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Auto merge of rust-lang#124141 - nnethercote:rm-Nonterminal-and-Token…
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…Kind-Interpolated, r=<try>

Remove `Nonterminal` and `TokenKind::Interpolated`

A third attempt at this; the first attempt was rust-lang#96724 and the second was rust-lang#114647.

r? `@ghost`
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@bors
bors committed Jun 24, 2024
2 parents d49994b + eacfbe6 commit b3e0500
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Showing 104 changed files with 1,542 additions and 1,340 deletions.
30 changes: 0 additions & 30 deletions compiler/rustc_ast/src/ast_traits.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,6 @@
//! The traits are not implemented exhaustively, only when actually necessary.

use crate::ptr::P;
use crate::token::Nonterminal;
use crate::tokenstream::LazyAttrTokenStream;
use crate::{Arm, Crate, ExprField, FieldDef, GenericParam, Param, PatField, Variant};
use crate::{AssocItem, Expr, ForeignItem, Item, NodeId};
Expand Down Expand Up @@ -228,35 +227,6 @@ impl HasTokens for Attribute {
}
}

impl HasTokens for Nonterminal {
fn tokens(&self) -> Option<&LazyAttrTokenStream> {
match self {
Nonterminal::NtItem(item) => item.tokens(),
Nonterminal::NtStmt(stmt) => stmt.tokens(),
Nonterminal::NtExpr(expr) | Nonterminal::NtLiteral(expr) => expr.tokens(),
Nonterminal::NtPat(pat) => pat.tokens(),
Nonterminal::NtTy(ty) => ty.tokens(),
Nonterminal::NtMeta(attr_item) => attr_item.tokens(),
Nonterminal::NtPath(path) => path.tokens(),
Nonterminal::NtVis(vis) => vis.tokens(),
Nonterminal::NtBlock(block) => block.tokens(),
}
}
fn tokens_mut(&mut self) -> Option<&mut Option<LazyAttrTokenStream>> {
match self {
Nonterminal::NtItem(item) => item.tokens_mut(),
Nonterminal::NtStmt(stmt) => stmt.tokens_mut(),
Nonterminal::NtExpr(expr) | Nonterminal::NtLiteral(expr) => expr.tokens_mut(),
Nonterminal::NtPat(pat) => pat.tokens_mut(),
Nonterminal::NtTy(ty) => ty.tokens_mut(),
Nonterminal::NtMeta(attr_item) => attr_item.tokens_mut(),
Nonterminal::NtPath(path) => path.tokens_mut(),
Nonterminal::NtVis(vis) => vis.tokens_mut(),
Nonterminal::NtBlock(block) => block.tokens_mut(),
}
}
}

/// A trait for AST nodes having (or not having) attributes.
pub trait HasAttrs {
/// This is `true` if this `HasAttrs` might support 'custom' (proc-macro) inner
Expand Down
31 changes: 22 additions & 9 deletions compiler/rustc_ast/src/attr/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@ use crate::ast::{DelimArgs, Expr, ExprKind, LitKind, MetaItemLit};
use crate::ast::{MetaItem, MetaItemKind, NestedMetaItem, NormalAttr};
use crate::ast::{Path, PathSegment, DUMMY_NODE_ID};
use crate::ptr::P;
use crate::token::{self, CommentKind, Delimiter, Token};
use crate::token::{self, CommentKind, Delimiter, InvisibleOrigin, MetaVarKind, Token};
use crate::tokenstream::{DelimSpan, Spacing, TokenTree};
use crate::tokenstream::{LazyAttrTokenStream, TokenStream};
use crate::util::comments;
Expand Down Expand Up @@ -327,7 +327,8 @@ impl MetaItem {
I: Iterator<Item = &'a TokenTree>,
{
// FIXME: Share code with `parse_path`.
let path = match tokens.next().map(|tt| TokenTree::uninterpolate(tt)).as_deref() {
let tt = tokens.next().map(|tt| TokenTree::uninterpolate(tt));
let path = match tt.as_deref() {
Some(&TokenTree::Token(
Token { kind: ref kind @ (token::Ident(..) | token::PathSep), span },
_,
Expand Down Expand Up @@ -363,11 +364,23 @@ impl MetaItem {
let span = span.with_hi(segments.last().unwrap().ident.span.hi());
Path { span, segments, tokens: None }
}
Some(TokenTree::Token(Token { kind: token::Interpolated(nt), .. }, _)) => match &**nt {
token::Nonterminal::NtMeta(item) => return item.meta(item.path.span),
token::Nonterminal::NtPath(path) => (**path).clone(),
_ => return None,
},
Some(TokenTree::Delimited(
_span,
_spacing,
Delimiter::Invisible(InvisibleOrigin::MetaVar(
MetaVarKind::Meta | MetaVarKind::Path,
)),
_stream,
)) => {
// This path is currently unreachable in the test suite.
unreachable!()
}
Some(TokenTree::Token(
Token { kind: token::OpenDelim(_) | token::CloseDelim(_), .. },
_,
)) => {
panic!("Should be `AttrTokenTree::Delimited`, not delim tokens: {:?}", tt);
}
_ => return None,
};
let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
Expand Down Expand Up @@ -404,7 +417,7 @@ impl MetaItemKind {
tokens: &mut impl Iterator<Item = &'a TokenTree>,
) -> Option<MetaItemKind> {
match tokens.next() {
Some(TokenTree::Delimited(.., Delimiter::Invisible, inner_tokens)) => {
Some(TokenTree::Delimited(.., Delimiter::Invisible(_), inner_tokens)) => {
MetaItemKind::name_value_from_tokens(&mut inner_tokens.trees())
}
Some(TokenTree::Token(token, _)) => {
Expand Down Expand Up @@ -542,7 +555,7 @@ impl NestedMetaItem {
tokens.next();
return Some(NestedMetaItem::Lit(lit));
}
Some(TokenTree::Delimited(.., Delimiter::Invisible, inner_tokens)) => {
Some(TokenTree::Delimited(.., Delimiter::Invisible(_), inner_tokens)) => {
tokens.next();
return NestedMetaItem::from_tokens(&mut inner_tokens.trees().peekable());
}
Expand Down
64 changes: 3 additions & 61 deletions compiler/rustc_ast/src/mut_visit.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -764,9 +764,9 @@ fn visit_lazy_tts<T: MutVisitor>(lazy_tts: &mut Option<LazyAttrTokenStream>, vis
visit_lazy_tts_opt_mut(lazy_tts.as_mut(), vis);
}

/// Applies ident visitor if it's an ident; applies other visits to interpolated nodes.
/// In practice the ident part is not actually used by specific visitors right now,
/// but there's a test below checking that it works.
/// Applies ident visitor if it's an ident. In practice this is not actually
/// used by specific visitors right now, but there's a test below checking that
/// it works.
// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`.
pub fn visit_token<T: MutVisitor>(t: &mut Token, vis: &mut T) {
let Token { kind, span } = t;
Expand All @@ -784,69 +784,11 @@ pub fn visit_token<T: MutVisitor>(t: &mut Token, vis: &mut T) {
token::NtLifetime(ident) => {
vis.visit_ident(ident);
}
token::Interpolated(nt) => {
let nt = Lrc::make_mut(nt);
visit_nonterminal(nt, vis);
}
_ => {}
}
vis.visit_span(span);
}

// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`.
/// Applies the visitor to elements of interpolated nodes.
//
// N.B., this can occur only when applying a visitor to partially expanded
// code, where parsed pieces have gotten implanted ito *other* macro
// invocations. This is relevant for macro hygiene, but possibly not elsewhere.
//
// One problem here occurs because the types for flat_map_item, flat_map_stmt,
// etc., allow the visitor to return *multiple* items; this is a problem for the
// nodes here, because they insist on having exactly one piece. One solution
// would be to mangle the MutVisitor trait to include one-to-many and
// one-to-one versions of these entry points, but that would probably confuse a
// lot of people and help very few. Instead, I'm just going to put in dynamic
// checks. I think the performance impact of this will be pretty much
// nonexistent. The danger is that someone will apply a `MutVisitor` to a
// partially expanded node, and will be confused by the fact that their
// `flat_map_item` or `flat_map_stmt` isn't getting called on `NtItem` or `NtStmt`
// nodes. Hopefully they'll wind up reading this comment, and doing something
// appropriate.
//
// BTW, design choice: I considered just changing the type of, e.g., `NtItem` to
// contain multiple items, but decided against it when I looked at
// `parse_item_or_view_item` and tried to figure out what I would do with
// multiple items there....
fn visit_nonterminal<T: MutVisitor>(nt: &mut token::Nonterminal, vis: &mut T) {
match nt {
token::NtItem(item) => visit_clobber(item, |item| {
// This is probably okay, because the only visitors likely to
// peek inside interpolated nodes will be renamings/markings,
// which map single items to single items.
vis.flat_map_item(item).expect_one("expected visitor to produce exactly one item")
}),
token::NtBlock(block) => vis.visit_block(block),
token::NtStmt(stmt) => visit_clobber(stmt, |stmt| {
// See reasoning above.
stmt.map(|stmt| {
vis.flat_map_stmt(stmt).expect_one("expected visitor to produce exactly one item")
})
}),
token::NtPat(pat) => vis.visit_pat(pat),
token::NtExpr(expr) => vis.visit_expr(expr),
token::NtTy(ty) => vis.visit_ty(ty),
token::NtLiteral(expr) => vis.visit_expr(expr),
token::NtMeta(item) => {
let AttrItem { unsafety: _, path, args, tokens } = item.deref_mut();
vis.visit_path(path);
visit_attr_args(args, vis);
visit_lazy_tts(tokens, vis);
}
token::NtPath(path) => vis.visit_path(path),
token::NtVis(visib) => vis.visit_vis(visib),
}
}

// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`.
fn visit_defaultness<T: MutVisitor>(defaultness: &mut Defaultness, vis: &mut T) {
match defaultness {
Expand Down
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