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use super::ptr::P;
use super::tokenstream::LazyTokenStream;
use super::{Arm, Field, FieldPat, GenericParam, Param, StructField, Variant};
use super::{AssocItem, Expr, ForeignItem, Item, Local};
use super::{AttrItem, AttrKind, Block, Pat, Path, Ty, Visibility};
use super::{AttrVec, Attribute, Stmt, StmtKind};
pub trait AstLike: Sized {
fn attrs(&self) -> &[Attribute];
fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>));
fn finalize_tokens(&mut self, _tokens: LazyTokenStream) {
panic!("`finalize_tokens` is not supported!")
}
}
impl<T: AstLike + 'static> AstLike for P<T> {
fn attrs(&self) -> &[Attribute] {
(**self).attrs()
}
fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
(**self).visit_attrs(f);
}
fn finalize_tokens(&mut self, tokens: LazyTokenStream) {
(**self).finalize_tokens(tokens)
}
}
fn visit_attrvec(attrs: &mut AttrVec, f: impl FnOnce(&mut Vec<Attribute>)) {
crate::mut_visit::visit_clobber(attrs, |attrs| {
let mut vec = attrs.into();
f(&mut vec);
vec.into()
});
}
impl AstLike for StmtKind {
fn attrs(&self) -> &[Attribute] {
match *self {
StmtKind::Local(ref local) => local.attrs(),
StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
StmtKind::Item(ref item) => item.attrs(),
StmtKind::Empty => &[],
StmtKind::MacCall(ref mac) => &*mac.attrs,
}
}
fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
match self {
StmtKind::Local(local) => local.visit_attrs(f),
StmtKind::Expr(expr) | StmtKind::Semi(expr) => expr.visit_attrs(f),
StmtKind::Item(item) => item.visit_attrs(f),
StmtKind::Empty => {}
StmtKind::MacCall(mac) => visit_attrvec(&mut mac.attrs, f),
}
}
fn finalize_tokens(&mut self, tokens: LazyTokenStream) {
let stmt_tokens = match self {
StmtKind::Local(ref mut local) => &mut local.tokens,
StmtKind::Item(ref mut item) => &mut item.tokens,
StmtKind::Expr(ref mut expr) | StmtKind::Semi(ref mut expr) => &mut expr.tokens,
StmtKind::Empty => return,
StmtKind::MacCall(ref mut mac) => &mut mac.tokens,
};
if stmt_tokens.is_none() {
*stmt_tokens = Some(tokens);
}
}
}
impl AstLike for Stmt {
fn attrs(&self) -> &[Attribute] {
self.kind.attrs()
}
fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
self.kind.visit_attrs(f);
}
fn finalize_tokens(&mut self, tokens: LazyTokenStream) {
self.kind.finalize_tokens(tokens)
}
}
impl AstLike for Attribute {
fn attrs(&self) -> &[Attribute] {
&[]
}
fn visit_attrs(&mut self, _f: impl FnOnce(&mut Vec<Attribute>)) {}
fn finalize_tokens(&mut self, tokens: LazyTokenStream) {
match &mut self.kind {
AttrKind::Normal(_, attr_tokens) => {
if attr_tokens.is_none() {
*attr_tokens = Some(tokens);
}
}
AttrKind::DocComment(..) => {
panic!("Called finalize_tokens on doc comment attr {:?}", self)
}
}
}
}
impl<T: AstLike> AstLike for Option<T> {
fn attrs(&self) -> &[Attribute] {
self.as_ref().map(|inner| inner.attrs()).unwrap_or(&[])
}
fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
if let Some(inner) = self.as_mut() {
inner.visit_attrs(f);
}
}
fn finalize_tokens(&mut self, tokens: LazyTokenStream) {
if let Some(inner) = self {
inner.finalize_tokens(tokens);
}
}
}
trait VecOrAttrVec {
fn visit(&mut self, f: impl FnOnce(&mut Vec<Attribute>));
}
impl VecOrAttrVec for Vec<Attribute> {
fn visit(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
f(self)
}
}
impl VecOrAttrVec for AttrVec {
fn visit(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
visit_attrvec(self, f)
}
}
macro_rules! derive_has_tokens_and_attrs {
($($ty:path),*) => { $(
impl AstLike for $ty {
fn attrs(&self) -> &[Attribute] {
&self.attrs
}
fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
VecOrAttrVec::visit(&mut self.attrs, f)
}
fn finalize_tokens(&mut self, tokens: LazyTokenStream) {
if self.tokens.is_none() {
self.tokens = Some(tokens);
}
}
}
)* }
}
macro_rules! derive_has_attrs_no_tokens {
($($ty:path),*) => { $(
impl AstLike for $ty {
fn attrs(&self) -> &[Attribute] {
&self.attrs
}
fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
VecOrAttrVec::visit(&mut self.attrs, f)
}
fn finalize_tokens(&mut self, _tokens: LazyTokenStream) {}
}
)* }
}
macro_rules! derive_has_tokens_no_attrs {
($($ty:path),*) => { $(
impl AstLike for $ty {
fn attrs(&self) -> &[Attribute] {
&[]
}
fn visit_attrs(&mut self, _f: impl FnOnce(&mut Vec<Attribute>)) {
}
fn finalize_tokens(&mut self, tokens: LazyTokenStream) {
if self.tokens.is_none() {
self.tokens = Some(tokens);
}
}
}
)* }
}
derive_has_tokens_and_attrs! {
Item, Expr, Local, AssocItem, ForeignItem
}
derive_has_attrs_no_tokens! {
StructField, Arm,
Field, FieldPat, Variant, Param, GenericParam
}
derive_has_tokens_no_attrs! {
Ty, Block, AttrItem, Pat, Path, Visibility
}