From d046ace4d8c5134875546f78775f097c5c099c25 Mon Sep 17 00:00:00 2001
From: Robin Voetter <robin@voetter.nl>
Date: Sat, 15 Mar 2025 13:24:36 +0100
Subject: [PATCH] default initialize packed flag structs to 0

---
 src/vulkan/generator.zig |  8 +++++++-
 src/vulkan/parse.zig     |  7 ++++++-
 src/vulkan/render.zig    | 13 +++++++++++--
 3 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/src/vulkan/generator.zig b/src/vulkan/generator.zig
index e89f740..b8d9138 100644
--- a/src/vulkan/generator.zig
+++ b/src/vulkan/generator.zig
@@ -199,7 +199,13 @@ pub const Api = reg.Api;
 /// and the resulting binding is written to `writer`. `allocator` will be used to allocate temporary
 /// internal datastructures - mostly via an ArenaAllocator, but sometimes a hashmap uses this allocator
 /// directly. `api` is the API to generate the bindings for, usually `.vulkan`.
-pub fn generate(allocator: Allocator, api: Api, spec_xml: []const u8, maybe_video_spec_xml: ?[]const u8, writer: anytype) !void {
+pub fn generate(
+    allocator: Allocator,
+    api: Api,
+    spec_xml: []const u8,
+    maybe_video_spec_xml: ?[]const u8,
+    writer: anytype,
+) !void {
     const spec = xml.parse(allocator, spec_xml) catch |err| switch (err) {
         error.InvalidDocument,
         error.UnexpectedEof,
diff --git a/src/vulkan/parse.zig b/src/vulkan/parse.zig
index 4607e5a..548572b 100644
--- a/src/vulkan/parse.zig
+++ b/src/vulkan/parse.zig
@@ -417,7 +417,12 @@ fn parseEnumAlias(elem: *xml.Element) !?registry.Declaration {
     return null;
 }
 
-fn parseEnums(allocator: Allocator, root: *xml.Element, api: registry.Api, decls: *std.ArrayListUnmanaged(registry.Declaration)) !void {
+fn parseEnums(
+    allocator: Allocator,
+    root: *xml.Element,
+    api: registry.Api,
+    decls: *std.ArrayListUnmanaged(registry.Declaration),
+) !void {
     var it = root.findChildrenByTag("enums");
     while (it.next()) |enums| {
         const name = enums.getAttribute("name") orelse return error.InvalidRegistry;
diff --git a/src/vulkan/render.zig b/src/vulkan/render.zig
index a573d08..9639586 100644
--- a/src/vulkan/render.zig
+++ b/src/vulkan/render.zig
@@ -993,11 +993,16 @@ fn Renderer(comptime WriterType: type) type {
 
         fn renderSimpleBitContainer(self: *Self, container: reg.Container) !bool {
             var total_bits: usize = 0;
+            var is_flags_container = true;
             for (container.fields) |field| {
-                total_bits += field.bits orelse {
+                const bits = field.bits orelse {
                     // C abi type - not a packed struct.
                     return false;
                 };
+                total_bits += bits;
+                if (bits != 1) {
+                    is_flags_container = false;
+                }
             }
 
             try self.writer.writeAll("packed struct(u32) {");
@@ -1012,7 +1017,11 @@ fn Renderer(comptime WriterType: type) type {
                     try self.writer.print(" u{} = 0,\n", .{field.bits.?});
                 } else if (bits == 1) {
                     // Assume its a flag.
-                    try self.writer.writeAll(" bool,\n");
+                    if (is_flags_container) {
+                        try self.writer.writeAll(" bool = false,\n");
+                    } else {
+                        try self.writer.writeAll(" bool,\n");
+                    }
                 } else {
                     try self.writer.print(" u{},\n", .{field.bits.?});
                 }