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// force-host
#![feature(plugin_registrar)]
#![feature(box_syntax, rustc_private)]
extern crate syntax;
extern crate syntax_pos;
extern crate rustc;
extern crate rustc_plugin;
use std::borrow::ToOwned;
use syntax::ast;
use syntax::ext::hygiene;
use syntax::ext::build::AstBuilder;
use syntax::ext::base::{TTMacroExpander, ExtCtxt, MacResult, MacEager, NormalTT};
use syntax::print::pprust;
use syntax::ptr::P;
use syntax::symbol::Symbol;
use syntax_pos::Span;
use syntax::tokenstream::TokenStream;
use rustc_plugin::Registry;
struct Expander {
args: Vec<ast::NestedMetaItem>,
}
impl TTMacroExpander for Expander {
fn expand<'cx>(&self,
ecx: &'cx mut ExtCtxt,
sp: Span,
_: TokenStream,
_: Option<Span>) -> Box<MacResult+'cx> {
let args = self.args.iter().map(|i| pprust::meta_list_item_to_string(i))
.collect::<Vec<_>>().join(", ");
MacEager::expr(ecx.expr_str(sp, Symbol::intern(&args)))
}
}
#[plugin_registrar]
pub fn plugin_registrar(reg: &mut Registry) {
let args = reg.args().to_owned();
reg.register_syntax_extension(Symbol::intern("plugin_args"),
NormalTT {
expander: Box::new(Expander { args: args, }),
def_info: None,
allow_internal_unstable: None,
allow_internal_unsafe: false,
local_inner_macros: false,
unstable_feature: None,
edition: hygiene::default_edition(),
});
}
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