why does Erlang define macros reserved for the C compiler?
Thu May 18 16:29:14 CEST 2006
Attached a patch that I use deal with the warnings.
Matthias Lang wrote:
> Attempting to answer my own question.
> A clue from Bengt and some googling gave me an answer for most of the
> defines. At least some of them are GCC voodoo:
> Grepping for the __deprecated that started me wondering reveals that
> it's only used in erts/emulator/beam/erl_alloc.h, to mark deprecated
> Conclusion: the warning can be ignored. It could be eliminated by
> testing for an existing definition before redefining it.
> I still don't know why the __SYS_H__ is there. For header files in the
> C library, it makes perfect sense to be using names with leading
> underscores---they're reserved, so you can be sure you don't screw up
> the user's namespace. Using it in Erlang, on the other hand, makes
> no sense. It's probably just historical cruft.
> Matthias Lang writes:
> > I'm looking at erts/emulator/beam/sys.h.
> > When building Erlang, the compiler prints out a bunch of warnings
> > about __deprecated being redefined. This seems to be C99 7.1.3 in
> > action, i.e. identifiers starting with _ are reserved for the C
> > compiler and C library.
> > The defines in that file with leading underscores:
> > __SYS_H__
> > _DOTS_
> > _VOID_
> > __noreturn
> > __deprecated
> > _POSIX_SOURCE
> > _XOPEN_SOURCE
> > Some of these, e.g. __deprecated, look like some sort of GCC
> > voodoo. Does anybody know more?
> > Matthias
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
More information about the erlang-questions