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rust/compiler/rustc_builtin_macros/src/cfg_accessible.rs
Nicholas Nethercote 80d2bdb619 Rename all ParseSess variables/fields/lifetimes as psess.
Existing names for values of this type are `sess`, `parse_sess`,
`parse_session`, and `ps`. `sess` is particularly annoying because
that's also used for `Session` values, which are often co-located, and
it can be difficult to know which type a value named `sess` refers to.
(That annoyance is the main motivation for this change.) `psess` is nice
and short, which is good for a name used this much.

The commit also renames some `parse_sess_created` values as
`psess_created`.
2024-03-05 08:11:45 +11:00

70 lines
2.2 KiB
Rust

//! Implementation of the `#[cfg_accessible(path)]` attribute macro.
use crate::errors;
use rustc_ast as ast;
use rustc_expand::base::{Annotatable, ExpandResult, ExtCtxt, Indeterminate, MultiItemModifier};
use rustc_feature::AttributeTemplate;
use rustc_parse::validate_attr;
use rustc_span::symbol::sym;
use rustc_span::Span;
pub(crate) struct Expander;
fn validate_input<'a>(ecx: &mut ExtCtxt<'_>, mi: &'a ast::MetaItem) -> Option<&'a ast::Path> {
use errors::CfgAccessibleInvalid::*;
match mi.meta_item_list() {
None => {}
Some([]) => {
ecx.dcx().emit_err(UnspecifiedPath(mi.span));
}
Some([_, .., l]) => {
ecx.dcx().emit_err(MultiplePaths(l.span()));
}
Some([nmi]) => match nmi.meta_item() {
None => {
ecx.dcx().emit_err(LiteralPath(nmi.span()));
}
Some(mi) => {
if !mi.is_word() {
ecx.dcx().emit_err(HasArguments(mi.span));
}
return Some(&mi.path);
}
},
}
None
}
impl MultiItemModifier for Expander {
fn expand(
&self,
ecx: &mut ExtCtxt<'_>,
span: Span,
meta_item: &ast::MetaItem,
item: Annotatable,
_is_derive_const: bool,
) -> ExpandResult<Vec<Annotatable>, Annotatable> {
let template = AttributeTemplate { list: Some("path"), ..Default::default() };
validate_attr::check_builtin_meta_item(
&ecx.sess.psess,
meta_item,
ast::AttrStyle::Outer,
sym::cfg_accessible,
template,
);
let Some(path) = validate_input(ecx, meta_item) else {
return ExpandResult::Ready(Vec::new());
};
match ecx.resolver.cfg_accessible(ecx.current_expansion.id, path) {
Ok(true) => ExpandResult::Ready(vec![item]),
Ok(false) => ExpandResult::Ready(Vec::new()),
Err(Indeterminate) if ecx.force_mode => {
ecx.dcx().emit_err(errors::CfgAccessibleIndeterminate { span });
ExpandResult::Ready(vec![item])
}
Err(Indeterminate) => ExpandResult::Retry(item),
}
}
}