30 lines
917 B
Rust
30 lines
917 B
Rust
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use crate::util::check_builtin_macro_attribute;
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use rustc_ast::{self as ast, AstLike};
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use rustc_expand::base::{Annotatable, ExtCtxt};
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use rustc_expand::config::StripUnconfigured;
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use rustc_span::symbol::sym;
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use rustc_span::Span;
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pub fn expand(
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ecx: &mut ExtCtxt<'_>,
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_span: Span,
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meta_item: &ast::MetaItem,
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item: Annotatable,
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) -> Vec<Annotatable> {
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check_builtin_macro_attribute(ecx, meta_item, sym::cfg_eval);
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let mut visitor =
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StripUnconfigured { sess: ecx.sess, features: ecx.ecfg.features, modified: false };
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let mut item = visitor.fully_configure(item);
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if visitor.modified {
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// Erase the tokens if cfg-stripping modified the item
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// This will cause us to synthesize fake tokens
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// when `nt_to_tokenstream` is called on this item.
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if let Some(tokens) = item.tokens_mut() {
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*tokens = None;
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}
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}
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vec![item]
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}
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