Abdelrazak Younes <[EMAIL PROTECTED]> writes:
> 
> Dear Enrico,
> 
> I have problems with the -mms-bitfields option passed to gcc for cygwin 
> and Mingw ports. Is it something related to structure in memory 
> apparently. Do you know if it is still necessary? I would like to remove 
> that from cygwin.m4 or create a mingw.m4 but I am not really proficient 
> in m4.

Abdel,

I always had that option automatically inserted but never cared because
it doesn't seem to hurt. For example, I compile Qt without that option
and LyX with it and never noticed a problem.

I remember that once it was documented in the gcc man page on cygwin
but now I don't see it anymore. This is what configure spits out:

checking how to get MSVC-compatible struct packing... -mms-bitfields

so it is something related to MSVC. A wild guess is that it may be needed
because LyX is then linked to several Windows libraries (kernel32, user32...)
but I really don't know, sorry.

This guess is supported by the following excerpt from configure:

  cygwin* | mingw* | pw32* )
    if test "$GCC" = yes; then
      # Ensure MSVC-compatible struct packing convention.
      # Depends on GCC version. gcc2 uses -fnative-struct while
      # gcc3 uses -mms-bitfields.
      #
[...]
      if test x"$msnative_struct" = x; then
        echo "$as_me:$LINENO: result: no way" >&5
echo "${ECHO_T}no way" >&6
        { echo "$as_me:$LINENO: WARNING: produced libraries might be 
incompatible with MSVC libs" >&5
echo "$as_me: WARNING: produced libraries might be incompatible with MSVC libs"
 >&2;}
      else
        CXXFLAGS="$CXXFLAGS $msnative_struct"
        echo "$as_me:$LINENO: result: ${msnative_struct}" >&5
echo "${ECHO_T}${msnative_struct}" >&6
      fi

The keywords there are "might be", so someone at a time found some problem.
As regards me, I have built gnuplot and gsview32 without using it and all
went always well.

Next time I will try to get rid of it and tell you. I can't right now,
because building from scratch takes 1.5 hours for me.

-- 
Enrico


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