bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Auto merge of #77255 - Aaron1011:feature/collect-attr-tokens, r=petrochenkov

Browse source 
Unconditionally capture tokens for attributes.

This allows us to avoid synthesizing tokens in `prepend_attr`, since we
have the original tokens available.

We still need to synthesize tokens when expanding `cfg_attr`,
but this is an unavoidable consequence of the syntax of `cfg_attr` -
the user does not supply the `#` and `[]` tokens that a `cfg_attr`
expands to.

This is based on PR https://github.com/rust-lang/rust/pull/77250 - this PR exposes a bug in the current `collect_tokens` implementation, which is fixed by the rewrite.
This commit is contained in:
bors 2020-10-24 19:23:32 +00:00
commit ffa2e7ae8f
19 changed files with 251 additions and 138 deletions
Download patch file Download diff file Expand all files Collapse all files

8
compiler/rustc_ast_lowering/src/expr.rs
View file

@ -210,9 +210,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
ex.span = e.span;
}
// Merge attributes into the inner expression.
let mut attrs = e.attrs.clone();
let mut attrs: Vec<_> = e.attrs.iter().map(|a| self.lower_attr(a)).collect();
attrs.extend::<Vec<_>>(ex.attrs.into());
ex.attrs = attrs;
ex.attrs = attrs.into();
return ex;
}
@ -1471,13 +1471,15 @@ impl<'hir> LoweringContext<'_, 'hir> {
hir::MatchSource::ForLoopDesugar,
));
let attrs: Vec<_> = e.attrs.iter().map(|a| self.lower_attr(a)).collect();
// This is effectively `{ let _result = ...; _result }`.
// The construct was introduced in #21984 and is necessary to make sure that
// temporaries in the `head` expression are dropped and do not leak to the
// surrounding scope of the `match` since the `match` is not a terminating scope.
//
// Also, add the attributes to the outer returned expr node.
self.expr_drop_temps_mut(desugared_span, match_expr, e.attrs.clone())
self.expr_drop_temps_mut(desugared_span, match_expr, attrs.into())
}
/// Desugar `ExprKind::Try` from: `<expr>?` into:

5
compiler/rustc_ast_lowering/src/lib.rs
View file

@ -972,7 +972,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
AttrKind::DocComment(comment_kind, data) => AttrKind::DocComment(comment_kind, data),
};
Attribute { kind, id: attr.id, style: attr.style, span: attr.span }
// Tokens aren't needed after macro expansion and parsing
Attribute { kind, id: attr.id, style: attr.style, span: attr.span, tokens: None }
}
fn lower_mac_args(&mut self, args: &MacArgs) -> MacArgs {
@ -1713,7 +1714,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
pat: self.lower_pat(&l.pat),
init,
span: l.span,
attrs: l.attrs.clone(),
attrs: l.attrs.iter().map(|a| self.lower_attr(a)).collect::<Vec<_>>().into(),
source: hir::LocalSource::Normal,
},
ids,