Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Temporarily accept [i|u][32|size] suffixes on a tuple index and warn #60186

Merged
merged 2 commits into from
Apr 24, 2019
Merged
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
34 changes: 31 additions & 3 deletions src/libsyntax/parse/parser.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1145,9 +1145,34 @@ impl<'a> Parser<'a> {
if text.is_empty() {
self.span_bug(sp, "found empty literal suffix in Some")
}
self.struct_span_err(sp, &format!("suffixes on {} are invalid", kind))
.span_label(sp, format!("invalid suffix `{}`", text))
.emit();
let mut err = if kind == "a tuple index" &&
["i32", "u32", "isize", "usize"].contains(&text.to_string().as_str())
{
// #59553: warn instead of reject out of hand to allow the fix to percolate
// through the ecosystem when people fix their macros
let mut err = self.struct_span_warn(
sp,
&format!("suffixes on {} are invalid", kind),
);
err.note(&format!(
"`{}` is *temporarily* accepted on tuple index fields as it was \
incorrectly accepted on stable for a few releases",
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This affects my opinion, by the way -- what is the range of time in which it was accepted? I was assuming it has been accepted forever.

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Bisected (using godbolt) to 1.27 being the point at which it was allowed;
Test program:

fn main() {
    let x = (0,);
    x.0usize;
}

text,
));
err.help(
"on proc macros, you'll want to use `syn::Index::from` or \
`proc_macro::Literal::*_unsuffixed` for code that will desugar \
to tuple field access",
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

👍 to giving some explicit help here!

);
err.note(
"for more context, see https://github.com/rust-lang/rust/issues/60210",
);
err
} else {
self.struct_span_err(sp, &format!("suffixes on {} are invalid", kind))
};
err.span_label(sp, format!("invalid suffix `{}`", text));
err.emit();
}
}
}
Expand Down Expand Up @@ -1455,6 +1480,9 @@ impl<'a> Parser<'a> {
fn struct_span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
self.sess.span_diagnostic.struct_span_err(sp, m)
}
fn struct_span_warn<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
self.sess.span_diagnostic.struct_span_warn(sp, m)
}
crate fn span_bug<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> ! {
self.sess.span_diagnostic.span_bug(sp, m)
}
Expand Down