From 9c45afca2ed3b9bc743fdcdab8c0b25aebf7c6bf Mon Sep 17 00:00:00 2001
From: bluesillybeard <bluesillybeard2@gmail.com>
Date: Wed, 10 Apr 2024 17:06:43 -0600
Subject: [PATCH] Add extension function metadata for #112

---
 generator/vulkan/render.zig | 67 +++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/generator/vulkan/render.zig b/generator/vulkan/render.zig
index d730758..a8841c1 100644
--- a/generator/vulkan/render.zig
+++ b/generator/vulkan/render.zig
@@ -1035,13 +1035,80 @@ fn Renderer(comptime WriterType: type) type {
                 \\    const Info = struct {
                 \\        name: [:0]const u8,
                 \\        version: u32,
+                \\        instance_functions: InstanceCommandFlags,
+                \\        device_functions: DeviceCommandFlags,
                 \\    };
             );
+            // The commands in an extension are not pre-sorted based on if they are instance or device functions.
+            var instance_commands = std.ArrayList([]const u8).init(self.allocator);
+            defer instance_commands.deinit();
+            var device_commands = std.ArrayList([]const u8).init(self.allocator);
+            defer device_commands.deinit();
             for (self.registry.extensions) |ext| {
                 try self.writer.writeAll("pub const ");
                 try self.writeIdentifierWithCase(.snake, trimVkNamespace(ext.name));
                 try self.writer.writeAll("= Info {\n");
                 try self.writer.print(".name = \"{s}\", .version = {},", .{ ext.name, ext.version });
+                // collect extension functions
+                for(ext.requires) |require| {
+                    for(require.commands) |command_name| {
+                        const decl = self.resolveDeclaration(command_name) orelse continue;
+                        // If the target type does not exist, it was likely an empty enum -
+                        // assume spec is correct and that this was not a function alias.
+                        const decl_type = self.resolveAlias(decl) catch continue;
+                        const command = switch (decl_type) {
+                            .command => |cmd| cmd,
+                            else => continue,
+                        };
+                        const class = classifyCommandDispatch(command_name, command);
+                        switch (class) {
+                            // Vulkan extensions cannot add base functions.
+                            .base => continue,
+                            // TODO: some extensions have multiple separate requirements.
+                            // For example, "VK_KHR_push_descriptor" depends on either "VK_VERSION_1_1" or "VK_KHR_descriptor_update_template",
+                            // which causes the same function to be mentioned twice; once for each requirement.
+                            // For now, duplicate functions are just removed,
+                            // However in the future it might be worth exposing these separate requirements somehow.
+                            .instance => {
+                                var duplicate = false;
+                                for(instance_commands.items) |cmd| {
+                                    if(std.mem.eql(u8, cmd, command_name)) {
+                                        duplicate = true;
+                                    }
+                                }
+                                if(!duplicate) try instance_commands.append(command_name);
+                            },
+                            .device => {
+                                var duplicate = false;
+                                for(device_commands.items) |cmd| {
+                                    if(std.mem.eql(u8, cmd, command_name)) {
+                                        duplicate = true;
+                                    }
+                                }
+                                if(!duplicate) try device_commands.append(command_name);
+                            },
+                        }
+                    }
+                }
+                // and write them out
+                try self.writer.writeAll(".instance_functions = .{\n");
+                for(instance_commands.items) |command_name| {
+                    try self.writer.writeAll(".");
+                    try self.writeIdentifierWithCase(.camel, trimVkNamespace(command_name));
+                    try self.writer.writeAll(" = true, \n");
+                }
+                try self.writer.writeAll("},\n");
+                instance_commands.clearRetainingCapacity();
+
+                try self.writer.writeAll(".device_functions = .{\n");
+                for(device_commands.items) |command_name| {
+                    try self.writer.writeAll(".");
+                    try self.writeIdentifierWithCase(.camel, trimVkNamespace(command_name));
+                    try self.writer.writeAll(" = true, \n");
+                }
+                try self.writer.writeAll("},\n");
+                device_commands.clearRetainingCapacity();
+
                 try self.writer.writeAll("};\n");
             }
             try self.writer.writeAll("};\n");