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Revert "Promote missing_fragment_specifier to hard error"

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This reverts commit 02eae432e7.
This commit is contained in:
Wesley Wiser 2020-12-19 16:30:56 -05:00
parent 9414f0b833
commit f1eb88b28a
14 changed files with 90 additions and 32 deletions
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2
compiler/rustc_expand/src/mbe.rs
View file

@ -84,7 +84,7 @@ enum TokenTree {
/// e.g., `$var`
MetaVar(Span, Ident),
/// e.g., `$var:expr`. This is only used in the left hand side of MBE macros.
MetaVarDecl(Span, Ident /* name to bind */, NonterminalKind),
MetaVarDecl(Span, Ident /* name to bind */, Option<NonterminalKind>),
}
impl TokenTree {

20
compiler/rustc_expand/src/mbe/macro_parser.rs
View file

@ -378,6 +378,11 @@ fn nameize<I: Iterator<Item = NamedMatch>>(
n_rec(sess, next_m, res.by_ref(), ret_val)?;
}
}
TokenTree::MetaVarDecl(span, _, None) => {
if sess.missing_fragment_specifiers.borrow_mut().remove(&span).is_some() {
return Err((span, "missing fragment specifier".to_string()));
}
}
TokenTree::MetaVarDecl(sp, bind_name, _) => match ret_val
.entry(MacroRulesNormalizedIdent::new(bind_name))
{
@ -446,6 +451,7 @@ fn or_pat_mode(edition: Edition) -> OrPatNonterminalMode {
///
/// A `ParseResult`. Note that matches are kept track of through the items generated.
fn inner_parse_loop<'root, 'tt>(
sess: &ParseSess,
cur_items: &mut SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>,
next_items: &mut Vec<MatcherPosHandle<'root, 'tt>>,
eof_items: &mut SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>,
@ -563,9 +569,16 @@ fn inner_parse_loop<'root, 'tt>(
})));
}
// We need to match a metavar (but the identifier is invalid)... this is an error
TokenTree::MetaVarDecl(span, _, None) => {
if sess.missing_fragment_specifiers.borrow_mut().remove(&span).is_some() {
return Error(span, "missing fragment specifier".to_string());
}
}
// We need to match a metavar with a valid ident... call out to the black-box
// parser by adding an item to `bb_items`.
TokenTree::MetaVarDecl(span, _, kind) => {
TokenTree::MetaVarDecl(span, _, Some(kind)) => {
// Built-in nonterminals never start with these tokens, so we can eliminate
// them from consideration.
//
@ -640,6 +653,7 @@ pub(super) fn parse_tt(parser: &mut Cow<'_, Parser<'_>>, ms: &[TokenTree]) -> Na
// parsing from the black-box parser done. The result is that `next_items` will contain a
// bunch of possible next matcher positions in `next_items`.
match inner_parse_loop(
parser.sess,
&mut cur_items,
&mut next_items,
&mut eof_items,
@ -701,7 +715,7 @@ pub(super) fn parse_tt(parser: &mut Cow<'_, Parser<'_>>, ms: &[TokenTree]) -> Na
let nts = bb_items
.iter()
.map(|item| match item.top_elts.get_tt(item.idx) {
TokenTree::MetaVarDecl(_, bind, kind) => format!("{} ('{}')", kind, bind),
TokenTree::MetaVarDecl(_, bind, Some(kind)) => format!("{} ('{}')", kind, bind),
_ => panic!(),
})
.collect::<Vec<String>>()
@ -731,7 +745,7 @@ pub(super) fn parse_tt(parser: &mut Cow<'_, Parser<'_>>, ms: &[TokenTree]) -> Na
assert_eq!(bb_items.len(), 1);
let mut item = bb_items.pop().unwrap();
if let TokenTree::MetaVarDecl(span, _, kind) = item.top_elts.get_tt(item.idx) {
if let TokenTree::MetaVarDecl(span, _, Some(kind)) = item.top_elts.get_tt(item.idx) {
let match_cur = item.match_cur;
// We use the span of the metavariable declaration to determine any
// edition-specific matching behavior for non-terminals.

15
compiler/rustc_expand/src/mbe/macro_rules.rs
View file

@ -401,7 +401,7 @@ pub fn compile_declarative_macro(
let diag = &sess.parse_sess.span_diagnostic;
let lhs_nm = Ident::new(sym::lhs, def.span);
let rhs_nm = Ident::new(sym::rhs, def.span);
let tt_spec = NonterminalKind::TT;
let tt_spec = Some(NonterminalKind::TT);
// Parse the macro_rules! invocation
let (macro_rules, body) = match &def.kind {
@ -578,7 +578,7 @@ fn check_lhs_no_empty_seq(sess: &ParseSess, tts: &[mbe::TokenTree]) -> bool {
TokenTree::Sequence(span, ref seq) => {
if seq.separator.is_none()
&& seq.tts.iter().all(|seq_tt| match *seq_tt {
TokenTree::MetaVarDecl(_, _, NonterminalKind::Vis) => true,
TokenTree::MetaVarDecl(_, _, Some(NonterminalKind::Vis)) => true,
TokenTree::Sequence(_, ref sub_seq) => {
sub_seq.kleene.op == mbe::KleeneOp::ZeroOrMore
|| sub_seq.kleene.op == mbe::KleeneOp::ZeroOrOne
@ -961,7 +961,7 @@ fn check_matcher_core(
// Now `last` holds the complete set of NT tokens that could
// end the sequence before SUFFIX. Check that every one works with `suffix`.
for token in &last.tokens {
if let TokenTree::MetaVarDecl(_, name, kind) = *token {
if let TokenTree::MetaVarDecl(_, name, Some(kind)) = *token {
for next_token in &suffix_first.tokens {
match is_in_follow(next_token, kind) {
IsInFollow::Yes => {}
@ -1019,7 +1019,7 @@ fn check_matcher_core(
}
fn token_can_be_followed_by_any(tok: &mbe::TokenTree) -> bool {
if let mbe::TokenTree::MetaVarDecl(_, _, kind) = *tok {
if let mbe::TokenTree::MetaVarDecl(_, _, Some(kind)) = *tok {
frag_can_be_followed_by_any(kind)
} else {
// (Non NT's can always be followed by anything in matchers.)
@ -1123,7 +1123,7 @@ fn is_in_follow(tok: &mbe::TokenTree, kind: NonterminalKind) -> IsInFollow {
}
_ => IsInFollow::No(TOKENS),
},
TokenTree::MetaVarDecl(_, _, NonterminalKind::Block) => IsInFollow::Yes,
TokenTree::MetaVarDecl(_, _, Some(NonterminalKind::Block)) => IsInFollow::Yes,
_ => IsInFollow::No(TOKENS),
}
}
@ -1158,7 +1158,7 @@ fn is_in_follow(tok: &mbe::TokenTree, kind: NonterminalKind) -> IsInFollow {
TokenTree::MetaVarDecl(
_,
_,
NonterminalKind::Ident | NonterminalKind::Ty | NonterminalKind::Path,
Some(NonterminalKind::Ident | NonterminalKind::Ty | NonterminalKind::Path),
) => IsInFollow::Yes,
_ => IsInFollow::No(TOKENS),
}
@ -1171,7 +1171,8 @@ fn quoted_tt_to_string(tt: &mbe::TokenTree) -> String {
match *tt {
mbe::TokenTree::Token(ref token) => pprust::token_to_string(&token),
mbe::TokenTree::MetaVar(_, name) => format!("${}", name),
mbe::TokenTree::MetaVarDecl(_, name, kind) => format!("${}:{}", name, kind),
mbe::TokenTree::MetaVarDecl(_, name, Some(kind)) => format!("${}:{}", name, kind),
mbe::TokenTree::MetaVarDecl(_, name, None) => format!("${}:", name),
_ => panic!(
"{}",
"unexpected mbe::TokenTree::{Sequence or Delimited} \

11
compiler/rustc_expand/src/mbe/quoted.rs
View file

@ -3,7 +3,7 @@ use crate::mbe::{Delimited, KleeneOp, KleeneToken, SequenceRepetition, TokenTree
use rustc_ast::token::{self, Token};
use rustc_ast::tokenstream;
use rustc_ast::NodeId;
use rustc_ast::{NodeId, DUMMY_NODE_ID};
use rustc_ast_pretty::pprust;
use rustc_session::parse::ParseSess;
use rustc_span::symbol::{kw, Ident};
@ -73,7 +73,7 @@ pub(super) fn parse(
.emit();
token::NonterminalKind::Ident
});
result.push(TokenTree::MetaVarDecl(span, ident, kind));
result.push(TokenTree::MetaVarDecl(span, ident, Some(kind)));
continue;
}
_ => token.span,
@ -83,8 +83,11 @@ pub(super) fn parse(
}
tree => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(start_sp),
};
sess.span_diagnostic.struct_span_err(span, "missing fragment specifier").emit();
continue;
if node_id != DUMMY_NODE_ID {
// Macros loaded from other crates have dummy node ids.
sess.missing_fragment_specifiers.borrow_mut().insert(span, node_id);
}
result.push(TokenTree::MetaVarDecl(span, ident, None));
}
// Not a metavar or no matchers allowed, so just return the tree