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Refactor ext::tt::macro_rules::compile to take a ParseSess instea…
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…d of an `ExtCtxt`.
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@jseyfried
jseyfried committed Sep 24, 2016
1 parent ee959a8 commit 1599461
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Showing 2 changed files with 33 additions and 40 deletions.
2 changes: 1 addition & 1 deletion src/libsyntax/ext/base.rs
View file
Expand Up @@ -816,7 +816,7 @@ impl<'a> ExtCtxt<'a> {
self.exported_macros.push(def.clone());
}
if def.use_locally {
let ext = macro_rules::compile(self, &def);
let ext = macro_rules::compile(self.parse_sess, &def);
self.resolver.add_macro(self.current_expansion.mark, def.ident, Rc::new(ext));
}
}
Expand Down
71 changes: 32 additions & 39 deletions src/libsyntax/ext/tt/macro_rules.rs
View file
Expand Up @@ -16,6 +16,7 @@ use ext::placeholders;
use ext::tt::macro_parser::{Success, Error, Failure};
use ext::tt::macro_parser::{MatchedSeq, MatchedNonterminal};
use ext::tt::macro_parser::parse;
use parse::ParseSess;
use parse::lexer::new_tt_reader;
use parse::parser::{Parser, Restrictions};
use parse::token::{self, gensym_ident, NtTT, Token};
Expand Down Expand Up @@ -204,7 +205,7 @@ fn generic_extension<'cx>(cx: &'cx ExtCtxt,
_ => cx.span_bug(sp, "malformed macro rhs"),
};
// rhs has holes ( `$id` and `$(...)` that need filled)
let trncbr = new_tt_reader(&cx.parse_sess().span_diagnostic,
let trncbr = new_tt_reader(&cx.parse_sess.span_diagnostic,
Some(named_matches),
imported_from,
rhs);
Expand Down Expand Up @@ -278,9 +279,7 @@ impl IdentMacroExpander for MacroRulesExpander {
// Holy self-referential!

/// Converts a `macro_rules!` invocation into a syntax extension.
pub fn compile<'cx>(cx: &'cx mut ExtCtxt,
def: &ast::MacroDef) -> SyntaxExtension {

pub fn compile(sess: &ParseSess, def: &ast::MacroDef) -> SyntaxExtension {
let lhs_nm = gensym_ident("lhs");
let rhs_nm = gensym_ident("rhs");

Expand Down Expand Up @@ -312,19 +311,12 @@ pub fn compile<'cx>(cx: &'cx mut ExtCtxt,
];

// 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 arg_reader = new_tt_reader(&sess.span_diagnostic, None, None, def.body.clone());

let argument_map = match parse(sess, Vec::new(), arg_reader, &argument_gram) {
Success(m) => m,
Failure(sp, str) | Error(sp, str) => {
panic!(cx.parse_sess().span_diagnostic
.span_fatal(sp.substitute_dummy(def.span), &str[..]));
panic!(sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &str));
}
};

Expand All @@ -335,27 +327,27 @@ pub fn compile<'cx>(cx: &'cx mut ExtCtxt,
MatchedSeq(ref s, _) => {
s.iter().map(|m| match **m {
MatchedNonterminal(NtTT(ref tt)) => {
valid &= check_lhs_nt_follows(cx, tt);
valid &= check_lhs_nt_follows(sess, tt);
(**tt).clone()
}
_ => cx.span_bug(def.span, "wrong-structured lhs")
_ => sess.span_diagnostic.span_bug(def.span, "wrong-structured lhs")
}).collect()
}
_ => 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() {
MatchedSeq(ref s, _) => {
s.iter().map(|m| match **m {
MatchedNonterminal(NtTT(ref tt)) => (**tt).clone(),
_ => cx.span_bug(def.span, "wrong-structured rhs")
_ => sess.span_diagnostic.span_bug(def.span, "wrong-structured rhs")
}).collect()
}
_ => 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 {
Expand All @@ -369,35 +361,35 @@ pub fn compile<'cx>(cx: &'cx mut ExtCtxt,
NormalTT(exp, Some(def.span), def.allow_internal_unstable)
}

fn check_lhs_nt_follows(cx: &mut ExtCtxt, lhs: &TokenTree) -> bool {
fn check_lhs_nt_follows(sess: &ParseSess, lhs: &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),
&TokenTree::Delimited(_, ref tts) => check_matcher(sess, &tts.tts),
_ => {
cx.span_err(lhs.get_span(), "invalid macro matcher; matchers must \
be contained in balanced delimiters");
let msg = "invalid macro matcher; matchers must be contained in balanced delimiters";
sess.span_diagnostic.span_err(lhs.get_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 {
fn check_rhs(sess: &ParseSess, rhs: &TokenTree) -> bool {
match *rhs {
TokenTree::Delimited(..) => return true,
_ => cx.span_err(rhs.get_span(), "macro rhs must be delimited")
_ => sess.span_diagnostic.span_err(rhs.get_span(), "macro rhs must be delimited")
}
false
}

fn check_matcher(cx: &mut ExtCtxt, matcher: &[TokenTree]) -> bool {
fn check_matcher(sess: &ParseSess, matcher: &[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, &first_sets, matcher, &empty_suffix);
err == sess.span_diagnostic.err_count()
}

// The FirstSets for a matcher is a mapping from subsequences in the
Expand Down Expand Up @@ -635,7 +627,7 @@ impl TokenSet {
//
// 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,
first_sets: &FirstSets,
matcher: &[TokenTree],
follow: &TokenSet) -> TokenSet {
Expand Down Expand Up @@ -667,7 +659,8 @@ fn check_matcher_core(cx: &mut ExtCtxt,
TokenTree::Token(sp, ref tok) => {
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))
let msg = format!("invalid fragment specifier `{}`", bad_frag);
sess.span_diagnostic.struct_span_err(sp, &msg)
.help("valid fragment specifiers are `ident`, `block`, \
`stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt` \
and `item`")
Expand All @@ -692,7 +685,7 @@ fn check_matcher_core(cx: &mut ExtCtxt,
}
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);
check_matcher_core(sess, first_sets, &d.tts, &my_suffix);
// don't track non NT tokens
last.replace_with_irrelevant();

Expand Down Expand Up @@ -724,7 +717,7 @@ fn check_matcher_core(cx: &mut ExtCtxt,
// 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, first_sets, &seq_rep.tts, my_suffix);
if next.maybe_empty {
last.add_all(&next);
} else {
Expand All @@ -744,9 +737,9 @@ fn check_matcher_core(cx: &mut ExtCtxt,
'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()) {
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(sp, &msg).help(help).emit();
// don't bother reporting every source of
// conflict for a particular element of `last`.
continue 'each_last;
Expand All @@ -761,7 +754,7 @@ fn check_matcher_core(cx: &mut ExtCtxt,
"may be"
};

cx.span_err(
sess.span_diagnostic.span_err(
sp,
&format!("`${name}:{frag}` {may_be} followed by `{next}`, which \
is not allowed for `{frag}` fragments",
Expand Down Expand Up @@ -818,7 +811,7 @@ fn frag_can_be_followed_by_any(frag: &str) -> bool {
/// 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)> {
fn is_in_follow(tok: &Token, frag: &str) -> Result<bool, (String, &'static str)> {
if let &CloseDelim(_) = tok {
// closing a token tree can never be matched by any fragment;
// iow, we always require that `(` and `)` match, etc.
Expand Down

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