rust/crates/hir/src/semantics.rs
2023-11-28 10:56:25 +01:00

1499 lines
58 KiB
Rust

//! See `Semantics`.
mod source_to_def;
use std::{cell::RefCell, fmt, iter, mem, ops};
use base_db::{FileId, FileRange};
use either::Either;
use hir_def::{
hir::Expr,
lower::LowerCtx,
macro_id_to_def_id,
nameres::MacroSubNs,
resolver::{self, HasResolver, Resolver, TypeNs},
type_ref::Mutability,
AsMacroCall, DefWithBodyId, FieldId, FunctionId, MacroId, TraitId, VariantId,
};
use hir_expand::{
db::ExpandDatabase, files::InRealFile, name::AsName, ExpansionInfo, HirFileIdExt, MacroCallId,
MacroFileId, MacroFileIdExt,
};
use itertools::Itertools;
use rustc_hash::{FxHashMap, FxHashSet};
use smallvec::{smallvec, SmallVec};
use stdx::TupleExt;
use syntax::{
algo::skip_trivia_token,
ast::{self, HasAttrs as _, HasGenericParams, HasLoopBody},
match_ast, AstNode, Direction, SyntaxKind, SyntaxNode, SyntaxNodePtr, SyntaxToken, TextSize,
};
use crate::{
db::HirDatabase,
semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
source_analyzer::{resolve_hir_path, SourceAnalyzer},
Access, Adjust, Adjustment, AutoBorrow, BindingMode, BuiltinAttr, Callable, ConstParam, Crate,
DeriveHelper, Field, Function, HasSource, HirFileId, Impl, InFile, Label, LifetimeParam, Local,
Macro, Module, ModuleDef, Name, OverloadedDeref, Path, ScopeDef, ToolModule, Trait, Type,
TypeAlias, TypeParam, VariantDef,
};
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum PathResolution {
/// An item
Def(ModuleDef),
/// A local binding (only value namespace)
Local(Local),
/// A type parameter
TypeParam(TypeParam),
/// A const parameter
ConstParam(ConstParam),
SelfType(Impl),
BuiltinAttr(BuiltinAttr),
ToolModule(ToolModule),
DeriveHelper(DeriveHelper),
}
impl PathResolution {
pub(crate) fn in_type_ns(&self) -> Option<TypeNs> {
match self {
PathResolution::Def(ModuleDef::Adt(adt)) => Some(TypeNs::AdtId((*adt).into())),
PathResolution::Def(ModuleDef::BuiltinType(builtin)) => {
Some(TypeNs::BuiltinType((*builtin).into()))
}
PathResolution::Def(
ModuleDef::Const(_)
| ModuleDef::Variant(_)
| ModuleDef::Macro(_)
| ModuleDef::Function(_)
| ModuleDef::Module(_)
| ModuleDef::Static(_)
| ModuleDef::Trait(_)
| ModuleDef::TraitAlias(_),
) => None,
PathResolution::Def(ModuleDef::TypeAlias(alias)) => {
Some(TypeNs::TypeAliasId((*alias).into()))
}
PathResolution::BuiltinAttr(_)
| PathResolution::ToolModule(_)
| PathResolution::Local(_)
| PathResolution::DeriveHelper(_)
| PathResolution::ConstParam(_) => None,
PathResolution::TypeParam(param) => Some(TypeNs::GenericParam((*param).into())),
PathResolution::SelfType(impl_def) => Some(TypeNs::SelfType((*impl_def).into())),
}
}
}
#[derive(Debug)]
pub struct TypeInfo {
/// The original type of the expression or pattern.
pub original: Type,
/// The adjusted type, if an adjustment happened.
pub adjusted: Option<Type>,
}
impl TypeInfo {
pub fn original(self) -> Type {
self.original
}
pub fn has_adjustment(&self) -> bool {
self.adjusted.is_some()
}
/// The adjusted type, or the original in case no adjustments occurred.
pub fn adjusted(self) -> Type {
self.adjusted.unwrap_or(self.original)
}
}
/// Primary API to get semantic information, like types, from syntax trees.
pub struct Semantics<'db, DB> {
pub db: &'db DB,
imp: SemanticsImpl<'db>,
}
pub struct SemanticsImpl<'db> {
pub db: &'db dyn HirDatabase,
s2d_cache: RefCell<SourceToDefCache>,
expansion_info_cache: RefCell<FxHashMap<MacroFileId, ExpansionInfo>>,
/// Rootnode to HirFileId cache
cache: RefCell<FxHashMap<SyntaxNode, HirFileId>>,
/// MacroCall to its expansion's MacroFileId cache
macro_call_cache: RefCell<FxHashMap<InFile<ast::MacroCall>, MacroFileId>>,
}
impl<DB> fmt::Debug for Semantics<'_, DB> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "Semantics {{ ... }}")
}
}
impl<'db, DB> ops::Deref for Semantics<'db, DB> {
type Target = SemanticsImpl<'db>;
fn deref(&self) -> &Self::Target {
&self.imp
}
}
impl<'db, DB: HirDatabase> Semantics<'db, DB> {
pub fn new(db: &DB) -> Semantics<'_, DB> {
let impl_ = SemanticsImpl::new(db);
Semantics { db, imp: impl_ }
}
pub fn hir_file_for(&self, syntax_node: &SyntaxNode) -> HirFileId {
self.imp.find_file(syntax_node).file_id
}
pub fn token_ancestors_with_macros(
&self,
token: SyntaxToken,
) -> impl Iterator<Item = SyntaxNode> + '_ {
token.parent().into_iter().flat_map(move |it| self.ancestors_with_macros(it))
}
/// Find an AstNode by offset inside SyntaxNode, if it is inside *Macrofile*,
/// search up until it is of the target AstNode type
pub fn find_node_at_offset_with_macros<N: AstNode>(
&self,
node: &SyntaxNode,
offset: TextSize,
) -> Option<N> {
self.imp.ancestors_at_offset_with_macros(node, offset).find_map(N::cast)
}
/// Find an AstNode by offset inside SyntaxNode, if it is inside *MacroCall*,
/// descend it and find again
pub fn find_node_at_offset_with_descend<N: AstNode>(
&self,
node: &SyntaxNode,
offset: TextSize,
) -> Option<N> {
self.imp.descend_node_at_offset(node, offset).flatten().find_map(N::cast)
}
/// Find an AstNode by offset inside SyntaxNode, if it is inside *MacroCall*,
/// descend it and find again
pub fn find_nodes_at_offset_with_descend<'slf, N: AstNode + 'slf>(
&'slf self,
node: &SyntaxNode,
offset: TextSize,
) -> impl Iterator<Item = N> + 'slf {
self.imp.descend_node_at_offset(node, offset).filter_map(|mut it| it.find_map(N::cast))
}
pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
self.imp.resolve_method_call(call).map(Function::from)
}
/// Attempts to resolve this call expression as a method call falling back to resolving it as a field.
pub fn resolve_method_call_field_fallback(
&self,
call: &ast::MethodCallExpr,
) -> Option<Either<Function, Field>> {
self.imp
.resolve_method_call_fallback(call)
.map(|it| it.map_left(Function::from).map_right(Field::from))
}
pub fn resolve_await_to_poll(&self, await_expr: &ast::AwaitExpr) -> Option<Function> {
self.imp.resolve_await_to_poll(await_expr).map(Function::from)
}
pub fn resolve_prefix_expr(&self, prefix_expr: &ast::PrefixExpr) -> Option<Function> {
self.imp.resolve_prefix_expr(prefix_expr).map(Function::from)
}
pub fn resolve_index_expr(&self, index_expr: &ast::IndexExpr) -> Option<Function> {
self.imp.resolve_index_expr(index_expr).map(Function::from)
}
pub fn resolve_bin_expr(&self, bin_expr: &ast::BinExpr) -> Option<Function> {
self.imp.resolve_bin_expr(bin_expr).map(Function::from)
}
pub fn resolve_try_expr(&self, try_expr: &ast::TryExpr) -> Option<Function> {
self.imp.resolve_try_expr(try_expr).map(Function::from)
}
pub fn resolve_variant(&self, record_lit: ast::RecordExpr) -> Option<VariantDef> {
self.imp.resolve_variant(record_lit).map(VariantDef::from)
}
pub fn to_module_def(&self, file: FileId) -> Option<Module> {
self.imp.to_module_def(file).next()
}
pub fn to_module_defs(&self, file: FileId) -> impl Iterator<Item = Module> {
self.imp.to_module_def(file)
}
}
impl<'db> SemanticsImpl<'db> {
fn new(db: &'db dyn HirDatabase) -> Self {
SemanticsImpl {
db,
s2d_cache: Default::default(),
cache: Default::default(),
expansion_info_cache: Default::default(),
macro_call_cache: Default::default(),
}
}
pub fn parse(&self, file_id: FileId) -> ast::SourceFile {
let tree = self.db.parse(file_id).tree();
self.cache(tree.syntax().clone(), file_id.into());
tree
}
pub fn parse_or_expand(&self, file_id: HirFileId) -> SyntaxNode {
let node = self.db.parse_or_expand(file_id);
self.cache(node.clone(), file_id);
node
}
pub fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
let sa = self.analyze_no_infer(macro_call.syntax())?;
let file_id = sa.expand(self.db, InFile::new(sa.file_id, macro_call))?;
let node = self.parse_or_expand(file_id.into());
Some(node)
}
/// If `item` has an attribute macro attached to it, expands it.
pub fn expand_attr_macro(&self, item: &ast::Item) -> Option<SyntaxNode> {
let src = self.wrap_node_infile(item.clone());
let macro_call_id = self.with_ctx(|ctx| ctx.item_to_macro_call(src))?;
Some(self.parse_or_expand(macro_call_id.as_file()))
}
pub fn expand_derive_as_pseudo_attr_macro(&self, attr: &ast::Attr) -> Option<SyntaxNode> {
let adt = attr.syntax().parent().and_then(ast::Adt::cast)?;
let src = self.wrap_node_infile(attr.clone());
let call_id = self.with_ctx(|ctx| {
ctx.attr_to_derive_macro_call(src.with_value(&adt), src).map(|(_, it, _)| it)
})?;
Some(self.parse_or_expand(call_id.as_file()))
}
pub fn resolve_derive_macro(&self, attr: &ast::Attr) -> Option<Vec<Option<Macro>>> {
let calls = self.derive_macro_calls(attr)?;
self.with_ctx(|ctx| {
Some(
calls
.into_iter()
.map(|call| {
macro_call_to_macro_id(ctx, self.db.upcast(), call?).map(|id| Macro { id })
})
.collect(),
)
})
}
pub fn expand_derive_macro(&self, attr: &ast::Attr) -> Option<Vec<SyntaxNode>> {
let res: Vec<_> = self
.derive_macro_calls(attr)?
.into_iter()
.flat_map(|call| {
let file_id = call?.as_file();
let node = self.db.parse_or_expand(file_id);
self.cache(node.clone(), file_id);
Some(node)
})
.collect();
Some(res)
}
fn derive_macro_calls(&self, attr: &ast::Attr) -> Option<Vec<Option<MacroCallId>>> {
let adt = attr.syntax().parent().and_then(ast::Adt::cast)?;
let file_id = self.find_file(adt.syntax()).file_id;
let adt = InFile::new(file_id, &adt);
let src = InFile::new(file_id, attr.clone());
self.with_ctx(|ctx| {
let (.., res) = ctx.attr_to_derive_macro_call(adt, src)?;
Some(res.to_vec())
})
}
pub fn is_derive_annotated(&self, adt: &ast::Adt) -> bool {
let file_id = self.find_file(adt.syntax()).file_id;
let adt = InFile::new(file_id, adt);
self.with_ctx(|ctx| ctx.has_derives(adt))
}
pub fn is_attr_macro_call(&self, item: &ast::Item) -> bool {
let file_id = self.find_file(item.syntax()).file_id;
let src = InFile::new(file_id, item.clone());
self.with_ctx(|ctx| ctx.item_to_macro_call(src).is_some())
}
/// Expand the macro call with a different token tree, mapping the `token_to_map` down into the
/// expansion. `token_to_map` should be a token from the `speculative args` node.
pub fn speculative_expand(
&self,
actual_macro_call: &ast::MacroCall,
speculative_args: &ast::TokenTree,
token_to_map: SyntaxToken,
) -> Option<(SyntaxNode, SyntaxToken)> {
let SourceAnalyzer { file_id, resolver, .. } =
self.analyze_no_infer(actual_macro_call.syntax())?;
let macro_call = InFile::new(file_id, actual_macro_call);
let krate = resolver.krate();
let macro_call_id = macro_call.as_call_id(self.db.upcast(), krate, |path| {
resolver
.resolve_path_as_macro(self.db.upcast(), &path, Some(MacroSubNs::Bang))
.map(|(it, _)| macro_id_to_def_id(self.db.upcast(), it))
})?;
hir_expand::db::expand_speculative(
self.db.upcast(),
macro_call_id,
speculative_args.syntax(),
token_to_map,
)
}
/// Expand the macro call with a different item as the input, mapping the `token_to_map` down into the
/// expansion. `token_to_map` should be a token from the `speculative args` node.
pub fn speculative_expand_attr_macro(
&self,
actual_macro_call: &ast::Item,
speculative_args: &ast::Item,
token_to_map: SyntaxToken,
) -> Option<(SyntaxNode, SyntaxToken)> {
let macro_call = self.wrap_node_infile(actual_macro_call.clone());
let macro_call_id = self.with_ctx(|ctx| ctx.item_to_macro_call(macro_call))?;
hir_expand::db::expand_speculative(
self.db.upcast(),
macro_call_id,
speculative_args.syntax(),
token_to_map,
)
}
pub fn speculative_expand_derive_as_pseudo_attr_macro(
&self,
actual_macro_call: &ast::Attr,
speculative_args: &ast::Attr,
token_to_map: SyntaxToken,
) -> Option<(SyntaxNode, SyntaxToken)> {
let attr = self.wrap_node_infile(actual_macro_call.clone());
let adt = actual_macro_call.syntax().parent().and_then(ast::Adt::cast)?;
let macro_call_id = self.with_ctx(|ctx| {
ctx.attr_to_derive_macro_call(attr.with_value(&adt), attr).map(|(_, it, _)| it)
})?;
hir_expand::db::expand_speculative(
self.db.upcast(),
macro_call_id,
speculative_args.syntax(),
token_to_map,
)
}
/// Maps a node down by mapping its first and last token down.
pub fn descend_node_into_attributes<N: AstNode>(&self, node: N) -> SmallVec<[N; 1]> {
// This might not be the correct way to do this, but it works for now
let mut res = smallvec![];
let tokens = (|| {
let first = skip_trivia_token(node.syntax().first_token()?, Direction::Next)?;
let last = skip_trivia_token(node.syntax().last_token()?, Direction::Prev)?;
Some((first, last))
})();
let (first, last) = match tokens {
Some(it) => it,
None => return res,
};
if first == last {
self.descend_into_macros_impl(first, 0.into(), &mut |InFile { value, .. }| {
if let Some(node) = value.parent_ancestors().find_map(N::cast) {
res.push(node)
}
false
});
} else {
// Descend first and last token, then zip them to look for the node they belong to
let mut scratch: SmallVec<[_; 1]> = smallvec![];
self.descend_into_macros_impl(first, 0.into(), &mut |token| {
scratch.push(token);
false
});
let mut scratch = scratch.into_iter();
self.descend_into_macros_impl(
last,
0.into(),
&mut |InFile { value: last, file_id: last_fid }| {
if let Some(InFile { value: first, file_id: first_fid }) = scratch.next() {
if first_fid == last_fid {
if let Some(p) = first.parent() {
let range = first.text_range().cover(last.text_range());
let node = find_root(&p)
.covering_element(range)
.ancestors()
.take_while(|it| it.text_range() == range)
.find_map(N::cast);
if let Some(node) = node {
res.push(node);
}
}
}
}
false
},
);
}
res
}
/// Descend the token into its macro call if it is part of one, returning the tokens in the
/// expansion that it is associated with. If `offset` points into the token's range, it will
/// be considered for the mapping in case of inline format args.
pub fn descend_into_macros(
&self,
token: SyntaxToken,
offset: TextSize,
) -> SmallVec<[SyntaxToken; 1]> {
let mut res = smallvec![];
self.descend_into_macros_impl(token, offset, &mut |InFile { value, .. }| {
res.push(value);
false
});
res
}
/// Descend the token into macrocalls to all its mapped counterparts that have the same text as the input token.
///
/// Returns the original non descended token if none of the mapped counterparts have the same text.
pub fn descend_into_macros_with_same_text(
&self,
token: SyntaxToken,
offset: TextSize,
) -> SmallVec<[SyntaxToken; 1]> {
let text = token.text();
let mut res = smallvec![];
self.descend_into_macros_impl(token.clone(), offset, &mut |InFile { value, .. }| {
if value.text() == text {
res.push(value);
}
false
});
if res.is_empty() {
res.push(token);
}
res
}
pub fn descend_into_macros_with_kind_preference(
&self,
token: SyntaxToken,
offset: TextSize,
) -> SyntaxToken {
let fetch_kind = |token: &SyntaxToken| match token.parent() {
Some(node) => match node.kind() {
kind @ (SyntaxKind::NAME | SyntaxKind::NAME_REF) => {
node.parent().map_or(kind, |it| it.kind())
}
_ => token.kind(),
},
None => token.kind(),
};
let preferred_kind = fetch_kind(&token);
let mut res = None;
self.descend_into_macros_impl(token.clone(), offset, &mut |InFile { value, .. }| {
if fetch_kind(&value) == preferred_kind {
res = Some(value);
true
} else {
if let None = res {
res = Some(value)
}
false
}
});
res.unwrap_or(token)
}
/// Descend the token into its macro call if it is part of one, returning the token in the
/// expansion that it is associated with. If `offset` points into the token's range, it will
/// be considered for the mapping in case of inline format args.
pub fn descend_into_macros_single(&self, token: SyntaxToken, offset: TextSize) -> SyntaxToken {
let mut res = token.clone();
self.descend_into_macros_impl(token, offset, &mut |InFile { value, .. }| {
res = value;
true
});
res
}
// FIXME: should only take real file inputs for simplicity
fn descend_into_macros_impl(
&self,
token: SyntaxToken,
// FIXME: We might want this to be Option<TextSize> to be able to opt out of subrange
// mapping, specifically for node downmapping
_offset: TextSize,
f: &mut dyn FnMut(InFile<SyntaxToken>) -> bool,
) {
// FIXME: Clean this up
let _p = profile::span("descend_into_macros");
let sa = match token.parent().and_then(|parent| self.analyze_no_infer(&parent)) {
Some(it) => it,
None => return,
};
let mut cache = self.expansion_info_cache.borrow_mut();
let mut mcache = self.macro_call_cache.borrow_mut();
let span = match sa.file_id.repr() {
base_db::span::HirFileIdRepr::FileId(file_id) => {
self.db.real_span_map(file_id).span_for_range(token.text_range())
}
base_db::span::HirFileIdRepr::MacroFile(macro_file) => cache
.entry(macro_file)
.or_insert_with(|| macro_file.expansion_info(self.db.upcast()))
.exp_map
.span_at(token.text_range().start()),
};
// fetch span information of token in real file, then use that look through expansions of
// calls the token is in and afterwards recursively with the same span.
// what about things where spans change? Due to being joined etc, that is we don't find the
// exact span anymore?
let def_map = sa.resolver.def_map();
let mut stack: SmallVec<[_; 4]> = smallvec![InFile::new(sa.file_id, token)];
let mut process_expansion_for_token =
|stack: &mut SmallVec<_>, macro_file, _token: InFile<&_>| {
let expansion_info = cache
.entry(macro_file)
.or_insert_with(|| macro_file.expansion_info(self.db.upcast()));
{
let InFile { file_id, value } = expansion_info.expanded();
self.cache(value, file_id);
}
let mapped_tokens = expansion_info.map_range_down(span, None)?;
let len = stack.len();
// requeue the tokens we got from mapping our current token down
stack.extend(mapped_tokens);
// if the length changed we have found a mapping for the token
(stack.len() != len).then_some(())
};
// Remap the next token in the queue into a macro call its in, if it is not being remapped
// either due to not being in a macro-call or because its unused push it into the result vec,
// otherwise push the remapped tokens back into the queue as they can potentially be remapped again.
while let Some(token) = stack.pop() {
let was_not_remapped = (|| {
// First expand into attribute invocations
let containing_attribute_macro_call = self.with_ctx(|ctx| {
token.value.parent_ancestors().filter_map(ast::Item::cast).find_map(|item| {
if item.attrs().next().is_none() {
// Don't force populate the dyn cache for items that don't have an attribute anyways
return None;
}
Some(ctx.item_to_macro_call(token.with_value(item.clone()))?)
})
});
if let Some(call_id) = containing_attribute_macro_call {
let file_id = call_id.as_macro_file();
return process_expansion_for_token(&mut stack, file_id, token.as_ref());
}
// Then check for token trees, that means we are either in a function-like macro or
// secondary attribute inputs
let tt = token.value.parent_ancestors().map_while(ast::TokenTree::cast).last()?;
let parent = tt.syntax().parent()?;
if tt.left_delimiter_token().map_or(false, |it| it == token.value) {
return None;
}
if tt.right_delimiter_token().map_or(false, |it| it == token.value) {
return None;
}
if let Some(macro_call) = ast::MacroCall::cast(parent.clone()) {
let mcall: hir_expand::files::InFileWrapper<HirFileId, ast::MacroCall> =
token.with_value(macro_call);
let file_id = match mcache.get(&mcall) {
Some(&it) => it,
None => {
let it = sa.expand(self.db, mcall.as_ref())?;
mcache.insert(mcall, it);
it
}
};
process_expansion_for_token(&mut stack, file_id, token.as_ref())
} else if let Some(meta) = ast::Meta::cast(parent) {
// attribute we failed expansion for earlier, this might be a derive invocation
// or derive helper attribute
let attr = meta.parent_attr()?;
let adt = if let Some(adt) = attr.syntax().parent().and_then(ast::Adt::cast) {
// this might be a derive, or a derive helper on an ADT
let derive_call = self.with_ctx(|ctx| {
// so try downmapping the token into the pseudo derive expansion
// see [hir_expand::builtin_attr_macro] for how the pseudo derive expansion works
ctx.attr_to_derive_macro_call(
token.with_value(&adt),
token.with_value(attr.clone()),
)
.map(|(_, call_id, _)| call_id)
});
match derive_call {
Some(call_id) => {
// resolved to a derive
let file_id = call_id.as_macro_file();
return process_expansion_for_token(
&mut stack,
file_id,
token.as_ref(),
);
}
None => Some(adt),
}
} else {
// Otherwise this could be a derive helper on a variant or field
if let Some(field) = attr.syntax().parent().and_then(ast::RecordField::cast)
{
field.syntax().ancestors().take(4).find_map(ast::Adt::cast)
} else if let Some(field) =
attr.syntax().parent().and_then(ast::TupleField::cast)
{
field.syntax().ancestors().take(4).find_map(ast::Adt::cast)
} else if let Some(variant) =
attr.syntax().parent().and_then(ast::Variant::cast)
{
variant.syntax().ancestors().nth(2).and_then(ast::Adt::cast)
} else {
None
}
}?;
if !self.with_ctx(|ctx| ctx.has_derives(InFile::new(token.file_id, &adt))) {
return None;
}
// Not an attribute, nor a derive, so it's either a builtin or a derive helper
// Try to resolve to a derive helper and downmap
let attr_name = attr.path().and_then(|it| it.as_single_name_ref())?.as_name();
let id = self.db.ast_id_map(token.file_id).ast_id(&adt);
let helpers =
def_map.derive_helpers_in_scope(InFile::new(token.file_id, id))?;
let mut res = None;
for (.., derive) in helpers.iter().filter(|(helper, ..)| *helper == attr_name) {
res = res.or(process_expansion_for_token(
&mut stack,
derive.as_macro_file(),
token.as_ref(),
));
}
res
} else {
None
}
})()
.is_none();
if was_not_remapped && f(token) {
break;
}
}
}
// Note this return type is deliberate as [`find_nodes_at_offset_with_descend`] wants to stop
// traversing the inner iterator when it finds a node.
// The outer iterator is over the tokens descendants
// The inner iterator is the ancestors of a descendant
fn descend_node_at_offset(
&self,
node: &SyntaxNode,
offset: TextSize,
) -> impl Iterator<Item = impl Iterator<Item = SyntaxNode> + '_> + '_ {
node.token_at_offset(offset)
.map(move |token| self.descend_into_macros(token, offset))
.map(|descendants| {
descendants.into_iter().map(move |it| self.token_ancestors_with_macros(it))
})
// re-order the tokens from token_at_offset by returning the ancestors with the smaller first nodes first
// See algo::ancestors_at_offset, which uses the same approach
.kmerge_by(|left, right| {
left.clone()
.map(|node| node.text_range().len())
.lt(right.clone().map(|node| node.text_range().len()))
})
}
/// Attempts to map the node out of macro expanded files returning the original file range.
/// If upmapping is not possible, this will fall back to the range of the macro call of the
/// macro file the node resides in.
pub fn original_range(&self, node: &SyntaxNode) -> FileRange {
let node = self.find_file(node);
node.original_file_range(self.db.upcast())
}
/// Attempts to map the node out of macro expanded files returning the original file range.
pub fn original_range_opt(&self, node: &SyntaxNode) -> Option<FileRange> {
let node = self.find_file(node);
node.original_file_range_opt(self.db.upcast())
.filter(|(_, ctx)| ctx.is_root())
.map(TupleExt::head)
}
/// Attempts to map the node out of macro expanded files.
/// This only work for attribute expansions, as other ones do not have nodes as input.
pub fn original_ast_node<N: AstNode>(&self, node: N) -> Option<N> {
self.wrap_node_infile(node).original_ast_node(self.db.upcast()).map(
|InRealFile { file_id, value }| {
self.cache(find_root(value.syntax()), file_id.into());
value
},
)
}
/// Attempts to map the node out of macro expanded files.
/// This only work for attribute expansions, as other ones do not have nodes as input.
pub fn original_syntax_node(&self, node: &SyntaxNode) -> Option<SyntaxNode> {
let InFile { file_id, .. } = self.find_file(node);
InFile::new(file_id, node).original_syntax_node(self.db.upcast()).map(
|InRealFile { file_id, value }| {
self.cache(find_root(&value), file_id.into());
value
},
)
}
pub fn diagnostics_display_range(&self, src: InFile<SyntaxNodePtr>) -> FileRange {
let root = self.parse_or_expand(src.file_id);
let node = src.map(|it| it.to_node(&root));
node.as_ref().original_file_range(self.db.upcast())
}
fn token_ancestors_with_macros(
&self,
token: SyntaxToken,
) -> impl Iterator<Item = SyntaxNode> + Clone + '_ {
token.parent().into_iter().flat_map(move |parent| self.ancestors_with_macros(parent))
}
/// Iterates the ancestors of the given node, climbing up macro expansions while doing so.
pub fn ancestors_with_macros(
&self,
node: SyntaxNode,
) -> impl Iterator<Item = SyntaxNode> + Clone + '_ {
let node = self.find_file(&node);
let db = self.db.upcast();
iter::successors(Some(node.cloned()), move |&InFile { file_id, ref value }| {
match value.parent() {
Some(parent) => Some(InFile::new(file_id, parent)),
None => {
self.cache(value.clone(), file_id);
file_id.call_node(db)
}
}
})
.map(|it| it.value)
}
pub fn ancestors_at_offset_with_macros(
&self,
node: &SyntaxNode,
offset: TextSize,
) -> impl Iterator<Item = SyntaxNode> + '_ {
node.token_at_offset(offset)
.map(|token| self.token_ancestors_with_macros(token))
.kmerge_by(|node1, node2| node1.text_range().len() < node2.text_range().len())
}
pub fn resolve_lifetime_param(&self, lifetime: &ast::Lifetime) -> Option<LifetimeParam> {
let text = lifetime.text();
let lifetime_param = lifetime.syntax().ancestors().find_map(|syn| {
let gpl = ast::AnyHasGenericParams::cast(syn)?.generic_param_list()?;
gpl.lifetime_params()
.find(|tp| tp.lifetime().as_ref().map(|lt| lt.text()).as_ref() == Some(&text))
})?;
let src = self.wrap_node_infile(lifetime_param);
ToDef::to_def(self, src)
}
pub fn resolve_label(&self, lifetime: &ast::Lifetime) -> Option<Label> {
let text = lifetime.text();
let label = lifetime.syntax().ancestors().find_map(|syn| {
let label = match_ast! {
match syn {
ast::ForExpr(it) => it.label(),
ast::WhileExpr(it) => it.label(),
ast::LoopExpr(it) => it.label(),
ast::BlockExpr(it) => it.label(),
_ => None,
}
};
label.filter(|l| {
l.lifetime()
.and_then(|lt| lt.lifetime_ident_token())
.map_or(false, |lt| lt.text() == text)
})
})?;
let src = self.wrap_node_infile(label);
ToDef::to_def(self, src)
}
pub fn resolve_type(&self, ty: &ast::Type) -> Option<Type> {
let analyze = self.analyze(ty.syntax())?;
let ctx = LowerCtx::with_file_id(self.db.upcast(), analyze.file_id);
let ty = hir_ty::TyLoweringContext::new(
self.db,
&analyze.resolver,
analyze.resolver.module().into(),
)
.lower_ty(&crate::TypeRef::from_ast(&ctx, ty.clone()));
Some(Type::new_with_resolver(self.db, &analyze.resolver, ty))
}
pub fn resolve_trait(&self, path: &ast::Path) -> Option<Trait> {
let analyze = self.analyze(path.syntax())?;
let span_map = self.db.span_map(analyze.file_id);
let ctx = LowerCtx::with_span_map(self.db.upcast(), span_map);
let hir_path = Path::from_src(&ctx, path.clone())?;
match analyze.resolver.resolve_path_in_type_ns_fully(self.db.upcast(), &hir_path)? {
TypeNs::TraitId(id) => Some(Trait { id }),
_ => None,
}
}
pub fn expr_adjustments(&self, expr: &ast::Expr) -> Option<Vec<Adjustment>> {
let mutability = |m| match m {
hir_ty::Mutability::Not => Mutability::Shared,
hir_ty::Mutability::Mut => Mutability::Mut,
};
let analyzer = self.analyze(expr.syntax())?;
let (mut source_ty, _) = analyzer.type_of_expr(self.db, expr)?;
analyzer.expr_adjustments(self.db, expr).map(|it| {
it.iter()
.map(|adjust| {
let target =
Type::new_with_resolver(self.db, &analyzer.resolver, adjust.target.clone());
let kind = match adjust.kind {
hir_ty::Adjust::NeverToAny => Adjust::NeverToAny,
hir_ty::Adjust::Deref(Some(hir_ty::OverloadedDeref(m))) => {
// FIXME: Should we handle unknown mutability better?
Adjust::Deref(Some(OverloadedDeref(
m.map(mutability).unwrap_or(Mutability::Shared),
)))
}
hir_ty::Adjust::Deref(None) => Adjust::Deref(None),
hir_ty::Adjust::Borrow(hir_ty::AutoBorrow::RawPtr(m)) => {
Adjust::Borrow(AutoBorrow::RawPtr(mutability(m)))
}
hir_ty::Adjust::Borrow(hir_ty::AutoBorrow::Ref(m)) => {
Adjust::Borrow(AutoBorrow::Ref(mutability(m)))
}
hir_ty::Adjust::Pointer(pc) => Adjust::Pointer(pc),
};
// Update `source_ty` for the next adjustment
let source = mem::replace(&mut source_ty, target.clone());
let adjustment = Adjustment { source, target, kind };
adjustment
})
.collect()
})
}
pub fn type_of_expr(&self, expr: &ast::Expr) -> Option<TypeInfo> {
self.analyze(expr.syntax())?
.type_of_expr(self.db, expr)
.map(|(ty, coerced)| TypeInfo { original: ty, adjusted: coerced })
}
pub fn type_of_pat(&self, pat: &ast::Pat) -> Option<TypeInfo> {
self.analyze(pat.syntax())?
.type_of_pat(self.db, pat)
.map(|(ty, coerced)| TypeInfo { original: ty, adjusted: coerced })
}
/// It also includes the changes that binding mode makes in the type. For example in
/// `let ref x @ Some(_) = None` the result of `type_of_pat` is `Option<T>` but the result
/// of this function is `&mut Option<T>`
pub fn type_of_binding_in_pat(&self, pat: &ast::IdentPat) -> Option<Type> {
self.analyze(pat.syntax())?.type_of_binding_in_pat(self.db, pat)
}
pub fn type_of_self(&self, param: &ast::SelfParam) -> Option<Type> {
self.analyze(param.syntax())?.type_of_self(self.db, param)
}
pub fn pattern_adjustments(&self, pat: &ast::Pat) -> SmallVec<[Type; 1]> {
self.analyze(pat.syntax())
.and_then(|it| it.pattern_adjustments(self.db, pat))
.unwrap_or_default()
}
pub fn binding_mode_of_pat(&self, pat: &ast::IdentPat) -> Option<BindingMode> {
self.analyze(pat.syntax())?.binding_mode_of_pat(self.db, pat)
}
fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<FunctionId> {
self.analyze(call.syntax())?.resolve_method_call(self.db, call)
}
fn resolve_method_call_fallback(
&self,
call: &ast::MethodCallExpr,
) -> Option<Either<FunctionId, FieldId>> {
self.analyze(call.syntax())?.resolve_method_call_fallback(self.db, call)
}
fn resolve_await_to_poll(&self, await_expr: &ast::AwaitExpr) -> Option<FunctionId> {
self.analyze(await_expr.syntax())?.resolve_await_to_poll(self.db, await_expr)
}
fn resolve_prefix_expr(&self, prefix_expr: &ast::PrefixExpr) -> Option<FunctionId> {
self.analyze(prefix_expr.syntax())?.resolve_prefix_expr(self.db, prefix_expr)
}
fn resolve_index_expr(&self, index_expr: &ast::IndexExpr) -> Option<FunctionId> {
self.analyze(index_expr.syntax())?.resolve_index_expr(self.db, index_expr)
}
fn resolve_bin_expr(&self, bin_expr: &ast::BinExpr) -> Option<FunctionId> {
self.analyze(bin_expr.syntax())?.resolve_bin_expr(self.db, bin_expr)
}
fn resolve_try_expr(&self, try_expr: &ast::TryExpr) -> Option<FunctionId> {
self.analyze(try_expr.syntax())?.resolve_try_expr(self.db, try_expr)
}
pub fn resolve_method_call_as_callable(&self, call: &ast::MethodCallExpr) -> Option<Callable> {
self.analyze(call.syntax())?.resolve_method_call_as_callable(self.db, call)
}
pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<Field> {
self.analyze(field.syntax())?.resolve_field(self.db, field)
}
pub fn resolve_record_field(
&self,
field: &ast::RecordExprField,
) -> Option<(Field, Option<Local>, Type)> {
self.analyze(field.syntax())?.resolve_record_field(self.db, field)
}
pub fn resolve_record_pat_field(&self, field: &ast::RecordPatField) -> Option<(Field, Type)> {
self.analyze(field.syntax())?.resolve_record_pat_field(self.db, field)
}
pub fn resolve_macro_call(&self, macro_call: &ast::MacroCall) -> Option<Macro> {
let sa = self.analyze(macro_call.syntax())?;
let macro_call = self.find_file(macro_call.syntax()).with_value(macro_call);
sa.resolve_macro_call(self.db, macro_call)
}
pub fn is_unsafe_macro_call(&self, macro_call: &ast::MacroCall) -> bool {
let sa = match self.analyze(macro_call.syntax()) {
Some(it) => it,
None => return false,
};
let macro_call = self.find_file(macro_call.syntax()).with_value(macro_call);
sa.is_unsafe_macro_call(self.db, macro_call)
}
pub fn resolve_attr_macro_call(&self, item: &ast::Item) -> Option<Macro> {
let item_in_file = self.wrap_node_infile(item.clone());
let id = self.with_ctx(|ctx| {
let macro_call_id = ctx.item_to_macro_call(item_in_file)?;
macro_call_to_macro_id(ctx, self.db.upcast(), macro_call_id)
})?;
Some(Macro { id })
}
pub fn resolve_path(&self, path: &ast::Path) -> Option<PathResolution> {
self.analyze(path.syntax())?.resolve_path(self.db, path)
}
fn resolve_variant(&self, record_lit: ast::RecordExpr) -> Option<VariantId> {
self.analyze(record_lit.syntax())?.resolve_variant(self.db, record_lit)
}
pub fn resolve_bind_pat_to_const(&self, pat: &ast::IdentPat) -> Option<ModuleDef> {
self.analyze(pat.syntax())?.resolve_bind_pat_to_const(self.db, pat)
}
pub fn record_literal_missing_fields(&self, literal: &ast::RecordExpr) -> Vec<(Field, Type)> {
self.analyze(literal.syntax())
.and_then(|it| it.record_literal_missing_fields(self.db, literal))
.unwrap_or_default()
}
pub fn record_pattern_missing_fields(&self, pattern: &ast::RecordPat) -> Vec<(Field, Type)> {
self.analyze(pattern.syntax())
.and_then(|it| it.record_pattern_missing_fields(self.db, pattern))
.unwrap_or_default()
}
fn with_ctx<F: FnOnce(&mut SourceToDefCtx<'_, '_>) -> T, T>(&self, f: F) -> T {
let mut cache = self.s2d_cache.borrow_mut();
let mut ctx = SourceToDefCtx { db: self.db, dynmap_cache: &mut cache };
f(&mut ctx)
}
pub fn to_def<T: ToDef>(&self, src: &T) -> Option<T::Def> {
let src = self.find_file(src.syntax()).with_value(src).cloned();
T::to_def(self, src)
}
fn to_module_def(&self, file: FileId) -> impl Iterator<Item = Module> {
self.with_ctx(|ctx| ctx.file_to_def(file)).into_iter().map(Module::from)
}
pub fn scope(&self, node: &SyntaxNode) -> Option<SemanticsScope<'db>> {
self.analyze_no_infer(node).map(|SourceAnalyzer { file_id, resolver, .. }| SemanticsScope {
db: self.db,
file_id,
resolver,
})
}
pub fn scope_at_offset(
&self,
node: &SyntaxNode,
offset: TextSize,
) -> Option<SemanticsScope<'db>> {
self.analyze_with_offset_no_infer(node, offset).map(
|SourceAnalyzer { file_id, resolver, .. }| SemanticsScope {
db: self.db,
file_id,
resolver,
},
)
}
/// Search for a definition's source and cache its syntax tree
pub fn source<Def: HasSource>(&self, def: Def) -> Option<InFile<Def::Ast>>
where
Def::Ast: AstNode,
{
let res = def.source(self.db)?;
self.cache(find_root(res.value.syntax()), res.file_id);
Some(res)
}
/// Returns none if the file of the node is not part of a crate.
fn analyze(&self, node: &SyntaxNode) -> Option<SourceAnalyzer> {
self.analyze_impl(node, None, true)
}
/// Returns none if the file of the node is not part of a crate.
fn analyze_no_infer(&self, node: &SyntaxNode) -> Option<SourceAnalyzer> {
self.analyze_impl(node, None, false)
}
fn analyze_with_offset_no_infer(
&self,
node: &SyntaxNode,
offset: TextSize,
) -> Option<SourceAnalyzer> {
self.analyze_impl(node, Some(offset), false)
}
fn analyze_impl(
&self,
node: &SyntaxNode,
offset: Option<TextSize>,
infer_body: bool,
) -> Option<SourceAnalyzer> {
let _p = profile::span("Semantics::analyze_impl");
let node = self.find_file(node);
let container = self.with_ctx(|ctx| ctx.find_container(node))?;
let resolver = match container {
ChildContainer::DefWithBodyId(def) => {
return Some(if infer_body {
SourceAnalyzer::new_for_body(self.db, def, node, offset)
} else {
SourceAnalyzer::new_for_body_no_infer(self.db, def, node, offset)
})
}
ChildContainer::TraitId(it) => it.resolver(self.db.upcast()),
ChildContainer::TraitAliasId(it) => it.resolver(self.db.upcast()),
ChildContainer::ImplId(it) => it.resolver(self.db.upcast()),
ChildContainer::ModuleId(it) => it.resolver(self.db.upcast()),
ChildContainer::EnumId(it) => it.resolver(self.db.upcast()),
ChildContainer::VariantId(it) => it.resolver(self.db.upcast()),
ChildContainer::TypeAliasId(it) => it.resolver(self.db.upcast()),
ChildContainer::GenericDefId(it) => it.resolver(self.db.upcast()),
};
Some(SourceAnalyzer::new_for_resolver(resolver, node))
}
fn cache(&self, root_node: SyntaxNode, file_id: HirFileId) {
assert!(root_node.parent().is_none());
let mut cache = self.cache.borrow_mut();
let prev = cache.insert(root_node, file_id);
assert!(prev == None || prev == Some(file_id))
}
pub fn assert_contains_node(&self, node: &SyntaxNode) {
self.find_file(node);
}
fn lookup(&self, root_node: &SyntaxNode) -> Option<HirFileId> {
let cache = self.cache.borrow();
cache.get(root_node).copied()
}
fn wrap_node_infile<N: AstNode>(&self, node: N) -> InFile<N> {
let InFile { file_id, .. } = self.find_file(node.syntax());
InFile::new(file_id, node)
}
/// Wraps the node in a [`InFile`] with the file id it belongs to.
fn find_file<'node>(&self, node: &'node SyntaxNode) -> InFile<&'node SyntaxNode> {
let root_node = find_root(node);
let file_id = self.lookup(&root_node).unwrap_or_else(|| {
panic!(
"\n\nFailed to lookup {:?} in this Semantics.\n\
Make sure to use only query nodes, derived from this instance of Semantics.\n\
root node: {:?}\n\
known nodes: {}\n\n",
node,
root_node,
self.cache
.borrow()
.keys()
.map(|it| format!("{it:?}"))
.collect::<Vec<_>>()
.join(", ")
)
});
InFile::new(file_id, node)
}
pub fn is_unsafe_method_call(&self, method_call_expr: &ast::MethodCallExpr) -> bool {
method_call_expr
.receiver()
.and_then(|expr| {
let field_expr = match expr {
ast::Expr::FieldExpr(field_expr) => field_expr,
_ => return None,
};
let ty = self.type_of_expr(&field_expr.expr()?)?.original;
if !ty.is_packed(self.db) {
return None;
}
let func = self.resolve_method_call(method_call_expr).map(Function::from)?;
let res = match func.self_param(self.db)?.access(self.db) {
Access::Shared | Access::Exclusive => true,
Access::Owned => false,
};
Some(res)
})
.unwrap_or(false)
}
pub fn is_unsafe_ref_expr(&self, ref_expr: &ast::RefExpr) -> bool {
ref_expr
.expr()
.and_then(|expr| {
let field_expr = match expr {
ast::Expr::FieldExpr(field_expr) => field_expr,
_ => return None,
};
let expr = field_expr.expr()?;
self.type_of_expr(&expr)
})
// Binding a reference to a packed type is possibly unsafe.
.map(|ty| ty.original.is_packed(self.db))
.unwrap_or(false)
// FIXME This needs layout computation to be correct. It will highlight
// more than it should with the current implementation.
}
pub fn is_unsafe_ident_pat(&self, ident_pat: &ast::IdentPat) -> bool {
if ident_pat.ref_token().is_none() {
return false;
}
ident_pat
.syntax()
.parent()
.and_then(|parent| {
// `IdentPat` can live under `RecordPat` directly under `RecordPatField` or
// `RecordPatFieldList`. `RecordPatField` also lives under `RecordPatFieldList`,
// so this tries to lookup the `IdentPat` anywhere along that structure to the
// `RecordPat` so we can get the containing type.
let record_pat = ast::RecordPatField::cast(parent.clone())
.and_then(|record_pat| record_pat.syntax().parent())
.or_else(|| Some(parent.clone()))
.and_then(|parent| {
ast::RecordPatFieldList::cast(parent)?
.syntax()
.parent()
.and_then(ast::RecordPat::cast)
});
// If this doesn't match a `RecordPat`, fallback to a `LetStmt` to see if
// this is initialized from a `FieldExpr`.
if let Some(record_pat) = record_pat {
self.type_of_pat(&ast::Pat::RecordPat(record_pat))
} else if let Some(let_stmt) = ast::LetStmt::cast(parent) {
let field_expr = match let_stmt.initializer()? {
ast::Expr::FieldExpr(field_expr) => field_expr,
_ => return None,
};
self.type_of_expr(&field_expr.expr()?)
} else {
None
}
})
// Binding a reference to a packed type is possibly unsafe.
.map(|ty| ty.original.is_packed(self.db))
.unwrap_or(false)
}
/// Returns `true` if the `node` is inside an `unsafe` context.
pub fn is_inside_unsafe(&self, expr: &ast::Expr) -> bool {
let Some(enclosing_item) =
expr.syntax().ancestors().find_map(Either::<ast::Item, ast::Variant>::cast)
else {
return false;
};
let def = match &enclosing_item {
Either::Left(ast::Item::Fn(it)) if it.unsafe_token().is_some() => return true,
Either::Left(ast::Item::Fn(it)) => {
self.to_def(it).map(<_>::into).map(DefWithBodyId::FunctionId)
}
Either::Left(ast::Item::Const(it)) => {
self.to_def(it).map(<_>::into).map(DefWithBodyId::ConstId)
}
Either::Left(ast::Item::Static(it)) => {
self.to_def(it).map(<_>::into).map(DefWithBodyId::StaticId)
}
Either::Left(_) => None,
Either::Right(it) => self.to_def(it).map(<_>::into).map(DefWithBodyId::VariantId),
};
let Some(def) = def else { return false };
let enclosing_node = enclosing_item.as_ref().either(|i| i.syntax(), |v| v.syntax());
let (body, source_map) = self.db.body_with_source_map(def);
let file_id = self.find_file(expr.syntax()).file_id;
let Some(mut parent) = expr.syntax().parent() else { return false };
loop {
if &parent == enclosing_node {
break false;
}
if let Some(parent) = ast::Expr::cast(parent.clone()) {
if let Some(expr_id) = source_map.node_expr(InFile { file_id, value: &parent }) {
if let Expr::Unsafe { .. } = body[expr_id] {
break true;
}
}
}
let Some(parent_) = parent.parent() else { break false };
parent = parent_;
}
}
}
fn macro_call_to_macro_id(
ctx: &mut SourceToDefCtx<'_, '_>,
db: &dyn ExpandDatabase,
macro_call_id: MacroCallId,
) -> Option<MacroId> {
let loc = db.lookup_intern_macro_call(macro_call_id);
match loc.def.kind {
hir_expand::MacroDefKind::Declarative(it)
| hir_expand::MacroDefKind::BuiltIn(_, it)
| hir_expand::MacroDefKind::BuiltInAttr(_, it)
| hir_expand::MacroDefKind::BuiltInDerive(_, it)
| hir_expand::MacroDefKind::BuiltInEager(_, it) => {
ctx.macro_to_def(InFile::new(it.file_id, it.to_node(db)))
}
hir_expand::MacroDefKind::ProcMacro(_, _, it) => {
ctx.proc_macro_to_def(InFile::new(it.file_id, it.to_node(db)))
}
}
}
pub trait ToDef: AstNode + Clone {
type Def;
fn to_def(sema: &SemanticsImpl<'_>, src: InFile<Self>) -> Option<Self::Def>;
}
macro_rules! to_def_impls {
($(($def:path, $ast:path, $meth:ident)),* ,) => {$(
impl ToDef for $ast {
type Def = $def;
fn to_def(sema: &SemanticsImpl<'_>, src: InFile<Self>) -> Option<Self::Def> {
sema.with_ctx(|ctx| ctx.$meth(src)).map(<$def>::from)
}
}
)*}
}
to_def_impls![
(crate::Module, ast::Module, module_to_def),
(crate::Module, ast::SourceFile, source_file_to_def),
(crate::Struct, ast::Struct, struct_to_def),
(crate::Enum, ast::Enum, enum_to_def),
(crate::Union, ast::Union, union_to_def),
(crate::Trait, ast::Trait, trait_to_def),
(crate::TraitAlias, ast::TraitAlias, trait_alias_to_def),
(crate::Impl, ast::Impl, impl_to_def),
(crate::TypeAlias, ast::TypeAlias, type_alias_to_def),
(crate::Const, ast::Const, const_to_def),
(crate::Static, ast::Static, static_to_def),
(crate::Function, ast::Fn, fn_to_def),
(crate::Field, ast::RecordField, record_field_to_def),
(crate::Field, ast::TupleField, tuple_field_to_def),
(crate::Variant, ast::Variant, enum_variant_to_def),
(crate::TypeParam, ast::TypeParam, type_param_to_def),
(crate::LifetimeParam, ast::LifetimeParam, lifetime_param_to_def),
(crate::ConstParam, ast::ConstParam, const_param_to_def),
(crate::GenericParam, ast::GenericParam, generic_param_to_def),
(crate::Macro, ast::Macro, macro_to_def),
(crate::Local, ast::IdentPat, bind_pat_to_def),
(crate::Local, ast::SelfParam, self_param_to_def),
(crate::Label, ast::Label, label_to_def),
(crate::Adt, ast::Adt, adt_to_def),
(crate::ExternCrateDecl, ast::ExternCrate, extern_crate_to_def),
];
fn find_root(node: &SyntaxNode) -> SyntaxNode {
node.ancestors().last().unwrap()
}
/// `SemanticsScope` encapsulates the notion of a scope (the set of visible
/// names) at a particular program point.
///
/// It is a bit tricky, as scopes do not really exist inside the compiler.
/// Rather, the compiler directly computes for each reference the definition it
/// refers to. It might transiently compute the explicit scope map while doing
/// so, but, generally, this is not something left after the analysis.
///
/// However, we do very much need explicit scopes for IDE purposes --
/// completion, at its core, lists the contents of the current scope. The notion
/// of scope is also useful to answer questions like "what would be the meaning
/// of this piece of code if we inserted it into this position?".
///
/// So `SemanticsScope` is constructed from a specific program point (a syntax
/// node or just a raw offset) and provides access to the set of visible names
/// on a somewhat best-effort basis.
///
/// Note that if you are wondering "what does this specific existing name mean?",
/// you'd better use the `resolve_` family of methods.
#[derive(Debug)]
pub struct SemanticsScope<'a> {
pub db: &'a dyn HirDatabase,
file_id: HirFileId,
resolver: Resolver,
}
impl SemanticsScope<'_> {
pub fn module(&self) -> Module {
Module { id: self.resolver.module() }
}
pub fn krate(&self) -> Crate {
Crate { id: self.resolver.krate() }
}
pub(crate) fn resolver(&self) -> &Resolver {
&self.resolver
}
/// Note: `VisibleTraits` should be treated as an opaque type, passed into `Type
pub fn visible_traits(&self) -> VisibleTraits {
let resolver = &self.resolver;
VisibleTraits(resolver.traits_in_scope(self.db.upcast()))
}
/// Calls the passed closure `f` on all names in scope.
pub fn process_all_names(&self, f: &mut dyn FnMut(Name, ScopeDef)) {
let scope = self.resolver.names_in_scope(self.db.upcast());
for (name, entries) in scope {
for entry in entries {
let def = match entry {
resolver::ScopeDef::ModuleDef(it) => ScopeDef::ModuleDef(it.into()),
resolver::ScopeDef::Unknown => ScopeDef::Unknown,
resolver::ScopeDef::ImplSelfType(it) => ScopeDef::ImplSelfType(it.into()),
resolver::ScopeDef::AdtSelfType(it) => ScopeDef::AdtSelfType(it.into()),
resolver::ScopeDef::GenericParam(id) => ScopeDef::GenericParam(id.into()),
resolver::ScopeDef::Local(binding_id) => match self.resolver.body_owner() {
Some(parent) => ScopeDef::Local(Local { parent, binding_id }),
None => continue,
},
resolver::ScopeDef::Label(label_id) => match self.resolver.body_owner() {
Some(parent) => ScopeDef::Label(Label { parent, label_id }),
None => continue,
},
};
f(name.clone(), def)
}
}
}
/// Resolve a path as-if it was written at the given scope. This is
/// necessary a heuristic, as it doesn't take hygiene into account.
pub fn speculative_resolve(&self, path: &ast::Path) -> Option<PathResolution> {
let ctx = LowerCtx::with_file_id(self.db.upcast(), self.file_id);
let path = Path::from_src(&ctx, path.clone())?;
resolve_hir_path(self.db, &self.resolver, &path)
}
/// Iterates over associated types that may be specified after the given path (using
/// `Ty::Assoc` syntax).
pub fn assoc_type_shorthand_candidates<R>(
&self,
resolution: &PathResolution,
mut cb: impl FnMut(&Name, TypeAlias) -> Option<R>,
) -> Option<R> {
let def = self.resolver.generic_def()?;
hir_ty::associated_type_shorthand_candidates(
self.db,
def,
resolution.in_type_ns()?,
|name, id| cb(name, id.into()),
)
}
pub fn extern_crates(&self) -> impl Iterator<Item = (Name, Module)> + '_ {
self.resolver.extern_crates_in_scope().map(|(name, id)| (name, Module { id }))
}
pub fn extern_crate_decls(&self) -> impl Iterator<Item = Name> + '_ {
self.resolver.extern_crate_decls_in_scope(self.db.upcast())
}
}
#[derive(Debug)]
pub struct VisibleTraits(pub FxHashSet<TraitId>);
impl ops::Deref for VisibleTraits {
type Target = FxHashSet<TraitId>;
fn deref(&self) -> &Self::Target {
&self.0
}
}