Re: [Boost-Users] MacOS.hpp and PowerPlant incompatibility

From: Bobby Thomale (bthomale_at_[hidden])
Date: 2002-06-06 09:09:40

on 6/6/02 6:17 AM, John Maddock at john_maddock_at_[hidden] wrote:

> Is PowerPlant a third party lib? If so then I don't think it should be
> setting a reserved symbol like __MACH__, however it's easy enough to change
> the boost code to verify that __MACH__ is greater than zero, so I'll make
> that change anyway unless there are objections (any Darwin experts out
> there?).

PowerPlant is an application framework written by Metrowerks and distributed
with CodeWarrior.  It is a very widely used framework in the Mac world
(probably as widely used as MFC is on Windows).

FWIW that was my first thought too - why are they even defining this?  But
if Mac programmers are going to try to use Boost, keeping it compatible with
PowerPlant is a good idea.  (I'll be sure and post about any other issues I
find - so far this is the only one!)

I got an interesting response when I posted this same question to the
Metrowerks newsgroup, from a MW employee.  The comment before the test says
it is trying to determine whether BSD or MSL libraries are being used.
CodeWarrior Pro 8 allows you to choose either MSL or BSD standard library
implementations in Mach-O binaries, so testing for __MACH__ will no longer
be a sufficient test.

(The following commented section was originally posted to the
comp.sys.mac.programmer.codewarrior newsgroup by Josef W. Wankerl of
Metrowerks):

> That may have worked with Pro 7, since it was true that whenever
> __MACH__ was defined, the BSD headers and libraries were being used.
> 
> For Pro 8, that's changed since you now have the option to use MSL C.
> The test should be something like:
> 
> #if __MACH__
> #include <ansi_parms.h>  /* Get __MSL__ and _MSL_USING_MW_C_HEADERS */
> 
> #if (__MSL__ >= 0x8000) && _MSL_USING_MW_C_HEADERS
> /* MSL C is being used */
> #else
> /* BSD C is being used */
> #endif
> #endif

As a further bit of clarification to the above code - the test (__MSL__ >=
0x8000) is testing for the version of the MSL libraries - it only tests for
using MSL headers with Mach on Pro 8 or later, because that is when it was
added.  

                                -- Bobby

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Bobby Thomale
Senior Software Developer
Inoveon Corporation
http://www.inoveon.com/
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