Alternative compiler for ObjC(++) with modern GCC

[barracuda156]

@iains There are a number of ports which fail to build specifically because the current GCC does not support Apple ObjC(++) extensions, even those which were supported by Xcode 3.2.6. At the same time when they require C11/C++11, building those with gcc-4.2 is not possible.
Will it work to use the current GCC (or the latest release) for everything besides ObjC(++), while using gcc-4.2 (or even some Clang?) for the latter?
This is mostly relevant, perhaps, for Qt-depending software, but also some GTK- and wxWidgets-.

[iains]

@iains There are a number of ports which fail to build specifically because the current GCC does not support Apple ObjC(++) extensions, even those which were supported by Xcode 3.2.6

You do not mention which OS versions ..

which extensions, specifically?

. At the same time when they require C11/C++11, building those with gcc-4.2 is not possible.

I see,

Will it work to use the current GCC (or the latest release) for everything besides ObjC(++), while using gcc-4.2 (or even some Clang?) for the latter? This is mostly relevant, perhaps, for Qt-depending software, but also some GTK- and wxWidgets-.

It is intended that it should work - for Darwin9/10 (apart from bugs, of course) there should be no issue ..
BUT NOTE: you will be limited to some of the tr1 C++ extensions there (or you will need to use libc++).

from Darwin11 the system supported native TLS - so you need to be careful about not mixing the two TLS implementations between TUs.

AFAIR the C++11 support was maybe somewhat incomplete until MacOSX 10.8 (Darwin12) that was when Apple switched to defaulting to libc++ (/usr/lib/libstdc++.6.dylib from Apple is C++98 + some tr1 stuff).

I do know that folks regularly mix gfortran and clang objects.

[barracuda156]

I primarily mean 10.6.8 on PowerPC now, but presumably this should be identical for 10.6.8 Intel. I.e., the current GCC does not support things like @autoreleasepool or Blocks, while gcc-4.2 (including for PowerPC) has some Blocks support (perhaps rudimentary, but better than none).

[iains]

I primarily mean 10.6.8 on PowerPC now, but presumably this should be identical for 10.6.8 Intel. I.e., the current GCC does not support things like @autoreleasepool or Blocks,

not yet, indeed - it's like everything else time and priorities ...
.. blocks is a higher priority than the ObjC arc stuff, but both will get done "one day".

while gcc-4.2 (including for PowerPC) has some Blocks support (perhaps rudimentary, but better than none).

Hmmm... I guess I'm a bit surprised that there's powerpc blocks runtime on 10.6.8 - given that it was not present on 10.5.8 .. and mostly the ppc stuff is there to run legacy code .. but cool - if it works.

[barracuda156]

I was of opinion that they are not supported for ppc regardless of OS and Xcode version, however came across few instances when a code containing some blocks stuff compiled with gcc-4.2 on 10.6 but failed on 10.5.8 with gcc-4.2 and/or on 10.6 with gcc14. FWIW.

[barracuda156]

I forgot which was a case with gcc-4.2 vs gcc14 on 10.6, but the one for 10.5.8 vs 10.6 is libdispatch, which fails on 10.5.8 from my port, but builds and works on 10a190 (it also builds on 10.6.8 but just redundant there). One of the errors on 10.5.8 was:

libdispatch-84.5.5/src/source.c:1767: error: expected expression before ‘^’ token