[Bug target/108493] Interaction with builtin_defines (on PowerPC) and -traditional-cpp

[gaius at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108493

Gaius Mulley <gaius at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
                 CC|                            |gaius at gcc dot gnu.org

--- Comment #3 from Gaius Mulley <gaius at gcc dot gnu.org> ---
I wonder if writing a filter program to strip comments out before cpp would fix
the problem.

The filter program (m2decom) would strip out any comment which does not have
'#' in the first column (and honour line continuation backslashes etc).  This
would allow the debugging technique in gcc/m2/gm2-libs/FormatStrings.mod to
work.

If I recall correctly the reason cpp -traditional is required is because ' is a
start of string character in m2 (so is ").  But the m2 string formed: '\'
causes:

$ gcc -x c -E ~/GCC/gcc-read-write/gcc/m2/gm2-libs/FormatStrings.mod
   <snip>
   DSdbEnter ;
   d := InitString ('') ;
/home/gaius/GCC/gcc-read-write/gcc/m2/gm2-libs/FormatStrings.mod:196:19:
warning: missing terminating ' character
  196 |    i := Index (s, '\', 0) ;
      |                   ^
   i := Index (s, '\', 0) ;