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Add toggle for parse_meta_item unsafe parsing

This makes it possible for the `unsafe(...)` syntax to only be
valid at the top level, and the `NestedMetaItem`s will automatically
reject `unsafe(...)`.
This commit is contained in:
carbotaniuman 2024-07-09 19:06:49 -05:00
parent d8bc8761a5
commit 49db8a5a99
19 changed files with 228 additions and 98 deletions

View file

@ -31,6 +31,12 @@ enum OuterAttributeType {
Attribute,
}
#[derive(Clone, Copy, PartialEq, Eq)]
pub enum AllowLeadingUnsafe {
Yes,
No,
}
impl<'a> Parser<'a> {
/// Parses attributes that appear before an item.
pub(super) fn parse_outer_attributes(&mut self) -> PResult<'a, AttrWrapper> {
@ -332,7 +338,7 @@ impl<'a> Parser<'a> {
/// Parses `cfg_attr(pred, attr_item_list)` where `attr_item_list` is comma-delimited.
pub fn parse_cfg_attr(&mut self) -> PResult<'a, (ast::MetaItem, Vec<(ast::AttrItem, Span)>)> {
let cfg_predicate = self.parse_meta_item()?;
let cfg_predicate = self.parse_meta_item(AllowLeadingUnsafe::No)?;
self.expect(&token::Comma)?;
// Presumably, the majority of the time there will only be one attr.
@ -368,7 +374,10 @@ impl<'a> Parser<'a> {
/// MetaItem = SimplePath ( '=' UNSUFFIXED_LIT | '(' MetaSeq? ')' )? ;
/// MetaSeq = MetaItemInner (',' MetaItemInner)* ','? ;
/// ```
pub fn parse_meta_item(&mut self) -> PResult<'a, ast::MetaItem> {
pub fn parse_meta_item(
&mut self,
unsafe_allowed: AllowLeadingUnsafe,
) -> PResult<'a, ast::MetaItem> {
// We can't use `maybe_whole` here because it would bump in the `None`
// case, which we don't want.
if let token::Interpolated(nt) = &self.token.kind
@ -384,7 +393,11 @@ impl<'a> Parser<'a> {
}
let lo = self.token.span;
let is_unsafe = self.eat_keyword(kw::Unsafe);
let is_unsafe = if unsafe_allowed == AllowLeadingUnsafe::Yes {
self.eat_keyword(kw::Unsafe)
} else {
false
};
let unsafety = if is_unsafe {
let unsafe_span = self.prev_token.span;
self.psess.gated_spans.gate(sym::unsafe_attributes, unsafe_span);
@ -427,7 +440,7 @@ impl<'a> Parser<'a> {
Err(err) => err.cancel(), // we provide a better error below
}
match self.parse_meta_item() {
match self.parse_meta_item(AllowLeadingUnsafe::No) {
Ok(mi) => return Ok(ast::NestedMetaItem::MetaItem(mi)),
Err(err) => err.cancel(), // we provide a better error below
}