[VCDImager Bugs/Devel] Re: macos port

[R. Bernstein]

Was looking at this problem now that the sourceforge Mac OSX box is
back on line.

Suppose we add in autoconf tests (e.g. AC_TRY_COMPILE) for how to
handle packed?  So instead of: 

#if !defined(__GNUC__) ...
# define PRAGMA_BEGIN_PACKED _Pragma("pack(1)")

we have this config.h:

#define PRAGMA_BEGIN_PACKED _Pragra("pack(1)")

or whatever is appropriate.

The next question then is what *is* appropriate for Mac OSX? Would it
be wrong to just ignore this altogether? 

The other compilation problem is saw was the recently change C99 stuff 
where this: 

  vcd_image_source_funcs _funcs = {
    read_mode2_sector: _read_mode2_sector,
    stat_size: _stat_size,
    free: _source_free,
    setarg: _source_set_arg
  };

becomes this:

  vcd_image_source_funcs _funcs = {
    .read_mode2_sector = _read_mode2_sector,
    .stat_size         = _stat_size,
    .free              = _source_free,
    .set_arg           = _source_set_arg
  };


A suggestion here is to have another configure test and a macro that
foo(a,b) which expands to "a: b" or ".a = b" as appropriate.

Comments? 

 > On Mon, 2003-03-03 at 14:28, Rolando Abarca (aka funkaster) wrote:
 > > Hi,
 > 
 > > I compiled the code in the cvs repository and it's working. I only had a
 > > problem with some structures that needed to be packed.
 > > In vcd_types.h you define this:
 > 
 > > #if !defined(__GNUC__) && !defined(macintosh)
 > > /* should work with most EDG-frontend based compilers */
 > > # define PRAGMA_BEGIN_PACKED _Pragma("pack(1)")
 > > # define PRAGMA_END_PACKED   _Pragma("pack()")
 > > #else
 > > /* for GCC we try to use GNUC_PACKED instead */
 > > # define PRAGMA_BEGIN_PACKED
 > > # define PRAGMA_END_PACKED
 > > #endif
 > 
 > > the problem here (at least for MacOS) is that I can't include preprocessor
 > > directives in a preprocessor directive, although #pragma is not really a
 > > preprocessor directive.
 > 
 > that's what ISO C99's _Pragma() is for btw... otherwise I would have
 > used '#pragma' directly above...
 > 
 > > So a simple solution was to add -align packed to
 > > the C compiler options. This packs every structure. I don't know the side
 > > effects of this. 
 > 
 > most likely some structures defined in the standard system headers will
 > get compacted as well... the question remains, whether this changes
 > anything relevant on the ABI level... 
 > 
 > > Another solution could be to add #ifdef macintosh/#endif
 > > between every struct that needs to be packed and there add the #pragma.
 > 
 > ...extremely ugly :-/ of course you can do that, but I won't add
 > something like that to CVS so soon...
 > 
 > > One last thing: I don't know how you feel about this macos port, I mean if
 > > you want it to be "official" or just unsopported. I can send you the files
 > > that needed some changes to make them work with macos...
 > 
 > if the changes are minimal, I'll most likely merge them, but stuff like
 > adding #ifdef macintosh around various places is not going to be
 > merged... ;-)
 > 
 > > #include <stdio.h> /*  square root by Newton's zero-finder method   */
 > > #include <float.h> /*  by Rolando Abarca  rabarca at ing.uchile.cl  */
 > > int main(int c, char* v[]){if (c==2){long d=atol(v[1]);double r1,r2=0;
 > > double E=DBL_MIN;for(r1=(1+d)/2;((r1-r2>0)?r1-r2:r2-r1)>E;){r2=r1;r1=(
 > > r2+d/r2)/2;}printf("%.15f\n",r1);}else printf(" usage: fsqrt <n>\n");}
 > -- 
 > Herbert Valerio Riedel       /    Phone: (EUROPE) +43-1-58801-18840
 > Email: address@hidden       /    Finger address@hidden for GnuPG Public Key
 > GnuPG Key Fingerprint: 7BB9 2D6C D485 CE64 4748  5F65 4981 E064 883F 4142
 > 
 > 
 > 
 > _______________________________________________
 > Bug-VCDImager mailing list
 > address@hidden
 > http://mail.gnu.org/mailman/listinfo/bug-vcdimager