// option. This file may not be copied, modified, or distributed
// except according to those terms.
-use ast;
+use {ast, attr};
use syntax_pos::{Span, DUMMY_SP};
use ext::base::{DummyResult, ExtCtxt, MacResult, SyntaxExtension};
use ext::base::{NormalTT, TTMacroExpander};
+use ext::expand::{Expansion, ExpansionKind};
use ext::tt::macro_parser::{Success, Error, Failure};
use ext::tt::macro_parser::{MatchedSeq, MatchedNonterminal};
-use ext::tt::macro_parser::parse;
-use parse::lexer::new_tt_reader;
-use parse::parser::{Parser, Restrictions};
-use parse::token::{self, gensym_ident, NtTT, Token};
+use ext::tt::macro_parser::{parse, parse_failure_msg};
+use ext::tt::quoted;
+use ext::tt::transcribe::transcribe;
+use feature_gate::{self, emit_feature_err, Features, GateIssue};
+use parse::{Directory, ParseSess};
+use parse::parser::Parser;
+use parse::token::{self, NtTT};
use parse::token::Token::*;
-use print;
-use ptr::P;
-use tokenstream::{self, TokenTree};
+use symbol::Symbol;
+use tokenstream::{TokenStream, TokenTree};
-use util::small_vector::SmallVector;
+use std::collections::HashMap;
+use std::collections::hash_map::Entry;
-use std::cell::RefCell;
-use std::collections::{HashMap};
-use std::collections::hash_map::{Entry};
-use std::rc::Rc;
+use rustc_data_structures::sync::Lrc;
-struct ParserAnyMacro<'a> {
- parser: RefCell<Parser<'a>>,
+pub struct ParserAnyMacro<'a> {
+ parser: Parser<'a>,
/// Span of the expansion site of the macro this parser is for
site_span: Span,
}
impl<'a> ParserAnyMacro<'a> {
- /// Make sure we don't have any tokens left to parse, so we don't
- /// silently drop anything. `allow_semi` is so that "optional"
- /// semicolons at the end of normal expressions aren't complained
- /// about e.g. the semicolon in `macro_rules! kapow { () => {
- /// panic!(); } }` doesn't get picked up by .parse_expr(), but it's
- /// allowed to be there.
- fn ensure_complete_parse(&self, allow_semi: bool, context: &str) {
- let mut parser = self.parser.borrow_mut();
- if allow_semi && parser.token == token::Semi {
+ pub fn make(mut self: Box<ParserAnyMacro<'a>>, kind: ExpansionKind) -> Expansion {
+ let ParserAnyMacro { site_span, macro_ident, ref mut parser } = *self;
+ let expansion = panictry!(parser.parse_expansion(kind, true));
+
+ // We allow semicolons at the end of expressions -- e.g. the semicolon in
+ // `macro_rules! m { () => { panic!(); } }` isn't parsed by `.parse_expr()`,
+ // but `m!()` is allowed in expression positions (c.f. issue #34706).
+ if kind == ExpansionKind::Expr && parser.token == token::Semi {
parser.bump();
}
- if parser.token != token::Eof {
- let token_str = parser.this_token_to_string();
- let msg = format!("macro expansion ignores token `{}` and any \
- following",
- token_str);
- let span = parser.span;
- let mut err = parser.diagnostic().struct_span_err(span, &msg[..]);
- let msg = format!("caused by the macro expansion here; the usage \
- of `{}!` is likely invalid in {} context",
- self.macro_ident, context);
- err.span_note(self.site_span, &msg[..])
- .emit();
- }
- }
-}
-
-impl<'a> MacResult for ParserAnyMacro<'a> {
- fn make_expr(self: Box<ParserAnyMacro<'a>>) -> Option<P<ast::Expr>> {
- let ret = panictry!(self.parser.borrow_mut().parse_expr());
- self.ensure_complete_parse(true, "expression");
- Some(ret)
- }
- fn make_pat(self: Box<ParserAnyMacro<'a>>) -> Option<P<ast::Pat>> {
- let ret = panictry!(self.parser.borrow_mut().parse_pat());
- self.ensure_complete_parse(false, "pattern");
- Some(ret)
- }
- fn make_items(self: Box<ParserAnyMacro<'a>>) -> Option<SmallVector<P<ast::Item>>> {
- let mut ret = SmallVector::zero();
- while let Some(item) = panictry!(self.parser.borrow_mut().parse_item()) {
- ret.push(item);
- }
- self.ensure_complete_parse(false, "item");
- Some(ret)
- }
-
- fn make_impl_items(self: Box<ParserAnyMacro<'a>>)
- -> Option<SmallVector<ast::ImplItem>> {
- let mut ret = SmallVector::zero();
- loop {
- let mut parser = self.parser.borrow_mut();
- match parser.token {
- token::Eof => break,
- _ => ret.push(panictry!(parser.parse_impl_item()))
- }
- }
- self.ensure_complete_parse(false, "item");
- Some(ret)
- }
- fn make_trait_items(self: Box<ParserAnyMacro<'a>>)
- -> Option<SmallVector<ast::TraitItem>> {
- let mut ret = SmallVector::zero();
- loop {
- let mut parser = self.parser.borrow_mut();
- match parser.token {
- token::Eof => break,
- _ => ret.push(panictry!(parser.parse_trait_item()))
- }
- }
- self.ensure_complete_parse(false, "item");
- Some(ret)
- }
-
-
- fn make_stmts(self: Box<ParserAnyMacro<'a>>)
- -> Option<SmallVector<ast::Stmt>> {
- let mut ret = SmallVector::zero();
- loop {
- let mut parser = self.parser.borrow_mut();
- match parser.token {
- token::Eof => break,
- _ => match parser.parse_full_stmt(true) {
- Ok(maybe_stmt) => match maybe_stmt {
- Some(stmt) => ret.push(stmt),
- None => (),
- },
- Err(mut e) => {
- e.emit();
- break;
- }
- }
- }
- }
- self.ensure_complete_parse(false, "statement");
- Some(ret)
- }
-
- fn make_ty(self: Box<ParserAnyMacro<'a>>) -> Option<P<ast::Ty>> {
- let ret = panictry!(self.parser.borrow_mut().parse_ty());
- self.ensure_complete_parse(false, "type");
- Some(ret)
+ // Make sure we don't have any tokens left to parse so we don't silently drop anything.
+ let path = ast::Path::from_ident(macro_ident.with_span_pos(site_span));
+ parser.ensure_complete_parse(&path, kind.name(), site_span);
+ expansion
}
}
struct MacroRulesMacroExpander {
name: ast::Ident,
- imported_from: Option<ast::Ident>,
- lhses: Vec<TokenTree>,
- rhses: Vec<TokenTree>,
+ lhses: Vec<quoted::TokenTree>,
+ rhses: Vec<quoted::TokenTree>,
valid: bool,
}
fn expand<'cx>(&self,
cx: &'cx mut ExtCtxt,
sp: Span,
- arg: &[TokenTree])
+ input: TokenStream)
-> Box<MacResult+'cx> {
if !self.valid {
return DummyResult::any(sp);
generic_extension(cx,
sp,
self.name,
- self.imported_from,
- arg,
+ input,
&self.lhses,
&self.rhses)
}
}
+fn trace_macros_note(cx: &mut ExtCtxt, sp: Span, message: String) {
+ let sp = sp.macro_backtrace().last().map(|trace| trace.call_site).unwrap_or(sp);
+ let values: &mut Vec<String> = cx.expansions.entry(sp).or_insert_with(Vec::new);
+ values.push(message);
+}
+
/// Given `lhses` and `rhses`, this is the new macro we create
-fn generic_extension<'cx>(cx: &'cx ExtCtxt,
+fn generic_extension<'cx>(cx: &'cx mut ExtCtxt,
sp: Span,
name: ast::Ident,
- imported_from: Option<ast::Ident>,
- arg: &[TokenTree],
- lhses: &[TokenTree],
- rhses: &[TokenTree])
+ arg: TokenStream,
+ lhses: &[quoted::TokenTree],
+ rhses: &[quoted::TokenTree])
-> Box<MacResult+'cx> {
if cx.trace_macros() {
- println!("{}! {{ {} }}",
- name,
- print::pprust::tts_to_string(arg));
+ trace_macros_note(cx, sp, format!("expanding `{}! {{ {} }}`", name, arg));
}
// Which arm's failure should we report? (the one furthest along)
let mut best_fail_spot = DUMMY_SP;
- let mut best_fail_msg = "internal error: ran no matchers".to_string();
+ let mut best_fail_tok = None;
for (i, lhs) in lhses.iter().enumerate() { // try each arm's matchers
let lhs_tt = match *lhs {
- TokenTree::Delimited(_, ref delim) => &delim.tts[..],
+ quoted::TokenTree::Delimited(_, ref delim) => &delim.tts[..],
_ => cx.span_bug(sp, "malformed macro lhs")
};
- match TokenTree::parse(cx, lhs_tt, arg) {
+ match TokenTree::parse(cx, lhs_tt, arg.clone()) {
Success(named_matches) => {
let rhs = match rhses[i] {
// ignore delimiters
- TokenTree::Delimited(_, ref delimed) => delimed.tts.clone(),
+ quoted::TokenTree::Delimited(_, ref delimed) => delimed.tts.clone(),
_ => cx.span_bug(sp, "malformed macro rhs"),
};
+
+ let rhs_spans = rhs.iter().map(|t| t.span()).collect::<Vec<_>>();
// rhs has holes ( `$id` and `$(...)` that need filled)
- let trncbr = new_tt_reader(&cx.parse_sess().span_diagnostic,
- Some(named_matches),
- imported_from,
- rhs);
- let mut p = Parser::new(cx.parse_sess(), cx.cfg(), Box::new(trncbr));
- p.filename = cx.filename.clone();
- p.mod_path_stack = cx.mod_path_stack.clone();
- p.restrictions = match cx.in_block {
- true => Restrictions::NO_NONINLINE_MOD,
- false => Restrictions::empty(),
+ let mut tts = transcribe(cx, Some(named_matches), rhs);
+
+ // Replace all the tokens for the corresponding positions in the macro, to maintain
+ // proper positions in error reporting, while maintaining the macro_backtrace.
+ if rhs_spans.len() == tts.len() {
+ tts = tts.map_enumerated(|i, tt| {
+ let mut tt = tt.clone();
+ let mut sp = rhs_spans[i];
+ sp = sp.with_ctxt(tt.span().ctxt());
+ tt.set_span(sp);
+ tt
+ });
+ }
+
+ if cx.trace_macros() {
+ trace_macros_note(cx, sp, format!("to `{}`", tts));
+ }
+
+ let directory = Directory {
+ path: cx.current_expansion.module.directory.clone(),
+ ownership: cx.current_expansion.directory_ownership,
};
- p.check_unknown_macro_variable();
+ let mut p = Parser::new(cx.parse_sess(), tts, Some(directory), true, false);
+ p.root_module_name = cx.current_expansion.module.mod_path.last()
+ .map(|id| id.name.as_str().to_string());
+
+ p.process_potential_macro_variable();
// Let the context choose how to interpret the result.
// Weird, but useful for X-macros.
return Box::new(ParserAnyMacro {
- parser: RefCell::new(p),
+ parser: p,
// Pass along the original expansion site and the name of the macro
// so we can print a useful error message if the parse of the expanded
macro_ident: name
})
}
- Failure(sp, ref msg) => if sp.lo >= best_fail_spot.lo {
+ Failure(sp, tok) => if sp.lo() >= best_fail_spot.lo() {
best_fail_spot = sp;
- best_fail_msg = (*msg).clone();
+ best_fail_tok = Some(tok);
},
Error(err_sp, ref msg) => {
cx.span_fatal(err_sp.substitute_dummy(sp), &msg[..])
}
}
- cx.span_fatal(best_fail_spot.substitute_dummy(sp), &best_fail_msg[..]);
+ let best_fail_msg = parse_failure_msg(best_fail_tok.expect("ran no matchers"));
+ cx.span_err(best_fail_spot.substitute_dummy(sp), &best_fail_msg);
+ cx.trace_macros_diag();
+ DummyResult::any(sp)
}
// Note that macro-by-example's input is also matched against a token tree:
// Holy self-referential!
/// Converts a `macro_rules!` invocation into a syntax extension.
-pub fn compile<'cx>(cx: &'cx mut ExtCtxt,
- def: &ast::MacroDef) -> SyntaxExtension {
-
- let lhs_nm = gensym_ident("lhs");
- let rhs_nm = gensym_ident("rhs");
+pub fn compile(sess: &ParseSess, features: &Features, def: &ast::Item) -> SyntaxExtension {
+ let lhs_nm = ast::Ident::with_empty_ctxt(Symbol::gensym("lhs"));
+ let rhs_nm = ast::Ident::with_empty_ctxt(Symbol::gensym("rhs"));
+
+ // Parse the macro_rules! invocation
+ let body = match def.node {
+ ast::ItemKind::MacroDef(ref body) => body,
+ _ => unreachable!(),
+ };
// The pattern that macro_rules matches.
// The grammar for macro_rules! is:
// $( $lhs:tt => $rhs:tt );+
// ...quasiquoting this would be nice.
// These spans won't matter, anyways
- let match_lhs_tok = MatchNt(lhs_nm, token::str_to_ident("tt"));
- let match_rhs_tok = MatchNt(rhs_nm, token::str_to_ident("tt"));
let argument_gram = vec![
- TokenTree::Sequence(DUMMY_SP, Rc::new(tokenstream::SequenceRepetition {
+ quoted::TokenTree::Sequence(DUMMY_SP, Lrc::new(quoted::SequenceRepetition {
tts: vec![
- TokenTree::Token(DUMMY_SP, match_lhs_tok),
- TokenTree::Token(DUMMY_SP, token::FatArrow),
- TokenTree::Token(DUMMY_SP, match_rhs_tok),
+ quoted::TokenTree::MetaVarDecl(DUMMY_SP, lhs_nm, ast::Ident::from_str("tt")),
+ quoted::TokenTree::Token(DUMMY_SP, token::FatArrow),
+ quoted::TokenTree::MetaVarDecl(DUMMY_SP, rhs_nm, ast::Ident::from_str("tt")),
],
- separator: Some(token::Semi),
- op: tokenstream::KleeneOp::OneOrMore,
+ separator: Some(if body.legacy { token::Semi } else { token::Comma }),
+ op: quoted::KleeneOp::OneOrMore,
num_captures: 2,
})),
// to phase into semicolon-termination instead of semicolon-separation
- TokenTree::Sequence(DUMMY_SP, Rc::new(tokenstream::SequenceRepetition {
- tts: vec![TokenTree::Token(DUMMY_SP, token::Semi)],
+ quoted::TokenTree::Sequence(DUMMY_SP, Lrc::new(quoted::SequenceRepetition {
+ tts: vec![quoted::TokenTree::Token(DUMMY_SP, token::Semi)],
separator: None,
- op: tokenstream::KleeneOp::ZeroOrMore,
+ op: quoted::KleeneOp::ZeroOrMore,
num_captures: 0
})),
];
- // Parse the macro_rules! invocation (`none` is for no interpolations):
- let arg_reader = new_tt_reader(&cx.parse_sess().span_diagnostic,
- None,
- None,
- def.body.clone());
-
- let argument_map = match parse(cx.parse_sess(),
- cx.cfg(),
- arg_reader,
- &argument_gram) {
+ let argument_map = match parse(sess, body.stream(), &argument_gram, None, true) {
Success(m) => m,
- Failure(sp, str) | Error(sp, str) => {
- panic!(cx.parse_sess().span_diagnostic
- .span_fatal(sp.substitute_dummy(def.span), &str[..]));
+ Failure(sp, tok) => {
+ let s = parse_failure_msg(tok);
+ sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &s).raise();
+ }
+ Error(sp, s) => {
+ sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &s).raise();
}
};
let mut valid = true;
// Extract the arguments:
- let lhses = match **argument_map.get(&lhs_nm).unwrap() {
+ let lhses = match *argument_map[&lhs_nm] {
MatchedSeq(ref s, _) => {
- s.iter().map(|m| match **m {
- MatchedNonterminal(NtTT(ref tt)) => {
- valid &= check_lhs_nt_follows(cx, tt);
- (**tt).clone()
+ s.iter().map(|m| {
+ if let MatchedNonterminal(ref nt) = *m {
+ if let NtTT(ref tt) = **nt {
+ let tt = quoted::parse(tt.clone().into(), true, sess, features, &def.attrs)
+ .pop().unwrap();
+ valid &= check_lhs_nt_follows(sess, features, &def.attrs, &tt);
+ return tt;
+ }
}
- _ => cx.span_bug(def.span, "wrong-structured lhs")
- }).collect()
+ sess.span_diagnostic.span_bug(def.span, "wrong-structured lhs")
+ }).collect::<Vec<quoted::TokenTree>>()
}
- _ => cx.span_bug(def.span, "wrong-structured lhs")
+ _ => sess.span_diagnostic.span_bug(def.span, "wrong-structured lhs")
};
- let rhses = match **argument_map.get(&rhs_nm).unwrap() {
+ let rhses = match *argument_map[&rhs_nm] {
MatchedSeq(ref s, _) => {
- s.iter().map(|m| match **m {
- MatchedNonterminal(NtTT(ref tt)) => (**tt).clone(),
- _ => cx.span_bug(def.span, "wrong-structured rhs")
- }).collect()
+ s.iter().map(|m| {
+ if let MatchedNonterminal(ref nt) = *m {
+ if let NtTT(ref tt) = **nt {
+ return quoted::parse(tt.clone().into(), false, sess, features, &def.attrs)
+ .pop().unwrap();
+ }
+ }
+ sess.span_diagnostic.span_bug(def.span, "wrong-structured lhs")
+ }).collect::<Vec<quoted::TokenTree>>()
}
- _ => cx.span_bug(def.span, "wrong-structured rhs")
+ _ => sess.span_diagnostic.span_bug(def.span, "wrong-structured rhs")
};
for rhs in &rhses {
- valid &= check_rhs(cx, rhs);
+ valid &= check_rhs(sess, rhs);
}
- let exp: Box<_> = Box::new(MacroRulesMacroExpander {
+ // don't abort iteration early, so that errors for multiple lhses can be reported
+ for lhs in &lhses {
+ valid &= check_lhs_no_empty_seq(sess, &[lhs.clone()])
+ }
+
+ let expander: Box<_> = Box::new(MacroRulesMacroExpander {
name: def.ident,
- imported_from: def.imported_from,
- lhses: lhses,
- rhses: rhses,
- valid: valid,
+ lhses,
+ rhses,
+ valid,
});
- NormalTT(exp, Some(def.span), def.allow_internal_unstable)
+ if body.legacy {
+ let allow_internal_unstable = attr::contains_name(&def.attrs, "allow_internal_unstable");
+ let allow_internal_unsafe = attr::contains_name(&def.attrs, "allow_internal_unsafe");
+
+ let unstable_feature = attr::find_stability(&sess.span_diagnostic,
+ &def.attrs, def.span).and_then(|stability| {
+ if let attr::StabilityLevel::Unstable { issue, .. } = stability.level {
+ Some((stability.feature, issue))
+ } else {
+ None
+ }
+ });
+
+ NormalTT {
+ expander,
+ def_info: Some((def.id, def.span)),
+ allow_internal_unstable,
+ allow_internal_unsafe,
+ unstable_feature
+ }
+ } else {
+ SyntaxExtension::DeclMacro(expander, Some((def.id, def.span)))
+ }
}
-fn check_lhs_nt_follows(cx: &mut ExtCtxt, lhs: &TokenTree) -> bool {
+fn check_lhs_nt_follows(sess: &ParseSess,
+ features: &Features,
+ attrs: &[ast::Attribute],
+ lhs: "ed::TokenTree) -> bool {
// lhs is going to be like TokenTree::Delimited(...), where the
// entire lhs is those tts. Or, it can be a "bare sequence", not wrapped in parens.
- match lhs {
- &TokenTree::Delimited(_, ref tts) => check_matcher(cx, &tts.tts),
- _ => {
- cx.span_err(lhs.get_span(), "invalid macro matcher; matchers must \
- be contained in balanced delimiters");
- false
- }
+ if let quoted::TokenTree::Delimited(_, ref tts) = *lhs {
+ check_matcher(sess, features, attrs, &tts.tts)
+ } else {
+ let msg = "invalid macro matcher; matchers must be contained in balanced delimiters";
+ sess.span_diagnostic.span_err(lhs.span(), msg);
+ false
}
// we don't abort on errors on rejection, the driver will do that for us
// after parsing/expansion. we can report every error in every macro this way.
}
-fn check_rhs(cx: &mut ExtCtxt, rhs: &TokenTree) -> bool {
+/// Check that the lhs contains no repetition which could match an empty token
+/// tree, because then the matcher would hang indefinitely.
+fn check_lhs_no_empty_seq(sess: &ParseSess, tts: &[quoted::TokenTree]) -> bool {
+ use self::quoted::TokenTree;
+ for tt in tts {
+ match *tt {
+ TokenTree::Token(..) | TokenTree::MetaVar(..) | TokenTree::MetaVarDecl(..) => (),
+ TokenTree::Delimited(_, ref del) => if !check_lhs_no_empty_seq(sess, &del.tts) {
+ return false;
+ },
+ TokenTree::Sequence(span, ref seq) => {
+ if seq.separator.is_none() && seq.tts.iter().all(|seq_tt| {
+ match *seq_tt {
+ TokenTree::MetaVarDecl(_, _, id) => id.name == "vis",
+ TokenTree::Sequence(_, ref sub_seq) =>
+ sub_seq.op == quoted::KleeneOp::ZeroOrMore,
+ _ => false,
+ }
+ }) {
+ sess.span_diagnostic.span_err(span, "repetition matches empty token tree");
+ return false;
+ }
+ if !check_lhs_no_empty_seq(sess, &seq.tts) {
+ return false;
+ }
+ }
+ }
+ }
+
+ true
+}
+
+fn check_rhs(sess: &ParseSess, rhs: "ed::TokenTree) -> bool {
match *rhs {
- TokenTree::Delimited(..) => return true,
- _ => cx.span_err(rhs.get_span(), "macro rhs must be delimited")
+ quoted::TokenTree::Delimited(..) => return true,
+ _ => sess.span_diagnostic.span_err(rhs.span(), "macro rhs must be delimited")
}
false
}
-fn check_matcher(cx: &mut ExtCtxt, matcher: &[TokenTree]) -> bool {
+fn check_matcher(sess: &ParseSess,
+ features: &Features,
+ attrs: &[ast::Attribute],
+ matcher: &[quoted::TokenTree]) -> bool {
let first_sets = FirstSets::new(matcher);
let empty_suffix = TokenSet::empty();
- let err = cx.parse_sess.span_diagnostic.err_count();
- check_matcher_core(cx, &first_sets, matcher, &empty_suffix);
- err == cx.parse_sess.span_diagnostic.err_count()
+ let err = sess.span_diagnostic.err_count();
+ check_matcher_core(sess, features, attrs, &first_sets, matcher, &empty_suffix);
+ err == sess.span_diagnostic.err_count()
}
// The FirstSets for a matcher is a mapping from subsequences in the
}
impl FirstSets {
- fn new(tts: &[TokenTree]) -> FirstSets {
+ fn new(tts: &[quoted::TokenTree]) -> FirstSets {
+ use self::quoted::TokenTree;
+
let mut sets = FirstSets { first: HashMap::new() };
build_recur(&mut sets, tts);
return sets;
let mut first = TokenSet::empty();
for tt in tts.iter().rev() {
match *tt {
- TokenTree::Token(sp, ref tok) => {
- first.replace_with((sp, tok.clone()));
+ TokenTree::Token(..) | TokenTree::MetaVar(..) | TokenTree::MetaVarDecl(..) => {
+ first.replace_with(tt.clone());
}
- TokenTree::Delimited(_, ref delimited) => {
+ TokenTree::Delimited(span, ref delimited) => {
build_recur(sets, &delimited.tts[..]);
- first.replace_with((delimited.open_span,
- Token::OpenDelim(delimited.delim)));
+ first.replace_with(delimited.open_tt(span));
}
TokenTree::Sequence(sp, ref seq_rep) => {
let subfirst = build_recur(sets, &seq_rep.tts[..]);
if let (Some(ref sep), true) = (seq_rep.separator.clone(),
subfirst.maybe_empty) {
- first.add_one_maybe((sp, sep.clone()));
+ first.add_one_maybe(TokenTree::Token(sp, sep.clone()));
}
// Reverse scan: Sequence comes before `first`.
- if subfirst.maybe_empty || seq_rep.op == tokenstream::KleeneOp::ZeroOrMore {
+ if subfirst.maybe_empty || seq_rep.op == quoted::KleeneOp::ZeroOrMore {
// If sequence is potentially empty, then
// union them (preserving first emptiness).
first.add_all(&TokenSet { maybe_empty: true, ..subfirst });
}
}
- return first;
+ first
}
}
// walks forward over `tts` until all potential FIRST tokens are
// identified.
- fn first(&self, tts: &[TokenTree]) -> TokenSet {
+ fn first(&self, tts: &[quoted::TokenTree]) -> TokenSet {
+ use self::quoted::TokenTree;
+
let mut first = TokenSet::empty();
for tt in tts.iter() {
assert!(first.maybe_empty);
match *tt {
- TokenTree::Token(sp, ref tok) => {
- first.add_one((sp, tok.clone()));
+ TokenTree::Token(..) | TokenTree::MetaVar(..) | TokenTree::MetaVarDecl(..) => {
+ first.add_one(tt.clone());
return first;
}
- TokenTree::Delimited(_, ref delimited) => {
- first.add_one((delimited.open_span,
- Token::OpenDelim(delimited.delim)));
+ TokenTree::Delimited(span, ref delimited) => {
+ first.add_one(delimited.open_tt(span));
return first;
}
TokenTree::Sequence(sp, ref seq_rep) => {
if let (Some(ref sep), true) = (seq_rep.separator.clone(),
subfirst.maybe_empty) {
- first.add_one_maybe((sp, sep.clone()));
+ first.add_one_maybe(TokenTree::Token(sp, sep.clone()));
}
assert!(first.maybe_empty);
first.add_all(subfirst);
if subfirst.maybe_empty ||
- seq_rep.op == tokenstream::KleeneOp::ZeroOrMore {
+ seq_rep.op == quoted::KleeneOp::ZeroOrMore {
// continue scanning for more first
// tokens, but also make sure we
// restore empty-tracking state
// we only exit the loop if `tts` was empty or if every
// element of `tts` matches the empty sequence.
assert!(first.maybe_empty);
- return first;
+ first
}
}
-// A set of Tokens, which may include MatchNt tokens (for
-// macro-by-example syntactic variables). It also carries the
+// A set of `quoted::TokenTree`s, which may include `TokenTree::Match`s
+// (for macro-by-example syntactic variables). It also carries the
// `maybe_empty` flag; that is true if and only if the matcher can
// match an empty token sequence.
//
// (Notably, we must allow for *-op to occur zero times.)
#[derive(Clone, Debug)]
struct TokenSet {
- tokens: Vec<(Span, Token)>,
+ tokens: Vec<quoted::TokenTree>,
maybe_empty: bool,
}
// Returns the set `{ tok }` for the single-token (and thus
// non-empty) sequence [tok].
- fn singleton(tok: (Span, Token)) -> Self {
+ fn singleton(tok: quoted::TokenTree) -> Self {
TokenSet { tokens: vec![tok], maybe_empty: false }
}
// Changes self to be the set `{ tok }`.
// Since `tok` is always present, marks self as non-empty.
- fn replace_with(&mut self, tok: (Span, Token)) {
+ fn replace_with(&mut self, tok: quoted::TokenTree) {
self.tokens.clear();
self.tokens.push(tok);
self.maybe_empty = false;
}
// Adds `tok` to the set for `self`, marking sequence as non-empy.
- fn add_one(&mut self, tok: (Span, Token)) {
+ fn add_one(&mut self, tok: quoted::TokenTree) {
if !self.tokens.contains(&tok) {
self.tokens.push(tok);
}
}
// Adds `tok` to the set for `self`. (Leaves `maybe_empty` flag alone.)
- fn add_one_maybe(&mut self, tok: (Span, Token)) {
+ fn add_one_maybe(&mut self, tok: quoted::TokenTree) {
if !self.tokens.contains(&tok) {
self.tokens.push(tok);
}
//
// Requires that `first_sets` is pre-computed for `matcher`;
// see `FirstSets::new`.
-fn check_matcher_core(cx: &mut ExtCtxt,
+fn check_matcher_core(sess: &ParseSess,
+ features: &Features,
+ attrs: &[ast::Attribute],
first_sets: &FirstSets,
- matcher: &[TokenTree],
+ matcher: &[quoted::TokenTree],
follow: &TokenSet) -> TokenSet {
- use print::pprust::token_to_string;
+ use self::quoted::TokenTree;
let mut last = TokenSet::empty();
let build_suffix_first = || {
let mut s = first_sets.first(suffix);
if s.maybe_empty { s.add_all(follow); }
- return s;
+ s
};
// (we build `suffix_first` on demand below; you can tell
// First, update `last` so that it corresponds to the set
// of NT tokens that might end the sequence `... token`.
match *token {
- TokenTree::Token(sp, ref tok) => {
+ TokenTree::Token(..) | TokenTree::MetaVar(..) | TokenTree::MetaVarDecl(..) => {
let can_be_followed_by_any;
- if let Err(bad_frag) = has_legal_fragment_specifier(tok) {
- cx.struct_span_err(sp, &format!("invalid fragment specifier `{}`", bad_frag))
- .help("valid fragment specifiers are `ident`, `block`, \
- `stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt` \
- and `item`")
+ if let Err(bad_frag) = has_legal_fragment_specifier(sess, features, attrs, token) {
+ let msg = format!("invalid fragment specifier `{}`", bad_frag);
+ sess.span_diagnostic.struct_span_err(token.span(), &msg)
+ .help("valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, \
+ `pat`, `ty`, `path`, `meta`, `tt`, `item` and `vis`")
.emit();
// (This eliminates false positives and duplicates
// from error messages.)
can_be_followed_by_any = true;
} else {
- can_be_followed_by_any = token_can_be_followed_by_any(tok);
+ can_be_followed_by_any = token_can_be_followed_by_any(token);
}
if can_be_followed_by_any {
// followed by anything against SUFFIX.
continue 'each_token;
} else {
- last.replace_with((sp, tok.clone()));
+ last.replace_with(token.clone());
suffix_first = build_suffix_first();
}
}
- TokenTree::Delimited(_, ref d) => {
- let my_suffix = TokenSet::singleton((d.close_span, Token::CloseDelim(d.delim)));
- check_matcher_core(cx, first_sets, &d.tts, &my_suffix);
+ TokenTree::Delimited(span, ref d) => {
+ let my_suffix = TokenSet::singleton(d.close_tt(span));
+ check_matcher_core(sess, features, attrs, first_sets, &d.tts, &my_suffix);
// don't track non NT tokens
last.replace_with_irrelevant();
let mut new;
let my_suffix = if let Some(ref u) = seq_rep.separator {
new = suffix_first.clone();
- new.add_one_maybe((sp, u.clone()));
+ new.add_one_maybe(TokenTree::Token(sp, u.clone()));
&new
} else {
&suffix_first
// At this point, `suffix_first` is built, and
// `my_suffix` is some TokenSet that we can use
// for checking the interior of `seq_rep`.
- let next = check_matcher_core(cx, first_sets, &seq_rep.tts, my_suffix);
+ let next = check_matcher_core(sess,
+ features,
+ attrs,
+ first_sets,
+ &seq_rep.tts,
+ my_suffix);
if next.maybe_empty {
last.add_all(&next);
} else {
// Now `last` holds the complete set of NT tokens that could
// end the sequence before SUFFIX. Check that every one works with `suffix`.
- 'each_last: for &(_sp, ref t) in &last.tokens {
- if let MatchNt(ref name, ref frag_spec) = *t {
- for &(sp, ref next_token) in &suffix_first.tokens {
- match is_in_follow(cx, next_token, &frag_spec.name.as_str()) {
+ 'each_last: for token in &last.tokens {
+ if let TokenTree::MetaVarDecl(_, ref name, ref frag_spec) = *token {
+ for next_token in &suffix_first.tokens {
+ match is_in_follow(next_token, &frag_spec.name.as_str()) {
Err((msg, help)) => {
- cx.struct_span_err(sp, &msg).help(help).emit();
+ sess.span_diagnostic.struct_span_err(next_token.span(), &msg)
+ .help(help).emit();
// don't bother reporting every source of
// conflict for a particular element of `last`.
continue 'each_last;
"may be"
};
- cx.span_err(
- sp,
+ sess.span_diagnostic.span_err(
+ next_token.span(),
&format!("`${name}:{frag}` {may_be} followed by `{next}`, which \
is not allowed for `{frag}` fragments",
name=name,
frag=frag_spec,
- next=token_to_string(next_token),
+ next=quoted_tt_to_string(next_token),
may_be=may_be)
);
}
last
}
-fn token_can_be_followed_by_any(tok: &Token) -> bool {
- if let &MatchNt(_, ref frag_spec) = tok {
+fn token_can_be_followed_by_any(tok: "ed::TokenTree) -> bool {
+ if let quoted::TokenTree::MetaVarDecl(_, _, frag_spec) = *tok {
frag_can_be_followed_by_any(&frag_spec.name.as_str())
} else {
// (Non NT's can always be followed by anthing in matchers.)
/// ANYTHING without fear of future compatibility hazards).
fn frag_can_be_followed_by_any(frag: &str) -> bool {
match frag {
- "item" | // always terminated by `}` or `;`
- "block" | // exactly one token tree
- "ident" | // exactly one token tree
- "meta" | // exactly one token tree
+ "item" | // always terminated by `}` or `;`
+ "block" | // exactly one token tree
+ "ident" | // exactly one token tree
+ "meta" | // exactly one token tree
+ "lifetime" | // exactly one token tree
"tt" => // exactly one token tree
true,
/// break macros that were relying on that binary operator as a
/// separator.
// when changing this do not forget to update doc/book/macros.md!
-fn is_in_follow(_: &ExtCtxt, tok: &Token, frag: &str) -> Result<bool, (String, &'static str)> {
- if let &CloseDelim(_) = tok {
+fn is_in_follow(tok: "ed::TokenTree, frag: &str) -> Result<bool, (String, &'static str)> {
+ use self::quoted::TokenTree;
+
+ if let TokenTree::Token(_, token::CloseDelim(_)) = *tok {
// closing a token tree can never be matched by any fragment;
// iow, we always require that `(` and `)` match, etc.
Ok(true)
// maintain
Ok(true)
},
- "stmt" | "expr" => {
- match *tok {
+ "stmt" | "expr" => match *tok {
+ TokenTree::Token(_, ref tok) => match *tok {
FatArrow | Comma | Semi => Ok(true),
_ => Ok(false)
- }
+ },
+ _ => Ok(false),
},
- "pat" => {
- match *tok {
+ "pat" => match *tok {
+ TokenTree::Token(_, ref tok) => match *tok {
FatArrow | Comma | Eq | BinOp(token::Or) => Ok(true),
- Ident(i) if (i.name.as_str() == "if" ||
- i.name.as_str() == "in") => Ok(true),
+ Ident(i, false) if i.name == "if" || i.name == "in" => Ok(true),
_ => Ok(false)
- }
+ },
+ _ => Ok(false),
},
- "path" | "ty" => {
- match *tok {
+ "path" | "ty" => match *tok {
+ TokenTree::Token(_, ref tok) => match *tok {
OpenDelim(token::DelimToken::Brace) | OpenDelim(token::DelimToken::Bracket) |
Comma | FatArrow | Colon | Eq | Gt | Semi | BinOp(token::Or) => Ok(true),
- MatchNt(_, ref frag) if frag.name.as_str() == "block" => Ok(true),
- Ident(i) if i.name.as_str() == "as" || i.name.as_str() == "where" => Ok(true),
+ Ident(i, false) if i.name == "as" || i.name == "where" => Ok(true),
_ => Ok(false)
- }
+ },
+ TokenTree::MetaVarDecl(_, _, frag) if frag.name == "block" => Ok(true),
+ _ => Ok(false),
},
- "ident" => {
- // being a single token, idents are harmless
+ "ident" | "lifetime" => {
+ // being a single token, idents and lifetimes are harmless
Ok(true)
},
"meta" | "tt" => {
// harmless
Ok(true)
},
+ "vis" => {
+ // Explicitly disallow `priv`, on the off chance it comes back.
+ match *tok {
+ TokenTree::Token(_, ref tok) => match *tok {
+ Comma => Ok(true),
+ Ident(i, is_raw) if is_raw || i.name != "priv" => Ok(true),
+ ref tok => Ok(tok.can_begin_type())
+ },
+ TokenTree::MetaVarDecl(_, _, frag) if frag.name == "ident"
+ || frag.name == "ty"
+ || frag.name == "path" => Ok(true),
+ _ => Ok(false)
+ }
+ },
+ "" => Ok(true), // keywords::Invalid
_ => Err((format!("invalid fragment specifier `{}`", frag),
"valid fragment specifiers are `ident`, `block`, \
- `stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt` \
- and `item`"))
+ `stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt`, \
+ `item` and `vis`"))
}
}
}
-fn has_legal_fragment_specifier(tok: &Token) -> Result<(), String> {
+fn has_legal_fragment_specifier(sess: &ParseSess,
+ features: &Features,
+ attrs: &[ast::Attribute],
+ tok: "ed::TokenTree) -> Result<(), String> {
debug!("has_legal_fragment_specifier({:?})", tok);
- if let &MatchNt(_, ref frag_spec) = tok {
- let s = &frag_spec.name.as_str();
- if !is_legal_fragment_specifier(s) {
- return Err(s.to_string());
+ if let quoted::TokenTree::MetaVarDecl(_, _, ref frag_spec) = *tok {
+ let frag_name = frag_spec.name.as_str();
+ let frag_span = tok.span();
+ if !is_legal_fragment_specifier(sess, features, attrs, &frag_name, frag_span) {
+ return Err(frag_name.to_string());
}
}
Ok(())
}
-fn is_legal_fragment_specifier(frag: &str) -> bool {
- match frag {
+fn is_legal_fragment_specifier(sess: &ParseSess,
+ features: &Features,
+ attrs: &[ast::Attribute],
+ frag_name: &str,
+ frag_span: Span) -> bool {
+ match frag_name {
"item" | "block" | "stmt" | "expr" | "pat" |
- "path" | "ty" | "ident" | "meta" | "tt" => true,
+ "path" | "ty" | "ident" | "meta" | "tt" | "" => true,
+ "lifetime" => {
+ if !features.macro_lifetime_matcher &&
+ !attr::contains_name(attrs, "allow_internal_unstable") {
+ let explain = feature_gate::EXPLAIN_LIFETIME_MATCHER;
+ emit_feature_err(sess,
+ "macro_lifetime_matcher",
+ frag_span,
+ GateIssue::Language,
+ explain);
+ }
+ true
+ },
+ "vis" => {
+ if !features.macro_vis_matcher &&
+ !attr::contains_name(attrs, "allow_internal_unstable") {
+ let explain = feature_gate::EXPLAIN_VIS_MATCHER;
+ emit_feature_err(sess,
+ "macro_vis_matcher",
+ frag_span,
+ GateIssue::Language,
+ explain);
+ }
+ true
+ },
_ => false,
}
}
+
+fn quoted_tt_to_string(tt: "ed::TokenTree) -> String {
+ match *tt {
+ quoted::TokenTree::Token(_, ref tok) => ::print::pprust::token_to_string(tok),
+ quoted::TokenTree::MetaVar(_, name) => format!("${}", name),
+ quoted::TokenTree::MetaVarDecl(_, name, kind) => format!("${}:{}", name, kind),
+ _ => panic!("unexpected quoted::TokenTree::{{Sequence or Delimited}} \
+ in follow set checker"),
+ }
+}
projects / rustc.git / blobdiff