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Avoid double-handling of attributes in collect_tokens.

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By keeping track of attributes that have been previously processed.

This fixes the `macro-rules-derive-cfg.stdout` test, and is necessary
for #124141 which removes nonterminals.

Also shrink the `SmallVec` inline size used in `IntervalSet`. 2 gives
slightly better perf than 4 now that there's an `IntervalSet` in
`Parser`, which is cloned reasonably often.
This commit is contained in:
Nicholas Nethercote 2024-08-21 14:16:42 +10:00
parent b7e7f6e903
commit 1fdabfbebb
6 changed files with 30 additions and 35 deletions
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1
Cargo.lock
View File

@ -4172,6 +4172,7 @@ dependencies = [
"rustc_errors",
"rustc_feature",
"rustc_fluent_macro",
"rustc_index",
"rustc_lexer",
"rustc_macros",
"rustc_session",

2
compiler/rustc_index/src/interval.rs
View File

@ -18,7 +18,7 @@
#[derive(Debug, Clone)]
pub struct IntervalSet<I> {
// Start, end
map: SmallVec<[(u32, u32); 4]>,
map: SmallVec<[(u32, u32); 2]>,
domain: usize,
_data: PhantomData<I>,
}

1
compiler/rustc_parse/Cargo.toml
View File

@ -12,6 +12,7 @@ rustc_data_structures = { path = "../rustc_data_structures" }
rustc_errors = { path = "../rustc_errors" }
rustc_feature = { path = "../rustc_feature" }
rustc_fluent_macro = { path = "../rustc_fluent_macro" }
rustc_index = { path = "../rustc_index" }
rustc_lexer = { path = "../rustc_lexer" }
rustc_macros = { path = "../rustc_macros" }
rustc_session = { path = "../rustc_session" }

23
compiler/rustc_parse/src/parser/attr_wrapper.rs
View File

@ -256,6 +256,20 @@ pub(super) fn collect_tokens<R: HasAttrs + HasTokens>(
res?
};
// Ignore any attributes we've previously processed. This happens when
// an inner call to `collect_tokens` returns an AST node and then an
// outer call ends up with the same AST node without any additional
// wrapping layer.
let ret_attrs: AttrVec = ret
.attrs()
.iter()
.cloned()
.filter(|attr| {
let is_unseen = self.capture_state.seen_attrs.insert(attr.id);
is_unseen
})
.collect();
// When we're not in "definite capture mode", then skip collecting and
// return early if either of the following conditions hold.
// - `None`: Our target doesn't support tokens at all (e.g. `NtIdent`).
@ -269,7 +283,7 @@ pub(super) fn collect_tokens<R: HasAttrs + HasTokens>(
// tokens.
let definite_capture_mode = self.capture_cfg
&& matches!(self.capture_state.capturing, Capturing::Yes)
&& has_cfg_or_cfg_attr(ret.attrs());
&& has_cfg_or_cfg_attr(&ret_attrs);
if !definite_capture_mode && matches!(ret.tokens_mut(), None | Some(Some(_))) {
return Ok(ret);
}
@ -289,7 +303,7 @@ pub(super) fn collect_tokens<R: HasAttrs + HasTokens>(
// outer and inner attributes. So this check is more precise than
// the earlier `needs_tokens` check, and we don't need to
// check `R::SUPPORTS_CUSTOM_INNER_ATTRS`.)
|| needs_tokens(ret.attrs())
|| needs_tokens(&ret_attrs)
// - We are in "definite capture mode", which requires that there
// are `#[cfg]` or `#[cfg_attr]` attributes. (During normal
// non-`capture_cfg` parsing, we don't need any special capturing
@ -328,7 +342,7 @@ pub(super) fn collect_tokens<R: HasAttrs + HasTokens>(
// `Parser::parse_inner_attributes`, and pair them in a `ParserReplacement` with `None`,
// which means the relevant tokens will be removed. (More details below.)
let mut inner_attr_parser_replacements = Vec::new();
for attr in ret.attrs() {
for attr in ret_attrs.iter() {
if attr.style == ast::AttrStyle::Inner {
if let Some(inner_attr_parser_range) =
self.capture_state.inner_attr_parser_ranges.remove(&attr.id)
@ -418,7 +432,7 @@ pub(super) fn collect_tokens<R: HasAttrs + HasTokens>(
// cfg-expand this AST node.
let start_pos =
if has_outer_attrs { attrs.start_pos.unwrap() } else { collect_pos.start_pos };
let target = AttrsTarget { attrs: ret.attrs().iter().cloned().collect(), tokens };
let target = AttrsTarget { attrs: ret_attrs, tokens };
tokens_used = true;
self.capture_state
.parser_replacements
@ -428,6 +442,7 @@ pub(super) fn collect_tokens<R: HasAttrs + HasTokens>(
// the outermost call to this method.
self.capture_state.parser_replacements.clear();
self.capture_state.inner_attr_parser_ranges.clear();
self.capture_state.seen_attrs.clear();
}
assert!(tokens_used); // check we didn't create `tokens` unnecessarily
Ok(ret)

7
compiler/rustc_parse/src/parser/mod.rs
View File

@ -35,6 +35,7 @@
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::sync::Lrc;
use rustc_errors::{Applicability, Diag, FatalError, MultiSpan, PResult};
use rustc_index::interval::IntervalSet;
use rustc_session::parse::ParseSess;
use rustc_span::symbol::{kw, sym, Ident, Symbol};
use rustc_span::{Span, DUMMY_SP};
@ -183,7 +184,7 @@ pub struct Parser<'a> {
// This type is used a lot, e.g. it's cloned when matching many declarative macro rules with nonterminals. Make sure
// it doesn't unintentionally get bigger.
#[cfg(target_pointer_width = "64")]
rustc_data_structures::static_assert_size!(Parser<'_>, 256);
rustc_data_structures::static_assert_size!(Parser<'_>, 288);
/// Stores span information about a closure.
#[derive(Clone, Debug)]
@ -261,6 +262,9 @@ struct CaptureState {
capturing: Capturing,
parser_replacements: Vec<ParserReplacement>,
inner_attr_parser_ranges: FxHashMap<AttrId, ParserRange>,
// `IntervalSet` is good for perf because attrs are mostly added to this
// set in contiguous ranges.
seen_attrs: IntervalSet<AttrId>,
}
/// Iterator over a `TokenStream` that produces `Token`s. It's a bit odd that
@ -458,6 +462,7 @@ pub fn new(
capturing: Capturing::No,
parser_replacements: Vec::new(),
inner_attr_parser_ranges: Default::default(),
seen_attrs: IntervalSet::new(u32::MAX as usize),
},
current_closure: None,
recovery: Recovery::Allowed,

31
tests/ui/proc-macro/macro-rules-derive-cfg.stdout
View File

@ -1,11 +1,9 @@
PRINT-DERIVE INPUT (DISPLAY): struct
Foo([bool; #[rustc_dummy(first)] #[rustc_dummy(second)]
{ #![rustc_dummy(third)] #[rustc_dummy(fourth)] #[rustc_dummy(fourth)] 30 }]);
{ #![rustc_dummy(third)] #[rustc_dummy(fourth)] 30 }]);
PRINT-DERIVE DEEP-RE-COLLECTED (DISPLAY): struct
Foo([bool; #[rustc_dummy(first)] #[rustc_dummy(second)]
{
#! [rustc_dummy(third)] #[rustc_dummy(fourth)] #[rustc_dummy(fourth)] 30
}]);
{ #! [rustc_dummy(third)] #[rustc_dummy(fourth)] 30 }]);
PRINT-DERIVE INPUT (DEBUG): TokenStream [
Ident {
ident: "struct",
@ -138,31 +136,6 @@ PRINT-DERIVE INPUT (DEBUG): TokenStream [
],
span: $DIR/macro-rules-derive-cfg.rs:25:6: 25:49 (#0),
},
Punct {
ch: '#',
spacing: Alone,
span: $DIR/macro-rules-derive-cfg.rs:25:5: 25:6 (#0),
},
Group {
delimiter: Bracket,
stream: TokenStream [
Ident {
ident: "rustc_dummy",
span: $DIR/macro-rules-derive-cfg.rs:25:28: 25:39 (#0),
},
Group {
delimiter: Parenthesis,
stream: TokenStream [
Ident {
ident: "fourth",
span: $DIR/macro-rules-derive-cfg.rs:25:40: 25:46 (#0),
},
],
span: $DIR/macro-rules-derive-cfg.rs:25:39: 25:47 (#0),
},
],
span: $DIR/macro-rules-derive-cfg.rs:25:6: 25:49 (#0),
},
Literal {
kind: Integer,
symbol: "30",