Make Vulkan enums always be 32-bit (fixes #26)

I am porting this example to [mach-glfw](github.com/hexops/mach-glfw), and noticed that no GLFW error handling callback is registered because in my port there are a lot of GLFW errors :)

`glfwSwapBuffers` here is emitting `GLFW_NO_WINDOW_CONTEXT` errors constantly, because calling it without a valid OpenGL context is illegal. It's not needed for Vulkan.

.github/workflows/build.yml

@@ -2,9 +2,9 @@ name: Build
 
 on:
   push:
-    branches: [ master ]
+    branches: [ zig-0.8.1-compat ]
   pull_request:
-    branches: [ master ]
+    branches: [ zig-0.8.1-compat ]
   schedule:
     - cron: '0 6 * * *'
 
@@ -18,7 +18,7 @@ jobs:
     - name: Setup Zig
       uses: goto-bus-stop/setup-zig@v1.3.0
       with:
-        version: master
+        version: 0.8.0
 
     - name: Test
       run: |
@@ -27,11 +27,20 @@ jobs:
     - name: Fetch Vulkan SDK
       run: |
         wget -qO - https://packages.lunarg.com/lunarg-signing-key-pub.asc | sudo apt-key add -
-        sudo wget -qO /etc/apt/sources.list.d/lunarg-vulkan-1.2.162-focal.list https://packages.lunarg.com/vulkan/1.2.162/lunarg-vulkan-1.2.162-focal.list
+        sudo wget -qO /etc/apt/sources.list.d/lunarg-vulkan-1.2.189-focal.list https://packages.lunarg.com/vulkan/1.2.189/lunarg-vulkan-1.2.189-focal.list
         sudo apt update
         sudo apt install shaderc libglfw3 libglfw3-dev
 
-    - name: Build with latest zig & vk.xml
+    - name: Fetch latest vk.xml
       run: |
         wget https://raw.githubusercontent.com/KhronosGroup/Vulkan-Docs/main/xml/vk.xml
+
+    - name: Build with latest zig & vk.xml
+      run: |
         zig build -Dvulkan-registry=./vk.xml
+
+    - name: Archive vk.xml
+      uses: actions/upload-artifact@v2
+      with:
+        name: vk.zig
+        path: zig-cache/vk.zig

.gitignore

@@ -1 +1,2 @@
 zig-cache/
+zig-out/

README.md

@@ -8,7 +8,11 @@ A Vulkan binding generator for Zig.
 
 vulkan-zig attempts to provide a better experience to programming Vulkan applications in Zig, by providing features such as integration of vulkan errors with Zig's error system, function pointer loading, renaming fields to standard Zig style, better bitfield handling, turning out parameters into return values and more.
 
-vulkan-zig is automatically tested against the latest vk.xml and zig, and supports vk.xml from version 1.x.163.
+vulkan-zig is automatically tested daily against the latest vk.xml and zig, and supports vk.xml from version 1.x.163.
+
+### Zig versions
+
+vulkan-zig aims to be always compatible with the ever-changing Zig master branch (however, development may lag a few days behind). Sometimes, the Zig master branch breaks a bunch of functionality however, which may make the latest version vulkan-zig incompatible with older releases of Zig. This repository aims to have a version compatible for both the latest Zig master, and the latest Zig release. The `master` branch is compatible with the `master` branch of Zig, and versions for older versions of Zig are maintained in the `zig-<version>-compat` branch.
 
 ## Features
 ### CLI-interface
@@ -32,10 +36,10 @@ pub fn build(b: *Builder) void {
     exe.step.dependOn(&gen.step);
 
     // Add the generated file as package to the final executable
-    exe.addPackagePath("vulkan", gen.full_out_path);
+    exe.addPackage(gen.package);
 }
 ```
-This reads vk.xml, parses its contents, and renders the Vulkan bindings to "vk.zig", which is then formatted and placed in `zig-cache`. The resulting file can then be added to an executable by using `addPackagePath`.
+This reads vk.xml, parses its contents, and renders the Vulkan bindings to "vk.zig", which is then formatted and placed in `zig-cache`. The resulting file can then be added to an executable by using `addPackage`, after which the bindings will be made available to the executable under the name `vulkan`.
 
 ### Function & field renaming
 Functions and fields are renamed to be more or less in line with [Zig's standard library style](https://ziglang.org/documentation/master/#Style-Guide):
@@ -63,23 +67,22 @@ For each function, a wrapper is generated into one of three structs:
 * InstanceWrapper. This contains wrappers for functions which are otherwise loaded by `vkGetInstanceProcAddr`.
 * DeviceWrapper. This contains wrappers for functions which are loaded by `vkGetDeviceProcAddr`.
 
-Each wrapper struct is to be used as a mixin on a struct containing **just** function pointers as members:
+Each wrapper struct can be called with an array of the appropriate enums:
 ```zig
 const vk = @import("vulkan");
-const BaseDispatch = struct {
+const BaseDispatch = vk.BaseWrapper(.{
-    vkCreateInstance: vk.PfnCreateInstance,
+    .CreateInstance,
-    usingnamespace vk.BaseWrapper(@This());
+});
-};
 ```
 The wrapper struct then provides wrapper functions for each function pointer in the dispatch struct:
 ```zig
-pub const BaseWrapper(comptime Self: type) type {
+pub const BaseWrapper(comptime cmds: anytype) type {
+    ...
+    const Dispatch = CreateDispatchStruct(cmds);
     return struct {
-        pub fn createInstance(
+        dispatch: Dispatch,
-            self: Self,
+
-            create_info: InstanceCreateInfo,
+        pub const CreateInstanceError = error{
-            p_allocator: ?*const AllocationCallbacks,
-        ) error{
             OutOfHostMemory,
             OutOfDeviceMemory,
             InitializationFailed,
@@ -87,9 +90,14 @@ pub const BaseWrapper(comptime Self: type) type {
             ExtensionNotPresent,
             IncompatibleDriver,
             Unknown,
-        }!Instance {
+        };
+        pub fn createInstance(
+            self: Self,
+            create_info: InstanceCreateInfo,
+            p_allocator: ?*const AllocationCallbacks,
+        ) CreateInstanceError!Instance {
             var instance: Instance = undefined;
-            const result = self.vkCreateInstance(
+            const result = self.dispatch.vkCreateInstance(
                 &create_info,
                 p_allocator,
                 &instance,
@@ -121,9 +129,11 @@ Wrappers are generated according to the following rules:
 * As of yet, there is no specific handling of enumeration style commands or other commands which accept slices.
 
 Furthermore, each wrapper contains a function to load each function pointer member when passed either `PfnGetInstanceProcAddr` or `PfnGetDeviceProcAddr`, which attempts to load each member as function pointer and casts it to the appropriate type. These functions are loaded literally, and any wrongly named member or member with a wrong function pointer type will result in problems.
-* For `BaseWrapper`, this function has signature `fn load(loader: PfnGetInstanceProcAddr) !Self`.
+* For `BaseWrapper`, this function has signature `fn load(loader: anytype) !Self`, where the type of `loader` must resemble `PfnGetInstanceProcAddr` (with optionally having a different calling convention).
-* For `InstanceWrapper`, this function has signature `fn load(instance: Instance, loader: PfnGetInstanceProcAddr) !Self`.
+* For `InstanceWrapper`, this function has signature `fn load(instance: Instance, loader: anytype) !Self`, where the type of `loader` must resemble `PfnGetInstanceProcAddr`.
-* For `DeviceWrapper`, this function has signature `fn load(device: Device, loader: PfnGetDeviceProcAddr) !Self`.
+* For `DeviceWrapper`, this function has signature `fn load(device: Device, loader: anytype) !Self`, where the type of `loader` must resemble `PfnGetDeviceProcAddr`.
+
+One can access the underlying unwrapped C functions by doing `wrapper.dispatch.vkFuncYouWant(..)`.
 
 ### Bitflags
 Packed structs of bools are used for bit flags in vulkan-zig, instead of both a `FlagBits` and `Flags` variant. Places where either of these variants are used are both replaced by this packed struct instead. This means that even in places where just one flag would normally be accepted, the packed struct is accepted. The programmer is responsible for only enabling a single bit.
@@ -221,7 +231,7 @@ pub fn build(b: *Builder) void {
 
     const gen = vkgen.VkGenerateStep(b, "path/to/vk.xml", "vk.zig");
     exe.step.dependOn(&gen.step);
-    exe.addPackagePath("vulkan", gen.full_out_path);
+    exe.addPackage(gen.package);
 
     const shader_comp = vkgen.ShaderCompileStep.init(
         builder,
@@ -242,5 +252,7 @@ Upon compilation, glslc is then invoked to compile each shader, and the result i
 A partial implementation of https://vulkan-tutorial.org is implemented in [examples/triangle.zig](examples/triangle.zig). This example can be ran by executing `zig build run-triangle` in vulkan-zig's root.
 
 ## See also
-* Implementation of https://vulkan-tutorial.org: https://github.com/andrewrk/zig-vulkan-triangle.
+* Implementation of https://vulkan-tutorial.org using `@cImport`'ed bindings: https://github.com/andrewrk/zig-vulkan-triangle.
 * Alternative binding generator: https://github.com/SpexGuy/Zig-Vulkan-Headers
+* Zig bindings for GLFW: https://github.com/hexops/mach-glfw
+  * With vulkan-zig integration example: https://github.com/hexops/mach-glfw-vulkan-example

build.zig

@@ -34,7 +34,7 @@ pub const ResourceGenStep = struct {
         return self;
     }
 
-    fn renderPath(self: *ResourceGenStep, path: []const u8, writer: anytype) void {
+    fn renderPath(path: []const u8, writer: anytype) void {
         const separators = &[_]u8{ std.fs.path.sep_windows, std.fs.path.sep_posix };
         var i: usize = 0;
         while (std.mem.indexOfAnyPos(u8, path, i, separators)) |j| {
@@ -42,7 +42,7 @@ pub const ResourceGenStep = struct {
             switch (std.fs.path.sep) {
                 std.fs.path.sep_windows => writer.writeAll("\\\\") catch unreachable,
                 std.fs.path.sep_posix => writer.writeByte(std.fs.path.sep_posix) catch unreachable,
-                else => unreachable
+                else => unreachable,
             }
 
             i = j + 1;
@@ -55,7 +55,7 @@ pub const ResourceGenStep = struct {
         var writer = self.resources.writer();
 
         writer.print("pub const {s} = @embedFile(\"", .{name}) catch unreachable;
-        self.renderPath(shader_out_path, writer);
+        renderPath(shader_out_path, writer);
         writer.writeAll("\");\n") catch unreachable;
     }
 
@@ -85,7 +85,7 @@ pub fn build(b: *Builder) void {
     triangle_exe.setTarget(target);
     triangle_exe.setBuildMode(mode);
     triangle_exe.install();
-    triangle_exe.linkSystemLibrary("c");
+    triangle_exe.linkLibC();
     triangle_exe.linkSystemLibrary("glfw");
 
     const vk_xml_path = b.option([]const u8, "vulkan-registry", "Override the to the Vulkan registry") orelse "examples/vk.xml";

examples/graphics_context.zig

@@ -3,85 +3,80 @@ const vk = @import("vulkan");
 const c = @import("c.zig");
 const Allocator = std.mem.Allocator;
 
-const required_device_extensions = [_][]const u8{
+const required_device_extensions = [_][]const u8{vk.extension_info.khr_swapchain.name};
-    vk.extension_info.khr_swapchain.name
-};
 
-const BaseDispatch = struct {
+const BaseDispatch = vk.BaseWrapper(&.{
-    vkCreateInstance: vk.PfnCreateInstance,
+    .createInstance,
-    usingnamespace vk.BaseWrapper(@This());
+});
-};
 
-const InstanceDispatch = struct {
+const InstanceDispatch = vk.InstanceWrapper(&.{
-    vkDestroyInstance: vk.PfnDestroyInstance,
+    .destroyInstance,
-    vkCreateDevice: vk.PfnCreateDevice,
+    .createDevice,
-    vkDestroySurfaceKHR: vk.PfnDestroySurfaceKHR,
+    .destroySurfaceKHR,
-    vkEnumeratePhysicalDevices: vk.PfnEnumeratePhysicalDevices,
+    .enumeratePhysicalDevices,
-    vkGetPhysicalDeviceProperties: vk.PfnGetPhysicalDeviceProperties,
+    .getPhysicalDeviceProperties,
-    vkEnumerateDeviceExtensionProperties: vk.PfnEnumerateDeviceExtensionProperties,
+    .enumerateDeviceExtensionProperties,
-    vkGetPhysicalDeviceSurfaceFormatsKHR: vk.PfnGetPhysicalDeviceSurfaceFormatsKHR,
+    .getPhysicalDeviceSurfaceFormatsKHR,
-    vkGetPhysicalDeviceSurfacePresentModesKHR: vk.PfnGetPhysicalDeviceSurfacePresentModesKHR,
+    .getPhysicalDeviceSurfacePresentModesKHR,
-    vkGetPhysicalDeviceSurfaceCapabilitiesKHR: vk.PfnGetPhysicalDeviceSurfaceCapabilitiesKHR,
+    .getPhysicalDeviceSurfaceCapabilitiesKHR,
-    vkGetPhysicalDeviceQueueFamilyProperties: vk.PfnGetPhysicalDeviceQueueFamilyProperties,
+    .getPhysicalDeviceQueueFamilyProperties,
-    vkGetPhysicalDeviceSurfaceSupportKHR: vk.PfnGetPhysicalDeviceSurfaceSupportKHR,
+    .getPhysicalDeviceSurfaceSupportKHR,
-    vkGetPhysicalDeviceMemoryProperties: vk.PfnGetPhysicalDeviceMemoryProperties,
+    .getPhysicalDeviceMemoryProperties,
-    vkGetDeviceProcAddr: vk.PfnGetDeviceProcAddr,
+    .getDeviceProcAddr,
-    usingnamespace vk.InstanceWrapper(@This());
+});
-};
 
-const DeviceDispatch = struct {
+const DeviceDispatch = vk.DeviceWrapper(&.{
-    vkDestroyDevice: vk.PfnDestroyDevice,
+    .destroyDevice,
-    vkGetDeviceQueue: vk.PfnGetDeviceQueue,
+    .getDeviceQueue,
-    vkCreateSemaphore: vk.PfnCreateSemaphore,
+    .createSemaphore,
-    vkCreateFence: vk.PfnCreateFence,
+    .createFence,
-    vkCreateImageView: vk.PfnCreateImageView,
+    .createImageView,
-    vkDestroyImageView: vk.PfnDestroyImageView,
+    .destroyImageView,
-    vkDestroySemaphore: vk.PfnDestroySemaphore,
+    .destroySemaphore,
-    vkDestroyFence: vk.PfnDestroyFence,
+    .destroyFence,
-    vkGetSwapchainImagesKHR: vk.PfnGetSwapchainImagesKHR,
+    .getSwapchainImagesKHR,
-    vkCreateSwapchainKHR: vk.PfnCreateSwapchainKHR,
+    .createSwapchainKHR,
-    vkDestroySwapchainKHR: vk.PfnDestroySwapchainKHR,
+    .destroySwapchainKHR,
-    vkAcquireNextImageKHR: vk.PfnAcquireNextImageKHR,
+    .acquireNextImageKHR,
-    vkDeviceWaitIdle: vk.PfnDeviceWaitIdle,
+    .deviceWaitIdle,
-    vkWaitForFences: vk.PfnWaitForFences,
+    .waitForFences,
-    vkResetFences: vk.PfnResetFences,
+    .resetFences,
-    vkQueueSubmit: vk.PfnQueueSubmit,
+    .queueSubmit,
-    vkQueuePresentKHR: vk.PfnQueuePresentKHR,
+    .queuePresentKHR,
-    vkCreateCommandPool: vk.PfnCreateCommandPool,
+    .createCommandPool,
-    vkDestroyCommandPool: vk.PfnDestroyCommandPool,
+    .destroyCommandPool,
-    vkAllocateCommandBuffers: vk.PfnAllocateCommandBuffers,
+    .allocateCommandBuffers,
-    vkFreeCommandBuffers: vk.PfnFreeCommandBuffers,
+    .freeCommandBuffers,
-    vkQueueWaitIdle: vk.PfnQueueWaitIdle,
+    .queueWaitIdle,
-    vkCreateShaderModule: vk.PfnCreateShaderModule,
+    .createShaderModule,
-    vkDestroyShaderModule: vk.PfnDestroyShaderModule,
+    .destroyShaderModule,
-    vkCreatePipelineLayout: vk.PfnCreatePipelineLayout,
+    .createPipelineLayout,
-    vkDestroyPipelineLayout: vk.PfnDestroyPipelineLayout,
+    .destroyPipelineLayout,
-    vkCreateRenderPass: vk.PfnCreateRenderPass,
+    .createRenderPass,
-    vkDestroyRenderPass: vk.PfnDestroyRenderPass,
+    .destroyRenderPass,
-    vkCreateGraphicsPipelines: vk.PfnCreateGraphicsPipelines,
+    .createGraphicsPipelines,
-    vkDestroyPipeline: vk.PfnDestroyPipeline,
+    .destroyPipeline,
-    vkCreateFramebuffer: vk.PfnCreateFramebuffer,
+    .createFramebuffer,
-    vkDestroyFramebuffer: vk.PfnDestroyFramebuffer,
+    .destroyFramebuffer,
-    vkBeginCommandBuffer: vk.PfnBeginCommandBuffer,
+    .beginCommandBuffer,
-    vkEndCommandBuffer: vk.PfnEndCommandBuffer,
+    .endCommandBuffer,
-    vkAllocateMemory: vk.PfnAllocateMemory,
+    .allocateMemory,
-    vkFreeMemory: vk.PfnFreeMemory,
+    .freeMemory,
-    vkCreateBuffer: vk.PfnCreateBuffer,
+    .createBuffer,
-    vkDestroyBuffer: vk.PfnDestroyBuffer,
+    .destroyBuffer,
-    vkGetBufferMemoryRequirements: vk.PfnGetBufferMemoryRequirements,
+    .getBufferMemoryRequirements,
-    vkMapMemory: vk.PfnMapMemory,
+    .mapMemory,
-    vkUnmapMemory: vk.PfnUnmapMemory,
+    .unmapMemory,
-    vkBindBufferMemory: vk.PfnBindBufferMemory,
+    .bindBufferMemory,
-    vkCmdBeginRenderPass: vk.PfnCmdBeginRenderPass,
+    .cmdBeginRenderPass,
-    vkCmdEndRenderPass: vk.PfnCmdEndRenderPass,
+    .cmdEndRenderPass,
-    vkCmdBindPipeline: vk.PfnCmdBindPipeline,
+    .cmdBindPipeline,
-    vkCmdDraw: vk.PfnCmdDraw,
+    .cmdDraw,
-    vkCmdSetViewport: vk.PfnCmdSetViewport,
+    .cmdSetViewport,
-    vkCmdSetScissor: vk.PfnCmdSetScissor,
+    .cmdSetScissor,
-    vkCmdBindVertexBuffers: vk.PfnCmdBindVertexBuffers,
+    .cmdBindVertexBuffers,
-    vkCmdCopyBuffer: vk.PfnCmdCopyBuffer,
+    .cmdCopyBuffer,
-    usingnamespace vk.DeviceWrapper(@This());
+});
-};
 
 pub const GraphicsContext = struct {
     vkb: BaseDispatch,
@@ -107,9 +102,9 @@ pub const GraphicsContext = struct {
 
         const app_info = vk.ApplicationInfo{
             .p_application_name = app_name,
-            .application_version = vk.makeVersion(0, 0, 0),
+            .application_version = vk.makeApiVersion(0, 0, 0, 0),
             .p_engine_name = app_name,
-            .engine_version = vk.makeVersion(0, 0, 0),
+            .engine_version = vk.makeApiVersion(0, 0, 0, 0),
             .api_version = vk.API_VERSION_1_2,
         };
 
@@ -125,14 +120,14 @@ pub const GraphicsContext = struct {
         self.vki = try InstanceDispatch.load(self.instance, c.glfwGetInstanceProcAddress);
         errdefer self.vki.destroyInstance(self.instance, null);
 
-        self.surface = try createSurface(self.vki, self.instance, window);
+        self.surface = try createSurface(self.instance, window);
         errdefer self.vki.destroySurfaceKHR(self.instance, self.surface, null);
 
         const candidate = try pickPhysicalDevice(self.vki, self.instance, allocator, self.surface);
         self.pdev = candidate.pdev;
         self.props = candidate.props;
         self.dev = try initializeCandidate(self.vki, candidate);
-        self.vkd = try DeviceDispatch.load(self.dev, self.vki.vkGetDeviceProcAddr);
+        self.vkd = try DeviceDispatch.load(self.dev, self.vki.dispatch.vkGetDeviceProcAddr);
         errdefer self.vkd.destroyDevice(self.dev, null);
 
         self.graphics_queue = Queue.init(self.vkd, self.dev, candidate.queues.graphics_family);
@@ -184,7 +179,7 @@ pub const Queue = struct {
     }
 };
 
-fn createSurface(vki: InstanceDispatch, instance: vk.Instance, window: *c.GLFWwindow) !vk.SurfaceKHR {
+fn createSurface(instance: vk.Instance, window: *c.GLFWwindow) !vk.SurfaceKHR {
     var surface: vk.SurfaceKHR = undefined;
     if (c.glfwCreateWindowSurface(instance, window, null, &surface) != .success) {
         return error.SurfaceInitFailed;
@@ -207,7 +202,7 @@ fn initializeCandidate(vki: InstanceDispatch, candidate: DeviceCandidate) !vk.De
             .queue_family_index = candidate.queues.present_family,
             .queue_count = 1,
             .p_queue_priorities = &priority,
-        }
+        },
     };
 
     const queue_count: u32 = if (candidate.queues.graphics_family == candidate.queues.present_family)
@@ -281,19 +276,14 @@ fn checkSuitable(
         return DeviceCandidate{
             .pdev = pdev,
             .props = props,
-            .queues = allocation
+            .queues = allocation,
         };
     }
 
     return null;
 }
 
-fn allocateQueues(
+fn allocateQueues(vki: InstanceDispatch, pdev: vk.PhysicalDevice, allocator: *Allocator, surface: vk.SurfaceKHR) !?QueueAllocation {
-    vki: InstanceDispatch,
-    pdev: vk.PhysicalDevice,
-    allocator: *Allocator,
-    surface: vk.SurfaceKHR
-) !?QueueAllocation {
     var family_count: u32 = undefined;
     vki.getPhysicalDeviceQueueFamilyProperties(pdev, &family_count, null);
 
@@ -307,7 +297,7 @@ fn allocateQueues(
     for (families) |properties, i| {
         const family = @intCast(u32, i);
 
-        if (graphics_family == null and properties.queue_flags.contains(.{.graphics_bit = true})) {
+        if (graphics_family == null and properties.queue_flags.graphics_bit) {
             graphics_family = family;
         }
 
@@ -319,7 +309,7 @@ fn allocateQueues(
     if (graphics_family != null and present_family != null) {
         return QueueAllocation{
             .graphics_family = graphics_family.?,
-            .present_family = present_family.?
+            .present_family = present_family.?,
         };
     }
 

examples/swapchain.zig

@@ -251,7 +251,7 @@ fn initSwapchainImages(gc: *const GraphicsContext, swapchain: vk.SwapchainKHR, f
     _ = try gc.vkd.getSwapchainImagesKHR(gc.dev, swapchain, &count, images.ptr);
 
     const swap_images = try allocator.alloc(SwapImage, count);
-    errdefer allocator.free(images);
+    errdefer allocator.free(swap_images);
 
     var i: usize = 0;
     errdefer for (swap_images[0..i]) |si| si.deinit(gc);

examples/triangle.zig

@@ -52,7 +52,7 @@ pub fn main() !void {
         @intCast(c_int, extent.height),
         app_name,
         null,
-        null
+        null,
     ) orelse return error.WindowInitFailed;
     defer c.glfwDestroyWindow(window);
 
@@ -78,7 +78,7 @@ pub fn main() !void {
     const render_pass = try createRenderPass(&gc, swapchain);
     defer gc.vkd.destroyRenderPass(gc.dev, render_pass, null);
 
-    var pipeline = try createPipeline(&gc, extent, pipeline_layout, render_pass);
+    var pipeline = try createPipeline(&gc, pipeline_layout, render_pass);
     defer gc.vkd.destroyPipeline(gc.dev, pipeline, null);
 
     var framebuffers = try createFramebuffers(&gc, allocator, render_pass, swapchain);
@@ -104,7 +104,7 @@ pub fn main() !void {
     defer gc.vkd.freeMemory(gc.dev, memory, null);
     try gc.vkd.bindBufferMemory(gc.dev, buffer, memory, 0);
 
-    try uploadVertices(&gc, pool, buffer, memory);
+    try uploadVertices(&gc, pool, buffer);
 
     var cmdbufs = try createCommandBuffers(
         &gc,
@@ -114,7 +114,7 @@ pub fn main() !void {
         swapchain.extent,
         render_pass,
         pipeline,
-        framebuffers
+        framebuffers,
     );
     defer destroyCommandBuffers(&gc, pool, allocator, cmdbufs);
 
@@ -146,19 +146,17 @@ pub fn main() !void {
                 swapchain.extent,
                 render_pass,
                 pipeline,
-                framebuffers
+                framebuffers,
             );
         }
 
-        c.glfwSwapBuffers(window);
         c.glfwPollEvents();
-
     }
 
     try swapchain.waitForAllFences();
 }
 
-fn uploadVertices(gc: *const GraphicsContext, pool: vk.CommandPool, buffer: vk.Buffer, memory: vk.DeviceMemory) !void {
+fn uploadVertices(gc: *const GraphicsContext, pool: vk.CommandPool, buffer: vk.Buffer) !void {
     const staging_buffer = try gc.vkd.createBuffer(gc.dev, .{
         .flags = .{},
         .size = @sizeOf(@TypeOf(vertices)),
@@ -297,12 +295,7 @@ fn destroyCommandBuffers(gc: *const GraphicsContext, pool: vk.CommandPool, alloc
     allocator.free(cmdbufs);
 }
 
-fn createFramebuffers(
+fn createFramebuffers(gc: *const GraphicsContext, allocator: *Allocator, render_pass: vk.RenderPass, swapchain: Swapchain) ![]vk.Framebuffer {
-    gc: *const GraphicsContext,
-    allocator: *Allocator,
-    render_pass: vk.RenderPass,
-    swapchain: Swapchain
-) ![]vk.Framebuffer {
     const framebuffers = try allocator.alloc(vk.Framebuffer, swapchain.swap_images.len);
     errdefer allocator.free(framebuffers);
 
@@ -374,7 +367,6 @@ fn createRenderPass(gc: *const GraphicsContext, swapchain: Swapchain) !vk.Render
 
 fn createPipeline(
     gc: *const GraphicsContext,
-    extent: vk.Extent2D,
     layout: vk.PipelineLayout,
     render_pass: vk.RenderPass,
 ) !vk.Pipeline {
@@ -506,7 +498,8 @@ fn createPipeline(
     _ = try gc.vkd.createGraphicsPipelines(
         gc.dev,
         .null_handle,
-        1, @ptrCast([*]const vk.GraphicsPipelineCreateInfo, &gpci),
+        1,
+        @ptrCast([*]const vk.GraphicsPipelineCreateInfo, &gpci),
         null,
         @ptrCast([*]vk.Pipeline, &pipeline),
     );

generator/id_render.zig

@@ -2,6 +2,64 @@ const std = @import("std");
 const mem = std.mem;
 const Allocator = mem.Allocator;
 
+pub fn isZigPrimitiveType(name: []const u8) bool {
+    if (name.len > 1 and (name[0] == 'u' or name[0] == 'i')) {
+        for (name[1..]) |c| {
+            switch (c) {
+                '0'...'9' => {},
+                else => return false,
+            }
+        }
+        return true;
+    }
+
+    const primitives = [_][]const u8{
+        "void",
+        "comptime_float",
+        "comptime_int",
+        "bool",
+        "isize",
+        "usize",
+        "f16",
+        "f32",
+        "f64",
+        "f128",
+        "c_longdouble",
+        "noreturn",
+        "type",
+        "anyerror",
+        "c_short",
+        "c_ushort",
+        "c_int",
+        "c_uint",
+        "c_long",
+        "c_ulong",
+        "c_longlong",
+        "c_ulonglong",
+    };
+
+    for (primitives) |reserved| {
+        if (mem.eql(u8, reserved, name)) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+fn needZigEscape(name: []const u8) bool {
+    return !std.zig.fmt.isValidId(name) or isZigPrimitiveType(name);
+}
+
+pub fn writeIdentifier(out: anytype, id: []const u8) !void {
+    // https://github.com/ziglang/zig/issues/2897
+    if (isZigPrimitiveType(id)) {
+        try out.print("{s}_", .{id});
+    } else {
+        try out.print("{}", .{std.zig.fmtId(id)});
+    }
+}
+
 pub const CaseStyle = enum {
     snake,
     screaming_snake,
@@ -138,14 +196,10 @@ pub const IdRenderer = struct {
         }
     }
 
-    pub fn render(self: IdRenderer, out: anytype, id: []const u8) !void {
-        try out.print("{z}", .{ id });
-    }
-
     pub fn renderFmt(self: *IdRenderer, out: anytype, comptime fmt: []const u8, args: anytype) !void {
         self.text_cache.items.len = 0;
         try std.fmt.format(self.text_cache.writer(), fmt, args);
-        try out.print("{z}", .{ self.text_cache.items });
+        try writeIdentifier(out, self.text_cache.items);
     }
 
     pub fn renderWithCase(self: *IdRenderer, out: anytype, case_style: CaseStyle, id: []const u8) !void {
@@ -162,7 +216,7 @@ pub const IdRenderer = struct {
             .camel => try self.renderCamel(false, adjusted_id, tag),
         }
 
-        try out.print("{z}", .{ self.text_cache.items });
+        try writeIdentifier(out, self.text_cache.items);
     }
 
     pub fn getAuthorTag(self: IdRenderer, id: []const u8) ?[]const u8 {

generator/index.zig

@@ -1,6 +1,5 @@
 pub const generateVk = @import("vulkan/generator.zig").generate;
 pub const VkGenerateStep = @import("vulkan/build_integration.zig").GenerateStep;
-pub const generateSpirv = @import("spirv/generator.zig").generate;
 pub const ShaderCompileStep = @import("build_integration.zig").ShaderCompileStep;
 
 test "main" {

generator/main.zig

@@ -5,7 +5,6 @@ const usage = "Usage: {s} [-h|--help] <spec xml path> <output zig source>\n";
 
 pub fn main() !void {
     const stderr = std.io.getStdErr();
-    const stdout = std.io.getStdOut();
 
     var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
     defer arena.deinit();
@@ -60,15 +59,22 @@ pub fn main() !void {
         return;
     };
 
-    const out_file = cwd.createFile(out_path, .{}) catch |err| {
-        try stderr.writer().print("Error: Failed to create output file '{s}' ({s})\n", .{ out_path, @errorName(err) });
-        return;
-    };
-    defer out_file.close();
-
     var out_buffer = std.ArrayList(u8).init(allocator);
     try generate(allocator, xml_src, out_buffer.writer());
-    const tree = try std.zig.parse(allocator, out_buffer.items);
 
-    _ = try std.zig.render(allocator, out_file.writer(), tree);
+    const tree = try std.zig.parse(allocator, out_buffer.items);
+    const formatted = try tree.render(allocator);
+    defer allocator.free(formatted);
+
+    if (std.fs.path.dirname(out_path)) |dir| {
+        cwd.makePath(dir) catch |err| {
+            try stderr.writer().print("Error: Failed to create output directory '{s}' ({s})\n", .{ dir, @errorName(err) });
+            return;
+        };
+    }
+
+    cwd.writeFile(out_path, formatted) catch |err| {
+        try stderr.writer().print("Error: Failed to write to output file '{s}' ({s})\n", .{ out_path, @errorName(err) });
+        return;
+    };
 }

generator/vulkan/build_integration.zig

@@ -65,16 +65,19 @@ pub const GenerateStep = struct {
     fn make(step: *Step) !void {
         const self = @fieldParentPtr(GenerateStep, "step", step);
         const cwd = std.fs.cwd();
-        var out_buffer = std.ArrayList(u8).init(self.builder.allocator);
+
         const spec = try cwd.readFileAlloc(self.builder.allocator, self.spec_path, std.math.maxInt(usize));
+
+        var out_buffer = std.ArrayList(u8).init(self.builder.allocator);
         try generate(self.builder.allocator, spec, out_buffer.writer());
 
         const tree = try std.zig.parse(self.builder.allocator, out_buffer.items);
+        std.debug.assert(tree.errors.len == 0); // If this triggers, vulkan-zig produced invalid code.
+
+        var formatted = try tree.render(self.builder.allocator);
 
         const dir = path.dirname(self.package.path).?;
         try cwd.makePath(dir);
-        const output_file = cwd.createFile(self.package.path, .{}) catch unreachable;
+        try cwd.writeFile(self.package.path, formatted);
-        defer output_file.close();
-        _ = try std.zig.render(self.builder.allocator, output_file.writer(), tree);
     }
 };

generator/vulkan/c_parse.zig

@@ -143,15 +143,12 @@ pub const CTokenizer = struct {
             ']' => kind = .rbracket,
             '(' => kind = .lparen,
             ')' => kind = .rparen,
-            else => return error.UnexpectedCharacter
+            else => return error.UnexpectedCharacter,
         }
 
         const start = self.offset;
         _ = self.consumeNoEof();
-        return Token{
+        return Token{ .kind = kind, .text = self.source[start..self.offset] };
-            .kind = kind,
-            .text = self.source[start .. self.offset]
-        };
     }
 };
 
@@ -365,7 +362,7 @@ fn parseDeclaration(allocator: *Allocator, xctok: *XmlCTokenizer) ParseError!Dec
             .array = .{
                 .size = array_size,
                 .child = child,
-            }
+            },
         };
 
         // update the inner_type pointer so it points to the proper
@@ -403,8 +400,8 @@ fn parseFnPtrSuffix(allocator: *Allocator, xctok: *XmlCTokenizer, return_type: T
                 .return_type = return_type_heap,
                 .success_codes = &[_][]const u8{},
                 .error_codes = &[_][]const u8{},
-            }
+            },
-        }
+        },
     };
 
     const first_param = try parseDeclaration(allocator, xctok);
@@ -500,31 +497,31 @@ fn parseArrayDeclarator(xctok: *XmlCTokenizer) !?ArraySize {
             .int = std.fmt.parseInt(usize, size_tok.text, 10) catch |err| switch (err) {
                 error.Overflow => return error.Overflow,
                 error.InvalidCharacter => unreachable,
-            }
+            },
         },
         .enum_name => .{ .alias = size_tok.text },
-        else => return error.InvalidSyntax
+        else => return error.InvalidSyntax,
     };
 
     _ = try xctok.expect(.rbracket);
     return size;
 }
 
-pub fn parseVersion(xctok: *XmlCTokenizer) ![3][]const u8 {
+pub fn parseVersion(xctok: *XmlCTokenizer) ![4][]const u8 {
     _ = try xctok.expect(.hash);
     const define = try xctok.expect(.id);
     if (!mem.eql(u8, define.text, "define")) {
         return error.InvalidVersion;
     }
 
-    const name = try xctok.expect(.name);
+    _ = try xctok.expect(.name);
     const vk_make_version = try xctok.expect(.type_name);
-    if (!mem.eql(u8, vk_make_version.text, "VK_MAKE_VERSION")) {
+    if (!mem.eql(u8, vk_make_version.text, "VK_MAKE_API_VERSION")) {
         return error.NotVersion;
     }
 
     _ = try xctok.expect(.lparen);
-    var version: [3][]const u8 = undefined;
+    var version: [4][]const u8 = undefined;
     for (version) |*part, i| {
         if (i != 0) {
             _ = try xctok.expect(.comma);
@@ -540,24 +537,20 @@ pub fn parseVersion(xctok: *XmlCTokenizer) ![3][]const u8 {
     return version;
 }
 
-fn testTokenizer(tokenizer: anytype, expected_tokens: []const Token) void {
+fn testTokenizer(tokenizer: anytype, expected_tokens: []const Token) !void {
     for (expected_tokens) |expected| {
         const tok = (tokenizer.next() catch unreachable).?;
-        testing.expectEqual(expected.kind, tok.kind);
+        try testing.expectEqual(expected.kind, tok.kind);
-        testing.expectEqualSlices(u8, expected.text, tok.text);
+        try testing.expectEqualSlices(u8, expected.text, tok.text);
     }
 
     if (tokenizer.next() catch unreachable) |_| unreachable;
 }
 
 test "CTokenizer" {
-    var ctok = CTokenizer {
+    var ctok = CTokenizer{ .source = "typedef ([const)]** VKAPI_PTR 123,;aaaa" };
-        .source = \\typedef ([const)]** VKAPI_PTR 123,;aaaa
-    };
 
-    testTokenizer(
+    try testTokenizer(&ctok, &[_]Token{
-        &ctok,
-        &[_]Token{
         .{ .kind = .kw_typedef, .text = "typedef" },
         .{ .kind = .lparen, .text = "(" },
         .{ .kind = .lbracket, .text = "[" },
@@ -571,13 +564,11 @@ test "CTokenizer" {
         .{ .kind = .comma, .text = "," },
         .{ .kind = .semicolon, .text = ";" },
         .{ .kind = .id, .text = "aaaa" },
-        }
+    });
-    );
 }
 
 test "XmlCTokenizer" {
-    const document = try xml.parse(
+    const document = try xml.parse(testing.allocator,
-        testing.allocator,
         \\<root>// comment <name>commented name</name> <type>commented type</type> trailing
         \\    typedef void (VKAPI_PTR *<name>PFN_vkVoidFunction</name>)(void);
         \\</root>
@@ -586,9 +577,7 @@ test "XmlCTokenizer" {
 
     var xctok = XmlCTokenizer.init(document.root);
 
-    testTokenizer(
+    try testTokenizer(&xctok, &[_]Token{
-        &xctok,
-        &[_]Token{
         .{ .kind = .kw_typedef, .text = "typedef" },
         .{ .kind = .id, .text = "void" },
         .{ .kind = .lparen, .text = "(" },
@@ -600,13 +589,11 @@ test "XmlCTokenizer" {
         .{ .kind = .id, .text = "void" },
         .{ .kind = .rparen, .text = ")" },
         .{ .kind = .semicolon, .text = ";" },
-        }
+    });
-    );
 }
 
 test "parseTypedef" {
-    const document = try xml.parse(
+    const document = try xml.parse(testing.allocator,
-        testing.allocator,
         \\<root> // comment <name>commented name</name> trailing
         \\    typedef const struct <type>Python</type>* pythons[4];
         \\ // more comments
@@ -621,10 +608,10 @@ test "parseTypedef" {
     var xctok = XmlCTokenizer.init(document.root);
     const decl = try parseTypedef(&arena.allocator, &xctok);
 
-    testing.expectEqualSlices(u8, "pythons", decl.name);
+    try testing.expectEqualSlices(u8, "pythons", decl.name);
     const array = decl.decl_type.typedef.array;
-    testing.expectEqual(ArraySize{.int = 4}, array.size);
+    try testing.expectEqual(ArraySize{ .int = 4 }, array.size);
     const ptr = array.child.pointer;
-    testing.expectEqual(true, ptr.is_const);
+    try testing.expectEqual(true, ptr.is_const);
-    testing.expectEqualSlices(u8, "Python", ptr.child.name);
+    try testing.expectEqualSlices(u8, "Python", ptr.child.name);
 }

generator/vulkan/generator.zig

@@ -9,41 +9,30 @@ const Allocator = mem.Allocator;
 const FeatureLevel = reg.FeatureLevel;
 
 const EnumFieldMerger = struct {
-    const EnumExtensionMap = std.StringArrayHashMap(std.ArrayListUnmanaged(reg.Enum.Field));
+    const EnumExtensionMap = std.StringArrayHashMapUnmanaged(std.ArrayListUnmanaged(reg.Enum.Field));
-    const FieldSet = std.StringArrayHashMap(void);
+    const FieldSet = std.StringArrayHashMapUnmanaged(void);
 
-    gpa: *Allocator,
+    arena: *Allocator,
-    reg_arena: *Allocator,
     registry: *reg.Registry,
     enum_extensions: EnumExtensionMap,
     field_set: FieldSet,
 
-    fn init(gpa: *Allocator, reg_arena: *Allocator, registry: *reg.Registry) EnumFieldMerger {
+    fn init(arena: *Allocator, registry: *reg.Registry) EnumFieldMerger {
         return .{
-            .gpa = gpa,
+            .arena = arena,
-            .reg_arena = reg_arena,
             .registry = registry,
-            .enum_extensions = EnumExtensionMap.init(gpa),
+            .enum_extensions = .{},
-            .field_set = FieldSet.init(gpa),
+            .field_set = .{},
         };
     }
 
-    fn deinit(self: *EnumFieldMerger) void {
-        for (self.enum_extensions.items()) |*entry| {
-            entry.value.deinit(self.gpa);
-        }
-
-        self.field_set.deinit();
-        self.enum_extensions.deinit();
-    }
-
     fn putEnumExtension(self: *EnumFieldMerger, enum_name: []const u8, field: reg.Enum.Field) !void {
-        const res = try self.enum_extensions.getOrPut(enum_name);
+        const res = try self.enum_extensions.getOrPut(self.arena, enum_name);
         if (!res.found_existing) {
-            res.entry.value = std.ArrayListUnmanaged(reg.Enum.Field){};
+            res.value_ptr.* = std.ArrayListUnmanaged(reg.Enum.Field){};
         }
 
-        try res.entry.value.append(self.gpa, field);
+        try res.value_ptr.append(self.arena, field);
     }
 
     fn addRequires(self: *EnumFieldMerger, reqs: []const reg.Require) !void {
@@ -61,11 +50,11 @@ const EnumFieldMerger = struct {
         self.field_set.clearRetainingCapacity();
 
         const n_fields_upper_bound = base_enum.fields.len + extensions.items.len;
-        const new_fields = try self.reg_arena.alloc(reg.Enum.Field, n_fields_upper_bound);
+        const new_fields = try self.arena.alloc(reg.Enum.Field, n_fields_upper_bound);
         var i: usize = 0;
 
         for (base_enum.fields) |field| {
-            const res = try self.field_set.getOrPut(field.name);
+            const res = try self.field_set.getOrPut(self.arena, field.name);
             if (!res.found_existing) {
                 new_fields[i] = field;
                 i += 1;
@@ -74,16 +63,16 @@ const EnumFieldMerger = struct {
 
         // Assume that if a field name clobbers, the value is the same
         for (extensions.items) |field| {
-            const res = try self.field_set.getOrPut(field.name);
+            const res = try self.field_set.getOrPut(self.arena, field.name);
             if (!res.found_existing) {
                 new_fields[i] = field;
                 i += 1;
             }
         }
 
-        // Existing base_enum.fields was allocatued by `self.reg_arena`, so
+        // Existing base_enum.fields was allocated by `self.arena`, so
         // it gets cleaned up whenever that is deinited.
-        base_enum.fields = self.reg_arena.shrink(new_fields, i);
+        base_enum.fields = self.arena.shrink(new_fields, i);
     }
 
     fn merge(self: *EnumFieldMerger) !void {
@@ -105,131 +94,8 @@ const EnumFieldMerger = struct {
     }
 };
 
-const TagFixerUpper = struct {
-    allocator: *Allocator,
-    registry: *reg.Registry,
-    names: std.StringHashMap(void),
-    id_renderer: *const IdRenderer,
-
-    fn init(allocator: *Allocator, registry: *reg.Registry, id_renderer: *const IdRenderer) TagFixerUpper {
-        return .{
-            .allocator = allocator,
-            .registry = registry,
-            .names = std.StringHashMap(void).init(allocator),
-            .id_renderer = id_renderer,
-        };
-    }
-
-    fn deinit(self: *TagFixerUpper) void {
-        self.names.deinit();
-    }
-
-    fn insertName(self: *TagFixerUpper, name: []const u8) !void {
-        const tagless = self.id_renderer.stripAuthorTag(name);
-        const result = try self.names.getOrPut(name);
-
-        if (result.found_existing) {
-            return error.DuplicateDefinition;
-        }
-    }
-
-    fn extractNames(self: *TagFixerUpper) !void {
-        for (self.registry.decls) |decl| {
-            try self.insertName(decl.name);
-
-            switch (decl.decl_type) {
-                .enumeration => |enumeration| {
-                    for (enumeration.fields) |field| {
-                        try self.insertName(field.name);
-                    }
-                },
-                else => {},
-            }
-        }
-    }
-
-    fn fixAlias(self: *TagFixerUpper, name: *[]const u8) !void {
-        if (self.names.contains(name.*)) {
-            // The alias exists, everything is fine
-            return;
-        }
-
-        // The alias does not exist, check if the tagless version exists
-        const tagless = self.id_renderer.stripAuthorTag(name.*);
-        if (self.names.contains(tagless)) {
-            // Fix up the name to the tagless version
-            name.* = tagless;
-            return;
-        }
-
-        // Neither original nor tagless version exists
-        return error.InvalidRegistry;
-    }
-
-    fn fixCommand(self: *TagFixerUpper, command: *reg.Command) !void {
-        for (command.params) |*param| {
-            try self.fixTypeInfo(&param.param_type);
-        }
-
-        try self.fixTypeInfo(command.return_type);
-        for (command.success_codes) |*code| {
-            try self.fixAlias(code);
-        }
-
-        for (command.error_codes) |*code| {
-            try self.fixAlias(code);
-        }
-    }
-
-    fn fixTypeInfo(self: *TagFixerUpper, type_info: *reg.TypeInfo) error{InvalidRegistry}!void {
-        switch (type_info.*) {
-            .name => |*name| try self.fixAlias(name),
-            .command_ptr => |*command| try self.fixCommand(command),
-            .pointer => |ptr| try self.fixTypeInfo(ptr.child),
-            .array => |arr| try self.fixTypeInfo(arr.child),
-        }
-    }
-
-    fn fixNames(self: *TagFixerUpper) !void {
-        for (self.registry.decls) |*decl| {
-            switch (decl.decl_type) {
-                .container => |*container| {
-                    for (container.fields) |*field| {
-                        try self.fixTypeInfo(&field.field_type);
-                    }
-                },
-                .enumeration => |*enumeration| {
-                    for (enumeration.fields) |*field| {
-                        if (field.value == .alias) {
-                            try self.fixAlias(&field.value.alias.name);
-                        }
-                    }
-                },
-                .bitmask => |*bitmask| {
-                    if (bitmask.bits_enum) |*bits| {
-                        try self.fixAlias(bits);
-                    }
-                },
-                .command => |*command| try self.fixCommand(command),
-                .alias => |*alias| try self.fixAlias(&alias.name),
-                .typedef => |*type_info| try self.fixTypeInfo(type_info),
-                else => {},
-            }
-        }
-    }
-
-    fn fixup(self: *TagFixerUpper) !void {
-        // Extract all non-aliases
-        try self.extractNames();
-
-        // Fix aliases
-        try self.fixNames();
-    }
-};
-
 pub const Generator = struct {
-    gpa: *Allocator,
+    arena: std.heap.ArenaAllocator,
-    reg_arena: std.heap.ArenaAllocator,
     registry: reg.Registry,
     id_renderer: IdRenderer,
 
@@ -240,27 +106,14 @@ pub const Generator = struct {
         for (tags) |*tag, i| tag.* = result.registry.tags[i].name;
 
         return Generator{
-            .gpa = allocator,
+            .arena = result.arena,
-            .reg_arena = result.arena,
             .registry = result.registry,
             .id_renderer = IdRenderer.init(allocator, tags),
         };
     }
 
     fn deinit(self: Generator) void {
-        self.gpa.free(self.id_renderer.tags);
+        self.arena.deinit();
-        self.reg_arena.deinit();
-    }
-
-    fn removePromotedExtensions(self: *Generator) void {
-        var write_index: usize = 0;
-        for (self.registry.extensions) |ext| {
-            if (ext.promoted_to == .none) {
-                self.registry.extensions[write_index] = ext;
-                write_index += 1;
-            }
-        }
-        self.registry.extensions.len = write_index;
     }
 
     fn stripFlagBits(self: Generator, name: []const u8) []const u8 {
@@ -273,49 +126,47 @@ pub const Generator = struct {
         return tagless[0 .. tagless.len - "Flags".len];
     }
 
-    fn fixupBitmasks(self: *Generator) !void {
-        var bits = std.StringHashMap([]const u8).init(self.gpa);
-        defer bits.deinit();
-
-        for (self.registry.decls) |decl| {
-            if (decl.decl_type == .enumeration and decl.decl_type.enumeration.is_bitmask) {
-                try bits.put(self.stripFlagBits(decl.name), decl.name);
-            }
-        }
-
-        for (self.registry.decls) |*decl| {
-            switch (decl.decl_type) {
-                .bitmask => |*bitmask| {
-                    const base_name = self.stripFlags(decl.name);
-
-                    if (bitmask.bits_enum) |bits_enum| {
-                        if (bits.get(base_name) == null) {
-                            bitmask.bits_enum = null;
-                        }
-                    } else if (bits.get(base_name)) |bits_enum| {
-                        bitmask.bits_enum = bits_enum;
-                    }
-                },
-                else => {}
-            }
-        }
-    }
-
     // Solve `registry.declarations` according to `registry.extensions` and `registry.features`.
     fn mergeEnumFields(self: *Generator) !void {
-        var merger = EnumFieldMerger.init(self.gpa, &self.reg_arena.allocator, &self.registry);
+        var merger = EnumFieldMerger.init(&self.arena.allocator, &self.registry);
-        defer merger.deinit();
         try merger.merge();
     }
 
-    fn fixupTags(self: *Generator) !void {
+    // https://github.com/KhronosGroup/Vulkan-Docs/pull/1556
-        var fixer_upper = TagFixerUpper.init(self.gpa, &self.registry, &self.id_renderer);
+    fn fixupBitFlags(self: *Generator) !void {
-        defer fixer_upper.deinit();
+        var seen_bits = std.StringArrayHashMap(void).init(&self.arena.allocator);
-        try fixer_upper.fixup();
+        defer seen_bits.deinit();
+
+        for (self.registry.decls) |decl| {
+            const bitmask = switch (decl.decl_type) {
+                .bitmask => |bm| bm,
+                else => continue,
+            };
+
+            if (bitmask.bits_enum) |bits_enum| {
+                try seen_bits.put(bits_enum, {});
+            }
+        }
+
+        var i: usize = 0;
+
+        for (self.registry.decls) |decl| {
+            switch (decl.decl_type) {
+                .enumeration => |e| {
+                    if (e.is_bitmask and seen_bits.get(decl.name) == null)
+                        continue;
+                },
+                else => {},
+            }
+            self.registry.decls[i] = decl;
+            i += 1;
+        }
+
+        self.registry.decls.len = i;
     }
 
     fn render(self: *Generator, writer: anytype) !void {
-        try renderRegistry(writer, &self.reg_arena.allocator, &self.registry, &self.id_renderer);
+        try renderRegistry(writer, &self.arena.allocator, &self.registry, &self.id_renderer);
     }
 };
 
@@ -330,9 +181,7 @@ pub fn generate(allocator: *Allocator, spec_xml: []const u8, writer: anytype) !v
     var gen = try Generator.init(allocator, spec.root);
     defer gen.deinit();
 
-    gen.removePromotedExtensions();
     try gen.mergeEnumFields();
-    try gen.fixupBitmasks();
+    try gen.fixupBitFlags();
-    try gen.fixupTags();
     try gen.render(writer);
 }

generator/vulkan/parse.zig

@@ -74,7 +74,7 @@ fn parseTypes(allocator: *Allocator, out: []registry.Declaration, types_elem: *x
             } else if (mem.eql(u8, category, "funcpointer")) {
                 break :blk try parseFuncPointer(allocator, ty);
             } else if (mem.eql(u8, category, "enum")) {
-                break :blk (try parseEnumAlias(allocator, ty)) orelse continue;
+                break :blk (try parseEnumAlias(ty)) orelse continue;
             }
 
             continue;
@@ -107,9 +107,24 @@ fn parseBitmaskType(ty: *xml.Element) !registry.Declaration {
             .decl_type = .{ .alias = .{ .name = alias, .target = .other_type } },
         };
     } else {
+        const flags_type = ty.getCharData("type") orelse return error.InvalidRegistry;
+
+        const bitwidth: u8 = if (mem.eql(u8, flags_type, "VkFlags"))
+            32
+        else if (mem.eql(u8, flags_type, "VkFlags64"))
+            64
+        else
+            return error.InvalidRegistry;
+
         return registry.Declaration{
             .name = ty.getCharData("name") orelse return error.InvalidRegistry,
-            .decl_type = .{.bitmask = .{.bits_enum = ty.getAttribute("requires")}},
+            .decl_type = .{
+                .bitmask = .{
+                    // Who knows why these are different fields
+                    .bits_enum = ty.getAttribute("requires") orelse ty.getAttribute("bitvalues"),
+                    .bitwidth = bitwidth,
+                },
+            },
         };
     }
 }
@@ -120,7 +135,9 @@ fn parseHandleType(ty: *xml.Element) !registry.Declaration {
         const alias = ty.getAttribute("alias") orelse return error.InvalidRegistry;
         return registry.Declaration{
             .name = name,
-            .decl_type = .{.alias = .{.name = alias, .target = .other_type}},
+            .decl_type = .{
+                .alias = .{ .name = alias, .target = .other_type },
+            },
         };
     } else {
         const name = ty.getCharData("name") orelse return error.InvalidRegistry;
@@ -136,7 +153,7 @@ fn parseHandleType(ty: *xml.Element) !registry.Declaration {
                 .handle = .{
                     .parent = ty.getAttribute("parent"),
                     .is_dispatchable = dispatchable,
-                }
+                },
             },
         };
     }
@@ -163,7 +180,9 @@ fn parseContainer(allocator: *Allocator, ty: *xml.Element, is_union: bool) !regi
     if (ty.getAttribute("alias")) |alias| {
         return registry.Declaration{
             .name = name,
-            .decl_type = .{.alias = .{.name = alias, .target = .other_type}},
+            .decl_type = .{
+                .alias = .{ .name = alias, .target = .other_type },
+            },
         };
     }
 
@@ -186,6 +205,18 @@ fn parseContainer(allocator: *Allocator, ty: *xml.Element, is_union: bool) !regi
 
     members = allocator.shrink(members, i);
 
+    var maybe_extends: ?[][]const u8 = null;
+    if (ty.getAttribute("structextends")) |extends| {
+        const n_structs = std.mem.count(u8, extends, ",") + 1;
+        maybe_extends = try allocator.alloc([]const u8, n_structs);
+        var struct_extends = std.mem.split(extends, ",");
+        var j: usize = 0;
+        while (struct_extends.next()) |struct_extend| {
+            maybe_extends.?[j] = struct_extend;
+            j += 1;
+        }
+    }
+
     it = ty.findChildrenByTag("member");
     for (members) |*member| {
         const member_elem = it.next().?;
@@ -199,8 +230,9 @@ fn parseContainer(allocator: *Allocator, ty: *xml.Element, is_union: bool) !regi
                 .stype = maybe_stype,
                 .fields = members,
                 .is_union = is_union,
-            }
+                .extends = maybe_extends,
-        }
+            },
+        },
     };
 }
 
@@ -278,12 +310,14 @@ fn parsePointerMeta(fields: Fields, type_info: *registry.TypeInfo, elem: *xml.El
     }
 }
 
-fn parseEnumAlias(allocator: *Allocator, elem: *xml.Element) !?registry.Declaration {
+fn parseEnumAlias(elem: *xml.Element) !?registry.Declaration {
     if (elem.getAttribute("alias")) |alias| {
         const name = elem.getAttribute("name") orelse return error.InvalidRegistry;
         return registry.Declaration{
             .name = name,
-            .decl_type = .{.alias = .{.name = alias, .target = .other_type}},
+            .decl_type = .{
+                .alias = .{ .name = alias, .target = .other_type },
+            },
         };
     }
 
@@ -317,6 +351,11 @@ fn parseEnumFields(allocator: *Allocator, elem: *xml.Element) !registry.Enum {
         return error.InvalidRegistry;
     }
 
+    const bitwidth = if (elem.getAttribute("bitwidth")) |bitwidth|
+        try std.fmt.parseInt(u8, bitwidth, 10)
+    else
+        32;
+
     const fields = try allocator.alloc(registry.Enum.Field, elem.children.items.len);
 
     var i: usize = 0;
@@ -328,6 +367,7 @@ fn parseEnumFields(allocator: *Allocator, elem: *xml.Element) !registry.Enum {
 
     return registry.Enum{
         .fields = allocator.shrink(fields, i),
+        .bitwidth = bitwidth,
         .is_bitmask = is_bitmask,
     };
 }
@@ -356,7 +396,7 @@ fn parseEnumField(field: *xml.Element) !registry.Enum.Field {
                 break :blk .{ .int = try std.fmt.parseInt(i32, value, 10) };
             }
         } else if (field.getAttribute("bitpos")) |bitpos| {
-            break :blk .{.bitpos = try std.fmt.parseInt(u5, bitpos, 10)};
+            break :blk .{ .bitpos = try std.fmt.parseInt(u6, bitpos, 10) };
         } else if (field.getAttribute("alias")) |alias| {
             break :blk .{ .alias = .{ .name = alias, .is_compat_alias = is_compat_alias } };
         } else {
@@ -401,7 +441,9 @@ fn parseCommand(allocator: *Allocator, elem: *xml.Element) !registry.Declaration
         const name = elem.getAttribute("name") orelse return error.InvalidRegistry;
         return registry.Declaration{
             .name = name,
-            .decl_type = .{.alias = .{.name = alias, .target = .other_command}}
+            .decl_type = .{
+                .alias = .{ .name = alias, .target = .other_command },
+            },
         };
     }
 
@@ -453,8 +495,8 @@ fn parseCommand(allocator: *Allocator, elem: *xml.Element) !registry.Declaration
                 .return_type = return_type,
                 .success_codes = success_codes,
                 .error_codes = error_codes,
-            }
+            },
-        }
+        },
     };
 }
 
@@ -528,9 +570,7 @@ fn parseDefines(types: *xml.Element, out: []registry.ApiConstant) !usize {
             var xctok = cparse.XmlCTokenizer.init(ty);
             out[i] = .{
                 .name = name,
-                .value = .{
+                .value = .{ .version = cparse.parseVersion(&xctok) catch continue },
-                    .version = cparse.parseVersion(&xctok) catch continue
-                },
             };
         }
         i += 1;
@@ -591,7 +631,7 @@ fn parseFeature(allocator: *Allocator, feature: *xml.Element) !registry.Feature
     return registry.Feature{
         .name = name,
         .level = feature_level,
-        .requires = allocator.shrink(requires, i)
+        .requires = allocator.shrink(requires, i),
     };
 }
 
@@ -624,7 +664,10 @@ fn parseEnumExtension(elem: *xml.Element, parent_extnumber: ?u31) !?registry.Req
         return registry.Require.EnumExtension{
             .extends = extends,
             .extnumber = actual_extnumber,
-            .field = .{.name = name, .value = .{.int = value}},
+            .field = .{
+                .name = name,
+                .value = .{ .int = value },
+            },
         };
     }
 
@@ -753,7 +796,6 @@ fn parseExtension(allocator: *Allocator, extension: *xml.Element) !registry.Exte
         const promotedto = extension.getAttribute("promotedto") orelse break :blk .none;
         if (mem.startsWith(u8, promotedto, "VK_VERSION_")) {
             const feature_level = try splitFeatureLevel(promotedto["VK_VERSION_".len..], "_");
-
             break :blk .{ .feature = feature_level };
         }
 
@@ -798,7 +840,7 @@ fn parseExtension(allocator: *Allocator, extension: *xml.Element) !registry.Exte
         .promoted_to = promoted_to,
         .platform = platform,
         .required_feature_level = requires_core,
-        .requires = allocator.shrink(requires, i)
+        .requires = allocator.shrink(requires, i),
     };
 }
 

generator/vulkan/registry.zig

@@ -37,7 +37,7 @@ pub const Alias = struct {
 pub const ApiConstant = struct {
     pub const Value = union(enum) {
         expr: []const u8,
-        version: [3][]const u8,
+        version: [4][]const u8,
     };
 
     name: []const u8,
@@ -65,19 +65,20 @@ pub const Container = struct {
     };
 
     stype: ?[]const u8,
+    extends: ?[]const []const u8,
     fields: []Field,
     is_union: bool,
 };
 
 pub const Enum = struct {
     pub const Value = union(enum) {
-        bitpos: u5, // 1 << bitpos
+        bitpos: u6, // 1 << bitpos
         bit_vector: i32, // Combined flags & some vendor IDs
         int: i32,
         alias: struct {
             name: []const u8,
             is_compat_alias: bool,
-        }
+        },
     };
 
     pub const Field = struct {
@@ -86,11 +87,13 @@ pub const Enum = struct {
     };
 
     fields: []Field,
+    bitwidth: u8,
     is_bitmask: bool,
 };
 
 pub const Bitmask = struct {
     bits_enum: ?[]const u8,
+    bitwidth: u8,
 };
 
 pub const Handle = struct {
@@ -116,7 +119,7 @@ pub const Pointer = struct {
         one,
         many, // The length is given by some complex expression, possibly involving another field
         other_field: []const u8, // The length is given by some other field or parameter
-        zero_terminated
+        zero_terminated,
     };
 
     is_const: bool,

generator/vulkan/render.zig

@@ -9,14 +9,17 @@ const IdRenderer = id_render.IdRenderer;
 
 const preamble =
     \\
-    \\// This file is generated from the Khronos Vulkan XML API registry
+    \\// This file is generated from the Khronos Vulkan XML API registry by vulkan-zig.
     \\
     \\const std = @import("std");
     \\const builtin = @import("builtin");
     \\const root = @import("root");
-    \\pub const vulkan_call_conv: builtin.CallingConvention = if (builtin.os.tag == .windows and builtin.cpu.arch == .i386)
+    \\
+    \\const GlobalScope = @This();
+    \\
+    \\pub const vulkan_call_conv: std.builtin.CallingConvention = if (builtin.os.tag == .windows and builtin.cpu.arch == .i386)
     \\        .Stdcall
-    \\    else if (builtin.abi == .android and (builtin.cpu.arch.isARM() or builtin.cpu.arch.isThumb()) and builtin.Target.arm.featureSetHas(builtin.cpu.features, .has_v7) and builtin.cpu.arch.ptrBitWidth() == 32)
+    \\    else if (builtin.abi == .android and (builtin.cpu.arch.isARM() or builtin.cpu.arch.isThumb()) and std.Target.arm.featureSetHas(builtin.cpu.features, .has_v7) and builtin.cpu.arch.ptrBitWidth() == 32)
     \\        // On Android 32-bit ARM targets, Vulkan functions use the "hardfloat"
     \\        // calling convention, i.e. float parameters are passed in registers. This
     \\        // is true even if the rest of the application passes floats on the stack,
@@ -24,9 +27,9 @@ const preamble =
     \\        .AAPCSVFP
     \\    else
     \\        .C;
-    \\pub fn FlagsMixin(comptime FlagsType: type) type {
+    \\pub fn FlagsMixin(comptime FlagsType: type, comptime Int: type) type {
     \\    return struct {
-    \\        pub const IntType = Flags;
+    \\        pub const IntType = Int;
     \\        pub fn toInt(self: FlagsType) IntType {
     \\            return @bitCast(IntType, self);
     \\        }
@@ -40,7 +43,7 @@ const preamble =
     \\            return fromInt(toInt(lhs) & toInt(rhs));
     \\        }
     \\        pub fn complement(self: FlagsType) FlagsType {
-    \\            return fromInt(~toInt(lhs));
+    \\            return fromInt(~toInt(self));
     \\        }
     \\        pub fn subtract(lhs: FlagsType, rhs: FlagsType) FlagsType {
     \\            return fromInt(toInt(lhs) & toInt(rhs.complement()));
@@ -50,16 +53,19 @@ const preamble =
     \\        }
     \\    };
     \\}
-    \\pub fn makeVersion(major: u10, minor: u10, patch: u12) u32 {
+    \\pub fn makeApiVersion(variant: u3, major: u7, minor: u10, patch: u12) u32 {
-    \\    return (@as(u32, major) << 22) | (@as(u32, minor) << 12) | patch;
+    \\    return (@as(u32, variant) << 29) | (@as(u32, major) << 22) | (@as(u32, minor) << 12) | patch;
     \\}
-    \\pub fn versionMajor(version: u32) u10 {
+    \\pub fn apiVersionVariant(version: u32) u3 {
-    \\    return @truncate(u10, version >> 22);
+    \\    return @truncate(u3, version >> 29);
     \\}
-    \\pub fn versionMinor(version: u32) u10 {
+    \\pub fn apiVersionMajor(version: u32) u7 {
+    \\    return @truncate(u7, version >> 22);
+    \\}
+    \\pub fn apiVersionMinor(version: u32) u10 {
     \\    return @truncate(u10, version >> 12);
     \\}
-    \\pub fn versionPatch(version: u32) u12 {
+    \\pub fn apiVersionPatch(version: u32) u12 {
     \\    return @truncate(u12, version);
     \\}
     \\
@@ -74,6 +80,8 @@ const builtin_types = std.ComptimeStringMap([]const u8, .{
     .{ "uint16_t", @typeName(u16) },
     .{ "uint32_t", @typeName(u32) },
     .{ "uint64_t", @typeName(u64) },
+    .{ "int8_t", @typeName(i8) },
+    .{ "int16_t", @typeName(i16) },
     .{ "int32_t", @typeName(i32) },
     .{ "int64_t", @typeName(i64) },
     .{ "size_t", @typeName(usize) },
@@ -98,6 +106,8 @@ const foreign_types = std.ComptimeStringMap([]const u8, .{
     .{ "xcb_visualid_t", @typeName(u32) },
     .{ "xcb_window_t", @typeName(u32) },
     .{ "zx_handle_t", @typeName(u32) },
+    .{ "_screen_context", "opaque {}" },
+    .{ "_screen_window", "opaque {}" },
 });
 
 fn eqlIgnoreCase(lhs: []const u8, rhs: []const u8) bool {
@@ -129,15 +139,16 @@ fn Renderer(comptime WriterType: type) type {
     return struct {
         const Self = @This();
         const WriteError = WriterType.Error;
-        const RenderTypeInfoError = WriteError || error {
+        const RenderTypeInfoError = WriteError || std.fmt.ParseIntError || error{ OutOfMemory, InvalidRegistry };
-            OutOfMemory,
-        };
 
         const BitflagName = struct {
             /// Name without FlagBits, so VkSurfaceTransformFlagBitsKHR
             /// becomes VkSurfaceTransform
             base_name: []const u8,
 
+            /// Optional flag bits revision, used in places like VkAccessFlagBits2KHR
+            revision: ?[]const u8,
+
             /// Optional tag of the flag
             tag: ?[]const u8,
         };
@@ -174,10 +185,6 @@ fn Renderer(comptime WriterType: type) type {
         declarations_by_name: std.StringHashMap(*const reg.DeclarationType),
 
         fn init(writer: WriterType, allocator: *Allocator, registry: *const reg.Registry, id_renderer: *IdRenderer) !Self {
-            const tags = try allocator.alloc([]const u8, registry.tags.len);
-            errdefer allocator.free(tags);
-            for (tags) |*tag, i| tag.* = registry.tags[i].name;
-
             var declarations_by_name = std.StringHashMap(*const reg.DeclarationType).init(allocator);
             errdefer declarations_by_name.deinit();
 
@@ -187,7 +194,7 @@ fn Renderer(comptime WriterType: type) type {
                     return error.InvalidRegistry;
                 }
 
-                result.entry.value = &decl.decl_type;
+                result.value_ptr.* = &decl.decl_type;
             }
 
             return Self{
@@ -201,12 +208,10 @@ fn Renderer(comptime WriterType: type) type {
 
         fn deinit(self: *Self) void {
             self.declarations_by_name.deinit();
-            self.allocator.free(self.id_renderer.tags);
-            self.id_renderer.deinit();
         }
 
         fn writeIdentifier(self: Self, id: []const u8) !void {
-            try self.id_renderer.render(self.writer, id);
+            try id_render.writeIdentifier(self.writer, id);
         }
 
         fn writeIdentifierWithCase(self: *Self, case: CaseStyle, id: []const u8) !void {
@@ -225,8 +230,8 @@ fn Renderer(comptime WriterType: type) type {
 
             while (true) {
                 const rest = field_it.rest();
+                const field_segment = field_it.next() orelse return error.InvalidRegistry;
                 const enum_segment = enum_it.next() orelse return rest;
-                const field_segment = field_it.next() orelse return error.FieldNameEqualsEnumName;
 
                 if (!eqlIgnoreCase(enum_segment, field_segment)) {
                     return rest;
@@ -234,16 +239,48 @@ fn Renderer(comptime WriterType: type) type {
             }
         }
 
-        fn extractBitflagName(self: Self, name: []const u8) ?BitflagName {
+        fn extractBitflagFieldName(bitflag_name: BitflagName, field_name: []const u8) ![]const u8 {
-            const tag = self.id_renderer.getAuthorTag(name);
+            var flag_it = id_render.SegmentIterator.init(bitflag_name.base_name);
-            const base_name = if (tag) |tag_name| name[0 .. name.len - tag_name.len] else name;
+            var field_it = id_render.SegmentIterator.init(field_name);
 
-            if (!mem.endsWith(u8, base_name, "FlagBits")) {
+            while (true) {
+                const rest = field_it.rest();
+                const field_segment = field_it.next() orelse return error.InvalidRegistry;
+                const flag_segment = flag_it.next() orelse {
+                    if (bitflag_name.revision) |revision| {
+                        if (mem.eql(u8, revision, field_segment))
+                            return field_it.rest();
+                    }
+
+                    return rest;
+                };
+
+                if (!eqlIgnoreCase(flag_segment, field_segment)) {
+                    return rest;
+                }
+            }
+        }
+
+        fn extractBitflagName(self: Self, name: []const u8) !?BitflagName {
+            const tag = self.id_renderer.getAuthorTag(name);
+            const tagless_name = if (tag) |tag_name| name[0 .. name.len - tag_name.len] else name;
+
+            // Strip out the "version" number of a bitflag, like VkAccessFlagBits2KHR.
+            const base_name = std.mem.trimRight(u8, tagless_name, "0123456789");
+
+            const maybe_flag_bits_index = mem.lastIndexOf(u8, base_name, "FlagBits");
+            if (maybe_flag_bits_index == null) {
                 return null;
+            } else if (maybe_flag_bits_index != base_name.len - "FlagBits".len) {
+                // It is unlikely that a type that is not a flag bit would contain FlagBits,
+                // and more likely that we have missed something if FlagBits isn't the last
+                // part of base_name
+                return error.InvalidRegistry;
             }
 
             return BitflagName{
                 .base_name = base_name[0 .. base_name.len - "FlagBits".len],
+                .revision = if (base_name.len != tagless_name.len) tagless_name[base_name.len..] else null,
                 .tag = tag,
             };
         }
@@ -255,16 +292,6 @@ fn Renderer(comptime WriterType: type) type {
             return mem.endsWith(u8, base_name, "Flags");
         }
 
-        fn containerHasField(self: Self, container: *const reg.Container, field_name: []const u8) bool {
-            for (container.fields) |field| {
-                if (mem.eql(u8, field, field_name)) {
-                    return true;
-                }
-            }
-
-            return false;
-        }
-
         fn isInOutPointer(self: Self, ptr: reg.Pointer) !bool {
             if (ptr.child.* != .name) {
                 return false;
@@ -333,7 +360,7 @@ fn Renderer(comptime WriterType: type) type {
                     }
                 },
                 .name => |name| {
-                    if (self.extractBitflagName(param.param_type.name) != null or self.isFlags(param.param_type.name)) {
+                    if ((try self.extractBitflagName(name)) != null or self.isFlags(name)) {
                         return .bitflags;
                     }
                 },
@@ -347,7 +374,7 @@ fn Renderer(comptime WriterType: type) type {
             return .other;
         }
 
-        fn classifyCommandDispatch(self: Self, name: []const u8, command: reg.Command) CommandDispatchType {
+        fn classifyCommandDispatch(name: []const u8, command: reg.Command) CommandDispatchType {
             const device_handles = std.ComptimeStringMap(void, .{
                 .{ "VkDevice", {} },
                 .{ "VkCommandBuffer", {} },
@@ -382,6 +409,7 @@ fn Renderer(comptime WriterType: type) type {
         fn render(self: *Self) !void {
             try self.renderCopyright();
             try self.writer.writeAll(preamble);
+            try self.renderCommandEnums();
 
             for (self.registry.api_constants) |api_constant| {
                 try self.renderApiConstant(api_constant);
@@ -396,6 +424,88 @@ fn Renderer(comptime WriterType: type) type {
             try self.renderWrappers();
         }
 
+        fn renderCommandEnums(self: *Self) !void {
+            try self.renderCommandEnumOfDispatchType(.base);
+            try self.renderCommandEnumOfDispatchType(.instance);
+            try self.renderCommandEnumOfDispatchType(.device);
+            try self.writer.writeAll("\n");
+        }
+
+        fn renderCommandEnumOfDispatchType(self: *Self, dispatch_type: CommandDispatchType) !void {
+            const dispatch_type_name = switch (dispatch_type) {
+                .base => "Base",
+                .instance => "Instance",
+                .device => "Device",
+            };
+
+            try self.writer.print("pub const {s}Command = enum {{\n", .{dispatch_type_name});
+            for (self.registry.decls) |decl| {
+                const command = switch (decl.decl_type) {
+                    .command => |cmd| cmd,
+                    else => continue,
+                };
+
+                if (classifyCommandDispatch(decl.name, command) == dispatch_type) {
+                    try self.writeIdentifierWithCase(.camel, trimVkNamespace(decl.name));
+                    try self.writer.writeAll(",\n");
+                }
+            }
+
+            {
+                try self.writer.print(
+                    \\
+                    \\pub fn symbol(self: {s}Command) [:0]const u8 {{
+                    \\    return switch (self) {{
+                    \\
+                    , .{dispatch_type_name}
+                );
+
+                for (self.registry.decls) |decl| {
+                    const command = switch (decl.decl_type) {
+                        .command => |cmd| cmd,
+                        else => continue,
+                    };
+
+                    if (classifyCommandDispatch(decl.name, command) == dispatch_type) {
+                        try self.writer.writeAll(".");
+                        try self.writeIdentifierWithCase(.camel, trimVkNamespace(decl.name));
+                        try self.writer.print(" => \"{s}\",\n", .{ decl.name });
+                    }
+                }
+
+                try self.writer.writeAll("};\n}\n");
+            }
+
+            {
+                try self.writer.print(
+                    \\
+                    \\pub fn PfnType(comptime self: {s}Command) type {{
+                    \\    return switch (self) {{
+                    \\
+                    , .{dispatch_type_name}
+                );
+
+                for (self.registry.decls) |decl| {
+                    const command = switch (decl.decl_type) {
+                        .command => |cmd| cmd,
+                        else => continue,
+                    };
+
+                    if (classifyCommandDispatch(decl.name, command) == dispatch_type) {
+                        try self.writer.writeAll(".");
+                        try self.writeIdentifierWithCase(.camel, trimVkNamespace(decl.name));
+                        try self.writer.writeAll(" => ");
+                        try self.renderCommandPtrName(decl.name);
+                        try self.writer.writeAll(",\n");
+                    }
+                }
+
+                try self.writer.writeAll("};\n}\n");
+            }
+
+            try self.writer.writeAll("};\n");
+        }
+
         fn renderCopyright(self: *Self) !void {
             var it = mem.split(self.registry.copyright, "\n");
             while (it.next()) |line| {
@@ -411,7 +521,7 @@ fn Renderer(comptime WriterType: type) type {
             switch (api_constant.value) {
                 .expr => |expr| try self.renderApiConstantExpr(expr),
                 .version => |version| {
-                    try self.writer.writeAll("makeVersion(");
+                    try self.writer.writeAll("makeApiVersion(");
                     for (version) |part, i| {
                         if (i != 0) {
                             try self.writer.writeAll(", ");
@@ -470,7 +580,7 @@ fn Renderer(comptime WriterType: type) type {
                         try self.writer.print("@as(f32, {s}.{s})", .{ tok.text, decimal.text });
 
                         const f = (try tokenizer.next()) orelse return error.InvalidConstantExpr;
-                        if (f.kind != .id or !mem.eql(u8, f.text, "f")) {
+                        if (f.kind != .id or f.text.len != 1 or (f.text[0] != 'f' and f.text[0] != 'F')) {
                             return error.InvalidApiConstant;
                         }
                     },
@@ -495,10 +605,11 @@ fn Renderer(comptime WriterType: type) type {
             if (builtin_types.get(name)) |zig_name| {
                 try self.writer.writeAll(zig_name);
                 return;
-            } else if (self.extractBitflagName(name)) |bitflag_name| {
+            } else if (try self.extractBitflagName(name)) |bitflag_name| {
-                try self.writeIdentifierFmt("{s}Flags{s}", .{
+                try self.writeIdentifierFmt("{s}Flags{s}{s}", .{
                     trimVkNamespace(bitflag_name.base_name),
-                    @as([]const u8, if (bitflag_name.tag) |tag| tag else "")
+                    @as([]const u8, if (bitflag_name.revision) |revision| revision else ""),
+                    @as([]const u8, if (bitflag_name.tag) |tag| tag else ""),
                 });
                 return;
             } else if (mem.startsWith(u8, name, "vk")) {
@@ -534,10 +645,11 @@ fn Renderer(comptime WriterType: type) type {
 
                 blk: {
                     if (param.param_type == .name) {
-                        if (self.extractBitflagName(param.param_type.name)) |bitflag_name| {
+                        if (try self.extractBitflagName(param.param_type.name)) |bitflag_name| {
-                            try self.writeIdentifierFmt("{s}Flags{s}", .{
+                            try self.writeIdentifierFmt("{s}Flags{s}{s}", .{
                                 trimVkNamespace(bitflag_name.base_name),
-                                @as([]const u8, if (bitflag_name.tag) |tag| tag else "")
+                                @as([]const u8, if (bitflag_name.revision) |revision| revision else ""),
+                                @as([]const u8, if (bitflag_name.tag) |tag| tag else ""),
                             });
                             try self.writer.writeAll(".IntType");
                             break :blk;
@@ -638,7 +750,7 @@ fn Renderer(comptime WriterType: type) type {
                     }
                 } else {
                     try self.renderTypeInfo(field.field_type);
-                    try self.renderContainerDefaultField(container, field);
+                    try self.renderContainerDefaultField(name, container, field);
                     try self.writer.writeAll(", ");
                 }
             }
@@ -646,7 +758,7 @@ fn Renderer(comptime WriterType: type) type {
             try self.writer.writeAll("};\n");
         }
 
-        fn renderContainerDefaultField(self: *Self, container: reg.Container, field: reg.Container.Field) !void {
+        fn renderContainerDefaultField(self: *Self, name: []const u8, container: reg.Container, field: reg.Container.Field) !void {
             if (mem.eql(u8, field.name, "pNext")) {
                 try self.writer.writeAll(" = null");
             } else if (mem.eql(u8, field.name, "sType")) {
@@ -661,9 +773,21 @@ fn Renderer(comptime WriterType: type) type {
 
                 try self.writer.writeAll(" = .");
                 try self.writeIdentifierWithCase(.snake, stype["VK_STRUCTURE_TYPE_".len..]);
+            } else if (field.field_type == .name and !container.is_union and mem.eql(u8, "VkBool32", field.field_type.name) and isFeatureStruct(name, container.extends)) {
+                try self.writer.writeAll(" = FALSE");
             }
         }
 
+        fn isFeatureStruct(name: []const u8, maybe_extends: ?[]const []const u8) bool {
+            if (std.mem.eql(u8, name, "VkPhysicalDeviceFeatures")) return true;
+            if (maybe_extends) |extends| {
+                return for (extends) |extend| {
+                    if (mem.eql(u8, extend, "VkDeviceCreateInfo")) break true;
+                } else false;
+            }
+            return false;
+        }
+
         fn renderEnumFieldName(self: *Self, name: []const u8, field_name: []const u8) !void {
             try self.writeIdentifierWithCase(.snake, try self.extractEnumFieldName(name, field_name));
         }
@@ -676,70 +800,90 @@ fn Renderer(comptime WriterType: type) type {
 
             try self.writer.writeAll("pub const ");
             try self.renderName(name);
-            try self.writer.writeAll(" = extern enum {");
+            try self.writer.writeAll(" = enum(i32) {");
 
             for (enumeration.fields) |field| {
-                if (field.value == .alias) {
+                if (field.value == .alias)
                     continue;
-                }
 
                 try self.renderEnumFieldName(name, field.name);
-
                 switch (field.value) {
                     .int => |int| try self.writer.print(" = {}, ", .{int}),
                     .bitpos => |pos| try self.writer.print(" = 1 << {}, ", .{pos}),
-                    .bit_vector => |value| try self.writer.print(" = 0x{X}, ", .{value}),
+                    .bit_vector => |bv| try self.writer.print("= 0x{X}, ", .{bv}),
                     .alias => unreachable,
                 }
             }
 
+            try self.writer.writeAll("_,");
+
             for (enumeration.fields) |field| {
-                if (field.value != .alias or field.value.alias.is_compat_alias) {
+                if (field.value != .alias or field.value.alias.is_compat_alias)
                     continue;
-                }
 
                 try self.writer.writeAll("pub const ");
                 try self.renderEnumFieldName(name, field.name);
-                try self.writer.writeAll(" = .");
+                try self.writer.writeAll(" = ");
+                try self.renderName(name);
+                try self.writer.writeByte('.');
                 try self.renderEnumFieldName(name, field.value.alias.name);
-                try self.writer.writeAll(";");
+                try self.writer.writeAll(";\n");
             }
 
             try self.writer.writeAll("};\n");
         }
 
+        fn bitmaskFlagsType(bitwidth: u8) ![]const u8 {
+            return switch (bitwidth) {
+                32 => "Flags",
+                64 => "Flags64",
+                else => return error.InvalidRegistry,
+            };
+        }
+
+        fn renderUsingFlagsMixin(self: *Self, name: []const u8, bitwidth: u8) !void {
+            const flags_type = try bitmaskFlagsType(bitwidth);
+            try self.writer.writeAll("pub usingnamespace FlagsMixin(");
+            try self.renderName(name);
+            try self.writer.print(", {s});\n", .{flags_type});
+        }
+
         fn renderBitmaskBits(self: *Self, name: []const u8, bits: reg.Enum) !void {
             try self.writer.writeAll("pub const ");
             try self.renderName(name);
             try self.writer.writeAll(" = packed struct {");
 
+            const bitflag_name = (try self.extractBitflagName(name)) orelse return error.InvalidRegistry;
+            const flags_type = try bitmaskFlagsType(bits.bitwidth);
+
             if (bits.fields.len == 0) {
-                try self.writer.writeAll("_reserved_bits: Flags = 0,");
+                try self.writer.print("_reserved_bits: {s} = 0,", .{flags_type});
             } else {
-                var flags_by_bitpos = [_]?[]const u8{null} ** 32;
+                var flags_by_bitpos = [_]?[]const u8{null} ** 64;
                 for (bits.fields) |field| {
                     if (field.value == .bitpos) {
                         flags_by_bitpos[field.value.bitpos] = field.name;
                     }
                 }
 
-                for (flags_by_bitpos) |opt_flag_name, bitpos| {
+                for (flags_by_bitpos[0..bits.bitwidth]) |maybe_flag_name, bitpos| {
-                    if (opt_flag_name) |flag_name| {
+                    if (maybe_flag_name) |flag_name| {
-                        try self.renderEnumFieldName(name, flag_name);
+                        const field_name = try extractBitflagFieldName(bitflag_name, flag_name);
+                        try self.writeIdentifierWithCase(.snake, field_name);
                     } else {
                         try self.writer.print("_reserved_bit_{}", .{bitpos});
                     }
 
                     try self.writer.writeAll(": bool ");
                     if (bitpos == 0) { // Force alignment to integer boundaries
-                            try self.writer.writeAll("align(@alignOf(Flags)) ");
+                        try self.writer.print("align(@alignOf({s})) ", .{flags_type});
                     }
                     try self.writer.writeAll("= false, ");
                 }
             }
             try self.writer.writeAll("pub usingnamespace FlagsMixin(");
             try self.renderName(name);
-            try self.writer.writeAll(");\n};\n");
+            try self.writer.print(", {s});\n}};\n", .{flags_type});
         }
 
         fn renderBitmask(self: *Self, name: []const u8, bitmask: reg.Bitmask) !void {
@@ -747,19 +891,21 @@ fn Renderer(comptime WriterType: type) type {
                 // The bits structure is generated by renderBitmaskBits, but that wont
                 // output flags with no associated bits type.
 
+                const flags_type = try bitmaskFlagsType(bitmask.bitwidth);
+
                 try self.writer.writeAll("pub const ");
                 try self.renderName(name);
-                try self.writer.writeAll(
+                try self.writer.print(
-                    \\ = packed struct {
+                    \\ = packed struct {{
-                    \\_reserved_bits: Flags = 0,
+                    \\_reserved_bits: {s} = 0,
                     \\pub usingnamespace FlagsMixin(
-                );
+                , .{flags_type});
                 try self.renderName(name);
-                try self.writer.writeAll(
+                try self.writer.print(
-                    \\);
+                    \\, {s});
-                    \\};
+                    \\}};
                     \\
-                );
+                , .{flags_type});
             }
         }
 
@@ -768,13 +914,13 @@ fn Renderer(comptime WriterType: type) type {
 
             try self.writer.writeAll("pub const ");
             try self.renderName(name);
-            try self.writer.print(" = extern enum({s}) {{null_handle = 0, _}};\n", .{backing_type});
+            try self.writer.print(" = enum({s}) {{null_handle = 0, _}};\n", .{backing_type});
         }
 
         fn renderAlias(self: *Self, name: []const u8, alias: reg.Alias) !void {
             if (alias.target == .other_command) {
                 return;
-            } else if (self.extractBitflagName(name) != null) {
+            } else if ((try self.extractBitflagName(name)) != null) {
                 // Don't make aliases of the bitflag names, as those are replaced by just the flags type
                 return;
             }
@@ -856,25 +1002,51 @@ fn Renderer(comptime WriterType: type) type {
         }
 
         fn renderWrappers(self: *Self) !void {
-            try self.renderWrappersOfDispatchType("BaseWrapper", .base);
+            try self.renderWrappersOfDispatchType(.base);
-            try self.renderWrappersOfDispatchType("InstanceWrapper", .instance);
+            try self.renderWrappersOfDispatchType(.instance);
-            try self.renderWrappersOfDispatchType("DeviceWrapper", .device);
+            try self.renderWrappersOfDispatchType(.device);
         }
 
-        fn renderWrappersOfDispatchType(self: *Self, name: []const u8, dispatch_type: CommandDispatchType) !void {
+        fn renderWrappersOfDispatchType(self: *Self, dispatch_type: CommandDispatchType) !void {
+            const name = switch (dispatch_type) {
+                .base => "Base",
+                .instance => "Instance",
+                .device => "Device",
+            };
+
             try self.writer.print(
-                \\pub fn {s}(comptime Self: type) type {{
+                \\pub fn {s}Wrapper(comptime cmds: []const {s}Command) type {{
+                \\    comptime var fields: [cmds.len]std.builtin.TypeInfo.StructField = undefined;
+                \\    inline for (cmds) |cmd, i| {{
+                \\        const PfnType = cmd.PfnType();
+                \\        fields[i] = .{{
+                \\            .name = cmd.symbol(),
+                \\            .field_type = PfnType,
+                \\            .default_value = null,
+                \\            .is_comptime = false,
+                \\            .alignment = @alignOf(PfnType),
+                \\        }};
+                \\    }}
+                \\    const Dispatch = @Type(.{{
+                \\        .Struct = .{{
+                \\            .layout = .Auto,
+                \\            .fields = &fields,
+                \\            .decls = &[_]std.builtin.TypeInfo.Declaration{{}},
+                \\            .is_tuple = false,
+                \\        }},
+                \\    }});
                 \\    return struct {{
+                \\        dispatch: Dispatch,
                 \\        
-                , .{name}
+                \\        const Self = @This();
-            );
+            , .{ name, name });
 
             try self.renderWrapperLoader(dispatch_type);
 
             for (self.registry.decls) |decl| {
                 if (decl.decl_type == .command) {
                     const command = decl.decl_type.command;
-                    if (self.classifyCommandDispatch(decl.name, command) == dispatch_type) {
+                    if (classifyCommandDispatch(decl.name, command) == dispatch_type) {
                         try self.renderWrapper(decl.name, decl.decl_type.command);
                     }
                 }
@@ -901,16 +1073,15 @@ fn Renderer(comptime WriterType: type) type {
             try self.writer.print(
                 \\pub fn load({s}) !Self {{
                 \\    var self: Self = undefined;
-                \\    inline for (std.meta.fields(Self)) |field| {{
+                \\    inline for (std.meta.fields(Dispatch)) |field| {{
                 \\        const name = @ptrCast([*:0]const u8, field.name ++ "\x00");
-                \\        const cmd_ptr = loader({s}name) orelse return error.InvalidCommand;
+                \\        const cmd_ptr = loader({s}name) orelse return error.CommandLoadFailure;
-                \\        @field(self, field.name) = @ptrCast(field.field_type, cmd_ptr);
+                \\        @field(self.dispatch, field.name) = @ptrCast(field.field_type, cmd_ptr);
                 \\    }}
                 \\    return self;
                 \\}}
                 \\
-                , .{params, loader_first_param}
+            , .{ params, loader_first_param });
-            );
         }
 
         fn derefName(name: []const u8) []const u8 {
@@ -939,7 +1110,8 @@ fn Renderer(comptime WriterType: type) type {
                     .bitflags, // Special stuff handled in renderWrapperCall
                     .buffer_len,
                     .mut_buffer_len,
-                    .other => {
+                    .other,
+                    => {
                         try self.writeIdentifierWithCase(.snake, param.name);
                         try self.writer.writeAll(": ");
                         try self.renderTypeInfo(param.param_type);
@@ -951,8 +1123,8 @@ fn Renderer(comptime WriterType: type) type {
 
             try self.writer.writeAll(") ");
 
-            if (command.return_type.* == .name and mem.eql(u8, command.return_type.name, "VkResult")) {
+            if (command.error_codes.len > 0) {
-                try self.renderErrorSet(command.error_codes);
+                try self.renderErrorSetName(name);
                 try self.writer.writeByte('!');
             }
 
@@ -966,7 +1138,7 @@ fn Renderer(comptime WriterType: type) type {
         }
 
         fn renderWrapperCall(self: *Self, name: []const u8, command: reg.Command, returns: []const ReturnValue) !void {
-            try self.writer.writeAll("self.");
+            try self.writer.writeAll("self.dispatch.");
             try self.writeIdentifier(name);
             try self.writer.writeAll("(");
 
@@ -987,10 +1159,7 @@ fn Renderer(comptime WriterType: type) type {
                         try self.writeIdentifierWithCase(.snake, param.name);
                         try self.writer.writeAll(".toInt()");
                     },
-                    .in_out_pointer,
+                    .in_out_pointer, .buffer_len, .mut_buffer_len, .other => {
-                    .buffer_len,
-                    .mut_buffer_len,
-                    .other => {
                         try self.writeIdentifierWithCase(.snake, param.name);
                     },
                 }
@@ -1045,6 +1214,11 @@ fn Renderer(comptime WriterType: type) type {
             try self.writeIdentifierFmt("{s}Result", .{trimVkNamespace(command_name)});
         }
 
+        fn renderErrorSetName(self: *Self, name: []const u8) !void {
+            try self.writeIdentifierWithCase(.title, trimVkNamespace(name));
+            try self.writer.writeAll("Error");
+        }
+
         fn renderReturnStruct(self: *Self, command_name: []const u8, returns: []const ReturnValue) !void {
             try self.writer.writeAll("pub const ");
             try self.renderReturnStructName(command_name);
@@ -1054,16 +1228,13 @@ fn Renderer(comptime WriterType: type) type {
                 try self.writer.writeAll(": ");
                 try self.renderTypeInfo(ret.return_value_type);
                 try self.writer.writeAll(", ");
-
             }
             try self.writer.writeAll("};\n");
         }
 
         fn renderWrapper(self: *Self, name: []const u8, command: reg.Command) !void {
-            const returns_vk_result = command.return_type.* == .name
+            const returns_vk_result = command.return_type.* == .name and mem.eql(u8, command.return_type.name, "VkResult");
-                and mem.eql(u8, command.return_type.name, "VkResult");
+            const returns_void = command.return_type.* == .name and mem.eql(u8, command.return_type.name, "void");
-            const returns_void = command.return_type.* == .name
-                and mem.eql(u8, command.return_type.name, "void");
 
             const returns = try self.extractReturns(command);
 
@@ -1071,6 +1242,14 @@ fn Renderer(comptime WriterType: type) type {
                 try self.renderReturnStruct(name, returns);
             }
 
+            if (command.error_codes.len > 0) {
+                try self.writer.writeAll("pub const ");
+                try self.renderErrorSetName(name);
+                try self.writer.writeAll(" = ");
+                try self.renderErrorSet(command.error_codes);
+                try self.writer.writeAll(";\n");
+            }
+
             try self.renderWrapperPrototype(name, command, returns);
 
             if (returns.len == 1 and returns[0].origin == .inner_return_value) {
@@ -1140,13 +1319,13 @@ fn Renderer(comptime WriterType: type) type {
             try self.writer.writeAll(") {\n");
 
             for (command.success_codes) |success| {
-                try self.writer.writeByte('.');
+                try self.writer.writeAll("Result.");
                 try self.renderEnumFieldName("VkResult", success);
                 try self.writer.writeAll(" => {},");
             }
 
             for (command.error_codes) |err| {
-                try self.writer.writeByte('.');
+                try self.writer.writeAll("Result.");
                 try self.renderEnumFieldName("VkResult", err);
                 try self.writer.writeAll(" => return error.");
                 try self.renderResultAsErrorName(err);

generator/xml.zig

@@ -7,13 +7,13 @@ const ArrayList = std.ArrayList;
 
 pub const Attribute = struct {
     name: []const u8,
-    value: []const u8
+    value: []const u8,
 };
 
 pub const Content = union(enum) {
     CharData: []const u8,
     Comment: []const u8,
-    Element: *Element
+    Element: *Element,
 };
 
 pub const Element = struct {
@@ -50,7 +50,7 @@ pub const Element = struct {
 
         return switch (child.children.items[0]) {
             .CharData => |char_data| char_data,
-            else => null
+            else => null,
         };
     }
 
@@ -74,7 +74,7 @@ pub const Element = struct {
     pub fn findChildrenByTag(self: *Element, tag: []const u8) FindChildrenByTagIterator {
         return .{
             .inner = self.elements(),
-            .tag = tag
+            .tag = tag,
         };
     }
 
@@ -129,7 +129,7 @@ pub const Element = struct {
 pub const XmlDecl = struct {
     version: []const u8,
     encoding: ?[]const u8,
-    standalone: ?bool
+    standalone: ?bool,
 };
 
 pub const Document = struct {
@@ -154,7 +154,7 @@ const ParseContext = struct {
             .source = source,
             .offset = 0,
             .line = 0,
-            .column = 0
+            .column = 0,
         };
     }
 
@@ -232,7 +232,7 @@ const ParseContext = struct {
                     ws = true;
                     _ = self.consumeNoEof();
                 },
-                else => break
+                else => break,
             }
         }
 
@@ -245,7 +245,7 @@ const ParseContext = struct {
 
     fn currentLine(self: ParseContext) []const u8 {
         var begin: usize = 0;
-        if (mem.indexOfScalarPos(u8, self.source[0 .. self.offset], '\n')) |prev_nl| {
+        if (mem.lastIndexOfScalar(u8, self.source[0..self.offset], '\n')) |prev_nl| {
             begin = prev_nl + 1;
         }
 
@@ -257,46 +257,46 @@ const ParseContext = struct {
 test "ParseContext" {
     {
         var ctx = ParseContext.init("I like pythons");
-        testing.expectEqual(@as(?u8, 'I'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 'I'), ctx.peek());
-        testing.expectEqual(@as(u8, 'I'), ctx.consumeNoEof());
+        try testing.expectEqual(@as(u8, 'I'), ctx.consumeNoEof());
-        testing.expectEqual(@as(?u8, ' '), ctx.peek());
+        try testing.expectEqual(@as(?u8, ' '), ctx.peek());
-        testing.expectEqual(@as(u8, ' '), try ctx.consume());
+        try testing.expectEqual(@as(u8, ' '), try ctx.consume());
 
-        testing.expect(ctx.eat('l'));
+        try testing.expect(ctx.eat('l'));
-        testing.expectEqual(@as(?u8, 'i'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 'i'), ctx.peek());
-        testing.expectEqual(false, ctx.eat('a'));
+        try testing.expectEqual(false, ctx.eat('a'));
-        testing.expectEqual(@as(?u8, 'i'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 'i'), ctx.peek());
 
         try ctx.expect('i');
-        testing.expectEqual(@as(?u8, 'k'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 'k'), ctx.peek());
-        testing.expectError(error.UnexpectedCharacter, ctx.expect('a'));
+        try testing.expectError(error.UnexpectedCharacter, ctx.expect('a'));
-        testing.expectEqual(@as(?u8, 'k'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 'k'), ctx.peek());
 
-        testing.expect(ctx.eatStr("ke"));
+        try testing.expect(ctx.eatStr("ke"));
-        testing.expectEqual(@as(?u8, ' '), ctx.peek());
+        try testing.expectEqual(@as(?u8, ' '), ctx.peek());
 
-        testing.expect(ctx.eatWs());
+        try testing.expect(ctx.eatWs());
-        testing.expectEqual(@as(?u8, 'p'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 'p'), ctx.peek());
-        testing.expectEqual(false, ctx.eatWs());
+        try testing.expectEqual(false, ctx.eatWs());
-        testing.expectEqual(@as(?u8, 'p'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 'p'), ctx.peek());
 
-        testing.expectEqual(false, ctx.eatStr("aaaaaaaaa"));
+        try testing.expectEqual(false, ctx.eatStr("aaaaaaaaa"));
-        testing.expectEqual(@as(?u8, 'p'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 'p'), ctx.peek());
 
-        testing.expectError(error.UnexpectedEof, ctx.expectStr("aaaaaaaaa"));
+        try testing.expectError(error.UnexpectedEof, ctx.expectStr("aaaaaaaaa"));
-        testing.expectEqual(@as(?u8, 'p'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 'p'), ctx.peek());
-        testing.expectError(error.UnexpectedCharacter, ctx.expectStr("pytn"));
+        try testing.expectError(error.UnexpectedCharacter, ctx.expectStr("pytn"));
-        testing.expectEqual(@as(?u8, 'p'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 'p'), ctx.peek());
         try ctx.expectStr("python");
-        testing.expectEqual(@as(?u8, 's'), ctx.peek());
+        try testing.expectEqual(@as(?u8, 's'), ctx.peek());
     }
 
     {
         var ctx = ParseContext.init("");
-        testing.expectEqual(ctx.peek(), null);
+        try testing.expectEqual(ctx.peek(), null);
-        testing.expectError(error.UnexpectedEof, ctx.consume());
+        try testing.expectError(error.UnexpectedEof, ctx.consume());
-        testing.expectEqual(ctx.eat('p'), false);
+        try testing.expectEqual(ctx.eat('p'), false);
-        testing.expectError(error.UnexpectedEof, ctx.expect('p'));
+        try testing.expectError(error.UnexpectedEof, ctx.expect('p'));
     }
 }
 
@@ -311,7 +311,7 @@ pub const ParseError = error {
     InvalidStandaloneValue,
     NonMatchingClosingTag,
     InvalidDocument,
-    OutOfMemory
+    OutOfMemory,
 };
 
 pub fn parse(backing_allocator: *Allocator, source: []const u8) !Document {
@@ -323,15 +323,20 @@ fn parseDocument(ctx: *ParseContext, backing_allocator: *Allocator) !Document {
     var doc = Document{
         .arena = ArenaAllocator.init(backing_allocator),
         .xml_decl = null,
-        .root = undefined
+        .root = undefined,
     };
 
     errdefer doc.deinit();
 
+    try trySkipComments(ctx, &doc.arena.allocator);
+
     doc.xml_decl = try tryParseProlog(ctx, &doc.arena.allocator);
     _ = ctx.eatWs();
+    try trySkipComments(ctx, &doc.arena.allocator);
+
     doc.root = (try tryParseElement(ctx, &doc.arena.allocator)) orelse return error.InvalidDocument;
     _ = ctx.eatWs();
+    try trySkipComments(ctx, &doc.arena.allocator);
 
     if (ctx.peek() != null) return error.InvalidDocument;
 
@@ -371,7 +376,7 @@ fn parseNameNoDupe(ctx: *ParseContext) ![]const u8 {
         switch (ch) {
             ' ', '\t', '\n', '\r' => break,
             '&', '"', '\'', '<', '>', '?', '=', '/' => break,
-            else => _ = ctx.consumeNoEof()
+            else => _ = ctx.consumeNoEof(),
         }
     }
 
@@ -386,8 +391,8 @@ fn tryParseCharData(ctx: *ParseContext, alloc: *Allocator) !?[]const u8 {
 
     while (ctx.peek()) |ch| {
         switch (ch) {
-            '<', '>' => break,
+            '<' => break,
-            else => _ = ctx.consumeNoEof()
+            else => _ = ctx.consumeNoEof(),
         }
     }
 
@@ -472,41 +477,41 @@ test "tryParseElement" {
 
     {
         var ctx = ParseContext.init("<= a='b'/>");
-        testing.expectEqual(@as(?*Element, null), try tryParseElement(&ctx, alloc));
+        try testing.expectEqual(@as(?*Element, null), try tryParseElement(&ctx, alloc));
-        testing.expectEqual(@as(?u8, '<'), ctx.peek());
+        try testing.expectEqual(@as(?u8, '<'), ctx.peek());
     }
 
     {
         var ctx = ParseContext.init("<python size='15' color = \"green\"/>");
         const elem = try tryParseElement(&ctx, alloc);
-        testing.expectEqualSlices(u8, elem.?.tag, "python");
+        try testing.expectEqualSlices(u8, elem.?.tag, "python");
 
         const size_attr = elem.?.attributes.items[0];
-        testing.expectEqualSlices(u8, size_attr.name, "size");
+        try testing.expectEqualSlices(u8, size_attr.name, "size");
-        testing.expectEqualSlices(u8, size_attr.value, "15");
+        try testing.expectEqualSlices(u8, size_attr.value, "15");
 
         const color_attr = elem.?.attributes.items[1];
-        testing.expectEqualSlices(u8, color_attr.name, "color");
+        try testing.expectEqualSlices(u8, color_attr.name, "color");
-        testing.expectEqualSlices(u8, color_attr.value, "green");
+        try testing.expectEqualSlices(u8, color_attr.value, "green");
     }
 
     {
         var ctx = ParseContext.init("<python>test</python>");
         const elem = try tryParseElement(&ctx, alloc);
-        testing.expectEqualSlices(u8, elem.?.tag, "python");
+        try testing.expectEqualSlices(u8, elem.?.tag, "python");
-        testing.expectEqualSlices(u8, elem.?.children.items[0].CharData, "test");
+        try testing.expectEqualSlices(u8, elem.?.children.items[0].CharData, "test");
     }
 
     {
         var ctx = ParseContext.init("<a>b<c/>d<e/>f<!--g--></a>");
         const elem = try tryParseElement(&ctx, alloc);
-        testing.expectEqualSlices(u8, elem.?.tag, "a");
+        try testing.expectEqualSlices(u8, elem.?.tag, "a");
-        testing.expectEqualSlices(u8, elem.?.children.items[0].CharData, "b");
+        try testing.expectEqualSlices(u8, elem.?.children.items[0].CharData, "b");
-        testing.expectEqualSlices(u8, elem.?.children.items[1].Element.tag, "c");
+        try testing.expectEqualSlices(u8, elem.?.children.items[1].Element.tag, "c");
-        testing.expectEqualSlices(u8, elem.?.children.items[2].CharData, "d");
+        try testing.expectEqualSlices(u8, elem.?.children.items[2].CharData, "d");
-        testing.expectEqualSlices(u8, elem.?.children.items[3].Element.tag, "e");
+        try testing.expectEqualSlices(u8, elem.?.children.items[3].Element.tag, "e");
-        testing.expectEqualSlices(u8, elem.?.children.items[4].CharData, "f");
+        try testing.expectEqualSlices(u8, elem.?.children.items[4].CharData, "f");
-        testing.expectEqualSlices(u8, elem.?.children.items[5].Comment, "g");
+        try testing.expectEqualSlices(u8, elem.?.children.items[5].Comment, "g");
     }
 }
 
@@ -560,24 +565,30 @@ test "tryParseProlog" {
 
     {
         var ctx = ParseContext.init("<?xmla version='aa'?>");
-        testing.expectEqual(@as(?*XmlDecl, null), try tryParseProlog(&ctx, alloc));
+        try testing.expectEqual(@as(?*XmlDecl, null), try tryParseProlog(&ctx, alloc));
-        testing.expectEqual(@as(?u8, '<'), ctx.peek());
+        try testing.expectEqual(@as(?u8, '<'), ctx.peek());
     }
 
     {
         var ctx = ParseContext.init("<?xml version='aa'?>");
         const decl = try tryParseProlog(&ctx, alloc);
-        testing.expectEqualSlices(u8, "aa", decl.?.version);
+        try testing.expectEqualSlices(u8, "aa", decl.?.version);
-        testing.expectEqual(@as(?[]const u8, null), decl.?.encoding);
+        try testing.expectEqual(@as(?[]const u8, null), decl.?.encoding);
-        testing.expectEqual(@as(?bool, null), decl.?.standalone);
+        try testing.expectEqual(@as(?bool, null), decl.?.standalone);
     }
 
     {
         var ctx = ParseContext.init("<?xml version=\"aa\" encoding = 'bbb' standalone   \t =   'yes'?>");
         const decl = try tryParseProlog(&ctx, alloc);
-        testing.expectEqualSlices(u8, "aa", decl.?.version);
+        try testing.expectEqualSlices(u8, "aa", decl.?.version);
-        testing.expectEqualSlices(u8, "bbb", decl.?.encoding.?);
+        try testing.expectEqualSlices(u8, "bbb", decl.?.encoding.?);
-        testing.expectEqual(@as(?bool, true), decl.?.standalone.?);
+        try testing.expectEqual(@as(?bool, true), decl.?.standalone.?);
+    }
+}
+
+fn trySkipComments(ctx: *ParseContext, alloc: *Allocator) !void {
+    while (try tryParseComment(ctx, alloc)) |_| {
+        _ = ctx.eatWs();
     }
 }
 
@@ -594,17 +605,14 @@ fn tryParseComment(ctx: *ParseContext, alloc: *Allocator) !?[]const u8 {
 }
 
 fn unescapeEntity(text: []const u8) !u8 {
-    const EntitySubstition = struct {
+    const EntitySubstition = struct { text: []const u8, replacement: u8 };
-        text: []const u8,
-        replacement: u8
-    };
 
     const entities = [_]EntitySubstition{
         .{ .text = "&lt;", .replacement = '<' },
         .{ .text = "&gt;", .replacement = '>' },
         .{ .text = "&amp;", .replacement = '&' },
         .{ .text = "&apos;", .replacement = '\'' },
-        .{.text = "&quot;", .replacement = '"'}
+        .{ .text = "&quot;", .replacement = '"' },
     };
 
     for (entities) |entity| {
@@ -638,10 +646,19 @@ test "dupeAndUnescape" {
     defer arena.deinit();
     var alloc = &arena.allocator;
 
-    testing.expectEqualSlices(u8, "test", try dupeAndUnescape(alloc, "test"));
+    try testing.expectEqualSlices(u8, "test", try dupeAndUnescape(alloc, "test"));
-    testing.expectEqualSlices(u8, "a<b&c>d\"e'f<", try dupeAndUnescape(alloc, "a&lt;b&amp;c&gt;d&quot;e&apos;f&lt;"));
+    try testing.expectEqualSlices(u8, "a<b&c>d\"e'f<", try dupeAndUnescape(alloc, "a&lt;b&amp;c&gt;d&quot;e&apos;f&lt;"));
-    testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&"));
+    try testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&"));
-    testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&&"));
+    try testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&&"));
-    testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&test;"));
+    try testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&test;"));
-    testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&boa"));
+    try testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&boa"));
+}
+
+test "Top level comments" {
+    var arena = std.heap.ArenaAllocator.init(testing.allocator);
+    defer arena.deinit();
+    var alloc = &arena.allocator;
+
+    const doc = try parse(alloc, "<?xml version='aa'?><!--comment--><python color='green'/><!--another comment-->");
+    try testing.expectEqualSlices(u8, "python", doc.root.tag);
 }