I'm trying to compile a pretty simple C-style variadic function.

extern(C)
void error(char* fmt, ...)
{
        vprintf(fmt, _argptr);
}

This gives the error:
Error: undefined identifier _argptr

According to http://digitalmars.com/d/function.html this should at least compile.

Whats up?

== Quote from Tomas Lindquist Olsen (tomas@famolsen.dk)'s article
> I'm trying to compile a pretty simple C-style variadic function.
> extern(C)
> void error(char* fmt, ...)
> {
>         vprintf(fmt, _argptr);
> }
> This gives the error:
> Error: undefined identifier _argptr
> According to http://digitalmars.com/d/function.html this should at least
> compile.
> Whats up?

I couldn't get your code to work either, but the following code seems to work
(tested with DMD 1.0):

import std.stdio;

void foo(...)
{
    writefln("\t%s", _argptr);
}


void main()
{
    foo(1, 2, 3L, 4.5, 7F, "my str");
}


A longer example is at: http://www.dsource.org/projects/tutorials/wiki/VariableArgumentsUsingStdStdargExample

jcc7 wrote:

> == Quote from Tomas Lindquist Olsen (tomas@famolsen.dk)'s article
>> I'm trying to compile a pretty simple C-style variadic function.
>> extern(C)
>> void error(char* fmt, ...)
>> {
>>         vprintf(fmt, _argptr);
>> }
>> This gives the error:
>> Error: undefined identifier _argptr
>> According to http://digitalmars.com/d/function.html this should at least
>> compile.
>> Whats up?
> 
> I couldn't get your code to work either, but the following code seems to
> work (tested with DMD 1.0):
> 
> import std.stdio;
> 
> void foo(...)
> {
>     writefln("\t%s", _argptr);
> }
> 
> 
> void main()
> {
>     foo(1, 2, 3L, 4.5, 7F, "my str");
> }
> 
> 
> A longer example is at:
>
http://www.dsource.org/projects/tutorials/wiki/VariableArgumentsUsingStdStdargExample

This is clearly a bug, so I filed it: http://d.puremagic.com/issues/show_bug.cgi?id=937

Tomas Lindquist Olsen wrote:
> I'm trying to compile a pretty simple C-style variadic function.
> 
> extern(C)
> void error(char* fmt, ...)
> {
>         vprintf(fmt, _argptr);
> }
> 
> This gives the error:
> Error: undefined identifier _argptr
> 
> According to http://digitalmars.com/d/function.html this should at least
> compile.
> 
> Whats up?

<rant mode="feel free to ignore>
Ugh, I wish _argptr/_arguments would go away completely.
There has to be a better way to handle variable numbers of arguments ... oh wait! there is!  You specify a *name* for the argument list, kinda like how the other variadic arguments work in D, the ones for templates.

_argptr/_arguments just look like a quick hack.  By far the most hackish looking thing in all of D.
</rant>

--bb

Bill Baxter wrote:
> 
> _argptr/_arguments just look like a quick hack.  By far the most hackish
> looking thing in all of D.
> </rant>
> 
> --bb

I agree.
It would still be nice if it worked according to spec though.

Tomas Lindquist Olsen wrote:
> I'm trying to compile a pretty simple C-style variadic function.
> 
> extern(C)
> void error(char* fmt, ...)
> {
>         vprintf(fmt, _argptr);
> }
> 
> This gives the error:
> Error: undefined identifier _argptr
> 
> According to http://digitalmars.com/d/function.html this should at least
> compile.
> 
> Whats up?

You need std.c.stdarg for C functions.

L.

Lionello Lunesu wrote:
>
> You need std.c.stdarg for C functions.
> 
> L.

Not according to the spec.