glib_macros/enum_derive.rs
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474
// Take a look at the license at the top of the repository in the LICENSE file.
use heck::{ToKebabCase, ToShoutySnakeCase, ToUpperCamelCase};
use proc_macro2::TokenStream;
use quote::{format_ident, quote, quote_spanned, ToTokens};
use crate::utils::{
crate_ident_new, gen_enum_from_glib, parse_nested_meta_items, parse_optional_nested_meta_items,
NestedMetaItem,
};
// generates glib::gobject_ffi::GEnumValue structs mapping the enum such as:
// glib::gobject_ffi::GEnumValue {
// value: Animal::Goat as i32,
// value_name: "Goat\0" as *const _ as *const _,
// value_nick: "goat\0" as *const _ as *const _,
// },
fn gen_enum_values(
enum_name: &syn::Ident,
enum_variants: &syn::punctuated::Punctuated<syn::Variant, syn::token::Comma>,
) -> (TokenStream, usize) {
let crate_ident = crate_ident_new();
// starts at one as GEnumValue array is null-terminated.
let mut n = 1;
let recurse = enum_variants.iter().map(|v| {
let name = &v.ident;
let mut value_name = name.to_string().to_upper_camel_case();
let mut value_nick = name.to_string().to_kebab_case();
let mut name_attr = NestedMetaItem::<syn::LitStr>::new("name").value_required();
let mut nick = NestedMetaItem::<syn::LitStr>::new("nick").value_required();
let found =
parse_nested_meta_items(&v.attrs, "enum_value", &mut [&mut name_attr, &mut nick]);
if let Err(e) = found {
return e.to_compile_error();
}
value_name = name_attr.value.map(|s| s.value()).unwrap_or(value_name);
value_nick = nick.value.map(|s| s.value()).unwrap_or(value_nick);
let value_name = format!("{value_name}\0");
let value_nick = format!("{value_nick}\0");
n += 1;
// generates a glib::gobject_ffi::GEnumValue.
quote_spanned! {syn::spanned::Spanned::span(&v)=>
#crate_ident::gobject_ffi::GEnumValue {
value: #enum_name::#name as i32,
value_name: #value_name as *const _ as *const _,
value_nick: #value_nick as *const _ as *const _,
},
}
});
(
quote! {
#(#recurse)*
},
n,
)
}
pub fn impl_enum(input: &syn::DeriveInput) -> syn::Result<TokenStream> {
let name = &input.ident;
let enum_variants = match input.data {
syn::Data::Enum(ref e) => &e.variants,
_ => {
return Err(syn::Error::new_spanned(
input,
"#[derive(glib::Enum)] only supports enums",
))
}
};
let (g_enum_values, nb_enum_values) = gen_enum_values(name, enum_variants);
let mut gtype_name = NestedMetaItem::<syn::LitStr>::new("name")
.required()
.value_required();
let mut allow_name_conflict =
NestedMetaItem::<syn::LitBool>::new("allow_name_conflict").value_optional();
let found = parse_nested_meta_items(
&input.attrs,
"enum_type",
&mut [&mut gtype_name, &mut allow_name_conflict],
)?;
if found.is_none() {
return Err(syn::Error::new_spanned(
input,
"#[derive(glib::Enum)] requires #[enum_type(name = \"EnumTypeName\")]",
));
}
let gtype_name = gtype_name.value.unwrap();
let allow_name_conflict = allow_name_conflict.found
|| allow_name_conflict
.value
.map(|b| b.value())
.unwrap_or(false);
let mut plugin_type = NestedMetaItem::<syn::Path>::new("plugin_type").value_required();
let mut lazy_registration =
NestedMetaItem::<syn::LitBool>::new("lazy_registration").value_required();
let found = parse_optional_nested_meta_items(
&input.attrs,
"enum_dynamic",
&mut [&mut plugin_type, &mut lazy_registration],
)?;
let crate_ident = crate_ident_new();
let register_enum = match found {
None => register_enum_as_static(
&crate_ident,
name,
gtype_name,
allow_name_conflict,
g_enum_values,
nb_enum_values,
),
Some(_) => {
if allow_name_conflict {
return Err(syn::Error::new_spanned(
input,
"#[enum_dynamic] and #[enum_type(allow_name_conflict)] are not allowed together",
));
}
let plugin_ty = plugin_type
.value
.map(|p| p.into_token_stream())
.unwrap_or(quote!(#crate_ident::TypeModule));
let lazy_registration = lazy_registration.value.map(|b| b.value).unwrap_or_default();
register_enum_as_dynamic(
&crate_ident,
plugin_ty,
lazy_registration,
name,
gtype_name,
g_enum_values,
nb_enum_values,
)
}
};
let from_glib = gen_enum_from_glib(name, enum_variants);
Ok(quote! {
impl #crate_ident::translate::IntoGlib for #name {
type GlibType = i32;
#[inline]
fn into_glib(self) -> i32 {
self as i32
}
}
impl #crate_ident::translate::TryFromGlib<i32> for #name {
type Error = i32;
#[inline]
unsafe fn try_from_glib(value: i32) -> ::core::result::Result<Self, i32> {
let from_glib = || {
#from_glib
};
from_glib().ok_or(value)
}
}
impl #crate_ident::translate::FromGlib<i32> for #name {
#[inline]
unsafe fn from_glib(value: i32) -> Self {
use #crate_ident::translate::TryFromGlib;
Self::try_from_glib(value).unwrap()
}
}
impl #crate_ident::value::ValueType for #name {
type Type = Self;
}
unsafe impl<'a> #crate_ident::value::FromValue<'a> for #name {
type Checker = #crate_ident::value::GenericValueTypeChecker<Self>;
#[inline]
unsafe fn from_value(value: &'a #crate_ident::value::Value) -> Self {
#crate_ident::translate::from_glib(#crate_ident::gobject_ffi::g_value_get_enum(
#crate_ident::translate::ToGlibPtr::to_glib_none(value).0
))
}
}
impl #crate_ident::prelude::ToValue for #name {
#[inline]
fn to_value(&self) -> #crate_ident::value::Value {
let mut value = #crate_ident::value::Value::for_value_type::<Self>();
unsafe {
#crate_ident::gobject_ffi::g_value_set_enum(
#crate_ident::translate::ToGlibPtrMut::to_glib_none_mut(&mut value).0,
#crate_ident::translate::IntoGlib::into_glib(*self)
)
}
value
}
#[inline]
fn value_type(&self) -> #crate_ident::Type {
<Self as #crate_ident::prelude::StaticType>::static_type()
}
}
impl ::std::convert::From<#name> for #crate_ident::Value {
#[inline]
fn from(v: #name) -> Self {
#crate_ident::value::ToValue::to_value(&v)
}
}
impl #crate_ident::prelude::StaticType for #name {
#[inline]
fn static_type() -> #crate_ident::Type {
Self::register_enum()
}
}
#register_enum
impl #crate_ident::HasParamSpec for #name {
type ParamSpec = #crate_ident::ParamSpecEnum;
type SetValue = Self;
type BuilderFn = fn(&::core::primitive::str, Self) -> #crate_ident::ParamSpecEnumBuilder<Self>;
fn param_spec_builder() -> Self::BuilderFn {
|name, default_value| Self::ParamSpec::builder_with_default(name, default_value)
}
}
})
}
// Registers the enum as a static type.
fn register_enum_as_static(
crate_ident: &TokenStream,
name: &syn::Ident,
gtype_name: syn::LitStr,
allow_name_conflict: bool,
g_enum_values: TokenStream,
nb_enum_values: usize,
) -> TokenStream {
let type_name_snippet = if allow_name_conflict {
quote! {
unsafe {
let mut i = 0;
loop {
let type_name = ::std::ffi::CString::new(if i == 0 {
#gtype_name
} else {
format!("{}-{}", #gtype_name, i)
})
.unwrap();
if #crate_ident::gobject_ffi::g_type_from_name(type_name.as_ptr()) == #crate_ident::gobject_ffi::G_TYPE_INVALID
{
break type_name;
}
i += 1;
}
}
}
} else {
quote! {
unsafe {
let type_name = ::std::ffi::CString::new(#gtype_name).unwrap();
assert_eq!(
#crate_ident::gobject_ffi::g_type_from_name(type_name.as_ptr()),
#crate_ident::gobject_ffi::G_TYPE_INVALID,
"Type {} has already been registered",
type_name.to_str().unwrap()
);
type_name
}
}
};
// registers the enum on first use (lazy registration).
quote! {
impl #name {
/// Registers the enum only once.
#[inline]
fn register_enum() -> #crate_ident::Type {
static TYPE: ::std::sync::OnceLock<#crate_ident::Type> = ::std::sync::OnceLock::new();
*TYPE.get_or_init(|| {
static mut VALUES: [#crate_ident::gobject_ffi::GEnumValue; #nb_enum_values] = [
#g_enum_values
#crate_ident::gobject_ffi::GEnumValue {
value: 0,
value_name: ::std::ptr::null(),
value_nick: ::std::ptr::null(),
},
];
let type_name = #type_name_snippet;
unsafe {
let type_ = #crate_ident::gobject_ffi::g_enum_register_static(type_name.as_ptr(), VALUES.as_ptr());
let type_: #crate_ident::Type = #crate_ident::translate::from_glib(type_);
assert!(type_.is_valid());
type_
}
})
}
}
}
}
// The following implementations follows the lifecycle of plugins and of dynamic types (see [`TypePluginExt`] and [`TypeModuleExt`]).
// An enum can be reregistered as a dynamic type.
fn register_enum_as_dynamic(
crate_ident: &TokenStream,
plugin_ty: TokenStream,
lazy_registration: bool,
name: &syn::Ident,
gtype_name: syn::LitStr,
g_enum_values: TokenStream,
nb_enum_values: usize,
) -> TokenStream {
// Wrap each GEnumValue to EnumValue
let g_enum_values_expr: syn::ExprArray = syn::parse_quote! { [#g_enum_values] };
let enum_values_iter = g_enum_values_expr.elems.iter().map(|v| {
quote_spanned! {syn::spanned::Spanned::span(&v)=>
#crate_ident::EnumValue::unsafe_from(#v),
}
});
let enum_values = quote! {
#crate_ident::enums::EnumValuesStorage<#nb_enum_values> = unsafe {
#crate_ident::enums::EnumValuesStorage::<#nb_enum_values>::new([
#(#enum_values_iter)*
])
}
};
// The following implementations follows the lifecycle of plugins and of dynamic types (see [`TypePluginExt`] and [`TypeModuleExt`]).
// An enum can be reregistered as a dynamic type.
if lazy_registration {
// registers the enum as a dynamic type on the first use (lazy registration).
// a weak reference on the plugin is stored and will be used later on the first use of the enum.
// this implementation relies on a static storage of a weak reference on the plugin and of the GLib type to know if the enum has been registered.
// the registration status type.
let registration_status_type = format_ident!("{}RegistrationStatus", name);
// name of the static variable to store the registration status.
let registration_status = format_ident!(
"{}",
registration_status_type.to_string().to_shouty_snake_case()
);
// name of the static array to store the enumeration values.
let enum_values_array = format_ident!("{}_VALUES", name.to_string().to_shouty_snake_case());
quote! {
/// The registration status type: a tuple of the weak reference on the plugin and of the GLib type.
struct #registration_status_type(<#plugin_ty as #crate_ident::clone::Downgrade>::Weak, #crate_ident::Type);
unsafe impl Send for #registration_status_type {}
/// The registration status protected by a mutex guarantees so that no other threads are concurrently accessing the data.
static #registration_status: ::std::sync::Mutex<Option<#registration_status_type>> = ::std::sync::Mutex::new(None);
/// Array of `EnumValue` for the possible enumeration values.
static #enum_values_array: #enum_values;
impl #name {
/// Registers the enum as a dynamic type within the plugin only once.
/// Plugin must have been used at least once.
/// Do nothing if plugin has never been used or if the enum is already registered as a dynamic type.
#[inline]
fn register_enum() -> #crate_ident::Type {
let mut registration_status = #registration_status.lock().unwrap();
match ::std::ops::DerefMut::deref_mut(&mut registration_status) {
// plugin has never been used, so the enum cannot be registered as a dynamic type.
None => #crate_ident::Type::INVALID,
// plugin has been used and the enum has not been registered yet, so registers it as a dynamic type.
Some(#registration_status_type(type_plugin, type_)) if !type_.is_valid() => {
*type_ = <#plugin_ty as glib::prelude::DynamicObjectRegisterExt>::register_dynamic_enum(type_plugin.upgrade().unwrap().as_ref(), #gtype_name, #enum_values_array.as_ref());
*type_
},
// plugin has been used and the enum has already been registered as a dynamic type.
Some(#registration_status_type(_, type_)) => *type_
}
}
/// Depending on the plugin lifecycle state and on the registration status of the enum:
/// If plugin is used (and has loaded the implementation) for the first time, postpones the registration and stores a weak reference on the plugin.
/// If plugin is reused (and has reloaded the implementation) and the enum has been already registered as a dynamic type, reregisters it.
/// An enum can be reregistered several times as a dynamic type.
/// If plugin is reused (and has reloaded the implementation) and the enum has not been registered yet as a dynamic type, do nothing.
#[inline]
pub fn on_implementation_load(type_plugin: &#plugin_ty) -> bool {
let mut registration_status = #registration_status.lock().unwrap();
match ::std::ops::DerefMut::deref_mut(&mut registration_status) {
// plugin has never been used (this is the first time), so postpones registration of the enum as a dynamic type on the first use.
None => {
*registration_status = Some(#registration_status_type(#crate_ident::clone::Downgrade::downgrade(type_plugin), #crate_ident::Type::INVALID));
true
},
// plugin has been used at least one time and the enum has been registered as a dynamic type at least one time, so re-registers it.
Some(#registration_status_type(_, type_)) if type_.is_valid() => {
*type_ = <#plugin_ty as glib::prelude::DynamicObjectRegisterExt>::register_dynamic_enum(type_plugin, #gtype_name, #enum_values_array.as_ref());
type_.is_valid()
},
// plugin has been used at least one time but the enum has not been registered yet as a dynamic type, so keeps postponed registration.
Some(_) => {
true
}
}
}
/// Depending on the plugin lifecycle state and on the registration status of the enum:
/// If plugin has been used (or reused) but the enum has not been registered yet as a dynamic type, cancels the postponed registration by deleting the weak reference on the plugin.
/// Else do nothing.
#[inline]
pub fn on_implementation_unload(type_plugin_: &#plugin_ty) -> bool {
let mut registration_status = #registration_status.lock().unwrap();
match ::std::ops::DerefMut::deref_mut(&mut registration_status) {
// plugin has never been used, so unload implementation is unexpected.
None => false,
// plugin has been used at least one time and the enum has been registered as a dynamic type at least one time.
Some(#registration_status_type(_, type_)) if type_.is_valid() => true,
// plugin has been used at least one time but the enum has not been registered yet as a dynamic type, so cancels the postponed registration.
Some(_) => {
*registration_status = None;
true
}
}
}
}
}
} else {
// registers immediately the enum as a dynamic type.
// name of the static variable to store the GLib type.
let gtype_status = format_ident!("{}_G_TYPE", name.to_string().to_shouty_snake_case());
quote! {
/// The GLib type which can be safely shared between threads.
static #gtype_status: ::std::sync::atomic::AtomicUsize = ::std::sync::atomic::AtomicUsize::new(#crate_ident::gobject_ffi::G_TYPE_INVALID);
impl #name {
/// Do nothing as the enum has been registered on implementation load.
#[inline]
fn register_enum() -> #crate_ident::Type {
let gtype = #gtype_status.load(::std::sync::atomic::Ordering::Acquire);
unsafe { <#crate_ident::Type as #crate_ident::translate::FromGlib<#crate_ident::ffi::GType>>::from_glib(gtype) }
}
/// Registers the enum as a dynamic type within the plugin.
/// The enum can be registered several times as a dynamic type.
#[inline]
pub fn on_implementation_load(type_plugin: &#plugin_ty) -> bool {
static VALUES: #enum_values;
let gtype = #crate_ident::translate::IntoGlib::into_glib(<#plugin_ty as glib::prelude::DynamicObjectRegisterExt>::register_dynamic_enum(type_plugin, #gtype_name, VALUES.as_ref()));
#gtype_status.store(gtype, ::std::sync::atomic::Ordering::Release);
gtype != #crate_ident::gobject_ffi::G_TYPE_INVALID
}
/// Do nothing as enums registered as dynamic types are never unregistered.
#[inline]
pub fn on_implementation_unload(type_plugin_: &#plugin_ty) -> bool {
true
}
}
}
}
}