use ast;
use attr;
use std::cell::Cell;
use ext::hygiene::{Mark, SyntaxContext};
use symbol::{Symbol, keywords};
use syntax_pos::{DUMMY_SP, Span};
use codemap::{ExpnInfo, MacroAttribute, dummy_spanned, hygiene, respan};
use ptr::P;
use tokenstream::TokenStream;
fn ignored_span(sp: Span) -> Span {
let mark = Mark::fresh(Mark::root());
mark.set_expn_info(ExpnInfo {
call_site: DUMMY_SP,
def_site: None,
format: MacroAttribute(Symbol::intern("std_inject")),
allow_internal_unstable: true,
allow_internal_unsafe: false,
local_inner_macros: false,
edition: hygiene::default_edition(),
});
sp.with_ctxt(SyntaxContext::empty().apply_mark(mark))
}
pub fn injected_crate_name() -> Option<&'static str> {
INJECTED_CRATE_NAME.with(|name| name.get())
}
thread_local! {
static INJECTED_CRATE_NAME: Cell<Option<&'static str>> = Cell::new(None);
}
pub fn maybe_inject_crates_ref(mut krate: ast::Crate, alt_std_name: Option<&str>) -> ast::Crate {
let names: &[&str] = if attr::contains_name(&krate.attrs, "no_core") {
return krate;
} else if attr::contains_name(&krate.attrs, "no_std") {
if attr::contains_name(&krate.attrs, "compiler_builtins") {
&["core"]
} else {
&["core", "compiler_builtins"]
}
} else {
&["std"]
};
for name in names.iter().rev() {
krate.module.items.insert(0, P(ast::Item {
attrs: vec![attr::mk_attr_outer(DUMMY_SP,
attr::mk_attr_id(),
attr::mk_word_item(ast::Ident::from_str("macro_use")))],
vis: dummy_spanned(ast::VisibilityKind::Inherited),
node: ast::ItemKind::ExternCrate(alt_std_name.map(Symbol::intern)),
ident: ast::Ident::from_str(name),
id: ast::DUMMY_NODE_ID,
span: DUMMY_SP,
tokens: None,
}));
}
let name = names[0];
INJECTED_CRATE_NAME.with(|opt_name| opt_name.set(Some(name)));
let span = ignored_span(DUMMY_SP);
krate.module.items.insert(0, P(ast::Item {
attrs: vec![ast::Attribute {
style: ast::AttrStyle::Outer,
path: ast::Path::from_ident(ast::Ident::new(Symbol::intern("prelude_import"), span)),
tokens: TokenStream::empty(),
id: attr::mk_attr_id(),
is_sugared_doc: false,
span,
}],
vis: respan(span.shrink_to_lo(), ast::VisibilityKind::Inherited),
node: ast::ItemKind::Use(P(ast::UseTree {
prefix: ast::Path {
segments: [name, "prelude", "v1"].into_iter().map(|name| {
ast::PathSegment::from_ident(ast::Ident::from_str(name))
}).collect(),
span,
},
kind: ast::UseTreeKind::Glob,
span,
})),
id: ast::DUMMY_NODE_ID,
ident: keywords::Invalid.ident(),
span,
tokens: None,
}));
krate
}