rust/crates/hir-def/src/lang_item.rs
2023-09-06 15:21:41 +02:00

446 lines
27 KiB
Rust

//! Collects lang items: items marked with `#[lang = "..."]` attribute.
//!
//! This attribute to tell the compiler about semi built-in std library
//! features, such as Fn family of traits.
use hir_expand::name::Name;
use rustc_hash::FxHashMap;
use syntax::SmolStr;
use triomphe::Arc;
use crate::{
db::DefDatabase, path::Path, AdtId, AssocItemId, AttrDefId, CrateId, EnumId, EnumVariantId,
FunctionId, ImplId, ModuleDefId, StaticId, StructId, TraitId, TypeAliasId, UnionId,
};
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum LangItemTarget {
EnumId(EnumId),
Function(FunctionId),
ImplDef(ImplId),
Static(StaticId),
Struct(StructId),
Union(UnionId),
TypeAlias(TypeAliasId),
Trait(TraitId),
EnumVariant(EnumVariantId),
}
impl LangItemTarget {
pub fn as_enum(self) -> Option<EnumId> {
match self {
LangItemTarget::EnumId(id) => Some(id),
_ => None,
}
}
pub fn as_function(self) -> Option<FunctionId> {
match self {
LangItemTarget::Function(id) => Some(id),
_ => None,
}
}
pub fn as_impl_def(self) -> Option<ImplId> {
match self {
LangItemTarget::ImplDef(id) => Some(id),
_ => None,
}
}
pub fn as_static(self) -> Option<StaticId> {
match self {
LangItemTarget::Static(id) => Some(id),
_ => None,
}
}
pub fn as_struct(self) -> Option<StructId> {
match self {
LangItemTarget::Struct(id) => Some(id),
_ => None,
}
}
pub fn as_trait(self) -> Option<TraitId> {
match self {
LangItemTarget::Trait(id) => Some(id),
_ => None,
}
}
pub fn as_enum_variant(self) -> Option<EnumVariantId> {
match self {
LangItemTarget::EnumVariant(id) => Some(id),
_ => None,
}
}
}
#[derive(Default, Debug, Clone, PartialEq, Eq)]
pub struct LangItems {
items: FxHashMap<LangItem, LangItemTarget>,
}
impl LangItems {
pub fn target(&self, item: LangItem) -> Option<LangItemTarget> {
self.items.get(&item).copied()
}
/// Salsa query. This will look for lang items in a specific crate.
pub(crate) fn crate_lang_items_query(db: &dyn DefDatabase, krate: CrateId) -> Arc<LangItems> {
let _p = profile::span("crate_lang_items_query");
let mut lang_items = LangItems::default();
let crate_def_map = db.crate_def_map(krate);
for (_, module_data) in crate_def_map.modules() {
for impl_def in module_data.scope.impls() {
lang_items.collect_lang_item(db, impl_def, LangItemTarget::ImplDef);
for assoc in db.impl_data(impl_def).items.iter().copied() {
match assoc {
AssocItemId::FunctionId(f) => {
lang_items.collect_lang_item(db, f, LangItemTarget::Function)
}
AssocItemId::TypeAliasId(t) => {
lang_items.collect_lang_item(db, t, LangItemTarget::TypeAlias)
}
AssocItemId::ConstId(_) => (),
}
}
}
for def in module_data.scope.declarations() {
match def {
ModuleDefId::TraitId(trait_) => {
lang_items.collect_lang_item(db, trait_, LangItemTarget::Trait);
db.trait_data(trait_).items.iter().for_each(|&(_, assoc_id)| {
if let AssocItemId::FunctionId(f) = assoc_id {
lang_items.collect_lang_item(db, f, LangItemTarget::Function);
}
});
}
ModuleDefId::AdtId(AdtId::EnumId(e)) => {
lang_items.collect_lang_item(db, e, LangItemTarget::EnumId);
db.enum_data(e).variants.iter().for_each(|(local_id, _)| {
lang_items.collect_lang_item(
db,
EnumVariantId { parent: e, local_id },
LangItemTarget::EnumVariant,
);
});
}
ModuleDefId::AdtId(AdtId::StructId(s)) => {
lang_items.collect_lang_item(db, s, LangItemTarget::Struct);
}
ModuleDefId::AdtId(AdtId::UnionId(u)) => {
lang_items.collect_lang_item(db, u, LangItemTarget::Union);
}
ModuleDefId::FunctionId(f) => {
lang_items.collect_lang_item(db, f, LangItemTarget::Function);
}
ModuleDefId::StaticId(s) => {
lang_items.collect_lang_item(db, s, LangItemTarget::Static);
}
ModuleDefId::TypeAliasId(t) => {
lang_items.collect_lang_item(db, t, LangItemTarget::TypeAlias);
}
_ => {}
}
}
}
Arc::new(lang_items)
}
/// Salsa query. Look for a lang item, starting from the specified crate and recursively
/// traversing its dependencies.
pub(crate) fn lang_item_query(
db: &dyn DefDatabase,
start_crate: CrateId,
item: LangItem,
) -> Option<LangItemTarget> {
let _p = profile::span("lang_item_query");
let lang_items = db.crate_lang_items(start_crate);
let start_crate_target = lang_items.items.get(&item);
if let Some(&target) = start_crate_target {
return Some(target);
}
db.crate_graph()[start_crate]
.dependencies
.iter()
.find_map(|dep| db.lang_item(dep.crate_id, item))
}
fn collect_lang_item<T>(
&mut self,
db: &dyn DefDatabase,
item: T,
constructor: fn(T) -> LangItemTarget,
) where
T: Into<AttrDefId> + Copy,
{
let _p = profile::span("collect_lang_item");
if let Some(lang_item) = db.lang_attr(item.into()) {
self.items.entry(lang_item).or_insert_with(|| constructor(item));
}
}
}
pub(crate) fn lang_attr_query(db: &dyn DefDatabase, item: AttrDefId) -> Option<LangItem> {
let attrs = db.attrs(item);
attrs.by_key("lang").string_value().and_then(|it| LangItem::from_str(&it))
}
pub enum GenericRequirement {
None,
Minimum(usize),
Exact(usize),
}
macro_rules! language_item_table {
(
$( $(#[$attr:meta])* $variant:ident, $module:ident :: $name:ident, $method:ident, $target:expr, $generics:expr; )*
) => {
/// A representation of all the valid language items in Rust.
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub enum LangItem {
$(
#[doc = concat!("The `", stringify!($name), "` lang item.")]
$(#[$attr])*
$variant,
)*
}
impl LangItem {
pub fn name(self) -> SmolStr {
match self {
$( LangItem::$variant => SmolStr::new(stringify!($name)), )*
}
}
/// Opposite of [`LangItem::name`]
pub fn from_str(name: &str) -> Option<Self> {
match name {
$( stringify!($name) => Some(LangItem::$variant), )*
_ => None,
}
}
}
}
}
impl LangItem {
/// Opposite of [`LangItem::name`]
pub fn from_name(name: &hir_expand::name::Name) -> Option<Self> {
Self::from_str(name.as_str()?)
}
pub fn path(&self, db: &dyn DefDatabase, start_crate: CrateId) -> Option<Path> {
let t = db.lang_item(start_crate, *self)?;
Some(Path::LangItem(t, None))
}
pub fn ty_rel_path(
&self,
db: &dyn DefDatabase,
start_crate: CrateId,
seg: Name,
) -> Option<Path> {
let t = db.lang_item(start_crate, *self)?;
Some(Path::LangItem(t, Some(seg)))
}
}
language_item_table! {
// Variant name, Name, Getter method name, Target Generic requirements;
Sized, sym::sized, sized_trait, Target::Trait, GenericRequirement::Exact(0);
Unsize, sym::unsize, unsize_trait, Target::Trait, GenericRequirement::Minimum(1);
/// Trait injected by `#[derive(PartialEq)]`, (i.e. "Partial EQ").
StructuralPeq, sym::structural_peq, structural_peq_trait, Target::Trait, GenericRequirement::None;
/// Trait injected by `#[derive(Eq)]`, (i.e. "Total EQ"; no, I will not apologize).
StructuralTeq, sym::structural_teq, structural_teq_trait, Target::Trait, GenericRequirement::None;
Copy, sym::copy, copy_trait, Target::Trait, GenericRequirement::Exact(0);
Clone, sym::clone, clone_trait, Target::Trait, GenericRequirement::None;
Sync, sym::sync, sync_trait, Target::Trait, GenericRequirement::Exact(0);
DiscriminantKind, sym::discriminant_kind, discriminant_kind_trait, Target::Trait, GenericRequirement::None;
/// The associated item of the [`DiscriminantKind`] trait.
Discriminant, sym::discriminant_type, discriminant_type, Target::AssocTy, GenericRequirement::None;
PointeeTrait, sym::pointee_trait, pointee_trait, Target::Trait, GenericRequirement::None;
Metadata, sym::metadata_type, metadata_type, Target::AssocTy, GenericRequirement::None;
DynMetadata, sym::dyn_metadata, dyn_metadata, Target::Struct, GenericRequirement::None;
Freeze, sym::freeze, freeze_trait, Target::Trait, GenericRequirement::Exact(0);
FnPtrTrait, sym::fn_ptr_trait, fn_ptr_trait, Target::Trait, GenericRequirement::Exact(0);
FnPtrAddr, sym::fn_ptr_addr, fn_ptr_addr, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
Drop, sym::drop, drop_trait, Target::Trait, GenericRequirement::None;
Destruct, sym::destruct, destruct_trait, Target::Trait, GenericRequirement::None;
CoerceUnsized, sym::coerce_unsized, coerce_unsized_trait, Target::Trait, GenericRequirement::Minimum(1);
DispatchFromDyn, sym::dispatch_from_dyn, dispatch_from_dyn_trait, Target::Trait, GenericRequirement::Minimum(1);
// language items relating to transmutability
TransmuteOpts, sym::transmute_opts, transmute_opts, Target::Struct, GenericRequirement::Exact(0);
TransmuteTrait, sym::transmute_trait, transmute_trait, Target::Trait, GenericRequirement::Exact(3);
Add, sym::add, add_trait, Target::Trait, GenericRequirement::Exact(1);
Sub, sym::sub, sub_trait, Target::Trait, GenericRequirement::Exact(1);
Mul, sym::mul, mul_trait, Target::Trait, GenericRequirement::Exact(1);
Div, sym::div, div_trait, Target::Trait, GenericRequirement::Exact(1);
Rem, sym::rem, rem_trait, Target::Trait, GenericRequirement::Exact(1);
Neg, sym::neg, neg_trait, Target::Trait, GenericRequirement::Exact(0);
Not, sym::not, not_trait, Target::Trait, GenericRequirement::Exact(0);
BitXor, sym::bitxor, bitxor_trait, Target::Trait, GenericRequirement::Exact(1);
BitAnd, sym::bitand, bitand_trait, Target::Trait, GenericRequirement::Exact(1);
BitOr, sym::bitor, bitor_trait, Target::Trait, GenericRequirement::Exact(1);
Shl, sym::shl, shl_trait, Target::Trait, GenericRequirement::Exact(1);
Shr, sym::shr, shr_trait, Target::Trait, GenericRequirement::Exact(1);
AddAssign, sym::add_assign, add_assign_trait, Target::Trait, GenericRequirement::Exact(1);
SubAssign, sym::sub_assign, sub_assign_trait, Target::Trait, GenericRequirement::Exact(1);
MulAssign, sym::mul_assign, mul_assign_trait, Target::Trait, GenericRequirement::Exact(1);
DivAssign, sym::div_assign, div_assign_trait, Target::Trait, GenericRequirement::Exact(1);
RemAssign, sym::rem_assign, rem_assign_trait, Target::Trait, GenericRequirement::Exact(1);
BitXorAssign, sym::bitxor_assign, bitxor_assign_trait, Target::Trait, GenericRequirement::Exact(1);
BitAndAssign, sym::bitand_assign, bitand_assign_trait, Target::Trait, GenericRequirement::Exact(1);
BitOrAssign, sym::bitor_assign, bitor_assign_trait, Target::Trait, GenericRequirement::Exact(1);
ShlAssign, sym::shl_assign, shl_assign_trait, Target::Trait, GenericRequirement::Exact(1);
ShrAssign, sym::shr_assign, shr_assign_trait, Target::Trait, GenericRequirement::Exact(1);
Index, sym::index, index_trait, Target::Trait, GenericRequirement::Exact(1);
IndexMut, sym::index_mut, index_mut_trait, Target::Trait, GenericRequirement::Exact(1);
UnsafeCell, sym::unsafe_cell, unsafe_cell_type, Target::Struct, GenericRequirement::None;
VaList, sym::va_list, va_list, Target::Struct, GenericRequirement::None;
Deref, sym::deref, deref_trait, Target::Trait, GenericRequirement::Exact(0);
DerefMut, sym::deref_mut, deref_mut_trait, Target::Trait, GenericRequirement::Exact(0);
DerefTarget, sym::deref_target, deref_target, Target::AssocTy, GenericRequirement::None;
Receiver, sym::receiver, receiver_trait, Target::Trait, GenericRequirement::None;
Fn, kw::fn, fn_trait, Target::Trait, GenericRequirement::Exact(1);
FnMut, sym::fn_mut, fn_mut_trait, Target::Trait, GenericRequirement::Exact(1);
FnOnce, sym::fn_once, fn_once_trait, Target::Trait, GenericRequirement::Exact(1);
FnOnceOutput, sym::fn_once_output, fn_once_output, Target::AssocTy, GenericRequirement::None;
Future, sym::future_trait, future_trait, Target::Trait, GenericRequirement::Exact(0);
GeneratorState, sym::generator_state, gen_state, Target::Enum, GenericRequirement::None;
Generator, sym::generator, gen_trait, Target::Trait, GenericRequirement::Minimum(1);
Unpin, sym::unpin, unpin_trait, Target::Trait, GenericRequirement::None;
Pin, sym::pin, pin_type, Target::Struct, GenericRequirement::None;
PartialEq, sym::eq, eq_trait, Target::Trait, GenericRequirement::Exact(1);
PartialOrd, sym::partial_ord, partial_ord_trait, Target::Trait, GenericRequirement::Exact(1);
CVoid, sym::c_void, c_void, Target::Enum, GenericRequirement::None;
// A number of panic-related lang items. The `panic` item corresponds to divide-by-zero and
// various panic cases with `match`. The `panic_bounds_check` item is for indexing arrays.
//
// The `begin_unwind` lang item has a predefined symbol name and is sort of a "weak lang item"
// in the sense that a crate is not required to have it defined to use it, but a final product
// is required to define it somewhere. Additionally, there are restrictions on crates that use
// a weak lang item, but do not have it defined.
Panic, sym::panic, panic_fn, Target::Fn, GenericRequirement::Exact(0);
PanicNounwind, sym::panic_nounwind, panic_nounwind, Target::Fn, GenericRequirement::Exact(0);
PanicFmt, sym::panic_fmt, panic_fmt, Target::Fn, GenericRequirement::None;
PanicDisplay, sym::panic_display, panic_display, Target::Fn, GenericRequirement::None;
ConstPanicFmt, sym::const_panic_fmt, const_panic_fmt, Target::Fn, GenericRequirement::None;
PanicBoundsCheck, sym::panic_bounds_check, panic_bounds_check_fn, Target::Fn, GenericRequirement::Exact(0);
PanicMisalignedPointerDereference, sym::panic_misaligned_pointer_dereference, panic_misaligned_pointer_dereference_fn, Target::Fn, GenericRequirement::Exact(0);
PanicInfo, sym::panic_info, panic_info, Target::Struct, GenericRequirement::None;
PanicLocation, sym::panic_location, panic_location, Target::Struct, GenericRequirement::None;
PanicImpl, sym::panic_impl, panic_impl, Target::Fn, GenericRequirement::None;
PanicCannotUnwind, sym::panic_cannot_unwind, panic_cannot_unwind, Target::Fn, GenericRequirement::Exact(0);
/// libstd panic entry point. Necessary for const eval to be able to catch it
BeginPanic, sym::begin_panic, begin_panic_fn, Target::Fn, GenericRequirement::None;
// Lang items needed for `format_args!()`.
FormatAlignment, sym::format_alignment, format_alignment, Target::Enum, GenericRequirement::None;
FormatArgument, sym::format_argument, format_argument, Target::Struct, GenericRequirement::None;
FormatArguments, sym::format_arguments, format_arguments, Target::Struct, GenericRequirement::None;
FormatCount, sym::format_count, format_count, Target::Enum, GenericRequirement::None;
FormatPlaceholder, sym::format_placeholder, format_placeholder, Target::Struct, GenericRequirement::None;
FormatUnsafeArg, sym::format_unsafe_arg, format_unsafe_arg, Target::Struct, GenericRequirement::None;
ExchangeMalloc, sym::exchange_malloc, exchange_malloc_fn, Target::Fn, GenericRequirement::None;
BoxFree, sym::box_free, box_free_fn, Target::Fn, GenericRequirement::Minimum(1);
DropInPlace, sym::drop_in_place, drop_in_place_fn, Target::Fn, GenericRequirement::Minimum(1);
AllocLayout, sym::alloc_layout, alloc_layout, Target::Struct, GenericRequirement::None;
Start, sym::start, start_fn, Target::Fn, GenericRequirement::Exact(1);
EhPersonality, sym::eh_personality, eh_personality, Target::Fn, GenericRequirement::None;
EhCatchTypeinfo, sym::eh_catch_typeinfo, eh_catch_typeinfo, Target::Static, GenericRequirement::None;
OwnedBox, sym::owned_box, owned_box, Target::Struct, GenericRequirement::Minimum(1);
PhantomData, sym::phantom_data, phantom_data, Target::Struct, GenericRequirement::Exact(1);
ManuallyDrop, sym::manually_drop, manually_drop, Target::Struct, GenericRequirement::None;
MaybeUninit, sym::maybe_uninit, maybe_uninit, Target::Union, GenericRequirement::None;
/// Align offset for stride != 1; must not panic.
AlignOffset, sym::align_offset, align_offset_fn, Target::Fn, GenericRequirement::None;
Termination, sym::termination, termination, Target::Trait, GenericRequirement::None;
Try, sym::Try, try_trait, Target::Trait, GenericRequirement::None;
Tuple, sym::tuple_trait, tuple_trait, Target::Trait, GenericRequirement::Exact(0);
SliceLen, sym::slice_len_fn, slice_len_fn, Target::Method(MethodKind::Inherent), GenericRequirement::None;
// Language items from AST lowering
TryTraitFromResidual, sym::from_residual, from_residual_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
TryTraitFromOutput, sym::from_output, from_output_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
TryTraitBranch, sym::branch, branch_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
TryTraitFromYeet, sym::from_yeet, from_yeet_fn, Target::Fn, GenericRequirement::None;
PointerLike, sym::pointer_like, pointer_like, Target::Trait, GenericRequirement::Exact(0);
ConstParamTy, sym::const_param_ty, const_param_ty_trait, Target::Trait, GenericRequirement::Exact(0);
Poll, sym::Poll, poll, Target::Enum, GenericRequirement::None;
PollReady, sym::Ready, poll_ready_variant, Target::Variant, GenericRequirement::None;
PollPending, sym::Pending, poll_pending_variant, Target::Variant, GenericRequirement::None;
// FIXME(swatinem): the following lang items are used for async lowering and
// should become obsolete eventually.
ResumeTy, sym::ResumeTy, resume_ty, Target::Struct, GenericRequirement::None;
GetContext, sym::get_context, get_context_fn, Target::Fn, GenericRequirement::None;
Context, sym::Context, context, Target::Struct, GenericRequirement::None;
FuturePoll, sym::poll, future_poll_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
Option, sym::Option, option_type, Target::Enum, GenericRequirement::None;
OptionSome, sym::Some, option_some_variant, Target::Variant, GenericRequirement::None;
OptionNone, sym::None, option_none_variant, Target::Variant, GenericRequirement::None;
ResultOk, sym::Ok, result_ok_variant, Target::Variant, GenericRequirement::None;
ResultErr, sym::Err, result_err_variant, Target::Variant, GenericRequirement::None;
ControlFlowContinue, sym::Continue, cf_continue_variant, Target::Variant, GenericRequirement::None;
ControlFlowBreak, sym::Break, cf_break_variant, Target::Variant, GenericRequirement::None;
IntoFutureIntoFuture, sym::into_future, into_future_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
IntoIterIntoIter, sym::into_iter, into_iter_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
IteratorNext, sym::next, next_fn, Target::Method(MethodKind::Trait { body: false}), GenericRequirement::None;
PinNewUnchecked, sym::new_unchecked, new_unchecked_fn, Target::Method(MethodKind::Inherent), GenericRequirement::None;
RangeFrom, sym::RangeFrom, range_from_struct, Target::Struct, GenericRequirement::None;
RangeFull, sym::RangeFull, range_full_struct, Target::Struct, GenericRequirement::None;
RangeInclusiveStruct, sym::RangeInclusive, range_inclusive_struct, Target::Struct, GenericRequirement::None;
RangeInclusiveNew, sym::range_inclusive_new, range_inclusive_new_method, Target::Method(MethodKind::Inherent), GenericRequirement::None;
Range, sym::Range, range_struct, Target::Struct, GenericRequirement::None;
RangeToInclusive, sym::RangeToInclusive, range_to_inclusive_struct, Target::Struct, GenericRequirement::None;
RangeTo, sym::RangeTo, range_to_struct, Target::Struct, GenericRequirement::None;
String, sym::String, string, Target::Struct, GenericRequirement::None;
CStr, sym::CStr, c_str, Target::Struct, GenericRequirement::None;
}