bjoernager/rust
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Move ast::Item::ident into ast::ItemKind.

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`ast::Item` has an `ident` field.

- It's always non-empty for these item kinds: `ExternCrate`, `Static`,
  `Const`, `Fn`, `Mod`, `TyAlias`, `Enum`, `Struct`, `Union`,
  `Trait`, `TraitAlias`, `MacroDef`, `Delegation`.

- It's always empty for these item kinds: `Use`, `ForeignMod`,
  `GlobalAsm`, `Impl`, `MacCall`, `DelegationMac`.

There is a similar story for `AssocItemKind` and `ForeignItemKind`.

Some sites that handle items check for an empty ident, some don't. This
is a very C-like way of doing things, but this is Rust, we have sum
types, we can do this properly and never forget to check for the
exceptional case and never YOLO possibly empty identifiers (or possibly
dummy spans) around and hope that things will work out.

The commit is large but it's mostly obvious plumbing work. Some notable
things.

- `ast::Item` got 8 bytes bigger. This could be avoided by boxing the
  fields within some of the `ast::ItemKind` variants (specifically:
  `Struct`, `Union`, `Enum`). I might do that in a follow-up; this
  commit is big enough already.

- For the visitors: `FnKind` no longer needs an `ident` field because
  the `Fn` within how has one.

- In the parser, the `ItemInfo` typedef is no longer needed. It was used
  in various places to return an `Ident` alongside an `ItemKind`, but
  now the `Ident` (if present) is within the `ItemKind`.

- In a few places I renamed identifier variables called `name` (or
  `foo_name`) as `ident` (or `foo_ident`), to better match the type, and
  because `name` is normally used for `Symbol`s. It's confusing to see
  something like `foo_name.name`.
This commit is contained in:
Nicholas Nethercote 2025-03-21 09:47:43 +11:00
parent 43018eacb6
commit df247968f2
54 changed files with 1072 additions and 864 deletions
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41
compiler/rustc_builtin_macros/src/proc_macro_harness.rs
View file

@ -92,7 +92,12 @@ impl<'a> CollectProcMacros<'a> {
}
}
fn collect_custom_derive(&mut self, item: &'a ast::Item, attr: &'a ast::Attribute) {
fn collect_custom_derive(
&mut self,
item: &'a ast::Item,
function_name: Ident,
attr: &'a ast::Attribute,
) {
let Some((trait_name, proc_attrs)) =
parse_macro_name_and_helper_attrs(self.dcx, attr, "derive")
else {
@ -104,7 +109,7 @@ impl<'a> CollectProcMacros<'a> {
id: item.id,
span: item.span,
trait_name,
function_name: item.ident,
function_name,
attrs: proc_attrs,
}));
} else {
@ -118,12 +123,12 @@ impl<'a> CollectProcMacros<'a> {
}
}
fn collect_attr_proc_macro(&mut self, item: &'a ast::Item) {
fn collect_attr_proc_macro(&mut self, item: &'a ast::Item, function_name: Ident) {
if self.in_root && item.vis.kind.is_pub() {
self.macros.push(ProcMacro::Attr(ProcMacroDef {
id: item.id,
span: item.span,
function_name: item.ident,
function_name,
}));
} else {
let msg = if !self.in_root {
@ -136,12 +141,12 @@ impl<'a> CollectProcMacros<'a> {
}
}
fn collect_bang_proc_macro(&mut self, item: &'a ast::Item) {
fn collect_bang_proc_macro(&mut self, item: &'a ast::Item, function_name: Ident) {
if self.in_root && item.vis.kind.is_pub() {
self.macros.push(ProcMacro::Bang(ProcMacroDef {
id: item.id,
span: item.span,
function_name: item.ident,
function_name,
}));
} else {
let msg = if !self.in_root {
@ -165,12 +170,6 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
}
}
// First up, make sure we're checking a bare function. If we're not then
// we're just not interested in this item.
//
// If we find one, try to locate a `#[proc_macro_derive]` attribute on it.
let is_fn = matches!(item.kind, ast::ItemKind::Fn(..));
let mut found_attr: Option<&'a ast::Attribute> = None;
for attr in &item.attrs {
@ -214,7 +213,13 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
return;
};
if !is_fn {
// First up, make sure we're checking a bare function. If we're not then
// we're just not interested in this item.
//
// If we find one, try to locate a `#[proc_macro_derive]` attribute on it.
let fn_ident = if let ast::ItemKind::Fn(fn_) = &item.kind {
fn_.ident
} else {
self.dcx
.create_err(errors::AttributeOnlyBeUsedOnBareFunctions {
span: attr.span,
@ -222,7 +227,7 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
})
.emit();
return;
}
};
if self.is_test_crate {
return;
@ -239,11 +244,11 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
}
if attr.has_name(sym::proc_macro_derive) {
self.collect_custom_derive(item, attr);
self.collect_custom_derive(item, fn_ident, attr);
} else if attr.has_name(sym::proc_macro_attribute) {
self.collect_attr_proc_macro(item);
self.collect_attr_proc_macro(item, fn_ident);
} else if attr.has_name(sym::proc_macro) {
self.collect_bang_proc_macro(item);
self.collect_bang_proc_macro(item, fn_ident);
};
let prev_in_root = mem::replace(&mut self.in_root, false);
@ -278,7 +283,7 @@ fn mk_decls(cx: &mut ExtCtxt<'_>, macros: &[ProcMacro]) -> P<ast::Item> {
let span = DUMMY_SP.with_def_site_ctxt(expn_id.to_expn_id());
let proc_macro = Ident::new(sym::proc_macro, span);
let krate = cx.item(span, proc_macro, ast::AttrVec::new(), ast::ItemKind::ExternCrate(None));
let krate = cx.item(span, ast::AttrVec::new(), ast::ItemKind::ExternCrate(None, proc_macro));
let bridge = Ident::new(sym::bridge, span);
let client = Ident::new(sym::client, span);