Issue with AS_TR_CPP, m4_cr_all and EBCDIC codeset

[Steve Goetze]

I'm trying to port autoconf to z/os, which uses an EBCDIC codeset.
I'm having trouble with autoconf where AC_CHECK_HEADERS_ONCE is
causing a bad string to be emitted to config.h.in.

For example, what should be "HAVE_STRING_H" is appearing as "_____STRING_H".

I've traced the problem down to the AS_TR_CPP macro which contains a
call to m4_translit as follows:

[m4_translit([$1],
  [*[]]]m4_dquote(m4_defn([m4_cr_letters])m4_defn([m4_cr_not_symbols2]))[,
  [P[]]]m4_dquote(m4_defn([m4_cr_LETTERS])m4_for(,1,255,,[[_]]))[)])

The second argument uses m4_cr_not_symbols2 which is defined with the
m4sugar macro m4_cr_all - the complete character range from 0-255.

When tracing the call to m4_translit, I see that the second argument
(the one that uses m4_cr_not_symbols2) looks something like this:

*[]abcdefghijklmnopqrstuvwxyz...<(+|&.........!HAVE_string.h);^/-...

The ... represent ranges of mostly unprintable characters.  In the
middle of the argument, the HAVE_string.h is embedded,
inappropriately.  Probably unfortunately in the EBCDIC codeset, the
characters !,$,*,) are adjacent; it appears as if the $* is being
interpolated to "HAVE_string.h".

At this point, I'm stuck - I'd appreciate any suggestions on how to
fix this, or even report it as a bug.

Thanks much,
--Steve Goetze