def __init__(self):
+        BaseGenerator.__init__(self)
+
+    def generate(self):
+        out = []
+        out.append(f'''// *** THIS FILE IS GENERATED - DO NOT EDIT ***
+// See {os.path.basename(__file__)} for modifications
+// Copyright 2023 The Khronos Group Inc.
+// Copyright 2023 Valve Corporation
+// Copyright 2023 LunarG, Inc.
+//
+// SPDX-License-Identifier: Apache-2.0
+\n''')
+
+        out.append('''
+#pragma once
+
+#include <vulkan/vulkan.h>
+
+#include <string.h>
+
+typedef PFN_vkVoidFunction (VKAPI_PTR *PFN_GetPhysicalDeviceProcAddr)(VkInstance instance, const char* pName);
+''')
+        out.append('''
+// Instance function pointer dispatch table
+typedef struct VulInstanceDispatchTable_ {
+    PFN_GetPhysicalDeviceProcAddr GetPhysicalDeviceProcAddr;
+
+''')
+        for command in [x for x in self.vk.commands.values() if x.instance]:
+            out.extend([f'#ifdef {command.protect}\n'] if command.protect else [])
+            out.append(f'    PFN_{command.name} {command.name[2:]};\n')
+            out.extend([f'#endif //{command.protect}\n'] if command.protect else [])
+        out.append('} VulInstanceDispatchTable;\n')
+
+        out.append('''
+// Device function pointer dispatch table
+typedef struct VulDeviceDispatchTable_ {
+''')
+        for command in [x for x in self.vk.commands.values() if x.device]:
+            out.extend([f'#ifdef {command.protect}\n'] if command.protect else [])
+            out.append(f'    PFN_{command.name} {command.name[2:]};\n')
+            out.extend([f'#endif //{command.protect}\n'] if command.protect else [])
+        out.append('} VulDeviceDispatchTable;\n')
+
+        out.append('''
+static inline void vulInitDeviceDispatchTable(VkDevice device, VulDeviceDispatchTable *table, PFN_vkGetDeviceProcAddr gdpa) {
+    memset(table, 0, sizeof(*table));
+    // Device function pointers
+    table->GetDeviceProcAddr = gdpa;
+''')
+
+        for command in [x for x in self.vk.commands.values() if x.device and x.name != 'vkGetDeviceProcAddr']:
+            out.extend([f'#ifdef {command.protect}\n'] if command.protect else [])
+            out.append(f'    table->{command.name[2:]} = (PFN_{command.name}) gdpa(device, "{command.name}");\n')
+            out.extend([f'#endif // {command.protect}\n'] if command.protect else [])
+        out.append('}\n')
+
+        out.append('''
+static inline void vulInitInstanceDispatchTable(VkInstance instance, VulInstanceDispatchTable *table, PFN_vkGetInstanceProcAddr gipa) {
+    memset(table, 0, sizeof(*table));
+    // Instance function pointers
+    table->GetInstanceProcAddr = gipa;
+    table->GetPhysicalDeviceProcAddr = (PFN_GetPhysicalDeviceProcAddr) gipa(instance, "vk_layerGetPhysicalDeviceProcAddr");
+''')
+
+        for command in [x for x in self.vk.commands.values() if x.instance and x.name not in [
+                'vkCreateInstance',
+                'vkCreateDevice',
+                'vkGetPhysicalDeviceProcAddr',
+                'vkEnumerateInstanceExtensionProperties',
+                'vkEnumerateInstanceLayerProperties',
+                'vkEnumerateInstanceVersion',
+                'vkGetInstanceProcAddr',
+        ]]:
+            out.extend([f'#ifdef {command.protect}\n'] if command.protect else [])
+            out.append(f'    table->{command.name[2:]} = (PFN_{command.name}) gipa(instance, "{command.name}");\n')
+            out.extend([f'#endif // {command.protect}\n'] if command.protect else [])
+        out.append('}\n')
+
+        self.write("".join(out))