Re: hexadecimal escape sequences

[Bruno Haible]

Ben Pfaff wrote:
> Wow.  This is a gigantic bug that I don't see documented
> anywhere.

I can't reproduce it with the "cc" compilers I have access to right now.
But it was apparently seen on HP-UX 11: [1] mentions a warning
  cc: "quotearg.c", line 275: warning 30: Character constant contains undefined 
escape sequence.
and quotearg.c line 275 in findutils-4.1.5.tar.gz contains (after preprocessor
expansion):
  case '\a': esc = 'a'; goto c_escape;
So that compiler did not understand '\a'. I believe the same holds for '\xNN'.

> "git ls-files | grep '\.c$' | xargs grep '\\x'" shows 
> that \x is used many places in the Gnulib tests directory.  Do we
> need to document this and avoid \x everywhere?

It looks like the problem has not been seen in the last 1-2 years, so
I'd say, let's consider it a problem of the past. If it reappears, we
may be able to recommend a different compiler.

Bruno

[1] 
<http://forums13.itrc.hp.com/service/forums/questionanswer.do?admit=109447627+1293905158136+28353475&threadId=859152>