Options included in CC/CXX vs. in gb_CFLAGS/gb_CXXFLAGS

[Tor Lillqvist]

> btw, why doesn't macosx.mk use --sysroot, which is much better than
> -isysroot because it mangles the library search path as well?  is the
> gcc too old for it?

man gcc:

       -isysroot dir
           This option is like the --sysroot option, but applies only
to header files, except for Apple's version of GCC, where it applies
to both header files and libraries and effectively replaces the
--sysroot option.  See the --sysroot option for more information.

man clang doesn't mention either option, but presumably they have it
meaning the same as in gcc.

--tml