[PATCH] D41834: [Lex] Fix handling numerical literals ending with ' and signed exponent.

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added a comment.

The lexer is doing the right thing; per the C++ lexical rules, the `+1` is not part of the token in this case.

I don't think this fix is in the right place; we will still examine characters after the end of the literal, even with this applied, and that doesn't seem right to me (even though the literal parser is constructed in such a way that it is valid to do so, as long as it doesn't read past a nul byte). It looks like the problem is that `NumericLiteralParser::ParseDecimalOrOctalCommon` will examine `*s` in cases where it might point past the end of the literal; changing

  if (*s == '+' || *s == '-')  s++; // sign

to

  if (s != ThisTokEnd && (*s == '+' || *s == '-'))  s++; // sign

would seem appropriate. But I think I'd be most in favor of that change plus your change plus a change to suppress the "no digits in suffix" error if we've already had an error. Seem reasonable?


https://reviews.llvm.org/D41834