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Improve tt-heavy expansion performance.

This commit is contained in:
Jeffrey Seyfried 2016-11-03 11:59:43 +00:00
parent 7ae083383d
commit 23ad6fdb66
3 changed files with 23 additions and 5 deletions

View file

@ -615,7 +615,9 @@ impl<'a> ExtCtxt<'a> {
pub fn new_parser_from_tts(&self, tts: &[tokenstream::TokenTree]) pub fn new_parser_from_tts(&self, tts: &[tokenstream::TokenTree])
-> parser::Parser<'a> { -> parser::Parser<'a> {
parse::tts_to_parser(self.parse_sess, tts.to_vec()) let mut parser = parse::tts_to_parser(self.parse_sess, tts.to_vec());
parser.allow_interpolated_tts = false; // FIXME(jseyfried) `quote!` can't handle these yet
parser
} }
pub fn codemap(&self) -> &'a CodeMap { self.parse_sess.codemap() } pub fn codemap(&self) -> &'a CodeMap { self.parse_sess.codemap() }
pub fn parse_sess(&self) -> &'a parse::ParseSess { self.parse_sess } pub fn parse_sess(&self) -> &'a parse::ParseSess { self.parse_sess }

View file

@ -496,10 +496,19 @@ pub fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
match name { match name {
"tt" => { "tt" => {
p.quote_depth += 1; //but in theory, non-quoted tts might be useful p.quote_depth += 1; //but in theory, non-quoted tts might be useful
let res: ::parse::PResult<'a, _> = p.parse_token_tree(); let mut tt = panictry!(p.parse_token_tree());
let res = token::NtTT(panictry!(res));
p.quote_depth -= 1; p.quote_depth -= 1;
return res; loop {
let nt = match tt {
TokenTree::Token(_, token::Interpolated(ref nt)) => nt.clone(),
_ => break,
};
match *nt {
token::NtTT(ref sub_tt) => tt = sub_tt.clone(),
_ => break,
}
}
return token::NtTT(tt);
} }
_ => {} _ => {}
} }

View file

@ -212,6 +212,7 @@ pub struct Parser<'a> {
pub expected_tokens: Vec<TokenType>, pub expected_tokens: Vec<TokenType>,
pub tts: Vec<(TokenTree, usize)>, pub tts: Vec<(TokenTree, usize)>,
pub desugar_doc_comments: bool, pub desugar_doc_comments: bool,
pub allow_interpolated_tts: bool,
} }
#[derive(PartialEq, Eq, Clone)] #[derive(PartialEq, Eq, Clone)]
@ -301,6 +302,7 @@ impl<'a> Parser<'a> {
expected_tokens: Vec::new(), expected_tokens: Vec::new(),
tts: Vec::new(), tts: Vec::new(),
desugar_doc_comments: desugar_doc_comments, desugar_doc_comments: desugar_doc_comments,
allow_interpolated_tts: true,
}; };
let tok = parser.next_tok(); let tok = parser.next_tok();
@ -2718,7 +2720,12 @@ impl<'a> Parser<'a> {
if self.tts.last().map(|&(_, i)| i == 1).unwrap_or(false) { if self.tts.last().map(|&(_, i)| i == 1).unwrap_or(false) {
let tt = self.tts.pop().unwrap().0; let tt = self.tts.pop().unwrap().0;
self.bump(); self.bump();
return Ok(tt); return Ok(if self.allow_interpolated_tts {
// avoid needlessly reparsing token trees in recursive macro expansions
TokenTree::Token(tt.span(), token::Interpolated(Rc::new(token::NtTT(tt))))
} else {
tt
});
} }
let parsing_token_tree = ::std::mem::replace(&mut self.parsing_token_tree, true); let parsing_token_tree = ::std::mem::replace(&mut self.parsing_token_tree, true);