Add feature info

generator/vulkan/render.zig

@@ -469,6 +469,7 @@ fn Renderer(comptime WriterType: type) type {
 
             try self.renderCommandPtrs();
             try self.renderExtensionInfo();
+            try self.renderFeatureInfo();
             try self.renderWrappers();
         }
 
@@ -1040,9 +1041,9 @@ fn Renderer(comptime WriterType: type) type {
                 \\    };
             );
             // 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);
+            var instance_commands = std.BufSet.init(self.allocator);
             defer instance_commands.deinit();
-            var device_commands = std.ArrayList([]const u8).init(self.allocator);
+            var device_commands = std.BufSet.init(self.allocator);
             defer device_commands.deinit();
             for (self.registry.extensions) |ext| {
                 try self.writer.writeAll("pub const ");
@@ -1065,38 +1066,104 @@ fn Renderer(comptime WriterType: type) type {
                             // Vulkan extensions cannot add base functions.
                             .base => return error.InvalidRegistry,
                             .instance => {
-                                try instance_commands.append(command_name);
+                                try instance_commands.insert(command_name);
                             },
                             .device => {
-                                try device_commands.append(command_name);
+                                try device_commands.insert(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(".instance_functions = ");
+                try self.renderCommandFlags(&instance_commands);
+                instance_commands.hash_map.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(".device_functions = ");
+                try self.renderCommandFlags(&device_commands);
+                device_commands.hash_map.clearRetainingCapacity();
 
                 try self.writer.writeAll("};\n");
             }
             try self.writer.writeAll("};\n");
         }
 
+        fn renderFeatureInfo(self: *Self) !void {
+            try self.writer.writeAll(
+                \\pub const feature_info = struct {
+                \\    const Info = struct {
+                \\        base_functions: BaseCommandFlags,
+                \\        instance_functions: InstanceCommandFlags,
+                \\        device_functions: DeviceCommandFlags,
+                \\    };
+            );
+            // The commands in a feature level are not pre-sorted based on if they are instance or device functions.
+            var base_commands = std.BufSet.init(self.allocator);
+            defer base_commands.deinit();
+            var instance_commands = std.BufSet.init(self.allocator);
+            defer instance_commands.deinit();
+            var device_commands = std.BufSet.init(self.allocator);
+            defer device_commands.deinit();
+            for (self.registry.features) |feature| {
+                try self.writer.writeAll("pub const ");
+                try self.writeIdentifierWithCase(.snake, trimVkNamespace(feature.name));
+                try self.writer.writeAll("= Info {\n");
+                // collect feature information
+                for (feature.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) {
+                            .base => {
+                                try base_commands.insert(command_name);
+                            },
+                            .instance => {
+                                try instance_commands.insert(command_name);
+                            },
+                            .device => {
+                                try device_commands.insert(command_name);
+                            },
+                        }
+                    }
+                }
+                // and write them out
+                // clear command lists for next iteration
+                try self.writer.writeAll(".base_functions = ");
+                try self.renderCommandFlags(&base_commands);
+                base_commands.hash_map.clearRetainingCapacity();
+
+                try self.writer.writeAll(".instance_functions = ");
+                try self.renderCommandFlags(&instance_commands);
+                instance_commands.hash_map.clearRetainingCapacity();
+
+                try self.writer.writeAll(".device_functions = ");
+                try self.renderCommandFlags(&device_commands);
+                device_commands.hash_map.clearRetainingCapacity();
+
+                try self.writer.writeAll("};\n");
+            }
+
+            try self.writer.writeAll("};\n");
+        }
+
+        fn renderCommandFlags(self: *Self, commands: *const std.BufSet) !void {
+            try self.writer.writeAll(".{\n");
+            var iterator = commands.iterator();
+            while (iterator.next()) |command_name| {
+                try self.writer.writeAll(".");
+                try self.writeIdentifierWithCase(.camel, trimVkNamespace(command_name.*));
+                try self.writer.writeAll(" = true, \n");
+            }
+            try self.writer.writeAll("},\n");
+        }
+
         fn renderWrappers(self: *Self) !void {
             try self.writer.writeAll(
                 \\pub fn CommandFlagsMixin(comptime CommandFlags: type) type {