rust/compiler/rustc_resolve/src/def_collector.rs
2025-04-01 16:07:23 +11:00

502 lines
20 KiB
Rust

use std::mem;
use rustc_ast::visit::FnKind;
use rustc_ast::*;
use rustc_ast_pretty::pprust;
use rustc_attr_parsing::{AttributeParser, OmitDoc};
use rustc_expand::expand::AstFragment;
use rustc_hir as hir;
use rustc_hir::def::{CtorKind, CtorOf, DefKind};
use rustc_hir::def_id::LocalDefId;
use rustc_span::hygiene::LocalExpnId;
use rustc_span::{Span, Symbol, sym};
use tracing::debug;
use crate::{ImplTraitContext, InvocationParent, Resolver};
pub(crate) fn collect_definitions(
resolver: &mut Resolver<'_, '_>,
fragment: &AstFragment,
expansion: LocalExpnId,
) {
let invocation_parent = resolver.invocation_parents[&expansion];
let mut visitor = DefCollector { resolver, expansion, invocation_parent };
fragment.visit_with(&mut visitor);
}
/// Creates `DefId`s for nodes in the AST.
struct DefCollector<'a, 'ra, 'tcx> {
resolver: &'a mut Resolver<'ra, 'tcx>,
invocation_parent: InvocationParent,
expansion: LocalExpnId,
}
impl<'a, 'ra, 'tcx> DefCollector<'a, 'ra, 'tcx> {
fn create_def(
&mut self,
node_id: NodeId,
name: Option<Symbol>,
def_kind: DefKind,
span: Span,
) -> LocalDefId {
let parent_def = self.invocation_parent.parent_def;
debug!(
"create_def(node_id={:?}, def_kind={:?}, parent_def={:?})",
node_id, def_kind, parent_def
);
self.resolver
.create_def(
parent_def,
node_id,
name,
def_kind,
self.expansion.to_expn_id(),
span.with_parent(None),
)
.def_id()
}
fn with_parent<F: FnOnce(&mut Self)>(&mut self, parent_def: LocalDefId, f: F) {
let orig_parent_def = mem::replace(&mut self.invocation_parent.parent_def, parent_def);
f(self);
self.invocation_parent.parent_def = orig_parent_def;
}
fn with_impl_trait<F: FnOnce(&mut Self)>(
&mut self,
impl_trait_context: ImplTraitContext,
f: F,
) {
let orig_itc =
mem::replace(&mut self.invocation_parent.impl_trait_context, impl_trait_context);
f(self);
self.invocation_parent.impl_trait_context = orig_itc;
}
fn collect_field(&mut self, field: &'a FieldDef, index: Option<usize>) {
let index = |this: &Self| {
index.unwrap_or_else(|| {
let node_id = NodeId::placeholder_from_expn_id(this.expansion);
this.resolver.placeholder_field_indices[&node_id]
})
};
if field.is_placeholder {
let old_index = self.resolver.placeholder_field_indices.insert(field.id, index(self));
assert!(old_index.is_none(), "placeholder field index is reset for a node ID");
self.visit_macro_invoc(field.id);
} else {
let name = field.ident.map_or_else(|| sym::integer(index(self)), |ident| ident.name);
let def = self.create_def(field.id, Some(name), DefKind::Field, field.span);
self.with_parent(def, |this| visit::walk_field_def(this, field));
}
}
fn visit_macro_invoc(&mut self, id: NodeId) {
let id = id.placeholder_to_expn_id();
let old_parent = self.resolver.invocation_parents.insert(id, self.invocation_parent);
assert!(old_parent.is_none(), "parent `LocalDefId` is reset for an invocation");
}
}
impl<'a, 'ra, 'tcx> visit::Visitor<'a> for DefCollector<'a, 'ra, 'tcx> {
fn visit_item(&mut self, i: &'a Item) {
// Pick the def data. This need not be unique, but the more
// information we encapsulate into, the better
let mut opt_macro_data = None;
let def_kind = match &i.kind {
ItemKind::Impl(i) => DefKind::Impl { of_trait: i.of_trait.is_some() },
ItemKind::ForeignMod(..) => DefKind::ForeignMod,
ItemKind::Mod(..) => DefKind::Mod,
ItemKind::Trait(..) => DefKind::Trait,
ItemKind::TraitAlias(..) => DefKind::TraitAlias,
ItemKind::Enum(..) => DefKind::Enum,
ItemKind::Struct(..) => DefKind::Struct,
ItemKind::Union(..) => DefKind::Union,
ItemKind::ExternCrate(..) => DefKind::ExternCrate,
ItemKind::TyAlias(..) => DefKind::TyAlias,
ItemKind::Static(s) => DefKind::Static {
safety: hir::Safety::Safe,
mutability: s.mutability,
nested: false,
},
ItemKind::Const(..) => DefKind::Const,
ItemKind::Fn(..) | ItemKind::Delegation(..) => DefKind::Fn,
ItemKind::MacroDef(ident, def) => {
let edition = i.span.edition();
// FIXME(jdonszelmann) make one of these in the resolver?
// FIXME(jdonszelmann) don't care about tools here maybe? Just parse what we can.
// Does that prevents errors from happening? maybe
let parser = AttributeParser::new(
&self.resolver.tcx.sess,
self.resolver.tcx.features(),
Vec::new(),
);
let attrs = parser.parse_attribute_list(
&i.attrs,
i.span,
OmitDoc::Skip,
std::convert::identity,
);
let macro_data =
self.resolver.compile_macro(def, *ident, &attrs, i.span, i.id, edition);
let macro_kind = macro_data.ext.macro_kind();
opt_macro_data = Some(macro_data);
DefKind::Macro(macro_kind)
}
ItemKind::GlobalAsm(..) => DefKind::GlobalAsm,
ItemKind::Use(..) => return visit::walk_item(self, i),
ItemKind::MacCall(..) | ItemKind::DelegationMac(..) => {
return self.visit_macro_invoc(i.id);
}
};
let def_id =
self.create_def(i.id, i.kind.ident().map(|ident| ident.name), def_kind, i.span);
if let Some(macro_data) = opt_macro_data {
self.resolver.macro_map.insert(def_id.to_def_id(), macro_data);
}
self.with_parent(def_id, |this| {
this.with_impl_trait(ImplTraitContext::Existential, |this| {
match i.kind {
ItemKind::Struct(_, ref struct_def, _)
| ItemKind::Union(_, ref struct_def, _) => {
// If this is a unit or tuple-like struct, register the constructor.
if let Some((ctor_kind, ctor_node_id)) = CtorKind::from_ast(struct_def) {
this.create_def(
ctor_node_id,
None,
DefKind::Ctor(CtorOf::Struct, ctor_kind),
i.span,
);
}
}
_ => {}
}
visit::walk_item(this, i);
})
});
}
fn visit_fn(&mut self, fn_kind: FnKind<'a>, span: Span, _: NodeId) {
match fn_kind {
FnKind::Fn(
_ctxt,
_vis,
Fn {
sig: FnSig { header, decl, span: _ }, ident, generics, contract, body, ..
},
) if let Some(coroutine_kind) = header.coroutine_kind => {
self.visit_ident(ident);
self.visit_fn_header(header);
self.visit_generics(generics);
if let Some(contract) = contract {
self.visit_contract(contract);
}
// For async functions, we need to create their inner defs inside of a
// closure to match their desugared representation. Besides that,
// we must mirror everything that `visit::walk_fn` below does.
let FnDecl { inputs, output } = &**decl;
for param in inputs {
self.visit_param(param);
}
let (return_id, return_span) = coroutine_kind.return_id();
let return_def = self.create_def(return_id, None, DefKind::OpaqueTy, return_span);
self.with_parent(return_def, |this| this.visit_fn_ret_ty(output));
// If this async fn has no body (i.e. it's an async fn signature in a trait)
// then the closure_def will never be used, and we should avoid generating a
// def-id for it.
if let Some(body) = body {
let closure_def =
self.create_def(coroutine_kind.closure_id(), None, DefKind::Closure, span);
self.with_parent(closure_def, |this| this.visit_block(body));
}
}
FnKind::Closure(binder, Some(coroutine_kind), decl, body) => {
self.visit_closure_binder(binder);
visit::walk_fn_decl(self, decl);
// Async closures desugar to closures inside of closures, so
// we must create two defs.
let coroutine_def =
self.create_def(coroutine_kind.closure_id(), None, DefKind::Closure, span);
self.with_parent(coroutine_def, |this| this.visit_expr(body));
}
_ => visit::walk_fn(self, fn_kind),
}
}
fn visit_use_tree(&mut self, use_tree: &'a UseTree, id: NodeId, _nested: bool) {
self.create_def(id, None, DefKind::Use, use_tree.span);
visit::walk_use_tree(self, use_tree, id);
}
fn visit_foreign_item(&mut self, fi: &'a ForeignItem) {
let (ident, def_kind) = match fi.kind {
ForeignItemKind::Static(box StaticItem {
ident,
ty: _,
mutability,
expr: _,
safety,
define_opaque: _,
}) => {
let safety = match safety {
ast::Safety::Unsafe(_) | ast::Safety::Default => hir::Safety::Unsafe,
ast::Safety::Safe(_) => hir::Safety::Safe,
};
(ident, DefKind::Static { safety, mutability, nested: false })
}
ForeignItemKind::Fn(box Fn { ident, .. }) => (ident, DefKind::Fn),
ForeignItemKind::TyAlias(box TyAlias { ident, .. }) => (ident, DefKind::ForeignTy),
ForeignItemKind::MacCall(_) => return self.visit_macro_invoc(fi.id),
};
let def = self.create_def(fi.id, Some(ident.name), def_kind, fi.span);
self.with_parent(def, |this| visit::walk_item(this, fi));
}
fn visit_variant(&mut self, v: &'a Variant) {
if v.is_placeholder {
return self.visit_macro_invoc(v.id);
}
let def = self.create_def(v.id, Some(v.ident.name), DefKind::Variant, v.span);
self.with_parent(def, |this| {
if let Some((ctor_kind, ctor_node_id)) = CtorKind::from_ast(&v.data) {
this.create_def(
ctor_node_id,
None,
DefKind::Ctor(CtorOf::Variant, ctor_kind),
v.span,
);
}
visit::walk_variant(this, v)
});
}
fn visit_where_predicate(&mut self, pred: &'a WherePredicate) {
if pred.is_placeholder {
self.visit_macro_invoc(pred.id)
} else {
visit::walk_where_predicate(self, pred)
}
}
fn visit_variant_data(&mut self, data: &'a VariantData) {
// The assumption here is that non-`cfg` macro expansion cannot change field indices.
// It currently holds because only inert attributes are accepted on fields,
// and every such attribute expands into a single field after it's resolved.
for (index, field) in data.fields().iter().enumerate() {
self.collect_field(field, Some(index));
}
}
fn visit_generic_param(&mut self, param: &'a GenericParam) {
if param.is_placeholder {
self.visit_macro_invoc(param.id);
return;
}
let def_kind = match param.kind {
GenericParamKind::Lifetime { .. } => DefKind::LifetimeParam,
GenericParamKind::Type { .. } => DefKind::TyParam,
GenericParamKind::Const { .. } => DefKind::ConstParam,
};
self.create_def(param.id, Some(param.ident.name), def_kind, param.ident.span);
// impl-Trait can happen inside generic parameters, like
// ```
// fn foo<U: Iterator<Item = impl Clone>>() {}
// ```
//
// In that case, the impl-trait is lowered as an additional generic parameter.
self.with_impl_trait(ImplTraitContext::Universal, |this| {
visit::walk_generic_param(this, param)
});
}
fn visit_assoc_item(&mut self, i: &'a AssocItem, ctxt: visit::AssocCtxt) {
let (ident, def_kind) = match &i.kind {
AssocItemKind::Fn(box Fn { ident, .. })
| AssocItemKind::Delegation(box Delegation { ident, .. }) => (*ident, DefKind::AssocFn),
AssocItemKind::Const(box ConstItem { ident, .. }) => (*ident, DefKind::AssocConst),
AssocItemKind::Type(box TyAlias { ident, .. }) => (*ident, DefKind::AssocTy),
AssocItemKind::MacCall(..) | AssocItemKind::DelegationMac(..) => {
return self.visit_macro_invoc(i.id);
}
};
let def = self.create_def(i.id, Some(ident.name), def_kind, i.span);
self.with_parent(def, |this| visit::walk_assoc_item(this, i, ctxt));
}
fn visit_pat(&mut self, pat: &'a Pat) {
match pat.kind {
PatKind::MacCall(..) => self.visit_macro_invoc(pat.id),
_ => visit::walk_pat(self, pat),
}
}
fn visit_anon_const(&mut self, constant: &'a AnonConst) {
let parent = self.create_def(constant.id, None, DefKind::AnonConst, constant.value.span);
self.with_parent(parent, |this| visit::walk_anon_const(this, constant));
}
fn visit_expr(&mut self, expr: &'a Expr) {
let parent_def = match expr.kind {
ExprKind::MacCall(..) => return self.visit_macro_invoc(expr.id),
ExprKind::Closure(..) | ExprKind::Gen(..) => {
self.create_def(expr.id, None, DefKind::Closure, expr.span)
}
ExprKind::ConstBlock(ref constant) => {
for attr in &expr.attrs {
visit::walk_attribute(self, attr);
}
let def =
self.create_def(constant.id, None, DefKind::InlineConst, constant.value.span);
self.with_parent(def, |this| visit::walk_anon_const(this, constant));
return;
}
_ => self.invocation_parent.parent_def,
};
self.with_parent(parent_def, |this| visit::walk_expr(this, expr))
}
fn visit_ty(&mut self, ty: &'a Ty) {
match &ty.kind {
TyKind::MacCall(..) => self.visit_macro_invoc(ty.id),
TyKind::ImplTrait(id, _) => {
// HACK: pprust breaks strings with newlines when the type
// gets too long. We don't want these to show up in compiler
// output or built artifacts, so replace them here...
// Perhaps we should instead format APITs more robustly.
let name = Symbol::intern(&pprust::ty_to_string(ty).replace('\n', " "));
let kind = match self.invocation_parent.impl_trait_context {
ImplTraitContext::Universal => DefKind::TyParam,
ImplTraitContext::Existential => DefKind::OpaqueTy,
ImplTraitContext::InBinding => return visit::walk_ty(self, ty),
};
let id = self.create_def(*id, Some(name), kind, ty.span);
match self.invocation_parent.impl_trait_context {
// Do not nest APIT, as we desugar them as `impl_trait: bounds`,
// so the `impl_trait` node is not a parent to `bounds`.
ImplTraitContext::Universal => visit::walk_ty(self, ty),
ImplTraitContext::Existential => {
self.with_parent(id, |this| visit::walk_ty(this, ty))
}
ImplTraitContext::InBinding => unreachable!(),
};
}
_ => visit::walk_ty(self, ty),
}
}
fn visit_stmt(&mut self, stmt: &'a Stmt) {
match stmt.kind {
StmtKind::MacCall(..) => self.visit_macro_invoc(stmt.id),
// FIXME(impl_trait_in_bindings): We don't really have a good way of
// introducing the right `ImplTraitContext` here for all the cases we
// care about, in case we want to introduce ITIB to other positions
// such as turbofishes (e.g. `foo::<impl Fn()>(|| {})`).
StmtKind::Let(ref local) => self.with_impl_trait(ImplTraitContext::InBinding, |this| {
visit::walk_local(this, local)
}),
_ => visit::walk_stmt(self, stmt),
}
}
fn visit_arm(&mut self, arm: &'a Arm) {
if arm.is_placeholder { self.visit_macro_invoc(arm.id) } else { visit::walk_arm(self, arm) }
}
fn visit_expr_field(&mut self, f: &'a ExprField) {
if f.is_placeholder {
self.visit_macro_invoc(f.id)
} else {
visit::walk_expr_field(self, f)
}
}
fn visit_pat_field(&mut self, fp: &'a PatField) {
if fp.is_placeholder {
self.visit_macro_invoc(fp.id)
} else {
visit::walk_pat_field(self, fp)
}
}
fn visit_param(&mut self, p: &'a Param) {
if p.is_placeholder {
self.visit_macro_invoc(p.id)
} else {
self.with_impl_trait(ImplTraitContext::Universal, |this| visit::walk_param(this, p))
}
}
// This method is called only when we are visiting an individual field
// after expanding an attribute on it.
fn visit_field_def(&mut self, field: &'a FieldDef) {
self.collect_field(field, None);
}
fn visit_crate(&mut self, krate: &'a Crate) {
if krate.is_placeholder {
self.visit_macro_invoc(krate.id)
} else {
visit::walk_crate(self, krate)
}
}
fn visit_attribute(&mut self, attr: &'a Attribute) -> Self::Result {
let orig_in_attr = mem::replace(&mut self.invocation_parent.in_attr, true);
visit::walk_attribute(self, attr);
self.invocation_parent.in_attr = orig_in_attr;
}
fn visit_inline_asm(&mut self, asm: &'a InlineAsm) {
let InlineAsm {
asm_macro: _,
template: _,
template_strs: _,
operands,
clobber_abis: _,
options: _,
line_spans: _,
} = asm;
for (op, _span) in operands {
match op {
InlineAsmOperand::In { expr, reg: _ }
| InlineAsmOperand::Out { expr: Some(expr), reg: _, late: _ }
| InlineAsmOperand::InOut { expr, reg: _, late: _ } => {
self.visit_expr(expr);
}
InlineAsmOperand::Out { expr: None, reg: _, late: _ } => {}
InlineAsmOperand::SplitInOut { in_expr, out_expr, reg: _, late: _ } => {
self.visit_expr(in_expr);
if let Some(expr) = out_expr {
self.visit_expr(expr);
}
}
InlineAsmOperand::Const { anon_const } => {
let def = self.create_def(
anon_const.id,
None,
DefKind::InlineConst,
anon_const.value.span,
);
self.with_parent(def, |this| visit::walk_anon_const(this, anon_const));
}
InlineAsmOperand::Sym { sym } => self.visit_inline_asm_sym(sym),
InlineAsmOperand::Label { block } => self.visit_block(block),
}
}
}
}