On Oct 4, 2011, at 11:59 AM, Pedro Alves wrote: > On Monday 03 October 2011 21:23:43, Joseph S. Myers wrote: >> On Mon, 3 Oct 2011, Douglas Rupp wrote: >> >>> On 9/30/2011 8:19 AM, Joseph S. Myers wrote: >>>> On Fri, 30 Sep 2011, Tristan Gingold wrote: >>>> >>>>> If you prefer a target hook, I'm fine with that. I will write such a >>>>> patch. >>>>> >>>>> I don't think it must be restricted to system headers, as it is possible >>>>> that the user 'imports' such a function (and define it in one of VMS >>>>> favorite languages such as macro-32 or bliss). >>>> If it's not restricted to system headers, then probably the option is >>>> better than the target hook. >>>> >>> I'm not sure I understand the reasoning here. This seems fairly VMS >>> specific >>> so what is the downside for a target hook and user written headers? >> >> The language accepted by the compiler in the user's source code (as >> opposed to in system headers) shouldn't depend on the target except for >> certain well-defined areas such as target attributes and built-in >> functions; behaving the same across different systems is an important >> feature of GCC. This isn't one of those areas of target-dependence; it's >> generic syntax rather than e.g. exploiting a particular processor feature. > > So I take it a `void foo(...);' declaration to mean the same thing > as an unprototyped `void foo();'?
No, that's not the case. This is a full prototype. > (If so, I think that should be > explicit in the documentation). That is, decc system headers are > probably declaring with: > > extern void foo(...); > > and then the function is defined somewhere with, say: > > void foo(int a, int b, void *c) > { > … > } No. > Do we need to consider ABIs that have calling conventions that > treat unprototyped and varargs functions differently? (is there any?) (Yes: x86-64) Tristan.